JPH045643A - Projection type display device - Google Patents

Abstract

PURPOSE:To prevent the loss of a luminous flux by arranging the center of the light emission of a lamp at the shared point of a parabolic mirror and a spherical mirror which are opposingly arranged so that the focal point of a paraboloid and the center of curvature of a spherical surface may be the shared point and providing a rectangular aperture on the paraboloid and the spherical surface. CONSTITUTION:The parabolic mirror 130 and the spherical mirror 140 are opposingly arranged so that the focal point of the paraboloid and the center of curvature of the spherical surface may be the shared point, and the lamp 120 is arranged so that the center of the light emission 121 is positioned at the shared point. A light beam emitted from the lamp 120 is directly reflected on the mirror 130 and emitted from the rectangular aperture 141 as the light beam parallel with a center line 20 or it is reflected between the mirror 140 and the mirror 130 and emitted from the aperture 141 as the light beam parallel with the optical axis 20. Thus, a part of the luminous flux which is a forward divergent luminous flux is made incident in the rectangular aperture as the collimated beam of light and the luminous flux emitted from a light source is made to a rectangular cross sectional shape similar to a liquid crystal light valve 3, so that the shape of the luminous flux which reaches a display surface is made nearly same as that of the display surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to increasing the brightness of a projection display device that enlarges and projects an image formed on a liquid crystal light valve onto a screen.

[Conventional technology] FIG. 9 is a first configuration diagram of a conventional projection display device.

In the figure, (1) is a light source, (120) is a lamp, (1
30) is a reflecting mirror, (2) is the illumination light flux emitted from the light source (1), (3) is a liquid crystal light valve, (8) and (9) are polarizing plates placed before and after the liquid crystal light valve, (4) ) is a projection lens, (5) is a screen, and (10) is a condenser lens.

Next, the operation will be explained.

The light source (1) consists of a lamp (120) and a reflector (130), and irradiates the liquid crystal light valve (3) with an illumination light beam (2). As the lamp (120), for example, a discharge lamp such as a metal halide lamp or a xenon lamp, or a halogen lamp is used. Further, the reflecting surface of the reflecting mirror (130) is a paraboloid that is rotationally symmetrical with respect to the center line (20) indicated by a dashed line in the figure, and as is known, the lamp (120) is placed at the focal point of the paraboloid. ) by arranging the emission center (121) of the parallel illumination beam (2) with a circular cross-sectional shape
is obtained. An image is displayed on the surface of the liquid crystal light valve (3) as described later, and the in-plane transmittance changes depending on the shading and color of the image. The light flux that has passed through the liquid crystal light valve (3) further passes through a projection lens (4) and becomes projection light (110), which is enlarged and imaged on a screen (5) for viewing. In addition, condenser lens lens (10
) is provided to make the illumination light flux enter the projection lens with high efficiency to obtain a high-brightness projected image.

Next, regarding the configuration and operation of the liquid crystal light valve (3),
This will be explained with reference to FIG. 1O.

The liquid crystal (6) is sandwiched between two glass substrates (7), and furthermore, polarizing plates (8) and (9) are arranged on both sides. When no voltage is applied and = 0 (Fig. 10 (a)), the linearly polarized light (2a) transmitted through the polarizing plate (8) on the incident side is reflected by the liquid crystal (6).
When transmitted, the polarization direction is 90° due to the optical rotation of the liquid crystal.
The light rotates and passes through the output polarizing plate (9), which is arranged so that the polarization axis is perpendicular to the input polarizing plate (8). On the other hand, a voltage ① higher than the threshold voltage vth is applied (Fig. 10(b)).
) and 1. The optical rotation of the liquid crystal decreases, and the polarizing plate on the output side (
9) The amount of light that passes through decreases as the voltage increases. By utilizing such a transmittance control effect and further configuring electrodes in a two-dimensional array, a two-dimensional image display element can be formed. Note that the above liquid crystal has an optical rotation angle of 90°.
An example in which an N (Twisted Nematic) liquid crystal is used in normally white mode has been described. Regarding the type of liquid crystal phase, the magnitude of the angle of optical rotation, etc., there are known modifications other than those described above, but their explanation will be omitted since they are not directly related to the subject matter of the present invention.

Furthermore, as a second conventional device, FIG. 11 shows an optical system of a device using three liquid crystal light valves. In the figure, (1) is a light source, specifically a lamp (120) that generates white light such as a metal halide lamp, xenon lamp, orogen lamp, and a rotationally symmetrical parabolic reflecting mirror (130). Become.

