# US 5,353,141 A · Method for aligning treatment of liquid crystal device including varying with time the feeding speed of the rubbing roller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,353,141 A - Document ID: US5353141A - Status: Granted - Kind: A - Application number: 07/956,400 - Filed: 1992-10-05 - Granted: 1994-10-04 - Earliest claimed: 1991-10-08 - Assignees: Canon Kabushiki Kaisha - Inventors: Kenji Onuma; Mayumi Yoshioka; Yukio Hanyu; Yasuto Kodera; Takatsugu Wada - Web page: https://patentgrep.com/patent/US5353141A ## CPC - G02F 1/133784: {by rubbing} - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract A liquid crystal device, particularly a ferroelectric liquid crystal device, is constituted by disposing a liquid crystal disposed between a pair of rubbing-treated substrates. The uniaxial alignment control force exerted by rubbing is gradually weakened as the rubbing treatment is successively applied to a large number of substrates. This is compensated by varying a rubbing condition, such as a relative moving speed, a rotational speed, or a pressing depth against the substrate of a rubbing roller. Alternatively, such a change in uniaxial alignment control force with time may be utilized for compensating for a difference in uniaxial alignment control force attributable to a difference in stripe electrode extension relative to the rubbing direction. ## Claims ### Claim 1 An aligning treatment method for a liquid crystal device including a liquid crystal between a pair of substrates, comprising successively rubbing a plurality of substrates with a rubbing roller while varying a feeding speed of the rubbing roller with time, wherein the feeding speed of the rubbing roller is varied by at least 0.5% per substrate. ### Claim 2 An aligning treatment method for a liquid crystal device including a liquid crystal between a pair of substrates, comprising successively rubbing a plurality of substrates with a rubbing roller while varying a feeding speed of the rubbing roller with time, wherein the feeding speed of the rubbing roller is varied by at least 1% per substrate. ### Claim 3 (depends on 1, 2) A method according to claim 1 or 2, wherein a rotational speed and/or a pressing depth against the substrate of the rubbing roller is additionally varied with time. ### Claim 4 (depends on 3) A method according to claim 3, wherein the rubbing roller pressing depth is varied by at least 1% per substrate. ### Claim 5 (depends on 1, 2) A method according to claim 1 or 2, wherein said liquid crystal is a ferroelectric liquid crystal. ### Claim 6 (depends on 5) A method according to claim 5, wherein the substrates are rubbed to align the ferroelectric liquid crystal at a pretilt angle of at least 10 degrees. ### Claim 7 (depends on 1, 2) A method according to claim 1 or 2, wherein the feeding speed of the rubbing roller is varied stepwise. ### Claim 8 (depends on 1, 2) A method according to claim 1 or 2, wherein the feeding speed of the rubbing roller is varied linearly. ### Claim 9 An alignment treatment method for a liquid crystal device including a pair of substrates each provided with stripe electrodes and a liquid crystal disposed between the substrates; the method comprising rubbing the pair of substrates with a rubbing roller such that one substrate having stripe electrodes extending in a direction perpendicular to the rubbing direction is rubbed first, and then the other substrate having stripe electrodes extending in a direction parallel to the rubbing direction is rubbed, wherein the rubbing is repeated while varying a feeding speed of the rubbing roller with time, and a feeding speed of the rubbing roller is varied by at least 0.5% per substrate. ### Claim 10 An aligning treatment method for a liquid crystal device including a pair of substrates each provided with stripe electrodes and a liquid crystal disposed between the substrates; the method comprising rubbing the pair of substrates with a rubbing roller such that one substrate having stripe electrodes extending in a direction perpendicular to the rubbing direction is rubbed first, and then the other substrate having stripe electrodes extending in a direction parallel to the rubbing direction is rubbed, wherein the rubbing is repeated while varying a feeding speed of the rubber roller with time, and a feeding speed of the rubbing roller is varied by at least 1% per substrate. ### Claim 11 (depends on 9, 10) A method according to claim 9 or 10, wherein the rubbing is repeated for other pairs of substrates. ### Claim 12 (depends on 9, 10) A method according to claim 9 or 10, wherein said liquid crystal is a ferroelectric liquid crystal. ### Claim 13 (depends on 12) A method according to claim 12, wherein the substrates are rubbed to align the ferroelectric liquid crystal at a pretilt angle of at least 10 degrees. ### Claim 14 (depends on 9, 10) A method according to claim 9 or 10, wherein a rotational speed and/or a pressing depth against the substrate of the rubbing roller is additionally varied with time. ### Claim 15 (depends on 14) A method according to claim 14, wherein the rubbing roller pressing depth is varied by at least 1% per substrate. ### Claim 16 (depends on 9, 10) A method according to claim 9 or 10, wherein the feeding speed of the rubbing roller is varied corresponding to the number of substrates or the number of pairs of substrates treated. ### Claim 17 (depends on 9, 10) A method according to claim 9 or 10, wherein the feeding speed of the rubbing roller is varied stepwise. ### Claim 18 (depends on 9, 10) A method according to claim 9 or 10, wherein the rubbing condition is varied linearly. ### Claim 19 An aligning treatment method for a liquid crystal device including a pair of substrates each provided with stripe electrodes and a liquid crystal disposed between the substrates; the method comprising rubbing the pair of substrates at different rubbing intensities. ### Claim 20 (depends on 19) A method according to claim 19, wherein the difference in rubbing intensity is given by varying one or more of a feeding speed, a rotational speed and a pressing depth against the substrate of a rubbing roller. ### Claim 21 (depends on 20) A method according to claim 20, wherein the rubbing roller feeding speed is varied by at least 0.5% per substrate. ### Claim 22 (depends on 20) A method according to claim 20, wherein the rubbing roller rotational speed is varied by at least 1% per substrate. ### Claim 23 (depends on 20) A method according to claim 20, wherein the rubbing roller pressing depth is varied by at least 1% per substrate. ### Claim 24 (depends on 20) A method according to claim 20, wherein the rubbing intensity is varied stepwise. ### Claim 25 (depends on 20) A method according to claim 20, wherein the rubbing intensity is varied linearly. ### Claim 26 (depends on 19) A method according to claim 19, wherein said liquid crystal is a ferroelectric liquid crystal. ### Claim 27 (depends on 26) A method according to claim 26, wherein the substrates are rubbed to align the ferroelectric liquid crystal at a pretilt angle of at least 10 degrees. ### Claim 28 (depends on 19) A method according to claim 19, wherein the rubbing intensity is varied further corresponding to the number of pairs of substrates treated. ### Claim 29 (depends on 28) A method according to claim 28, wherein the further variation in rubbing intensity is given by one or more of a feeding speed, a rotational speed and a pressing depth against the substrate of a rubbing roller. ### Claim 30 (depends on 29) A method according to claim 29, wherein the rubbing roller feeding speed is varied by at least 0.5% per substrate. ### Claim 31 (depends on 29) A method according to claim 29, wherein the rubbing roller rotational speed is varied by at least 1% per substrate. ### Claim 32 (depends on 29) A method according to claim 29, wherein the rubbing roller pressing depth is varied by at least 1% per substrate. ### Claim 33 (depends on 29) A method according to claim 29, wherein the rubbing intensity is varied stepwise. ### Claim 34 (depends on 29) A method according to claim 29, wherein the rubbing intensity is varied linearly.