JP2003207845A - Projector and lamp unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a small-sized, inexpensive projector suitable for displaying a television image, and wherein the luminance of a screen becomes gradually higher from the peripheral part toward the center part. <P>SOLUTION: The projector, in which light emitted from a light source 1 is guided to the incident surface of a light valve 6 through at least one lens array 3 wherein several concave lenses are two-dimensionally arranged, and the image light formed by the light valve 6 is projected through a projecting lens, is provided with a light condensing means 2 for condensing the light emitted from respective concave lenses constituting the lens array 3 to a prescribed light condensing position between the lens array 3 and the light valve 6 as illuminating light, and the illuminating light condensed at the light condensing position is constituted so as to have a prescribed cross-sectional shape and a prescribed intensity distribution. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection device such as a projection television for displaying an image on a target object such as a screen, and more specifically, to an optical system for irradiating a light valve for forming an image with light. Involved in the structure of the means.

[0002]

2. Description of the Related Art By using a projection device, it is possible to realize a large-screen television having a screen diagonal length of more than 40 inches. In general, a projection device reflects light from a lamp by a reflection plate and advances the light in a predetermined direction, and then passes the light integrator to convert the light into a light having a uniform intensity in a cross section perpendicular to the light traveling direction. The light valve is then irradiated. The projection device is required to be able to display a bright and even screen. Therefore, as a light source of the projection device, a metal halide lamp, an ultra-high pressure mercury lamp or the like, which has high light utilization efficiency and can be regarded as a point light source, is used. A liquid crystal element or a micromirror element is used as the light valve.

FIG. 14 shows an example of the electrode structure of a metal halide lamp, which is a type of discharge lamp, and the spatial distribution of emission intensity. In the figure, 11 is an anode, 12 is a cathode, 13 is a curve showing the emission center of the arc, and 14 is a curve showing the region where the emission brightness is equal to 10% of the emission center brightness. Also,
G is an inter-electrode distance, which is usually about several millimeters. In an actual lamp, the electrode part is sealed in a spherical glass tube (not shown) to keep the electrode interval constant, and
High-pressure gas is enclosed in the glass tube.

As shown in FIG. 14, the anode 11 and the cathode 1
Rays are emitted from the arc region that occurs between the two and these rays travel in various directions. In general, a means for converging the paths of most of these light rays and condensing the light rays at a position beyond the anode 11, for example, an ellipse having the emission center 13 as the first focal point and a predetermined position on the axis of the anode 11 as the second focal point. A mirror is provided on the opposite side of the cathode 12. However, since the intensity distribution of the condensed light beam has a shadow of the electrode 11 and the central portion is dark, even if it is transmitted to the light valve as it is, the light valve cannot be uniformly illuminated. For this reason, the conventional projection apparatus uses an optical integrator in order to obtain uniform illumination light. Examples of the optical integrator include a system using two lens arrays and a system using columnar optical elements. A projection device using two lens arrays as an optical integrator is disclosed in, for example, Japanese Patent Laid-Open No. 2001-1.
No. 25193, and a projection device using a columnar optical element as an optical integrator is described, for example, in Japanese Patent Application Laid-Open No. 7-98479.

[0005]

By using the optical integrator, the uniformity of the brightness of each part of the screen is improved, but the uniformity of the brightness becomes too high, resulting in flatness when displaying a television image. The image becomes unrealistic. Therefore, the above-mentioned JP 2001-1251 A
The projection device described in Japanese Patent Publication No. 93 has a configuration in which the brightness at the center of the screen is increased while using an optical integrator. However, in this device, each lens forming the first lens array forms an outer shape image of the lens in the central portion of the light valve surface, and therefore it is necessary to provide a large number of lenses in the lens array in order to smooth the luminance change. Therefore, the structure becomes complicated and the light utilization efficiency is impaired. Further, since the optical integrator is provided, an extra space is required and the device becomes large.

On the other hand, in a projection device using a columnar optical element as an optical integrator as described in Japanese Patent Laid-Open No. 7-98479, the number of reflections inside the columnar optical element is sufficient in order to obtain uniform illumination light. It is necessary to secure it, and as a result, the dimension of the columnar optical element becomes long and the device becomes large. In addition, it is technically difficult to display only the center of the screen brightly using the columnar optical element.

The present invention has been made in order to solve the above-mentioned problems of the conventional projection apparatus, and it is possible to illuminate the light valve with a small number of parts, which is small in size, inexpensive and excellent in image quality. The first object is to realize a projection device.

A second object of the present invention is to realize a projection apparatus which is suitable for displaying a television image because the brightness of the central portion of the screen is higher than that of the peripheral portion.

A third object of the present invention is to provide a projection device with high light utilization efficiency.

A fourth object of the present invention is to provide a projection apparatus that is not easily affected by the tolerances of parts and mounting variations and therefore has stable performance.

