JP2001066694A - Color synthesizing prism, its manufacturing method and projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the convergence accuracy of an image projected to a screen by making one of the incident surfaces on which light beams of plural colors are made incident have lens action in a color synthesizing prism synthesizing the separated light beams of plural colors after separating the light beam from a light source to plural colors and modulating it. SOLUTION: A red image modulated by a liquid crystal panel 12 and a blue image modulated by a liquid crystal panel 26 pass through a convex lens in comparison with a green image modulated by a liquid crystal panel 18, so that raster size gets small. Emitted light 29 including image information color- synthesized in such a way is projected by a projection lens unit 28 and formed into the image on the screen. In the unit 28, enlarging magnification for red and blue is different from that for green because of transverse chromatic aberration, but the enlarging magnification is previously corrected by the lens action of convex lens surfaces 271a and 273a before the light is made incident on the unit 28 so that the image having no convergence deviation is formed on the screen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention separates white light from a light source into three color lights of red, blue, and green, and, after including each color light with image information by a liquid crystal panel or the like, re-combines each color light. The present invention relates to a projection type display device technology for enlarging and projecting onto a screen via a projection lens. Further, the present invention relates to a color synthesizing prism constituting a color synthesizing means in an optical system of such a projection type display device, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A projection display device having a color synthesizing means is disclosed in, for example, JP-A-63-216026 and JP-A-8-184797. This prior art is configured as shown in FIGS.

FIG. 7 is a schematic view showing an optical system of a conventional projection display device. In the figure, a white light beam 33 from a light source 31 is turned into a uniform white light beam by a reflector 32 of a parabolic mirror, a first lens array 34, a cold mirror 35 as a first reflection mirror, and a second lens array 36, and the blue light beam is blue. The red light beam 38 and the blue-green light beam 43 are separated by the green reflection dichroic mirror 37. The red light beam 38 is reflected by the reflection increasing mirror 39, passes through the condenser lens 40 and the deflection plate 41, and is incident on the transmission type liquid crystal panel 42. The blue-green light flux 43 is converted to a green light flux 4 by a green reflection dichroic mirror 44.
5 and a blue luminous flux 49. The green luminous flux 45 passes through the condenser lens 46 and the deflecting plate 47 and passes through the transmission type liquid crystal panel 4.
8 is incident. The blue luminous flux 49 includes a relay lens 50, a reflection mirror 51, a relay lens 52, a reflection mirror 53,
The light enters the transmissive liquid crystal panel 54 via the condenser lens 54 and the deflecting plate 55. The red light flux including the image information emitted from the liquid crystal panel 42, the green light flux including the image information emitted from the liquid crystal panel 48, and the blue light flux including the image information emitted from the liquid crystal panel 56 are respectively transmitted to the color combining cross prism 57. Incident. The color combining cross prism 57 is configured as shown in FIG.

FIG. 9 is a top view of a color combining cross prism. In the figure, a red light flux including image information emitted from a liquid crystal panel 42 is applied to a surface 571 of a color combining cross prism 57.
a, and the bonding surfaces 571c and 57
The light is reflected 90 degrees at 4d, and emitted from the surface 574b.
The blue luminous flux including the image information emitted from the liquid crystal panel 56 enters the color combining cross prism 57 from the surface 573a, and is 90 ° at the bonding surfaces 573c and 574c.
And is emitted from the surface 574b. LCD panel 4
The green luminous flux including the image information emitted from 8 is incident on the color combining cross prism 57 from the surface 572a, passes through the bonding surfaces 571c, 573c, 574c, 574d and passes through the surface 5
It is emitted from 74b. The emitted light 59 including the image information thus color-combined is projected by the projection lens unit 58 and is imaged on a screen (not shown). In addition, 571, 572, 573, and 574 are four triangular prisms made of glass having the same refractive index and having a right-angled isosceles triangular cross section.

FIG. 8 is a perspective view of a color synthesizing prism, and a method of attaching a triangular prism is described with reference to FIG. As shown in FIGS. 8 and 9, the color combining cross prism 57 has four triangular prisms 571, 572, 573, and 57 each having a right-angled isosceles triangular cross section and made of glass having the same refractive index.
4 are bonded to each other. A red reflection film having a selective reflection characteristic of red is formed on the bonding surfaces 571c and 574d. A blue reflection film having blue selective reflection characteristics is formed on the bonding surfaces 573c and 574c.

