cathode-ray tube display screens factory

A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen.waveforms (oscilloscope), pictures (television set, computer monitor), radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer. The term

In CRT television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and blue) with a video signal as a reference.magnetic deflection, using a deflection yoke. Electrostatic deflection is commonly used in oscilloscopes.

Since the mid-late 2000"s, CRTs have been superseded by flat-panel display technologies such as LCD, plasma display, and OLED displays which are cheaper to manufacture and run, as well as significantly lighter and less bulky. Flat-panel displays can also be made in very large sizes whereas 40 in (100 cm) to 45 in (110 cm)

Cathode rays were discovered by Julius Plücker and Johann Wilhelm Hittorf.cathode (negative electrode) which could cast shadows on the glowing wall of the tube, indicating the rays were traveling in straight lines. In 1890, Arthur Schuster demonstrated cathode rays could be deflected by electric fields, and William Crookes showed they could be deflected by magnetic fields. In 1897, J. J. Thomson succeeded in measuring the charge-mass-ratio of cathode rays, showing that they consisted of negatively charged particles smaller than atoms, the first "subatomic particles", which had already been named George Johnstone Stoney in 1891. The earliest version of the CRT was known as the "Braun tube", invented by the German physicist Ferdinand Braun in 1897.cold-cathode diode, a modification of the Crookes tube with a phosphor-coated screen. Braun was the first to conceive the use of a CRT as a display device.

The first cathode-ray tube to use a hot cathode was developed by John Bertrand Johnson (who gave his name to the term Johnson noise) and Harry Weiner Weinhart of Western Electric, and became a commercial product in 1922.

In 1926, Kenjiro Takayanagi demonstrated a CRT television receiver with a mechanical video camera that received images with a 40-line resolution.Philo Farnsworth created a television prototype.Vladimir K. Zworykin.: 84 RCA was granted a trademark for the term (for its cathode-ray tube) in 1932; it voluntarily released the term to the public domain in 1950.

In 1947, the cathode-ray tube amusement device, the earliest known interactive electronic game as well as the first to incorporate a cathode-ray tube screen, was created.

In the mid-2000s, Canon and Sony presented the surface-conduction electron-emitter display and field-emission displays, respectively. They both were flat-panel displays that had one (SED) or several (FED) electron emitters per subpixel in place of electron guns. The electron emitters were placed on a sheet of glass and the electrons were accelerated to a nearby sheet of glass with phosphors using an anode voltage. The electrons were not focused, making each subpixel essentially a flood beam CRT. They were never put into mass production as LCD technology was significantly cheaper, eliminating the market for such displays.

Beginning in the late 90s to the early 2000s, CRTs began to be replaced with LCDs, starting first with computer monitors smaller than 15 inches in size,Hitachi in 2001,Flat-panel displays dropped in price and started significantly displacing cathode-ray tubes in the 2000s. LCD monitor sales began exceeding those of CRTs in 2003–2004

Despite being a mainstay of display technology for decades, CRT-based computer monitors and televisions are now virtually a dead technology. Demand for CRT screens dropped in the late 2000s.

A popular consumer usage of CRTs is for retrogaming. Some games are impossible to play without CRT display hardware, and some games play better. Reasons for this include:

The design of the high voltage power supply in a product using a CRT has an influence in the amount of x-rays emitted by the CRT. The amount of emitted x-rays increases with both higher voltages and currents. If the product such as a TV set uses an unregulated high voltage power supply, meaning that anode and focus voltage go down with increasing electron current when displaying a bright image, the amount of emitted x-rays is as its highest when the CRT is displaying a moderately bright images, since when displaying dark or bright images, the higher anode voltage counteracts the lower electron beam current and vice versa respectively. The high voltage regulator and rectifier vacuum tubes in some old CRT TV sets may also emit x-rays.

Since it is a hot cathode, it is prone to cathode poisoning, which is the formation of a positive ion layer that prevents the cathode from emitting electrons, reducing image brightness significantly or completely and causing focus and intensity to be affected by the frequency of the video signal preventing detailed images from being displayed by the CRT. The positive ions come from leftover air molecules inside the CRT or from the cathode itself

Burn-in is when images are physically "burned" into the screen of the CRT; this occurs due to degradation of the phosphors due to prolonged electron bombardment of the phosphors, and happens when a fixed image or logo is left for too long on the screen, causing it to appear as a "ghost" image or, in severe cases, also when the CRT is off. To counter this, screensavers were used in computers to minimize burn-in.

Various phosphors are available depending upon the needs of the measurement or display application. The brightness, color, and persistence of the illumination depends upon the type of phosphor used on the CRT screen. Phosphors are available with persistences ranging from less than one microsecond to several seconds.

Doming is a phenomenon found on some CRT televisions in which parts of the shadow mask become heated. In televisions that exhibit this behavior, it tends to occur in high-contrast scenes in which there is a largely dark scene with one or more localized bright spots. As the electron beam hits the shadow mask in these areas it heats unevenly. The shadow mask warps due to the heat differences, which causes the electron gun to hit the wrong colored phosphors and incorrect colors to be displayed in the affected area.

Aperture grille screens are brighter since they allow more electrons through, but they require support wires. They are also more resistant to warping.

CRT monitors can still outperform LCD and OLED monitors in input lag, as there is no signal processing between the CRT and the display connector of the monitor, since CRT monitors often use VGA which provides an analog signal that can be fed to a CRT directly. Video cards designed for use with CRTs may have a RAMDAC to generate the analog signals needed by the CRT.multisyncing.

Picture tube CRTs have overscan, meaning the actual edges of the image are not shown; this is deliberate to allow for adjustment variations between CRT TVs, preventing the ragged edges (due to blooming) of the image from being shown on screen. The shadow mask may have grooves that reflect away the electrons that do not hit the screen due to overscan.

A shadow mask tube uses a metal plate with tiny holes, typically in a delta configuration, placed so that the electron beam only illuminates the correct phosphors on the face of the tube;aperture grille of tensioned vertical wires to achieve the same result.

Due to limitations in the dimensional precision with which CRTs can be manufactured economically, it has not been practically possible to build color CRTs in which three electron beams could be aligned to hit phosphors of respective color in acceptable coordination, solely on the basis of the geometric configuration of the electron gun axes and gun aperture positions, shadow mask apertures, etc. The shadow mask ensures that one beam will only hit spots of certain colors of phosphors, but minute variations in physical alignment of the internal parts among individual CRTs will cause variations in the exact alignment of the beams through the shadow mask, allowing some electrons from, for example, the red beam to hit, say, blue phosphors, unless some individual compensation is made for the variance among individual tubes.