In order to achieve the above-mentioned first object, the invention according to claim 1 is characterized in that light emitted from a light source is
At least one in which a plurality of concave lenses are arranged two-dimensionally
In the projection device configured to guide the light of the image formed by the light valve through the projection lens through the one lens array to the incident surface of the light valve, the projection device between the lens array and the light valve. Is provided with a condensing means for condensing the light emitted from each concave lens forming the lens array as illumination light at a predetermined condensing position, and the illumination light condensed at the converging position has a predetermined cross-sectional shape. And a predetermined light intensity distribution.

According to a second aspect of the present invention, in the first aspect of the present invention, the exit surface of each concave lens forming the lens array has a shape corresponding to the predetermined cross-sectional shape and the predetermined light intensity distribution. It has a curvature corresponding to.

According to a third aspect of the invention, in the second aspect of the invention, the predetermined cross-sectional shape is similar to the shape of the incident surface of the light valve.

In order to achieve the second object, the invention according to claim 4 is the same as the invention according to claim 2 or 3,
It is characterized in that the predetermined light intensity distribution is a distribution in which the light intensity gradually decreases from the central portion toward the peripheral portion.

The invention described in claim 5 is from claim 1 to claim 4.
In the invention described in any one of (1) to (7) above, the condensing unit includes a concave mirror in which the light source is arranged at its focal point.

According to a sixth aspect of the invention, in the fifth aspect of the invention, the condensing means further includes a convex lens arranged between the lens array and the light valve.

According to a seventh aspect of the present invention, in the sixth aspect of the invention, the concave mirror is formed by combining a reflecting mirror having a concave surface with a cylindrical spherical mirror.

The invention described in claim 8 is characterized in that, in the invention described in claim 1, the incident surface of the light valve is located at the converging position.

A ninth aspect of the present invention is characterized in that, in the first aspect of the invention, an optical element having a primary color light selecting function is arranged at the condensing position.

A tenth aspect of the invention is characterized in that, in the first aspect of the invention, an optical element having an optical scanning function is arranged at the condensing position.

The eleventh aspect of the present invention is characterized in that, in the first aspect of the invention, an optical element having an optical shutter function is arranged at the converging position.

A twelfth aspect of the present invention is characterized in that, in the first aspect of the invention, an optical element having an opening for passing a light beam of a predetermined shape is arranged at the converging position.

According to a thirteenth aspect of the present invention, in order to achieve the third object, in the invention according to any one of the ninth to twelfth aspects, the optical element is a light not used for projecting an image. Is provided to the light source side.

According to a fourteenth aspect of the present invention, in the thirteenth aspect of the invention, the optical means is formed of a reflecting mirror.

[0024] In order to achieve the first object, the claim 15
According to another aspect of the present invention, light emitted from a light source is guided to an incident surface of a light valve through at least one lens array in which a plurality of concave lenses are two-dimensionally arranged, and light of an image formed by the light valve is guided. In a projection device configured to project via a projection lens, a first and a second lens array arranged to face each other between the light source and the light valve, and the first lens array. It has a condensing means for condensing the light emitted from each of the concave lenses constituting the condensing lens at a predetermined condensing position between the first lens array and the second lens array, and an opening for passing the light. And an opening means arranged at the light collecting position, wherein the second lens array is placed at a position where the light passing through the first lens array forms a light source image, and the opening is the light. valve And having a shape corresponding to the shape of the incident surface.

According to a sixteenth aspect of the present invention, in the invention according to the fifteenth aspect, a convex lens is arranged on the exit surface side of the second lens array to form a concave lens and the light which constitute the first lens array. It is characterized in that it has a conjugate relationship with the valve.

According to a seventeenth aspect of the invention, in order to achieve the second object, in the invention according to the sixteenth aspect, the light intensity distribution on the incident surface of the light valve goes from the central portion to the peripheral portion. In order to have a distribution in which the light intensity gradually decreases, a portion in which the light transmittance gradually decreases as the distance from the center of the opening is provided is provided at the periphery of the opening.

In order to achieve the fourth object, claim 18
In a lamp unit for generating a light beam for illuminating an incident surface of a light valve of a projection device, a light source, a reflecting mirror for directing light from the light source to the outside of the lamp unit, and a plurality of A concave lens is arranged two-dimensionally, and a lens array for condensing the light emitted from the lamp unit to a predetermined position is provided, and the shape and curvature of the lens surface of each concave lens is set to the predetermined position. The cross-sectional shape of the condensed light and the intensity distribution of the light are set to have a desired shape and distribution, the lens array is fixed to the reflecting mirror, and the space surrounded by the lens array and the reflecting mirror is set. It is characterized in that the light source is fixedly arranged.

In order to achieve the fourth object, the invention as set forth in claim 19,
The invention described in (1) is characterized in that the projection device is provided with the lamp unit according to (18).

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. Embodiment 1. FIG. 1 shows the configuration of a projection apparatus that is Embodiment 1 of the present invention. In the figure, 1 is a lamp which is a light source, 2 is a reflector having an elliptical surface,
3 is a lens array in which concave lenses having a rectangular lens surface are two-dimensionally arranged, 4 is a concave lens, 6 is a light valve for forming a projected image, and 5 is a size and shape corresponding to the effective area of the light valve 6. An opening having a rectangular opening, P1 is the second focus of the reflection plate 2, and L1 is the light valve 6.
Represents an illumination light beam that illuminates.

