JP3465831B2 - Display integrated coordinate input device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display-integrated coordinate input device in which a tablet for coordinate input is integrated with a matrix display.

[0002]

2. Description of the Related Art A pen input device is used as an information input means in place of a keyboard and a mouse because it is easy to input images such as graphics and is small in size. Particularly in recent years, by integrating a display device and a coordinate detection device, an input image can be immediately displayed on the display device, and operability is improved.

In order to realize a coordinate input device having such a display function at a low cost, the display electrodes normally used for displaying a matrix panel such as a liquid crystal display are also used as the coordinate detecting electrodes, and the display and the coordinate detecting are performed. Display-integrated coordinate input device for performing time division in Japanese Patent Application Laid-Open No. 2-2559
No. 11 publication.

A conventional display-integrated coordinate input device will be described below. The principle of a capacitively coupled display-integrated tablet is disclosed in JP-A-54-24538 and JP-A-62-180417.

Further, as shown in FIG. 37, the conventional coordinate input device integrated with a display has row electrodes Y orthogonal to each other.
A matrix panel (for example, a liquid crystal panel) 11 to which display elements are connected at intersections of _{1 to} Y _n and column electrodes X _{1 to} X _m.
An electrode drive circuit including a row electrode drive circuit 12 and a column electrode drive circuit 13 for driving the row electrodes and column electrodes of the matrix panel 11, a detection electrode 2 for detecting a scanning signal of the matrix panel 11, and a detection electrode 2. A coordinate detection circuit 3 including a row coordinate detection circuit and a column coordinate detection circuit for detecting row coordinates and column coordinates from the obtained signal, and control for controlling the row electrode drive circuit 12, the column electrode drive circuit 13, and the coordinate detection circuit 3. And a circuit 7.

In the display period, the row electrode drive circuit 12
From the column electrode driving circuit 13 to the column electrodes of the matrix panel 11 in accordance with the coordinate detection pulse sequentially supplied to the row electrodes of the matrix panel 11. The matrix panel 11 is displayed by supplying a voltage corresponding to the display data.

On the other hand, in the row coordinate detection period, when the coordinate detection pulse is sequentially supplied from the row electrode drive circuit 12 to the row electrodes of the matrix panel 11 and the detection electrode 2 is brought into contact with an arbitrary position of the matrix panel 11, The row coordinate detection circuit 3 detects the row coordinate of the detection electrode contact position from the coordinate detection pulse detected through the electrostatic coupling capacitance between the detection electrode 2 and the row electrode. Further, during the column coordinate detection period, coordinate detection pulses are sequentially supplied from the column electrode drive circuit 13 to the 11 column electrodes of the matrix panel, and when the detection electrodes 2 are brought into contact with arbitrary positions of the matrix panel 11, the detection electrodes are detected. The column coordinate of the detection electrode contact position is detected by the column coordinate detection circuit 3 from the coordinate detection pulse detected through the electrostatic coupling capacitance between the column electrode and the column electrode. As a result, one matrix panel displays an image and detects coordinates.

Since the obtained row and column coordinate data are immediately displayed as display data, the input image such as a figure or a character functions as if it were handwritten on the paper.

In the coordinate detecting circuit 3, the coordinate detecting pulse is detected through the electrostatic coupling capacitance between the detecting electrode 2 and the row electrode, and the coordinate is detected from the time when the output becomes maximum (hereinafter, "coordinate detecting pulse"). "Peak detection coordinates".).

Here, in detecting the coordinates, the position is detected by using the time when the detection signal becomes maximum. This is to prevent the position from being erroneously recognized due to the height of the detection electrode 2. This means that the scanning electrode connected to the power source V ₀ is moved at a constant speed v over the sheet electrode connected to the GND as shown in FIG. Can be understood by a simple model that detects

The coordinate of the center of the electrode is x_c, The width of the electrode is 2x
_w, The position of the detection electrode is P (x_p, Y _p, H_p), Scanning
The coupling capacitance per unit area of each part of the pole is C (x, y)
Then, the output V (t) becomes as shown in the following (Equation 1).

[0012]

[Equation 1]

Here, the denominator is set as shown in the following (Equation 2).

[0014]

[Equation 2]

By the way, when the coordinate of the center of the electrode is x _c , the scanning speed is v, and the time from the start of scanning is t, the following relationship (Equation 3) is established.

[0016]

[Equation 3]

Therefore, if the output V (t) is differentiated with respect to the time t under the condition that the coupling capacitance between the detection electrode 2 and the drive electrode does not change, the following formula (4) is obtained.

[0018]

[Equation 4]

Here, if the conditions that (1) V (x, y) does not change with respect to x and (2) C (x, y, h) is an even function with respect to x are satisfied, the output The differential value of V (t) becomes 0 when the following (Equation 5) is satisfied (that is,
The output becomes maximum).

[0020]

[Equation 5]

As described above, the y coordinate of the detection electrode 2 can be detected by using the time of appearance of the maximum value,
In addition, the x of the detection electrode 2 does not depend on the h coordinate (height coordinate).
The coordinates can be detected. Similarly, x of the detection electrode 2
The coordinates can be detected, and the y coordinate of the detection electrode 2 can be detected without depending on the h coordinate.

As a method of obtaining the appearance time of the maximum value, first, there is a method (a) using a differential filter to detect the zero point. In this case, the potential change of the maximum value becomes zero. There is also a method of performing (b) edge detection and midpoint detection (average value processing). In this case, the intermediate value of the appearance time of the rising edge and falling edge of the comparator output is the peak appearance time. Match. Also, (c) 2
There is a method of detecting the peak value by the interpolated curve. According to this method, the detection signal waveform near the maximum value is approximated by a quadratic curve, and the peak appearance time is measured based on the potential information at three or more points. The method for obtaining the time of appearance of the maximum value is appropriately selected from these.

However, when an STN type liquid crystal panel, which is a typical matrix panel, is used for coordinate detection, there are the following problems. For example, the electrode width is 27 for an electrode pitch of 300 μm.
As wide as 0 μm, 90% of the induced signal from the back electrode is blocked. Especially when a TFT active matrix panel or the like is used, the effective area is further limited.

A protective plate such as an acrylic plate or glass is provided to protect the panel, and the height of the pen (detection electrode) is limited, so that the intensity of the detection signal is weakened. Therefore, in order to increase the intensity of the detection signal, it is necessary to secure the detection intensity by widening the width of the coordinate detection pulse (that is, increasing the number of electrodes that are simultaneously scanned). However, because of the structural problem of the panel in which the electrodes used for coordinate detection exist only in the display area, x _w becomes small at the peripheral portion when the signal intensity becomes maximum,
Misalignment occurs.

Further, as described above, the electrode width is wide and the cell thickness of the panel is as narrow as 6 to 8 μm, so that the coupling capacitance between the electrodes is large. In addition, since the electrode resistance of ITO is large, the signal transmitted through ITO is delayed in transmission.
And, for this reason, a position shift occurs.

Next, the positional deviation caused by the structure near the extraction electrodes to the row electrode driving circuit and the column electrode driving circuit of the matrix panel will be described. FIG. 39 is a perspective view showing a detailed configuration of a matrix panel portion of a conventional display-integrated input device using an STN liquid crystal panel, for example. As shown in FIG. 39, the matrix panel 11 includes a first glass substrate 31 arranged on the upper side in the figure.
0, a second glass substrate 320 arranged on the lower side, and a liquid crystal layer 35 provided between the first glass substrate 310 and the second glass substrate 320. On the first glass substrate 310, the column electrodes 15 (x coordinate) arranged at the first predetermined pitch in the first predetermined direction are formed. On the other hand, on the second glass substrate 320, rows arranged at a second predetermined pitch (generally the same pitch as the first predetermined pitch) in a second predetermined direction orthogonal to the first predetermined direction. The electrode 19 (y coordinate) is formed.

Generally, the first and second glass substrates 31
On 0 and 320, the portion where the column electrode 15 and the row electrode 19 spatially overlap corresponds to the display area, and the other portion corresponds to the non-display area. At the end portion of the first glass substrate 310 orthogonal to the first predetermined direction, one tab 34 is provided for each predetermined number of column electrodes 311, and a plurality of tabs 34 are arranged in the first predetermined direction as a whole. ing.
The tab 34 corresponds to the column electrode drive circuit 13 and the column electrode 1 shown in FIG.
The pitch of the connection terminals on the tab 34 is different from the first pitch of the column electrodes 15, and is generally narrower than the first pitch. Therefore, in the non-display area on the first glass substrate 310, in order to connect the column electrodes 15 to the connection terminals of the tabs 34 and the like, the parallel connection electrodes 313 having the same pitch as the connection terminals of the tabs 34 and the like. , Connection electrode 313 and column electrode 1
5, non-parallel (oblique) lead-out electrodes 312 and the like are formed. Similarly, one tab 34 is provided for each predetermined number of row electrodes 19 at an end portion of the second glass substrate 320 orthogonal to the second predetermined direction, and the plurality of tabs 34 as a whole are arranged in the second predetermined direction. Are arranged in. The tab 34 is for connecting the row electrode drive circuit 12 and the row electrode 19 shown in FIG. 37, and the pitch of the connection terminals on the tab 34 is different from the second pitch of the row electrode 19. Is. In the non-display area on the second glass substrate 320, in order to connect each row electrode 19 to the connection terminals of the tabs 34, etc., the connection electrodes 323 parallel to the connection terminals of the tabs 34 and the connection electrodes parallel to each other are formed. 324 and non-parallel (oblique) extraction electrode 322 connecting the row electrode 19
Etc. are formed. First and second glass substrates 31
At 0 and 320, the triangular dummy electrodes 16 are formed near the adjacent portions of the two tabs 34. The dummy electrode 16 is generally provided for the purpose of preventing charge accumulation and light leakage during the manufacturing process, and is connected to one line adjacent to the extraction electrodes 312 and 322.

The coordinate detection of the panel end portion in the display-integrated coordinate input device using the conventional matrix panel configured as described above will be described. In FIG. 39, when the first predetermined direction in which the column electrodes 15 are arranged is X and the second predetermined direction in which the row electrodes 19 are arranged is Y, the detection electrodes 2 are arranged near the center of the matrix panel 11. When instructed, both the X coordinate and the Y coordinate can be detected with an accuracy of about 1 dot. However, the detection electrode 2 is placed near the end of the matrix panel 11, for example, 50
When moved in the X direction on the line indicated by 0, a positional shift corresponding to several dots occurs in the X direction due to the influence of the coordinate detection pulse applied to the dummy electrode portion 16. Further, there is also a positional shift due to the shape of the non-parallel electrode portion 312 of the extraction electrode. For example, when the detection electrode 2 is moved in the Y direction on the line of the matrix panel 11 indicated by 600, a displacement corresponding to several dots occurs in the X direction. This phenomenon changes according to the shape of the non-parallel electrode portion 312 of the extraction electrode portion. Further, this deviation also occurs with respect to the extraction electrode 322.

As described above, in the display-integrated type coordinate input device using the conventional matrix panel, the influence of the coordinate detection pulse applied to the dummy electrode portion 16 and the extraction electrode in the vicinity of the end of the matrix panel 11. There is a problem in that a positional deviation occurs depending on the shapes of the non-parallel electrode portions 312 and 322, and good coordinate detection accuracy cannot be obtained in the vicinity of the panel end portion.

Next, conventional display-integrated coordinate input
The drive voltage of the coordinate detection pulse in the device will be explained.
It FIG. 40 shows a conventional display-integrated coordinate input device.
An example of the voltage waveform applied to the electrode group of the matrix panel
Is shown. In FIG. 40, T_wIs the display period
While T_dIs the detection period, and is generally the display period T_wIs detected
Period T_dMuch longer than that. Also, t₁Is
Display period T_wScanning period of one line in t ₂Is detected
Period T_dIs a scanning period of one line in
₁Is t₂Much longer than that. Also, R₁,
R₂, R_mAre waveforms applied to the row electrodes, S₁,
S₂, S_nShows the waveform applied to each column electrode.

In the display period T _w , the voltage of V ₀ or V ₅ level is applied to the row electrode group when selected, and the voltage of V ₁ or V ₄ level is applied when not selected. Further, for example, when the display is ON, a voltage of V ₀ or V ₅ level is applied to the column electrode group, and when the display is OFF, V ₂ or V _{3 is applied.}
Apply level voltage.

On the other hand, during the detection period T _d , as described above, the coordinate detection pulse is sequentially applied to the row electrode group and the column electrode group. Although there are several kinds of possible settings for the amplitude of the pulse to be applied, it is assumed that V ₀ is applied during selection and V ₅ is applied during non-selection from the viewpoint that no DC component remains in the detection period T _d .

FIG. 41 shows an example of a conventional liquid crystal drive power supply circuit. As shown in FIG. 41, in this liquid crystal drive power supply circuit, a display liquid crystal drive voltage V _LCD is supplied to voltages V ₀ , V ₁ , V ₂ , V ₃ , V ₄ , V ₅ used for driving the liquid crystal.
Resistors r and R that divide the voltage into two and operational amplifiers 901, 902, and 9
03 and 904. When the driving condition of the liquid crystal display changes due to a temperature change or the like, the display can be optimized by changing V _LCD to change V _{0 to} V ₅ .

By the way, in the above-mentioned conventional driving method,
The voltage level is uniquely determined by V _LCD , and since the voltage level of the drive pulse applied to the electrode during the display period and the voltage level of the coordinate detection pulse applied to the electrode during the detection period are common, When the driving condition of No. 2 changes, it is necessary to change the driving voltage value.

However, when the drive voltage value is changed in this way, the amplitude of the coordinate detection pulse in the detection period also changes, and the intensity of the signal detected by the detection electrode also changes, so the detection accuracy changes. Such a problem occurs.

[0036]

As described above, the conventional display-integrated type coordinate input device is particularly inferior in the detection accuracy at the edge of the matrix panel to that at the center, so that the windows are not easily detected. However, it is not suitable for an input device that requires relatively high detection accuracy at the panel end.

According to the present invention, various detection methods and correction functions, or a novel panel structure and drive method are provided for the problems such as the positional deviation and the fluctuation of the detection accuracy that have occurred in the conventional display-integrated coordinate input device. It is an object of the present invention to provide a display-integrated coordinate input device that can improve the above-mentioned problems, and in particular, can improve the detection accuracy at the end portion of the matrix panel by including the device using the.

