JPH10222303A - Electronic whiteboard device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately perform coordinate position detection even in the case of large screen display size by detecting row electrode coordinates and column electrode coordinates through electrostatic capacity coupling by bringing a detection pen into contact with an arbitrary position on a display part in row coordinate detection mode and column coordinate detection mode. SOLUTION: In display mode, scanning pulses are supplied sequentially from a row electrode driver 4, electrode by electrode, and each time the scanning pulses are supplied to row electrodes 2a to 2h, signals corresponding to display data are supplied to column electrodes 3a to 3l at the same time. In the row coordinate detection mode, the scanning pulses are supplied sequentially from the row electrode driver 4 to the row electrodes 2a to 2h and the detection pen 9 is brought into contact with an arbitrary position on the display part to detect the row electrode coordinates by electrostatic capacity coupling. In the column coordinate detection mode, scanning pulses are supplied sequentially from a row electrode driver 5 to the column electrodes 3a to 3l and the detection pen 9 is brought into contact with an arbitrary position of the display part to detect the column electrode coordinates through electrostatic capacity coupling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display tablet-integrated electronic whiteboard device in which a tablet for pen input is integrated with the ferroelectric liquid crystal panel made of a liquid crystal material containing ferroelectric liquid crystal. is there.

[0002]

2. Description of the Related Art FIG. 9 is a simplified structural view of a conventional electronic whiteboard device. Conventionally, as shown in FIG. 9, a display tablet-integrated electronic whiteboard device made of a liquid crystal material containing a ferroelectric liquid crystal has a ferroelectric liquid crystal panel 1 as a display unit and a tablet 20 separately and independently. And are integrally formed by bringing them into close contact with each other. Here, as the tablet 20, a capacitive coupling type, an electromagnetic induction type, or a resistive film type is used.

[0003]

However, in the above-described conventional configuration, in order to obtain position detection accuracy at the level of one pixel, the display surface of the ferroelectric liquid crystal panel 1 and the tablet 20 are required.
It is necessary to match the input surface over the entire surface with the accuracy of one display pixel, which is difficult to manufacture.

In the case where the ferroelectric liquid crystal panel 1 and the tablet 20 are of a capacitive coupling type, both the ferroelectric liquid crystal panel 1 and the tablet 20 have electrodes arranged in a matrix. Since a driver and the like having the same functions are provided, the circuit is wasted and the circuit is expensive.

Further, in a large-screen display size (for example, A0 size) required for an electronic whiteboard device, in a capacitive coupling type tablet, the electrode wiring length becomes longer, the resistance increases, and the ferroelectric liquid crystal panel 1 With the increase in the capacity of the liquid crystal material, the scanning pulse differs depending on the detection position, and erroneous detection of the coordinate position has occurred.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and is of a display tablet integrated type using a ferroelectric liquid crystal panel which can be manufactured at low cost and easily and which can accurately detect a coordinate position even with a large screen display size. It is an object to provide an electronic whiteboard device.

[0007]

According to the first aspect of the present invention,
A ferroelectric liquid crystal panel composed of a liquid crystal material including a ferroelectric liquid crystal having row and column electrodes, a row electrode driver and a column electrode driver for driving the ferroelectric liquid crystal panel, a detection pen, and the detection pen , A coordinate control unit that calculates the position coordinates of the detection pen based on the signal, a detection control unit that generates a scanning pulse to be supplied to the row and column electrodes, and a display scanning pulse to be supplied to the row and column electrodes. A display control unit; a switching unit for switching the outputs of the detection control unit and the display control unit; and a timing control unit for controlling all timings. Each time the scanning pulse is sequentially supplied to the row electrode, a signal corresponding to the display data is simultaneously supplied to the column electrode, and the row coordinate detection mode is provided. In, a scanning pulse is sequentially supplied to the row electrodes from the row electrode driver, and the row electrodes are detected by capacitive coupling by bringing the detection pen into contact with an arbitrary position on the display unit.In the column coordinate detection mode, A scanning pulse is sequentially supplied to the column electrodes from the column electrode driver, and the detection pen is brought into contact with an arbitrary position on the display unit to detect the column electrode coordinates by capacitive coupling.

According to a second aspect of the present invention, the display mode corresponds to an initial display mode in which a scanning pulse is sequentially supplied to each row electrode for performing full-screen display, and a row coordinate detected in the row coordinate detection mode. And a display change mode for supplying a pulse only to the row electrode to be changed.

