JPH07109579B2 - Image terminal - Google Patents

Description

The present invention relates to an image terminal device for inputting and outputting image information to and from an electronic computer, and has a particularly simple structure and a highly accurate screen. The present invention relates to an image terminal device capable of detecting an upper position.

[Conventional technology]

2. Description of the Related Art Conventionally, as an image terminal device for inputting and outputting image information such as characters, symbols, and figures with an electronic computer, various configurations have been used in various fields. There is one that uses a CRT and a light pen. Fifth
The figure shows the configuration of a conventional image terminal device. In the figure, (1) is a CRT, (6) is a control circuit (CPU), (16) is a position detector, (17) is a display memory, and (18) is a CRT. driver,
(19) is a light pen. Next, the operation will be described. According to the information written in the display memory (17)
The CRT driver (18) drives the CRT (1) and emits an electron beam.
Images are displayed by raster scanning on the CRT (1) surface. While displaying this image, light pen (19)
To a position on the CRT (1) surface. When the electron beam scans beneath the tip of the light pen (19), the light pen (19) outputs a detection signal (d). On the other hand, the scanning of the electron beam is performed at a fixed cycle, so the CRT is started from the time when the electron beam starts scanning.
(1) The time until the time of scanning to the above specific position is constant. Therefore, the position detector (16) is the CRT driver (1
The light pen (19) depends on the time between the output time of the beam scanning start signal (so-called synchronization signal) (sy) output from 8) and the output time of the detection signal (d) output from the light pen (19). The position of can be detected.

[Problems to be solved by the invention]

However, the conventional image terminal device as described above is
It is not easy to align the light pen to the desired point on the image displayed on the CRT because the thickness of the glass on the front of the screen is thick, and the light pen does not react in the low brightness area of the screen. There was a problem that the position could not be detected.

The present invention has been made to solve such a problem, and the position on the screen can be detected by detecting a predetermined signal voltage applied to the linear electrode of the liquid crystal cell, and thus a simple structure is provided. In addition, an object of the present invention is to obtain an image terminal device capable of highly accurate position detection.

[Means for solving problems]

An image terminal device according to the present invention has a liquid crystal between two parallel light transmitting plates, and a plurality of linear lines are formed on the liquid crystal side surface between the light transmitting plates in a direction orthogonal to each other through the liquid crystal. A liquid crystal cell having electrodes attached thereto, a drive means for uniformly and periodically applying a display signal voltage and a position detection signal voltage to each of the horizontal and vertical electrodes of the linear electrode, and the liquid crystal cell Detection means for detecting by capacitive coupling the signal voltage applied to the linear electrodes by being close to the surface of the electrode, the position detection signal voltage is applied to the horizontal electrodes and the vertical electrodes, and All of them are sequentially applied at the same time without being superimposed, and the position detecting signal voltage detected by the detecting means is synchronized with the timing of the position detecting signal voltage generated by the driving means. Sequential ratio It is obtained to detect the position of the detecting means on the liquid crystal cell by.

[Action]

In the image terminal device according to the present invention, since the display and position detection signal voltages are applied to the respective linear electrodes of the liquid crystal cell, the intersections of the horizontal and vertical electrodes to which the display signal voltage is applied are colored to form an image. Is displayed, and the position detecting means detects the signal voltage for position detection applied to each of the horizontal and vertical electrodes and detects the timing of the detection voltage from both electrodes to detect the position. You can That is, since signal voltages for display and position detection are centrally applied to the horizontal and vertical electrodes to perform liquid crystal display and position detection, the display position can be detected with high accuracy.

Example of Invention

An embodiment of the present invention will be described below in detail with reference to FIGS.

