JP5268118B2 - Touch panel, touch panel drive method, contact information acquisition program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel, a driving method of the touch panel, a contact information acquisition program and a recording medium that are capable of reducing influence on a touch sensor caused by driving of a display device side. <P>SOLUTION: The touch panel having an AC driving display 70 and a touch sensor 10 which periodically reads contact information on an input plane comprises: contact information detection means 21 that detects the contact information for each frame by synchronizing a start period of a reading operation of the touch sensor with a frame period of the display; and contact information calculation means 25 that obtains calculated contact information in each frame by calculating a moving average of the contact information for the consecutive even number of frames. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a touch panel, and more particularly, to a touch panel having a display that is AC driven and a touch sensor that periodically reads contact information on an input surface.

  Conventionally, capacitive touch panels do not have a sensor glass dedicated to touch sensors, and a touch sensor transparent electrode is formed on the lower surface of the color filter glass of the liquid crystal display device, and touches the liquid crystal display device. A so-called in-cell touch panel incorporating a sensor is known (for example, see Patent Document 1).

  Such an in-cell type touch panel has a single glass substrate that is smaller than a touch panel in which an independent touch sensor is mounted on a liquid crystal display device. Therefore, the in-cell touch panel can be configured to be thin, improve transmittance, and reduce costs. There is an advantage that you can.

JP 2008-32756 A

  However, since the in-cell touch panel described above is close to the array glass of a liquid crystal display device in which TFTs (Thin Film Transistors) are formed, it is easily affected by the operation of the transistor, and coupling noise is generated. There is a problem that the detection sensitivity of the touch input to the touch panel may be relatively lowered.

  Therefore, the present invention provides a touch panel, a touch panel driving method, a contact information acquisition program, and a recording medium that can reduce noise due to the influence on the touch sensor due to driving on the display device side and that can detect a contact input with high S / N. For the purpose.

In order to achieve the above object, a touch panel according to a first invention is a touch panel having a display that is AC driven and a touch sensor that periodically reads contact information on an input surface,
A contact information detecting means for detecting the contact information for each frame in synchronization with a start cycle of the reading operation of the touch sensor;
For an even number of said successive frames, by calculating the average of the contact information, it possesses the contact information calculating means for obtaining the calculated contact information in a given frame, and
The reading operation is an operation in which the contact information on the input surface is circulated and read a plurality of times during one frame,
The contact information detection means detects a plurality of the contact information in each frame,
The contact information calculation means calculates an average of the contact information detected in the same order for the plurality of contact information detected in each frame .

As a result, noise generated by driving the display is canceled by the positive polarity driving and the negative polarity driving, and contact information with less noise can be acquired. In addition, when the scan cycle of the touch sensor is ½ or less of the time length of one frame of the display, reading can be performed a plurality of times, and contact information can be obtained with high accuracy using a large number of data. In addition to canceling out data with the same conditions, contact information can be obtained with high accuracy using a large amount of data.

The second invention is the touch panel according to the first invention,
The average is a moving average,
The predetermined frame is a frame in which the continuous even number of the contact information already exists.

  Thereby, contact information with little noise can be obtained for each frame, and highly accurate contact information can be acquired.

A third invention is the touch panel according to the first or second invention,
The reading operation is an operation of sequentially scanning the electrodes arranged in a matrix for detecting the contact information for each line.

  Accordingly, even when a touch panel that reads contact information by line scanning is employed, contact information with less influence of noise can be acquired.

A fourth invention is the touch panel according to any one of the first to third inventions,
The touch sensor is a capacitive touch sensor.

  Thereby, even if it is a case where the influence of the coupling noise by the drive of a display is easy to generate | occur | produce, the exact contact information with little influence of noise can be acquired.

A fifth invention is the touch panel according to any one of the first to fourth inventions,
It is an in-cell type touch panel in which the touch sensor is incorporated in the display.

  As a result, even when the distance between the TFT array glass of the display and the touch sensor is close and the TFT is easily affected by the operation of the TFT, contact information with less noise can be acquired.

A sixth invention is the touch panel according to any one of the first to fifth inventions,
It is an on-cell touch panel in which the touch sensor is installed on the display.

  Thereby, even when the touch sensor is directly installed on the display, the influence of the display on the touch sensor can be reduced.

A seventh invention is the touch panel according to any one of the first to fifth inventions,
The touch sensor is configured as a discrete product formed on a sensor glass, and the discrete product is installed on the display.

  Accordingly, even when a touch sensor configured as a discrete product is used, the influence from the display can be surely eliminated.

An eighth invention is the touch panel according to any one of the first to ninth inventions,
The even number of consecutive frames is two consecutive frames.

  Thereby, it is possible to acquire contact information with a high S / N ratio by a simple calculation process by combining the front and back positive and negative frames.

A ninth invention is the touch panel according to any one of the first to eighth inventions,
The display is a liquid crystal display.

  Thereby, even when a liquid crystal display frequently used for a touch panel is used, contact information can be obtained with high accuracy without being affected by the drive of the display.

A touch panel drive method according to a tenth aspect of the present invention is a touch panel drive method including a display that is AC driven and a touch sensor that periodically reads contact information on the input surface.
A contact information detection step of detecting the contact information for each frame in synchronization with a start cycle of a reading operation of the touch sensor in a frame cycle of the display;
For an even number of consecutive frames, by calculating the average of the contact information, it possesses the contact information calculating step of obtaining a calculated contact information in a given frame, and
The reading operation is an operation in which the contact information on the input surface is circulated and read a plurality of times during one frame,
In the contact information detection step, a plurality of the contact information is detected in each frame,
In the contact information calculation step, an average of the contact information detected in the same order is calculated for the plurality of contact information detected in each frame .

