Imaging apparatus for capturing an object with low luminance by adding pixels of the same color from different fields

• US 7,345,704 B2
• Filed: 01/22/2004
• Issued: 03/18/2008
• Est. Priority Date: 01/29/2003
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Sakaguchi, Norihiro
• Primary Examiner(s): Villecco; John M.
• Application Number:
  US10/761,329
• Publication Number:
  US 20050078201A1
• Time in Patent Office: 1,517 Days
• Field of Search: 348/229.1, 348/216.1, 348363-366, 348/208.12, 348/216, 348/273, 348/280, 348/281
• US Class Current: 348/282
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 23/951 by using two or more images to influence resolution, frame rate or aspect ratio
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements

Abstract

In the present invention, first of all, an image in each field is monitored by carrying out monitoring. An evaluation value of an AE is calculated from a result of the monitoring, and if the result of the calculation shows that the image is not in low luminance, data in each of the fields is read out by carrying out an exposure, and a normal process for a still image is performed. If the result of the calculation shows that the image is in the low luminance, the exposure and read out of the field data such as a difference in a luminance in each of the fields are carried out, and first and second field data are compared. Then, whether an object moves or not is determined from a result of the comparison, and if the object is determined to be moved, the normal process for the still image is performed. If the object is determined not to be moved, the entire field data from the first to third field data are added.

Claims

1. An imaging apparatus, comprising:

a color image pick-up device constituting an image in one frame by a plurality of fields for imaging an image of an object and having an output capable of carrying out a playback of an image in each of said fields;

a driving circuit for driving the color image pick-up device;

a timing generating circuit for generating a drive timing of said color image pick-up device; and

a signal processing device for processing an output signal of said color image pick-up device,

wherein pixels of a same color in each of all said fields are added when a luminance of said image of the object is determined to be low and when the object is determined to be not moving according to a comparison between outputted images which are in adjacent fields of said color image pick-up device.

2. The imaging apparatus according to claim 1, wherein said color image pick-up device is operated only when a size of a file which can be played in one field is selected.

3. The imaging apparatus according to claim 1, further comprising a device for selecting whether or not to add pixels at a time of low luminance which is capable of selecting whether or not to add the pixels of the same color in each of all said fields.

4. An imaging apparatus, comprising:

a color image pick-up device constituting an image in one frame by a plurality of fields for imaging an image of an object and having an output capable of carrying out a playback of an image in each of said fields;

a driving circuit for driving the color image pick-up device;

a timing generating circuit for generating a drive timing of said color image pick-up device; and

a signal processing device for processing an output signal of said color image pick-up device,

wherein pixels of a same color in each of all said fields are added after re-exposing a next field which is the next field of adjacent fields of said color image pick-up device when a luminance of said image of the object is determined to be low and when the object is determined to be not moving according to a comparison between outputted images which are in said adjacent fields of said color image pick-up device.

5. The imaging apparatus according to claim 4, further comprising a variable clock generator capable of generating multiple clock frequencies for said timing generating circuit;

wherein the pixels of the same color in each of all said fields are added after lowering a speed of a clock frequency of said timing generating circuit and re-exposing the next field which is the next of the adjacent fields of said color image pick-up device when the luminance of said image of the object is determined to be low and when the object is determined to be not moving according to a comparison between the outputted images which are in said adjacent fields of said color image pick-up device.

6. An imaging apparatus, comprising:

a color image pick-up device constituting an image in one frame by a plurality of fields for imaging an image of an object and having an output capable of carrying out a playback of an image in each of said fields;

a driving circuit for driving the color image pick-up device;

a timing generating circuit for generating a drive timing of said color image pick-up device;

a signal processing device for processing an output signal of said color image pick-up device; and

a controller configured to add pixels of a same color in each of all said fields when a luminance of said image of the object is determined to be low and when the object is determined to be not moving according to a comparison between outputted images which are in adjacent fields of said color image pick-up device.

7. The imaging apparatus according to claim 6, further comprising a variable clock generator capable of generating multiple clock frequencies for said timing generating circuit,

wherein the controller adds the pixels of the same color in each of all said fields after lowering a speed of a clock frequency of said timing generating circuit and re-exposing the next field which is the next field of the adjacent fields of said color image pick-up device which the luminance of said image of the object is determined to be low and when the object is determined to be not moving according to the comparison between the outputted images which are in said adjacent fields of said color image pick-up device.

8. The imaging apparatus according to claim 6, wherein said color image pick-up device is operated only when a size of a file which can be played in one field is selected.

9. The imaging apparatus according to claim 6, further comprising a device for selecting whether or not to add pixels at a time of low luminance which is capable of selecting whether or not to add the pixels of the same color in each of all said fields.

10. An imaging apparatus, comprising:

a color image pick-up device constituting an image in one frame by a plurality of fields for imaging an image of an object and having an output capable of carrying out a playback of an image in each of said fields;

a driving circuit for driving the color image pick-up device;

a timing generating circuit for generating a drive timing of said color image pick-up device;

a signal processing device for processing an output signal of said color image pick-up device; and

a controller configured to add pixels of same color in each of all said fields after re-exposing a next field which is next of adjacent fields of said color image pick-up device when a luminance of said image of the object is determined to be low and when the object is determined to be not moving according to a comparison between outputted images which are in said adjacent fields of said color image pick-up device.