(2) is an illumination light flux emitted from the light source (1), which is a parallel light flux having a circular cross-sectional shape as in the first conventional example. (14R), (14B) are dichroic mirrors for color separation (15B), (15G) are dichroic mirrors for color synthesis (11), (12) are mirrors (3R)
), (3G), (3B) are liquid crystal light valves, (8
R), (8G), (8B) are polarizing plates on the incident side, (9R
), (9G), (9B) are output side polarizing plates, (IOR
).

(IOC) and (IOB) are condenser lenses.

Next, the operation of the second conventional device will be explained.

The illumination light flux (2) exits the white light source lamp (120) placed at the focal point of the parabolic reflector, and then passes through the reflector (13'0).
), it becomes a parallel beam of light and exits the light source (1). The dichroic mirror (+4R) reflects red light and transmits blue and green light. In addition, dichroic mirror (14
B) reflects blue light and transmits green light. Therefore,
LCD light bulb (3G).

(3B) and (3R) are irradiated with green, blue, and red illumination light beams, respectively. LCD light valve (3G), (3B),
(3R) is set to green by an external circuit (not shown).
Images corresponding to blue and red color lights are formed, and the irradiated light is transmitted and modulated within the plane of the light valve. LCD light color (3
The output lights of G), (3B), and (3R) are converted into a composite light beam (100) by a dichroic mirror (15B) that reflects blue light, a dichroic mirror (15G) that reflects green light, and a reflecting mirror (12). The light enters the projection lens (4) and forms an image on the screen (5) as a projection light beam (110), so that an enlarged color image is presented for viewing. In addition, it is a condenser lens (IOR).

(IOC) and (IOB) are used to make red, green, and blue light enter the projection lens (4) with high efficiency, respectively. In addition, each liquid crystal light valve (3R), (3G),
The configuration and operation of (3B) are the same as those previously explained in FIG. 10.

[Problems to be Solved by the Invention] Since the conventional projection display device is configured as described above, the substantially circular illumination light flux is eclipsed by the rectangular display surface of the liquid crystal light valve, resulting in a loss of luminous flux. was. This problem will be explained below using figures. FIG. 12 is an explanatory diagram of the luminous flux loss, which is a problem with the conventional device.
It is a diagram in which only the parts necessary for explanation are extracted from the first conventional example shown in the figure. Since the light emitting center (121) of the lamp (1, 20) is located at the focal point of the parabolic reflector (130) having a circular aperture, the cross-sectional shape of the approximately collimated illumination light (2) is shown by a broken line. As shown, it is approximately circular. Generally, the display surface of a liquid crystal light valve is rectangular (rectangular); for example, the display surface that complies with the NTSC standard has a long side: short side ratio of 4:3, and the display surface that conforms to the No. 1 Vision standard has a ratio of 16:1.
It is 9. The approximately circular illumination light (2) enters the rectangular liquid crystal light valve (3), but the luminous flux that passes through the display surface (in this figure, for convenience of explanation, it is assumed to be the same as the entire area of the liquid crystal light valve (3)) contributes to the projected image display.

For this reason, for example, the light flux shown by the hatched area drawn in the dashed-dotted line frame at the bottom of FIG. 12 becomes a loss. As an example of this loss ratio, consider a case where a circular light beam with a -like intensity distribution and a diameter equal to the diagonal length of a rectangular display surface is incident on a liquid crystal light valve having a display screen of high-definition standard. In this case, the loss of luminous flux amounted to 46% of the total circular luminous flux, which was a major obstacle in increasing the brightness of the projected image. In addition, in the conventional optical system, a condenser lens (10) is placed just before the liquid crystal light valve (3) as shown in FIGS. 9 and 11 if necessary, but the light flux immediately after the condenser lens The liquid crystal light valve is also circular in shape, and the problem of vignetting due to the rectangular display surface of the liquid crystal light valve explained in FIG. 12 is exactly the same as in the previous example.

Furthermore, as shown in FIG. 12(d), a reflecting mirror (130
) The light beam that is not reflected by the liquid crystal light valve (3) and diverges forward hardly enters the liquid crystal light valve (3), which increases the loss of the light beam and becomes a factor that prevents high brightness.

The present invention was made to solve the above-mentioned problems, and it prevents the loss of illumination luminous flux that occurs due to the vignetting of the rectangular display surface of conventional liquid crystal light valves, and enables higher-brightness image display. The present invention provides a projection type display device that can be realized.

