JP2002090881A - Projector device and image quality improving mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector device, capable of reducing speckled noise which being interference noise. SOLUTION: In the projector device 1 for modulating incident light 70 from a light source 20 by an LCD 28 and projecting the modulated light to a screen 5 through a lens system 30, an optical part 41 for providing a slight optical path difference to outgoing light 71 is arranged on the screen side of the system 30 and rotated by a driving means 45 using a motor 48. Since an image quality improving mechanism 40 is provided with the optical part 41 and the driving means 45, various speckled patterns are generated and are time-wise changed and the changed speckled patterns are time-wise mixed on a retina, so that the mixed pattern is whitened. Thereby speckled noise caused on the screen can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector such as a data projector and a video projector.

[0002]

2. Description of the Related Art An apparatus for projecting or projecting an image, such as a data projector or a video projector, uses a white light source such as a xenon lamp, a high-pressure mercury lamp, or a metal halide, and is a small image display device such as a liquid crystal or a micromirror device. The light is modulated by a (light valve), and a desired image is projected on a reflective or transmissive screen by a lens system including a plurality of lenses or prisms.

[0003]

Such a projector device is required to display a compact, bright and beautiful image. For this reason, the light-emitting part of the light source has been further reduced so as to be compact and improve the light efficiency, thereby increasing coherence and causing a speckle pattern to appear strongly on the screen. I have.

[0004] The speckle pattern is a spot-like pattern having a high contrast generated on a screen when the screen or the like is illuminated with coherent light. The speckle pattern is a complex interference pattern caused by light scattered at each point on the screen interfering with each other in an irregular phase relationship. When it is seen by human eyes, coherent noise (spec Noise). Therefore, in a device that projects an image on a screen, such as a projector, speckle noise caused by the coherence of light gives an impression that the image quality is degraded. Is required.

Further, compact and high quality (high gradation)
In a projector device capable of displaying the image of (1), a light valve (image display device) such as a liquid crystal panel which is compact and has high resolution is used. When a high-resolution and compact device is used, a pixel that is a unit element constituting a screen in an image display device is subdivided (reduced).
As a result, the light emitted from the image display device (emitted light) becomes more coherent. As a result, speckle noise easily occurs on the screen as described above. Become.

[0006] In addition, for viewing moving images such as movies, there is a great demand for a rear-type projector integrated with a transmissive screen, and in order to obtain a bright image, the directivity of emitted light from a hologram screen or the like is high. Things are used.
In such a screen, coherence is increased in order to align the light beam with a thin light beam in order to increase the directivity, and speckle noise is likely to be remarkable, and the image quality of a displayed image is reduced.

[0007] As described above, in the projector which has been developed in recent years and is capable of displaying a high-resolution image with a small size, it is necessary to reduce speckle noise in order to collect a compact and project a brighter and higher quality image. Has become indispensable.

Accordingly, it is an object of the present invention to provide a projector apparatus and an image quality improving mechanism capable of projecting a bright and high-quality image with a compact structure while suppressing speckle noise.

[0009]

Therefore, in the present invention,
An optical component that gives a slight optical path difference to the emitted light is arranged on the optical path from the image display device to the screen, and various speckle patterns are generated by moving it by driving means, and they are mixed on the retina with time. This reduces speckle noise visible on the screen.

That is, the image quality improving mechanism of the present invention modulates light from a light source by an image display device, and projects the light onto a screen via a lens system on an optical path from the image display device of the projector to the screen. And an optical component that generates an optical path difference distribution that does not affect the image displayed on the screen, and a driving unit that moves the optical component so that the optical path difference distribution varies with time. . Further, the projector device according to the present invention has this image quality improvement mechanism, that is,
A light source, an image display device capable of modulating light from the light source, a lens system for projecting light from the image display device onto a screen, and a light system arranged on an optical path from the image display device to the screen, and displayed on the screen. An optical component that generates an optical path difference distribution that does not affect the image to be reproduced, and a driving unit that moves the optical component so that the optical path difference distribution varies with time.

