METHOD OF DETECTING CONTACT STATE OF RESISTIVE TOUCH PANEL DEVICE, TOUCH PANEL DEVICE, AND DISPLAY DEVICE

• US 20110261011A1
• Filed: 04/26/2011
• Published: 10/27/2011
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Sakamoto, Masanori
• Granted Patent: US 8,842,092 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A method of detecting a contact state of resistive touch panel device includes measuring a potential at both ends of a first resistive film, as viewed in a first direction, as a first-film-potential. At this time, the both ends of the first resistive film are short circuited, and a predetermined current is applied between both ends of a second resistive film, as viewed in a second direction. The method further includes measuring a potential at the both ends of the second resistive film as a second-film-potential. At this time, the both ends of the second resistive film are short circuited, and the current is applied between the both ends of the first resistive film. The method further includes deriving distance information between two contact points of the first and the second resistive film, based on the first-film-potential and the second-film-potential.

Claims

1. A method of detecting a contact state of a resistive touch panel device, the method comprising:

measuring, in a state in which (i) both ends of a first resistive film, as viewed in a first direction, are short circuited and (ii) a predetermined current is applied between both ends of a second resistive film, as viewed in a second direction, a potential at the both ends of the first resistive film as a first-film-potential;

measuring, in a state in which (i) the both ends of the second resistive film are short circuited and (ii) the current is applied between the both ends of the first resistive film, a potential at the both ends of the second resistive film as a second-film-potential; and

deriving distance information between two points when the first resistive film contacts the second resistive film at the two points, based on the first-film-potential and the second-film-potential.

2. A method of detecting a contact state of a resistive touch panel device, the method comprising:

measuring, in a first state in which (i) a predetermined voltage is applied between a first end region and a second end region and (ii) a third end region is made open, a potential at a fourth end region as a first potential, the first end region being an end region of a first resistive film, as viewed in a first direction, the second end region being an end region of the first resistive film opposite to the first end region, the third end region being an end region of a second resistive film, as viewed in a second direction which intersects the first direction, and the fourth end region being an end region of the second resistive film opposite to the third end region;

measuring, in a second state in which (i) the voltage is applied between the third end region and the fourth end region and (ii) the first end region is made open, a potential at the second end region as a second potential;

measuring, in a third state in which (i) the first end region and the fourth end region are short-circuited and (ii) the voltage is applied between the first end region and the second end region, a potential at the third end region as a third potential;

measuring, in a fourth state in which (i) the first end region and the third end region are short-circuited and (ii) the voltage is applied between the first end region and the second end region, a potential at the fourth end region as a fourth potential;

measuring, in a fifth state in which (i) the first end region and the second end region are short-circuited and (ii) a predetermined current is applied between the third end region and the fourth end region, a potential at the first end region and the second end region as a fifth potential;

measuring, in a sixth state in which (i) the third end region and the fourth end region are short-circuited and (ii) the current is applied between the first end region and the second end region, a potential at the third end region and the fourth end region as a sixth potential; and

deriving distance information between two points when the first resistive film contacts the second resistive film at the two points, based on the first potential, the second potential, the third potential, the fourth potential, the fifth potential and the sixth potential.

3. The method according to claim 2, further comprising deriving position information of a midpoint between the two points based on the first potential and the second potential.

4. The method according to claim 2, wherein deriving the distance information between the two points is carried out when a number of contact points between the first resistive film and the second resistive film is determined to be not one.

5. The method according to claim 2, wherein deriving the distance information between the two points includes:

deriving first distance information between the two points in the first direction based on the first potential, the second potential and the fifth potential, and

deriving second distance information between the two points in the second direction based on the first potential, the second potential and the sixth potential.

6. The method according to claim 2, wherein the first direction and the second direction are perpendicular to each other.

7. The method according to claim 2, wherein the first resistive film and the second resistive film are arranged so as to face each other.

8. A resistive touch panel device comprising:

a touch panel including

(i) a first resistive film, and

(ii) a second resistive film which faces the first resistive film; and

a driving circuit configured to perform

(i) measuring, in a state in which (a) both ends of a first resistive film, as viewed in a first direction, are short circuited and (b) a predetermined current is applied between both ends of a second resistive film, as viewed in a second direction, a potential at the both ends of the first resistive film as a first-film-potential,

(ii) measuring, in a state in which (a) the both ends of the second resistive film are short circuited and (b) the current is applied between the both ends of the first resistive film, a potential at the both ends of the second resistive film as a second-film-potential, and

(iii) deriving distance information between two points when the first resistive film contacts the second resistive film at the two points, based on the first-film-potential and the second-film-potential.

