JP2024018134A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type image display device that modulates and projects a laser beam according to an image signal, and that is small, easily driven and controlled, and utilizes light with high efficiency.

SOLUTION: A projection type image display device comprises: a plurality of illumination parts each forming a rectangle illumination area; a deflection element configured to be able to deflect and scan the rectangle illumination area formed by each of the plurality of illumination parts; and a transfer optical system enlarging and transferring the rectangle illumination area deflected and scanned by the deflection element into a reflection type optical modulation element. The deflection element is rotatable about a rotation axis and includes a plurality of reflection surfaces formed along a plurality of concentric circles with the rotation axis as a centre. Each of the plurality of reflection surfaces is configured to change an angle of inclination to the rotation axis along a periphery on which the reflection surfaces are formed. Each angle of inclination of each of the plurality of reflection surfaces is configured such that, when the reflection surface is continuously rotated at a constant speed, the rectangle illumination area reflected on the reflection surface is recursively deflected and scanned in a constant direction at a constant speed.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

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 illumination units each forming a rectangular illumination area, and the rectangular illumination area formed by each of the plurality of illumination units can be deflected and scanned. a deflection element, a transfer optical system that combines the rectangular illumination area deflected and scanned by the deflection element, and enlarges and transfers the image onto a reflection type light modulation element; and a transfer optical system that projects image light output from the reflection type light modulation element. a projection lens, each of the plurality of illumination units includes a plurality of semiconductor lasers, and a collimating lens that collimates the laser beams output from the plurality of semiconductor lasers, and the deflection element is arranged such that the deflection element is centered on a rotation axis. and includes a plurality of reflective surfaces formed along the circumference of a plurality of concentric circles centered on the rotation axis, and each of the plurality of reflective surfaces is rotated around the circumference on which the reflective surface is formed. The inclination angle of each of the plurality of reflecting surfaces changes along the rotation axis, and when the reflecting surface is continuously rotated at a constant speed, the inclination angle of each of the plurality of reflecting surfaces changes along the reflecting surface. The projection type display device is characterized in that the reflected rectangular illumination area is configured to be deflected and scanned recursively in a constant direction at a constant speed.

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 top view showing the appearance of an example of the deflector 210a. (b) A side view of an example of the deflector 210a. (c) A bottom view showing the appearance of an example of the deflector 210a. (a) A side view of a modified example of the deflector 210a. (b) A side view of another modified example of the deflector 210a. (c) A side view of yet another modification of the deflector 210a. (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. 7 is a diagram showing a schematic configuration of an optical system of a projection display device according to Embodiment 3. FIG. 7 is a diagram showing a schematic configuration of an optical system of a projection display device according to a fourth embodiment. FIG. 7 is a diagram showing a schematic configuration of an optical system of a projection display device according to Embodiment 5. FIG. FIG. 3 is a diagram showing an integrator illumination system INT according to an embodiment including a rod integrator.

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 designated with 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 deflector 210a, 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. Further, a front transfer lens 201 is arranged between the deflector 210a and the light combining section 220, and a rear transfer lens 202 is arranged between the light combining section 220 and the optical path conversion mirror 330. The front transfer lens 201 and the rear transfer lens 202 are collectively referred to as a first transfer lens 200 (first transfer optical system). The 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 deflector 210a deflects and scans the B light emitted by the B light source 100B in the DB direction, deflects and scans the G light emitted by the G light source 100G in the DG direction, and deflects and scans the R light emitted by the R light source 100R in the DR direction. It is a vessel. The deflector 210a will be described in detail 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 201R 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. This is because the reflective surface of the deflector 210a is configured and the light sources of each color are arranged so that the B, G, and R lights do not overlap each other on the screen of the reflective light modulator 340. The deflection scanning method will be explained in detail 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 light modulation device is performed in synchronization with the deflection scanning of each color light by the deflector 210a.

