fluorescent lamp in lcd panel for lighting factory

LCD Lighting produces specialty fluorescent lamps for point-of-purchase (POP) displays. We offer a wide variety of colors and color correction so that sign and POP display makers can stay true to the brand.

We design our T5, T8 and T12 lamps with display designers and other professional servicemen in mind, creating features that are optimized for indoor and outdoor signage, advertising displays, exhibits, and point-of-purchase (POP) displays, retail, and mood lighting.

We designed our Long Life lamps for both hot and cold (low-temperature) operating environments. The cold weather Long Life lamp encapsulates the T8 lamp in a T12 sleeve providing a thermal insulation for the fluorescent tube to reach full brightness. For those new or retrofit applications where a more even distribution of light in the sign cabinet is required, Long Life T8’s are available with a single or diffused coating inside the T12 sleeve. The diffused sleeve provides the same benefits as the thermal lamp while softening the light to prevent hot spots on the sign or display face. The T5 and T8 hot environment lamps use a long stem mount to create stable “cold spot” for optimum output and performance.

Long Life T12 fluorescent tubes offer direct retrofitting with electronic and magnetic ballasts. They can directly replace existing T12 HO lamps with up to 25 percent greater efficiency. Whether building, designing, or retrofitting an existing sign or display, the Long Life T12 is easy to incorporate into your advertising or display program. We have designed these lamps to operate on magnetic and electronic sign ballasts for easy changeover.

Readily available colors include: cool white, warm white, daylight, blue, green, red, and tri-band. We also provide ultraviolet and infrared phosphors. Colors can be blended to produce the precise desired color requirements in a wide range within the visible spectrum. Please visit our High CRI page for more information.

LCD Lighting can work with OEMs to make connections for their specific applications. Please visit or Lamp Sub-Assembly page for more information about our value-added solutions.

Standard phosphors can be blended for customization, matching your exact color requirements in a wide range within the visible spectrum. Standard colors include cool white, warm white, daylight, blue, green, red, ultraviolet, infrared, and tri-band.

Are you looking for outdoor sign fluorescent lamps that reduce energy costs and work in a variety of environments? Our long life sign lamps from Voltarc – an LCD Lighting affiliate company – offer everything you need, including thermal and thermal diffused lamps for cold operating environment.Click here to learn more.

With cutting-edge technology and the experience of designing and manufacturing thousands of T-2, T-4, T-5, T8 and T-12 fluorescent lamps, we are world market leaders in our industry.

We provide lamp sub assemblies (LSA), a value-added service. On site, LCD Lighting can produce fully assembled LSA units according to our clients’ design drawings and specifications; our OEM clients receive ready-to-go equipment, saving valuable time and money.

Backlighting for LCD and AMLCD displays formilitary and civilian aircrafts, shipboards, and vehicles, the NASA space shuttle and in vetronics, and computers.

Light therapy for medical uses, including neo-natal jaundice, sleep disorders, Seasonal Affective Disorder (SAD), skin disorders (eczema, psoriasis, and acne), wound healing, and Parkinson’s.

Our proprietary and innovative specialty fluorescent technologies and specially-designed solutions help provide our OEM clients with a measurable advantage in their respective markets

Ultra-Bright™ – With this technology, LCD Lighting offers lamps with double the efficacy (lm/watts), 50% improvement in lumen maintenance, and maximized lighting uniformity.

High CRI (Color Rendering Index) – Our proprietary color rendering index (CRI) has more rare earth tri-phosphors to provide the truest color with a natural look.

Laptops, computer screens, tablets, notebooks. Is your display not lighting up? Maybe it is getting dim or even starting to have a reddish or pinkish hue, maybe it has completely gone dark. The good news: you need a new CCFL backlight lamp and we have them. We stock LCD backlight bulbs for most LCDs. The backlight repair is actually easier than you think, and once you replace the CCFL lamp in your LCD you have essentially restored your LCD display to new condition, as bright and vibrant as it was the first day you got it. And best of all, one less old LCD panel in a landfill somewhere! Call us today, we are here to help (402) 330-2222.

CCFL warehouse is the leading supplier and vendor direct to the largest department stores, grocery stores, and restaurant chains in the country. These companies purchase their CCFL lamps directly from us for use in their own POS repair facilities. We have replacement CCFL lamps in stock for all touch screen displays commonly used in POS cash registers and we stock them in large quantities.

Nearly every piece of Industrial equipment now made has an LCD control panel of some sort. Expensive equipment like CNC machines, heavy machinery, industrial control panels, medial and military displays, sewing machines, food processing equipment, you name it! What they also have in common is they are all heavily used and the LCD displays eventually fail. The equipment manufacturers charge exorbitant amounts for new displays, but the fact is all that is needed is new CCFL backlights. Install a new CCFL lamp assembly and your critical piece of equipment is back on line.

ATMs, amusement displays such as casino gaming, video games, juke boxes, and kiosks- these LCD displays are notorious for failure due to the 24 hour high demand usage. Again, a new CCFL lamp, and they are back up and running like new. CCFL Warehouse supplies CCFL backlights to many of the largest LCD display repair companies in the world. Our high-quality CCFL lamps are trusted for ultra long life in these demanding environments. If you do not find the exact CCFL lamp that you need on our website, drop us an email or give us a call, we will make it for you.

There is a reason all of the most respected LCD repair facilities in the country, both big and small, purchase their CCFL Backlight lamps from us, quite simply our expertise in the area of LCD backlights is simply unparalleled. Not only do we stock more cold cathode fluorescent lamps than any other company, produce the highest quality lamps, offer exceptional pricing, but we are here to help!

Quite simply, we are the experts in CCFL lamps and LCD backlighting, that is all we do and anything we can do to help you in your repair efforts we are more than happy to accommodate.

CCFLwarehouse.com is the single largest CCFL backlight supplier in North America. We specialize in CCFL lamps, producing the highest quality lamps available and stocking them in high volumes so that they are available for our customer when they need them. Our lamps are used all over the world by a wide range of clients, some just looking to get their laptop back up and running and others who operate some of the largest repair facilities in the world. Whatever your backlight repair needs, we can help.

