Display device integrated with an input device

• US 5,684,505 A
• Filed: 06/20/1995
• Issued: 11/04/1997
• Est. Priority Date: 06/21/1994
• Status: Expired due to Term

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Furuhashi, Tsutomu, Takita, Isao, Mano, Hiroyuki, Nishitani, Shigeyuki, Futami, Toshio, Tsunekawa, Satoru, Kitajima, Masaaki, Hamada, Tatsuzo
• Primary Examiner(s): BRIER, JEFFERY A
• Application Number:
  US08/492,520
• Time in Patent Office: 868 Days
• Field of Search: 345/104, 345/174, 345/179, 178/18-20, 349/12
• US Class Current: 345/104
• 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 display device integrated with an input device comprises a display panel having picture elements being scanned line-at-a-time,

a detector for detecting a voltage pulse applied on one of the picture elements through electrostatic coupling,

a first circuit for applying a voltage pulse of a type differing with a plurality of regions into which the display panel are divided, on electrodes associated with the picture element in one of the plurality of regions during the non-display period,

a second circuit for determining a region of the picture element by the type of the voltage pulse detected by the detector,

a fourth circuit for determining a relative X coordinate in the determined region by counting clock pulses synchronized with sequential application of a voltage on electrodes until the fourth circuit receives the voltage pulse detected by the detector during the non-display period, and

a fifth circuit for determining an absolute X-coordinate by the determined region and the relative X-coordinate.

Claims

1. A display device integrated with an input device comprising:

a display panel having M×

N picture elements arranged in a matrix of M rows×

N columns, said M×

N picture elements being scanned line-at-a-time with a period comprising a display period and a non-display period, a detector for detecting a voltage pulse applied on one of said M×

N picture elements through electrostatic coupling by being pointed to said one of said M×

N picture elements,

a first circuit for applying a first voltage pulse of a type differing with a plurality of regions into which said matrix of M rows×

N columns are divided column-wise, on electrodes associated with corresponding ones of said N columns in one of said plurality of regions during said non-display period,

a second circuit for determining one of said plurality of regions in which said one of said M×

N picture elements pointed to by said detector lies, by said type of said first voltage pulse detected by said detector,

a third circuit for determining a relative Y coordinate in said determined region by counting clock pulses synchronized with sequential application of a second voltage pulse on electrodes associated with said M rows until said third circuit receives said second voltage pulse detected by said detector during said display period,

a fourth circuit for determining a relative X coordinate in said determined region by counting clock pulses synchronized with sequential application of said first voltage pulse on electrodes associated with said N columns until said fourth circuit receives said first voltage pulse detected by said detector during said non-display period, and

a fifth circuit for determining an absolute X-coordinate and an absolute Y-coordinate by said determined region, said relative X-coordinate and said relative Y-coordinate.

2. The display device integrated with an input device defined in claim 1, wherein said first voltage pulses to be applied during said non-display period are a plurality of pulses whose width differs with said plurality of regions.

3. The display device integrated with an input device defined in claim 1, wherein said first voltage pulses to be applied during said non-display period are a plurality of pulses whose polarity differs with said plurality of regions.

4. The display device integrated with an input device defined in claim 1, wherein said first voltage pulses to be applied during said non-display period are a plurality of pulses whose combination of one of different widths and one of different polarities differs with said plurality of regions.

16. The display device integrated with an input device defined in one of claims 1 to 10, further comprising

means for detecting proximity of said detector to said display panel;

and

means for controlling polarity of voltages to be applied on said X and Y electrodes with a first period when said detector is not held close to said display panel, and with a second period longer than said first period when said detector is held close to said display panel.