In the projector device and the image quality improving mechanism of the present invention, the optical components (optical elements) cause optical path differences distributed on the optical path to such an extent that the image is not affected, that is, the diffraction angle is sufficiently reduced. As a result, speckle patterns appearing on the screen due to light emitted from the image display device toward the screen increase. Then, since the optical component is moved by the driving means, these various speckle patterns are superimposed, and an image in which these speckle patterns are time-integrated and mixed is recognized on the retina. For this reason, since the intensity of each speckle pattern is weakened and an image obtained by time-integrating them is recognized, the distribution of coherence is suppressed, and speckle noise that can be recognized by a human on the screen can be reduced. For this reason, even in a projector device in which strong coherent light is projected to achieve a compact and high resolution, speckle noise can be reduced and a high-quality image can be projected, and a bright and beautiful image can be displayed. it can.

As described above, not only a light source but also an image display device is a factor in enhancing coherence in a projector device capable of displaying a compact and high-resolution image. Therefore, by arranging the optical components of the image quality improvement mechanism behind the image display device, that is, on the optical path on the screen side, it is possible to reduce speckle noise due to light modulated by the image display device. It is possible to solve the problem of speckle noise in a compact and high-performance projector device as a whole.

Further, several advantages can be obtained by arranging the optical components on the optical path from the image display device to the screen. By arranging the optical components on the screen side of the lens system, an image quality improvement mechanism can be introduced without affecting the optical system from the light source to the lens system. For this reason, it is possible to reduce the trouble such as design changes accompanying the introduction of the image quality improvement mechanism,
A compact projector device that can display high-quality video at low cost can be provided. Further, it is also possible to provide an image quality improvement mechanism that can be installed as an option in an existing or future sold projector device.

In an optical system from a light source to an image display device, a liquid crystal is adopted as an image display device.
In particular, when a dichroic prism is used, a telecentric system is used to prevent the angle dependence of these optical elements from appearing. On the optical path from the image display device to the screen, the luminous flux is restricted. There is an aperture position that can be adjusted. Therefore, by arranging the optical component that generates the optical path difference near the stop position, the optical component can be compactly assembled. An aperture position is often provided in a lens system, and by providing an optical component in the lens system, it is possible to provide a projector device capable of displaying a compact and clear image as a whole including an image quality improvement mechanism. Can be.

According to the image quality improving mechanism of the present invention, in order to efficiently increase the number of speckle patterns which are coherent patterns in the visible light region, the wavelength of the image display device is about one wavelength or less for light in the visible light region. It is desirable to generate an optical path difference of Therefore, it is desirable to generate an optical path difference of about one wavelength or less with respect to light in the visible light region in a portion of the optical component that transmits or reflects the light flux from the image display device to the screen. In order to generate an optical path difference, an unevenness that generates a step of about the wavelength of light in the visible light region or less, or a method such as doping with iodine, by a method such as doping iodine, is about the wavelength of light in the visible light region or less. Regions having different refractive indexes can be distributed so as to generate an optical path difference.

The driving means can rotate or reciprocate the optical component in order to temporally change the distribution of the optical path difference, and can drive the optical component at 24 to 30 Hz which is higher than the resolution of human vision. By moving faster than this, various speckle patterns can be mixed on the retina so that they are not individually recognized, and flicker can be prevented. Therefore, it is possible to provide a projector device that can output a high-quality image without noise due to a speckle pattern and image flicker due to the noise.

Further, in the projector device of the present invention,
A screen provided separately, of course, a reflective screen that reflects and displays the output image, or a transmissive screen that transmits and outputs the image on the image display device. Combined projector devices are also included. In particular, a rear-type projector device employs a transmissive screen having high directivity and in which speckle noise is easily recognized, and image quality can be greatly improved by applying the present invention.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a rear projector 1 including an image quality improving mechanism 40 of the present invention. In the rear type projector 1 of this example, display light (emission light) 71 output from the projection lens system 30 forms an image on a transmissive screen (rear screen) 5, and a user 90 can view an image through the screen 5. It is a device that can do.

