Image pickup apparatus

• US 7,505,680 B2
• Filed: 06/14/2006
• Issued: 03/17/2009
• Est. Priority Date: 06/16/2005
• Status: Expired due to Fees

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Niwa, Toshio
• Primary Examiner(s): Assouad; Patrick J
• Assistant Examiner(s): Strieb; Michael A
• Application Number:
  US11/452,274
• Publication Number:
  US 20060285845A1
• Time in Patent Office: 1,007 Days
• Field of Search: 396/155, 396/164, 396/175, 396/176, 396/439, 362/18, 362/16, 348/371
• US Class Current: 396/155
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation

Abstract

An image pickup apparatus includes an imaging optical system, an image sensor, an image signal processing section and a light-amount characteristic giving section. The imaging optical system has a distortion in such a way as to form an image whose center part is stretched, and whose peripheral part is squeezed. The image sensor has a light reception surface at which a subject image is formed through the imaging optical system, and converts the formed subject image into image signals. The image signal processing section performs an image processing for correcting the image signals with respect to the distortion. The light-amount characteristic giving section gives the subject image a characteristic in which the amount of light at a center part of the subject image formed at the light-reception surface of the image sensor is larger than that at a peripheral part of the subject image.

Claims

1. An image pickup apparatus comprising:

an imaging optical system having a distortion in which a center part of an image is stretched, and a peripheral part of the image is squeezed;

an image sensor including a light reception surface at which an image of a subject is formed as a subject image through the imaging optical system, and configured to convert the subject image formed at the light reception surface into image signals;

an image signal processing section configured to perform an image processing to correct a distortion of an image corresponding to the image signals; and

a light-amount characteristic giving section configured to give the subject image a characteristic in which an amount of light at a center part of the subject image formed at the light reception surface of the image sensor is larger than that at a peripheral part of the subject image.

2. The image pickup apparatus according to claim 1, wherein the light-amount characteristic giving section includes a light-emitting section configured to illuminate the subject by applying light to the subject such that an amount of light applied to a center part of the subject is larger than that of light applied to a peripheral part of the subject.

3. The image pickup apparatus according to claim 2, wherein the light-emitting section comprises:

a first light-emitting section configured to illuminate only the center part of the subject; and

a second light-emitting section configured to illuminate both the center part and peripheral part of the subject.

4. The image pickup apparatus according to claim 1, wherein the light-amount characteristic giving section includes an optical filter which passes light reflected from the subject, and an amount of light which is transmitted from the center part of the subject through the optical filter is larger than that from the peripheral part of the subject through the optical filter.

5. The image pickup apparatus according to claim 2, wherein the light-amount characteristic giving section includes an optical filter which passes light reflected from the subject, and an amount of light which is transmitted from the center part of the subject through the optical filter is larger than that from the peripheral part of the subject through the optical filter.

6. An image pickup apparatus comprising:

imaging optical means having a distortion in which a center part of an image is stretched, and a peripheral part of the image is squeezed;

image pickup means including a light reception surface at which an image of a subject is formed as a subject image through the imaging optical means, and for converting the subject image formed at the light reception surface into image signals;

image signal processing means for performing an image processing to correct a distortion of an image corresponding to the image signals; and

light-amount characteristic giving means for giving the subject image a characteristic in which an amount of light at a center part of the subject image formed at the light reception surface of the image sensor is larger than that at a peripheral part of the subject image.

7. The image pickup apparatus according to claim 6, wherein the light-amount characteristic giving means includes light-emitting means for illuminating the subject by applying light to the subject such that an amount of light applied to a center part of the subject is larger than that of light applied to a peripheral part of the subject.

8. The image pickup apparatus according to claim 7, wherein the light-emitting means comprises:

first light-emitting means for illuminating only the center part of the subject; and

second light-emitting means for illuminating both the center part and peripheral part of the subject.

9. The image pickup apparatus according to claim 6, wherein the light-amount characteristic giving means includes optical filter means for passing light reflected from the subject, and an amount of light which is transmitted from the center part of the subject through the optical filter means is larger than that from the peripheral part of the subject through the optical filter means.

10. The image pickup apparatus according to claim 7, wherein the light-amount characteristic giving means includes optical filter means for passing light reflected from the subject, and an amount of light which is transmitted from the center part of the subject through the optical filter means is larger than that from the peripheral part of the subject through the optical filter means.