CN1790093A - Projection display system - Google Patents

Abstract

A projection display system comprising: a lighting device, a reflection type light valve, a prism group arranged between the lighting device and the reflection type light valve, and a collimation device arranged between the prism group and the reflection type light valve and capable of converting non-parallel light beams incident on the prism group into parallel light beams; the light beam is incident into the prism set, reflected by the light beam selecting surface of the prism set, passes through the collimating device, and then enters the reflective light valve, and is processed by the reflective light valve to generate the modulated light beam, and finally, the modulated light beam passes through the collimating device and the light beam selecting surface and is projected into a projection lens. The projection display system can reduce the back focal length of the system and the volume of the projection lens.

Description

projection display system

[technical field]

The present invention relates to a projection display system, in particular to a projection display system with a reflective light valve.

[Background technique]

The conventional projection display system uses the light beams emitted by the light source to focus on one or several light valves, so that the light beams carry image signals, and then project images onto the screen through the lens; however, due to the prevalence of multimedia presentations, in order to achieve portability , The projection system and equipment are designed towards the goal of thinness and shortness. Therefore, the display devices for general presentations mostly use single-chip reflective light valves.

As for the projection display system 10 of the single reflective light valve, as disclosed in U.S. Patent No. 5,552,922, please refer to FIG. There are two mutually parallel surfaces 121, 122, the light valve 13 and a lens 14 are arranged adjacent to the surfaces 121, 122, the light valve 13 is a digital micro-mirror device (Digital Micro-mirror Device, DMD), and the illumination beam provided by the light source 11 First enter the prism (Prism) 12, and then use total reflection to project the light beam on the light valve 13, then the light beam reflected by the light valve 13 passes through the prism 12, and finally, the light beam enters the lens 14 and is projected onto the screen (not shown in the figure) However, the back focal length (Back Focal Length, BFL) of the system refers to the distance from the last surface of a lens system to its imaging surface, and the distance between the light valve 13 (ie imaging surface) and the lens 14 (ie lens system) in the above system The prism 12 is installed, resulting in a large back focal length of the system, and the larger the back focal length, the greater the aberration of the image formed on the lens 14 and the need to use a larger lens 14, so the volume of the entire system cannot be reduced.

And another single reflective light valve projection display system 20, as disclosed in U.S. Patent No. 5,309,188, please refer to FIG. Between the lens 24, and the coupling prism group 22 includes an isosceles right angle prism (Right angle prism) 221 and a wedge shape prism (Wedge prism) 222, and one side of the wedge shape prism 222 is the hypotenuse with the isosceles right angle prism 221 Adjacent, the light valve 23 is arranged adjacent to one side of the right-angle prism 221, the light provided by the light source 21 is incident on the light valve 23 after passing through the coupling prism group 22, after the light is reflected by the light valve 23, passes through the right-angle prism 221 After being reflected by the hypotenuse, it is projected into the lens 24, and finally, the image is presented on the screen (not shown in the figure); however, although the above-mentioned system changes the light valve 23 and the lens 24 to be vertically arranged, the coupling prism group 22 still causes rear The focal length cannot be effectively shortened.

To sum up, the existing single reflective light valve projection display system still has the problems of long back focal length and large size of projection lens, and relevant research and development personnel have to propose a solution.

[Content of the invention]

The purpose of the present invention is to provide a projection display system. A collimation device is arranged between the reflective light valve and the prism group to reduce the back focal length of the system and the size of the projection lens.

Another object of the present invention is to provide a projection display system, which reduces the back focal length of the system and the size of the projection lens by setting one of the light-emitting surfaces of the curved prism group as an optical curved surface.

Another object of the present invention is to provide a projection display system, which simplifies the imaging group by setting the light emitting surface of the curved prism group adjacent to the imaging group as an optical curved surface.

Yet another object of the present invention is to provide a projection display system, which simplifies the lighting device by setting the incident surface of the prism group adjacent to the lighting device as an optical curved surface.

