Arrangement comprising a sensor matrix

• US 5,572,257 A
• Filed: 03/03/1995
• Issued: 11/05/1996
• Est. Priority Date: 06/03/1991
• Status: Expired due to Term

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Conrads, Norbert, Wieczorek, Herfried, Schiebel, Ulrich
• Primary Examiner(s): Razavi, Michael T.
• Assistant Examiner(s): SHALWALA, BIPIN H
• Application Number:
  US08/400,427
• Time in Patent Office: 613 Days
• Field of Search: 348/294, 348/299, 348/302-304, 348/308-310, 348/314, 250/208.1
• US Class Current: 348/308
• CPC Class Codes: H04N 25/626 Reduction of noise due to residual charges remaining after image readout, e.g. to remove ghost images or afterimages
• CPC Class Codes: H04N 25/74 Circuitry for scanning or addressing the pixel array
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30

Abstract

In an arrangement of light-sensitive or X-ray sensitive sensors (S₁,1, . . . , S₂₀₄₈,2048) arranged in a matrix in rows and columns, which sensors produce charge states in dependence upon the amount of incident radiation and each have an electrical switch, for each sensor row a switching line (33₁, . . . , 33₂₀₄₈) via which the switches (3) can be activated so that the charge states of the sensors of the activated sensor row are read or reset simultaneously via associated read lines (8, 9, 10), there is provided a reset device (30a, 30b) for resetting the charge states of previously read sensor rows, which device activates at least one of the previously read sensor rows, which activates another of the previously read sensor rows after a predetermined number of clock pulses of a reset clock signal (T₃₂), and which deactivates each activated sensor row a predetermined number of clock pulses after its activation.

Claims

1. An apparatus comprising light-sensitive or X-ray sensitive sensors arranged in a matrix in rows and columns, which sensors produce charge states in dependance upon the amount of incident radiation, each sensor having its own electrical switch, and each row of sensors having an associated switching line of a plurality of switching lines coupled to a control device for selectively activating rows for reading purposes and for selectively activating rows for resetting purposes by controlling the conductive state of said switch of each sensor in an activated row in a manner that for said reading purposes, charge states of the sensors of the activated row are read simultaneously via a plurality of read lines coupled to said switch of the sensors in the activated row, and in the course of reading, these charge states are changed at least partially toward an initial charge state, and for said resetting purposes, the charge states of previously read rows of sensors are changed substantially completely to the initial charge state, and wherein said control device comprises reset means, responsive to successive clock pulses of a reset clock signal, for activating at least one of the previously read rows via said switches of the sensors of the activated previously read row, for, after a first predetermined number of successive clock pulses of the reset clock signal, activating another of the previously read rows, and for deactivating each activated previously read row a second predetermined number of successive clock pulses of the reset clock signal after activating the previously read row.

2. An apparatus as claimed in claim 1, wherein the reset means comprises a shift register device having a clock input for receiving the reset clock signal, an input side for receiving a further pulse signal in the clock rhythm of the reset clock signal, and respective outputs coupled to the respective switching lines, said shift register device comprising means for causing each pulse of the further pulse signal to appear on said respective outputs shifted in time.

3. An apparatus as claimed in claim 1, wherein said read lines are arranged such that the sensors of each column of the matrix have an associated common one of the read lines, and wherein the reset means comprises means for resetting all the sensor rows via said read lines.

4. An apparatus as claimed in claim 1, wherein the reset means comprises means for initially activating one row of sensors and subsequently, after the first predetermined number of clock pulses, activating another of the rows while the initially activated row remains activated.

5. An apparatus as claimed in claim 4, wherein the reset clock signal has a frequency which is higher than a cycling frequency with which the rows are activated successively during the read process.

6. An apparatus as claimed in claim 1, wherein the reset means comprises means for initially activating a third predetermined number, greater than one, of rows of sensors and subsequently, after the first predetermined number of clock pulses, activating said third predetermined number of further rows.

7. An apparatus as claimed in claim 2, wherein the shift-register device comprises a plurality of shift registers associated with respective different groups of the plurality of switch lines, each shift register having a clock input for receiving the reset clock signal, an input side for receiving a further pulse signal in the clock rhythm of the reset clock signal, and respective outputs coupled to respective switching lines of the group associated with the shift register, and means for coupling the input sides of the shift registers to the input side of the shift register, whereby the further pulse signal received at the input side of the shift-register device is applied simultaneously to the input sides of each of the plurality of shift registers, each shift register comprising means for causing each pulse of the further pulse signal to traverse the shift registers in the clock rhythm of the reset clock signal, whereby said further pulse signal appears on the respective outputs of said shift register, successively shifted in time.