According to a third aspect of the present invention, there is provided a coordinate detection number counting section for counting the number of detected coordinates, and a coordinate comparison section for comparing the detected row coordinates. , The display change mode or the row and column coordinate detection mode is determined.

According to a fourth aspect of the present invention, in the ferroelectric liquid crystal panel, electrodes are formed on both sides of the substrate.

According to a fifth aspect of the present invention, in the ferroelectric liquid crystal panel, a plurality of substrates on which electrodes are formed are stacked.

[0012] According to a sixth aspect of the present invention, the detection pen includes:
It includes an acceleration sensor for detecting acceleration and a gyro for detecting inclination, and detects coordinates of the detection pen.

[0013]

According to the first aspect of the present invention, a row electrode and a column electrode and a row electrode driver and a column electrode driver constituting a ferroelectric liquid crystal panel can be used for both display control and detection control. Eliminates sticking with the tablet.

According to the second aspect of the present invention, in the display change mode, the display change time is shortened, so that the number of samples for coordinate detection can be increased.

According to the third aspect of the present invention, in the display change mode, display change processing corresponding to a plurality of coordinate detections can be performed by one display change processing, so that the number of samples for coordinate detection can be increased.

According to the fourth aspect of the present invention, since a fixed scanning pulse can be detected regardless of the detection position, coordinate detection can be accurately performed even with a large-screen electronic whiteboard device.

According to the fifth aspect of the present invention, since a fixed scanning pulse can be detected regardless of the detection position, coordinate detection can be accurately performed even with a large-screen electronic whiteboard device.

According to the sixth aspect of the present invention, row and column coordinate detection and display change can be performed simultaneously, so that the number of samples for coordinate detection can be increased.

(Embodiment 1) FIG. 1 is a block diagram of an electronic whiteboard apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a timing chart showing the same operation. In FIG. 1, reference numeral 1 denotes a ferroelectric liquid crystal panel, and 2a, 2b, 2c... 2
h is a row electrode, and 3a, 3b, 3c... 3l are column electrodes.

Reference numeral 4 denotes a row electrode driver, the plurality of output terminals of which are 2a, 2b, 2c,.
Are connected to the row electrodes. A column electrode driver 5 has a plurality of output terminals 3a, 3b, 3c, respectively.
... Connected to 31 column electrodes.

A switching unit 6 switches between the output of the detection control unit 8 for generating a detection signal and the output of the display control unit 7 for generating a display signal. Reference numeral 9 denotes a detection pen. When the detection pen 9 is brought into contact with an arbitrary position on the ferroelectric liquid crystal panel 1, a scanning pulse is detected by capacitive coupling.
Reference numeral 10 denotes a coordinate calculation unit that calculates row and column coordinates based on the detected scanning pulse. Reference numeral 11 denotes a timing control unit that controls all timings.

The operation of the electronic whiteboard apparatus of the first embodiment configured as described above will be described with reference to FIGS. First, in the display mode in the timing chart shown in FIG. 2, based on the timing control unit 11, the display control unit 7 sends a scan pulse to each of the row electrodes 2a, 2b, 2c,. ... 3l each time a scanning pulse is sequentially supplied to the row electrodes, while being supplied in units of one electrode.
At the same time. As a result, the display is driven by line-sequential scanning, and an image corresponding to the display data is displayed.

Next, in the row coordinate detection mode, based on the timing control section 11, the detection control section 8 switches the row electrodes 2a, 2b, 2c,.
A scanning pulse is sequentially supplied to 2h, and the scanning pulse is detected by capacitive coupling by bringing the detection pen 9 into contact with an arbitrary position of the ferroelectric liquid crystal panel 1. After that, the coordinate calculation unit 10 calculates the row coordinates based on the timing control unit 11.

In the column coordinate detection mode, based on the timing control unit 11, the detection control unit 8 switches the column electrodes 3a, 3b, 3c,.
A scanning pulse is sequentially supplied to 3l, and the scanning pulse is detected by capacitive coupling by bringing the detection pen 9 into contact with an arbitrary position on the ferroelectric liquid crystal panel 1. After that, the coordinate calculation unit 10 calculates the column coordinates based on the timing control unit 11.

Further, in order to display the display contents reflecting the detected pen coordinates, the display control section 7 is switched by the row electrode driver 4 via the switching section 6 based on the timing control section 11 in the display mode of the next frame. Each row electrode 2a,
2b, 2c... 2h are sequentially supplied with a scanning pulse in units of one electrode, and each time the scanning pulses are sequentially supplied to the row electrodes, the display reflects the pen coordinates on the column electrodes 3a, 3b, 3c. A signal corresponding to the data is simultaneously supplied.
As a result, an image corresponding to the display data reflecting the pen coordinates is displayed. By repeating the above operation, it is possible to provide a display tablet-integrated electronic whiteboard device using a ferroelectric liquid crystal panel capable of inputting with a pen.