The solution to the static convergence and purity problems is a set of color alignment ring magnets installed around the neck of the CRT.magnetic fields parallel to the planes of the magnets, which are perpendicular to the electron gun axes. Often, one ring has two poles, another has 4, and the remaining ring has 6 poles.vector can be fully and freely adjusted (in both direction and magnitude). By rotating a pair of magnets relative to each other, their relative field alignment can be varied, adjusting the effective field strength of the pair. (As they rotate relative to each other, each magnet"s field can be considered to have two opposing components at right angles, and these four components [two each for two magnets] form two pairs, one pair reinforcing each other and the other pair opposing and canceling each other. Rotating away from alignment, the magnets" mutually reinforcing field components decrease as they are traded for increasing opposed, mutually cancelling components.) By rotating a pair of magnets together, preserving the relative angle between them, the direction of their collective magnetic field can be varied. Overall, adjusting all of the convergence/purity magnets allows a finely tuned slight electron beam deflection or lateral offset to be applied, which compensates for minor static convergence and purity errors intrinsic to the uncalibrated tube. Once set, these magnets are usually glued in place, but normally they can be freed and readjusted in the field (e.g. by a TV repair shop) if necessary.

The convergence signal may instead be a sawtooth signal with a slight sine wave appearance, the sine wave part is created using a capacitor in series with each deflection coil. In this case, the convergence signal is used to drive the deflection coils. The sine wave part of the signal causes the electron beam to move more slowly near the edges of the screen. The capacitors used to create the convergence signal are known as the s-capacitors. This type of convergence is necessary due to the high deflection angles and flat screens of many CRT computer monitors. The value of the s-capacitors must be chosen based on the scan rate of the CRT, so multi-syncing monitors must have different sets of s-capacitors, one for each refresh rate.

Dynamic color convergence and purity are one of the main reasons why until late in their history, CRTs were long-necked (deep) and had biaxially curved faces; these geometric design characteristics are necessary for intrinsic passive dynamic color convergence and purity. Only starting around the 1990s did sophisticated active dynamic convergence compensation circuits become available that made short-necked and flat-faced CRTs workable. These active compensation circuits use the deflection yoke to finely adjust beam deflection according to the beam target location. The same techniques (and major circuit components) also make possible the adjustment of display image rotation, skew, and other complex raster geometry parameters through electronics under user control.

Color CRT displays in television sets and computer monitors often have a built-in degaussing (demagnetizing) coil mounted around the perimeter of the CRT face. Upon power-up of the CRT display, the degaussing circuit produces a brief, alternating current through the coil which fades to zero over a few seconds, producing a decaying alternating magnetic field from the coil. This degaussing field is strong enough to remove shadow mask magnetization in most cases, maintaining color purity.deform (bend) the shadow mask, causing a permanent color distortion on the display which looks very similar to a magnetization effect.

Dot pitch defines the maximum resolution of the display, assuming delta-gun CRTs. In these, as the scanned resolution approaches the dot pitch resolution, moiré appears, as the detail being displayed is finer than what the shadow mask can render.

Beam-index tubes, also known as Uniray, Apple CRT or Indextron,Philco to create a color CRT without a shadow mask, eliminating convergence and purity problems, and allowing for shallower CRTs with higher deflection angles.

Flat CRTs are those with a flat screen. Despite having a flat screen, they may not be completely flat, especially on the inside, instead having a greatly increased curvature. A notable exception is the LG Flatron (made by LG.Philips Displays, later LP Displays) which is truly flat on the outside and inside, but has a bonded glass pane on the screen with a tensioned rim band to provide implosion protection. Such completely flat CRTs were first introduced by Zenith in 1986, and used

flat tensioned shadow masks, where the shadow mask is held under tension, providing increased resistance to blooming.TV80, and in many Sony Watchmans were flat in that they were not deep and their front screens were flat, but their electron guns were put to a side of the screen.

Radar CRTs such as the 7JP4 had a circular screen and scanned the beam from the center outwards. The screen often had two colors, often a bright short persistence color that only appeared as the beam scanned the display and a long persistence phosphor afterglow. When the beam strikes the phosphor, the phosphor brightly illuminates, and when the beam leaves, the dimmer long persistence afterglow would remain lit where the beam struck the phosphor, alongside the radar targets that were "written" by the beam, until the beam re-struck the phosphor.

In oscilloscope CRTs, electrostatic deflection is used, rather than the magnetic deflection commonly used with television and other large CRTs. The beam is deflected horizontally by applying an electric field between a pair of plates to its left and right, and vertically by applying an electric field to plates above and below. Televisions use magnetic rather than electrostatic deflection because the deflection plates obstruct the beam when the deflection angle is as large as is required for tubes that are relatively short for their size. Some Oscilloscope CRTs incorporate post deflection anodes (PDAs) that are spiral-shaped to ensure even anode potential across the CRT and operate at up to 15,000 volts. In PDA CRTs the electron beam is deflected before it is accelerated, improving sensitivity and legibility, specially when analyzing voltage pulses with short duty cycles.

When displaying fast one-shot events, the electron beam must deflect very quickly, with few electrons impinging on the screen, leading to a faint or invisible image on the display. Oscilloscope CRTs designed for very fast signals can give a brighter display by passing the electron beam through a micro-channel plate just before it reaches the screen. Through the phenomenon of secondary emission, this plate multiplies the number of electrons reaching the phosphor screen, giving a significant improvement in writing rate (brightness) and improved sensitivity and spot size as well.

Most oscilloscopes have a graticule as part of the visual display, to facilitate measurements. The graticule may be permanently marked inside the face of the CRT, or it may be a transparent external plate made of glass or acrylic plastic. An internal graticule eliminates parallax error, but cannot be changed to accommodate different types of measurements.

Where a single brief event is monitored by an oscilloscope, such an event will be displayed by a conventional tube only while it actually occurs. The use of a long persistence phosphor may allow the image to be observed after the event, but only for a few seconds at best. This limitation can be overcome by the use of a direct view storage cathode-ray tube (storage tube). A storage tube will continue to display the event after it has occurred until such time as it is erased. A storage tube is similar to a conventional tube except that it is equipped with a metal grid coated with a dielectric layer located immediately behind the phosphor screen. An externally applied voltage to the mesh initially ensures that the whole mesh is at a constant potential. This mesh is constantly exposed to a low velocity electron beam from a "flood gun" which operates independently of the main gun. This flood gun is not deflected like the main gun but constantly "illuminates" the whole of the storage mesh. The initial charge on the storage mesh is such as to repel the electrons from the flood gun which are prevented from striking the phosphor screen.