To achieve the above purpose, a projection display system of the present invention includes:

A lighting device provides a non-parallel lighting beam; a reflective light valve is used to process the lighting beam to generate a modulated light beam; a prism group is arranged between the lighting device and the reflective light valve between, and it has a beam selection surface, the beam selection surface reflects the illumination beam incident on the prism group from the illumination device, and allows the modulated beam reflected by the reflective light valve to pass through; it is characterized in that it also includes A collimation device is arranged between the prism group and the reflective light valve to convert the non-parallel illumination beam incident on the prism group into a parallel illumination beam;

The illuminating light beam is incident on the prism group, reflected by the light beam selection surface, passes through the collimation device, and then incident on the reflective light valve, the modulated light beam is generated after being processed by the reflective light valve, and finally, The modulated light beam is projected into a projection lens through the collimation device and the light beam selection surface.

The present invention also provides a projection display system, which includes: an illumination device that provides a non-parallel illumination beam; a reflective light valve that processes the illumination beam to generate a modulated beam; a prism group, It is arranged between the illuminating device and the reflective light valve, and it has a beam selection surface, which allows the illuminating beam incident on the prism group from the illuminating device to pass through, and makes the reflective light Modulated beam reflection for valve reflection;

It is characterized in that: it also includes a collimation device, which is arranged between the prism group and the reflective light valve, so as to convert the non-parallel illumination beam incident on the prism group into a parallel illumination beam; the illumination beam is incident on the prism group, and pass through the beam selection surface and the collimation device, and then incident on the reflective light valve, after being processed by the reflective light valve, the modulated beam is generated, and finally, the modulated beam passes through the collimator The straight device is reflected through the selective surface of the light beam and projected into a projection lens.

The present invention also provides a projection display system, which is characterized in that it includes: an illuminating device that provides an illuminating light beam; a curved prism group that is arranged on the light path of the illuminating light beam, and has an incident surface and A plurality of light-emitting surfaces, at least one of which is an optically curved surface; a projection lens disposed adjacent to the light-emitting surface; and a reflective light valve disposed adjacent to the light-emitting surface for processing the illumination light beam to generate a modulated light beam;

The illuminating light beam enters the curved prism group from the incident surface and is incident on the reflective light valve. After being processed by the reflective light valve, the modulated light beam is generated. Finally, the modulated light beam is projected through the curved prism group. in the projection lens.

The projection display system of the present invention can reduce the back focal length of the system and the volume of the projection lens, and can simplify the imaging group and the lighting device.

[Description of drawings]

FIG. 1 is a schematic diagram of an optical system of a conventional projection display system.

FIG. 2 is a schematic diagram of an optical system of another conventional projection display system.

3A, 3B, 3C and 3D are optical schematic diagrams of the projection display system according to the first embodiment of the present invention.

FIG. 4 is an optical schematic diagram of a projection display system in which the second light-emitting surface is a lens surface according to the present invention.

FIG. 5 is an optical schematic diagram of a projection display system in which the first incident surface is a lens surface according to the present invention.

FIG. 6 is an optical schematic diagram of a projection display system derived from the first embodiment of the present invention.

FIG. 7 is an optical schematic diagram of a projection display system according to a second embodiment of the present invention.

8 is an optical schematic diagram of a projection display system in which the first light-emitting surface and the second light-emitting surface are lens surfaces according to the present invention.

9 is an optical schematic diagram of a projection display system in which the first light-emitting surface and the first incident surface are lens surfaces according to the present invention.

FIG. 10 is an optical schematic diagram of a projection display system derived from the second embodiment of the present invention.

FIG. 11 is an optical schematic diagram of a projection display system according to a third embodiment of the present invention.

FIG. 12 is an optical schematic diagram of a projection display system according to a fourth embodiment of the present invention.

[Detailed ways]

Relevant present invention is to achieve above-mentioned purpose, the technical means that adopts and all the other effects, give four preferred embodiments hereby, and cooperate accompanying drawing to illustrate as follows:

First embodiment:

