LENS DRIVE DEVICE, IMAGE PICKUP DEVICE AND LENS DRIVE METHOD

• US 20090141135A1
• Filed: 11/13/2008
• Published: 06/04/2009
• Est. Priority Date: 11/14/2007
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Ito, Kaoru, Suzuki, Yohsuke, Nuno, Katsuhiko, Yasuda, Takuroh
• Granted Patent: US 8,089,553 B2
• Time in Patent Office: Days
• US Class Current: 348/208.990
• CPC Class Codes: G02B 7/102 controlled by a microcomputer cameras with interchangeable lenses G03B17/14
• CPC Class Codes: G03B 17/04 collapsible, foldable or extensible, e.g. book type
• CPC Class Codes: G03B 17/12 with means for supporting objectives, supplementary lenses, filters, masks, or turrets
• CPC Class Codes: G03B 2217/002 Details of arrangement of components in or on camera body
• CPC Class Codes: H04N 2101/00 Still video cameras
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors

Abstract

A lens drive device in at least one lens barrel holding a lens moveably includes a motor to drive the lens; an acceleration detection section to detect an acceleration; and an output control section to control an output of the motor corresponding to the acceleration detected by the acceleration detection section. The output control section determines whether the acceleration detected by the acceleration detection section falls within a predetermined acceleration range or not. When the acceleration is determined to be within the range, a further determination of whether the lens drive device is in a stationary state is performed. When it is determined not being in the stationary state, the motor is driven by a maximum drive voltage. When it is determined being in the stationary state, a further determination of whether the posture is horizontal or not is performed.

Claims

1. A lens drive device holding at least one lens moveably along an optical axis, the lens drive device comprising:

a drive section to drive the lens;

an acceleration detection section to detect an acceleration; and

an output control section to control an output of the drive section corresponding to the acceleration detected by the acceleration detection section.

2. The lens drive device according to claim 1, wherein

the drive section includes a motor to drive the lens;

and

the output control section determines whether the acceleration detected by the acceleration detection section falls within a predetermined acceleration range or not, when the acceleration is determined to be within the range, a further determination of whether the lens drive device is in a stationary state is performed, and when it is determined not being in the stationary state, the motor is driven by a maximum drive voltage, while when it is determined being in the stationary state, a further determination of whether a posture is horizontal or not is performed, when being horizontal is determined, the motor is driven by a drive voltage appropriate for a horizontal posture, while when it is determined not being horizontal, a further determination is performed of whether to drive the motor in the gravity direction or in the direction opposite to the gravity direction, when it is determined to drive the motor in the gravity direction, the motor is driven by a lower voltage than the drive voltage appropriate for the horizontal posture, while when otherwise, the motor is driven by a voltage higher than the drive voltage appropriate for the horizontal posture and lower than the maximum drive voltage.

3. The lens drive device according to claim 2, wherein when the acceleration detection section detects the acceleration exceeding the predetermined acceleration range, the output control section is configured not to drive the motor.

4. The lens drive device according to claim 3, wherein even when the acceleration is detected to exceed the predetermined acceleration range by the acceleration detection section and the output control section does not drive the motor, once the acceleration detection section detects the acceleration falling within the predetermined acceleration range, the motor can be driven by the output control section.

5. An image pickup device comprising.

the lens drive device according to claim 1;

and

an imaging element circuit board, provided with an image pickup element to convert a subject image obtained by the lens into an electrical signal.

6. The image pickup device according to claim 5, wherein the acceleration detection section is provided on the imaging element circuit board.

7. The image pickup device according to claim 6, wherein the acceleration detection section is provided on a surface of the imaging element circuit board opposite to a surface whereon the image pickup element is provided.

8. The image pickup device according to claim 5, wherein the image pickup device includes a lens barrel unit and the acceleration detection section is provided in the lens barrel unit.

9. The image pickup device according to claim 8, wherein the acceleration detection section is provided on a rear surface of the lens barrel unit.

10. The image pickup device according to claim 5 wherein when the image pickup device is switched on, the acceleration detection is performed prior to the lens drive, and upon the detected acceleration exceeding a prescribed range, the lens drive is terminated, followed by a shift to a suspension state in which a photographing cannot be performed.