When the main electron gun writes an image to the screen, the energy in the main beam is sufficient to create a "potential relief" on the storage mesh. The areas where this relief is created no longer repel the electrons from the flood gun which now pass through the mesh and illuminate the phosphor screen. Consequently, the image that was briefly traced out by the main gun continues to be displayed after it has occurred. The image can be "erased" by resupplying the external voltage to the mesh restoring its constant potential. The time for which the image can be displayed was limited because, in practice, the flood gun slowly neutralises the charge on the storage mesh. One way of allowing the image to be retained for longer is temporarily to turn off the flood gun. It is then possible for the image to be retained for several days. The majority of storage tubes allow for a lower voltage to be applied to the storage mesh which slowly restores the initial charge state. By varying this voltage a variable persistence is obtained. Turning off the flood gun and the voltage supply to the storage mesh allows such a tube to operate as a conventional oscilloscope tube.

The Williams tube or Williams-Kilburn tube was a cathode-ray tube used to electronically store binary data. It was used in computers of the 1940s as a random-access digital storage device. In contrast to other CRTs in this article, the Williams tube was not a display device, and in fact could not be viewed since a metal plate covered its screen.

In some vacuum tube radio sets, a "Magic Eye" or "Tuning Eye" tube was provided to assist in tuning the receiver. Tuning would be adjusted until the width of a radial shadow was minimized. This was used instead of a more expensive electromechanical meter, which later came to be used on higher-end tuners when transistor sets lacked the high voltage required to drive the device.

Some displays for early computers (those that needed to display more text than was practical using vectors, or that required high speed for photographic output) used Charactron CRTs. These incorporate a perforated metal character mask (stencil), which shapes a wide electron beam to form a character on the screen. The system selects a character on the mask using one set of deflection circuits, but that causes the extruded beam to be aimed off-axis, so a second set of deflection plates has to re-aim the beam so it is headed toward the center of the screen. A third set of plates places the character wherever required. The beam is unblanked (turned on) briefly to draw the character at that position. Graphics could be drawn by selecting the position on the mask corresponding to the code for a space (in practice, they were simply not drawn), which had a small round hole in the center; this effectively disabled the character mask, and the system reverted to regular vector behavior. Charactrons had exceptionally long necks, because of the need for three deflection systems.

Nimo was the trademark of a family of small specialised CRTs manufactured by Industrial Electronic Engineers. These had 10 electron guns which produced electron beams in the form of digits in a manner similar to that of the charactron. The tubes were either simple single-digit displays or more complex 4- or 6- digit displays produced by means of a suitable magnetic deflection system. Having little of the complexities of a standard CRT, the tube required a relatively simple driving circuit, and as the image was projected on the glass face, it provided a much wider viewing angle than competitive types (e.g., nixie tubes).

Flood-beam CRTs are small tubes that are arranged as pixels for large video walls like Jumbotrons. The first screen using this technology (called Diamond Vision by Mitsubishi Electric) was introduced by Mitsubishi Electric for the 1980 Major League Baseball All-Star Game. It differs from a normal CRT in that the electron gun within does not produce a focused controllable beam. Instead, electrons are sprayed in a wide cone across the entire front of the phosphor screen, basically making each unit act as a single light bulb.light-emitting diode displays. Unfocused and undeflected CRTs were used as grid-controlled stroboscope lamps since 1958.Electron-stimulated luminescence (ESL) lamps, which use the same operating principle, were released in 2011.

In the late 1990s and early 2000s Philips Research Laboratories experimented with a type of thin CRT known as the Zeus display, which contained CRT-like functionality in a flat-panel display.

Some CRT manufacturers, both LG.Philips Displays (later LP Displays) and Samsung SDI, innovated CRT technology by creating a slimmer tube. Slimmer CRT had the trade names Superslim,

At low refresh rates (60 Hz and below), the periodic scanning of the display may produce a flicker that some people perceive more easily than others, especially when viewed with peripheral vision. Flicker is commonly associated with CRT as most televisions run at 50 Hz (PAL) or 60 Hz (NTSC), although there are some 100 Hz PAL televisions that are flicker-free. Typically only low-end monitors run at such low frequencies, with most computer monitors supporting at least 75 Hz and high-end monitors capable of 100 Hz or more to eliminate any perception of flicker.sonar or radar may have long persistence phosphor and are thus flicker free. If the persistence is too long on a video display, moving images will be blurred.

This problem does not occur on 100/120 Hz TVs and on non-CGA (Color Graphics Adapter) computer displays, because they use much higher horizontal scanning frequencies that produce sound which is inaudible to humans (22 kHz to over 100 kHz).

High vacuum inside glass-walled cathode-ray tubes permits electron beams to fly freely—without colliding into molecules of air or other gas. If the glass is damaged, atmospheric pressure can collapse the vacuum tube into dangerous fragments which accelerate inward and then spray at high speed in all directions. Although modern cathode-ray tubes used in televisions and computer displays have epoxy-bonded face-plates or other measures to prevent shattering of the envelope, CRTs must be handled carefully to avoid personal injury.

Under some circumstances, the signal radiated from the electron guns, scanning circuitry, and associated wiring of a CRT can be captured remotely and used to reconstruct what is shown on the CRT using a process called Van Eck phreaking.TEMPEST shielding can mitigate this effect. Such radiation of a potentially exploitable signal, however, occurs also with other display technologies

As electronic waste, CRTs are considered one of the hardest types to recycle.phosphors, both of which are necessary for the display. There are several companies in the United States that charge a small fee to collect CRTs, then subsidize their labor by selling the harvested copper, wire, and printed circuit boards. The United States Environmental Protection Agency (EPA) includes discarded CRT monitors in its category of "hazardous household waste"

Musgraves, J. David; Hu, Juejun; Calvez, Laurent (8 November 2019). "Cathod Ray-Tube Design". Springer Handbook of Glass. Springer Nature. p. 1367. ISBN 978-3-319-93728-1.

Martin, André (1986). "Cathode Ray Tubes for Industrial and Military Applications". In Hawkes, Peter (ed.). Advances in Electronics and Electron Physics. Vol. 67. Academic Press. pp. 183–328. doi:10.1016/S0065-2539(08)60331-5. ISBN 9780080577333. Evidence for the existence of "cathode-rays" was first found by Plücker and Hittorf ...

Lehrer, Norman, H. (1985). "The Challenge of the Cathode-Ray Tube". In Tannas, Lawrence E. Jr. (ed.). Flat-Panel Displays and CRTs. New York: Van Nostrand Reinhold Company Inc. pp. 138–176. doi:10.1007/978-94-011-7062-8_6. ISBN 978-94-011-7062-8.