The projector 1 of this embodiment includes a light source 20 that emits white light, such as a white metal halide lamp, in order from the light source 20 to the screen 5, and an incident light 70 from the light source 20 which is not shown in the drawing. An image display device (LCD) 28 that outputs an emission light 71 for displaying a desired image by modulating based on an image signal from the apparatus, and outputs the emission light 71 emitted from the LCD 28 to a screen 5.
Has a lens system 30 for projecting (projecting) on the image. Further, in the projector device 1 of the present example, on the side (rear) of the screen 5 near the projection lens system 30,
The image quality improvement mechanism 40 is arranged so that the optical component 41 of the image improvement mechanism 40 crosses the optical path 72 through which the emitted light 71 passes.

The image improving mechanism 40 uses a disk-shaped transmission type optical component (optical element) 41, and a portion (optical surface) of the optical component 41 crossing the optical path 72.
When the outgoing light 71 is transmitted through 42, approximately λ /
It is processed so that an optical path difference (phase difference) of about 2 is generated. Further, the image quality improvement mechanism 40 includes a driving unit 45 that drives the optical component 41 to rotate. The drive means 45 of the present example is attached to the rotation center of the optical component 41, and is configured to rotate the shaft 47 substantially parallel to the optical axis 75 of the optical path 72 in a region passing through the lens system 30. A rotation motor 49 is provided, and the optical component 41 is moved in a direction orthogonal to the optical axis 75 by the driving means 45.

FIG. 2 schematically shows an example of the optical component 41 of the present embodiment, and FIG. The optical component 41 of the present example is a transparent substrate made of a transparent material such as glass, which is substantially transparent and has the same refractive index as a whole, and the optical surface 42 has an uneven surface having a step of about 300 to 700 nm. And the like. These recesses 4
The 3 and the projection 44 extend radially outward from the shaft hole 46 at the center of rotation on the order of at least about mm or more in width. And these concave part 43 and convex part 44 are formed alternately in the circumferential direction,
The disc-shaped optical surface 42 of the optical component 41
And the projection 44 equally divides the circumference.

The relationship between the step (depth) L due to the concave portion 43 and the convex portion 44 and the optical path difference Δ is given by the following equation (1).

NL−L = Δ (1) Therefore, if an attempt is made to set the wavelength of light in the visible light region to be substantially a half wavelength, the green light G having a wavelength near the center of the visible light region is obtained. When a typical refractive index n (about 1.5) of glass is used to represent (wavelength λG about 550 nm), the step L is about 550 nm. Further, red light and blue light can be calculated in the same manner. Therefore, by setting the step (depth) L of the concave portion 43 and the convex portion 44 of the optical surface 42 of the optical component 41 to about 300 to 700 nm, the optical path difference of about one half wavelength and one wavelength or less with respect to light in the visible light region. Can be generated.

In the projector device 1 of the present embodiment, the light flux of the outgoing light 71 output from the projection lens system 30 passes (transmits) through the optical component 41 as shown by a broken line A in FIG. The drive unit 45 rotates in the direction of arrow B. Therefore, in the state shown in FIG. 2, the emitted light 71 forms an image on the screen 5 through an optical path having an optical path difference of about a half wavelength on the left and right sides of the light flux, and the distribution of the optical path difference is such that the optical component 41 rotates. It fluctuates with time. Since the speckle pattern generated on the screen 5 is a coherent pattern, it does not occur between lights having different half wavelengths. In the state shown in FIG. 2, the screen passes through an optical path having an optical path difference of about right and left half wavelengths. In the light imaged in 5,
There is a high possibility that different speckle patterns are generated, and further, different speckle patterns are generated due to different wavelengths of light. Therefore, a large number of speckle patterns are displayed on the screen by passing through the optical components 41 having different optical path differences of about half a wavelength, and the speckle patterns vary with time by rotating the optical components 41. For this reason, the intensity of one speckle pattern becomes extremely small and further fluctuates with time, so that it is superimposed or time-integrated (time-mixed) on the retina of the user 90 who recognizes the image displayed on the screen 5, It is hardly recognized as a pattern. As a result, the speckle patterns on the screen 5 cannot be individually recognized, and the speckle noise cannot be seen by the user 90.