The light beam emitted from the lamp 1 is reflected by the reflecting plate 2 to change its direction and becomes a convergent light beam toward the second focal point P1 of the ellipse. The convergent light rays are converted into substantially parallel light rays by the concave lenses forming the lens array 3 and enter the concave lens 4. The concave lens 4 changes the degree of convergence of this light ray and emits it as an illuminating light ray L1 having a spread suitable for illuminating the light valve 6. This illumination ray L1
Is the light valve 6 after the portion of the light incident surface of the light valve 6 that extends outside the irradiation range is removed by the opening 5.
Is irradiated. The light valve 6 is driven by a driving unit (not shown) and emits a light beam forming an image toward a projection lens (not shown), which projects the image on a target object (not shown) such as a screen. Project.

FIG. 2A is a front view of the lens array 3, and as shown in the figure, the lens array 3 is an array of rectangular concave lenses 31 having an aspect ratio of 1: 2. FIG. 2B is a partial cross-sectional view of the lens array 3,
A part of the cross section of the lens array 3 cut in the vertical direction (cut in the direction perpendicular to the long side of the concave lens 31) is shown. In FIG. 2B, reference numeral 32 denotes a surface on which the convergent light from the reflection plate 2 is incident, and 33 denotes a lens surface of the concave lens 31. The curvature of the lens surface 33 of each concave lens 31 forming the lens array 3 is set to such a value that the convergent light rays entering the entrance surface 32 of the lens array 3 are emitted as substantially parallel light rays.

When the lamp 1 can be regarded as an ideal point light source, the lens array is formed on a cross section perpendicular to the optical axis at the position of the second focal point P1 of the reflecting plate 2 which is elliptical without the lens array 3. The light from each of the rectangular concave lenses forming the image No. 3 is projected, and the light rays having a varying intensity distribution that have passed through the large number of concave lenses are superimposed, so that a uniform illumination light beam having a substantially rectangular cross section can be obtained. However, in reality, the light from the lamp 1 is the light emitted from the spatial region having the spread as shown in FIG. For example, the electrode interval is 1.5
According to an actual measurement using an ultra-high pressure mercury lamp of mm, when light is focused on the second focus P1 without the lens array 3, a bright spot having a spread about 2 to 3 times the size of the light emitting area of the lamp. (However, the extent of this spread is of course influenced by the size and shape of the light emitting region of the lamp, the shape and surface accuracy of the reflector, and the positional relationship between the lamp and the reflector). Therefore, in the state where the lens array 3 is provided, the light from the lamp reaches the point P1 as a light beam having a rectangular cross section with a blurred outer shape.

Referring to FIG. 3, the shape of the incident surface of the light valve 6, the bright spot shape when the light rays of the lamp are condensed (when the lens array 3 is not provided), and the lens of the concave lens forming the lens array 3 are used. The relationship between the surface shapes is described below. In FIG. 3, 7 is a rectangular area having an aspect ratio of 9:16, which is similar to the incident surface of the light valve 6, and 8 is the lamp 1.
Of bright spots when the light rays of 8A, 8B and 8C are collected
Is an area representing the range of spread of the light rays that have passed through the peripheral edge of the lens array 3, 9 is an area in which 50% of the brightness of the central portion is in the brightness distribution due to the sum of the light rays that have passed through the lens array 3, and 10 is an ideal lamp The projection shape of the concave lens by the lens array 3 when the target point light source is shown.

In this embodiment, the concave lenses forming the lens array 3 are shaped such that the projected shape 10 of the concave lenses spreads to the rectangular shape 7 required by the light valve as the bright spot shape 8 spreads. There is. The size, shape, and arrangement of the concave lenses that form the lens array 3 can be variously set according to the bright spot shape 8, the shape of the reflection plate 2, and the shape of the light valve 6. Further, the ratio of the brightness of the central part of the illumination light to the brightness of the peripheral part can be set in various ways. It may be increased to reduce the effect of uniforming the luminance due to the spread of the bright spots.

The brightness distribution of the illumination light beam L1 can be obtained by light ray tracing calculation if the output energy distribution of the light emitting region of the lamp is obtained. FIG. 4 shows an example of the output energy distribution in the light emitting region of the lamp, which is modeled in a layered region. FIG. 4 (A) is an energy distribution diagram in which the output energy distribution of each point of the light emitting region is projected on the surface perpendicular to the rotational symmetry axis of the lamp electrode and is displayed as a bright spot, and FIG. It is an energy distribution map in the cross section which passes along the center. Figure 4
In (B), the energy of Deff is 50% of the central part.
Is the effective bright spot diameter and the Deff value is about 1.8 m.
m. It should be noted that, in FIG. 4, the bright spots have small unevenness due to a calculation error caused by the termination of the calculation by a finite number of times.

