KR101726629B1 - Method For Detecting Touch - Google Patents

Abstract

The present invention relates to a corner reflection correction of an optical input device that prevents a touch recognition error due to reflection when a touch is generated in the vicinity of a light receiving unit. A first step of driving each of the infrared sensor modules, a second step of sensing the amount of light from each of the infrared sensor modules, A third step of determining whether a pixel whose light amount is sensed is a corner part, a fourth step of determining whether the sensed pixel is a corner part, And a fifth step of determining that the sensed pixel is a single touch when the amount of light with respect to the threshold value in the neighboring pixels includes low / high / low when the sensed pixel is a corner portion.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for detecting a touch,

The present invention relates to an optical input device, and more particularly to a touch detection method for preventing a touch recognition error due to reflections when a touch is generated in the vicinity of a light receiving portion (sensor portion).

In general, a touch screen is one of various methods of configuring an interface between an information communication device and a user using various displays, and is an input device that allows a user to interface with the device by directly touching the screen with a hand or a pen.

Since the touch screen is an input device that can be easily used by both sexes by interactively and intuitively manipulating the buttons displayed on the display by simply touching the buttons with the finger, it is now possible to use the issuance devices of banks and public offices, various medical equipment, It is applied in many fields such as guide of the institution, traffic guidance.

Such a touch screen is classified into a resistive type, a capacitive type, an ultrasonic wave type, and an infrared type depending on the method of recognition.

Although the advantages of each of the above-described methods are different from each other, in recent years, the pressure applied to the touch surface has been minimized, and an infrared touch screen has been attracting attention due to the convenience of disposition.

The infrared touch screen senses a touch by a change in the amount of received light when sensing infrared light. The infrared touch screen includes an infrared light emitting unit (not shown) for emitting infrared light, and an infrared light emitting unit And an infrared ray receiving unit (not shown) for sensing the light.

At this time, there is a problem that the accuracy of the touch detection varies depending on the approach distance of the infrared light-receiving portion irrespective of the touch.

Especially, the sensitivity of the touch detection is considerably lowered in the vicinity of the corner portion where the infrared ray receiving portion is located, and even when there is one touch at this portion, the phenomenon that the amount of received light increases due to reflection by a nail or the like and is detected by multi- Accordingly, efforts have been made to prevent errors in touch detection.

The conventional infrared touch screen has the following problems.

In a conventional infrared touch screen, a touch detection process is performed in the same manner without considering a difference in sensing sensitivity generated in each of the touch screen areas. However, when the same touch detection process is applied, there is a difference in the angular range of sensing depending on whether the touch position is adjacent to the infrared light receiving unit, even if the same area is used, and sensitivity difference of touch detection is generated.

Particularly, since the touch area is generated over an angle of a wide area when the touch is equivalent to a corner part adjacent to the light receiving part, even when a slight reflection is present in the touch area, the touch area is recognized A single touch may be mistaken for multi-touch.

The error of the touch detection due to the reflection of the corner portion can not be corrected in the conventional touch detection process, and efforts have been made to solve this problem.

It is an object of the present invention to provide a touch detection method for preventing a touch recognition error due to reflection when a touch is generated in the vicinity of a light receiving unit.

According to an aspect of the present invention, there is provided a touch detection method of an optical input device having a plurality of infrared sensor modules, each sensor unit including a plurality of pixels arranged on different corners of a display panel, A second step of sensing the amount of light from each of the infrared sensor modules, a third step of determining whether the pixel of which the amount of light is sensed is a touch, Determining whether the pixel is a corner; And a fifth step of determining, when a pixel judged as a touch is a corner part, when the light amount with respect to the threshold value in the neighboring pixels includes low / high / low, by a single touch.

The method may further include a sixth step of separately detecting the single touch and the multi-touch when the sensed light amount is less than the threshold value when the pixel judged as the touch is not a corner part in the fourth step.

In the fifth step, when the sensed light amount is lower than the threshold value in the case where the light amount with respect to the threshold value does not include low / high / low in adjacent pixels, a seventh step of discriminating the single touch and the multi- .

The corner portion is set before the first step.

And a controller for controlling the operation of the infrared sensor module based on the reflected light, wherein the setting of the corner part comprises: a step A for driving the infrared sensor modules; a step B for sensing the amount of light from the infrared sensor modules; And a step C for setting a corner portion to be observed by the multi-touch for each infrared sensor module.

