JP3486106B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device capable of displaying an image by means of light rays that pass through a liquid crystal display panel.

[0002]

2. Description of the Related Art Conventionally, various display devices such as a CRT display device and a liquid crystal display device have been developed. In particular, the liquid crystal display device is the most effective display device in the future from the viewpoint of space saving and power saving. Is one. Since the flexibility of the liquid crystal display device is extremely effective in constructing a man-machine interface with a computer, a large number of liquid crystal display devices have recently been used as input / output devices.

For example, in a municipal office, a device for introducing the history of the local government may be installed. In such devices, a touch panel that detects pressure is provided on the front of the display screen, and when the device is activated, a selection area (input button) showing options such as "city map", "tourist attraction", "industry guide" is displayed. The displayed menu screen appears. When the user presses a portion on the display screen where the input button is displayed and selects a desired option, for example, “tourist guide”, a moving image for tourist guide is reproduced. Then, an input button such as "return" or "end" is displayed in one area of the screen displaying the image so that the reproduction can be stopped at any time and the screen can be returned to the menu screen.

As described above, the liquid crystal display device is effectively used as an input / output device in various places, and in addition to this, it is also used as an input / output device such as an automatic payment machine of a financial institution.

[0005]

However, since the display device is originally configured to display the image to be provided as the first purpose, it is used as an input / output device for displaying an input button for prompting an input. To use, in addition to VRAM for displaying images, VRAM for displaying input buttons
Is required. As described above, when the display device is used for other purposes (for example, the above-mentioned input / output device), a complicated structure is required, and there is a problem that the manufacturing cost increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display device capable of easily performing an operation other than displaying an image to be displayed.

[0007]

Means for Solving the Problems and Effects of the Invention The invention according to claim 1 made in order to solve the above problems has a plurality of pixels for changing the light transmittance when a voltage is applied. A plate-shaped liquid crystal display panel, visible light irradiation means for irradiating the rear surface of the liquid crystal display panel with visible light, and control means for applying a voltage to the pixels to display an image on the liquid crystal display panel In a liquid crystal display device including
The liquid crystal display panel is provided with an ultraviolet irradiation means for irradiating the rear surface with ultraviolet rays, and the control means sequentially turns on the visible light irradiation means and the ultraviolet irradiation means, and applies a voltage to the pixel in synchronization with the lighting. It is characterized in that an image is applied to display an image on the liquid crystal display panel.

That is, in the liquid crystal display device according to the present invention (claim 1), the rear surface of the liquid crystal display panel is provided with ultraviolet ray irradiating means, and the control means includes the visible light irradiating means and the ultraviolet ray irradiating means. , Turn on the lights one by one,
A voltage is applied to the pixel in synchronization with the lighting, and an image is displayed on the liquid crystal display panel.

Therefore, according to the liquid crystal display device of the first aspect, since ultraviolet rays can be radiated from the liquid crystal display panel, for example, a luminescent ink that emits light when receiving ultraviolet rays is used on the front surface of the liquid crystal display panel. Put the banknotes
It can also be used for the purpose of performing the authenticity verification.

Such a liquid crystal display device may be a device which simply displays two colors of black and white or a device which displays color. Of these, to display in color,
Conventionally, any one of red, green, and blue filters has been arranged in each pixel, but there is a problem that the image density is rough because one color is expressed by three types of pixels. Also, since the filter absorbs light,
There is also a problem that the displayed image becomes dark. Therefore, as described in claim 2, the visible light irradiating means includes a red light irradiating means for irradiating the rear surface of the liquid crystal display panel with red light.
Equipped with a green light irradiating means for irradiating green light and a blue light irradiating means for irradiating blue light, the control means is sequentially turned on by the red light irradiating means, the green light irradiating means, the blue light irradiating means and the ultraviolet irradiating means. At the same time, it is preferable to apply a voltage to the pixel in synchronization with the lighting so that an image is displayed on the liquid crystal display panel. By doing so, the filter provided in each pixel for displaying in color is not necessary, so that the image can be brightened. Further, since one pixel can express various colors, a high-density color image can be displayed.