(Embodiment 2) FIG. 3 is a timing chart showing the operation of an electronic whiteboard apparatus according to Embodiment 2 of the present invention. The configuration of the electronic whiteboard device is the same as that of the first embodiment.

First, in the initial display mode in the timing chart shown in FIG. 3, the display control section 7 is controlled by the row electrode driver 4 via the switching section 6 to control the row electrodes 2a, 2b, 2c. Are sequentially supplied to the column electrodes 3a, 3b, and 3c each time the scanning pulse is sequentially supplied to the row electrodes.
... A signal corresponding to the display data is simultaneously supplied to 3l. As a result, the display is driven by line-sequential scanning, and an initial image corresponding to the display data is displayed. The operations in the next row coordinate detection mode and column coordinate detection mode are the same as those in the first embodiment, and a description thereof will be omitted.

Subsequently, in the display change mode, in order to display the display contents reflecting the detected pen coordinates, the display control unit 7 controls the row electrodes of the pen coordinates detected through the switching unit 6 based on the timing control unit 11. Are supplied in units of one electrode from the row electrode driver 4 corresponding to the column electrodes 3a, and when the scan pulse is supplied to the row electrodes, the column electrodes 3a,
A voltage corresponding to the display data reflecting the pen coordinates is simultaneously supplied to 3b, 3c... 3l. As a result, an image corresponding to the display data reflecting the pen coordinates is displayed, and by repeating the above operation as shown in FIG. 3, it is possible to provide an electronic whiteboard device capable of inputting with the pen. As a result, only the row electrode corresponding to changing the display content reflecting the detected pen coordinates supplies the scanning pulse, so that the number of coordinate detection samplings can be increased as compared with the first embodiment.

Here, since the ferroelectric liquid crystal has a memory effect, if it is not necessary to change the displayed content once displayed, it is only necessary to supply a scanning pulse. That is,
The scan pulse is supplied only to the row electrode corresponding to the detected pen coordinates to change the display, and the previous display can be held without supplying the scan pulse to the other row electrodes.

Further, the pulses supplied in the initial display mode and the change processing mode are sufficiently longer than the pulses supplied in the row and column coordinate detection mode (usually on the order of mS, where mS is 1/1000 second). Therefore, supplying the pulse only to the row electrode corresponding to the detected pen coordinates without supplying the scan pulse to all the row electrodes can greatly reduce the display change processing time, as described above. It can be said that the number of coordinate detection samplings can be increased.

Further, in the row and column coordinate detection mode, the scanning pulse for detection is supplied to all the row and column electrodes. However, as shown in the figure, the display is changed because the absolute value and width of the pulse are sufficiently small. Absent.

(Embodiment 3) FIG. 4 is a block diagram of an electronic whiteboard apparatus according to Embodiment 3 of the present invention, and FIG. 5 is a flowchart showing the same operation. In FIG. 4, reference numeral 12 denotes a coordinate detection number counting unit that counts the number of detected coordinates, and 13 denotes a coordinate comparison unit that compares the detected row coordinates. In addition,
Elements denoted by reference numerals 1 to 11 are the same as those in FIG.

Next, the operation will be described. First, as the initial display processing, the same operation as in the initial display mode of the second embodiment is performed, and the coordinate detection number counting unit 12 is cleared (step 1). Next, row coordinate detection and column coordinate detection are performed, and the detection count is incremented by the coordinate detection number counting unit 12 (step 2). Further, similar operations (row coordinate detection, column coordinate detection, and increment of detection count) are performed (step 3). Then, in step 4, the coordinate comparing unit 13 compares whether the detected row coordinates of the two coordinates match. If there is a match, the process proceeds to step 5, where it is determined whether the detected count is equal to or less than a predetermined number (k). Here, if the detected count number is still less than the predetermined number (k), the process returns to step 3 and the processes of steps 3, 4, and 5 are repeated thereafter.

If it is determined in step 4 that the row coordinates of the coordinates do not match, or if the detected count has still reached the predetermined number (k) in step 5, the process proceeds to step 6, where the display change processing (implementation) is performed. The same operation as in the display change mode described in the second embodiment) and the coordinate detection count section are cleared. Thereafter, the process proceeds to step 2 and the subsequent processing is repeated.

