WO2014021479A1

WO2014021479A1 - Display device capable of optical pointing input

Info

Publication number: WO2014021479A1
Application number: PCT/KR2012/006068
Authority: WO
Inventors: 김성환; 안상진
Original assignee: 서울시립대학교 산학협력단
Priority date: 2012-07-30
Filing date: 2012-07-30
Publication date: 2014-02-06

Abstract

The present invention relates to a display device capable of optical pointing input, the display device comprising a screen unit in which unit recognition elements constituted by optical sensors are arranged according to a predetermined arrangement rule, each optical sensor including a thin film transistor and a light-receiving diode connected to a signal output part of the thin film transistor; and a driving/recognition unit for recognizing the point at which light is input using a change in the output voltage characteristics of the thin film transistor, caused by a change in the value of electric resistance of the light-receiving diode when light is input to the screen unit from an external source. When the light input to the screen unit causes a change in the output voltage characteristics of three or more unit recognition elements, the driving/recognition unit detects the three unit recognition elements which output the largest change in the voltage characteristics, and recognizes the point at which the light is input, using the arrangement rule of the unit recognition elements and a triangulation method.

Description

Display device capable of optical pointing input

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device capable of optical pointing input, and more particularly, to an optical sensor including a thin film transistor and a light receiving diode connected to a signal output part thereof, wherein the unit recognition element constituted by the optical sensor has a predetermined arrangement rule. In accordance with the screen unit disposed along, various execution commands can be input through a laser pointer, and in particular, optical pointing position recognition is configured to enable accurate optical pointing input to optical input generated in a plurality of unit recognition elements using triangulation. This relates to a possible display device.

TV, the most popular medium for the general public, has recently evolved into an interactive concept called IPTV (Internet Protocol Television). By utilizing the characteristics of IPTV's two-way information transmission, learners can effectively build an active learning environment for learners, and many experts point to the education content market as the most competitive market in the new media market, IPTV.

However, in order to enhance the effectiveness of the educational content using IPTV, the active participation of the trainees must be ensured, and for this purpose, a pointing device capable of efficiently communicating the intentions of the trainees to the education subjects must be guaranteed.

Here, the pointing device refers to a device that designates a specific position on the display and detects the position to use as an input signal. The most common example of a pointing device is a laser pointer used for a presentation. Until now, a laser pointer shows only a pointed position, and unlike other devices, there is a technical limitation that cannot be used as an input device.

In order to overcome these technical limitations, a display device capable of an optical pointing input has been proposed. 1 is a diagram illustrating an arrangement structure of optical fibers formed on a screen portion of a display device capable of optical pointing input according to an example of the related art.

According to the related art, a display device capable of optical pointing input includes a grating type optical fiber that recognizes and transmits an optical input to a screen unit as shown in FIG. 1 in order to recognize an optical input from a laser pointer on a screen unit. It is configured so that the laser pointer can accurately recognize the coordinates of the current point.

An optical fiber is an optical device having excellent light transmission characteristics, and when light is input from one end, the light is transmitted to the other end with almost no loss. Therefore, when the optical fiber is arrayed as shown in FIG. It performs the same function as the sensor that informs you of the position of.

FIG. 2 is a diagram illustrating a principle of recognizing a light input position on a screen portion of a display device capable of light pointing input according to an example of the related art.

As shown in Fig. 2, the horizontal detection elements Dx1, ..., Dxn provided on the horizontal side of the optical fiber arranged in a lattice shape and the vertical detection elements Dy1, ..., Dyn provided on the vertical side are specified on the screen portion. When there is an optical input at the point P, signals of a Gaussian distribution having a maximum value are detected at the detection elements Dyp and Dxp, respectively. The coordinates of the intersection point P corresponding to the maximum value can be calculated from this detection signal, and the coordinates of this intersection point P will be recognized as the coordinates of the point to which the laser point is pointing (pointing).