Setting the optical path difference by the optical component 41 also causes a diffraction phenomenon, but the distribution of the optical path difference, that is,
In this example, the diffraction angle becomes very small by setting the distribution of the irregularities to the order of mm, for example, about 5 mm or more. Therefore, it is possible to generate a large number of speckle patterns without affecting the imaging performance of the lens system 30 by providing irregularities of an appropriate size. It is possible to prevent the user from recognizing. Therefore, in the projector device 1 of this example, by providing the image improving mechanism 40, speckle noise visible on the screen 5 can be reduced. That is, even in a compact high-resolution projector apparatus, the light source is small, and the projector apparatus irradiated with the coherent emission light 71 due to the miniaturization of the image display device, Improvement mechanism 4
By providing 0, the substantial coherence of the outgoing light transmitted through the image quality improvement mechanism 40 can be reduced, and speckle noise, which is coherent noise, can be reduced. By doing so, a high-quality image can be displayed on the screen 5.

Further, the optical component 41 of the present embodiment is
5, rotation is performed at a high speed so that the optical path difference can be changed at a cycle of about 24 to 30 Hz or more.
By driving the optical component 41 at a speed higher than the speed at which a human can slightly recognize individual pattern variations,
It is also possible to prevent flickering of the speckle pattern which fluctuates with time and flicker. Therefore, the speckle pattern cannot be seen, and the influence of flicker can be prevented by time-varying the speckle pattern. Therefore, a projector device that displays a high-quality image without adverse effects due to the rotation of the optical component 41 can be provided. Can be provided.

To cope with the increase in coherence due to the reduction in the size of the light source 20, even if the optical component 41 is disposed between the light source 20 and the image display device 28, it is effective in reducing speckle noise. . However, it cannot cope with an increase in speckle noise accompanying the miniaturization of the image display device 28. On the other hand, in the projector device 1 of the present embodiment, as described above, the optical element 41 of the image quality improvement mechanism 40 is connected to the light source 20 and the LCD as an image display device.
By arranging it on the optical path 72 from the LCD 28 to the screen 5 instead of on the optical path between the LCDs 28, the speckle noise accompanying the coherence of light due to the miniaturization of the LCD 28 is also reduced. it can. Therefore, the entire configuration is suitable for a projector device that is more compact, and the projector device 1 that can project a compact, bright, high-resolution image can be provided.

Further, in this embodiment, the optical component 41 of the image quality improving mechanism 40 is connected to the lens system 30 behind the LCD 28.
, The image quality improving mechanism 40 can be incorporated without changing the layout of the optical system from the light source 20 to the lens system 30. Therefore, speckle noise can be reduced very easily and image quality can be improved. Further, instead of incorporating the image quality improving mechanism 40 into the projector device 1, it is also possible to add on the optical system of the projector device 1 as an option.

In the above description, the optical surface 4 of the optical component 41
The step (depth) L formed by the concave portion 43 and the convex portion 44 formed in FIG. 2 is selected from a range of about 300 to 700 nm. The optical path difference can be set on the optical path 71. In FIG. 2, a step (level) LR that can set an optical path difference of about half a wavelength of the red light R by a broken line and a step LG that can set an optical path difference of about a half wavelength of the green light G
Further, an example is shown in which an LB capable of setting an optical path difference of about a half wavelength of the blue light B is formed. In this way, by providing an optical path difference of about half a wavelength at a wavelength corresponding to the three primary colors of light, it is possible to generate an infinite number of speckle patterns without color bias, and to reduce the influence of the speckle pattern. It can be further suppressed.

The pattern formed for providing an optical path difference in the optical component 41 is not limited to the pattern shown in FIG. In the optical component 41 shown in FIG. 4A, the concave portions 43 and the convex portions 44 are alternately arranged in the circumferential direction, and the concave portions 43 and the convex portions 44 are alternately arranged in the radial direction. The concave portions 43 and the convex portions 44 are arranged in a shape. Therefore, the luminous flux of the outgoing light 71 traversing the optical component 41 is inverted not only left and right but also up and down, and more speckle patterns are formed on the screen 5.
Formed. For this reason, the intensity of each speckle pattern further decreases, and the number of speckle patterns also increases. Therefore, by mixing them for a time, the speckle noise is easily whitened.

