Liquid crystal display apparatus including touch panel

• US 20070002192A1
• Filed: 06/27/2006
• Published: 01/04/2007
• Est. Priority Date: 06/29/2005
• Status: Abandoned Application

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Kobayashi, Kunpei, Iwasaki, Makoto, Nishino, Toshiharu, Morita, Hidehiro
• Application Number:
  US11/475,620
• Publication Number:
  US 20070002192A1
• Time in Patent Office: Days
• US Class Current: 349/12
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133562 on the viewer side
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A liquid crystal display apparatus includes a liquid crystal display device and a touch panel. The display device includes first and second substrates positioned on observation and opposite sides, respectively, a liquid crystal layer interposed between the substrates, a first electrode provided on one of opposed inner surface sides of the substrates, a second electrode provided on an inner surface side of one of the substrates and supplies a voltage between itself and the first electrode to apply an electric field to the liquid crystal layer, and two polarizing plates respectively arranged on the observation and opposite sides on the other side of the substrates. The touch panel includes an electroconductive film arranged on an outer surface of the substrate or the polarizing plate on the observation side, and detects a specified position on the electroconductive film based on a voltage previously applied thereto and a voltage measured at the specified position.

Claims

1. A liquid crystal display apparatus comprising:

a liquid crystal display device; and

a touch panel,

the liquid crystal display device including;

first and second substrates which are arranged to face each other with a gap therebetween, the first substrate being positioned on an observation side and the second substrate being positioned on an opposite side of the observation side where the first substrate is positioned;

a liquid crystal layer interposed between the first and second substrates;

a first electrode which is provided on one of opposed inner surface sides of the substrates, and a second electrode which is provided on an inner surface side of one of the first and second substrates and supplies a voltage between itself and the first electrode to apply an electric field to the liquid crystal layer; and

a pair of polarizing plates respectively arranged on the observation side and the opposite side on the other side of the substrates,

the touch panel having at least one first electroconductive film which is arranged on at least one of an outer surface of the substrate and the polarizing plate on the observation side in the liquid crystal display device and has a predetermined resistance value, and detecting a specified position on the first electroconductive film based on a voltage previously applied to the first electroconductive film and a voltage measured at the specified position.

2. The liquid crystal display apparatus according to claim 1, wherein the touch panel comprises:

means for applying a predetermined voltage to the first electroconductive film;

means for measuring a voltage at the specified position on the first electroconductive film; and

position detecting means for detecting the specified position based on a value of the measured voltage.

3. The liquid crystal display device according to claim 1, wherein the touch panel is formed of a contact type touch panel adopting a resistance mode which includes a second electroconductive film arranged to face the first electroconductive film with a gap therebetween, and deforms the second electroconductive film by locally pushing the second electroconductive film from the observation side, whereby the pushed part of the second electroconductive film is locally brought into contact with the first electroconductive film.

4. The liquid crystal display apparatus according to claim 1, wherein the touch panel comprises:

a second electroconductive film arranged to face the first electroconductive film with a gap therebetween;

means for supplying a voltage to the first and second electroconductive films;

means for measuring a voltage at the specified position on the first electroconductive film and a voltage at the specified position on the second electroconductive film, respectively; and

means for detecting the specified position based on values of the plurality of measured voltages.

5. The liquid crystal display device according to claim 4, wherein the first electroconductive film of the touch panel is provided on an outer surface of the observation-side substrate in the liquid crystal display device.

6. The liquid crystal display apparatus according to claim 5, wherein the liquid crystal display device comprises an observation-side polarizing plate arranged on the observation side on the outer side of the substrates with a predetermined gap, and

the second electroconductive film of the touch panel is formed on a surface of the observation-side polarizing plate facing the observation-side substrate.

7. The liquid crystal display apparatus according to claim 5, wherein the liquid crystal display device further comprises an optical film having a phase plate which is arranged on the observation side of the observation-side substrate with a predetermined gap and optically compensates transmitted light, and the second electroconductive film of the touch panel is formed on a surface of the optical film facing the observation-side substrate.

8. The liquid crystal display apparatus according to claim 5, wherein the liquid crystal display device further comprises an optical film having of a phase plate which is arranged between the observation-side substrate and the observation-side polarizing plate and optically compensates transmitted light, and

the touch panel further comprises a transparent protection film which is arranged on the first electroconductive film provided on the observation side of the observation-side substrate in the liquid crystal display device with a predetermined gap therebetween and has the second electroconductive film formed on its surface facing the first electroconductive film.

9. The liquid crystal display apparatus according to claim 5, wherein the liquid crystal display device comprises at least two of first and second electrodes which are formed on the inner surface side of one of substrates facing each other and apply a voltage between themselves to apply an electric field in a direction substantially parallel to the surfaces of the substrates to the liquid crystal layer, and a third electrode which is provided on the inner surface of the other substrate and applies an electric field in a thickness direction of the liquid crystal layer between itself and at least one of the first electrode and the second electrode.

