Digital camera

• US 7,692,715 B2
• Filed: 03/10/2004
• Issued: 04/06/2010
• Est. Priority Date: 03/20/2003
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Kitajima, Tatsutoshi
• Primary Examiner(s): NGUYEN, LUONG TRUNG
• Application Number:
  US10/796,022
• Publication Number:
  US 20040239795A1
• Time in Patent Office: 2,218 Days
• Field of Search: 348/208.99, 348/364, 348/221.1
• US Class Current: 348/362
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/684 performed by controlling the image sensor readout, e.g. by controlling the integration time
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

A digital camera according to the present invention includes a device to set up a plurality of exposure conditions, a device to obtain a plurality of imaging data imaged in accordance with the plurality of exposure conditions set by the plurality exposure conditions set up device, and a device to compare a sharpness based on the plurality of imaging data obtained by the plurality of imaging data obtaining device, and a shake of the camera or a blur of a subject is determined corresponding to the comparison result of the sharpness comparison device.

Claims

1. A digital camera having an image forming device configured to image a subject by a setup exposure condition and a digital image processing device configured to convert imaging data from the image forming device into a digital image, the digital camera comprising:

a setup device configured to set up a plurality of exposure conditions,

an imaging data obtaining device configured to obtain a plurality of imaging data imaged in accordance with the plurality of exposure conditions set by the setup device, and

a sharpness comparison device configured to compare sharpness based on the plurality of imaging data obtained by the imaging data obtaining device, and to determine whether a difference in sharpness corresponding to different exposure times of the plurality of imaging data indicates one of a shake of the digital camera, a movement of the subject, and absence of a blur based on the compared sharpness,

wherein the sharpness comparison device compares a sharpness value corresponding to a first time period having a first exposure time with a sharpness value corresponding to a second time period having a second exposure time, and if the sharpness value for the first exposure time is greater than or equal to the sharpness value for the second exposure time, then it is determined that a blur has not occurred, and if the sharpness value for the first exposure time is less than the sharpness value for the second exposure time, then it is determined that a blur has occurred.

2. The digital camera according to claim 1, further comprising:

a handshake preventing exposure time output device configured to output an exposure time for preventing a blur in an image caused by the shake of the digital camera based on a focal length of a photographic lens in the image forming device,

wherein an existence of the camera shake is determined based on the exposure time output by the handshake preventing exposure time output device.

3. The digital camera according to claim 2, further comprising:

a warning device configured to warn of the shake of the digital camera when the existence of the shake of the digital camera is determined.

4. The digital camera according to claim 2, wherein when the existence of the shake of the digital camera is determined, a predetermined exposure time while recording a still image is shortened, and a strobe is flashed in accordance with shortening the predetermined exposure time.

5. The digital camera according to claim 2, wherein when a movement of the subject is determined to exist, a sensitivity for increasing the output of the imaging data while recording a still image is increased.

6. The digital camera according to claim 1, further comprising:

a display device configured to display an image processed by the digital image processing device,

wherein a display time to the display device is made constant regardless of an exposure time in the image forming device.

7. The digital camera according to claim 2, further comprising:

a display device configured to display an image processed by the digital image processing device,

wherein a display time to the display device is made constant regardless of an exposure time in the image forming device.

8. The digital camera according to claim 3, further comprising:

a display device configured to display an image processed by the digital image processing device,

wherein a display time to the display device is made constant regardless of an exposure time in the image forming device.

9. The digital camera according to claim 4, further comprising:

a display device configured to display an image processed by the digital image processing device,

wherein a display time to the display device is made constant regardless of an exposure time in the image forming device.

10. The digital camera according to claim 5, further comprising:

a display device configured to display an image processed by the digital image processing device,

wherein a display time to the display device is made constant regardless of an exposure time in the image forming device.

11. The digital camera according to claim 1, wherein when the sharpness comparison device determines that a blur has occurred, a second comparison is made between the sharpness value corresponding to the time period having the second exposure time and a sharpness value corresponding to a second time period having the second exposure time, and if the result of the second comparison is that the sharpness values are equal then it is determined that a shake of the digital camera has occurred, and if the result of the second comparison is that the sharpness values are not equal then it is determined that a movement of the subject has occurred.

12. A digital camera having an image forming device configured to image a subject by a setup exposure condition and a digital image processing device configured to convert imaging data from the image forming device into a digital image, the digital camera comprising:

a setup device configured to set up a plurality of exposure conditions,

an imaging data obtaining device configured to obtain a plurality of imaging data imaged in accordance with the plurality of exposure conditions set by the setup device, and

a sharpness comparison device configured to compare sharpness based on the plurality of imaging data obtained by the imaging data obtaining device, and to determine whether a difference in sharpness corresponding to different exposure times of the plurality of imaging data indicates one of a shake of the digital camera, a movement of the subject, and absence of a blur based on the compared sharpness,

wherein the sharpness comparison device compares a sharpness value corresponding to a first time period having a first exposure time with a sharpness value corresponding to a second time period having the first exposure time, and if the sharpness value for the first time period having the first exposure time and the sharpness value for the second time period having the first exposure time is the same then it is determined that a blur has not occurred.

13. A digital camera having an image forming device configured to image a subject by a setup exposure condition and a digital image processing device configured to convert imaging data from the image forming device into a digital image, the digital camera comprising:

a setup device configured to set up a plurality of exposure conditions,

an imaging data obtaining device configured to obtain a plurality of imaging data imaged in accordance with the plurality of exposure conditions set by the setup device, and

a sharpness comparison device configured to compare sharpness based on the plurality of imaging data obtained by the imaging data obtaining device, and to determine whether a difference in sharpness corresponding to different exposure times of the plurality of imaging data indicates one of a shake of the digital camera, a movement of the subject, and absence of a blur based on the compared sharpness,

wherein the sharpness comparison device compares a sharpness value corresponding to a first time period having a first exposure time with a sharpness value corresponding to a second time period having the first exposure time, and if the sharpness value for the first time period having the first exposure time and the sharpness value for the second time period having the first exposure time is the same then it is determined that a blur has not occurred, and

wherein when the sharpness comparison device determines that there is a difference between the sharpness value for the first time period having the first exposure time and the sharpness value for the second time period having the first exposure time, then a second comparison is made between a sharpness value corresponding to a first time period having a second exposure time and a sharpness value corresponding to a second time period having the second exposure time, and based on the result of the second comparison it is determined whether a difference in the sharpness values indicates one of a shake of the digital camera and a movement of the subject.