In the step C, the corner is assigned to a pixel of the sensor unit in the infrared sensor module.

And a step D between the steps B and C for setting an effective angle of each infrared sensor module on the basis of the direct light received by each infrared sensor module during driving of the other infrared sensor module other than itself, The setting of the effective angle of the infrared sensor module is performed by setting a pixel that generates the direct light at a reference angle to an infrared sensor module other than itself.

The touch detection method of the present invention as described above has the following effects.

First, a corner portion where a touch error occurs due to the influence of reflection adjacent to the infrared sensor module is preliminarily set, and when the light amount is sensed with a certain tendency at the corner portion, the touch detection can be performed in the same pattern as the actual touch .

Second, the touch detection process is made different for the corner portion and the other portions, and in particular, the reflection correction algorithm is applied only to the corner portion with weak touch sensitivity, and the normal touch detection By proceeding the process, the overall touch sensitivity can be improved.

Third, it is possible to correctly correct that the single touch is observed by multi-touch by reflection based on the amount of light sensed by the infrared sensor module without physical correction.

1 is a view showing angle sensing of an infrared sensor module;
FIG. 2 is a graph showing the sensing data per pixel of the sensor unit of the infrared sensor module corresponding to P1 in FIG.
FIG. 3 is a graph showing the sensing data per pixel in the sensor section of the infrared sensor module corresponding to P2 in FIG.
4 is a view showing the touch of the corner portion in the display device of the present invention
FIG. 5 is a graph showing sensing data per pixel in the sensor unit of the infrared sensor module when touching the corner of FIG. 4
6 is a block diagram showing a display apparatus according to the present invention.
7 is a block diagram showing the touch control unit of Fig. 6
8A to 8C are plan views showing corner portions adjacent to the respective infrared sensor modules
Fig. 9 is a view showing the center two-touch in the display device of the present invention
FIG. 10 is a graph showing sensing data per pixel in the sensor unit of the infrared-ray sensor module at the time of touching in FIG. 9
11 is a flowchart showing a corner portion setting method of the display device of the present invention
12 is a flowchart showing a touch detection method of the display device of the present invention
13 is a flowchart showing a corner portion reflection correction method of FIG.

In the present invention, an optical input device refers to a display module including an infrared sensor module on a corner. In this case, the surface of the display device in the display module acts as an input surface.

First, the reason why the reflection of the corner portion of the optical input device is weak is examined, and the light amount sensing by the region is examined.

FIG. 1 is a view showing angle sensing of an infrared sensor module. FIG. 2 is a graph showing sensing data of each sensor in a sensor unit of the infrared sensor module corresponding to P1 of FIG. 1, and FIG. , And the sensing data of each pixel in the sensor unit of the infrared sensor module.

1, when the infrared sensor module 21A is disposed at the upper left corner of the display panel 10, the two sides of the adjacent display panel where the infrared sensor module 21A is located are set at 0 ° and 90 °, respectively, The infrared sensor module 21A receives the amount of light for each angle.

The infrared sensor module 21A receives infrared light and includes a sensor unit (not shown) in which a plurality of pixels are formed in a row, and the sensor unit converts an optical signal into an electrical signal, .

Accordingly, the infrared sensor module 21A can detect whether or not the amount of light received varies by angle, and the touch control unit can detect the touch position based on the angle at which the light amount falls below the threshold value.

In general, one infrared sensor module can calculate only the angle of the touch position viewed from one corner. In the optical input device, at least two infrared sensor modules are provided to calculate the angle of the touch position viewed from at least two corners, And the touch position is detected by measurement.

Here, the pixels in the sensor unit are each a kind of light receiving element, and each of the pixels corresponds to one of angles from 0 to 90 degrees, and receives light coming from the corresponding angle.

As shown in the figure, the angle between 0 deg. And 90 deg. Is divided into 9 deg. By 10 deg. At this time, if the first touch region P1 near the infrared sensor module 21A and the second touch region P2 far from the infrared sensor module 21A are examined, it can be seen that the angles of sensing ranges are different even if they are the same area .

