WO2005078519A1

WO2005078519A1 - Projection display and projection displaying method

Info

Publication number: WO2005078519A1
Application number: PCT/JP2005/002485
Authority: WO
Inventors: Shigekazu Yamagishi; Yoshimasa Fushimi
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2004-02-18
Filing date: 2005-02-17
Publication date: 2005-08-25
Also published as: JPWO2005078519A1; JP4144713B2

Abstract

Although high pressure mercury lamps exhibit excellent absolute output value and emission efficiency, they have a drawback of a large etendue in addition to poor instantaneous lighting performance and short lifetime, and thereby they are not necessarily suitable for condensing light to a light bulb. Therefore, high pressure mercury lamps cannot be appropriately adapted to light bulbs the size of which has been being reduced more and more. Accordingly projectors employing a laser light source are predicted to be employed. However, it has been difficult to condense the light from a light source efficiently while suppressing occurrence of speckles and relaxing restriction on the use environment. An image projector of the invention comprises a light source (101) generating a light having coherent characteristics, a modulating section (102) for modulating the generated light, a projection optical system (106) for projecting the modulated light, and an oscillating mechanism (112) for oscillating the optical path of the light before or after it is modulated by the modulating section (102).

Description

Specification

Projection display device and projection display method

Technical field

The present invention relates to a projection display device and a projection display method.

Background art

[0002] At present, miniaturization of projectors is required from the factory.

[0003] More specifically, regarding a light valve, which is a small image display element having a two-dimensional pixel array, the size of the reflective liquid crystal has been sufficiently reduced, and the size of the transmissive liquid crystal has been reduced to 0.5. Inch panels are being commercialized. In addition, small one-dimensional array light valves are being realized by MEMS, typified by Silicon Light Machine's GLV.

[0004] On the other hand, projector power using a high-pressure mercury lamp as a light source has become mainstream.

[0005] However, high-pressure mercury lamps, although excellent in absolute value of output and luminous efficiency, are not necessarily suitable for focusing on a light valve having a large etendue in consideration of instantaneous lighting and life. .

[0006] For this reason, it cannot be said that the high-pressure mercury lamp can sufficiently cope with a light valve that is being miniaturized.

[0007] Therefore, it is expected that a projector using a laser as a light source will be used.

[0008] Since a laser has an extremely small etendue as compared with a high-pressure mercury lamp, it is advantageous in terms of light-collecting performance for the above-mentioned small light valve.

[0009] However, laser light sources have coherent characteristics.

[0010] For this reason, when the laser light source is handled in the same manner as the conventional light source, remarkable speckles are generated in the projected image, and an image that can be used practically may not be obtained.

[0011] Techniques for solving such a problem include a technique for reducing speckles by moving a screen, which is an image forming position (see, for example, US Pat. No. 5,272,473), and a technique using an optical diffusion plate. Technology to reduce speckles by installing in the system (for example,

No. 476). [0012] The entire disclosure of US Pat. No. 5,272,473 is incorporated herein by reference in its entirety. Also, the entire disclosure of Japanese Patent Application Laid-Open No. 2003-98476 is incorporated by reference (referred to here) as it is.

Disclosure of the invention

Problems to be solved by the invention

[0013] However, in the former, there is a tendency that the use environment is restricted in the use of a two-body projector, and in the latter, the etendue becomes large due to the diffusion direction of the incident light being diffused by the diffusion plate. Tend to be.

[0014] The present invention, in consideration of the above-described conventional problems, suppresses the occurrence of speckles and minimizes the use environment while efficiently condensing light from a light source. An object of the present invention is to provide a method of indicating a pattern.

Means for solving the problem

[0015] A first aspect of the present invention provides a generating means for generating light having coherent characteristics,

Modulating means for modulating the generated light;

Projection means for projecting the modulated light,

Rocking means for rocking the optical path of light after being modulated by the modulation means or before being modulated by the modulation means,

And a projection display device.

[0016] The second invention is the projection display according to the first invention, wherein the swing means swings the optical path of the light modulated by the modulation means.