Further, the optical component 41 shown in FIG.
In the figure, concave portions 43 and convex portions 44 are formed on the optical surface 42 almost at random. Therefore, it is possible to project various speckle patterns on the screen at random timing, thereby eliminating regularity and further preventing flicker from occurring.

The optical component 41 shown in FIG.
In the figure, concave portions 43 and convex portions 44 are alternately formed at regular intervals (a constant pitch p) in parallel with the entire disk.
Since all the concave portions 43 and the convex portions 44 can be formed in parallel, the production of the optical component 41 is simple, and
In addition, the configuration is such that the protrusions 44 are easily miniaturized. Outgoing light 7
Considering the area where one light flux A crosses, a plurality of recesses 43
Since the concave portion 44 crosses the area A, the number of speckle patterns increases, and the angles of the concave portion 43 and the convex portion 44 change according to the rotation of the optical component 41. Therefore, by setting the pitch p so as to be arranged, the same effect as in the above example can be obtained. Further, such an optical surface 42 can be easily formed.
However, it can be said that the configuration is such that speckle noise is easily whitened and flicker is unlikely to occur.

Further, a pattern similar to these concavo-convex patterns may be formed by ion doping. By doping appropriate ions, the refractive index of the glass substrate can be changed, and a difference in refractive index can generate an optical path difference of about λ / 2. Then, by making the distribution of the refractive index into the above-mentioned pattern or another appropriate pattern, a number of speckle patterns can be generated and mixed for time. In addition, plastic, an optical material having birefringence, or the like can be used instead of the plate-like glass, and the same effect as described above can be obtained by forming an appropriate pattern that generates an optical path difference.

FIG. 5 shows a projector device 2 different from the example shown in FIG. The projector device 1 shown in FIG. 1 is a projector that employs a transmissive screen 5 known as a rear projector or the like, and uses a highly directional screen such as a hologram screen. Therefore, when speckle noise occurs, it is easily recognized by the user's eyes 90, and the effect of providing the image quality improvement mechanism 40 is very large. On the other hand, the projector device 2 shown in FIG.
Device 2 that projects an image on a screen 10, and a light source 2 inside a housing 10 that is separate from the screen 6.
0, an LCD panel 28, a lens system 30, and an image quality improvement mechanism 40 are housed therein. In this type of projector device 2, the screen and other components can be separated, so that the projector can be downsized and has a configuration suitable for carrying. And the reflective screen 6
Is used, the projector main body 10 is further miniaturized and the LCD 28 is miniaturized, so that the configuration is such that speckle noise is easily generated.

On the other hand, in the projector 2 of this embodiment,
A plurality of lenses 31 and 32 constituting the lens system 30
The optical component 41 of the image quality improving mechanism 40 is provided between the lenses 31 and 32 of the optical system 33 and 33, and the speckle noise is reduced by moving the optical surface 42 having the unevenness that generates the optical path difference. Image quality improvement mechanism 40 of this example
Adopts a plate-like and substantially rectangular optical component 41, which is reciprocated by a linear motor 48 so that the speckle pattern can be time-mixed and whitened. As a pattern for generating an optical path difference, an appropriate pattern such as a pattern in which unevenness is alternately arranged in a direction orthogonal to the driving direction, a random pattern as shown in FIG. Of course, an optical path difference may be provided by a difference in refractive index. Further, by driving the linear motor 48 in units of mm or more, it is possible to prevent the optical component 41 from acting as a diffraction grating for separating a light beam.

For this reason, since the image quality improving mechanism 40 of the linear drive system reciprocates the optical component 41, it is necessary to sufficiently consider countermeasures such as vibration. However, since the position of the optical component 41 is temporally moved. Since the space required for the projector 2 can be small, the configuration is suitable for the compact projector 2.

Further, in the projector device 2 of the present embodiment, the optical component 41 is arranged at or near the position of the stop in the lens system 30 to reduce the size of the optical component 41 and include the image quality improving mechanism 40. The projector device 2 can be designed to be more compact. That is, there is a stop position in the projector lens system 30 where the cross-sectional area of the light beam is small, and in many cases, a stop is provided at that position to remove ambient light and improve image quality. Therefore, by arranging the optical component 41 at or near the stop position, the optical component 41 can be downsized, and the optical path difference can be set efficiently. On the other hand, a new optical component 4 is added to the lens system 30.
Since it is necessary to dispose the optical component 41, it is necessary to provide a sufficient space for disposing the optical component 41, and in the case of the zoom lens system 30, it is necessary to dispose the optical component 41 at a position that does not affect zooming. . Therefore, although some time is required for designing, the projector 2 including the image quality improving mechanism 40 can be most compactly integrated.

