Patent US5423804A successfully refreshed from Google Patents.
US4884876A
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US
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Achromatic liquid crystal shutter for stereoscopic and other applications
Assignee: LEDOR LLC
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Filing: 1988-11-02
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Granted: 1989-12-05
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Expires: 2008-11-02
Abstract
Abstract An achromatic liquid-crystal shutter with high dynamic range, good transmission, and high speed. The inventive shutter reduces the phenomenon of "ghosting" (image doubling) that typically occurs in conventional plano-stereoscopic CRT displays due to the low dynamic range of surface mode liquid crystal electro-optical shutters included within such displays. The inventive shutter reduces crosstalk, thus allowing comfortable fusion to take place. In one preferred embodiment, the inventive shutter system is driven by a carrier-less voltage signal having time-averaged voltage substantially equal to zero, so that a simple, low power driving circuit suffices to drive the shutter. A pair of the inventive achromatic shutters may be employed in a wireless mode as a selection device for a field-sequential stereoscopic electronic display system.
Inventors
- 👤 Lenny Lipton
- 👤 Arthur Berman
- 👤 Lawrence D. Meyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:21
CPC Classifications
G; G03; G03B; G03B35/00; G03B35/18; G03B35/24; G02; G02B; G02B30/00; G02B30/20; G02B30/22; G02B30/25; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528; G02F1/137; G02F1/139; G02F1/1393; H; H04; H04N; H04N13/00; H04N13/30; H04N13/332; H04N13/341; G02F1/13363; G02F1/133638; H04N13/398
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
76 words
An achromatic liquid crystal shutter system, including: (a) a first polarizer, having an absorption axis oriented in a first direction; (b) a first surface mode liquid crystal cell, having a rub axis oriented in a second direction; and (c) a first analyzer, having a slow axis oriented in a third direction; wherein the first, second, and third directions are selected so that the system is capable of being driven so as to have optimal dynamic range.
Claim 2
Dependent Claim
76 words
An achromatic liquid crystal shutter system, including: (a) a first polarizer, having an absorption axis oriented in a first direction; (b) a first surface mode liquid crystal cell, having a rub axis oriented in a second direction; and (c) a first analyzer, having a slow axis oriented in a third direction; wherein the first, second, and third directions are selected so that the system is capable of being driven so as to have optimal dynamic range.
Claim 3
Dependent Claim
70 words
The system of claim 1, wherein the first analyzer includes a first retardation plate whose slow axis is oriented in said third direction and a second linear polarizer having an absorption axis oriented in a fourth direction, wherein the liquid crystal cell is positioned between the first polarizer and the first retardation plate, and the first retardation plate is positioned between the liquid crystal cell and the second linear polarizer.
Claim 4
Dependent Claim
51 words
The system of claim 2, wherein the first direction is separated from the second direction by an angle substantially equal to 45 degrees, the first direction is separated from the fourth direction by an angle substantially equal to 78 degrees, and the first direction is substantially parallel to the third direction.
Claim 5
Dependent Claim
114 words
The system of claim 1, wherein the first analyzer includes a first retardation plate whose slow axis is oriented in said third direction and a second linear polarizer having an absorption axis oriented in a fourth direction, wherein the liquid crystal cell is positioned between the first polarizer and the first retardation plate, the first retardation plate is positioned between the liquid crystal cell and the second linear polarizer, the second direction is separated from the first direction by an angle substantially equal to 45 degrees, the first direction is separated from the fourth direction by an angle substantially equal to 12 degrees, and the first direction is substantially orthogonal to the third direction.
Claim 6
Dependent Claim
90 words
The system of claim 1, wherein the first polarizer is a right circular polarizer including a linear polarizing element whose absorption axis is oriented in the first direction, the first analyzer includes a first retardation plate whose slow axis is oriented in said third direction and a second linear polarizer having absorption axis oriented in a fourth direction, wherein the first retardation plate is positioned between the first polarizer and the liquid crystal cell, and the liquid crystal cell is positioned between the first retardation plate and the second polarizer.