The lengths of the triangular prisms 273 and 274 in the vertical direction are longer than those of the triangular prisms 271 and 272. To assemble the color combining cross prism 57, first, the triangular prisms 273 and 274 are fixed to the jig, the triangular prisms 271 and 272 are fixed to the jig, and the triangular prisms 273 and 274 and the triangular prisms 271 and 272 are further fixed. The jig is supported so that the upper surface is parallel, and the triangular prism 271,
272 is moved in the horizontal direction and the triangular prisms 273 and 27 are moved.
4 are bonded so that the bonding surfaces of the triangular prisms 271 and 272 are linear. The color combining cross prism 57 manufactured in this manner is held in a prism holder (not shown) of a holding member for holding the optical system. The projection lens unit 58 performs aberration correction by a configuration in which a convex lens, a concave lens, and an aspheric lens are combined, and projects an image with little distortion or color shift on a screen (not shown).

[0007]

However, in the above-mentioned conventional projection type display device, a slight aberration exists in the projection lens unit. In particular, the magnification projected on the screen due to chromatic magnification aberration is red, green and blue. In contrast, there is a problem that the convergence of red, green and blue is shifted in a part of the image. In addition, when trying to correct aberrations using a combination of lenses in the projection lens unit, there is a problem that the number of lenses increases and the projection lens becomes heavier and heavier.

If another component is provided between the liquid crystal panel and the color synthesizing prism, the space between the liquid crystal panel and the color synthesizing prism is so small that the components interfere with each other and the cooling air flow of the liquid crystal panel decreases. There were challenges. Further, when the color combining prism is made of plastic resin, there is a problem that color unevenness occurs due to molding distortion and birefringence.
In addition, when a reflective film is formed on the prism, there is a problem that the film-forming substance wraps around a surface other than the color combining / reflecting surface, thereby causing contamination.

An object of the present invention is to provide a prism having reduced chromatic magnification aberration, a method of manufacturing the same, and a projection display device. Another object of the present invention is to provide a technique for realizing satisfactory optical characteristics when a color combining prism is made of plastic.

[0010]

In order to achieve the above object, according to the present invention, a plastic is used as a material of a color synthesizing prism, and a chromatic magnification aberration of a projection lens unit is corrected on an incident surface of the color synthesizing prism. A color magnification correction lens shape was provided. Further, after the step of performing the injection compression molding, a step of maintaining the temperature within a predetermined range for a predetermined time and a step of cooling after that are provided. When forming a film on the triangular prism, two of the four prisms used in the color synthesizing prism were vapor-deposited such that the surfaces orthogonal to the film-forming surface were arranged without gaps.

According to a first aspect of the present invention, there is provided a color combining prism for separating light from a light source into a plurality of colors, modulating the light, and then combining the separated lights of a plurality of colors. One of the light incident surfaces of the plurality of colors has a lens function.

In the second invention, the light from the light source is separated into a first-color light beam, a second-color light beam, and a third-color light beam, and these separated light beams are modulated by image information. In the color synthesizing prism for synthesizing the light beam, the surface on which the light beam of the first color is incident has a lens function. Further, in the second aspect, a surface on which the light beam of the second color is incident has a lens function. Further, a surface on which the first color light beam and the second color light beam are incident has a convex lens function. Also,
The surface on which the first color light beam and the second color light beam are incident has a concave lens function. Further, the surface on which the first color light beam is incident has a convex lens function, and the surface on which the second color light beam is incident has a concave lens effect.

In the first and second inventions, the color synthesizing prism comprises four triangular prisms.

In the third invention, the light from the light source is converted into a red light flux,
In the color synthesizing prism in which four triangular prisms are bonded together to separate the blue light and the green light, and modulate the separated light with the image information, and synthesize these light beams, A surface on which a light beam is incident has a lens function, and a blue reflection film and a red reflection film are provided between the bonding surfaces of the triangular prisms.

In a fourth aspect, the projection display apparatus includes means for separating the light from the light source into a first color light beam, a second color light beam, and a third color light beam, and converting the separated light beam into an image. Modulating means for modulating with information, a color synthesizing prism for synthesizing the light fluxes of the respective modulated colors, and projecting means for projecting light synthesized by the color synthesizing prisms; The convergence shift caused by the projection means is corrected by giving a lens effect to the surface to be subjected to the projection. Further, in the fourth aspect, the color synthesis prism is formed in a prism shape by bonding four triangular prisms together, and the third color beam is formed between the bonding surfaces of the triangular prisms from the first color light flux. A first reflection film that reflects one of the light beams and a second reflection film that reflects the other light beam, so that the light beams of the first to third colors are incident on the projection means; Constitute.