As shown in FIG. 2, when the first touch region P1 is touched and the light amount of each pixel is sensed by the sensor portion of the first infrared sensor module 21A, It can be seen that the angle is about 38 ° to 52 ° and the amount of light in the corresponding pixels is observed to be lower than the threshold value.

3, when the light amount is sensed for each pixel in the sensor part of the first infrared sensor module 21A when the second touch area P2 is touched, the first touch area P1 It can be seen that a considerable angle of the incident light is in the range of about 42 ° to 45 °, and the light amount in the corresponding pixels is observed to be lower than the threshold value.

This is because there is light interception due to a touch at the corresponding angle in the touch area and accordingly the light amount enters the infrared sensor module 21A at a small angle at an angle corresponding to the touch.

Although the number of pixels of the sensor unit of the infrared sensor module 21A is shown as 500 in the illustrated example, the number of pixels is not limited to 500, and the number may be increased or decreased as necessary. In addition to the line sensor A two-dimensional image sensor may be used.

FIG. 4 is a diagram showing a corner touch in the display device of the present invention, and FIG. 5 is a graph showing sensing data of each pixel in a sensor portion of the infrared sensor module when the corner portion of FIG. 4 is touched.

4 shows an example in which the infrared sensor modules 21A to 21C are arranged at the three corners of the display panel 10 for the purpose of triangulating the touch position.

4 shows a case where a touch is made at a corner portion adjacent to the infrared sensor module 21A. For example, when there is a reflection of a nail or the like, or when the input device is a reflective material such as a metal, A portion B in which the amount of light is raised beyond the threshold value due to reflection occurs in the region.

That is, when the touch is normally performed, the touch area of the corner portion should be observed in a region (A) where the amount of light as a whole is lower than the threshold value with a single touch, and there is a region (B) And is observed with two touches.

This is because, as described above, since the sensing range is large even in the single touch region near the corner portion, it is greatly affected by small reflection.

Hereinafter, a corner reflection correction method of the optical input device of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 6 is a block diagram showing a display device of the present invention, and FIG. 7 is a block diagram showing a touch control section of FIG.

6 and 7, the display device of the present invention includes a display module 20 in which infrared sensor modules 21A to 21C are arranged at corners of a display panel 10 in which an image is displayed, a display module 20, (RGB) to be displayed on the display panel 10 of the display module 20 together with the timing signal to the control board 30 and the control board 30 that perform an algorithm for controlling the touch panel 30 And a system 40 for feeding.

Here, the infrared sensor modules 21A to 21C further include an infrared light source in addition to the sensor unit for sensing the light amount.

A retroreflector is formed corresponding to each side of the display panel 10 to reflect and return light emitted from the infrared light source of the infrared sensor module. The sensor unit of the infrared sensor module receives the light of each angle and transmits the light to the touch controller 32, and the touch is detected by the light amount change.

The display module 20 includes a display panel 10 on which an image is displayed, a source driver 11 for supplying a data voltage to the data lines D1 to Dm of the display panel 10, A gate driver 12 for supplying scan pulses to the gate lines G1 to Gn of the display panel 10 and infrared sensor modules 21A to 21C arranged on the corners of the display panel 10 respectively.

Although not shown, the display module 20 includes a case top (not shown) formed in a frame shape so as to surround the edge and side portions of the display panel 10 and the infrared sensor modules 21A to 21C located on the corner of the display panel And a casing structure of a bottom cover (not shown) formed to engage with the case top to house the display panel 10 from the bottom.

Although the infrared sensor modules 21A to 21C are arranged at three corners, the infrared sensor modules 21A to 21C are not limited thereto and may be formed corresponding to two or four corners.

In addition, the display panel 10 may be a flat panel display, and typically its shape is rectangular. The display panel 10 includes both substrates and an intermediate layer formed therebetween, and the display panel 10 is different in kind depending on the components and functions of the intermediate layer. For example, the liquid crystal display panel is not limited thereto, and may be any one of an electrophoretic display panel, an organic light emitting display panel, a field emission display panel, a quantum dot display panel, and a plasma display panel.

