transmissive lcd display free sample

Transmissive LCD is the most common LCD screen, which requires a backlight as the light source and there is no reflective film at the back of the LCD screen.

Advantage: we can see the graphic and character on the screen very clearly if there is only little light. It is such a mature and cheap technology that 90% of LCD screens in the market are transmissive LCD display.

Reflective LCD is the cheapest LCD screen because there is no backlight, which uses light from outside as the light source, such as sunshine or lamplight and there is a reflective film at the back of the LCD screen.

Transflective LCD is the best and most expensive LCD screen, which has a semi-reflective film at the back of the LCD screen. The front light can’t go through the semi-reflective film, but the backlight can go through it. Like sunglasses.

Advantage: it has the advantages of both transmissive LCD and reflective LCD. We not only can see it very clearly in the outdoor like the reflective LCD, but also can see it vividly when we are in a dark place like a transmissive LCD. We see the transflective LCD in the front as the reflective LCD because it can reflect the sunshine, but the LED backlight panel can also supply the light which can penetrate the semi-reflective film at the back of LCD screen.

Dr Pan: Hello, Greg. FSTN is the abbreviation for Film Super Twisted Nematic. The main difference between TN, HTN, STN and FSTN LCD is the view angle. FSTN is the advanced version of STN with one compensation film, the view angle is better. It has the true 360° full view angle.

When it is a positive and reflective display, it can display without LED backlight; when it is a positive and transmissive/ transflective display, it can’t display without LED backlight,the background color could be grey-white or grey-green, and the letters could be black/purple/blue.

When it is a negative and transmissive/ transflective display, it can’t display without LED backlight, the background could be dark-purple/ blue/ black (not pure) and the color of the letters is the color of LED backlight.

By the way, no matter it is a positive or negative display, the background color is affected by the color of LED backlight on some level. That is why the color of LED backlight is usually white.

Theoretically, we can add one more compensation film to FSTN LCD, it becomes DFSTN (Double Film STN) and the view angle is better. Actually, it is barely used because it is too expensive.

This 128x64 graphic LCD display module (CFAG12864T3-NFH) is a small, thin, and very low-power. This display is visible in most lighting situations, including normal office lighting up to bright sunlight.

Since this LCD module has no backlight, there is no power used for the backlight, however, the display is not viewable in dark environments without an external light source. This display is well suited for low-power hand-held devices that are normally used in well-lit environments.

This LCD display has an integrated controller and voltage generating components mounted on the flexible tail. The tail connects to a ZIF connector, found here: standard 18-conductor 0.5mm pitch ZIF connector.

This complete transflective LCD demonstration kit makes evaluating this low power 128x64 graphic LCD or the low power transflective LCD with adapter board super easy. Just plug in the included USB cable to a power source and a demo program will begin.

The CFAG12864U3-NFH (just the display) and the CFAG12864U3-NFH-E1-1 (display with adapter board) are great monochrome LCD displays. They are transflective, so they"re readable in just about any lighting condition, only needing supplied light if used in a dark environment. For a display with a built in backlight, check out the family of 128x64 Backlit Low Power LCDs.

Let us start with the basics first; refresh the knowledge about TN and LCD displays in general, later we will talk about TFTs (Thin Film Transistors), how they differ from regular monochrome LCD displays. Then we will go on to the ghosting effect, so we will not only discuss the technology behind the construction of the TFT, but also some phenomena, like the ghosting effect, or grayscale inversion, that are important to understand when using an LCD TFT display.

Next, we will look at different technologies of the TFT LCD displays like TN, IPS, VA, and of course about transmissive and transflective LCD displays, because TFT displays also can be transmissive and transflective. In the last part we will talk about backlight.

Let us start with a short review of the most basic liquid crystal cell, which is the TN (twisted nematic) display. On the picture above, we can see that the light can be transmit through the cell or blocked by the liquid crystal cell using voltage. If you want to learn more about monochrome LCD displays and the basics of LCD displays, follow this link.

What is a TFT LCD display and how it is different from a monochrome LCD display? TFT is called an active display. Active, means we have one or more transistors in every cell, in every pixel and in every subpixel. TFT stands for Thin Film Transistor, transistors that are very small and very thin and are built into the pixel, so they are not somewhere outside in a controller, but they are in the pixel itself. For example, in a 55-inch TV set, the TFT display contains millions of transistors in the pixels. We do not see them, because they are very small and hidden, if we zoom in, however, we can see them in every corner of each pixel, like on the picture below.

On the picture above we can see subpixels, that are basic RGB (Red, Green, Blue) colors and a black part, with the transistors and electronic circuits. We just need to know that we have pixels, and subpixels, and each subpixel has transistors. This makes the display active, and thus is called  the TFT display. TFT displays are usually color displays, but there are also monochrome TFT displays, that are active, and have transistors, but have no colors. The colors in the TFT LCD display are typically added by color filters on each subpixel. Usually the filters are RGB, but we also have RGBW (Red, Green, Blue, White) LCD displays with added subpixels without the filter (White) to make the display brighter.

Going a little bit deeper, into the TFT cell, there is a part inside well known to us from the monochrome LCD display Riverdi University lecture. We have a cell, liquid crystal, polarizers, an ITO (Indium Tin Oxide) layer for the electrodes, and additionally an electronic circuit. Usually, the electronic circuit consists of one transistor and some capacitors to sustain the pixel state when we switch the pixel OFF and ON. In a TFT LCD display the pixels are much more complicated because apart from building the liquid crystal part, we also need to build an electronic part.

That is why TFT LCD display technologies are very expensive to manufacture. If you are familiar with electronics, you know that the transistor is a kind of switch, and it allows us to switch the pixel ON and OFF. Because it is built into the pixel itself, it can be done very quickly and be very well controlled. We can control the exact state of every pixel not only the ON and OFF states, but also all the states in between. We can switch the light of the cells ON and OFF in several steps. Usually for TFT LCD displays it will be 8-bit steps per color, so we have 256 steps of brightness for every color, and every subpixel. Because we have three subpixels, we have a 24-bit color range, that means over 16 million combinations, we can, at least theoretically, show on our TFT LCD display over 16 million distinct colors using RGB pixels.