Our CCFL lamps are designed specifically for repairs of LCD panels made by many of largest LCD panel manufacturers in the world such as: AU Optronics (AUO), Samsung, Sanyo, LG, Innolux, Torisan, Sharp, Che Mei, Chunghwa, NEC, Mitsubishi, Toshiba, Boe Hydis, Hitachi, Fujitsu, HannStar and many more.

In addition we stock LCD backlights specific for the repair of laptop and notebook computers and desktop monitors. Our CCFL lamps are used to repair LCD panels in all major computer brands such as; Acer, Asus, Gateway, Dell, Hewlett Packard (HP), Compaq, Lenova, Apple, Sony, BenQ, Alien Ware, Sager, Quanta, Clevo, and many more.

How do you replace your fluorescent tubes with LED? Let us count the ways! In today"s blog, we break down the advantages and disadvantages of each of your options.

If you have fluorescent fixtures and are eying the cost- and energy-savings of switching to LED lighting, you"ll find there are two paths you can take: convert your existing fixtures to work with LED or replace those fixtures with new LED fixtures. But within those paths are a number of options, depending on the type and location of your fixtures, your lighting goals, and your budget. Whichever you go with in the end, you"re guaranteed reduce both your energy use and operating costs by a significant amount. And don"t forget the other benefit of LED lighting: you"re going to enjoy a much (much) longer lamp life than you"ve been used to!

A 4-lamp 4-foot fixture can go from what you have now (about 7200 lumens in LED terms) to nearly twice as bright (about 13,200 lumens with four 3300-lumen LED tubes), depending on the lumen rating of your LED replacement tube.

LEDs use between 60W and 80W per 4-lamp, 4-foot fixture vs 128W to 172W, but they can do even better than that: our high-efficiency, Ultra High Lumen lights can act as 1-for-2 replacements, allowing you to light a 4-lamp fluorescent fixture with just 2 LED tubes, or a total of 40W vs 128W.

The fact that strips use an external driver, as opposed to the small driver manufactured within an LED tube, allows for better airflow and heat dissipation, which translates longer life & increased reliability for strips

No need to wire power to tombstone sockets—simply connect your building"s power to the driver, then quick-connect the driver to the strips with the included cables

If you ask which we think is best between tubes and strips, in most cases we favor strips. If you have questions about your application, reach out to us!

Not sure which way to go? Our expert team is available to help with your conversion from fluorescent to LED. Contact our West Coast facility at 858.581.0597, our East Coast facility at 215.355.7200, or email sales@eledlights.com.

Keep in mind that, although the lumen output may seem lower for LED tubes than fluorescents, there are a number of reasons why you"ll experience LED lights as being as bright as, if not brighter than, fluorescents (something we"ve covered in more detail in this blog post). With today"s technology, you can rest assured that if you"re buying an LED tube from a reputable manufacturer, it will be at least as bright as the fluorescent you"re replacing. Which means that the lumen rating for various LED tubes is best used to compare one LED option against another. The higher the number, the greater the light output.

This website is using a security service to protect itself from online attacks. The action you just performed triggered the security solution. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data.

This website is using a security service to protect itself from online attacks. The action you just performed triggered the security solution. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data.

Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters

H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices

H05B41/3921—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor with possibility of light intensity variations

H05B41/3927—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor with possibility of light intensity variations by pulse width modulation

An improved LCD back light panel lamp connecting structure arranges a high voltage end and a feedback end of adjacent cold cathode fluorescent lamp (CCFL) modules alternately, and the feedback end of the CCFL is coupled to a single return board. The return board is coupled to a pulse width modulation (PWM) control unit so that the two return boards feed back the current to the PWM control unit. The high voltage end of the CCFL is coupled to a transformer.

The present invention relates to an improved LCD back light panel lamp connecting structure, more particularly to a plurality of cold cathode fluorescent lamp (CCFL) modules, and the adjacent CCFL modules have their high voltage ends and feedback ends arranged alternately. BACKGROUND OF THE INVENTION

A traditional LCD TV or touch screen of a LCD display requires a high brightness to compensate the visual requirements. In general, a cold cathode fluorescent lamp (CCFL) is lit by high voltage; the larger the current, the brighter is the lamp. Therefore several CCFL lamps are generally used to compensate the brightness and evenness, and it is the most important issue is to keep the current of the lamp even and minimize the error. The installation of several sets of loading also increases the number of control units for the lighting and the area of the circuit board, and thus making the manufacturing more complicated and the cost higher. In FIG. 1, it shows a driving device that lights up a CCFL, and comprises a power supply unit 13, a pulse width modulation (PWM) control unit 14, a driving unit 15, a transformer 11, and a loaded cold cathode florescent lamp (FFCL) 12. When the input of the input voltage is initialized, the driving unit 15 immediately drives the transformer 11 to light up the CCFL 12 by the negative/positive voltage effect and the PWM control 14 detects the current of the CCFL lamp 12 through the current feedback 16 and outputs a resonant frequency. The average current of the CCFL lamp 12 can be controlled by means of the driving unit 15 and the transformer 11. Therefore, the light produced can be projected onto the back light panel of the LCD.

Please refer to FIG. 2 for the schematic circuit diagram of a plurality of lamps in accordance with a prior art. In the figure, the high voltage ends of a plurality of lamps 21 respectively connect to a connector 221 and a connector of a transformer 23, and the plurality of transformers 23 are integrated to a circuit board 26 to form an inverter 20, and the feedback end of the plurality of lamps 21 are mutually coupled and connected to the PWM control unit 25, so that the PWM control unit 25 can detect the current of the lamp 21 through the current feedback to output a resonant frequency and control the average current of the CCFL lamp 12.

However, the connection method of the CCFL lamps described above has the following shortcomings: 1. Firstly, the feedback end of the prior-art multiple lamps generally makes the wiring job more complicated, not only increasing the size of the circuit board, but also making the manufacturing complicated, increasing the cost, and unnecessarily consuming higher voltage.

2. Secondly, since the high voltage ends of the cold cathode fluorescent lamps are installed on the same side of the lamp, therefore when the lamp is lit, the temperature at that side is usually too high and thus affecting the life of the lamp.

