JPH0749669A - Matrix panel coordinate position detection method - Google Patents

Abstract

PURPOSE:To provide a thin thickness and light weight display device with an information input function with a simple structure by detecting only a voltage on scanning wiring in a matrix panel displaying an image, or both voltages on a scanning line and a signal line, and detecting the X, Y coordinates of an input pen. CONSTITUTION:By a Y electrode driving circuit 2 and an X electrode driving circuit 3, a prescribed driving voltage or a pulse for coordinate position timing applied to the Y electrode 1A and the X electrode 1B of the matrix panel 1 is generated. A position voltage detection means (input pen) 4 is provided with a function detecting the voltage of the Y electrode 1A or the X electrode 1B without contacting. The X, Y coordinates are detected by a phase difference between a scanning voltage detected by the position voltage detection means 4 and a timing signal operating the Y electrode driving circuit 2. Further, the signal voltages of the signal lines are varied successively in the unit of plural pieces in a vertical blanking interval, and the X coordinate is detected from a phase relation between the signal voltage at this time and the timing signal operating the X electrode driving circuit 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of detecting a coordinate position of a matrix panel and a matrix display device, and more particularly to a coordinate position of the matrix panel suitable for inputting data to a liquid crystal matrix panel using an input pen or the like. The present invention relates to a detection method and a matrix display device using the detection method.

[0002]

2. Description of the Related Art In order to provide a device for inputting data on an image display panel using an input pen, components for detecting the X and Y coordinates of the input pen and an image such as a liquid crystal display panel have been conventionally used. The display parts were stacked.

[0003]

In the conventional coordinate position detecting method for the input pen, it is difficult to reduce the size, weight and power consumption of the device because the components for detecting the coordinates are laminated on the image display panel. For this reason, it is not suitable for handheld devices.

According to the present invention, the components for detecting the coordinate position of the input pen are not laminated on the image display panel,
It is to realize a matrix panel coordinate position detection method and a matrix display device that are thin and lightweight and can realize circuit simplification and low power consumption.

[0005]

It is possible to detect only the voltage on the scanning line or both the voltage on the scanning line and the voltage on the signal line, and the position voltage detecting means, that is, the coordinates of the input pen can be detected by this detected voltage.

[0006]

The X and Y coordinates can be detected by the phase difference between the scanning voltage detected by the position voltage detecting means and the timing signal for operating the Y electrode drive circuit.

Further, the signal voltage of the signal line is sequentially changed in units of a plurality of lines during the vertical baseline period, the signal voltage at this time is detected, and the phase of the detected voltage and the timing signal for operating the X electrode drive circuit. The X coordinate can be detected from the relationship.

[0008]

EXAMPLES Examples according to the present invention will be described step by step.
FIG. 1 shows an example of the overall configuration of a matrix display device according to the present invention. The device is composed of a matrix panel 1, a Y electrode drive circuit 2, an X electrode drive circuit 3, a position voltage detection means 4, a display control circuit 5 and a coordinate position calculation circuit 6, and further, a display control circuit 5 and a coordinate if necessary. The position calculation circuit 6 is connected to an external system.

Y electrode drive circuit 2 and X electrode drive circuit 3
Generates a predetermined drive voltage applied to the Y electrodes 1A and X electrodes 1B of the matrix panel 1 or a timing pulse for coordinate position detection in order to display an image on the matrix panel. The position voltage detecting means 4 has a function of detecting the voltage of the Y electrode 1A or the X electrode 1B in a non-contact manner. Further, the coordinate position calculation circuit 6 processes the signal detected by the position voltage detection means 4 to detect the position voltage detection means 4
The X and Y coordinates indicated by are calculated. Display control circuit 5
Generates a timing signal and a data signal for operating the Y electrode drive circuit 2 and the X electrode drive circuit 3.

The X and Y coordinates obtained by the coordinate position calculation circuit 6 are sent to the external circuit 7. The external circuit 7 is connected to a microprocessor circuit, a communication circuit and the like.

