JP2001033752A - Rear projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an information input and output device in which information can be inputted at a position on a screen of a liquid crystal electro-optic device to change display contents of the device by constituting the projector equipped with a display device, screen and position detecting means to detect the position of a specified point which is optionally designated on the screen. SOLUTION: The light from a halogen lamp 2 enters a liquid crystal electro- optic device 3 which is disposed in a main body 1 to display an image, and the light transmitted through the liquid crystal electro-optic device 3 is enlarged while passing through an optical system 4 and projected on a screen 5 to display the image on the screen 5. A position detecting means 6 is disposed on the screen 5 so that when an input pen touches the screen 5, a signal corresponding to the coordinate on the screen 5 is sent to a driving circuit of the liquid crystal electro-optic device 3 and the signal corresponding to the input signal is outputted from the driving circuit to the display device. The liquid crystal electro-optic device 3 has crystalline thin film transistors including thin film transistors for switching and thin film transistors for the driving circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information input / output device using a projection type liquid crystal electro-optical device. The present invention relates to an information input / output device capable of inputting information on a position on a display surface specified by contact, light emission, and the like on the display surface. In addition, the present invention relates to an information input / output device that reads image information such as a drawing arranged on a display surface or displays the read image information.

[0002]

2. Description of the Related Art Conventionally, with respect to information displayed on a display surface of a display device such as a CRT or a liquid crystal electro-optical device, information is externally received on the display surface in the same sense as writing characters on paper with a writing instrument. 2. Description of the Related Art There is known an apparatus that inputs a signal and displays an image corresponding to the input information signal on a display surface.

A method of inputting an information signal to a display device is to provide a position detection means for detecting a position on the display surface on the display surface, and to apply some external force such as pressure, magnetic force, or light to a certain point on the display surface. The position where the external force is applied is detected and transmitted as an information signal to the display device, and the displayed image is changed.

As a means for detecting a position on the display surface, a touch panel using a light-transmitting resistive film or a transparent electrode matrix, an infrared sensor, or the like is used.

[0005] Such information input / output devices have recently been
It is common to use a liquid crystal electro-optical device as a means for displaying image information.

[0006] With such a configuration, the operator can perform input as if he or she operates the display contents of the display device as it is. Alternatively, by displaying the input information on a display device in which the same coordinate system is set in real time,
Characters and images can be input as if they were written on paper with a writing instrument.

[Problems of the prior art] However, when a conventional configuration is used using a liquid crystal electro-optical device, various problems have occurred. For example, when pressure is applied to the display surface of the liquid crystal electro-optical device, the orientation of the liquid crystal material in the liquid crystal electro-optical device may be disturbed, and display may not be possible. Further, there has been a problem that display contents change due to magnetism, static electricity, or the like when indicating a position on the display surface, or elements formed on the liquid crystal electro-optical device are destroyed, so that display becomes impossible thereafter. In most cases, information can be input by tracing the display surface with a pen or a finger, and it has not been possible to input information such as documents and images all at once.

For this reason, a solution can be achieved by adopting a configuration in which the liquid crystal electro-optical element is not affected at all by an external force applied to the display surface. As a liquid crystal electro-optical device capable of such a configuration, a projection type liquid crystal electro-optical device (liquid crystal projector) is known. The projection type liquid crystal electro-optical device is capable of displaying a large screen with a diagonal of 40 inches or more, but is small, lightweight, and does not require adjustment, and is not affected by geomagnetism, which is a problem when a large screen is used in a CRT. It is expected to be a display device replacing a large screen CRT.

The basic structure of the projection type liquid crystal electro-optical device is to display a transmission type or reflection type liquid crystal electro-optical device,
The liquid crystal electro-optical device is irradiated with light, the transmitted light or the reflected light is enlarged through an optical system, and an image is projected and displayed on a screen as a display surface. The projection-type liquid crystal electro-optical device has a front type in which the reflected light is visually recognized as an image by projecting toward the display surface side (front side) of the screen, and a surface opposite to the display surface side of the screen (back side of the screen). It can be distinguished into a rear type in which the transmitted scattered light is projected and visually recognized as an image.

However, although the projection type liquid crystal electro-optical device can display a large screen, a position on the display surface arbitrarily designated from the screen surface, which is a display surface of an image, is transmitted to the display device as an information signal. There was no device for transmitting and changing the displayed content.

For this reason, the projection type liquid crystal electro-optical device can display an image such as a movie or a TV, but is not used in a field requiring a large screen such as a CAD or a workstation to simplify the operation. Was.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a liquid crystal electro-optical device of the projection type in which a pen, a finger or the like instructs a screen of a liquid crystal electro-optical device to input information on a position on the screen. It is an object of the present invention to provide an information input / output device capable of changing the information.

According to the present invention, there is provided a display device for displaying an image on a large-area screen large enough to be visually recognized by many people.
It is an object of the present invention to provide an information input / output device that changes display contents of a display device according to information directly input on a display surface.