[0038]

In order to achieve the above object, the first structure of the display-integrated coordinate input device according to the present invention has a plurality of row electrodes (y direction) and a plurality of column electrodes (y direction) orthogonal to each other. x direction) and a display element enclosed between them, a row electrode drive circuit for driving the row electrodes, a column electrode drive circuit for driving the column electrodes, and a row electrode of the matrix panel. And a detection electrode that is electrically coupled to the column electrode by an electrostatic coupling capacitance and detects a scanning signal applied to the row electrode and the column electrode of the matrix panel, and a coordinate value according to a certain characteristic of the output signal of the detection electrode. A coordinate detection circuit for obtaining position information by outputting a correction circuit for correcting the coordinate value output from the coordinate detection circuit, the matrix panel, and the row electrode drive circuit.
Path, column electrode drive circuit, detection electrode, coordinate detection circuit and correction
Disupu comprising at least a control circuit for controlling the circuit
A ray-integrated coordinate input device, wherein the correction circuit comprises:
X coordinate (column position) output from the coordinate detection circuit, y coordinate
Y coordinate that converts the y coordinate (row position) according to the mark (row position)
X coordinate output from the coordinate conversion circuit and the coordinate detection circuit
(Column position) and y coordinate (row position) according to x coordinate (column position)
X) coordinate conversion circuit for converting the
At least a storage circuit for storing is provided .

[0039]

[0040]

Further, the in the first aspect of the present invention, preferably a correction value corresponding to the delay time of the drive signal to the memory circuit are example further Bei the correction value calculation circuit for Case <br/> housed .

[0042]

The display-integrated seat according to the present invention
The second configuration of the standard input device is a plurality of power lines that are orthogonal to each other.
A pole (y direction) and a plurality of column electrodes (x direction),
A matrix panel in which a display element is enclosed between
A row electrode drive circuit for driving electrodes and a drive circuit for the column electrodes
Column electrode drive circuit and the row electrodes and matrix electrodes of the matrix panel.
And column electrodes and electrostatic coupling capacitance to electrically couple the
Scan signal applied to row and column electrodes of matrix panel
Signal for detecting the signal and the output signal of the detection electrode.
Position information by outputting coordinate values according to the characteristics
And a coordinate detection circuit that obtains
Correction circuit that corrects the coordinate value
Row, row electrode drive circuit, column electrode drive circuit, detection electrode, coordinates
Minimize the control circuit that controls the detection circuit and the correction circuit.
A display-integrated coordinate input device also includes, prior to
Serial correction circuit includes a first correction circuit for outputting a correction value that varies depending on the distance from the panel edge in the x-direction until the detection <br/> out electrode, the <br/> from the panel edge in the y-direction A second correction circuit that outputs a correction value that changes according to the distance to the detection electrode, and a multiplication circuit that outputs the product of the output of the first correction circuit and the output of the second correction circuit are provided .
It is characterized by

The display-integrated seat according to the present invention
The third configuration of the standard input device is a plurality of power lines that are orthogonal to each other.
A pole (y direction) and a plurality of column electrodes (x direction),
A matrix panel in which a display element is enclosed between
A row electrode drive circuit for driving electrodes and a drive circuit for the column electrodes
Column electrode drive circuit and the row electrodes and matrix electrodes of the matrix panel.
And column electrodes and electrostatic coupling capacitance to electrically couple the
Scan signal applied to row and column electrodes of matrix panel
Signal for detecting the signal and the output signal of the detection electrode.
Position information by outputting coordinate values according to the characteristics
And a coordinate detection circuit that obtains
Correction circuit that corrects the coordinate value
Row, row electrode drive circuit, column electrode drive circuit, detection electrode, coordinates
Minimize the control circuit that controls the detection circuit and the correction circuit.
A display-integrated coordinate input device also includes, prior to
The coordinate detection circuit includes a first coordinate detection circuit which is a magnitude comparator whose output changes at the moment when the signal detected by the detection electrode exceeds a predetermined comparison potential, and a signal detected by the detection electrode is predetermined. consists of a second coordinate detection circuit is a magnitude comparator which outputs the instantaneous changes below the comparison potential of, and the correction circuit, the two coordinate values sent from the coordinate detection circuit of the detecting electrode It is characterized by having an arithmetic circuit for calculating a position. The third aspect of the present invention
In the above configuration, it is preferable that a means for switching the comparison potential of the magnitude comparator in each of the row coordinate detection period and the column coordinate detection period is further provided. Further, in the third configuration of the present invention, it is preferable to further include means for detecting the drive voltage of the matrix panel and switching the comparison potential of the magnitude comparator each time. In addition, the first aspect of the present invention
In the configuration of No. 3, it is preferable to further include means for switching the comparison potential of the magnitude comparator at any time according to the signal intensity generated in the detection electrode. In the third configuration of the present invention, the correction circuit is
The arithmetic circuit further includes an average value circuit that outputs an average value of the first and second coordinate detection circuits, and the arithmetic circuit has a coordinate having a first predetermined value.
When the above is the case, the output of the first coordinate detection circuit is selected,
When the coordinate is less than or equal to the second predetermined value, the output of the second coordinate detection circuit is selected, and the coordinate is equal to the first predetermined value or
It is preferable to have a selector that selects the output of the average value circuit when it is between the second predetermined value .

The display-integrated seat according to the present invention
The fourth configuration of the standard input device is a plurality of power lines that are orthogonal to each other.
A pole (y direction) and a plurality of column electrodes (x direction),
A matrix panel in which a display element is enclosed between
A row electrode drive circuit for driving electrodes and a drive circuit for the column electrodes
Column electrode drive circuit and the row electrodes and matrix electrodes of the matrix panel.
And column electrodes and electrostatic coupling capacitance to electrically couple the
Scan signal applied to row and column electrodes of matrix panel
Signal for detecting the signal and the output signal of the detection electrode.
Position information by outputting coordinate values according to the characteristics
And a coordinate detection circuit that obtains
Correction circuit that corrects the coordinate value
Row, row electrode drive circuit, column electrode drive circuit, detection electrode, coordinates
Minimize the control circuit that controls the detection circuit and the correction circuit.
A display-integrated coordinate input device also includes, prior to
Serial coordinate detection circuit includes a first coordinate detection circuit is a magnitude comparator which output change at the moment of exceeding the comparison potential is signal detected by the detection electrode, the comparison potential which is the signal to be detected by the detection electrode the below consists of a second coordinate detection circuit is a magnitude comparator which output change at the moment, the third coordinate detection circuit signal detected by the detection electrode is output change at the moment when the maximum and the correction circuit is characterized by having said first arithmetic circuit for calculating the position of the detection electrode from three coordinate values sent from the second and third coordinate detection circuit. Further , the fourth configuration of the present invention
In the above, it is preferable to further include means for switching the comparison potential of the magnitude comparator in each of the row coordinate detection period and the column coordinate detection period.
Further, in the fourth configuration of the present invention, it is preferable to further include means for detecting the drive voltage of the matrix panel and switching the comparison potential of the magnitude comparator each time. Further , the fourth structure of the present invention
In the formation, it is preferable to further include means for switching the comparison potential of the magnitude comparator at any time according to the signal intensity generated at the detection electrode. Also, the above
In the fourth configuration of the present invention, the arithmetic circuit has the coordinates of the first position .
When the value is greater than or equal to the predetermined value of 1, the first coordinate detection circuit outputs.
Force is selected and when the coordinate is less than or equal to the second predetermined value, the first
The output of the coordinate detection circuit 2 is selected, and the coordinate is the first position.
It is preferable to have a selector that selects the output of the third coordinate detection circuit when it is between a constant value and the second predetermined value . In the fourth configuration of the present invention, when the coordinate is equal to or larger than the first predetermined value, the first coordinate detection time
If the coordinates are less than or equal to the second predetermined value by using the output of the road,
Utilizing the output of the second coordinate detection circuit to come, coordinates the first
When the value is between the predetermined value of 1 and the second predetermined value, the output of the third coordinate detection circuit is used, and the weight is gradually changed in the vicinity of the switching area to switch gradually. It is preferable that the means is further provided.

[0046]

[0047]

[0048] Also, a fifth configuration of the display-integrated coordinate input device according to the present invention includes a plurality of row electrodes (y direction) perpendicular to each other, a plurality of column electrodes (x-direction), the row electrodes and The tab (TAB) and the tab (TA) in the lead-out portion of the matrix panel are electrically insulated from the column electrodes.
B), a matrix panel including at least a dummy electrode formed in a space between the row electrode and the column electrode, a display element enclosed between the row electrode and the column electrode, and a row electrode drive circuit connected to each of the row electrodes. A column electrode drive circuit connected to each of the column electrodes, a dummy electrode drive circuit connected to a dummy electrode that outputs a constant voltage in the coordinate detection period, a row electrode and a column electrode of the matrix panel, and an electrostatic capacitor. A detection electrode that is electrically coupled by a coupling capacitance and that detects a scanning signal applied to a row electrode and a column electrode of the matrix panel; a coordinate detection circuit that obtains position information by an output signal of the detection electrode; and the matrix panel, Row electrode
Drive circuit, column electrode drive circuit, dummy electrode drive circuit, detection
At least a control circuit for controlling the electrodes and the coordinate detection circuit is provided.

In the fifth structure of the present invention, the voltage applied to the dummy electrodes on the matrix panel is
The voltage is preferably such that the display element enclosed between the dummy electrode and the adjacent row or column electrode does not respond.

Further, in the fifth structure of the present invention, it is preferable that the voltage applied to the dummy electrode is an alternating signal used in the display mode of the matrix panel.
In the first to fifth configurations of the present invention, the matrix panel includes the column electrodes arranged on the first glass substrate in the first predetermined direction at the first predetermined pitch, and the display material layer. Row electrodes arranged at a second predetermined pitch in a second predetermined direction orthogonal to the first predetermined direction on a second glass substrate provided to face the first glass substrate via The column electrode and the row electrode have a seal in a non-display area other than a display area in which at least the column electrode and the row electrode are overlapped with each other while having the first and second predetermined pitches, respectively. It is preferable that it is pulled out to the vicinity of the portion without a bending point.

In the first to fifth structures of the present invention, the matrix panel includes the column electrodes arranged on the first glass substrate in the first predetermined direction at the first predetermined pitch, and the display. Arranged at a second predetermined pitch in a second predetermined direction orthogonal to the first predetermined direction on a second glass substrate provided so as to face the first glass substrate via a material layer. A row electrode, a lead electrode portion provided in a non-display region other than the display region where the column electrode and the row electrode on the first and second glass substrates overlap, and a lead electrode portion provided on the lead electrode portion. A conductive film that electrically shields the extraction electrode portion is preferably provided.

In the first to fifth structures of the present invention, it is preferable that the matrix panel is a liquid crystal panel .

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

According to the first structure of the display-integrated coordinate input device of the present invention, it has a plurality of row electrodes (y direction) and a plurality of column electrodes (x direction) orthogonal to each other, and displays between them. A matrix panel in which elements are encapsulated, a row electrode drive circuit for driving the row electrodes, a column electrode drive circuit for driving the column electrodes, and a row electrode and a column electrode of the matrix panel are electrically connected by electrostatic coupling capacitance. And a detection electrode for detecting a scanning signal applied to the row electrodes and column electrodes of the matrix panel, and coordinate detection for obtaining position information by outputting a coordinate value according to a certain feature of the output signal of the detection electrode. A circuit, a correction circuit for correcting the coordinate value output from the coordinate detection circuit, the matrix panel,
A display-integrated coordinate input device comprising at least a row electrode drive circuit, a column electrode drive circuit, a detection electrode, a coordinate detection circuit, and a control circuit for controlling a correction circuit.
The positive circuit outputs the x coordinate (column) output from the coordinate detection circuit.
Position), y coordinate (row position) according to y coordinate (row position)
Y coordinate conversion circuit for conversion and output from the coordinate detection circuit
X according to the x coordinate (column position) and y coordinate (row position)
X coordinate conversion circuit for converting coordinates (column position), and
At least a memory circuit for storing a correction value of
With this feature, it becomes possible to input coordinates at the peripheral edge of the panel, which was difficult to detect with the peak detection coordinates calculated from the time when the detected signal reaches its maximum, and the coordinates can be set with high position accuracy over the entire input range. You can enter. Further, by providing the correction means for compensating the positional deviation caused by the characteristics of the matrix panel, the coordinate detectable area is expanded and the linearity is improved. Further, by using the coordinate signal obtained by the level detection in which the linearity is secured even at the panel end, it becomes possible to input over the entire panel. Further, by switching between the coordinate signal obtained by peak detection in which the detected coordinates do not change depending on the height of the detection electrode and the coordinate signal obtained by level detection capable of ensuring the linearity at the end of the panel, the panel is switched. Higher detection accuracy can be obtained over the entire surface. In addition, the correction circuit outputs from the coordinate detection circuit.
Y according to the x coordinate (column position) and y coordinate (row position)
A y-coordinate conversion circuit for converting coordinates (row position), and the coordinates
X-coordinate outputted from the detection circuit (column position), y coordinates (row
X coordinate conversion that transforms the x coordinate (column position) according to the position
A small number of circuits and memory circuits that store the respective correction values
Since it is equipped with at least, especially on the matrix panel
The accuracy of detecting the coordinates of the four corners is improved.

[0059]

[0060]

In the first structure of the present invention ,
According to a preferred embodiment that has e further Bei the correction value calculation circuit for storing a correction value corresponding to the delay time of the serial憶回path to the drive signal, in particular improved the four corners of the coordinate detection accuracy on the matrix panel.

[0062]

Display integrated coordinate input of the present invention
According to the second configuration of the device, a plurality of power lines that are orthogonal to each other are provided.
A pole (y direction) and a plurality of column electrodes (x direction),
A matrix panel in which a display element is enclosed between
A row electrode drive circuit for driving electrodes and a drive circuit for the column electrodes
Column electrode drive circuit and the row electrodes and matrix electrodes of the matrix panel.
And column electrodes and electrostatic coupling capacitance to electrically couple the
Scan signal applied to row and column electrodes of matrix panel
Signal for detecting the signal and the output signal of the detection electrode.
Position information by outputting coordinate values according to the characteristics
And a coordinate detection circuit that obtains
Correction circuit that corrects the coordinate value
Row, row electrode drive circuit, column electrode drive circuit, detection electrode, coordinates
Minimize the control circuit that controls the detection circuit and the correction circuit.
It is a coordinate input device with integrated display that also has
Serial correction circuit includes a first correction circuit for outputting a correction value that varies depending on the distance from the panel edge in the x-direction until the detection <br/> out electrode, the <br/> from the panel edge in the y-direction A second correction circuit that outputs a correction value that changes according to the distance to the detection electrode, and a multiplication circuit that outputs the product of the output of the first correction circuit and the output of the second correction circuit are provided .
By virtue of this feature, the accuracy of detecting the coordinates of the four corners on the matrix panel is improved.

