OPTICAL POSITION DETECTING DEVICE AND DISPLAY DEVICE WITH POSITION DETECTING FUNCTION

• US 20110304589A1
• Filed: 05/13/2011
• Published: 12/15/2011
• Est. Priority Date: 06/11/2010
• Status: Active Grant

• Current Assignee: Columbia Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: YOSHIDA, Kazuki
• Granted Patent: US 9,030,443 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421

Abstract

An optical position detecting device includes: a plurality of detection light source sections which includes a first light emitting element which emits a first detection light and a second light emitting element which is turned on at a timing different from a timing when the first light emitting element is turned on and emits a second detection light having a peak wavelength different from that of the first detection light; a light source driving section which turns on a part of the plurality of detection light source sections, and turns on the other part thereof; a light detecting section which detects the first detection light and the second detection light reflected by a object; and a position detecting section which detects the position of the object on the basis of the intensity of the first detection light and the intensity of the second detection light in the light detecting section.

Claims

1. An optical position detecting device comprising:

a plurality of detection light source sections which includes a first light emitting element which emits a first detection light and a second light emitting element which is turned on at a timing different from a timing when the first light emitting element is turned on and emits a second detection light having a peak wavelength different from that of the first detection light;

a light source driving section which turns on a part of the plurality of detection light source sections in a first period, and turns on the other part thereof in a second period;

a light detecting section which detects the first detection light and the second detection light reflected by a object; and

a position detecting section which detects the position of the object on the basis of the intensity of the first detection light and the intensity of the second detection light in the light detecting section in the first and second periods.

2. The optical position detecting device according to claim 1,

wherein the position detecting section detects the position of the object on the basis of the difference between the intensity of the first detection light and the intensity of the second detection light.

3. The optical position detecting device according to claim 1,

further comprising a light guiding plate which is provided with a light incident section to which the first detection light and the second detection light emitted from the plurality of detection light source sections are incident and a light exiting section from which the first detection light and the second detection light incident from the light incident section exit,

wherein a first light intensity distribution for a first coordinate detection in which the light intensity monotonically decreases from one side of a first direction which intersects with a light exiting direction of the first detection light and the second detection light from the light guiding plate toward the other side thereof, and a second light intensity distribution for the first coordinate detection in which the light intensity monotonically decreases from the other side of the first direction to the one side thereof, are sequentially formed in the first period and the second period for the first coordinate detection.

4. The optical position detecting section according to claim 3, wherein a first light intensity distribution for a second coordinate detection in which the light intensity monotonically decreases from one side of a second direction which intersects with the light exiting direction of the detection lights from the light guiding plate and the first direction toward the other side thereof, and a second light intensity distribution for a second coordinate detection in which the light intensity monotonically decreases from the other side of the second direction to the one side thereof, are sequentially formed in the first period and the second period for the second coordinate detection.

5. The optical position detecting device according to claim 1,

wherein the light source driving section drives the part of the plurality of detection light source sections and the other part thereof so that the detection intensity in the light detection section when the part of the plurality of detection light source sections is turned on becomes equal to the detection intensity in the light detection section when the other part thereof is turned on.

6. The optical position detecting device according to claim 1,

further comprising a reference light source section which emits a reference light incident to the light detecting section without being reflected by the object,

wherein the light source driving section drives the reference light source section and the part of the plurality of detection light source sections so that the detection intensity in the light detection section when the reference light source section is turned on becomes equal to the detection intensity in the light detection section when the part of the plurality of detection light source sections is turned on.

7. The optical position detecting device according to claim 1, wherein the detection lights are infrared light.

8. A display device with a position detecting function which is provided with the optical position detecting device in claim 1, comprising:

an image generating device which forms an image,

wherein the first detection light and the second detection light are emitted to be overlapped with the image.