US4591886A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Driving method and apparatus for optical printer with liquid-crystal switching element
Assignee: Hitachi Ltd
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Filing: 1984-07-09
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Granted: 1986-05-27
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Expires: 2004-07-09
Abstract
Abstract A driving method for an optical printer and an optical printer having a liquid-crystal light switching element including a ferroelectric liquid crystal sandwiched between a pair of plates provided with electrodes on adjacent surfaces thereof. The liquid-crystal light switching element is disposed between a light source and a movable photosensitive surface and controlled so as to at least one of transmit and block light from the light source to the photosensitive surface for enabling a printing operation. Voltages v1 and v2 are applied to the liquid-crystal switching element substantially in accordance with the equation <IMAGE> and the intensity of light from the light source incident on the liquid-crystal switching element is controlled so that incident light intensity during a period T2 is weaker than the incident light intensity during a period T1, where t0, t1, t2 and t3 represents times, T1 (=t1-t0) is the period during which a printing operation is effected, T2 (=t3-t2) is the period during which the photosensitive surface moves, v1 is the voltage which is applied to the liquid-crystal switching element during the period T1, and v2 is the voltage which is applied to the liquid-crystal switching element during the period T2.
Inventors
- 👤 Takao Umeda
- 👤 Kazuya Ooishi
- 👤 Tatsuo Igawa
- 👤 Yasuro Hori
- 👤 Yoshiharu Nagae
- 👤 Masato Isogai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:06
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1238; G06K15/1242; G06K15/1252
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
226 words
A driving method for an optical printer having a liquid-crystal light switching element including a ferroelectric liquid crystal sandwiched between a pair of plates provided with electrodes on adjacent surfaces thereof, the liquid-crystal light switching element being disposed between light source means and a movable photosensitive surface and being switched so as to at least one of transmit and block light from the light source means to the photosensitive surface for enabling a printing operation, the method comprising the steps of applying voltages v 1 and v 2 to the liquid-crystal switching element substantially in accordance with the equation ##EQU8## and controlling the intensity of light from the light source means incident on the liquid-crystal switching element so that incident light intensity during a period T 2 is weaker than the incident light intensity during a period T 1 , where t 0 , t 1 , t 2 and t 3 represent times, T 1 (=t 1 -t 0 ) is the period during which a printing operation is effected, T 2 (=t 3 -t 2 ) is the period during which the photosensitive surface moves, v 1 is the voltage which is applied to the liquid-crystal switching element during the period T 1 , and v 2 is the voltage which is applied to the liquid-crystal switching element during the period T 2 .
Claim 2
Dependent Claim
226 words
A driving method for an optical printer having a liquid-crystal light switching element including a ferroelectric liquid crystal sandwiched between a pair of plates provided with electrodes on adjacent surfaces thereof, the liquid-crystal light switching element being disposed between light source means and a movable photosensitive surface and being switched so as to at least one of transmit and block light from the light source means to the photosensitive surface for enabling a printing operation, the method comprising the steps of applying voltages v 1 and v 2 to the liquid-crystal switching element substantially in accordance with the equation ##EQU8## and controlling the intensity of light from the light source means incident on the liquid-crystal switching element so that incident light intensity during a period T 2 is weaker than the incident light intensity during a period T 1 , where t 0 , t 1 , t 2 and t 3 represent times, T 1 (=t 1 -t 0 ) is the period during which a printing operation is effected, T 2 (=t 3 -t 2 ) is the period during which the photosensitive surface moves, v 1 is the voltage which is applied to the liquid-crystal switching element during the period T 1 , and v 2 is the voltage which is applied to the liquid-crystal switching element during the period T 2 .
Claim 3
Dependent Claim
13 words
The driving method according to claim 1, wherein t 1 =t 2 .
Claim 4
Dependent Claim
13 words
The driving method according to claim 1, wherein T 1 ≧T 2 .
Claim 5
Dependent Claim
31 words
The driving method according to claim 1, wherein the voltage v 2 having a peak of one polarity is applied during at least a portion of the period T 2 .
Claim 6
Dependent Claim
29 words
The driving method according to claim 4, wherein the peak of one polarity of the voltage v 2 is provided at the end of the period T 2 .
Claim 7
Dependent Claim
33 words
The driving method according to claim 1, wherein the incident light intensity on the liquid-crystal switching element is controlled so that the incident light intensity during the period T 2 is substantially zero.