FIG. 6 shows a further different projector device 3.
Is shown. In the above description, the projector apparatus having the image quality improvement mechanism 40 using the transmission type optical component 41 is described as an example. However, the image quality improvement mechanism 50 can be formed by a reflection type optical element (optical component) 51. It is. That is, in the projector device 3 shown in FIG.
A mirror 51 that bends the direction of the emitted light 71 by 90 degrees is disposed on an optical path 72 from the LCD 28, which is an image display device, to the screen 6, and the reflection surface of the reflective optical component 51 is used as an optical surface 52 to reduce the optical path difference. A plurality of concave portions 53 and convex portions 54 to be generated are formed, and furthermore, the mirror 51 is rotationally driven by a motor 49 which is a driving unit 55, so that the distribution of the optical path difference fluctuates over time and speckle noise can be whitened. Like that.

As shown in FIG. 7, when the reflecting surface is used as a surface for generating an optical path difference, the relationship between the uneven step L2 and the optical path difference Δ is as shown in the following equation (2).

√2L = Δ (2) Therefore, to generate an optical path difference Δ of about half a wavelength when green light G having a wavelength λG of about 550 nm is reflected,
It is desirable to provide a step L2 of 194 nm. Therefore, in order to provide an optical path difference of one wavelength or less in the visible light region, it is desirable to process the surface 52 of the mirror 51 by etching or the like so that the step L2 is about 200 nm.

A pattern similar to that shown in each of FIGS. 2 and 4 is used for the optical component 5 of the image quality improving mechanism 50 of this embodiment.
It can be adopted as a pattern of concavities and convexities formed in 1 and, like the image quality improvement mechanism employing transmission type optical components, generates a myriad of speckle patterns and whitens them by mixing them for time. can do. Furthermore, the present invention is not limited to these patterns, and may be any pattern in which the distribution of the optical path difference fluctuates at an appropriate frequency. At this time, as described above, it is necessary to pay attention to the pattern or the moving distance when the pattern is driven is as small as the order of nm, so that the diffraction angle increases and the image quality is affected.

In the above description, a single-plate type projector (projection device) 10 has been described as an example. However, the present invention is not limited to this, and a three-plate type projector may be used. By providing the image quality improvement mechanism according to the present invention disclosed above on the optical path, speckle noise can be reduced. The image quality improvement mechanism
Optical components for generating an optical path difference suitable for the wavelength of each color may be arranged behind the LCD for generating an image of each color to vary with time, or may cover the entire visible light region described above. A special optical component may be installed on the optical path from the dichroic prism to the screen to reduce speckle noise.

In the above description, a transmissive LCD 28 is described as an example of a video display system. However, the present invention is not limited to this, and other image display devices such as a reflective LCD or a micromirror device may be used. In the case of high resolution with a compact size, it is the same that the miniaturization advances and the emitted light becomes coherent. By applying the present invention, speckle noise is reduced and a higher quality image is displayed on the screen. can do.

Further, in the above description, the drive means for moving the optical component on the optical path is provided exclusively. However, in a projector apparatus provided with means for driving a rotary type color filter, these drive means are provided. Can also be used, and a simpler and more compact projector can be provided.

The light source is not limited to the metal halide lamp 20 described above, but may be a xenon lamp that emits white light, a high-pressure mercury lamp, or a laser or LE.
A similar effect can be obtained even when a monochromatic and highly coherent light source such as D is employed.