In the fourth aspect, the surface of the color combining prism on which the light beam of the second color is incident has a lens function. A surface on which the first color light beam and the second color light beam are incident has a convex lens function. Further, the surface on which the first color light beam and the second color light beam are incident has a concave lens function. The surface on which the first color light beam is incident has a convex lens effect, and the surface on which the second color light beam is incident has a concave lens effect.

In the fifth invention, a light source, and color separation means for separating white light emitted from the light source into three primary color light beams,
Modulating means for modulating each of the separated color lights to include image information, color synthesizing means for synthesizing the modulated light of each color, and means for enlarging and projecting the modulated light containing the synthesized image information onto a screen In the projection type display device, the color synthesizing unit is a quadrangular prism as a whole formed by bonding four triangular prisms having the same refractive index to each other. At least one of the surfaces has a lens shape, and the lens shape is formed integrally with the triangular prism.
In the fifth invention, a triangular prism shaped by molding a thermoplastic cycloolefin polymer is used as the color synthesizing means. In addition, the quadrangular prism formed by bonding the triangular prisms is one of the four sides constituting the bonding surface, and after bonding, the length of one side located at the center of the square prism is parallel to the side. Is configured to be shorter than the side of.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a color synthesizing prism, wherein four triangular prisms are bonded to form a quadrangular prism color synthesizing prism, and a surface forming a first diagonal of the quadrangular prism is formed. In order to form a first reflective film on the surface and form a second reflective film on the surface forming the second diagonal, the surfaces of the two triangular prisms on which the first reflective film is provided are flat. Forming a first reflection film, and forming a second reflection film by arranging the two triangular prisms provided with the second reflection film such that the surfaces of the two prisms are flat. In the sixth invention, the surfaces of the two triangular prisms forming the reflection film are formed by inverting one of the triangular prisms of the opposing triangular prisms of the triangular prism constituting the color synthesizing prism of the quadrangular prism to form a plane. Then, a reflection film is formed on the plane of the two prisms.

In the sixth aspect, the reflection film is provided on one surface of a bonding surface of the four triangular prisms. Further, the reflection films are provided on both surfaces of the four triangular prisms that are opposed to each other. Also,
The reflection film is formed on both surfaces of the four triangular prisms where the first prism is bonded, and the reflection film is formed on one of the surfaces where the triangular prisms adjacent to the first triangular prism are bonded. .

According to a seventh aspect of the present invention, there is provided a method of manufacturing a color synthesizing prism, comprising: a step of injection-compression molding a triangular prism; a step of maintaining the temperature within a predetermined range for a predetermined time; The method includes a step of forming a reflective film and a step of bonding a triangular prism. In the seventh invention, the temperature range is set to a temperature range 5 ° C. to 1 ° C. lower than the glass transition point of the plastic material used.

According to an eighth aspect of the present invention, a method of manufacturing a color synthesizing prism includes the steps of forming four color triangular prisms when forming a color reflection film on a bonding surface of the triangular prisms constituting the square prism color synthesizing prism. Two of the triangular prisms are vapor deposited side by side without any gap.

According to a ninth aspect of the present invention, the method of manufacturing a color combining prism includes the steps of: forming a color reflecting film on a bonding surface of the triangular prisms constituting the square prism color combining prism; The film is formed only on two or three of the triangular prisms.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to the drawings by using some embodiments. FIG. 1 is a schematic diagram showing an embodiment of an optical system of a projection display according to the present invention. In the figure, a white light beam 3 from a light source 1 is reflected by a parabolic mirror reflector 2, a first lens array 4,
The cold mirror 5 serving as the first reflecting mirror and the second lens array 6 form a uniform white light flux, and are separated by the blue-green reflecting dichroic mirror 7 into a red light flux 8 and a blue-green light flux 13. The red light flux 8 is reflected by the reflection increasing mirror 9, passes through the condenser lens 10 and the deflecting plate 11, and enters the transmission type liquid crystal panel 12. The blue-green light flux 13 is separated into a green light flux 15 and a blue light flux 19 by a green reflection dichroic mirror. The green luminous flux 15 includes a condenser lens 16,
And is incident on the transmission type liquid crystal panel 18. The blue luminous flux 19 includes a relay lens 20, a reflective mirror 21, a relay lens 22, a reflective mirror 23, a condenser lens 24,
The light enters the transmissive liquid crystal panel 24 via the deflecting plate 25.