For example, when the display panel 10 is a liquid crystal panel, it includes a thin film transistor (hereinafter referred to as "TFT ") substrate and a color filter substrate. A liquid crystal layer is formed between the TFT substrate and the color filter substrate. On the TFT substrate, the data lines D1 to Dm and the gate lines G1 to Gn are formed to be orthogonal to each other on the lower glass substrate. The liquid crystal cells Clc are arranged in a matrix form in the cell regions defined by the data lines D1 to Dm and the gate lines G1 to Gn. The TFT formed at the intersection of the data lines D1 to Dm and the gate lines G1 to Gn is supplied via the data lines D1 to Dm in response to the scan pulse from the gate lines G1 to Gn To the pixel electrode of the liquid crystal cell Clc. To this end, the gate electrode of the TFT is connected to the gate lines G1 to Gn, and the source electrode thereof is connected to the data lines D1 to Dm. The drain electrode of the TFT is connected to the pixel electrode of the liquid crystal cell Clc. A common voltage (Vcom) is supplied to the common electrode facing the pixel electrode. The color filter substrate includes a black matrix and a color filter formed on the upper glass substrate.

The common electrode is formed on the upper glass substrate in a vertical electric field driving method such as a TN (Twisted Nematic) mode and a VA (Vertical Alignment) mode, and a horizontal electric field such as IPS (In Plane Switching) mode and FFS (Fringe Field Switching) Is formed on the lower glass substrate together with the pixel electrode in the driving method.

The source driver 11 includes a plurality of data integration circuits and converts the digital video data RGB input from the control board 30 into a positive or negative analog gamma compensation voltage under the control of the control board 30, And supplies the analog gamma compensation voltage to the data lines D1 to Dm as analog data voltages.

The gate driver 12 includes a plurality of gate integrated circuits and sequentially supplies scan pulses to the gate lines G1 to Gn under the control of the control board 30. [

The data integrated circuits of the source driver 11 and the gate integrated circuits of the gate driver 12 are connected to each other by tape automated bonding (TAB) using a tape carrier package (TCP) on glass (COG) method. The gate integrated circuits of the gate drive 12 may be formed directly on the lower glass substrate simultaneously with the TFTs of the display panel 10 and in the same process as the TFT process.

The control board 30 is connected to the source driver 11 and the gate driver 12 through a flexible printed circuit (FPC) and a connector. The control board 30 includes a timing controller 31 and a touch controller 32.

The timing controller 31 generates a gate control signal for controlling the operation timing of the gate driver 12 and an operation timing of the source driver 11 using the vertical and horizontal synchronous signals V and H and the clock CLK And generates a data control signal for controlling. The timing controller 31 supplies digital video data (RGB) input from the system 40 to the source driver 11.

Meanwhile, the touch control circuit of the touch control unit 32 stores a reference value to be compared for each pixel of the sensor unit included in the infrared sensor modules 21A to 21C, and compares the reference value with the infrared light signal received from the infrared sensor module Thereby performing touch position detection.

The touch control unit 32 supplies the system 32 with the touch position coordinate information Txy. The touch controller 32 operates in synchronization with the timing controller 31 because the timing controller 31 shares the timing signals such as the vertical and horizontal synchronizing signals V and H and the clock CLK with the timing controller 31.

7, the touch controller 32 includes a touch coordinate calculator 321 for receiving infrared optical signals received from the infrared sensor modules 21A to 21C and calculating touch coordinate information, And a corner portion reflection corrector 322 for performing reflection correction.

Here, the system 40 includes a memory having an application program built therein, a central processing unit for executing an application program, and a display unit 10 for synthesizing a touch image and an image to be displayed on the display panel 10, And a graphics processing circuit for processing signal interpolation processing and resolution conversion. The system 40 receives touch position information Txy from the touch control unit 32 and executes an application program associated with the touch position information Txy. For example, if there is an icon for a particular program in the coordinates of the touch location, the system 40 loads and executes the program in memory. In addition, the system 40 generates digital video data (RGB) by compositing the touch image and the image to be displayed on the display panel 10. The system 40 may be implemented as a personal computer (PC), and may exchange data with the touch control unit 32 through a serial or universal serial bus (USB) interface.

On the other hand, before performing the calculation on the above-described touch position coordinate information, the corner portion to be subjected to reflection correction is set in advance by an angle relationship from another infrared sensor module not adjacent to the corner portion. That is, the range of pixels in the sensor unit of the infrared sensor module corresponding to the corner portion can be set by the observer's measurement.

