JP3834778B2 - Coordinate input display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information input device for a data processing system using an electronic pen. More specifically, the present invention is a coordinate system that is arranged in a tablet or a computer display device, detects a coordinate position indicated by an information input indicator such as an electronic pen, and displays information obtained thereby on the computer display device. The present invention relates to an input display device.
[0002]
[Prior art]
It is well known in the art that a coordinate input device using electronic pen input is provided in a computer display device, thereby providing data input means more easily than an input medium using a conventional keyboard or mouse. In particular, portable computers have been pursued with good portability and operability, and information input using an electronic pen is the most powerful input method.
[0003]
Conventionally devised electrical coupling methods as coordinate position detection methods are classified into electromagnetic induction methods and electrostatic coupling methods.
[0004]
A conventional coordinate input device based on an electromagnetic induction method has a loop coil and information arranged on the tablet side so that both directions of the X-axis and the Y-axis are orthogonal to each other, as disclosed in, for example, JP-A-2-162410. A method has been devised in which an electromagnetic wave signal is transmitted to and received from an input indicator and a coordinate position indicated by the information input indicator is specified.
[0005]
FIG. 1 shows a loop coil and a selection circuit arranged in a coordinate input device having such an input device, for transmitting and receiving electromagnetic wave signals. The plurality of loop coils 1 are two-dimensionally arranged, and the loop coils 1 at the respective coordinate positions are wired so as to overlap each other, and switching of the loop coils 1 is constituted by two selection circuits 2.
[0006]
However, among these methods, when applied to a computer display device having a coordinate detection function, a method of arranging a loop coil-shaped electrode with a transparent conductive film in a display screen is an ordinary comb-shaped electrode. In comparison, there is a drawback that the resistance value of the coil itself is increased by increasing the wiring length per electrode, and the wiring area is increased because the electrode is in a loop shape.
[0007]
In addition, as disclosed in JP-A-6-317783, an example in which a computer display device having a coordinate position detection function using an electrostatic coupling method is applied to a liquid crystal display device, data is input to each pixel of the active matrix liquid crystal display device. It has a structure in which an output electrode is disposed side by side with a pixel electrode.
[0008]
However, disposing a coordinate detection electrode alongside a pixel electrode in an active matrix type liquid crystal display device has a drawback that the aperture ratio is lowered, thereby reducing the light transmittance. In addition, the electrostatic coupling method can detect the position but cannot detect the pen pressure.
[0009]
[Problems to be solved by the invention]
The present invention improves the shape of the loop coil itself into a shape that can be easily wired to a liquid crystal display device, etc., without lowering the signal reception sensitivity of the position detection unit in the electromagnetic coordinate input device, particularly the active matrix type. When applied to a liquid crystal display device, an object of the present invention is to provide an electrode-shaped coordinate input display device that reduces the wiring resistance as much as possible even when it is provided as a transparent conductive film without reducing the aperture ratio.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, FIG. 2 shows a basic configuration of an electromagnetic wave signal receiving sensor in the coordinate input display device of the present invention. The configuration of the present invention is not a loop coil shape, but a plurality of comb-shaped sensors are arranged in the X-axis direction and the Y-axis direction to form one matrix, and the entire area portion of the comb-shaped sensor wired in this matrix A ground layer 4 is disposed below the first and second ends of the comb-shaped sensor group in the X-axis direction and the Y-axis direction are connected to the ground layer, and the other end is connected to the selection circuit 2. 2 is selected, and comb sensors are sequentially selected. By adopting these basic configurations, as shown in FIG. 3, the loop coils are not electrically arranged in a two-dimensional plane, but a plurality of loop coils are arranged perpendicular to the XY plane. It becomes equivalent.
[0011]
Further, when the present invention is applied to a computer display device, for example, it is arranged on the back side opposite to the display surface in an active matrix liquid crystal display device, and a display pixel electrode, a scanning signal electrode, a data signal electrode, and a thin film transistor are arranged in a matrix. On the same substrate, the X-axis direction comb sensor and the scanning signal electrode are arranged so as to overlap each other through an insulating layer, and the Y-axis direction comb sensor and the data signal electrode are arranged so as to overlap each other with interlayer insulation.