FIG. 2 is a top view showing a first embodiment of the color combining cross prism shown in FIG. The red light beam 8, the blue light beam 19, and the green light beam 15 are incident on the color combining cross prism 27 shown in FIG. The red light beam 8 containing image information emitted from the liquid crystal panel 12 is
7 from the surface 271a. The surface 271a has a radius of 40
It has a convex lens shape of about 00 mm. Convex lens surface 27
The red luminous flux 8 having passed through 1a is reflected 90 degrees by the bonding surfaces 271c and 274d, and is emitted from the surface 274b. The blue luminous flux 19 containing the image information emitted from the liquid crystal panel 26 enters the color combining cross prism 27 shown in FIG. 2 from the convex lens surface 273a. The surface 273a has a convex lens shape with a radius of about 5000 mm. The blue luminous flux 19 that has passed through the convex lens surface 273a is reflected by the bonding surface 273c and the surface 274c at 90 degrees, and is emitted from the surface 274b. The green light flux 15 including the image information emitted from the liquid crystal panel 18 is incident on the color combining cross prism 27 from the surface 272a. The surface 272a has one unevenness (550 nm).
It is a plane managed below. The green luminous flux 15 that has passed through the surface 272a is bonded to the bonding surfaces 271c, 273c, and 274.
c, 274d and exits from surface 274b. In this case, the red image modulated by the liquid crystal panel 12 and the blue image modulated by the liquid crystal panel 26 are combined with the liquid crystal panel 18.
The raster size is smaller than that of the green image modulated by the above because the light passes through the convex lens. The emitted light 29 including the image information thus color-combined is projected by the projection lens unit 28 to form an image on a screen. The projection lens unit 28 has different magnifications of red and blue than green because of chromatic magnification aberration.
Since the magnification is corrected beforehand by the lens function of the convex lens surface 271a and the convex lens surface 273a, an image having no convergence deviation is formed on the screen. Also, the convex lens surface 271a, the convex lens surface 27
Since the lens 3a is integrated with the triangular prism-shaped prism parts 271 and 273, the distance between the liquid crystal panels 12 and 26 can be secured to be equal to the distance between the liquid crystal panels 18 and 272a. , 26 and the prism, it is possible to secure a sufficient amount of cooling air as compared with the case where another part is inserted to correct the convergence.

Next, a second embodiment of the color combining cross prism according to the present invention will be described with reference to FIG. FIG.
FIG. 7 is a top view showing a second embodiment of the color combining cross prism according to the present invention. In this embodiment, the red light beam incident surface 271a
Is provided with a color magnification correction lens composed of a convex lens. In this case, the green light beam incident surface 272a and the blue light beam incident surface 273a
Is a plane in which the unevenness is controlled to one wavelength or less. If the blue light is more distant from the green light than the red light on the screen, and if it is desired to make the blue light closer to the green light, a color magnification correction lens having a convex lens effect only on the blue light flux incident surface 273a is similarly provided. May be provided.

Next, a color combining prism according to a third embodiment of the present invention will be described with reference to FIG.

FIG. 4 is a top view showing a third embodiment of the color combining cross prism according to the present invention. In this embodiment, the red light beam incident surface 271a is formed in a concave lens shape.
The green light beam incident surface is a flat surface with unevenness controlled to one wavelength or less. The blue light flux incident surface 273a is formed in a convex lens shape. With such a shape, the number of achromatic lenses in the projection lens unit 28 can be reduced.

Referring to FIG. 5, how the convergence of the red or blue pixels is corrected using the color combining cross prisms of FIGS. 2 to 4 will be described below. FIG.
(A)-(c) is a schematic diagram which shows the convergence of each color pixel in the upper left of the screen. In FIG. 5A, a green pixel 501 is shown.
The red pixel 502 is projected to the upper left, and the blue pixel 503 is projected to the lower right. In this case, when the red light beam incident surface 271a of the triangular prism 271 is a convex lens, the red pixel 502 moves toward the green pixel 501. When the blue light beam incident surface 273a of the triangular prism 273 is a concave lens, the blue pixel 503 can be moved in the direction of the green pixel 501.

As shown in FIG. 5B, the green pixel 501
On the other hand, when the red pixel 502 and the blue pixel 503 are below, the red light beam incident surface 271a of the triangular prism 271 is a concave lens, and the blue light incident surface 273a of the triangular prism 273 is a concave lens. The blue pixel 503 moves toward the green pixel 501 and the convergence is corrected.