FIG. 1 is a block diagram showing an image terminal device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the structure of a liquid crystal cell (1) in FIG. In Figures 1 and 2, (1)
Is a liquid crystal cell composed of a liquid crystal (10) having electro-optical effect characteristics, a sealing material (11) for sealing the liquid crystal (10), and glass plates (light transmitting plates) (12) (13) on both sides. . Since the liquid crystal (10) enclosed in the liquid crystal cell (1) has a large electro-optical effect characteristic, the output signals of the drive circuits (4) and (5) may be small, and the drive circuit (4) ( The configuration of 5) may be simple. (2) (3)
Is a linear electrode adhered to the glass plates (12) and (13) of this liquid crystal cell (1), of which (2) is the liquid crystal cell (1)
The electrodes (vertical electrodes) and (3) attached to the inner surface (flow crystal side surface) of one of the glass plates (12) are the liquid crystal cell (1).
Electrodes (horizontal electrodes) which are attached to the inner surface (liquid crystal side surface) of the other glass plate (13) so as to be orthogonal to the electrode (2) through the liquid crystal (10). (2)
The material of (3) is a nesa film, a transparent conductive film made of ITO (indium oxide / tin oxide), or aluminum whose width is sufficiently smaller than the deposition interval length on each glass plate (12) (13) of each electrode. It is formed by a vapor deposition film or the like. (4) and (5) are drive circuits connected to the electrodes (2) and (3), respectively, and these drive circuits (4) and (5) are selective to the connected electrodes (2) and (3). A predetermined drive signal voltage is applied to. Reference numeral (6) is a control circuit for controlling these drive circuits (4) and (5), and controls so that a signal voltage can be sequentially applied to the electrodes (2) and (3) from the drive circuits (4) and (5), respectively. To do. On the other hand, in the detecting means, the tip of the sensor (7) is applied to the surface of the liquid crystal cell (1), and the drive voltage signal applied to each electrode (2) (3) is applied to the glass plate (12) or the glass plate (12). This is a part to be detected by capacitively coupling through the electrostatic capacity of the liquid crystal (10). The amplifier (8) converts the signal from the sensor (7) into a voltage of a predetermined magnitude and outputs it to the control unit (6). The image terminal device of the present invention configured as described above includes a drive circuit (4)
It is divided into a display mode and a position detection mode according to the time width of the signal applied from (5) to each electrode (2) and (3). It functions as an image display device in the display mode and as a tablet device in the position detection mode. work.

FIG. 3 shows the electrodes (2) from the driving device in FIG.
FIG. 3 is a diagram showing the types of signals applied to (3) in a time chart, in which a display signal Sout (driving signal) and a position detection signal Sin are periodically or regularly arranged as shown in the figure. 4) Output from (5).

Next, the operation of the image terminal device of the present invention having the above configuration will be described. In the present device, the display mode and the position detection mode are sorted by the two kinds of signals as described above, and the display mode will be described below. Drive circuit (4) (5)
When a voltage is applied between the electrodes (2) and (3) and the time average value Vd of the absolute value of the potential difference is sufficiently larger than the threshold value Vth necessary for changing the molecular orientation of the liquid crystal (10), the liquid crystal ( In 10), the selected pixel is colored, and if it is smaller than the threshold value Vth, it remains transparent, that is, it is not colored. That is, in FIG. Then, if the length of time To is determined so that Vd> Vth in the selected pixel and Vd <Vth in the non-selected pixel,
Works as an image display device.

Next, the position detection mode will be described. A signal as shown in FIG. 3 is applied to all the electrodes (2) and (3) on the liquid crystal cell (1). Display ON / OFF of each pixel, which is the intersection of the electrodes (2) and (3), depends on only the length of the application time To of the display signal to the electrodes (2) and (3) as described above. The determined position detection signal Sin shown in the figure is applied to all electrodes (2) and (3) for Ti only during a certain time Tint. The position detection signal Sin is applied to all electrodes (2) (3).
No electrodes are overlapped at the same time.