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, G light source 100G, and R light source 100R as illumination units 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 R light source 100R in FIG. 1. 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 R light source 100R 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, a deflector 210a is arranged between the B light source 100B, the G light source 100G, and the R light source 100R, and a rectangular irradiation area IM1 irradiated by each. The deflector 210a is a deflection element that can deflect and scan a plurality of rectangular irradiation areas (three in this embodiment) by itself. The deflector 210a includes a disc-shaped base 211 and a motor 212 that rotates the base 211 around a rotation axis AX.

FIG. 9(a) is a top view of the deflector 210a viewed from the side of the light combining unit 220, and FIG. 9(b) is a side view of the deflector 210a viewed from a direction perpendicular to the rotation axis AX. FIG. 9C is a bottom view of the deflector 210a viewed from the side opposite to the light combining section 220. In FIGS. 9(a) and 9(c), the rotation direction is shown as RO.

As shown in FIG. 9(a), a reflective surface 213a and a reflective surface 213b, which are strip-shaped optical surfaces, are provided on the upper surface of the disc-shaped base 211. The reflective surface 213a and the reflective surface 213b are provided along concentric circles having different radii centered on the rotation axis AX. As shown in FIG. 9C, a reflective surface 213c, which is a band-shaped optical surface, is provided on the lower surface of the disc-shaped base 211 along a circle centered on the rotation axis AX.

As shown in FIG. 9B, the disk-shaped base 211 is formed by stacking and integrating a substrate 211a, a substrate 211b, and a substrate 211c, each of which has a reflective surface formed thereon. However, the base body 211 does not necessarily have to be formed by stacking and integrating three substrates, and may have a structure as shown in side views in FIGS. 10(a) to 10(c), for example. FIG. 10A shows an example in which a substrate 211a having a reflective surface 213a and a reflective surface 213b on one side and a substrate 211c having a reflective surface 213c are stacked and integrated to form a base 211. Further, FIG. 10(b) shows an example in which a substrate 211c provided with a reflective surface 213a and a reflective surface 213c, and a substrate 211b provided with a reflective surface 213b are stacked and integrated to form the base body 211. Further, FIG. 10(c) is an example in which a reflective surface 213a, a reflective surface 213b, and a reflective surface 213c are formed on a base 211, which is originally a single substrate.

The G light output from the G light source 100G shown in FIG. , are deflected and scanned by the reflecting surface 213c. Each of the reflective surface 213a, the reflective surface 213b, and the reflective surface 213c is configured such that the angle of the reflective surface with respect to the rotation axis AX changes depending on the location (position), as will be described later.

The principle of deflection scanning by each reflective surface is basically the same, so for convenience of explanation, a case where the base body 211 is provided with a single reflective surface 213 will be described with reference to the drawings. In each of the integrated reflecting surfaces 213a, 213b, and 213c, deflection scanning is basically performed using the same principle as that of the single reflecting surface 213 described below.

6(a) is a perspective view showing the appearance of the deflector 210 provided with a single reflective surface 213, 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 location on the reflective surface, angular coordinates are set counterclockwise around the rotation axis AX, as shown in FIG. 6(a). (0°, 90°, 180°, and 270° are shown in the figure). Moreover, the axis BX shown in the figure is parallel to the rotation axis AX and is an axis passing 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 (namely, the rotation axis AX) changes depending on the location (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°. In FIG. 6A, the position where the inclination angle of the reflective surface becomes discontinuous is indicated as NC.

When the base body 211 is rotated in the RO 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) changes. 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 reflection 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 of 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 reflecting surface 213 is continuously rotated in the RO 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 instantaneously 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 RO 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.

FIG. 8A shows the positional relationship between the deflector 210 and the rectangular irradiation area IM1. 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. In addition, in FIGS. 8(a) to 8(c), the coordinate systems are added for convenience to make it easier to understand the mutual relationships, and they do not correspond to the coordinate system in FIG. 1. do.

Regarding the manufacturing method of the deflector 210, the disc-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 a press extrusion method, for example. Is possible. 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.