As shown in FIG. 5C, when the red pixel 502 and the blue pixel 503 are projected upward to the green pixel 501, the red light incident surface 271a of the triangular prism 271 is formed as a convex lens. And the triangular prism 27
When the blue light beam incident surface 273a of No. 3 is a convex lens, the red pixel 502 and the blue pixel 503 move toward the green pixel 501, and the convergence is corrected.

FIG. 6A is a top view of the triangular prism constituting the color combining prism according to the present invention.
6 (b) is a view as viewed from A in FIG. 6 (a), and FIG. 6 (c) is a view as viewed from B. In FIG. 6, reference numeral 271e denotes a gate cut surface which is a portion obtained by cutting the gate during injection molding. A side 271f passing through a vertical angle forming a right angle of a right-angled isosceles triangle is the other side 2
71g, shorter than 271h. Therefore, as shown in FIG. 6C, the surface on which the gate cut surface 271e is disposed is disposed obliquely with respect to the opposing surface. Further, the triangular prism 271 and the color synthesis prism formed by the triangular prism are injection-compression molded using a thermoplastic norbornene resin in order to avoid a dimensional change due to moisture absorption.

The triangular prisms 272, 273 and 274 are obtained by changing the shape of the red light beam incident surface 271a of the triangular prism 271 shown in FIG. The color combining prism 27 shown in FIGS. 2 to 4 has four triangular prisms 271, 272, 273, and 274 having the same refractive index bonded to each other to form a cross section shown in FIGS. 2 to 4. It has a quadrangular prism shape (however, the incident surface may be in the form of a lens), and a red reflective film or a blue reflective film, which is a dielectric multilayer film, is formed on each bonding surface to obtain desired optical characteristics. Has been granted.

Next, a method of manufacturing a color combining prism according to the present invention will be described with reference to FIGS. FIG.
12 to 12 are top views each showing one embodiment of the color combining prism according to the present invention. 10 to 12, the surface 271a of the triangular prism 271 has a radius R of 3000.
mm convex lens shape. Similarly, a triangular prism 2
The surface 273a of the 73 has a convex lens shape with a radius R of 5000 mm. The surface 272a of the triangular prism 272 and the surface 274a of the triangular prism 274 have a planar shape. These triangular prisms 271, 272, 273,
The material of 274 is cycloolefin resin (ZEONEX-480R or ZEONEX- manufactured by Zeon Corporation).
E48R) was used. The glass transition point of this cycloolefin resin at atmospheric pressure is 138 ° C. These triangular prisms are formed by injection compression molding in which injection molding and compression are performed using an injection compression mold having a core compression mechanism.
Compression is performed on the surfaces 271a, 272a, 27 of the triangular prism.
The movable parts provided in 3a and 274a were compressed by applying pressure.

Specifically, the mold temperature is increased from 130 ° C. to 13
The temperature is set to 5 ° C., and the molten resin at 290 ° C. to 300 ° C. is injected and filled, and gate portions 271e, 272e, 273e, 27
After applying the holding pressure to 4e, 0.8 kg / c
Compressed by applying a pressure of 1.0 kg / cm2 from m2
After maintaining for at least one minute, the molded product is taken out and naturally cooled to room temperature in the air. Next, the molded product is placed at a temperature of 1 ° C.
Then, the substrate is heated to a temperature lower by 5 ° C., kept at this temperature for a certain period of time, and then annealed to cool to room temperature.

In the case of the embodiment shown in FIGS.
Heat to 7 ° C, hold at this temperature for at least 14 hours,
Thereafter, cooling is performed at a rate of 0.1 ° C./min to 0.2 ° C./min. From 137 ° C. to 122 ° C., and cooling is performed at a rate of 0.5 ° C./min. ° C
To 60 ° C. at a rate of 1 ° C./min. Thereafter, triangular prisms 271, 272, 27
3, 274 are taken out and cooled naturally in air to room temperature. After cooling, store in a desiccator (cooling box) with a humidity of 10% or less.

Next, the triangular prisms 271, 272,
A color reflection film or a dichroic film is formed on all or a part of the surfaces of 273 and 274. In the case of this embodiment, the dichroic film has a first layer having a refractive index in the range of 1.65 to 1.75 at a measurement wavelength of 550 nm, a mixed substance of zirconium oxide (ZrO2) and aluminum oxide (Al2O3), or lanthanum ( La) and aluminum oxide (Al)
2O3), and titanium dioxide (TiO2) and silicon dioxide (SiO2) are alternately formed in the second and subsequent layers, and the layer immediately before the final layer is formed of titanium oxide (T
iO2), the final layer is formed of the same material as the first layer, and a dichroic film composed of a total of 17 or more odd layers is formed.