Now that we know how the TFT LCD display works, we can now learn some practical things one of which is LCD TFT ghosting. We know how the image is created, but what happens when we have the image on the screen for a prolonged time, and how to prevent it. In LCD displays we have something called LCD ghosting. We do not see it very often, but in some displays this phenomenon still exists.

If some elements of the picture i.e., your company logo is in the same place of the screen for a long period of time, for couple of weeks, months or a year, the crystals will memorize the state and later, when we change the image, we may see some ghosting of those elements. It really depends on many conditions like temperature and even the screen image that we display on the screen for longer periods of time. When you build your application, you can use some techniques to avoid it, like very rapid contrast change and of course to avoid the positioning the same image in the same position for a longer time.

You may have seen this phenomenon already as it is common in every display technology, and even companies like Apple put information on their websites, that users may encounter this phenomenon and how to fix it. It is called image ghosting or image persistence, and even Retina displays are not free of it.

Another issue present in TFT displays, especially TN LCD displays, is grayscale inversion. This is a phenomenon that changes the colors of the screen according to the viewing angle, and it is only one-sided. When buying a TFT LCD display, first we need to check what kind of technology it is. If it is an IPS display, like the Riverdi IPS display line, then we do not need to worry about the grayscale inversion because all the viewing angles will be the same and all of them will be very high, like 80, 85, or 89 degrees. But if you buy a more common or older display technology type, like the TN (twisted nematic) display, you need to think where it will be used, because one viewing angle will be out. It may be sometimes confusing, and you need to be careful as most factories define viewing direction of the screen and mistake this with the greyscale inversion side.

On the picture above, you can see further explanation of the grayscale inversion from Wikipedia. It says that some early panels and also nowadays TN displays, have grayscale inversion not necessary up-down, but it can be any angle, you need to check in the datasheet. The reason technologies like IPS (In-Plane Switching), used in the latest Riverdi displays, or VA, were developed, was to avoid this phenomenon. Also, we do not want to brag, but the Wikipedia definition references our website.

We know already that TN (twisted nematic) displays, suffer from grayscale inversion, which means the display has one viewing side, where the image color suddenly changes. It is tricky, and you need to be careful. On the picture above there is a part of the LCD TFT specification of a TN (twisted nematic) display, that has grayscale inversion, and if we go to this table, we can see the viewing angles. They are defined at 70, 70, 60 and 70 degrees, that is the maximum viewing angle, at which the user can see the image. Normally we may think that 70 degrees is better, so we will choose left and right side to be 70 degrees, and then up and down, and if we do not know the grayscale inversion phenomena, we may put our user on the bottom side which is also 70 degrees. The viewing direction will be then like a 6 o’clock direction, so we call it a 6 o’clock display. But you need to be careful! Looking at the specification, we can see that this display was defined as a 12 o’clock display, so it is best for it to be seen from a 12 o’clock direction. But we can find that the 12 o’clock has a lower viewing angle – 60 degrees. What does it mean? It means that on this side there will be no grayscale inversion. If we go to 40, 50, 60 degrees and even a little bit more, probably we will still see the image properly. Maybe with lower contrast, but the colors will not change. If we go from the bottom, from a 6 o’clock direction where we have the grayscale inversion, after 70 degrees or lower we will see a sudden color change, and of course this is something we want to avoid.

To summarize, when you buy older technology like TN and displays, which are still very popular, and Riverdi is selling them as well, you need to be careful where you put your display. If it is a handheld device, you will see the display from the bottom, but if you put it on a wall, you will see the display from the top, so you need to define it during the design phase, because later it is usually impossible or expensive to change the direction.

We will talk now about the other TFT technologies, that allow us to have wider viewing angles and more vivid colors. The most basic technology for monochrome and TFT LCD displays is twisted nematic (TN). As we already know, this kind of displays have a problem with grayscale inversion. On one side we have a higher retardation and will not get a clear image. That is why we have other technologies like VA (Vertical Alignment), where the liquid crystal is differently organized, and another variation of the TFT technology – IPS which is In-Plane Switching. The VA and IPS LCD displays do not have a problem with the viewing angles, you can see a clear image from all sides.

Apart from the different organization of the liquid crystals, we also organize subpixels a little bit differently in a VA and IPS LCD displays. When we look closer at the TN display, we will just see the subpixels with color filters. If we look at the VA or IPS display they will have subpixels of subpixels. The subpixels are divided into smaller parts. In this way we can achieve even wider viewing angles and better colors for the user, but of course, it is more complicated and more expensive to do.

The picture above presents the TN display and grayscale inversion. For IPS or VA technology there is no such effect. The picture will be the same from all the sides we look so these technologies are popular where we need wide viewing angles, and TN is popular where we don’t need that, like in monitors. Other advantages of IPS LCD displays are they give accurate colors, and wide viewing angles. What is also important in practice, in our projects, is that the IPS LCD displays are less susceptible to mechanical force. When we apply mechanical force to the screen, and have an optically bonded touch screen, we push the display as well as squeeze the cells. When we have a TN display, every push on the cell changes the image suddenly, with the IPS LCD displays with in-plane switching, different liquid crystals organization, this effect is lesser. It is not completely removed but it is much less distinct. That is another reason IPS displays are very popular for smartphones, tablets, when we have the touchscreens usually optically bonded.

If we wanted to talk about disadvantages, there is a question mark over it, as some of them may be true, some of them do not rely on real cases, what kind of display, what kind of technology is it. Sometimes the IPS displays can have higher power consumption than others, in many cases however, not. They can be more expensive, but not necessarily. The new IPS panels can cost like TN panels, but IPS panels definitely have a longer response time. Again, it is not a rule, you can make IPS panels that are very fast, faster than TN panels, but if you want the fastest possible display, probably the TN panel will be the fastest. That is why the TN technology is still popular on the gaming market. Of course, you can find a lot of discussions on the internet, which technology is better, but it really depends on what you want to achieve.