3. Thirdly, when several lamps are used to compensate the brightness and evenness, it generally causes uneven current and brightness between the lamps since there generally exists a discrepancy between lamps for their production. Thus, it becomes an issue of selecting lamps, or it may require more lamps to improve the brightness and evenness. Such arrangement will increase the cost, and make the manufacture more complicated and the adjustment more difficult.

The primary objective of the present invention is to overcome the shortcomings and avoid the deficiencies of the prior art. The present invention alternately arranges the high voltage end and the feedback end of adjacent cold cathode fluorescent lamp modules to save wire materials, average the current of the lamp, and enhance the stability of the current.

To achieve the above objective, the improved LCD back light panel lamp connection structure of the present invention arranges high voltage ends and feedback ends of adjacent cold cathode fluorescent lamp (CCFL) modules alternately, and the feedback end of the CCFL is coupled to a single return board. The return board is coupled to a pulse width modulation (PWM) control unit so that the two return boards feed back the current to the PWM control unit. The high voltage end of the CCFL respectively couples to a transformer and drives the transformer to light up several sets of cold cathode fluorescent lamps, and the feedback end of the plurality of CCFLs feeds back the current through the single return board to a PWM control unit. Such PWM control unit detects the current of the lamp to output a resonant frequency and control the average current of the several sets of CCFLs. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 5 is a schematic view of an LCD back light panel lamp connecting structure according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 3 and 4 for the block diagram of the circuit and the schematic diagram of the transformer and power supply board of the present invention respectively. In the figures, the improved LCD back light panel lamp connecting structure comprises at least one cold cathode fluorescent lamp (CCFL) 31 a, 31 b, 31 a′, 31 b′ grouped into a CCFL module 31, 31′ such that a high voltage end 32 of a CCFL module 31, 31′ is coupled to a first voltage end, and a feedback end 33 is coupled to a second voltage end, and the lamps are arranged in parallel in a first direction forming a row in a second direction perpendicular to the first second direction. The high voltage end 32 and the feedback end 33 of the adjacent CCFL modules 31, 31′ are arranged alternately, and the feedback ends 33 of adjacent CCFL modules 31, 31′ coupled to a single return board 39. The return board 39 is coupled to a pulse width modulation (PWM) control unit 36 so that the return board 39 feeds back the current to the PWM control unit 36; the high voltage end 32 of the CCFL module 31, 31′ couples to a connector 38 at an output end of a transformer 45 by a connector 37; the feedback end 33 of the CCFL module 31, 31′ mutually couples to the feedback ends 34, 35 together with a single return board 39, and the feedback ends 34, 35 could be the same feedback end; the transformer 45 comprises at least one transformer or ceramic transformer being coupled to the connector 37 of the CCFL module 31, 31′ by a connector 38, and each transformer 45 is integrated on a circuit board 43 to form a inverter 46, and then connected to a connector 40 on a power supply board 41 by a connector 44 on the circuit board 43. The power supply board 41 is coupled to a power supply unit 42 so that the power can be supplies to each transformer 45 on the inverter 46 via the power supply board 41, which can save wire materials and simplify the structure.

Referring to FIG. 3, the cold cathode fluorescent lamp modules 31, 31′ can contain two CCFLs or four CCFLs. The CCFLs 31 aand 31 bare grouped as a module and the CCFLs 31 a′ and 31 b′ are grouped as another module, and the high voltage end 32 and feedback end 33 of adjacent CCFL modules 31, 31′ are arranged alternately. The transformer 45 is driven to light up several CCFL modules 31, 31′, and the feed back end 33 of each CCFL module 31, 31′ feeds back the current to the PWM control unit 36 through the two return boards 34, 35, and the PWM control unit 36 detects the current of the CCFL module 31, 31′ to output a resonant frequency, and control the average current of several CCFL modules 31, 31′.

In view of the description above, the present invention definitely overcomes the shortcomings of the prior art and has the following advantages: 1. The present invention arranges adjacent CCFL modules alternately, such that the high voltage ends of the lamps are arranged alternately, and thus will not overheat one side of the lamp when the lamp is lit.

2. The feedback ends of several lamps of the present invention are connected in series, and all coupled to the two return boards, not only saving wire material, lowering the consumption of voltage for transmission, and increasing the stability of the circuit, but also making the manufacture easy and the cost lower.

3. The present invention arranges the high voltage end and the feedback end of several lamps alternately, so that the current of each CCFL can be more evenly distributed, and thus achieving the purpose of even lighting.

While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.

1. An improved LCD back light panel lamp connection structure, comprising at least one cold cathode fluorescent lamp (CCFL) as a module, and each CCFL having a high voltage end coupled to a first high voltage end and a feedback end coupled to a second high voltage end, and the CCFLs being arranged in parallel in a first direction forming a row in a second direction perpendicular to the first second direction, the high voltage end and the feedback end of adjacent CCFL modules being arranged alternately, and all feedback ends of the CCFL modules being coupled to a single return board.

2. The improved LCD back light panel lamp connection structure of claim 1, wherein light in the CCFL is evenly distributed between the high voltage end and the feedback end.

3. The improved LCD back light panel lamp connection structure of claim 1, wherein heat is distributed evenly between the high voltage end and the feedback end.

Inverter device, liquid crystal display device using the inverter device, and method of monitoring lamps of the liquid crystal display device using the inverter device

Inverter device, liquid crystal display device using the inverter device, and method of monitoring lamps of the liquid crystal display device using the inverter device

Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters

H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices

H05B41/3921—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor with possibility of light intensity variations

H05B41/3927—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor with possibility of light intensity variations by pulse width modulation

An improved LCD back light panel lamp connecting structure arranges a high voltage end and a feedback end of adjacent cold cathode fluorescent lamp (CCFL) modules alternately, and the feedback end of the CCFL is coupled to a single return board. The return board is coupled to a pulse width modulation (PWM) control unit so that the two return boards feed back the current to the PWM control unit. The high voltage end of the CCFL is coupled to a transformer.