Further, conventionally, a liquid crystal display device has been used as a display part of an input / output device such as a library search terminal or an ATM of a financial institution to give various kinds of information to users.
Therefore, as described in claim 3, if a light emitting plate having a light emitting substance that transmits visible light and emits visible light when receiving ultraviolet rays is provided on the front surface of the liquid crystal display panel, It is possible to irradiate a predetermined region with ultraviolet rays to cause the light-emitting substance in the region to emit light, to more conspicuously display information that the user particularly needs to know, and to reliably provide the operator with the information. As such a light-emitting plate, for example, a plate-shaped body of glass having a light-emitting substance dispersed therein can be considered. Note that light emission includes fluorescence and phosphorescence.

As described above, a pushable button is provided near the liquid crystal display device used as the display unit of the input / output device, and various commands can be given by pushing the button. Has been However, in order to push the button, it is troublesome to move the line of sight to the button outside the liquid crystal display panel. Therefore, as described in claim 4, it is preferable to provide, on the front surface of the liquid crystal display panel, a pressing position detecting means for detecting the position where the pressing force is applied when the pressing force is applied from the outside. In this way, without moving the line of sight outside the liquid crystal display panel to press the button,
It is convenient and preferable because various instructions can be input by pressing the front surface of the liquid crystal display panel.

Here, as the input / output device using the display device, there is not only a device for designating one area as described above but also a device for drawing a graphic by tracing on the display screen. Among them, as one using a CRT display device,
By detecting the visible light emitted from the display screen,
A method of drawing a figure by designating a position on the screen is known.

However, in the liquid crystal display device, the method of detecting the light and designating the position on the screen cannot be adopted. In a liquid crystal display device, since the operating speed of the pixel is slow, a plurality of pixels emit visible light at the same time, and the position (pixel) at which visible light is emitted is uniquely determined with respect to time. Because I could not do it. Therefore, as described in claim 5, there is provided an ultraviolet ray detecting means for detecting, on the liquid crystal display panel, the ultraviolet rays emitted from the ultraviolet ray irradiating means and transmitted through the liquid crystal display panel. During lighting, a voltage is sequentially applied to the pixels so that the transmissive position where the ultraviolet light emitted from the ultraviolet irradiation means can be uniquely determined with respect to time, and the ultraviolet light which passes through the transmissive position is detected by the ultraviolet light detecting means. It is preferable to detect and to calculate the transmission position where the ultraviolet ray detected by the ultraviolet ray detecting means has transmitted based on the detected timing. That is, since the ultraviolet rays cannot be confirmed with the naked eye, the transmission position may be moved relatively slowly so that the transmission position of the ultraviolet rays is uniquely determined with respect to time. It is possible to calculate the transmission position where the detected ultraviolet ray is transmitted, based on the detection timing. By doing so, even on the liquid crystal display panel, it is possible to specify the position by detecting light, and it is possible to draw a smooth figure. Even at a position where visible light is not emitted, the light receiving part of the light receiving element is brought close to an arbitrary position on the liquid crystal display panel to specify coordinates,
The coordinates can be input (for example, drawing of a figure).

For the detection of ultraviolet rays, a filter that transmits only ultraviolet rays having the same wavelength as the wavelength of the ultraviolet rays emitted from the ultraviolet ray irradiation means, and a light receiving element (for example, a photodiode, which can detect the ultraviolet rays that have passed through the filter). It can be realized by combining a phototransistor, a photomultiplier tube, and the like).

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the electrical configuration of a liquid crystal display device 2 according to the first embodiment of the present invention.

The liquid crystal display device 2 is used in an information terminal for introducing administrative services of local public bodies. As shown in FIG. 1, a CPU that controls the entire device
4, a ROM 6 for storing information such as control processing programs and character data executed by the CPU 4, a RAM 8 for storing data generated during processing of the CPU 4, and a CPU 4
Based on the image signal transferred from the liquid crystal display panel 10
A liquid crystal display panel drive circuit 12 for applying a voltage to the pixels to display an image on the liquid crystal display panel 10, and a back light drive circuit 16 for turning on a back light source 14 to be described later at regular intervals based on an instruction from the CPU 4. A touch panel 18 for detecting the pressing by the operator, and a touch panel matrix circuit 20 (hereinafter, simply referred to as "matrix circuit 20") for outputting the position coordinates on the touch panel 18 pressed by the operator to the CPU 4. These are connected via a bus 22 to a control computer that controls many information terminals. Among them, the liquid crystal display panel 10 and the backlight light source 14 are configured as a part of the liquid crystal display section D1.

