# US 9,883,086 B2 · Camera module for a motor vehicle and method of pre-focusing a lens objective in a lens holder > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,883,086 B2 - Document ID: US9883086B2 - Status: Granted - Kind: B2 - Application number: 14/704,194 - Filed: 2015-05-05 - Published: 2015-11-12 - Granted: 2018-01-30 - Earliest claimed: 2014-05-07 - Assignees: Autoliv Development AB - Applicants: Autoliv Development AB - Inventors: Per Knutsson; Peter Fredriksson; Bo Malmborg; Mikael Johansson; Melih Gunes - Web page: https://patentgrep.com/patent/US9883086B2 ## CPC - H04N 23/54: Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils - B60R 11/04: Mounting of cameras operative during drive; Arrangement of controls thereof relative to the vehicle - G02B 7/028: {with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation} - H04N 23/55: Optical parts specially adapted for electronic image sensors; Mounting thereof - H04N 23/57: Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A camera module for a motor vehicle having a lens objective, a lens holder holding said lens objective, and a back plate connected to said lens holder and holding an image sensor in or close to an image plane of the lens objective. The materials, shapes and/or relative positions of the components of the lens objective are designed to keep the image plane in or close to the sensitive plane of the image sensor over an operating temperature range of the camera module. ## Claims ### Claim 1 A camera module for a motor vehicle, comprising: a lens objective, a lens holder, to which the lens objective is mounted, the lens holder holding the lens objective, in which a plurality of lenses are spaced from one another by at least one metal spacer ring between adjacent ones of the plurality of lenses, and a back plate disposed below the lens holder and fixedly connected to the lens holder and holding an image sensor in or close to an image plane of the lens objective, wherein the lens holder holds the lens objective at a distance from the image sensor and the lens holder is configured such that thermal expansion and contraction of the lens holder changes the distance between the lens objective and the image plane, wherein the distance increases with increasing temperature over an operating temperature range of the camera module, wherein an outer thread of the lens objective is screwed into an inner thread of the lens holder and glue is disposed between the outer thread and the inner thread in a bottom half of the outer thread. ### Claim 2 (depends on 1) The camera module as claimed in claim 1, wherein the lens objective is configured to keep the image plane in or close to the sensitive plane of the image sensor. ### Claim 3 (depends on 1) The camera module as claimed in claim 1, wherein the lens objective is configured such that Δd2/ΔT=hH·CH, wherein Δd2/ΔT is the change of the distance d2 between the lens objective and the image plane with temperature caused by changes of and within the lens objective, and CH and hH are the thermal expansion coefficient and the free height of the lens holder, respectively. ### Claim 4 (depends on 1) The camera module as claimed in claim 1, wherein the lens objective comprises lenses made of different materials. ### Claim 5 (depends on 1) The camera module as claimed in claim 1, wherein the lens objective comprises positive lenses and negative lenses. ### Claim 6 (depends on 1) The camera module as claimed in claim 1, wherein the lens objective comprises a lens barrel made of metal. ### Claim 7 (depends on 1) The camera module as claimed in claim 1 , wherein the spacer rings are made of brass. ### Claim 8 (depends on 1) The camera module as claimed in claim 1, wherein the lens objective comprises outer threads and the lens holder comprises co-operating inner threads. ### Claim 9 (depends on 1) The camera module as claimed in claim 1, wherein the lens holder is made of metal. ### Claim 10 A method of pre-focusing a lens objective in a lens holder for a camera module, the method comprising the steps of: providing a lens objective, a lens holder and a pre-mounting image sensor, applying glue to an interface between the lens objective and the lens holder, wherein an outer thread of the lens objective is screwed into an inner thread of the lens holder and the glue is applied to at least one of the inner thread and the outer thread, positioning the lens objective and the lens holder relative to each other and positioning the pre-mounting image sensor in a set distance to the lens holder, moving the lens objective and the lens holder relative to each other along an optical z-axis to a final relative position, hardening the glue while the lens objective and the lens holder are in the final relative position, and subsequently removing the pre-mounting image sensor from the lens holder. ### Claim 11 (depends on 10) The method according to claim 10, further comprising the step of: taking a reference image prior to reaching the final relative position, wherein the final relative position is reached when the image quality determined by the pre-mounting image sensor becomes optimal. ### Claim 12 (depends on 11) The method as claimed in claim 11, wherein the lens objective is configured to keep the image plane in or close to the sensitive plane of the image sensor. ### Claim 13 (depends on 11) The method as claimed in claim 11, wherein the lens objective is configured such that Δd2/ΔT=hH·CH, wherein Δd2/ΔT is the change of the distance d2 between the lens objective and the image plane with temperature caused by changes of and within the lens objective, and CH and hH are the thermal expansion coefficient and the free height of the lens holder, respectively. ### Claim 14 (depends on 10) The method according to claim 10, further comprising the step of: providing a stop element between the lens objective (20) and the lens holder (53) prior to moving the lens objective (20) and the lens holder (53) relative to each other, wherein the final relative position is reached when the stop element terminates the movement. ### Claim 15 (depends on 14) The method as claimed in claim 14, wherein the lens objective is configured to keep the image plane in or close to the sensitive plane of the image sensor. ### Claim 16 (depends on 14) The method as claimed in claim 14, wherein the lens objective is configured such that Δd2/ΔT=h·CH, wherein Δd2/ΔT is the change of the distance d2 between the lens objective and the image plane with temperature caused by changes of and within the lens objective, and CH and hH are the thermal expansion coefficient and the free height of the lens holder, respectively. ### Claim 17 (depends on 6) The camera module as claimed in claim 6, wherein the lens barrel is made of brass. ### Claim 18 A camera module for a motor vehicle, comprising: a lens objective including lenses made of glass, lenses made of plastics, and brass spacer rings between adjacent ones of the lenses, a lens holder holding the lens objective, and a back plate disposed below the lens holder and fixedly connected to the lens holder and holding an image sensor in or close to an image plane of the lens objective, wherein the lens objective is configured such that the distance between the lens objective and the image plane increases with increasing temperature over an operating temperature range of the camera module, wherein an outer thread of the lens objective is screwed into an inner thread of the lens holder and glue is disposed between the outer thread and the inner thread in a bottom half of the outer thread.