Methods and apparatus for charge coupled device image acquisition with independent integration and readout
AssigneeCognex Corporation
InventorDavid R. King
Life of this patent
Estimating the term…
Abstract
Methods and apparatus for image acquisition utilize a charge coupled device having a photosensitive region that responds to an applied transfer signal by transferring charge accumulated on the collection sites to the corresponding readout sites. The non-photosensitive region responds to a read signal, applied independently of the transfer signal, by outputting (e.g., to the host camera or image acquisition system) charges on the readout sites. The methods and apparatus take advantage of the inherent storage capability of the non-photosensitive sites by using them to hold image information pending application of the readout signal, thereby, conserving host resources.
Claims35
An image acquisition apparatus comprising:
- A. a charge coupled device including a photosensitive region having one or more photosensitive charge collection sites, a non-photosensitive region having one or more non-photosensitive readout sites, the readout sites being coupled any of directly and indirectly to corresponding charge collection sites, the photosensitive region responding to an applied transfer signal for moving charges accumulated on the charge collection sites to corresponding non-photosensitive readout sites, the non-photosensitive region responding to a read signal applied independently of the transfer signal for outputting charges from the readout sites,
- B. a head unit, coupled to the charge coupled device, that generates an image signal based on charges output from the readout sites.
An image acquisition apparatus comprising:
- A. a plurality of head units, each including a charge coupled device, and each that generates an image signal from charges output from readout sites of the respective charge coupled device,
- B. each charge coupled device including a photosensitive region having one or more photosensitive charge collection sites, a non-photosensitive region having one or more non-photosensitive readout sites, the readout sites being coupled to corresponding charge collection sites, the photosensitive region responding to an applied transfer signal for moving charges accumulated on the charge collection sites to corresponding non-photosensitive readout sites, the non-photosensitive region responding to a read signal applied independently of the transfer signal for outputting the charges from the readout sites, and
- C. a control unit, that is coupled to the plurality of head units, selectively generates and applies to each head unit signals for acquiring an image.
A method of image acquisition using a charge coupled device of the type having
- i. a photosensitive region having one or more photosensitive charge collection sites,
- ii. a non-photosensitive region having one or more non-photosensitive readout sites, the non-photosensitive readout sites being coupled to corresponding photosensitive charge collection sites,
- the method comprising the steps of
- A. responding to an applied transfer signal for moving charges accumulated on the charge collection sites to corresponding readout sites, and
- B. responding to a read signal applied independently of the transfer signal for outputting the charges in the non-photosensitive readout sites.
Dependencies are inferred from the claim text.