Touch panel and electronic device including touch panel

• US 8,310,465 B2
• Filed: 07/29/2009
• Issued: 11/13/2012
• Est. Priority Date: 07/31/2008
• Status: Expired due to Fees

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Iwasaki, Makoto, Nishino, Toshiharu, Sasaki, Kazuhiro
• Primary Examiner(s): Wang, Quan-Zhen
• Assistant Examiner(s): Ma, Calvin C
• Application Number:
  US12/511,309
• Publication Number:
  US 20100026663A1
• Time in Patent Office: 1,203 Days
• Field of Search: 345/173, 345/174, 345/178, 345/179, 345/182, 345/189
• US Class Current: 345/174
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A resistive film type touch panel includes first and second resistive films respectively provided on the inner surfaces of a pair of substrates on the touch side and the opposite side, protruding contacts which are provided on the first resistive film so as to protrude to a predetermined height, and come into contact with the second resistive film upon bending/deformation of the touch-side substrate by a touch to electrically connect the touch-side substrate to the second resistive film, insulating spacers which are arranged between the substrates except the positions of the protruding contacts, and define the space between the substrates to a height higher than that of protruding contacts, and a liquid or liquid crystal sealed in the space between the substrates. This arrangement reduces the bending/deformation amount of the touch-side substrate and the refraction of transmitted light at a portion bent/deformed by a touch on the touch-side substrate.

Claims

1. A touch panel comprising:

a first substrate and a second substrate which are arranged so as to face each other;

a first resistive film provided on a surface of the first substrate facing the second substrate;

a second resistive film provided on a surface of the second substrate facing the first substrate;

a protruding contact provided on the surface of the first substrate facing the second substrate and protruding to a predetermined height from the first substrate toward the second substrate, wherein, when the first substrate or the second substrate is pressed, the protruding contact electrically connects the first resistive film and the second resistive film at an area corresponding to a pressed portion due to bending and deforming of the pressed substrate;

an insulating spacer arranged between the first substrate and the second substrate and defining a height of a space between the first substrate and the second substrate to be larger than the height of the protruding contact;

a frame-like seal member which seals the space between the first substrate and the second substrate throughout peripheral portions of the first substrate and the second substrate; and

an insulating liquid sealed in the space between the first substrate and the second substrate surrounded by the seal member,

wherein the insulating spacer is arranged in an area surrounded by the seal member, and is positioned at one of a plurality of first lattice points which are arranged in a first direction at a first interval and in a second direction orthogonal to the first direction at a second interval,

wherein the protruding contact is arranged in the area surrounded by the seal member, and is positioned at one of a plurality of second lattice points, excluding lattice points overlapping with the plurality of first lattice points, wherein the plurality of second lattice points are arranged in the first direction at a third interval which is narrower than the first interval and are arranged in the second direction at a fourth interval which is narrower than the second interval, and

wherein the first interval is set to be an integral multiple of the third interval, the second interval is set to be an integral multiple of the fourth interval, and each of the plurality of first lattice points in the area surrounded by the seal member is set to overlap with one of the plurality of second lattice points.

2. The touch panel according to claim 1, wherein the protruding contact comprises a resin portion formed into a protruding shape and one of the first resistive film and the second resistive film which covers the resin portion.

3. The touch panel according to claim 1, wherein the insulating spacer comprises a columnar spacer which is provided on one of the first resistive film and the second resistive film and includes a distal end in contact with the other resistive film.

4. The touch panel according to claim 3, wherein the columnar spacer is provided on the first substrate on which the protruding contact is provided.

5. The touch panel according to claim 3, wherein the columnar spacer is provided on the second substrate on which the protruding contact is not provided.

6. The touch panel according to claim 3, wherein the protruding contact is formed by providing, on the surface of the first substrate facing the second substrate, a projection corresponding to the height of the protruding contact, and forming the first resistive film so as to cover the projection.

7. The touch panel according to claim 6, wherein the columnar spacer and the projection are formed by a same material.

8. The touch panel according to claim 1, wherein the insulating spacer comprises a spherical spacer.

9. The touch panel according to claim 1, wherein the insulating liquid has a predetermined resistance value.

10. The touch panel according to claim 1, wherein the insulating liquid has a refractive index difference of not more than 0.1 with respect to visible light relative to the first substrate and the second substrate.

11. The touch panel according to claim 1, wherein the insulating liquid comprises a liquid crystal material which is optically isotropic at room temperature.

12. The touch panel according to claim 1, wherein the insulating liquid comprises one of an organic material and an inorganic material having a boiling point of not less than 100°

C.

13. The touch panel according to claim 1, wherein the second substrate includes a protruding portion that protrudes with respect to the first substrate, and the protruding portion is provided with terminals which electrically connect the first resistive film and the second resistive film to a touch panel driving circuit.

14. The touch panel according to claim 13, wherein a conductive member which electrically connects the first resistive film to the second substrate is arranged in an area in which the seal member is arranged.

15. The touch panel according to claim 1 , wherein each of the first resistive film and the second resistive film is formed into one film.

16. The touch panel according to claim 15, further comprising a touch panel driving circuit which detects a contact position at which the first resistive film comes into contact with the second resistive film.

17. The touch panel according to claim 1, wherein the insulating liquid comprises a material exhibiting an isotropic phase at a temperature of 5°

C. or more.

18. The touch panel according to claim 1, wherein the first interval and the second interval are set to equal values, and the third interval and the fourth interval are set to equal values.

19. An electronic device comprising a touch panel, wherein the touch panel includes:

a first substrate and a second substrate which are arranged so as to face each other;

a first resistive film provided on a surface of the first substrate facing the second substrate;

a second resistive film provided on a surface of the second substrate facing the first substrate;

a protruding contact provided on the surface of the first substrate facing the second substrate and protruding to a predetermined height from the first substrate toward the second substrate, wherein when the first substrate or the second substrate is pressed, the protruding contact electrically connects the first resistive film and the second resistive film at an area corresponding to a pressed portion due to bending and deforming of the pressed substrate;

an insulating spacer arranged between the first substrate and the second substrate and defining a height of a space between the first substrate and the second substrate to be larger than the height of the protruding contact;

a frame-like seal member which seals the space between the first substrate and the second substrate throughout peripheral portions of the first substrate and the second substrate; and

an insulating liquid sealed in the space between the first substrate and the second substrate surrounded by the seal member,

wherein the insulating spacer is arranged in an area surrounded by the seal member, and is positioned at one of a plurality of first lattice points which are arranged in a first direction at a first interval and in a second direction orthogonal to the first direction at a second interval,

wherein the protruding contact is arranged in the area surrounded by the seal member, and is positioned at one of a plurality of second lattice points, excluding lattice points overlapping with the plurality of first lattice points, wherein the plurality of second lattice points are arranged in the first direction at a third interval which is narrower than the first interval and are arranged in the second direction at a fourth interval which is narrower than the second interval, and

wherein the first interval is set to be an integral multiple of the third interval, the second interval is set to be an integral multiple of the fourth interval, and each of the plurality of first lattice points in the area surrounded by the seal member is set to overlap with one of the plurality of second lattice points.