Claim 8
Dependent Claim
32 words
The driving method according to claim 1, wherein the ferroelectric liquid crystal is a liquid crystal having at least one of a chiral smectic C phase and a chiral smectic H phase.
Claim 9
Dependent Claim
46 words
The driving method according to claim 1, further comprising the step of driving the light source means to intermittently emit light incident onto the liquid-crystal switching element, and driving the light source means to emit light in synchronism with the switching of the liquid-crystal switching element.
Claim 10
Dependent Claim
32 words
The driving method according to claim 8, wherein the light source means is driven so as to emit light incident on the liquid-crystal switching element only during the period T 1 .
Claim 11
Dependent Claim
218 words
An optical printer comprising a liquid-crystal light switching element including a ferroelectric liquid crystal sandwiched between a pair of plates provided with electrodes on adjacent surfaces thereof, the liquid-crystal switching element being disposed between light source means and a movable photosensitive surface and being switched so as to at least one of transmit and block light from the light source means to the photosensitive surface for enabling a printing operation, means for applying voltages v 1 and v 2 to the liquid-crystal switching element in accordance with the equation ##EQU9## and means for controlling the intensity of light from the light source means incident on the liquid-crystal switching element so that incident light intensity during a period T 2 is weaker than the incident light intensity during a period T 1 , where t 0 , t 1 , t 2 and t 3 represent times, T 1 (=t 1 -t 0 ) is the period during which a printing operation is effected, T 2 (=t 3 -t 2 ) is the period during which the photosensitive surface moves, v 1 is the voltage which is applied to the liquid-crystal switching element during the period T 1 , and v 2 is the voltage which is applied to the liquid crystal element during the period T 2 .
Claim 12
Dependent Claim
218 words
An optical printer comprising a liquid-crystal light switching element including a ferroelectric liquid crystal sandwiched between a pair of plates provided with electrodes on adjacent surfaces thereof, the liquid-crystal switching element being disposed between light source means and a movable photosensitive surface and being switched so as to at least one of transmit and block light from the light source means to the photosensitive surface for enabling a printing operation, means for applying voltages v 1 and v 2 to the liquid-crystal switching element in accordance with the equation ##EQU9## and means for controlling the intensity of light from the light source means incident on the liquid-crystal switching element so that incident light intensity during a period T 2 is weaker than the incident light intensity during a period T 1 , where t 0 , t 1 , t 2 and t 3 represent times, T 1 (=t 1 -t 0 ) is the period during which a printing operation is effected, T 2 (=t 3 -t 2 ) is the period during which the photosensitive surface moves, v 1 is the voltage which is applied to the liquid-crystal switching element during the period T 1 , and v 2 is the voltage which is applied to the liquid crystal element during the period T 2 .
Claim 13
Dependent Claim
13 words
The optical printer according to claim 1, wherein t 1 =t 2 .
Claim 14
Dependent Claim
13 words
The optical printer according to claim 1, wherein T 1 ≧T 2 .
Claim 15
Dependent Claim
29 words
The optical printer according to claim 1, wherein the voltage v 2 has a peak of one polarity during at least a portion of the period T 2 .
Claim 16
Dependent Claim
29 words
The optical printer according to claim 13, wherein the peak of one polarity of the voltage v 2 is provided at the end of the period T 2 .
Claim 17
Dependent Claim
40 words
The optical printer according to claim 1, wherein the means for controlling the intensity of the light incident on the liquid-crystal switching element controls the intensity of the light incident to be substantially zero during the period T 2 .
Claim 18
Dependent Claim
32 words
The optical printer according to claim 1, wherein the ferroelectric liquid crystal is a liquid crystal having at least one of a chiral smectic C phase and a chiral smectic H phase.
Claim 19
Dependent Claim
40 words
The optical printer according to claim 1, further comprising means for driving the light source means so that the light source means provides light incident on the liquid-crystal switching element in synchronism with the switching of the liquid-crystal switching element.
Claim 20
Dependent Claim
37 words
The optical printer according to claim 17, wherein the means for driving the light source means enables the light source means to emit light incident on the liquid-crystal switching element only during the period T 1 .
Claim 21
Dependent Claim
20 words
The optical printer according to claim 1, including means for moving the photosensitive surface during the period T 2 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-26 | 1989-11-25 | 1990-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-26 | 1993-11-25 | 1994-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-26 | 1997-11-25 | 1998-05-27 | $7700.00 | Window Closed / Lapsed |