Digital camera

• US 20040189822A1
• Filed: 01/09/2004
• Published: 09/30/2004
• Est. Priority Date: 01/09/2003
• Status: Active Grant

• Current Assignee: OM Digital Solutions Corporation
• Original Assignee: Olympus Company Limited (Olympus Corporation)
• Inventors: Shimada, Yoshinao
• Granted Patent: US 7,522,210 B2
• Time in Patent Office: Days
• US Class Current: 348/229.1
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

In a first exposure condition calculating operation, proper exposure conditions in imaging are calculated by the imaging element including the effective exposure time and ISO sensitivity without preliminary light emission from the strobo part. In a second exposure condition calculating operation, the exposure condition is determined by compensating at least the ISO sensitivity among the exposure conditions calculated in the first exposure condition calculating operation by dimmer or light control operation with preliminary light emission of the strobo part. Exposure of the imaging element is executed as a regular imaging operation under the exposure condition calculated and determined in the second exposure condition calculating operation.

Claims

1. A digital camera comprising an imaging element for providing a photo-electric output corresponding to an image of a scene focused on an imaging surface of said imaging element, an exposure time control part for controlling an exposure time effective in the imaging element, a sensitivity control function part for controlling an ISO sensitivity of the camera corresponding to an amplification factor of a photo-electric output of the imaging element and a strobo part for projecting light onto the scene, the digital camera further comprising:

a main control part for collectively controlling a first exposure condition calculating operation for calculating proper exposure conditions in imaging by the imaging element including the effective exposure time and ISO sensitivity without preliminary light emission from the strobo part, a second exposure condition calculating operation of the exposure condition by compensating at least the ISO sensitivity among the exposure conditions calculated in the first exposure condition calculating operation by dimmer or light control operation with the preliminary light emission of the strobo part, and an operation of enabling exposure of the imaging element as a regular imaging operation under the exposure condition calculated and determined in the second exposure condition calculating operation.

2. The digital camera according to claim 1, wherein the main control part, in the second exposure condition calculating operation, sets the exposure condition used for the regular imaging operation by compensating the effective exposure time calculated in the first exposure condition calculating operation.

3. The digital camera according to claim 1, wherein the main control part determines the exposure condition to be applied to the regular imaging operation with compensation of the ISO sensitivity calculated in the first exposure condition calculating operation with execution of the second exposure condition calculating operation by calculating, as the effective exposure time, a first exposure time with provision of a condition that this exposure time is within a predetermined threshold value, and a second exposure time without providing said condition, and calculating a necessary extent of control of the ISO sensitivity corresponding to a difference between the first and second exposure times.

4. The digital camera according to claim 1, wherein the main control part calculates the exposure condition to be applied to the regular imaging operation with compensation of the ISO sensitivity calculated in the first exposure condition calculating operation and the effective exposure time with execution of the second exposure condition calculating operation by calculating, as the effective exposure time, a first exposure time with provision of a condition that this exposure time is within a predetermined threshold value, and a second exposure time without providing said condition, and calculating necessary extent of controls of the ISO sensitivity and the effective exposure time corresponding to compensation of a difference between the first and second exposure times, taking at least the calculated value into consideration.

5. A digital camera comprising an imaging element for providing a photo-electric output corresponding to an image of a scene focused on an imaging surface of said imaging element, an exposure time control part for controlling an exposure time effective in the imaging element, a sensitivity control function part for controlling an ISO sensitivity of the camera corresponding to an amplification factor of the photo-electric output of the imaging element and a strobo part for projecting light onto the scene, the digital camera further comprising:

a main control part for collectively controlling a first exposure condition calculating operation for calculating proper exposure conditions in imaging by the imaging element including the effective exposure time and ISO sensitivity without preliminary light emission from the strobo part, a second exposure condition calculating operation of the exposure condition for compensating at least the ISO sensitivity among the exposure conditions calculated in the first exposure condition calculating operation by dimmer or light control operation with the preliminary light emission of the strobo part, and an operation of enabling exposure in the imaging element as a regular imaging operation under the exposure condition calculated and determined in the second exposure condition calculating operation,

the main control part executing, in a first control mode in which the effective exposure time is not limited to be within a predetermined threshold value, the calculating of the exposure condition to be applied to the regular imaging operation by compensating the effective exposure time calculated in the first exposure condition calculating operation, and executing, in a second control mode in which the effective exposure time is limited to be within the predetermined threshold value, the calculating of the exposure condition to be applied to the regular imaging operation with compensation of the ISO sensitivity calculated in the first exposure condition calculating operation by calculating, as effective exposure time, a first exposure time with provision of a condition that this exposure time is within a predetermined threshold, and a second exposure time without providing said condition, and calculating the necessary extent of control of the ISO sensitivity corresponding to the compensation of the difference between the first and second exposure times, taking at least the calculated value into consideration.

