JP2023143587A - Projection type display device - Google Patents

Abstract

To meet the need for the realization of a device which is compact, easy to control drive and has high light utilization efficiency in the field of projection type image display devices that modulate in accordance with an image signal and project a laser beam.SOLUTION: Provided is a projection type display device comprising: a plurality of semiconductor lasers; a collimator lens that collimates the plurality of laser beams outputted by the plurality of semiconductor lasers; an integrator lighting system that superimposes the plurality of laser beams collimated by the collimator lens and forms a rectangular lighting region; a deflection element that is disposed at a position closer to the collimator lens than a position where the rectangular lighting region is formed by the integrator lighting system; a transfer optical system that enlarges, and transfers to a reflection type light modulation element, the rectangular lighting region that is deflected by the deflection element and scanned; and a projection lens that projects the video light outputted by the reflection type light modulation element.SELECTED DRAWING: Figure 1

Description

The present invention relates to a projection display device equipped with a light source device.

2. Description of the Related Art Projection display devices using laser light have been known.
Patent Document 1 includes a laser light source, a photoacoustic modulator that optically modulates laser light according to a video signal, a polygonal mirror that horizontally scans the modulated laser light, and a galvano mirror that vertically scans the modulated laser light. A projection type display device is disclosed.

Japanese Patent Application Publication No. 2000-180759

The projection type display device described in Patent Document 1 is equipped with an optical scanning means that uses both a polygonal mirror that scans horizontally and a galvano mirror that scans vertically. In order to perform scanning, a large optical path space is required, which poses a problem of increasing the size of the device.

Therefore, in the field of projection-type image display devices that modulate and project laser light according to image signals, it has been expected to realize a device that is small, easy to drive, and has high light utilization efficiency.

A first aspect of the present invention includes a plurality of semiconductor lasers, a collimating lens that collimates a plurality of laser beams outputted from the plurality of semiconductor lasers, and a rectangular shape by overlapping the plurality of laser beams collimated by the collimating lens. an integrator illumination system that forms an illumination area of , a deflection element disposed at a position closer to the collimating lens than a position where the rectangular illumination area is formed by the integrator illumination system, and a deflection element that is deflected and scanned by the deflection element. A projection display comprising: a transfer optical system that enlarges and transfers the rectangular illumination area onto a reflective light modulator; and a projection lens that projects image light output from the reflective light modulator. It is a device.

According to the present invention, in the field of projection-type image display devices that modulate and project laser light according to image signals, it is possible to realize a device that is small, easy to drive, and has high light utilization efficiency.

1 is a diagram showing a schematic configuration of an optical system of a projection display device according to Embodiment 1. FIG. (a) A schematic diagram showing one of the pairs of a semiconductor laser and a collimating lens included in the laser module LM. (b) A schematic diagram showing a laser module LM in which 4×2 pairs of semiconductor lasers 11 and collimating lenses 102 are arranged. (a) A diagram illustrating a near-field pattern of output light from the semiconductor laser 11. (b) A diagram illustrating a Far-Field Pattern of output light from the semiconductor laser 11. (a) A diagram showing the spread of a beam in the parallel direction. (b) A diagram showing the spread of the beam in orthogonal directions. (a) A diagram of the integrator illumination system INT seen from one direction. (b) A diagram of the integrator illumination system INT viewed from a direction perpendicular to (a). (c) A diagram showing a pair of microlens arrays. (d) A diagram showing a rectangular irradiation area IM1. (a) A perspective view showing the appearance of an example of the deflector 210. (b) A side view of the deflector 210. (a) A cross-sectional view for explaining the position and inclination angle of the reflective surface of the deflector 210. (b) A graph for explaining the position and inclination angle of the reflective surface of the deflector 210. (a) A diagram showing the positional relationship between the deflector 210 and the rectangular irradiation area IM1. (b) An enlarged view of the vicinity of the beam irradiation position 214 on the reflective surface. (c) A diagram showing that the blue rectangular irradiation area IM1 is deflected and scanned in the direction of DB. (a) A schematic diagram for explaining the effects of the front transfer lens 201 and the rear transfer lens 202. (b) A diagram showing the relationship between the screen of the reflective light modulator 340 and the scanning range SA of a rectangular laser beam. (c) A diagram showing how each of the rectangular B beam, G beam, and R beam irradiates the screen of the reflective light modulation element 340, with the horizontal axis as the time axis. 7 is a diagram showing a schematic configuration of an optical system of a projection display device according to a second embodiment. FIG. FIG. 7 is a diagram for explaining an integrator illumination system according to a third embodiment. (a) A diagram of an integrator illumination system INT according to Embodiment 3 viewed from one direction. (b) A diagram of the integrator illumination system INT according to Embodiment 3 viewed from a direction orthogonal to (a). (c) A diagram showing a rectangular irradiation area IM1. (a) A diagram showing a bulk rod used in the integrator illumination system. (b) A diagram showing a hollow rod used in the integrator illumination system. 7 is a diagram showing a schematic configuration of an optical system of a projection display device according to Embodiment 3. FIG. FIG. 7 is a diagram showing the positional relationship between a deflector and a rectangular irradiation area IM1 in Embodiment 3. 7 is a diagram showing a schematic configuration of an optical system of a projection display device according to a fourth embodiment. FIG. (a) A diagram of an anamorphic optical system that can be used in each embodiment viewed from one direction. (b) A diagram of an anamorphic optical system that can be used in each embodiment, viewed from a direction orthogonal to (a).

A projection type display device that is an embodiment of the present invention will be described with reference to the drawings.
It should be noted that the embodiments shown below are illustrative, and those skilled in the art can modify and implement the detailed configurations as appropriate without departing from the spirit of the present invention. In the drawings referred to in the following embodiments and descriptions, unless otherwise specified, elements denoted by the same reference numerals have similar functions. Note that since the optical elements in the figures are schematically represented, their actual shapes and configurations are not necessarily faithfully represented. For example, even if the lens is depicted as a single lens in the drawings, it may be composed of a plurality of lenses unless otherwise specified.