3A, the projection display system 30 of the present invention includes an illumination device (not shown), a reflective light valve 32, a prism group 33, a collimating device (Collimating means) 34 and a projection lens 35 ; wherein the lighting device provides a non-parallel lighting beam 31; the prism group 33 is arranged between the lighting device and the reflective light valve 32, and has a beam selection surface 331, a first incident surface 332, a first light output surface 333 and a second light-emitting surface 334, the beam selection surface 331 can reflect the illumination beam 31 of the incident prism group 33 by the illumination device, and can make the modulation beam 36 reflected by the reflective light valve 32 penetrate; the collimation device 34 It is arranged between the prism group 33 and the reflective light valve 32 to convert the non-parallel illumination beam 31 incident on the prism group 33 into a parallel illumination beam 31A. The collimation device 34 can be a lens or a diffractive element (Diffactive Optical Element, DOE); the projection lens 35 is arranged adjacent to the second light-emitting surface 334, and the main plane of the projection lens 35 is parallel to the reflective light valve 32; the reflective light valve 32 is arranged adjacent to the first light-emitting surface 333, and is used for processing illumination The light beam 31A is to generate a modulated light beam 36, and the light valve 32 is a digital micromirror device (Digital micromirror device, DMD);

And the above-mentioned prism group 33 can further comprise a first prism 335 and a second prism 336, the first incident surface 332, the first light-emitting surface 333 and the beam selection surface 331 are connected to form the first prism 335, the beam selection surface 331 and the second light-emitting surface 334 are located on the adjacent surface of the second prism 336, and the beam selection surface 331 is formed by bonding the two surfaces of the first prism 335 and the second prism 336 with an air gap, and The beam selection surface 331 can be a plane (as shown in Figure 3A) or a curved surface (as shown in Figure 3B);

The non-parallel illuminating beam 31 is incident on the first prism 335 of the prism group 33 by the first incident surface 332 , passes through the beam selection surface 331 to reflect the illuminating beam 31 , passes through the collimating device 34 and turns into a parallel illuminating beam 31A, and then incident on the reflective light valve 32, after being processed by the reflective light valve 32, the modulated light beam 36 is generated, and then the modulated light beam 36 passes through the collimation device 34, the first light exit surface 333, the light beam selection surface 331, and the second light-emitting surface 334 are projected into the projection lens 35 , and finally the projection lens 35 presents an image on a screen (not shown).

Because the collimating device 34 of a lens is arranged between the reflective light valve 32 and the prism group 33, the back focal length a of the system is from the collimating device 34 (i.e. the surface of the lens) to the surface of the light valve 33 (i.e. the imaging surface) The distance causes the back focus a of the system to be shortened and the size of the projection lens 35 to be reduced. In addition, the modulated light beam 36 reflected by the light valve 32 can be converged by the collimation device 34 and then projected on the projection lens 35. The size of the projection lens 35 can be reduced to reduce the component cost, and the collimation device 34 can be used to replace the lens function of the projection lens 35 or the lighting device, so the projection lens 35 or the lighting device can be simplified.

Please refer to FIG. 3C, the collimation device can be integrally formed with the first prism 335, or formed by attaching a lens on the first light-emitting surface 333 (as shown in FIG. 3D);

The prism group 33 and the collimation device 34 also form a module with the projection lens 35, so that the number of system parts can be simplified and the prism group 33 and the collimation device 34 can be fixed through the housing of the projection lens 35;

In addition, in this embodiment, the second light-emitting surface 334 can also be set as an optical curved surface (as shown in FIG. 4 ) to simplify the number of lenses of the projection lens 35, or the first incident surface 332 can be set as an optical curved surface (such as 5) to simplify the number of lenses of the lighting device, so that the projection lens and the lighting device can be simplified.

Furthermore, referring to FIG. 6, the first light-emitting surface 333 in FIG. The surface of the valve 32 (i.e., the imaging surface), so the back focal length b is the distance from the optical curved surface to the surface of the light valve 32 (i.e., the imaging surface), which shortens the back focal length b of the system and reduces the size and number of lenses of the projection lens.