The liquid crystal display panel 10 is of a simple matrix type, and has a large number of pixels (not shown) each having a TN mode liquid crystal element vertically and horizontally. When a voltage is applied to each pixel, the light transmittance of that pixel is increased and the light can be transmitted. As shown in FIG. 2, a backlight light source 14 for irradiating the rear surface of the liquid crystal display panel 10 with light is provided near a side end portion of the liquid crystal display panel 10, and the light emitted from the backlight light source 14 is converted into liquid crystal. A light guide plate 24 for uniformly irradiating the back surface of the display panel 10 is arranged on the back surface of the backlight light source 14.

The backlight light source 14 includes a first light source 14R for emitting red light, a second light source 14G for emitting green light on the rear surface of the liquid crystal display panel 10, and a blue light on the rear surface of the liquid crystal display panel 10. Third light source 1 for emitting light
4B and a fourth light source 14UV for irradiating the rear surface of the liquid crystal display panel 10 with ultraviolet rays, and emits three primary color lights of red (R), green (G) and blue (B) and ultraviolet rays (UV). It is possible. These backlight light sources 14 are all cold cathode fluorescent lamps, and among them, the first light source 14R, the second light source 14G, and the third light source 14B are covered with three color filters of R, G, and B, respectively, and three primary colors are provided. It is possible to emit light, and a black light is used as the fourth light source 14UV to emit ultraviolet light. A light reflection sheet (not shown) is provided around the backlight source 14 and the rear surface of the light guide plate 24 so that the light emitted from the backlight source 14 can be efficiently emitted to the rear surface of the liquid crystal display panel 10. There is.

Further, on the front surface of the liquid crystal display panel 10, there is provided a fluorescent plate 26 constituted by adhering a fluorescent substance to the surface of a glass plate which transmits visible light. This fluorescent plate 2
When 6 is exposed to ultraviolet rays, the fluorescent substance in the area exposed to the ultraviolet rays emits light. Liquid crystal display device 2 configured in this way
In the above, in the 1st frame (for example, a frequency of 30 Hz), which is a period for forming the color to be expressed by the backlight drive circuit 16 (that is, a period for displaying one completed color image), The first light source 14R, the second light source 14G, the third light source 14B, and the fourth light source 14UV are sequentially lit at equal intervals (for example, a frequency of 120 Hz), and the liquid crystal display panel drive circuit 12 synchronizes the lighting with the liquid crystal display. By applying a voltage to the pixels arranged in parallel on the panel 10 to change the transmittance of the pixels, the liquid crystal display panel 1
Display a color image on top of 0. For example, as shown in FIG. 3A, while the first light source 14R and the second light source 14G are turned on, a voltage is applied to the pixels to increase the transmittance, while the third light source 14B is turned on. When the blue light is blocked without applying a voltage, it is possible to make the pixel appear to emit yellow light due to the additive color mixture of red light and green light.

Therefore, as shown in FIG. 3B, one frame is a first sub-frame for displaying a red light image (hereinafter referred to as "first image"), and a green light image (hereinafter, referred to as "first image").
A second sub-frame for displaying a "second image"), a third sub-frame for displaying a blue light image (hereinafter referred to as "third image"), an ultraviolet image (hereinafter referred to as "fourth image") Image)) is divided into fourth sub-frames for displaying, and a voltage is applied to each pixel along the scanning line on the liquid crystal display panel 10 during each divided sub-frame. A color image can be displayed by writing an image and turning on the backlight light source 14 corresponding to the light of each color.