[0017] In a third aspect of the present invention, the rocking means is configured so that generation of speckle and deterioration of focus are not substantially recognized in an image generated by the projected light. 9 is a projection display device according to the second aspect of the present invention, which swings the optical path.

A fourth aspect of the present invention is the projection display apparatus according to the first aspect, wherein the swinging means swings an optical path of light before being modulated by the modulation means.

[0019] A fifth aspect of the present invention includes a scanning unit that scans the generated light,

The oscillating means oscillates the optical path such that generation of speckles and deterioration of focus are substantially not recognized in an image generated by the projected light. A projection display apparatus according to a fourth aspect of the present invention.

In a sixth aspect of the present invention, the direction in which the swinging unit swings the optical path includes a component in a direction perpendicular to a scanning direction of a scanning line on which the scanning unit scans light,

The projection type display device according to a fifth aspect of the present invention, wherein the amplitude of the component in the vertical direction in which the swinging means swings the optical path is substantially half or less of the scanning line pitch of the scanning line. is there.

[0021] A seventh aspect of the present invention includes an expanding means for expanding the generated light,

The projection type display device according to a fourth aspect of the present invention, wherein the rocking means rocks the optical path so that generation of speckles is not substantially recognized in an image generated by the projected light.

In an eighth aspect of the present invention, the generation unit includes a red laser light source that generates red light, a green laser light source that generates green light, and a blue laser light source that generates blue light. A second image display element unit that modulates the generated red light, a green image display element unit that modulates the generated green light, and a blue image display element unit that modulates the generated blue light. 3 is a projection type display device according to the present invention.

[0023] A ninth aspect of the present invention is the projection type of the eighth aspect of the present invention, comprising a color synthesizing prism that synthesizes the modulated red light, the modulated green light, and the modulated blue light. It is a display device.

[0024] A tenth aspect of the present invention is the projection type display device according to the first aspect of the present invention, wherein said swing means is integrally formed with said projection means.

An eleventh aspect of the present invention is based on the tenth aspect of the tenth aspect of the present invention, wherein the swinging means swings the optical path by rotating the projection means or changing the size of the projection means. It is a projection type display device.

[0026] A twelfth aspect of the present invention is the projection display apparatus according to the fifth aspect of the present invention, wherein said swing means is integrally formed with said scanning means.

A thirteenth aspect of the present invention is the projection display apparatus according to the first aspect, wherein said modulating means is an image display element having a plurality of pixels each capable of modulating said light. [0028] A fourteenth aspect of the present invention is the projection display apparatus according to the _{thirteenth aspect} of the present invention, wherein an amplitude of the swinging means swinging in the optical path is substantially half or less of a pixel pitch of the pixel. .

According to a fifteenth aspect of the present invention, the speed at which the rocking means rocks the optical path is set so that a dark portion between the pixels is not substantially recognized in an image generated by the projected light. A thirteenth aspect of the invention is a projection display apparatus.

[0030] In a sixteenth aspect of the present invention, the speed at which the rocking means rocks the optical path is substantially recognized in an image generated by the projected light that the optical path is rocking. 1 is a projection type display device according to the first aspect of the present invention, which is not within a range.

[0031] A seventeenth aspect of the present invention is the first aspect of the present invention, wherein the amplitude at which the swinging unit swings the optical path is adjustable according to the type of image generated by the projected light. It is a projection type display device.

[0032] An eighteenth aspect of the present invention provides a generating step for generating light having coherent characteristics,

A modulating step of modulating the generated light,

A projecting step of projecting the modulated light,

An oscillating step for oscillating the optical path of the light after the modulation or before the modulation;

Is a projection display method.

The invention's effect

According to the present invention, it is possible to provide a projection display device and a projection display method capable of efficiently condensing light from a light source while minimizing the use environment while suppressing the occurrence of speckle. Is possible.

Brief Description of Drawings

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

FIG. 2 is a diagram showing a scanning state on a screen of the image projection device according to the first embodiment of the present invention. FIG. 3 is an overall configuration diagram of the image projection device according to the second embodiment of the present invention.