Second embodiment:

Please refer to FIG. 7, the projection display system 40 of the present invention includes an illuminating device (not shown), a curved prism group 422, a projection lens 42 and a light valve 43; wherein the illuminating device provides an illuminating light beam 41; The curved prism group 422 has a first incident surface 4221, a first light exit surface 4222 and a second light exit surface 4223, and the first light exit surface 4222 is an optical curved surface, the first light exit surface 4222 and the second light exit surface 4223 The prism group 422 can be arranged inside or outside the projection lens 42, and the number of parts can be simplified when the prism group 422 is arranged inside the projection lens 42; the projection lens 42 is adjacent to the second light-emitting surface 4223 Setting; the light valve 43 is arranged adjacent to the first light-emitting surface 4222, and is used to process the illumination beam 41 to generate a modulated light beam 44, and the light valve 43 is a digital micromirror device (Digital Micromirror device, DMD);

The above-mentioned prism group 422 further includes a rectangular prism 4224, a wedge prism 4225, a third light-emitting surface 4226, and a second total reflection surface 4227. On the side, the first light-emitting surface 4222, the second light-emitting surface 4223 and the second total reflection surface 4227 are connected to form a rectangular prism 4224, and the second total reflection surface 4227 is the hypotenuse of the rectangular prism 4224, while the third The light emitting surface 4226 is connected to the second total reflection surface 4227 with an air layer 4228 therebetween (that is, forming a beam selection surface).

The illuminating light beam 41 enters the wedge-shaped prism 4225 of the prism group 422 from the first incident surface 4221, passes through the third light-emitting surface 4226, the second total reflection surface 4227 and the first light-emitting surface 4222 to project the illuminating light beam 41 to the light valve 43 Above, the modulated light beam 44 is generated after being processed by the light valve 43, the modulated light beam 44 passes through the first light-emitting surface 4222 and is incident on the rectangular prism 4224, and the modulated light beam 44 is reflected by the second total reflection surface 4227, and then the modulated light beam 44 passes through The second light emitting surface 4223 is projected into the imaging group 421, and finally the imaging group 421 presents the image on a screen (not shown).

Since the first light-emitting surface 4222 of the prism group 422 is set as an optical curved surface, the back focal length of the system is the distance from the first light-emitting surface 4222 (that is, the lens surface) to the surface of the light valve 43 (that is, the imaging surface), so that the back focus of the system is The focal length is shortened and the size of the projection lens 42 is reduced.

In addition, in this embodiment, the second light-emitting surface 4223A can also be set as an optical curved surface (as shown in FIG. 8 ) to simplify the number of lenses of the imaging group 421, and the second light-emitting surface 4223A can be the same as the first light-emitting surface 4222. The connection forms a semi-spherical surface, so that the prism group can be manufactured with a simple spherical surface processing method.

Furthermore, the first incident surface 4221A can also be set as an optical curved surface (as shown in FIG. 9 ) to simplify the number of lenses of the lighting device, so that the lighting device can be simplified.

In addition, as shown in FIG. 10, the first light-emitting surface 4222 in FIG. The surface of the light valve 43 (that is, the imaging surface) can shorten the back focus.

Third embodiment:

11, the projection display system 60 of the present invention includes an illumination device (not shown), a reflective light valve 62, a prism group 63, a collimating device (Collimating means) 64 and a projection lens 65 ; wherein the lighting device provides a non-parallel lighting beam 61; the prism group 63 is arranged between the lighting device and the reflective light valve 62, and has a beam selection surface 631, a first incident surface 632, a first light output surface 633 and a second light-emitting surface 634, the beam selection surface 631 can be penetrated by the illumination beam 61 of the incident prism group 63 of the illumination device, and can reflect the modulated beam 66 reflected by the reflective light valve 62; the collimation device 64 is Set between the prism group 63 and the reflective light valve 62, to convert the non-parallel illumination beam 61 incident on the prism group 63 into a parallel illumination beam 61A, the collimation device 64 can be a lens or a diffractive element (Diffactive Optical Element , DOE); the projection lens 65 is arranged adjacent to the second light-emitting surface 634, and the main plane of the projection lens 65 is perpendicular to the reflective light valve 62; the reflective light valve 62 is arranged adjacent to the first light-emitting surface 633, and is used for processing illumination The light beam 61A is to generate a modulated light beam 66, and the light valve 62 is a digital micromirror device (Digital micromirror device, DMD);

And above-mentioned prism group 63 can further comprise a wedge-shaped prism 635 and rectangular prism 636, and the first incident surface 632 and beam selection surface 631 are to be positioned at its non-adjacent surface of wedge-shaped prism 635, and the beam selection surface 631, the first light output The surface 633 and the second light-emitting surface 634 constitute a rectangular prism 636, and the beam selection surface 631 is formed by bonding the two surfaces of the wedge-shaped prism 635 and the rectangular prism 636 with an air gap;