[Means for Solving the Problems] A projection display device according to the present invention includes a light source that emits a rectangular illumination beam that is substantially similar to the display surface of a liquid crystal light valve,
This prevents the loss of luminous flux due to the substantially circular illumination luminous flux being eclipsed by the rectangular display surface of the liquid crystal light, which was a problem with conventional devices.

For this purpose, the light source of the projection display device of the present invention (which has a parabolic mirror and a spherical mirror that share an optical axis and are arranged opposite to each other so that the focal point of the paraboloid and the center of curvature of the spherical surface are the common point) The light emitting center of the lamp is located at the common point position.Furthermore, a liquid crystal light/(
A rectangular opening wall is formed with the same or substantially similar shape to the display surface of the bulb, and a collimated illumination beam having a rectangular cross section is emitted from the rectangular opening.

[Operation] Parabolic mirrors and spherical mirrors that share the optical axis as described above and are arranged opposite each other so that the focal point of the paraboloid and the center of curvature of the spherical surface are the common points, conventionally have a circular cross section. This has the effect of causing the peripheral light flux that has been a loss to be emitted from the second rectangular aperture as a parallel light flux.

Further, a part of the light beam that was conventionally diverged forward without being reflected by the parabolic mirror is emitted from the second rectangular aperture as a parallel light beam, thereby producing an effective illumination light beam. Furthermore, since the light beam emitted from the light source has a rectangular cross-sectional shape similar to that of a liquid crystal light valve, the shape of the light beam reaching the display surface and the shape of the display surface can be made almost the same, and loss of light flux due to vignetting can be almost eliminated.

[Example] Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is an explanatory diagram showing a first embodiment of a projection type display device of the present invention.

In the figure, (120) is the lamp, (130) is the parabolic mirror, (131) is the first rectangular opening provided in the parabolic mirror, (+40) is the spherical mirror, and (+41) is the first rectangular opening provided in the spherical mirror. The second rectangular opening is located between the first and second rectangular openings.
13]) and (141) have a rectangular shape similar to the image display area of the liquid crystal light valve (3) when viewed from two directions in the figure (the emission direction of the illumination light (2)). Note that the inner surface of the parabolic mirror (130) other than the first rectangular opening (+31) and the inner surface of the spherical mirror (140) other than the second rectangular opening (141) are mirror-finished so that they function as reflecting mirrors. A reflective film coating is applied as necessary.

The above lamp (120), parabolic mirror (130), spherical mirror (140), and rectangular apertures (131) and (141) constitute the light source (1). The other components are the same as those shown in FIG. 9 showing the first conventional example.

Next, the operation of the embodiment will be explained.

The parabolic mirror (130) and the spherical mirror (140) are arranged to face each other so that the focal point of the paraboloid and the center of curvature of the spherical surface are common points. The lamp (120) is arranged so that the light emitting center (121) is located at this common point position. lamp(
120) is directly reflected by the parabolic mirror (130) and exits from the second rectangular aperture (141) as a ray parallel to the center line (20) indicated by the dashed line, or
The light is reflected between the parabolic mirror (140) and the spherical mirror (141) and exits from the second rectangular aperture (141) as a ray parallel to the optical axis (20).

This situation will be explained based on FIG.

In the figure, the inner surfaces of the parabolic mirror (130) and the spherical mirror (140) indicated by diagonal lines are the parts that act as reflecting mirrors,
Portions (131) and (141) indicated by broken lines are rectangular openings. Three representative rays (a) are shown in the figure.

The behavior shown in (b) and (c) is shown. The light ray (a) is a light ray that is emitted from the lamp (120), reflected by the parabolic mirror (130), and emitted through the end of the second rectangular opening (141). The light emitting center (121) of the lamp (120) is -
Since it is placed at a common point between the focal point of the parabolic mirror (130) and the center of curvature of the spherical mirror (140), which face each other in a plane perpendicular to the optical axis (20) shown by the dotted chain line, the ray (a ) becomes an illumination ray (2) parallel to the optical axis (20).

A parabolic mirror (1
The light beam reflected by 30) is emitted from the second rectangular aperture (141) as a parallel illumination light beam, similar to the light beam (a).

Light ray (b) is reflected by a parabolic mirror (
After passing through the first rectangular opening (131), it is reflected by the spherical mirror (140), and the common point (lamp (1)
20) through the emission center (121) ) of the parabolic mirror (1
30) and exits from the second rectangular aperture (141) as a ray parallel to the optical axis (20). The light ray (b) is a light ray that has conventionally been lost due to the vignetting of the circular light beam by the rectangular display surface (see the shaded area at the bottom right of FIG. 12).