[0014]

The present invention has the following arrangement in order to solve the above-mentioned problems. That is, the present invention includes a display device, a screen on which an image displayed on the display device is enlarged and projected, and position detecting means for detecting a position of a specified point on the screen arbitrarily designated. An information input / output device characterized in that:

Further, the present invention has a liquid crystal electro-optical device, a screen, and an image pickup device, and the screen is configured such that an image displayed on the liquid crystal electro-optical device is enlarged and projected on the back side, The imaging device is an information input / output device provided on the back side of the screen and receiving light incident from the front side to the back side of the screen.

According to another aspect of the present invention, there is provided a liquid crystal electro-optical device, a screen, and an image pickup device. The screen is configured such that an image displayed on the liquid crystal electro-optical device is enlarged and projected on the back side, The imaging device is an information input / output device that is provided on the back side of the screen and reads an image present on the front side of the screen.

Further, the present invention has a liquid crystal electro-optical device, a screen, an image pickup device, and a position detecting means, wherein the screen displayed on the liquid crystal electro-optical device is enlarged when an image displayed on the liquid crystal electro-optical device is enlarged. Projected on the screen, the image pickup device is provided on the back side of the screen, reads an image present on the front side of the screen, the position detection means is provided on the front side of the screen, and is arbitrarily designated on the screen. The information input / output device is characterized by detecting a position of a specific point.

According to the present invention, there is provided a screen for displaying an image,
An information input / output device having information input / output mediating means comprising means for detecting a position of a specific point arbitrarily designated on the screen. FIG. 1 shows a conceptual diagram of the information input / output device of the present invention. In FIG. 1, reference numeral 1 denotes a main body of an information input / output device;
Denotes a light source, 3 denotes a liquid crystal electro-optical device, 4 denotes an optical system, 5 denotes a screen, and 6 denotes position detecting means. The specific configuration will be described below.

In FIG. 1, the optical system is of a rear type. A xenon lamp, a halogen lamp, a metal halide lamp, or the like can be used as the light source 2. The light source 2 has a high luminance, a high luminous efficiency, a well-balanced distribution of RGB color components, a long life, and the like. It is desirable to use a metal halide lamp as satisfying the above condition.

Light emitted from the light source is condensed optical system (not shown)
After that, the liquid crystal electro-optical device 3 is irradiated. The light transmitted through the liquid crystal electro-optical device 3 is magnified by the optical system 4 and is projected on a screen 5, and an image displayed on the liquid crystal electro-optical device 3 is magnified and projected on the screen 5.

The operation modes of the liquid crystal electro-optical device include:
TN type, STN type, scattering type and the like can be used.
As the liquid crystal material used in the liquid crystal electro-optical device, nematic liquid crystal, smectic liquid crystal, ferroelectric liquid crystal, PDLC (polymer dispersed liquid crystal) containing them in a polymer resin, or the like can be used.

As a driving method, a simple matrix method or an active matrix type can be used. However, since a high-speed and high-quality image is provided, an active element provided with a switching element, particularly a crystalline thin-film transistor, is provided for each pixel on the substrate. Matrix type is preferred.

Particularly, in the case of an active matrix type liquid crystal electro-optical device using a crystalline thin film transistor, a switching thin film transistor connected to each pixel and a driving peripheral circuit for driving as a liquid crystal electro-optical device are provided on the same substrate. Since a so-called monolithic structure can be provided above, miniaturization and cost reduction of the device can be realized, which is preferable.

In FIG. 1, the light from the light source is transmitted from the rear of the liquid crystal electro-optical device. However, the liquid crystal electro-optical device is of a reflection type, and the display surface is irradiated with light, and the reflected light is transmitted to the optical system 4. Through to the screen.

Further, when performing color display, one of a pair of substrates constituting a liquid crystal electro-optical device is
Provide three color filters for RGB corresponding to each pixel or prepare three liquid crystal electro-optical devices, and separate the light from the light source into three colors with a dichroic mirror or the like that reflects only one of the three colors RGB once. Then, light of each color may be incident on a different liquid crystal electro-optical device, and light transmitted through the liquid crystal electro-optical device may be combined again by a dichroic mirror and projected on a screen.

In the case of this spectroscopic method, three ferroelectric liquid crystal electro-optical devices which are of a transmission type and have only a high-speed shutter function in which the entire display surface is composed of one pixel are prepared, and only image display is performed. Liquid crystal electro-optical device that performs
And a display method in which three colors are switched by a shutter within one frame.

A self-luminous type display device such as a cathode ray tube can be used as the display device.

Next, the screen 5 will be described. As a basic configuration of the screen, a substrate having a thickness of 3.0 mm and having light transmitting and scattering properties was used. As the substrate, glass, plastic, or the like can be used, but it is desirable to use a plastic substrate in terms of reducing the weight of the device. In order to improve the brightness of an image, a combination of a Fresnel lens and a lenticular lens may be used. Further, when a decrease in contrast due to external light is expected, a polarizing sheet may be attached to the substrate.

When light from the liquid crystal electro-optical device is diffracted on the screen 5 and the outline of each pixel is blurred, the aperture ratio of the display surface is not reduced extremely.
A black matrix may be formed in a grid pattern on the front side or the back side of the screen.