The non-parallel illuminating light beam 61 is converted into a parallel illuminating light beam 61A by passing through the light beam selection surface 631, the first light-emitting surface 633 and the collimating device 64 after the first incident surface 632 enters the wedge-shaped prism 635 of the prism group 63, and then Incident on the reflective light valve 62, the modulated light beam 66 is generated after being processed by the reflective light valve 62, and then the modulated light beam 66 passes through the collimation device 64, the first light-emitting surface 633, and is reflected by the beam selection surface 631. The second light-emitting surface 634 is projected into the projection lens 65 , and finally the projection lens 65 presents an image on a screen (not shown).

Because the collimating device 64 of a lens is arranged between the reflective light valve 62 and the prism group 63, the back focal length of the system is shortened and the size of the projection lens is reduced, and the modulated light beam 66 reflected by the light valve 62 can be transmitted. After the collimation device 64 converges the light beam and then projects it on the projection lens 65, it can also reduce the size of the projection lens 65 and reduce the component cost, and the collimation device 64 can be used to replace the lens function in the projection lens 65 or the lighting device, so Simplification of the projection lens 65 or lighting arrangement can be achieved.

Fourth embodiment:

Please refer to Fig. 12, the present embodiment is a projection display system 50 applied to a monolithic liquid crystal silicon substrate (LIQUID Crystal On Silicon, LCOS) panel, which utilizes a polarization beam splitter (Polarization Beam Splitter, The prism group of PBS) separates the light beam of the incident LCOS panel from the reflected light beam. The prism group 522 is formed by bonding two 45-degree isosceles right-angle prisms 5224 and 5225 hypotenuses, and the two sides of the right-angle prism 5224 The sides are respectively the first incident surface 5221 and the first light-emitting surface 5222. The side of one of the rectangular prisms 5225 opposite to the first light-emitting surface 5222 is set as the second light-emitting surface 5223, the first incident surface 5221, and the first light-emitting surface 5222. And the second light-emitting surface 5223 is set as an optical curved surface, the light valve 53 is arranged adjacent to the first light-emitting surface 5222, and the imaging group 521 is arranged adjacent to the second light-emitting surface 5223. When the nonlinearly polarized illumination beam 51 is incident by the first Face 5221 incident prism group 522, prism group 522 can reflect the S polarized light of incident light (vertical incident ray plane) and let P polarized light (horizontal incident ray plane) pass through, or prism group 522 can reflect the P polarized light of incident light (horizontal incident ray plane) incident ray plane) and let S polarized light (perpendicular to the incident ray plane) pass through to obtain polarized light, which is reflected by the light valve 53 to project the beam through the imaging group 521 onto a screen (not shown).

Since part of the surface of the prism group 522 is also set as an optical curved surface in this embodiment, the rear focal length can be shortened, and the illumination device and imaging group can be simplified.

The above description is only used to facilitate the description of the preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to these preferred embodiments. Any changes made according to the present invention will not depart from the spirit of the present invention. All belong to the protection scope of the present invention.

Claims (25)

1, a kind of projection display system is to comprise:

One lighting device provides a nonparallel illuminating bundle;

One optical valve in reflection type is in order to handle this illuminating bundle to produce a modulation light beam;

One prism group is to be arranged between this lighting device and this optical valve in reflection type, and it has a light beam to select face, this light beam selection face be the illuminating bundle of reflection by this this prism group of lighting device incident, and the modulation light beam by this optical valve in reflection type reflection is penetrated;

It is characterized in that: also comprising a collimation device, is to be located between this prism group and this optical valve in reflection type, is converted to a parallel illuminating bundle with the non-parallel illuminating bundle that will be incident in this prism group;

This illuminating bundle is this prism group of incident, pass this collimator apparatus after seeing through this light beam selection face reflection, be incident in again on this optical valve in reflection type, after handling, this optical valve in reflection type produces this modulation light beam, at last, this modulation light beam passes this collimator apparatus and this light beam selection face and is projected in the projection lens.

2, projection display system as claimed in claim 1 is characterized in that: this collimator apparatus is lens or diffraction element.