In FIGS. 10 to 12, 271r and 27
Reference numeral 3r denotes a film having the same characteristics, that is, a red reflection film having red reflection characteristics. 272r and 274r are blue reflection films having blue reflection characteristics.

FIG. 13 is a perspective view of two triangular prisms, and a method of forming a color reflection film on the triangular prisms shown in FIGS. 10 and 11 will be described with reference to FIGS. The red reflection films 271r and 273 shown in FIGS.
When forming the r or blue reflection films 272r and 274r, as shown in FIG. 13, they are arranged so that the direction of the gate cut surface 272e of the triangular prism 272 and the direction of the gate cut surface 274e of the triangular prism 274 are opposite. And face 2
The surfaces forming the surfaces 72c and 274c are combined so as to be one plane, and the ridges, which are the apex angles of the triangular prisms, are combined exactly without gaps. After that, the blue reflection films 272r and 274r are simultaneously formed on the surfaces 272c and 274c. Similarly, by combining the triangular prisms 271 and 273, the red reflection film 27 is simultaneously formed on the surfaces 271c and 273c.
2r and 273r are formed.

Similarly, in the case of FIG. 11, triangular prisms 272 and 274 are combined as shown in FIG.
Blue reflection films 272r and 274r are formed on the surface 72c and the surface 274c. After that, the evaporation surfaces are exchanged, and red reflection films 272s and 274s are formed on the surfaces 272d and 274d.

FIG. 14 is a perspective view of two triangular prisms. A blue reflecting film 273 is provided on the color combining prism shown in FIG.
s, 274r and the red reflective films 271r, 274s, the gate cut surfaces 273e,
74e is provided so that the position where it is provided is on the same surface,
After the two triangular prisms 273 and 274 are combined exactly as in the case of FIG.
The blue reflection films 273s and 274r are formed on the surface 74c.
In addition, similarly, triangular prisms 271 and 274 are combined to form a red reflective film 271r on the 271c surface and the 274d surface.
274s are formed.

Next, four triangular prisms 271 to 27 are provided.
4 is adhered. Specifically, an adhesive, for example, a VU visible light curable adhesive is applied between the triangular prisms 273 and 274 and held in a jig, and similarly, a UV visible light curable adhesive is applied between the triangular prisms 271 and 272. A mold adhesive is applied, and for example, a UV-visible light-curable adhesive is applied between the prisms 273 and 274 and the prisms 271 and 272, which are temporarily combined, and fixed with a jig. After adjusting the positions so that the apical corners of the four triangular prisms are aligned with one point, visible light, for example, light having a wavelength of 420 mm to 480 mm is irradiated to cure the adhesive. Through the above steps, one dichroic cross prism is completed.

According to the present invention, it is possible to provide an optical system and a prism of a projection display device capable of sufficiently suppressing chromatic magnification aberration even when the projection lens unit is reduced in size and weight and the number of aberration correction lenses is reduced. it can. further,
An object of the present invention is to provide an optical system configuration in which extra components can be sufficiently cooled with a liquid crystal panel even when an optical system that suppresses chromatic magnification aberration is used.

In the present invention, when manufacturing a color combining prism, the surfaces of two triangular prisms on which a blue reflecting film or a red reflecting film are formed are aligned, and a blue reflecting film or a red reflecting film is formed thereon. Is formed, the thickness of the reflective film can be made uniform. In addition, since the blue reflection film or the blue reflection film can be simultaneously formed on the two triangular prisms, the process of forming the reflection film can be simplified.

Further, according to the present invention, plastic is used as the material of the color synthesizing prism, and a color magnification correcting lens shape for correcting the chromatic magnification aberration of the projection lens unit is integrally formed on the color synthesizing prism entrance surface. The convergence accuracy of the image projected on the screen is improved. Further, there is an effect that an air path for flowing cooling air can be secured between the liquid crystal panel and the color combining prism.

[0045]

As described above, according to the present invention,
Since the chromatic magnification correcting lens shape for correcting the chromatic magnification aberration of the projection lens unit is integrally formed on the entrance surface of the color combining prism, the convergence accuracy of the image projected on the screen is improved.

