JP2002072361A - Lighting optical system, optical device having the same lighting optical system, and image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting optical system which practically makes it possible to improve gradations with inexpensive constitution without increasing the space, an optical device which has the lighting optical system, and an optical device and an image processor which are suitable for an image projection device such as, specially, a large-light-quantity AV projector having higher luminance. SOLUTION: The lighting optical system which generates and uses pieces of luminous flux for lighting is equipped with a stop means having variable stops corresponding to the pieces of luminous flux at the separation positions of the pieces of luminous flux.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination optical system, an optical device having the illumination optical system, and an image processing device, and more particularly to an optical device such as an image projection device including the illumination optical system as a component thereof, data, and AV applications. The present invention relates to an optical device such as an image projection device used for an enlarged projection projector.

[0002]

2. Description of the Related Art FIG. 6 shows a basic configuration of a conventional transmission liquid crystal three-panel image projection apparatus. In FIG. 1, white light emitted from a light source unit 1 is emitted as parallel light by a parabolic reflector 2 and passes through a UV-IR cut filter UVIR for removing infrared and ultraviolet components, each of which is in a direction parallel to the plane of the paper. The light beam is split by a so-called fly-eye integrator, which is composed of known fly-eye lenses 3 and 4 composed of convex lens groups arranged in a grid shape in a direction orthogonal to the above. The respective light beams converge and enter the polarization conversion element group PSM, and are emitted with their polarization directions aligned. After passing through the condenser lens 6 and the like, light in the red band is transmitted by the dichroic mirror DM1, and light in the blue band is reflected from green. In general, as a light source for optical equipment relating to high-brightness projection, a plasma light source using an arc discharge in a gas such as a halogen lamp, a metal halide lamp, or an ultra-high pressure mercury lamp is used. Lamps are preferred. As the color separation / synthesis optical element, a dichroic mirror, a dichroic prism, or the like is used, and a technique using a hologram element or a diffraction element for the purpose is disclosed in a patent.

The red band light transmitted through the dichroic mirror DM1 has its optical path changed by 90 degrees by the total reflection mirror M1 and passes through a field lens 7R, which has liquid crystal display elements 8R and 8 having a rectangular display range having a long side parallel to the paper.
G, 8B is incident on 8R which displays the red component light component image, where the light is modulated according to the input signal. The light that has been modulated enters the dichroic prism 9 and changes the optical path by 90 degrees in the dichroic prism to change the projection lens 10.
And is magnified and projected to form an image on the screen 11.

On the other hand, the green-blue band light reflected by the dichroic mirror DM1 and having its optical path changed by 90 degrees enters the dichroic mirror DM2. Since the dichroic mirror DM2 has a characteristic of reflecting green band light, the green band light is reflected here, its optical path is changed by 90 degrees, and the liquid crystal display element 8G is changed via the field lens 7G.
, Where the light is modulated according to the input signal. The light-modulated green band light enters the dichroic prism 9 and the projection lens 10 in this order, and is enlarged and projected to the screen 11.
Imaged on top.

The blue band light transmitted through the dichroic mirror DM2 is incident on the liquid crystal display element 8B via the lens 7B, the total reflection mirror, and M2 and M3, where the light is modulated according to an input signal. The light-modulated blue band light enters the dichroic prism 9, changes the optical path by 90 degrees by the dichroic prism 9, enters the projection lens, is enlarged and projected, and is imaged on the screen 11. As described above, a color image is displayed by superimposing the projected images of the three colors on the screen 11. In the following description, the same numbers are assigned to the same functional members with the same numbers and names in the description of the drawings, and the description will be omitted.

An image projection apparatus of the above-mentioned type has already been commercialized as a liquid crystal projector, and a liquid crystal rear projection television / monitor product in which the screen is of a transmissive type and incorporated in a television set housing has been put to practical use. . In such a projector application, there is a strong demand for high brightness because the projector is used even in a bright environment.
Some products have reached 000 ANSIlm.

By the way, even in such a high-brightness projector, it is important to darken the room and lower the screen illuminance in consideration of black level reproduction.
At that time, when viewing a source such as a movie in which a video luminance difference is large in a time series, highlights of an image may be dazzling and eyes may easily be tired. In such a case, luminance adjustment is required.

Here, when the signal level is manipulated and the light illuminating means (here, liquid crystal) is adjusted to a level at which the screen illuminance in the highlight is easy to see, the brightness of the illumination system remains constant, so that a black float appears. As a result, the image quality becomes poor, and the contrast is lowered. In addition, the number of controllable gradations depends on the device performance (non-linear controllability,
In the case of the DMD, the drive frequency is limited, and the processing resolution in digital control (insufficient number of bits) is reduced, and a smooth multi-tone image cannot be displayed.

[0009] The above-mentioned floating black causes leakage of the liquid crystal itself in the all-black display (the same problem arises in that the black display in the diffuse-type reflection type liquid crystal element is incomplete in the all-black display). This is due to incidental reflection components (flares and ghosts) in the optical system. The occurrence of black floating due to the latter is generated as stray light leakage of unnecessary light even in an image projection apparatus using a micro machine mirror element such as a reflection type DMD element, which causes deterioration of image quality. As described above, the above-described conventional configuration has a problem in that the image quality is reduced.

FIG. 7 shows a known example (US Pat. No. 5,053,934) of a light amount adjusting mechanism in which a diaphragm means is applied to an illumination system as a light amount control device of an image projection apparatus used in this field. In this conventional example, an elliptical reflector is used as a reflector, and an illumination light beam is condensed and used. A diaphragm mechanism of two blades is inserted in the middle of light beam converging, and two skewer-shaped diaphragm blade members are used. This reduces illumination unevenness. Fundamental measures for these floating blacks are to control the light amount in the illumination system itself or the light amount in the projection optical system after the light modulation unit to fully enhance the gradation display capability of the light modulation unit, regardless of the signal level. It is best to use.