The present invention relates to an improved LCD back light panel lamp connecting structure, more particularly to a plurality of cold cathode fluorescent lamp (CCFL) modules, and the adjacent CCFL modules have their high voltage ends and feedback ends arranged alternately. BACKGROUND OF THE INVENTION

A traditional LCD TV or touch screen of a LCD display requires a high brightness to compensate the visual requirements. In general, a cold cathode fluorescent lamp (CCFL) is lit by high voltage; the larger the current, the brighter is the lamp. Therefore several CCFL lamps are generally used to compensate the brightness and evenness, and it is the most important issue is to keep the current of the lamp even and minimize the error. The installation of several sets of loading also increases the number of control units for the lighting and the area of the circuit board, and thus making the manufacturing more complicated and the cost higher. In FIG. 1, it shows a driving device that lights up a CCFL, and comprises a power supply unit 13, a pulse width modulation (PWM) control unit 14, a driving unit 15, a transformer 11, and a loaded cold cathode florescent lamp (FFCL) 12. When the input of the input voltage is initialized, the driving unit 15 immediately drives the transformer 11 to light up the CCFL 12 by the negative/positive voltage effect and the PWM control 14 detects the current of the CCFL lamp 12 through the current feedback 16 and outputs a resonant frequency. The average current of the CCFL lamp 12 can be controlled by means of the driving unit 15 and the transformer 11. Therefore, the light produced can be projected onto the back light panel of the LCD.

Please refer to FIG. 2 for the schematic circuit diagram of a plurality of lamps in accordance with a prior art. In the figure, the high voltage ends of a plurality of lamps 21 respectively connect to a connector 221 and a connector of a transformer 23, and the plurality of transformers 23 are integrated to a circuit board 26 to form an inverter 20, and the feedback end of the plurality of lamps 21 are mutually coupled and connected to the PWM control unit 25, so that the PWM control unit 25 can detect the current of the lamp 21 through the current feedback to output a resonant frequency and control the average current of the CCFL lamp 12.

However, the connection method of the CCFL lamps described above has the following shortcomings: 1. Firstly, the feedback end of the prior-art multiple lamps generally makes the wiring job more complicated, not only increasing the size of the circuit board, but also making the manufacturing complicated, increasing the cost, and unnecessarily consuming higher voltage.

2. Secondly, since the high voltage ends of the cold cathode fluorescent lamps are installed on the same side of the lamp, therefore when the lamp is lit, the temperature at that side is usually too high and thus affecting the life of the lamp.

3. Thirdly, when several lamps are used to compensate the brightness and evenness, it generally causes uneven current and brightness between the lamps since there generally exists a discrepancy between lamps for their production. Thus, it becomes an issue of selecting lamps, or it may require more lamps to improve the brightness and evenness. Such arrangement will increase the cost, and make the manufacture more complicated and the adjustment more difficult.

The primary objective of the present invention is to overcome the shortcomings and avoid the deficiencies of the prior art. The present invention alternately arranges the high voltage end and the feedback end of adjacent cold cathode fluorescent lamp modules to save wire materials, average the current of the lamp, and enhance the stability of the current.

To achieve the above objective, the improved LCD back light panel lamp connection structure of the present invention arranges high voltage ends and feedback ends of adjacent cold cathode fluorescent lamp (CCFL) modules alternately, and the feedback end of the CCFL is coupled to a single return board. The return board is coupled to a pulse width modulation (PWM) control unit so that the two return boards feed back the current to the PWM control unit. The high voltage end of the CCFL respectively couples to a transformer and drives the transformer to light up several sets of cold cathode fluorescent lamps, and the feedback end of the plurality of CCFLs feeds back the current through the single return board to a PWM control unit. Such PWM control unit detects the current of the lamp to output a resonant frequency and control the average current of the several sets of CCFLs. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 5 is a schematic view of an LCD back light panel lamp connecting structure according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 3 and 4 for the block diagram of the circuit and the schematic diagram of the transformer and power supply board of the present invention respectively. In the figures, the improved LCD back light panel lamp connecting structure comprises at least one cold cathode fluorescent lamp (CCFL) 31 a, 31 b, 31 a′, 31 b′ grouped into a CCFL module 31, 31′ such that a high voltage end 32 of a CCFL module 31, 31′ is coupled to a first voltage end, and a feedback end 33 is coupled to a second voltage end, and the lamps are arranged in parallel in a first direction forming a row in a second direction perpendicular to the first second direction. The high voltage end 32 and the feedback end 33 of the adjacent CCFL modules 31, 31′ are arranged alternately, and the feedback ends 33 of adjacent CCFL modules 31, 31′ coupled to a single return board 39. The return board 39 is coupled to a pulse width modulation (PWM) control unit 36 so that the return board 39 feeds back the current to the PWM control unit 36; the high voltage end 32 of the CCFL module 31, 31′ couples to a connector 38 at an output end of a transformer 45 by a connector 37; the feedback end 33 of the CCFL module 31, 31′ mutually couples to the feedback ends 34, 35 together with a single return board 39, and the feedback ends 34, 35 could be the same feedback end; the transformer 45 comprises at least one transformer or ceramic transformer being coupled to the connector 37 of the CCFL module 31, 31′ by a connector 38, and each transformer 45 is integrated on a circuit board 43 to form a inverter 46, and then connected to a connector 40 on a power supply board 41 by a connector 44 on the circuit board 43. The power supply board 41 is coupled to a power supply unit 42 so that the power can be supplies to each transformer 45 on the inverter 46 via the power supply board 41, which can save wire materials and simplify the structure.

Referring to FIG. 3, the cold cathode fluorescent lamp modules 31, 31′ can contain two CCFLs or four CCFLs. The CCFLs 31 aand 31 bare grouped as a module and the CCFLs 31 a′ and 31 b′ are grouped as another module, and the high voltage end 32 and feedback end 33 of adjacent CCFL modules 31, 31′ are arranged alternately. The transformer 45 is driven to light up several CCFL modules 31, 31′, and the feed back end 33 of each CCFL module 31, 31′ feeds back the current to the PWM control unit 36 through the two return boards 34, 35, and the PWM control unit 36 detects the current of the CCFL module 31, 31′ to output a resonant frequency, and control the average current of several CCFL modules 31, 31′.