Further, the thicknesses of the blue reflection film and the red reflection film provided on the color combining prism can be made uniform.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of an optical system of a projection display device according to the present invention.

FIG. 2 is a top view showing a first embodiment of the color combining cross prism shown in FIG. 1;

FIG. 3 is a top view showing a second embodiment of the color combining cross prism according to the present invention.

FIG. 4 is a top view showing a third embodiment of the color combining cross prism according to the present invention.

FIG. 5 is a schematic diagram showing the convergence of each color pixel on the upper left of the screen.

FIG. 6 is a top view, a view A and a view B of a triangular prism constituting the color combining prism according to the present invention.

FIG. 7 is a schematic diagram showing an optical system of a conventional projection display device.

FIG. 8 is a perspective view of a color combining prism.

FIG. 9 is a top view of the color combining cross prism.

FIG. 10 is a top view showing one embodiment of a color combining prism according to the present invention.

FIG. 11 is a top view showing another embodiment of the color combining prism according to the present invention.

FIG. 12 is a top view showing still another embodiment of the color combining prism according to the present invention.

FIG. 13 is a perspective view of two triangular prisms.

FIG. 14 is a perspective view of two triangular prisms.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lamp, 2 ... Lamp reflector, 4 ... First lens array, 5 ... Cold mirror, 6 ... Second lens array, 7
... first dichroic mirror, 9 ... increase reflection mirror, 10
... condenser lens, 11 ... deflecting plate, 12 ... red light liquid crystal panel, 14 ... second dichroic mirror, 16 ... condenser lens, 17 ... deflecting plate, 18 ... green light liquid crystal panel, 20 ... first relay lens, 21 ... Increasing reflection mirror, 2
2, a second relay lens, 23, a reflection increasing mirror, 24, a condenser lens, 25, a polarizing plate, 26, a liquid crystal panel for blue light, 27, a color combining prism, 271, a triangular prism, 2
71a: Red light beam incident surface, 271c: Red light beam reflecting dichroic mirror surface, 271e: Gate cut surface, 272: Triangular prism, 272a: Green light beam incident surface, 273: Triangular prism, 273a: Blue light beam incident surface, 273c: Blue light beam Reflection dichroic mirror surface, 274 ... triangular prism, 2
74b: combined light beam exit surface, 274c: blue light beam reflection dichroic mirror surface, 274d: red light beam reflection dichroic mirror surface, 28: projection lens unit, 271r,
273r: blue reflection film, 272r, 274r: red reflection film.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H042 CA06 CA10 CA14 CA15 CA17 5C060 BA04 BA08 BC05 EA00 GA01 GB02 GB06 HC00 HC20 HC24 HC25 JA20 JB06

Claims (26)