5. A display device integrated with an input device to be driven with a control unit period comprising a display period and a non-display period, comprising

a display panel comprising M×

N picture elements for a display arranged as a matrix of M rows and N columns, M pieces of Y electrodes, each of said M piece of Y electrodes being connected to all of N pieces of said picture elements in one of said M rows for applying a voltage on said N pieces of picture elements, and N pieces of X electrodes, each of said N pieces of X electrodes being connected to all of M pieces of said picture elements in one of said N columns for applying a voltage on said M pieces of picture elements;

a Y electrode driver circuit for applying a scan voltage pulse on said Y electrodes sequentially during said display period;

means for supplying a train of data indicating voltage pulses corresponding to a pattern to be displayed in each one of said M rows sequentially during said display period; and

an X electrode driver circuit for applying said voltage pulses indicated by said train of data on said N pieces of X electrodes;

said display device displaying an image by turning said picture elements on by being supplied with specified voltages on said X electrodes and Y electrodes associated with said picture elements by said X and Y electrode driver circuits, respectively; and

said display device further including

means for generating a display control signal for distinguishing between said display period and non-display periods;

means for applying a first voltage pulse for coordinate determination of one of types differing with L regions into which said matrix of M rows and N columns are divided column-wise, on electrodes associated with corresponding ones of said N columns in one of L regions sequentially-during said non-display period;

a detector for detecting said first voltage pulse for coordinate determination and said scan voltage pulse applied on one of said X electrodes and one of said Y electrodes, respectively, associated with one of said M×

N picture elements at a location on a surface of said display panel pointed to by said detector, through electrostatic coupling;

means for determining a Y coordinate of said location according to said one of said Y electrodes on which said scan voltage pulse is applied when said detector detects said scan voltage pulse during said display period;

means for identifying said one of L regions by judging said type of said first voltage pulse;

means for determining a relative X coordinate of said location in one of said L regions according to said one of said X electrodes on which said first voltage pulse for coordinate determination is applied when said detector detects said first voltage pulse; and

means for determining an absolute X coordinate according to said relative coordinate and said identified region.

6. The liquid crystal display device integrated with an input device defined in claim 5, wherein said types differ in voltage pulse width with said L regions.

7. The display device integrated with an input device defined in claim 5, wherein said types differ in polarity of said voltage pulse.

8. A display device integrated with an input device to be driven with a control unit period comprising a display period and a non-display period, comprising

a pair of upper and lower display panels disposed in a plane comprising M×

N picture elements for a display arranged as a matrix of M rows and N columns, M pieces of Y electrodes, each of said M pieces of Y electrodes being connected to all of N pieces of said picture elements in one of said M rows for applying a voltage on said N pieces of picture elements, and N pieces of X electrodes, each of said N pieces of X electrodes being connected to all of M pieces of said picture elements in one of said N columns for applying a voltage on said M pieces of picture elements;

a Y electrode driver circuit for applying a scan voltage pulse on corresponding ones of said Y electrodes of said pair of upper and lower display panels at a time sequentially during said display period;

means for supplying a train of data indicating voltage pulses corresponding to a pattern to be displayed in each one of said M rows sequentially during said display period; and

X electrode driver circuits for applying said voltage pulses indicated by said train of data on said N pieces of X electrodes of said pair of display panels;

said display device displaying an image by turning said picture elements on by being supplied with specified voltages on said X electrodes and Y electrodes associated with said picture elements by said x and Y electrode driver circuits, respectively; and

said display device further including

means for generating a display control signal for distinguishing between said display period and non-display periods;

means for applying a first voltage pulse for coordinate determination of one of types differing with 2×

L regions into which said matrix of M rows and N columns of said pair of upper and lower display panels are divided column-wise, on electrodes associated with corresponding ones of said N columns in one of 2×

L regions sequentially during said non-display period;

a detector for detecting said first voltage pulse for coordinate determination and said scan voltage pulse applied on one of said X electrodes and one of said Y electrodes, respectively, associated with one of said M×

N picture elements at a location on a surface of said display panel pointed to by said detector, through electrostatic coupling;

means for determining a relative Y coordinate of said location on said pair of upper and lower display panels according to said one of said Y electrodes on which said scan voltage pulse is applied when said detector detects said scan voltage pulse during said display period;

means for identifying said one of 2×

L regions by judging said type of said first voltage pulse;

means for determining a relative X coordinate of said location in one of said 2×

L regions according to said one of said X electrodes on which said first voltage pulse for coordinate determination is applied when said detector detects said first voltage pulse; and

means for determining absolute X and Y coordinates according to said relative coordinates and said identified region.