The light beam (c) enters the spherical mirror (140) at a higher position than the second rectangular aperture (141), and after reflection, it reaches the common point (lamp (
120) through the emission center (121) ) of the parabolic mirror (
130), and after reflection, exits from the second rectangular aperture (+41) as a ray parallel to the optical axis (20). As is clear from the above explanation, all light rays other than those directly entering the second rectangular aperture (141) from the lamp (120) are parallel to the optical axis (20) from the second rectangular aperture (141). The illumination light beam (2) is emitted as an illumination light beam (2) having a rectangular cross-sectional shape.

The illumination light flux (2) passes through a condenser lens (10) and enters a liquid crystal light valve (3) placed immediately after it. The illumination light flux (2) is irradiated through a rectangular aperture (131) so as to be irradiated as a rectangular light flux approximately equal in size to the rectangular display area within the liquid crystal light valve (3).

(141) and the arrangement relationship between the condenser lens (lO) and the liquid crystal light valve (3) are set.

In addition, in an optical system in which the condenser lens (lO) is omitted, the illumination light flux (2) remains a parallel light flux and the liquid crystal light valve (
3), but in this case, the cross-sectional shape of the collimated illumination light beam (2) is set to approximately the same size as the rectangular display area of the liquid crystal light valve. In Figure 1, the liquid crystal light valve (
After the transmitted light (3) passes through the projection lens (4), the transmitted light (
110) and is enlarged and projected onto the screen (5), which is similar to the conventional device.

Next, a method for creating the light source (1) will be described.

First, the rectangular openings (131) and (141) are
Holes provided in the parabolic mirror (130) and the spherical mirror (140) are preferable because unnecessary reflections from the openings can be prevented. The parabolic mirror (130) and the spherical mirror (140) are made by molding or cutting a metal such as Af, or by molding a glass material, as is well known. If it is made of glass, it is appropriate to apply a reflective coating to the inner surface. In order to prevent the liquid crystal light valve (3) side from being irradiated with unnecessary infrared and ultraviolet rays, the parabolic mirror (130) selectively reflects only visible light (for example, wavelengths of 400 to 700 nm). The coating is applied to the rectangular opening (14) of the spherical mirror (140).
1) Broadband reflection (for example, 200 to 110
A coating with a reflectance of 90% or more in the wavelength range of 00n may be applied.

Second, the rectangular openings (131), (141) are made of a parabolic mirror (130) and a spherical mirror (130) made of transparent glass material.
140), it is not necessary to physically make a hole as the transparent region (window region). In this case, the rectangular openings (131) and (141) may be simply transparent glass windows without a reflective coating, or may be coated with a non-reflective coating for visible light (wavelength 400 to 700 nm) as necessary. good. It is appropriate that the inner surface of the spherical mirror (140) other than the second rectangular aperture (141) is provided with a broadband reflective coating (for example, a reflectance of 90% or more in the wavelength range of 200 to 11000 nm).

In addition, the second rectangular opening (241) is coated with ultraviolet light (wavelength 400 nm or less) and infrared light (wavelength 700 nm or less).
Liquid crystal light valve (3) with the reflective function of (above)
It may also be possible to prevent irradiation of unnecessary spectrum to.

Thirdly, the parabolic mirror (130) and the spherical mirror (140) may be opposed to each other and joined by a known method such as welding as shown in FIG. In this case, as in the second configuration, the rectangular openings (131) and (141) are made of transparent glass,
The insides of the parabolic mirror and spherical mirror facing each other are hermetically sealed using a known method, and the insides are filled with N2. Enclosing an inert gas such as Ar can prevent oxidation of the electrodes (not shown) of the lamp (120) and the lead wires connecting the electrodes and the drive circuit, which is effective for extending the lamp's life.

Parabolic and spherical surfaces (
The method for determining the shape of the inner surface) will be explained.

In FIG. 3, the following equations ① and ② hold true.

Y,”=4fX, ・・・■”=(L
−f)”+Y, 2. , ,・■ However, X is the depth from the apex of the parabolic mirror (130), and Y is the depth from the vertex of the parabolic mirror (130).
), f is the focal length of the parabolic mirror (130),
r is the radius of curvature of the spherical mirror (140).

