# US 9,817,332 B2 · Optical scanning device and image forming apparatus including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,817,332 B2 - Document ID: US9817332B2 - Status: Granted - Kind: B2 - Application number: 15/216,459 - Filed: 2016-07-21 - Published: 2017-02-02 - Granted: 2017-11-14 - Earliest claimed: 2015-07-27 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Jun Igarashi - Web page: https://patentgrep.com/patent/US9817332B2 ## CPC - G03G 15/043: with means for controlling illumination or exposure (G03G15/041 takes precedence) - 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)} - H04N 1/02481: {Arrangements for positioning elements within a head (H04N1/02409 takes precedence)} - H04N 1/113: using oscillating or rotating mirrors - H04N 2201/0094: Multifunctional device, i.e. a device capable of all of reading, reproducing, copying, facsimile transception, file transception - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An optical scanning device includes a deflecting unit having a deflecting surface, and arranged to deflect a light beam and optically scan a scanned surface in a main-scanning direction; an incident optical system arranged to cause the light beam to be obliquely incident on the deflecting surface in a sub-scanning section; and a light receiving unit arranged to receive a light beam deflected by the deflecting surface and generate a signal. A following condition is satisfied, |β|≦|α|, where α (deg) is an incident angle of the light beam from the incident optical system with respect to the deflecting surface in the sub-scanning section, and β (deg) is an angle defined by the light beam incident on the deflecting surface and the light beam deflected by the deflecting surface and directed toward the light receiving unit in a main-scanning section. ## Claims ### Claim 1 An optical scanning device comprising: a deflecting unit having a first deflecting surface, and arranged to deflect a light beam and optically scan a scanned surface in a main-scanning direction; an incident optical system arranged to cause the light beam to be obliquely incident on the first deflecting surface in a sub-scanning section; an imaging optical system arranged to guide a light beam deflected by the first deflecting surface onto the scanned surface; and a light receiving unit arranged to receive a light beam deflected by the first deflecting surface and generate a signal, wherein the incident optical system and the imaging optical system do not include optical elements integrally formed with each other, and wherein a following condition is satisfied, |β|≦|α|, where α (deg) is an incident angle of the light beam from the incident optical system with respect to the first deflecting surface in the sub-scanning section, and (β (deg) is an angle defined by the light beam incident on the first deflecting surface and the light beam deflected by the first deflecting surface and directed toward the light receiving unit in a main-scanning section. ### Claim 2 (depends on 1) The optical scanning device according to claim 1, wherein at least one of following conditions is satisfied, 1.5≦|α|≦10, and 0≦|β|≦5.0. ### Claim 3 (depends on 1) The optical scanning device according to claim 1, wherein at least one of following conditions is satisfied, 1.5≦|α|≦5.0, and 0≦|β|≦3.0. ### Claim 4 (depends on 1) The optical scanning device according to claim 1, wherein the light beam incident on the first deflecting surface is aligned with the light beam deflected by the first deflecting surface and directed toward the light receiving unit in the main-scanning section. ### Claim 5 (depends on 1) The optical scanning device according to claim 1, wherein the light receiving unit is arranged downstream of the incident optical system in a rotation direction of the deflecting unit. ### Claim 6 (depends on 1) The optical scanning device according to claim 1, wherein an optical path between the incident optical system and the first deflecting surface and an optical path between the first deflecting surface and the light receiving unit each are an optical path in which a chief ray of the light beam is not refracted or reflected in the main-scanning section. ### Claim 7 (depends on 1) The optical scanning device according to claim 1, wherein the incident optical system includes a first optical element arranged to condense a light beam, the light receiving unit includes a second optical element arranged to condense a light beam, and the first and second optical elements are integrated. ### Claim 8 (depends on 1) The optical scanning device according to claim 1, wherein the incident optical system includes a light source arranged to emit a light beam, the light receiving unit includes a photoelectric conversion element arranged to receive a light beam, and the light source and the photoelectric conversion element are mounted on a same substrate. ### Claim 9 (depends on 1) The optical scanning device according to claim 1, wherein the incident optical system includes a plurality of incident optical systems, and the deflecting unit deflects light beams from the plurality of incident optical systems and optically scans a plurality of scanned surfaces. ### Claim 10 (depends on 9) The optical scanning device according to claim 9, wherein the respective