An eleventh invention is the touch panel driving method according to the tenth invention, wherein
The average is a moving average,
The predetermined frame is a frame in which the continuous even number of the contact information already exists.

A twelfth invention is a touch panel driving method according to the tenth or eleventh invention,
The reading operation is an operation of sequentially scanning the electrodes arranged in a matrix for detecting the contact information for each line.

A thirteenth aspect of the invention is a touch panel driving method according to any one of the tenth to twelfth aspects of the invention,
The touch sensor is a capacitive touch sensor.

A fourteenth invention is a touch panel driving method according to any one of the tenth to thirteenth inventions,
The even number of consecutive frames is two consecutive frames.

A recording medium according to a fifteenth aspect of the invention is a computer-readable recording medium recording a program for executing the touch panel driving method according to any of the tenth to fourteenth aspects of the invention.

A program according to a sixteenth aspect is a program for causing a touch panel driving method according to any one of the tenth to fourteenth aspects of the invention to be executed.

  According to the present invention, contact information with less noise can be acquired.

1 is a cross-sectional configuration diagram illustrating an example of a touch panel according to Embodiment 1. FIG. 3 is a plan view showing an example of an electrode configuration of a touch sensor of the touch panel according to Embodiment 1. FIG. 2 is a block configuration diagram illustrating an example of a touch panel according to Embodiment 1. FIG. It is a figure for demonstrating the drive by a frame inversion system. It is explanatory drawing of the arithmetic processing performed with a contact information calculation means. FIG. 5A is a diagram illustrating an example of read data of the touch sensor detected in a state affected by noise. FIG. 5B is a diagram showing an example of contact information data after the arithmetic processing by the contact information calculation means. It is explanatory drawing of the touch sensor which concerns on Embodiment 1, and the drive method of a touch sensor. It is the figure which showed an example of the processing flow for every flame | frame of the touchscreen which concerns on Embodiment 1, and its drive method. It is the figure which showed the Example of the touch sensor which concerns on Embodiment 1, and its drive method. It is explanatory drawing of the touch sensor which concerns on Embodiment 2, and its drive method. It is explanatory drawing of the touchscreen which concerns on Embodiment 3, and its drive method. It is explanatory drawing of the touch sensor which concerns on Embodiment 4, and its drive method. It is the figure which showed an example of the electrode structure of the touch sensor which concerns on Embodiment 5. FIG. FIG. 12A is a plan view configuration illustrating an example of a Y detection electrode layer of the touch sensor according to the fifth embodiment. FIG. 12B is a plan view configuration illustrating an example of the X detection electrode layer of the touch sensor according to the fifth embodiment. It is the figure which showed the structure of the touch sensor 19 which concerns on Embodiment 5. FIG. FIG. 13A is a plan configuration diagram of an electrode layer of the touch sensor according to the fifth embodiment. FIG. 13B is an overall configuration perspective view of the touch sensor according to the fifth embodiment. FIG. 10 is a cross-sectional configuration diagram illustrating an example of a touch panel according to a sixth embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

Embodiment 1
FIG. 1 is a cross-sectional configuration diagram illustrating an example of a touch panel according to Embodiment 1 of the present invention. In FIG. 1, the touch panel according to the first embodiment includes a touch sensor 10, a touch sensor controller 20, a color filter glass 40, an array glass 50, and a liquid crystal driving circuit 60.

  The touch sensor 10 and the touch sensor controller 20 constitute a touch sensor module, and the color filter glass 40, the array glass 50, and the liquid crystal driving circuit 60 constitute a liquid crystal display 70. The touch sensor 10 is formed on the lower surface of the color filter glass 40 of the liquid crystal display 70 so as to be sandwiched between the array glass 50 and is configured as an in-cell touch panel in which the touch sensor 10 is incorporated in the liquid crystal display 70. ing. The touch sensor 10 is configured by a transparent electrode layer such as ITO (Indium Tin Oxide), and is formed by forming a transparent electrode layer on the lower surface of the color filter glass 40. Such an in-cell type touch sensor does not have a glass substrate dedicated to the touch sensor 10, and thus has various advantages that it can be configured thinly, has high transmittance, and can be configured at low cost.

  Liquid crystal is filled between the color filter glass 40 and the array glass 50 to constitute a liquid crystal panel. TFTs are formed on the array glass 50 and are driven by the liquid crystal driving circuit 60 to display images. Here, since the touch sensor 10 is disposed at a position very close to the array glass 50 on which the TFT is formed, the touch sensor 10 is easily affected by noise generated by driving the TFT. In particular, when the touch sensor 10 is configured as a capacitive touch sensor, coupling noise is generated, and the S / N is likely to decrease.

  The touch sensor controller 20 is means for driving and controlling the touch sensor. In the touch panel according to the present embodiment, by mounting various functions to be described later on the touch sensor controller 20, even an in-cell touch panel having the configuration shown in FIG.

  FIG. 2 is a plan view illustrating an example of an electrode configuration of the touch sensor 10 of the touch panel according to the first embodiment of the present invention. The touch sensor 10 includes a plurality of X detection electrodes 11 extending in parallel in the vertical (vertical) direction and a plurality of Y detection electrodes 12 extending in parallel in the horizontal (horizontal) direction. The X detection electrode 11 and the Y detection electrode 12 are arranged in a matrix so as to be orthogonal to each other. In FIG. 2, M X detection electrodes 11 and N Y detection electrodes 12 are provided to form a matrix of M × N (M rows and N columns).

  A sensor coordinate system is set for the X detection electrodes 11 and the Y detection electrodes 12 arranged in a matrix. In FIG. 2, the lower left corner of the touch sensor 10 is set to (1, 1), and the upper right corner is set to (M, N). In addition, although shown in a plan view in FIG. 2, the X detection electrode 11 and the Y detection electrode 12 are arranged to face each other with a gap in the vertical direction. When a conductor such as a finger or a pen comes into contact with the input surface of the touch sensor 10, if it is a capacitance type touch sensor, the capacitance between the X detection electrode 11 and the Y detection electrode 12 changes, In the case of the resistance film type, the contact position is detected by detecting conduction.