[0012]
When the present invention is applied to an active matrix liquid crystal display device, it is desirable to dispose the comb-shaped sensor without reducing the aperture area of the pixel electrode, thereby suppressing a decrease in aperture ratio.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
A schematic view of the present invention is shown in FIG. The Y-axis comb sensor group 6 of the X-axis comb sensor group 5 is arranged on the matrix, the ground layer 4 is arranged below the entire arrangement region of the biaxial comb sensor group, One end of the axial comb sensor group 5 is connected to the earth layer 4, and the other end is connected to the selection circuit 9. Further, one end of the Y-axis direction comb sensor group 6 is connected to the earth layer 4 and the other end is connected to the selection circuit 2. A signal selected from each selection circuit 2 is switched via an amplifier 7 between a reception signal from the X-axis direction comb sensor group 5 and a reception signal from the Y-axis direction comb sensor group 6 in a subsequent XY axis switching circuit 8. The signal processing circuit 9 performs position detection and writing pressure detection processing.
[0014]
【Example】
Example 1 of the present invention will be described below.
[0015]
(Embodiment 1) FIGS. 5 and 6 show an embodiment in which the present invention is applied to an active matrix display device. An example in which a thin film transistor (TFT) is applied as an active element is shown.
[0016]
FIG. 5 shows a pixel configuration diagram in this embodiment. The scanning signal electrode 17 and the data signal electrode 16 for controlling the TFT 20 arranged on the pixel electrode side transparent substrate 19 intersect with each other, and an insulating layer is formed. The X-axis direction comb sensor 13 and the Y-axis direction comb sensor 14 for receiving an electromagnetic wave signal from the information input indicator are formed so as to intersect and overlap each other, and the source electrode 21 of the TFT 20 is the data signal electrode 16. The gate electrodes are arranged in a matrix with the scanning signal electrodes 17 and the drain electrodes 22 connected to the pixel electrodes 23, respectively.
[0017]
FIG. 6 is a cross-sectional view of the active matrix liquid crystal display device taken along the line AA ′ in FIG. The basic structure of the present embodiment has two transparent substrates facing each other with the liquid crystal 12 in between, the transparent substrate 10 on the counter electrode 11 side is an information input target surface, and the transparent substrate 19 on the pixel electrode side is It is arranged as the back side. On the transparent substrate 19 on the pixel electrode side, a scanning signal electrode 17 and a data signal electrode 16 are disposed with a gate insulating film 18 interposed therebetween, and for receiving an electromagnetic wave signal from an information input indicator such as an electronic pen. The X-axis direction comb sensor 13 and the Y-axis direction comb sensor 14 are arranged orthogonal to each other with the sensor insulating film 15 interposed therebetween.
[0018]
Thus, the signal level of the electromagnetic wave signal generated from the information input indicator is provided in the liquid crystal display device by arranging the comb-shaped sensor that receives the electromagnetic wave signal from the information input indicator in a lattice shape with each pixel interposed therebetween. The frequency change amount is received by selecting the X-axis direction comb sensor 13 and the Y-axis direction comb sensor 14 sequentially by the selection circuit 2, and the signal processing circuit 9 receives the signal level as position information and the frequency change as a brush. By performing signal processing as pressure information, the position and writing pressure of the information input indicator are specified, and the information is displayed on the computer display screen.
[0019]
The X-axis direction comb sensor 13 and the Y-axis direction comb sensor 14 are arranged by patterning the data signal electrode 16 and then using a material such as SiNx, SiOx, TaOx on the data signal electrode 16 by plasma CVD or the like. The sensor insulating film 15 is formed with a thickness of 300 to 600 nm, and the X-axis direction comb sensor 13 is deposited on the transparent insulating film with a metal material such as Ta, Ti, Al, and Cr by sputtering. Then, patterning is performed. Further, the sensor insulating film 15 is formed again by the above-described method, the Y-axis comb sensor 14 is patterned by the same method as the X-axis comb sensor 13, and one of the wirings is connected to the selection circuit and the other is connected. Connect to the surrounding earth layer.
[0020]
It is desirable that each comb sensor has a pattern width of several μm and a surface resistance of about several hundreds of Ω to be patterned as low as possible. This is because each comb sensor receives the signal without reducing the signal level of the electromagnetic wave signal from the information input indicator as much as possible.
[0021]
As another method, Example 2 is shown below.
[0022]
(Embodiment 2) FIGS. 7 and 8 show a method of disposing the X-axis direction comb sensor 13 and the Y-axis direction comb sensor 14 by another method. The liquid crystal display device is applied to an active matrix liquid crystal display device using TFTs as in the first embodiment.
