Coordinate input/detection device detecting installation position of light-receiving device used for detecting coordinates

• US 20020163505A1
• Filed: 02/16/2001
• Published: 11/07/2002
• Est. Priority Date: 02/18/2000
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Takekawa, Kenichi
• Granted Patent: US 6,587,099 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06F 3/0423 using sweeping light beams, e.g. using rotating or vibrating mirror

Abstract

A coordinate input/detection device is provided with a coordinate input area. The coordinate input/detection device uses first and second light-emitting units to emit light to a plurality of retro reflectors provided around the coordinate input area. The plurality of retro reflectors reflect the light from the first light-emitting unit toward a first light-receiving unit provided at one of first and second positions, and the light from the second light-emitting unit toward a second light-receiving unit provided at the other position among the first and second positions, the first and second light-receiving units corresponding to the first and second positions respectively. A position recognition unit recognizes whether each of the first and second light-receiving units is installed at the first position or the second position, based on an output signal of each of the first and second light-receiving units. Additionally, a coordinate detection unit detects coordinates of a pointing unit inserted to the coordinate input area, based on output signals of said first and second light-receiving units.

Claims

1. A coordinate input/detection device provided with a coordinate input area, comprising:

a plurality of retro reflectors provided around the coordinate input area;

a first light-emitting unit;

a second light-emitting unit;

a first light-receiving unit that corresponds to a first position, and is installed at one of first and second positions, at which said first light-receiving unit receives light emitted from said first light-emitting unit to the plurality of retro reflectors and reflected by the plurality of retro reflectors;

a second light-receiving unit that corresponds to the second position, and is installed at the other position among the first and second positions, at which said second light-receiving unit receives the light emitted from said second light-emitting unit to the plurality of retro reflectors and reflected by the plurality of retro reflectors; and

a position recognition unit recognizing whether each of said first and second light-receiving units is installed at the first position or the second position, based on an output signal of each of said first and second light-receiving units.

2. The coordinate input/detection device as claimed in claim 1, further comprising a coordinate detection unit detecting coordinates of a pointing unit inserted to the coordinate input area, based on output signals of said first and second light-receiving units.

3. The coordinate input/detection device as claimed in claim 1, wherein said first and second light-emitting units are unified respectively with said first and second light-receiving units.

4. The coordinate input/detection device as claimed in claim 1, wherein each of said first and second light-emitting units emits the light from a single light source through a lens to the plurality of retro reflectors.

5. The coordinate input/detection device as claimed in claim 1, wherein each of said first and second light-emitting units executes a deflection scanning on the light from a single light source, and emits the light to the plurality of retro reflectors.

6. The coordinate input/detection device as claimed in claim 1, wherein two adjacent retro reflectors among the plurality of retro reflectors have a space between them, and said position recognition unit recognizes whether each of said first and second light-receiving units is installed at the first position or the second position, based on a shape of an output waveform of each of said first and second light-receiving units, said output waveform corresponding to the space.

7. The coordinate input/detection device as claimed in claim 1, wherein said position recognition unit recognizes whether each of said first and second light-receiving units is installed at the first position or the second position, based on a ratio of lengths of output waveforms of each of said first and second light-receiving units, said output waveforms corresponding to two adjacent retro reflectors among the plurality of retro reflectors.

8. The coordinate input/detection device as claimed in claim 1, wherein lengths of the plurality of retro reflectors are predetermined.

9. The coordinate input/detection device as claimed in claim 1, wherein a ratio of a height to a width of two adjacent retro reflectors among the plurality of retro reflectors is variable, and said position recognition unit recognizes whether each of said first and second light-receiving units is installed at the first position or the second position, in a condition in which said ratio is not one to one, if a shape of the coordinate input area is a square.

10. The coordinate input/detection device as claimed in claim 9, wherein said ratio is variable because of the plurality of retro reflectors capable of being expanded or contracted.

11. The coordinate input/detection device as claimed in claim 9, wherein said ratio is variable since installation positions of the plurality of retro reflectors are variable.

12. The coordinate input/detection device as claimed in claim 9, further comprising a detachable retro reflector, wherein said coordinate input/detection device adjusts said ratio by installing said detachable retro reflector in the coordinate input area.

13. The coordinate input/detection device as claimed in claim 9, further comprising an installation mechanism installing said first and second light-receiving units at a temporary installation position at which each of said first and second light-receiving units detects whether its installation position is the first or second position, and installing said first and second light-receiving units at a primary installation position shifted from the temporary installation position, said first and second light-receiving units detecting coordinates of a pointing unit inserted to the coordinate input area at said primary installation position.

14. The coordinate input/detection device as claimed in claim 13, further comprising a link mechanism moving the plurality of retro reflectors so that said ratio becomes one to one, in accordance with said first and second light-receiving units shifting from the temporary installation position to the primary installation position.

15. The coordinate input/detection device as claimed in claim 1, further comprising a notification unit notifying a user of information obtained by said position recognition unit about whether each of said first and second light-receiving units is installed at the first position or the second position.

16. The coordinate input/detection device as claimed in claim 1, wherein said coordinate input/detection device recognizes the output signal of said first light-receiving unit as the output signal of said second light-receiving unit, and the output signal of said second light-receiving unit as the output signal of said first light-receiving unit, if said position recognition unit detects a condition in which said first and second light-receiving units are installed at the second and first positions respectively.