In the following description, for example, when the X-plus direction is written, it refers to the same direction as the X-axis arrow in the illustrated coordinate system, and when the X-minus direction is written, the X-axis arrow in the illustrated coordinate system refers to the same direction. It shall point 180 degrees in the opposite direction. Furthermore, when simply referring to the X direction, it refers to a direction parallel to the X axis, regardless of whether it is different from the direction indicated by the illustrated X axis arrow. The same applies to directions other than X.

In the following description, red may be referred to as "R," green as "G," and blue as "B." Therefore, for example, R light is synonymous with red light, G light source is synonymous with green light source, and B laser is synonymous with blue laser.

[Embodiment 1]
FIG. 1 is a diagram showing a schematic configuration of an optical system of a projection display device according to a first embodiment. For convenience of explanation, mechanical mechanisms for installing optical elements, a housing, electrical wiring, etc. are omitted in this figure.

[overall structure]
The projection display device 1000 includes a B light source 100B, a G light source 100G, an R light source 100R, a B deflector 210B, a G deflector 210G, an R deflector 210R, a light combining section 220, an optical path conversion mirror 330, a TIR prism 350, It includes a reflective light modulation element 340 and a projection lens 360. Further, a front transfer lens 201 is arranged between the light source of each color and a deflector of each color, and a rear transfer lens 202 is arranged between the light combining section 220 and the optical path conversion mirror 330. The front light combining section 220 includes a dichroic mirror 221 and a dichroic mirror 222. Projection display device 1000 may optionally include a projection screen 190.

The B light source 100B includes a semiconductor laser that emits B light, the G light source 100G includes a semiconductor laser that emits G light, and the R light source 100R includes a semiconductor laser that emits R light. The light source will be detailed later.

The B deflector 210B is a deflector that deflects the B light emitted by the B light source 100B in the DB direction. Similarly, the G deflector 210G is a deflector that deflects the G light emitted by the G light source 100G in the DG direction, and the R deflector 210R is a deflector that deflects the R light emitted by the R light source 100R in the DR direction. It is. The deflector will be detailed later.

The light combining section 220 includes a dichroic mirror 221 and a dichroic mirror 222. The dichroic mirror 221 has an optical property of transmitting G light and reflecting B light. The dichroic mirror 222 has an optical property of transmitting G light and B light and reflecting R light. Each optical element is arranged on the dichroic mirror 221 so that the center of the optical axis of the front transfer lens 201 for B light and the center of the optical axis of the front transfer lens 201 for G light overlap. Furthermore, on the dichroic mirror 222, the optical axis center of the front transfer lens 201 for B light, the optical axis center of the front transfer lens 201 for G light, and the optical axis center of the front transfer lens 201 for R light are The optical elements are arranged so as to overlap.

The light combining unit 220 aligns the traveling directions of the B light (dotted line), G light (solid line), and R light (dotted chain line) to the Z plus direction, but these lights are arranged so that they do not overlap each other at any timing. is synthesized into. The timing of deflection scanning by the B deflector 210B, the G deflector 210G, and the R deflector 210R is adjusted so that the B light, G light, and R light do not overlap each other on the screen of the reflective light modulation element 340. This is because (the phase of deflection) is controlled. The scanning method will be detailed later.
The B light, G light, and R light emitted from the light combining section 220 have their paths changed in the X-plus direction by the optical path conversion mirror 330 and enter the TIR prism 350 .

The TIR prism 350 is, for example, a total internal reflection prism configured by combining two prisms, and completely reflects the illumination light (B light, G light, R light) on the air gap surface, and the reflective light modulation element 340 incident at a predetermined angle. As described above, the B light, G light, and R light each illuminate a part of the screen of the reflective light modulation element 340 without overlapping each other.

As the reflective light modulation element 340, for example, a DMD in which micromirror devices are arranged in an array is used. The micromirror corresponding to each display pixel is driven so that its reflection direction is changed by pulse width modulation according to the brightness level of the video signal. However, it is also possible to use other types of reflective light modulation devices, such as reflective liquid crystal devices.

Pixels in the screen area illuminated by the B light are driven according to the brightness level of the B component of the video signal, and reflect the B video light toward the TIR prism 350 at a predetermined angle. Similarly, pixels in the screen area illuminated with G light are driven according to the brightness level of the G component of the video signal, and reflect the G video light toward TIR prism 350 at a predetermined angle. Furthermore, the pixels in the screen area illuminated with the R light are driven according to the brightness level of the R component of the video signal, and reflect the R video light toward the TIR prism 350 at a predetermined angle. In this way, the modulation operation of the reflective optical modulation device is performed in synchronization with the deflection scanning by the B deflector 210B, the G deflector 210G, and the R deflector 210R.

The image light (B image light, G image light, R image light) passes through the TIR prism 350, is guided to the projection lens 360, and is projected as a color image. The projection lens 360 is composed of a single lens or a plurality of lenses, and can also have an automatic focus adjustment function and a zoom function.

The projection screen 190 is used when configuring a rear projection type display device. Further, although it is often installed in the case of a front projection type, it is not necessarily necessary to install it when the user projects onto an arbitrary wall surface.

[light source]
The B light source 100B, the G light source 100G, and the R light source 100R will be explained. The B light source 100B is a laser module LM-B that includes a semiconductor laser that emits B light and a collimating lens. The G light source 100G is a laser module LM-G that includes a semiconductor that emits G light and a laser collimating lens. The R light source 100R is a laser module LM-B that includes a semiconductor laser that emits B light and a collimating lens. Each laser module LM-R includes a semiconductor laser that emits light and a collimating lens. Except for the emission wavelength of the semiconductor laser, the basic configuration of the light sources for each color is the same, so hereinafter, the light source 100 may be simply described without distinguishing between each color light.

(laser module)
The light source 100 includes a laser module LM in which pairs of semiconductor lasers and collimating lenses are arranged in a one-dimensional or two-dimensional array.
FIG. 2A is a schematic diagram showing one of the pairs of a semiconductor laser and a collimating lens included in the laser module LM. 11 is a semiconductor laser, and 12 is a light emitting part of the semiconductor laser 11. In addition, in FIG. 2(a), the direction of the XYZ coordinate system is displayed in accordance with the arrangement of the B light source 100B in FIG. In FIG. 2A, the longitudinal direction H of the light emitting section 12 is shown to be parallel to the Y direction, and the traveling direction of light emitted from the light emitting section 12 is shown to be parallel to the Z direction.

