# US 2010/0165404 A1 · Laser Print Apparatus That Generates Pulse With Value And Justification Value Based On Pixels In A Multi-Bit Image > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0165404 A1 - Document ID: US20100165404A1 - Status: Published application - Kind: A1 - Application number: 12/564,646 - Filed: 2009-09-22 - Published: 2010-07-01 - Earliest claimed: 2003-02-12 - Assignees: Marvell International Technology Ltd. - Inventors: John D. Marshall; Douglas G. Keithley - Web page: https://patentgrep.com/patent/US20100165404A1 ## CPC - H04N 1/4056: {the pattern varying in one dimension only, e.g. dash length, pulse width modulation [PWM]} - B41J 2/47: using the combination of scanning and modulation of light - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A laser print apparatus includes a memory for storing a multi-bit image including a plurality of pixels. Each pixel is represented by an N-bit value, wherein N is greater than one. A modulation code generator analyzes three adjacent pixels. The three adjacent pixels include a left pixel, a center pixel, and a right pixel. The modulation code generator is configured to generate a pulse width value based on the value of the center pixel, and a justification value based on the values of the left pixel and the right pixel. A laser print engine forms an output pixel on media based on the pulse width value and the justification value. ## Claims ### Claim 1 A laser print apparatus comprising: a memory to store a multi-bit image including a plurality of pixels, each pixel represented by an N-bit value; a modulation code generator to generate an M-bit pulse width value from the N-bit value; and a laser print engine to form an output pixel on media based on the M-bit pulse width value, wherein the modulation code generator is operative to concatenate at least one most significant bit of a current pixel to a least significant end of the current pixel. ### Claim 2 (depends on 1) The laser print apparatus of claim 1, wherein a window is moved across the multi-bit image to read the plurality of pixels and the plurality of pixels includes at least a center pixel, a left pixel, and a right pixel. ### Claim 3 (depends on 2) The laser print apparatus of claim 2, further comprising: a justification generator to generate a justification value by comparing an N-bit value of the center pixel to either an N-bit value of the left pixel or an N-bit value of the right pixel. ### Claim 4 (depends on 1) The laser print apparatus of claim 1, wherein generating the M-bit value from the N-bit value is nonlinear. ### Claim 5 A laser print apparatus comprising: a memory to store a multi-bit image, wherein a window is moved across the multi-bit image to read a plurality of pixels at a time, the plurality of pixels including at least a center pixel, a left pixel, and a right pixel, each pixel represented by an N-bit value; a pulse width generator to generate an M-bit pulse width value from an N-bit value of the center pixel; and a laser print engine to form an output pixel on media based on the M-bit pulse width value. ### Claim 6 (depends on 5) The laser print apparatus of claim 5, wherein the pulse width generator generates the M-bit pulse width value by multiplying the N-bit value by a multi-bit scaling factor. ### Claim 7 (depends on 5) The laser print apparatus of claim 5, wherein the pulse width generator generates the M-bit pulse width value by accessing a look up table indexed by the N-bit value of the center pixel. ### Claim 8 (depends on 5) The laser print apparatus of claim 5, wherein the pulse width generator generates the M-bit pulse width value by accessing a look up table indexed by a combination of the N-bit value of the center pixel and a portion of at least one of an N-bit value of the left pixel and an N-bit value of the right pixel. ### Claim 9 (depends on 5) The laser print apparatus of claim 5, further comprising: a justification generator to generate a justification value based on the N-bit value of the center pixel and either an N-bit value of the left pixel or an N-bit value of the right pixel. ### Claim 10 (depends on 9) The laser print apparatus of claim 9, further comprising: a comparator configured to determine whether the N-bit value of the right pixel subtracted from the N-bit value of the left pixel exceeds a predetermined number, wherein the justification value is set to a left justification when the N-bit value of the right pixel subtracted from the N-bit value of the left pixel exceeds the predetermined number. ### Claim 11 (depends on 9) The laser print apparatus of claim 9, further comprising: a comparator configured to determine whether the N-bit value of the left pixel subtracted from the N-bit value of the right pixel exceeds a predetermined number, wherein the justification value is set to a right justification when the N-bit value of the left pixel subtracted from the N-bit value of the right pixel exceeds the predetermined number. ### Claim 12 (depends on 9) The laser print apparatus of claim 9, further comprising: a comparator configured to determine whether the N-bit value of the left pixel added to the N-bit value of the right pixel exceeds a predetermined number, wherein the justification value is set to a split justification when the N-bit value of the left pixel added to the N-bit value of the right pixel exceeds the predetermined number. ### Claim 13 (depends on 5) The laser print apparatus of claim 5, wherein generating the M-bit pulse width value from the N-bit value is nonlinear. ### Claim 14 A method for calculating modulation data for modulating a laser, the method comprising: rendering data to be printed into a multi-bit image including a plurality of pixels, each pixel represented by an N-bit value; generating an M-bit pulse width value from the N-bit value by concatenating at least one more significant bit of a current pixel to a least significant end of the current pixel; and printing an output pixel on a medium based on the M-bit pulse width value. ### Claim 15 (depends on 14) The method of claim 14, further comprising: moving a window across the multi-bit image to read the plurality of pixels, wherein the plurality of pixels includes a center pixel, a left pixel, and a right pixel. ### Claim 16 (depends on 15) The method of claim 15, further comprising: generating a justification value by comparing an N-bit value of the center pixel to either an N-bit value of the left pixel or an N-bit value of the right pixel. ### Claim 17 (depends on 15) The method of claim 15, further comprising: generating a justification value by comparing an N-bit value of the left pixel to an N-bit value of the right pixel. ### Claim 18 (depends on 17) The method of claim 17, wherein the justification value indicates a left justification when the N-bit value of the left pixel exceeds the N-bit value of the right pixel by a first predetermined amount, and the justification value indicates a right justification when the N-bit value of the right pixel exceeds the N-bit value of the left pixel by the first predetermined amount. ### Claim 19 (depends on 14) The method of claim 14, wherein generating the M-bit pulse width value from the N-bit value is nonlinear. ### Claim 20 (depends on 14) The method of claim 14, wherein generating the M-bit pulse width value from the N-bit value is linear.