9. A resistive touch panel device comprising:

a touch panel including

(i) a first resistive film, and

(ii) a second resistive film which faces the first resistive film; and

a driving circuit configured to perform

(i) measuring, in a first state in which (a) a predetermined voltage is applied between a first end region and a second end region and (b) a third end region is made open, a potential at a fourth end region as a first potential, the first end region being an end region of a first resistive film, as viewed in a first direction, the second end region being an end region of the first resistive film opposite to the first end region, the third end region being an end region of a second resistive film, as viewed in a second direction which intersects the first direction, and the fourth end region being an end region of the second resistive film opposite to the third end region,

(ii) measuring, in a second state in which (a) the voltage is applied between the third end region and the fourth end region and (b) the first end region is made open, a potential at the second end region as a second potential,

(iii) measuring, in a third state in which (a) the first end region and the fourth end region are short-circuited and (b) the voltage is applied between the first end region and the second end region, a potential at the third end region as a third potential,

(iv) measuring, in a fourth state in which (a) the first end region and the third end region are short-circuited and (b) the voltage is applied between the first end region and the second end region, a potential at the fourth end region as a fourth potential,

(v) measuring, in a fifth state in which (a) the first end region and the second end region are short-circuited and (b) a predetermined current is applied between the third end region and the fourth end region, a potential at the first end region and the second end region as a fifth potential,

(vi) measuring, in a sixth state in which (a) the third end region and the fourth end region are short-circuited and (b) the current is applied between the first end region and the second end region, a potential at the third end region and the fourth end region as a sixth potential, and

(vii) deriving distance information between two points when the first resistive film contacts the second resistive film at the two points, based on the first potential, the second potential, the third potential, the fourth potential, the fifth potential and the sixth potential.

10. The resistive touch panel device according to claim 9, wherein the driving circuit further derives position information of a midpoint between the two points based on the first potential and the second potential.

11. The resistive touch panel device according to claim 9, wherein the driving circuit carries out deriving the distance information between the two points when a number of contact points between the first resistive film and the second resistive film is determined to be not one.

12. The resistive touch panel device according to claim 9, wherein the first direction and the second direction are perpendicular to each other.

13. The resistive touch panel device according to claim 9, wherein the touch panel further includes:

a first substrate, the first resistive film being formed on the first substrate, and

a plurality of projections arranged so as to be interposed between the first substrate and the first resistive film.

14. The resistive touch panel device according to claim 9, wherein deriving the distance information between the two points includes:

deriving first distance information between the two points in the first direction based on the first potential, the second potential and the fifth potential, and

deriving second distance information between the two points in the second direction based on the first potential, the second potential and the sixth potential.

15. A display device comprising:

a display panel which displays an image;

a touch panel including

(i) a first resistive film, and

(ii) a second resistive film which faces the first resistive film; and

a driving circuit configured to perform)

(i) measuring, in a state in which (a) both ends of a first resistive film, as viewed in a first direction, are short circuited and (b) a predetermined current is applied between both ends of a second resistive film, as viewed in a second direction, a potential at the both ends of the first resistive film as a first-film-potential,

(ii) measuring, in a state in which (a) the both ends of the second resistive film are short circuited and (b) the current is applied between the both ends of the first resistive film, a potential at the both ends of the second resistive film as a second-film-potential, and

(iii) deriving distance information between two points when the first resistive film contacts the second resistive film at the two points, based on the first-film-potential and the second-film-potential.

16. A display device comprising:

a display panel which displays an image;

a touch panel including

(i) a first resistive film, and

(ii) a second resistive film which faces the first resistive film; and

a driving circuit configured to perform

(i) measuring, in a first state in which (a) a predetermined voltage is applied between a first end region and a second end region and (b) a third end region is made open, a potential at a fourth end region as a first potential, the first end region being an end region of a first resistive film, as viewed in a first direction, the second end region being an end region of the first resistive film opposite to the first end region, the third end region being an end region of a second resistive film, as viewed in a second direction which intersects the first direction, and the fourth end on being an end region of the second resistive film opposite to the third end region,

(ii) measuring, in a second state in which (a) the voltage is applied between the third end region and the fourth end region and (b) the first end region is made open, a potential at the second end region as a second potential,

(iii) measuring, in a third state in which (a) the first end region and the fourth end region are short-circuited and (b) the voltage is applied between the first end region and the second end region, a potential at the third end region as a third potential,

(iv) measuring, in a fourth state in which (a) the first end region and the third end region are short-circuited and (b) the voltage is applied between the first end region and the second end region, a potential at the fourth end region as a fourth potential,

(v) measuring, in a fifth state in which (a) the first end region and the second end region are short-circuited and (b) a predetermined current is applied between the third end region and the fourth end region, a potential at the first end region and the second end region as a fifth potential,

(vi) measuring, in a sixth state in which (a) the third end region and the fourth end region are short-circuited and (b) the current is applied between the first end region and the second end region, a potential at the third end region and the fourth end region as a sixth potential, and

(vii) deriving distance information between two points when the first resistive film contacts the second resistive film at the two points, based on the first potential, the second potential, the third potential, the fourth potential, the fifth potential and the sixth potential.

17. The display device according to claim 16, wherein the display panel is arranged such that an image display region of the display panel faces a touch detection region of the touch panel.