8A to 8C are plan views showing corner portions adjacent to the respective infrared sensor modules.

8A shows a corner portion E adjacent to the second infrared sensor module 21B and corresponds to an area from 0 DEG to 1 in the first infrared sensor module 21A. Corresponds to an area from &thetas; 2 to &thetas; 3.

In this case, the setting of the corner portion E sets a portion to be sensed as having two or more touch detection (multi-touch) when the observer makes a single touch with the finger.

The corner portion D adjacent to the first infrared sensor module 21A is set as shown in FIG. 8B and corresponds to an area from 0 to 5 in the position of the second infrared sensor module 21B, And corresponds to an area from 0 DEG to &thetas; 4 in the position of the sensor module 21C.

The corner portion F adjacent to the third infrared sensor module 21C is set as shown in FIG. 8C, and corresponds to an area from the angle of? 8 to 90 degrees with respect to the first infrared sensor module 21A, The sensor module 21B corresponds to an area from &thetas; 6 to &thetas; 7.

Here, with respect to the corner portions E and the remaining corner portions D and F, when the observer touches the finger with a single touch, a portion having the touch detection of double or more is specified. Such a corner setting is usually performed before shipment of the display device. In some cases, after the product is shipped, the corner setting may be performed by a user's selection for setting of a new corner portion according to a time- The function can be added to the control unit.

As described above, after the corner portion is set, a touch is generated in the corresponding corner portion, and the amount of light sensed by each infrared sensor module is A (sensed light amount larger than the threshold value) / B (Area where the amount of light is smaller than the threshold value) / A (area where the amount of sensed light is larger than the threshold value) is continuous, it is detected by a single touch rather than a divided multi-touch.

In this way, it is assumed that a touch occurs in a non-corner area in a display device adjacent to each infrared sensor module with corner portions. FIG. 9 is a diagram showing the center touch of the touch screen in the display device of the present invention, and FIG. 10 is a graph showing sensing data of each pixel in the sensor unit of the infrared-ray sensor module during touching in FIG.

As shown in FIG. 9, when two-touch occurs in the central portion of the display panel 10, the amount of light sensed in the normally touched region is observed to be lower than the threshold value. In the non-touch region, the light amount is observed to be higher than the threshold value, The touch position can be detected.

Thus, even if the light amount graph of FIG. 5 and the light amount graph of FIG. 10 with respect to the central portion show similar characteristics with respect to the corner portion, by applying the corner portion reflection correction method to only the predetermined corner portion of the present invention, The touch can be normally detected.

11 is a flowchart showing a corner setting method of the display device of the present invention.

In most cases, the corner area is set before shipment of the display device due to the angular relationship with other infrared sensor modules that are not adjacent.

First, in order to start the process of the corner setting method, the power source of the display device is first applied as shown in FIG. 11 (S1).

Next, the amount of light is sensed from each infrared sensor module (S2).

Next, an effective angle for each infrared sensor module is searched based on the sensed light amount (S3). At this time, an auto calibration algorithm that automatically sets the effective angle of view of the infrared sensor modules 21A to 21C is applied. To this end, an automatic angle setting unit (not shown) may be further provided in addition to the touch coordinate operation unit.

The effective angle of each of the infrared sensor modules is based on the assumption that the infrared sensor module includes a light source in addition to the sensor unit. Even if the infrared sensor module is not fixed, It is possible because there is a light amount difference between the reflected light coming from the portion where the other recursive reflection plate is located.

The actual angle of view of each of the infrared sensor modules 21A to 21C is about 95 to 100 degrees and exceeds 90 degrees. The angle of view of each infrared sensor module is set to be more than 90 degrees when the angle of view is exactly 90 degrees, even if the case top surrounding the display panel, the retroreflective plate or the infrared sensor modules 21A to 21C are slightly turned An area which is not touched is formed on the active area of the actual display panel 10 by a predetermined angle. Therefore, the angle of view of the infrared sensor modules 21A to 21C must be sufficiently large in view of the allowable tolerances.

However, even if the angle of view of the infrared sensor modules 21A to 21C is more than 90 degrees, a region other than the 0 ° to 90 ° region is formed on the two sides adjacent to the infrared sensor modules 21A to 21C, Is covered by the retroreflective plate 25 and the case top 26 mechanically so that the area where the actual touch detection is possible is between 0 and 90 degrees. Each of the infrared sensor modules 21A to 21C includes a sensor unit for receiving light, and the sensor unit includes a plurality of pixels, and receives light corresponding to the corresponding angle for each pixel.