9. The display device integrated with an input device defined in claim 8, wherein said types differ in voltage pulse width with said 2×

L regions.

10. The display device integrated with an input device defined in claim 8, wherein said types differ in polarity of said voltage pulse.

11. The display device integrated with an input device defined in claim 7 or 10, wherein said polarity of said voltage pulses is inverted once per said control unit.

13. The display device integrated with an input device defined in one of claims 5 to 10, further comprising

means for generating an oscillating signal induced by said first voltage pulse for coordinate determination in a circuit comprising an electrostatic capacity of said electrostatic coupling and a coil connected to said detector;

and

a filter for passing a frequency band of said oscillating signal;

wherein said means for determining an X coordinate determines said X coordinate by said oscillating signal passed through said filter.

14. The display device integrated with an input device defined in claim 11, further comprising

means for generating an oscillating signal induced by said first voltage pulse for coordinate determination in a circuit comprising an electrostatic capacity of said electrostatic coupling and a coil connected to said detector;

and a filter for passing a frequency band of said oscillating signal;

wherein said means for determining an X coordinate determines said X coordinate by said oscillating signal passed through said filter.

17. The display device integrated with an input device defined in claim 11, further comprising

means for detecting proximity of said detector to said display panel;

and

means for controlling polarity of voltages to be applied on said X and Y electrodes with a first period when said detector is not held close to said display panel, and with a second period longer than said first period when said detector is held close to said display panel.

19. The display device integrated with an input device defined in one of claims 5 to 10, further comprising

means for determining an X coordinate of said location in one of said L regions according to said one of said X electrodes on which said first voltage pulse for coordinate determination is applied when said detector detects said first voltage pulse;

means for determining an absolute X coordinate according to said relative coordinate and said identified region; and

means for detecting contact of said detector with said display panel; and

means for controlling polarity of voltages to be applied on said X and Y electrodes with a first period when said detector is not in contact with said display panel, and with a second period longer than said first period when said detector is in contact with said display panel.

12. A display device integrated with an input device to be driven with a control unit period comprising a display period and a non-display period, comprising

a display panel comprising M×

N picture elements for a display arranged as a matrix of M rows and N columns, M pieces of Y electrodes, each of said M pieces of Y electrodes being connected to all of N pieces of said picture elements in one of said M rows for applying a voltage on said N pieces of picture elements, and N pieces of X electrodes, each of said N pieces of X electrodes being connected to all of M pieces of said picture elements in one of said N columns for applying a voltage on said M pieces of picture elements;

a Y electrode driver circuit for applying a scan voltage pulse on said Y electrodes sequentially during said display period;

means for supplying a train of data indicating voltage pulses corresponding to a pattern to be displayed in each one of said M rows sequentially during said display period; and

an X electrode driver circuit for applying said voltage pulses indicated by said train of data on said N pieces of X electrodes;

said display device displaying an image by turning said picture elements on by being supplied with specified voltages on said X electrodes and Y electrodes associated with said picture elements by said X and Y electrode driver circuits, respectively; and

said display device further including

means for generating a display control signal for distinguishing between said display period and non-display periods;

means for applying a first voltage pulse for coordinate determination on electrodes associated with corresponding ones of said N columns sequentially during said non-display period;

a detector for detecting said first voltage pulse for coordinate determination and said scan voltage pulse applied on one of said X electrodes and one of said Y electrodes, respectively, associated with one of said M×

N picture elements at a location on a surface of said display panel pointed to by said detector, through electrostatic coupling;

means for determining a Y coordinate of said location according to said one of said Y electrodes on which said scan voltage pulse is applied when said detector detects said scan voltage pulse during said display period;

means for generating an oscillating signal induced by said first voltage pulse for coordinate determination in a circuit comprising an electrostatic capacity of said electrostatic coupling and a coil connected to said detector;

a filter for passing a frequency band of said oscillating signal; and

means for determining an X coordinate of said location according to said one of said X electrodes on which said first voltage pulse for coordinate determination is applied when said detector detects said voltage pulse by said oscillating signal passed through said filter.