[0046]

As described above, according to the present invention, on the optical path from the image display device to the screen, the optical component that gives a slight optical path difference to the emitted light is moved to change the distribution of the optical path difference with time. By providing an image quality improvement mechanism
By generating various speckle patterns and integrating them over time, it is possible to reduce speckle noise visible on the screen. Furthermore, in the present invention, by arranging on the optical path of the emitted light behind the image display device such as an LCD, not only the coherence due to the downsizing of the light source but also the image display device is miniaturized. Speckle noise caused by an increase in the coherence of light due to the above can be reduced. Therefore, it is possible to provide a projector device that can project a bright and beautiful high-resolution image on a screen while being compact.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a rear-type projector device using a projector having an image quality improving mechanism of the present invention.

FIG. 2 is a diagram showing an outline of a pattern formed on an optical component of the image quality improving mechanism shown in FIG.

FIG. 3 is an enlarged view showing a part of a pattern of the optical component shown in FIG. 2;

FIG. 4 is a view showing some examples of patterns different from the uneven pattern shown in FIG. 2;

FIG. 5 is a diagram showing an outline of a projector device different from the projector device shown in FIG.

FIG. 6 is a diagram showing an outline of still another projector device.

FIG. 7 is an enlarged view showing a part of a pattern of the reflective optical component shown in FIG. 6;

[Explanation of symbols]

1, 2, 3 Projector device 5 Transmissive screen (rear screen) 6 Reflective screen 10 Housing (projector body) 20 Light source 28 Image display device (light valve, LC
D) 30 Lens system 40, 50 Image quality improvement mechanism 41, 51 Optical component 42, 52 Optical surface 43, 53 Concave part 44, 54 Convex part 45, 55 Driving means 48, 49 Motor 70 Incident light 71 Outgoing light 72 Optical path 75 Light Axis 90 User

Claims (17)

[Claims] A light source, an image display device capable of modulating light from the light source, a lens system for projecting light from the image display device onto a screen, and an optical path from the image display device to a screen. A projector that is disposed and generates an optical path difference distribution that does not affect the image displayed on the screen; and a driving unit that moves the optical part so that the optical path difference distribution varies with time. apparatus. 2. The part according to claim 1, wherein the optical component transmits or reflects a light flux from the image display device to a screen, and generates an optical path difference of about one wavelength or less for light in a visible light region. Projector device comprising: 3. The projector device according to claim 2, wherein the portion of the optical component that generates the optical path difference has unevenness that generates a step of about the wavelength of light in a visible light region or less. 4. The optical component according to claim 2, wherein the optical path difference is generated in a region having a different refractive index so as to generate an optical path difference of about the wavelength of light in a visible light region or less. Projector device. 5. The projector device according to claim 1, wherein the driving unit rotationally drives the optical component. 6. The projector according to claim 1, wherein the driving unit reciprocates the optical component. 7. The projector according to claim 1, wherein the driving unit moves the optical component at about 24 to 30 Hz or higher. 8. The projector according to claim 1, wherein the optical component is disposed on the screen side of the lens system. 9. The projector according to claim 1, wherein the optical component is disposed near a stop position of an optical path from the image display device to a screen. 10. The optical component according to claim 1, wherein:
A projector device disposed inside the lens system. 11. The projector device according to claim 1, comprising the reflective or transmissive screen. 12. A projector device that modulates light from a light source with an image display device and projects the light onto a screen via a lens system, is disposed on an optical path from the image display device to a screen, and is provided on the screen. An image quality improvement mechanism comprising: an optical component that generates an optical path difference distribution that does not affect a displayed image; and a driving unit that moves the optical component so that the optical path difference distribution varies with time. 13. The part according to claim 12, wherein the optical component transmits or reflects a light beam from the image display device to the screen, and generates an optical path difference of about one wavelength or less for light in a visible light region. Image quality improvement mechanism equipped with. 14. The image quality improvement mechanism according to claim 13, wherein a portion of the optical component that generates the optical path difference has unevenness that generates a step of about the wavelength of light in a visible light region or less. 15. The optical component according to claim 13, wherein the optical path difference is generated in a region having a different refractive index so as to generate an optical path difference of about the wavelength of light in a visible light region or less. Image quality improvement mechanism. 16. The image quality improvement mechanism according to claim 12, wherein the driving unit rotates or reciprocates the optical component. 17. An image quality improvement mechanism according to claim 12, wherein said driving means moves said optical component at about 24 to 30 Hz or higher.