  In the present embodiment, a case where a capacitive touch sensor is used will be described as an example. In the capacitive touch sensor, (1,1) → (2,1) →... → (M, 1) → (2,1) →... (M−1, N) → (M , N), scanning is performed one coordinate point at a time along the line, and the contact information for each coordinate is read and detected. When one line is finished, each line is sequentially scanned, such as the next line. Finally, contact information of all coordinates of all lines is detected, and one input surface (contact surface) of the touch sensor 10 is totaled. Contact information is detected. The contact information includes contact position data because the contact position is specified from the contact strength data including the presence / absence of contact and the detected coordinates. In the case of binary data, only the presence or absence of contact is detected, not the strength of contact.

  FIG. 3 is a block diagram showing an example of a touch panel according to Embodiment 1 of the present invention. In FIG. 3, only components necessary for realizing the functions are extracted and shown.

  In FIG. 3, the touch panel according to the first embodiment includes a touch sensor 10, a touch sensor controller 20, an array glass 50, and a liquid crystal drive circuit 60. The touch sensor 10 includes an X detection electrode 11 and a Y detection electrode 12. The touch sensor controller 20 includes a contact information detection unit 21 and a contact information calculation unit 25, and the contact information detection unit 21 further includes a reading unit 22, a timing control unit 23, and a storage unit 24.

  Since the touch sensor 10 and the array glass 50 have been described in FIG. 1, the same reference numerals are assigned and description thereof is omitted.

  The liquid crystal driving circuit 60 is a means for driving the liquid crystal display 70, and is configured by a driver IC or the like. The liquid crystal display 70 of the touch sensor according to the present embodiment is driven by a frame inversion method.

  FIG. 4 is a diagram for explaining driving by the frame inversion method. FIG. 4 shows an example of a data signal source voltage waveform for a signal period of 2T. As shown in FIG. 4, the data signal voltage applied to the liquid crystal display 70 is an alternating voltage waveform in which the positive polarity and the negative polarity are alternately inverted every cycle. As shown in FIG. 4, this is reversed at the same period T even if the applied voltage differs from V1, V2, and V3 depending on the magnitude (luminance) of the signal. The period T is the same period as one frame for displaying one image on the liquid crystal display 70. Generally, since the liquid crystal display 70 is driven at 60 Hz, the frame period is 1/60 = 0.166... = 16.6 msec. In other words, the polarity is reversed every 16.6 msec, and a new image is displayed and a moving image is displayed on the liquid crystal display 70.

  In this embodiment, for the sake of easy understanding, a frame inversion driving method in which subpixels are inverted with the same polarity on the entire screen for each frame will be described as an example. However, every other subpixel for each frame. In addition, a dot inversion driving method in which the positive polarity and the negative polarity are alternately inverted and a line inversion driving method in which the positive polarity and the negative polarity are alternately inverted in units of lines for each frame are also included. Both inversion driving methods are common in that the polarity is inverted for each frame in units of pixels, and AC driving is performed in which a positive data signal voltage and a negative data signal voltage are alternately applied. . The line inversion driving method includes a row line inversion driving method in which positive and negative are alternately inverted for each row line, a column line inversion driving method in which positive and negative are alternately inverted for each column line, an H line inversion driving method, V Various line inversion driving methods such as a line inversion driving method are included. Further, the dot inversion driving method is not limited to the inversion of every other sub-pixel, and includes various dot inversion driving methods such as a two-dot inversion driving method.

  Returning to FIG. The liquid crystal driving circuit 60 drives the TFTs formed on the array glass 50 and performs driving so as to display one image with a period of 16.6 msec.

  The contact information detection unit 21 is a unit that starts the reading operation of the touch sensor 10 in synchronization with the frame period of the liquid crystal display 70 and detects the contact information to the touch sensor 10 for each frame. Conventionally, in the touch panel, the liquid crystal driving circuit 60 and the touch sensor controller 20 operate independently, but in the touch sensor according to the present embodiment, contact information of the touch sensor 10 in synchronization with the frame period of the liquid crystal display 70. Read.

  The reading unit 22 is a unit that reads contact information input to the input surface of the touch sensor 10. As described in FIG. 2, scanning is performed along the Y detection electrode 12 or the X detection electrode 11, and the contact information of each coordinate is read. Specifically, the contact information is sequentially detected by reading the capacitance of each line, and the read contact information data is stored in the storage unit 24. The reading means 22 also has a predetermined reading cycle because scanning of the entire surface is completed by reading all the electrodes 11 and 12.

  The timing control unit 23 is a unit that controls the start timing of the reading operation of the reading unit 22. In the touch panel according to the present embodiment, the start of the reading operation by the reading unit 22 is synchronized with the frame period of the liquid crystal display 70. Therefore, the timing control unit 23 acquires the frame period of the liquid crystal display 70 from the liquid crystal driving circuit 60 and starts the operation of the reading unit 22 in synchronization with this.

  The storage means 24 is means for sequentially storing contact information read by the reading means. The storage unit 24 only needs to have a buffer for one detection surface of the touch sensor 10 at a minimum, but is configured to store more contact information when acquiring a plurality of contact information in one frame. It's okay. The storage unit 24 may be configured as a general memory used in a computer or the like.

  The reading unit 22, the timing control unit 23, and the storage unit 24 constitute a contact information detection unit 21 that detects contact information for each frame of the liquid crystal display 70.