Display-integrated coordinate input of the present invention
According to the third configuration of the device, a plurality of power lines that are orthogonal to each other are provided.
A pole (y direction) and a plurality of column electrodes (x direction),
A matrix panel in which a display element is enclosed between
A row electrode drive circuit for driving electrodes and a drive circuit for the column electrodes
Column electrode drive circuit and the row electrodes and matrix electrodes of the matrix panel.
And column electrodes and electrostatic coupling capacitance to electrically couple the
Scan signal applied to row and column electrodes of matrix panel
Signal for detecting the signal and the output signal of the detection electrode.
Position information by outputting coordinate values according to the characteristics
And a coordinate detection circuit that obtains
Correction circuit that corrects the coordinate value
Row, row electrode drive circuit, column electrode drive circuit, detection electrode, coordinates
Minimize the control circuit that controls the detection circuit and the correction circuit.
It is a coordinate input device with integrated display that also has
Serial coordinate detection circuit, the signal signal detected by the detection electrode is detected in the first coordinate detection circuit is a magnitude comparator which outputs the instantaneous changes exceeding a predetermined comparison voltage, by the detection electrode is predetermined consists of a second coordinate detection circuit is a magnitude comparator which outputs the instantaneous changes below the comparison potential of, and the correction circuit, the two coordinate values sent from the coordinate detection circuit of the detecting electrode by further comprising a calculation circuit for calculating a position coordinate detection precision of the end portion on the matrix panel is improved. Also,
In the third configuration of the present invention, in the row coordinate detection period and the column coordinate detection period, according to a preferable example further comprising means for switching the comparison potential of the magnitude comparator each time, the row coordinate, the column coordinate It is possible to keep the potential level at constant and to stably obtain row coordinates and column coordinates. Also, the book
In the third configuration of the invention , according to a preferable example in which the driving voltage of the matrix panel is detected, and the comparison potential of the magnitude comparator is switched each time, according to the preferable example, the position shift occurs due to the change of the driving voltage. Can be suppressed. In addition, the first aspect of the present invention
According to a preferred example in which the configuration of No. 3 further includes means for switching the comparison potential of the magnitude comparator at any time according to the signal intensity generated in the detection electrode, the detection electrode structure of the matrix panel is It is possible to suppress the occurrence of positional deviation due to the change in signal intensity caused by the difference. In addition, in the third configuration of the present invention,
The correction circuit further includes an average value circuit that outputs the average value of the first and second coordinate detection circuits, and the arithmetic circuit detects the first coordinate when the coordinate is equal to or larger than the first predetermined value. Selecting the output of the circuit, selecting the output of the second coordinate detection circuit when the coordinate is less than or equal to the second predetermined value, and setting the coordinate to the first
According to the preferred example of having a selector for selecting the output of the average value circuit when it is between the predetermined value of the above and the second predetermined value, it is possible to input coordinates over the entire area of the matrix panel. In addition, it is possible to suppress the coordinate skip at the time of coordinate detection in switching each level.

[0065]Display integrated coordinate input of the present invention
According to the fourth configuration of the device, a plurality of power lines that are orthogonal to each other are provided.
A pole (y direction) and a plurality of column electrodes (x direction),
A matrix panel in which a display element is enclosed between
A row electrode drive circuit for driving electrodes and a drive circuit for the column electrodes
Column electrode drive circuit and the row electrodes and matrix electrodes of the matrix panel.
And column electrodes and electrostatic coupling capacitance to electrically couple the
Scan signal applied to row and column electrodes of matrix panel
Signal for detecting the signal and the output signal of the detection electrode.
Position information by outputting coordinate values according to the characteristics
And a coordinate detection circuit that obtains
Correction circuit that corrects the coordinate value
Row, row electrode drive circuit, column electrode drive circuit, detection electrode, coordinates
Minimize the control circuit that controls the detection circuit and the correction circuit.
It is a coordinate input device with integrated display that also has
RecordThe coordinate detection circuitThe aboveThe signal detected by the detection electrode
Output changes at the moment when the signal exceeds a certain comparison potential
A first coordinate detection circuit which is a mode comparator, and
The signal detected by the detection electrode is below the comparison potential.
Magnitude comparator that changes output at the moment it turns
And a second coordinate detection circuit that is
The third locus where the output changes at the moment when the output signal becomes maximum
And a target detection circuit, andThe aboveThe correction circuit is the above-mentioned
The three signals sent from the first, second and third coordinate detection circuits
From coordinate valuesThe aboveEquipped with a calculation circuit that calculates the position of the detection electrode
DoBy featuring thatMatrix panel
Detection accuracy at the edge is improved and third coordinate detection
Due to the existence of the circuit, the detection in the central part of the matrix panel
The output accuracy is also improved.WellWasIn the fourth configuration of the present invention
There, The arithmetic circuit determines that the coordinates are greater than or equal to the first predetermined value.
The output of the first coordinate detection circuit is selected,
When the value is less than a predetermined value, the output of the second coordinate detection circuit
And the coordinates are the first predetermined value and the second predetermined value.
Select the output of the third coordinate detection circuit if it is between the values
According to a preferred example of having a selector for
Depending on the position of the electrode, peak detection coordinates and level detection seat
Selecting the appropriate one of the three outputs
Since it can be
It is possible to enter the mark. Also,Fourth configuration of the present invention
At, When the coordinate is greater than or equal to the first predetermined value, the first
The output of the coordinate detection circuit of is used to set the coordinate to the second predetermined value.
Utilizing the output of the second coordinate detection circuit when
The coordinates are between the first predetermined value and the second predetermined value
If the output of the third coordinate detection circuit is used,
Gradually change the weight near the switching area,
It is said that there is more means to gradually switch.
According to a preferred example, the peak and level switching areas are
Even in this case, it is possible to obtain coordinate values that maintain continuity and are not misaligned.
You can

[0066]

[0067]

[0068]

The display-integrated seat of the present invention is also provided.
According to the fifth configuration of the standard input device, a plurality of row electrodes (y direction) orthogonal to each other, a plurality of column electrodes (x direction), and a matrix that is electrically insulated from the row electrodes and the column electrodes. A matrix panel having at least a dummy electrode formed in a gap between the tabs (TAB) in the lead-out portion of the panel and a display element enclosed between the row electrodes and the column electrodes; A row electrode drive circuit connected to each of the row electrodes, a column electrode drive circuit connected to each of the column electrodes, and a dummy electrode drive circuit connected to a dummy electrode that outputs a constant voltage during the coordinate detection period, Detection electrodes that are electrically coupled to the row electrodes and column electrodes of the matrix panel by electrostatic coupling capacitances and that detect scanning signals applied to the row electrodes and column electrodes of the matrix panel; A coordinate detection circuit for obtaining positional information by the output signal of the serial detection electrodes, said matrix panel,
Since at least the row electrode drive circuit, the column electrode drive circuit, the dummy electrode drive circuit, and the control circuit for controlling the detection electrode and the coordinate detection circuit are provided, the voltage applied to the dummy electrode does not include the coordinate detection pulse, and the dummy Since the distortion of the detection signal near the electrodes is eliminated, the detection accuracy is improved.

In the fifth structure of the present invention,
According to the preferable example in which the voltage applied to the dummy electrode on the matrix panel is such that the display element enclosed between the dummy electrode and the adjacent row or column electrode does not respond, good display quality is maintained. It becomes possible.

By the way, there is generally a space of 100 μm or more between the dummy electrode and the column electrode or row electrode adjacent thereto. Therefore, in the fifth configuration of the present invention, according to a preferable example in which the voltage applied to the dummy electrode is an alternating signal used in the display mode of the matrix panel, the voltage applied to the dummy electrode and the column adjacent thereto. The effective voltage difference of the voltage applied to the electrodes or row electrodes is reduced. As a result, even if such a voltage is applied, the display element enclosed between the dummy electrode and the adjacent column electrode or row electrode does not respond, so that good display quality can be maintained. Becomes

Further, in the first to fifth configurations of the present invention,
And the matrix panel has a first glass substrate on which the first
A column electrode arranged in a predetermined direction at a first predetermined pitch,
It faces the first glass substrate through the display material layer.
The first predetermined direction on the second glass substrate provided
Arranged at a second predetermined pitch in a second predetermined direction orthogonal to the direction
Row electrodes, the column electrodes and the row electrodes
Have said first and second predetermined pitches, respectively
As it is, at least the column electrode and the row electrode overlap each other.
In the non-display area other than the display area
Therefore, according to a preferred example in which it is pulled out without a bending point.
The dummy battery near the edge of the matrix panel.
The influence of the coordinate detection pulse applied to the pole and the extraction
Coordinate detection pulse depending on the shape of the non-parallel electrode part
Of the edge of the matrix panel without being affected by
The detection accuracy is improved .

In the first to fifth structures of the present invention, the matrix panel has the first glass substrate and the first glass substrate.
A column electrode arranged in a predetermined direction at a first predetermined pitch,
It faces the first glass substrate through the display material layer.
The first predetermined direction on the second glass substrate provided
Arranged at a second predetermined pitch in a second predetermined direction orthogonal to the direction
Row electrodes and the front of the first and second glass substrates
Except for the display area where the column electrodes and the row electrodes overlap.
The extraction electrode portion provided in the non-display area and the extraction electrode
It is provided on the lead-out electrode portion and the lead-out electrode portion is electrically
According to a preferred embodiment of you and a conductive film shield to the shape of the extraction electrode and the dummy electrode and the conventional
Even with the same pattern, the dummy electrode part and the extraction electrode
The pulse for coordinate detection in the section is detected by the detection electrode.
The accuracy of the detection of the edge of the matrix panel is
Improve .

[0074] Further, in the first to fifth configuration of the present invention, according to a preferable embodiment of the matrix panel is Ru crystal panel der, liquid crystal capable of performing stable detection
It is possible to realize a coordinate input device integrated with a display .

According to the present invention, by providing the above-mentioned functions, the detection accuracy at the edge of the matrix panel can be improved and the external environment such as the change of the display condition can be affected. It is possible to realize a display-integrated coordinate input device. By using the display-integrated coordinate input device of the present invention, even in a device such as Windows that requires a comparatively high accuracy at the end of the matrix panel, the peripheral end of the matrix panel can be instructed. Also, even when handwriting a graphic, the peripheral edge of the matrix panel can be input while maintaining good accuracy.
Further, since the image is displayed immediately, it can be applied to a portable information terminal such as a pen personal computer and a PDA as an input device with high end accuracy.

[0076]

EXAMPLES The present invention will be described in more detail below with reference to examples. <First Embodiment> FIG. 1 is a configuration diagram showing a first embodiment of a display-integrated coordinate input device according to the present invention. In FIG. 1, reference numeral 1 denotes a liquid crystal module. The liquid crystal module 1 has a plurality of row electrodes Y _{1 to} Y _n and column electrodes X _{1 to} X _m which are orthogonal to each other, and a liquid crystal layer is provided between them as a display element. The liquid crystal panel 11, the row electrode drive circuit 12 that drives the row electrodes of the liquid crystal panel 11, and the column electrode drive circuit 13 that drives the column electrodes. Further, 2 is a detection electrode which is electrically coupled to the row electrode and the column electrode of the liquid crystal panel 11 by electrostatic coupling capacitance, and which detects a scanning signal applied to the row electrode and the column electrode of the liquid crystal panel 11, 3
Is a coordinate detection circuit for converting the signals obtained by the detection electrodes 2 into row coordinates and column coordinates, and 5 is a correction calculation circuit for correcting the positional deviation using the correction parameters of the device that have previously captured the output values of the coordinate detection circuit 3. , 7 are control circuits for controlling the liquid crystal module 1, the coordinate detection circuit 3, and the correction calculation circuit 5.

The display-integrated coordinate input device configured as described above sequentially supplies the scanning pulse from the row electrode drive circuit 12 to the row electrodes of the liquid crystal panel 11 in a unit of one electrode during the display period. Then, in accordance with the scanning pulse sequentially supplied to the row electrodes of the liquid crystal panel 11, the column electrode drive circuit 13 supplies a voltage corresponding to the display data to the column electrodes of the liquid crystal panel 11, thereby displaying the liquid crystal panel 11. . In the row coordinate detection period, the row electrode drive circuit 12 sequentially scans the row electrodes of the liquid crystal panel 11 with coordinate detection pulses. Then, the detection electrode 2 is connected to the liquid crystal panel 11
When an arbitrary position is touched, the row coordinate of the detection electrode contact position is detected and corrected from the coordinate detection pulse detected by the row coordinate detection circuit 3 through the electrostatic coupling capacitance between the detection electrode 2 and the row electrode. The arithmetic circuit 5 corrects the coordinates. In the column coordinate detection period, the column electrode drive circuit 13 sequentially scans the column electrodes of the liquid crystal panel 11 with coordinate detection pulses. Then, when the detection electrode 2 is brought into contact with an arbitrary position of the liquid crystal panel 11, the detection electrode contact is made from the coordinate detection pulse detected by the column coordinate detection circuit 3 through the electrostatic coupling capacitance between the detection electrode 2 and the column electrode. The column coordinates of the position are detected, and the correction calculation circuit 5 corrects the coordinates. This gives 1
An image is displayed and coordinates are detected on the liquid crystal panel 11.

Hereinafter, a method of correcting the positional deviation caused by using the liquid crystal panel 11 for coordinate detection will be described. (ITO (indium tin oxide) delay correction) First,
The positional deviation caused by the signal transmission delay in ITO will be described.

The signal transmission system when focusing on one segment electrode is as shown in the equivalent circuit of FIG. For example, when the electrode pitch of the liquid crystal panel is 0.3 mm, the ITO space is usually 30 μm, which is 1/10 of the electrode pitch, I
The sheet resistance of the TO electrode is normally 30Ω □, the cell thickness of the liquid crystal is 7 μm, the relative permittivity is about 7, the resistance per unit pixel is 33Ω, and the distributed capacitance per cell is 0.
It becomes 7 pF, and these must be handled as distributed constant circuits.

Therefore, the driven signal is delayed in transmission. As a result, as shown in FIG. 3, the detected y-coordinate value is not constant even if the detected signal is on the straight line parallel to the x-axis, and the detected signal is on the straight line parallel to the y-axis. Even if there is, the detected x coordinate is not constant. For example, even if the y-coordinate value is below the straight line parallel to the x-axis,
A distance of 40 pixels results in a transmission delay of about 3 μsec. Therefore, by using a circuit as shown in FIG.
The positional deviation caused by the signal transmission delay at the electrodes is eliminated.

In FIG. 4, reference numeral 501x is a storage means for storing correction information required to correct the x coordinate, 502x is an error amount calculation circuit for calculating a deviation amount from the y coordinate value and the correction information of the storage means 501x, and 503x is the x coordinate. Error amount calculation circuit 5
An addition circuit for adding the output of 02x, 501y is a storage unit for storing correction information required for correction of the y coordinate, 502y is an error amount calculation circuit for calculating a deviation amount from the x coordinate value and the correction information of the storage unit 501y, and 503y is This is an addition circuit that adds the output of the error amount calculation circuit 502y to the y coordinate.