In FIG. 1, a position detecting means 6 is provided on the screen 5. FIG. 5 shows a typical configuration of the position detecting means. FIG. 5A shows an elastic translucent substrate having a plurality of strip-shaped translucent electrodes made of ITO (Indium Tin Oxide) or the like on the surface, and superimposing them via a spacer such that the electrodes are orthogonal to each other. It is a thing. When pressure is applied to a specific location from the substrate surface, the opposing strip electrodes at that point come into contact and conduct. A current is sequentially applied to the opposing strip-shaped translucent electrodes and scanning is performed to detect the position of the conduction point.

FIG. 5 (B) shows that a translucent electrode is formed on substantially the entire inner surface of the opposing elastic translucent substrate, and both ends of the translucent electrode on one substrate in the lateral direction are formed. Are provided on the other substrate, and terminals are provided on both ends in the vertical direction on the other substrate, and are opposed to each other via a spacer.

As in the case of the position detecting means of FIG. 5A, when a pressure is applied to a specific portion from the substrate surface, the electrodes facing each other at that point come into contact and conduct. At this time, the position of the conduction point can be detected by measuring the resistance value between both terminals on both substrates. Polyethylene terephthalate or the like can be used for the substrate as the position detecting means in FIGS. 5A and 5B. One of the substrates may be a glass or plastic plate.

FIG. 5C shows a state in which an electric field is applied to an input pen having a coil wound around the tip of a pen made of glass or plastic, and a transparent electrode provided on a light-transmitting substrate by a magnetic field generated by the input pen. It is possible to generate information on the position where the input has been performed by the electromagnetic induction effect that occurs between the input and the output.

The position detecting means shown in FIGS. 5A and 5B are provided on the front side (viewing side) of the screen. If the material of the screen is flexible, it may be provided on the back surface of the screen. The position detection means in FIG. 5C may be on the back side or the front side of the screen as long as the input position can be detected.

In addition, as a position detecting means, FIG.
By providing the infrared light source and the infrared sensor on both sides of the screen in the vertical and horizontal directions as shown in (1), the position where the infrared light is blocked by some shield can be detected as the input position. Input can be performed on the display surface with a finger or the like.

In any case, the information on the position on the screen input from the above-described position detecting means is input to a drive circuit of the liquid crystal electro-optical device or a computer connected thereto, and corresponds to this information. The image is displayed on the screen.

In order to accurately correspond the position of the screen 5 detected by the position detecting means to the image displayed by the liquid crystal electro-optical device 3, the image from the liquid crystal electro-optical device is detected on the screen. There is a need for a method for forming an image without shifting the means. As an example, an alignment pixel different from the display pixel is formed on the display surface of the liquid crystal electro-optical device, and a similar alignment marker is formed at a corresponding position on the screen to actually display an image. Before the adjustment, the tilt angle of the liquid crystal electro-optical device, the focus of the lens of the optical system, and the like may be adjusted so that the light transmitted through the alignment pixel matches the marker on the screen. The alignment may be performed at specific pixels (for example, at the center and four corners of the display unit) of the display unit of the liquid crystal electro-optical device.

FIG. 2 shows another conceptual diagram of the information input / output device of the present invention. Further, as shown in FIG. 2, an imaging device 8 may be provided in the main body 1 to serve as a position detecting unit. In this case, light may be emitted from the front side to the back side of the screen 5 using a light emitting pen or the like, and the position may be detected by the imaging device 8. In this way, even if the screen is large, it is only necessary to adjust the optical system to cope with the size, and it is not necessary to change the size of the light receiving surface of the imaging device 8 itself.

Therefore, as shown in FIGS.
Compatibility with a large screen is extremely easy as compared with a position detecting means using a substrate having the same size as a screen. Furthermore, by using an object having a high screen resolution for the imaging apparatus itself, the resolution can be easily increased. Furthermore, when the light emission color of a light irradiation device such as a light emitting pen is changed, it is possible to detect a difference in light emission color (a difference in light wavelength) by providing a color filter in the imaging device.

Therefore, an image is displayed on a large-sized screen large enough to be viewed by many people, and information is directly input on the screen (screen) with a light emitting pen or the like, and a display corresponding to the information is performed. And an electronic blackboard that replaces a conventional blackboard or whiteboard. Of course, a computer or the like may be used to perform calculations, character recognition, and the like based on the input information.

As an imaging device, a charge-coupled device (CC)
D) or a photoconductive element can be used. In FIG. 2, a half mirror 7 is provided between the optical system 4 and the liquid crystal electro-optical device 3, and light incident from the front side to the rear side of the screen is made incident on the imaging device 8 through the optical system 4 and read. I have. Of course, light entering the imaging device 8 from the front side to the rear side of the screen may be read using an optical system different from the optical system 4.

The screen 5 may be variably controlled so as to have high translucency from the light scattering state, and an original or an object existing on the front side of the screen may be read as an image. A light illuminating the document for reading may be provided in the main body 1. That is, the imaging device 8 is used as an image sensor. The read image information can be stored in a storage device and displayed on a screen.