  The contact information calculation unit 25 is a unit for calculating an average of an even number of consecutive frames from the read data for each frame detected by the contact information detection unit 21 and acquiring calculated contact information in which noise is canceled. is there. The average calculation method may be, for example, a moving average method that calculates an average from a predetermined number of average read data that is continuous for each frame, or an even number that is continuous without acquiring calculated contact information for each frame. It may be calculated by a total average method in which sections are obtained by obtaining calculated contact information in a frame in which individual pieces of contact information are arranged. In other words, if you want to obtain the calculated contact information for each frame with high accuracy, you only need to perform the average calculation by the moving average method, and if you want to reduce the computation burden even if the number of data is reduced, What is necessary is just to perform the average calculation by the average method. By reducing the calculation burden, the calculation circuit can be reduced in size and the cost can be reduced. As described above, various average methods can be used as the calculation method of the average value of the contact information by the contact information calculation unit 25 depending on the application.

  FIG. 5 is a diagram for explaining a calculation process performed by the contact information calculation unit 25. FIG. 5A is a diagram showing an example of the read data of the touch sensor 10 detected in a state affected by noise, and FIG. 5B shows the contact after the arithmetic processing by the contact information calculation unit 25. It is the figure which showed an example of information data.

  In FIG. 5A, the detection data 101 of the touch sensor 10 when the liquid crystal display 70 is driven with a positive polarity is shown on the positive polarity side, and the detection data 102 of the touch sensor 10 when the liquid crystal display 70 is driven with a negative polarity on the negative polarity side. It is shown. The detection data 101 on the positive side is composed of positive side noise 81 by driving the liquid crystal display 70 and contact information data 91 of the touch sensor 10, and the detection data 102 on the negative side is by driving the liquid crystal display 70. It comprises negative side noise 82 and contact information data 92 of the touch sensor 10. In addition, since the positive and negative drive are generated in different cycles, the positive and negative drive does not occur in the same cycle. However, for easy understanding, FIG. A) shows the detection data 101 of the touch sensor 10 in the positive frame and the detection data 102 in the negative frame within the same period.

  In the positive polarity and negative polarity detection data 101 and 102, the contact information data 91 is influenced by the positive polarity side noise 81 in the positive polarity frame. In the negative frame, the contact information data 92 is affected by the negative noise 82. That is, it can be seen that the contact information data 91 and 92 are affected by noise according to the frame polarity.

  Here, the positive polarity side noise 81 and the negative polarity side noise 82 have substantially the same waveform and differ only in polarity. On the other hand, both the contact information data 91 and 92 have substantially the same waveform, and both are positive data. Therefore, when the positive polarity detection data 101 and the negative polarity detection data 102 are added, only the positive polarity side noise 81 and the negative polarity side noise 82 cancel each other, and the contact information data 91 and 92 are added to the positive polarity to generate noise. A clear signal is obtained in which is canceled.

  FIG. 5B shows calculation data 103 obtained by adding the detection data 101 and the detection data 102. As shown in FIG. 5B, the positive polarity side noise 81 and the negative polarity side noise 82 cancel each other, and the calculation data 103 which is the sum of the contact information data 91 and 92 is acquired without noise.

  As described above, the detection data 101 of the touch sensor 10 when the liquid crystal display 70 is driven in the positive polarity frame and the detection data 102 of the touch sensor 10 when the negative polarity frame is driven are added, and the moving average is calculated. Thus, it is possible to obtain a high S / N contact information signal in which noise is canceled.

  In FIG. 5B, the waveform of the calculation data 103 is shown in a state where there is no noise at all. However, in the case of a moving image, the data written in successive frames is different, so the noise is not necessarily completely zero. It doesn't mean. However, since there are few images in which extremely different data is written in successive frames, it is possible to substantially cancel most of the noise.

  Returning to FIG. The contact information calculation unit 25 adds the read data detected in synchronization with the positive frame as described in FIG. 5 and the read data detected in synchronization with the negative frame, and calculates a moving average thereof. The arithmetic processing to be performed is performed. Thereby, contact information data with little noise can be acquired.

  In FIG. 3, the contact information detecting means 21 and the contact information calculating means 25 are electronic means including an ASIC (Application Specific Integrated Circuit) and a CPU that operates by reading a program, as long as the various arithmetic processes described above are possible. It can be realized by various arithmetic processing means such as a (Center Processing Unit) or a computer. Moreover, you may comprise as a recording medium which recorded the program which makes a computer function as the contact information detection means 21 and the contact information calculation means 25, and recorded such a program so that a computer could read.

  FIG. 6 is a diagram for explaining a touch sensor and a touch sensor driving method according to the first embodiment of the present invention. In FIG. 6, various operation timings of the touch sensor 10 synchronized with the frame period of the liquid crystal display 70 are shown. Specifically, the touch sensor scan timing, the noise influence, the data average value, and the noise influence are shown in accordance with the frame of the liquid crystal display 70 and the drive timing.

  First, when the liquid crystal display 70 is turned off, only the scan reference data of each coordinate (1, 1) to (M, N) is acquired. The scan reference data is acquired in order to cancel naturally occurring noise and perform calibration. The scan reference data is used later when calculating contact information data. At this stage, since the liquid crystal display 70 is not driven, no influence of noise occurs.

  In the first frame, the liquid crystal display 70 is driven by applying a positive data voltage. In the touch sensor 10, reading is started by the reading unit 22 of the contact information detecting unit 21 in synchronization with the timing of starting positive frame driving. The reading operation may be performed by a scanning operation that sequentially scans line by line. Note that the timing of the reading operation of the reading unit 22 is controlled by the timing control unit 23.

