Image pickup apparatus

• US 20040165091A1
• Filed: 02/25/2003
• Published: 08/26/2004
• Est. Priority Date: 02/25/2002
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nishimaki, Akio, Takemura, Yasuo
• Application Number:
  US10/372,656
• Publication Number:
  US 20040165091A1
• Time in Patent Office: Days
• US Class Current: 348/296
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors

Abstract

An image pickup apparatus comprises an image pickup device for obtaining a first image signal picked up with a first exposure time and a second image signal picked up with a second exposure time different from the first exposure time, an image signal processing unit for conducting image signal processing on the first image signal and the second image signal and combining them into one image signal, a control unit for controlling the image pickup device and the image signal processing unit, and an image signal output unit for taking out the image signal subjected to the signal processing. The image pickup means includes a CMOS sensor, and the first image signal and the second image signal supplied from the image pickup means are subjected to photoelectric conversion, immediately output as signals and subjected to the signal processing in the image signal output unit.

Claims

1. An image pickup apparatus comprising:

image pickup means for obtaining a first image signal picked up with a first exposure time and a second image signal picked up with a second exposure time different from the first exposure time;

image signal processing means for conducting image signal processing on the first image signal and the second image signal and combining the first image signal and the second image signal into one image signal;

control means for controlling said image pickup means and said image signal processing means; and

image signal output means for taking out the image signal subjected to the signal processing in the image signal processing means,

said image pickup means including a CMOS sensor, wherein the first image signal and the second image signal supplied from the image pickup means are subjected to photoelectric conversion, immediately output as signals and subjected to the signal processing in the image signal output means.

2. The image pickup apparatus according to claim 1, wherein said control means comprises image signal information acquisition means for acquiring image signal information of the first image signal and the second image signal from the image pickup means and control signal generation means for varying the first image signal and the second image signal independently by using the image signal information acquired from the image signal information acquisition means and said control means controls the image signal processing means.

3. The image pickup apparatus according to claim 2, wherein said control signal generation means comprises:

automatic gain control signal generation means for individually controlling amplification factors of the first image signal and the second image signal supplied from the image pickup means, on the basis of a result of computation of a ratio between the first exposure time and the second exposure time;

characteristic conversion control signal generation means for individually conducting conversion control on input-output characteristics of the first image signal and the second image signal supplied from the image pickup means; and

image combination ratio control signal generation means for individually controlling an image signal combination ratio used to combine the first image signal and the second image signal supplied from the image pickup means.

4. The image pickup apparatus according to claim 1, wherein said control means comprises image signal information acquisition means for acquiring image signal information of the first image signal and image signal information of the second image signal from the image pickup means and luminance average value calculation means for calculating a luminance average value of the first image signal and the second image signal.

5. The image pickup apparatus according to claim 4, wherein said image signal information acquisition means includes means for dividing a picture obtained by image pickup into a plurality of parts in order to acquire a luminance average value of each of the first image signal and the second image signal in luminance average value calculation means, and wherein said image signal information acquisition means comprises divided image luminance accumulation means for accumulating luminance of a divided image every divided picture division and divided image luminance peak value detection means for detecting a luminance peak value of a divided image, and said image signal information acquisition means calculates a luminance average value of each of the first image signal and the second image signal on the basis of a luminance accumulation result obtained by the divided image luminance accumulation means and a luminance peak value detection result obtained by the divided image luminance peak value detection means.

6. The image pickup apparatus according to claim 4, wherein said image signal information acquisition means includes means for dividing a picture obtained by image pickup into a plurality of parts in order to acquire a luminance average value of each of the first image signal and the second image signal in a luminance average value calculation means, and wherein said image signal information acquisition means comprises divided image luminance accumulation means for accumulating luminance of a divided image every divided picture division and divided image luminance peak value detection means for detecting a luminance peak value of a divided image, and when calculating a luminance average value in the luminance average value calculation means for obtaining a luminance average value of each of the first image signal and the second image signal, on the basis of luminance accumulation result of the divided image and the luminance peak value detection result of the divided image, said image signal information acquisition means extracts a high luminance area of the first image signal, calculates a luminance average value of the first image signal with the extracted area excluded, and calculates a luminance average value for an area of the second image signal corresponding to the extracted high luminance area of the first image signal.