The case where the base body 211 is provided with a single reflective surface 213 has been described above, but in this embodiment, as shown in FIGS. 9(a) to 9(c), the base body 211 has a reflective surface Three surfaces are provided: a surface 213a, a reflective surface 213b, and a reflective surface 213c. Each of the reflective surfaces is configured with an inclined surface that allows the laser beam to be recursively deflected and scanned at a constant speed in a predetermined direction, similar to the reflective surface 213 described above. However, when the G light polarized and scanned by the reflective surface 213a, the B light polarized and scanned by the reflective surface 213b, and the R light polarized and scanned by the reflective surface 213c are combined by the light combining section 220, they overlap each other. In order to prevent this, each reflective surface is configured so that the starting and ending points of the inclination of each reflective surface, that is, the positions where the inclination angle of the reflective surface becomes discontinuous, are shifted from each other when viewed along the circumferential direction. There is.

As can be seen from FIG. 1, on the upper surface of the deflector 210a, the position irradiated by the B light source 100B is on the opposite side of the rotation axis AX from the position irradiated by the G light source 100G. Furthermore, the position on the lower surface of the deflector 210a that is illuminated by the R light source 100R is on the opposite side of the rotation axis AX from the position that is illuminated by the G light source 100G on the upper surface of the deflector 210a. The inclination of each reflecting surface is set so that when the beams of each color reflected at the respective irradiation positions are combined by the light combining section 220, the phases of deflection scanning are shifted by 120 degrees from each other. For example, in FIG. 9A, when the position NC where the inclination of the reflective surface 213a is discontinuous is at the 12 o'clock position, the position NC where the inclination of the reflective surface 213b is discontinuous is at the 2 o'clock position. It is configured to be in position. At that time, the configuration is such that the position NC where the slope of the reflective surface 213c becomes discontinuous is the 8 o'clock position in FIG. 9(c). Note that the rotational direction RO of the base body 211 is apparently reversed between the upper surface shown in FIG. 9(a) and the lower surface shown in FIG. 9(c). In this way, in order to prevent each of the rectangular illumination areas from overlapping each other when being recursively deflected and scanned, the phase of change in the tilt angle of each reflective surface is adjusted at the irradiation position on the disk of the deflector. are configured to be offset from each other along the rotation direction.

By the deflector 210a 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. Note that the R light is deflected and scanned by the reflecting surface 213c disposed on the lower surface side of the deflector 210a, but the R light is directed to the reflecting mirror 209F so that it is guided to the dichroic mirror 222 of the light combining section 220 without interfering with components. The optical path is changed by the reflecting mirror 209R, and the light is made to take a detour before entering the dichroic mirror 222. As a result of detouring the optical path, a difference occurs between the optical path length of the R light and the optical path length of the G and B lights, but in this embodiment, the optical path length is different between the reflecting mirror 209F and the reflecting mirror 209R. A correction lens 203 is provided to correct the effect of the difference.

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

FIG. 11A 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. 11(b) 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. 11C 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, the projection display device of this embodiment is provided with a plurality of semiconductor lasers, a collimating lens, and an integrator illumination system for each different color of light, and each color of illumination light is transmitted through a single deflection element. This enables deflection scanning. On the rotating body of the deflection element, reflective surfaces for deflecting and scanning the respective colored lights are arranged with a phase difference of 120 degrees when viewed in the rotation direction, and each reflective surface is moved using a single motor. It can be rotated as a unit. Therefore, there is no need to separately provide a motor for rotating each reflective surface for each color light, and there is no need to adjust the phase of deflection scanning of each color light by controlling the drive of each motor. Since it is sufficient to provide a single rotating body and a single motor, the number of parts can be reduced and deflection scanning can be easily controlled.

The projection display device of this embodiment includes a light combining section that combines illumination lights of different colors deflected and scanned by a single deflection element, and the rectangular illumination areas of different color lights are formed by reflective light modulation. The images are enlarged and transferred onto the screen of the device, and scanned along the scanning direction SD so as not to overlap 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. .

