# US 2010/0060964 A1 · Optical beam scanning apparatus, and 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 2010/0060964 A1 - Document ID: US20100060964A1 - Status: Published application - Kind: A1 - Application number: 12/558,471 - Filed: 2009-09-11 - Published: 2010-03-11 - Earliest claimed: 2008-09-09 - Assignees: Kabushiki Kaisha Toshiba; Toshiba Tec Kabushiki Kaisha - Inventors: Takashi Shiraishi - Web page: https://patentgrep.com/patent/US20100060964A1 ## CPC - G02B 26/125: {Details of the optical system between the polygonal mirror and the image plane (G02B26/123, G02B26/127 take precedence; F-Theta lenses G02B13/0005)} - G02B 26/124: {Details of the optical system between the light source and the polygonal mirror (G02B26/123, G02B26/127 take precedence)} - G02B 26/127: {Adaptive control of the scanning light beam, e.g. using the feedback from one or more detectors (G02B27/0031 takes precedence)} - G06K 15/129: {Colour printing} - H04N 1/1135: {for the main-scan only} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An optical beam scanning apparatus according to the present invention includes a light source, a pre-deflection optical system, a light deflecting device, a post-deflection optical system, a first sensor configured to detect a part of the luminous fluxes deflected by the light deflecting device, one or plural first optical elements configured to be provided in the post-deflection optical system and act on the luminous fluxes deflected by all the deflection surfaces of the light deflecting device; and a second optical element having positive power in the sub-scanning direction configured to be provided in an optical path between any one of the first optical elements and the first sensor and act on the luminous fluxes deflected by all the deflection surfaces of the light deflecting device. ## Claims ### Claim at position 1 -19. (canceled) ### Claim 20 An optical beam scanning apparatus comprising: a light source configured to emit one or plural luminous fluxes; a pre-deflection optical system configured to shapes the luminous fluxes emitted from the light source to image the luminous fluxes as a line image in a direction corresponding to a main scanning direction; a light deflecting device configured to separate the luminous fluxes imaged by the pre-deflection optical system in a sub-scanning direction for each of color components using plural deflection surfaces having different angles with respect to a rotation center axis and scan the luminous fluxes against a scanning object in the main scanning direction; a post-deflection optical system, having one or plural first optical elements configured to act on the luminous fluxes for all color components, configured to image the luminous fluxes deflected by the light deflecting device on the scanning object; and a first sensor configured to detect a part of the luminous fluxes deflected by at least one deflection surface having a predetermined angle with respect to the rotation center axis. ### Claim 21 (depends on 20) The optical beam scanning apparatus according to claim 20, wherein plural second optical elements which respectively act on the luminous fluxes for each of color components are further provided in the post-deflection optical system. ### Claim 22 (depends on 20) The optical scanning apparatus according to claim 20, further comprising a second sensor configured to detect a part of the luminous fluxes deflected by the light deflecting device; and a second optical element having positive power in the sub-scanning direction configured to be provided in an optical path between any one of first optical elements and the second sensor and act on the luminous fluxes for all color components. ### Claim 23 (depends on 22) The optical beam scanning apparatus according to claim 22, wherein the second optical element is a cylindrical lens. ### Claim 24 (depends on 22) The optical beam scanning apparatus according to claim 22, wherein the first sensor is provided on a downstream side of the optical paths of the second optical element. ### Claim 25 (depends on 20) The optical beam scanning apparatus according to claim 20, further comprising a light blocking member configured to be provided in an optical path between any one of the first optical elements and the first sensor and blocks luminous fluxes other than the luminous fluxes deflected by at least one deflection surface having a predetermined angle with respect to the rotation center axis. ### Claim 26 (depends on 25) The optical beam scanning apparatus according to claim 25, further comprising a second sensor configured to detect a part of the luminous fluxes deflected by the light deflecting device; and a second optical element having positive power in the sub-scanning direction configured to be provided in an optical path between any one of first optical elements and the second sensor and act on the luminous fluxes for all color components, wherein the light blocking member is provided