FIG. 4 illustrates a configuration of a projection lens unit of the image projection device according to the second embodiment of the present invention. FIG. 5 illustrates a configuration of a projection lens unit of the image projection device according to the embodiment of the present invention. 6] Overall configuration diagram of image projection device according to Embodiment 3 of the present invention [7] A diagram illustrating a configuration of a light beam oscillating unit of the image projection apparatus according to the embodiment of the present invention. [FIG. 8] An image according to the embodiment of the present invention in which the optical path of light before being modulated oscillates. Projection device overall configuration diagram (part 1)

FIG. 9 is an overall configuration diagram of an image projection apparatus according to an embodiment of the present invention, in which the optical path of light before being modulated swings (part 2)

Explanation of symbols

101 laser light source

102 Modulation section

103 polygon mirror

104 F seater lens

105 Galvanomirror

106, 115, 133 Projection optics

107 Reflecting mirror

108 screen

109 Galvano mirror actuator

110, 117, 118, 120 Actuator

111 Hinge

112 swing mechanism

113, 124, 125 beam expander optics

114 Image display device

115 Projection optics

116 Projection optical system optics

117 Horizontal Actuator

118 Vertical actuator

119 System axis

121 Blue laser light source

122 green laser light source

123 red laser light source 127, 128, 129 Image display element unit

130 color synthesis prism

131 λ Ζ2 plate

132, 146 Birefringent element

134, 139, 143 Incident polarizing plate

135, 140, 144 LCD panel

136, 141, 145 Outgoing side polarizing plate

137 Blue light reflective surface

138 System axis

142 red light reflective surface

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)

First, the configuration and operation of the image projection apparatus according to the present embodiment will be described mainly with reference to FIGS. Note that while describing the operation of the image projection apparatus of the present embodiment, an embodiment of the projection display method of the present invention will also be described (the same applies to the following embodiments). .

Here, FIG. 1 is an overall configuration diagram of the image projection device according to the first embodiment of the present invention. Also

FIG. 2 is a diagram showing a scanning state on a screen of the image projection device according to the first embodiment of the present invention.

[0039] The image projection apparatus according to the present embodiment includes a laser light source 101, which is an example of a light source, a modulating unit 102, a polygon mirror 103, which is an example of a scanning unit, an F seater lens 104, which emits coherent light. The scanning unit includes a galvano mirror 105 as an example of a scanning unit, a projection optical system 106, a reflection mirror 107 as an oscillating unit, and a screen 108 as an example of a projection target.

The light emitted from laser light source 101 enters modulator 102.

[0041] Modulating section 102 is composed of an acousto-optic element and an aperture, and has a configuration in which the amount of transmitted light can be modulated according to a video signal!

The emitted light enters the polygon mirror 103, and the polygon mirror 103 is driven by a motor (see FIG. (Not shown), the incident light is reflected at successively different angles on the same plane as the paper in FIG.

The reflected light enters the galvanomirror 105 via the F-seater lens 104.

The galvanometer mirror 105 is driven by a galvanometer mirror actuator 109 to scan incident light on a plane perpendicular to the paper surface in FIG. 1 so as to continuously change the reflection angle. It is configured.

[0045] The scanning unit in the present embodiment also has a function of expanding by scanning with a laser beam.

The light emitted here is given a desired magnification by the projection optical system 106 and reaches the screen 108.

[0047] In the meantime, a reflection mirror 107 is provided.

[0048] A swing mechanism 112 including an actuator 110 and a hinge 111 is provided on the back surface of a reflection mirror 107 between the projection optical system 106 and the screen 108, and controls the illumination light reaching the screen 108. Swing in the direction perpendicular to the scanning line.

[0049] Then, speckles, which are considered to occur due to the interference between the projection light and the reflected light on the screen, which have occurred in the conventional projection type image display device, are recognized by the user.

[0050] Of course, according to the configuration of the present embodiment, since a diffuser plate or the like is used as speckle eliminating means, the light use efficiency without increasing the etendue is not impaired.

Incidentally, the amount of movement of the illumination light on the screen 108 is set to be sufficiently smaller than the formed projection image.