Note that the layout of the light sources of each color relative to the deflector is not limited to the example shown in FIG. 1; for example, the positions of the light sources of each color may be exchanged. In that case, the reflection/transmission characteristics of the dichroic mirror forming the light combining section 220 may be adjusted according to the layout of each color light source. Furthermore, the three-color light sources are not necessarily limited to blue, green, and red, and light sources of other colors may also be used. In that case as well, the reflection/transmission characteristics of the dichroic mirror constituting the light combining section 220 may be adjusted depending on the light emission characteristics of the light source used.

[Embodiment 2]
FIG. 12 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 first transfer lens 200 including a front transfer lens 201 and a rear transfer lens 202, a light combining unit 220, and an optical path converter. This embodiment is common to the first embodiment in that it includes a mirror 330, a TIR prism 350, a reflective light modulation element 340, and a projection lens 360.

In the first embodiment, a single deflector 210a is used to deflect and scan B, G, and R lights, but in this embodiment, a deflector 210c equipped with two optical surfaces (reflecting surfaces) is used to scan the B, G, and R lights. The B light and the G light are deflected and scanned, and the R light is deflected and scanned using a deflector 210b having one optical surface (reflecting surface). However, this embodiment and Embodiment 1 are common in that a deflector having a plurality of optical surfaces (reflecting surfaces) (two in this embodiment) is used.

In this embodiment, the deflector 210c, which is a single deflection element, can deflect and scan both the G light emitted by the G light source 100G and the B light emitted by the B light source 100B. On the rotating body of the deflection element, reflecting surfaces for deflecting and scanning each of the G light and B light are arranged with a phase difference of 120 degrees when viewed in the rotation direction, and each reflecting surface is a single reflection surface. It can be rotated as a unit using a motor. Therefore, there is no need to provide separate motors to rotate the reflecting surfaces corresponding to the G and B lights, and the phase of the deflection scan of the G and B lights can be controlled by driving each motor. No need to adjust.

In this embodiment, a deflector 210b for deflecting and scanning the R light is provided, but as can be seen by comparing FIG. 1 and FIG. Compared to the case where the R light is guided to the mirror 222, when the deflector 210b is used, the R light can be guided to the dichroic mirror 222 without detouring the optical path. In this case, it is possible to arrange the layout so that the optical path length of the R light is equal to the optical path length of the G light and the B light. Therefore, the deflected and scanned R light can be guided to the dichroic mirror 222 of the light combining section 220 without providing the reflecting mirror 209F, the reflecting mirror 209R, or the correction lens 203 for detouring the optical path. In this embodiment, in order to prevent the deflected and scanned R light from overlapping with the G light and the B light, the phase of the motor that rotates the deflector 210b and the motor that rotates the deflector 210c is adjusted by the motor drive circuit. be adjusted. As described in Embodiment 1 with reference to FIG. 11(c), the modulation operation of the reflective light modulation device is performed in synchronization with the vertical scanning of illumination light of each color, which is also the same in this embodiment. .

In the projection display device of this embodiment, the illumination area of G light and B light can be deflected and scanned by a single deflector 210c. It also includes a light combining unit that combines the three colors of illumination light that have been deflected and scanned using the deflector 210c and the deflector 210b, and the rectangular illumination area of the different color lights is enlarged and transferred onto the screen of the reflective light modulation element. and are scanned along the scanning direction SD on the screen so as not to overlap 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. .

Note that the layout of the light sources of each color relative to the deflector is not limited to the example shown in FIG. 12; for example, the positions of the light sources of each color may be exchanged. In that case, the reflection/transmission characteristics of the dichroic mirror forming the light combining section 220 may be adjusted according to the layout of each color light source. Furthermore, the three-color light sources are not necessarily limited to blue, green, and red, and light sources of other colors may also be used. In that case as well, the reflection/transmission characteristics of the dichroic mirror constituting the light combining section 220 may be adjusted depending on the light emission characteristics of the light source used.

[Embodiment 3]
FIG. 13 is a diagram showing a schematic configuration of an optical system of a projection display device 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. Descriptions of items common to Embodiment 1 will be simplified or omitted.

[overall structure]
The projection display device 1002 of this embodiment includes a B light source 100B, a G light source 100G, an R light source 100R, a deflector 210a, a first transfer lens 200 including a front transfer lens 201 and a rear transfer lens 202, and a correction lens. 203, a reflecting mirror 209F, a reflecting mirror 209R, 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, which are the same as in the first embodiment.

