Liquid crystal display device with a touch panel

• US 6,456,279 B1
• Filed: 07/13/1999
• Issued: 09/24/2002
• Est. Priority Date: 07/14/1998
• Status: Expired due to Term

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd. (Japan Display Incorporated)
• Inventors: Suzuki, Masaru, Nagashima, Yoshikuni, Kubo, Kiichiro, Saito, Terunori
• Primary Examiner(s): Saras, Steven
• Assistant Examiner(s): Spencer, William C.
• Application Number:
  US09/352,359
• Time in Patent Office: 1,169 Days
• Field of Search: 345/173, 345/104, 345/176, 345/102, 349/12, 349/63, 349/65
• US Class Current: 345/173
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133616 Front illuminating devices
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A liquid crystal display device has a position information input device over an image-displaying surface of liquid crystal panel. The position information input device is formed by a first substrate and a second substrate more easily deformable than the first substrate. A transparent insulation film is provided over a surface of the first substrate opposed to the second substrate. By providing a first transparent electrode on the transparent insulation film, the flatness of the first transparent electrode is improved and a connection failure of the position information input device is prevented.

Claims

1. A liquid crystal display device, comprising:

a liquid crystal display panel having a first surface for displaying an image and a second surface different from said first surface; and

a position information input device provided on a first-surface side of said liquid crystal display panel;

wherein said position information input device is made of a first substrate and a second substrate more easily deformable than said first substrate;

a transparent insulation film is formed over a surface of said first substrate opposed to said second substrate; and

a first transparent electrode is provided on said transparent insulation film;

wherein said first substrate of said position information input device is provided between said second substrate and said liquid crystal display panel;

wherein a second transparent electrode is provided over a surface of said second substrate opposed to said first substrate;

wherein a spacer made of an insulating material is provided between said first substrate and said second substrate; and

wherein a recess portion is formed on the surface of said substrate opposed to said second substrate, said transparent insulation film covering said recess portion to reduce unevenness of the surface over which said transparent electrode is provided.

2. A liquid crystal display device, comprising:

a liquid crystal display panel having a first surface for displaying an image and a second surface different from said first surface; and

a position information input device provided on a first-surface side of said liquid crystal display panel;

wherein said position information input device is made of a first substrate and a second substrate more easily deformable than said first substrate;

a transparent insulation film is formed over a surface of said first substrate opposed to said second substrate; and

a first transparent electrode is provided on said transparent insulation film;

wherein said first substrate of said position information input device is provided between said second substrate and said liquid crystal display panel;

wherein a second transparent electrode is provided over a surface of said second substrate opposed to said first substrate;

wherein a spacer made of an insulating material is provided between said first substrate and said second substrate; and

wherein a printed layer partly reflecting light is formed on the surface of-said first substrate opposed to said second substrate, said transparent insulation film covering said printed layer to reduce unevenness of the surface over which said transparent electrode is provided.

3. A liquid crystal display device comprising:

a reflection type of liquid crystal display panel;

an illumination device provided over a display surface of said reflection type of liquid crystal display panel; and

an input device provided over said illumination device,

wherein said input device is made of a first substrate which is hard and a second substrate which is soft and superimposed on said first hard substrate;

a second transparent electrode is provided over a surface of said second substrate opposed to said first substrate;

a transparent insulation film is formed over said first substrate; and

a first transparent electrode is formed over said transparent insulation film.

4. A liquid crystal display device according to claim 3, wherein said first transparent electrode is made of an integral electrical resistance film which flatly spreads over an entire coordinate input area, while said second transparent electrode is made of an integral electrical resistance film which flatly spreads over the entire coordinate input area.

5. A liquid crystal display device according to claim 4, wherein a line for electrically connecting said first transparent electrode and a corresponding terminal is provided at a periphery of said first transparent electrode over said first substrate, and a fixing member fixing said first substrate and said second substrate to each other is provided in an area of said first substrate in which said line is provided.

6. A liquid crystal display device according to claim 3, wherein said first transparent electrode is made of a plurality of X electrodes arranged in a first direction, and said second transparent electrode is made of a plurality of Y electrodes arranged in a second direction.

7. A liquid crystal display device according to claim 6, wherein said liquid crystal panel has a plurality of display electrodes arranged in the first direction or the second direction, and a distance between adjacent ones of said X electrodes or said Y electrodes is made equal to a distance between adjacent ones of said display electrodes.

8. A liquid crystal display device comprising a reflection type of liquid crystal panel and a touch panel stacked on a display-surface side of said liquid crystal panel for externally inputting information, wherein said touch panel includes:

a hard lower transparent substrate opposed to said liquid crystal panel;

a soft upper substrate for externally inputting information;

transparent electrodes formed over inner surfaces of said lower transparent substrate and said upper substrate, respectively; and

a spacer which is clamped between said lower substrate and said upper substrate and which isolates said transparent electrodes from each other with a predetermined spacing,

a light source installed along at least one edge of said lower substrate, a surface-treated surface provided over a surface of said lower substrate which is closer to said transparent electrode, said surface-treated surface reflecting and scattering light from said light source toward said liquid crystal panel and allowing light reflected from said liquid crystal panel to exit toward said display surface side, and a transparent insulation film formed between said surface-treated surface and said transparent electrode.

9. A liquid crystal display device according to claim 8, wherein a plurality of microprisms are formed over said surface-treated surface of said lower substrate, said transparent insulation film covering said microprisms and differing in refractive index from said lower substrate.

10. A liquid crystal display device according to claim 9, wherein a distance between adjacent ones of said microprisms which are on a side of said lower substrate which is close to said light source is larger than a distance between adjacent ones of said microprisms which are on a side of said lower substrate which is far from said light source.

11. A liquid crystal display device according to claim 9, wherein ones of said microprisms which arc on a side of said lower substrate which is close to said light source are smaller in size than ones of said microprisms which are on a side of said lower substrate which is far from said light source.

12. A liquid crystal display device according to claim 8, wherein a plurality of printed patterns are flatly formed over said surface-treated surface of:

said lower substrate so and said transparent insulation film covers said printed patterns to substantially flatten the surface over which said transparent electrode is provided.

13. A liquid crystal display device according to claim 12, wherein a distance between adjacent ones of said printed patterns which are on a side of said lower substrate which is close to said light source is larger than a distance between adjacent ones of said printed patterns which are on a side of said lower substrate which is far from said light source.

14. A liquid crystal display device according to claim 12, wherein ones of said printed patterns which are on a side of said lower substrate which is close to said light source are smaller in size than ones of said printed patterns which are on a side of said lower substrate which is far from said light source.

15. A liquid crystal display device according to claim 8, further comprising:

a terminal which is electrically connected to said transparent electrode provided on a side of said touch panel on which said light source is not provided.