35. An information processor, comprising a CPU that processes M-bit (N≦

M) data according to received N bit instruction codes and processes address data represented by L bits synchronously with clocks,

means for generating clocks with which said CPU operates,

a memory that can write and read data and instruction codes in and from positions specified with L-bit address signals,

an external memory that can write and read data and instruction codes with one of an electric, magnetic, and optical means,

a display memory that can write and read display data in and from positions specified with L-bit address signals,

a system bus that outputs I/O data and address data from said CPU,

a local bus that connects each of said means locally independently of said system bus,

a display control means that outputs data from said display memory to a display device sequentially and outputs display data to said display memory,

means for displaying data corresponding to said data output by said display control means sequentially,

means for specifying coordinate positions on said display means, and

coordinate detecting means that detects specified positions and output coordinates corresponding to said specified positions,

wherein said display device defined in one of claims 8, 12, 15 and 18 is used as a display means and coordinate determination means.

15. A display device integrated with an input device to be driven with a control unit period comprising a display period and a non-display period, comprising

a display panel comprising M×

N picture elements for a display arranged as a matrix of M rows and N columns, M pieces of Y electrodes, each of said M pieces of Y electrodes being connected to all of N pieces of said picture elements in-one of said M rows for applying a voltage on said N pieces of picture elements, and N pieces of X electrodes, each of said N pieces of X electrodes being connected to all of M pieces of said picture elements in one of said N columns for applying a voltage on said M pieces of picture elements;

a Y electrode driver circuit for applying a scan voltage pulse on said Y electrodes sequentially during said display period;

means for supplying a train of data indicating voltage pulses corresponding to a pattern to be displayed in each one of said M rows sequentially during said display period; and

an X electrode driver circuit for applying said voltage pulses indicated by said train of data on said N pieces of X electrodes;

said display device displaying an image by turning said picture elements on by being supplied with specified voltages on said X electrodes and Y electrodes associated with said picture elements by said X and Y electrode driver circuits, respectively; and

said display device further including

means for generating a display control signal for distinguishing between said display period and non-display periods;

means for applying a first voltage pulse for coordinate determination on electrodes associated with corresponding ones of said N columns sequentially during said non-display period;

a detector for detecting said first voltage pulse for coordinate determination and said scan voltage pulse applied on one of said X electrodes and one of said Y electrodes, respectively, associated with one of said M×

N picture elements at a location on a surface of said display panel pointed to by said detector, through electrostatic coupling;

means for determining a Y coordinate of said location according to said one of said Y electrodes on which said scan voltage pulse is applied when said detector detects said scan voltage pulse during said display period;

means for determining an X coordinate of said location according to said one of said X electrodes on which said first voltage pulse for coordinate determination is applied when said detector detects said first voltage pulse;

means for detecting proximity of said detector to said display panel; and

means for controlling polarity of voltages to be applied on said X and Y electrodes with a first period when said detector is not held close to said display panel, and with a second period longer than said first period when said detector is held close to said display panel.

18. A display device integrated with an input device to be driven with a control unit period comprising a display period and a non-display period, comprising

a display panel comprising M×

N picture elements for display arranged as a matrix of M rows and N columns, M pieces of Y electrodes, each of said M pieces of Y electrodes being connected to all of N pieces of said picture elements in one of said M rows for applying a voltage on said N pieces of picture elements, and N pieces of X electrodes, each of said N pieces of X electrodes being connected to all of M pieces of said picture elements in one of said N columns for applying a voltage on said M pieces of picture elements;

a Y electrode driver circuit for applying a scan voltage pulse on said Y electrodes sequentially during said display period;

means for supplying a train of data indicating voltage pulses corresponding to a pattern to be displayed in each one of said M rows sequentially during said display period; and

an X electrode driver circuit for applying said voltage pulses indicated by said train of data on said N pieces of X electrodes;

said display device displaying an image by turning said picture elements on by being supplied with specified voltages on said X electrodes and Y electrodes associated with said picture elements by said X and Y electrode driver circuits, respectively; and

said display device further including

means for generating a display control signal for distinguishing between said display period and non-display periods;

means for applying a first voltage pulse for coordinate determination on electrodes associated with corresponding ones of said N columns sequentially during said non-display period;

a detector for detecting said first voltage pulse for coordinate determination and said scan voltage pulse applied on one of said X electrodes and one of said Y electrodes, respectively, associated with one of said M×