However, the display apparatus according to the related art has a problem in that mass production is difficult, manufacturing costs are high, and operation errors are frequently generated due to scattering noise generated in the process of inputting light into the optical fiber.

In addition, the display device according to the related art has a problem in that it is not possible to receive various execution commands by an optical signal from a laser pointer.

SUMMARY OF THE INVENTION An object of the present invention for solving the problems according to the prior art is to configure an optical sensor including a thin film transistor and a light receiving diode connected to the signal output unit, and the unit recognition element constituted by the optical sensor is arranged according to a predetermined arrangement rule. It is equipped with a screen portion, various execution commands can be input through the laser pointer, in particular, it is possible to recognize the optical pointing position configured to enable accurate optical pointing input to the optical input generated in the plurality of unit recognition elements using triangulation method In providing a display device.

According to an aspect of the present invention for achieving the above object, a screen unit in which a unit recognition element consisting of an optical sensor is arranged according to a predetermined arrangement rule-the optical sensor is connected to the thin film transistor and the signal output of the thin film transistor Consisting of a light receiving diode; And a driving / recognition for recognizing a position at which the light is input using a change in the output voltage characteristic of the thin film transistor, which is generated when the light from the outside is input to the screen unit, according to a change in the electrical resistance value of the light receiving diode. And a unit, wherein the driving / recognition unit outputs the largest voltage characteristic change when the light input to the screen unit generates output voltage characteristic changes to three or more unit recognition elements. And a display apparatus capable of optical pointing input configured to recognize a position at which light is input using the arrangement rule of the unit recognition element and triangulation.

Preferably, the present invention is characterized in that, when light is input to the unit recognition element, the electrical resistance of the light receiving diode is lowered.

The thin film transistor may be a MOS field effect transistor composed of a conductor, an insulator, and an amorphous silicon.

In addition, the light-emitting diode has a structure in which a layer to which an impurity of a Group 3 element is added, an amorphous silicon layer, and a layer to which an Impurity of a Group 5 element is added are sequentially stacked.

In addition, the light from the outside is characterized in that it has a wavelength of 380nm to 770nm.

The present invention may further include a counter unit for counting the number of times per unit time of the voltage signal output from the unit recognition element.

In addition, the light from the outside is frequency-modulated by a pulse generator, the number of times per unit time of the voltage signal is characterized in that it changes according to the frequency of the light from the outside.

Preferably, the present invention detects three unit recognition elements that output the largest voltage characteristic change, generates each virtual circle centered on each unit recognition element, and generates the shortest distance from each center point of the three circles. Characterized in that configured to recognize the position of the intersection forming the light input position.

According to the present invention, there is provided an optical sensor including a thin film transistor and a light-receiving diode connected to the signal output unit, and the unit pointer comprising the optical sensor is provided with a screen unit arranged according to a certain arrangement rule, so that the laser pointer is currently instructed. By accurately recognizing the coordinates of the location, the screen of the display device can be used as an input tool together with an output tool. In addition, various execution commands through the laser pointer may be input through the screen unit of the display device. In addition, by applying the TFT-LCD batch process, it can be mass-produced at low cost and has the advantage of being implanted in an active matrix flat panel display.

In particular, the present invention is configured to enable accurate optical pointing input to optical input generated in a plurality of unit recognition elements by using triangulation, so that the arrangement rule (interval and number) of the optical scanning area of the laser pointer and the optical sensor can be properly adjusted. By adjusting, the number of arrangements of the optical sensors can be minimized, thereby providing a further improved effect on production and economics of the product.