Harland, Doug. "Picture Tubes: Motorola Prototype Rectangular Color CRT". www.earlytelevision.org. Early Television Museum. Retrieved 11 November 2021.

Keller, Peter A. (October 2007). "Tektronic CRT History: Part 5: The hybrid years: 1961-64" (PDF). The Tube Collector. Vol. 9, no. 5. Ashland, Oregon: Tube Collectors Association. p. 5. Retrieved 11 November 2021.

Mekeel, Tim; Knowles, Laura (12 September 2013). "RCA pioneers remember making the first color TV tube". LancasterOnline. LNP Media Group Inc. Archived from the original on 4 August 2021. Retrieved 11 November 2021.

US 3440080, Tamura, Michio & Nakamura, Mitsuyoshi, "Cathode ray tube color screen and method of producing same", published 1969-04-22, assigned to Sony Corp.

Warren, Rich (30 September 1991). "TV makers tuning in to flat screens to help round out sales". chicagotribune.com. Chicago Tribune. Retrieved 11 November 2021.

EP 0088122B1, "Large metal cone cathode ray tubes, and envelopes therefor" calls it faceplate US 20040032200A1, "CRT having a contrast enhancing exterior coating and method of manufacturing the same" also calls it faceplate US 20060132019A1, "Funnel for use in a cathode ray tube"

Ha, Kuedong; Shin, Soon-Cheol; Kim, Do-Nyun; Lee, Kue-Hong; Kim, Jeong-Hoon (2006). "Development of a 32-in. slim CRT with 125° deflection". Journal of the Society for Information Display. 14 (1): 65. doi:10.1889/1.2166838. S2CID 62697886.

"GW-12.10-130: NEW APPROACH TO CATHODE RAY TUBE (CRT) RECYCLING" (PDF). www.glass-ts.com. 2003. Archived from the original (PDF) on 13 November 2020. Retrieved 11 December 2020.

Lee, Ching-Hwa; Hsi, Chi-Shiung (1 January 2002). "Recycling of Scrap Cathode Ray Tubes". Environmental Science & Technology. 36 (1): 69–75. Bibcode:2002EnST...36...69L. doi:10.1021/es010517q. PMID 11811492.

Xu, Qingbo; Li, Guangming; He, Wenzhi; Huang, Juwen; Shi, Xiang (August 2012). "Cathode ray tube (CRT) recycling: Current capabilities in China and research progress". Waste Management. 32 (8): 1566–1574. doi:10.1016/j.wasman.2012.03.009. PMID 22542858.

"TV and Monitor CRT (Picture Tube) Information". repairfaq.cis.upenn.edu. Archived from the original on 22 November 2020. Retrieved 8 December 2020. 90 degrees in monitors, 110 in TVs

Ozawa, Lyuji (15 January 2002). "Electron flow route at phosphor screens in CRTs". Materials Chemistry and Physics. 73 (2): 144–150. doi:10.1016/s0254-0584(01)00360-1.

Gassler, Gerhard (2016). "Cathode Ray Tubes (CRTS)". Handbook of Visual Display Technology. pp. 1595–1607. doi:10.1007/978-3-319-14346-0_70. ISBN 978-3-319-14345-3.

den Engelsen, Daniel; Ferrario, Bruno (1 March 2004). "Gettering by Ba films in color cathode ray tubes". Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena. 22 (2): 809–817. Bibcode:2004JVSTB..22..809D. doi:10.1116/1.1689973.

DeBoer, Clint. "Cathode Ray Tube (CRT) Direct View and Rear Projection TVs". Audioholics Home Theater, HDTV, Receivers, Speakers, Blu-ray Reviews and News.

US 7138755B2, "Color picture tube apparatus having beam velocity modulation coils overlapping with convergence and purity unit and ring shaped ferrite core"

Ozeroff, M. J.; Thornton, W. A.; Young, J. R. (29 April 1953). Proposed Improvement in Evacuation Technique for TV Tubes (PDF) (Report). Archived (PDF) from the original on 15 February 2020.

Goetz, D.; Schaefer, G.; Rufus, J. (4 June 1998). "The use of turbomolecular pumps in television tube production". Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 5 (4): 2421. doi:10.1116/1.574467.

Yin, Xiaofei; Wu, Yufeng; Tian, Xiangmiao; Yu, Jiamei; Zhang, Yi-Nan; Zuo, Tieyong (5 December 2016). "Green Recovery of Rare Earths from Waste Cathode Ray Tube Phosphors: Oxidative Leaching and Kinetic Aspects". ACS Sustainable Chemistry & Engineering. 4 (12): 7080–7089. doi:10.1021/acssuschemeng.6b01965.

"Implementing Display Standards in Modern Video Display Technologies" (PDF). www.cinemaquestinc.com. Archived (PDF) from the original on 14 June 2016. Retrieved 11 December 2020.

Martindale, Jon (17 September 2019). "New Report States CRT Monitors Are Still Better Than Modern Gaming Displays". Digital Trends. Retrieved 11 December 2020.

Bowie, R.M. (December 1948). "The Negative-Ion Blemish in a Cathode-Ray Tube and Its Elimination". Proceedings of the IRE. 36 (12): 1482–1486. doi:10.1109/JRPROC.1948.232950. S2CID 51635920.

Dudding, R.W. (1951). "Aluminium backed screens for cathode ray tubes". Journal of the British Institution of Radio Engineers. 11 (10): 455–462. doi:10.1049/jbire.1951.0057.

Ohno, K.; Kusunoki, T. (5 August 2010). "ChemInform Abstract: Effect of Ultrafine Pigment Color Filters on Cathode Ray Tube Brightness, Contrast, and Color Purity". ChemInform. 27 (33): no. doi:10.1002/chin.199633002.

Abend, U.; Kunz, H. -J.; Wandmacher, J. (1 January 1981). "A vector graphic CRT display system". Behavior Research Methods & Instrumentation. 13 (1): 46–50. doi:S2CID 62692534.

"Futaba TL-3508XA "Jumbotron" Display". The Vintage Technology Association: Military Industrial Electronics Research Preservation. The Vintage Technology Association. 11 March 2010. Retrieved 19 December 2014.

"CK1366 CK1367 Printer-type cathode ray tube data sheet" (PDF). Raytheon Company. 1 November 1960. Archived from the original (PDF) on 19 December 2019. Retrieved 29 July 2017.

"CK1368 CK1369 Printer-type cathode ray tube data sheet" (PDF). Raytheon Company. 1 November 1960. Archived from the original (PDF) on 19 December 2019. Retrieved 29 July 2017.