17. The coordinate input/detection device as claimed in claim 1, wherein said coordinate input/detection device allows a user to attach said first and second light-receiving units to, or detach said first and second light-receiving units from the first and second positions.

20. The electronic blackboard as claimed in claim 19, wherein said writing surface is an image display device displaying the coordinates detected by said coordinate detection unit.

18. A light-receiving device applied to a coordinate input/detection device emitting light from a pair of light-emitting units to a plurality of retro reflectors provided around a coordinate input area, and obtaining coordinates of a pointing unit inserted to the coordinate input area by detecting the light reflected by the plurality of retro reflectors, said light-receiving device comprising:

a first light-receiving unit that corresponds to a first position, and is installed at one of first and second position, at which said first light-receiving unit receives the light emitted by one of the light-emitting units to the plurality of retro reflectors and reflected by the plurality of retro reflectors;

a second light-receiving unit that corresponds to the second position, and is installed at the other position among the first and second positions, at which said second light-receiving unit receives the light emitted by the other light-emitting unit to the plurality of retro reflectors and reflected by the plurality of retro reflectors; and

a position recognition unit recognizing whether each of said first and second light-receiving units is installed at the first position or the second position based on an output signal of each of said first and second light-receiving units.

19. An electronic blackboard comprising:

a writing surface providing a coordinate input area; and

a coordinate input/detection device attached to the coordinate input area, including;

a plurality of retro reflectors provided around the coordinate input area;

a first light-emitting unit;

a second light-emitting unit;

a first light-receiving unit that corresponds to a first position, and is installed at one of first and second positions, at which said first light-receiving unit receives light emitted from said first light-emitting unit to the plurality of retro reflectors and reflected by the plurality of retro reflectors;

a second light-receiving unit that corresponds to the second position, and is installed at the other position among the first and second positions, at which said second light-receiving unit receives the light emitted from said second light-emitting unit to the plurality of retro reflectors and reflected by the plurality of retro reflectors;

a position recognition unit recognizing whether each of said first and second light-receiving units is installed at the first position or the second position based on an output signal of each of said first and second light-receiving units; and

a coordinate detection unit detecting coordinates of a pointing unit inserted to the coordinate input area based on output signals of said first and second light-receiving units.

21. A method of detecting installation positions of first and second light-receiving units respectively corresponding to first and second positions, in a coordinate input/detection device including a pair of light-emitting units, and a plurality of retro reflectors around a coordinate input area, said method comprising the steps of:

emitting light to the plurality of retro reflectors by use of said pair of light-emitting units;

receiving the light emitted from one of the first and second light-emitting units and reflected by the plurality of retro reflectors, by use of the first light-receiving unit installed at one of the first and second positions;

receiving the light emitted from the other light-emitting unit and reflected by the plurality of retro reflectors, by use of the second light-receiving unit installed at the other position among the first and second positions; and

recognizing whether each of said first and second light-receiving units is installed at the first position or the second position, based on an output signal of each of said first and second light-receiving units.

22. The method as claimed in claim 21, comprising the step of recognizing whether each of said first and second light-receiving units is installed at the first position or the second position, based on a shape of an output waveform of each of said first and second light-receiving units, said output waveform corresponding to a space between two adjacent retro reflectors among the plurality of retro reflectors.

23. The method as claimed in claim 21, comprising the step of recognizing whether each of said first and second light-receiving units is installed at the first position or the second position, based on a ratio of lengths of output waveforms of each of said first and second light-receiving units, said output waveforms corresponding to two adjacent retro reflectors among the plurality of retro reflectors.

24. The method as claimed in claim 21, comprising the step of recognizing whether each of said first and second light-receiving units is installed at the first position or the second position, in a condition in which a ratio of a height to a width of two adjacent retro reflectors is not one to one, if a shape of the coordinate input area is a square.

26. The recording medium as claimed in claim 25, wherein said position recognition function recognizes whether each of said first and second light-receiving units is installed at the first position or the second position, based on a shape of an output waveform of each of said first and second light-receiving units, said output waveform corresponding to a space between two adjacent retro reflectors among the plurality of retro reflectors.

27. The recording medium as claimed in claim 25, wherein said position recognition function recognizes whether each of said first and second light-receiving units is installed at the first position or the second position, based on a ratio of lengths of output waveforms of each of said first and second light-receiving units, said output waveforms corresponding to two adjacent retro reflectors among the plurality of retro reflectors.

25. A recording medium readable by a machine, tangibly embodying a program of instructions executable by the machine to control a coordinate input/detection device provided with a coordinate input area, said coordinate input/detection device comprising:

a plurality of retro reflectors provided around the coordinate input area;

a first light-emitting unit;

a second light-emitting unit;

a first light-receiving unit that corresponds to a first position, and is installed at one of first and second positions, at which said first light-receiving unit receives light emitted from said first light-emitting unit to the plurality of retro reflectors and reflected by the plurality of retro reflectors;

a second light-receiving unit that corresponds to the second position, and is installed at the other position among the first and second positions, at which said second light-receiving unit receives the light emitted from said second light-emitting unit to the plurality of retro reflectors and reflected by the plurality of retro reflectors; and

a coordinate detection unit detecting coordinates of a pointing unit inserted to the coordinate input area based on output signals of said first and second light-receiving units,

wherein said program is executed by the machine to perform a position recognition function to recognize whether each of said first and second light-receiving units is installed at the first position or the second position, based on an output signal of each of said first and second light-receiving units.