It is also possible to use a method of instantly inputting and outputting an image having a huge amount of information. In order to variably control the screen 5 between the light-transmitting state and the scattering state, a liquid crystal material is sandwiched between a pair of light-transmitting substrates having electrodes as the screen 5, and the screen 5 is placed between the transmission and scattering states by an electric field applied between the electrodes. May be used. In this case, when an image is displayed on a screen, the image may be in a scattering state, and when an image is read from the outside, the image may be in a transmission state. A ferroelectric liquid crystal electro-optical device or a polymer dispersed liquid crystal electro-optical device may be used. Examples will be described below.

[0044]

[Embodiment 1] FIG. 1 shows the configuration of an information input / output device of this embodiment. Light from the halogen lamp 2 is incident on a liquid crystal electro-optical device 3 provided in the main body 1 and displaying an image, and the light transmitted through the liquid crystal electro-optical device 3 is enlarged through an optical system 4 and projected on a screen 5. , The image is projected on the screen 5. Position detecting means 6 on screen 5
When an input pen (not shown) is brought into contact with the screen, a signal corresponding to coordinates on the screen is transmitted to the drive circuit of the liquid crystal electro-optical device, and the drive circuit transmits the signal to the input signal. A corresponding signal is output to the display.

FIG. 6 is a conceptual diagram of a liquid crystal electro-optical device manufactured according to this embodiment. The liquid crystal electro-optical device is an active matrix drive type in which a switching element formed of a crystalline thin film transistor (TFT) is formed for each pixel. Further, a monolithic configuration in which a peripheral drive circuit for driving the liquid crystal electro-optical device is provided on the same substrate is also provided.

FIGS. 3 and 4 show steps of manufacturing a thin film transistor. FIG. 3 is a cross section of a portion shown by a dashed dotted line in FIG. First, a substrate (Corning 705)
9, a diagonal 1.6 inches) 201, a silicon oxide film having a thickness of 1000 to 3000 Å, for example, 2000 Å is formed as a base oxide film 202. As a method for forming this oxide film, a sputtering method in an oxygen atmosphere was used. But,
In order to further improve mass productivity, a film in which TEOS is decomposed and deposited by a plasma CVD method may be used.

Thereafter, the amorphous silicon film is formed into a thickness of 300 to 5000 by a plasma CVD method or an LPCVD method.
{Preferably 500-1000} and deposit 5
It was left in a reducing atmosphere at 50 to 600 ° C. for 24 hours to be crystallized. This step may be performed by laser irradiation. Then, the silicon film thus crystallized is patterned to form island-like active layer regions 203 and 2.
04 was formed. Further, a silicon oxide film 205 having a thickness of 700 to 1500 ° was formed thereon by sputtering.

Thereafter, an aluminum film (containing 1 wt% of Si or 0.1 to 0.3 wt% of Sc) having a thickness of 1000 to 3 μm, for example, 6000 °, was formed by electron beam evaporation or sputtering. Then, a photoresist (for example, OFPR8 manufactured by Tokyo Ohka)
00/30 cp) by spin coating.
If an aluminum oxide film having a thickness of 100 to 1000 ° is formed on the entire surface of the aluminum film by anodic oxidation before forming the photoresist, adhesion to the photoresist is good, and By suppressing the current leakage, it was effective in forming the porous anodic oxide only on the side surfaces in the subsequent anodic oxidation step. Thereafter, the photoresist and the aluminum film are patterned and etched together with the aluminum film to form wiring portions 206 and 209 and gate electrode portions 207 and 20.
8, 210 were formed. (FIG. 3 (A))

The above-mentioned photoresist is left on these wirings and gate electrodes, and functions as a mask for preventing anodic oxidation in a later anodic oxidation step. FIG. 4 shows this state viewed from above. Also in this case, similarly to the first embodiment, the gate electrodes 207 and 208 and the wiring 2
09, the wiring 206 and the gate electrode 210 are electrically independent, and the former is referred to as an A-series and the latter is referred to as a B-series.
(FIG. 4 (A))

Then, of the above wirings and gate electrodes,
Anodization was performed by passing an electric current in an electrolytic solution only for the B series, and anodic oxides 211 and 212 having a thickness of 3000 to 25 μm, for example, 0.5 μm, were formed on the side surfaces of the wiring and the gate electrode. The anodic oxidation was performed using a 3 to 20% aqueous solution of citric acid or an acidic aqueous solution of oxalic acid, phosphoric acid, chromic acid, sulfuric acid or the like, and a constant current of 5 to 30 V, for example, 8 V was applied to the gate electrode. The anodic oxide thus formed was porous. In this embodiment, the voltage is set to 8 V in an oxalic acid solution (30 to 80 ° C.),
Anodized for ~ 240 minutes. The thickness of the anodized oxide was controlled by the anodizing time and temperature. At this time, since no current flows through the A series, the gate electrodes 207, 20
8. No anodic oxide was formed on the wiring 209.
(FIG. 3 (B), FIG. 4 (B))

Next, the mask was removed, and a current was again applied to the gate electrode and wiring in the electrolytic solution. This time,
Both series A and series B were energized using a PH ％ 7 ethylene glycol solution containing 3-10% tartaric acid, boric acid and nitric acid. A better oxide film was obtained when the temperature of the solution was lower than room temperature around 10 ° C. For this reason, barrier type anodic oxides 213 to 217 were formed on the upper surfaces and side surfaces of the gate electrodes / wirings 206 to 210. Anodic oxides 213-2
The thickness of 17 is proportional to the applied voltage.
At 00V, 1200 ° of anodic oxide was formed. In this example, since the voltage was increased to 100 V, the thickness of the obtained anodic oxide was 1200 °. The thickness of the barrier type anodic oxide is arbitrary, but if it is too thin, there is a risk that aluminum will be eluted when the porous anodic oxide is etched later, so that 500 mm or more was preferred. .