Assuming that the transmission (reflection) contrast ratio of the light modulating means is constant with respect to the absolute illuminance variation, by controlling the amount of light in a low-luminance scene, it is possible to reduce the floating of black by a proportional amount due to the decrease in illuminance and to express the gradation This is because expansion becomes possible.

[0012]

However, high brightness lamps such as halogen lamps, metal halide lamps, ultra high pressure mercury lamps and xenon lamps for projectors which have been commercialized and put into practical use have a long life and improved lighting stability. In view of this, it is desirable to use the lamp under a constant light emission condition while avoiding dynamic lighting condition fluctuations, so that the light amount control by the lamp itself is hardly performed. Therefore, another light control means is required for light amount adjustment.

US Pat. No. 5,053,93, cited above, discloses an example in which a diaphragm (light control means) is provided in an illumination system near a lamp.
In the case of the specification No. 4, a condensing illumination type using an elliptical reflecting umbrella is used. In order to apply this to a case using a parabolic reflecting umbrella, a combination with a convex lens and a similar condensing illumination are used. Is limited to Also, with respect to the brightness uniformity of the screen required in recent data projectors, the technology disclosed in the above conventional example does not sufficiently remove the illumination unevenness,
At present, it cannot be used directly in lighting systems using a mainstream fly-eye integrator and parabolic reflector.

Incidentally, in the case of a lighting device for a semiconductor printing device in which light is condensed by an elliptical reflector and collimated by a convex lens, and illumination unevenness is removed by a fly-eye integrator or a multi-glass rod integrator, the elliptical reflector has an elliptical shape. The above prior art can be applied to the vicinity of the second focal point. As described above, in order to use the technology disclosed in the above-mentioned US Pat. No. 5,053,934, the illumination light is once converged and the stop is converged at the convergence point. In this case, an aperture is provided for the light source, so that the illumination light path before entering the integrator becomes long, and the size of the projector device becomes large.

As another dimming means, there is a known example in which an iris diaphragm device, which is the most common and well-known means, is incorporated in a lens. When this technology is applied to a recent large-amount light projector device, some heat generation of the light blocking member in a small aperture state increases, so that some cooling and heat radiation treatment is required. However, due to the difficulty in installation of cooling means in the space inside the lens, heat radiation processing, and the like, the configuration incorporating the iris diaphragm device has not been generalized.

In general, a large-aperture zoomable lens is generally used in a large-intensity projector, so that the optical path in the lens is wide and a cam ring is arranged on the outer periphery. However, there is a problem that the cam ring and the outer diameter of the lens become unnecessarily large due to the arrangement space.

As described above, since there is no practical light amount control means that can be implemented in a small space, a dimmable illumination device suitable for uniform illumination with a large amount of light cannot be produced at present. Therefore, in manufacturing an image projection apparatus that requires such an illumination device, it is difficult to deal with deterioration in contrast ratio and reduction in the number of reproducible gradations due to environmental light, that is, deterioration in image quality. There is a problem that a projection device cannot be made.

In the future, when shifting from film media to movie distribution using digital media (digital cinema), in an image projection apparatus having a brightness exceeding 10,000 ANSIlm used in this field, deterioration of the contrast ratio and decrease in the number of reproducible gradations will be reduced. Significantly inferior to the image quality,
Since it is not permissible to perform pay projection, the current large-sized image projection apparatus, in which the above-mentioned image quality deterioration is unavoidable, seriously hinders digitization of movie screening.

Therefore, the present invention solves the problem and provides an illumination optical system which can practically improve the gradation by an inexpensive configuration without increasing the space, an optical device having the illumination optical system, In particular, it is an object of the present invention to provide an optical device and an image processing device suitable for an image projection device such as a high-intensity AV projector in which the luminance is increasing.

[0020]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an illumination optical system constructed as in the following (1) to (13), an optical device having the illumination optical system, and image processing. An apparatus is provided. (1) In an illumination optical system that forms a plurality of light beams and illuminates with the light beams, the illumination optical system includes a diaphragm unit provided with a variable stop corresponding to each of the light beams at a separation position of the plurality of light beams. Illumination optics. (2) The plurality of luminous fluxes are formed by illuminating luminous fluxes from a plasma light emitting source due to discharge between the electrodes being emitted through illuminating luminous flux condensing means including a reflector and then divided by illuminating luminous flux splitting means. The illumination optical system according to the above (1), wherein the light beam is a focused light beam. (3) The illumination optical system according to (2), wherein the stop means has a mechanically movable stop mechanism using a light shielding plate that moves at a position where the plurality of light beams are separated. (4) The illumination optical system according to the above (2) or (3), wherein the illumination light beam splitting means has a fly-eye integrator in which a plurality of lens arrays are arranged in the optical axis direction. (5) The illumination light beam splitting means includes a kaleidoscope (rod-type integrator) having a polygonal cross section and a lens system for condensing each of a plurality of light beams from the integrator at different positions. The illumination optical system according to the above (2) or (3). (6) The illumination optical system according to (5), wherein the mechanical movable stop mechanism is located near a position where the plurality of light beams converge. (7) The aperture means has a light-shielding portion intersecting with each of the multi-divided and condensed light beams, and the light-shielding portion is changed by moving each light-shielding portion in the optical axis direction to change the amount of intersection. The illumination optical system according to any one of the above (1) to (6), wherein an amount of the illumination is changed. (8) The diaphragm means has a plurality of diaphragm plates which are relatively movable, moves forward and backward by symmetrical movement with respect to each central ray of the plurality of light beams, and has a plurality of apertures which each of the plurality of diaphragm plates has Alternatively, any one of the above (1) to (6) is characterized in that the amount of light shielding is adjusted from the outer peripheral portion of each light beam by a synthetic aperture formed by overlapping the opening forming notches. Illumination optical system as described. (9) A polarization conversion element that is arranged in conformity with the arrangement pitch of the lens groups of the fly-eye integrator and outputs light in a specific polarization direction, and at least one of the portions that does not contribute to light blocking in the diaphragm means. (1) to (4), (6), wherein the portion is configured as a mask for removing unnecessary light from light incident on the polarization conversion element.
The illumination optical system according to any one of (7). (10) The plasma light source is a halogen lamp, a metal halide lamp, a mercury lamp, an ultra-high pressure mercury lamp,
The illumination optical system according to any one of (1) to (9), wherein the illumination optical system includes any one of xenon lamps. (11) An optical device having an illumination optical system, wherein the illumination optical system is configured by the illumination optical system according to any one of (1) to (10). (12) The above (1), which is an image projection device.
The optical device according to 1). (13) An image processing apparatus comprising: the optical device according to (12); and a computing device (computer) that inputs image information (data) to the optical device.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an embodiment of the present invention,
By applying the above configuration, a practically practicable light amount control means can be obtained, and the above-described problems can be solved without making significant changes in the basic structure, manufacturing cost, and device dimensions of the conventional image projection apparatus. can do. In addition, the need for dimming devices, which are becoming increasingly necessary for projectors with ever-increasing brightness, can be realized with an inexpensive configuration without increasing the space for lighting systems using fly-eye integrators and parabolic reflectors, which are currently the mainstream. It is possible to improve gradation in AV projectors and so-called digital cinema applications. Also, with the above-described configuration, it is possible to easily realize dimming and light amount control in various types of exposure having a lighting system using a fly-eye integrator, and in the entire projection apparatus, except for the light source itself and the projection optical system. It is possible to easily improve the device specifications related to.

