Tablet integrated with display

• US 5,418,551 A
• Filed: 07/12/1993
• Issued: 05/23/1995
• Est. Priority Date: 12/19/1988
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ise, Masahiro
• Primary Examiner(s): Weldon, Ulysses
• Assistant Examiner(s): Liang, Regina
• Application Number:
  US08/089,776
• Time in Patent Office: 680 Days
• Field of Search: 345/173, 345/174, 345/175, 345/176, 345/177, 345/180, 345/181, 345/182, 345/183, 178/18, 178/19, 341/5, 341/33
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0441 using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals

Abstract

A tablet integrated with a display is provided comprising a matrix panel having row and column electrodes, a detecting conductor, a row electrode driver, a column electrode driver, and row and column coordinate detecting circuits. In a display mode, the row electrode driver applies a row scanning pulse successively to each row electrode of the matrix panel, and the column electrode driver simultaneously applies a display voltage to each column electrode of the matrix panel each time a corresponding row scanning pulse is applied. In a row detection mode, the row electrode driver applies the row scanning pulse successively to each row electrode of the matrix panel, and analyzes the timing of the row scanning pulse detected by a detecting conductor touching the matrix panel, so as to determine the row coordinate of the position of the detecting conductor. In a column detection mode, the column electrode driver applies the column scanning pulse successively to each column electrode of the matrix panel, and the column coordinate detecting circuit analyzes the timing of the column scanning pulse detected by the detecting conductor touching the matrix panel, so as to determine the column coordinate of the detecting conductor.

Claims

1. A tablet integrated with a display comprising:

a matrix panel for display, having row and column electrodes;

a row electrode driver for applying a row scanning pulse successively to every row electrode of the matrix panel;

a column electrode driver for applying a column scanning pulse successively to every column electrode of the matrix panel and applying a voltage corresponding to display data;

a detecting conductor, which can be coupled capacitively with the row and column electrodes by contacting the matrix panel, for picking up the row and column scanning pulses from the matrix panel;

a timing generator for transferring the display data to the column electrode driver and applying timing signals, for determining timings of the row and column scanning pulses, to the row electrode driver and the column electrode driver; and

row and column coordinate detecting circuits electrically connected to the detecting conductor;

wherein,

during a display mode, the row electrode driver applies the row scanning pulse successively to every row electrode of the matrix panel, and the column electrode driver applies a voltage, in accordance with the display data, simultaneously to the column electrode of the matrix panel each time the row scanning pulse is applied successively to the row electrode of the matrix panel;

during a row detection mode, the row electrode driver applies the row scanning pulse successively to the row electrodes of the matrix panel, and the row coordinate detecting circuit analyzes the timing of the row scanning pulse picked up by the detecting conductor touching an arbitrary position on the matrix panel, so as to determine the row coordinate of the position which the detecting conductor touches; and

during a column detection mode, the column electrode driver applies the column scanning pulse successively to the column electrodes of the matrix panel, and the column coordinate detecting circuit analyzes the timing of the column scanning pulse picked up by the detecting conductor touching an arbitrary position on the matrix panel, so as to determine the column coordinate of the position which the detecting conductor touches;

said tablet integrated with a display further comprising means for effecting said display mode, row detection mode, and column detection mode during alternate periods of time in a time sharing manner.

2. A tablet according to claim 1, further comprising:

signaling means for signaling when said row electrode driver starts to successively apply row scanning pulses and for signaling when said column electrode driver starts to successively apply column scanning pulses;

said row detecting circuit comprising a row counter for counting the number of row scanning pulses applied to row electrodes of the matrix panel; and

said column detecting circuit comprising a column counter for counting the number of column scanning pulses applied to the column electrodes of the matrix panel.

3. A tablet according to claim 2, further comprising:

column counter stopping means for stopping the counting by said column counter when said detecting conductor picks up a column scanning pulse from the matrix panel; and

row counter stopping means for stopping the counting by said row counter when said detecting conductor picks up the row scanning pulse from the matrix panel.