The error amount calculation circuits 502x and 502y include
From the coordinate detection circuit 3 (see FIG. 1), the y coordinate value determined based on the appearance time of the peak value in the row coordinate (y coordinate) detection period and the appearance time of the peak value in the column coordinate (x coordinate) detection period are displayed. The x-coordinate value determined based on this is input. Then, the shift amount with respect to the x coordinate is calculated using the input y coordinate value, and the shift amount with respect to the y coordinate is calculated using the input x coordinate value. The parameters required for the calculation are stored in the storage means 501x, 50 by the method described later.
It is stored in 1y, and these are used in the calculation.

In the adder circuits 503x and 503y,
By subtracting the shift amount based on the delay detected by the error amount calculation circuits 502x and 502y from the coordinate value obtained by the coordinate detection circuit 3 (see FIG. 1), the position shift caused by the ITO delay is corrected.

Next, the correction method and means for obtaining the correction information will be described. (1) Method by calculation from the physical parameters of the device The delay time of the drive signal by the ITO is the physical parameters of the ITO electrode (area resistance σ, width w, length L, distributed capacitance C), drive signal source impedance R _i , It can be calculated using the termination impedance R _o . The deviation of the peak position of the detection signal is calculated by adding the driving frequency and the pulse width to this. (2) Acquisition of correction data by position adjustment When correcting a position shift in the x-axis direction, for example, refer to FIG.
As shown in (a), alignment is performed at points P ₁ (X ₁ , Y ₁ ) and P ₂ (X ₂ , Y ₂ ) on a straight line parallel to the y-axis on the panel. At the point on the straight line parallel to the y-axis, the following relationship (Equation 6) holds, so the x-coordinates of all the points on this straight line are supposed to be x _o , but actually the transmission delay in the ITO electrode is Because of the difference.

[0085]

[Equation 6]

At this time, if the coordinate values obtained at the point P ₁ are x ₁ and y ₁ and the coordinate values obtained at the point P ₂ are x ₂ and y ₂ , the deviation amount Δx is as follows (Equation 7). Can be calculated by

[0087]

[Equation 7]

In the case of a double liquid crystal panel, since the drive circuits are located above and below, for example, two points P on a straight line parallel to the y-axis.
Positioning is performed with ₁ (x _o , Y ₁ ) and P ₂ (x _o , Y ₂ ) (see FIG. 5B). The coordinates obtained at this time are P
_{If 1} (x ₁ , y ₁ ) and P ₂ (x ₂ , y ₂ ), the shift amount Δx can be calculated by the following (Equation 8).

[0089]

[Equation 8]

The same applies to the y-axis direction.
The deviation Δy can be calculated, but it is longer than the x electrode.
In addition, since the delay time is large, a sufficient correction must be made with the linear equation.
Can not do it. Therefore, a quadratic expression or a broken line
The shift amount is calculated by. For example, as shown in Fig. 5 (c), 3
Point P₁, P₂, P₃Position with, coordinate P₁(X
₁, Y₁), P₂(X₂, Y₂), P₃(X₃, Y₃)
To measure.

When approximated by a quadratic equation, the shift amount Δy can be calculated by the following (Equation 9).

[0092]

[Equation 9]

When approximated by a polygonal line,
By utilizing the fact that there is little change near the end,
The shift amount Δy can be calculated by the following (Equation 10).

[0094]

[Equation 10]

In this embodiment, a linear expression is used for the x coordinate and a quadratic expression or a broken line is used for the y coordinate. However, higher order correction may be performed to improve accuracy. In applications where accuracy is not required, low order correction may be used. Incidentally, the x-coordinate has a small amount of deviation due to delay, and therefore it is considered that there is no particular problem even if it is handled as a constant. It is also possible to increase the number of points to be measured. Moreover, by performing the alignment at the points shown in FIG. 5D, it becomes possible to reduce the number of input points.

(Panel edge γ correction) By utilizing the time when the maximum value appears, the position of the pen can be detected without affecting the height of the pen, but the electrode arrangement area is the object of coordinate detection. It is the same as the area, and because the signal strength is weak, scanning is performed with multiple electrode widths.
Misalignment occurs at the edge of the panel.

FIG. 6 shows the result of measuring the peak appearance time at the time of detecting the x coordinate. As shown in FIG. 6, since γ becomes small at the end, it is necessary to raise γ at the end. Therefore, a circuit as shown in FIG. 7 is used to remove the positional deviation caused by the signal transmission delay in the ITO electrode.

In FIG. 7, 511x is a storage means for storing the correction information required for the correction of the x coordinate, and 512x is a γ for correcting the deviation from the x coordinate value and the correction information of the storage means 511x.
The conversion circuit 511y is a storage means for storing correction information required for y coordinate correction, and 512y is a y coordinate value and a storage means 51.
It is a γ conversion circuit that corrects the deviation from the correction information of 1y.

In the γ conversion circuits 512x and 512y, inclination conversion is performed on the detected coordinates as shown in the following (Equation 11).

[0100]

[Equation 11]

This γ function is shown in FIG. Ideally, the switching width λ should be set to a half x _w / 2 of the drive electrode width x _w , but there is a problem in the circuit system, so it is better to use the actual measurement value as the switching width λ. .

(Tab connection vicinity correction processing) As described above, at the end, as shown in FIG. 39, the electrode pitch is different from the display area due to the connection with the tab 34, and the position is changed by the difference in the electrode pitch. Misalignment occurs. An example of this result is shown in b of FIG. Therefore, in order to eliminate the influence of this line collection, it is necessary to perform correction using a correction processing circuit as shown in FIG.

In FIG. 10, 521x is a storage means for storing correction information required to correct the x coordinate, 522x is an error amount calculation circuit for calculating a deviation amount from the x coordinate value, y coordinate value and the correction information of the storage means 521x. Reference numeral 523x is an addition circuit for adding the output of the error amount calculation circuit 522x to the x coordinate, 52
1y is a storage means for storing correction information required to correct the y coordinate, and 522y is an x coordinate value, ay coordinate value, and a storage means 521y.
Error amount calculation circuit for calculating the amount of deviation from the correction information of
Reference numeral 3y is an addition circuit for adding the output of the error amount calculation circuit 522y to the y coordinate.

The error amount calculation circuits 522x and 522y are
From the coordinate detection circuit 3 (see FIG. 1), the y coordinate value determined based on the appearance time of the peak value in the row coordinate (y coordinate) detection period and the appearance time of the peak value in the column coordinate (x coordinate) detection period are displayed. The x-coordinate value determined based on this is input. Then, using the input x coordinate value and y coordinate value, x
The shift amount from the coordinate is calculated, and the input x coordinate, y
A displacement amount with respect to the y coordinate is calculated using the coordinate value. For example, when obtaining the shift amount Δx (x, y) in the x direction, a function Δ that depends on the x coordinate, as shown in the following (Equation 12).
It can be calculated by the product of a function Δx _y that depends on the x _x and y coordinates.

[0105]

[Equation 12]

It should be noted that Δx _x (x) and Δx _y (y) can be expressed as in the following (Equation 13).

[0107]

[Equation 13]

Further, by allocating the tabs evenly, the correction process can be realized by a simple iterative process, and the correction calculation can be easily performed. Also,
Even if the dummy electrode described later is not subjected to any processing, it is possible to reduce noise by the same processing.

By adding various kinds of correction processing in this way, it is possible to improve the detection accuracy, for example, by removing the positional deviation that occurs when the liquid crystal panel is used for coordinate detection.

<Second Embodiment> FIG. 11 is a block diagram showing a second embodiment of the display-integrated coordinate input device according to the present invention. In FIG. 11, reference numeral 1 denotes a liquid crystal module. The liquid crystal module 1 has a plurality of row electrodes Y _{1 to} Y _n and column electrodes X _{1 to} X _m which are orthogonal to each other, and a liquid crystal layer is provided between them. The liquid crystal drive circuit includes a panel 11, a row electrode drive circuit 12 that drives the row electrodes of the liquid crystal panel 11, and a column electrode drive circuit 13 that drives the column electrodes. Further, in FIG. 11, 2 is a liquid crystal panel 1.
The detection electrodes 4 for detecting the scanning signal 1 detect the time (rising edge, falling edge) when the signal obtained by the detection electrode 2 reaches the comparison potential level, and output the coordinates corresponding to the row coordinates and the column coordinates. The coordinate detection circuit 5 removes a fixed offset from the output value of the coordinate detection circuit 4 and corrects the positional deviation from the physical parameters of the device that are loaded in advance. 6 selects two output signals of the correction operation circuit 5. Reference numeral 7 denotes a control circuit for controlling the liquid crystal module 1, the coordinate detection circuit 4, the correction calculation circuit 5, and the selection circuit 6.

The display-integrated coordinate input device of the present embodiment is intended to eliminate the positional deviation that occurs due to the low γ of the detection signal in the peripheral portion in the configuration of FIG. Basically, since the same operation as that of the first embodiment shown in FIG. 1 is performed, the display-integrated coordinate input device of the present embodiment will be described focusing on different points.

(Level Detection Processing) The point that this embodiment is largely different from the display-integrated coordinate input device of the first embodiment is that when the coordinates are detected, the coordinates are not determined by the appearance time of the peak, but the detection signal. The point is that the coordinates are determined according to the time when a certain comparison potential level is reached (hereinafter, the coordinates thus determined are referred to as "level detection coordinates").

In the above (Equation 1), for example, when the detection electrode 2 is placed in the center of the liquid crystal panel 11 (x _a = X _L /
_{2), x a = x p} + x w the potential level of the moment it became V
_{If c} , then the following (Equation 14) is obtained.

[0114]

[Equation 14]

On the other hand, the potential V _R measured at the point where x _a = x _p + x _{w at the} right end (right to left in the scanning direction) is as shown in the following (Equation 15).

[0116]

[Equation 15]

Actually, there is a slight difference because C _sum is different, but if the relative distance (including direction) is equal,
The output value at that time is the same. Therefore, the V _R in a region excluding the left end, by monitoring the time to reach the voltage V _R with the detection voltage V, it is possible to detect the coordinates at the right end.

At the left end (scanning direction right → left), measurement is performed at a point where x _a = x _p −x _w . The potential V _{L at} this time is as shown in the following (Equation 16), and similarly, in the region excluding the right end, the output value is the same when the relation of x _a = x _p −x _w is satisfied.

[0119]

[Equation 16]

Therefore, similarly, the coordinates can be detected at the left end by monitoring the time when the detection voltage V reaches a certain voltage V _L. Under this idea,
FIG. 12 shows the result of detecting the coordinates by using the times at which the potentials V _L and V _R are reached. As mentioned above, V _L is at the right end,
Although V _R cannot ensure linearity at the left end, if the selection circuit 6 uses V _R in the right half and V _{L in the} left half, coordinates can be input over the entire area.

Specifically, it can be realized by a circuit as shown in FIG. 13, for example. FIG. 13 shows in detail the functions of the respective parts of the coordinate detection circuit 4, the correction calculation circuit 5 and the selection circuit 6 in FIG. Here, the coordinate detection circuit 4 includes a first detection circuit including a magnitude comparator 41 that changes its output at the moment when a signal detected by the detection electrode 2 exceeds a certain comparison potential, and a comparison with a signal detected by the detection electrode. The second detection circuit is composed of a magnitude comparator 42 that changes its output at the moment when it falls below the potential. In addition, the correction calculation circuit 5
Is an offset removing circuit 43 for removing a fixed offset.
And a correction circuit 44 that corrects the positional deviation based on the physical parameters of the device that have been captured in advance. The selection circuit 6 is composed of a selector that selects one of the two outputs from the correction calculation circuit 5.

Under the circuit configuration as described above, according to the detection example of FIG. 13, the first detection circuit outputs V _L , the second detection circuit outputs V _R, and the position of the detection electrode 2 is detected. According to the above, by selecting one of the two outputs by the selector, an accurate coordinate value can be output.

As another example of using level detection,
VR is output on the right side where linearity cannot be ensured, _VL is output on the left side, and V _R is output in other areas.
Configuration that outputs an average value of _L and V _R is also conceivable.
According to this configuration, the coordinates can be input over the entire area, and the insertion of the average value circuit can prevent the coordinates from being skipped when the coordinates are detected when the levels are switched.

Specifically, it can be realized by a circuit as shown in FIG. 14, for example. In FIG. 14, an average value circuit 45 for outputting the average value of the outputs of the first detection circuit and the second detection circuit is provided between the coordinate detection circuit 4 and the offset removal circuit 43 of FIG. is there. The output of the average value circuit 45 is connected to the selection circuit 6 through the correction calculation circuit 5 as in the case of the first detection circuit and the second detection circuit. The average value circuit 45 outputs V _L by the first detection circuit on the left side of the panel and V _R by the second detection circuit on the right side of the panel according to the position of the detection electrode 2.
Can be realized by outputting an average value at a position between them and selecting one of three outputs by a selector provided in the selection circuit 6.

It should be noted that when the level detection coordinate is used, the magnitude of the detection signal is different between when detecting the x coordinate and when detecting the y coordinate, and it is normal for the same comparison voltage level. It does not work.

For example, the y electrode is more sensitive than the x electrode to the detection electrode 2
On the side close to, the signal obtained by scanning the y electrode is about 10 times as strong as the signal obtained by scanning the x electrode. Therefore, even if an attempt is made to detect the x-coordinate at the comparison level most suitable for detecting the y-coordinate, the signal intensity obtained by scanning the x-electrode cannot reach the comparison voltage and cannot be detected. Therefore,
It is necessary to set the optimum comparison voltage level for each. Actually, it is necessary to switch the comparison potential of each magnitude comparator shown in FIGS. 13 and 14 in each of the x and y detection periods.

Further, when the characteristics of the display element enclosed in the matrix panel change according to the ambient temperature or the like (for example, the optical characteristics of liquid crystal or the like change according to the ambient temperature). It is necessary to change the voltage applied to the matrix panel according to the temperature. Normally, a contrast volume (variable resistor) or the like is used to realize the above function, but in this case, the intensity of the coordinate detection signal also changes at the same time.

As a method for solving this problem, the comparison voltage level (magnitude comparator) is changed according to the drive voltage of the matrix panel, and the comparison voltage level (magnitude comparator) is changed according to the intensity of the coordinate detection signal. Variable method, method of detecting the drive voltage of the matrix panel and correcting the detected coordinates,
A method of detecting the intensity of the coordinate detection signal to correct the detected coordinates, a method of keeping the coordinate detection drive signal at a constant potential without interlocking with the display drive signal, and the like are conceivable.