In view of the description above, the present invention definitely overcomes the shortcomings of the prior art and has the following advantages: 1. The present invention arranges adjacent CCFL modules alternately, such that the high voltage ends of the lamps are arranged alternately, and thus will not overheat one side of the lamp when the lamp is lit.

2. The feedback ends of several lamps of the present invention are connected in series, and all coupled to the two return boards, not only saving wire material, lowering the consumption of voltage for transmission, and increasing the stability of the circuit, but also making the manufacture easy and the cost lower.

3. The present invention arranges the high voltage end and the feedback end of several lamps alternately, so that the current of each CCFL can be more evenly distributed, and thus achieving the purpose of even lighting.

While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.

1. An improved LCD back light panel lamp connection structure, comprising at least one cold cathode fluorescent lamp (CCFL) as a module, and each CCFL having a high voltage end coupled to a first high voltage end and a feedback end coupled to a second high voltage end, and the CCFLs being arranged in parallel in a first direction forming a row in a second direction perpendicular to the first second direction, the high voltage end and the feedback end of adjacent CCFL modules being arranged alternately, and all feedback ends of the CCFL modules being coupled to a single return board.

2. The improved LCD back light panel lamp connection structure of claim 1, wherein light in the CCFL is evenly distributed between the high voltage end and the feedback end.

3. The improved LCD back light panel lamp connection structure of claim 1, wherein heat is distributed evenly between the high voltage end and the feedback end.

Inverter device, liquid crystal display device using the inverter device, and method of monitoring lamps of the liquid crystal display device using the inverter device

Inverter device, liquid crystal display device using the inverter device, and method of monitoring lamps of the liquid crystal display device using the inverter device

Top: two non-integrated compact fluorescent lamps. Bottom: two fluorescent tube lamps. Both types require a ballast in the light fixture. A matchstick, left, is shown for scale.

Typical F71T12 100 W G13 bi-pin lamp used in tanning beds. The (Hg) symbol indicates that this lamp contains mercury. In the US, this symbol is now required on all mercury-containing fluorescent lamps.

Inside the lamp end of a preheat G13 lamp. In this lamp, the filament is surrounded by an oblong metal cathode shield, which helps reduce lamp end darkening.

A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than an incandescent lamp. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. For comparison, the luminous efficacy of an incandescent bulb may only be 16 lumens per watt.

Fluorescent lamp fixtures are more costly than incandescent lamps because, among other things, they require a ballast to regulate current through the lamp, but the initial cost is offset by a much lower running cost. Compact fluorescent lamps are now available in the same popular sizes as incandescents and are used as an energy-saving alternative in homes.

Because they contain mercury, many fluorescent lamps are classified as hazardous waste. The United States Environmental Protection Agency recommends that fluorescent lamps be segregated from general waste for recycling or safe disposal, and some jurisdictions require recycling of them.

The fluorescence of certain rocks and other substances had been observed for hundreds of years before its nature was understood. By the middle of the 19th century, experimenters had observed a radiant glow emanating from partially evacuated glass vessels through which an electric current passed. One of the first to explain it was the Irish scientist Sir George Stokes from the University of Cambridge in 1852, who named the phenomenon "fluorescence" after fluorite, a mineral many of whose samples glow strongly because of impurities. The explanation relied on the nature of electricity and light phenomena as developed by the British scientists Michael Faraday in the 1840s and James Clerk Maxwell in the 1860s.

Little more was done with this phenomenon until 1856 when German glassblower Heinrich Geissler created a mercury vacuum pump that evacuated a glass tube to an extent not previously possible. Geissler invented the first gas-discharge lamp, the Geissler tube, consisting of a partially evacuated glass tube with a metal electrode at either end. When a high voltage was applied between the electrodes, the inside of the tube lit up with a glow discharge. By putting different chemicals inside, the tubes could be made to produce a variety of colors, and elaborate Geissler tubes were sold for entertainment. More important, however, was its contribution to scientific research. One of the first scientists to experiment with a Geissler tube was Julius Plücker, who systematically described in 1858 the luminescent effects that occurred in a Geissler tube. He also made the important observation that the glow in the tube shifted position when in proximity to an electromagnetic field. Alexandre Edmond Becquerel observed in 1859 that certain substances gave off light when they were placed in a Geissler tube. He went on to apply thin coatings of luminescent materials to the surfaces of these tubes. Fluorescence occurred, but the tubes were very inefficient and had a short operating life.

Inquiries that began with the Geissler tube continued as even better vacuums were produced. The most famous was the evacuated tube used for scientific research by William Crookes. That tube was evacuated by the highly effective mercury vacuum pump created by Hermann Sprengel. Research conducted by Crookes and others ultimately led to the discovery of the electron in 1897 by J. J. Thomson and X-rays in 1895 by Wilhelm Röntgen. But the Crookes tube, as it came to be known, produced little light because the vacuum in it was too good and thus lacked the trace amounts of gas that are needed for electrically stimulated luminescence.

One of the first mercury vapor lamps invented by Peter Cooper Hewitt, 1903. It was similar to a fluorescent lamp without the fluorescent coating on the tube and produced greenish light. The round device under the lamp is the ballast.

Thomas Edison briefly pursued fluorescent lighting for its commercial potential. He invented a fluorescent lamp in 1896 that used a coating of calcium tungstate as the fluorescing substance, excited by X-rays, but although it received a patent in 1907,Nikola Tesla made similar experiments in the 1890s, devising high-frequency powered fluorescent bulbs that gave a bright greenish light, but as with Edison"s devices, no commercial success was achieved.

One of Edison"s former employees created a gas-discharge lamp that achieved a measure of commercial success. In 1895 Daniel McFarlan Moore demonstrated lamps 2 to 3 meters (6.6 to 9.8 ft) in length that used carbon dioxide or nitrogen to emit white or pink light, respectively. They were considerably more complicated than an incandescent bulb, requiring both a high-voltage power supply and a pressure-regulating system for the fill gas.