[0052] This is a force that may cause the sweetness of focus to be recognized if the amount of movement of the illumination light on the screen 108 is too large.

More specifically, the amount of fluctuation (oscillation amplitude) should be up to half the vertical scanning line pitch PH so that the peaks of adjacent illumination spots do not overlap and blur the displayed image. All settings have been made. In other words, the vertical swing range is within the scanning line pitch PH around the position without swing (see Fig. 2).

[0054] Of course, if the amount of such movement is small, the speckle improvement effect tends to decrease. [0055] Therefore, as described above, since the amount of movement is recognized as a large amount of blur! /, The focus is blurred. Therefore, the movement width is considered to be desirable within the scanning line pitch PH. Since it is affected by the intensity distribution of the illumination spot, it is desirable to optimize it by the device.

For example, the swing amount of the illumination light may be finally determined by looking at the actual device.

[0057] In addition, when displaying a PC image, in which the focus is more important than the speckle improvement and character display is often more important, the amount of movement is reduced to improve the speckle. In many cases, more importantly, natural image display is mainly performed, and in the case of displaying moving images, an adjustment mechanism that can increase the swing amount may be used. Such an adjusting mechanism can be realized by feeding back the switching state of the input signal source to a circuit for controlling the swing amount.

[0058] The swing speed may be a high speed that exceeds a range in which the observer's power S-screen 108 can recognize the swing of the illumination spot, or a low speed that falls below such a range. May be.

When the swing speed is high, the illumination spot is treated as having a size obtained by adding the swing width. However, when the swing speed is low, the illumination spot has the swing width. Is treated as having the original size without taking into account. When the swing speed is low, the pitch between the scanning lines changes depending on the position, which may lead to deterioration of the projected image, and when the swing speed is high, Therefore, it is desirable to pay attention to the speed setting because the speckle reduction effect is smaller than in the case of.

Note that the laser light source 101 corresponds to the generating unit of the present invention, the modulating unit 102 corresponds to the modulating unit of the present invention, the projection optical system 106 corresponds to the projecting unit of the present invention, and the swing mechanism 112 Corresponds to the swinging means of the present invention.

(Embodiment 2)

Next, the configuration and operation of the image projection apparatus according to the present embodiment will be described mainly with reference to FIGS.

Here, FIG. 3 is an overall configuration diagram of the image projection device according to the second embodiment of the present invention. FIG. 4 is a diagram illustrating a configuration of a projection lens unit of the image projection device according to the second embodiment of the present invention. The image projection apparatus according to the present embodiment includes a laser light source 101 that emits coherent light, a beam expander optical system 113 that is an example of an expansion unit, and an image display element that is an example of a modulation unit.

114, projection optics 115, screen 108 power!

The coherent light emitted from the laser light source 101 is incident on the image display element 114 via the beam expander optical system 113 that emits the light with the diameter of the incident light enlarged.

[0065] The image display element 114 is a DMD (digital micromirror 'device') element having a plurality of pixels. The tilt angle of the two-dimensionally arranged micromirror is determined by an external signal (not shown) for each pixel. ) To perform image display.

[0066] Of the light having the light source power, the light incident on the above-mentioned minute mirror, which should reach the screen 108, is reflected in the direction of the projection optical system 115, reaches the screen 108 via the projection optical system 115, and displays an image. The image display of element 114 is projected onto screen 108.

[0067] As shown in FIG. 4, the projection optical system 115 has an optical unit 116 attached to a fixed lens barrel via a horizontal swing actuator 117 and a vertical swing actuator 118.

The horizontal motion actuator 117 and the vertical motion actuator 118 are elements whose total length is expanded and contracted by an external signal, and the projection optical system 115 can swing vertically and horizontally with respect to the system axis 119. Become.

[0069] The image on the screen 108 swings by an amount obtained by multiplying the swing amount of the projection optical system 115 by the enlargement factor when the projection optical system 115 swings with respect to the system axis 119.

[0070] Then, as in the case of Embodiment 1 described above, the scattering is considered to occur due to the interference between the projected light and the reflected light on the screen, which has been generated in the conventional projection type image display device. Becomes difficult for the user to recognize.