light beams from the plurality of incident optical systems have different incident angles with respect to the first deflecting surface in the main-scanning section. ### Claim 11 (depends on 9) The optical scanning device according to claim 9, wherein the respective light beams from the plurality of incident optical systems have incident angles having equivalent absolute values with respect to the first deflecting surface in the sub-scanning section. ### Claim 12 (depends on 1) The optical scanning device according to claim 1, wherein the light receiving unit generates a signal for determining a write-start position on the scanned surface in the main-scanning direction. ### Claim 13 (depends on 1) The optical scanning device according to claim 1, further comprising a control circuit arranged to determine a write-start position on the scanned surface in the main-scanning direction on the basis of the signal. ### Claim 14 (depends on 1) The optical scanning device according to claim 1, further comprising: a light source, wherein the incident optical system causes a light beam from the light source to be incident on the first deflecting surface from the outside of a scanned area in the main-scanning section, and wherein the light source emits the light beam at a timing at which the light beam from the incident optical system is vertically incident on the first deflecting surface in the main-scanning section. ### Claim 15 (depends on 14) The optical scanning device according to claim 14, wherein the light receiving unit receives the light beam reflected by the first deflecting surface at the timing and generates a signal. ### Claim 16 (depends on 15) The optical scanning device according to claim 15, further comprising a synchronous control unit arranged to determine a write-start position on the scanned surface in the main-scanning direction on the basis of the signal. ### Claim 17 (depends on 14) The optical scanning device according to claim 14, further comprising: a light detecting unit arranged to receive the light beam emitted from the light source at the timing and to generate a signal; and a light quantity control unit arranged to control a light emitting quantity of the light source on the basis of the signal. ### Claim 18 (depends on 17) The optical scanning device according to claim 17, further comprising a light separating element arranged to separate the light beam from the light source into a light beam directed toward the first deflecting surface and a light beam directed toward the light detecting unit. ### Claim 19 An image forming apparatus comprising: an optical scanning device; a developing unit arranged to develop an electrostatic latent image formed on a scanned surface by the optical scanning device, as a toner image; a transfer unit arranged to transfer the developed toner image on a transferred material; and a fixing unit arranged to fix the transferred toner image to the transferred material, wherein the optical scanning device includes a deflecting unit having a first deflecting surface and arranged to deflect a light beam and optically scan the scanned surface in a main-scanning direction, an incident optical system arranged to cause the light beam to be obliquely incident on the first deflecting surface in a sub-scanning section, an imaging optical system arranged to guide a light beam deflected by the first deflecting surface onto the scanned surface, and a light receiving unit arranged to receive a light beam deflected by the first deflecting surface and generate a signal, wherein the incident optical system and the imaging optical system do not include optical elements integrally formed with each other, and wherein a following condition is satisfied, |β|≦|α|, where α (deg) is an incident angle of the light beam from the incident optical system with respect to the first deflecting surface in the sub-scanning section, and β (deg) is an angle defined by the light beam incident on the first deflecting surface and the light beam deflected by the deflecting surface and directed toward the light receiving unit in a main-scanning section. ### Claim 20 An optical scanning device comprising: a light source; a deflecting unit having a first deflecting surface, and arranged to deflect a light beam from the light source and optically scan a scanned surface in a main-scanning direction; and an incident optical system arranged to guide the light beam from the light source to the first deflecting surface; and an imaging optical system arranged to guide a light beam deflected by the first deflecting surface onto the scanned surface, wherein the deflecting unit is formed of a single rotating polygon mirror, wherein the incident optical system and the imaging optical system do not include optical elements integrally formed with each other, wherein the incident optical system causes the light beam to be incident on the first deflecting surface from the outside of a scanned area in a main-scanning section, and causes the light beam to be obliquely incident on the first deflecting surface in a sub-scanning section, and wherein the light source emits the light beam at a timing at which the light beam from the incident optical system is vertically incident on the first deflecting surface in the main-scanning section.