[0129] For example, as shown in FIG. 15, since the peak value of the drive signal for coordinate detection to be applied to the liquid crystal panel 11 is substantially proportional to the liquid crystal drive voltage V _LCD, a liquid crystal drive voltage V _LCD and GND The potential divided by the resistors 71 and 72 is applied to the inverting input of the comparator 74, and the detection signal passing through the reset circuit 73 designed so that the detection signal potential at the time of non-scan becomes the GND potential is supplied to the comparator 74. It can be realized by constructing a circuit to be added to the non-inverting input.

With respect to, for example, the same function can be realized by holding the peak value of the detection signal for a certain period by the peak hold circuit and changing this voltage to the liquid crystal drive voltage V _LCD .
The period for obtaining the peak value does not necessarily have to be the coordinate detection period, but may be the display period. For example, a period during which the alternating signal changes may be included.

With respect to the liquid crystal panel 11, for example, a correction value according to the drive potential of the liquid crystal panel 11 is calculated in advance and stored in the storage means, and a correction value according to the detected drive voltage of the liquid crystal panel 11 is obtained. It can be configured by a subtraction circuit that subtracts from the coordinate value.

[0132] Since the description will be made in the section "Height correction" (third embodiment), it will not be illustrated here. Also, since this will be described in the section (seventh embodiment) related to the “method of driving the matrix panel”, it will not be illustrated here.

When a differential signal is used as the detection signal, a positive (negative) comparison voltage level is used to detect the time corresponding to the rising edge, and the time corresponding to the falling edge is detected. Use a negative (positive) comparison voltage level for. This makes it possible to eliminate the influence of the differential capacitance formed by the coupling capacitance between the drive electrode and the detection electrode and the input impedance of the detection electrode.

It should be noted that one comparison voltage level should be prepared for each of the x and y axes, except for adding a frequency compensating filter that makes the entire frequency characteristic flat and removing the influence of the differentiating circuit formed in the input section. It's enough.

<Third Embodiment> FIG. 16 is a block diagram showing a third embodiment of the display-integrated coordinate input device according to the present invention.

In FIG. 16, reference numeral 1 denotes a liquid crystal module. This liquid crystal module 1 has a plurality of row electrodes Y _{1 to} Y _n and column electrodes X _{1 to} X _m which are orthogonal to each other, and a liquid crystal layer is provided between them. The liquid crystal panel 11 includes a liquid crystal panel 11, a row electrode drive circuit 12 that drives the row electrodes of the liquid crystal panel 11, and a column electrode drive circuit 13 that drives the column electrodes. Further, 2 is a detection electrode for detecting a scanning signal of the liquid crystal panel 11, 3 is a time when the signal obtained by the detection electrode 2 reaches a maximum, and outputs coordinates corresponding to row coordinates and column coordinates. The second coordinate detection circuit 4 detects the time (rising edge, falling edge) when the signal obtained by the detection electrode 2 reaches a fixed potential level and outputs the coordinates corresponding to the row coordinates and the column coordinates. A circuit 5 is a correction arithmetic circuit that removes a fixed offset from the output values of the first and second coordinate detection circuits 3 and 4 and corrects the positional deviation from the physical parameters of the device that has been captured in advance. 6 is an output of the correction arithmetic circuit 5. A selection circuit for selecting a signal, and a control circuit 7 for controlling the liquid crystal module 1, the coordinate detection circuit 4, the correction calculation circuit 5, and the selection circuit 6.

The display-integrated coordinate input device according to the present embodiment has a positional deviation which occurs in the coordinate input device having the structure shown in FIG. The purpose is to correct from the beginning. Basically, since the same operation as the configuration of the second embodiment is performed, the display-integrated coordinate input device of the present embodiment will be described here focusing on the points different from the second embodiment.

(Peak detection / level detection switching processing)
As described above, the peripheral portion cannot be detected by the coordinate detection by the peak detection (first embodiment), and the pen height due to the bending of the panel cannot be detected by the coordinate detection by the level detection (second embodiment). A positional shift occurs due to the change.

In order to solve this, basically, the coordinates are detected by the peak detection, and the coordinates are determined by the level detection for the parts that cannot be dealt with by the peak detection.
For example, in the x-axis direction, the coordinate value obtained by the first coordinate detection circuit 3 is x _p , and the coordinate value obtained by the second coordinate detection circuit 4 is x _u (x _a = x _p −x _The position is detected by switching the values as shown in the following (Equation 17), where x is the coordinate detected at the point of _w ) and x _d (the coordinate detected at the point of x _a = x _p + x _w ).

[0140]

[Equation 17]

In the y-axis direction, the first coordinate detecting circuit 3
The coordinate value obtained by y _{p is} the second coordinate detection circuit 4
When the coordinate value obtained was _{y u (y a = y p} -y w become point coordinates detected _{by), y d (y a =} y p + y w become point coordinates detected by) by the following The position is detected by switching the value as in (Equation 18).

[0142]

[Equation 18]

By performing the switching control in this way,
Positional deviation due to the influence of height can be reduced in the central portion, and the position can be detected also in the periphery.

Specifically, for example, it can be realized by a circuit as shown in FIG. FIG. 17 shows the first coordinate detection circuit 3, the second coordinate detection circuit 4 in FIG.
The respective parts of the correction calculation circuit 5 and the selection circuit 6 are shown in detail. Here, the first coordinate detection circuit 3 is composed of a third detection circuit including a magnitude comparator 36 that changes its output at the moment when the signal detected by the detection electrode 2 reaches its maximum. Also, the coordinate detection circuit 4
Is a first detection circuit including a magnitude comparator 41 whose output changes at the moment when the signal detected by the detection electrode 2 exceeds a certain comparison potential, and at a moment when the signal detected by the detection electrode 2 falls below the certain comparison potential. The second composed of a magnitude comparator 42 whose output changes
And a detection circuit of. The correction calculation circuit 5 is composed of an offset removal circuit 43 that removes a fixed offset and a correction circuit 44 that corrects the positional deviation based on the physical parameters of the device that have been captured in advance. In addition, the selection circuit 6 operates from the correction calculation circuit 5 to the detection electrode 2
It is configured by a selector that selects one of the three outputs output from the first and second coordinate detection circuits 3 and 4 according to the position.

If the circuit configuration as described above is adopted, by selecting one of the three outputs of the peak detection coordinate and the level detection coordinate according to the position of the detection electrode 2, the entire area of the panel is selected. It becomes possible to input over.

Further, in order to maintain the continuity of each connecting portion of the peak and level coordinates, the following (Equation 19) is used,
The specific gravity of α, β and γ is controlled as shown in FIG.

[0147]

[Formula 19]

Specifically, as shown in FIG.
In addition to the above circuit configuration, between the offset removal circuit 43 and the correction circuit 44, a first average value circuit 46 that outputs the average value of the outputs of the first detection circuit and the third detection circuit,
A second average value circuit 47 that outputs the average value of the outputs of the second detection circuit and the third detection circuit is provided, and as shown in FIG. 18, a first average value circuit 46 and a second average value circuit are provided. This can be realized by using the output of the circuit 47 in the switching region for the peak and level detection.

If such a circuit configuration is adopted, one of the five outputs of the correction calculation circuit 5 is selected according to the position of the detection electrode 2 so that even in the peak and level switching regions. , It is possible to obtain coordinate values that maintain continuity and are free of positional deviation.

(Height Correction) By the way, in the above-mentioned method, the distance from the liquid crystal layer to the writing surface (the surface of an acrylic plate or the like normally used for protecting the matrix panel) (hereinafter referred to as “height of detection electrode”). Must be constant. If the height of the detection electrode is not constant, the offset value of the coordinate value obtained by level detection at the time of alignment (one point in the center) is different from the offset value in the periphery actually used, and the detection coordinate is not correct at the switching unit. It will be continuous. Therefore, it is necessary to know the offset value in the periphery.

As this method, it is conceivable to perform position adjustment at several points and directly obtain the offset value, but it is necessary to always input several points at the time of position adjustment for parallax correction. Parallax correction processing becomes complicated.

Therefore, as another means for avoiding this, there is a method of detecting the height and calculating the offset value from the previously measured data. In fact, the height of the detection electrode does not change much at the edges, which can be determined at design time. Therefore, according to FIG. 20, which shows the change in the height of the detection electrode versus the detected coordinate value when the normal voltage is applied to the liquid crystal panel, the differences Δx _uh , Δx _dh , and Δy _{uh from the} coordinates obtained by the peaks. , Δy _dh (hereinafter referred to as “offset value deviation”) is calculated and removed.

For example, when the distance from the liquid crystal layer to the surface of the protective acrylic plate is 3 mm, the offset value shift is about 2 dots (Δx _uh , Δx _dh ) for the x coordinate and about 2 dots for the y coordinate. It becomes 7 dots (Δy _uh , Δy _dh ).

By using the correction value thus obtained,
The conversion is performed as shown below (Equation 20).

[0155]

[Equation 20]

Further, by controlling the specific gravities of α, β and γ as shown in FIG. 18 and determining the coordinates according to the following (Equation 21), the continuity of the connecting portion can be obtained.

[0157]

[Equation 21]

(Power Supply Voltage Correction) By the way, the detection coordinates obtained in the level detection change depending on not only the height of the detection electrode but also the inclination of the detection electrode, but the size of the portion where the detection electrode is coupled to the drive electrode is large. It is possible to take a countermeasure by making the diameter closer to a sphere so that the bond strength does not change even if the inclination changes a little.

The signal strength also changes with the drive signal voltage (which changes with the contrast adjustment volume). That is, x increases as the drive signal voltage increases.
_u changes in the direction in which the coordinate value decreases, and x _d changes in the direction in which the coordinate value increases.

In this case, it is possible to consider first a driving method in which the intensity of the coordinate detection pulse does not change depending on the driving conditions (this method will be described later, so it is not shown here), or as shown in FIG. There is a method in which a power supply voltage monitoring circuit 8 for monitoring the power supply voltage is provided and the offset of the previously obtained offset value is corrected based on this output.

[0161] Further, when in the vicinity of the center of the liquid crystal panel 11 has the detecting electrode 2, x _p -x _u, examines the x _d -x _p, it is also possible to detect the drive signal intensity (detection electrode height If there is little fluctuation).

In the first to third embodiments,
Although the case where the liquid crystal panel is used as the matrix panel has been described as an example, the matrix panel is not necessarily limited to the liquid crystal panel, and another matrix panel having a plurality of electrodes in the row direction and the column direction may be used.

<Fourth Embodiment> (Method of Applying Voltage on Dummy Electrodes) In this embodiment, by applying a voltage to the dummy electrodes formed on the matrix panel, the edge portion of the matrix panel, especially It is intended to improve the detection accuracy in the vicinity of the dummy electrode.

As shown in FIG. 39, at the end of the matrix panel 11, the electrode pitch is narrowed because the electrodes are connected to the tabs connected to the row electrode drive circuit 12 and the column electrode drive circuit 13. A triangular gap is created between the tabs. If left as it is, more light will pass through this part than in other regions, and since it will look unattractive, electrodes (dummy electrodes) are formed in this region as well as other regions.
I try to limit the amount of light that leaks.

Further, when a signal is not applied to the triangular dummy electrode, electric charges are accumulated in the coupling capacitance formed by the peripheral electrodes to emit light, so that the potential of this portion must be fixed. Normally, the signal is connected to the adjacent signal line, and a signal similar to that of the connected signal line is generated. However, when a drive signal is applied to a portion having such a large area, a displacement as shown in FIG. 9a occurs. In this case, the influence of the dummy electrode can be suppressed by electrically disconnecting the dummy electrode and fixing the potential.

However, if the potential of the dummy electrode is kept constant, the liquid crystal between the adjacent electrodes on the same surface reacts with each other, and the phenomenon that the boundary portion emits light again occurs. In order to solve this problem, the dummy electrodes are driven as follows.

FIG. 22 shows, for example, in the liquid crystal panel 11.
It is the figure which expanded and showed the dummy electrode vicinity of FIG. In FIG. 22, 15a to 15f are column electrodes, and 19a to 19f.
f is a row electrode, which is generally composed of a transparent electrode. Further, numeral 34 is a tab for connecting to the column electrode drive circuit 12, and its output terminals are respectively column electrodes 15a to 15a.
connected to f. Reference numeral 16 is a dummy electrode provided in order to eliminate the difference in brightness between the place where the column electrodes 15a to 15f are present and the place where they are not present in the visible region, and is generally composed of a transparent electrode. Here, the dummy electrode 16 is taken out by the transparent electrode 17 and is connected to the column dummy electrode voltage V _dm .

FIG. 23 shows an example of the column dummy electrode voltage V _dm . In FIG. 23, V ₂ and V ₃ are column non-selection voltages in the display mode, V ₀ and V ₅ are selection voltages, and V ₀ > V
_2> V _3> are in a relationship of V _5. 20a is a dummy electrode 16
Shows the voltage waveform of the column electrode 15d adjacent to, and 20b shows the voltage waveform of the dummy electrode 16. That is, the voltage V ₃ is applied to the dummy electrode 16 during the display period 1 and the voltage V ₂ is applied during the display period 2. Further, the voltage V ₅ is applied to the dummy electrode 16 during the coordinate detection period.

Since the voltage applied to the dummy electrode 16 is the voltage having the above waveform, the voltage component of the dummy electrode 16 does not include the coordinate detection pulse. Therefore, when the detection electrode 2 is located near the dummy electrode 16,
Detection electrode 2 and column electrodes 15a to 15f or row electrodes 19a to
Even if an attempt is made to detect the coordinate detection pulse by capacitive coupling with 19f, the dummy electrode 16 does not generate the coordinate detection pulse at the same timing as the column electrode 15c or 15d adjacent thereto, and the signal at that timing is generated. Since only the intensity does not increase, the coordinate detection signal detected at the timing before and after that does not become distorted. Therefore, the coordinates in the effective display area can be accurately detected including the panel periphery (in particular, the vicinity of the dummy electrode 16).

By the way, the distance between the dummy electrode 16 and the column electrode 15c or 15d adjacent thereto is generally 100 μm.
There is an interval above. In this case, the dummy electrode 16
Since the alternating signal used in the display mode of the liquid crystal panel 11 is used as the voltage applied to the voltage waveform, the effective voltage difference between the voltage waveform 20a and the voltage waveform 20b is small. Therefore, even if a voltage as shown in FIG. 23 is applied, the liquid crystal sandwiched between the dummy electrode 16 and the column electrode 15c or 15d adjacent thereto does not respond from OFF to ON, so that the display quality is improved. There is no loss.

FIG. 24 shows another example of the column dummy electrode voltage V _dm . Similar to FIG. 23, 21a shows the voltage waveform of the column electrode 15d adjacent to the dummy electrode 16, and 21b shows the voltage waveform of the dummy electrode 16. That is, the dummy electrode 16
, The voltage V ₃ is applied during the display period 1 and the coordinate detection period, and the voltage V ₂ is applied during the display period 2.