This embodiment further includes a diffusion plate 310a disposed between the rear transfer lens 202 of the first transfer optical system and the optical path conversion mirror 330, and a second transfer optical system 320. The second transfer optical system 320 is composed of a front transfer lens 321 and a rear transfer lens 322, which are arranged with an optical path conversion mirror 330 in between.

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 lens). 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. 13, 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 this embodiment, as in the first embodiment, the deflector 210a only needs to be provided with a single rotating body and a single motor, so the number of parts can be reduced, and control of deflection scanning is also easy. . The projection display device of this embodiment includes a light combining section that combines illumination lights of different colors polarized and scanned by a single deflection element, and the rectangular illumination areas of the different color lights are formed by the first transfer optical system. The images are enlarged and transferred onto the screen of the reflective light modulation element via the optical system and the second transfer optical system, and scanned along the scanning direction SD on the screen so as not to overlap 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. .

Note that the layout of the light sources of each color with respect to the deflector is not limited to the example shown in FIG. 13; for example, the positions of the light sources of each color may be exchanged. In that case, the reflection/transmission characteristics of the dichroic mirror forming the light combining section 220 may be adjusted according to the layout of each color light source. Furthermore, the three-color light sources are not necessarily limited to blue, green, and red, and light sources of other colors may also be used. In that case as well, the reflection/transmission characteristics of the dichroic mirror constituting the light combining section 220 may be adjusted depending on the light emission characteristics of the light source used.

[Embodiment 4]
FIG. 14 is a diagram showing a schematic configuration of an optical system of a projection display device according to Embodiment 4. 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 1003 of this embodiment includes a B light source 100B, a G light source 100G, an R light source 100R, a deflector 210a, a first transfer optical system, a reflecting mirror 209F, a reflecting mirror 209R, a second transferring optical system 320, and 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, which are common to the third embodiment.

Similarly to Embodiment 3, also in this embodiment, a secondary transfer image IM2 is formed at the position of the diffusion plate 310a by the first transfer optical system. However, in this embodiment, the lens configuration of the first transfer optical system is different from that in the third embodiment. In the first transfer optical system (first transfer lens 200) of the third embodiment, the front transfer lens 201 is individually arranged corresponding to the light source of each color, and the rear transfer lens 202 common to each color is arranged more closely than the light combining unit 220. It was placed earlier.

On the other hand, in this embodiment, the front transfer lens 201 is arranged corresponding to each of the G light source 100G and the B light source 100B, and the rear transfer lens 202 common to the G light and B light is connected to the dichroic mirror 221. It is arranged between the mirrors 222. That is, the first transfer lens 200 is configured to act only on G light and B light. Separately, in this embodiment, a front transfer lens 201R corresponding to the R light source 100R is arranged between the deflector 201a and the reflector 209F, and a rear transfer lens 202R for R light is arranged between the reflector 209R and the dichroic mirror. 222. That is, a first transfer optical system (first transfer lens 200R) exclusively for R light is provided. In the third embodiment, the correction lens 203 was provided to correct the effect of the optical path length of the R light being longer than that of the B light and the G light, but in this embodiment, the front transfer lens 201R and By appropriately setting the characteristics of the rear transfer lens 202R, the correction lens 203 can be omitted.

According to this embodiment, as in the third embodiment, the deflector 210a only needs to be provided with a single rotating body and a single motor, so the number of parts can be reduced, and the control of deflection scanning is easy. . The projection display device of this embodiment includes a light combining section that combines illumination lights of different colors polarized and scanned by a single deflection element, and the rectangular illumination areas of the different color lights are formed by the first transfer optical system. The images are enlarged and transferred onto the screen of the reflective light modulation element via the optical system and the second transfer optical system, and scanned along the scanning direction SD on the screen so as not to overlap each other.