6. A digital camera comprising an imaging element for providing a photo-electric output corresponding to an image of a scene focused on an imaging surface of said imaging element, an exposure time control part for controlling an exposure time effective in the imaging element, a sensitivity control function part for controlling an ISO sensitivity of the camera corresponding to an amplification factor of a photo-electric output of the imaging element and a strobo part for projecting light onto the scene, the digital camera further comprising:

a main control part for collectively controlling a first exposure condition calculating operation for calculating proper exposure conditions in imaging by the imaging element including the effective exposure time and ISO sensitivity without preliminary light emission from the strobo part, a second exposure condition calculating operation of the exposure condition for compensating at least the ISO sensitivity among the exposure conditions calculated in the first exposure condition calculating operation by dimmer or light control operation with the preliminary light emission of the strobo part, and an operation of enabling exposure of the imaging element as a regular imaging operation under the exposure condition calculated and determined in the second exposure condition calculating operation,

the main control part calculating, in a first control mode in which the effective exposure time is not limited to be within a predetermined threshold value, the exposure condition to be applied to the regular imaging operation by compensating the effective exposure time calculated in the first exposure condition calculating operation, and executing, in a second control mode in which the effective exposure time is limited to be within the predetermined threshold value, the calculating of the exposure condition to be applied to the regular imaging operation with compensation of the ISO sensitivity calculated in the first exposure condition calculating operation and the effective exposed time by calculating, as effective exposure time, a first exposure time with provision of a condition that this exposure time is within a predetermined threshold, and a second exposure time without providing said condition, and calculating the necessary extent of control of the ISO sensitivity corresponding to the compensation of the difference between the first and second exposure times and the effective exposure time, taking at least the calculated value into consideration.

7. A method for operating digital camera comprising an imaging element for providing a photo-electric output corresponding to an image of a scene focused on an imaging surface of the imaging element, an exposure time control part for controlling the exposure time effective in the imaging element, a sensitivity control function part for controlling the ISO sensitivity of the camera corresponding to the amplification factor of the photo-electric output of the imaging element and a strobo part for projecting light onto the scene, the method comprising:

a) determining proper exposure conditions for imaging by the imaging element including an effective exposure time and ISO sensitivity with the strobo part being off,

b) compensating at least the ISO sensitivity among the exposure conditions determined in step (a) during emission of the strobo part, and (c) exposing the imaging element during a regular imaging operation employing the exposure condition determined at step (b).

8. The method of claim 7, wherein step (b) further comprises:

setting the exposure condition used for the regular imaging operation by compensating the effective exposure time determined in step (a).

9. The method of claim 7, wherein step (b) further comprises:

determining as the effective exposure time, a first exposure time with provision of a condition that said first exposure time is within a predetermined threshold value;

determining a second exposure time in the absence of said condition; and

controlling the ISO sensitivity corresponding to a difference between said first and second exposure times.

10. The method of claim 7 wherein step (b) further comprises:

determining a first exposure time with provision of a condition that said first exposure time is within a predetermined threshold value,

determining a second exposure time absent said condition, and

determining a necessary extent of controls of the ISO sensitivity and the effective exposure time corresponding to compensation of a difference between the first and second exposure times.

11. A method for operating a digital camera comprising an imaging element for providing a photo-electric output corresponding to an image of a scene focused on an imaging surface of the imaging element, an exposure time control part for controlling an effective exposure time for the imaging element, a sensitivity control function part for controlling the ISO sensitivity of the camera corresponding to the amplification factor of the photo-electric output of the imaging element and a strobo part for projecting light onto the scene, the method comprising:

a) determining proper exposure conditions for imaging by the imaging element including the effective exposure time and ISO sensitivity while the strobo part is off,

b) compensating at least the ISO sensitivity among the exposure conditions determined during step (a) by dimmer or light control operation during preliminary light emission of the strobo part, and

c) operating the control part for controlling exposure of the imaging element as a regular imaging operation based on the exposure condition determined during step (b),

step (b) further comprising;

determining the exposure condition to be employed during the regular imaging operation by compensating the effective exposure time determined during step (a) wherein the effective exposure time is not limited to be within a given threshold;

determining the exposure condition to be applied to the regular imaging operation wherein the effective exposure time is limited to be within the predetermined threshold value;

compensating the ISO sensitivity determined during step (a) by determining the first exposure time employing the condition that the first exposure time is within a predetermined threshold,

determining a second exposure time absent said condition, and

determining a necessary extent of control of the ISO sensitivity based upon the compensation of the difference between the first and second exposure times.

12. The method of claim 11 wherein at least a calculated value of the exposure time is taken into consideration when determining the necessary extent of control of the ISO sensitivity based upon the compensation of the difference between the first and second exposure time.

13. A method for operating a digital camera comprising an imaging element for providing a photo-electric output corresponding to an image of a scene focused on an imaging surface of said imaging element, an exposure time control part for controlling the exposure time effective in the imaging element, a sensitivity control function part for controlling the ISO sensitivity of the camera corresponding to the amplification factor of the photo-electric output of the imaging element and a strobo part for projecting light onto the scene, the method comprising:

a) determining proper exposure conditions for imaging by the imaging element including the effective exposure time and ISO sensitivity with the strobo part off,

b) compensating at least the ISO sensitivity among the exposure conditions determined in step (a) by dimmer or light control operation during a preliminary light emission of the strobo part, and

(c) operating the control part for controlling exposure of the imaging element as regular imaging operation under the exposure condition determined during step (b),

step (b) further comprising;

determining, during a first mode in which the effective exposure time is not limited to be within a predetermined threshold value, the exposure condition to be employed during step (c) by compensating the effective exposure time determined during step (a) and determining, in a second mode in which the effective exposure time is limited to be within the predetermined threshold value, the exposure condition to be employed during step (c) with compensation of the ISO sensitivity determined during step (a) and the effective exposed time by determining, as the effective exposure time, a first exposure time with provision of a condition that the first exposure time is within a predetermined threshold, and a second exposure time absent said condition, and determining the necessary extent of control of the ISO sensitivity based upon a compensation of the difference between the first and second exposure times and the effective exposed time.

14. The method of claim 13 wherein at least the calculated value of the ISO sensitivity is taken into consideration for determining the necessary extent of control of the ISO sensitivity.