Moore invented an electromagnetically controlled valve that maintained a constant gas pressure within the tube, to extend the working life.General Electric’s motivation to improve the incandescent lamp, especially its filament. GE"s efforts came to fruition with the invention of a tungsten-based filament. The extended lifespan and improved efficacy of incandescent bulbs negated one of the key advantages of Moore"s lamp, but GE purchased the relevant patents in 1912. These patents and the inventive efforts that supported them were to be of considerable value when the firm took up fluorescent lighting more than two decades later.

At about the same time that Moore was developing his lighting system, Peter Cooper Hewitt invented the mercury-vapor lamp, patented in 1901 (). Hewitt"s lamp glowed when an electric current was passed through mercury vapor at a low pressure. Unlike Moore"s lamps, Hewitt"s were manufactured in standardized sizes and operated at low voltages. The mercury-vapor lamp was superior to the incandescent lamps of the time in terms of energy efficiency, but the blue-green light it produced limited its applications. It was, however, used for photography and some industrial processes.

Mercury vapor lamps continued to be developed at a slow pace, especially in Europe, and by the early 1930s, they received limited use for large-scale illumination. Some of them employed fluorescent coatings, but these were used primarily for color correction and not for enhanced light output. Mercury vapor lamps also anticipated the fluorescent lamp in their incorporation of a ballast to maintain a constant current.

Cooper-Hewitt had not been the first to use mercury vapor for illumination, as earlier efforts had been mounted by Way, Rapieff, Arons, and Bastian and Salisbury. Of particular importance was the mercury-vapor lamp invented by Küch and Retschinsky in Germany. The lamp used a smaller bore bulb and higher current operating at higher pressures. As a consequence of the current, the bulb operated at a higher temperature which necessitated the use of a quartz bulb. Although its light output relative to electrical consumption was better than that of other sources of light, the light it produced was similar to that of the Cooper-Hewitt lamp in that it lacked the red portion of the spectrum, making it unsuitable for ordinary lighting. Due to difficulties in sealing the electrodes to the quartz, the lamp had a very short life.

The next step in gas-based lighting took advantage of the luminescent qualities of neon, an inert gas that had been discovered in 1898 by isolation from the atmosphere. Neon glowed a brilliant red when used in Geissler tubes.Georges Claude, a Frenchman who had developed a technology and a successful business for air liquefaction, was obtaining enough neon as a byproduct to support a neon lighting industry.electrodes with a lot of surface area, it showed that a major impediment to gas-based lighting could be overcome.

The development of the neon light also was significant for the last key element of the fluorescent lamp, its fluorescent coating.Edmund Germer, who were employees of a German firm in Berlin. A German patent was granted but the lamp never went into commercial production.

All the major features of fluorescent lighting were in place at the end of the 1920s. Decades of invention and development had provided the key components of fluorescent lamps: economically manufactured glass tubing, inert gases for filling the tubes, electrical ballasts, long-lasting electrodes, mercury vapor as a source of luminescence, effective means of producing a reliable electrical discharge, and fluorescent coatings that could be energized by ultraviolet light. At this point, intensive development was more important than basic research.

In 1934, Arthur Compton, a renowned physicist and GE consultant, reported to the GE lamp department on successful experiments with fluorescent lighting at General Electric Co., Ltd. in Great Britain (unrelated to General Electric in the United States). Stimulated by this report, and with all of the key elements available, a team led by George E. Inman built a prototype fluorescent lamp in 1934 at General Electric’s Nela Park (Ohio) engineering laboratory. This was not a trivial exercise; as noted by Arthur A. Bright, "A great deal of experimentation had to be done on lamp sizes and shapes, cathode construction, gas pressures of both argon and mercury vapor, colors of fluorescent powders, methods of attaching them to the inside of the tube, and other details of the lamp and its auxiliaries before the new device was ready for the public."

In addition to having engineers and technicians along with facilities for R&D work on fluorescent lamps, General Electric controlled what it regarded as the key patents covering fluorescent lighting, including the patents originally issued to Hewitt, Moore, and Küch. More important than these was a patent covering an electrode that did not disintegrate at the gas pressures that ultimately were employed in fluorescent lamps. Albert W. Hull of GE"s Schenectady Research Laboratory filed for a patent on this invention in 1927, which was issued in 1931.

While the Hull patent gave GE a basis for claiming legal rights over the fluorescent lamp, a few months after the lamp went into production the firm learned of a U.S. patent application that had been filed in 1927 for the aforementioned "metal vapor lamp" invented in Germany by Meyer, Spanner, and Germer. The patent application indicated that the lamp had been created as a superior means of producing ultraviolet light, but the application also contained a few statements referring to fluorescent illumination. Efforts to obtain a U.S. patent had met with numerous delays, but were it to be granted, the patent might have caused serious difficulties for GE. At first, GE sought to block the issuance of a patent by claiming that priority should go to one of their employees, Leroy J. Buttolph, who according to their claim had invented a fluorescent lamp in 1919 and whose patent application was still pending. GE also had filed a patent application in 1936 in Inman"s name to cover the “improvements” wrought by his group. In 1939 GE decided that the claim of Meyer, Spanner, and Germer had some merit, and that in any event a long interference procedure was not in their best interest. They therefore dropped the Buttolph claim and paid $180,000 to acquire the Meyer, et al. application, which at that point was owned by a firm known as Electrons, Inc. The patent was duly awarded in December 1939.Sylvania Electric Products, Inc., which claimed infringement on patents that it held.

Even though the patent issue was not completely resolved for many years, General Electric"s strength in manufacturing and marketing gave it a pre-eminent position in the emerging fluorescent light market. Sales of "fluorescent lumiline lamps" commenced in 1938 when four different sizes of tubes were put on the market. They were used in fixtures manufactured by three leading corporations, Lightolier, Artcraft Fluorescent Lighting Corporation, and Globe Lighting. The Slimline fluorescent ballast"s public

introduction in 1946 was by Westinghouse and General Electric and Showcase/Display Case fixtures were introduced by Articraft Fluorescent Lighting Corporation in 1946.Westinghouse publicized the new lights through exhibitions at the New York World"s Fair and the Golden Gate International Exposition in San Francisco. Fluorescent lighting systems spread rapidly during World War II as wartime manufacturing intensified lighting demand. By 1951 more light was produced in the United States by fluorescent lamps than by incandescent lamps.