Now, let us look at the backlight types. As we see here, on the picture above, we have four distinct types of backlight possible. The most common, 95 or 99 per cent of the TFT LCD displays on the market are the transmissive LCD display type, where we need the backlight from the back. If you remember from our Monochrome LCD Displays lecture, for transmissive LCD displays you need the backlight to be always on. If you switch the backlight off, you will not see anything. The same as for monochrome LCD displays, but less popular for TFT displays, we have the transflective LCD display type. They are not popular because usually for transflective TFT displays, the colors lack in brightness, and the displays are not very practical to use. You can see the screen, but the application is limited. Some transflective LCD displays are used by military, in applications where power consumption is paramount; where you can switch the backlight off and you agree to have lower image quality but still see the image. Power consumption and saving energy is most important in some kind of applications and you can use transflective LCD displays there. The reflective type of LCD displays are almost never used in TFT. There is one technology called Low Power Reflective Displays (LPRD) that is used in TFT but it is not popular. Lastly, we have a variation of reflective displays with frontlight, where we add frontlight to the reflective display and have the image even without external light.

Just a few words about Low Power Reflective Displays (LPRD). This kind of display uses environmental light, ambient light to reflect, and produce some colors. The colors are not perfect, not perfectly clear, but this technology is becoming increasingly popular because it allows to have color displays in battery powered applications. For example, a smartwatch would be a case for that technology, or an electrical bike or scooter, where we can not only have a standard monochrome LCD display but also a TFT LCD color display without the backlight; we can see the image even in

strong sunlight and not need backlight at all. So, this kind of TFL LCD display technology is getting more and more popular when we have outdoor LCD displays and need a low power consumption.

On the picture above, we have some examples of how transmissive and reflective LCD displays work in the sunlight. If we have a simple image, like a black and white pattern, then on a transmissive LCD display, even with 1000 candela brightness, the image probably will be lower quality than for a reflective LCD display; if we have sunlight, we have very strong light reflections on the surface of the screen. We have talked about contrast in more detail in the lecture Sunlight Readable Displays. So, reflective LCD displays are a better solution for outdoor applications than transmissive LCD displays, where you need a really strong backlight, 1000 candela or more, to be really seen outdoors.

To show you how the backlight of LCD displays is built, we took the picture above. You can see the edge backlight there, where we have LEDs here on the small PCB on the edge, and we have a diffuser that distributes the light to the whole surface of LCD screen.

In addition to the backlight, we have something that is called a frontlight. It is similar to backlight, it also uses the LEDs to put the light into it, but the frontlight needs to be transparent as we have the display behind. On the example on the picture above we can see an e-paper display. The e-paper display is also a TFT display variation, but it is not LCD (liquid crystal), it is a different technology, but the back of the display is the same and it is reflective. The example you see is the Kindle 4 eBook reader. It uses an e-paper display and a frontlight as well, so you can read eBooks even during the night.

LCD (Liquid Crystal Displays) have two options or display modes.Positive mode (dark characters on a light colored background) and negative mode (lighter colored characters on a darker background).

Please see Fig.1: Yellow green STN (Super Twisted Nematic) display, the background of yellow green is lighter than dark blue characters. It is a positive mode. Fig. 2 is a blue STN display, its background of blue is darker than the white characters.It is negative mode.

Positive mode displays have the advantage of their lighter background and no backlights are needed. They normally use transflective or reflective polarizers and have lower power consumption. They can be seen with ambient light.

Negative mode displays need backlit in order to be seen. They normally use transmissive polarizers. They have better contrast and wider viewing angles in the indoor dim environment. The readability is much better than positive displays.

But under bright ambient light or even under direct sunlight, the displays will be easily washed out. In order to be seen under the bright surrounding light, the backlight brightness has to be increased to over 800 nits. The sunlight readable displays consume much power.

Of course, we can always use LED backlight in the LCD module with fewer LED chips and turn off LED backlight when not use to save power. When can also add transflective polarizer to some negative LCDs to make it sunlight readable, but the contrast will be compromised.

Positive and negative mode concept is not only limited to monochrome LCD displays (LCD panels, character LCDs, graphic LCDs etc.), it also uses for color displays, or even other display technologies.  We will categorize the displays as below,

Character LCD modules (Alphanumeric LCD display modules) with character sets: 8×1 LCD display, 8×2 LCD display, 16×1 LCD display, 16×2 LCD display, 16×4 LCD display, 20×2 LCD display, 20×4 LCD display, 24×2 LCD display, 40×2 LCD display, 40×4 LCD display. COB (Chip on Board) bonded, 4 or 8 bits parallel, SPI, I2C interface

Graphic LCD modules with dot matrix sets 122×32, graphic LCD display, 128×64 graphic LCD display, 192×48 graphic LCD display,192×64 graphic LCD display,240×64 graphic LCD display,240×128 graphic LCD display,240×160 graphic LCD display with different color LED backlights, with COB and COG (Chip on Glass) assembling technologies

Monochrome and Color Graphic OLED modules with dot matrix sets 128×32 graphic OLED display,128×64 graphic OLED display, 128×96 graphic OLED display, 160×128 graphic OLED display, 128×128 graphic OLED display, 256×65 graphic OLED display

Full Color TN and IPS displays with panel sizes: 1.3”IPS display, 1.44” TN display, 1.5” IPS display, 1.77”TN and IPS displays, 2.0” TN and IPS displays, 2.2” IPS display, 2.35” IPS display, 2.4” TN and IPS displays, 2.8” TN and IPS displays, 3.5” TN and IPS displays, 4.3” TN display, 5.0” TN and IPS display, 7.0” TN and IPS display, 10.1” IPS display with medium and high brightness (sunlight readable), with parallel, SPI, RGB, LVDS, MIPI interfaces.

“Reflective”, “transmissive” and “transflective” are terms often used in connection with liquid crystal display (LCD) technology. They describe the ways in which LCD display modules are illuminated. In contrast to the emissive display technologies, like OLED displays (organic light-emitting diode) and VFDs (vacuum fluorescence displays), LCDs require a light source such as the sun, or artificial room light, or an integrated backlight, which is typically lit by LED (light-emitting diode) semiconductors.