Parameters (f, Xl, Y+) of parabolic mirror (130)
is given, the equation (2) can be obtained by eliminating Yl from the equations (2) and (2).

r”=(x++D” ・ ・ −
−■Here, r is a positive value, so the solution to ■ is r=X,
+f...■.

In addition, the right side of FIG. 3 shows a plan view of the parabolic mirror (130) and the spherical mirror (140). First rectangular opening (13
1) and the second rectangular opening (141) are located on the long side H in the plan view.
It has dimensions of 2 short sides V. H:v is approximately equal to the long side:short side ratio of the effective display area of the liquid crystal light valve (3).

Next, a method for determining the depth X3 from the apex of the spherical mirror and the radius Y2 of the aperture of the spherical mirror will be described.

As shown in Figure 4, L=V”/16f, X4=H”/1
It becomes 6f. Here, since H>V, X<X4.

Therefore, x2 and Y may be set to values such that the light beam (e) passing through the deepest part of the notch formed by providing the first rectangular opening (131) can be reflected. However, if f≧x3, there will be light rays that are repeatedly reflected within the spherical mirror (140) and do not exit the second rectangular aperture (141), as shown in FIGS. 5(b) and (c). Therefore, the focal length of the parabolic mirror (130) needs to be f<V/4.

By using a spherical mirror (140) with the radius r in equation (2) and the parameters x2 and Y2 as explained above, the parabolic mirror and spherical mirror joined as described above can be obtained.

FIG. 6 is a perspective view of a parabolic mirror and a spherical mirror used in the present invention.

L numerical example] f=12.5n+m, y++=+4[i, 5mm,
Using a parabolic mirror with X = 43.245 mm, H =
70+nm, V=55++++n, the spherical mirror has r=55.745mm from formula (■), Yz*55.493mm from the conditions explained in Figure 4, X2=50.448
+am.

In reality, it is better to allow some leeway for y and x, and to set them to slightly larger values.

[Other Examples] Next, a second embodiment of the present invention will be described with reference to FIG.

This embodiment uses a parabolic mirror (130) similar to that shown in FIG. This is an example in which a light source (1) consisting of apertures (131) and (141) is applied to the optical system of FIG. 11 showing the second conventional example. As in the first embodiment, an illumination light beam (2) having a rectangular cross section is emitted from the second rectangular opening (141) and enters the optical system after the dichroic mirror (14R). If the size of the effective display area of the liquid crystal light valves (3R), (3G), and (3B) is set so that the dimensions of the irradiated light beam approximately match, the liquid crystal light valves can be used as in the first embodiment. It is possible to reduce the luminous flux loss that occurs when the circular section illumination luminous flux is eclipsed on the display surface.

Note that the configuration and operation of the second conventional example are the same as those of the second conventional example except for the light source (1), so the explanation thereof will be omitted.

Although each embodiment of the present invention uses a transmissive liquid crystal light valve, devices using reflective liquid crystal light valves are also known.

FIG. 8 shows a third embodiment in which the light source (1) of the present invention is applied to an optical system using a reflective liquid crystal light valve (3).

Similar to the first and second embodiments, the first rectangular opening (13
1), a parabolic mirror (130) with a second rectangular aperture (1
A spherical mirror (140) with a light emitting center (41) at a common point (
A light source (121) consisting of a lamp (120) arranged with
The illumination light beam (2) with a rectangular cross section emitted from the light source 1) is reflected by the polarizing beam splitter (200) and becomes S-polarized illumination light directed toward the liquid crystal light valve (3). When no voltage is applied to the pixel, the light flux incident on the reflective light valve is reflected by the reflective mirror provided on the lower glass substrate (7), and when it exits from the liquid crystal, the plane of polarization is 90°. Although it rotates, if a voltage V higher than the threshold value is applied to the pixel, the optical rotation effect becomes smaller. On the other hand, the reflected light from the liquid crystal light valve passes through the polarizing beam splitter (200) and then heads toward the projection lens (4). The polarizing beam splitter (200) has the characteristic of transmitting P-polarized light and reflecting S-polarized light whose polarization plane is orthogonal to this, so the transmittance within the cross section of the light beam changes depending on the strength of the voltage applied to the pixels of the liquid crystal light valve. is modulated and becomes image information. The light emitted from the projection lens (4) is enlarged and projected onto the screen (5) f, as in the conventional example.