  In general, the data reading cycle of the touch sensor 10 is shorter than 16.6 msec of one frame display period of the liquid crystal display 70, and the reading speed (frequency) is often faster than 60 Hz. Reading of the contact information of the touch sensor 10 is finished before the frame is finished. Here, even if the reading is completed, the first frame of the liquid crystal display 70 is awaited without performing the next scan. The read detection data RAW [1] is stored in the storage unit 24. Note that the data obtained by this reading is affected by positive polarity noise from the liquid crystal display 70.

  In the second frame, the liquid crystal display 70 is driven by applying a negative data voltage. In the touch sensor 10, the reading operation is started in synchronization with the negative frame driving start timing. At this time, the contact information data is affected by negative-polarity noise from the liquid crystal display 70. The read contact information detection data RAW [2] is calculated by the contact information calculation means 25 as a moving average (RAW [1] + RAW [2]) / 2 with the RAW [1] stored in the storage means 24. Calculated as the detected data average value AVG [1]. In the detected data average value AVG [1], the noise is canceled out in the first frame of the positive polarity drive and the second frame of the negative polarity drive, and the contact information data without the influence of noise from the liquid crystal display 70 can be acquired.

  In the third frame, the liquid crystal display 70 is driven by applying a positive data voltage. Similar to the first and second frames, the touch sensor 10 starts scanning of the reading operation and detects contact information data in synchronization with the positive frame drive start timing. At this time, the detection data of the contact information is affected by the positive polarity noise from the liquid crystal display 70, but the moving average (RAW [2] with the detection data of the second frame which is affected by the negative polarity noise. ] + RAW [3]) / 2 is calculated, the positive and negative noises are canceled and the detected data average value AVG [2] free from noise is obtained.

  Similarly, for the fourth frame to which the negative data voltage is applied, the detection data average value AVG [3] is calculated from the moving average with the third frame to which the previous positive data voltage is applied. That's fine. Further, the fifth frame of positive polarity driving may be calculated by calculating the moving average of the fourth frame of negative polarity driving immediately before to obtain the detection data average value AVG [4]. As described above, the frames before and after the liquid crystal display 70 are always combined with positive and negative driving polarities, so that by calculating the average value of the contact information data detected in the previous and subsequent frames, the liquid crystal display 70 It is possible to acquire the contact information data in which the noise is canceled.

  FIG. 7 is a diagram illustrating an example of a processing flow for each frame of the touch panel and the driving method thereof according to the first embodiment of the present invention.

  In step 100, the reading of the contact information of the touch sensor 10 is started in synchronization with the frame of the liquid crystal display 70. Reading is performed by the reading unit 22 of the contact information detecting unit 21, and the timing of the reading start is controlled by the timing control unit 23. Note that the reading start timing does not have to be completely coincident with the start of the frame of the liquid crystal display 70, and may be synchronized at a slightly delayed timing. This is because the scan cycle of the touch sensor is often shorter than the frame cycle of the liquid crystal display 70, and it is not a problem if the contact information data can be reliably detected within the frame cycle.

  In step 110, contact information of the touch sensor 10 in the synchronized frame is detected. The detected contact information data is stored in the storage unit 24.

  In step 120, a moving average of detected data is calculated for an even number of consecutive frames including the frame detected in step 110. Since the object in which the contact information has already been detected is an object, the detection data acquired in the frame before the frame detected in steps 100 to 110 is an object. Thereby, the noise by the influence from the liquid crystal display 70 can be offset, and high S / N contact information data can be acquired. The moving average is calculated by the contact information calculation means 25.

  In Embodiment 1, the moving average of the detection data is calculated for two consecutive frames. However, if the same number of positive drive frames and negative drive frames are included, four consecutive frames and six consecutive frames are included. It is also possible to calculate a moving average to obtain an average value of contact information detection data. By increasing the number of data to be averaged, it is possible to acquire contact information with higher accuracy. A specific embodiment in which the number of frames to be averaged is increased will be described later.

  By executing steps 100 to 120 sequentially for each frame, contact information with less noise can be acquired.

  In the first embodiment, the moving average of the detection data is calculated and the average calculation data is obtained for each frame. However, the average calculation data is obtained for each pair of two consecutive positive and negative drive frames. May be obtained. Average contact information data is calculated every other frame, but if the number of data that is half of the number of frames is sufficient, the average contact information data may be acquired at intervals of every two frames. . Thereby, the burden of arithmetic processing can be reduced and the contact information calculation means 25 can be comprised simply. Further, when it is desired to further reduce the calculation processing load, instead of the average calculation every two frames, one average calculated contact information is acquired every four frames, or one calculated contact information is acquired every six frames. It is also possible to do. The section that is the average value calculation range can be various sections as long as they are continuous even frames.

〔Example〕
FIG. 8 is a diagram illustrating an example in which the touch sensor and the driving method thereof according to the first embodiment of the present invention are implemented. 8A is reference data, FIG. 8B is contact information detection data when the liquid crystal display 70 is an odd-numbered frame, and FIG. 8C is contact information when the liquid crystal display 70 is an even-numbered frame. Detection data, FIG. 8D is a diagram showing the contact information data obtained by averaging the contact information detection data. In addition, the same reference number is attached | subjected about the component similar to the component demonstrated until now. In each figure, the horizontal plane represents sensor coordinates (X, Y), and the vertical axis represents the sensor signal level.

  In FIG. 8A, the reference data is detected before the liquid crystal display 70 starts to be driven. Since the liquid crystal display 70 that displays the input screen is not driven, the reference data is detected in a non-contact state in which contact input is not performed. Thereby, the state of the signal zero of each coordinate can be grasped.

  FIG. 8B shows contact information detection data RAW [1] when the liquid crystal display 70 is driven in an odd-numbered frame. FIG. 8C shows contact information detection data RAW [1] when the liquid crystal display 70 is driven in an even-numbered frame. 2] is shown. In both FIGS. 8B and 8C, a finger image indicating contact with a finger is detected as contact information. When both are compared, the position of the finger image is the same at the position of the previous coordinate, and the sensor signal level is also common in that it has a negative sign. On the other hand, in the portions other than the finger image, it can be seen that the positions of the peaks are shifted in FIGS. 8B and 8C.