The longitudinal direction H of the light emitting section 12 is typically the direction in which the active layer sandwiched between the P-type cladding layer and the N-type cladding layer extends on the side surface of the semiconductor chip constituting the semiconductor laser 11. be. As shown in FIG. 2(a), in the following description, a direction parallel to the longitudinal direction H of the light emitting section 12 of the semiconductor laser 11 will be referred to as a "parallel direction" or a slow axis, and the direction is perpendicular to the longitudinal direction of the light emitting section 12. The direction may be referred to as the "orthogonal direction" or the Fast axis. Linearly polarized light is emitted from the semiconductor laser 11, and the vibration direction of the electric field is parallel to the direction (Y direction).

It is known that the output light of the semiconductor laser 11 has different angular characteristics depending on the emission direction. FIG. 3(a) shows the near-field pattern of the output light, and FIG. 3(b) shows the far-field pattern of the output light. An example of Pattern is given below.

As shown in FIG. 3A, it can be seen that in the Near-Field Pattern, the beam profile reflects the shape (longitudinal and short sides) of the light emitting part. On the other hand, as the beam advances, the beam spreads as illustrated in the Far-Field Pattern of FIG. 3(b). That is, when looking at the parallel direction, it can be seen that the beam emitted from the semiconductor laser 11 has a small spread and propagates in a pattern with a uniform intensity distribution within a narrow angular range. On the other hand, in the orthogonal direction, it can be seen that the beam emitted from the semiconductor laser 11 has a mountain-shaped intensity distribution pattern (Gaussian), and as it progresses, it spreads over a wider angular range than in the parallel direction. This is because the active layer of a semiconductor laser has a small thickness in the orthogonal direction and is therefore greatly affected by diffraction when emitting light. In the Far-Field Pattern, the parallel direction where the spread is small can be called the slow axis, and the orthogonal direction where the spread is large can be called the fast axis.

In this embodiment, the laser beam emitted from the semiconductor laser 11 is shaped using a collimating lens 102 (first collimating lens) as shown in FIG. 2(a). That is, the light emitted from the light emitting section 12 whose length in the longitudinal direction is Hy1 is collimated by the collimating lens 102, becomes a beam having an elliptical cross section, and travels in the Z direction. Note that the major axis of the elliptical shape is parallel to the X direction, and the minor axis is parallel to the Y direction.

Even if the beam passes through the collimating lens 102, it does not become completely parallel to the optical axis (Z direction), and the beam is not completely parallel to the optical axis (Z direction), but in the parallel direction (longitudinal direction of the light emitting part) and orthogonal direction (short direction of the light emitting part). The spread will be different. The difference in the way the beam spreads after passing through the collimating lens 102 will be explained with reference to FIGS. 4(a) and 4(b). FIG. 4(a) shows the spread in the parallel direction, and FIG. 4(b) shows the spread in the orthogonal direction.

As shown in FIG. 4A, in the parallel direction, although the top of the beam intensity is flat, the beam diameter increases as it advances in the Z direction, so it cannot be said that the divergence is good. On the other hand, as shown in FIG. 4B, when viewed in the orthogonal direction, it can be seen that even if the distance from the collimating lens 102 changes, the beam intensity distribution and beam diameter change little. That is, the laser beam after passing through the collimating lens 102 has higher parallelism in the orthogonal direction (Fast axis of the semiconductor laser) than in the parallel direction (Slow axis of the semiconductor laser), and has better divergence.

As will be described later, in the present invention, by utilizing the property that the divergence of the beam output from the light source 100 is excellent in the orthogonal direction (the short side direction of the rectangle) (the beam is highly parallel), The beam is deflected and scanned to illuminate the light modulation element. This is because it is more advantageous to deflect and scan the beam along a direction with excellent divergence in order to prevent the B, G, and R color illumination regions from overlapping on the screen of the light modulation element.

The light source 100 includes a laser module LM including a plurality of semiconductor lasers and a pair of collimating lenses 102 (first collimating lenses). FIG. 2(b) is a schematic diagram showing a laser module LM in which 4×2 pairs of semiconductor lasers 11 and collimating lenses 102 are arranged. In addition, in FIG. 2(b), the direction of the XYZ coordinate system is displayed in accordance with the B light source 100B of FIG.

In the laser module LM, a plurality of semiconductor lasers are arranged at regular intervals along the Y direction. Further, all the semiconductor lasers are arranged so that the longitudinal direction of the light emitting section 12 is along the Y direction. Although an example using a 4×2 element semiconductor laser is shown, the number of elements is not limited to this example. The laser module LM may have a configuration in which a plurality of semiconductor lasers are arranged in one row or three or more rows along the Y direction. Even if the light source 100 includes one or more than three semiconductor laser element arrays along the Y direction, the output beam has better divergence in the lateral direction of the light emitting section than in the longitudinal direction.

(Integrator illumination system/optical superimposition means)
The light source 100 of this embodiment includes an integrator illumination system INT for forming a rectangular illumination area by overlapping a plurality of laser beams emitted from the laser module LM. The integrator illumination system INT will be described with reference to FIGS. 5(a) to 5(d).

The laser beams emitted from each of the semiconductor lasers 11 included in the laser module LM become approximately parallel due to the action of the collimating lens 102, but the divergence is as described above. The light source of this embodiment includes an integrator illumination system INT that overlaps laser beams emitted from each semiconductor laser to form a rectangular irradiation area IM1 shown in FIG. 5(d).

As shown in FIGS. 5A and 5B, the integrator illumination system INT includes a microlens array 103, a microlens array 104, and a condenser lens 106. The microlens array 103 and the microlens array 104 are configured as a pair.