It should be noted that the barrier type anodic oxide is
Porous anodic oxide despite being obtained in the process
Rather than forming barrier-type anodic oxide on the outside of the
Barrier-type anodic oxidation between porous anodic oxide and gate electrode
The thing is to be formed. (FIG. 3 (C)) Thereafter, the active layer of the TFT is formed by ion doping.
Gate electrode portions (that is, gate electrode portions)
And the surrounding anodic oxide film) and gate insulating film
As a self-aligned impurity
Drain) regions 218, 219 and 220 were formed. Do
Phosphine (PH_Three) And di
Borane (B_TwoH₆) Was used. The dose is 5 × 10¹⁴~
5 × 10 ^Fifteencm^-2, Acceleration energy is 50-90 keV
And Regions 218 and 220 are N-type, and region 219 is
Impurities were introduced so as to be P-type. By region 218
The PTFT 22 by the NTFT 228 and the region 219.
9. NTFT 230 is formed by the region 220.

As a result, in the two TFTs 228 and 229 on the left side of the figure (these are complementary TFTs), the thickness of the anodic oxides 214 and 215 on the side surfaces of the gate electrode is about 12
Since it is 00 °, the widths x ₁ and x ₃ of the region (offset region) where the gate electrode and the impurity region do not overlap are about 1000 ° in consideration of the rounding during ion doping. On the other hand, in the right TFT 230, the anodic oxide 212
The offset width x ₂ was about 6000 ° because the thicknesses of and 217 totaled about 6200 °.

Thereafter, the porous anodic oxides 211 and 213 were etched using a mixed acid of phosphoric acid, acetic acid and nitric acid. In this etching, only the anodic oxides 211 and 213 were etched, and the etching rate was about 600 ° / min. Barrier type anodic oxides 213 to 217 and silicon oxide film 2
05 remained as it was. Thereafter, irradiation with a KrF excimer laser (wavelength: 248 nm, pulse width: 20 nsec) was performed to activate the impurity ions introduced into the active layer. (FIG. 3 (E))

Then, the gate electrode and the wiring were cut to obtain the required size and shape. (FIG. 4 (C).
A silicon oxide film having a thickness of 6000 mm was formed as an interlayer insulator 221 on the entire surface by a CVD method. Next, thickness 800
The ITO film of Å was formed by a sputtering method, and this was patterned to form a pixel electrode 222. Then, the interlayer insulator 221 and the gate insulating film 205 are etched to form contact holes in the source / drain of the TFT, and at the same time, the interlayer insulator 221 and the anodic oxide 2 are formed.
13 to 217 were etched to form contact holes in the gate electrode and wiring. In this embodiment, since the anodic oxide has substantially the same thickness in both the A series and the B series,
These can be etched simultaneously. Finally,
Aluminum wiring / electrodes 223 to 226 are formed and 20
Hydrogen annealing was performed at 0 to 400 ° C.

The wiring 223 is complementary to the wiring 206
The source of the N-channel TFT of the FT is connected, and the wiring 22 is connected.
5 connects the source of the P-channel TFT of the complementary TFT and the wiring 209. The wiring 224 (that is, 226) connects the output terminal of the complementary TFT (that is, the drain of the N-channel TFT and the drain of the P-channel TFT) to the drain of the right TFT. Further, the wiring 227
Connects the drain of the right TFT to the pixel electrode 222. Thus, an integrated circuit having a TFT is completed. (FIG. 3 (F))

Further, especially in the A series, as shown in the embodiment, since the driver is driven by a large current, the PTF
T (the high resistance region width is x _1), NTFT (the high resistance region width x ₄₎ with little degradation. Further, a decoder, a CPU, a shift register, a memory, and other driving circuits consume low power and operate at high frequency, so that both channel width and channel length are small, and deterioration due to hot carriers easily occurs. NT used in these circuits
The width of the high resistance region of the FT x _3, it is necessary to become larger than the width x ₁ of the high resistance region of PTFT. In addition, NTFTs in the active matrix circuit to which a large voltage is applied (the width of the high-resistance region is x ₂ ) have a small required mobility, so that they are very liable to be deteriorated. For improvement, it is required that x ₂ > x ₃ > x ₄ ≧ x ₁ . For example, x ₂ is 0.5 to 1 [mu] m, x ₃
Is 0.2~0.3μm, x ₄ is 0~0.2μm, x ₁ is 0~0.1μm. Thus, the shift register could operate at 1 to 50 MHz. In this embodiment, the effect of suppressing the leak current when the width of the offset of the TFT (right TFT) for controlling the pixel electrode is sufficiently large is great.