Lambert, N.; Montie, E.A.; Baller, T.S.; Van Gorkom, G.G.P.; Hendriks, B.H.W.; Trompenaars, P.H.F.; De Zwart, S.T. (1996). "Transport and extraction in Zeus displays". Philips Journal of Research. 50 (3–4): 295. doi:10.1016/S0165-5817(97)84677-3.

Doyle, T.; Van Asma, C.; McCormack, J.; De Greef, D.; Haighton, V.; Heijnen, P.; Looymans, M.; Van Velzen, J. (1996). "The application and system aspects of the Zeus display". Philips Journal of Research. 50 (3–4): 501. doi:10.1016/S0165-5817(97)84688-8.

van Eck, Wim (1 December 1985). "Electromagnetic radiation from video display units: An eavesdropping risk?". Computers & Security. 4 (4): 269–286. CiteSeerX doi:10.1016/0167-4048(85)90046-X.

Yuan, Wenyi; Li, Jinhui; Zhang, Qiwu; Saito, Fumio; Yang, Bo (1 January 2013). "Lead recovery from cathode ray tube funnel glass with mechanical activation". Journal of the Air & Waste Management Association. 63 (1): 2–10. doi:10.1080/10962247.2012.711796. PMID 23447859. S2CID 24723465.

Lu, Xingwen; Ning, Xun-an; Chen, Da; Chuang, Kui-Hao; Shih, Kaimin; Wang, Fei (1 June 2018). "Lead extraction from Cathode Ray Tube (CRT) funnel glass: Reaction mechanisms in thermal reduction with addition of carbon (C)". Waste Management. 76: 671–678. doi:10.1016/j.wasman.2018.04.010. PMID 29650298. S2CID 4800544.

Yin, Xiaofei; Tian, Xiangmiao; Wu, Yufeng; Zhang, Qijun; Wang, Wei; Li, Bin; Gong, Yu; Zuo, Tieyong (20 December 2018). "Recycling rare earth elements from waste cathode ray tube phosphors: Experimental study and mechanism analysis". Journal of Cleaner Production. 205: 58–66. doi:10.1016/j.jclepro.2018.09.055. S2CID 105023020.

Yu, Miao; Liu, Lili; Li, Jinhui (1 January 2016). "An overall Solution to Cathode-Ray Tube (CRT) Glass Recycling". Procedia Environmental Sciences. 31: 887–896. doi:

Herat, Sunil (2008). "Recycling of Cathode Ray Tubes (CRTs) in Electronic Waste". CLEAN – Soil, Air, Water. 36 (1): 19–24. doi:10.1002/clen.200700082. hdl:

Goldwasser, Samuel M. (28 February 2006). "TV and Monitor CRT (Picture Tube) Information". repairfaq.org. Archived from the original on 26 September 2006.

Manufacturer of ignition tubes, electronic tubes, electron tubes, geiger-muller counter tubes, & cathode ray (CRTs) tubes. Available varieties of electron tubes include backward wave oscillators, cathode ray tubes, cold cathode tubes, CW magnetrons, diodes, display devices, duplexers, electro-optical devices, gas relays, hydrogen thyratrons, ignitrons, image intensifiers, klystrons, klystron amplifiers, magnetrons, microwave tubes, modulators, oscillators, pencil tubes, pentodes, photomultiplier tubes, phototubes, planar triodes, pulse rated tetrodes & triodes. Includes rectifiers, solid state replacements, spark gap tubes, tetrodes, thyratrons, thyristors, triodes, TR limiters, tube sockets, vidicons, & x-ray tubes. Applications include broadcast, industrial, medical, military, scientific & audio.

Manufacturer of standard & custom cathode ray tube & electroluminescent displays. Features include 17 in. to 23 in. LCD, rugged steel & aluminum construction, optional resistive or capacitive touch-screens, light textured powder coated black color, contrast filters, transmissive daylight modification, hard coated vandal shields, 16.7 million display colors, anti-glare hard coating, analog RGB input, weight ranging 13 lbs to 24 lbs & 1280 x 1024 SXGA or 1600 x 1200 UXGA or 920 x 1200 maximum resolution. Applications include use for rack, wall, panel or kiosk installations in commercial, military & broadcast industries. One year limited warranty. RoHS compliant. Meet NEMA & Military Spec.

Sony Electronics’ cathode ray tube manufacturing facility was located alongside headquarters in Rancho Bernado, CA. The facility was shuttered in 2006 when Sony transitioned wholly onto digital displays like the flat-panel LCD line of Bravia televisions. [Glenn]’s video shows that the manufacturing process was almost entirely automated from end to end. A point that was made even more clear with the distinct lack of human beings in the video.

The Trinitron line of televisions first appeared in 1968. At a time where most manufacturer’s were offering black and white picture tubes, Sony’s Trinitron line was in color. That name carried through until the end when it was retired alongside tube televisions themselves. Sony’s focus on technological innovation (and proprietary media formats) made them a giant in the world of consumer electronics for over forty years in the United States, but in the transition to a digital world saw them seeding market share to their competitors.

Cathode ray tube (CRT) display uses CRT that is a vacuum tube medium interpreting electrical phenomenon of an image projected on a phosphorescent screen by sharp focused beam of electrons being controlled by an intensity of electrical signals. It consists of one or more electron guns and a phosphorescent screen to display images or signals. CRT displays are used in the residential sector as they can operate at any resolution, geometry, and aspect ratio without the need to rescale an image.

CRT displays are mostly preferred in PC gaming circles as they offer high pixel resolution, respond to input faster, have less motion blur than LCDs, and are suitable for use in both dimly lit and dark environments. CRT displays are less expensive and produce perfectly smooth gray scale with an infinite number of intensity levels, which enhances product quality standards in the market. Significant advantages of this display technology over smart LCDs and LEDs implies that the cathode ray tube display market share would grow at a steady pace in the coming years.

Rise in demand for use of consumer electronics display devices with reduced display costs as well as constant upgrade in display technology acts as primary factor that propels the cathode ray display tube the cathode ray tube display market growth. However, presence of alternative technologies such as LED & LCD displays and intense competition faced due to presence of many local and domestic brands restrain the market growth.

On the other hand, constant demand for cathode ray tube display in medical diagnosis in which patient safety relies on ability of the display to present accurate, high-resolution images rapidly further boosts the cathode ray tube display market revenue. Further developments in display technologies, huge expense of modernized translucent displays with complex configuration, and use of low-cost CRT displays in the middle-class residential sector are anticipated to present new pathways to the cathode ray tube display industry.