From these, in order to obtain a finger image in which noise has been canceled, a calculation as shown in equation (1) is performed.
Reference data- (RAW [1] + RAW [2]) / 2 = Noise-cancelled finger image data (1)
FIG. 8D is a diagram showing noise-cancelled finger image data calculated by performing the calculation of equation (1). As shown in FIG. 8D, noise other than the finger image was canceled, and a high S / N finger image could be obtained.

  As described above, according to the touch sensor and the driving method thereof according to the first embodiment, a clear finger image with a high S / N is obtained by averaging two consecutive frames and subtracting them from the reference data. be able to.

[Embodiment 2]
FIG. 9 is a diagram for explaining a touch sensor and a driving method thereof according to Embodiment 2 of the present invention. FIG. 9 shows a timing chart of the same format as in FIG. 6 of the first embodiment. In the second embodiment, components similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  In FIG. 9, the frame and drive timing of the liquid crystal display 70 are the same as those in FIG. In the second embodiment, the scan start timing of the touch sensor 10 is synchronized with the frame start timing of the liquid crystal display 70 as in the first embodiment. The second embodiment is different from the first embodiment in that contact information of the touch sensor 10 is read twice within a display period of one frame. As described in the first embodiment, the reading cycle of the touch sensor 10 is generally shorter than 16.6 msec and the reading speed is higher than 60 Hz. For example, if the reading speed of the touch sensor 10 is set to 120 Hz or higher, as shown in FIG. 9, it is possible to circulate and perform two full scans in one frame.

  In this case, two pieces of contact information data are detected in each frame. In this case as well, the moving average is calculated in consecutive frames before and after, and the contact information data in which noise is canceled is calculated. At this time, the detection data RAW [1] of the first frame and the detection data of the second frame are calculated. A moving average of detected data detected in the same order in each frame, such as a moving average of RAW [2], detection data RAW [2] of the first frame, and detected data RAW [4] of the second frame calculate. That is, the moving average is calculated by the equation (RAW [X] + RAW [X−2]) / 2.

  Since one frame of the liquid crystal display 70 is a time for writing one image, if an image is written from the upper side in the vertical direction, the upper half image is written in the first half of the frame and the lower half is written in the second half of the frame. You are writing an image. If the detection data of the touch sensor is not added between images in the same region, synchronization within the frame is not achieved, and different data are added, so the detection data becomes meaningless. Therefore, the detection data average value AVG [1] is obtained from the moving average of the detection data RAW [1] read first in the first frame and the detection data RAW [3] read first in the second frame. The detection data average value AVG [2] is acquired from the moving average of the detection data RAW [2] read second in one frame and the detection data RAW [4] read second in the second frame. By such calculation, it is possible to obtain the detected data average values AVG [1] and AVG [2] in which the influence of noise from the liquid crystal display 70 is eliminated. Thereafter, AVG [1] and AVG [2] may be used as they are as data corresponding to the two second frames, or the average value calculated by (AVG [1] + AVG [2]) / 2 You may make it use as contact information data corresponding to 2 frames.

  Further, with respect to the subsequent third frames and thereafter, high-precision contact information data calculated from a large amount of detection data can be acquired by performing the same processing. As described above, according to the touch panel and the driving method thereof according to the second embodiment, it is possible to acquire highly accurate contact information data using two data for each frame.

  Note that, in the average calculation, the average contact interval may be determined and the total average may be calculated for each predetermined frame to obtain the calculated contact information, as in the first embodiment.

[Embodiment 3]
FIG. 10 is a diagram for explaining a touch panel and a driving method thereof according to Embodiment 3 of the present invention. FIG. 10 shows a timing chart of the same format as in FIG. 6 of the first embodiment and FIG. 9 of the second embodiment.

  In the second embodiment, reading is performed twice during one frame. However, the third embodiment is different from the second embodiment in that reading is performed three times during one frame. In this case, the reading speed by the reading means 22 is set to 180 Hz or higher. Then, as shown in FIG. 10, three detection data can be acquired during one frame.

  Note that the calculation for canceling the noise by the contact information calculation means 25 is the same as before in the previous and subsequent frames, but as described in the second embodiment, for each of the three detection data, the frame is calculated. The moving average of the detection data read in the same detection order is calculated. That is, the moving average of the detection data RAW [1] scanned first in the first frame and the detection data RAW [4] scanned first in the second frame, the second scan in the first frame The moving average of the detection data RAW [2] and the detection data RAW [5] scanned second in the second frame, the detection data RAW [3] scanned third in the first frame and 3 in the second frame The moving average of the detection data RAW [6] scanned the second time is calculated. Thereby, detection data average values AVG [1], AVG [2], and AVG [3] in which noise is canceled can be calculated as the contact information data of the second frame. These three data in one frame may be used as they are in the subsequent calculation. When one data is made in one frame, the average of the three data (AVG [1] + AVG [2] + AVG [3]) / 3 may be calculated.

  By performing similar detection and calculation processing for the third and subsequent frames, three pieces of contact information data can be acquired within one frame, and contact information is calculated with higher accuracy using a large number of data. can do.

  In the second embodiment, the touch sensor 10 is scanned twice in one frame, and in the third embodiment, the touch sensor 10 is scanned three times in one frame. Needless to say, if the speed is further increased, a larger number of scans can be performed within one frame.

  In addition, the average calculation method is not limited to the moving average, but is performed by the total average method that defines the section, and the calculated contact information may be acquired for each predetermined frame, as in the first and second embodiments. is there.

