Tablet integrated with display

• US 5,283,556 A
• Filed: 12/18/1989
• Issued: 02/01/1994
• 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:
  US07/452,243
• Time in Patent Office: 1,506 Days
• Field of Search: 340/706, 340/707, 340/709, 340/708, 340/711, 340/712, 340/781, 340/784, 341/33, 341/5, 178/18, 178/19, 178/20
• 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 comprising a matrix panel having row and column electrodes, a detecting conductor, a row electrode driver, a column electrode driver, a row coordinate detecting circuit and a column coordinate detecting circuit, in case of display mode, the row electrode driver applying the row scanning pulse successively to every row electrode of the matrix panel from one to another, and the column electrode driver applying 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, in case of row detection mode, the row electrode driver applying the row scanning pulse successively to the row electrode of the matrix panel, and receiving the row scanning pulse detected through electrostatic capacitive coupling caused by the detecting conductor touching an arbitrary position on the matrix panel, so as to present the row coordinate of the position which the detecting conductor touches, and in case of column detection mode, the column electrode driver applying the column scanning pulse successively to the column electrode of the matrix panel, and the column coordinate detecting circuit receiving the column scanning pulse detected through electrostatic capacitive coupling caused by the detecting conductor touching an arbitrary position on the matrix panel, so as to present the column coordinate of the position which the detecting conductor touches.

Claims

1. A tablet integrated with a display comprising:

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

a detecting conductor which can be coupled capacitively with the row and column electrodes when touched on the matrix panel;

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 for a predetermined amount of time;

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;

a row coordinate detecting circuit electrically connected to the detecting conductor, for detecting a row coordinate; and

a column coordinate detecting circuit electrically connected to the detecting conductor, for detecting a column coordinate;

wherein,

during a display mode, the row electrode driver applies the row scanning pulse successively to every row electrode of the matrix panel from one to another, 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 electrode of the matrix panel, and the row coordinate detecting circuit receives the row scanning pulse detected through electrostatic capacitive coupling caused by the detecting conductor touching an arbitrary position on the matrix panel, so as to present 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 electrode of the matrix panel, and the column coordinate detecting circuit receives the column scanning pulse detected through electrostatic capacitive coupling caused by the detecting conductor touching an arbitrary position on the matrix panel, so as to present 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;

said row electrode driver including;

a first shift register having output terminals corresponding in number to the row electrodes of the matrix panel, a first switch circuit having changeover switches which correspond in number to the row electrodes and change over in response to a signal outputted from each of the output terminals of the first shift register, and a first gate circuit applying a row scanning pulse of a specified voltage to each of the row electrodes in response to a signal outputted from the first switch circuit;

said column electrode driver including;

a second shift register having output terminals corresponding in number to the column electrodes of the matrix panel, a latch circuit having output terminals corresponding in number to the column electrodes, for latching a signal outputted from each of the output terminals of the second shift register, a second switch circuit having changeover switches which correspond in number to the column electrodes and change over in response to a signal outputted from the latch circuit, and a second gate circuit for applying voltage corresponding to the display data and the column scanning pulse to each of the column electrodes in response to a signal outputted from the second switch circuit, with timesharing.

2. A tablet according to claim 1, wherein each of the row and column coordinate detecting circuits is a resettable counter.

3. A tablet according to claim 1, further comprising a comparator electrically connected to the row and column coordinates detecting circuits, for comparing a signal outputted from the detecting conductor with a reference voltage,

each of the row and column coordinate detecting circuits starts its operation when the signal outputted from the detecting conductor equals or is above the reference voltage.

4. A tablet integrated with a display comprising:

a matrix for display, having row and column electrodes;

a detecting conductor which can be coupled capacitively with the row and column electrodes when touched on the matrix panel;

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 to the matrix panel and applying a voltage corresponding to display data for a predetermined amount of time;

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

a row coordinate detecting circuit electrically connected to the detecting conductor, for detecting a row coordinate, and

a column coordinate detecting circuit electrically connected to the detecting conductor, for detecting a column coordinate;

wherein,

during a display mode, the row electrode driver applies the row scanning pulse successively to every row electrode of the matrix panel from one to another, 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 electrode of the matrix panel, and the row coordinate detecting circuit receives the row scanning pulse detected through electrostatic capacitive coupling caused by the detecting conductor touching an arbitrary position on the matrix panel, so as to present 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 electrode of the matrix panel, and the column coordinate detecting circuit receives the column scanning pulse detected through electrostatic capacitive coupling caused by the detecting conductor touching an arbitrary position on the matrix panel, so as to present the column coordinate of the position which the detecting conductor touches;

said tablet integrated with a display further comprising means for effecting display mode concurrently with said row detection mode.