Next, referring to FIG.
On 1, a transparent electrode 302 made of ITO was formed on the entire surface. Next, an alignment film 303 made of polyimide was formed as an alignment film on the substrates 201 and 301. Next, the alignment film was rubbed by an ordinary method. At this time, the rubbing direction was such that the upper and lower substrates formed an angle of 90 °. Next, a spacer made of silicon oxide having a diameter of 5 μm was sprayed on the substrate coated with the alignment film (not shown). next,
A sealant (not shown) is printed on the substrate 201 and the substrate 2 is printed.
01 and 301 were overlaid and fixed. Next, the liquid crystal material 3
04 was injected into the cell by a vacuum injection method. The liquid crystal material used was a nematic liquid crystal ZLI-4792 (trade name) manufactured by Merck. Thus, the liquid crystal electro-optical device 3 of FIG.
Was formed. The number of pixels was 640 × 480.
The number of pixels may be 1280 × 1024.

As the light source 2, a metal halide lamp was used. The output of the light source was 250 W, and the ambient temperature of the liquid crystal electro-optical device was 50 ° C. Screen 5 is 800x600m
m were used. An optical system including a lens, a mirror, and the like was provided. Next, on two polyethylene terephthalate substrates of about the same size as the screen and having a thickness of 0.5 mm, a transparent electrode made of ITO was formed on the upper surface of the substrate by a normal process, and the two substrates were overlapped to form a transparent electrode as shown in FIG. (C)
The patterning shown in FIG. A protective film made of polyethylene terephthalate was formed on the electrode surface. The position detecting means 6 is completed. The matrix scale of the transparent electrode was 640 × 480, which is the same as that of the liquid crystal display device. Thus, the information input / output device shown in FIG. 1 was completed.

FIG. 5C shows an input pen on the lower side. The input pen is made of acrylic, glass, or the like, and has a coil wound at one end. An electric field is applied to the electrodes formed on the screen, and an electric field is also applied to the input pen. When the input pen is brought into contact with any position on the screen, the interaction between the magnetic field generated from the input pen coil and the electric field applied to the transparent electrode on the screen causes the input pen to touch Because the current value is different from the part
A portion where the pen is in contact is detected from a current detection circuit formed for each matrix. Next, a signal relating to coordinates at which the screen pen is in contact with the driving circuit is input from the current detection circuit to the driving circuit, and a signal relating to the coordinates is input from the driving circuit to a display signal on a matrix having the same coordinates as the coordinates of the liquid crystal electro-optical device. Is output. As a result, an image is displayed on the screen at the position where the input pen is in contact.

When a character is drawn with the input pen, the liquid crystal display device may be driven so as to hold the display content changed after the pen is touched. Further, a black matrix was formed on the screen. This makes it possible to display the outline of the dot without being blurred due to diffraction.

Embodiment 2 In Embodiment 2, an information input / output device was produced in which the position detecting means 6 of the information input / output device manufactured in Embodiment 1 was changed to one using an infrared sensor. As shown in FIG. 5D, an infrared ray source 501 and an infrared ray sensor 502 were arranged on the vertical and horizontal edges of the screen 5. The infrared sensor 502 has a triangular shape with an opening of 3 mm at the bottom and 5 mm in height, and is formed at intervals of 1 cm on each of the vertical and horizontal sides. On the other side, an infrared source was provided corresponding to the infrared sensor 501.

When a finger or a pen is brought into contact with an arbitrary position on the screen, infrared rays corresponding to the coordinates are blocked, and light does not reach the sensor. If infrared sources and sensors are arranged vertically and horizontally as in this embodiment,
The position where the finger was placed could be detected as the vertical and horizontal coordinates. The coordinate signal detected in this way is input to the driving circuit of the liquid crystal display device, and a signal for changing the display state is input to the same coordinates of the matrix of the liquid crystal display device,
It is possible to indicate that information has been input on the screen.

Further, a black matrix surrounding the periphery of each pixel was formed on the screen. This makes it possible to display the outline of the pixel without blurring due to diffraction.

[Third Embodiment] In a third embodiment, an information input / output device in which the position detection means 6 of the information input / output device manufactured in the first embodiment is replaced with a touch panel shown in FIG. The touch panel is made of a plurality of stripe-shaped I on a 800 × 600 mm polyethylene terephthalate substrate having elasticity.
Polyethylene terephthalate on which a transparent electrode made of TO (indium tin oxide) is formed, rubber spacers having a diameter of 40 μm are provided on this substrate at a pitch of 300 μm vertically and horizontally, and a plurality of stripe-shaped transparent electrodes made of ITO are formed. A substrate was used in which the electrodes were overlapped so that the electrodes were orthogonal to each other. When the touch panel was pressed with a finger or a pen or the like, the upper and lower substrates were brought into contact, and an input signal could be generated at a position corresponding to the pressed portion on the matrix formed by the stripe electrodes.

