Position detection apparatus using area image sensor

• US 20070089915A1
• Filed: 04/23/2004
• Published: 04/26/2007
• Est. Priority Date: 05/19/2003
• Status: Active Grant

• Current Assignee: Minato Advanced Technologies Inc. (Minato Holdings Inc.), Newcom, Inc.
• Original Assignee: EIT Co. Ltd. (Minato Holdings Inc.), Xiroku, Inc.
• Inventors: Tsunezaki, Kenji, Ogawa, Yasuji
• Granted Patent: US 8,330,726 B2
• Time in Patent Office: Days
• US Class Current: 178/18.90
• 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

A position detection apparatus, with which the setting position adjustment of imaging sections is not required and the maintenance can be made easily, structuring of which can be realized with low-cost components, is provided. In the position detection apparatus, imaging sections (7), each of those which includes an area image sensor (70), in which light-sensitive elements are arrayed in a two-dimensional pattern, and an image formation lens (71), are placed to the lateral two points of a detection plane (1), respectively. A selection device (10) selects particular pixels corresponding to a particular field of view of a reflex reflection frame (4) or the like from the light-sensitive elements within a range of a given field of view having been imaged by the imaging sections (7). An image processing device (11) image-processes a particular image signal corresponding to the selected particular pixels and then outputs an indicating position coordinate of a pointing device (2).

Claims

1. A position detection apparatus for detecting a pointing device being situated on a detection plane, said position detection apparatus comprising;

a pair of imaging sections, each of those which includes an area image sensor, in which light-sensitive elements are arrayed in a two-dimensional pattern, and an image formation lens, and images an area over the detection plane in a given field of view from the lateral two points of the detection plane to output an image signal,

marker means each functioning as a reference for defining a particular field of view within the range of the given field of view to be imaged by the imaging sections,

a selection means utilizing the image signal as an input to select particular pixels, based on the marker means, corresponding to the particular field of view within the range of the given field of view from the light-sensitive elements, and

an image processing means, which utilizes a particular image signal corresponding to the particular pixels having been selected by the selection means as an input to execute the image processing, thereby outputting a coordinate of an indicating position on the detection plane indicated by the pointing device.

2. A position detection apparatus as claimed in claim 1, wherein the imaging section further includes a light source for emitting light alongside of the detection plane and the light source is placed in the vicinity of the image formation lens.

3. A position detection apparatus as claimed in claim 2, characterized by further including a reflex reflection member for reflex-reflecting the light.

4. A position detection apparatus as claimed in claim 3, wherein the reflex reflection member is provided to the pointing device.

5. A position detection apparatus as claimed in claim 3, wherein the reflex reflection member is provided to at least three surrounding sides of the detection plane in solid manner.

6. A position detection apparatus as claimed in claim 5, wherein the particular field of view corresponding to the particular pixels is an area including a part or all of the image of the reflex reflection member.

8. A position detection apparatus as claimed in any of claims 1-4, wherein the marker means are disposed to at least four points of the detection plane.

9. A position detection apparatus as claimed in claim 8, wherein the marker means is a reflex reflection member being configured such that the reflected image thereof is formed in a characteristic shape.

10. A position detection apparatus as claimed in claim 8, wherein the marker means is a light-emitting section for emitting light.

11. A position detection means as claimed in claim 10, wherein the marker means is a light-emitting section being configured such that the image produced by the light-emitting is formed in a characteristic shape.

12. A position detection apparatus as claimed in claim 10 or 11, wherein the light-emitting section emits light only at the time of defining the particular field of view.

13. A position detection apparatus as claimed in any of claims 1 to 12, wherein the apparatus further includes a calibration means and the calibration means causes the selection means automatically at a given interval or manually at operator'"'"'s option to select particular pixels.

14. A position detection apparatus as claimed in any of claims 1 to 13, wherein the particular pixels to be selected by the selection means are any of pixels being linearly arrayed in accordance with the pixel array, pixels being obliquely arrayed, or pixels being arrayed with containing an inflected portion.

15. A position detection apparatus as claimed in any of claims 1 to 14, wherein the apparatus further includes a memory for storing pixel selection information with respect to the particular pixels to be selected by the selection means and the selection means uses the pixel selection information having stored in the memory to output a particular image signal corresponding to the particular pixels from the image signal to be imaged by the imaging sections.

16. A position detection apparatus as claimed in claim 15, wherein the apparatus further includes a buffer memory for temporarily storing the image signal to be imaged by the imaging sections and the selection means uses the pixel selection information having been stored in the memory to output the particular image signal corresponding to the particular pixels from the image signal having been stored in the buffer memory.

17. A position detection apparatus as claimed in claim 15, wherein the memory is a memory of the serial access mode and the pixel selection information having been stored is read out in synchronization with a clock signal being inputted.

18. A position detection apparatus as claimed in any of claims 1 to 17, wherein a high-speed serial transfer interface is provided in between the selection means and the image processing means so that the interface connect them and the image processing means is included in a personal computer.

19. A position detection apparatus as claimed in any of claims 1 to 17, wherein the image processing means is consisted of a microcomputer and the coordinate of the indicating position is outputted through an interface included in the microcomputer.

20. A position detection apparatus as claimed in any of claims 1 to 19, wherein the apparatus further includes a display device and the detection plane is a transparent plate that protects the display screen of the display device.

22. A position detection apparatus as claimed in claim 5 or 6, wherein the reflex reflection member is the marker means.

7. (canceled)

21. A position detection apparatus for detecting a pointing device being situated on a detection plane, the position detection apparatus comprising;

a pair of imaging sections, each of those which includes an area image sensor, in which light-sensitive elements are arrayed in a two-dimensional pattern, and an image formation lens, and images an area over the detection plane in a given field of view from the lateral two points of the detection plane to output an image signal,

marker means each functioning as a reference for defining a given part within the range of the given field of view to be imaged by the imaging sections,

an image processing means that utilizes an image signal being outputted from the imaging sections as an input, defines a given part of the image signal on the basis of the marker means, and uses the image signal of the given part having been defined to work out a coordinate of an indicating position on the detection plane being indicated by a pointing device, and

a follow-up means for detecting the changes in the positions of the marker means either automatically at a given interval or manually at operator'"'"'s option to renewedly define the given part.