For example, by providing a mechanical movable diaphragm mechanism using a light-shielding plate at an axial position where a light beam is multi-divided and each is in a translationally separated state in the illumination optical system, the light-shielding plate is disposed in a retracted state. Can coexist between light flux groups, and by shielding light with a metal layer, a high light shielding ratio can be obtained in a wide wavelength range even with a thin material. Further, when the temperature rises due to shading, the heat transfer efficiency is higher than that of a plastic material or a ceramic material, so that cooling becomes easy. Also, in the case where it is difficult to dimming with the light source itself with respect to the illumination system of the illumination device having the illumination optical system including the illumination light beam condensing means and the illumination light beam splitting means, the mechanism member to the outer periphery of the illumination light path Protrusion can be minimized, and a thin diaphragm device can be incorporated in the direction of the optical path, thereby preventing an increase in the size of the device. In addition, when a thin diaphragm device is used as a unit, it is easy to arrange the lens and optical members in the air space, and the same material as the conventional illumination system without a diaphragm mechanism can be applied to the structural material around the diaphragm mechanism. Becomes

Further, by arranging the aperture mechanism near the position where the light beams multi-divided by the fly-eye integrator converge, the aperture of the aperture member and the stroke of opening and closing the aperture can be reduced, and the non-opening portion can be reduced. A reduction in strength is prevented, the degree of freedom in designing the blade drive mechanism is increased, and a mechanical movable diaphragm using a metal light shielding plate can provide a space for the evacuation space in the evacuation state outside the light beam. In addition, the aperture mechanism is intersected with each of the light flux groups divided by the fly-eye integrator, and a light flux effective for illumination is arranged so as to be able to advance and retreat in a variable amount of light shielding, so that light quantity control can be smoothly performed, and a few light flux groups can be obtained. It is easy to advance and retreat at the same time,
The light-shielded state is averaged by the number of luminous flux divisions involved in the control of the amount of light as the diaphragm advances and retreats, making it possible to equalize the illumination state during dimming.

The diaphragm mechanism has a plurality of diaphragm plates which can move relatively to each other. The diaphragm mechanism advances and retreats in a substantially symmetrical motion with respect to each optical axis of the divided light beam group, and each of the plurality of diaphragm plates has. By adjusting the amount of light shielding from the outer peripheral portion of each light beam by a synthetic aperture formed by superimposing a plurality of openings or opening forming notches, the light shielding state is further averaged,
The lighting condition at the time of dimming can be made uniform. In addition, the light from the light source portion having a large deviation from the ideal point light source position and the light passing through the portion of the reflector with low surface accuracy are preferentially shielded from light, and the angle condition can be more limited as the aperture is narrowed. In addition, there is little illumination unevenness, optical element position variation,
The variation of the aperture effect due to the variation of the focal point position with the component accuracy is averaged. Further, since a plurality of light-shielding positions are generated in accordance with the number of divided light beams, heat-generating positions of the light-shielding member are dispersed, so that cooling conditions are improved, and the degree of freedom in material selection in consideration of thermal deformation strength is increased. It is possible to achieve an effect similar to a diaphragm in a lens, such as a narrowing of a range of incident angles of light rays on a projection lens, an improvement in aberration, and a reduction in flare and ghost caused by internal reflection of a lens barrel and surface reflection of glass.

Further, if the diaphragm mechanism is configured to normally function as a mask for removing unnecessary light from the incident light of the polarization conversion element, the device is often designed with a structure that can be cooled as a heat generating portion in the conventional configuration. Therefore, in such a case, even if a throttle mechanism, which is a new heat source, is configured here, there is no need to change the cooling structure, or only a small change is required, and an increase in the number of members can be prevented, and manufacturing costs can be reduced. , Space efficiency can be increased. In addition, halogen lamps, metal halide lamps,
By using any one of various mercury lamps, an ultra-high pressure mercury lamp, and a xenon lamp, it is possible to use a light source capable of making a short arc and easily improving light use efficiency.

