Lexmark International, Inc.

Marvell International Limited

Mark Lane Mayberry

Karl Mark Thompson

Edward William Yohon, Jr

Michael Jo Phelps

Rickey Carter Brown

Douglas G Keithley

Keith Bryan Hardin

James Francis Webb

Chengwu Cui

John Parker Richey

Zachary Nathan Fister

Christopher Wilson Case

Cuong Manh Hoang

Carl P Cole

Stephen R Troyer

Joseph Kamal Yackzan

Michael James Klein

James D Lewis

David B Callister

Bennett Fornal

A method of calibrating a document scanner contact image sensor scan bar having an LED array to increase LED sensor array output and/or reduce total color scan line cycle time.

Method of calibrating a contact image sensor scan bar in a document scanner

A fiducial on a backer of a flatbed scanner is used for determining a media size of a target scanned on the platen of the scanner. The fiducial is comprised of a plurality of symbols, either arranged in a predetermined pattern or randomly within a fiducial frame, and is placed at a predetermined location on the backer on the scanner lid. Each symbol has a finish that reflects light differently than a finish on the backer and has a high peak correlation value and a low off-peak correlation value when scanned. Image data from a scan of a target along with the backer is searched for the fiducial image. When the fiducial image is found, the media is selected to be of a first shorter length target type and, when the fiducial is not found, the target is selected to be of a second longer length target type.

Fiducial for use in determining two media types of different lengths used on a flatbed scanner

A method for determining a media size of a target scanned on the platen of the flatbed scanner using a fiducial placed on a backer of the flatbed scanner at a predetermined location. The fiducial is comprised of a plurality of objects, either placed in a predetermined pattern or randomly within a fiducial frame. A target is placed on the platen of the flatbed scanner and scanned along with the backer. The scanned image data of the target and backer is searched for the fiducial image. When the fiducial image is found, the media is selected to be of a first target type having a first length, and, when the fiducial is not found the target is selected to be of a second target type have a second length longer than the first length.

Method of using a fiducial in determining two media types of different lengths used on a flatbed scanner

A method for reducing electromagnetic emissions by an image scanner comprises cyclically dithering a frequency of a clock signal of the image scanner by repeated dither cycles, determining a phase of the dither cycle when a scan pass of a page of a document commences; and commencing all subsequent scan passes of the page of the document at a particular phase shift from the determined phase of the dither cycle.

Method and apparatus for scanning an image

A method for adjusting a controller of a scanner includes obtaining a scan of a predefined image. The method further includes moving the sensor-element signals of the control signal pattern generated by the controller earlier in the pattern by at least one unit and obtaining an additional scan. The obtaining and moving are repeated until a comparison of a latest additional scan to the image is worse than a comparison of a second-latest additional scan to the image. Another method obtains a noise-reducing heuristic which modifies a time parameter of a sensor-element signal. A set of repeated scans of a same scan line is obtained, noise is measured there from, the time parameter is modified by one predetermined unit, and the process repeats until the noise measured from the latest set of repeated scans is worse than that from the second-latest set of repeated scans.

Method for adjusting a controller of a scanner

An improved communications buffer system is provided which dynamically allocates the size and number of buffers to optimally receive and transmit packets of communications data over a communications link, while efficiently using the amount of available memory so as to provide optimal throughput capability with respect to the allocated amount of memory. The printer first determines how much 'free' memory is available in its 'pool area' and then how best to divide up that pool area into both transmit and receive buffers for a single port. Once the entire pool area has been allocated for these transmit and receive buffers, the communication session can begin between the host computer and the printer for communicating the actual print job data. A second embodiment of an improved communications buffer system is also provided which dynamically allocates the size and number of buffers for each of several different communications ports that are installed on a printer, while efficiently using the allocated memory so as to provide optimal throughput capability. This second communications buffer system is primarily designed to efficiently assign memory space for buffers used by the several communications ports from a predetermined amount of memory space (as a 'pool' of memory) that has been allocated for external communications functions by the printer. Upon initialization of the printer, each individual port will only be allocated a fairly small portion of that pool area of RAM to give that port a minimal buffer configuration that is sufficient to begin to receive data as it arrives at that port. When a port becomes active, it then requests more memory from the pool area of RAM. Only 'active' ports are dynamically allocated any relatively large amounts of RAM out of the pool area of the printer's RAM that is made available for communications. The maximum amount of the pool area that will be assigned to a port typically will be a different quantity for different types of ports, and preferably is never 100% of the pool area.

Method and apparatus for dynamic buffering of input/output ports used

An improved communications buffer system is provided which dynamically allocates the size and number of buffers to optimally receive packets of communications data over a communications link, while efficiently using the amount of available memory so as to provide optimal throughput capability with respect to the allocated amount of memory. This buffer system is readily adaptable for infrared communications ports used on printers. Once a communications session has begun, the printer will obtain sufficient information to most effectively allocate the size and number of buffers. At the beginning of this procedure, the printer must first determine how much 'free' memory is available in its 'pool area' and then determine how best to divide up that pool area into both transmit and receive buffers. The size and number of transmit buffers is first determined, and this determination is made after considering how much pool area is available in the printer's memory system at that moment. Once the size and number of transmit buffers has been determined, then the receive buffers are next configured. The first step is to perform a preliminary calculation to ensure that the receive buffer size is not set greater than the amount of data that can be received during the maximum turnaround time for this particular configuration between a host computer and the printer. After this has been determined, the receive buffer size is provisionally set to a power of 2, and the number of buffers is set equal to the remaining pool size divided by this receiver buffer size. After ensuring that there are at least a certain minimum number of receive buffers, then a 'window size' is set to a certain maximum size, at least for infrared communications ports. Once the entire pool area has been allocated for these transmit and receive buffers, the communication session can begin between the host computer and the printer for communicating the actual print job data.

System for dynamically determining the size and number of communication

An electrophotographic printer (1) adjusts high resolution data while preserving the resolution capabilities of the printer. Data in a 600.times.600 bit map is assigned alternately to two rows of a 300.times.1200 bit map. Excellent visual effects are realized.

Bit map adjustment preserving resolution

Printer (1) monitors current control language being interpreted for end of page and end of job codes, depending upon the language. Upon observing such commands, up to 500 bytes in buffer memory (19) are observed for command codes characteristic of specific languages. ASCII language is recognized by any one of several command codes, many of which have ESC. PostScript language is recognized by any one of several commands including the ASCII sequence of the percent sign. PCL4 or PCL5 and pen movement graphics languages are also recognized. Operator intervention and special coding defining the language are completely avoided.

Growing community of inventors

Wilmore, KY, United States of America

Mark Lane Mayberry