The mode of operation when light from a backlight passes through the LCD glass is called transmissive. The LCD glass or LCD panel functions as an “optical switch” where light from the backlight passes through the LCD cell depending on the orientation of liquid crystal molecules. The orientation can be “switched” on or off by an electrical field. Backlights produce a lot of light, making the display content very bright. The negative side of using backlights is that they require a significant amount of energy within an LCD display module, especially because the backlight is required to be on all the time even if there’s no content showing on the display. In direct sunlight, a transmissive LCD screen can become ‘washed-out’ if the sunlight overpowers the luminance of the backlight. Strong enough backlights to maintain sufficient contrast in direct sunlight – such as in aviation displays – are not compatible with the requirements of portable devices.

Some displays use ambient light rather than a backlight (View our Sun Vision Display brand of outdoor digital signage for an excellent example). This mode of operation is called reflective. In reflective mode, a mirror is installed behind the liquid crystal layer, either inside the LCD cell or on the rear polarizer. Ambient light passes through the LCD cell from the front side and is reflected by the mirror back to the viewer. The advantage is lower power consumption and excellent visibility in direct sunlight, making such displays excellent solutions for outdoor daytime applications. To be visible at night or in dark settings, reflective LCDs require additional lighting.

Transflective LCD displays have both transmissive and reflective characteristics. They contain an integrated backlight unit and a semi-transparent reflector or a reflector with a hole for each pixel. Again, the reflector can be behind the rear polarizer or inside the LCD cell behind the liquid crystal layer. Light from the backlight can pass the semi-transparent reflector and operate the display in the transmissive mode. At the same time, ambient light can be reflected so that the display is visible in direct sunlight as well. Care must be taken to account for the fact that in the transmissive mode of operation the light passes the liquid crystal layer once, while in the reflective mode it passes the liquid crystal layer twice. The appearance of transflective displays is a compromise. It is the most flexible solution as it allows for lower power consumption in bright environments and readability in any lighting condition. This comes at the expense of top performance in the pure illumination modes and sometimes significant additional manufacturing cost.

The present invention relates generally to gaming machines and, more particularly, to a gaming machine with a video image superimposed over a primary display of the machine.

A reel spinning slot machine generally comprises a plurality of mechanical rotatable reels controlled by a processor. In response to a wager, the processor randomly selects an outcome from a plurality of possible outcomes and then causes the reels to be rotated and stopped to display the selected outcome. The selected outcome is represented by certain symbols on the reels being in visual association with a display area. If the selected outcome corresponds to a winning outcome identified on a pay table, the processor instructs a payoff mechanism to award a payoff for that winning outcome to the player in the form of coins or credits.

Heretofore, the display area of reel spinning slot machines has been fairly mundane. Any proposals for changing the appearance of the display area have been fairly minor and limited in capability. For example, in U.S. Pat. No. 6,056,642 to Bennett, reel symbols are colored by backlighting the symbols with colored light bulbs or similar means. In U.S. Pat. No. 6,027,115 to Griswold et al., the reels themselves contain electroluminescent elements that define one or more reel symbols, such as cherries, bars, a number “7,” etc. If multiple electroluminescent elements are provided for a particular symbol, that symbol may be displayed in multiple formats. Although the above proposals change the appearance of the display area to some extent, a need exists for a structure capable of effecting more extravagant changes to the appearance of the display area.

Accordingly, an embodiment of a gaming machine has a primary game display, such as a reel, operable to display the outcome of a game, and a secondary display overlaying the primary game display. The secondary display may have a stand alone transmissive LCD display and at least one backlight assembly, the backlight assembly spaced apart from the transmissive LCD display and located between the transmissive LCD display and the primary game display. With the backlight assembly spaced apart from the transmissive LCD display, the backlight assembly may be removed from or inserted into the gaming machine. This permits different games to be installed in the gaming machine during manufacture or as a retrofit.

FIG. 14 depicts an embodiment of a gaming machine that has a primary game display 1400, such as a reel, operable to display the outcome of a game, and a secondary display 1402 overlaying the primary game display 1400.

FIGS. 27 and 28 depict an embodiment in which the backlight assembly 2700 may be used with a curved LCD display 2702 with mechanical segmented barrier.

Some portions of the detailed descriptions that follow are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the ways used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar computing device, that manipulates and transforms data represented as physical (e.g., electronic) quantities within the computer system"s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

FIG. 1aillustrates an exemplary gaming machine 100 in which embodiments of the invention may be implemented. In some embodiments, gaming machine 100 is operable to conduct a wagering game. These wagering games may include reel based wagering games such as mechanical or video slots, card based games such as video poker, or other types of wagering games such as video keno, video bingo or a video dice game (e.g. a Yahtzee® like dice game). If based in video, the gaming machine 100 includes a video display 112 such as a cathode ray tube (CRT), liquid crystal display (LCD), plasma, or other type of video display known in the art. In the illustrated embodiment, the gaming machine 100 is an “upright” version in which the display 112 is oriented vertically relative to a player. Alternatively, the gaming machine may be a “slant-top” version in which the display 112 is slanted at about a thirty-degree angle toward the player.

In some embodiments, gaming machine 100 includes a top box 40. Top box 40 may contain a video display, a mechanical display, or a diorama display that supplements display 112. For example, the display in top box 40 may be a wheel such as a rotating wheel, mechanical dice, a board for a board game, or other such display.

A processor controls operation of the gaming machine 100. In response to receiving a wager and a command to initiate play, the processor randomly selects a game outcome from a plurality of possible outcomes and causes the display 112 to depict indicia representative of the selected game outcome. In the case of slots for example mechanical or simulated slot reels are rotated and stopped to place symbols on the reels in visual association with one or more pay lines. If the selected outcome is one of the winning outcomes defined by a pay table, the CPU awards the player with a number of credits associated with the winning outcome.