As shown in FIG. 5(c), each microlens array has a microlens with a size of V0 in the X direction and H0 in the Y direction when viewed along the traveling direction of the laser beam (Z direction in the figure). are arranged two-dimensionally along the XY plane. The entrance surface of each microlens in the microlens array 103 and the exit surface of each microlens in the microlens array 104 are spherical. Furthermore, the exit surface of each microlens in the microlens array 103 and the entrance surface of each microlens in the microlens array 104 are flat surfaces. The focal lengths of each microlens in the microlens array 103 and each microlens in the microlens array 104 are set so that images can be formed at the spherical positions of the other.

The laser beam that has passed through the microlens array 103 and the microlens array 104 is focused by the condenser lens 106, and as shown in FIG. 5(d), the length in the X direction is V1 and the length in the Y direction is H1. A rectangular irradiation area IM1 is formed.

Since the semiconductor laser 11 has better divergence than a lamp light source, for example, if the array pitch of the microlens is set within the range of 0.05 mm or more and 0.5 mm or less, a rectangular shape with V1 or H1 of about 1 mm to 2 mm can be used. An irradiation area IM1 can be obtained. The longitudinal direction of the rectangular irradiation region IM1 corresponds to the parallel direction (the slow axis direction of the semiconductor laser), and the transversal direction corresponds to the orthogonal direction (the fast axis direction of the semiconductor laser). The beam output from the light source 100 has better divergence in the short direction of the rectangle than in the long direction. In this embodiment, a pair of microlens arrays in which microlenses each having a spherical surface and a flat surface are arranged in an array is used. Pairs of lenses may also be used. Alternatively, if the light source has good divergence (NA is small), a single microlens array may be used instead of a pair.

(deflector)
As shown in FIG. 1, deflectors (B deflector 210B, G deflector 210B, G deflector A deflector 210G and an R deflector 210R) are arranged.
The B deflector 210B, the G deflector 210G, and the R deflector 210R will be explained. These are deflection elements used to deflect and scan laser beams of different colors, but since the basic configuration is the same, they may be described below as the deflector 210 without specifying the color. .

6(a) is a perspective view showing the appearance of an example of the deflector 210, and FIG. 6(b) is a side view of the deflector 210.
The deflector 210 includes a rotatable disc-shaped base 211 and a motor 212 that rotates the base 211 around a rotation axis AX. A reflective surface 213, which is a band-shaped optical surface, is provided on the main surface of the disc-shaped base 211 along the circumference. Here, in order to specify the position of the reflective surface, as shown in FIG. 6(a), angular coordinates are set counterclockwise around the rotation axis AX. (0°, 90°, 180°, and 270° are shown in the figure). Moreover, the axis BX shown in the figure is an axis that is parallel to the rotation axis AX and passes through the reflective surface 213. The beam irradiation position 214 is the beam position where the beam output from the light source 100 is reflected before reaching the rectangular irradiation area IM1.

The band-shaped reflective surface 213 is twisted so that the angle with respect to the axis BX (ie, the rotation axis AX) changes depending on the position. The angle of the reflective surface will be explained with reference to FIGS. 7(a) and 7(b). In FIGS. 7(a) and 7(b), the position of the reflecting surface is defined by the angular coordinates explained in FIG. 6(a). Furthermore, the inclination angle of the reflective surface is the inclination angle of the reflective surface with respect to the main surface of the disc-shaped base 211 (that is, the surface perpendicular to the axis BX).

As shown in FIG. 7(b), the reflective surface 213 is configured such that the inclination angle of the reflective surface changes linearly with respect to the position of the reflective surface. As shown in FIGS. 6(a) and 7(b), the inclination angle of the reflecting surface becomes discontinuous when the position of the reflecting surface is 0° (360°). The angle of inclination is shown when the position of the reflecting surface is 1° and 359°.

When the base body 211 is rotated in the R direction by the motor, the reflective surface 213 also rotates around the rotation axis AX, so the angle of the part irradiated with the laser beam at the beam irradiation position 214 shown in FIG. 6(a) The coordinates change continuously like 0° → 90° → 180° → 360° (=0°) → 90°, and so on.

Even if the reflective surface rotates and the part of the reflective surface that is irradiated with the laser beam changes, the incident beam always enters the reflective surface 213 at an angle α with respect to the axis BX, as shown in FIG. 7(a). do. On the other hand, the inclination angle of the reflective surface changes in the range of -θ to +θ depending on the position of the reflective surface. Therefore, as shown in FIG. 7(a), the direction of the laser beam reflected by the reflecting surface 213 is 4θ from (α-2×θ) to (α+2×θ) with axis BX as the reference. Varies within an angular range. In other words, the tilt angle is configured such that when the optical surface (reflection surface) is continuously rotated at a constant speed, the laser beam is recursively deflected in a constant direction at a constant deflection speed.

In other words, as shown in FIG. 6(b), the deflector 210 changes the output beam from RD1 ((α-2×θ) with respect to axis BX) to RD2 ((α+2×θ) with respect to axis BX). Deflection scanning can be performed within an angular range of up to When the reflective surface 213 is continuously rotated in the R direction in FIG. 6(a), the output beam is continuously deflected (scanned) from RD1 to RD2 in FIG. 6(b), and when it reaches RD2, it instantly Then, it returns to RD1 and is again deflected (scanned) toward RD2. Furthermore, if the reflective surface 213 is rotated in the opposite direction to the R direction, the output beam will be continuously deflected (scanned) from RD2 to RD1 in FIG. 6(b), and when it reaches RD1, It instantly returns to RD2 and is again deflected (scanned) toward RD1.

In this way, according to the deflector 210, the laser beam can be recursively deflected and scanned in a predetermined direction at a constant speed by a simple driving method of continuously rotating the rotating body at a constant speed. As will be described later, by controlling the motor 212 to rotate in synchronization with the drive timing of the reflective light modulator 340 (or the image signal input to the reflective light modulator 340), the illumination light can be converted into a reflective light modulator. The screen of the light modulation element 340 can be scanned in the V direction.

Note that in carrying out the present invention, a galvanometer mirror may be used instead of the deflector 210 including a rotating body. However, if a galvanometer mirror is used, it is expected that the device will become larger, vibrations will occur, and costs will increase, so it is desirable to use a deflector 210 that includes a rotating body.

