Multiple mode raster scanner
First Claim
1. In a raster input scanner, the combination of:
- (a) multiple speed scanning means for scanning originals to provide image signals representative of the image on said originals, said scanning means being selectively operable at a first scanning rate for predominantly line images and at a second scanning rate for other images;
(b) first image processing means for procesing image signals produced by said scanning means at said first scanning rate to provide a binary level image signal output;
(c) second and third image processing means for processing image signals produced by said scanning means at said second scanning rate;
said second image processing means being adapted for use when said other images comprise predominantly continuous tone images, said second image processing means providing a binary level image signal output;
said third image processing means being adapted for use when said other images comprise halftone and/or continuous tone images, said third image processing means providing a digital signal output representing the gray scale level of the image signals processed; and
(d) selector means for selecting one of said scanning means first and second scanning rates, and one of said second and third image processing means when said second scanning rate is selected.
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Accused Products
Abstract
An image input terminal (IIT) with automatic document handler for feeding documents to be scanned into registered position on the IIT platen. The IIT includes a pair of multi-element scanning arrays with cooperating scan lamp and optics on a movable carriage disposed in scanning relationship with the platen. Analog image signals generated by the scanning arrays are initially processed in separate channels and then combined into a serial stream. The stream of analog image signals may optionally be thresholded or screened to provide binary level image signals or converted to multi-bit gray scale. A control system including microprocessor provides timing and control signals for synchronizing operation of the scanning carriage, document handler, and image signal reading and processing together with electronic crossover between arrays to avoid loss of data, automatic signal gain and deletion of bad image signals or pixels. On board array alignment apparatus permits adjustment of array focus, skew, height, position and overlap.
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Citations
12 Claims
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1. In a raster input scanner, the combination of:
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(a) multiple speed scanning means for scanning originals to provide image signals representative of the image on said originals, said scanning means being selectively operable at a first scanning rate for predominantly line images and at a second scanning rate for other images; (b) first image processing means for procesing image signals produced by said scanning means at said first scanning rate to provide a binary level image signal output; (c) second and third image processing means for processing image signals produced by said scanning means at said second scanning rate; said second image processing means being adapted for use when said other images comprise predominantly continuous tone images, said second image processing means providing a binary level image signal output; said third image processing means being adapted for use when said other images comprise halftone and/or continuous tone images, said third image processing means providing a digital signal output representing the gray scale level of the image signals processed; and (d) selector means for selecting one of said scanning means first and second scanning rates, and one of said second and third image processing means when said second scanning rate is selected. - View Dependent Claims (2, 3, 4, 5, 7, 8, 9, 10, 11)
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6. The scanner according to claim 14 in which said second image processing means includes means to vary the threshold level of said thresholding means.
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12. A method of processing image bearing originals, the steps which comprise:
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(a) where the original image is made up of predominantly lines, scanning said line image at a relatively high speed to provide a binary level signal output representing said line image; (b) where the original image is made up predominantly of continuous tones, scanning said continuous tone image at a relatively slow speed to provide a binary level signal output representing, said continuous tone image; (c) multiplying said binary level signal outputs by a predetermined factor to provide additional binary level signals to enhance image resolution; (d) selectively varying the number of image signals that comprise said binary level signal output to vary selectively image size; (e) where the original is made up predominantly of halftones, scanning said halftone image at said relatively slow speed to provide a digital signal output representing the gray level content of said halftone image; and (f) converting said binary level signal output and said digital signal output to signals having the same bit size.
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Specification