[Claims] 1. A color synthesizing prism for separating light from a light source into a plurality of colors, modulating the light, and combining the separated lights of a plurality of colors, a lens is provided on one of incident surfaces of the lights of the plurality of colors. A color combining prism characterized by having an action. 2. A light beam from a light source is separated into a first color light beam, a second color light beam, and a third color light beam, and these separated light beams are modulated by image information, and then these respective color light beams are combined. A color combining prism, wherein a surface on which the first color light beam is incident has a lens function. 3. The color combining prism according to claim 2, wherein
A color combining prism, wherein a surface on which the second color light beam is incident has a lens function. 4. The color combining prism according to claim 2, wherein
A color combining prism, wherein a surface on which the first color light beam and the second color light beam are incident has a convex lens function. 5. The color combining prism according to claim 2, wherein
A color synthesizing prism, wherein a surface on which the first color light beam and the second color light beam are incident has a concave lens function. 6. The color combining prism according to claim 2, wherein
A color combining prism, wherein a surface on which the first color light beam enters has a convex lens effect, and a surface on which the second color light beam enters has a concave lens effect. 7. The color combining prism according to claim 2, wherein
The color synthesizing prism is characterized by comprising four triangular prisms. 8. A light beam from a light source is separated into a red light beam, a blue light beam and a green light beam, and these separated light beams are modulated by image information.
In order to combine these light beams, in a color combining prism in which four triangular prisms are bonded, a surface on which one of the light beams is incident has a lens function, and the triangular prisms are bonded together. A color synthesizing prism comprising a blue reflection film and a red reflection film provided between surfaces. 9. A means for separating light from a light source into a first color light flux, a second color light flux, and a third color light flux, a modulation means for modulating the separated light flux with image information, and the modulation means. A color synthesizing prism for synthesizing the luminous fluxes of the respective colors, and projection means for projecting light that has been color-combined by the color synthesizing prism, and having a lens function on a surface on which the luminous flux of the first color is incident. Wherein the convergence deviation caused by the projection means is corrected. 10. The projection type display device according to claim 9, wherein the color synthesis prism is formed in a prism shape by bonding four triangular prisms, and the color combining prism is provided between the bonding surfaces of the triangular prisms. A first reflection film that reflects one of the third color light beams from one color light beam and a second reflection film that reflects another light beam; and a light beam of the first to third colors. Is incident on the projection means. 11. A projection display device according to claim 9, wherein a surface of said color combining prism on which the light beam of said second color is incident has a lens function. 12. The projection display device according to claim 11, wherein a surface on which the first color light beam and the second color light beam are incident has a convex lens function. 13. The projection display device according to claim 11, wherein a surface on which the first color light beam and the second color light beam are incident has a concave lens function. 14. A projection type display device according to claim 11, wherein a surface on which said first color light beam is incident has a convex lens effect, and a surface on which said second color light beam is incident has a concave lens effect. A projection-type display device characterized by causing the display device to emit light. 15. A light source and a white light emitted from the light source.
A color separation unit that separates each color light of primary colors, a modulation unit that modulates each separated color light to include image information, a color synthesis unit that synthesizes the modulated light of each color, and a modulation that includes the synthesized image information And a means for enlarging and projecting light onto a screen, wherein the color synthesizing means is a quadratic prism as a whole formed by bonding together four triangular prisms having the same refractive index. Yes,
A projection display device, wherein at least one of the three-way modulated light incidence surfaces of the quadrangular prism has a lens shape, and the lens shape is integrally formed with the triangular prism. 16. A projection type display device according to claim 15, wherein a triangular prism shaped by molding a thermoplastic cycloolefin polymer is used as said color synthesizing means. 17. The projection display device according to claim 15, wherein the quadrangular prism formed by laminating the triangular prisms is located at the center of the quadrangular prism after being laminated among the four sides constituting the lamination surface. A projection display device, wherein the length of one side located is shorter than other sides parallel to the side. 18. A quadrangular prism color synthesizing prism is formed by bonding four triangular prisms together, and a first reflection film is formed on a surface forming a first diagonal of the quadrangular prism.
In order to form the second reflection film on the surface forming the second diagonal, the first reflection film is formed by arranging the two triangular prisms on which the first reflection film is provided so that the surfaces thereof are flat. A method of manufacturing a color combining prism, comprising: forming a second reflection film by arranging two triangular prisms on which a second reflection film is provided so that the surfaces of the two prisms are flat. 19. The method of manufacturing a color synthesizing prism according to claim 18, wherein the reflecting film is formed by inverting one of the triangular prisms of the opposing triangular prisms constituting the square prism color synthesizing prism. A method for manufacturing a color combining prism, comprising: arranging two triangular prisms to be formed so that the surfaces of the prisms form a plane; and forming a reflection film on the plane of the two prisms. 20. The method of manufacturing a color combining prism according to claim 18, wherein the reflection film is provided on one surface of a bonding surface of the four triangular prisms. 21. The method of manufacturing a color combining prism according to claim 18, wherein said reflection films are provided on both surfaces of said four triangular prisms which are opposed to each other. Production method. 22. The method for manufacturing a color combining prism according to claim 18, wherein the reflection films are formed on both surfaces of the four triangular prisms to which the first prisms are bonded, and the first triangular prisms are formed. Forming the reflection film on one of the bonding surfaces of the adjacent triangular prisms. 23. A step of injection-compressing a triangular prism, holding a triangular prism in a temperature range within a predetermined range for a predetermined time,
A method for manufacturing a color combining prism, comprising a step of cooling after that, a step of forming a reflection film, and a step of bonding a triangular prism. 24. A method for manufacturing a color synthesis prism according to claim 23, wherein said temperature range is in a temperature range of 5 ° C. to 1 ° C. lower than a glass transition point of a plastic material used. Manufacturing method of prism. 25. When forming a color reflection film on a surface to which triangular prisms constituting a quadrangular prism color synthesizing prism are bonded, two triangular prisms among the four triangular prisms are arranged without gaps. A method for producing a color combining prism, comprising vapor deposition. 26. When a color reflection film is formed on a surface to which triangular prisms constituting a square prism color synthesizing prism are bonded, two to three of the four triangular prisms are converted into three triangular prisms. A method of manufacturing a color combining prism, comprising forming a film only.