An example of the structure of the matrix panel 1 is shown in FIG. The panel includes signal electrodes 8 to 10 and scanning electrodes 11 to 1.
3, a TFT (Thin Film Transistor) 14, a liquid crystal 15, and a common electrode 16. Further, as an example of the configuration of the matrix panel 1, it may be as shown in FIG. FIG. 3 includes signal electrodes 17 and 18, scanning electrodes 19 and 20, a non-linear element 22 and a liquid crystal 21. The liquid crystal portion shown in FIGS. 2 and 3 may be another display body and is not particularly limited. Although not shown, the present invention can also be achieved by using a matrix panel that can display an image without using TFTs or nonlinear elements.

In the present invention, an embodiment will be described using the matrix panel shown in FIG. FIG. 4 shows a plan view of one pixel of the matrix panel, and FIG. 5 shows a sectional view thereof. The same parts as those in FIG. 2 are designated by the same reference numerals.

As shown in FIG. 5, the TFT comprises a gate electrode 28, a gate insulating film 26, a semiconductor layer 25 and a source electrode 29 formed on one glass substrate 27. The gate electrode 28 is connected to the scan electrode 11, and the source electrode 2
9 are connected to the signal electrodes 8, respectively. The common electrode 16 is formed on the other glass substrate 24. The liquid crystal 15 is sealed between the one substrate and the other substrate.

The position voltage detecting means 4 detects the voltage on the scanning line 11 or the voltage on the signal line 8. By appropriately processing the detected signal, the coordinates of the position in the X and Y directions indicated by the position voltage detecting means 4 can be obtained. Thus, for example, it is possible to realize a display device having a data writing function to the liquid crystal matrix panel, that is, a light pen input function.

By the way, in order to accurately detect the voltage on the scanning line 11 or the signal line 8, it is effective to perform it from the glass substrate 27 side where the TFT is formed. This is because when the voltage is detected from the other substrate 24 side on which the common electrode is formed, the common electrode 16 serves as a shield plate and the voltage cannot be accurately detected.

Next, the coordinate position detection according to the present invention will be described. FIG. 6 shows the operation of the Y electrode drive circuit shown in FIG. The circuit generates scanning signals Vg (1) to Vg (n) at the timing of the FLM signal and the CL3 signal. When the scanning voltage becomes Vgh, the TFT is turned on, and when it becomes Vgl, the TFT is turned off. This operation is a known matter and will not be described in detail.

When the scan voltage shown in FIG. 6 is applied to the scan lines 1 to m shown in FIG. 2, the scan voltage is changed to the voltage shown in FIG. 8 by the circuit in the panel shown in FIG. The waveform is distorted. The resistor 30 is the resistance of the scanning line, and the capacitor 31 is the parasitic capacitance between the terminals of the TFT.

The waveform example of FIG. 8 shows the third scanning voltage Vg.
(I). The coordinate in the Y direction can be known by calculating the time tv from the FLM signal, and X by calculating the time th1 or th2 from CL3.
Know the direction coordinates. The scanning voltage on the scanning line is as shown in FIG.
The scanning voltage can be detected by electrostatic coupling through the glass substrate 27 shown in FIG. The detection voltage at this time is Vs described above.
It is the same as the waveform.

The reference voltage Vb may be any level, but the higher the level Vsh, the higher the detection accuracy. Further, since the voltage level of the detection voltage Vs varies depending on the distance between the voltage position detecting means 4 and the matrix panel 1, a circuit for correcting the distance may be provided. Further, the detected voltage may be temporarily stored in a memory or the like, and predetermined processing may be performed based on the content.

Next, an embodiment of the coordinate position calculating circuit 1 shown in the figures is shown in FIGS. FIG. 9 shows an embodiment of the Y coordinate calculation circuit. The circuit includes a counter 32 and a latch circuit 33.
And a comparator 34. The operation at this time is shown in FIG. The example shown in FIG. 10 is a waveform example when the voltage position detection means 4 is brought close to the vicinity of the third scanning line.
The counter 32 is reset at the timing of the FLM signal and counted up by the CL3 signal. Further, the detected voltage Vs and the reference voltage Vb are compared by the comparator 34, and the counter 3 is generated at the timing of the STB signal obtained thereby.
Latch the output value DATAC of 2. The output DATA (Y) of this latch circuit becomes the coordinate in the Y direction.