In the first years zinc orthosilicate with varying content of beryllium was used as greenish phosphor. Small additions of magnesium tungstate improved the blue part of the spectrum yielding acceptable white. After it was discovered that beryllium was toxic, halophosphate-based phosphors took over.

The fundamental mechanism for the conversion of electrical energy to light is the emission of a photon when an electron in a mercury atom falls from an excited state into a lower energy level. Electrons flowing in the arc collide with the mercury atoms. If the incident electron has enough kinetic energy, it transfers energy to the atom"s outer electron, causing that electron to temporarily jump up to a higher energy level that is not stable. The atom will emit an ultraviolet photon as the atom"s electron reverts to a lower, more stable, energy level. Most of the photons that are released from the mercury atoms have wavelengths in the ultraviolet (UV) region of the spectrum, predominantly at wavelengths of 253.7 and 185 nanometers (nm). These are not visible to the human eye, so ultraviolet energy is converted to visible light by the fluorescence of the inner phosphor coating. The difference in energy between the absorbed ultra-violet photon and the emitted visible light photon goes toward heating up the phosphor coating.

Electric current flows through the tube in a low-pressure arc discharge. Electrons collide with and ionize noble gas atoms inside the bulb surrounding the filament to form a plasma by the process of impact ionization. As a result of avalanche ionization, the conductivity of the ionized gas rapidly rises, allowing higher currents to flow through the lamp.

The fill gas helps determine the electrical characteristics of the lamp but does not give off light itself. The fill gas effectively increases the distance that electrons travel through the tube, which allows an electron a greater chance of interacting with a mercury atom. Additionally, argon atoms, excited to a metastable state by the impact of an electron, can impart energy to a mercury atom and ionize it, described as the Penning effect. This lowers the breakdown and operating voltage of the lamp, compared to other possible fill gases such as krypton.

A fluorescent lamp tube is filled with a mix of argon, xenon, neon, or krypton, and mercury vapor. The pressure inside the lamp is around 0.3% of atmospheric pressure.fluorescent coating made of varying blends of metallic and rare-earth phosphor salts. The lamp"s electrodes are typically made of coiled tungsten and are coated with a mixture of barium, strontium and calcium oxides to improve thermionic emission.

A germicidal lamp uses a low-pressure mercury-vapor glow discharge identical to that in a fluorescent lamp, but the uncoated fused quartz envelope allows ultraviolet radiation to transmit.

Fluorescent lamp tubes are often straight and range in length from about 100 millimeters (3.9 in) for miniature lamps, to 2.43 meters (8.0 ft) for high-output lamps. Some lamps have the tube bent into a circle, used for table lamps or other places where a more compact light source is desired. Larger U-shaped lamps are used to provide the same amount of light in a more compact area, and are used for special architectural purposes. Compact fluorescent lamps have several small-diameter tubes joined in a bundle of two, four, or six, or a small diameter tube coiled into a helix, to provide a high amount of light output in little volume.

Light-emitting phosphors are applied as a paint-like coating to the inside of the tube. The organic solvents are allowed to evaporate, then the tube is heated to nearly the melting point of glass to drive off remaining organic compounds and fuse the coating to the lamp tube. Careful control of the grain size of the suspended phosphors is necessary; large grains lead to weak coatings, and small particles leads to poor light maintenance and efficiency. Most phosphors perform best with a particle size around 10 micrometers. The coating must be thick enough to capture all the ultraviolet light produced by the mercury arc, but not so thick that the phosphor coating absorbs too much visible light. The first phosphors were synthetic versions of naturally occurring fluorescent minerals, with small amounts of metals added as activators. Later other compounds were discovered, allowing differing colors of lamps to be made.

Fluorescent lamps are negative differential resistance devices, so as more current flows through them, the electrical resistance of the fluorescent lamp drops, allowing for even more current to flow. Connected directly to a constant-voltage power supply, a fluorescent lamp would rapidly self-destruct because of the uncontrolled current flow. To prevent this, fluorescent lamps must use a ballast to regulate the current flow through the lamp.

The terminal voltage across an operating lamp varies depending on the arc current, tube diameter, temperature, and fill gas. A general lighting service 48-inch (1,219 mm) T12

The simplest ballast for alternating current (AC) use is an inductor placed in series, consisting of a winding on a laminated magnetic core. The inductance of this winding limits the flow of AC current. This type of ballast is common in 220–240V countries (And in North America, up to 30W lamps). Ballasts are rated for the size of lamp and power frequency. In North America, the AC voltage is insufficient to start long fluorescent lamps, so the ballast is often a step-up autotransformer with substantial leakage inductance (so as to limit the current flow). Either form of inductive ballast may also include a capacitor for power factor correction.

Fluorescent lamps can run directly from a direct current (DC) supply of sufficient voltage to strike an arc. The ballast must be resistive, and would consume about as much power as the lamp. When operated from DC, the starting switch is often arranged to reverse the polarity of the supply to the lamp each time it is started; otherwise, the mercury accumulates at one end of the tube. Fluorescent lamps are (almost) never operated directly from DC for those reasons. Instead, an inverter converts the DC into AC and provides the current-limiting function as described below for electronic ballasts.

The performance of fluorescent lamps is critically affected by the temperature of the bulb wall and its effect on the partial pressure of mercury vapor within the lamp.

Using an amalgam with some other metal reduces the vapor pressure and extends the optimum temperature range upward; however, the bulb wall "cold spot" temperature must still be controlled to prevent condensing. High-output fluorescent lamps have features such as a deformed tube or internal heat-sinks to control cold spot temperature and mercury distribution. Heavily loaded small lamps, such as compact fluorescent lamps, also include heat-sink areas in the tube to maintain mercury vapor pressure at the optimum value.

A Sankey diagram of energy losses in a fluorescent lamp. In modern designs, the biggest loss is the quantum efficiency of converting high-energy UV photons to lower-energy visible light photons.

