# US 2003/0202030 A1 · Carriage for an image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2003/0202030 A1 - Document ID: US20030202030A1 - Status: Published application - Kind: A1 - Application number: 10/442,445 - Filed: 2003-05-21 - Published: 2003-10-30 - Earliest claimed: 2001-10-31 - Assignees: Hewlett-Packard Development Company, L.P. - Inventors: William J. Allen; George C. Ross - Web page: https://patentgrep.com/patent/US20030202030A1 ## CPC - B41J 19/207: {Encoding along a bar} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract An image forming apparatus includes a fiducial reference point sensor that individually monitors the position of first and second fiducial reference points on a moving print device that are in spaced relation to one another. ## Claims ### Claim 1 An image forming apparatus, comprising: a movable print device; at least first and second fiducial reference points on the movable print device in spaced relation to one another; and a fiducial reference point sensor that individually monitors the position of the first and second fiducial reference points. ### Claim 2 (depends on 1) An image forming apparatus as claimed in claim 1, wherein the movable print device includes at least one ink jet pen having a plurality of nozzles. ### Claim 3 (depends on 1) An image forming apparatus as claimed in claim 1, wherein the movable print device comprises a plurality of printer elements. ### Claim 4 (depends on 1) An image forming apparatus as claimed in claim 1, wherein the movable print device comprises a plurality of printer elements arranged in first and second banks. ### Claim 5 (depends on 1) An image forming apparatus as claimed in claim 1, wherein the first and second fiducial reference points comprise first and second cooperative elements carried by the movable print device and the fiducial reference point sensor comprises a cooperative element sensor. ### Claim 6 (depends on 5) An image forming apparatus as claimed in claim 5, wherein the first and second cooperative elements comprise first and second reflectors and the cooperative element sensor directs individual beams of light at the first and second reflectors and senses reflected beams of light from the first and second reflectors. ### Claim 7 (depends on 6) An image forming apparatus as claimed in claim 6, wherein the first and second reflectors comprise first and second mirrors. ### Claim 8 (depends on 6) An image forming apparatus as claimed in claim 6, wherein the cooperative element sensor comprises first and second light source and sensor devices that are respectively associated with the first and second reflectors. ### Claim 9 (depends on 1) An image forming apparatus as claimed in claim 1, further comprising: a controller, operably connected to the print device and the fiducial reference point sensor, that controls a first portion of the print device at least partially in response to data derived by monitoring the position of the first fiducial reference point and controls a second portion of the print device at least partially in response to data derived by monitoring the position of the second fiducial reference point. ### Claim 10 (depends on 9) An image forming apparatus as claimed in claim 9, wherein the print device includes at least first and second printer elements and the controller controls the first printer element at least partially in response to data derived by monitoring the position of the first fiducial reference point and controls the second printer element at least partially in response to data derived by monitoring the position of the second fiducial reference point. ### Claim 11 (depends on 9) An image forming apparatus as claimed in claim 9, wherein the print device includes a relatively tall printer element defining first and second longitudinal ends and the controller controls a portion of the printer element adjacent to the first longitudinal end at least partially in response to data derived by monitoring the position of the first fiducial reference point and controls a portion of the printer element adjacent to the second longitudinal end at least partially in response to data derived by monitoring the position of the second fiducial reference point. ### Claim 12 A scanning carriage for use in an image forming apparatus, the image forming apparatus including at least one cooperative element sensor, the scanning carriage comprising: a main body configured to at least one printer element; and at least first and second cooperative elements carried by the main body in spaced relation to one another. ### Claim 13 (depends on 12) A scanning carriage as claimed in claim 12, wherein the main body is configured to carry a bank of printer elements, the main body defines first and second longitudinal ends, and the first and second cooperative elements are respectively located near the first and second longitudinal ends of the main body. ### Claim 14 (depends on 12) A scanning carriage as claimed in claim 12, wherein the main body is configured to carry first and second banks of printer elements, the first cooperative element is closer to the first bank, and the second cooperative element is closer to the second bank. ### Claim 15 (depends on 14) A scanning carriage as claimed in claim 14, wherein the first and second banks define respective longitudinal ends, the first cooperative element is located between the longitudinal ends of the first bank, and the second cooperative element is located between the longitudinal ends of the second bank. ### Claim 16 (depends on 12) A scanning carriage as claimed in claim 12, wherein the at least one printer element defines first and second longitudinal ends, the first