PROJECTION TYPE IMAGE DISPLAY APPARATUS

• US 20110019109A1
• Filed: 03/17/2009
• Published: 01/27/2011
• Est. Priority Date: 03/18/2008
• Status: Active Grant

• Current Assignee: Konica Minolta Inc.
• Original Assignee: Konica Minolta OPTO Incorporated (Konica Minolta Inc.)
• Inventors: Terada, Masahiro, Maeda, Norio, Inoue, Kazuhiko, Ohta, Takashi, Sawai, Yasumasa, Wataru, Kohei
• Granted Patent: US 9,010,944 B2
• Time in Patent Office: Days
• US Class Current: 348/745
• CPC Class Codes: G03B 21/00 Projectors or projection-type viewers; Accessories therefor devices for changing pictures G03B23/00
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: G03B 21/53 Means for automatic focusing, e.g. to compensate thermal effects
• 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 projection type image display apparatus (1) comprises a focus correction system (30). The system includes a temperature detection mechanism (16) for measuring temperature in the vicinity of a projection lens group (13), a correction amount calculation unit (18) for calculating a correction amount for correcting the focus shift caused by a temperature change, and a driving signal generation unit (19) for generating, based on the correction amount, a driving signal for driving a focus adjustment mechanism (15). If the user performs a focus adjustment using a focus operation input unit (23), a focus operation determination unit (21) determines that a focus adjustment has occurred independently of the focus correction system and changes a correction condition stored in a memory (20).

Claims

1. A projection type image display apparatus comprising:

a projection optical system that includes a focus lens whose position is movable along an optical axis;

a temperature sensor that measures a temperature in the vicinity of the projection optical system;

a memory that stores lens position data that represents a relationship between the temperature measured by the temperature sensor and the position of the focus lens;

a focus lens control portion that controls the position of the focus lens based on temperature information from the temperature sensor and the lens position data;

a determination portion that determines whether or not there is a movement of the focus lens that is not performed by the focus lens control portion; and

a lens position data correction portion that, in a case where the determination portion determines that there is a movement of the focus lens that is not performed by the focus lens control portion, corrects the lens position data based on a movement amount of the focus lens in the movement.

2. The projection type image display apparatus according to claim 1, wherein

in the case where the determination portion determines that there is the movement of the focus lens that is not performed by the focus lens control portion, the temperature information measured by the temperature sensor and the position information of the focus lens immediately after the movement are stored in the memory;

and

the lens position data correction portion, immediately before turning-off of a power supply of the apparatus, corrects the lens position data based on the temperature information and the position information of the focus lens that are stored in the memory.

3. The projection type image display apparatus according to claim 1, wherein the determination portion is so disposed as to be able to determine whether or not there is a movement of the focus lens that is performed by a user.

4. The projection type image display apparatus according to claim 3, further comprising an input portion with which the user moves the focus lens;

wherein, based on presence of an operation of the input portion, the determination portion determines whether or not there is the movement of the focus lens that is not performed by the focus lens control portion.

5. The projection type image display apparatus according to claim 1, further comprising a displacement detection portion that detects a position displacement of the focus lens;

wherein

based on a signal from the displacement detection portion, the determination portion determines whether or not there is a movement of the focus lens that is not performed by the focus lens control portion.

12. The projection type image display apparatus according to claim 2, wherein the determination portion is so disposed as to be able to determine whether or not there is a movement of the focus lens that is performed by a user.

13. The projection type image display apparatus according to claim 12, further comprising an input portion with which the user moves the focus lens;

wherein, based on presence of an operation of the input portion, the determination portion determines whether or not there is the movement of the focus lens that is not performed by the focus lens control portion.

14. The projection type image display apparatus according to claim 2, further comprising a displacement detection portion that detects a position displacement of the focus lens;

wherein

based on a signal from the displacement detection portion, the determination portion determines whether or not there is a movement of the focus lens that is not performed by the focus lens control portion.

6. A projection type image display apparatus that has a focus correction system which corrects a time-dependent change of a focus based on a specific physical amount, the projection type image display apparatus comprises a determination portion that determines whether or not there is a focus operation that is not performed by the focus correction system;

wherein

in a case where the determination portion determines that there is the focus operation, the focus operation system changes a correction condition to a new condition to perform a correction.

7. The projection type image display apparatus according to claim 6, wherein the determination portion is so disposed as to be able to determine whether or not there is the focus operation that is performed by a user.

8. The projection type image display apparatus according to claim 7, wherein, based on presence of an operation of an input portion that is disposed to give a command for an operation of the focus, the determination portion determines whether or not there is the focus operation.

9. The projection type image display apparatus according to claim 6, wherein, based on a signal from a displacement detection portion that detects a displacement of a lens position at a focus operation time, the determination portion determines whether or not there is a focus operation that is not performed by the focus correction system.

10. The projection type image display apparatus according to claim 6, wherein the specific physical amount is a temperature, and in a case where the determination portion determines that there is the focus operation, a correction start temperature of the focus correction system is updated to a new temperature.

11. The projection type image display apparatus according to claim 6, wherein the specific physical amount is a temperature;

the focus correction system corrects the time-dependent change of the focus by moving a position of a focus lens based on lens position data that is related to the temperature; and

in a case where the determination portion determines that there is the focus operation, the lens position data are corrected based on a movement amount of the focus lens performed by the focus operation; and

the focus correction system perform the correction by using the corrected lens position data as the new condition.