In some embodiments, gaming machine 100 may include signage 120. Signage 120 may be a transmissive LCD device capable of displaying advertising, gaming information (e.g. type of game, denomination of game etc.) or other information to a player or potential player. Because portions of a transmissive LCD may be transparent or semitransparent, the signage need not fully obstruct views beyond the gaming machine 100.

FIG. 1bis a side view of a game display according to embodiments of the invention and illustrates further details of the display 112. In some embodiments, display 112 includes a primary game display 120, and a secondary game display 122. In some embodiments, primary game display 120 may be a mechanical display, such as a plurality of reels for a slot machine (described further below), a wheel, including a roulette wheel, one or more dice, a pachinko board, or other board game. No embodiment of the invention is limited to any particular mechanical display. In alternative embodiments, primary game display may be a video based display such as a CRT or LCD. In further alternative embodiments, primary game display 120 may be a diorama presenting a three-dimensional model for a game environment. In some implementations the diorama may be stationary, while in other implementations the diorama may slide or move in one or more dimensions.

Secondary game display 122 is positioned over primary game display 120. In some embodiments, secondary game display 122 provides a video image that may be selectively made transparent or semi-transparent (opaque), thus allowing the display of images on secondary game display 122 while allowing selective portions of the primary game display 120 to be seen through secondary game display 122. In some embodiments, secondary display 122 is a transmissive liquid crystal display (LCD). Line of sight indicator 130 shows the viewing direction, wherein images on primary display 120 pass through transparent or semi-transparent portions of secondary game display 122 to a player.

FIG. 1cis a side view illustrating a gaming machine 140 according to alternative embodiments of the invention. In some embodiments, a gaming machine cabinet 142 houses components of a gaming machine such as a processor and memory that control the operation of the gaming machine. A game display 144 is coupled to the processor of the gaming machine, and may be rotatably mounted to game machine cabinet 142. In some embodiments, game display 144 is placed in a substantially horizontal position when not in use, and is rotated to a non-horizontal position when a player desires to play a wagering game. Game display 144 may be a transmissive LCD device, thereby allowing a player to see through transparent or semi-transparent portions of the display.

FIG. 1dillustrates an embodiment of the invention where the primary game display comprises a spinning reel slot machine 10 that includes a plurality of mechanical rotatable reels 12a, 12b, 12cand a video display (see FIGS. 2aand 2b). In response to a wager, the reels 12a, 12b, 12care rotated and stopped to randomly place symbols on the reels in visual association with a display area 16. Payouts are awarded based on combinations and arrangements of the symbols appearing in the display area 16. The video display provides a video image 18 occupying the display area 16 and superimposed on the reels 12a, 12b, 12c. The video image 18 may be interactive with the reels 12a, 12b, 12c, may be static or dynamic, and may include such graphics as payout values, a pay table, pay lines, bonus game features, special effects, thematic scenery, and instructional information. In the illustrated embodiment, the slot machine 10 is an “upright” version in which the display area 16 is oriented vertically relative to the player. Alternatively, the slot machine 10 may be a “slant-top” version in which the display area 16 is slanted at about a thirty degree angle toward the player of the slot machine 10.

Referring to FIGS. 2aand 2b, the video image 18 in the display area 16 may be either a direct image (FIG. 2a) or a virtual image (FIG. 2b). If the video image 18 is a direct image, as in FIG. 2a, the direct image is preferably generated by a flat panel transmissive video display 14apositioned in front of the reels 12a, 12b, 12c. The transmissive display 14amay, for example, be a transmissive liquid crystal display (LCD) commercially available from LG Phillips LCD Co., Ltd., of Seoul, Korea. The transmissive display 14amay be outfitted with a touch screen mounted to a front surface of the display 14a. The touch screen contains soft touch keys denoted by the image on the underlying display 14aand used to operate the slot machine 10.

If the video image 18 is a virtual image, as in FIG. 2b, the virtual image is preferably generated by a projection arrangement including a video display 14band a partially reflective mirror 20. The video display 14band the partially reflective mirror 20 are relatively positioned to project the virtual image in front of the reels 12a, 12b, 12cbetween the reels and a player. The video display 14bis preferably mounted below the reels 12a, 12b, 12cand is generally perpendicular to the display area 16. The mirror 20 is preferably mounted in front of the reels 12a, 12b, 12cand is oriented at approximately a forty-five degree angle relative to both the video display 14band the display area 16. The virtual image is generally parallel to the display area 16 and may, in fact, occupy the display area 16. Also, the virtual image may be three dimensional. In the embodiment of FIG. 2b, the display area 16 includes a glass cover/window. This cover is optionally outfitted with a touch screen that contains soft touch keys denoted by the virtual image and used to operate the slot machine 10.

The video display 14bin FIG. 2bmay be a CRT, LCD, dot matrix, LED, electro-luminescent, or other type of video display known in the art. Also, instead of mounting the video display 14bbelow the reels 12a, 12b, 12c, the display 14bmay be mounted above the reels with the mirror 20 still oriented at approximately a forty-five degree angle relative to both the video display 14band the display area 16.

Each of five pay lines 22a, 22b, 22c, 22d, 22eextends through one symbol on each of the three mechanical reels (and may extend through video reels 1102 in some embodiments). The number of pay lines may be more or less than five and may have various configurations. In some embodiments, one or more pay lines may be displayed on the superimposed video image 18. In addition, pay lines may be modified or skewed by the superimposed video image 18 such that the pay line passes through at least one different symbol that it did prior to the modification or skewing. A pay line may be modified or skewed at random times, predetermined times, or upon selection by a player. For example, a straight pay line may be skewed such that the pay line is no longer a straight line, but passes through symbols not in a straight line. Additional pay lines may be generated at random or at predetermined intervals during game play to provide additional opportunities for winning combinations from those pay lines initially presented to a player.

Generally, game play is initiated by inserting a number of coins or playing a number of credits, causing a central processing unit to activate a number of pay lines corresponding to the number of coins or credits played. As shown in FIG. 3, the superimposed video image 18 may depict instructional information prompting the player to insert coins or play credits. The player selects the number of pay lines (between one and five) to play by pressing a “Select Lines” key on a button panel 24. In alternative embodiments, a player may select particular pay lines displayed on the superimposed video image using the touch screen. The player then chooses the number of coins or credits to bet on the selected pay lines by pressing a “Bet Per Line” key on the button panel 24. As shown in FIG. 4, the superimposed video image 18 may depict the activated pay lines and the number of wagered credits per pay line.