Thus, when the detected row coordinates match, the display change processing corresponding to a plurality of coordinate detections can be performed in one display change processing, which is different from the second embodiment. Thus, the number of coordinate detection samplings can be further increased. Further, even when the detected row coordinates match, coordinate detection is not performed continuously for a predetermined number of times or more and display change processing is performed, so that display responsiveness of pen input is not impaired.

(Embodiment 4) FIG. 6 is a sectional view of a ferroelectric liquid crystal panel of an electronic whiteboard device according to Embodiment 4 of the present invention. 14 is a ferroelectric liquid crystal, 15a, 15b
Is a substrate on which a row electrode and a column electrode are formed, respectively.
16a, 16b, 16c, 16d, and 16e are row electrodes formed on the opposite surface of the substrate on which the conventional row electrodes are formed. Reference numerals 17a, 17b, 17c... Denote column electrodes formed on the opposite surface of the substrate on which the conventional column electrodes are formed.

When a large-screen electronic whiteboard device is constructed using the ferroelectric liquid crystal panel as described above, a scanning pulse is applied to the row and column electrodes by the row and column electrode drivers 4 and 5 for coordinate detection. Even if supplied, a scanning pulse independent of the position where the detection pen 9 is brought into contact can be detected from a row electrode and a column electrode which are not in contact with the ferroelectric liquid crystal 14, so a large-screen ferroelectric liquid crystal panel is used. The coordinate detection can be performed accurately even with the conventional electronic whiteboard device.

(Embodiment 5) FIG. 7 is a sectional view of a ferroelectric liquid crystal panel of an electronic whiteboard device according to Embodiment 5 of the present invention. 14 is a ferroelectric liquid crystal, 15a, 15b
Is a substrate on which a row electrode and a column electrode are formed, respectively.
Each of them has a configuration in which a plurality of them are stacked.

When a large-screen electronic whiteboard device is constructed using the ferroelectric liquid crystal panel as described above, a scanning pulse is applied to the row and column electrodes by the row and column electrode drivers 4 and 5 for coordinate detection. Even if supplied, the scanning pulse independent of the position where the detection pen 9 is brought into contact can be detected from the row electrode and the column electrode which are not in contact with the ferroelectric liquid crystal 14, so that the coordinate detection can be performed even with a large-screen electronic whiteboard device. Can be done accurately.

(Embodiment 6) FIG. 8 is a block diagram of a detection pen of an electronic whiteboard device according to Embodiment 6 of the present invention. The configuration of the electronic whiteboard device is the same as that of FIG. 18a,
Reference numeral 18b denotes an acceleration sensor, and 19 denotes a gyro for detecting the inclination of the detection pen 9.

The operation of the detection pen 9 of the electronic whiteboard device according to the sixth embodiment configured as described above will be described. By the acceleration sensors 18a and 18b provided in the detection pen 9,
By measuring the acceleration of the detection pen 9 and integrating it twice on the time axis, the movement locus of the detection pen 9 can be traced. Accordingly, the corresponding row and column coordinates can be calculated by the coordinate calculation unit 10 and the display can be changed. Here, since the gyro 19 can detect the inclination of the detection pen 9, it is possible to remove the influence of the gravitational acceleration from the acceleration detected by the acceleration sensors 18a and 18b.

Further, the absolute position at the start of writing of the detection pen can be detected by the method described in the first embodiment, and thereafter, can be measured and calculated by each sensor of the detection pen 9 in combination. It is. As a result, row and column coordinate detection and display change can be performed simultaneously, so that the number of samples for coordinate detection can be increased.

[0043]

As described above, according to the present invention, in an electronic whiteboard device using a ferroelectric liquid crystal panel, the ferroelectric liquid crystal panel is used for both display and coordinate detection. Display surface and tablet input surface
In order to make sure that they match over the entire surface with the accuracy of one display pixel,
The effort for matching can be saved, the device can be easily manufactured, and the row electrode driver and the column electrode driver can be commonly used, so that the configuration can be made at low cost.

Further, by utilizing the memory effect of the ferroelectric liquid crystal panel to supply a pulse to only the row electrode corresponding to the detected row electrode coordinates, the display change processing period is shortened.
Since the number of coordinate detection samplings can be increased, an accurate pen input function can be realized.