7. The image pickup apparatus according to claim 1, wherein said control means comprises image signal information acquisition means for acquiring image signal information of the first image signal and image signal information of the second image signal from the image pickup means and said image signal information acquisition means divides a picked-up picture into a plurality of parts, acquires image information for each of picture divisions and acquires image signal information of the first image signal and the second image signal by using the image information for each of the picture divisions.

8. The image pickup apparatus according to claim 1, wherein said control means comprises image signal information acquisition means for acquiring image signal information of the first image signal and image signal information of the second image signal from the image pickup means, and said image signal information acquisition means comprises divided image luminance accumulation means and divided image luminance peak value detection means as means for dividing a picked-up picture into a plurality of parts and acquiring image information for each of picture divisions.

9. The image pickup apparatus according to claim 1, wherein said control means comprises computation means for calculating a ratio between the first exposure time and the second exposure time, and said control means independently varies the first exposure time and the second exposure time by using a result of calculation conducted in said computation means.

10. The image pickup apparatus according to claim 1, wherein said control means comprises computation means for calculating a ratio between the first exposure time and the second exposure time, and in order to obtain a suitable image signal, said control means executes a result of calculation conducted in said computation means on the basis of image information acquired by the image signal information acquisition means for acquiring image signal information of the first image signal and image signal information of the second image signal from the first image signal and the second image signal.

11. The image pickup apparatus according to claim 1, wherein said control means comprises computation means for calculating a ratio between the first exposure time and the second exposure time when varying the first exposure time and the second exposure time independently and automatic gain control signal generation means for individually controlling amplification factors of the first image signal and the second image signal obtained by said image pickup means, on the basis of a result of calculation conducted by the computation means.

12. The image pickup apparatus according to claim 1, wherein said control means comprises computation means for calculating a ratio between the first exposure time and the second exposure time and characteristic conversion control signal generation means for individually conducting conversion and control on input-output characteristics of the first image signal and the second image signal obtained by the image pickup means, on the basis of a result of calculation conducted by the computation means.

13. The image pickup apparatus according to claim 1, wherein said control means comprises computation means for calculating a ratio between the first exposure time and the second exposure time when varying the first exposure time and the second exposure time independently and image combination ratio control signal generation means for individually controlling an image signal combination ratio used to combine the first image signal and the second image signal obtained by the image pickup means, on the basis of a result of calculation conducted by the computation means.

14. The image pickup apparatus according to claim 1, wherein said control means includes means for shifting final generation timing of an electronic shutter so as to determine the first exposure time and the second exposure time, by taking one CLOCK of a timing generator as unit.

15. The image pickup apparatus according to claim 1, wherein said image signal processing means comprises:

an automatic gain control circuit provided on a signal path of the first image signal and the second image signal so as to control gains of the first image signal and the second image signal;

input-output characteristic conversion circuits each provided on each of signal paths of the first image signal and the second image signal subjected to gain control in the automatic gain control circuit so as to control input-output characteristics of the first image signal and the second image signal; and

image signal combination means for combining the first image signal and the second image signal subjected to input-output characteristic conversion in the input-output characteristic conversion circuits into one image signal.

16. An image pickup apparatus comprising:

image pickup means, installed on a moving body, for picking up an image, said image pickup means including a CMOS sensor;

area selection and extraction means for selecting and extracting an arbitrary area from a picture range included in an image signal corresponding to one picture picked up by the image pickup means; and

image signal output means for conducting signal processing on an image signal selected and extracted by said area selection and extraction means and outputting a resultant signal.

17. The image pickup apparatus according to claim 16, wherein said image pickup means outputs the image signal obtained by the image pickup means immediately after photoelectric conversion, said image signal output means conducting signal processing on the image signal output from the image pickup means and then outputting a resultant image signal.

18. The image pickup apparatus according to claim 16, wherein said area selection and extraction means includes means for selecting and extracting an arbitrary area of the image signal picked up by the image pickup means so as to narrow down information contents of the image signal, said image signal processing means conducting signal processing and then outputting a resultant signal.

19. The image pickup apparatus according to claim 16, wherein said moving body is a moving vehicle including an automatic two-wheeled vehicle, an automobile, or a train, or an aeroplane or a ship.