Pressure-sensitive tablet

• US 4,963,417 A
• Filed: 07/01/1988
• Issued: 10/16/1990
• Est. Priority Date: 07/03/1987
• Status: Expired due to Fees

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Taniguchi, Takashi, Kurasaki, Shoichi, Oka, Koichiro
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Brown, Christopher
• Application Number:
  US07/214,438
• Time in Patent Office: 837 Days
• Field of Search: 178/18, 178/19, 178/20, 428/327, 340/706
• US Class Current: 428/327
• 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: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/254 Polymeric or resinous material

Abstract

A pressure-sensitive tablet having desired sensitivity, excellent durability, and a good appearance. The pressure-sensitive tablet comprises an electro-conductive substrate; deformable insulative particles with an average diameter of 0.1 μm to 100 μm, which are distributed on the substrate and an electron-conductive film superimposed on the deformable particles.

Claims

1. A pressure-sensitive tablet comprising:

an electro-conductive substrate;

deformable insulative particles with an average particle size of 0.1 μ

m to 100 μ

m, distributed on the substrate, said deformable particles being made of a resin with a deformability of not less than 10%, said deformability being expressed by the following formula;

##EQU2## wherein D represents the deformability of the resin constituting the particles, L₀ is the thickness of a block made of the resin when no pressure is applied to the block, and L is the thickness of the block to which a pressure of 20 kg/cm² is applied; and

an electro-conductive film superimposed on the deformable particles.

2. The pressure-sensitive tablet of claim 1, wherein the particles are substantially spherical.

3. The pressure-sensitive tablet of claim 2, wherein each of the particles is fixed to the electro-conductive substrate substantially at a single point.

4. The pressure-sensitive tablet of claim 1, wherein the electro-conductive film comprises a base film and an electro-conductive membrane formed on the base film, the electro-conductive membrane facing the deformable particles.

5. The pressure-sensitive tablet of claim 1, wherein the outer surface of the electro-conductive film is hard-coat treated.

6. The pressure-sensitive tablet of claim 1, wherein the electro-conductive substrate comprises a base substrate and an electro-conductive membrane formed on the base substrate, the electro-conductive membrane facing the deformable particles.

7. The pressure-sensitive tablet of claim 1, wherein the deformable particles have a particles-substrate area ratio of 1×

10^-4 to 15×

10^-3 and have a population density of 2 to 50,000 per cm².

8. The pressure-sensitive tablet of claim 1, wherein the average diameter of the deformable particles is 1.5-40 μ

m, the deformable particles have a particles-substrate area ratio of 2×

10^-3 to 15×

10^-3 and have a population density of 4,100 to 50,000 per cm².

9. The pressure-sensitive tablet of claim 1, wherein the average diameter of the deformable particles is 7.0-100 μ

m, the deformable particles have a particles-substrate area ratio of 0.5×

10^-3 to 6.5×

10^-3 and have a population density of 200 to 4,000 per cm².

10. The pressure-sensitive tablet of claim 1, wherein the average diameter of the deformable particles is 1.0- 50 μ

m, the deformable particles have a particles-substrate area ratio of 1×

10^-4 to 10×

10^-3 and have a population density of 2 to 200 per cm².

11. The pressure-sensitive tablet of claim 1 wherein the electro-conductive film has a surface resistance of 1 ×

10⁰ -5×

10³ Ω

□

.

12. The pressure-sensitive tablet of claim 1, wherein the electro-conductive substrate has a surface resistance of 1×

10⁰ -5×

10³ Ω

□

.

13. The pressure-sensitive tablet of claim 1, wherein the electro-conductive film and the electro-conductive substrate arc substantially transparent.

14. The pressure-sensitive tablet of claim 1, wherein the deformable particles are made of an epoxy resin or a polyester resin.

15. The pressure-sensitive tablet of claim 1, wherein the deformable particles consists essentially of 30-95% by weight of a thermoset resin component and 5-70% by weight of a rubber component.

16. The pressure-sensitive tablet of claim 15, wherein the thermoset resin is a phenol resin or an epoxy resin.

17. The pressure-sensitive tablet of claim 1, wherein the electro-conductive film has an UV light-cutoff property.

18. The pressure-sensitive tablet of claim 1, further comprising an UV light-cutoff layer formed on the electro-conductive film.