Specifically, first, during the first sub-frame period, the liquid crystal display panel 10 is turned on by turning on the first light source 14R.
While irradiating red light to the liquid crystal display panel 10, the R image is written to the liquid crystal display panel 10, and the R image is displayed on the liquid crystal display panel 10. Also during each subsequent sub-frame period, the G image, the B image, and the UV image are processed in the same procedure as the first sub-frame.
Display the image. As a result, a color image is displayed on the liquid crystal display panel 10 by the additive color mixture of the three primary color lights. The UV image is displayed by exposing the fluorescent plate 26 provided on the front surface of the liquid crystal display panel 10 to ultraviolet rays.
In addition, the lighting time of each backlight light source 14, the radiation intensity of each backlight light source 14, etc. are determined by the backlight drive circuit 1.
6 adjusts appropriately.

The touch panel 18 is the liquid crystal display panel 10.
It is a transparent electrode plate formed in the same shape as, and is provided on the front surface of the fluorescent plate 26. The transparent electrode plate is formed by stacking two thin (for example, 0.1 to 0.2 mm) polyester films with minute (for example, 30 μm) intervals. Conductive films in which indium tin oxide (ITO) is vapor-deposited are formed in a strip shape on opposite surfaces of both films, and both films are laminated so that the strip-shaped conductive films intersect each other in the vertical and horizontal directions. ing. When one part of the touch panel 18 configured as described above is pressed with a finger or the like, the conductive films of both films come into contact with each other, so that the matrix circuit 20 detects the coordinates of the pressed part and transfers the coordinates to the CPU 4.

Hereinafter, the liquid crystal display device 2 thus constructed will be described.
The image display processing performed by the CPU 4 will be described with reference to the flowchart shown in FIG. This image display process is
For example, one frame is started based on a signal transmitted from the control computer, that is, an RGB signal for displaying a color image and a signal for displaying an input button, which is started every 1/30 seconds (that is, a frequency of 30 Hz). This is a process of displaying the color image and the input button for prompting the input.

When the image display process is started, first, 1 is substituted for N indicating the subframe number (S110). Next, the Nth light source is turned on based on the substituted N (S12
0), the Nth image is written on the liquid crystal display panel 10 (S1
30) After the writing is completed, the Nth light source is turned off (S
140), and 1 is added to N (S150). Thus, first, the image of the first sub-frame, that is, the image of red light is displayed. Then, it is determined whether N = 5 (that is, whether or not the fourth subframe has ended) (S160),
If N = 5 is not satisfied (NO in S160), the image of the next subframe is displayed (S120 to S140). In this way, during the first to third sub-frame periods, RGB
The color image based on the signal is displayed, and the input button based on the signal for displaying the input button is displayed during the fourth sub-frame period.

On the other hand, when it is judged that N = 5 (S
If YES, it is determined whether the touch panel 18 is pressed (S170), and if it is pressed (YES in S170), the pressed coordinates are output to the control computer (S180). If there is no input (S180), the image display process is terminated.

As described above, the present liquid crystal display device 2 includes the fourth light source 14UV which emits ultraviolet rays and the fluorescent plate 26 which emits light when irradiated with ultraviolet rays. Therefore, the image for urging the touch panel 18 to be pressed can be displayed on the fluorescent plate 26, not on the liquid crystal display panel 10 that displays a general color image, and thus signals input separately (that is, an RGB signal and an input button). Separate images based on display signals) can be easily overlaid. Therefore, there is no need for a circuit configuration that has been complicated in the past to synthesize separate signals, and the burden on the control computer can be reduced. In addition, it is preferable that an image (characters, figures, etc.) for prompting an input, various notes, etc. can be displayed more conspicuously.

Next, a liquid crystal display device according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a block diagram showing an electronic configuration of the liquid crystal display device 52 of the second embodiment. The same parts as those in FIG. 1 are designated by the same reference numerals. Liquid crystal display device 5
Reference numeral 2 is used in a graphic creation device capable of drawing a graphic on a display screen. As shown in FIG. 5, the electronic configuration of the liquid crystal display device 52 of the second embodiment is almost the same as that of the liquid crystal display device 2 of the first embodiment, but the liquid crystal display portion D2 of the second embodiment is A light pen for detecting ultraviolet rays transmitted through the liquid crystal display panel 10 in place of the touch panel 18 and the matrix circuit 20 of the first embodiment, in addition to the configuration in which the fluorescent plate 26 is removed from the liquid crystal display unit D1 of the first embodiment. 54 and a timing detection circuit 5 that detects the timing at which the light pen 54 detects ultraviolet rays and transfers the detected ultraviolet rays to the CPU 4.
6 and 6 are provided. The bus 22 of the second embodiment is
It is connected to the control unit of the graphic creation device.