Cathode ray tube displays are the most versatile and high-quality imaging display devices available, however, they are not getting as much good press as alternative newer display technologies, owing to plenty of shortcomings. CRT displays are not as sharp as LCDs, owing to imperfect focus and color registration. In addition, these displays are subject to geometric distortion and screen regulation problems, which are also affected by magnetic fields from other equipment as well as other CRTs. Some CRTs have round, spherical or cylindrical shaped screen with bulky size, which fail to attract attention of viewers. Moreover, heavy weight CRT displays consumes high power and produce high heat. CRTs give off electric, magnetic, and electromagnetic fields which are not harmful but create inconvenience.

Use of advanced instrumentation in automobiles has evolved over the years. Design, development, and build of an advanced modern vehicle allows automobile and instrumentation engineers to explore use of advanced instrumentation for vehicle display functions. Cathode ray tube displays are used for primary information display, secondary information display, and functional control, in-vehicle navigation display and rear vision.

Emergence of coronavirus, a deadly respiratory disease originating in Wuhan, has become a serious health threat worldwide. China being the main manufacturing hub of electronic goods has been adversely affected, owing to the COVID-19 virus outbreak that caused substantial slowdown in manufacturing operations. In February 2020, the electronic display industry was already facing shortage of components, which are mainly imported from China.

The ongoing pandemic has also taken adverse toll on consumer demand for display integrated devices. In April 2020, Panasonic India reported that consumer electronics industry would witness 50% loss in sales during April-June, owing to the lockdown. Annual demand has also dropped by an unprecedented 6 to 7%.

The COVID-19 virus outbreak has attributed profound negative impact on the already strained demand-supply chain of the cathode ray tube display market. In response to the unprecedented lockdown, there is a shortfall in demand in industrial as well residential sector.

Key benefits of the stakeholders:The study gives an analytical overview of the cathode ray tube display market forecast with current trends and future estimations to determine imminent investment pockets.

Global Cathode Ray Tube Display Market, By Type (Curved Screen, and Others), Application (Television Screens, Desktop Computer Monitors, Wireless Phone and Portable IT Devices, Commercial and Industrial), End User (Electronics, Automotive, and Consumer Goods) – Industry Trends and Forecast to 2029

Cathode ray tube display (CRT) are being widely used in PC gaming circles as they deliver high pixel resolution, are suitable for use in both dimly lit and dark environments. CRT displays are being preferred as they create perfectly smooth gray scale with an infinite number of intensity levels, and are less expensive.

Global Cathode Ray Tube Display Market was valued at USD 729.19 million in 2021 and is expected to reach USD 1225.05 million by 2029, registering a CAGR of 6.70% during the forecast period of 2022-2029. Electronics accounts for the largest end user segment in the respective market owing to the rapid digitization. The market report curated by the Data Bridge Market Research team includes in-depth expert analysis, import/export analysis, pricing analysis, production consumption analysis, and pestle analysis.

Cathode ray tube (CRT) refer to the displays that use CRT. This technology is a vacuum tube medium that interprets electrical phenomenon of an image projected on a phosphorescentscreen. The interpretation is done by sharp focused beam of electrons being generally controlled by an intensity of electrical signals.

Type (Curved Screen, and Others), Application (Television Screens, Desktop Computer Monitors, Wireless Phone and Portable IT Devices, Commercial and Industrial), End User (Electronics, Automotive, and Consumer Goods)

Toshiba Corporation. (Japan), Panasonic Corporation (Japan), Koninklijke Philips N.V. (Netherlands), Schneider Electric (France), Siemens (Germany), Mitsubishi Electric Corporation (Japan), SONY INDIA. (India), and Chunghwa Picture Tubes, LTD. (Taiwan), among others

Increase in the use of Cathode ray tube display (CRT) in customer electronics across the globe acts as one of the major factors driving the growth of cathode ray tube display market. Also, rise in the adoption of these displays owing to reduction in display costs.

The increase in the usage of consumer electronics display devices along with reduced display costs further influence the market. Also, constant upgrade in display technology assist in the expansion of the market.

Additionally, rapid urbanization, change in lifestyle, surge in investments and increased consumer spending positively impact the cathode ray tube display market.

Furthermore, advancements in the cathode ray tube display technology extend profitable opportunities to the market players in the forecast period of 2022 to 2029. Also, surge in investments will further expand the market.

On the other hand, high cost associated with the manufacturing is expected to obstruct market growth. Also, lack of awareness and low refresh rate are projected to challenge the cathode ray tube display market in the forecast period of 2022-2029.

This cathode ray tube display market report provides details of new recent developments, trade regulations, import-export analysis, production analysis, value chain optimization, market share, impact of domestic and localized market players, analyses opportunities in terms of emerging revenue pockets, changes in market regulations, strategic market growth analysis, market size, category market growths, application niches and dominance, product approvals, product launches, geographic expansions, technological innovations in the market. To gain more info on cathode ray tube display market contact Data Bridge Market Research for an Analyst Brief, our team will help you take an informed market decision to achieve market growth.

The COVID-19 has impacted cathode ray tube display market. The limited investment costs and lack of employees hampered sales and production of cathode ray tube display technology. However, government and market key players adopted new safety measures for developing the practices. The advancements in the technology escalated the sales rate of cathode ray tube display as it targeted the right audience. The increase in sales of devices such as consumer electronics across the globe is expected to further drive the market growth in the post-pandemic scenario.

The cathode ray tube display market is segmented on the basis of type, application and end user. The growth amongst these segments will help you analyze meager growth segments in the industries and provide the users with a valuable market overview and market insights to help them make strategic decisions for identifying core market applications.

The cathode ray tube display market is analyzed and market size insights and trends are provided by country, type, application and end user as referenced above.

The countries covered in the cathode ray tube display market report are U.S., Canada, Mexico, Brazil, Argentina, Rest of South America, Germany, Italy, U.K., France, Spain, Netherlands, Belgium, Switzerland, Turkey, Russia, Rest of Europe, Japan, China, India, South Korea, Australia, Singapore, Malaysia, Thailand, Indonesia, Philippines, Rest of Asia-Pacific, Saudi Arabia, U.A.E, South Africa, Egypt, Israel, Rest of Middle East and Africa (MEA).

North America dominates the cathode ray tube display market because of the introduction of advanced technology along with rising disposable income of the people within the region.

The cathode ray tube display market competitive landscape provides details by competitor. Details included are company overview, company financials, revenue generated, market potential, investment in research and development, new market initiatives, global presence, production sites and facilities, production capacities, company strengths and weaknesses, product launch, product width and breadth, application dominance. The above data points provided are only related to the companies" focus related to cathode ray tube display market.

A CRT (cathode-ray tube) monitor is an analog display device that creates a visible image on the screen by directing three electron beams over millions of phosphor dots to make them light up. In a color monitor, the screen is composed of numerous stripes of alternating red, green, and blue phosphor dots, which get activated by the electrons and combine to make countless different hues.