4. A tablet according to claim 1, wherein the matrix panel comprises a thin film electroluminescent matrix panel.

5. A tablet according to claim 1, wherein the matrix panel comprises a liquid crystal matrix panel.

6. A tablet according to claim 1, wherein the matrix panel comprises an AC plasma display.

7. A tablet according to claim 1, further comprising a comparator, electrically connected to the row and column coordinate detecting circuits, for comparing a signal outputted from the detecting conductor with a reference voltage, wherein each of the row and column coordinate detecting circuits starts operating when a signal outputted from the detecting conductor is greater than or equal to the reference voltage.

8. A tablet according to claims 1, further comprising a disturbing signal cancelling conductor for detecting the scanning pulse of each of the row electrodes, and a differential amplifier, outputting to each of the row and column coordinate detecting circuits, a difference signal which represents the difference between a signal outputted from the disturbing signal cancelling conductor and a signal outputted from the detecting conductor.

9. A tablet integrated with a display comprising:

a matrix display panel, having row and column electrodes;

a row electrode driver for applying a row scanning pulse to individual row electrodes of the matrix panel;

a column electrode driver for applying a column scanning pulse to individual column electrodes of the matrix panel and applying a voltage corresponding to display data to individual column electrodes;

a detecting conductor, which can be coupled capacitively with the row and column electrodes by contacting the matrix panel, for picking up the row and column scanning pulses from the matrix display panel;

a timing generator for transferring the display data to the column electrode driver and applying timing signals to the row electrode driver and the column electrode driver; and

row and column coordinate detecting circuits electrically connected to the detecting conductor;

wherein,

during a display mode, the row electrode driver successively applies the row scanning pulse to individual row electrodes of the matrix panel, and the column electrode driver applies a voltage, in accordance with the display data, to the column electrodes of the matrix panel each time the row scanning pulse is applied to the row electrode of the matrix panel;

during a row detection mode, the row electrode driver successively applies the row scanning pulse to individual row electrodes of the matrix panel, and the row coordinate detecting circuit analyzes the timing of the row scanning pulse picked up by the detecting conductor touching an arbitrary position on the matrix panel, so as to determine the row coordinate of the position of the detecting conductor; and

during a column detection mode, the column electrode driver successively applies the column scanning pulse to the column electrodes of the matrix panel, and the column coordinate detecting circuit analyzes the timing of the column scanning pulse picked up by the detecting conductor touching an arbitrary position on the matrix panel, so as to determine the column coordinate of the position of the detecting conductor.

10. A tablet according to claim 9, further comprising:

signaling means for signaling when said row electrode driver starts to successively apply row scanning pulses and for signaling when said column electrode driver starts to successively apply column scanning pulses;

said row detecting circuit comprising a row counter for counting the number of row scanning pulses applied to the row electrodes of the matrix panel; and

said column detecting circuit comprising a column counter for counting the number of column scanning pulses applied to the column electrodes of the matrix panel.

11. A tablet according to claim 10, further comprising:

column counter stopping means for stopping the said counting by said column counter when said detecting conductor picks up a column scanning pulse from the matrix panel; and

row counter stopping means for stopping the counting by said row counter when said detecting conductor picks up a row scanning pulse from the matrix panel.

12. A tablet according to claim 9, wherein the matrix panel comprises a thin film electroluminescent matrix panel.

13. A tablet according to claim 9, wherein the matrix panel comprises a liquid crystal matrix panel.

14. A tablet according to claim 9, wherein the matrix panel comprises an AC plasma display.

15. A tablet according to claim 9, further comprising a comparator electrically connected to the row and column coordinate detecting circuits for comparing a signal outputted from the detecting conductor with a reference voltage, wherein each of the row and column coordinate detecting circuits starts its operating when a signal outputted from the detecting conductor is greater than or equal to the reference voltage.