1 is a view illustrating an arrangement structure of optical fibers formed on a screen portion of a display device capable of optical pointing input according to an example of the prior art;

2 is a view for explaining a principle of recognizing a light input position on a screen portion of a display device capable of optical pointing input according to an example of the prior art;

3 is a plan view showing a screen portion of a display device capable of optical pointing input according to an embodiment of the present invention;

4 is a view for explaining an operation principle when an optical signal is applied on the screen of the display device capable of optical pointing input according to an embodiment of the present invention;

5a and 5b are views showing a vertical cut surface of the unit recognition element in the screen unit according to an embodiment of the present invention,

6 is a functional block diagram of a laser pointer device used for input of an optical signal to a display device capable of optical pointing input according to an embodiment of the present invention;

7 is a view for explaining an operation according to an input of an optical signal in a display device capable of an optical pointing input according to an embodiment of the present invention;

8 is a view for explaining the concept of the triangulation method used in the display device capable of optical pointing input according to an embodiment of the present invention;

9 is a cross-sectional view conceptually illustrating a display device capable of an optical pointing input according to an embodiment of the present invention.

The present invention can be embodied in many other forms without departing from the spirit or main features thereof. Therefore, the embodiments of the present invention are merely examples in all respects and should not be interpreted limitedly.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise", "comprise", "have", and the like are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification. Or other features or numbers, steps, operations, components, parts or combinations thereof in any way should not be excluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be denoted by the same reference numerals regardless of the reference numerals and redundant description thereof will be omitted. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

3 is a plan view illustrating a screen portion of a display device capable of optical pointing input according to an embodiment of the present invention.

Referring to FIG. 3, the screen unit of the display device capable of optical pointing input according to the present invention may include a gate electrode 21, a data electrode 22, and a voltage for controlling 'on / off' of a thin film transistor TFT. And a drive / recognition unit 10 which drives the thin film transistor and recognizes the light input. On the other hand, in practicing the present invention, it is preferable that the TFT is a MOS type field effect transistor composed of a conductor-insulator-amorphous silicon.

The unit recognition element 20 exists at the point where the gate electrode 21 and the data electrode 22 intersect, and the input of the optical signal to the local area is converted into an electrical signal through the unit recognition element 20.

Specifically, the unit recognition element 20 is composed of one gate electrode 21 and one data electrode 22 formed in duplicate. The data electrode 22 is a data electrode 22 applied to both a TFT and a light receiving diode, and is composed of a first data electrode 201, a second data electrode 202, and a third data electrode 203.

The first data electrode 201 is a data signal input electrode of a TFT, the second data electrode 202 is a data signal output electrode of a TFT and at the same time a signal input electrode of a light receiving diode, and the third data electrode 203 is Corresponds to the signal output electrode of the light-receiving diode.

That is, the second data electrode 202 performs the function of the electrode of the data signal output part of the TFT and the signal input part electrode of the light receiving diode, thereby outputting by the TFT when the electric resistance value of the light receiving diode is changed by light input from the outside. The characteristics of the voltage to be changed.

Specifically, when the gate signal and the data signal from the driving / recognition unit 10 are input to the TFT of the unit recognition element 20 of the specific region, the TFT is turned on and thus the first data which is the data signal input electrode. Current flows through the electrode 201 and the second data electrode 202, which is a signal input electrode of the data signal output electrode and the light receiving diode.

In this state, when an optical signal is applied to the unit recognition element 20 of a specific region, the electrical resistance of the light receiving diode is lowered, and as a result, a current is generated between the second data electrode 202 and the third data electrode 203. Will flow. On the other hand, if the optical signal is not applied, the resistance value between the second data electrode 202 and the third data electrode 203 is increased to be electrically opened.

Hereinafter, referring to FIG. 4, an operation principle of a display device capable of optical pointing input according to the present invention when an optical signal is applied to the unit recognition element 20 will be described.

When the light emitted from the laser pointer 40 is irradiated to the screen unit 70 in which the unit recognition element 20 composed of the TFT and the light receiving diode is arranged in a lattice form, the unit recognition element in the region to which the optical signal is applied as described above The resistance value of the light receiving diode constituting (20) decreases.