Even if the voltage applied to the dummy electrode 16 is a voltage having the above waveform, the voltage component of the dummy electrode 16 does not include the coordinate detection pulse. Therefore, when the detection electrode 2 is located near the dummy electrode 16, the coordinate detection pulse will be detected by the electrostatic coupling capacitance between the detection electrode 2 and the column electrodes 15a to 15f or the row electrodes 19a to 19f. Even if the dummy electrode 16 is adjacent to the column electrode 1
The coordinate detection pulse is not generated at the same timing as 5c or 15d, and only the signal strength at that timing is not increased, so that the coordinate detection signals detected at the timings before and after that are not distorted. Therefore, the coordinates in the effective display area can be accurately detected including the panel periphery (in particular, the vicinity of the dummy electrode 16). Further, for the same reason as above, even if a voltage as shown in FIG. 24 is applied, the liquid crystal sandwiched between the dummy electrode 16 and the column electrode 15c or 15d adjacent thereto responds from off to on. Therefore, the display quality is not impaired.

In the liquid crystal panel 11 of FIG. 39, row dummy electrodes (not shown) as well as column dummy electrodes 16 exist. FIG. 25 shows an example of the voltage applied to the row dummy electrodes. In FIG. 25, V ₁ and V ₄ are row non-selection voltages in the display mode, V ₀ and V ₅ are selection voltages, and each voltage is V
There is a relation of ₀ > V ₁ > V ₄ > V ₅ . 22a shows a voltage waveform of the row electrode adjacent to the row dummy electrode, and 22b
Shows the voltage waveform of the row dummy electrodes. That is, the voltage V ₄ is applied to the row dummy electrodes during the display period 1 and the coordinate detection period, and the voltage V ₁ is applied during the display period 2.

If the voltage applied to the row dummy electrodes is a voltage having the above waveform, the voltage component of the row dummy electrodes does not include the coordinate detection pulse. Therefore, when the detection electrode 2 is located near the row dummy electrode, the coordinate detection pulse will be detected by the electrostatic coupling capacitance between the detection electrode 2 and the column electrodes 15a to 15f or the row electrodes 19a to 19f. However, since the row dummy electrode does not generate the coordinate detection pulse at the same timing as the row electrode adjacent to it, only the signal strength at that timing does not increase, so the coordinates detected at the timing before and after that The detection signal is not distorted. Therefore, the coordinates in the effective display area can be accurately detected including the periphery of the panel (in particular, the vicinity of the row dummy electrode). Further, for the same reason as above, even if a voltage as shown in FIG. 25 is applied, the liquid crystal sandwiched between the row dummy electrode and the row electrode adjacent thereto does not respond from OFF to ON. , The display quality is not impaired.

<Fifth Embodiment> (Panel Structure and Treatment of Lead-out Electrodes) This embodiment is deteriorated due to the dummy electrodes and the lead-out electrodes to the tabs, especially by changing the configuration of the matrix panel itself. It is intended to improve the detection accuracy.

FIG. 26 is a perspective view showing a fifth embodiment of the display-integrated coordinate input device according to the present invention, and particularly shows the detailed structure of the matrix panel portion. Figure 2
6, the matrix panel 11 is, for example, 480 ×
This is a 320-dot STN liquid crystal panel, and a protective plate is provided on the surface of the STN liquid crystal panel with a gap of about 1 mm (illustration is omitted for clarity). The matrix panel 11 includes a first glass substrate 310 arranged on the upper side and a second glass substrate 320 arranged on the lower side in the figure.
And a first glass substrate 310 and a second glass substrate 320.
And a liquid crystal layer 35 provided between the first and second glass substrates 310 and 320, and the peripheral portions of the first and second glass substrates 310 and 320 are sealed with a sealing resin portion. The sealed portion is indicated by the one-dot chain line 33. A column electrode 15 is formed on the first glass substrate 310. The column electrode 15 is composed of a plurality of electrodes X ₁ , X ₂ , ... X _n arranged in a first predetermined direction at a first predetermined pitch. On the other hand, a plurality of second glass substrates 320 are arranged at a second predetermined pitch (generally, the same pitch as the first predetermined pitch) in a second predetermined direction orthogonal to the first predetermined direction. Row electrodes 19 composed of the electrodes Y ₁ , Y ₂ , ..., Y _n are formed.

First and second glass substrates 310 and 320
In the above, the portion where the column electrode 15 and the row electrode 19 spatially overlap corresponds to the display area 32, and the other portion corresponds to the non-display area. At the end portion of the first glass substrate 310 orthogonal to the first predetermined direction, a predetermined number of column electrodes 1
One tab 34 is provided for every five, and the plurality of tabs 34 are arranged in the first predetermined direction as a whole. Tab 34
Is for connecting the column electrode drive circuit 13 and the column electrode 15 shown in FIG. 1, and the pitch of the connection terminals on the tab 34 is different from the first pitch of the column electrode 15, The interval is narrower than the first pitch. Therefore, in the non-display area on the first glass substrate 310, in order to connect each column electrode 15 to the connection terminals of the tabs 34, etc., the parallel connection electrodes 31 of the same pitch as the connection terminals of the tabs 34 are connected.
3 and non-parallel (oblique) lead-out electrodes 312 that connect the connection electrodes 313 and the column electrodes 15 are formed. Similarly, at the end portion of the second glass substrate 320 orthogonal to the second predetermined direction, one tab 34 is provided for each of the predetermined number of row electrodes 19, and the plurality of tabs 34 are secondly provided as a whole.
Are arranged in a predetermined direction. The tab 34 is for connecting the row electrode drive circuit 12 and the row electrode 19 shown in FIG. 1, and the pitch of the connection terminals on the tab 34 is different from the second pitch of the row electrode 19. Is. In the non-display area on the second glass substrate 320, in order to connect each row electrode 19 and the connection terminal of the tab 34, the tab 3
4 parallel connection electrodes 323 with the same pitch as the connection terminals
And non-parallel (oblique) lead-out electrodes 322 connecting the connection electrodes 323 and the row electrodes 19 are formed. The row electrodes 19 and the column electrodes 15 are led out without bending points to at least the vicinity of the seal portion 33 in the non-display area while maintaining the pitch in the display area 32, and are drawn to the lead electrode portions 312 and 322 below the seal portion 33. It has a connected configuration. In this case, the constraints due to the surface area of the first and second glass substrates 310, 320 and the tab 34.
In consideration of the matching with the pitch of the first and second glass substrates 310 and 320, a dummy electrode portion having a triangular shape as seen in the conventional example is provided in the vicinity of a portion adjacent to the two tabs 34. Need not be formed. The operation of the display-integrated coordinate input device in this embodiment is basically the same as that of the conventional example.

Next, the characteristics of the display-integrated coordinate input device according to this embodiment will be described with reference to FIGS. First, the row electrode direction is Y and the column electrode direction is X. When the detection electrode 2 is designated near the center of the liquid crystal panel 11 which is the matrix panel in FIG. 26, the coordinate detection can be performed with an accuracy of about 1 dot for both the X coordinate and the Y coordinate, as shown in the conventional example.

Next, consider the detection coordinates when the detection electrode 2 is moved to the vicinity of the extraction electrode, that is, to the end of the liquid crystal panel 11. For example, when the detection electrode 2 is moved in the X direction on the line 500 of the liquid crystal panel 11 in FIG. 26, the peak position of the coordinate detection waveform of the detection signal in the X direction of the column electrode 15 and the conventional example. The comparison result is shown in FIG. In FIG. 27, if the frequency of the coordinate detection signal is set to 3 MHz, for example, in the conventional coordinate device with a display-integrated type, due to the influence of the dummy electrode, the extraction electrode, etc., the linearity of the detection accuracy equivalent to about 8 dots is obtained. Deterioration is occurring. On the other hand, in the display-integrated coordinate input device according to the present embodiment, the linearity between the pen (detection electrode) position and the detection position is maintained with an accuracy of 1 dot or less, as in the vicinity of the panel center. From the above results, the display-integrated coordinate input device using the matrix panel of the present embodiment can realize good coordinate detection accuracy not only near the center of the panel but also at the edge of the panel. This is particularly effective when using software such as Windows that requires the ability to read coordinates near the edges.

As described above, according to the present embodiment, the extraction electrode 322 of the row electrode 19 to the tab 34 and the extraction electrode 31 of the column electrode 15 to the tab 34 in the matrix panel.
2 is drawn out to the vicinity of the seal portion 33 in the matrix panel without a bending point while maintaining the pitch of the row electrodes 19 and the column electrodes 15 in the display region 32, so that the dummy electrodes having a triangular shape in structure. The part disappears, and the electrode can be pulled out straight. Therefore, the problem that the coordinate detection accuracy is lowered depending on the shape of the electrode is solved, and a display-integrated coordinate input device having good coordinate detection accuracy over the entire panel can be realized.

<Sixth Embodiment> Similar to the fifth embodiment, this embodiment is deteriorated due to the dummy electrodes and the lead electrodes to the tabs, especially by changing the configuration of the matrix panel itself. It is intended to improve the detection accuracy.

FIG. 28 is a perspective view showing a sixth embodiment of the display-integrated coordinate input device according to the present invention, and particularly shows the detailed structure of the matrix panel portion. Figure 2
8, the matrix panel 11 is, for example, 480 ×
This is a 320-dot STN liquid crystal panel, and a protective plate is provided on the surface of the STN liquid crystal panel with a gap of about 1 mm (illustration is omitted for clarity). The matrix panel 11 includes a first glass substrate 310 arranged on the upper side and a second glass substrate 320 arranged on the lower side in the figure.
And a first glass substrate 310 and a second glass substrate 320.
And a liquid crystal layer 35 provided between the first and second glass substrates 310 and 320 are sealed by a sealing resin portion (the sealing portion is 33). . A column electrode 15 is formed on the first glass substrate 310. The column electrode 15 is composed of a plurality of electrodes X ₁ , X ₂ , ... X _n arranged in a first predetermined direction at a first predetermined pitch. On the other hand, the first glass is on the second glass substrate 320.
Of a plurality of electrodes Y ₁ , Y ₂ , ..., Y _n arranged at a second predetermined pitch (generally the same pitch as the first predetermined pitch) in a second predetermined direction orthogonal to the predetermined direction of The electrode 19 is formed.

First and second glass substrates 310 and 320
In the above, the portion where the column electrode 15 and the row electrode 19 spatially overlap corresponds to the display area 32, and the other portion corresponds to the non-display area. At the end portion of the first glass substrate 310 orthogonal to the first predetermined direction, a predetermined number of column electrodes 1
One tab 34 is provided for every five, and the plurality of tabs 34 are arranged in the first predetermined direction as a whole. Tab 34
Is for connecting the column electrode drive circuit 13 and the column electrode 15 shown in FIG. 1, and the pitch of the connection terminals on the tab 34 is different from the first pitch of the column electrode 15, The interval is narrower than the first pitch. Therefore, in the non-display area on the first glass substrate 310, in order to connect each column electrode 15 to the connection terminals of the tabs 34, etc., the parallel connection electrodes 31 of the same pitch as the connection terminals of the tabs 34 are connected.
3 and non-parallel (oblique) lead-out electrodes 312 that connect the connection electrodes 313 and the column electrodes 15 are formed. Similarly, at the end portion of the second glass substrate 320 orthogonal to the second predetermined direction, one tab 34 is provided for each of the predetermined number of row electrodes 19, and the plurality of tabs 34 are secondly provided as a whole.
Are arranged in a predetermined direction. The tab 34 is for connecting the row electrode drive circuit 12 and the row electrode 19 shown in FIG. 1, and the pitch of the connection terminals on the tab 34 is different from the second pitch of the column electrode 15. Is. In the non-display area on the second glass substrate 320, in order to connect each row electrode 19 and the connection terminal of the tab 34, the tab 3
4 parallel connection electrodes 323 with the same pitch as the connection terminals
And non-parallel (oblique) lead electrodes 322 for connecting the connection electrodes 223 and the row electrodes 19 are formed. In addition, 2 on the first and second glass substrates 310 and 320
A triangular dummy electrode 16 similar to the conventional example is formed in the vicinity of the adjacent portion of the two tabs 34. The shape of each electrode on the first and second glass substrates 310 and 320 is almost the same as that of the conventional example shown in FIG. Further, in order to protect the matrix panel 11, a transparent protective plate 340 is provided on the non-display area outside the display area 32 with a space of about 1 mm. The protective plate 340 is formed by applying a conductive resin for shielding to the non-display area portion of the panel surface of the matrix panel 11, and has a structure connected to a ground terminal (not shown). The operation of the display-integrated coordinate input device in this embodiment is basically the same as that of the conventional example.

The characteristics of the display-integrated coordinate input device according to this embodiment will be described with reference to FIGS. 27, 28 and 29. First, the row electrode direction is Y and the column electrode direction is X. When the detection electrode 2 is designated near the center of the matrix panel 11 in FIG. 28, coordinate detection can be performed with an accuracy of about 1 dot for both the X coordinate and the Y coordinate, as in the conventional example. Next, the detection electrode 2 is connected in the vicinity of the extraction electrode 312 of FIG. 28, that is, the matrix panel 11
28, the peak position of the coordinate detection waveform in the X direction when the detection electrode 2 is moved in the Y direction and the position above the line 600 on the matrix panel 11 in FIG. The result of comparison with the example is shown in FIG. Here, for example, if the cycle of the coordinate detection signal is 3 MHz,
In the conventional example, the extraction electrode portion 31 is provided from the display area portion 2
As the value approaches 2, the linearity deteriorates by a maximum of 3.6 dots in the X direction of the solid line, and the line 600
There was a change in linearity depending on the shape of each corresponding electrode above. On the other hand, in the display-integrated coordinate input device of the present embodiment, which is a shielded structure,
As indicated by the □ mark in the figure, the linearity change between the pen (detection electrode) position and the detection position is about 1 dot at maximum, as in the vicinity of the center of the panel, and it can be seen that the coordinate detection accuracy is improved. Similarly, with respect to the coordinate detection value when the detection electrode 2 is moved in the X direction on the line 500 of the matrix panel 11 in FIG. 28, the same result as above can be obtained as shown in FIG.

As described above, according to this embodiment, the row electrode 1
9 and the column electrode 15 electrically shield the portions of the extraction electrodes 312, 322 to the tab 34 in the non-display area other than the display area 32 with respect to the detection electrode 2 by a conductive film, and thus the matrix panel 11 Even when the electrode pattern is almost the same as the conventional one, the detection electrode 2 does not detect the coordinate detection pulse in the dummy electrode portion 16 and the extraction electrode portions 312 and 322. As a result, it is possible to prevent the coordinate detection accuracy from deteriorating, and it is possible to realize a display-integrated coordinate input device having good coordinate detection accuracy over the entire panel.