The electron beam repetitively scans the entire front of the tube to “paint” and refresh the image nearly 100 times every second. Computer monitors and televisions that use CRT technology have large, heavy physical casings. The long length between the front screen and the back of the case is necessary to accommodate the length of the vacuum tube.

Cathode-ray tubes were commonly used in televisions and computer monitors throughout the mid-to-late 1900s. Throughout that time, manufacturers continually improved performance and resolution. Most computer monitors in the 1970s only displayed green text on a black screen. By 1990, IBM’s Extended Graphics Array (XGA) display boasted 16.8 million colors in 800 x 600 pixel resolution.

In the early 2000s, advances in technology made flat-panel displays more accessible. These newer display types (LCD, plasma, and OLED) don’t require a large casing and are more energy efficient. Manufacturing costs are lower than for CRT monitors, and flat-panel displays can be made in larger sizes than CRTs. These factors make flat-panel displays far more popular among consumers.

While flat-panel LCD and OLED monitors and televisions are more common nowadays than CRTs, the older technology is still superior in some ways. A CRT monitor can display/refresh an image faster than an LCD screen. This means the monitor can respond faster to input and avoid motion-blur issues that are common in LCD screens. The color range and contrast is often better on a CRT, and this type of monitor supports deeper black tones. For some computer gamers, these advantages are enough to warrant scouring the internet for old CRT monitors.

When LCDs took over the market in the early 2000s, most companies drastically reduced their CRT manufacturing to account for the decreased demand. Sony stopped making CRT monitors in 2005, and 2008 was the last year Samsung introduced new CRT models. Despite pleas from a small number of passionate gamers who prefer CRT screens over LCDs, the lack of adequate market demand will likely prevent any major company from restarting production any time soon.

CRT, which stands for Cathode-Ray Tube, is an antiquated type of display technology that was commonly used in televisions and computer monitors in the 1900s. While CRT displays are no longer manufactured, they maintain some advantages over modern LCD, OLED, and plasma displays, and are sometimes prized by gamers.

With the advent of LCD screens in the early 2000s, CRT displays became less popular. LCDs are more compact, more energy-efficient, and cost less to make. They can also be made with larger screen sizes than CRT monitors. They’re vastly lighter; a 21-inch CRT display can weigh between 50 and 60 pounds, and some weigh nearly 100 pounds. One of the rarest and most sought-after CRT monitors, the Sony GDM-FW900, had a screen size of 24” and a widescreen aspect ratio of 16:9 and weighed about that much.

However, modern displays are not totally superior to CRT screens. CRT displays can refresh the display at a faster rate than LCDs, making motion on the screen appear smoother with less motion blur. CRTs also have higher contrast ratios and tend to have superior color ranges.

While CRT displays are no longer made, they are sometimes sought after by gamers for their superior refresh rates and contrast ratios. They are also able to avoid the problem of input lag, which is when commands on a controller take longer to register.

LCD gaming displays are catching up to CRTs, however, and can be obtained with comparable refresh rates to CRTs. Still, motion blur remains an issue even on the highest-end gaming monitors.

Finally, retro games were simply designed with CRT in mind, meaning older video games don’t have an authentic look on modern display technologies. Retro gamers commonly want their experience to be as close to the original as possible, and using a modern LCD monitor just doesn’t have the same effect.

CRTs do not support modern display interfaces such as HDMI or DisplayPort. Instead, they typically use VGA. Unlike CRT, the VGA interface is still manufactured today. However, modern graphics cards and motherboards typically do not have a VGA port. Thankfully, you can remedy this with an adapter. Not all adapters are equal, though, so make sure the adapter you use supports the resolution and refresh rate you plan to use.

If you want the sharpest possible display on a CRT monitor, you’ll want one with a dot pitch below .28 millimeters. It’s very rare for a dot pitch to fall below .21 millimeters, but the lower, the better.

If you want to display an image with a high resolution (say, above 1600 x 1200) on a CRT monitor, the dot pitch becomes especially relevant. If the dot pitch is too large, an image will look blurry at higher resolutions. However, if you only intend to use lower resolutions, dot pitch has little impact on the sharpness of the screen. Regardless of the resolution you use, it is best not to go above .28 millimeters to ensure adequate clarity.

Generally, an aperture grill will display a better image than a shadow mask, creating a brighter and more colorful image because it handles light better. However, this is not always the case, and some CRTs with shadow masks have superior image quality than those with aperture grills.

This paper will analyze the fundamental construction of the CRT, its basic functioning as well as how CRTs age over time, outlining their specific signs of deterioration and malfunction. Possibilities for the conservation, replacement, or both, of CRTs and CRT-based displays on a long-term basis will be examined, while considering market options and availability as well as the best estimates for the CRT’s life span. Also to be discussed are current possibilities in terms of refurbishment and the options for migration from CRT based display towards new technologies. The specific elements related to the build of the CRT that one should look for when considering a migration will be analyzed. Finally, the optimal conditions for conservation of CRT devices that are still in use or held in museums and private collections as back-ups planned for the restoration of art works will be presented.

Here are some basic descriptions of how a CRT is composed and functions: A CRT display-unit is composed usually of an outer case and, inside the case, an array of components of which the main part is a glass tube called a Cathode Ray Tube (CRT) and electronic circuit boards which drive the CRT, providing power and signal. The CRT is composed of a cathode and an anode. The front internal glass is a phosphor-coated screen. The neck of the CRT tube is wrapped in coils of wires.

The following are some details to help understand the relationship between the phosphor coating and the coils visible on the neck: The terms anode and cathode are used in electronics as synonyms for positive and negative terminals. For example, one could refer to the positive terminal of a battery as the anode and the negative terminal as the cathode. In a cathode ray tube, the “cathode” is a heated filament, not unlike the filament in a normal light bulb. The heated filament is in a vacuum created inside a glass “tube.” The “ray” is a stream of electrons that naturally pour off a heated cathode into the vacuum. As electrons are negative and the anode positive, it attracts the electrons pouring off the cathode. In a cathode ray tube, the stream of electrons is focused, by a focusing anode, into a tight beam and then accelerated by an accelerating anode. This tight, high-speed beam of electrons flies through the vacuum in the tube and hits the flat phosphor coated screen at the other end of the tube. The phosphor is arranged in dots, which glow when struck by the beam. In a color CRT, the phosphor dots are grouped together in threes, with one phosphor dot that is red, one that is green and one that is blue. The three dots combine together to make one point of light, or pixel, that you see on the screen. The signal input tells the unit what color each pixel should be and how bright it should shine. The cathode or “electron gun” shoots out three electron beams. The beams aim at one pixel on the screen at a time. One beam will hit the green phosphor dot, one will hit the red dot and one will hit the blue dot of the pixel. Back toward the narrow end of CRT, there are steering coils made of copper windings, which are wrapped around the neck of the tube. These coils, through an electrical input, are able to create magnetic fields inside the tube, and the electron beam responds to the fields. One set of coils creates a magnetic field that moves the electron beam vertically, while another set moves the beam horizontally. By controlling the current in the coils, the electron beams can be positioned at any point on the screen. In the case of a black and white CRT display, the same principles apply except that a single electron beam is projected from the cathode, the phosphor coating is monochromatic, and shades of gray are generated through the brightness circuit triggered by the originating signal. Depending on the model the image scanning or creation of the image on the screen occurs at different speeds. The circuit boards driving the CRTs have evolved dramatically since their creation going from vacuum tube based circuitry, to solid-state capacitors, advanced printed circuit boards and to IC chip driven circuitry.