Claim 7
Dependent Claim
51 words
The system of claim 5, wherein the fourth direction is separated from the first direction by an angle substantially equal to 90 degrees, the second direction is separated from the third direction by an angle substantially equal to 45 degrees, and the first direction is substantially orthogonal to the fourth direction.
Claim 8
Dependent Claim
72 words
The system of claim 1, also including: a second retardation plate having a slow axis oriented in a fifth direction; and wherein: the first polarizer is a linear polarizer; the first and second retardation plates are positioned between the second polarizer and the liquid crystal cell; the liquid crystal cell is positioned between the first polarizer and the second retardation plate; and the first direction is substantially orthogonal to the second direction.
Claim 9
Dependent Claim
58 words
The system of claim 7, wherein the second direction is separated by an angle substantially equal to 45 degrees from the first direction; the fourth direction is separated by an angle substantially equal to 355 degrees from the second direction; and the fifth direction is separated by an angle substantially equal to 5 degrees from the second direction.
Claim 10
Dependent Claim
116 words
The system of claim 1, also including: a second retardation plate having a slow axis oriented in a fifth direction; and wherein: the first polarizer is a linear polarizer; the first and second retardation plates are positioned between the second polarizer and the liquid crystal cell; the liquid crystal cell is positioned between the first polarizer and the second retardation plate; the first direction is substantially orthogonal to the second direction; the second direction is separated by an angle substantially equal to 45 degrees from the first direction; the fourth direction is separated by an angle substantially equal to 33 degrees from the second direction; and the fifth direction is substantially parallel to the second direction.
Claim 11
Dependent Claim
41 words
The system of claim 1, including: (d) a driver electrically coupled to the first liquid crystal cell and capable of supplying a driving voltage signal to the cell that will drive the system so as to have the optimal dynamic range.
Claim 12
Dependent Claim
22 words
The system of claim 10, wherein the driving voltage signal is a carrier-less wave, whose time-averaged voltage is substantially equal to zero.
Claim 13
Dependent Claim
30 words
The system of claim 1, wherein the first, second, and third directions are selected so that the system is capable of being driven so as to have maximum dynamic range.
Claim 14
Dependent Claim
81 words
The system of claim 1, wherein the first cell comprises two substantially parallel glass plates each having two parallel flat faces and an outer edge, a gasket attached between the facing flat faces of the glass plates and having an outer edge, and liquid crystal material contained between the glass plates and the gasket, wherein the outer edge of the gasket aligns with the outer edges of the plates as a result of having been cut by a common cutting stroke.
Claim 15
Dependent Claim
85 words
An achromatic liquid crystal shutter system, including: (a) a first linear polarizer having a first absorption axis; (b) a surface mode liquid crystal cell with a rub axis oriented at a first angle with respect to the first absorption axis; and (c) an elliptical polarizer unit having a slow axis oriented at a second angle with respect to the rub axis, where the first and second angles are selected so that the system is capable of being driven so as to have optimal dynamic range.
Claim 16
Dependent Claim
85 words
An achromatic liquid crystal shutter system, including: (a) a first linear polarizer having a first absorption axis; (b) a surface mode liquid crystal cell with a rub axis oriented at a first angle with respect to the first absorption axis; and (c) an elliptical polarizer unit having a slow axis oriented at a second angle with respect to the rub axis, where the first and second angles are selected so that the system is capable of being driven so as to have optimal dynamic range.
Claim 17
Dependent Claim
41 words
The system of claim 14, also including: (d) a driver electrically coupled to the liquid crystal cell and capable of supplying a driving voltage signal to the cell that will drive the system so as to have the optimal dynamic range.
Claim 18
Dependent Claim
25 words
The system of claim 15, wherein the driving voltage signal consists of alternating AC signal portions, having high peak-to-peak voltage and low peak-to-peak voltage, respectively.
Claim 19
Dependent Claim
21 words
The system of claim 15, wherein the driving signal is a carrier-less signal whose time-averaged magnitude is substantially equal to zero.
Claim 20
Dependent Claim
63 words
The system of claim 14, wherein the first angle is substantially equal to 45 degrees, and the elliptical polarizer unit includes: (d) a quarter-wave retarding plate having a slow axis oriented substantially parallel to the first absorption axis; and (e) a second linear polarizer having a second absorption axis separated by an angle substantially equal to 78 degrees from the first absorption axis.
Claim 21
Dependent Claim
61 words
The system of claim 14, wherein the first angle is substantially equal to 45 degrees, and the elliptical polarizer unit includes: (f) a quarter-wave retarding plate having slow axis oriented substantially orthogonal to the first absorption axis; and (g) a second linear polarizer having a second absorption axis separated by an angle substantially equal to 348 degrees from the slow axis.
Claim 22
Dependent Claim
84 words
An achromatic liquid crystal shutter system, including: (a) a first linear polarizer having a first absorption axis; (b) a second polarizer having a second absorption axis; (c) a surface mode liquid crystal cell having a first rub axis; (d) a first retardation plate having a first slow axis; wherein: the first and second absorption axes, the first rub axis, and the first slow axis have relative orientation selected so that the system is capable of being driven so as to have optimal dynamic range.
Claim 23
Dependent Claim
84 words
An achromatic liquid crystal shutter system, including: (a) a first linear polarizer having a first absorption axis; (b) a second polarizer having a second absorption axis; (c) a surface mode liquid crystal cell having a first rub axis; (d) a first retardation plate having a first slow axis; wherein: the first and second absorption axes, the first rub axis, and the first slow axis have relative orientation selected so that the system is capable of being driven so as to have optimal dynamic range.
Claim 24
Dependent Claim
42 words
The system of claim 20, also including: (e) a driver electrically coupled to the liquid crystal cell, and capable of supplying a driving voltage signal to liquid crystal cell that will drive the system so as to have the optimal dynamic range.
Claim 25
Dependent Claim
56 words
The system of claim 20, wherein the second polarizer is a right circular polarizer including a linear polarizing element whose absorption axis is said second absorption axis, the retardation plate is positioned between the second polarizer and the liquid crystal cell, and the liquid crystal cell is positioned between the retardation plate and the first polarizer.
Claim 26
Dependent Claim
57 words
The system of claim 20, also including: (e) a second retardation plate having a second slow axis; and wherein: the second polarizer is a linear polarizer; the first and second retardation plates are positioned between the first the liquid crystal cell; and the liquid crystal cell is positioned between the second polarizer and the second retardation plate.
Claim 27
Dependent Claim
126 words
An achromatic shutter system capable of selecting alternating ones of the fields of a field-sequential image, including (a) a polarizer having an absorption axis; (b) a surface mode liquid crystal cell having a rub axis; (c) an analyzer having a slow axis, wherein the absorption axis, the rub axis, and the slow axis have relative orientation selected so that the system may be driven so as to have optimum dynamic range; (d) a receiver capable of receiving remotely generated synchronization pluses characterizing the image; and (e) a driving circuit electrically coupled to the receiver and the cell, and capable of producing a driving voltage signal for the cell, said driving voltage signal having low voltage portions at the field rate in synchronization pulses with the image.
Claim 28
Dependent Claim
126 words
An achromatic shutter system capable of selecting alternating ones of the fields of a field-sequential image, including (a) a polarizer having an absorption axis; (b) a surface mode liquid crystal cell having a rub axis; (c) an analyzer having a slow axis, wherein the absorption axis, the rub axis, and the slow axis have relative orientation selected so that the system may be driven so as to have optimum dynamic range; (d) a receiver capable of receiving remotely generated synchronization pluses characterizing the image; and (e) a driving circuit electrically coupled to the receiver and the cell, and capable of producing a driving voltage signal for the cell, said driving voltage signal having low voltage portions at the field rate in synchronization pulses with the image.
Claim 29
Dependent Claim
33 words
The system of claim 24, wherein the amplitude of each voltage portion is selected so as to drive the subsystem comprising elements (a), (b), and (c) so as to have maximum dynamic range.
Claim 30
Dependent Claim
22 words
The system of claim 24, wherein the driving voltage signal is a carrier-less signal whose time-averaged magnitude is substantially equal to zero.
Claim 31
Dependent Claim
43 words
The system of claim 24, wherein the receiver is capable of receiving an infrared signal modulated by the synchronization pulses, and wherein elements (b), (d) and (e) are mounted in an eyeglass frame dimensioned to be worn by an observer of the image.
Claim 32
Dependent Claim
80 words
The system of claim 24, wherein the cell comprises two substantially parallel glass plates each having two parallel flat faces and an outer edge, a gasket attached between the facing flat faces of the glass plates and having an outer edge, and liquid crystal material contained between the glass plates and the gasket, wherein the outer edge of the gasket aligns with the outer edges of the plates as a result of having been cut by a common cutting stroke.
Claim 33
Dependent Claim
48 words
The system of claim 24, wherein the polarizer is positioned remotely from the surface mode liquid crystal cell and the analyzer, and also including: an emitter for generating the synchronization pulses and transmitting the synchronization pulses to the receiver, wherein the emitter is positioned remotely from the receiver.
Claim 34
Dependent Claim
25 words
The system of claim 24, also including: a monitor for displaying the field-sequential image, wherein the emitter and the polarizer are mounted on the monitor.
Claim 35
Dependent Claim
74 words
An achromatic liquid crystal shutter system, including: (a) a polarizer, having an absorption axis oriented in a first direction; (b) a liquid crystal cell, having an alignment layer with an alignment axis oriented in a second direction; (c) an analyzer, having a slow axis oriented in a third direction; wherein the first, second, and third directions are selected so that the system is capable of being driven so as to have optimal dynamic range.
Claim 36
Dependent Claim
74 words
An achromatic liquid crystal shutter system, including: (a) a polarizer, having an absorption axis oriented in a first direction; (b) a liquid crystal cell, having an alignment layer with an alignment axis oriented in a second direction; (c) an analyzer, having a slow axis oriented in a third direction; wherein the first, second, and third directions are selected so that the system is capable of being driven so as to have optimal dynamic range.
Claim 37
Dependent Claim
42 words
The system of claim 31, also including: (d) a driver electrically coupled to the liquid crystal cell and capable of supplying a carrier-less driving voltage signal to the cell that will drive the system so as to have the optimal dynamic range.
Claim 38
Dependent Claim
134 words
An achromatic shutter system capable of selecting alternating ones of the fields of a field sequential image, including: (a) a polarizer having an absorption axis; (b) a liquid crystal cell having an alignment layer with an alignment axis oriented in a second direction; (c) an analyzer having a slow axis, wherein the absorption axis, the alignment axis, and the slow axis have relative orientation selected so that the system may be driven so as to have optimum dynamic range; (d) a receiver capable of receiving remotely generated synchronization pulses characterizing the image; and (e) a driving circuit electrically coupled to the receiver and the cell and capable of producing a driving voltage signal for the cell, said driving voltage signal having low voltage portions at the field rate in synchronization pulses with the image.
Claim 39
Dependent Claim
134 words
An achromatic shutter system capable of selecting alternating ones of the fields of a field sequential image, including: (a) a polarizer having an absorption axis; (b) a liquid crystal cell having an alignment layer with an alignment axis oriented in a second direction; (c) an analyzer having a slow axis, wherein the absorption axis, the alignment axis, and the slow axis have relative orientation selected so that the system may be driven so as to have optimum dynamic range; (d) a receiver capable of receiving remotely generated synchronization pulses characterizing the image; and (e) a driving circuit electrically coupled to the receiver and the cell and capable of producing a driving voltage signal for the cell, said driving voltage signal having low voltage portions at the field rate in synchronization pulses with the image.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-04 | 1993-06-05 | 1993-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-04 | 1997-06-05 | 1997-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-04 | 2001-06-05 | 2001-12-05 | $7700.00 | Window Closed / Lapsed |