FIG. 8A shows the positional relationship between the deflector 210 and the rectangular irradiation area IM1. The coordinate system is shown based on the B light source 100B. Further, FIG. 8(b) shows an enlarged view of the vicinity of the beam irradiation position 214 on the reflective surface. A beam irradiation position 214 on the reflective surface is arranged a distance L closer to the light source than the rectangular irradiation area IM1. As shown in FIG. 8C, the blue rectangular irradiation area IM1 is deflected and scanned in the direction of DB according to the rotation of the deflector 210.

Additionally, regarding the manufacturing method of the deflector 210, the disk-shaped base 211 provided with the band-shaped reflective surface 213 along the circumference can be manufactured at low cost by processing a metal base material using, for example, a press extrusion method. It is possible to manufacture. As illustrated in FIG. 7(a), there are parts protruding from the main surface of the base 211 and recessed parts near the reflecting surface 213, but in order to improve rotational balance, a cross section passing through the rotation axis AX is When viewed from above, it is desirable to have a shape with the same cross-sectional area no matter where the cross-section is located. Furthermore, the maximum height of the base 211 that protrudes from the main surface and the maximum depth of the recess from the main surface are desirably 3/4 or less of the average plate thickness in order to reduce wind noise. Specifically, the average thickness of the base 211 is desirably 0.7 mm or more and 2 mm or less, and θ is desirably 3 degrees or more and 6 degrees or less.

By the deflector described above, the rectangular irradiation areas IM1 of each color formed by the B, G, and R laser beams are deflected and scanned in the directions of DB, DG, and DR, respectively, as shown in FIG.

(Photosynthesis part)
The traveling directions of the laser beams of each color are aligned by the light combining section 220, and the operation of the light combining section 220 is as already explained in the section of the overall configuration.

(Transfer optical system)
The rectangular irradiation area IM1 formed by the laser beam of each color is illuminated by reflective light by a first transfer lens 200 (first transfer optical system) composed of a front transfer lens 201 and a rear transfer lens 202 for each color. The image is enlarged and transferred onto the screen of the modulation element 340. The front transfer lens 201 and the rear transfer lens 202 are convex lenses each having positive power.

FIG. 9A is a schematic diagram for explaining the functions of the front transfer lens 201 and the rear transfer lens 202. As illustrated, the rectangular irradiation area IM1 is enlarged and transferred as a rectangular secondary transfer image IM2. The rectangular secondary transfer image IM2 is set at the screen position of the reflective light modulation element 340, as shown in FIG. The transfer magnification for enlarging the rectangular irradiation area IM1 into the rectangular secondary transfer image IM2 is, for example, about 6 times (V1:V2=1:6).

FIG. 9B shows the relationship between the screen of the reflective light modulator 340 and the scanning range SA of the rectangular laser beam. If the screen size of the reflective light modulation element 340 is H (horizontal direction) x V (vertical direction), the scanning range SA of the rectangular laser beam covers an area of H' x V' that is larger than the screen size. Note that the scanning range SA of the rectangular laser beam is expanded by the above-mentioned transfer magnification with respect to the scanning range in which the rectangular irradiation area IM1 is scanned by the deflector 210.

FIG. 9C is a diagram showing how the screen of the reflective light modulation element 340 is irradiated with each of the rectangular B beam, G beam, and R beam, with the horizontal axis as the time axis. The B beam, G beam, and R beam vertically scan the screen of the reflective light modulation element 340 along the scanning direction SD, and complete scanning of one screen in one frame time. In order to prevent color mixing at the boundaries of each color area, the B, G, and R beams are configured so that they do not overlap each other, and the vertical width V2 of each beam is necessarily 1 of V'. /3 or less. The width of each beam in the vertical direction may be set to 1/6 or more and 1/3 or less of the vertical width of the screen of the reflective light modulation element 340.

As described above, in the projection display device of this embodiment, a lighting unit including a plurality of semiconductor lasers, a collimating lens, an integrator illumination system, and a deflection element is provided for each different color light, and Equipped with a light combining section that combines the illumination light output from the colored light illumination units, the rectangular illumination areas output by each of the different colored light illumination units are enlarged and transferred to the reflective light modulation element while being deflected and scanned so that they do not overlap with each other. be done.

According to the present embodiment, in the field of projection-type image display devices that modulate and project laser light according to image signals, it is possible to realize a device that is small, easy to drive, and has high light utilization efficiency. .

[Embodiment 2]
FIG. 10 is a diagram showing a schematic configuration of an optical system of a projection display device according to the second embodiment. For convenience of explanation, mechanical mechanisms for installing optical elements, a housing, electrical wiring, etc. are omitted in this figure. Descriptions of items common to Embodiment 1 will be simplified or omitted.

[overall structure]
The projection display device 1001 of this embodiment includes a B light source 100B, a G light source 100G, an R light source 100R, a B deflector 210B, a G deflector 210G, an R deflector 210R, a front transfer lens 201, and a rear transfer lens. 202, a light combining section 220, an optical path conversion mirror 330, a TIR prism 350, a reflective light modulation element 340, and a projection lens 360 are common to the first embodiment.

This embodiment further includes a diffusion plate 310a disposed between the rear transfer lens 202 and the optical path conversion mirror 330, and a front transfer lens 321 and a rear transfer lens 322 disposed with the optical path conversion mirror 330 in between. A second transfer optical system 320 configured as shown in FIG.

The first transfer lens 200 of the first embodiment enlarged and transferred the rectangular irradiation area IM1 onto the screen of the reflective light modulation element 340, but the first transfer lens 200 (first transfer optical system) of the present embodiment A secondary transfer image IM2 is formed at the position of the plate 310a. The secondary transfer image IM2 scattered by the diffusion plate 310a is enlarged and transferred to the screen of the reflective light modulation element 340 as a tertiary transfer image IM3 by the second transfer optical system 320 (second transfer optical system). The size of each image is typically set in the following relationship.
IM1:IM2:IM3=1:2:6
According to this embodiment having such a configuration, it becomes easy to control the F-number of the illumination light that illuminates the reflective light modulation element 340.

