Strobe flash photographic illumination

A document scanning system comprising a camera, the camera comprising an electronic detector array for image capture, an objective lens with a field of view to image optical radiation from an object plane onto the electronic detector array, a strobe flash for illuminating the object plane, electronic pulse circuitry to pulse the strobe flash at a rate which is sufficiently quick that the illumination appears to a user of the camera to be substantially steady owing to persistence of vision, and a shutter arrangement comprising electronic control circuitry to synchronize the capture of an image by the detector array with the strobe flash, each image being captured with at least one pulse from the strobe flash, wherein the shutter arrangement is adapted to capture images at a rate substantially below the rate at which the strobe flash is pulsed, the camera further including an actuator to scan the field of view of the objective lens in the object plane as the control circuitry captures images of different fields of view;

• the document scanning system further comprising a mount by which the camera may be positioned to image onto the electronic detector array a portion of a document in the object plane, wherein the actuator is operable to scan the field of view of the objective lens as the control circuitry captures images of different portions of the document.

A method of imaging a document using a camera comprising an electronic detector array for image capture, an objective lens with a field of view to image optical radiation from an object plane onto the electronic detector array, a strobe flash for illuminating the object plane, electronic pulse circuitry to pulse the strobe flash at a rate which is sufficiently quick that the illumination appears to a user of the camera to be substantially steady owing to persistence of vision, and a shutter arrangement comprising electronic control circuitry to synchronize the capture of an image by the detector array with the strobe flash, each image being captured with at least one pulse from the strobe flash, wherein the shutter arrangement is adapted to capture images at a rate substantially below the rate at which the strobe flash is pulsed, the camera further including an actuator to scan the field of view of the objective lens in the object plane as the control circuitry captures images of different fields of view, wherein the method comprises the steps of:

• (a) aiming the camera at a document in the object plane so that a portion of the document falls within the field of view;
• and
• (b) using the actuator to scan the field of view of the objective lens as the control circuitry captures images of different portions of the document.

A camera comprising a detector for image capture, an objective lens with a field of view to image optical radiation from an object plane onto the detector for image capture, a strobe flash for illuminating the object plane, electronic pulse circuitry to pulse the strobe flash at a rate of at least 16 times/second, and a shutter arrangement to synchronize the capture of one or more images by the detector for image capture, each image being captured with at least one pulse from the strobe flash, wherein the shutter arrangement is adapted to capture images at a rate substantially below the rate at which the strobe flash is pulsed.

A document scanning system comprising a camera, the camera comprising an electronic detector array for image capture, an objective lens with a field of view to image optical radiation from an object plane onto the electronic detector array, a strobe flash for illuminating the object plane, electronic pulse circuitry to pulse the strobe flash at a rate of at least 16 times/second, and a shutter arrangement comprising electronic control circuitry to synchronize the capture of an image by the detector array with the strobe flash, each image being captured with at least one pulse from the strobe flash, wherein the shutter arrangement is adapted to capture images at a rate substantially below the rate at which the strobe flash is pulsed, the camera further including an actuator to scan the field of view of the objective lens in the object plane as the control circuitry captures images of different fields of view;

• the document scanning system further comprising a mount by which the camera may be positioned to image onto the electronic detector array a portion of a document in the object plane, wherein the actuator is operable to scan the field of view of the objective lens as the control circuitry captures images of different portions of the document.

A method of imaging a document using a camera comprising an electronic detector array for image capture, an objective lens with a field of view to image optical radiation from an object plane onto the electronic detector array, a strobe flash for illuminating the object plane, electronic pulse circuitry to pulse the strobe flash at a rate of at least 16 times/second, and a shutter arrangement comprising electronic control circuitry to synchronize the capture of an image by the detector array with the strobe flash, each image being captured with at least one pulse from the strobe flash, wherein the shutter arrangement is adapted to capture images at a rate substantially below the rate at which the strobe flash is pulsed, the camera further including an actuator to scan the field of view of the objective lens in the object plane as the control circuitry captures images of different fields of view, wherein the method comprises the steps of:

• (a) aiming the camera at a document in the object plane so that a portion of the document falls within the field of view;
• and
• (b) using the actuator to scan the field of view of the objective lens as the control circuitry captures images of different portions of the document.