Semiconductor image sensor with a plurality of different resolution areas

• US 6,320,618 B1
• Filed: 08/28/1997
• Issued: 11/20/2001
• Est. Priority Date: 08/30/1996
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Aoyama, Chiaki
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Harrington, Alicia M
• Application Number:
  US08/919,890
• Time in Patent Office: 1,545 Days
• Field of Search: 348/307, 348/308, 348/218, 348/335, 348/362, 348/229, 348/113
• US Class Current: 348/335
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/533 by using differing integration times for different sensor regions
• CPC Class Codes: H04N 25/58 involving two or more exposures
• CPC Class Codes: H04N 25/702 SSIS architectures characterised by non-identical, non-equidistant or non-planar pixel layout
• CPC Class Codes: H04N 25/745 Circuitry for generating timing or clock signals
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 25/7795 Circuitry for generating timing or clock signals
• CPC Class Codes: H04N 3/1512 for MOS image-sensors, e.g. MOS-CCD H04N3/1581 takes precedence
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

A semiconductor image sensor comprises a number of photosensitive elements which are provided as a two dimensional array on a substrate. This image sensor also comprises a plurality of different resolution areas in a single plane. This is made possible by changing the size or density of the photosensitive elements which are used for a respective different resolution areas in the array on the substrate. In this image sensor, an output from each photosensitive element as a pixel composes an image signal. Particularly, if this semiconductor image sensor is designed as a sensor for monitoring forward views of a vehicle, then the photosensitive portion is divided into a plurality of areas in a vertical direction so that a resultant imaging device is suitable for monitoring views from the front of a vehicle, comprising a high resolution area in the upper portion of the photosensitive portion where distant views are captured and subsequently lower resolution areas in the succeeding lower portions of the photosensitive portion where subsequently closer views are captured.

Claims

1. A semiconductor image sensor comprising:

a multiplicity of photosensitive elements provided as a two dimension array on a substrate, an output of each of said photosensitive elements being an image signal;

wherein;

a plurality of separate and different resolution areas are provided in a photosensitive portion on said substrate comprised of a like plurality and location of separate areas of different densities of said photosensitive elements in the array for sensing an entire image in said photosensitive portion;

said separate areas being arranged vertically, one above another, across the entire horizontal width of the photosensitive portion;

said separate areas located on an upper portion of said photosensitive portion in the vertical direction comprise high resolution areas for imaging objects at a distance from the sensor for a distant view, said high resolution areas having a high density of said photosensitive elements in both the vertical direction and the horizontal direction; and

said separate areas located on a lower portion of said photosensitive portion in the vertical direction comprise low resolution areas for imaging objects near the sensor for a near view, said low resolution areas having a low density of said photosensitive elements in both the vertical direction and the horizontal direction, and said low density of photosensitive elements being of a lower density than said high density of photosensitive elements in both the vertical and horizontal directions.

2. The semiconductor image sensor as set forth in claim 1 further comprising:

shutter-speed control circuits independently provided for each of said separate and different resolution areas;

wherein;

each of said shutter-speed control circuits is used to variably set a shutter speed for a respective separate and different resolution area of said separate and different resolution areas.

3. The semiconductor image sensor as set forth in claim 1 further comprising:

clock signal generators each independently provided for each of said separate and different resolution areas;

wherein;

a clock signal of each of said clock signal generators is used to variably set a framing time for a respective separate and different resolution area of said separate and different resolution areas.

4. The semiconductor image sensor as set forth in claim 1 further comprising:

a circuit for partially collecting outputs, i.e., image signals, of the photosensitive elements of at least a high-resolution area in said array so that such partially collected image signals can be used for magnification of a part of an image.

5. The semiconductor image sensor as set forth in claim 1 further comprising:

a circuit for grouping a plurality of adjacent photosensitive elements to extract therefrom a single unified image signal;

wherein;

one said separate and different resolution area on said substrate is a high-resolution area in which each photosensitive element gives an image signal; and

said one area is transformed to a low-resolution area when said circuit groups a plurality of adjacent photosensitive elements to produce a single unified image signal.

6. The semiconductor image sensor of claim 1, wherein said sensor is provided on a land vehicle and pointed substantial horizontally for sensing said entire image comprised of the land and objects from near the vehicle to said distance from the vehicle.

7. A semiconductor image sensor comprising, a two dimensional photosensitive area with an array of a multiplicity of photosensitive elements for sensing an entire image, said photosensitive area comprised of at least two separate areas arranged vertically, one above another, across the entire horizontal width of the photosensitive area, and each said separate area having a different number of said photosensitive elements per unit of area for causing different densities of said photosensitive elements in said separate areas for producing different levels of image resolution from different said separate areas for the entire image, said separate areas located on an upper portion of said photosensitive portion in the vertical direction comprise high resolution areas for imaging objects at a distance from the sensor for a distant view, said high resolution areas having a high density of said photosensitive elements in both the vertical direction and the horizontal direction, said separate areas located on a lower portion of said photosensitive portion in the vertical direction comprise low resolution areas for imaging objects near the sensor for a near view, said low resolution areas having a low density of said photosensitive elements in both the vertical direction and the horizontal direction, and said low density of photosensitive elements being of a lower density than said high density of photosensitive elements in both the vertical and horizontal directions.

8. The semiconductor image sensor of claim 7, wherein said at least two separate areas include a first rectangular area of one level of resolution and located directly above a second rectangular area of another level of resolution.

9. The semiconductor image sensor of claim 8, wherein said first and second rectangular areas comprise the entire said photosensitive area.

10. The semiconductor image sensor of claim 8, wherein a third rectangular area is located below said second rectangular area and has a level of resolution lower than said first and second rectangular areas.

11. The semiconductor image sensor of claim 10, wherein said first, second and third rectangular areas comprise the entire said photosensitive area.

12. The semiconductor image sensor of claim 7, wherein said sensor is provided on a land vehicle and pointed substantial horizontally for sensing said entire image comprised of the land and objects from near the vehicle to said distance from the vehicle.