on an upstream side of optical paths of the second optical element. ### Claim 27 An image forming apparatus including an optical beam scanning apparatus, the optical beam scanning apparatus comprising: a light source configured to emit one or plural luminous fluxes; a pre-deflection optical system configured to form the luminous fluxes emitted from the light source to image the luminous fluxes as a line image in a direction corresponding to a main scanning direction; a light deflecting device configured to separate the luminous fluxes imaged by the pre-deflection optical system in a sub-scanning direction for each of color components using plural deflection surfaces having different angles with respect to a rotation center axis and scan the luminous fluxes against a scanning object in the main scanning direction; a post-deflection optical system, having one or plural first optical elements configured to act on the luminous fluxes for all color components, configured to image the luminous fluxes deflected by the light deflecting device on the scanning object; and a sensor configured to detect a part of the luminous fluxes deflected by at least one deflection surface having a predetermined angle with respect to the rotation center axis. ### Claim 28 An optical beam scanning apparatus comprising: a light source configured to emit one or plural luminous fluxes; a pre-deflection optical system configured to form the luminous fluxes emitted from the light source to image the luminous fluxes as a line image in a direction corresponding to a main scanning direction; a light deflecting device configured to separate the luminous fluxes imaged by the pre-deflection optical system in a sub-scanning direction for each of color components using plural deflection surfaces having different angles with respect to a rotation center axis and scan the luminous fluxes against a scanning object in the main scanning direction; a post-deflection optical system configured to image the luminous fluxes deflected by the light deflecting device on the scanning object; and a first sensor configured to detect a part of the luminous fluxes deflected by at least one deflection surface having a predetermined angle with respect to the rotation center axis. ### Claim 29 (depends on 28) The optical beam scanning apparatus according to claim 28, wherein one or plural optical elements configured to act on the luminous fluxes for all color components are provided in the post-deflection optical system. ### Claim 30 (depends on 29) The optical beam scanning apparatus according to claim 29, further comprising a light blocking member configured to be provided in an optical path between any one of the first optical elements and the first sensor and blocks luminous fluxes other than the luminous fluxes deflected by at least one deflection surface having a predetermined angle with respect to the rotation center axis. ### Claim 31 (depends on 28) The optical beam scanning apparatus according to claim 28, wherein plural optical elements which respectively act on the luminous fluxes for each of color components are further provided in the post-deflection optical system. ### Claim 32 (depends on 28) The optical beam scanning apparatus according to claim 28, further comprising a second sensor configured to detect a part of the luminous fluxes deflected by the light deflecting device; and an optical element having positive power in the sub-scanning direction configured to be provided in an optical path between the light deflecting device and the second sensor and act on the luminous fluxes for all color components. ### Claim 33 (depends on 32) The optical beam scanning apparatus according to claim 32, wherein the optical element is a cylindrical lens. ### Claim 34 (depends on 32) The optical beam scanning apparatus according to claim 32, wherein the first sensor is provided on a downstream side of the optical paths of the optical element. ### Claim 35 An image forming apparatus including an optical beam scanning apparatus, the optical beam scanning apparatus comprising: a light source configured to emit one or plural luminous fluxes; a pre-deflection optical system configured to form the luminous fluxes emitted from the light source to image the luminous fluxes as a line image in a direction corresponding to a main scanning direction; a light deflecting device configured to separate the luminous fluxes imaged by the pre-deflection optical system in a sub-scanning direction for each of color components using plural deflection surfaces having different angles with respect to a rotation center axis and scan the luminous fluxes against a scanning object in the main scanning direction; a post-deflection optical system configured to image the luminous fluxes deflected by the light deflecting device; and a sensor configured to detect a part of the luminous fluxes deflected by at least one deflection surface having a predetermined angle with respect to the rotation center axis.