In the liquid crystal display device 52, rather than using ultraviolet rays for image display, the light pen 5 is made to raster scan the ultraviolet ray transmission position on the liquid crystal display panel 10.
4 is used as a means for detecting the position coordinates on the liquid crystal display panel. The raster scanning of the ultraviolet transmission position is specifically performed as follows.

As shown in FIG. 7, the liquid crystal display panel 10 is
A large number of scan electrodes X orthogonal to each other (for example, 200 scan electrodes X).
First scan electrode X1 to 200th scan electrode X200) and signal electrode Y (for example, 600 lines. First signal electrode Y1 to 60th)
0 signal electrode Y600), and the liquid crystal display panel drive circuit 12 includes a scan electrode drive circuit 12a for applying a voltage to the scan electrode X and a signal electrode drive circuit 12b for applying a voltage to the signal electrode Y. In the liquid crystal display panel 10,
The scan electrode drive circuit 12a sequentially applies a voltage to the scan electrodes X, and the signal electrode drive circuit 12b adjusts the voltage to apply the voltage to each pixel.

The image of each sub-frame is
Writing is performed along a number of scan electrodes X provided in parallel, but in the case of writing an image (that is, a fourth image) by ultraviolet rays, for example, 20 lines are written in the fourth sub-frame period of the first time. The voltage is applied only to the signal electrodes Y1 to Y20 (which will be referred to as “a first group of signal electrodes”), and the next 20 signals are applied during the second fourth sub-frame period.
The voltage is applied only to the signal electrodes Y21 to Y40 of the book (this will be referred to as a "second group of signal electrodes"). In this way, for example, a group including 20 signal electrodes Y is divided into 30 times (600/20) fourth sub-frames, and a voltage is applied to all the signal electrodes, so that the liquid crystal display panel It is possible to raster-scan the ultraviolet ray transmission position on 10.

On the other hand, the light pen 54 is formed in a substantially cylindrical shape, and a filter is provided at the tip of the light pen 54 to pass the ultraviolet light having the same wavelength as the ultraviolet light emitted from the fourth light source 14UV and to block the visible light. . Further, inside the light pen 54 (inside the filter), a photodiode capable of detecting the light transmitted through the filter, that is, the ultraviolet ray is provided. When the tip of the light pen 54 is brought close to one position on the liquid crystal display panel 10, the ultraviolet rays transmitted through the liquid crystal display panel 10 are detected by the photodiode at the timing corresponding to the coordinates of the transmission position.

Hereinafter, the liquid crystal display device 5 thus constructed will be described.
The graphic drawing process performed by the second CPU 4 will be described with reference to the flowchart shown in FIG. The graphic drawing process is started, for example, every one second, and a color image for 30 frames is displayed based on a signal sent from the control unit of the graphic drawing apparatus, that is, an RGB signal for displaying a color image. Processing.

When the graphic drawing process is started, first, 1 is substituted for M indicating the group number of the signal electrode Y (S31).
0), 1 is substituted for N indicating the subframe number (S)
320). Next, the Nth light source corresponding to the substituted N is turned on (S330), the Nth image is written on the liquid crystal display panel 10 (S340), and after the writing is finished, the Nth light source is turned off (S350), 1 is added to N (S360).
Thus, first, the image of the first sub-frame, that is, the image of red light is displayed. Then, it is determined whether or not N = 4 (that is, whether or not the third subframe has ended) (S370), and if N = 4 (NO in S370),
The image of the next sub-frame is displayed (S330-).
S350). In this way, a color image based on the RGB signals is displayed during the first to third sub-frame periods.