Only a fraction of the electrical energy input into a lamp is converted to useful light. The ballast dissipates some heat; electronic ballasts may be around 90% efficient. A fixed voltage drop occurs at the electrodes, which also produces heat. Some of the energy in the mercury vapor column is also dissipated, but about 85% is turned into visible and ultraviolet light.

Not all the UV radiation striking the phosphor coating is converted to visible light; some energy is lost. The largest single loss in modern lamps is due to the lower energy of each photon of visible light, compared to the energy of the UV photons that generated them (a phenomenon called Stokes shift). Incident photons have an energy of 5.5 electron volts but produce visible light photons with energy around 2.5 electron volts, so only 45% of the UV energy is used; the rest is dissipated as heat.

A cold-cathode fluorescent lamp from an emergency-exit sign. Operating at a much higher voltage than other fluorescents, the lamp produces a low-amperage glow discharge rather than an arc, similar to a neon light. Without direct connection to line voltage, current is limited by the transformer alone, negating the need for a ballast.

Most fluorescent lamps use electrodes that emit electrons into the tube by heat, known as hot cathodes. However, cold cathode tubes have cathodes that emit electrons only due to the large voltage between the electrodes. The cathodes will be warmed by current flowing through them, but are not hot enough for significant thermionic emission. Because cold cathode lamps have no thermionic emission coating to wear out, they can have much longer lives than hot cathode tubes. This makes them desirable for long-life applications (such as backlights in liquid crystal displays). Sputtering of the electrode may still occur, but electrodes can be shaped (e.g. into an internal cylinder) to capture most of the sputtered material so it is not lost from the electrode.

Cold cathode lamps are generally less efficient than thermionic emission lamps because the cathode fall voltage is much higher. Power dissipated due to cathode fall voltage does not contribute to light output. However, this is less significant with longer tubes. The increased power dissipation at tube ends also usually means cold cathode tubes have to be run at a lower loading than their thermionic emission equivalents. Given the higher tube voltage required anyway, these tubes can easily be made long, and even run as series strings. They are better suited for bending into special shapes for lettering and signage, and can also be instantly switched on or off.

The gas used in the fluorescent tube must be ionized before the arc can "strike" . For small lamps, it does not take much voltage to strike the arc and starting the lamp presents no problem, but larger tubes require a substantial voltage (in the range of a thousand volts). Many different starting circuits have been used. The choice of circuit is based on cost, AC voltage, tube length, instant versus non-instant starting, temperature ranges and parts availability.

A preheat fluorescent lamp circuit using an automatic starting switch. A: Fluorescent tube, B: Power (+220 volts), C: Starter, D: Switch (bi-metallic thermostat), E: Capacitor, F: Filaments, G: Ballast

Preheating, also called switchstart, uses a combination filament–cathode at each end of the lamp in conjunction with a mechanical or automatic (bi-metallic) switch (see circuit diagram to the right) that initially connect the filaments in series with the ballast to preheat them; after a short preheating time the starting switch opens. If timed correctly relative to the phase of the supply AC, this causes the ballast to induce a voltage over the tube high enough to initiate the starting arc.

Before the 1960s, four-pin thermal starters and manual switches were used.glow switch starter automatically preheats the lamp cathodes. It consists of a normally open bi-metallic switch in a small sealed gas-discharge lamp containing inert gas (neon or argon). The glow switch will cyclically warm the filaments and initiate a pulse voltage to strike the arc; the process repeats until the lamp is lit. Once the tube strikes, the impinging main discharge keeps the cathodes hot, permitting continued electron emission. The starter switch does not close again because the voltage across the lit tube is insufficient to start a glow discharge in the starter.

With glow switch starters a failing tube will cycle repeatedly. Some starter systems used a thermal over-current trip to detect repeated starting attempts and disable the circuit until manually reset.

Electronic starters use a different method to preheat the cathodes.integrated circuit chip. Electronic starters may be optimized for fast starting (typical start time of 0.3 seconds),

Electronic starters only attempt to start a lamp for a short time when power is initially applied, and do not repeatedly attempt to restrike a lamp that is dead and unable to sustain an arc; some automatically stop trying to start a failed lamp.

T12 fluorescent tubes. The first two are rapid start, (for "tombstone" and socket holders respectively) while the third is an instant-start lamp. The instant-start has a characteristic, rounded, single pin, for plugging into the spring-loaded socket holders.

Instant start fluorescent tubes were invented in 1944. Instant start simply uses a high enough voltage to break down the gas column and thereby start arc conduction. Once the high-voltage spark "strikes" the arc, the current is boosted until a glow discharge forms. As the lamp warms and pressure increases, the current continues to rise and both resistance and voltage falls, until mains or line-voltage takes over and the discharge becomes an arc. These tubes have no filaments and can be identified by a single pin at each end of the tube (for common lamps; compact cold-cathode lamps may also have a single pin, but operate from a transformer rather than a ballast). The lamp holders have a "disconnect" socket at the low-voltage end which disconnects the ballast when the tube is removed, to prevent electric shock. Instant-start lamps are slightly more energy efficient than rapid start, because they do not constantly send a heating current to the cathodes during operation, but the cold cathodes starting increases sputter, and they take much longer to transition from a glow discharge to an arc during warm up, thus the lifespan is typically about half of those seen in comparable rapid-start lamps.

Because the formation of an arc requires the thermionic emission of large quantities of electrons from the cathode, rapid start ballast designs provide windings within the ballast that continuously warm the cathode filaments. Usually operating at a lower arc voltage than the instant start design; no inductive voltage spike is produced for starting, so the lamps must be mounted near a grounded (earthed) reflector to allow the glow discharge to propagate through the tube and initiate the arc discharge via capacitive coupling. In some lamps a grounded "starting aid" strip is attached to the outside of the lamp glass. This ballast type is incompatible with the European energy saver T8 fluorescent lamps because these lamps requires a higher starting voltage than that of the open circuit voltage of rapid start ballasts.

Quick-start ballasts use a small auto-transformer to heat the filaments when power is first applied. When an arc strikes, the filament heating power is reduced a