  As described above, according to the touch sensors of Embodiments 2 and 3 and the driving method thereof, the calculated contact information can be obtained with higher accuracy by scanning the touch sensor 10 a plurality of times within one frame.

[Embodiment 4]
FIG. 11 is a diagram for explaining a touch sensor and a driving method thereof according to Embodiment 4 of the present invention. FIG. 11 shows a timing chart in the same format as FIG. 6 of the first embodiment, FIG. 9 of the second embodiment, and FIG. 10 of the third embodiment.

  In the fourth embodiment, the scan timing of the touch sensor 10 and the detection method of the contact information data are the same as those in the first embodiment. The calculation method of the detection data average values AVG [1] and AVG [2] of the second frame and the third frame is the same as that of the first embodiment.

  In the fourth embodiment, when the detection data average value AVG [3] is calculated in the fourth frame, the four detection data RAW [1] and RAW [2] detected in the four frames of the first to fourth frames, respectively. ], RAW [3], RAW [4] is different from the first embodiment in that the moving average is calculated. The first frame is positive polarity driving, the second frame is negative polarity driving, the third frame is positive polarity driving, the fourth frame is negative polarity driving, and the number of positive and negative driving is the same. In the inversion frame drive type liquid crystal display 70, positive and negative drive are always alternated, and therefore, the same number of positive and negative drives are always provided in an even number of consecutive frames. Therefore, even when the average value of the detection data is calculated for four or more consecutive even frames, the noise caused by the liquid crystal display 70 is canceled with positive and negative, and the contact data with the noise canceled can be acquired. .

In FIG. 11, detection is also performed in the fifth and subsequent frames using detection data RAW [2] to RAW [5] and RAW [3] to RAW [6] detected in four consecutive frames. Data average values AVG [4] and AVG [5] are calculated. Moreover, the general formula of a moving average becomes like (2) Formula.
(RAW [X] + RAW [X-1] + RAW [X-2] + RAW [X-3]) / 4 (2)
Thus, by calculating the average value by increasing the number of data, the accuracy of the average is improved, and in addition to the coupling noise affected by the liquid crystal display 70, it is possible to correct thermal noise and the like.

  In the fourth embodiment, for the second frame and the third frame, the detection data AVG [1] and AVG [2] are obtained from two consecutive frames, as in the first embodiment, so as not to reduce the number of data. Although the calculation is performed, calculation of the detection data average value may be started from the fourth frame by applying all of the expression (2). The details of such calculation processing can be variously determined depending on the application.

  According to the touch panel and the driving method thereof according to the fourth embodiment, by using four or more consecutive even number of detection data, the number of sampling data for calculating the average value can be increased, and high accuracy with less noise. Contact information data can be acquired.

  In the fourth embodiment, the average value may be calculated every time when four or more predetermined consecutive even numbers of detection data are prepared. Although the total number of data decreases, the accuracy of the calculated contact information average value becomes very high, and the burden of calculation processing can be greatly reduced.

[Embodiment 5]
FIG. 12 is a diagram illustrating an example of an electrode configuration of the touch sensor according to the fifth embodiment of the present invention. 12A is a plan view showing an example of the Y detection electrode layer of the touch sensor according to the fifth embodiment, and FIG. 12B shows the X detection electrode layer of the touch sensor according to the fifth embodiment. It is the top view structure which showed an example.

  In FIGS. 2 and 3 of the first embodiment, the configuration in which the touch sensor 10 is configured using the striped X detection electrodes 11 and the Y detection electrodes 12 has been described. As illustrated in FIGS. Alternatively, a configuration may be adopted in which small square pieces are skewered and connected. FIG. 12A shows a Y detection electrode layer 14 having Y detection electrodes 16 connected in a horizontal direction, and in FIG. 12B, it is connected in a vertical direction. An X detection electrode layer 13 having the X detection electrode 15 formed is shown. In both cases, the electrode shape is different from the X detection electrode 11 and the Y detection electrode 12 of FIGS. 2 and 3, but in FIG. 12A, a plurality of Y detection electrodes 16 extending in the lateral direction are arranged in parallel. In FIG. 12B, a plurality of X detection electrodes 15 extending in the vertical direction are arranged in parallel. In terms of arrangement configuration, the Y detection electrodes 12, X Each is common with the detection electrode 11.

  FIG. 13 is a diagram illustrating a configuration of the touch sensor 19 according to the fifth embodiment of the present invention. FIG. 13A is a diagram illustrating a planar configuration of the electrode layer 17 inside the touch sensor 19 according to the fifth embodiment, and FIG. 13B illustrates an overall configuration of the touch sensor 19 according to the fifth embodiment. It is the shown perspective view.

  In FIG. 13A, the planar configuration of the electrode layer 17 is shown. The X detection electrode 15 and the Y detection electrode 16 are arranged so as not to overlap each other and are configured to have a large surface area.

  Further, in FIG. 13B, the entire configuration of the touch panel 19 is shown. The Y detection electrode 14 and the X electrode detection layer 13 are laminated, and the glass cover 18 covers the surface. The touch sensor 19 having such a configuration may be used to configure the touch panel according to the present embodiment.

  In addition, the configuration of the touch sensors 10 and 19 can be various configurations depending on the application, both the internal electrode configuration and the external configuration, and a touch panel with less noise is configured using the various touch sensors 10 and 19. can do.

[Embodiment 6]
FIG. 14 is a cross-sectional configuration diagram illustrating an example of a touch panel according to Embodiment 6 of the present invention. In FIG. 14, the touch panel according to the sixth embodiment includes a touch sensor 10, a touch sensor controller 20, a sensor glass 30, a color filter glass 40, an array glass 50, and a liquid crystal driving circuit 60. The touch sensor 10, the touch sensor controller 20, and the sensor glass 30 constitute a touch sensor module, and the color filter glass 40, the array glass 50, and the liquid crystal drive circuit 60 constitute a liquid crystal display 71.