Winning basic game outcomes (e.g., symbol combinations resulting in payment of coins or credits) are identifiable to the player by a pay table. The pay table may change over time, for example if play changes from a base wagering game to a bonus game. The superimposed video image 18 may be used to display the changed pay table.

As shown in FIG. 5, the superimposed video image 18 may depict the pay table in response to a command by the player (e.g., by pressing a “Pay Table” key on the button panel 24). A winning basic game outcome occurs when the symbols appearing on the reels 12a, 12b, 12calong an active pay line correspond to one of the winning combinations on the pay table. A winning combination, for example, could be three matching symbols along an active pay line. If the displayed symbols stop in a winning combination, the game credits the player an amount corresponding to the award in the pay table for that combination multiplied by the amount of credits bet on the winning pay line.

As shown in FIG. 6a, the superimposed video image 18 may highlight the winning combination(s) (e.g., “7,” “7,” “7”) and its associated pay line (e.g., pay line 22c) and depict the award for that winning combination. Alternatively, as shown in FIG. 6b, the video image 18 may obscure all symbols not appearing on an active pay line or not part of a winning outcome. The video image 18 may further include special effects such as flashing the winning pay line(s) and/or the award and providing explosions. The winning pay line(s) may flash, be accompanied by exploding flashes, and display a portion of the pay table. The player may collect the amount of accumulated credits by pressing a “Collect” key on the button panel 24. In one implementation, the winning combinations start from the first reel 12a(left to right) and span adjacent reels. In an alternative implementation, the winning combinations start from either the first reel 12a(left to right) or the third reel 12c(right to left) and span adjacent reels.

In addition, some embodiments of the invention provide supplemental game display on superimposed video image 18. For example, in some implementations, an animated or live character may interact with the game. For example, a character may be used to identify an outcome (e.g. by pointing) or the outcome may be a winning outcome because the character is pointing at it.

In some embodiments, superimposed video image 18, along with a touch screen may be used to implement side betting. For example, a player may select a symbol from the primary game display and make a side bet as to whether or not the symbol will appear during the wagering game. The side bet information may be displayed on superimposed video 18. Such a side bet is independent of the outcome of the wagering game itself. Further details on side bets used in some embodiments are disclosed in U.S. patent application Ser. No. 10/428,516 filed May 1, 2003 and entitled “Gaming Machine with Interactive Pop-up Windows,” which is hereby incorporated by reference herein.

In some embodiments, superimposed video image 18 may display a multiplier at random or predetermined intervals. The multiplier may then cause any winning outcome to be multiplied by the indicated multiplier.

In addition, in some embodiments, superimposed video image 18 may provide a foreground image that interacts with a background image on the primary display. For example, in some implementations, the background is a pachinko game comprising a plurality of pins and one or more lanes representing winning outcomes. The foreground image on superimposed video image 18 may comprise a simulated pachinko ball where the path through the pins is randomly generated to simulate an actual pachinko game. Similarly, the background image may comprise a roulette wheel and the foreground image on superimposed video image may be a roulette ball that “moves” around the roulette wheel and stops over a randomly selected position of the wheel. Additionally, the background may comprise a backlit board, and the foreground image may provide one or more tokens or markers that are moved to positions on the game board. In some implementations, the backlit board may comprise a ladder (i.e. a vertical strip) divided into positions having values. The foreground image may display an indicator or character (possibly animated) that points to a winning position on the ladder. Further, the background may comprise a diorama, and the foreground image may comprise one or more tokens or markers that are moved over positions in the diorama.

In some embodiments of the invention, superimposed video image 18 may be used to provide additional games instead of or in addition to interacting with a wagering game display on a primary game display 120. In one embodiment of the invention, an additional game played using superimposed video image 18 is a bank symbols game. In general, a bank symbols game operates by identifying certain symbols as “bankable” symbols. When these symbols appear on a reel or other game display, the symbol is collected in a bank symbolically displayed on superimposed video image 18. At some point during game play, if a predetermined symbol (sometimes referred to as a “break the bank” symbol) appears, the banked symbols may be redeemed for credit. Further details concerning the bank symbols game are disclosed in U.S. Pat. No. 6,159,098 entitled “Dual-Award Bonus Game for a Gaming Machine,” which is hereby incorporated by reference herein. In an alternative implementation, the banked symbols may be used to play a second game, for example tic-tac-toe.

Other additional games that may be implemented include but are not limited to horse racing and other animated games, and video bingo, keno, slots etc. that may be displayed on superimposed video image 18.

If the display area 16 includes a touch screen mounted to either the transmissive display 14ain the direct image embodiment of FIG. 2aor the glass cover in the virtual image embodiment of FIG. 2b, the video image 18 may duplicate some or all of the aforementioned keys on the button panel 24 as touch keys 26 as shown in various Figures. A player can then enable a desired function either by touching the touch screen at an appropriate touch key 26 denoted by the video image 18 or by pressing an appropriate key on the button panel 24. Touch keys 26 may also be used to implement buttons in addition to those appearing on button panel 24. For example, one or more touch keys 26 may be used to select a denomination for the wagering game, call an attendant, solicit help in playing the game, request food or drink, or request “comps.”

Additionally, in implementations having a diorama as a primary game display, the touch screen may be used to indicate one or more elements of the diorama that a player desires to select. The superimposed video image may be used to highlight selected elements, for example by displaying a highlighted box around the selected element.

Included among the plurality of basic game outcomes is a start-bonus outcome for triggering play of a bonus game. A start-bonus outcome may be defined in a number of ways. For example, a start-bonus outcome may occur when a special start-bonus symbol or a special combination of symbols appears on one or more of the reels 12a, 12b, 12c. The start-bonus outcome may require the combination of symbols to appear along an active pay line or may, alternatively, require that the combination of symbols appear anywhere on the display, regardless of whether the symbols are along an active pay line. The appearance of a start-bonus outcome causes the central processing unit to shift operation from the basic slot game to the bonus game.