This is particularly effective when using software such as Windows that requires the ability to read coordinates near the edges relatively. In the fifth and sixth embodiments, the case where the STN type liquid crystal panel is used as the matrix panel has been described as an example, but the present invention is not limited to these. Needless to say, the same applies to the case of using a matrix panel other than the STN type, an EL panel, a plasma display panel, and other types of matrix panels.

<Seventh Embodiment> In this embodiment, a method of driving a scanning pulse used particularly in the coordinate detection period and a configuration for realizing the method will be described.

FIG. 30 shows a display integrated type according to the present invention.
Electrodes of matrix panel of seventh embodiment of coordinate input device
It is a figure which shows the voltage waveform applied to a group. Figure 30 Smell
T_wIs the display period, T_dIs the detection period, T_w>>
T_dIs. Also, t₁Is the display period T_w1 rai in
Scanning period, t₂Is the detection period T _dOf one line in
Scanning period, t₁>> t₂Is. Also, R₁, R
₂, R_mRepresents the waveform applied to the row electrode, and S₁,
S₂, S_nShows the waveform applied to the column electrodes.

In the display period T _w , the voltage of V ₀ or V ₅ level is applied to the row electrode group when selected, and the voltage of V ₁ or V ₄ level is applied when not selected. Further, for example, when the display is ON, a voltage of V ₀ or V ₅ level is applied to the column electrode group, and when the display is OFF, a voltage of V ₂ or V ₃ level is applied.

On the other hand, in the detection period T _d , the scanning pulse for detection is sequentially applied to the row electrode group and the column electrode group. As the scanning pulse for detection, V _d is applied at the time of selection and V ₅ is applied at the time of non-selection so that the amplitude has a constant value regardless of the driving condition of the display.

FIG. 31 shows an example of a liquid crystal driving power supply circuit of the display-integrated coordinate input device in this embodiment. As shown in FIG. 31, this liquid crystal drive power supply circuit divides the display liquid crystal drive voltage V _LCD into the voltages V ₀ , V ₁ , V ₂ , V ₃ , V ₄ , V ₅ used for driving the liquid crystal. Resistors r and R for compressing and operational amplifiers 201, 202, 20
3, 204, 205 are provided. If the driving conditions of the liquid crystal display change due to temperature changes, etc.,
By changing the display liquid crystal drive voltage V _LCD , it is possible to optimize the display by changing the voltages V _{0 to} V ₅ . A switching circuit 206 is provided in this liquid crystal drive power supply circuit, and the switching circuit 206
The output of is connected to V _{0 of the} liquid crystal drive circuit. Then, according to the switching signal, the display period T _w and the detection period T _d
The output voltage from the switching circuit 206 can be switched to V _LCD or the detection liquid crystal drive voltage V _d . With this configuration, in the display period T _w , the display drive pulse in which V _LCD is changed according to the drive condition of the matrix panel can be applied to obtain an optimum display, while the display period is detected. T _d
In the above, the voltage V _d having a constant amplitude value can always be applied as the scanning pulse for detection. as a result,
The strength of the detection signal is not affected by changes in the driving conditions for display, and stable detection can be performed.

In this embodiment, the liquid crystal drive circuit
The case where the output voltage is 0 V or higher has been described as an example.
However, depending on the liquid crystal drive circuit, not only the level of positive polarity
There is also a type that outputs a negative voltage level.
It FIG. 32 is a display-integrated coordinate in this embodiment.
It shows another example of the liquid crystal drive power supply circuit of the input device.
is there. In FIG. 32, r and R are resistors and 301 and 30.
2, 303, 304, and 305 are operational amplifiers, and 306 is a switch.
Itching circuit, V_LCDIs the liquid crystal drive voltage for display, V _dIs
The liquid crystal drive voltage for detection is shown. In this case, the negative voltage
Switch to change the drive voltage
The output of the driving circuit 306 is V of the liquid crystal drive circuit._FiveConnected to
ing.

FIG. 33 shows still another example of the liquid crystal drive power supply circuit of the display-integrated coordinate input device of this embodiment. In FIG. 33, r and R are resistors,
Reference numerals 401, 402, 403, 404, and 405 denote operational amplifiers, 406 denotes a switching circuit, V _LCD denotes a display liquid crystal drive voltage, and V _d denotes a detection liquid crystal drive voltage. in this case,
The switching circuit 406 includes a V _LCD and an operational amplifier 401.
It is provided between and. Then, by the switching signal, only the input voltage to V ₀ of the liquid crystal drive circuit can be switched to the detection liquid crystal drive voltage V _d . With this configuration, the same effect as above can be obtained.

By the way, in the liquid crystal drive circuit, for example, V ₀ > V ₁ , V
_It is general to set the use conditions of ₂ > V ₃ , V ₄ > V ₅ , and in this case, V _d > V ₁ , V ₂ , V ₃ ,
It is necessary to satisfy V ₄ and V ₅ . Therefore, the value of V _d
This usage condition can always be satisfied if the _LCD is set to be equal to or higher than the maximum value that can be set.

Similar considerations can be applied to the case where a liquid crystal drive circuit having a negative output is used. Figure 3
4 shows still another example of the liquid crystal drive power supply circuit of the display-integrated coordinate input device in this embodiment. In FIG. 34, r and R are resistors and 5010 and 502.
0, 5030, 5040, 5050 are operational amplifiers, 50
Reference numeral 60 represents a switching circuit, V _LCD represents a display liquid crystal drive voltage, and V _d represents a detection liquid crystal drive voltage. In this case, V _LCD is connected to V _{5 of the} liquid crystal drive circuit in order to change the voltage on the negative polarity side and change the drive voltage. The switching circuit 5060 is provided between the V _LCD and the operational amplifier 5050. Then, by the switching signal, only the input voltage to V ₅ of the liquid crystal drive circuit can be switched to the detection liquid crystal drive voltage V _d . With this configuration, the same effect as above can be obtained.

In this case, V _d <V ₄ , V ₃ , V ₂ ,
It is necessary to set V _d so as to satisfy V ₁ and V ₀ .
If V _d is set to be equal to or less than the minimum value that V _LCD can set, this condition can always be satisfied.

As in any of the above examples, the voltage level to be switched is not limited to this embodiment, and the amplitude value of the detection scanning pulse in the detection period is constant and the liquid crystal driving is performed. Any circuit may be used as long as it satisfies the usage conditions of the circuit.

<Eighth Embodiment> In this embodiment, a liquid crystal drive power supply circuit having the above switching circuit is provided inside a row electrode drive circuit and a column electrode drive circuit.

FIG. 36 shows a display integrated type according to the present invention.
The electric power of the matrix panel of the eighth embodiment of the coordinate input device.
It is a figure showing the voltage waveform applied to the pole group. Fig. 36
At T_wIs the display period, T_dIs the detection period, T
_w>>> T_dSatisfy the relationship. Also, t₁Is the display period
T_wScanning period of one line in t₂Is the detection period T _d
Is a scanning period of one line in₁>> t₂Toi
Meet a relationship Also, R₁, R₂, R_mIs marked on the row electrode
Waveform applied, S₁, S₂, S_nIs applied to the column electrodes
The waveform is shown.

In the display period T _w , the voltage of V ₀ or V ₅ level is applied to the row electrode group when selected, and the voltage of V ₁ or V ₄ level is applied when not selected. Further, for example, when the display is ON, a voltage of V ₀ or V ₅ level is applied to the column electrode group, and when the display is OFF, V ₂ or V _{3 is applied.}
Apply level voltage.

On the other hand, in the detection period T _d , the scanning pulse for detection is sequentially applied to the row electrode group and the column electrode group. As the scanning pulse for detection, V _d is applied at the time of selection and V ₅ is applied at the time of non-selection so that the amplitude has a constant value regardless of the driving condition of the display period T _w . With this, the amplitude value of the detection scanning pulse in the detection period can be set independently to the change in the display driving condition, so that the intensity of the signal detected by the detection electrode can always be kept at a constant level.

FIG. 35 shows a drive circuit of a drive device of an eighth embodiment of the display-integrated type coordinate input device according to the present invention. The drive circuit shown in FIG. 35 is a drive circuit for both row electrodes and column electrodes. In FIG. 35, 101 is an LCD driver, 102 is a level shifter for adjusting a logical value level, 103 is a data latch / shift register, 104 is a data register, 105 is a chip enable, and 106 is a control circuit. Also, V ₀ , V
_1,2, V _3,4, V ₅ is the input terminal of the liquid crystal drive voltage.
When used as a row electrode drive circuit, V ₁ to V ₁
Enter the level of the voltage inputs V ₄ level voltage to V _{3, 4.} When used as a column electrode driving circuit inputs the V ₂ level voltage to V _{1, 2,} V ₃ to V _{3, 4}
Input the level voltage. Also, O ₁ ~ O _n output terminals, DF is the AC signal input terminals, / DISPOFF is disabled terminal, COM / SEG row electrode driving-column electrode driving switching signal input terminal of the driver output, DISP
/ GRID is a display / detection switching signal input terminal, RST
Is a clear signal input terminal of the data latch circuit, LOAD is a latch pulse or shift pulse input terminal of the data latch / shift register circuit, and CP is the data register 104.
Shift lock input terminal, D _{0 to} D ₃ are display data input terminals, SHL is a control signal input terminal in the data shift direction,
VCC is a high voltage logic circuit power supply input terminal, VDD is a 5V system logic circuit power supply input terminal, and VSS is a ground level terminal. When used as a column electrode drive circuit, EIO ₁ and EIO ₂ function as a chip enable input terminal for cascade connection and a coordinate detection pulse input / output terminal during detection operation, and when used as a row electrode drive circuit. Function as input / output terminals for shift data.

First, a case where the above drive circuit is used as a column electrode drive circuit will be described. In the display period, for example, the input logic of DISP / GRID (display / detection switching signal input terminal) is set to “0”, and D _{0 to} D
₃ Display data is input from (Display data input terminal),
CP (shift lock input terminal of data register 104)
The data is latched in the data register 104 in synchronization with the shift clock input from. Chip enable 1
Reference numeral 05 counts the shift clock input from the CP, and when the shift clock reaches a fixed number, the enable signal is output from EIO ₁ or EIO ₂ whichever is the output terminal. As a result, the data register 104
Stops reading data. The data latch / shift register 103 latches the data in the data register 104 in synchronization with the latch pulse input from LOAD (latch pulse or shift pulse input terminal), and the level shifter 102 causes the data latch / shift register 103 to latch.
5V system output is level-shifted and LCD driver 10
1 indicates the output of the level shifter 102, DF (AC signal input terminal), / DISPOFF (driver output disable terminal), COM / SEG (row electrode drive / column electrode drive switching signal input terminal), DISP / GRID. According to the logic, V ₀ and V ₅ are selected and output for ON data, and V ₂ and V ₃ are selected and output for OFF data.

On the other hand, during the detection period, DISP / G
Set the input logic of RID to "1" and EIO₁Or EIO₂
Scan pulse for detection from the one that has become the input terminal
Enter the data of. Input scan pulse data for detection
Data is input to the data latch / shift register 103.
And is synchronized with the shift clock input to LOAD.
Be put up. The level shifter 102 is a data latch / shifter.
Level shift the output of the 5V system of the shift register 103,
The LCD driver 101 outputs the level shifter 102.
And DF, / DISPOFF, COM / SEG, DIS
For OFF data according to P / GRID logic
Is V_FiveIs output and V is for ON data _dOutput
It In this case, V data for OFF data_dOutput
And V for ON data_FiveMay output
Yes.

Next, a case where the above drive circuit is used as a row electrode drive circuit will be described. In the display period, for example, the input logic of DISP / GRID is set to "0", and the data of the scan pulse for display is input from EIO ₁ or EIO ₂ whichever is the input terminal. The input display scan pulse data is input to the data latch / shift register 103 and is shifted in synchronization with the shift clock input to LOAD. Selects and outputs V _0, V ₅ for data ON, the select and output V _1, V ₄ for OFF data.

On the other hand, during the detection period, DISP / G
Set the input logic of RID to "1" and EIO₁Or EIO₂
Scan pulse for detection from the one that has become the input terminal
Enter the data of. Input scan pulse data for detection
Data is input to the data latch / shift register 103.
And is synchronized with the shift clock input to LOAD.
Be put up. The level shifter 102 is a data latch / shifter.
Level shift the output of the 5V system of the shift register 103,
The LCD driver 101 outputs the level shifter 102.
And DF, / DISPOFF, COM / SEG, DIS
For OFF data according to P / GRID logic
Is V_FiveIs output and V is for ON data _dOutput
It In this case, V data for OFF data_dOutput
And V for ON data_FiveMay output
Yes.

The input / output logic is shown below (Table 1).

[0208]

[Table 1]

Needless to say, the output voltage levels are not limited to the above combinations in any of the configurations for implementing the driving method.

[0210]

As described above, according to the present invention,
It is possible to realize a display-integrated type coordinate input device capable of improving the detection accuracy at the end portion of the matrix panel.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a display-integrated coordinate input device according to the present invention.

FIG. 2 is a diagram showing an equivalent circuit of a signal transmission system in the ITO electrode according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a measurement result of a positional shift due to a drive signal delay of the ITO electrode according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram showing a drive signal delay correction circuit using ITO electrodes according to the first embodiment of the present invention.

FIG. 5 is a diagram showing alignment coordinates in the ITO delay correction according to the first embodiment of the present invention.

FIG. 6 is a diagram showing detection coordinates in peak detection according to the first embodiment of this invention.

FIG. 7: γ at the panel end portion of the first embodiment of the present invention
It is a block diagram which shows a correction circuit.

FIG. 8 is a diagram showing a γ function of the first embodiment of the present invention.

FIG. 9 is a diagram for explaining a coordinate detection result in the vicinity of the tab connection portion according to the first embodiment of this invention.

FIG. 10 is a configuration diagram showing a correction circuit in the line concentrator of the first embodiment of the present invention.

FIG. 11 is a configuration diagram showing a second embodiment of a coordinate input device with a display according to the present invention.

FIG. 12 is a diagram showing detection coordinates in level detection according to the second embodiment of the present invention.

FIG. 13 is a configuration diagram showing details of a coordinate detection circuit, a correction calculation circuit, and a selection circuit according to a second embodiment of the present invention.

FIG. 14 is another coordinate detection circuit according to the second embodiment of the present invention,
It is a block diagram which shows the detail of a correction arithmetic circuit and a selection circuit.

FIG. 15 is a configuration diagram showing a circuit for changing a level according to a liquid crystal drive voltage according to a second embodiment of the present invention.

FIG. 16 is a configuration diagram showing a third embodiment of the coordinate input device with a display according to the present invention.

FIG. 17 is a configuration diagram showing details of a coordinate detection circuit, a correction calculation circuit, and a selection circuit according to a third embodiment of the present invention.