Even in the embodiment using the reflection type light valve described above, the image display surface of the liquid crystal light valve (3) is rectangular as in the case of the transmission type, and the light source (
The effect of 1) makes it possible to increase the brightness. In the above embodiments, a liquid crystal light valve that utilizes the optical rotation of liquid crystal has been described as an example. In addition, there are other methods to electrically control the birefringence of liquid crystals, such as E CB (ele
critically controlled biref
It goes without saying that the present invention can also be applied to a projection type display device using a liquid crystal light valve having an optical display mechanism other than optical rotation. Further, the number of light valves is not limited to three, but three or more, or even one or two light valves may be used (applicable).

As is clear from the above description, the main features of the present invention are as follows.

(1) The first rectangular opening is provided in a part of the parabolic mirror, and has a rectangular hole shape when viewed from the optical axis direction.

(2) The first rectangular opening is a transparent portion provided in a part of the parabolic mirror, and has a rectangular shape when viewed from the optical axis direction.

(3) The second rectangular opening is provided in a part of the spherical mirror, and has a rectangular hole shape when viewed from the optical axis direction.

(4) The second rectangular opening is a transparent portion provided in a part of the spherical mirror, and has a rectangular shape when viewed from the optical axis direction.

(5) The parabolic mirror and the spherical mirror are each rotationally symmetrical with respect to the optical axis, and are bonded facing each other to form a sealed structure.

[Effects of the Invention] As described in detail above, the light sources of the projection display device of the present invention share an optical axis and are arranged opposite to each other so that the focal point of the paraboloid and the center of curvature of the spherical surface are the common points. The light emitting center of the lamp is located at the common point of the parabolic mirror and the spherical mirror, and rectangular openings are provided on the parabolic and spherical surfaces. A part of the light beam that was not reflected by the parabolic mirror and became a forward divergent light beam is made to enter the rectangular aperture as a parallel light beam, and the light beam emitted from the light source can have a rectangular cross-sectional shape similar to that of a liquid crystal light valve. So,
The shape of the light flux reaching the display surface can be made almost the same as the shape of the display surface, and loss of light flux due to vignetting can be almost eliminated.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the projection display device of the present invention, FIG. 2 is a detailed explanatory diagram of a light source used in the present invention, and FIG. 3 is a light source of the projection display device of the present invention. constitute,
A diagram explaining the design method of opposing parabolic mirrors and spherical mirrors and the shape of the rectangular aperture. Figure 4 is the depth x2 from the apex of the spherical mirror.
, and the radius Y of the aperture of the spherical mirror, FIG. 5 is an explanatory diagram of the confinement of light rays, FIG. 6 is a perspective view of the parabolic mirror and spherical mirror used in the present invention, and FIG. An explanatory diagram showing a second embodiment of the projection display device of the present invention, FIG. 8 is an explanatory diagram showing a third embodiment of the projection display device of the present invention, and FIG. 9 is a conventional projection display device. The first configuration diagram, the first
0 is an explanatory diagram of the operating principle of a liquid crystal light valve, FIG. 11 is a second configuration diagram of a conventional projection type display device, and FIG. 12 is an explanatory diagram of luminous flux loss, which is a problem with the conventional device. In the figure, (3), (3R), (3G), (3
B) is a liquid crystal light valve, (4) is a projection lens, (1)
is a light source means, (120) is a lamp, (130) is a parabolic mirror, (+31) is a first rectangular aperture, (140) is a spherical mirror, (141) is a second rectangular aperture, and (121) is a light emitting device. It is central. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Diagram (a) Diagram (b) Diagram 2゜3゜Procedural amendment (voluntary) Person amending the name of the invention Name and address related to the case (601) Projection display device

Claims (1)

[Scope of Claims] An optical system comprising a liquid crystal light valve that forms an image in a rectangular area, a projection lens that enlarges and projects the image formed on the liquid crystal light valve, and a light source that emits a luminous flux that illuminates the light valve. In the projection type display device having a projection type display system, the light source means includes a lamp, a parabolic mirror, and a first light valve formed in a part of the parabolic mirror and having a shape substantially similar to the rectangular area of the liquid crystal light valve. It is composed of a rectangular opening, a spherical mirror, and a second rectangular opening formed in a part of the spherical mirror and having a shape substantially similar to the rectangular area of the liquid crystal light valve, and the parabolic mirror and the spherical mirror share an optical axis. and are arranged to face each other so that the focal point of the parabolic mirror and the center of curvature of the spherical surface form a common point, the light emitting center position of the lamp is arranged at the common point position, and the cross section from the second rectangular opening A projection display device characterized in that it emits a light beam having a rectangular shape.