N picture elements at a location on a surface of said display panel pointed to by said detector, through electrostatic coupling;

means for determining a Y coordinate of said location according to said one of said Y electrodes on which said scan voltage pulse is applied when said detector detects said scan voltage pulse during said display period;

means for determining an X coordinate of said location according to said one of said X electrodes on which said first voltage pulse for coordinate determination is applied when said detector detects said first voltage pulse;

means for detecting contact of said detector with said display panel; and

means for controlling polarity of voltages to be applied on said X and Y electrodes with a first period when said detector is not in contact with said display panel, and with a second period longer than said first period when said detector is in contact with said display panel.

20. The liquid crystal display device integrated with an input device, comprising

a matrix panel forming picture element at each of intersection points of a plurality of scan electrodes and a plurality of data electrodes,

scanning means for applying a select voltage or non-select voltage to a plurality of said scan electrodes,

means for a applying a data voltage to a plurality of said data electrodes,

coordinate detecting means for detecting voltage levels of said plurality of scan and data electrodes, wherein a coordinate of one of said plurality of scan electrodes is determined by detecting an output voltage from said scanning means and a coordinate of one of said plurality of data electrodes is determined by detecting an output other than said data voltage from said means for applying said data voltage,

said liquid crystal display device integrated with an input device further comprising

a flat display panel comprising M×

N display elements arranged as a matrix of M rows and N columns, M pieces of Y electrodes being connected to said display elements in each row and N pieces of X electrodes being connected to said display elements in each column,

a Y electrode driver circuit that applies voltage pulses to said Y electrodes sequentially during a display period,

an X electrode driver circuit that applies voltage pulses to said N pieces of X electrodes according to a voltage pulse application pattern specified for a data string,

a detector that detects voltage pulses applied to said Y and X electrodes corresponding to a position pointed to by said detector on a surface of said flat display panel through electrostatic coupling, and

means for amplifying signals from said detector;

said liquid crystal display device displaying images by turning on each of said picture elements when specified voltages are applied to both said Y and X electrodes connected therewith, and

said liquid crystal display device integrated with an input device is further provided with

means for generating a signal specifying polarity of a voltage to be applied between said plurality of scan electrodes and said plurality of data electrodes,

means for generating a signal specifying both said display period and an X coordinate detection period,

Y coordinate detection means for digitizing a first signal output from said detector during a display period associated with one of said Y electrodes to which voltage pulses are applied when said detector detects said first signal,

X coordinate detection means for digitizing a second signal output from said detector during said non-display period associated with one of said X electrodes to which voltage pulses are applied when said detector detects said second signal, and

coordinate determination means for determining an X coordinate according to said second signal and determining a Y coordinate according to said first signal, and

an integrator in said X and Y coordinate detection means respectively.

22. The liquid crystal display device integrated with an input device defined in claim 20, including a filter that passes only signals in a specified frequency band in both said X coordinate detecting means and said Y coordinate detecting means respectively.

23. The liquid crystal display device integrated with an input device defined in claim 20, including

means for inverting said output signal from said detector and means for selecting a signal inverted in said inverting means or said signal from said detector using a control signal for AC driving in said X coordinate detecting means and said Y coordinate detecting means respectively.

24. The liquid crystal display device integrated with an input device defined in claim 20, including

means for amplifying detected signals, said X coordinate detecting means, and said Y coordinate detecting means inside said detector.

25. The liquid crystal display device integrated with an input device defined in claim 20, wherein means for amplifying said detected signals, said X coordinate detecting means, and said Y coordinate detecting means are packaged into one LSI.

26. The liquid crystal display device integrated with an input device defined in claim 20, wherein means for amplifying said detected signals, said X coordinate detecting means, said Y coordinate detecting means, said coordinate determination means, and means for supplying said data string are packaged into one LSI.