[0023]
FIG. 7 shows a pixel configuration diagram in the present embodiment, in which an X-axis direction comb sensor 13 is disposed in parallel with the scanning signal electrode 17 for controlling the TFT 20 disposed on the pixel electrode side transparent substrate 19, Crossing these two patterns, the data signal electrode 16 and the Y-axis direction comb sensor 14 are formed in parallel, the source electrode 21 of the TFT 20 is the data signal electrode 16, and the gate electrode is the scanning signal. The electrode 17 and the drain electrode 22 are arranged in a matrix in a state of being connected to the pixel electrode 23.
[0024]
FIG. 8 is a cross-sectional view of the active matrix type liquid crystal display device between BB ′ in FIG. The basic structure of the present embodiment has two transparent substrates facing each other with the liquid crystal 12 in between, the transparent substrate 10 on the counter electrode 11 side is the information input target surface, and the pixel electrode side transparent substrate 19 is the back surface. It is arranged as a side. A scanning signal electrode 17 and a data signal electrode 16 are disposed on the pixel electrode side transparent substrate 19 with a gate insulating film 18 interposed therebetween, and further for receiving an electromagnetic wave signal from an information input indicator such as an electronic pen. The X-axis direction comb sensor 13 and the Y-axis direction comb sensor 14 are arranged orthogonal to each other with the sensor insulating film 15 interposed therebetween.
[0025]
As described in the first embodiment, the comb-like sensor that receives the electromagnetic wave signal from the information input indicator is arranged in a lattice shape with each pixel interposed therebetween in the liquid crystal display device, and is generated from the information input indicator. The signal processing circuit 9 receives the signal level and the frequency change amount of the received electromagnetic wave signal by sequentially selecting the X-axis direction comb sensor 13 and the Y-axis direction comb sensor 14 by the selection circuit 2, and the signal level is determined by the signal processing circuit 9. In addition, the frequency change is signal-processed as writing pressure information, thereby specifying the position and writing pressure of the information input indicator and displaying the information on the display screen.
[0026]
The X-axis comb sensor 13 and the Y-axis comb sensor 14 are arranged by patterning the scanning signal electrode 17 and the X-axis comb sensor 13 and then forming SiNx thereon by plasma CVD or the like. The sensor insulating film 15 is formed with a thickness of 300 to 600 nm using a material such as SiOx, TaOx, etc., and the data signal electrode 16 and the Y-axis comb sensor 14 are sputtered thereon to form Ta, Ti, Al, Cr. After depositing on the transparent insulating film with a metal material such as the above, patterning is performed, and one of the wirings is connected to a selection circuit, and the other is grounded to a ground layer provided around.
[0027]
It is desirable that each comb sensor has a pattern width of several μm and a surface resistance of about several hundreds of Ω to be patterned as low as possible. This is because each comb sensor receives the signal without reducing the signal level of the electromagnetic wave signal from the information input indicator as much as possible.
[0028]
As another method, Example 3 is shown below.
[0029]
(Embodiment 3) FIG. 9 is a schematic view showing an embodiment of the present invention on a CRT. A comb-shaped sensor group 25 wired with a transparent conductive film is arranged in a matrix inside the display side glass surface of the display screen of the CRT display device 24, and based on the position and writing pressure information indicated by the information input indicator. Is displayed on the display screen.
[0030]
【The invention's effect】
As described above, according to the coordinate input display device of the present invention, when receiving an electromagnetic wave signal from the information input indicator by the electromagnetic induction method, the portion corresponding to the reception sensor is made into a comb-like sensor, thereby displaying the computer display. By arranging the TFT drive control transparent electrode used in the device, for example, a liquid crystal display device, and the transparent electrode of the coordinate input comb sensor on the same surface of the same transparent electrode substrate, the number of parts materials can be reduced and the manufacturing process can be reduced. Manufacturing costs can be reduced by shortening.
[0031]
When the present invention is applied as described above, the display screen can be made thinner by integrating the computer display device and the coordinate input device, and particularly when applied to a portable device or the like, the portability is improved. I can expect.
[0032]
By making the electromagnetic wave signal receiving sensor part of the coordinate input part into a comb shape instead of a loop coil shape, the wiring area can be reduced and the selection circuit can be reduced to a half. Therefore, it is incorporated as a coordinate input sensor for a computer display device. In this case, the number of pixels is very large, and when a sensor is arranged close to the same number of pixels, a considerable number of selection circuits are required for both XY axes. Therefore, in order to increase the position accuracy, a large number of sensors are required, and if the comb sensor according to the present invention is used, it is possible to expect an improvement in coordinate accuracy at a low cost.
[0033]
Further, by recognizing an individual with a handwritten handwritten signature based on high positional accuracy and writing pressure information from an information input indicator, signature recognition with higher security can be realized. In recent years, such a technique has been used for electronic commerce by a computer connected to the Internet, and the technique according to the present invention can be expected to be effective in such a field.