Now, the sensor (7) which is brought close to the liquid crystal cell (1) is the capacitance of the glass plate (12) with the electrode (2) and the capacitance of the glass plate (12) and the liquid crystal (10) with the electrode (3). A voltage corresponding to the position detection signal Sin detected by the electrodes (2) and (3) is output from the sensor (7). This is led to the amplifier (8) and amplified to an appropriate voltage. The output signal of the amplifier (8) is sequentially compared in synchronism with the timing of the position detection signal Sin between the electrodes (2) and (3) corresponding to all the pixels, whereby the sensor (7) It is possible to detect the intersection position of the electrode (2) and the electrode (3) where

FIG. 4 is a sectional view showing another embodiment of the liquid crystal cell according to the present invention. Polarizing plates are provided on the surfaces of the glass plates (12) and (13) described on both surfaces of the medium shown in FIG. It is a combination of (14) and (15). Such superposition of the polarizing plates (14) (15) and the liquid crystal (10) is
Depending on whether the display image is positive or negative, the polarization direction may be orthogonal or parallel to the initial alignment of the liquid crystal (10).

In this embodiment, the case of a transmissive display device is shown.
The light source that emits the light L is placed on the side opposite to the eye E, but in order to realize a reflective display device, a reflector is attached to the polarizing plate (14) on the side opposite to the eye E, and the light source is the same as the eye E. Put it on your side.

Also, if a 3-color filter having a pattern corresponding to the electrodes (2) and (3) is attached on the glass plates (12) and (13) of the liquid crystal (10), an image having an input / output function for color images can be easily obtained. A display terminal device is obtained.

〔The invention's effect〕

As described above, according to the present invention, a liquid crystal cell having horizontal and vertical linear electrodes is provided, and an image is displayed by centrally applying signal voltages for display and position detection to the linear electrodes. Since it is configured to display and detect the position on the screen, it is possible to improve the detection accuracy of the display position and realize an image terminal device without false detection. Further, the device is simple because it does not need to prepare a special device for realizing the position detection function and the display function, and only needs to add a few drive circuits, detection circuits, and detection circuits and to prepare one sensor. There are many effects such as becoming.

[Brief description of drawings]

FIG. 1 is a block diagram showing an image terminal device according to an embodiment of the present invention, FIG. 2 is a sectional view showing the structure of the liquid crystal cell in FIG. 1, and FIG. 3 is a linear electrode of the liquid crystal cell in FIG. FIG. 4 is a waveform diagram showing an example of the waveform of the signal voltage applied to, FIG. 4 is a sectional view showing another embodiment of the liquid crystal cell of the present invention, and FIG. 5 is a configuration diagram showing a conventional image terminal device. In the figure, (1) is a liquid crystal cell, (2) is a linear electrode (vertical electrode), (3) is a linear electrode (horizontal electrode), (4) and (5).
Is a drive circuit (drive means), (6) is a control circuit, (7) is a sensor (detection means), (8) is an amplifier (detection means),
(10) is a liquid crystal, (11) is a sealing material, (12) and (13) are glass plates (light transmitting plates). The same reference numerals in the drawings indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-208877 (JP, A) JP-A-57-199035 (JP, A) Actual development Sho-60-158246 (JP, U)

Claims (1)

[Claims] 1. A liquid crystal is provided between two parallel light transmitting plates,
Further, for a liquid crystal cell in which a plurality of linear electrodes are coated on the liquid crystal side surface between the light transmitting plates in directions orthogonal to each other through the liquid crystal, and for each horizontal electrode and vertical electrode of the linear electrodes, Driving means for uniformly and periodically applying the display signal voltage and the position detection signal voltage, and the signal voltage applied to the linear electrode by proximity to the surface of the liquid crystal cell are detected by capacitive coupling. And a detection means for performing the position detection signal voltage to the horizontal electrodes and the vertical electrodes,
The timing of the position detection signal voltage generated by the drive means is applied to all of these electrodes at the same time without being superimposed, and the position detection signal voltage detected by the detection means is applied. An image terminal device characterized by being configured to detect the position of the detecting means on the liquid crystal cell by sequentially comparing in synchronism with.