As shown in FIG. 7, the video image 18 may depict the bonus game and any bonuses resulting therefrom. The bonus game may, for example, include free spins of a new set of video reels included in the video image 18. Winning combinations on the video reels may be defined by the same pay table as used for the mechanical reels or a different pay table altogether. The bonus game may be interactive and require a player to select one or more selectable elements 28 to earn bonuses. Also, the bonus game may depict one or more animated events and award bonuses based on an outcome of the animated events. Furthermore, the bonus game may be depicted by the video image 18 alone or in conjunction with a video image depicted on an optional top box video display 40 (see FIG. 1d). The two video images may be linked to appear like one unified image. Upon completion of the bonus game, the central processing unit shifts operation back to the basic slot game.

In some embodiments, a bonus game may implement a shuffle feature. In these implementations, symbols on a reel may be converted to a number. The numbers are then displayed on superimposed video 18, and during the bonus game the numbers are shuffled. The resulting shuffled number represents the outcome of the bonus game. Further details on the shuffle feature may be found in U.S. Pat. No. 6,589,114 entitled “Shuffle Feature for a Game of Chance” which is hereby incorporated by reference herein.

In alternative embodiments, a bonus game may be played on the primary game display, and the superimposed video image 18 may be used to highlight symbols on the primary game display to indicate that a bonus game (and not a wagering game) is being played. For instance, in a reel based wagering game, the appearance of the reels or the symbols on the reels may be changed during bonus games. Examples of such appearance changes include changing the color, border highlighting, or shape of the reel or symbol using superimposed video 18 to indicate a bonus game is being played.

In addition, referring to FIGS. 9a-c, in response to a predetermined random or non-random event, the video image 18 may depict an animation in which a video indicator 29 is moved from a periphery of the display area (e.g., a corner of the display area away from the mechanical reels) to one or more of the symbols on the reels. The moving indicator 29 may identify the reel symbols to which it moves as a special symbol to be evaluated as, for example, a wild symbol or a scatter pay symbol. In further implementations, the moving indicator may comprise a window that moves over symbols.

In FIGS. 10a-c, a video indicator 29 has moved to a CHERRY symbol on mechanical reel 12c. If the CHERRY symbol is thereby designated a wild symbol, the displayed symbol array includes a winning combination of three MELON symbols along pay line 22cwhere one of the three MELON symbols is formed by the wild symbol. Further, in FIGS. 10a-c, the video image 18 depicts an animation transforming a BELL symbol on reel 12cinto a SEVEN symbol to form a winning combination of three SEVEN symbols along pay line 22c. The replacement SEVEN symbol generated by the video image 18 is sufficiently opaque or translucent to substantially cover the BELL symbol printed on mechanical reel 12c.

In some embodiments, the symbols display on a primary game display may be either blank or generic, and the superimposed video image 18 may be used to differentiate the symbols by adding supplemental indicia. For example, a generic reel based gaming machine may comprise reels having blank or generic symbols, and the superimposed video image may be used to provide a theme for the wagering game. Further, the symbols may be blank and the supplemental indicia may add a value to the symbol. In some embodiments, the supplemental indicia may add a rank and/or suit to symbols representing playing cards. In some embodiments, the video image 18 may be synchronized with the movement of the reels. In further implementations, a live video or generated animation may be displayed over one or more symbols on a mechanical reel.

While symbols on reels have been described above, it should be noted that any type of symbol display mechanism may be used. For example, the symbols may appear on a “flipper” comprising a series of tabs arranged on a hub. Two of the tabs, a top and bottom tab are exposed to the player and present a symbol. As the hub rotates, the next tab “flips” over, thereby exposing a new top and bottom tab. A video image may be superimposed over such a top and bottom tab in the same manner as discussed above with respect to symbols on reels. The invention is not limited to any particular mechanism for displaying a symbol or symbol space.

Further, in the direct image embodiment of FIG. 2a, the transmissive video display 14amay be backed by an extendable opaque shade during the bonus game. The shade is retracted from the display area 16 during the basic slot game. When the central processing unit shifts operation from the basic slot game to the bonus game, the shade extends through the display area to separate the transmissive video display 14afrom the underlying reels and thereby completely shield the underlying reels.

Superimposed video image 18 may be used to display non-gaming images. For example, in some implementations, superimposed video image 18 may display advertising. Further, in attract mode, a superimposed video image 18 may be used to display images designed to entice a player to keep playing, or a potential player to start playing the wagering game.

In further embodiments of the invention, superimposed video image 18 may be used to provide a live broadcast stream to a player. For example, a player may wish to view a sporting event being broadcast over public airwaves or cable channels. The superimposed video image 18 may be used to display such broadcasts while the player is playing the wagering game.

FIG. 12 is a block diagram of a control system suitable for operating the gaming machine. The control system includes a central processing unit with a microcontroller 30 and system memory 32. The memory 32 preferably comprises a separate read-only memory (ROM) and battery-backed random-access memory (RAM). It will be appreciated, however, that the system memory 32 may be implemented on any of several alternative types of memory structures or may be implemented on a single memory structure. For example, the read-only memory may be replaced or supplemented with a mass storage unit such as a removable flash memory or a hard drive. The system memory may be used to store game-related data associated with the chance games played on the gaming machine. The game-related data may, for example, include game code, math tables, a random number generator, audio resources, and video resources. The player may select an amount to wager and other game play functions via the touch screen keys 26 (if provided) or button panel 24. The wager amount is signaled to the microcontroller 30 by a coin/credit detector 34. In response to the wager, the microcontroller 30 executes the game code which generates a randomly based outcome. In the case of slots, the microcontroller 30, based on the randomly generated outcome, rotates and stops the mechanical reels 12a, 12b, 12cat the selected outcome. Also, the microcontroller 30 selectively accesses the video resources to be included in the video image 18 provided by the video display 14a(FIG. 2a) or 14b(FIG. 2b) and the audio resources to be played through one or more audio speakers 36 mounted to a housing of the slot machine. If the outcome corresponds to a winning outcome identified on the pay table, the microcontroller 30 instructs a payoff mechanism 38 to award a payoff for that winning outcome to the player in the form of coins or credits.