[0034]
In the first embodiment, the gap between the pixel electrodes of the transparent conductive film for liquid crystal display and the transparent conductive film of the coordinate input comb sensor can be effectively used without increasing the wiring area. As a result, the aperture ratio can be prevented from being lowered and the performance as the brightness of the TFT liquid crystal display device can be maintained.
[0035]
In the second embodiment, the manufacturing process can be shortened by arranging the transparent conductive film for liquid crystal display and the transparent conductive film of the comb-shaped sensor for coordinate input in parallel, and the wiring area is larger than that of the first embodiment. However, by making the TFT material polycrystalline silicon, the active element size can be made smaller than that of the a-Si.multidot.TFT, and it is possible to devise such that the aperture ratio does not need to be lowered much.
[Brief description of the drawings]
FIG. 1 shows a loop coil sensor applied in a conventional coordinate input display device.
FIG. 2 is a basic configuration diagram of a comb sensor devised by the present invention.
FIG. 3 shows an equivalent circuit configuration diagram of a comb sensor devised by the present invention.
FIG. 4 is a diagram showing an embodiment of a coordinate input display device using a comb sensor.
FIG. 5 is a pixel configuration diagram of a liquid crystal display device according to Embodiment 1 of the present invention.
FIG. 6 is a cross-sectional view of a liquid crystal display device showing Embodiment 1 of the present invention.
FIG. 7 is a pixel configuration diagram of a liquid crystal display device showing Embodiment 2 of the present invention.
FIG. 8 is a cross-sectional view of a liquid crystal display device according to Embodiment 2 of the present invention.
FIG. 9 is a schematic view of a CRT display device showing Embodiment 3 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Loop coil 2 Selection circuit 3 Comb-shaped sensor 4 Ground layer 5 X-axis direction comb-shaped sensor group 6 Y-axis direction comb-shaped sensor group 7 Amplifier 8 XY-axis switching circuit 9 Signal processing circuit 10 Transparent substrate 11 Opposite electrode 12 Liquid crystal 13 X-axis direction comb sensor 14 Y-axis direction comb sensor 15 Sensor insulating film 16 Data signal electrode 17 Scan signal electrode 18 Gate insulating film 19 Pixel electrode side transparent substrate 20 TFT
21 Source electrode 22 Drain electrode 23 Pixel electrode 24 CRT display device 25 Comb sensor group

Claims (3)

  A coordinate detection apparatus for obtaining a coordinate value of a position pointed to by an information input indicator by receiving and detecting an electromagnetic wave signal from an information input indicator having an electromagnetic wave generating means for generating at a predetermined frequency, comprising: a computer An X-axis comb sensor group in which a plurality of comb sensors are arranged in the X-axis direction and a Y-axis comb shape in which a plurality of comb sensors are arranged in the Y-axis direction in a device including a display. A position detection unit configured by grounding one end of each comb-shaped sensor of the sensor group to a ground layer provided in a lower portion of the entire region where the comb-shaped sensor is provided, and the other end of the X-axis direction comb-shaped sensor group A coordinate input display device comprising: X-axis direction selection means for sequentially selecting the Y-axis direction selection means; and Y-axis direction selection means for sequentially selecting the other end of the Y-axis direction comb-shaped sensor group. In a liquid crystal display device having active elements, a coordinate input display device is arranged on the front side and the opposite side for performing display, and display pixel electrodes, scanning signal lines, data signal lines, and active elements arranged in a matrix are arranged. The X-axis comb sensor is provided with a scanning signal line and interlayer insulation on the substrate, and the Y-axis comb sensor is provided with a data signal line and interlayer insulation. 2. The coordinate input display device according to claim 1, wherein wiring is performed in an overlapping manner, and a coordinate position designated by an information input indicator is detected by the comb sensor and displayed on a liquid crystal display screen. . In a liquid crystal display device having active elements, a coordinate input display device is arranged on the front side and the opposite side for performing display, and display pixel electrodes, scanning signal lines, data signal lines, and active elements arranged in a matrix are arranged. The X-axis comb sensor is provided with a scanning signal line and interlayer insulation on the substrate, and is wired in parallel with each other, and the Y-axis comb sensor is provided with a data signal line and interlayer insulation. The coordinate input according to claim 1, wherein wiring is performed in parallel with each other, and the coordinate position designated by the information input indicator is detected by the comb sensor and displayed on the liquid crystal display screen. Display device.

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