[0026]

Embodiments of the present invention will be described below. [Embodiment 1] FIG. 1 is a diagram showing a basic configuration of a transmission liquid crystal three-panel image projection apparatus using an illumination device according to Embodiment 1 of the present invention. In the present embodiment, FIG.
, The drive motor unit 2 is used instead of the mask PSM provided between the fly eye 4 and the polarization conversion element 5.
The configuration is basically the same as that of FIG. 6 except for the configuration in which the aperture unit 100 having 00 is inserted.

In FIG. 1, white light emitted from a light source unit 1 is emitted as parallel light by a parabolic reflector 2, passed through a UV-IR cut filter UVIR for removing infrared and ultraviolet components, and fly-eye. The light beams are split by the lenses 3 and 4. Each light beam is converged by the first fly-eye lens 3 near the second fly-eye lens. Unnecessary light that goes out of the light beam and goes out of the entrance of the polarization conversion element is blocked by the constituent members of the aperture unit 100, and then the polarization conversion element group 5
The P-polarized light component parallel to the plane of the drawing is transmitted and separated by the polarizing beam splitter, travels straight, and is then converted into S-polarized light by the phase plate and emitted. The S-polarized light component reflected and separated by the same polarization beam splitter returns its path to the next reflection surface and exits,
As a result, the polarization directions of both separated components are aligned with S-polarized light. After the emitted S-polarized light beam passes through the condenser lens 6 and the like, red light is transmitted by the dichroic mirror DM1, and green to blue light is reflected. As the light source, a halogen lamp, a metal halide lamp, an ultra-high pressure mercury lamp, or the like is used, and as the color separation / synthesis optical element, a dichroic mirror is used.

The optical path of the red band light transmitted through the dichroic mirror DM1 is changed by 90 degrees by the total reflection mirror M1, and the liquid crystal display element 8R is passed through the field lens 7R.
, Where the light is modulated according to the input signal. The light thus modulated enters the dichroic prism 9, changes its optical path by 90 degrees in the dichroic prism, enters the projection lens 10, and is enlarged and projected to form an image on the screen 11. On the other hand, the green to blue band light reflected by the dichroic mirror DM1 and having its optical path changed by 90 degrees enters the dichroic mirror DM2. Since the dichroic mirror DM2 has a characteristic of reflecting green band light,
Here, the green band light is reflected and changes its optical path by 90 degrees.
The light enters the liquid crystal display element 8G via the field lens 7G, where the light is modulated according to the input signal. The light-modulated green band light enters the dichroic prism 9 and the projection lens 10 in this order, is enlarged and projected, and forms an image on the screen 11.

The blue band light transmitted through the dichroic mirror DM2 enters the liquid crystal display element 8B via the lens 7B, the total reflection mirror, and M2 and M3, where the light is modulated according to the input signal. The light-modulated blue band light enters the dichroic prism 9, changes the optical path by 90 degrees by the dichroic prism 9, enters the projection lens, is enlarged and projected, and is imaged on the screen 11. With the above configuration, a color image is displayed by superimposing the projected images of the three colors on the screen 11.

FIG. 2 is a diagram for explaining a partial configuration of the illumination device according to the first embodiment. 100 is an aperture unit, 11
Reference numeral 0 denotes an aperture blade 1, 120 denotes an aperture blade 2, 130 denotes an aperture unit base plate, and 200 denotes an aperture drive motor unit.
The aperture unit 100 is a thin stainless steel sheet having a thickness of 0.1 MM and having two sufficiently smooth and highly reflective surfaces.
A plurality of 110 and 120 aperture blades 1 and 2 are provided in which a plurality of rectangular openings in a direction perpendicular to the paper surface are provided in accordance with the arrangement pitch of the fly-eye lenses in the horizontal direction of the paper surface of the fly-eye lens. These two diaphragm blades are held movably within a predetermined range in a direction parallel to the paper surface and opposite to each other with respect to a diaphragm unit base plate 130 as a plate-like structure provided in parallel with the diaphragm blades. An aperture drive motor unit 200 is integrally fixed to the plate-like structure.

The aperture drive motor unit 200 uses a stepping motor, is driven in two phases by a drive circuit 210, and is controlled by a controller unit 220. CPU
230 calculates an input signal to the CPU using a predetermined algorithm, and outputs a drive signal to the controller. The driving step is to adjust the dimming range to three steps (100% to 12.5%
(Up to the amount of light), and by setting the number of steps to be 16 or more per stage, a sensuously smooth light amount variation operation is obtained.

A known rack and pinion mechanism or a mechanical driving force transmitting means using a lead screw or the like, the driving force of the motor is used to resist the one-way urging force of a backlash removing spring (not shown). The width of a rectangular opening, which is a synthetic opening of two blades, is made variable by reciprocating the 120 aperture blades 1 and 2 in opposite directions. If the resolution is insufficient with the simple two-phase drive for realizing the number of step divisions, duty control of each phase is performed, and the rotation step angle is further internally divided by the two-phase holding force balance determined by the duty ratio. Obtained rotation angle resolution.

Whether or not the above high resolution control is applied, the lead angle of the screw, the number of gear teeth, the material, the accuracy, etc., depend on the aperture size and the number of dimming steps / required resolution / required drive responsiveness and the required life of the equipment. This is a selection decision item when performing optimal design. The reference position for driving is provided with a mechanical stopper for defining the aperture blade driving range, and is used as a contact position against the mechanical stopper. A simple configuration can be obtained by performing a pulse drive of the aperture blade in the opening direction or more at the time of starting the illumination device and performing position initialization and then performing open loop control.

It is also easy to use an inexpensive DC motor for the motor unit 200. In this case, monitoring means is added to confirm the initial position and drive amount, and the position is controlled. The monitor means may use an optical or magnetic encoder to directly detect the relative movement between the fixed part and the blades 1 and 2, or the relative movement between the blade 1 and the blade 2, or to detect any rotational speed of the shaft in the drive system. The detection is performed indirectly from the detection means, or a change in the amount of light transmitted through the aperture and at least a signal of light having high correlation are detected by an optical sensor such as a silicon photocell or a photointerrupter, and feedback is performed.