In this case, it is important to find a pixel corresponding to the effective angle of view of the sensor unit in the infrared sensor module. Since a value outside the range of 0 ° to 90 ° which is capable of actual touch detection is not effective as a touch area, a pixel corresponding to 0 ° and a pixel corresponding to 90 ° are set in the sensor unit of the infrared sensor, The pixels after the pixel corresponding to 90 degrees are excluded at the time of detecting the touch position since they are inaccurate even if there is an optical signal for each pixel.

On the other hand, in the display device 20 of the present invention, the infrared sensor modules 21A to 21C for receiving light are mounted on two or more corners of the display panel 10, and the infrared sensor modules 21A to 21C are mounted on the other corners Detects the light from the infrared sensor module located. At this time, the light emitted from the infrared sensor module of the other corner is directly reflected by the light emitted from the light emitting portion rather than the reflected light, and has impulse characteristics (observed as a peak value) . Here, the light emitted from the relative infrared sensor module is divided into a direct light and the light emitted from the recursive reflector into a reflecting light.

If the impulse is measured when the light received from the sensor unit in the infrared sensor module is observed on a pixel by pixel basis, this implies an infrared sensor module located at another corner, so that the pixel having the impulse is mapped to an absolute angle corresponding to the corner, reference points.

When a pixel with an impulse is used as a reference point, a reference is automatically set each time the display device is driven each time, so that when the infrared sensor modules 21A to 21C are mounted on the display panel 10, It is possible to prevent a touch measurement error caused by a deviation due to the tolerance of the infrared sensor modules 21A to 21C. The process of finding such an effective angle is called auto calibration, which can be performed without direct physical correction.

Referring to FIG. 4, the second infrared sensor module 21B and the third infrared sensor module 21C correspond to 0 ° and 90 °, respectively, in the first infrared sensor module 21A.

At this time, since the second and third infrared sensor modules 21B and 21C have light sources, the amount of light of pixels corresponding to 0 ° and 90 ° when sensing the light amount of the sensor part of the first infrared sensor module 21A And a pixel corresponding to 90 degrees with a start point of a pixel corresponding to 0 degrees is regarded as an end point. The range is defined as an effective angle, and the amount of light is sensed within this range.

Next, the observer performs a touch in an area adjacent to each infrared sensor module, and sets a corner where a reflection error occurs (S4). At this time, the corner part is set not to the area adjacent to the infrared sensor module where the actual reflection error occurs but to the corner part within the effective angle set in the other infrared sensor module. That is, referring to FIG. 8B, corner portions adjacent to the first infrared sensor module 21A are set in the second infrared sensor module 21B and the third infrared sensor module 21C, respectively. At this time, the second infrared sensor module 21B is designated as an area for the corner portion D from the start point to the pixel for the angle? 5, and the third infrared sensor module 21C designates the area for the angle? Up to the pixel is designated as the area for the corner D.

Corner portions of different infrared sensor modules should be designated for each infrared sensor module, and two corner portions are respectively defined. In the case of arranging two infrared sensor modules, only one corner portion will be assigned to each infrared sensor module. When four infrared sensor modules are arranged, three corner portions are designated Will be.

In this manner, the corners of each infrared sensor module are assigned to the pixels in the sensor unit, stored in the touch control unit, and then the process of the corner setting method ends.

FIG. 12 is a flowchart showing a touch detection method of a display device of the present invention, and FIG. 13 is a flowchart showing a corner portion reflection correction method of FIG.

After the corner portion is set, as shown in FIG. 12, a region where the corner portion is not a corner portion is divided at the time of touch detection, and the touch detection process is performed. This touch detection process is for a completed and shipped display device.

First, the display device is driven (S11)

Next, the infrared sensor modules are respectively driven (S12). At this time, the infrared sensor module can be driven simultaneously or sequentially.

Next, the amount of light (infrared data) from each infrared sensor module is sensed by each pixel in the sensor unit (S13).