Specifically, the light emitting diode layer constituting the unit recognition element 20 of the screen unit 70 may include a p-type semiconductor layer 36 made of amorphous silicon (a-Si) to which impurities of group 3 elements are added, and an amorphous silicon ( an intrinsic semiconductor layer made of a-Si) and an n-type semiconductor layer made of amorphous silicon (a-Si) to which impurity of a Group 5 element is added, and whether or not an optical signal is applied to the unit recognition element 20. Depending on the amount of charge generated.

That is, as can be seen through the operation state diagram 25 showing the operation state of the TFT according to the presence / absence of the optical signal applied to the unit recognition element 20, the unit recognition with the light signal (Light-On) The light-emitting diode layer of the element 20 increases the amount of charge, thereby reducing the resistance value, and the light-off diode layer of the light-off unit recognition element 20 has a low amount of charge. The value will increase.

In this case, when the driving / recognition unit 10 oscillates the gate signal and the data signal to drive the TFT of the unit recognition element, as shown in the voltage state diagram 27, the voltage is changed depending on whether the optical signal is applied or not. The output waveform will be different.

That is, the electric resistance value of the light-receiving diode layer decreases in the unit recognition element 20 to which the optical signal is applied, so that the waveform of the output voltage of the TFT appears high, but the light-receiving diode is applied to the unit recognition element 20 to which the optical signal is not applied. The resistance value of the layer increases, so that the waveform of the output voltage of the TFT appears low. As a result, the presence or absence of the input of the optical signal in the unit recognition element 20 can be confirmed by changing the height of the output voltage of the TFT in the unit recognition element 20.

8 is a view for explaining the concept of the triangulation method used in the display device capable of optical pointing input according to an embodiment of the present invention.

In the display device capable of optical pointing input according to the present embodiment, an optical sensor constituting a unit recognition element is disposed, and the arrangement of the unit recognition elements may be a dense lattice, a lattice, an oblique lattice, an arbitrary arrangement, or the like. The arrangement rule (interval and number) depends on resolution and economy.

When the arrangement rule is determined and, for example, the optical sensors P1, P2, and P3 are arranged in an arbitrary space, when the laser input having a wide scan area is scanned, the input value (change in output voltage characteristic of the thin film transistor) is Three high optical sensors P1, P2, P3 are detected, and each of P1, P2, P3 has an input intensity according to the intensity of light.

The positions of P1, P2, and P3 can be determined by a predetermined arrangement rule (interval and number) of the optical sensor, and each imaginary circle centering on P1, P2, and P3 is shown in FIG. 8 according to the input intensity. You can make it together. The position of the intersection which forms the shortest distance from each center point of the three circles can be calculated using triangulation. The intersection thus calculated is regarded as the input coordinate. In the example where three circles meet at one intersection as shown in FIG. 8, the point B at which the three circles overlap is an intersection.

Triangulation method is a method of accurately determining the position between each point by applying a triangulation method, taking the example of Figure 8, by accurately measuring one side of the triangle (P1-P2 line, the base line in Figure 8), and determines both ends of the base line In FIG. 8, the positions of the intersection points (B points in FIG. 8) may be obtained by determining the points (B points in FIG. 8) connected to each other to measure the angles formed by both ends of the base line and the triangular points.

Meanwhile, in the embodiment of the present invention, the screen unit 70 may not only check whether the optical signal is input to the specific unit recognition element 20, but also classify the optical signal according to the frequency of the input optical signal. In this case, the display apparatus according to the present invention may perform different operations according to the type of the optical signal.

To this end, in the practice of the present invention, the laser pointer 40 is preferably manufactured to control the waveform of the output optical signal within a predetermined frequency range (for example, 1 ~ 60Hz range), for example For example, when the left button provided on the laser pointer 40 is clicked, an optical signal of 10 Hz is output, when the right button is clicked, an optical signal of 6 Hz is output, and when the scroll wheel is turned, an optical signal of 30 Hz is output. can do.