In this embodiment as well, a plurality of semiconductor lasers, collimating lenses, and integrator illumination systems are provided for each different color of light, and each color of illumination light can be deflected and scanned by a single deflection element. On the rotating body of the deflection element, reflective surfaces for deflecting and scanning the respective colored lights are arranged with a phase difference of 120 degrees when viewed in the rotation direction, and each reflective surface is moved using a single motor. It can be rotated as a unit. Therefore, there is no need to separately provide a motor for rotating each reflective surface for each color light, and there is no need to adjust the phase of deflection scanning of each color light by controlling the drive of each motor. Since it is sufficient to provide a single rotating body and a single motor, the number of parts can be reduced and deflection scanning can be easily controlled.

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. .

Note that the layout of the light sources of each color with respect to the deflector is not limited to the example shown in FIG. 14; for example, the positions of the light sources of each color may be exchanged. In that case, the reflection/transmission characteristics of the dichroic mirror forming the light combining section 220 may be adjusted according to the layout of each color light source. Furthermore, the three-color light sources are not necessarily limited to blue, green, and red, and light sources of other colors may also be used. In that case as well, the reflection/transmission characteristics of the dichroic mirror constituting the light combining section 220 may be adjusted depending on the light emission characteristics of the light source used.

[Embodiment 5]
FIG. 15 is a diagram showing a schematic configuration of an optical system of a projection display device according to Embodiment 5. 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 type display device 1004 of this embodiment includes a B light source 100B, a G light source 100G, an R light source 100R, a deflector 210a, a reflecting mirror 209F, a reflecting mirror 209R, a light combining section 220, an optical path conversion mirror 330, a TIR prism 350, a reflective type This embodiment is similar to the first embodiment in that it includes a light modulation element 340 and a projection lens 360.

In Embodiments 1 to 4, each of the B light source 100B, the G light source 100G, and the R light source 100R includes a light source equipped with the integrator illumination system INT described with reference to FIGS. 5(a) to 5(d). Using. The light sources of each color in this embodiment have a simpler configuration, and include a laser module LM that emits a rectangular laser beam, and the laser beam emitted by the laser module LM is focused as a point image on the reflective surface of the deflector 210a. A condensing lens 500 is provided. Furthermore, the projection display device 1004 of this embodiment includes a collimating lens 501 that collimates the diverging light beam reflected by the reflective surface of the deflector 210a into parallel light, and enlarges and transfers it to the reflective light modulation element as a rectangular illumination area. It is equipped with

Also in this embodiment, the illumination light of each color can be deflected and scanned by a single deflection element. On the rotating body of the deflection element, reflective surfaces for deflecting and scanning the respective colored lights are arranged with a phase difference of 120 degrees when viewed in the rotation direction, and each reflective surface is moved using a single motor. It can be rotated as a unit. Therefore, there is no need to separately provide a motor for rotating each reflective surface for each color light, and there is no need to adjust the phase of deflection scanning of each color light by controlling the drive of each motor. Since it is sufficient to provide a single rotating body and a single motor, the number of parts can be reduced and deflection scanning can be easily controlled.

The projection display device of this embodiment includes a light combining section that combines illumination lights of different colors deflected and scanned by a single deflection element, and the rectangular illumination areas of different color lights are formed by reflective light modulation. The images are enlarged and transferred onto the screen of the device, and scanned along the scanning direction SD so as not to overlap 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. .

Note that the layout of the light sources of each color relative to the deflector is not limited to the example shown in FIG. 15, and for example, the positions of the light sources of each color may be exchanged. In that case, the reflection/transmission characteristics of the dichroic mirror forming the light combining section 220 may be adjusted according to the layout of each color light source. Further, the three-color light sources are not necessarily limited to blue, green, and red, and light sources of other colors may also be used. In that case as well, the reflection/transmission characteristics of the dichroic mirror constituting the light combining section 220 may be adjusted depending on the light emission characteristics of the light source used.

[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 of Embodiments 1 to 4, a diffractive diffusion element (so-called top hat element) may be arranged instead of the microlens array 103 and 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 the 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 a striped microlens in the Y direction may be used. An array of (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.

