CMOS TDI image sensor

• US 6,906,749 B1
• Filed: 09/10/1999
• Issued: 06/14/2005
• Est. Priority Date: 09/16/1998
• Status: Expired due to Term

• Current Assignee: Teledyne Digital Imaging, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: Dalsa Incorporated (Teledyne Technologies Incorporated)
• Inventors: Fox, Eric
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Henn, Timothy J.
• Application Number:
  US09/393,311
• Time in Patent Office: 2,104 Days
• Field of Search: 348/295, 348/302
• US Class Current: 348/295
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 25/768 for time delay and integration [TDI]
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

A column slice of a CMOS TDI sensor includes a column bus, a column of pixels, plural first switches, a column of accumulators, plural second switches, plural third switches and output bus 39. Each of the plural first switches is coupled between the column bus and a corresponding pixel of the column of pixels, and each of the plural second switches is coupled between the column bus and a corresponding accumulator of the column of accumulators. In operation, only one switch at a time of plural first switches is “on” to connect the voltage signal from a corresponding pixel to the column bus while all remaining plural first switches are “off” to isolate the column bus from all remaining pixels. Only one of the plural second switches is “on” to connect the signal on the column bus to an accumulator while all remaining plural second switches are “off” to isolate the bus from all remaining accumulators. A main control circuit includes first and second shift registers to control the plural first and second switches to couple a signal from each pixel of the column of pixels into a corresponding accumulator of the column of accumulators while updating the accumulator until signals from all pixels have been transferred into corresponding accumulators. After this update cycle, an accumulated signal from the one accumulator that is currently addressed by a third shift register is read to the output. Then, the first and third shift registers are incremented. A new update cycle begins when a point in a moving image focused on the column slice crosses a pixel boundary. The same pattern repeats continuously. Valid TDI data is produced at the output after a number of full cycles of the transfer of pixels signals to the accumulators has been complete, the number being equal to the number of pixels.

Claims

1. A sensor comprising:

a column bus;

a column of pixels;

a first plurality of switches, each switch being coupled between the column bus and a corresponding pixel of the column of pixels;

a column of accumulators;

a second plurality of switches, each switch being coupled between the column bus and a corresponding accumulator of the column of accumulators;

a first switch control circuit operable to control a switch of the first plurality of switches to connect the signal from the pixel of the column of pixels to the column bus while controlling all remaining switches of the first plurality of switches to isolate the column bus from all remaining pixels of the column of pixels;

a second switch control circuit operable to control a switch of the second plurality of switches to connect the signal on the column bus to the accumulator of the column of accumulators while controlling all remaining switches of the second plurality of switches to isolate the column bus from all remaining accumulators of the column of accumulators;

a first increment control circuit operable to increment the first switch control circuit to control a next in succession switch of the first plurality of switches to connect a signal from a next in succession pixel of the column of pixels to the column bus while controlling all remaining switches of the first plurality of switches to isolate the column bus from all remaining pixels of the column of pixels;

a second increment control circuit operable to increment the second switch control circuit to control a next in succession switch of the second plurality of switches to connect the signal on the column bus to a next in succession accumulator of the column of accumulators while controlling all remaining switches of the second plurality of switches to isolate the column bus from all remaining accumulators of the column of accumulators;

a first repeat control circuit operable to repetitively operate the first increment control circuit, the first switch control circuit, the second increment control circuit, and the second switch control circuit; and

a second repeat control circuit operable to operate the first increment control circuit and then operate the first repeat control circuit each time the second repeat control circuit is operated.

2. The sensor of claim 1, wherein the second repeat control circuit operates each time a point in a moving image projected on the column of pixels transverses a pixel boundary.

3. The sensor of claim 2, wherein the second repeat control circuit repetitively operates until the point in the moving image traverses the column of pixels.

4. The sensor of claim 1 further comprising:

an output bus; and

a third plurality of switches, each switch being coupled between the output bus and a corresponding accumulator of the column of accumulators.

5. The sensor of claim 4 further comprising a third switch control circuit operable to control a switch of the third plurality of switches to connect the accumulated signal from the accumulator of the column of accumulators to the output bus while controlling all remaining switches of the third plurality of switches to isolate the output bus from all remaining accumulators of the column of accumulators.

6. The sensor of claim 5 further comprising a third increment control circuit operable to increment the third switch control circuit to control a next in succession switch of the third plurality of switches to connect the accumulated signal at a next in succession accumulator of the column of accumulators to the output bus while controlling all remaining switches of the third plurality of switches to isolate the output bus from all remaining accumulators of the column of accumulators.

7. The sensor of claim 6, wherein:

the second repeat control circuit repetitively operates the third increment control circuit and the third switch control circuit; and

each repetitive operation of the third switch control circuit couples a signal from a successive accumulator of the column of accumulators.

8. The sensor of claim 7, wherein each time the second repeat control circuit is operated, the second repeat control circuit repetitively operates the third increment control circuit and the third switch control circuit until all accumulators of the column of accumulators have been successively coupled onto the output bus.

9. The sensor of claim 8, wherein the second repeat control circuit operates each time a point in a moving image projected on the column of pixels transverses a pixel boundary.

10. The sensor of claim 9, wherein the second repeat control circuit repetitively operates until the point in the moving image traverses the column of pixels.