Then, the sensed light amount is compared with a threshold value to determine whether or not the touch is made. That is, when it is less than the threshold value, it is judged as a touch, otherwise it is judged as non-touch.

In the method of FIG. 11, it is determined whether or not the corner determined by the touch is a stored corner (S14). Corner portions are designated by predetermined pixels in the sensor portion of each infrared sensor module by the method of FIG.

At this time, if the corner is not the corner, the touch controller divides the single touch and the multitouch, and detects the touch coordinates based on the sensed light amount (S16).

In the case of the corner portion, the corner portion reflection correction algorithm (S15) described in FIG. 13 is applied.

That is, as shown in FIG. 13, only the light amount data corresponding to the corner portion is filtered (S21).

Next, whether or not the sensed amount of light is A (an area where the sensed light amount is larger than the threshold value) / B (an area where the sensed light amount is smaller than the threshold value) / A (an area where the sensed light amount is larger than the threshold value) It is judged by a single touch in such a case.

If an interval such as A / B / A does not appear for adjacent pixels, the process of touch coordinate detection for detecting the single touch and the multi-touch in Fig. 12 is performed as it is (see S16). That is, when the sensed light amount is lower than the threshold value, the single touch and the multi-touch are distinguished and detected.

The corner reflection correction method in the optical input device using the infrared sensor module described above implements a corner reflection corresponding algorithm that corrects a touch recognition error caused by optical signal distortion.

In an optical input device, an optical signal reflected by a retroreflector attached to the periphery of a display panel is received by the sensor unit, wherein the touched portion is a characteristic that a low signal is sensed by the sensor unit . When a corner reflection corresponding algorithm is not applied, when a touch object is touched by an object capable of reflecting light at a corner portion, the reflected light directly enters the sensor portion and a rather high signal appears. There was a problem. In order to solve this problem, it is necessary to define the corner portion where the corner reflection occurs. When one touch occurs, the region recognized by the two touches can be determined from the pixels of the sensor portion in each infrared sensor module to determine the reflection corresponding region. When a touch occurs in the pixels set as the corner reflection corresponding area, the touch recognition is recognized as one touch by a plurality of touches, and the touch recognition error is reduced.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

10: Display panel 21A, 21B, 21C: Infrared sensor module
11: Source driver 12: Gate driver
20: Display module
30: control board 31: timing controller
32: touch control unit 40:
321: Touch coordinate calculation unit 322: Corner reflection correction unit

Claims (8)

A touch detection method of an optical input device having a plurality of infrared sensor modules, each sensor portion including a plurality of pixels arranged on different corners of a display panel,
A first step of driving each infrared sensor module;
A second step of sensing the amount of light from each of the infrared sensor modules;
A third step of determining whether the pixel whose light amount is sensed is a touch;
A fourth step of determining whether a pixel judged as a touch is a corner part; And
And a fifth step of determining, when a pixel judged as a touch is a corner part, a single touch when the light amount with respect to the threshold value in adjacent pixels includes low / high / low. The method according to claim 1,
In the fourth step,
Further comprising a sixth step of separately detecting the single touch and the multi-touch when the sensed light amount is less than the threshold value when the pixel determined as the touch is not a corner part. The method according to claim 1,
The method further includes a seventh step of separately detecting the single touch and the multi-touch when the sensed light amount is lower than the threshold value in the neighboring pixels when the light amount with respect to the threshold does not include low / high / low The touch detection method comprising: The method according to claim 1,
Wherein the corner portion is set before the first step. 5. The method of claim 4,
In the setting of the corner portion,
An A step of driving each of the infrared sensor modules;
A step B for sensing the amount of light from each of the infrared sensor modules;
And a step (C) of setting a corner part adjacent to each of the infrared sensor modules and for which a single touch is observed by multi-touch according to reflection, for each infrared sensor module. 6. The method of claim 5,
Wherein the step (C) assigns the corner to a pixel of the sensor unit in the infrared sensor module. 6. The method of claim 5,
Between steps B and C,
And a step (D) of setting an effective angle of each infrared sensor module based on the direct light received by each of the infrared sensor modules when the other infrared sensor module other than the infrared sensor module is driven. 8. The method of claim 7,
Wherein the setting of the effective angle of the infrared sensor module is performed by setting a pixel that generates the direct light at a reference angle to an infrared sensor module other than itself.

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