Since the display change processing or the row and column coordinate detection processing is performed in accordance with the detected row electrode coordinates and the detected number of coordinates using the memory effect of the ferroelectric liquid crystal panel, the ratio of the display change processing is reduced. As a result, the number of coordinate detection samplings can be increased, so that an accurate pen input function can be realized. Furthermore, since the display responsiveness of pen input is not impaired, comfortable pen input can be realized.

Further, even with an electronic whiteboard apparatus using a ferroelectric liquid crystal panel having a large screen size, an accurate pen input function independent of the contact position of the detection pen can be realized. Furthermore, by providing the detection pen with an acceleration sensor and a gyro, row and column coordinate detection and display change can be performed simultaneously, so that the number of samples for coordinate detection can be increased, so that an accurate pen input function can be realized. Since the display responsiveness is not impaired, comfortable pen input can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram of an electronic whiteboard device according to a first embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of the electronic whiteboard device according to the first embodiment of the present invention.

FIG. 3 is a timing chart showing the operation of the electronic whiteboard device according to the second embodiment of the present invention.

FIG. 4 is a block diagram of an electronic whiteboard device according to a third embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of the electronic whiteboard device according to the third embodiment of the present invention.

FIG. 6 is a sectional view of a ferroelectric liquid crystal panel of an electronic whiteboard device according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view of a ferroelectric liquid crystal panel of an electronic whiteboard device according to a fifth embodiment of the present invention.

FIG. 8 is a block diagram of a detection pen of the electronic whiteboard device according to the sixth embodiment of the present invention.

FIG. 9 is a simplified configuration diagram of a conventional electronic whiteboard device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ferroelectric liquid crystal panel 2a, 2b, 2c ... 2h Row electrode 3a, 3b, 3c ... 3l Column electrode 4 Row electrode driver 5 Column electrode driver 6 Switching part 7 Display control part 8 Detection control part 9 Detection pen DESCRIPTION OF SYMBOLS 10 Coordinate calculation part 11 Timing control part 12 Detection number count part 13 Coordinate comparison part 14 Ferroelectric liquid crystal 15a, 15b Substrate 16a, 16b, 16c, 16d, 16e Row electrode 17a, 17b ... Column electrode 18a, 18b Acceleration Sensor 19 Gyro

Claims (6)

[Claims] 1. A ferroelectric liquid crystal panel comprising a liquid crystal material including a ferroelectric liquid crystal having row and column electrodes, a row electrode driver and a column electrode driver for driving the ferroelectric liquid crystal panel, and a detection pen. A coordinate calculation unit that calculates the position coordinates of the detection pen based on the signal of the detection pen; a detection control unit that generates a detection scanning pulse to be supplied to the row and column electrodes; A display control unit that generates a scanning pulse, a switching unit that switches the outputs of the detection control unit and the display control unit, and a timing control unit that controls all timings. A scanning pulse is sequentially supplied in units of one electrode, and a signal corresponding to display data is simultaneously supplied to a column electrode every time a scanning pulse is sequentially supplied to the row electrode, and In the target detection mode, a scanning pulse is sequentially supplied to the row electrodes from the row electrode driver, and the row electrodes are detected by electrostatic coupling by bringing the detection pen into contact with an arbitrary position on the display unit, and the column coordinates are detected. In the detection mode, a scanning pulse is sequentially supplied to the column electrode from the column electrode driver, and the column electrode coordinates are detected by capacitive coupling by bringing the detection pen into contact with an arbitrary position on the display unit. Electronic whiteboard equipment. 2. The display mode includes an initial display mode in which a scanning pulse is sequentially supplied to each row electrode for performing full-screen display, and a pulse only in a row electrode corresponding to a row coordinate detected in the row coordinate detection mode. 2. The electronic whiteboard device according to claim 1, further comprising: a display change mode for supplying the electronic whiteboard. 3. A coordinate detection unit for counting the number of detected coordinates, and a coordinate comparison unit for comparing the detected row coordinates, and a display change mode according to the coordinate detection unit and the coordinate comparison unit. 2. The electronic whiteboard device according to claim 1, wherein it is determined whether or not to perform the row and column coordinate detection mode. 4. The electronic whiteboard device according to claim 1, wherein said ferroelectric liquid crystal panel has electrodes formed on both sides of a substrate. 5. The electronic whiteboard device according to claim 1, wherein the ferroelectric liquid crystal panel includes a plurality of substrates on which electrodes are formed. 6. The electronic whiteboard device according to claim 1, wherein the detection pen includes an acceleration sensor for detecting acceleration and a gyro for detecting inclination, and detects coordinates of the detection pen.