PROJECTOR, IMAGE PROJECTION METHOD, AND HEAD-UP DISPLAY DEVICE USING THE PROJECTOR

• US 20090289950A1
• Filed: 04/28/2009
• Published: 11/26/2009
• Est. Priority Date: 05/20/2008
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: KAWASAKI, Toshiyuki, KASAHARA, Ryosuke, HAMANO, Yukiko
• Granted Patent: US 8,648,904 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G03B 21/006 using LCD's
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: H04N 9/317 Convergence or focusing systems electronic adjustment of convergence H04N9/3185; convergence or focusing arrangements for cathode ray tubes H04N9/28; means for automatic focusing of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/53

Abstract

A projector projecting an image on an object by scanning the object with a light beam includes a light source; a divergence angle converter converting the divergence angle of the light beam; a light deflector deflecting the light beam in a light beam scanning direction and a direction perpendicular to the light beam scanning direction; alight deflector drive controller controlling the light deflector to form the focused light spots at the respective pixel positions of the object on the basis of positional data for the pixels; a light amount controller controlling light amount of the light beam on the basis of luminance data for the pixels; and an image processor correcting the luminance data on the basis of previously obtained deterioration data of the projected image and outputting the corrected luminance data to the light amount controller while outputting the positional data to the light deflector drive controller.

Claims

1. A projector which projects an image corresponding to an original image on a projection object by scanning the projection object with a light beam, comprising:

a light source configured to emit a light beam;

a projection optical system including;

a divergence angle converter configured to convert a divergence angle of the light beam so that focused spots are formed on the projection object; and

a light deflector configured to deflect the light beam from the divergence angle converter in a light beam scanning direction and a direction perpendicular to the light beam scanning direction to form the focused light spots on pixel portions of the projection object such that positions of the pixel portions correspond to positions of pixels of the original image;

a light deflector drive controller configured to control the light deflector to form the focused light spots on the pixel portions of the projection object on the basis of positional data of the pixels;

a light amount controller configured to control light amount of the light beam emitted by the light source on the basis of luminance data for the pixels; and

an image processor configured to correct the luminance data for each pixel on the basis of previously obtained data concerning deterioration in quality of the projected image and to output the corrected luminance data to the light amount controller while outputting the positional data to the light deflector drive controller.

2. The projector according to claim 1, wherein the image processor includes:

a pixel data correction part configured to correct the luminance data for each pixel on the basis of the previously obtained deterioration data of the projected image;

a judgment part configured to judge whether the corrected luminance data for each pixel falls out of an adjustable range of the light amount controller; and

a re-correction process part configured to re-correct the corrected luminance data judged to fall out of the adjustable range so as to fall in the adjustable range.

3. The projector according to claim 2, wherein the light deflector is subjected to a sine wave drive, and wherein the pixel data correction part has a function of re-correcting the corrected luminance data on the basis of light amount distribution property, and the judgment part determines whether the re-corrected luminance data falls out of the adjustable range of the light amount controller.

4. The projector according to claim 1, wherein the image processor includes:

a pixel data correction part configured to correct the luminance data for each pixel on the basis of the previously obtained deterioration data of the projected image;

a judgment part configured to judge whether the corrected luminance data for each pixel falls out of an adjustable range of the light amount controller; and

a substitution process part configured to substitute the corrected luminance data judged to fall out of the adjustable range with the luminance data of the original image.

5. The projector according to claim 1, wherein the image processor includes:

a pixel data correction part configured to correct the luminance data for each pixel on the basis of the previously obtained deterioration data of the projected image;

a judgment part configured to judge whether the corrected luminance data for each pixel falls out of an adjustable range of the light amount controller; and

a substitution process part configured to substitute the corrected luminance data judged to be greater than a maximum value of the adjustable range with the maximum value, and to substitute the corrected luminance data judged to be less than a minimum value of the adjustable range with the minimum value.

6. The projector according to claim 5, wherein the light source emits red, green and blue light beams, and the luminance data include red, green and blue color luminance data, and wherein when the judgment part judges that one of the red, green and blue color luminance data is greater than the maximum value, the substitution process part substitutes the corrected color luminance data with the maximum value while adjusting the other two color luminance data so that a ratio of the re-corrected three color luminance data is the same as that before the re-correction processing, and when the judgment part judges that one of the red, green and blue color luminance data is less than the minimum value, the substitution process part substitutes the corrected color luminance data with the minimum value while adjusting the other two color luminance data so that a ratio of the re-corrected three color luminance data is the same as that before the re-correction processing.

7. The projector according to claim 1, wherein the light deflector includes a first deflector configured to perform one dimensional light deflection and a second deflector configured to perform two dimensional light deflection, wherein the first and second deflectors are integrated or separated from each other.

13. A head-up display device comprising:

the projector according to claim 1; and

at least one of a partial reflection plane configured to reflect a light beam emitted from the light source of the projector, and

an eyepiece optical system configured to convert diffusion light beam emitted from the projector to parallel light beam.

8. An image projection method for projecting an image corresponding to an original image on a projection object, comprising:

emitting a light beam;

converting a divergence angle of the light beam so that focused spots are formed on the projection object;

deflecting the light beam in a light beam scanning direction and a direction perpendicular to the light beam scanning direction to form the focused light spots on respective pixel portions of the projection object such that positions of the pixel portions correspond to positions of pixels of the original image; and

performing image controlling, including;

correcting luminance data for each pixel on the basis of previously obtained data concerning deterioration in quality of the projected image to prevent the deterioration in quality of each pixel portion of the projected image; and

controlling light amount of the light beam on the basis of the corrected luminance data while controlling the deflection angle on the basis of positional data of the pixels.

9. The image projection method according to claim 8, wherein the correcting step includes:

correcting the luminance data for each pixel on the basis of the previously obtained deterioration data of the projected image;

judging whether the corrected luminance data for each pixel falls out of a light amount adjustable range; and

re-correcting the corrected luminance data judged to fall out of the light amount adjustable range so as to fall in the light amount adjustable range.

10. The image projection method according to claim 8, wherein the correcting step includes:

correcting the luminance data for each pixel on the basis of the previously obtained deterioration data of the projected image;

judging whether the corrected luminance data for each pixel falls out of a light amount adjustable range; and

substituting the corrected luminance data judged to fall out of the light amount adjustable range with the luminance data of the original image.

11. The image projection method according to claim 8, wherein the correcting step includes:

correcting the luminance data for the pixels of the image on the basis of the previously obtained deterioration data of the projected image;

judging whether the corrected luminance data for each pixel falls out of a light amount adjustable range; and

substituting the corrected luminance data judged to be greater than a maximum value of the light amount adjustable range with the maximum value, and substituting the corrected luminance data judged to be less than a minimum value of the light amount adjustable range with the minimum value.

12. The image projection method according to claim 11, wherein the light emitting step includes:

emitting red, green and blue light beams, and the judging step includes;

judging whether one of the red, green and blue color luminance data is greater than the maximum value or less than the minimum value, and including;

when judging that one of the red, green and blue color luminance data is greater than the maximum value, substituting the corrected color luminance data with the maximum value while adjusting the other two color luminance data so that a ratio of the re-corrected three color luminance data is the same as that before the re-correction processing; and

when judging that one of the red, green and blue color luminance data is less than the minimum value, substituting the corrected color luminance data with the minimum value while adjusting the other two color luminance data so that a ratio of the re-corrected three color luminance data is the same as that before the re-correction processing.