An important question for museums with CRTs in their collections is the best way for them to be stored. CRTs are vacuum devices therefore the phosphor screen and cathode have minimal change during storage. The rated storage temperature for a CRT is -10°C to +65°C. The storage room humidity level should be kept below 80% (because of the metal in the electron gun or pin and related circuit boards) and any storage should never allow condensation on any of the parts. The main concern for long-term storage is the potential for parts to rust as humidity levels increase. For storage and handling of a loose CRT that has been extracted from its case, or purchased unassembled to any electronic parts, the CRT should be sealed in plastic to keep any potential humidity away. The tube should be stored in normal position for viewing. It should not be stored face down in case any loose internal particles might collect on the face and create black spots on the phosphor. Special care should be taken to protect the neck of the CRT against potential shocks and breakage during handling. A unit still fully assembled, including manufacturer’s case, should be wrapped in plastic and conserved under the same guidelines as above. Once it is removed from storage make sure there is no sudden temperature change, such as, going from air-conditioned room to a non air-conditioned room, as these different room temperatures will generate water condensation on the circuit board on a microscopic level which could cause damage. Because a CRT tube is under vacuum it should operate as well 20 years from now as it does today as long as humidity levels are low where it is stored. After storage it may have a slow emission rise (slowly coming to full brightness). A standard technique is to run the unit from 24 hours up to a week to “age-in” the CRT and get it back to an optimal performance level. Any given unit in operation is normally warranted for 10,000 hours or 12 months – whichever comes first. CRT displays stored for a long period of time can have component degradation even in optimal settings. The rate of decline depends, in good conditions, generally upon the quality of components and overall usage. As a CRT advances in long-term use, without rest time, the degradation rate can increase due to the cathode loosing the ability to generate electrons.

General safety precautions when working with the internal parts of CRT display are multiple and only trained specialists should handle these. The most critical thing to know, as a brief overview, is that since the CRT tube is under vacuum, any puncturing or breakage of the tube can cause an implosion which can be very hazardous. In addition high voltage is stored inside the tube so it must be discharged before handling. Black and white devices hold about 10,000 volts, with low current, whereas color devices hold between 10,000 to 40,000 volts, also with low current,; these voltages increase based on the size of the tube. Some of the capacitors on the circuit boards can also hold charge.

Some of the basic signs of aging of a CRT tube are as follows: loss of image focus or loss of image sharpness, overall darkened picture, discoloration, general yellowish or reddish hue (loss of white and blue hue), image purity problems ( discoloration of image in certain areas of the screen), phosphor burn (irreversible image birn into the screen phosphor), slow warm-up time during initial turn on before full brightness is achieved. Electrically one can have flickering, vertical hold problems (image rolling top to bottom on the screen, failing to hold still) and image banding, all of which would be due to faulty circuitry. If a device has been in operation for extensive periods (hours use) there is no permanent way to revive it. The cathode material in the electron gun is already used up. If a device is unused and appears weak upon initial operation it could just be a matter of an “under-aged” gun which at one time could be corrected by rejuvenating via refurbishing firms but those businesses have closed in the last 5 years so this is no longer an option. The only option is to attempt to age-in the CRT by running the device as previously mentioned.

CRT devices that have been manufactured before 1990 usually are very difficult to source new or used. Any unit that is sourced must be tested once received. Depending on the quantities and sizes sought the task of finding exact models can go from difficult to impossible. The smaller the CRT is, the earlier it has gone out of production, starting with the 5 in. and upwards in size. From the early 90’s smaller units such as the 5 in. became reserved for specialty monitors in use in security and broadcast television studios, both stationary and mobile and in public settings such as buses and used for applications such as for medical equipment and the military. The smaller consumer grade units were the first to be phased out of the market as consumers began to want larger and larger viewing screens. Comparable LCD screens were produced and consecutively replacing CRT based devices overall, starting from smaller to larger. The price drop of the LCD screens generally then fast forwarded the changeover and forced the CRT out of market as it lost its competitive edge.

The market of CRT-based displays has seen sweeping changes over the last 5 years. To our knowledge, all CRT manufacturing has ceased worldwide and most companies, which offer any, are either end-of-stock or assembled using recycled CRT tubes extracted from disassembled used consumer televisions and monitors. Remaining brand-new stocks are rarely above quantities of 10 of the same model and often companies list stocks, which actually aren’t, upon further queries, available. Having a tube refurbished is not possible as all companies within the United States refurbishing CRTs have closed, the latest within the last six months (except for military applications which is not available to the public and is only for black and white units). As of yet, no refurbishing companies have been located overseas. Furthermore, there are no remaining electron gun manufacturers left to supply the electron gun (each tube requiring its own matching electron gun). Many countries have generated laws, which restrict or forbid the manufacturing and import of CRT-based devices (for ecological reasons and to keep incoming technology up to standard with the prevailing application in use at the moment, e.g., digital instead of analog, etc.). Currently the last existing stocks that are still available, in quantity, are industrial grade monitors. These are built with extensive circuit boards to accommodate their industrial applications, which in turn, requires a much more advanced knowledge in order to service them. Their external aspect ratio is typically rectangular with an easily identifiable and distinct “monitor” look. Their cost can be prohibitive but always are worth considering on a case-by-case basis.

Unreleased stocks of new or used CRT-based displays within the United States might still be available via universities, schools and hospitals as well as from disassembled industrial display walls. A constant scanning of the market via the Internet and professional networks is necessary in order to track these sources. Finally new CRTs only (without matching circuit boards or casing) are available for purchase within the United States, but then the challenge remains to find the matching circuit boards. This is a potential course when