Referring again to FIG. 4, an optical signal having a specific frequency output from the laser pointer 40 is applied to the unit recognition element 20 of the screen unit 70 to generate a voltage signal in the voltage state diagram 27. The generated voltage signal is input to the counter unit 50.

On the other hand, the counter unit 50 counters the number of times of the voltage signal output from the unit recognition element 20 per unit time, so that the left button click (10 Hz), right button click (6 Hz), scroll wheel ( 30Hz).

By distinguishing and recognizing the frequencies of the optical signals applied to the specific unit recognition element 20 as described above, the display device capable of optical pointing input according to the present invention can perform different operations according to the input frequencies. .

5A and 5B are views showing a vertical cut plane of the unit recognition element in the screen unit according to the present invention. 5A illustrates an example of a structure by a basic process, and FIG. 5B illustrates a structure by a process capable of reducing the number of photoetch masks.

Referring to FIG. 5A, in the manufacturing process of the screen unit 70 according to a basic process, a metal is deposited on the glass substrate 30 and then the pattern is etched to etch the light blocking film 311 of the gate electrode 310 and the light receiving diode. Make

After that, through the continuous process, the insulating film 32, the intrinsic semiconductor layer 33 made of amorphous silicon (a-Si), and the n-type semiconductor layer 34 made of amorphous silicon (a-Si) to which impurities of the Group 5 element were added. 35 is deposited successively, and the pattern of the active layer is etched.

Next, the pattern is etched after the first data electrode 201 and the second data electrode 202 are deposited, and the n-type semiconductor layer 34 made of amorphous silicon (a-Si) to which impurities of group 5 elements are added. And 35, the p-type semiconductor layer 36 made of amorphous silicon (a-Si) to which the impurities of the group 3 element are added is stacked.

Next, the data electrode (third data electrode) 203 of the light-receiving diode is deposited, the pattern is etched, and the passivation (SiNx) layer 38 is deposited. Next, a metal thin film layer for the light blocking film 37 of the TFT is stacked, followed by pattern etching, and a final passivation (SiNx) layer 39 is deposited.

Referring to FIG. 5B, in the manufacturing process of the screen unit 70 by reducing the number of photoetch masks, the gate electrode 310 made of a conductor on the glass substrate 30 and the light blocking film of the light receiving diode ( 311), a gate electrode pattern formed by an etching process is formed (Mask 1).

Then, the insulating film 32, the intrinsic semiconductor layer 330 made of amorphous silicon (a-Si), and the n-type semiconductor layers 34 and 350 made of amorphous silicon (a-Si) to which impurities of the Group 5 element are added are successively. After deposition, an active pattern is formed by an etching process (Mask 2).

Next, after depositing the first data electrode 201 and the second data electrode 202, which are data electrodes composed of a conductor, a first data pattern is formed by an etching process (Mask 3).

Subsequently, an etching process of a film made of amorphous silicon to which n-type impurities are added between the first data electrode 201 and the second data electrode 202 is performed to secure operating characteristics of the channel. P-type semiconductor layer 36 made of added amorphous silicon (a-Si), intrinsic semiconductor layer 331 made of amorphous silicon (a-Si), amorphous silicon (a-Si) to which impurities of group 5 elements are added A triple film composed of an n-type semiconductor layer 351 is continuously deposited.

As a result, the light-emitting diode according to the present invention has a structure in which a layer to which an impurity of a group 3 element is added, an amorphous silicon layer, and a layer to which an impurity of a Group 5 element are added are sequentially stacked.

Then, a photosensitive diode pattern for signal output of the photodiode is formed through an etching process (Mask 4), and then a metal thin film for the third data electrode 203 composed of a conductor and the light blocking layer 37 of the TFT is deposited. Thereafter, a second data pattern formed by an etching process is formed (Mask 5). The process is then completed by depositing a passivation (SiNx) layer 38.

