IMAGE READING APPARATUS AND IMAGE READING METHOD

• US 20100238523A1
• Filed: 10/02/2009
• Published: 09/23/2010
• Est. Priority Date: 03/23/2009
• Status: Active Grant

• Current Assignee: Fujifilm Business Innovation Corp. (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Ooi, Kazushige
• Granted Patent: US 8,513,547 B2
• Time in Patent Office: Days
• US Class Current: 358/488
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface
• CPC Class Codes: G06F 3/0321 by optically sensing the absolute position with respect to a regularly patterned surface forming a passive digitiser, e.g. pen optically detecting position indicative tags printed on a paper sheet constructional details of pen-shaped pointing devices G06F3/03545, G06F3/03542, G06F3/037

Abstract

An image reading apparatus includes: a pointer having an axis extending along an axis line, that indicates a position on a medium; N (N≧3) irradiating units that respectively irradiate light toward an area that includes the position; and a signal generator that generates, from the irradiated light reflected by the medium, a signal representing an image on the medium.

Claims

1. An image reading apparatus comprising:

a pointer having an axis extending along an axis line, that indicates a position on a medium;

N (N≧

3) irradiating units that respectively irradiate light toward an area that includes the position; and

a signal generator that generates, from the irradiated light reflected by the medium, a signal representing an image on the medium.

2. The image reading apparatus according to claim 1, wherein the N irradiating units are respectively disposed one in each of non-adjacent dividing equally areas selected from 2N dividing equally areas, where a circle centered on the axis line is divided by 2N into equal segments.

3. The image reading apparatus according to claim 2, wherein N=3, and each of the irradiating units is disposed at a vertex of an equilateral triangle whose centroid is the axis line.

4. The image reading apparatus according to claim 1, wherein when a direction and an extent of tilt of the axis line with respect to the medium is predetermined, an illuminance of light reaching the medium from an irradiating unit positioned farther from the medium is larger than an illuminance of light reaching the medium from an irradiating unit positioned closer to the medium.

5. The image reading apparatus according to claim 2, wherein when a direction and an extent of tilt of the axis line with respect to the medium is predetermined, an illuminance of light reaching the medium from an irradiating unit positioned farther from the medium is larger than an illuminance of light reaching the medium from an irradiating unit positioned closer to the medium.

6. The image reading apparatus according to claim 1, further comprising:

a specifying unit that specifies one of the irradiating units positioned farther from the medium; and

an adjustor that adjusts an amount of light irradiated toward the medium from each of the irradiating units, to cause an illuminance of light reaching the medium from the specified one of the irradiating units to be larger than an illuminance of light reaching the medium from an irradiating unit other than the specified one of the irradiating units.

7. The image reading apparatus according to claim 6, wherein the specifying unit identifies an intensity of reflected light corresponding to each of the irradiating units, so as to specify an irradiating unit corresponding to reflected light having a smaller intensity as an irradiating unit positioned farther from the medium.

8. The image reading apparatus according to claim 6, further comprising a first detector that detects a direction of tilt of the axis line with respect to the medium,

wherein the specifying unit specifies an irradiating unit positioned farther from the medium, based on the direction of tilt detected by the detector.

9. The image reading apparatus according to claim 7, further comprising a second detector that detects an extent of tilt of the axis line with respect to the medium,

wherein the adjustor calculates an amount of light irradiated toward the medium from the specified one of the irradiating units, based on the extent of tilt detected by second detector, to cause the amount of light irradiated toward the medium from the specified one of the irradiating units to be equal to the calculated amount of light.

10. The image reading apparatus according to claim 6, wherein the N irradiating units are respectively disposed one in each of non-adjacent dividing equally areas, out of 2N dividing equally areas, where a circle centered on the axis line is divided by 2N into equal segments.

11. An image reading method comprising:

pointing to a position on a medium with an end of an axis extending along an axis line;

irradiating light toward a medium area that includes the pointed to position on the medium by N (N≧

3) irradiating parts; and

generating, from the irradiated light reflected by the medium, a signal representing an image on the medium.

12. The image reading method according to claim 11, wherein the N irradiating units are respectively disposed one in each of non-adjacent dividing equally areas, out of 2N equally divided areas, where a circle centered on the axis line is divided by 2N into equal segments.

13. The image reading method according to claim 12, wherein N=3, and each irradiating unit is disposed at a vertex of an equilateral triangle whose centroid is the axis line.

14. The image reading method according to claim 11, wherein when a direction and an extent of tilt of the axis line with respect to the medium is predetermined, an illuminance of light reaching the medium from an irradiating unit positioned farther from the medium is larger than an illuminance of light reaching the medium from an irradiating unit positioned closer to the medium.

15. The image reading method according to claim 12, wherein when a direction and an extent of tilt of the axis line with respect to the medium is predetermined, an illuminance of light reaching the medium from an irradiating unit positioned farther from the medium is larger than an illuminance of light reaching the medium from an irradiating unit positioned closer to the medium.

16. The image reading method according to claim 11, further comprising:

specifying one of the irradiating units positioned farther from the medium; and

adjusting an amount of light irradiated toward the medium from each of the irradiating units, to cause an illuminance of light reaching the medium from the specified one of the irradiating units to be larger than an illuminance of light reaching the medium from an irradiating unit other than the specified one of the irradiating units.

17. The reading method according to claim 16, wherein in the specifying step, an intensity of the reflected light for each of the irradiating units is identified, so as to specify an irradiating unit corresponding to reflected light having a smaller intensity as an irradiating unit positioned farther from the medium.

18. The reading method according to claim 16, further comprising detecting a direction of tilt of the axis line with respect to the medium,

wherein in the specifying step, an irradiating unit positioned farther from the medium is specified based on the detected direction of tilt.

19. The reading method according to claim 17, further comprising detecting an extent of tilt of the axis line with respect to the medium,

wherein the adjusting step comprises calculating an amount of light irradiated toward the medium from the specified one of the irradiating units, based on the detected extent of tilt, to cause the amount of light irradiated toward the medium from the specified one of the irradiating units to be equal to the calculated amount of light.