[0071] In addition, if the amount of swing is large, the focus blur will be recognized. Therefore, it is often desirable that the swing width be within the pitch between pixels. However, the optimal movement width is also affected by the illumination intensity distribution of one pixel. Therefore, the swing amount of the illumination light may be finally determined by looking at the actual machine.

[0072] Further, the swing speed may be a high speed that exceeds a range in which the observer's power S screen 108 can recognize the swing of the illumination spot, or a low speed that falls below such a range. May be.

[0073] However, in the present embodiment, if the projected image fluctuates at a high speed, it may occur between the pixels of the image display element (more specifically, the minute mirror of the DMD element). The dark areas become invisible, and high-quality images can be obtained at the same time. In particular, when the image display device is a transmissive liquid crystal light valve, it is effective to set the swing speed to a high speed because the signal lines are arranged between the pixels, so that the dark area between the pixels tends to be relatively large. It is.

In the projection optical system 106, a configuration in which the optical unit 116 can be inclined (that is, rotated) with respect to the system axis 119 may be used. More specifically, as shown in FIG. 5 illustrating the configuration of the projection lens unit of the image projection apparatus according to the embodiment of the present invention, the projection optical system 115 An actuator 120 may be provided. Of course, only a part of the optical unit 116 may be moved instead of swinging the entire optical unit 116, or other directions may be used instead of swinging the optical unit 116 in the vertical or horizontal direction. May swing. Further, as in the case of the above-described first embodiment, a configuration may be used in which an optical element such as a mirror having a swing function is disposed before and after the projection optical system 106. Further, the size of a part of the projection optical system may be changed by sandwiching the projection lens with a bimorph element whose length changes when a voltage is applied.

[0075] Instead of the DMD, another image display element having a plurality of pixels and capable of modulating each pixel by an external signal may be used.

Note that the image display element 114 corresponds to the modulation unit of the present invention, and the projection optical system 115 corresponds to a unit including the projection unit and the swing unit of the present invention.

(Embodiment 3)

Next, the configuration and operation of the image projection device of the present embodiment will be described mainly with reference to FIG.

Here, FIG. 6 is an overall configuration diagram of the image projection device according to the third embodiment of the present invention.

[0079] The image projection apparatus according to the present embodiment includes, as examples of light sources, a blue laser light source 121 that emits coherent blue light, a green laser light source 122 that emits coherent green light, and a red laser that emits coherent red light. A light source 123, a beam expander optical system 124, 125, 126 as an example of the extension unit, an image display element unit 127, 128, 129 as an example of the modulation unit, The color synthesis prism 130, λ 、 2 plate 131, birefringent element 132, projection optical system 133, and screen 1 08 consist of!

First, blue light will be described.

[0081] Light emitted from the blue laser light source 121 that emits coherent blue light is expanded by a beam expander optical system 124 that includes at least an optical element that expands incident light and an optical element that emits emitted light as parallel light. To the image display element unit 127.

The image display element unit 127 is composed of an incident side polarizing plate 134, a liquid crystal panel 135, and an exit side polarizing plate 136!

[0083] The incident-side polarizing plate 134 selects and transmits only light having a polarization direction determined in advance.

The transmitted light enters the liquid crystal panel 135.

[0085] The liquid crystal panel 135 is composed of an effective portion having a large number of pixel openings.

[0086] At a certain pixel aperture, an external signal causes blue light having content to be displayed to be emitted with its polarization direction changed, and blue light having no content to be displayed remains unchanged without changing its polarization direction. Is emitted.

The polarization axis of the output side polarizing plate 136 is arranged to be orthogonal to the polarization axis of the incident side polarizing plate 134. For this reason, the light whose polarization direction has been changed in the liquid crystal panel 135 passes through the output-side polarizing plate 136, and the light whose polarization direction has not been changed in the liquid crystal panel 135 is the output-side polarizing plate 136. Will be absorbed.

In this way, it is possible to modulate the output from the image display element unit 127 for each pixel of the liquid crystal panel 135 according to the external force signal.