17. The liquid crystal display apparatus according to claim 1, wherein the liquid crystal display device is a viewing angle control type liquid crystal display device in which a third electrode is formed on the other one of opposed inner surfaces of the first and second substrates and an electric field is generated between the third electrode and at least one of the first and second electrodes to obliquely align the liquid crystal molecules with respect to the surfaces of the substrates, thereby controlling a viewing angle of the liquid crystal display device.

10. A liquid crystal display apparatus comprising:

a liquid crystal display device; and

a touch panel,

the liquid crystal display device having;

first and second substrates which are arranged to face each other with a gap therebetween, the first substrate being positioned on an observation side and the second substrate being positioned on an opposite side of the observation side where the first substrate is positioned;

a liquid crystal layer interposed between the first and second substrates;

a first electrode which is provided on one of opposed inner surfaces of the substrates, i.e., an inner surface of one substrate, and a second electrode which is provided on an inner surface of the one substrate or the other substrate and supplies a voltage between itself and the first electrode to apply an electric field to the liquid crystal layer; and

a pair of polarizing plates which are arranged on the observation side and the opposite side on the outer sides of the first and second substrates, respectively,

the touch panel having;

a first electroconductive film which is provided on an outer surface of the first substrate in the liquid crystal layer and has a predetermined resistance value;

a second electroconductive film which is arranged to face the first electroconductive film with a gap therebetween, partially deformed to come into contact with the first electroconductive film when a specified position in a region corresponding to the first electroconductive film is pushed, and has a predetermined resistance value, a voltage being supplied to the first and second electroconductive films; and

position detecting means for measuring a voltage at a position where the first electroconductive film and the second electroconductive film come into contact with each other, and detecting the contact position on the first electroconductive film based on the measured voltage.

11. The liquid crystal display apparatus according to claim 10, wherein the liquid crystal display device comprises an observation-side polarizing plate arranged on the observation side on the outer side of the first and second substrates with a predetermined gap, and

the second electroconductive film of the touch panel is provided on a surface of the observation-side polarizing plate facing the first substrate.

12. The liquid crystal display apparatus according to claim 10, wherein the liquid crystal display device further comprises a film-like optical element which is arranged on the observation side of the first substrate with a predetermined gap and optically compensates transmitted light, and the second electroconductive film of the touch panel is formed on a surface of the optical element facing the first substrate.

13. The liquid crystal display apparatus according to claim 12, wherein the optical element is formed of a phase plate which compensates the viewing angle dependence of a transmission factor of the liquid crystal display device.

14. The liquid crystal display apparatus according to claim 10, wherein the touch panel further comprises a transparent protection film which is arranged on the observation side of the first substrate of the liquid crystal display device with a predetermined gap, and

the second electroconductive film is formed on a surface of the protection film facing the first substrate.

15. The liquid crystal display apparatus according to claim 10, wherein the liquid crystal display device is a liquid crystal display device in which first and second electrodes which generate an electric field in a thickness direction of the liquid crystal layer are respectively formed on opposed inner surfaces of the first and second substrates and an inclination of liquid crystal molecules in the liquid crystal layer with respect to the substrate surfaces is controlled to control a transmission factor.

16. The liquid crystal display apparatus according to claim 10, wherein the liquid crystal display device is a transverse electric field type liquid crystal display device in which first and second electrodes which generate an electric field substantially parallel to surfaces of the first and second substrates are formed on one of opposed inner surfaces of the pair of substrates and an alignment direction of liquid crystal molecules in the liquid crystal layer is controlled within a plane parallel to the surfaces of the substrates to control a transmission factor.

18. A liquid crystal display apparatus comprising:

a liquid crystal display device; and

a touch panel,

the liquid crystal display device having;

first and second substrates which are arranged to face each other with a gap therebetween, the first substrate being positioned on an observation side and the second substrate being positioned on an opposite side of the observation side where the first substrate is positioned;

a liquid crystal layer interposed between the first and second substrates;

a first electrode provided on one of opposed inner surfaces of the first and second substrates, and a second electrode which is provided on an inner surface of the one substrate or the other substrate and supplies a voltage between itself and the first electrode to apply an electric field to the liquid crystal layer; and

a pair of polarizing plates respectively arranged on the observation side and the opposite side on the outer sides of the first and second substrates,

the touch panel having;

an electroconductive film which is arranged on the observation side of the liquid crystal display device and has a resistance value;

voltage applying means for supplying a voltage from both ends of the electroconductive film in one direction and both ends in the other direction crossing one direction;

means for specifying an arbitrary position on the electroconductive film; and

position detecting means for measuring a voltage at a position on the electroconductive film specified by the means for specifying the position, and detecting the specified position based on the measured voltage.

19. The liquid crystal display apparatus according to claim 18, wherein the touch panel comprises another electroconductive film formed on the observation side of a transparent film which is arranged on the observation side of the liquid crystal display device with a predetermined gap through a spacer.

20. The liquid crystal display apparatus according to claim 18, wherein the touch panel comprises another electroconductive film formed on the observation side of a transparent film closely arranged on the observation-side polarizing plate in the liquid crystal display device.