Solid-state imaging apparatus for motion detection

• US 6,753,904 B1
• Filed: 07/28/1999
• Issued: 06/22/2004
• Est. Priority Date: 12/08/1997
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nomura, Hitoshi
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Villecco, John M.
• Application Number:
  US09/363,304
• Time in Patent Office: 1,791 Days
• Field of Search: 348/169, 348/170, 348/171, 348/172, 348/208.1, 348/208.14, 348/208.16, 348/155, 348/302, 348/303, 348/304, 348/319, 348/320, 348/321, 382/107
• US Class Current: 348/208.1
• CPC Class Codes: H04N 25/40 Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled
• CPC Class Codes: H04N 25/707 Pixels for event detection
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

A solid-state imaging apparatus for motion detection that detects motion based on differences between pixel frames to make external image comparison processing unnecessary and to reduce erroneous detection of motion is disclosed. The solid-state imaging apparatus includes a plurality of photoreceptive units arranged in a matrix of rows and columns, a plurality of vertical read lines disposed on each column of the plurality of photoreceptive units, a vertical transfer circuit that sequentially selects a specified row of the plurality of photoreceptive units and successively outputs to a vertical read line a previous pixel output, saved from a previous exposure of incident light on the photoreceptors, and a current pixel output newly generated from exposure of incident light on the photoreceptors, a comparison circuit that compares the previous pixel output and the current pixel output transferred by time division via the vertical read lines, a horizontal transfer circuit which serially transfers the comparison circuit'"'"'s signals, and a logical calculation circuit that performs a logical calculation on the comparison circuit'"'"'s signals and reduces the isolated regions of logical change to provide an object motion signal.

Claims

1. An imaging apparatus for detecting motion of objects in an image field, comprising:

an imaging unit having a plurality of pixels, wherein the imaging unit provides an image signal corresponding to a pixel output generated by incident light from the image field that is incident on the imaging unit, and wherein the imaging unit compares plural pixel outputs from a first pixel of the plurality of pixels and provides a motion signal indicative of a change in the incident light; and

a motion signal processing circuit that receives plural image signals and motion signals associated with the first pixel and controls output of the motion signals to an output terminal in accordance with a value of the image signals, wherein the motion signal processing circuit controls output of the motion signals so as to provide motion signals to the output terminal when the value of corresponding image signals is indicative of a brightness level that is within a predetermined range.

2. The imaging apparatus of claim 1, wherein the value of an image signal that is indicative of the brightness level that is within the predetermined range corresponds to a change in the image field.

3. The imaging apparatus of claim 1, wherein the imaging unit further comprises:

a plurality of photoreceptors, wherein the pixel output is generated by the incident light on the photoreceptors; and

a plurality of read lines coupled to a first group set of the photoreceptors;

a first transfer circuit that selects a second group set of the photoreceptors and outputs to the read lines a first pixel output and a second pixel output;

a plurality of comparison circuits in communication with a respective plurality of read lines that receives and compares the first pixel output and the second pixel output;

a second transfer circuit that transfers outputs of the comparison circuits; and

an image signal output circuit that transfers either the first pixel output or the second pixel output sequentially transferred via the aforesaid read lines.

4. The imaging apparatus of claim 3, wherein the motion signal processing circuit includes a data selector and a voltage comparator.

5. An imaging apparatus for detecting motion of objects in an image field, comprising:

an imaging unit having a plurality of pixels, wherein the imaging unit provides an image signal corresponding to a pixel output generated by incident light from the image field that is incident on the imaging unit, and wherein the imaging unit compares plural pixel outputs from a first pixel of the plurality of pixels and provides a motion signal indicative of a change in the incident light; and

a motion signal processing circuit that receives plural image signals and motion signals associated with the first pixel and controls output of the motion signals to an output terminal in accordance with a value of the image signals, wherein the motion signal processing circuit control output of the motion signals so as to block output of the motion signals when the value of corresponding image signals is indicative of a brightnes level that is outside the predetermined range.

6. The imaging apparatus of claim 5, wherein the value of an image signal that is indicative of the brightness level that is outside the predetermined range corresponds to no change in the image field.