The blue light transmitted through the image display element unit 127 enters the color combining prism 130, is reflected by the blue light reflecting surface 137, and enters the λΖ2 plate 131.

[0090] The λ 1312 plate 131 is rotatably provided, and the incident light depends on its polarization direction and the λΖ2 plate.

The polarization direction is changed according to the shift angle of 131 from the phase axis, and the light is emitted, and reaches the birefringent element 132.

[0091] The birefringent element 132 having the shape of a plane-parallel plate has a property of transmitting ordinary light as it is and refracting extraordinary light, and transmits the light in accordance with the polarization direction of incident light. (The height from the system axis 138).

The emitted light reaches a screen 108 via a projection optical system 133 provided so that the pixel structure of the liquid crystal panel 135 can be enlarged and projected.

Next, green light will be described.

[0094] Light emitted from the green laser light source 122 that emits coherent green light is expanded by a beam expander optical system 125 that includes at least an optical element that expands incident light and an optical element that emits emitted light as parallel light. To the image display element unit 128.

[0095] The image display element unit 128, like the blue image display element unit 127, includes an incident-side polarizer 139, a liquid crystal panel 140, and an output-side polarizer 141, and responds to an external signal. The output from the image display element unit 128 is modulated for each pixel of the liquid crystal panel 140.

[0096] The green light transmitted through the image display element unit 128 is incident on the color combining prism 130, transmitted through the blue light reflecting surface 137 and the red light reflecting surface 142, and proceeds along the same optical path as the above-described blue light, and λ Ζ2 It is incident on the plate 131.

[0097] Similarly to the blue light, the green light also passes through the λΖ2 plate 131 and the birefringent element 132, so that the outgoing position of the transmitted light according to the polarization direction of the incident light (from the system axis 138) Is swung.

The emitted light reaches the screen 108 via the projection optical system 133 provided so that the pixel structure of the liquid crystal panel 140 can be enlarged and projected.

Next, the red light will be described.

[0100] The light emitted from the red laser light source 123 that emits coherent red light is expanded by a beam expander optical system 126 including at least an optical element that expands incident light and an optical element that emits emitted light as parallel light. To the image display element unit 129.

[0101] Like the blue image display element unit 127, the image display element unit 129 includes an incident-side polarizer 143, a liquid crystal panel 144, and an output-side polarizer 145, and responds to an external signal. The output from the image display element unit 129 is modulated for each pixel of the liquid crystal panel 144.

[0102] The red light transmitted through the image display element unit 129 enters the color combining prism 130, and The light is reflected by the color light reflecting surface 142, and travels along the same optical path as the blue light and the green light described above.

入射 It is incident on the second plate 131.

[0103] Similarly to the blue light and the green light, the red light also passes through the λ 1312 plate 131 and the birefringent element 132, so that the outgoing position of the transmitted light according to the polarization direction of the incident light (system (The height from the shaft 138) is swung.

Then, the emitted light reaches the screen 108 via the projection optical system 133 provided so that the pixel structure of the liquid crystal panel 140 can be enlarged and projected.

As described above, a color image can be reproduced on the screen 108 using blue light, green light, and red light.

As in Embodiments 1 and 2 described above, with this configuration, it is possible to reduce the distortion generated in a conventional projection type image display device using a laser that is a coherent light source. Speckle, which is considered to be caused by interference between the projected light and reflected light of the light source, can be improved.

[0107] The blue, green, and red lights are constantly changed over time on the screen by the rotating λ Ζ2 plate 131 and the birefringent element 132, so the specs on the screen due to the interference of the coherent light are changed. Is greatly improved.

By the way, if the swing amount that appears as a shift of the projection position is too large compared to the pixel pitch, it will be recognized as defocus.

[0109] Ideally, if such a shift in the projection position is suppressed in the width of the dark portion (black matrix) generated between the pixels of the liquid crystal panel, the dark portion becomes less conspicuous, and a smooth image is realized. Improvements in speckle should be possible.

[0110] In actuality, the intensity distribution of the illumination light per pixel is not always constant, and the rotation speed of the λΖ2 plate, the intensity of speckle, and the required degree of speckle improvement, It may be necessary to increase the swing amount.