FIG. 5 shows the output energy distribution of the lamp as shown in FIG. 4, and the concave lens forming the lens array has a height (short side) of 5 mm and a width (long side) of 10 mm. 2 shows the distribution of light rays transmitted to the P1 position in the apparatus shown in FIG. FIG. 5A is a diagram in which the energy distribution of light rays is displayed as bright spots, and FIGS. 5B and 5C are energy distribution diagrams in cross sections in the horizontal direction and the vertical direction, respectively. Hef in these figures
f is an effective width in the horizontal direction, Veff is an effective width in the vertical direction, Heff is about 9 mm, and Veff is about 5 mm.
In this case, Heff / Veff = 1.8, which is approximately equal to 16/9 = 1.77 which is the horizontal width / vertical width of the light valve corresponding to the high definition television. Light in the range of the effective width Heff in the horizontal direction and the effective width Veff in the vertical direction is used as illumination light for irradiating the light valve. The brightness ratio around the center of the light illuminating the light valve is less than 50% at the screen corner, but the television signal is usually overscanned and the outer periphery is outside the television screen. 10% area is not visible. Therefore, in the area visible on the screen, the center is bright, and the brightness gradually decreases toward the periphery, and it is possible to obtain the illumination light with the center peripheral brightness ratio of about 50%.

In FIG. 1, the concave lens 4 is for correcting the convergence angle in advance so that the cross section of the illuminating light beam L1 has an appropriate size for illuminating the light valve 6, and the opening portion. Reference numeral 5 is for absorbing or reflecting light rays that spread to the outside of the illumination area 7 and for preventing unnecessary light rays from irradiating the light valve and generating stray light. The opening 5 may be composed of a plane mirror, in which case the light beam reflected by the opening 5 returns to the lamp 1 and is used as the illumination light beam L1.

Embodiment 2. FIG. 6 shows the configuration of the projection device according to the second embodiment of the present invention. In the figure, 5B is an opening, 16 is a color wheel, 17 is a motor, 18 is a light beam transmitting means, and 19 is a convex lens. In FIG.
Elements that are the same as or correspond to the elements shown in FIG.

The white light beam emitted from the lamp 1 is reflected by the reflection plate 2 and becomes a convergent light beam. The lens array 3 emits the convergent light rays as parallel light rays having a rectangular cross section similar to the outer shape of the lens surface of the concave lens 31. The parallel light rays from the lens array 3 become rectangular illumination light rays similar to the incident surface of the light valve 6 at the second focal point P1 of the reflection plate 2. Opening 5
B is a light-absorbing material or a light-reflecting material in which a rectangular opening is formed, and removes light rays outside the irradiation range of the incident surface of the light valve 6. The color wheel 16 is formed by sequentially arranging dichroic filters that pass only red, green, and blue primary color rays, respectively, in the circumferential direction of the disk. By rotating the color wheel 16 with the motor 17,
The color of the illumination light beam can be switched in time sequence. The light beam transmission means 18 is composed of a lens or a mirror,
The light beam having a rectangular cross section formed at the position of point P1 is transmitted to the light valve 6 with its convergence angle adjusted so as to have a cross sectional dimension suitable for illuminating the light valve 6. Light beam transmission means 1
8 may be arranged so that the point P1 and the incident surface of the light valve 6 are in a conjugate relationship. For example, the convex lens 19 is imaged so that the opening shape of the opening 5B overlaps the outer shape of the incident surface of the light valve 6. You can do it.

The light valve 6 is a driving means (not shown).
Are driven in synchronism with the color of the emitted light beam to form a light beam of an image of each primary color and emit it to a projection lens (not shown). As a result, a full-color image is projected.

Embodiment 3. FIG. 7 shows the configuration of the projection apparatus according to the third embodiment of the present invention. 3 in the figure
B is the first lens array, 31B is the first lens array 3B
Is a concave lens, 5C is an opening, and 20 is a light beam transmitting means. The light beam transmitting means 20 includes a second lens array 21.
And a condenser lens 22. In FIG. 7, the same or corresponding elements as those shown in FIG. 1 are designated by the same reference numerals.

The white light beam emitted from the lamp 1 is reflected by the reflection plate 2 and becomes a convergent light beam. The first lens array 3B emits this convergent ray as a convergent ray having a rectangular cross section similar to the lens surface of the concave lens 31B. First lens array 3
B has the same configuration as the lens array 3 in the first embodiment, but the concave lens 31B of the first lens array 3B has a longer focal length than the concave lens 31 of the lens array 3, and therefore the light rays that have passed through the first lens array 3B are It is not a parallel ray but a convergent ray that forms a light source image at the position of the second lens array 21. The light beam that has passed through the first lens array 3B becomes an illumination light beam having a rectangular cross section similar to the outer shape of the incident surface of the light valve 6 at the second focus P1 of the reflection plate 2. Also,
The light intensity distribution of the cross section is such that the amount of transmitted light is limited by the opening 5C so that the light intensity is large in the central portion and gradually decreases toward the periphery.

The structure and characteristics of the opening 5C will be described with reference to FIG. 8A is a front view of the opening 5C, FIG.
8B is a partially enlarged view thereof, FIG. 8C is a diagram showing a change in the light transmittance T of the opening 5C in the vertical direction (direction perpendicular to the long side), and FIG. 8D is a view of the opening 5C. It is a figure which shows the change of the light ray reflectance R of a perpendicular direction. In FIG. 8A, 50 is a light reflecting portion, 51 is a light transmitting portion, and 52 is a light semi-transmitting portion. As shown in FIG. 8 (B), the light semi-transmissive portion 52 includes the transparent portion 5
21 is composed of a reflective portion 522, and the area ratio of the reflective portion 522 is small in the vicinity of the transparent portion 51, and most of the light rays pass through. On the other hand, in the vicinity of the light reflecting portion 50, the reflecting portion 522
Has a large area ratio, and passes approximately 70% of the light rays.

FIG. 8C is a diagram showing a change in the light transmittance of the opening 5C in the vertical direction, and as shown in this figure, the transmittance in the region of the light transmitting portion 51 and the semi-transmissive portions 52 on both sides thereof. Has a characteristic 53 in which the central portion is 100% and the peripheral portion is 70%. On the other hand, FIG. 8D is a diagram showing a change in the light reflectance of the opening 5C in the vertical direction. As shown in this figure, the light reflecting portion 50 has a reflectance of 1 or less.
00%, and all rays are reflected. Further, in the regions of the light transmitting portion 51 and the semi-transmissive portions 52 on both sides thereof, the reflectance is 0% at the central portion, and the characteristic 54 gradually increases toward the peripheral portion. The light beam reflected by the opening 5C passes through the first lens array 3B and reaches the reflection plate 2, is reflected by the reflection plate 2 and reaches the lamp 1, and is used as an illumination light beam as a result.

The second lens array 21 is a two-dimensional array of concave lenses similar to the first lens array 3B, and one concave lens is one of the concave lenses constituting the first lens array 3b in transmitting light rays. There is a corresponding relationship. The light source image formed by the concave lens forming the first lens array 3B at the position of the lens array 21 is included in the surface of the corresponding concave lens forming the second lens array 21.
The convex lens 22 collects the light rays emitted from the second lens array 21 and illuminates the light valve 6.

Due to the total optical characteristics of the second lens array 21 and the lens 22, the concave lenses constituting the lens array 3B and the light valve 6 have a conjugate relationship.
By forming an image so that the outer shape of the concave lens 31B overlaps the outer shape of the incident surface of the light valve 6, the concave lens 3B is formed.
A light ray passing through 1B can be efficiently transmitted to the light valve 6.

As described above, in the present embodiment, the first lens array 3B and the second lens array 21 form a light integrator, and the second lens array 21 and the lens 22 form an illumination light beam that passes through the opening 5C. The light beam transmitting means 20 for transmitting while maintaining its cross-sectional shape is formed. Further, since the light beam transmitting means 20 transmits the image of the opening 5C to the position of the light valve 6 with a slight blur, the areas of the fine mirrors of the opening 5C are averaged, and the brightness of the central portion of the light valve 6 is small. You will receive a gently rising illumination beam.

Fourth Embodiment FIG. 9 shows the configuration of the projection device according to the fourth embodiment of the present invention. In the figure,
Reference numerals 23 and 24 denote a first rotary shutter and a second rotary shutter which constitute an optical shutter, 25 and 26 denote a motor, 27
Is a dichroic mirror that reflects only red, 28 is a dichroic mirror that reflects only green, and 29 is a total reflection mirror. In FIG. 9, the same or corresponding elements as those shown in FIG. 1 are designated by the same reference numerals.

FIG. 10 is a front view of the first rotary shutter 23. The first rotary shutter 23 is composed of a disk-shaped glass plate, and on the glass plate, a transparent region 231 and a mirror-reflecting region 232 are spirally formed. The width of the area 232 where the mirror is formed is twice the width of the transparent area 231. AP in the figure represents the projected position of the rectangular opening of the opening 5B. The second rotary shutter 24 has the same configuration as the first rotary shutter 23, but a black light absorbing region is arranged instead of the mirror region 232.

The first rotary shutter 23 and the second rotary shutter 24 are rotationally driven in synchronization with each other by motors 25 and 26, respectively, to pass the light beam having the cross-sectional shape of the transparent area 231 in the opening AP and transmit the light beam. 18
Emit to. FIG. 11 shows the cross-sectional shape of the light beam after passing through the rotary shutter. In the figure, AP indicates the range of light rays limited by the shape of the opening 5B, LB indicates the range of light rays reaching the light valve 6, and L231 indicates the range of light rays that have passed through the transparent region 231. By adjusting the rotation angle difference (phase difference) between the first rotary shutter and the second rotary shutter, it is possible to change the size of the portion where the region 231 and the region 232 overlap each other, so that the opening of the optical shutter can be controlled. You can For example, if the rotation angles of the second rotary shutter and the first rotary shutter match, the optical shutter is in the fully open state, if the rotation angle difference is 30 degrees, it is in the half open state, and if the rotation angle difference is 60 degrees. Fully closed.

In SH of FIG. 11, half of the light ray L231 which has passed through the transparent area 231 of the first rotary shutter 23 by the second rotary shutter 24 due to the shift of the rotational phases of the first rotary shutter 23 and the second rotary shutter 24. The state of blocking is shown, and in this state, the cross section of the passing ray is limited to the upper right half of the line segment SH.

Although the band-shaped white light beam shown in FIG. 11 is transmitted by the light beam transmitting means 18, the red dichroic mirror 27 and then the green dichroic mirror 2 are transmitted on the way.
8. Then, the path is bent by the total reflection mirror 29, thereby forming a band of red, green and blue rays to reach the light valve 6. FIG. 12 shows the cross-sectional shape of the light beam that has reached the light valve 6. In the figure, LR, LG, and LB are irradiation areas of red, green, and blue light rays, respectively.

As shown in FIG. 12, the light valve 6 is irradiated with the primary color light rays in a band shape, and the area moves on the light valve as the rotary shutter rotates.
Looking at the individual pixels that make up the light valve, the colors of the radiated light rays are sequentially switched. Therefore, by driving the light valve 6 in accordance with the timing of the radiated light rays of each color, the image of each color is displayed. It becomes possible to project, and a full-color image can be projected as a composite image thereof.

Since the extinction ratio of the light valve 6 is a finite value, the contrast of the projection device is also restricted. When projecting an image such as a movie, in a scene where the entire screen is dark, the black image area may appear to be raised due to the human being accustomed to the dark environment.In that case, close the optical shutter. Thus, the blackness of the entire screen can be made darker, and an image with a wide range of brightness change can be projected.

The pattern of each color light when the light valve 6 is irradiated with light may be any pattern as long as it can drive the light valve 6 in synchronization with the pattern, and other than the pattern shown in FIG. The band may be a vertical or vertical band, and the width of the band may be wider or narrower.

Embodiment 5. FIG. 13 shows the configuration of a projection device that is Embodiment 5 of the present invention. In the figure, 100 is a lamp unit, and the lamp unit 100 includes a first reflection plate 201, a second reflection plate 202, and a lens array 300. In FIG. 13, the same or corresponding elements as those shown in FIG. 1 are designated by the same reference numerals.

The first reflecting plate 201 is an elliptical mirror on which the lamp 1 is placed, and the second focal point is P1.
The second reflector 202 transmits the light beam from the lamp 1 to the lamp 1.
It is a spherical mirror fixed so that its center of curvature coincides with the position of the lamp 1 so as to return to. The position with respect to the lamp 1 is fixed. The lens array 300 is a two-dimensional array of concave lenses similar to the lens array 3 in the first embodiment of the present invention, and is fixed to the second reflecting plate 202. The concave lens forming the lens array 300 is set to have a curvature such that a light ray passing through the lens surface becomes a light ray that converges at a slight angle. As described above, the lamp unit 100 includes the first reflector 20.
The lamp 1 is fixedly arranged in a space surrounded by the first, second reflection plates 202, and the lens array 300.

In order to make the luminance distribution of the illumination light that illuminates the light valve 6 at the second focal point P1 accurate, the first reflector 201, the second reflector 202, the lens array 300 and the lamp 1 are provided. It is necessary to maintain the proper positional relationship between them. In the present embodiment, these are adjusted and assembled to form the integrated lamp unit 100, so that the brightness variation of the illumination light beam and the central position of the illumination light beam due to the error in the mounting position of the lens array 300 that has been generated conventionally. It is possible to realize a projection device which prevents variations and therefore has stable performance.

The opening 5B has a rectangular opening that reflects unnecessary light rays that are not used for illumination of the light valve 6. In FIG. 13, for example, the unnecessary light ray L10 is reflected by the opening 5B, passes through the lens array 300 as the light ray L11, is reflected by the first reflection plate 201, passes through the lamp 1, and is directed to the second reflection plate 202. It becomes L12. The light ray L12 is reflected by the second reflection plate, and is approximately the light ray L1.
By tracing the path of 1 in the opposite direction, the opening 5B is reached again. In this way, the light ray L11 returned to the lamp unit 100 passes through the lens array 300 forming the lamp unit 100 twice, and is reflected twice or three times by the reflection plate, and then at different positions of the opening 5B. When the light ray reaches the transmission area again and reaches the transmission area, the light ray is used as an illumination light ray, so that the light use efficiency is improved.

The reflecting plate constituting the lamp unit 100 is not limited to the above-mentioned two types of concave mirrors, but may be one type or three or more types of concave mirrors as long as the light utilization efficiency is high. Alternatively, in addition to the concave mirror, a flat mirror or a corner cubic mirror may be combined.

[0061]

Since the present invention is constructed as described above, it has the following effects.

According to the first aspect of the present invention, the cross-sectional shape suitable for illuminating the light valve is provided at the position where the light beam emitted from the light source is first condensed using one lens array. Since it is possible to obtain illumination light having a light intensity distribution, a place for providing a conventional light integrator is not required, and the number of parts of the illumination optical means can be reduced, so that a compact and inexpensive projection device can be realized.

According to the second aspect of the invention, the size of the light emitting point and the spread of the light emitting angle of the light source and the passage of the light beam of the light converging means are obtained so that a desired cross-sectional shape and light intensity distribution of the illumination light can be obtained. By individually setting the shape and curvature of the concave lens forming the lens array while considering the change of the f-number depending on the position, it is possible to realize illumination light having an appropriate cross-sectional shape and brightness distribution.

According to the third aspect of the present invention, the illumination light having a cross-sectional shape similar to that of the light valve is obtained at the light collecting position of the light collecting means. It is possible to arrange the means, and it is possible to realize a compact projection device.

According to the invention described in claim 4, at the light-collecting position of the light-collecting means, illumination light having a light intensity distribution in which the light intensity gently decreases from the central portion toward the peripheral portion is obtained. Therefore, it is possible to realize a projection device suitable for projecting an image such as a television signal.

According to the fifth or sixth aspect of the present invention, since the light collecting means is a concave mirror or a convex lens, the light collecting means has the same structure as the light collecting means widely used in the conventional projection apparatus. A projection device that is easy to manufacture and inexpensive can be realized.

According to the invention described in claim 7, since the concave mirror as the light converging means is constituted by combining the mirror having the concave surface with the cylindrical spherical mirror, the light rays emitted from the lamp are collected in a wide angle range. It becomes possible to shine, and further, the light rays reflected from the condensing point and returning to the lamp,
It is possible to reflect the light again to the condensing point over a wide angle range, and as a result, the light can be effectively used.

According to the invention described in claim 8, since the light valve is provided at the light collecting position of the light collecting means, the projection device can be realized with a simple structure.

According to the invention described in claim 9, since the optical element having the primary color light selecting function is provided at the condensing position of the condensing means, a color image of a compact structure using a single light valve is provided. A projection device can be realized.

According to the tenth aspect of the invention, since the optical element having the optical scanning function is provided at the condensing position of the condensing means, the projection of a color image using a single light valve has a compact structure. The device can be realized.

According to the eleventh aspect of the present invention, since the optical element having the optical shutter function is provided at the condensing position of the condensing means, the variation range of the brightness is wide due to the compact structure.
Therefore, a projection device with high contrast can be realized.

According to the twelfth aspect of the invention, since the optical element having the opening for passing the light beam is provided at the light collecting position of the light collecting means, it is possible to reduce stray light and improve the contrast.

According to the thirteenth aspect of the present invention, since the optical element arranged at the condensing position is provided with the optical means for returning the light rays not used for the image projection to the light source side, the light rays which have not been used once are regenerated. It is possible to use the light, the efficiency of light utilization is improved, and as a result, a projection device with high brightness can be realized.

According to the fourteenth aspect of the invention, since the optical means for returning the light rays not used for the projection of the image to the light source side is constituted by the reflecting mirror, the projection device which is easy to manufacture and has a high brightness can be manufactured at a low cost. Can be realized.

According to the fifteenth and sixteenth aspects of the invention, the optical integrator is constituted by the two lens arrays, and the opening means is provided at the light-converging point located between the two lens arrays. Since the illumination light having a cross-sectional shape and a light intensity distribution suitable for illuminating the light valve is generated, it is possible to realize a projection device suitable for projecting an image such as a television signal.

According to the seventeenth aspect of the present invention, since the portion where the light transmittance gradually decreases as the distance from the center of the opening is provided in the periphery of the opening at the light collecting position, the light incident surface of the light valve is provided. The light intensity distribution can be a distribution in which the light intensity gently decreases from the central portion toward the peripheral portion.

According to the eighteenth and nineteenth aspects of the invention, the light source for illuminating the light valve of the projection device, the light source, the reflecting mirror for directing the light from the light source to the outside, and the lens surface. A plurality of concave lenses are arranged two-dimensionally so that the shape and the curvature of the light are converged at a predetermined position and the cross-sectional shape of the light and the intensity distribution of the light have a desired shape and distribution. The light is generated from a lamp unit that is integrally formed with a lens array that condenses light at a predetermined position, and the lens array is fixed to a reflecting mirror so that a light source is placed in a space surrounded by the lens array and the reflecting mirror. Since it is fixedly arranged, it is possible to fix the lamp, the reflecting mirror, and the lens array to the projection device after adjusting the positions of the lamp array, and it is possible to reduce variations in illumination light. It is possible to realize a stable projection device performance by.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a projection device according to a first embodiment of the present invention.

2A and 2B are a front view and a partial cross-sectional view of a lens array of the projection device according to the first embodiment.

FIG. 3 is a diagram for explaining the relationship between the shape of a concave lens forming the lens array of the projection device of the first embodiment and the converging shape of passing light.

FIG. 4 is an example of a model of a light emission intensity distribution of a light source lamp of the projection device according to the first embodiment.

5 is a diagram showing a result of calculation by a ray tracing simulation of a condensed state of light rays passing through a lens array when the light source lamp of the model of FIG. 4 is assumed in the projection apparatus of the first embodiment.

FIG. 6 is a diagram showing a configuration of a projection device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a projection device according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of an opening of a projection device according to a third embodiment.

FIG. 9 is a diagram showing a configuration of a projection device according to a fourth embodiment of the present invention.

FIG. 10 is a front view showing a configuration of a rotary shutter of a projection device according to a fourth embodiment.

FIG. 11 is a diagram showing a cross-sectional shape of a light beam that has passed through the rotary shutter of the projection device according to the fourth embodiment.

FIG. 12 is a diagram showing light rays emitted to a light valve in the projection device according to the fourth embodiment.

FIG. 13 is a diagram showing a configuration of a projection device according to a fifth embodiment of the present invention.

FIG. 14 is a diagram showing an electrode part structure and a light emitting region of a discharge lamp.

[Explanation of symbols]

1 lamp, 2 concave mirror, 3 lens array,
5, 5B, 5C opening, 6 light valve, 16
Color wheel, 31 concave lens forming lens array, 23, 24 rotary shutter, 50, 23
2,522 reflector, 100 lamp units.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinji Okamori             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd.

Claims (19)

[Claims] 1. Light from a light source is guided to an incident surface of a light valve through at least one lens array in which a plurality of concave lenses are two-dimensionally arranged, and light of an image formed by the light valve is projected. In a projection device configured to project through a lens, light emitted from each concave lens forming the lens array at a predetermined condensing position between the lens array and the light valve is used as illumination light. A projection device, comprising a condensing unit for condensing, so that the illumination light condensed at the condensing position has a predetermined cross-sectional shape and a predetermined light intensity distribution. 2. The light emitting surface of each concave lens forming the lens array has a shape corresponding to the predetermined cross-sectional shape and a curvature corresponding to the predetermined light intensity distribution. Projection device. 3. The projection device according to claim 2, wherein the predetermined cross-sectional shape is similar to the shape of the incident surface of the light valve. 4. The projection apparatus according to claim 2, wherein the predetermined light intensity distribution is a distribution in which the light intensity gently decreases from the central portion toward the peripheral portion. 5. The projection apparatus according to claim 1, wherein the light condensing unit includes a concave mirror in which the light source is arranged at its focal point. 6. The projection apparatus according to claim 5, wherein the light condensing unit further includes a convex lens arranged between the lens array and the light valve. 7. The projection apparatus according to claim 6, wherein the concave mirror is configured by combining a reflecting mirror having a concave surface with a cylindrical spherical mirror. 8. The projection device according to claim 1, wherein an incident surface of the light valve is located at the light collecting position. 9. The projection device according to claim 1, wherein an optical element having a primary color light selecting function is arranged at the light collecting position. 10. The projection device according to claim 1, wherein an optical element having an optical scanning function is arranged at the condensing position. 11. The projection device according to claim 1, wherein an optical element having an optical shutter function is arranged at the condensing position. 12. The projection device according to claim 1, wherein an optical element having an opening for passing a light beam having a predetermined shape is arranged at the condensing position. 13. The projection apparatus according to claim 9, wherein the optical element has an optical unit that returns light not used for image projection to the light source side. 14. The projection device according to claim 13, wherein the optical unit is a reflecting mirror. 15. The light emitted from a light source is guided to an incident surface of a light valve through at least one lens array in which a plurality of concave lenses are two-dimensionally arranged, and light of an image formed by the light valve is projected. In a projection device configured to project through a lens, the first and second lens arrays are arranged between the light source and the light valve so as to face each other, and the first lens array is configured. Light-collecting means for collecting light emitted from each concave lens at a predetermined light-collecting position between the first lens array and the second lens array, and an opening through which the light passes, An opening means arranged at the condensing position, wherein the second lens array is placed at a position where light passing through the first lens array forms a light source image, and the opening is the light bulb. Projection apparatus characterized by having a shape corresponding to the shape of the incident surface of the. 16. A convex lens is arranged on the exit surface side of the second lens array so that the concave lens forming the first lens array and the light valve are in a conjugate relationship. Item 16. The projection device according to item 15. 17. The light intensity distribution on the incident surface of the light valve is such that the light intensity distribution gradually decreases from the central portion toward the peripheral portion, and the light intensity distribution is gradually reduced from the center of the opening to the periphery of the opening. The projection device according to claim 16, further comprising a portion where the light transmittance gradually decreases. 18. A lamp unit for generating a light beam for illuminating an incident surface of a light valve of a projection device, a light source, a reflecting mirror for directing light from the light source to the outside of the lamp unit, and a plurality of concave lenses. And a lens array for condensing light emitted from the lamp unit to the outside at a predetermined position, and collecting the shape and curvature of the lens surface of each concave lens at the predetermined position. The cross-sectional shape of the light to be emitted and the intensity distribution of the light are set to have a desired shape and distribution, the lens array is fixed to the reflecting mirror, and the space surrounded by the lens array and the reflecting mirror is set. A lamp unit in which the light source is fixedly arranged. 19. A projection device comprising the lamp unit according to claim 18.