In addition, in FIG. 10, the diffusion plate 310a is fixed at a fixed position, but the irradiation position of the laser beam on the diffusion plate may be moved over time by, for example, rotating the diffusion plate or moving it back and forth in a straight line. It is also possible to do this. According to this embodiment, scintillation of the illumination light caused by the laser can be suppressed.

According to the present embodiment, in the field of projection-type image display devices that modulate and project laser light according to image signals, it is possible to realize a device that is small, easy to drive, and has high light utilization efficiency. .

[Embodiment 3]
In the first and second embodiments, the light source was equipped with an integrator illumination system INT for overlapping a plurality of laser beams emitted from the laser module LM to form a rectangular illumination area. This embodiment is also common in that it includes an integrator illumination system INT for forming a rectangular illumination area, but whereas the integrator illumination systems of Embodiments 1 and 2 were equipped with a microlens array, this embodiment The integrator illumination system of this embodiment differs in that it includes a rod integrator. Descriptions of items common to Embodiment 1 will be simplified or omitted.

FIG. 11 is a diagram for explaining a light source according to Embodiment 3, that is, an integrator illumination system including a rod integrator. The integrator illumination system according to this embodiment includes a laser module LM, a condensing lens 401, a diffusing element 402, a rod 403, and a relay lens 406, and forms a rectangular irradiation area IM1. The semiconductor laser, the light emitting section 12 of the semiconductor laser, the collimating lens 102, etc. included in the laser module LM are the same as those in Embodiment 1 described with reference to FIGS. 2(a) to 4(b), so they will not be described here. The explanation will be omitted.

The laser beams emitted from each of the semiconductor lasers included in the laser module LM become approximately parallel due to the action of the collimator lens 102, but the divergence is as described above. A substantially collimated laser beam output from the laser module LM is focused by a condenser lens 401 toward an incident surface INP of a rod 403. In the figure, the condenser lens 401 is shown as one convex lens, but it may be composed of a plurality of lenses for the purpose of suppressing aberrations or the like.

A diffusing element 402 is arranged near the incident surface INP of the rod 403, and the laser beam diffused by the diffusing element 402 enters the rod 403 from the incident surface INP. Since the beam output from the laser module LM has a better divergence in the short direction of the rectangle than in the long direction, it is possible to suppress the loss of light taken in at the entrance plane INP of the rod 403 and improve the utilization efficiency. I can do it. The light incident on the rod 403 undergoes repeated total reflection on the side surface and then exits from the exit surface EXP. By appropriately setting the diffusion power (diffusion angle) of the diffusion element 402 and the length of the rod 403, the light exits from the exit surface EXP. It is possible to make the illuminance distribution uniform in the area.

By transferring the image emitted from the exit surface EXP of the rod 403 with the relay lens 406, a rectangular irradiation area IM1 with high uniformity of illuminance can be obtained. By appropriately setting the transfer magnification of the relay lens, it is possible to obtain the irradiation area IM1 of a desired size, which is reduced, the same size, or enlarged. In FIG. 11, the relay lens 406 is composed of two lenses, a front convex lens 406a and a rear convex lens 406b, but the configuration of the relay lens 406 is not limited to this example.

FIG. 12A is a diagram showing the light source 400 including the integrator illumination system INT in an orientation in which the lateral direction (X direction) of the light emitting section 12 of the semiconductor laser is visible. FIG. 12(b) is a diagram showing the light source 400 including the integrator illumination system INT in an orientation in which the longitudinal direction (Y direction) of the light emitting section 12 of the semiconductor laser is visible.

The rod 403 may be any optical element as long as it can totally reflect the incident light on its side surface, and for example, the rod 403 shown in FIG. 13(a) or the one shown in FIG. 13(b) may be used. Preferably, the rod 403 is configured such that the shape of the entrance surface INP, the shape of the exit surface EXP, and the cross-sectional shape of the rod portion are the same.
The rod 403 shown in FIG. 13(a) is a solid quadrangular prism-shaped element made of an optical material such as optical glass or transparent resin, and the shapes of the end surfaces, i.e., the entrance surface INP and the exit surface EXP, are as follows. It is a rectangle whose long side is H0 and short side is V0. It is desirable to apply an antireflection film (AR coat) to the entrance surface INP and the exit surface EXP.
Further, the rod 403 shown in FIG. 13(b) is a hollow quadrangular prism, that is, a cylindrical element, and a reflective surface made of, for example, aluminum is formed on the inner surface of the cylinder. The shapes of the entrance plane INP and the exit plane EXP, which are the openings of the cylinder, are rectangular with a long side H0 and a short side V0. For example, it can be manufactured relatively inexpensively by depositing a reflective film such as an aluminum film on a plate-shaped substrate made of glass or metal, and then laminating the substrates together to form a cylindrical shape.

The shapes of the entrance surface INP and the exit surface EXP of the rod 403 are rectangular with the long side H0 and the short side V0 as described above, but due to the relay lens 406, the long sides are H1 and H1 as shown in FIG. 12(c). A rectangular irradiation area IM1 whose short side is V1 is formed. The long sides of the rectangular irradiation area IM1 correspond to the parallel direction (the slow axis direction of the semiconductor laser), and the short sides correspond to the orthogonal direction (the fast axis direction of the semiconductor laser). For example, the shape of the entrance surface INP and the exit surface EXP of the rod 403 is a rectangle with a length of 0.33 mm in the X direction (short side V0) and 1.67 mm in the Y direction (long side H0), and the magnification of the relay lens 406 is set to 1. If it is doubled, a rectangular irradiation area IM1 with V1 of about 0.4 mm and H1 of about 2 mm can be obtained.

FIG. 14 shows a schematic configuration of an optical system of a projection display device 1002 according to the third embodiment. For convenience of explanation, mechanical mechanisms for installing optical elements, a housing, electrical wiring, etc. are omitted in this figure. This embodiment replaces the B light source 100B, G light source 100G, and R light source 100R of the projection display device 1000 according to Embodiment 1 described with reference to FIG. 1 with a B light source 400B, a G light source 400G, and This is replaced with an R light source 400R. Descriptions of items common to the projection display device 1000 according to the first embodiment will be omitted.