For the highly correlated light, the illuminance of the light path wall surface between the stop and the illuminated surface and the illuminance of the illuminated surface itself are used. Or a known sub-aperture opening is added to the aperture blades 1 and 2, and the combined aperture transmitted light amount is used as a substitute for the combined aperture transmitted light amount of the aperture element that actually contributes to dimming, and is detected by the photo interrupter. Thus, a dimming ratio monitor signal is obtained.

Whether to use the absolute light amount information or the relative change as the dimming ratio is determined based on the light source (temporal fluctuation characteristics, life) and the purpose of use of the lighting device. Since the present embodiment is a liquid crystal projector, the result of the sensory detection of the image brightness by a human being is used as an evaluation criterion in dimming, and the illuminance change with time is not conspicuous. This enables rational aperture control. On the other hand, when an illumination device is used for an exposure device or the like, reproducibility of absolute illuminance is an important specification. Therefore, of the above methods, the method of detecting the absolute (after excluding luminance fluctuation of the light source) post-dimming light amount is used. Note that, after a predetermined stable lighting waiting delay time after the light source is turned on, the light amount at that time is stored as a maximum light amount reference value (aperture opening position) so that the light amount after dimming (excluding the light source luminance fluctuation) is obtained. Approximate relative change information / signal can be obtained by detecting and comparing, and therefore, it may be used for drive control as substitute aperture position monitor signal generating means.

FIG. 3 is a schematic diagram showing the relationship between the state of light near the fly-eye lens and the aperture blades of the illumination device according to the first embodiment of the present invention. FIG. FIG. 2 is a view showing a frame-by-frame corresponding to a lens array constituting a fly-eye lens group. 100 is an aperture unit, 1
Reference numeral 10 denotes an aperture blade 1, 120 denotes an aperture blade 2, and 130 denotes an aperture unit base plate. The fly-eye lenses 3 and 4 have the same convex power and are arranged near the respective focal planes. The substantially parallel rays incident on the fly-eye lens 3 form a beam waist near the fly-eye lens 4 and pass through the aperture unit aperture after emission.

The aperture blades 110 and 120 move in parallel in the plane orthogonal to the optical axis in opposite directions to the optical axis, respectively, and change the synthetic aperture width to change the amount of light passing therethrough. 110
And the aperture blades 1 and 2 are located at different positions on the axis, so that the amount of light blocking is not uniform according to the difference in the on-axis position. However, since the apex angle of the cone formed by the incident light beam is acute, the position difference , The dimming can be performed while maintaining a practically sufficiently uniform illumination state.

In the example using a fly-eye integrator having a configuration of 9 × 10 frames (frame pitch ≒ 5 mm), the blade thickness was 0.1 mm and the blade interval was 0.1 mm with respect to the aperture width of 2.5 mm when the aperture was opened. When the ratio of the illuminance at the position of the outermost periphery of the illumination range (100%) to the on-axis illuminance includes 75% in the open state, the ratio includes 75% in the open state.
In the state of% light shielding (two-step aperture), approximately 55% or more can be secured. In the intermediate aperture state and the intermediate image height in the illumination range, the behavior becomes smooth and proportional, respectively. Therefore, it can be said that the level can be applied without any problem except for the illumination mechanism device of the strict projection printing apparatus. This illuminance ratio depends on the position of the fly-eye lens with respect to the focal position and the position of the diaphragm blade.
Although it is possible to further improve the arrangement, it is preferable to determine the axial arrangement of each element in consideration of the balance between the improvement of the aperture uniformity and the improvement of the illumination efficiency at the maximum aperture.

[Embodiment 2] FIG. 4 is a diagram showing a configuration of a transmission liquid crystal three-panel image projection apparatus using an illumination device with an integrator according to Embodiment 2 of the present invention. In this embodiment,
Unlike the first embodiment, the diaphragm unit 100 having the drive motor unit 200 is inserted immediately before the fly eye 4, and a mask PSM is inserted between the fly eye 4 and the polarization conversion element 5 as in the configuration of FIG. The configuration is basically the same as the configuration of the first embodiment except for the configuration. Therefore, although the description of the same configuration as that of the first embodiment is omitted, as described with reference to FIG. 3, the aperture position is changed in order to improve the aperture efficiency in relation to the beam waist position or for the convenience of the mechanical layout. In this case, adopting this configuration increases the degree of freedom in configuration.

[Embodiment 3] FIG. 5 shows an example of the configuration of a dimming mechanism of an illumination device according to Embodiment 3 of the present invention. FIG. 5 includes, from above, a side view of the diaphragm open state, a perspective view of the assembled state, and a side view of the diaphragm state from above. In FIG. 5, 3 is a first fly-eye lens, 4 is a second fly-eye lens, 1
00 is an aperture unit, 120 is aperture blades, 130 is an aperture unit base plate, and 200 is an aperture drive motor unit.

The diaphragm unit 100 is provided with a plurality of circular openings in a single thin stainless steel plate having a sufficiently smooth and highly reflective surface in accordance with the arrangement pitch of the fly-eye lenses in the direction in which the fly-eye lenses are arranged. A diaphragm blade 120 having a guide bar fitting guide section 140 and a lead screw engaging section 150 provided in the section. The blade 120 is a plate-shaped structure, and is held movably within a predetermined range in the optical axis direction with respect to an aperture unit base plate 130 holding the guide bar 141 and the lead screw 151 parallel to the optical axis. The aperture drive motor unit 200 is integrally fixed to the aperture unit base plate 130.

