Position detecting device and position detecting method
First Claim
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1. A position detecting device for detecting a pointed position of a position pointing device having a light emitting means or a shadow generating means, comprising:
- a flat board having a position detecting area which defines a range where said position pointing device can be moved by an operator on said flat board; and
optical units disposed at least at two positions adjacent to said position detecting area of said flat board, and detecting said pointed position of said position pointing device by the principle of triangulation using light, each of said optical units comprising;
a one-dimensional light receiving element array having a plurality of light receiving elements;
a sequential output circuit outputting sequentially an analog value of an output of said one-dimensional light receiving element array;
a clock circuit supplying a timing signal to said sequential output circuit;
an output level comparing circuit judging whether the output from said sequential output circuit is higher or lower than a predetermined voltage level, and converting said analog value into a digital timing signal; and
a variation timing measuring circuit for obtaining a variation timing of said output level comparing circuit, said pointed position of said position pointing device being detected from the output of said variation timing measuring circuit of each of said optical units by obtaining an incident angle of light or shadow from said position pointing device to each of said optical units.
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Abstract
For providing an optical digitizer without expensive parts and for minimizing the device, a variation timing of an output of a linear image sensor in an optical unit is detected as a time data by using a comparator. A variation timing measuring circuit detects a variation timing of the output of the comparator. A pointed position of a position pointing device is detected from the output of the variation timing measuring circuit by obtaining an incident angle of light or shadow from the position pointing device to the optical unit.
22 Citations
16 Claims
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1. A position detecting device for detecting a pointed position of a position pointing device having a light emitting means or a shadow generating means, comprising:
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a flat board having a position detecting area which defines a range where said position pointing device can be moved by an operator on said flat board; and
optical units disposed at least at two positions adjacent to said position detecting area of said flat board, and detecting said pointed position of said position pointing device by the principle of triangulation using light, each of said optical units comprising;
a one-dimensional light receiving element array having a plurality of light receiving elements;
a sequential output circuit outputting sequentially an analog value of an output of said one-dimensional light receiving element array;
a clock circuit supplying a timing signal to said sequential output circuit;
an output level comparing circuit judging whether the output from said sequential output circuit is higher or lower than a predetermined voltage level, and converting said analog value into a digital timing signal; and
a variation timing measuring circuit for obtaining a variation timing of said output level comparing circuit, said pointed position of said position pointing device being detected from the output of said variation timing measuring circuit of each of said optical units by obtaining an incident angle of light or shadow from said position pointing device to each of said optical units. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A position detecting method in a position detecting device for detecting a pointed position of a position pointing device having a light emitting means or a shadow generating means, and having a flat board having a position detecting area which defines a range where said position pointing device can be moved by an operator on said flat board, and optical units disposed at least at two positions adjacent to said position detecting area of said flat board, and detecting said pointed position of said position pointing device by the principle of triangulation using light, said position detecting method comprising the steps of:
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a light receiving element output extracting step for sequentially taking an output of a one-dimensional light receiving element array having a plurality of light receiving elements provided in each of said optical units;
an output level comparing step for judging whether the output taken at said light receiving element output extracting step is higher or lower than a predetermined voltage level, and converting said output into a digital timing signal; and
a variation timing measuring step for obtaining an output variation timing from said digital timing signal obtained at said output level comparing step, said pointed position of said position pointing device being detected from the output at said variation timing measuring step through each of said optical units by obtaining an incident angle of light or shadow from said position pointing device to each of said optical units. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification