US6304302B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display system and light projection system
Assignee: Transpacific IP Ltd
•
Filing: 1999-02-24
•
Granted: 2001-10-16
•
Expires: 2019-02-24
Abstract
Abstract A projection system used in a liquid crystal display (LCD) system is provided. The projection system has a light source, a polarization set which further includes a double dove prism, a vertical prism and a half-wave plate, a polarization beam splitter (PBS), a dichroic prism, and a projection lens. The light source emits a white light, which enters the polarization set and is split into a P-state polarized blue light and a mixed light. The mixed light includes an S-state polarized red light and an S-state polarized green light. The PBS allows the P-state polarized blue light to transmit and enter onto a blue light LCD panel, and deflects the mixed light by 90°. The dichroic prism splits the S-state polarized red light and the S-state polarized green light of the mixed light, which respectively enter a red light LCD panel and a green light LCD panel. The projection lens collects light from the red, green, blue LCD panels and project the lights onto a screen.
Inventors
- 👤 Junejei Huang
- 👤 Fang-Chuan Ho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:58
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
241 words
A projection system with a liquid crystal display (LCD) system, the projection system comprising: a light source, used to emit a light beam; a double-dove-prism set, used to split the light beam into a first blue light BP with P-state polarization and a mixed light, wherein the mixed light comprises a red/green light with S-state polarization and a second blue light BP′ with P-state polarization; a polarization beam splitter (PBS), used to accept the first blue light BP and the mixed light, in which the PBS allows any passing light with P-state polarization to continuous travel through without deflection but deflects any passing light with S-state polarization; a dichroic prism, used to intercept the mixed light and split a deflected constituent of the mixed light into a polarized green light and a polarized red light; a red LCD panel, a green LCD panel, and a blue LCD panel, respectively used to reflect the polarized red light, the polarized green light, and both the first blue light BP and the second blue light BP′ back to the PBS with inverted polarization state, in which the first blue light BP and the second blue light BP′ respectively become a blue light BS and a second blue light BS′; and a projection lens, used to collect the polarized red light, the polarized green light, and both the first blue light BS and the second blue light BS′, and project them onto a desired direction.
Claim 2
Dependent Claim
241 words
A projection system with a liquid crystal display (LCD) system, the projection system comprising: a light source, used to emit a light beam; a double-dove-prism set, used to split the light beam into a first blue light BP with P-state polarization and a mixed light, wherein the mixed light comprises a red/green light with S-state polarization and a second blue light BP′ with P-state polarization; a polarization beam splitter (PBS), used to accept the first blue light BP and the mixed light, in which the PBS allows any passing light with P-state polarization to continuous travel through without deflection but deflects any passing light with S-state polarization; a dichroic prism, used to intercept the mixed light and split a deflected constituent of the mixed light into a polarized green light and a polarized red light; a red LCD panel, a green LCD panel, and a blue LCD panel, respectively used to reflect the polarized red light, the polarized green light, and both the first blue light BP and the second blue light BP′ back to the PBS with inverted polarization state, in which the first blue light BP and the second blue light BP′ respectively become a blue light BS and a second blue light BS′; and a projection lens, used to collect the polarized red light, the polarized green light, and both the first blue light BS and the second blue light BS′, and project them onto a desired direction.
Claim 3
Dependent Claim
118 words
The projection system of claim 1 , wherein the double-dove-prism set comprises: a double dove prism, which further comprises a first optical film, a second optical film parallel to the first optical film, and a reflection mirror, wherein the first optical film behaves like a PBS for blue light constituent and behaves like a dichroic mirror for red/green light constituent and the second optical film behaves like a PBS for red/green light constituent and behaves like a dichroic mirror for blue light constituent; a vertical prism, used to compensate the double dove prism to form a box corner; and a half-wave plate, located on the vertical prism so as to change a polarization state of any passing light.
Claim 4
Dependent Claim
211 words
The projection system of claim 2 , wherein the double-dove-prism set comprises a light path so as to produce the first blue light BP and the mixed light, in which the light path structure comprises that: as the light beam enters the double dove set, the first optical film splits the light beam into the first blue light BP which is further deflected by the reflection mirror without passing the half-wave plate, and a first mixed light RG+BS which is deflected by the first optical film onto the second optical film; the second optical film splits the first mixed light RG+BS into a second mixed light RPGP+BS without deflection and a third mixed light RSGS with deflection; the third mixed light RSGS is deflected out of the double-dove-prism set by the first optical film without passing the half-wave plate; the second mixed light RPGP+BS passes the vertical prism and the half-wave plate and becomes a fourth mixed light RS′GS′+BP′, in which BP′ represents the second blue light and polarization states are inverted due to the half-wave plate so that the original mixed light includes the fourth mixed light RS′GS′+BP′, the first blue light BP, and the third mixed light RSGS, all of which are split and accordingly deflected by the PBS.
Claim 5
Dependent Claim
24 words
The projection system of claim 3 , wherein each time of light deflection in the projection system comprises substantially deflecting passing light by 90°.
Claim 6
Dependent Claim
17 words
The projection system of claim 3 , wherein the first optical film comprises a first stacked-layer structure.
Claim 7
Dependent Claim
24 words
The projection system of claim 5 , wherein the first stacked-layer structure comprises at least two different optical film materials with different refractive indices.
Claim 8
Dependent Claim
28 words
The projection system of claim 5 , wherein the first optical film is at least suitable for at range of wavelength between about 400 nm and 690 nm.
Claim 9
Dependent Claim
17 words
The projection system of claim 3 , wherein the second optical film comprises a second stacked-layer structure.
Claim 10
Dependent Claim
23 words
The projection system of claim 8 , wherein the second stacked-layer structure comprises at least two different film materials with different refractive indices.
Claim 11
Dependent Claim
28 words
The projection system of claim 8 , wherein the second optical film is at least suitable for at range of wavelength between about 400 nm and 690 nm.
Claim 12
Dependent Claim
24 words
The projection system of claim 1 , wherein each time of light deflection in the projection system comprises substantially deflecting passing light by 90°.
Claim 13
Dependent Claim
31 words
The projection system of claim 1 , wherein the green LCD panel and the red LCD panel are properly mounted on the dichroic prism so as to reduce a reflection distance.
Claim 14
Dependent Claim
14 words
The projection system of claim 1 , wherein the light source comprises a lamp.
Claim 15
Dependent Claim
16 words
The projection system of claim 1 , wherein the light beam comprises a white light beam.
References Cited (Backward Citations)
US5575548A
Cited
US5729306A
Cited
US5812223A
Cited
US6130728A
Cited
US6010221A
Cited
US6042234A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-10-15 | 2005-04-16 | 2005-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-10-15 | 2009-04-16 | 2009-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-10-15 | 2013-04-16 | 2013-10-16 | $7700.00 | Window Closed / Lapsed |