The aperture drive motor unit 200 uses a stepping motor, and is driven and controlled in the same manner as in the previous embodiment. The driving force of the motor reciprocates the perforated blade against a one-way biasing force of a backlash removing spring (not shown) to change the amount of intersection between the cone formed by the light beam and the hole. The aperture effect has been obtained. In this example,
It can be easily inferred from the figure that the sensitivity to the amount of light reduction with respect to the moving amount can be lowered, but it is not suitable for increasing the absolute light shielding amount, that is, the number of diaphragm steps. Therefore, this embodiment is suitable for fine dimming in applications where it is not necessary to increase the dimming range.

In this embodiment, the moving amount of the blade in the axial direction is large. However, in this embodiment, the divided light beam group accommodating space, which is originally provided as the air space of the fly-eye lens, is used as the blade moving space. In addition, it is possible to realize a rational arrangement that does not adversely affect the dimensions of the lighting device.

[0045]

As described above, according to the present invention, an illuminating optical system capable of providing gradation in a small space, an optical device having the illuminating optical system, and particularly an optical system suitable for a large-volume AV projector and the like. An apparatus or an image processing apparatus can be realized.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a partial configuration of the lighting device according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram showing a relationship between a light beam state and a stop blade near a fly-eye lens of the illumination device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a configuration of a lighting device according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a configuration example of a light control mechanism of an illumination device according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a basic configuration of a conventional transmissive liquid crystal three-panel image projection device.

FIG. 7 shows a conventional light control device (US Pat. No. 5,053,934).
FIG.

[Description of Signs] 1: Light source section 2: Parabolic reflector 3: Fly-eye lens 4: Fly-eye lens 5: Polarization conversion element group 6: Condenser lens 7: Field lens 8: Liquid crystal display element 9: Dichroic prism 10: Projection Lens 11: Screen 100: Aperture unit 110: Blade 1 120: Blade 2 130: Aperture unit main plate 200: Aperture drive motor unit

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[Procedure amendment]

[Submission date] December 21, 2000 (200.12.
21)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 4

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 5

[Correction method] Change

[Correction contents]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

[0020]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an illumination optical system constructed as in the following (1) to (13), an optical device having the illumination optical system, and image processing. An apparatus is provided. (1) In an illumination optical system that forms a plurality of light beams and illuminates with the light beams, the illumination optical system includes a diaphragm unit provided with a variable stop corresponding to each of the light beams at a separation position of the plurality of light beams. Illumination optics. (2) The plurality of luminous fluxes are formed by illuminating luminous fluxes from a plasma light emitting source due to discharge between the electrodes being emitted through illuminating luminous flux condensing means including a reflector and then divided by illuminating luminous flux splitting means. The illumination optical system according to the above (1), wherein the light beam is a focused light beam. (3) The illumination optical system according to (2), wherein the stop means has a mechanically movable stop mechanism using a light shielding plate that moves at a position where the plurality of light beams are separated. (4) The illumination optical system according to the above (2) or (3), wherein the illumination light beam splitting means has a fly-eye integrator in which a plurality of lens arrays are arranged in an optical axis direction. (5) The illumination beam splitting means is a rod having a polygonal cross section.
The illumination optical system according to the above (2) or (3), comprising: a mold integrator (a kaleidoscope); and a lens system for condensing each of the plurality of light beams from the integrator at different positions. (6) The illumination optical system according to (5), wherein the mechanical movable stop mechanism is located near a position where the plurality of light beams converge. (7) The aperture means has a light-shielding portion intersecting with each of the multi-divided and condensed light beams, and the light-shielding portion is changed by moving each light-shielding portion in the optical axis direction to change the amount of intersection. The illumination optical system according to any one of the above (1) to (6), wherein an amount of the illumination is changed. (8) The diaphragm means has a plurality of diaphragm plates which are relatively movable, moves forward and backward by symmetrical movement with respect to each central ray of the plurality of light beams, and has a plurality of apertures which each of the plurality of diaphragm plates has Alternatively, any one of the above (1) to (6) is characterized in that the amount of light shielding is adjusted from the outer peripheral portion of each light beam by a synthetic aperture formed by overlapping the opening forming notches. Illumination optical system as described. (9) A polarization conversion element that is arranged in conformity with the arrangement pitch of the lens groups of the fly-eye integrator and outputs light in a specific polarization direction, and at least one of the portions that does not contribute to light blocking in the diaphragm means. (1) to (4), (6), wherein the portion is configured as a mask for removing unnecessary light from light incident on the polarization conversion element.
The illumination optical system according to any one of (7). (10) The plasma light source is a halogen lamp, a metal halide lamp, a mercury lamp, an ultra-high pressure mercury lamp,
The illumination optical system according to any one of (1) to (9), wherein the illumination optical system includes any one of xenon lamps. (11) An optical device having an illumination optical system, wherein the illumination optical system is configured by the illumination optical system according to any one of (1) to (10). (12) The above (1), which is an image projection device.
The optical device according to 1). (13) An image processing apparatus comprising: the optical device according to (12); and an arithmetic device (computer) for inputting image information (data) to the optical device.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

The diaphragm mechanism has a plurality of diaphragm plates which can move relatively to each other. The diaphragm mechanism advances and retreats in a substantially symmetrical motion with respect to each optical axis of the divided light beam group, and each of the plurality of diaphragm plates has. By adjusting the amount of light shielding from the outer peripheral portion of each light beam by a synthetic aperture formed by superimposing a plurality of openings or opening forming notches, the light shielding state is further averaged,
The lighting condition at the time of dimming can be made uniform. In addition, the light from the light source portion having a large deviation from the ideal point light source position and the light passing through the portion of the reflector with low surface accuracy are preferentially shielded from light, and the degree of limitation of the angle condition can be increased as the aperture is narrowed. In addition, there is little illumination unevenness, optical element position variation,
The variation of the aperture effect due to the variation of the focal point position with the component accuracy is averaged. Further, since a plurality of light-shielding positions are generated in accordance with the number of divided light beams, heat-generating positions of the light-shielding member are dispersed, so that cooling conditions are improved, and the degree of freedom in material selection in consideration of thermal deformation strength is increased. It is possible to achieve an effect similar to a diaphragm in a lens, such as a narrowing of a range of incident angles of light rays on a projection lens, an improvement in aberration, and a reduction in flare and ghost caused by internal reflection of a lens barrel and surface reflection of glass.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0025