6 is a functional block diagram of a laser pointer device used for input of an optical signal to a display device capable of optical pointing input according to the present invention. Referring to FIG. 6, a display device capable of an optical pointing input according to the present invention includes a pulse generator 41, an optical cutter 42, and a light source 45.

The optical signal 43 before the frequency modulation generated by the light source 45 of the laser pointer 40 is transmitted to the pulse generator 41 in the form of a continuous beam. When the pulse generator 41 transmits an electric signal having a predetermined range of frequencies to the optical cutter 42, the optical cutter 42 emits a continuous beam of light from the light source 45 of the pulse generator 41. The pulse is converted into a pulse having a frequency equal to the frequency. In practicing the present invention, the optical cutter 42 may be an optical switch made of a liquid crystal cell.

In addition, in the practice of the present invention, it is preferable that the optical signal applied from the pulse generator 41 to the screen portion of the display device according to the present invention has a wavelength of 380 nm to 770 nm. That is, since the wavelength range of visible light recognized by the eye generally corresponds to a range of 380 nm to 770 nm, it is preferable to have a wavelength range of 380 nm to 770 nm, which is a visible light region, in order for the point to be recognized by the user.

7 is a view illustrating an operation according to an input of an optical signal in a display device capable of an optical pointing input according to the present invention. In describing the operation according to the input of the optical signal in the display apparatus capable of the optical pointing input in FIG. 7, the case of driving the XGA (1024 × 768) resolution at 60 Hz is taken as an example.

The timing controller 53 of the driving / recognition unit 10 included in the display device capable of optical pointing input according to the present invention generates a clock signal 501 for timing a flat panel display such as a TFT-LCD. The clock signal 501 is transmitted to the gate driving IC 51, the data driving IC 52, the counter 50, and the processor 54 to serve as a time reference for the overall signal processing.

On the other hand, the gate signal generated in synchronization with the clock signal in the timing controller 53 is switched to the gate applied voltage of the TFT in the gate driver IC 51. The gate voltage signal 511 is transmitted to the gate electrode and the counter unit 50 in the corresponding row. Therefore, in the case of 60 Hz driving, 768 gate signals are sequentially applied to the counter unit 50 during one frame. The signal separating the frame from the frame is generated by the timing controller 53.

The data signal generated in synchronization with the clock signal in the timing controller 53 is switched to the data application pressure of the TFT in the data driver IC 52. The data voltage signal 521 is transmitted to the data electrode of the corresponding column and the counter unit 50. Therefore, in the case of 60Hz driving, 768 gate signals are sequentially applied, and when 1024 gate signals are applied, the 1024 data signals are sequentially applied to the counter unit 50.

The signal 531 of the pixel output from the screen is input to the counter unit 50. Therefore, the clock signal 501, the gate drive driving signal 511, and the data drive driving signal 521 are input to the counter together with the pixel signal 531. In the counter, the input signal is a clock signal 501 for dividing a frame, a gate signal 511 for dividing a row from a row, an optical signal by performing an AND operation of the data signal 521 and a signal 531 of a pixel. The preprocessing signal 532 composed of the input data signal is switched.

On the other hand, the preprocessing signal 532 is converted to Low Voltage Differential Signaling (LVDS), Reduced Swing Differential Signaling (RSDS), or the like, which is a signal 55 that is transmitted to the processor 54 and can be processed as an output in a display.

For reference, as is well known to those skilled in the art, a signal basically required for driving an active matrix display is a clock signal, which is a signal that distinguishes a frame from a frame, and one frame. Is a data signal associated with all columns corresponding to each row while the gate signal is applied.

Here, the general display device expresses the contrast using the voltage size of the data signal. In the present invention, the optical signal input from the outside is converted into an on / off data signal. Therefore, the display device according to the present invention follows the exact same standard as the display driving signal system which is generally used.

The state in which the screen portion of this embodiment is installed in a general TFT-LCD display device will be described by way of example.