On the other hand, when it is judged that N = 4 (S
In step 370, the fourth light source is turned on (S38).
0), applying a voltage to the signal electrodes of the M-th group corresponding to the substituted M, and sequentially to the scan electrodes X,
A voltage is applied (that is, synonymous with displaying the fourth image). After that, the fourth light source is turned off (S400). In this way, when the image display for one frame is completed, 1 is added to M (S410) to determine whether M = 31 (that is, whether the raster scan of the ultraviolet transmission position is completed).
Is determined (S420), and if M = 31 is not satisfied (S420)
If NO, the process returns to S320, and the image of the next frame is displayed.

When it is determined that M = 31 (YES in S420), it is determined whether or not the detection of ultraviolet rays by the light pen 54 is correct (S430). When ultraviolet rays are detected (YES in S430), the coordinates at which the ultraviolet rays are detected are calculated from the detection timing of the ultraviolet rays read from the timing detection circuit 56 and the image data of the fourth image, and output to the figure drawing device. Yes (S440). On the other hand, if no ultraviolet light is detected (N in S430,
O), the image display process is terminated. If the coordinates at which the ultraviolet rays are detected are included in a predetermined area, an RGB signal indicating that visible light is to be emitted from the coordinates is input to the CPU 4 from the graphic drawing device, and the RGB signal is displayed on the liquid crystal display panel 10. Is displayed.

As described above, in the present liquid crystal display device 52, ultraviolet rays are emitted from the fourth light source 14UV to the liquid crystal display panel 10.
Since the rear surface of the liquid crystal panel is irradiated, and the ultraviolet ray transmitting position on the liquid crystal display panel 10 is raster-scanned,
Even on a black screen where no visible light is emitted, the coordinates can be specified by the light pen 54 that can detect ultraviolet rays, and a figure or a character can be written.

In the description of the above embodiment, the first light source 14R corresponds to the red light irradiation means, the second light source 14G corresponds to the green light irradiation means, and the third light source 14B corresponds to the blue light irradiation means. The fourth light source 14UV corresponds to ultraviolet ray irradiation means, the fluorescent substance corresponds to a light emitting substance, and the fluorescent plate 26 corresponds to a light emitting plate. Further, the image display processing and the graphic drawing processing correspond to the processing as the control means. The touch panel 18 and the matrix circuit 20 form a contact coordinate detection circuit, and the light pen 54 and the timing detection circuit 56 form an ultraviolet ray detecting means.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, but can take various forms. For example, in the above-described second embodiment, the signal electrodes Y to which a voltage is applied are divided into groups of 20 in each fourth sub-frame in order to raster scan the ultraviolet transmission position, but the present invention is not limited to this. Instead, for example, one each may be used. In this case, the smaller the number of signal electrodes Y forming one group, the finer the area can be specified, but the time required for one raster scan increases, so the display speed of the liquid crystal display panel 10 increases. It is preferable to decide in consideration of. However, in the above embodiment, the fluorescent plate 26 is formed by attaching a fluorescent substance that emits fluorescence to the surface of the glass plate when it receives ultraviolet rays.
Not limited to this, it may be contained inside the glass plate. Further, the material of the fluorescent plate 26 is not limited to glass, but may be any material such as acrylic resin, polycarbonate, polyethylene terephthalate, etc., as long as it is transparent, that is, capable of transmitting visible light.

Further, in the liquid crystal display device 2 of the above-described embodiment, the explanation has been made by assuming that the fluorescent plate 26 and the liquid crystal display panel 10 are separate bodies, but they are combined to form a liquid crystal display panel 10 on the surface. A fluorescent substance that emits fluorescence upon receiving ultraviolet rays may be attached, or the fluorescent substance may be contained inside the liquid crystal display panel 10.

In the above embodiment, the TN mode liquid crystal display panel 10 in which the nematic liquid crystal is sealed is used, but the STN mode liquid crystal display panel may be used. Furthermore, it is not limited to a simple matrix type liquid crystal display panel, but a thin film transistor (TFT)
Alternatively, an active matrix type liquid crystal display panel using a thin film diode or the like may be used. Further, it is preferable to use a ferroelectric liquid crystal because ON / OFF switching is performed at high speed.