27. The liquid crystal display device integrated with an input device defined in claim 20, wherein said coordinate determination means and said means for supplying said data string are packaged into one LSI.

21. The liquid crystal display device integrated with an input device, comprising

a matrix panel forming a picture element at each of intersection points of a plurality of scan electrodes and a plurality of data electrodes,

scanning means for applying a select voltage or non-select voltage to a plurality of said scan electrodes,

means for applying a data voltage to a plurality of said data electrodes,

coordinate detecting means for detecting voltage levels of said plurality of scan and data electrodes, wherein a coordinate of one of said plurality of scan electrodes is determined by detecting an output voltage from said scanning means and a coordinate of one of said plurality of data electrodes is determined by detecting an output other than said data voltage from said means for applying said data voltage,

said liquid crystal display device integrated with an input device further comprising

a flat display panel provided with M×

N display elements arranged as a matrix of M rows×

N columns;

M pieces of Y electrodes being connected to said display elements in each row and N pieces of X electrodes being connected to said display elements in each column,

a Y electrode driving circuit that applies voltage pulses to said Y electrodes sequentially during a display period,

an X electrode driving circuit that applies voltage pulses to said N pieces of X electrodes according to a voltage pulse application pattern specified for a data string,

a detector that detects voltage pulses applied to said Y and X electrodes corresponding to a position pointed to by said detector on a surface of said flat display panel through electrostatic coupling,

means for amplifying said signals from said detector with a first amplification, and

means for amplifying said signals from said detector with a second amplification, and

said liquid crystal display device displaying images when specified voltages are applied to both said Y and X electrodes, and

said liquid crystal display device integrated with an input device further including,

means for generating a signal specifying polarity of a voltage to be applied between said plurality of scan electrodes and said plurality of data electrodes,

means for generating a signal specifying said display period and an X coordinate detection period,

X and Y coordinate detecting means for digitizing a first output signal amplified with said means for amplifying with said first amplification after it is output from said detector associated with said Y electrode to which voltage pulses are applied during said display period when said detector detects said first signal and for digitizing a second output signal amplified with said means for amplifying with said second amplification after it is output from said detector associated with said X electrode to which voltage pulses are applied during a non-display period when said detector detects said second output signal,

coordinate determination means for determining X and Y coordinates according to said first and second output signals from said X and Y coordinate detecting means and said signal specifying said display period and said X coordinate detection period, and

an integrator in the said X and Y coordinate detecting means.

28. The liquid crystal display device integrated with an input device defined in claim 21, including

a filter that passes only signals in a specified frequency band in said X and Y coordinate detecting means.

29. The liquid crystal display device integrated with an input device defined in claim 21, including means for inverting said output signal from said detector, and means for selecting said signal inverted in said inverting means or said signal from said detector using a control signal for AC driving in said X and Y coordinate detecting means.

30. The liquid crystal display device integrated with an input device defined in claim 21, wherein said detector is provided therein with means for amplifying said detected signals with said first amplification, means for amplifying said detected signals with said second amplification, and said X and Y coordinate detecting means.

31. The liquid crystal display device integrated with an input device defined in claim 21, wherein said means for amplifying said detected signals with said first amplification, means for amplifying said detected signals with said second amplification, and said X and Y coordinate detecting means are packaged in one LSI.

32. The liquid crystal display device integrated with an input device defined in claim 21, wherein said means for amplifying said detected signals with said first amplification, said means for amplifying said detected signals with said second amplification, said X and Y coordinate detecting means, and said coordinate determination means are packaged into one LSI.

33. The liquid crystal display device integrated with an input device defined in claim 21, wherein said means for amplifying said detected signals with said first amplification, said means for amplifying said detected signals with said second amplification, said X and Y coordinate detecting means, said coordinate determination means, and said means for supplying said data string are packaged into one LSI.

34. The liquid crystal display device integrated with an input device defined in claim 21, wherein said coordinate determination means, and said means for supplying said data string are packaged into one LSI.