PROJECTOR, TRAPEZOIDAL DISTORTION CORRECTION METHOD, AND STORAGE MEDIUM STORING TRAPEZOIDAL DISTORTION CORRECTION PROGRAM

• US 20130335451A1
• Filed: 05/20/2013
• Published: 12/19/2013
• Est. Priority Date: 06/19/2012
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Shigekazu Tsuji
• Inventors: TSUJI, Shigekazu
• Granted Patent: US 9,607,363 B2
• Time in Patent Office: Days
• US Class Current: 345/647
• CPC Class Codes: G03B 21/145 Housing details, e.g. position adjustments thereof
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: G06T 5/80 Geometric correction
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A projector includes a projection unit to project an image on a screen; an angle detector to detect shaking of the projection unit; and a trapezoidal distortion correction unit to conduct automatic trapezoidal distortion correction of the image displayed on the screen based on an inclination angle of the projection unit detected by the angle detector, and to enable manual trapezoidal distortion correction of the image displayed on the screen. When the manual trapezoidal distortion correction is conducted after the automatic trapezoidal distortion correction, the trapezoidal distortion correction unit determines whether an angle deviation of the inclination angle exceeds for a given threshold angle for a given time period. When the trapezoidal distortion correction unit determines that the angle deviation exceeds the given threshold angle, the automatic trapezoidal distortion correction is conducted again.

Claims

1. A projector, comprising:

a projection unit to project and display an image on a screen disposed substantially vertically;

an angle detector to detect shaking of the projection unit; and

a trapezoidal distortion correction unit, using a processing circuit, to conduct automatic trapezoidal distortion correction of the image displayed on the screen based on an inclination angle of the projection unit detected by the angle detector, and to enable manual trapezoidal distortion correction of the image displayed on the screen,

wherein, when manual trapezoidal distortion correction is conducted after automatic trapezoidal distortion correction, the trapezoidal distortion correction unit determines whether an angle deviation occurs to the inclination angle, set by the manual trapezoidal distortion correction, exceeding a given threshold angle for a given time period,

wherein, when the trapezoidal distortion correction unit determines that the angle deviation exceeds the given threshold angle, the automatic trapezoidal distortion correction is conducted again.

2. The projector of claim 1, wherein, when manual trapezoidal distortion correction is conducted after automatic trapezoidal distortion correction, the trapezoidal distortion correction unit determines whether the angle deviation occurs to the inclination angle, set by the manual trapezoidal distortion correction, for at least one degree or more for at least one second or more,

wherein, upon the trapezoidal distortion correction unit determining that the angle deviation of one degree or more occurs to the inclination angle, the trapezoidal distortion correction unit conducts automatic trapezoidal distortion correction again.

3. The projector of claim 1, wherein the angle detector is a gravity acceleration sensor.

4. A method of correcting trapezoidal distortion of an image projected by a projector including a projection unit to project and display an image onto a screen disposed substantially vertically;

an angle detector to detect shaking of the projection unit; and

a trapezoidal distortion correction unit, using a processing circuit, to conduct automatic trapezoidal distortion correction of the image displayed on the screen based on an inclination angle of the projection unit detected by the angle detector, and to enable manual trapezoidal distortion correction of the image displayed on the screen,

the method comprising the steps of;

1) correcting trapezoidal distortion automatically using the trapezoidal distortion correction unit;

2) correcting trapezoidal distortion manually using the trapezoidal distortion correction unit after correcting trapezoidal distortion automatically in step

     1);

3) determining, using the trapezoidal distortion correction unit, whether an angle deviation occurs to the inclination angle, set by the manual trapezoidal distortion correction in step

     2), exceeding a given threshold angle for a given time period; and

4) correcting trapezoidal distortion automatically again using the trapezoidal distortion correction unit upon determining that the angle deviation exceeds the given threshold angle in step

     3).

5. The method of claim 4, wherein, when manual trapezoidal distortion correction is conducted in step 2), the trapezoidal distortion correction unit determines whether the angle deviation occurs to the inclination angle, set by conducting the manual trapezoidal distortion correction at step 2), for at least one degree or more for at least one second or more in step 3),

wherein, upon determining that the angle deviation of one degree or more occurs, the trapezoidal distortion correction unit conducts automatic trapezoidal distortion correction again.

6. A non-transitory computer-readable carrier medium storing a program that, when executed by a computer, causes the computer to execute a method of correcting trapezoidal distortion of an image projected by a projector including a projection unit to project and display an image onto a screen disposed substantially vertically;

an angle detector to detect shaking of the projection unit; and

a trapezoidal distortion correction unit, using a processing circuit, to conduct automatic trapezoidal distortion correction of the image displayed on the screen based on an inclination angle of the projection unit detected by the angle detector, and to enable manual trapezoidal distortion correction of the image displayed on the screen,

the method comprising the steps of;

1) correcting trapezoidal distortion automatically using the trapezoidal distortion correction unit;

2) correcting trapezoidal distortion manually using the trapezoidal distortion correction unit after correcting trapezoidal distortion automatically in step

     1);

3) determining, using the trapezoidal distortion correction unit, whether an angle deviation occurs to the inclination angle, set by the manually trapezoidal distortion correction in step

     2), exceeding a given threshold angle for a given time period; and

4) correcting trapezoidal distortion automatically again using the trapezoidal distortion correction unit upon determining that the angle deviation exceeds the given threshold angle in step

     3).