Alternatively, an integrator illumination system INT including a rod integrator may be used instead of the microlens array. FIG. 16 is a diagram for explaining an integrator illumination system including a rod integrator. This integrator illumination system 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 described in the first embodiment.

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. 16, 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.

The rod 403 may be any optical element as long as it can totally reflect the incident light on its side surface. 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 may be, for example, a solid quadrangular prism-shaped element made of an optical material such as optical glass or translucent resin. Further, the rod 403 may be a hollow quadrangular prism, that is, a cylindrical element, and a reflective surface made of aluminum or the like is formed on the inner surface of the cylinder.

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, but the relay lens 406 creates a rectangular irradiation area IM1 with the long side H1 and the short side V1. It 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.

Note that the rod 403 is not the same in the shape of the entrance surface INP, the shape of the exit surface EXP, and the cross-sectional shape of the rod portion, but a rod in which the shape of the entrance surface INP and the shape of the exit surface EXP are different, such as a so-called tapered rod, is used. You can.

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/210a, 210b, 210c...Deflector/211...Base /211a, 211b, 211c...Substrate/212...Motor/213, 213a, 213b, 213c...Reflecting surface/214...Beam irradiation position/220...Light combining unit/221, 222...・Dichroic mirror/310a... Diffusion plate/320... Second transfer optical system/321... Front transfer lens/322... Rear transfer lens/330... Optical path conversion mirror/340... Reflective light modulation element/350...TIR prism/360...Projection lens/401...Condensing lens/402...Diffusion element/403...Rod/406...Relay lens/406a. ...Front convex lens/406b...Rear convex lens/500...Condensing lens/501...Collimating lens/1000, 1001, 1002, 1003, 1004...Projection type display device

Claims (10)

a plurality of illumination parts each forming a rectangular illumination area;
a deflection element configured to deflect and scan the rectangular illumination area formed by each of the plurality of illumination units;
a transfer optical system that combines the rectangular illumination area deflected and scanned by the deflection element and enlarges and transfers it to a reflective light modulation element;
a projection lens for projecting the image light output by the reflective light modulation element;
Each of the plurality of illumination units includes a plurality of semiconductor lasers and a collimating lens that collimates a laser beam outputted by the plurality of semiconductor lasers,
The deflection element is rotatable about a rotation axis, and includes a plurality of reflective surfaces formed along the circumference of a plurality of concentric circles centered on the rotation axis, and each of the plurality of reflection surfaces The reflective surface is configured such that the inclination angle with respect to the rotation axis changes along the circumference on which the reflective surface is formed,
The inclination angle of each of the plurality of reflective surfaces is such that when the reflective surface is continuously rotated at a constant speed, the rectangular illumination area reflected by the reflective surface is recursively deflected in a constant direction at a constant speed. configured to be scanned,
A projection display device characterized by: The plurality of reflective surfaces are such that the phases of changes in inclination angles of the plurality of reflective surfaces are shifted from each other along the rotation direction so that each of the rectangular illumination areas enlarged and transferred to the reflective light modulation element does not overlap with each other.
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 or 2, characterized in that: Each of the plurality of illumination units includes an integrator illumination system that overlaps a plurality of laser beams collimated by the collimating lens to form a rectangular illumination area.
The projection type display device according to claim 1 or 2, 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.
5. The projection type display device according to claim 4. 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;
5. The projection type display device according to claim 4. Each of the plurality of illumination units includes a condenser lens that focuses the plurality of laser beams collimated by the collimating lens onto any of the plurality of reflective surfaces of the deflection element.
The projection type display device according to claim 1 or 2, characterized in that: The plurality of reflective surfaces include a reflective surface formed on the upper surface of the deflection element, and a reflective surface formed on the lower surface of the deflection element.
The projection type display device according to claim 1 or 2, characterized in that: The plurality of reflective surfaces include two reflective surfaces formed on one side of the deflection element.
The projection type display device according to claim 1 or 2, characterized in that: Each of the plurality of reflective surfaces deflects and scans the rectangular illumination area with a different color of light,
The projection type display device according to claim 1 or 2, characterized in that:

Images