[0111] When considered comprehensively, the swing range is 1Z of the pixel pitch of the liquid crystal panel when viewed from the swing center force.

Within the range of 2 or less! /, Do it! /, Many things!

[0112] Note that the laser light source has a polarization property, and a DMD element may be used instead of the transmissive liquid crystal panel. Of course, a reflective liquid crystal may be used. [0113] Instead of the rotatable λ 、 2 plate 131 and the birefringent element 132, a liquid crystal panel having no pixel structure that can be electrically switched at high speed from outside is used as polarization conversion means. May be. Further, as shown in FIG. 7, which is a diagram illustrating a configuration of a light beam oscillating unit of the image projection apparatus according to the embodiment of the present invention, instead of the rotatable λΖ2 plate 131 and the birefringent element 132, A rotatable birefringent element 146 provided immediately before the projection optical system 133 'may be used.

The blue laser light source 121, the green laser light source 122, and the red laser light source 123 correspond to the generating means of the present invention, and the image display element units 127, 128, and 129 correspond to the modulating means of the present invention. The system 133 corresponds to the projection means of the present invention, and the λΖ2 plate 131 and the birefringent element 132 correspond to the oscillating means of the present invention. The color combining prism 130 corresponds to the color combining prism of the present invention.

[0115] In the foregoing, Embodiments 13 have been described in detail.

(Α) Note that, in the above-described embodiment, the optical path of the light of the present invention was swung after being modulated. However, the optical path of the light of the present invention may be swung before being modulated.

More specifically, FIG. 8 is an overall configuration diagram (No. 1) of the image projection apparatus according to the embodiment of the present invention in which the optical path of the light before being modulated swings. As described above, a polygon mirror 103 for scanning light and a galvano mirror 105 are provided, and the swing mechanism 112 does not substantially recognize speckle generation and focus deterioration in an image generated by the projected light. Thus, the optical path may be swung. Of course, the direction in which the swing mechanism 112 moves in the optical path includes a component in a direction perpendicular to the scanning direction of the scanning line on which the polygon mirror 103 and the galvanomirror 105 scan light, and the swing mechanism 112 operates in the optical path. It is desirable that the amplitude of the component in the vertical direction that oscillates is substantially half or less of the scanning line pitch of the scanning lines. Note that the polygon mirror 103 and the galvanometer mirror 105 correspond to the scanning unit of the present invention.

Further, as shown in FIG. 9, which is an overall configuration diagram (No. 2) of the image projection device according to the embodiment of the present invention in which the optical path of the light before being modulated swings, The optical unit is fixed via a horizontal actuator 117 and a vertical oscillator 118 (see Fig. 4). A beam expander optics 113 ^ is provided mounted on the beam expander optics 113 ^, and the beam expander optics 113 'is used to generate speckles substantially in the image generated by the projected light. The optical path may be swung so that it is not recognized. In such an embodiment, the use of the swing mechanism in front of the image display element 114 does not need to limit the swing direction and amplitude of the optical path. Note that the beam expander optical system 11 corresponds to a unit including the expanding unit and the swinging unit of the present invention.

Note that a configuration in which an image display element 114 and the like are installed after the polygon mirror 103 and the galvanometer mirror 105 is also conceivable.

(B) Further, in the above-described embodiment, the oscillating means of the present invention is configured separately from the scanning means of the present invention. However, the oscillating means of the present invention may be integrally formed with the scanning means of the present invention.

[0121] More specifically, the swing mechanism 112 may be provided on the galvano mirror 105 or the polygon mirror 103 (see FIG. 1). Of course, the galvanometer mirror 109 may swing the optical path of light.

Note that a configuration in which the swing mechanism is provided between the galvanomirror 105 and the projection optical system 106 is also conceivable.

(C) Further, the direction in which the optical path of the present invention swings is a direction perpendicular to the scanning direction of the scanning line on which light is scanned in the first embodiment. However, the direction in which the optical path of the present invention oscillates may be, for example, a direction along a straight line inclined by about 45 degrees from a direction perpendicular to the scanning direction of the scanning line, or a circumferential direction. May be along the direction ヽ. In short, the light path of the light of the present invention may include a component in a direction perpendicular to the scanning direction of the scanning line on which the light is scanned.