16. A tablet according to claim 9, further comprising a disturbing signal cancelling conductor for detecting the scanning pulse of each of the row electrodes, and a differential amplifier, outputting to each of the row and column coordinate detecting circuits, a difference signal which represents the difference between a signal outputted from the disturbing signal cancelling conductor and a signal outputted from the detecting conductor.

19. A tablet according to claim 9, further comprising a peak point detector electrically connected to the row and column coordinate detecting circuits for detecting a peak point of a signal output from the detecting conductor, wherein each of the row and column coordinate detecting circuits starts operating when the peak point detector detects the peak point.

17. A tablet integrated with a display comprising:

a matrix panel for display, having row and column electrodes;

a row electrode driver for applying a row scanning pulse successively to every row electrode of the matrix panel;

a column electrode driver for applying a column scanning pulse successively to every column electrode of the matrix panel and applying a voltage corresponding to display data;

a detecting conductor, which can be coupled capacitively with the row and column electrodes by contacting the matrix panel, for picking up the row and column scanning pulses from the matrix panel;

a timing generator for transferring the display data to the column electrode driver and applying timing signals for determining timings of the row and column scanning pulses to the row electrode driver and the column electrode driver; and

row and column coordinate detecting circuits electrically connected to the detecting conductor;

the row electrode driver comprising means for applying, during a display mode, the row scanning pulse successively to every row electrode of the matrix panel, and means for applying a voltage, in accordance with the display data, simultaneously to the column electrode of the matrix panel each time the row scanning pulse is applied successively to the row electrodes of the matrix panel;

the row electrode driver comprising means for applying, during a row detection mode, the row scanning pulse successively to the row electrodes of the matrix panel, and means for analyzing the timing of the row scanning pulse picked up by the detecting conductor touching an arbitrary position on the matrix panel, so as to determine the row coordinate of the position which the detecting conductor touches;

the column electrode comprising means for applying, during a column detection mode, the column scanning pulse successively to the column electrodes of the matrix panel, and means for analyzing the timing of the column scanning pulse picked up by the detecting conductor touching an arbitrary position on the matrix panel, so as to determine the column coordinate of the position which the detecting conductor touches;

said tablet integrated with a display further comprising means for effecting said display mode, row detection mode, and column detection mode during alternate periods of time in a time sharing manner.

20. A tablet according to claim 17, further comprising a peak point detector electrically connected to the row and column coordinate detecting circuits for detecting a peak point of a signal output from the detecting conductor, wherein each of the row and column coordinate detecting circuits starts operating when the peak point detector detects the peak point.

18. A tablet integrated with a display comprising:

a matrix display panel, having row and column electrodes;

a row electrode driver for applying a row scanning pulse to individual row electrodes of the matrix panel;

a column electrode driver for applying a column scanning pulse to individual column electrodes of the matrix panel and applying a voltage corresponding to display data to individual column electrodes;

a detecting conductor, which can be coupled capacitively with the row and column electrodes by contacting the matrix panel, for picking up the row and column scanning pulses from the matrix display panel;

a timing generator for transferring the display data to the column electrode driver and applying timing signals to the row electrode driver and the column electrode driver; and

row and column coordinate detecting circuits electrically connected to the detecting conductor;

the row electrode driver comprising means for successively applying, during a display mode, the row scanning pulse to individual row electrodes of the matrix panel, and means for applying a voltage, in accordance with the display data, to the column electrodes of the matrix panel each time the row scanning pulse is applied to the row electrodes of the matrix panel;

the row electrode driver comprising means for successively applying, during a row detection mode, the row scanning pulse to individual row electrodes of the matrix panel, and means for analyzing the timing of the row scanning pulse picked up by the detecting conductor touching an arbitrary position on the matrix panel, so as to determine the row coordinate of the position of the detecting conductor; and

the column electrode driver comprising means for successively applying, during a column detection mode, the column scanning pulse to the column electrodes of the matrix panel, and means for analyzing the timing of the column scanning pulse picked up by the detecting conductor touching an arbitrary position on the matrix panel, so as to determine the column coordinate of the position of the detecting conductor.