  In the touch panel according to the sixth embodiment, the touch sensor 10 is not provided inside the liquid crystal display 71, the sensor glass 30 is disposed on the upper surface of the color filter glass 40, and a transparent electrode layer such as ITO is formed thereon. The touch sensor 10 is formed and installed. That is, unlike the in-cell touch panel shown in FIG. 1 of the first embodiment, the touch panel according to the sixth embodiment has a configuration in which an independent discrete touch sensor module is provided on the upper surface of the liquid crystal display 71. .

  Thus, the touch panel according to the present embodiment may have a configuration in which the touch sensor module and the liquid crystal display 71 are independent. In general, in such a separate stand-alone touch panel, the sensor glass 30 is provided between the touch sensor 10 and the color filter glass 40 and the shielding effect is often high. When the influence of noise from the touch panel is large, the touch information with less noise can be acquired by applying the touch panel and the driving method thereof according to the present invention.

  Further, as a modification of the sixth embodiment, in FIG. 14, the sensor glass 30 may be removed and the touch sensor 10 may be formed on the upper surface of the color filter glass 40 to be configured as an on-cell touch panel. In the on-cell touch panel, although the color filter glass 40 exists between the touch sensor 10 and the array glass 50, there is a sufficient possibility that the on-cell touch panel is affected by the transistors of the array glass 50. Therefore, the present embodiment can be preferably applied also to an on-cell touch panel, whereby high S / N calculated contact information can be acquired.

  As described above, the touch panel and the driving method thereof according to the present invention can be applied to touch panels having various configurations in which the touch sensors 10 and 19 may be affected by the liquid crystal displays 70 and 71, thereby reducing noise. It is possible to obtain a touch panel with few contact information with high S / N.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the present embodiment, the example in which the image display means is a liquid crystal display has been described. However, the display is driven by alternating current and the polarity of the drive alternating voltage applied to each pixel is reversed for each frame. For example, various displays can be used.

  INDUSTRIAL APPLICABILITY The present invention can be used for all touch panels that display an image on a display screen and perform an input operation by touching a finger or the like.

DESCRIPTION OF SYMBOLS 10, 19 Touch sensor 11, 15 X detection electrode 12, 16 Y detection electrode 13 X electrode layer 14 Y electrode layer 17 Electrode layer 18 Glass cover 20 Touch sensor controller 21 Contact information detection means 22 Reading means 23 Timing control means 24 Storage means 25 Contact information calculation means 30 Sensor glass 40 Color filter glass 50 Array glass 60 Liquid crystal drive circuit 70, 71 Liquid crystal display 81 Positive noise 82 Negative noise 91, 92 Contact information data 101, 102 Detection data 103 Calculation data

Claims (16)

A touch panel having a display that is AC driven and a touch sensor that periodically reads contact information on the input surface,
A contact information detecting means for detecting the contact information for each frame in synchronization with a start cycle of the reading operation of the touch sensor;
For an even number of said successive frames, by calculating the average of the contact information, it possesses the contact information calculating means for obtaining the calculated contact information in a given frame, and
The reading operation is an operation in which the contact information on the input surface is circulated and read a plurality of times during one frame,
The contact information detection means detects a plurality of the contact information in each frame,
The touch information calculating means calculates an average of the contact information detected in the same order for the plurality of contact information detected in each frame . The average is a moving average,
The touch panel as set forth in claim 1, wherein the predetermined frame is a frame in which the continuous even number of the contact information already exists.   The touch panel according to claim 1, wherein the reading operation is an operation of sequentially scanning the electrodes arranged in a matrix shape for detecting the contact information for each line.   The touch panel according to claim 1, wherein the touch sensor is a capacitive touch sensor.   The touch panel according to any one of claims 1 to 4, wherein the touch sensor is an in-cell touch panel in which the touch sensor is incorporated in the display.   The touch panel according to any one of claims 1 to 4, wherein the touch sensor is an on-cell touch panel in which the touch sensor is installed on the display.   The touch panel according to any one of claims 1 to 4, wherein the touch sensor is configured as a discrete product formed on a sensor glass, and the discrete product is installed on the display. The touch panel according to any one of claims 1 to 7 , wherein the even number of consecutive frames are two back and forth frames. Said display includes a touch panel according to any one of claims 1 to 8, characterized in that a liquid crystal display. A method for driving a touch panel having an AC-driven display and a touch sensor that periodically reads contact information on the input surface,
A contact information detection step of detecting the contact information for each frame in synchronization with a start cycle of a reading operation of the touch sensor in a frame cycle of the display;
For an even number of consecutive frames, by calculating the average of the contact information, it possesses the contact information calculating step of obtaining a calculated contact information in a given frame, and
The reading operation is an operation in which the contact information on the input surface is circulated and read a plurality of times during one frame,
In the contact information detection step, a plurality of the contact information is detected in each frame,
In the contact information calculation step, an average of the contact information detected in the same order is calculated for the plurality of the contact information detected in each frame . The average is a moving average,
The touch panel driving method according to claim 10 , wherein the predetermined frame is a frame in which the continuous even number of the contact information already exists. The read operation, the driving method for a touch panel according to claim 10 or 11, characterized in that the electrodes arranged in a matrix form to detect the contact information is an operation of sequentially scanning each line. The touch sensor driving method for a touch panel according to any one of claims 10 to 12, characterized in that a capacitive touch sensor. The touch panel driving method according to any one of claims 10 to 13 , wherein the even number of consecutive frames are two consecutive frames. The computer-readable recording medium which recorded the program for performing the drive method of the touchscreen as described in any one of Claims 10 thru | or 14 . The program for performing the drive method of the touchscreen as described in any one of Claims 10 thru | or 14 .

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