cooperative element is positioned adjacent to the first longitudinal end, and the second cooperative element is positioned adjacent the second longitudinal end. ### Claim 17 (depends on 16) A scanning carriage as claimed in claim 16, wherein main body is configured to carry a plurality of printer elements. ### Claim 18 (depends on 12) A scanning carriage as claimed in claim 12, wherein the first and second cooperative elements comprise reflectors. ### Claim 19 (depends on 12) A scanning carriage as claimed in claim 12, wherein the first and second cooperative elements comprise mirrors. ### Claim 20 An image forming apparatus, comprising: a print device, including a carriage and a plurality of printer elements supported on the carriage, movable along a scan axis; at least first and second cooperative elements carried by the print device in spaced relation to one another; a cooperative element sensor; and a controller, operably connected to the printer elements and the cooperative element sensor, that controls the operation of a first group of printer elements at least partially in response to data obtained by monitoring the first cooperative element with the cooperative element sensor and controls the operation of a second group of printer elements at least partially in response to data obtained by monitoring second first cooperative element with the cooperative element sensor. ### Claim 21 (depends on 20) An image forming apparatus as claimed in claim 20, wherein the printer elements comprise ink jet pens. ### Claim 22 (depends on 20) An image forming apparatus as claimed in claim 20, wherein the plurality of printer elements are arranged in a bank defining first and second longitudinal ends, the first cooperative element is located adjacent to the first longitudinal end, and the second cooperative element is located adjacent to the second longitudinal end. ### Claim 23 (depends on 20) An image forming apparatus as claimed in claim 20, wherein the plurality of printer elements are arranged in first and second banks, the first cooperative element is located adjacent to the first bank, and the cooperative element sensor is located adjacent to the second bank. ### Claim 24 (depends on 20) An image forming apparatus as claimed in claim 20, wherein the printer elements define first and second longitudinal ends, the first cooperative element is positioned adjacent to the first longitudinal ends, and the second cooperative element is positioned adjacent to the second longitudinal ends. ### Claim 25 (depends on 20) An image forming apparatus as claimed in claim 20, wherein the first and second cooperative elements comprise first and second reflectors and the cooperative element sensor directs individual beams of light at the first and second reflectors and senses reflected beams of light from the first and second reflectors. ### Claim 26 A method of operating a print device having first and second fiducial reference points in spaced relation to one another, the method comprising the steps of: moving the print device; and individually monitoring the position of the first and second fiducial reference points. ### Claim 27 (depends on 26) A method as claimed in claim 26, wherein the first and second fiducial reference points comprise cooperative elements and the step of individually monitoring the position of the first and second fiducial reference points comprises individually monitoring the position of the first and second cooperative elements. ### Claim 28 (depends on 26) A method as claimed in claim 26, wherein the first and second fiducial reference points comprise first and second reflectors and step of individually monitoring the position of the first and second fiducial reference points comprises directing individual beams of light at the first and second reflectors and sensing reflected beams of light from the first and second reflectors. ### Claim 29 (depends on 26) A method as claimed in claim 26, further comprising the steps of: controlling operation of a first portion of the print device at least partially in response to data obtained by monitoring the position of the first fiducial reference point; and controlling operation of a second portion of the print device at least partially in response to data obtained by monitoring the position of the second fiducial reference point. ### Claim 30 (depends on 29) A method as claimed in claim 29, wherein the print device includes at least first and second printer elements, the step of controlling operation of the first portion of the print device comprises controlling the first printer element at least partially in response to data obtained by monitoring the position of the first fiducial reference point, and the step of controlling operation of the second portion of the print device comprises controlling the second printer element at least partially in response to data obtained by monitoring the position of the second fiducial reference point. ### Claim 31 (depends on 29) A method as claimed in claim 29, wherein the print device includes a relatively tall printer element defining first and second longitudinal ends, the step of controlling operation of the first portion of the print device comprises controlling a portion of the printer element adjacent to the first longitudinal end at least partially in response to data obtained by monitoring the position of the first fiducial reference point, and the step of controlling operation of the second portion of the print device comprises controlling a portion of the printer element adjacent to the second longitudinal end at least partially in response to data obtained by monitoring the position of the second fiducial reference point.