PROJECTOR FOR ADJUSTING A PROJECTED IMAGE SIZE AND LUMINANCE DEPENDING ON VARIOUS ENVIRONMENTS

• US 20040223120A1
• Filed: 05/07/2004
• Published: 11/11/2004
• Est. Priority Date: 05/09/2003
• Status: Active Grant

• Current Assignee: BenQ Corporation (Qisda Corporation)
• Original Assignee: BenQ Corporation (Qisda Corporation)
• Inventors: Tan, Ming-Che
• Granted Patent: US 7,108,379 B2
• Time in Patent Office: Days
• US Class Current: 353/30
• CPC Class Codes: G03B 21/145 Housing details, e.g. position adjustments thereof
• CPC Class Codes: G03B 21/26 Projecting separately subsidiary matter simultaneously with main image

Abstract

A projector includes a housing, an image module for projecting onto a screen toward a front side, a detecting module for detecting distances from the projector to the front side and from the projector to the back side, a processor for adjusting luminance of the projected image from the image module based on the distances from the projector to the front side and from the projector to the back side.

Claims

1. A projector comprising:

a housing;

an image module installed within the housing for projecting an image toward a screen at the front side of the projector;

a detecting module for detecting distances from the projector to the front side of the projector and from the projector to the back side of the projector; and

a processor connected with the detecting module for adjusting the luminance of the projecting image projected by the image module based on the distances from the projector to the front side of the projector, and from the projector to the back side of the projector.

2. The projector of claim 1, wherein the detecting module comprises:

a transmitter for emitting detecting signals toward the front side of the projector and the back side of the projector;

a receiver for receiving the reflected detecting signals from the front side of the projector and the back side of the projector; and

a decision module for determining the distances from the projector to the front side of the projector, and from the projector to the back side of the projector based on the detecting signals emitted by the transmitter.

3. The projector of claim 1, wherein the detecting module comprises:

a transmitter for emitting a beam toward the front side of the projector and the back side of the projector;

an image-taking module for taking analog images projected by the beams to the front side of the projector and the back side of the projector;

an analog-to-digital converter for transforming the taken analog image by the image-taking module into a digital image;

a comparison module for comparing gray level of each pixel of the digital image; and

a decision module for determining the distances from the projector to the front side of the projector, and from the projector to the back side of the projector, based on the position of the pixel with highest gray level.

4. The projector of claim 3, wherein the beam is a laser beam.

5. The projector of claim 2, wherein the processor adjusts the luminance of the image projected by the image module based on the total distances from the projector to the front side of the projector, and from the projector to the back side of the projector.

6. The projector of claim 2, wherein the transmitter further emits detecting signals toward the left and right sides of the projector, and thus the decision module determines the distances from the projector to the left and right sides of the projector based on the detecting signals to be emitted to the left and right sides of the projector by the transmitter, respectively.

7. The projector of claim 3, wherein the transmitter further emits beams towards toward the left and right sides of the projector, the image-taking module taking analog images projected by the beams to the left and right sides of the projector, the analog-to-digital converter transforming the analog images taken by the image-taking module into a digital image, the comparison module comparing a gray level of each pixel of the digital image, and the decision module determining distances from the projector to the left and right sides of the projector based on the position of the pixel with highest gray level.

8. The projector of claim 6, wherein the processor determines an ideal distance from the projector to the screen based on a shorter distance between the distances from the projector to the left sides of the projector, and from the projector to the right side of the projector, the projector further comprising a display device coupled to the processor for outputting a display signal based on a difference between an actual distance from the projector to the screen and the ideal distance from the projector to the screen.

9. The projector of claim 8, wherein the processor determines an ideal distance from the projector to the screen based on the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector, and a predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector.

10. The projector of claim 9, wherein if the shorter distance between the distances from the projector to the left and right sides of the projector and from the projector to the right side of the projector is longer than or equal to the predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector, the luminance of the image projected by the image module is adjusted based on the total distances from the projector to the front side of the projector and from the projector to the back side of the projector;

if the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector is shorter than the predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector, the image projected by the image module is adjusted based on the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector.

11. The projector of claim 1, wherein the detecting module is rotatable inside the housing for detecting distances from the projector outwards in various directions.

12. A projector comprising:

a housing;

an image module installed within the housing for projecting an image toward a screen at the front side of the projector;

a detecting module for detecting distances from the projector to the front, back, left, and right sides of the projector;

a processor coupled with the detecting module for determining an ideal distance from the projector to the screen based on the distances from the projector to the front, back, left, and right sides of the projector; and

a display device coupled to the processor for outputting a display signal based on the ideal distance from the projector to the screen.

13. The projector of claim 12, wherein the detecting module comprises:

a transmitter for emitting detecting signals toward the front, back, left, and right sides of the projector;

a receiver for receiving the reflected detecting signals from the front, back, left, and right sides of the projector; and

a decision module for determining the distances from the projector to the front, back, left, and right sides of the projector based on the detecting signals emitted by the transmitter.

14. The projector of claim 12, wherein the detecting module comprises:

a transmitter for emitting a beam toward the front, back, left, and right sides of the projector;

an image-taking module for taking analog images projected by the beams to the front, back, left, and right sides of the projector;

an analog-to-digital converter for transforming the taken analog image by the image-taking module into a digital image;

a comparison module for comparing gray level of each pixel of the digital image; and

a decision module for determining the distances from the projector to the front, back, left, and right sides of the projector, based on the position of the pixel with highest gray level.

15. The projector of claim 14, wherein the beam is a laser beam.

16. The projector of claim 12, wherein the processor determines an ideal distance from the projector to the screen based on a shorter distance between the distances from the projector to the left sides of the projector and from the projector to the right side of the projector.

17. The projector of claim 16, wherein the processor determines an ideal distance from the projector to the screen based on the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector, and a predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector.

18. The projector of claim 16, wherein the processor adjusts the luminance of the image projected by the image module based on the distances from the projector to the front side of the projector and from the projector to the back side of the projector.

19. The projector of claim 18, wherein the processor adjusts the luminance of the image projected by the image module based on the total distances from the projector to the front side of the projector and from the projector to the back side of the projector.

20. The projector of claim 19, wherein if the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector is longer than or equal to the predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector, the luminance of the image projected by the image module is adjusted based on the total distances from the projector to the front side of the projector and from the projector to the back side of the projector;

if the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector is shorter than the predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector, the image projected by the image module is adjusted based on the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector.

21. The projector of claim 12, wherein the detecting module is rotatable inside the housing for detecting distances from the projector outwards in various directions.

22. A method for adjusting an ideal projecting distance and projecting luminance of a projector comprising:

(a) detecting distances from the projector to the front, back, left, and right sides of the projector;

(b) comparing the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector, and a predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector; and

(c) determining a projecting parameter, based on the result of step (b).

23. The method of claim 22 further comprising:

(d) controlling the operation of the projector based on the projecting parameter, wherein the projecting parameter indicates a width of an image projected by the projector, an ideal distance from the projector to the front side of the projector, or luminance of an image projected by the projector.

24. The method of claim 23, wherein the step (c) comprises:

(c1) determining the projecting parameter based on the total distances from the projector to the front side of the projector and from the projector to the back side of the projector, if the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector is longer than or equal to the predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector; and

(c2) determining the projecting parameter based on the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector, if the shorter distance between the distances from the projector to the left side of the projector and from the projector to the right side of the projector is shorter than the predetermined ratio to the total distances from the projector to the front side of the projector and from the projector to the back side of the projector.