3, projection display system as claimed in claim 1 is characterized in that: this collimator apparatus is to be arranged on this prism group.

4, projection display system as claimed in claim 3 is characterized in that: this collimator apparatus is an optical surface.

5, projection display system as claimed in claim 3 is characterized in that: this collimator apparatus is one-body molded with this prism group.

6, projection display system as claimed in claim 3 is characterized in that: this collimator apparatus is a sphere.

7, projection display system as claimed in claim 1 is characterized in that: the principal plane of this optical valve in reflection type and this projection lens is to be set in parallel.

8, projection display system as claimed in claim 1 is characterized in that: this prism group and this collimator apparatus are to be located in this projection lens, and form a module.

9, projection display system as claimed in claim 1 is characterized in that: this light beam selection face is a curved surface.

10, projection display system as claimed in claim 1 is characterized in that: this optical valve in reflection type can be the silica-based panel of a liquid crystal, and this prism group is to have a polarization spectroscope.

11, a kind of projection display system is to comprise:

One lighting device provides a nonparallel illuminating bundle;

One optical valve in reflection type is in order to handle this illuminating bundle to produce a modulation light beam;

One prism group, be to be arranged between this lighting device and this optical valve in reflection type, and it has a light beam and selects face, and this light beam selection face is that the illuminating bundle by this this prism group of lighting device incident is penetrated, and makes the modulation beam reflection by this optical valve in reflection type reflection;

It is characterized in that: also comprising a collimation device, is to be located between this prism group and this optical valve in reflection type, is converted to a parallel illuminating bundle with the non-parallel illuminating bundle that will be incident in this prism group; This illuminating bundle is this prism group of incident, and pass this light beam and select face and this collimator apparatus, be incident in again on this optical valve in reflection type, after handling, this optical valve in reflection type produces this modulation light beam, at last, this modulation light beam passes this collimator apparatus and is projected in the projection lens via this light beam selection face reflection.

12, projection display system as claimed in claim 11 is characterized in that: this collimator apparatus is lens or diffraction element.

13, projection display system as claimed in claim 11 is characterized in that: this collimator apparatus is to be arranged on this prism group.

14, projection display system as claimed in claim 13 is characterized in that: this collimator apparatus is an optical surface.

15, projection display system as claimed in claim 13 is characterized in that: this collimator apparatus and this prism group are one-body molded.

16, projection display system as claimed in claim 13 is characterized in that: this collimator apparatus is a sphere.

17, projection display system as claimed in claim 13 is characterized in that: the principal plane of this optical valve in reflection type and this projection lens is to be vertical setting.

18, projection display system as claimed in claim 11 is characterized in that: this prism group and this collimator apparatus are to be located in this projection lens, and form a module.

19, projection display system as claimed in claim 11 is characterized in that: this light beam selection face is a curved surface.

20, a kind of projection display system is characterized in that: be to comprise:

One lighting device provides an illuminating bundle;

One curved surface prism group is to be located on the light path of this illuminating bundle, and it has a plane of incidence and a plurality of exiting surface, and to have an exiting surface in these a plurality of exiting surfaces at least be optical surface;

One projection lens is contiguous this exiting surface setting; And

One optical valve in reflection type is contiguous this exiting surface setting, and in order to handle this illuminating bundle to produce a modulation light beam;

This illuminating bundle is to be incident on this optical valve in reflection type after entering this curved surface prism group by this plane of incidence, produces this modulation light beam after this optical valve in reflection type is handled, and last, this modulation light beam is projeced in this projection lens via this curved surface prism group again.

21, projection display system as claimed in claim 20 is characterized in that: this optical surface is to be arranged on this contiguous exiting surface of this optical valve in reflection type.

22, projection display system as claimed in claim 20 is characterized in that: this optical surface is to be arranged on this contiguous exiting surface of this projection lens.

23, projection display system as claimed in claim 20 is characterized in that: this plane of incidence is an optical surface.

24, projection display system as claimed in claim 20 is characterized in that: this optical valve in reflection type is perpendicular or parallel mutually with this projection lens principal plane or becomes arbitrarily angled.

25, projection display system as claimed in claim 20 is characterized in that: this curved surface prism group is to be located in this projection lens, and forms a module.

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