This coordinate signal is connected to a touch panel so as to be inputted to a drive circuit or a computer circuit of the liquid crystal display device, and a point can be displayed on the screen 5 at a position where pressure is applied by a pen or the like. . In addition, moving the position where the pressure was applied could draw a line. When a button is displayed on the screen and pressure is applied to the button, it becomes possible to delete the function of the button, for example, to erase all the displayed contents. in this way,
It was also possible to compose a tablet on the screen.

Further, a black matrix surrounding the periphery of each pixel was formed on the screen. This makes it possible to display the outline of the pixel without blurring due to diffraction.

[Fourth Embodiment] In the fourth embodiment, in the information input / output device manufactured in the third embodiment, the liquid crystal electro-optical device 3 is replaced by
Liquid crystal electro-optical device 3 for shutter using ferroelectric liquid crystal
First, the liquid crystal display device was constituted by an active matrix type liquid crystal electro-optical device for image display using a ferroelectric liquid crystal.

The liquid crystal material used for the liquid crystal electro-optical device for a shutter will be described. The liquid crystal material is a phenylpyrimidine-based ferroelectric liquid crystal whose phase series is Iso-SmA
-SmC ^* whose phase transition temperature is Iso-SmA
Was 85 ° C and SmA-SmC ^* was 55 ° C. The magnitude of spontaneous polarization was 20 nC / cm ² .

A cell was formed by opposing a light-transmitting substrate having a light-transmitting electrode formed on the entire surface thereof through a spacer and a sealing material, and the liquid crystal was injected into the cell at a temperature showing an Iso phase. Furthermore, in order to obtain a good alignment state, the temperature is increased by 5 ° C.
The panel was gradually cooled to room temperature at a rate of ° C / hr. The contrast of the panel at room temperature was 80 when measured by driving with a voltage of ± 20 V and a rectangular wave of 5 Hz. Three liquid crystal electro-optical devices for shutters were produced corresponding to red (R), green (G), and blue (B).

Further, the liquid crystal electro-optical device for displaying an image
An active drive type liquid crystal electro-optical device having a structure shown in FIG. 6, wherein anti-parallel rubbing is performed on both substrates,
The same ferroelectric liquid crystal material as that used in the liquid crystal electro-optical device for the shutter was injected into the liquid crystal cell in which the distance between the substrates was maintained by a spacer having a diameter of 1.6 μm in the same process between the substrates.

Next, the liquid crystal electro-optical device of this embodiment is shown in FIG.
Shown in The light from the light source is split into three types by a half mirror and is incident on a shutter that displays red, green, and blue. A shutter is driven from the outside so as to show a desired display color, and light transmitted through the shutter is mixed by a half mirror and is incident on an image display panel. The transmitted light 700 transmitted through the image display panel illuminates the screen through an optical system to perform color display on the screen.

In the first period, the shutter for red is turned on.
N, the color for green was turned on in the second period, and the color for blue was turned on in the third period, and the color supplied to the first device was changed in time series according to the three primary colors of light. As a result, gray scale display of eight levels of three colors, that is, display of 512 colors is made possible. A position detection device 6 using translucent electrodes arranged in a matrix similar to that shown in Example 3 was used.

Further, a black matrix surrounding the periphery of each pixel was formed on the screen. This makes it possible to display the outline of the pixel without blurring due to diffraction.

[Embodiment 5] FIG. 2 shows an information input / output device of this embodiment. In this embodiment, an image pickup device 8 that receives light incident from the front side to the back side of the screen 5 is provided inside the main body 1, that is, on the back side of the screen 5. The size of the screen is 1000 × 7
It was 50 mm.

Here, a charge-coupled device (CCD) capable of reading color is provided as the imaging device 8. Although not shown, an optical system different from the optical system 4 was used to receive the incident light from the screen 5. The optical system 4 and the half mirror 7 may be used. In this optical system, a filter that transmits only light having a certain level of brightness or more may be provided.

The signal of the incident light read by the imaging device is connected so as to be input to a computer circuit (not shown). An output image from the computer circuit is displayed on the liquid crystal electro-optical device 3, enlarged by the light source 2 and the optical system 4, and projected on a screen 5.

The light-emitting pen is turned on when it comes into contact with the screen, and emits light of a specific color toward the back of the screen (inside the main body). Here, a pen capable of emitting any one of three colors of red, blue, and green toward the back side of the screen 5 was used.

When a specific location on the screen 5 (front side) was designated using a light emitting pen set to emit red light, red light was emitted toward the back side of the screen 5. The emitted red light enters the imaging device 8 through the optical system, detects the position on the screen and the emission color in the imaging device 8, and transmits the information signal to a computer circuit or a driving circuit of the liquid crystal electro-optical device 3. It was transmitted to.

A dot was displayed on the screen 5 in red in the same color as the light emission color of the light emitting pen. When the light-emitting pen was moved on the screen 5, a line was displayed in red according to the trajectory. Similarly, when the light emission color of the light emitting pen is green, a dot or line is displayed in green, and when the light emission color is blue, a dot or line is displayed in blue. As a matter of course, here, the driving method and programming are performed so that the color of the incident light and the displayed color are the same. One or more button-shaped areas may be displayed on a part of the display screen, and if the area is designated with a light-emitting pen, settings may be made to greatly change the display state. When not only points and lines but also two points on the screen are designated, for example, a rectangle having the diagonal lines may be displayed, or the area may be filled with a specific color. Further, when a character is input, the input character may be recognized, and a well-formed character built in a computer circuit corresponding to the input character may be displayed. In addition, various applications such as spreadsheets and graphic drawing are possible.