As shown in FIG. 9, the LCD panel LP includes a liquid crystal layer 1000 formed between the first substrate 4000 and the second substrate 2000 and between the first substrate 4000 and the second substrate 2000. It consists of. The first substrate 4000 is a thin film transistor (TFT) array substrate which is a driving element. Although not shown in the drawing, a plurality of pixels are formed in the first substrate 4000 in a lattice arrangement, for example, and a driving element such as a TFT is formed in each pixel. The second substrate 2000 is a color filter substrate, and a color filter layer for real color is formed. In addition, a pixel electrode and a common electrode are formed on the first substrate 4000 and the second substrate 2000, respectively, and an alignment layer for aligning liquid crystal molecules of the liquid crystal layer 1000 is coated.

The first substrate 4000 and the second substrate 2000 are bonded by a sealing material 3000, and a liquid crystal layer 1000 is formed therebetween to form a TFT formed on the first substrate 4000. By driving the liquid crystal molecules by controlling the amount of light passing through the liquid crystal layer, information is displayed.

The screen unit 70 of the present embodiment may be formed, for example, between the first substrate 4000 and the liquid crystal layer 1000. The arrangement of the unit recognition elements of the screen unit 70 may be performed in the same manner as the TFT array of the first substrate 4000, or may take a lattice structure and use fewer optical sensors than the TFT array of the first substrate 4000. It may be formed in a regular arrangement.

Basic driving of the TFT of the screen unit 70 may be performed together with the driving unit of the first substrate 4000. However, unlike the first substrate 4000, a data signal for pixel control is unnecessary.

On the other hand, when the arrangement of the unit recognition elements of the screen unit 70 takes a lattice structure and forms fewer optical sensors in a regular arrangement than the TFT array of the first substrate 4000, the screen unit 70 The separate drive control may be performed by the driving / recognition unit 10 as a whole.

While the above has been shown and described with respect to preferred embodiments and applications of the present invention, the present invention is not limited to the specific embodiments and applications described above, the invention without departing from the gist of the invention claimed in the claims Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims

A screen unit in which a unit recognition element composed of an optical sensor is disposed according to a predetermined arrangement rule, wherein the optical sensor comprises a thin film transistor and a light receiving diode connected to a signal output of the thin film transistor; And

When light from the outside is input to the screen unit, a driving / recognition unit that recognizes a position where the light is input using a change in output voltage characteristic of the thin film transistor, which is generated according to a change in an electrical resistance value of the light receiving diode. Consisting of;

When the light input to the screen unit generates an output voltage characteristic change in three or more unit recognition elements, the driving / recognition unit detects three unit recognition elements that output the largest voltage characteristic change, And a light pointing input configured to recognize a position at which light is input using the alignment rule and the triangulation method.
The method of claim 1,

And a light input to the unit recognition element, wherein the electrical resistance of the light receiving diode is lowered.
The method of claim 1,

And the thin film transistor is a MOS type field effect transistor composed of a conductor, an insulator, and an amorphous silicon.
The method of claim 1,

And the light receiving diode has a structure in which a layer to which an impurity of a Group 3 element is added, an amorphous silicon layer, and a layer to which an Impurity of a Group 5 element is added are sequentially stacked.
The method of claim 1,

And the light from the outside has a wavelength of 380 nm to 770 nm.
The method of claim 1,

And a counter unit for counting the number of times per unit time of the voltage signal output from the unit recognition element.
The method of claim 6,

The light from the outside is frequency-modulated by a pulse generator, and the number of times of the voltage signal per unit time is a display device capable of optical pointing input, characterized in that it changes in accordance with the frequency of the light from the outside.
The method of claim 1,

Detects three unit recognition elements that output the largest voltage characteristic change, generates each virtual circle centered on each unit recognition element, and locates the intersection of the shortest distance from each center point of the three circles. And a light pointing input configured to recognize light as an input position.