Further, in the liquid crystal display device 2 of the above embodiment, when the ultraviolet rays are not required, it is preferable to cover the liquid crystal display panel 10 with glass capable of blocking the ultraviolet rays.
Ultraviolet rays do not necessarily have a good effect on the human body, but by doing so, the effect of ultraviolet rays on the human body can be suppressed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a configuration near a liquid crystal display unit according to the first embodiment.

FIG. 3 is a time chart illustrating the principle of color display performed by the liquid crystal display device according to the first embodiment.

FIG. 4 is a flowchart showing an image display process executed by the liquid crystal display device of the first embodiment.

FIG. 5 is a block diagram showing an electrical configuration of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a configuration near a liquid crystal display portion of a second embodiment.

FIG. 7 is a block diagram showing an electrical configuration of a liquid crystal display panel and a liquid crystal display panel drive circuit of a second embodiment.

FIG. 8 is a flowchart showing a graphic drawing process executed by the liquid crystal display device of the second embodiment.

[Explanation of symbols]

2 ... Liquid crystal display device, 4 ... CPU, 6 ... ROM, 8 ... RA
M, 10 ... Liquid crystal display panel, 12 ... Liquid crystal display panel drive circuit, 12a ... Scan electrode drive circuit, 12b ... Signal electrode drive circuit, 14 ... Backlight light source, 14R ... First light source,
14G ... 2nd light source, 14B ... 3rd light source, 14UV ... 4th
Light source, 16 ... Backlight drive circuit, 18 ... Touch panel, 20 ... Touch panel matrix circuit (matrix circuit), 54 ... Light pen, 56 ... Timing drive circuit,
26 ... Fluorescent plate.

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Claims (5)

(57) [Claims] 1. A liquid crystal display panel formed in a plate shape having a plurality of pixels for changing light transmittance when a voltage is applied, and visible light irradiation for irradiating a rear surface of the liquid crystal display panel with visible light. A liquid crystal display device comprising: a means for applying a voltage to the pixel to display an image on the liquid crystal display panel; and an ultraviolet irradiation means for irradiating the rear surface of the liquid crystal display panel with ultraviolet rays, The control means sequentially turns on the visible light irradiation means and the ultraviolet irradiation means, applies a voltage to the pixels in synchronization with the lighting, and displays an image on the liquid crystal display panel. Display device. 2. The liquid crystal display device according to claim 1, wherein the visible light irradiating means irradiates red light onto the rear surface of the liquid crystal display panel, and green light irradiates onto the rear surface of the liquid crystal display panel. Green light irradiating means for irradiating the liquid crystal display panel, and blue light irradiating means for irradiating the rear surface of the liquid crystal display panel with blue light, and the control means includes the red light irradiating means, the green light irradiating means, and the blue light irradiating means. A liquid crystal display device characterized in that an irradiation means and the ultraviolet irradiation means are sequentially turned on, and a voltage is applied to the pixel in synchronization with the lighting to display an image on the liquid crystal display panel. 3. The liquid crystal display device according to claim 1, wherein the liquid crystal display panel has a light emitting plate that emits visible light when exposed to ultraviolet light, and a light emitting plate that transmits visible light on the front surface of the liquid crystal display panel. Liquid crystal display device characterized by. 4. The liquid crystal display device according to claim 1, wherein when a pressing force is applied to the front surface of the liquid crystal display panel from the outside, the pressing position is detected. A liquid crystal display device comprising detection means. 5. The liquid crystal display device according to claim 1, wherein the ultraviolet rays emitted from the ultraviolet ray irradiation means and transmitted through the liquid crystal display panel are detected on the liquid crystal display panel. The control means sequentially applies a voltage to the pixels so that the transmission position where the ultraviolet light emitted from the ultraviolet light irradiation means can be uniquely determined with respect to time while the ultraviolet light irradiation means is turned on. At the same time, the ultraviolet ray detecting means is caused to detect the ultraviolet ray passing through the transmitting position, and the transmitting position where the ultraviolet ray detected by the ultraviolet ray detecting means is transmitted is calculated based on the detection timing. Liquid crystal display device.