[Correction method] Change

[Correction contents]

Further, if the diaphragm mechanism is configured to normally function as a mask for removing unnecessary light from the incident light of the polarization conversion element, the device is often designed with a structure that can be cooled as a heat generating portion in the conventional configuration. because, such a case is also not required to change the cooling structure configured here a stop mechanism comprising a new heating source to such, or small that requires change, also the production cost can be prevented an increase in the member Lowering space efficiency. In addition, by using any of halogen lamps, metal halide lamps, various mercury lamps, ultra-high pressure mercury lamps, and xenon lamps as the plasma light source, a short arc can be achieved and a light source that can easily improve light use efficiency can be obtained. It can be used.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction contents]

[0026]

Embodiments of the present invention will be described below. [Embodiment 1] FIG. 1 is a diagram showing a basic configuration of a transmission liquid crystal three-panel image projection apparatus using an illumination device according to Embodiment 1 of the present invention. In the present embodiment, FIG.
6, the configuration is basically the same as that of FIG. 6 except that a diaphragm unit 100 having a drive motor unit 200 is inserted instead of the mask PSM provided between the fly-eye lens 4 and the polarization conversion element 5. have.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

In FIG. 1, white light emitted from a light source unit 1 is emitted as parallel light by a parabolic reflector 2, passed through a UV-IR cut filter UVIR for removing infrared and ultraviolet components, and fly-eye. Multiple lights with lenses 3 and 4
Divided into bundles . Each light beam is converged by the first fly-eye lens 3 near the second fly-eye lens. Unnecessary light that goes out of the light beam to the outside of the entrance of the polarization conversion element is shielded by the constituent members of the aperture unit 100, and then enters the polarization conversion element group 5, where the P-polarized component parallel to the plane of the drawing is transmitted and separated by the polarization beam splitter and goes straight. Thereafter, the light is converted into S-polarized light by the phase plate and emitted. The S-polarized light component reflected and separated by the same polarization beam splitter returns its path to the next reflection surface and exits, and as a result, the polarization directions of both separated components are aligned by S-polarized light. The emitted S-polarized light beam passes through the condenser lens 6 and the like, and then becomes a dichroic mirror DM1.
As a result, light in the red band is transmitted, and light in the green and blue bands is reflected. Halogen lamps, metal halide lamps, ultra-high pressure mercury lamps, etc. are used as light sources.
In this embodiment, a dichroic mirror is used as the combining optical element.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

FIG. 2 is a diagram for explaining a partial configuration of the illumination device according to the first embodiment. 100 is an aperture unit, 11
Reference numeral 0 denotes an aperture blade 1, 120 denotes an aperture blade 2, 130 denotes an aperture unit base plate, and 200 denotes an aperture drive motor unit.
The aperture unit 100 is a thin stainless steel sheet having a thickness of 0.1 mm having two sufficiently smooth and highly reflective surfaces.
A rectangular opening in the direction orthogonal to the surface and plurality fit fly-eye lens arrangement pitch in the paper transverse direction of the fly-eye lens, having 110 and diaphragm blade 1 and the diaphragm blades 2 of 120. These two diaphragm blades 110 and 120 are a diaphragm unit base plate 1 as a plate-like structure provided in parallel with the diaphragm blades.
30 is held movably within a predetermined range in a direction parallel to the paper surface and in a direction opposite to each other. An aperture drive motor unit 200 is integrally fixed to the plate-like structure.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

A known rack and pinion mechanism or a mechanical driving force transmitting means using a lead screw or the like, the driving force of the motor is used to resist the one-way urging force of a backlash removing spring (not shown). By reciprocating the aperture blades 1 and 2 in the opposite directions, respectively, the width of the rectangular opening, which is the combined aperture of the two blades 110 and 120 , is variable. If the resolution is insufficient with the simple two-phase drive for realizing the number of step divisions, duty control of each phase is performed, and the rotation step angle is further internally divided by the two-phase holding force balance determined by the duty ratio. Obtained rotation angle resolution.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

Whether or not the above high resolution control is applied, the lead angle of the screw, the number of gear teeth, the material, the accuracy, etc., depend on the aperture size and the number of dimming steps / required resolution / required drive responsiveness and the required life of the equipment. This is a selection decision item when performing optimal design. The reference position for driving is provided with a mechanical stopper for defining the aperture blade driving range, and is used as a contact position against the mechanical stopper. The aperture blades 110 and 120 at the time of starting the lighting device
By initializing the position by performing pulse drive in the opening direction more than the maximum drive amount, and then performing open loop control,
A simple configuration is obtained.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

It is also easy to use an inexpensive DC motor for the motor unit 200. In this case, monitoring means is added to confirm the initial position and drive amount, and the position is controlled. The monitor means may directly detect the relative movement between the fixed portion and the blades 1 and 2 or the 110 blade 1 and the 120 blade 2 using an optical or magnetic encoder,
Or, indirectly detected from any of the shaft rotation number detecting means in the drive system, or at least light having a high correlation with the change in the amount of light transmitted through the aperture by an optical sensor such as a silicon photocell or photo interrupter. The detected signal is fed back and controlled.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

For the highly correlated light, the illuminance of the light path wall surface between the stop and the illuminated surface and the illuminance of the illuminated surface itself are used. A known sub-aperture aperture is added to the aperture blades 1 and 2 of 110 and 120, and the combined aperture transmitted light amount is used as a substitute for the combined aperture transmitted light amount of the aperture element that actually contributes to dimming. A dimming ratio monitor signal is obtained by detecting with an interrupter.