11. The image pickup device according to claim 10, wherein even when in the suspension state, the acceleration detection is still performed by the acceleration detection section, and upon the detected acceleration falling within the prescribed range, the suspension state is discontinued, followed by a shift to a state in which the photographing can be performed.

12. The lens drive device according to claim 1, wherein the lens drive device comprises:

a lens position detection section to detect a position of the lens;

an operating section to perform an input operation so as to operate the lens drive device;

a drive direction discrimination section to discriminate a drive direction of the lens drive device, based on an input from the operating section and a lens position detection signal obtained from the lens position detection section; and

wherein

the output control section includes an acceleration discrimination section to discriminate an acceleration pattern among

a first acceleration pattern in which the lens drive device is driven by a first output;

a second acceleration pattern in which both an operation output for extension and an operation output for collapse are increased to be larger than the first output, based on an input from the operating section;

a third acceleration pattern in which compared with the first output, the operation output for extension is decreased while the operation output for collapse is increased, based on the input from the operating section; and

a fourth acceleration pattern in which compared with the first output, the operation output for extension is increased while the operation output for collapse is decreased, based on the input from the operating section; and

the output control section controls the output of the lens drive device based on both a discriminated lens drive direction, obtained from the lens drive direction discrimination section, and a discriminated acceleration pattern obtained by the acceleration discrimination section.

13. The lens drive device according to claim 12, when even the input from the operating section remains unchanged and the lens drive direction is switched in the middle of the lens movement, wherein before the lens is driven to a switching position, an output of the lens drive device is increased.

14. The lens drive device according to claim 12, wherein when an acceleration pattern other than anyone of the acceleration patterns from the first to the fourth is detected by the acceleration discrimination section, the lens drive is terminated by the lens drive device.

15. The lens drive device according to claim 12, wherein when an acceleration pattern other than anyone of the acceleration patterns from the first to the fourth is detected by the acceleration discrimination section, the lens is returned to an initial position thereof.

16. The lens drive device according to claim 12, wherein while the lens is driven by the lens drive device, the output of the lens drive device is varied with an output from the lens position detection section and the acceleration detection section.

17. An image pickup device including the lens drive device according to claim 12.

18. An image pickup device capable of shifting at least one lens state between a housed state in which the lens is located out of an optical axis, and a photographing state in which the lens is located on the optical axis via extending or retracting the lens with respect to the optical axis, wherein the image pickup device comprising:

a motor to drive the lens;

an acceleration detection section to detect an acceleration;

an output control section to control an output of the motor corresponding to the acceleration detected by the acceleration detection section;

wherein

when the power is on, an output of the acceleration detection section is detected; and

when the detected output of the acceleration detection device exceeds a certain threshold, a shift from the housed state of the lens to the photographing state thereof is not performed.

19. A method of driving at least one lens in a lens barrel holding the lens moveably by a motor, the method comprising:

detecting an acceleration working on the lens; and

controlling an output of the motor to select an optimum output of the motor corresponding to the detected acceleration;

wherein

the controlling of the output of the motor comprising;

determining whether the acceleration detected by the acceleration detection section falls within a predetermined acceleration range or not, and then when the acceleration is determined to be within the range, further determining whether being in a stationary state or not; and

when it is determined not being in the stationary state, driving the motor with a maximum drive voltage;

further determining whether being horizontal or not, based on the determination of being in the stationary state, and then when being horizontal is determined, driving the motor by a drive voltage appropriate for being horizontal;

further determining whether to drive the motor in the gravity direction or in the direction opposite to the gravity direction, based on the determination of not being horizontal;

driving the motor by a lower voltage than the drive voltage appropriate for being horizontal, based on the determination of driving the motor in the gravity direction; and

driving the motor by a voltage higher than the drive voltage appropriate for being horizontal and lower than the maximum drive voltage, based on the determination of driving the motor in the direction opposite to the gravity direction.

20. The lens drive method according to claim 19, wherein when the acceleration is detected exceeding the predetermined acceleration range in the step of detecting the acceleration working on the lens, in the step of controlling the output of the motor, the motor is not driven.