It is desirable that the amplitude of such a component in the vertical direction be substantially half or less of the scanning line pitch of the scanning lines, and in many cases.

(D) Further, the generating means of the present invention is a laser light source in the above-described Embodiments 13 to 13. However, in short, the generating means of the present invention may be any means for generating light having coherent characteristics.

[0126] As described above, according to the present invention, a coffee that is advantageous for condensing light on a small area having a small etendue. A speckle phenomenon that occurs when a projection-type image display device is configured using a light source such as a laser having a single characteristic can be realized without deterioration in light-collecting performance.

[0127] Further, since the etendue of the laser light source is small! / The advantages of the laser light source are kept as it is, by suppressing the generation of speckles, it is possible to efficiently collect light even on a small light valve. realizable.

Industrial applicability

The present invention is useful because it can efficiently condense light from a light source while minimizing the use environment while suppressing the generation of speckles.

Claims

The scope of the claims

[1] generating means for generating light having coherent characteristics;

Modulating means for modulating the generated light;

Projection means for projecting the modulated light,

, A projection display device.

2. The projection display device according to claim 1, wherein the swing unit swings an optical path of the light modulated by the modulation unit.

[3] The oscillating means oscillates the optical path such that generation of speckles and deterioration of focus are substantially not recognized in an image generated by the projected light. 3. The projection display device according to item 2, wherein

4. The projection display device according to claim 1, wherein the swing unit swings an optical path of light before being modulated by the modulation unit.

[5] scanning means for scanning the generated light,

The method according to claim 10, wherein the rocking means rocks the optical path such that generation of speckle and deterioration of focus are substantially not recognized in an image generated by the projected light. 4. The projection display device according to item 4.

[6] The direction in which the swinging unit swings the optical path includes a component in a direction perpendicular to a scanning direction of a scanning line on which the scanning unit scans light,

6. The projection display according to claim 5, wherein the amplitude of the component in the vertical direction in which the swinging unit swings the optical path is substantially equal to or less than a half of a scanning line pitch of the scanning line. apparatus.

[7] An extension means for extending the generated light,

5. The swinging means according to claim 4, wherein the swinging means swings the optical path so that generation of speckles is substantially not recognized in an image generated by the projected light. , Projection type display device.

[8] The generation means includes a red laser light source that generates red light, and a green laser light that generates green light. A light source, and a blue laser light source that generates blue light,

The modulation unit includes a red image display element unit that modulates the generated red light, a green image display element unit that modulates the generated green light, and a blue image display element unit that modulates the generated blue light. 3. The projection display device according to claim 2, comprising:

9. The projection display according to claim 8, further comprising a color combining prism that combines the modulated red light, the modulated green light, and the modulated blue light.

10. The projection display device according to claim 1, wherein the swing means is formed integrally with the projection means.

11. The projection display device according to claim 10, wherein the swing unit swings the optical path by rotating the projection unit or changing a size of the projection unit.

12. The projection display device according to claim 5, wherein the swinging unit is configured integrally with the scanning unit.

13. The projection display device according to claim 1, wherein the modulation means is an image display element having a plurality of pixels capable of modulating the light.

14. The projection display device according to claim 13, wherein an amplitude at which the swing unit swings the optical path is substantially equal to or less than a half of a pixel pitch of the pixel.

15. The speed at which the oscillating means oscillates in the optical path is in a range where a dark portion between the pixels is not substantially recognized in an image generated by the projected light. , Projection type display device.

[16] The speed at which the rocking means rocks the optical path is in a range where the fact that the optical path is rocked is not substantially recognized in the image generated by the projected light. 2. The projection display device according to item 1, wherein

17. The projection display device according to claim 1, wherein an amplitude at which the rocking means rocks the optical path is adjustable according to a type of an image generated by the projected light.

[18] a generating step of generating light having coherent characteristics;

A modulating step of modulating the generated light, A projecting step of projecting the modulated light,

, A projection display method.