US 5,572,251 AGranted

Optical position detecting unit and optical coordinate input unit

AssigneeWacom Co., Ltd.

InventorYasuji Ogawa

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Abstract

An optical position detecting unit which includes: an image pickup device having a pixel array region, an imaging lens for forming an image of a light-emitting point, a converging lens for converging light come from the light-emitting point image formed by the imaging lens onto the pixel array region, a pattern member having a pattern which contains code information uniquely corresponding to the position of the light-emitting point and disposed on a path of light from the light-emitting point and at a position near the light-emitting point image, and a signal processing unit for extracting information of the position of the light-emitting point by using code information contained in an image of the pattern projected onto the pixel array region of the image pickup device on the basis of image data generated by the image of the projected pattern.

Claims24

Dependent claims

An optical position detecting unit for optically detecting a position of a freely movable light point comprising:

an image sensor having a pixel array region configured by a relatively small number of pixels;
an imaging lens for forming an image of said light point at a position in front of the pixel array region of said image sensor;
a converging lens disposed between said image sensor and the position of the image of said light point on an optical axis of said imaging lens for converging light coming from said light point onto the pixel array region of said image sensor, the light passing through the image of said light point;
a transparent optical pattern plate having a pattern containing optical code information uniquely corresponding to the position of said light point on the screen, the plate being disposed between said converging lens and the position of the image of said light point in a plane parallel with the pixel array region of said image sensor, the code information pattern enabling the position of said light point to be determined by means of optical codes included in a region through which the light from said light point passes, said optical codes in the region being projected onto the pixel array region by the converging light coming from said light point onto the pixel array region;
and
signal processing means for processing signals outputted from said image sensor on which said codes are projected onto said pixel array region so as to extract information of the position of said light point by using said codes.

3 more elements

Apparatus for detecting the position of a point optical image, comprising a screen surface from which the image is derived, an optical system located a predetermined distance from the screen surface and positioned to be responsive to the image, the optical system deriving an indication of the image position, and including:

an image sensor having a pixel array region configured by a relatively small number of pixels;
an imaging lens for forming an image of said light point at a position in front of the pixel array region of said image sensor;
a converging lens disposed between said image sensor and the position of the image of said light point on an optical axis of said imaging lens for converging light coming from said light point onto the pixel array region of said image sensor, the light passing through the image of said light point;
a transparent optical pattern plate having a pattern containing optical code information uniquely corresponding to the position of said light point on the screen, the plate being disposed between said converging lens and the position of the image of said light point in a plane parallel with the pixel array region of said image sensor, the code information pattern enabling the position of said light point to be determined by means of optical codes included in a region through which the light from said light point passes, said optical codes in the region being projected onto the pixel array region by the converging light coming from said light point onto the pixel array region;
the apparatus further including
signal processing means for processing signals outputted from said image sensor on which said codes are projected onto said pixel array region so as to extract information of the position of said light point by using said codes.

3 more elements

Apparatus for detecting the position of a point optical image on a surface, an optical beam being derived in response to the point optical image being incident on the surface, the optical beam having an axis and path intersecting the position on the surface where the point optical image is incident, the apparatus comprising an optical system remote from the surface for intercepting the beam, the optical system including an optical detecting surface in the beam path, and a transparent optical pattern including optically coded position identifying regions having positions uniquely corresponding to different positions of the point optical image on the surface from which the beam is derived, the pattern being positioned in the beam path between the optical detecting surface and the surface from which the beam is derived so the beam as incident on the optical detecting surface is modified in accordance with the optically coded regions in the beam path, the optical detecting surface causing derivation of a signal having values corresponding to the optically coded regions in the beam path.

Dependencies are inferred from the claim text.