8. An apparatus as claimed in claim 1, wherein the reset means also serves for reading the charge states of the sensor during the read process.

9. An apparatus as claimed in claim 8, wherein the frequency of the reset clock signal is equal to a cycling frequency with which the sensor rows are activated successively during the read process.

10. An apparatus as claimed in claim 2, wherein said read lines are arranged such that the sensors of each column of the matrix have an associated common one of the read lines, and wherein the reset means comprises means for resetting all the sensor rows via said read lines.

11. An apparatus as claimed in claim 2, wherein the reset means comprises means for initially activating one row of sensors and subsequently, after the first predetermined number of clock pulses, activating another of the rows while the initially activated row remains activated.

12. An apparatus as claimed in claim 3, wherein the reset means comprises means for initially activating one row of sensors and subsequently, after the first predetermined number of clock pulses, activating another of the rows while the initially activated row remains activated.

13. An apparatus as claimed in claim 11, wherein the reset clock signal has a frequency which is higher than a cycling frequency with which the rows are activated successively during the read process.

14. An apparatus as claimed in claim 12, wherein the reset clock signal has a frequency which is higher than a cycling frequency with which the rows are activated successively during the read process.

15. An apparatus as claimed in claim 2, wherein the reset means comprises means for initially activating a third predetermined number, greater than one, of rows of sensors and subsequently, after the first predetermined number of clock pulses, activating said third predetermined number of further rows.

16. An apparatus as claimed in claim 3, wherein the reset means comprises means for initially activating a third predetermined number, greater than one, of rows of sensors and subsequently, after the first predetermined number of clock pulses, activating said third predetermined number of further rows.

17. An apparatus as claimed in claim 10, wherein the reset means comprises means for initially activating a third predetermined number, greater than one, of rows of sensors and subsequently, after the first predetermined number of clock pulses, activating said third predetermined number of further rows.

18. An apparatus as claimed in claim 16, wherein the shift-register device comprises a plurality of shift registers associated with respective different groups of the plurality of switch lines, each shift register having a clock input for receiving the reset clock signal, an input side for receiving a further pulse signal in the clock rhythm of the reset clock signal, and respective outputs coupled to respective switching lines of the group associated with the shift register, and means for coupling the input sides of the shift registers to the input side of the shift register, whereby the further pulse signal received at the input side of the shift-register device is applied simultaneously to the input sides of each of the plurality of shift registers, each shift register comprising means for causing each pulse of the further pulse signal to traverse the shift registers in the clock rhythm of the reset clock signal, whereby said further pulse signal appears on the respective outputs of said shift register, successively shifted in time.

19. An apparatus as claimed in claim 15, wherein the shift-register device comprises a plurality of shift registers associated with respective different groups of the plurality of switch lines, each shift register having a clock input for receiving the reset clock signal, an input side for receiving a further pulse signal in the clock rhythm of the reset clock signal, and respective outputs coupled to respective switching lines of the group associated with the shift register, and means for coupling the input sides of the shift registers to the input side of the shift register, whereby the further pulse signal received at the input side of the shift-register device is applied simultaneously to the input sides of each of the plurality of shift registers, each shift register comprising means for causing each pulse of the further pulse signal to traverse the shift registers in the clock rhythm of the reset clock signal, whereby said further pulse signal appears on the respective outputs of said shift register, successively shifted in time.

20. An apparatus as claimed in claim 16, wherein the shift-register device comprises a plurality of shift registers associated with respective different groups of the plurality of switch lines, each shift register having a clock input for receiving the reset clock signal, an input side for receiving a further pulse signal in the clock rhythm of the reset clock signal, and respective outputs coupled to respective switching lines of the group associated with the shift register, and means for coupling the input sides of the shift registers to the input side of the shift register, whereby the further pulse signal received at the input side of the shift-register device is applied simultaneously to the input sides of each of the plurality of shift registers, each shift register comprising means for causing each pulse of the further pulse signal to traverse the shift registers in the clock rhythm of the reset clock signal, whereby said further pulse signal appears on the respective outputs of said shift register, successively shifted in time.