FIG. 18 is a diagram showing the specific gravity of α, β, and γ according to the third embodiment of the present invention.

FIG. 19 is another coordinate detection circuit according to the third embodiment of the present invention,
It is a block diagram which shows the detail of a correction arithmetic circuit and a selection circuit.

FIG. 20 is a diagram showing the detection electrode height dependency of the detection coordinates of the third embodiment of the present invention.

FIG. 21 is a configuration diagram showing another aspect of the display-integrated coordinate input device according to the third embodiment of the present invention.

FIG. 22 is a configuration diagram of dummy electrodes existing in the peripheral portion of the fourth embodiment of the display-integrated coordinate input device according to the present invention.

FIG. 23 is a waveform diagram showing applied voltages to column dummy electrodes in the dummy electrode processing of the fourth example of the present invention.

FIG. 24 is a waveform diagram showing another voltage applied to the column dummy electrodes in the dummy electrode processing of the fourth example of the present invention.

FIG. 25 is a waveform chart of voltages applied to row dummy electrodes in the dummy electrode processing of the fourth example of the present invention.

FIG. 26 is a perspective view showing the configuration of a simple matrix panel of a fifth embodiment of the coordinate input device with a display according to the present invention.

FIG. 27 is a comparison diagram of a linearity characteristic at an end portion when a matrix panel according to a fifth embodiment of the present invention is used, as compared with a conventional example.

FIG. 28 is a configuration diagram showing a sixth embodiment of the coordinate input device with a display integrated according to the present invention.

FIG. 29 is a comparison diagram of a linearity characteristic at an end portion when the matrix panel of the sixth embodiment of the present invention is used, as compared with a conventional example.

FIG. 30 is a diagram showing voltage waveforms applied to the electrode group of the matrix panel of the seventh embodiment of the coordinate input device with a display according to the present invention.

FIG. 31 is a diagram showing an example of a liquid crystal drive power supply circuit according to a seventh embodiment of the present invention.

FIG. 32 is a diagram showing another example of the liquid crystal drive power supply circuit of the seventh embodiment of the present invention.

FIG. 33 is a diagram showing still another example of the liquid crystal drive power supply circuit according to the seventh embodiment of the present invention.

FIG. 34 is a diagram showing still another example of the liquid crystal drive power supply circuit according to the seventh embodiment of the present invention.

FIG. 35 is a diagram showing a drive circuit of a drive device of an eighth embodiment of the coordinate input device with integrated display according to the present invention.

FIG. 36 is a waveform diagram showing a voltage applied to an electrode group of a matrix panel according to an eighth example of the present invention.

FIG. 37 is a configuration diagram showing a conventional display-integrated coordinate input device.

FIG. 38 is a diagram showing the principle of a conventional display-integrated coordinate input device.

[Fig. 39] Fig. 39 is a configuration diagram of a matrix panel used in a conventional display-integrated coordinate input device.

FIG. 40 is a waveform diagram showing a voltage applied to an electrode group of a conventional coordinate input device integrated with a display.

FIG. 41 is a diagram showing a drive power supply circuit of a conventional display-integrated coordinate input device.

[Explanation of symbols]

1 LCD module 2 Detection electrode (pen) 3 Coordinate detection circuit 5 Correction calculation circuit 7 control circuit 11 Liquid crystal panel (matrix panel) 12 row electrode drive circuit 13 column electrode drive circuit

─────────────────────────────────────────────────── ─── Continuation of front page (31) Priority claim number Japanese Patent Application No. 6-281877 (32) Priority date November 16, 1994 (November 16, 1994) (33) Country of priority claim Japan (JP) (31) Priority claim number Japanese Patent Application No. 6-281878 (32) Priority date November 16, 1994 (November 16, 1994) (33) Country of priority claim Japan (JP) (72) Inventor Masanori Matsunami Ren 1006 Kadoma, Kadoma City, Osaka Prefecture Matsuda Denki Sangyo Co., Ltd. (72) Inventor, Hiroshi Tomiya, Kadoma City, Osaka Prefecture 1006 Kadoma, Matsushita Electric Industrial Co., Ltd. (72) Inventor Masahiro Yamamoto, Kadoma City, Osaka Pref. 1006 Kadoma Matsushita Electric Industrial Co., Ltd. (72) Inventor Naoyuki Ito 1006 Kadoma, Kadoma, Osaka Prefecture Matsuda Electric Industrial Co., Ltd. (72) Hideo Koseki 1006 Kadoma, Kadoma, Osaka Matsushita Electric Sangyo Co., Ltd. (56) Reference text JP 5-324174 (JP, A) JP 5-127808 (JP, A) JP 4-62621 (JP, A) JP 5-53726 (JP, A) JP 4-337824 (JP, A) JP 61-228525 (JP, A) JP 7-104911 (JP, A) JP 764721 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) G06F 3/03-3/037 G02F 1/00

Claims (17)

(57) [Claims] 1. A plurality of row electrodes (y direction) orthogonal to each other
A matrix panel having a plurality of column electrodes (in the x direction) and a display element enclosed between them, a row electrode drive circuit for driving the row electrodes, and a column electrode drive circuit for driving the column electrodes, There are a detection electrode that is electrically coupled to a row electrode and a column electrode of the matrix panel by electrostatic coupling capacitance and that detects a scanning signal applied to the row electrode and the column electrode of the matrix panel, and an output signal of the detection electrode. A coordinate detection circuit that obtains position information by outputting coordinate values according to characteristics, a correction circuit that corrects the coordinate values output from the coordinate detection circuit, the matrix panel, a row electrode drive circuit, and a column electrode drive circuit , the detection electrode, and at least includes a display-integrated coordinate input device and a control circuit for controlling the coordinate detection circuit and the correction circuit, the correction circuit, the coordinate detection circuit X seat to be al output
Depending on the mark (column position) and y coordinate (row position), y coordinate (row position)
Position conversion circuit, and the coordinate detection circuit described above.
Depending on the x coordinate (column position) and y coordinate (row position) output from
And an x-coordinate conversion circuit that converts the x-coordinate (column position).
At least a storage circuit for storing each correction value
A coordinate input device integrated with a display . 2. A memory circuit according to a delay time of a drive signal.
The display-integrated coordinate input device according to claim 1 , further comprising a correction value calculation circuit that stores a correction value . 3. A plurality of row electrodes (y direction) orthogonal to each other
And a plurality of column electrodes (x direction), between which a display element
Drive the row electrodes and the matrix panel in which
Row electrode drive circuit and column electrode drive for driving the column electrode
The circuit and the row and column electrodes of the matrix panel.
The matrix pattern is electrically coupled by a capacitance.
Detect scanning signals applied to the row and column electrodes of the channel
Depending on the detection electrode and certain characteristics of the output signal of the detection electrode
Coordinate detection to obtain position information by outputting the coordinate values
The output circuit and the coordinate value output from the coordinate detection circuit are complemented.
Correcting circuit, matrix panel, row electrode drive
Circuit, column electrode drive circuit, detection electrode, coordinate detection circuit and auxiliary
And a control circuit for controlling the positive circuit.
A play-integrated coordinate input device, wherein the correction circuit is configured to detect the panel edge in the x direction from the panel edge.
Outputs a correction value that changes according to the distance to the detection electrode
First correction circuit and front from panel edge in y direction
Outputs a correction value that changes according to the distance to the detection electrode.
A second correction circuit, the output of the first correction circuit, and
A multiplication circuit for outputting the product of the outputs of the second correction circuit
A coordinate input device with a built- in display. 4. A plurality of row electrodes (y direction) orthogonal to each other
And a plurality of column electrodes (x direction), between which a display element
Drive the row electrodes and the matrix panel in which
Row electrode drive circuit and column electrode drive for driving the column electrode
The circuit and the row and column electrodes of the matrix panel.
The matrix pattern is electrically coupled by a capacitance.
Detect scanning signals applied to the row and column electrodes of the channel
Depending on the detection electrode and certain characteristics of the output signal of the detection electrode
Coordinate detection to obtain position information by outputting the coordinate values
The output circuit and the coordinate value output from the coordinate detection circuit are complemented.
Correcting circuit, matrix panel, row electrode drive
Circuit, column electrode drive circuit, detection electrode, coordinate detection circuit and auxiliary
And a control circuit for controlling the positive circuit.
A play-integrated coordinate input device, wherein the coordinate detection circuit is detected by the detection electrodes.
The output changes when the signal exceeds the specified comparison potential.
First coordinate detection circuit which is a magnitude comparator
And a signal detected by the detection electrode is compared with a predetermined signal.
Magnitude controller whose output changes at the moment when it falls below the potential
It consists of a second coordinate detection circuit that is a palator,
The correction circuit is sent from the coordinate detection circuit.
Calculation times for calculating the position of the detection electrode from two coordinate values
A coordinate input device integrated with a display, which has a path . 5. The correction circuit further comprises an average value circuit for outputting an average value of the first and second coordinate detection circuits, and the arithmetic circuit outputs the first value when the coordinates are equal to or more than a first predetermined value. Output of the coordinate detection circuit is selected, and the output of the second coordinate detection circuit is selected when the coordinate is equal to or less than the second predetermined value, and the coordinate has the first predetermined value and the second predetermined value. 5. The display-integrated coordinate input device according to claim 4 , further comprising a selector for selecting the output of the average value circuit when the value is between the value of and. 6. A plurality of row electrodes (y direction) orthogonal to each other
And a plurality of column electrodes (x direction), between which a display element
Drive the row electrodes and the matrix panel in which
Row electrode drive circuit and column electrode drive for driving the column electrode
The circuit and the row and column electrodes of the matrix panel.
The matrix pattern is electrically coupled by a capacitance.
Detect scanning signals applied to the row and column electrodes of the channel
Depending on the detection electrode and certain characteristics of the output signal of the detection electrode
Coordinate detection to obtain position information by outputting the coordinate values
The output circuit and the coordinate value output from the coordinate detection circuit are complemented.
Correcting circuit, matrix panel, row electrode drive
Circuit, column electrode drive circuit, detection electrode, coordinate detection circuit and auxiliary
And a control circuit for controlling the positive circuit.
A play-integrated coordinate input device, wherein the coordinate detection circuit is detected by the detection electrodes.
The output changes when the signal exceeds a certain reference potential.
A first coordinate detection circuit which is a tub comparator,
A comparison potential having a signal detected by the detection electrode
Magnitude comparator that changes output when it falls below
The second coordinate detection circuit, which is a
The output changes at the moment when the detected signal becomes maximum.
A coordinate detection circuit, and the correction circuit comprises:
Three sent from the first, second and third coordinate detection circuits
A calculation circuit that calculates the position of the detection electrode from the coordinate values of
A display-integrated coordinate input device having. 7. The display-integrated coordinate input device according to claim 4, further comprising means for switching the comparison potential of the magnitude comparator in each of the row coordinate detection period and the column coordinate detection period. 8. The display-integrated coordinate input device according to claim 4, further comprising means for detecting the drive voltage of the matrix panel and switching the comparison potential of the magnitude comparator each time. 9. The display-integrated coordinate input device according to claim 4, further comprising means for switching the comparison potential of the magnitude comparator at any time according to the signal intensity generated at the detection electrode. 10. The arithmetic circuit selects the output of the first coordinate detection circuit when the coordinate is equal to or larger than the first predetermined value, and the second output when the coordinate is equal to or smaller than the second predetermined value. claim a selector which selects the output of the coordinate detection circuit, coordinates selects the output of the third coordinate detection circuit when is between said second predetermined value and said first predetermined value 6 The display-integrated coordinate input device according to [1]. 11. The output of the first coordinate detection circuit is used when the coordinate is equal to or more than a first predetermined value, and the output of the second coordinate detection circuit is used when the coordinate is equal to or less than a second predetermined value. Using the output, the output of the third coordinate detection circuit is used when the coordinates are between the first predetermined value and the second predetermined value, and the weight is gradually increased in the vicinity of the switching area. 請 that varied, further provided gradually switched go means
Display-integrated coordinate input device according to Motomeko 6. 12. A plurality of row electrodes (y direction) orthogonal to each other, a plurality of column electrodes (x direction), and a tab (in a lead portion of a matrix panel electrically insulated from the row electrodes and column electrodes). A matrix panel including at least a dummy electrode formed in a gap between the TAB) and the tab (TAB), and a display element enclosed between the row electrode and the column electrode, and connected to the row electrode, respectively. Row electrode drive circuit, column electrode drive circuits respectively connected to the column electrodes, dummy electrode drive circuits connected to dummy electrodes that output a constant voltage during the coordinate detection period, row electrodes of the matrix panel, and Outputs of the detection electrodes, which are electrically coupled to the column electrodes by electrostatic coupling capacitances and detect a scanning signal applied to the row electrodes and the column electrodes of the matrix panel. Display integrated coordinates including at least a coordinate detection circuit for obtaining position information by a signal and a control circuit for controlling the matrix panel, row electrode drive circuit, column electrode drive circuit, dummy electrode drive circuit, detection electrode and coordinate detection circuit Input device. 13. The voltage applied to the dummy electrode on the matrix panel is such that the display element enclosed between the dummy electrode and the adjacent row or column electrode does not respond.
The display-integrated coordinate input device according to claim 12 . 14. The voltage applied to the dummy electrodes are AC signal used for display mode of the matrix panel 請
13. A display-integrated coordinate input device according to claim 12. 15. The matrix panel opposes the first glass substrate with a column electrode arranged on the first glass substrate in a first predetermined direction at a first predetermined pitch and a display material layer. Row electrodes arranged at a second predetermined pitch in a second predetermined direction orthogonal to the first predetermined direction on the second glass substrate provided in such a manner that the column electrodes and the row electrodes are provided. Are drawn out without bending points to at least the vicinity of the seal portion in the non-display area other than the display area where the column electrodes and the row electrodes overlap each other, while having the first and second predetermined pitches, respectively. Claim 1,
13. A display-integrated coordinate input device according to any one of 3, 4, 6 and 12 . 16. The matrix panel opposes the first glass substrate with a column electrode arranged on the first glass substrate in a first predetermined direction at a first predetermined pitch and a display material layer. Row electrodes arranged at a second predetermined pitch in a second predetermined direction orthogonal to the first predetermined direction on the second glass substrate provided in the above manner, and on the first and second glass substrates. And a lead-out electrode portion provided in a non-display area other than the display area where the column electrodes and the row electrodes overlap each other, and a conductive film provided on the lead-out electrode portion and electrically shielding the lead-out electrode portion. A contract with
13. A display-integrated coordinate input device according to any one of claim 1, 3, 4, 6 or 12 . 17. The matrix panel is a liquid crystal panel.
The display-integrated coordinate input device according to claim 1, 3, 4, 6, or 12 .