FIG. 15 is a diagram corresponding to FIG. 8(a) in Embodiment 1, and shows the positional relationship between the deflector and the rectangular irradiation area IM1. The coordinate system is shown based on the B light source 400B.

In the projection display device of this embodiment, a lighting unit including a plurality of semiconductor lasers, a collimating lens, an integrator lighting system, and a deflection element is provided for each different color light. The rectangular illumination area outputted by each of the illumination units of different colors is enlarged and transferred to the reflective light modulation element while being deflected and scanned so as not to overlap with each other.

According to the present embodiment, in the field of projection-type image display devices that modulate and project laser light according to image signals, it is possible to realize a device that is small, easy to drive, and has high light utilization efficiency. .

[Embodiment 4]
FIG. 16 shows a schematic configuration of an optical system of a projection display device 1003 according to the fourth embodiment. For convenience of explanation, mechanical mechanisms for installing optical elements, a housing, electrical wiring, etc. are omitted in this figure. This embodiment replaces the B light source 100B, G light source 100G, and R light source 100R of the projection display device 1001 according to Embodiment 2 described with reference to FIG. 10 with the B light source using the rod integrator described in Embodiment 3. 400B, G light source 400G, and R light source 400R. Descriptions of items common to the projection display device 1001 according to the second embodiment will be omitted.

Similar to the second embodiment, the first transfer lens 200 (first transfer optical system) of this embodiment forms a secondary transfer image IM2 at the position of the diffuser plate 310a. The secondary transfer image IM2 scattered by the diffusion plate 310a is enlarged and transferred to the screen of the reflective light modulation element 340 as a tertiary transfer image IM3 by the second transfer optical system 320 (second transfer optical system). The size of each image is typically set in the following relationship.
IM1:IM2:IM3=1:2:6
According to this embodiment having such a configuration, it becomes easy to control the F-number of the illumination light that illuminates the reflective light modulation element 340.

In addition, in FIG. 17, the diffusion plate 310a is fixed at a fixed position, but the irradiation position of the laser beam on the diffusion plate may be moved over time by, for example, rotating the diffusion plate or moving it back and forth in a straight line. It is also possible to do this. According to this embodiment, scintillation of the illumination light caused by the laser can be suppressed.

According to the present embodiment, in the field of projection-type image display devices that modulate and project laser light according to image signals, it is possible to realize a device that is small, easy to drive, and has high light utilization efficiency. .

[Other embodiments]
Note that the present invention is not limited to the embodiments described above, and many modifications can be made within the technical idea of the present invention.

For example, in the integrator illumination system INT, a diffraction type diffusion element (so-called top hat element) may be arranged instead of the microlens array 103 and the microlens array 104 that form a pair. As long as the top hat element has different diffusion angles in the X direction and the Y direction, it is not necessarily necessary to provide two top hat elements, and it is also possible to use one top hat element.

Alternatively, instead of the microlens array 103 and microlens array 104 in which microlenses having a spherical shape are arranged two-dimensionally, an array of striped microlenses (cylindrical lenses) in the X direction and striped microlenses in the Y direction may be used. (Cylindrical lenses) may be provided independently. With such a configuration, the focal length and array spacing can be set regardless of the stripe pitch, making it possible to suppress instability in capture due to an insufficient number of array divisions, and to generate a more elongated and uniform rectangular spot. It becomes easier to do.

In addition, although the rod 403 has been exemplified in such a manner that the shape of the entrance surface INP, the shape of the exit surface EXP, and the cross-sectional shape of the rod portion are the same, the shape of the entrance surface INP and the shape of the exit surface Rods with different shapes may also be used.

Further, in Embodiments 1 to 4, the transfer optical system used to transfer the image, that is, the first transfer lens 200 (first transfer optical system), the second transfer optical system 320, and the relay lens 406 have both sides Although it is desirable that the configuration be telecentric, other configurations are also possible. For example, a so-called anamorphic optical system (anamorphic lens) having different optical characteristics in two cross sections around the optical axis may be employed as one or more of these transfer optical systems.

17(a) and 17(b) are examples in which an anamorphic optical system is adopted as the relay lens 406 in Embodiment 3 or 4, and each figure is a view seen from directions perpendicular to each other. The combination of the front convex lens 406a and the rear convex lens 406b is configured to transfer an image with a magnification of 2 times, but a cylindrical lens (concave lens 407a and convex lens 407b) with curvature added only in the X direction is designed to be afocal. By adding an anamorphic optical system to the above, it is possible to change the magnification in only one direction. In this example, the image emitted from the exit surface EXP of the rod 403 is transferred as a rectangular irradiation area IM1 that is equal in size in the X direction and twice in the Y direction. Of course, this is just an example, and the magnification of enlargement or reduction can be set arbitrarily.

In this way, if the transfer optical systems such as the first transfer lens 200 (first transfer optical system), the second transfer optical system 320, and the relay lens 406 are made into anamorphic optical systems, the magnification in only one direction can be reduced. Since it can be enlarged, it becomes possible to adjust the NA and the aspect of the transferred image, and it is possible to further improve the efficiency of light use.

11...Semiconductor laser/12...Light emitting unit/100B...B light source/100G...G light source/100R...R light source/102...Collimating lens/103, 104...Micro lens Array/106...Condensing lens/190...Projection screen/201...Front transfer lens/202...Rear transfer lens/210...Deflector/210B...B deflector/ 210G...Deflector for G/210R...Deflector for R/211...Base body/212...Motor/213...Reflection surface/214...Beam irradiation position/220...Photosynthesis Parts/221, 222...Dichroic mirror/310a...Diffusion plate/320...Second transfer optical system/321...First illumination lens/322...Second illumination lens/330... Optical path conversion mirror/340...Reflective light modulation element/350...TIR prism/360...Projection lens/400...Light source/400B...B light source/400G...G light source/400R. ... R light source / 401 ... Condensing lens / 402 ... Diffusion element / 403 ... Rod / 406 ... Relay lens / 406a ... Front convex lens / 406b ... Rear convex lens / 407a. ...Concave lens/407b...Convex lens/1000, 1001, 1002, 1003...Projection type display device

A first aspect of the present invention includes a plurality of semiconductor lasers, a collimating lens that collimates a plurality of laser beams outputted from the plurality of semiconductor lasers, and a rectangular shape by overlapping the plurality of laser beams collimated by the collimating lens. an integrator illumination system that forms an illumination area, a deflection element disposed on the collimating lens side with respect to a position where the rectangular illumination area is formed by the integrator illumination system, and a deflection element that is deflected and scanned by the deflection element. A projection display device comprising: a transfer optical system that enlarges and transfers a rectangular illumination area onto a reflective light modulator; and a projection lens that projects image light output from the reflective light modulator. It is.