FIG. 11 shows an embodiment of the X coordinate calculation circuit. The circuit includes a counter 34 and a latch circuit 35. The counter 34 is reset by the CL3 signal and CL
Count up by the K signal. Then, the counter output is fetched into the latch circuit at the timing of the STB signal. The output signal DATA (X) of this latch circuit is X
It becomes the coordinate of the direction. The STB signal may be the output signal of the comparator 34 shown in FIG. Further, the calculation of the above-mentioned coordinates may use a microprocessor and is not particularly limited.

Another embodiment of coordinate detection in the X direction is shown in FIG.
This will be described with reference to FIG. Vertical blanking period t shown in FIG.
The voltage shown in FIG. 12 is applied to the signal line within fh0. Figure 1
In the second embodiment, the voltage is sequentially set to the high level Vdh in units of eight signal lines. The position detection means at this time is
Since it is the same as the scanning voltage detecting means described above, details thereof will be omitted. Note that the number of signal lines and the operating method of the circuit which are simultaneously changed when the signal voltage is sequentially set to the high level Vdh are not particularly limited.

FIG. 13 shows another embodiment when the signal voltage is sequentially changed. The voltage of the signal voltage is alternately switched at different levels of Vdh1 and Vdh2. As a result, since the position information can be obtained from the detected voltage level, the number of signal lines that change the voltage can be increased at the same time. As a result, the operating speed of the circuit can be reduced, which is advantageous in terms of power consumption.

[0024]

As described above, the X and Y coordinates of the input pen can be detected by detecting only the voltage on the scanning line in the matrix panel for displaying an image or the voltage on the scanning line and the signal line. A display device with an information input function having a simple structure can be configured.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of the overall configuration of an embodiment according to the present invention.

FIG. 2 is a configuration diagram of a matrix panel used in the present invention.

FIG. 3 is a configuration diagram of the same.

FIG. 4 is a configuration diagram of the same.

FIG. 5 is a configuration diagram of the same.

FIG. 6 is a diagram showing the timing of the scanning voltage of the TFT liquid crystal matrix panel.

FIG. 7 is an equivalent circuit diagram of a matrix panel.

FIG. 8 is a diagram showing a specific example of a method of detecting X and Y coordinates.

FIG. 9 is a diagram of a similar example.

FIG. 10 is a diagram which similarly shows a specific example.

FIG. 11 is a diagram showing a similar example.

FIG. 12 is a diagram which similarly shows a specific example.

FIG. 13 is a diagram similarly showing a specific example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Matrix panel, 2 ... Y electrode drive circuit, 3 ... X electrode drive circuit, 4 ... Position voltage detection means, 5 ... Display control circuit, 6 ... Coordinate position calculation circuit.

Claims (2)

[Claims] 1. A matrix panel comprising a plurality of scan electrodes and a plurality of signal electrodes in which pixels are arranged in a matrix, a Y electrode drive circuit for driving the scan electrodes, and an X electrode drive circuit for driving the signal electrodes. Voltage detection means for detecting the voltage of the scan electrodes in the matrix panel, and coordinates in the X direction depending on the phase difference between the scan voltage obtained by the voltage detection means and the timing signal for operating the Y electrode drive circuit. And a coordinate position detection method for a matrix panel, characterized by detecting coordinates in the Y direction. 2. A matrix panel having a plurality of scan electrodes and a plurality of signal electrodes in which pixels are arranged in a matrix, a Y electrode drive circuit for driving the scan electrodes, and an X electrode drive circuit for driving the signal electrodes. A voltage detection means for detecting the voltage of the scan electrodes or the signal electrodes in the matrix panel, and a means for sequentially applying different voltage levels to the signal electrodes during the blanking period, The phase difference between the obtained scanning voltage and the timing signal for operating the Y electrode drive circuit, the signal voltage obtained by the voltage detecting means, and the X signal.
A coordinate position detecting method for a matrix panel, wherein the coordinate in the X direction and the coordinate in the Y direction are detected by a phase difference with a timing signal for operating the electrode driving circuit.