Liquid crystal displays (LCDs) are categorized as non-emissive display devices since they do not produce any form of light. LCDs either pass or block light that is reflected from an external light source or provided by a backlight lighting system. There are two modes of operation for LCDs during the absence of an electric field (applied power); a mode describes the transmittance state of the liquid crystal elements. Normal white mode means the display is white or clear and allows light to pass through. Normal black mode means the display is dark and all light is diffused.

Typically, in a dot matrix LCD a twisted nematic (TN) LCD has two polarizers, two pieces of glass, some form of switching element or electrode to define pixels, and driver integrated circuits (ICs) to address the rows and columns of pixels. To define a pixel (or subpixel element for a color display), a rectangle is constructed out of Indium Tin Oxide (ITO), which is a semi-transparent metal oxide, and charge is applied to this area in order to change the orientation of the liquid crystal material (change from a white pixel to a dark pixel).

Polarizers are an integral part of a LCD, possessing the unique property of only passing light if it is oriented in a specific (oriented) direction. To utilize this phenomenon in TN LCD, the bottom polarizer orients incoming light in one direction. The oriented light passes through the liquid crystal display material and is either unaltered or “bent” 90 degrees. Depending on the orientation of the top polarizer, this light will either pass through or be diffused. If the light is diffused, it will appear as a dark area.

Polarizers are also one of the major reasons that LC displays require bright back lighting. The polarizers and liquid crystal materials absorb more than 50% of the incident light.

After final assembly in known LCDs, excess glass is cut and driver ICs are mounted. The finished display is mounted onto a backlight assembly and encased in metal. There are a number of methods for backlighting a LCD. Some displays usually have a side, top, or bottom lighting system. In a side-lit display one or two fluorescent tubes are located at the left and or right edges of the display. A fluorescent tube, normally 4 mm in diameter, is used.

Also in known LCDs a plastic plate around the entire area of the display disperses light from the fluorescent tubes. A dispersion plate may look like a white sheet with small holes, each of the holes providing a small point of light. On top of the dispersion plate, a diffuser may be placed. A diffuser takes the numerous points of light and uniformly spreads it out over the entire area of the display. The net effect is providing a backlighting source around 4 or 5 mm thick.

When used to produce displays, OLED technology produces self-luminous displays that do not require backlighting. These properties result in thin, very compact displays. The displays also have a wide viewing angle, up to 160 degrees and require very little power, only 2-10 volts.

FIG. 13 depicts an embodiment of a gaming machine that has a primary game display 1300, which is a reel, operable to display the outcome of a game. A secondary display 1302 overlays the primary game display 1300 and may have a stand alone transmissive LCD display 1304 and at least one backlight assembly 1306, the backlight assembly 1306 spaced apart from the transmissive LCD display 1304 and located between the transmissive LCD display 1304 and the primary game display 1300. In an embodiment the stand alone transmissive LCD display 1304 may have at least one non-transmissive display area 1310, and at least one transmissive display area 1312.

A window or cutout 1314 in the backlight assembly 1306 is in alignment with the transmissive area 1312 in the transmissive LCD display 1304 so that an image may be formed on the transmissive area 1312 over the item 1316 on the reel 1300. The primary game display 1300 may also have a white area 1318, for example, that when aligned with the window or cutout 1314 allows only the image in the transmissive area 1312 to be viewed.

As described above the primary game display may be operable to display a sequence of symbols in a symbol array having at least one row and a plurality of columns, the sequence defining a first award. The bonus game may encompass a reordering of the sequence of symbols in the symbol array. The primary game display may be operable to display a sequence of symbols in a symbol array having at least one row and a plurality of columns, the sequence defining a first award. In this embodiment the secondary game display may be operable to change the appearance of at least one symbol in the primary game display. Also, as described above, the stand-alone transmissive LCD display may also have a touch screen.

In an embodiment the secondary game display may be operable to highlight an area around at least one of the plurality of columns. In another embodiment the secondary game display may be operable to change the appearance, such as a color, of at least one symbol in the primary game display.

In a further embodiment the primary game display may be operable to display a sequence of symbols in a symbol array having at least one column and a plurality of rows, the sequence defining a first award. The secondary game may be operable to copy at least one symbol from the primary game display to a saved collection of symbols displayed on the secondary game display.

FIG. 14 depicts an embodiment of a gaming machine that has a primary game display 1400, such as a reel, operable to display the outcome of a game, and a secondary display 1402 overlaying the primary game display 1400. The secondary display 1402 may have a stand alone transmissive LCD display 1404 and at least one backlight assembly 1406, the backlight assembly 1406 spaced apart from the transmissive LCD display 1404 and located between the transmissive LCD display 1404 and the primary game display 1400. With the backlight assembly 1406 spaced apart front the transmissive LCD display 1404, the backlight assembly 1406 may be removed from or inserted into the gaming machine (as indicated by arrow 1408). This permits different games to be installed in the gaming machine during manufacture or as a retrofit as described below.

In further embodiments of the gaming machine, the primary display 1400 may be at least one of a plurality of reels, a plurality of scrolling devices, a curved LCD display with mechanical segmented barrier, a fiber optic reel simulation, and volumetric displays (such as, persistence of vision devices). The secondary display 1402 may be a secondary game display operable to display the results of a secondary game, such as a bonus game.

For example, the transmissive LCD display 1404 may be programmed to display a variety of different images or effects for different games. Selected areas of the transmissive portion of the transmissive LCD display 1404 may be used for different games by using different backlight assemblies 1406.

FIGS. 15-20 depict different backlight assemblies 1500, 1600, 1700, 1800, 1900, 2000 that may have different configurations of windows (clear, that is non-lit areas) or cutouts 1502, 1602, 1702, 1802, 1902, 2002 for use with different games. For example, the backlight assemb