The information input / output device of this embodiment has a sufficiently large screen.
The characters and figures drawn above could be viewed by as many as tens to hundreds of people, and could be used like electronic blackboards.

Further, a black matrix surrounding the periphery of each pixel may be formed on the screen 5.

[Embodiment 6] In this embodiment, a configuration is shown in which an image input device 8 reads a document or object existing on the front side of the screen 5 as image data in the information input / output device shown in FIG. The same liquid crystal electro-optical device, optical system, and light source as in Example 1 were used. In order to read a document or object on the front side of the screen 5 as image data,
It is necessary that the state in which the screen 5 transmits light and the state in which light is scattered can be variably controlled. As a configuration of the screen 5 suitable for this, a scattering mode ferroelectric liquid crystal electro-optical device or a polymer dispersed liquid crystal electro-optical device can be used.

The ferroelectric liquid crystal electro-optical device in the scattering mode is
The transmittance can be increased to about 90% without using a polarizing plate, and the scattering state can be changed by applying an electric field. In polymer dispersed liquid crystal electro-optical devices,
It has a transmittance of 80% or more, and a similar effect can be obtained. Here, a scattering mode ferroelectric liquid crystal electro-optical device was used as the screen 5.

Two 800 × 600 mm substrates having a light-transmitting electrode provided on one entire surface thereof are opposed to each other via a spacer having a diameter of 50 μm and a sealing material, with the electrode surface inside. A cell was formed, and a ferroelectric liquid crystal was injected into the cell to form a liquid crystal electro-optical device serving as the screen 5.

An information input / output device was constructed using this screen, and an image on the front side of the screen 5 was read.
Further, in order to improve the quality of the read image, a light for irradiating a subject such as a document is provided in the main body 1.

First, an original on which a drawing is drawn is attached to the front side of the screen 5, and a DC voltage is applied between the electrodes of both substrates of the liquid crystal electro-optical device constituting the screen 5.
Screen 5 became clear with 0% transmission. The original was irradiated with light by a light, and the reflected light was read by the imaging device 8 to store the image data in the storage device.

Subsequently, an AC voltage is applied to the liquid crystal electro-optical device constituting the screen 5 to make the screen 5 in a scattering state, and the image is displayed on the image data screen, which is displayed on the liquid crystal electro-optical device 3 and which is read earlier. Was. In the apparatus of the present embodiment, the object to be read by the imaging device 8 is not only the original on the screen 5 but also the object existing on the front side of the screen 5, for example, the image displayed on the screen 5 by modifying the optical system. It is also possible to read the face of the viewer and display it on the screen at the next moment.

Further, the position detecting means 6 may be provided on the screen 5. Further, a black matrix surrounding each pixel may be formed on the screen 5.

[0090]

As described in detail above, according to the present invention,
Providing an information input / output device that can change the display content of the liquid crystal electro-optical device by inputting information on the position on the screen by pointing on the screen of the projection type liquid crystal electro-optical device with a pen, finger, etc. We were able to.

The present invention also relates to a display device for displaying an image on a large-area screen large enough to be visually recognized by a large number of people.
An information input / output device that changes the display content of the display device based on the information directly input on the display surface can be provided.

Further, an information input / output device that detects a position pointed by a pen or the like on the screen and performs a corresponding display on the screen without deteriorating the quality of an image projected on the screen can be provided.

Further, it is possible to read a document or a subject existing on the front side of the screen as image data.

As described above, according to the present invention, it is possible to input information on a screen with the same feeling as writing characters or pictures on paper.

[Brief description of the drawings]

FIG. 1 shows an example of a conceptual diagram of an information input / output device of the present invention.

FIG. 2 shows an example of another conceptual diagram of the information input / output device of the present invention.

FIG. 3 illustrates a manufacturing process of a thin film transistor.

FIG. 4 illustrates a manufacturing process of a thin film transistor.

FIG. 5 shows a typical configuration of a position detecting means.

FIG. 6 is a conceptual diagram of a liquid crystal electro-optical device manufactured in an example.

FIG. 7 shows a configuration of a liquid crystal electro-optical device section in an example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Light source 3 Liquid crystal electro-optical device 4 Optical system 5 Screen 6 Position detecting means 7 Half mirror 8 Imaging device 201 Substrate 222 Pixel electrode 230 Thin film transistor 301 Substrate 302 Counter electrode 303 Alignment film 304 Liquid crystal material 501 Infrared light source 502 Infrared sensor 700 Transmitted light

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/64 501 H04N 5/74 F 5/74 G02F 1/136 500

Claims (1)

[Claims] 1. A light source, a liquid crystal electro-optical device for receiving light from the light source, and a screen on which transmitted light from the light source is projected, wherein the liquid crystal electro-optical device includes a switching thin film transistor; A rear projector having a plurality of crystalline thin film transistors including a thin film transistor for a driving circuit.