[overall structure]
The projection display device 1000 includes a B light source 100B, a G light source 100G, an R light source 100R, a B deflector 210B, a G deflector 210G, an R deflector 210R, a light combining section 220, an optical path conversion mirror 330, a TIR prism 350, It includes a reflective light modulation element 340 and a projection lens 360. Further, a deflector of each color is arranged between the light source of each color and the front transfer lens 201 of each color, and a rear transfer lens 202 is arranged between the light combining section 220 and the optical path conversion mirror 330. The front light combining section 220 includes a dichroic mirror 221 and a dichroic mirror 222. Projection display device 1000 may optionally include a projection screen 190.

Note that in carrying out the present invention, a galvanometer mirror may be used instead of the deflector 210 including a rotating body. However, if a galvanometer mirror is used, it is expected that the device will become larger, vibrations will occur, and costs will increase, so it is desirable to use a deflector 210 that includes a rotating body.

The rod 403 may be any optical element as long as it can totally reflect the incident light on its side surface, and for example, the rod 403 shown in FIG. 13(a) or the one shown in FIG. 13(b) may be used. Preferably, the rod 403 is configured such that the shape of the entrance surface INP, the shape of the exit surface EXP, and the cross-sectional shape of the rod portion are the same.
The rod 403 shown in FIG. 13(a) is a solid quadrangular prism-shaped element made of an optical material such as optical glass or transparent resin, and the shapes of the end surfaces, i.e., the entrance surface INP and the exit surface EXP, are as follows. It is a rectangle whose long side is H0 and short side is V0. It is desirable to apply an antireflection film (AR coat) to the entrance surface INP and the exit surface EXP.
Further, the rod 403 shown in FIG. 13(b) is a hollow quadrangular prism, that is, a cylindrical element, and a reflective surface made of, for example, aluminum is formed on the inner surface of the cylinder. The shapes of the entrance plane INP and the exit plane EXP, which are the openings of the cylinder, are rectangular with a long side H0 and a short side V0. For example, it can be manufactured relatively inexpensively by depositing a reflective film such as an aluminum film on a plate-shaped substrate made of glass or metal, and then laminating the substrates together to form a cylindrical shape.

In FIG. 16 , the diffuser plate 310a is fixed at a fixed position, but the irradiation position of the laser beam on the diffuser plate may be moved over time by, for example, rotating the diffuser plate or moving it back and forth in a straight line. It can also be a form. According to this embodiment, scintillation of the illumination light caused by the laser can be suppressed.

Claims (9)

multiple semiconductor lasers;
a collimating lens that collimates the plurality of laser beams output by the plurality of semiconductor lasers;
an integrator illumination system that overlaps a plurality of laser beams collimated by the collimating lens to form a rectangular illumination area;
a deflection element disposed at a position closer to the collimating lens than a position where the rectangular illumination area is formed by the integrator illumination system;
a transfer optical system that enlarges and transfers the rectangular illumination area deflected and scanned by the deflection element to a reflective light modulation element;
a projection lens that projects the image light output from the reflective light modulation element;
A projection display device characterized by: The deflection element is rotatable around a rotation axis and includes an optical surface formed along a circumference around the rotation axis,
The optical surface is configured such that an inclination angle with respect to the rotation axis changes along the circumference,
The tilt angle is configured such that when the optical surface is continuously rotated at a constant speed, the laser beam is recursively deflected in a constant direction at a constant deflection speed.
The projection type display device according to claim 1, characterized in that: The plurality of semiconductor lasers are arranged so that the direction of the slow axis and the direction of the fast axis are aligned,
The longitudinal direction of the rectangular illumination area is the direction of the slow axis of the semiconductor laser,
The lateral direction of the rectangular illumination area is the direction of the Fast axis of the semiconductor laser,
The deflection element deflects and scans the laser beam along the width direction of the rectangular illumination area.
The projection type display device according to claim 1, characterized in that: The integrator illumination system includes either a microlens array in which spherical microlenses are arranged two-dimensionally, a diffractive diffusion element, or a microlens array in which striped microlenses are arranged.
The projection type display device according to any one of claims 1 to 3, characterized in that: The integrator illumination system includes a rod, a condensing lens that focuses a plurality of laser beams collimated by the collimating lens toward the rod, a diffusing element disposed near an incident surface of the rod, and a relay lens that transfers an image of the exit surface of the rod;
The projection type display device according to any one of claims 1 to 3, characterized in that: The rod is a prism made of an optical material or a hollow cylinder whose inner surface is a reflective surface.
6. The projection type display device according to claim 5. Either the integrator illumination system or the transfer optical system includes an anamorphic lens,
The projection type display device according to any one of claims 1 to 3, characterized in that: The transfer optical system includes a first transfer optical system that enlarges and transfers the rectangular illumination area to a diffuser plate;
a second transfer optical system that enlarges and transfers the rectangular illumination area enlarged and transferred to the diffusion plate by the first transfer optical system to the reflective light modulation element;
The projection type display device according to any one of claims 1 to 3, characterized in that: An illumination unit including the plurality of semiconductor lasers, the collimating lens, the integrator illumination system, and the deflection element is provided for each different color light,
comprising a light combining unit that combines illumination light outputted by the illumination units of different colors,
The rectangular illumination areas output by each of the illumination units of different colors are enlarged and transferred to the reflective light modulation element while being deflected and scanned so as not to overlap with each other.
The projection type display device according to any one of claims 1 to 3, characterized in that:

Images