Optical position detecting unit and optical coordinate input unit utilizing a sub-portion of a M-sequence pattern

An optical coordinate input unit comprising:

• a position pointer including a light-emitting means;
• and
• a coordinate detector including at least two optical position detecting units for detecting direction of incidence of a light beam emitted from the light-emitting means of said position pointer;
• each of said optical position detecting units comprising:
• a light-receiving means including a pixel array forming a light-receiving region for outputting signals through pixels of said pixel array which detect light;
• a pattern member disposed in front of said pixel array having a pattern with a specific characteristic such that an arbitrary sub-portion of said pattern contains a digital code indicating coordinate information concerning a position of the arbitrary sub-portion in said pattern, wherein when a sub-portion of said pattern is projected onto said light-receiving region by an incident light beam, the direction of incidence of said light beam can be determined by use of the digital code contained in an image of said sub-portion formed on said light-receiving region;
• and
• a signal processing means for processing the signals outputted from the pixels and thereby extracting information concerning the direction of incidence of said light beam, the processing of signals including a process of extracting bits forming said digital code contained in the image of said sub-portion from the signals outputted from the pixels,
• wherein said optical position detecting units obtain coordinate data of a position pointed by said position-pointer by detecting a light beam emitted from said light-emitting means.

An apparatus for detecting an originating position of a source emitting an optical beam comprising:

• a member having a predetermined pattern;
• means for detecting an image formed by a sub-portion of said member which is caused by an interaction between the optical beam and said predetermined pattern, said image containing a digital code indicative of coordinate information regarding a position of a particular arrangement of patterns in said predetermined pattern forming said image, and said detecting means outputting signals indicative of said digital code;
• and
• means for processing said signals from said detecting means to extract bit information from said digital code representative of said coordinate information and determining the originating position of the source emitting the optical beam from said bit information.