[Procedure amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Change

[Correction contents]

FIG. 3 is a schematic diagram showing the relationship between the state of light near the fly-eye lens 4 and the aperture blades of the illumination device according to the first embodiment of the present invention. It is a schematic plan view which shows a relationship. FIG. 2 is a view showing a frame-by-frame corresponding to a lens array constituting a fly-eye lens group. 100 is an aperture unit,
Reference numeral 110 denotes an aperture blade 1, 120 denotes an aperture blade 2, and 130 denotes an aperture unit base plate. The fly-eye lenses 3 and 4 have the same convex power and are arranged near the respective focal planes. The substantially parallel rays incident on the fly-eye lens 3 form a beam waist near the fly-eye lens 4 and pass through the aperture unit aperture after emission.

[Procedure amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

The stop blades 110 and 120 move in parallel in the plane perpendicular to the optical axis in opposite directions to the optical axis, respectively, and change the synthetic aperture width to change the amount of light passing therethrough. 110
And the aperture blades 1 and 2 are located at different positions on the axis, so that the amount of light blocking is not uniform according to the difference in the on-axis position. However, since the apex angle of the cone formed by the incident light beam is acute, the position difference , The dimming can be performed while maintaining a practically sufficiently uniform illumination state.

[Procedure amendment 15]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction contents]

[Embodiment 2] FIG. 4 is a diagram showing a configuration of a transmission liquid crystal three-panel image projection apparatus using an illumination device with an integrator according to Embodiment 2 of the present invention. In this embodiment,
Is inserted the aperture unit 100 having a drive motor unit 200 just before the fly-eye lens 4 Differently from Example 1, as in the arrangement of FIG. 6 and the fly-eye lens 4 a mask PSM between the polarization conversion element 5 The configuration is basically the same as the configuration of the first embodiment except that the configuration is inserted. Therefore, although the description of the same configuration as that of the first embodiment is omitted, as described with reference to FIG. 3, the aperture position is changed in order to improve the aperture efficiency in relation to the beam waist position or for the convenience of the mechanical layout. In this case, adopting this configuration increases the degree of freedom in configuration.

[Procedure amendment 16]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G02F 1/13357 G03B 21/00 E 5C060 G03B 21/00 G09F 9/00 360K 5G435 G09F 9/00 360 H04N 9/31 C H04N 9/31 G02F 1/1335 530 F-term (reference) 2H042 AA01 AA08 AA28 2H052 BA02 BA03 BA09 BA14 2H088 EA15 HA13 HA18 HA21 HA24 HA28 MA06 MA13 MA16 2H091 FA05X FA07Z FA14Z FA26X FA26Z FA41ZLA07 LA09 LA09 LA09 5C060 BA04 BA08 BC05 EA01 GA02 GB02 HC00 HC11 HC20 HC22 HD04 JB06 5G435 AA18 BB12 BB17 DD02 DD06 DD09 FF07 FF12 FF13 GG02 GG09 GG23 GG28 LL15

Claims (13)

[Claims] 1. An illumination optical system for forming a plurality of light beams and illuminating the plurality of light beams, comprising an aperture means provided with a variable stop corresponding to each of the light beams at a separation position of the plurality of light beams. Characteristic illumination optical system. 2. The method according to claim 1, wherein the plurality of light beams are split by an illumination light beam splitting unit after an illumination light beam from a plasma light emitting source due to discharge between electrodes is emitted through an illumination light beam collecting unit including a reflector. The illumination optical system according to claim 1, wherein the illumination optical system is a light flux formed by the irradiation. 3. The illumination optical system according to claim 2, wherein said stop means has a mechanically movable stop mechanism using a light shielding plate which moves at a position where said plurality of light beams are in a separated state. 4. The illumination optical system according to claim 2, wherein said illumination light beam splitting means has a fly-eye integrator in which a plurality of lens arrays are arranged in an optical axis direction. 5. The illumination light beam splitting means includes a kaleidoscope (rod-type integrator) having a polygonal cross section and a lens system for condensing a plurality of light beams from the integrator at different positions. Claim 2
Or the illumination optical system according to claim 3. 6. The illumination optical system according to claim 5, wherein said mechanical movable stop mechanism is located near a position where said plurality of light beams converge. 7. The stop means has a light-shielding portion intersecting with each of the multi-divided and condensed light beams.
The illumination optical system according to any one of claims 1 to 6, wherein the amount of light shielding is changed by changing the amount of crossing by moving each light shielding unit in the optical axis direction. 8. The diaphragm means has a plurality of diaphragm plates which are relatively movable, and advances and retreats by symmetrical movement with respect to each central ray of the plurality of light beams, and a plurality of diaphragm plates respectively provided in the plurality of diaphragm plates. 7. The light emitting device according to claim 1, wherein a light blocking amount is adjusted from an outer peripheral portion of each light beam by an opening or a synthetic opening formed by overlapping the opening forming notch. 2. The illumination optical system according to 1. 9. A portion of the fly-eye integrator, which is arranged in conformity with the arrangement pitch of the lens groups and outputs a light in a specific polarization direction, and which does not contribute to light blocking in the diaphragm means. The illumination optical system according to any one of claims 1 to 4, wherein at least a part of the illumination optical system is configured as a mask for removing unnecessary light from light incident on the polarization conversion element. 10. The plasma light source according to claim 1, wherein said light source comprises one of a halogen lamp, a metal halide lamp, a mercury lamp, an ultra-high pressure mercury lamp, and a xenon lamp. 1
An illumination optical system according to the item. 11. An optical device having an illumination optical system,
An optical device, wherein the illumination optical system is configured by the illumination optical system according to claim 1. 12. The optical device according to claim 11, wherein the optical device is an image projection device. 13. An image processing apparatus comprising: the optical device according to claim 12; and an arithmetic unit (computer) for inputting image information (data) to the optical device.