JP6515616B2 - projector - Google Patents

Description

  The present invention relates to a projector which projects an image in an enlarged manner by scanning light on a surface to be illuminated.

  In an optical device such as a projector, a plurality of optical elements are disposed in an optical system to correct focal position deviation due to temperature drift while maintaining miniaturization, and the entire optical system is displaced by displacing the plurality of optical elements. What makes it possible to change power as is known (refer to patent document 1).

  However, in the technique disclosed in, for example, Patent Document 1 or the like, although it is possible to correct the focal position shift due to the temperature drift, it is not always possible to correct the aberration generated in the image formation.

  Here, in general, in image projection in a projector, it is conceivable that the amount of aberration generated differs depending on the image height position. In order to suppress such an aberration, for example, after increasing the number of lenses in the projection optical system, it is assumed that the adjustment is made in the state in which the aberration balance is best obtained as the entire image height, that is, the entire image. However, in this case, it is necessary to increase the number of lenses in order to further suppress the aberration. In addition, since the aberration amount balance as a whole is given priority so that the aberration amount at each image height position does not increase locally, it is possible to make the best aberration suppressed state at all image height positions. In addition, some degree of aberration will have to be compromised.

JP, 2012-242721, A

  The present invention has been made in view of the above-described background, and an object of the present invention is to provide a projector which can miniaturize an apparatus by suppressing aberration without increasing the number of lenses.

  In order to achieve the above object, a projector according to the present invention comprises a light source for emitting light, a scanning optical system for emitting light emitted from the light source as scanning light for scanning the surface to be illuminated, and light from the scanning optical system And a light path variable member disposed in the subsequent stage of the optical path of the scanning optical system and changing the optical path of light from the scanning optical system in synchronization with scanning by the scanning optical system.

  In the above projector, by adjusting the optical path of light from the scanning optical system by the optical path variable member in synchronization with the scanning of the scanning optical system, aberration is caused according to the scanning position, that is, the image height position corresponding thereto. It becomes possible to adjust the degree of correction. Therefore, highly accurate aberration correction becomes possible at all image height positions, and high-performance image formation becomes possible. In this case, the aberration can be suppressed without increasing the number of lenses simply by providing the light path variable member, for example, in the projection optical system, so, for example, the enlargement of the projection optical system can be suppressed and the apparatus can be miniaturized as a whole. be able to.

  According to a specific aspect of the present invention, the light path variable member is disposed at the pupil position of the projection optical system. In this case, by providing the light path variable member at the pupil position, which is the position of the diaphragm at which the components of the image light are superimposed and the position near it, the image light from any image height position The light path can be changed while being synchronized with the scanning of the scanning optical system by refraction or reflection with respect to the entire light flux which is a component of light, and efficient aberration correction can be performed. Here, the passage of light in each member includes not only passage by transmission (passage of light transmissive member) but also passage by reflection (passage of light reflective member).

  According to another aspect of the present invention, the optical system further comprises a relay optical system for relaying an image, and the light path variable member is disposed at a pupil position of the relay optical system. In this case, the aberration can be suppressed in the relay optical system.

  According to still another aspect of the present invention, the optical path changing member changes the refractive index in pixel units in accordance with the passing area of light emitted from the scanning optical system, thereby reducing the refractive index of the light from the scanning optical system. It is a refractive index distribution variable panel which changes distribution. In this case, by changing the refracting state of the light passing through the refractive index distribution variable panel, it is possible to highly accurately suppress the aberration without increasing the number of lenses.

  According to still another aspect of the present invention, the optical path changing member changes the optical path of light from the scanning optical system by changing its shape. In this case, by changing the shape of the light path variable member in synchronization with the operation of the scanning optical system, it is possible to change the light path of the light passing through the light path variable member in time division.

  According to still another aspect of the present invention, the light path variable member includes a deformable mirror that reflects light while changing its shape in synchronization with scanning by the scanning optical system. In this case, the light path of the light passing through the light path variable member can be changed in time division by changing the reflection state at the deformable mirror.

  According to still another aspect of the present invention, the light path variable member changes in accordance with the image height position of light from the scanning optical system. In this case, aberration correction can be performed well in accordance with each image height position.

  According to still another aspect of the present invention, the optical path changing member changes in response to the amount of aberration that increases or decreases in accordance with the image height position. In this case, the correction amount is adjusted according to each image height position, and aberration correction can be performed well at all the image height positions.

  According to still another aspect of the present invention, the light path variable member adjusts the degree of change of the light path for each predetermined irradiation area unit. In this case, aberration correction can be performed in irradiation area units.

(A) is a figure which shows schematic structure of the projector of 1st Embodiment or Example 1, (B) is a ray diagram which shows the appearance of the image projection by the projection optical system of the projector of (A), (C) to (E) are ray diagrams at each image height position. (A) and (B) are aberration diagrams showing the state of aberration at each image height position in a state in which the light path variable member is controlled so as to minimize the aberration at the position of image height 0% in Example 1. , (C) is a spot diagram showing how light is collected at each image height position. (A) and (B) are aberration diagrams showing the state of aberration at each image height position in a state in which the light path variable member is controlled so as to minimize the aberration at the position of 50% of the image height in Example 1. , (C) is a spot diagram showing how light is collected at each image height position. (A) and (B) are aberration diagrams showing the state of aberration at each image height position in a state in which the light path variable member is controlled so as to minimize the aberration at the position of image height 70% in Example 1. , (C) is a spot diagram showing how light is collected at each image height position. (A) and (B) are aberration diagrams showing the state of aberration at each image height position in a state in which the light path variable member is controlled so as to minimize the aberration at a position of 90% of the image height in Example 1. , (C) is a spot diagram showing how light is collected at each image height position. (A) and (B) are aberration diagrams showing the state of aberration at each image height position in a state in which the light path variable member is controlled so as to minimize the aberration at the position of image height 100% in Example 1. , (C) is a spot diagram showing how light is collected at each image height position. (A) and (B) are aberration diagrams showing the state of aberration at each image height position in the projector of the comparative example, and (C) is a spot diagram showing states of light collection at each image height position . (A), (B) and (C) are an aberrational figure and a spot diagram figure for every image height position in the projector of the comparative example shown in FIG. 7, (C), (D) and (E) are the implementation FIG. 6 shows an aberration diagram and a spot diagram at each image height position in the projector of Example 1; It is a ray diagram which shows the appearance of the image projection by the projector of 2nd Embodiment. (A) is a figure for demonstrating one structural example of a refractive index distribution variable panel, (B) is a figure which shows notionally the mode of the liquid crystalline compound which comprises a liquid crystal layer. It is a ray diagram which shows the appearance of the image projection by the projector of 3rd Embodiment. It is a ray diagram showing an imaging optical system applied to a projector of a 4th embodiment. FIG. 21 is a ray diagram showing a modified example of an imaging optical system applied to a projector.

First Embodiment
A projector incorporating the image display device according to the first embodiment of the present invention will be described in detail below with reference to the drawings.

  As shown in FIG. 1A, a laser projector 100 shown as an example of a projector according to the first embodiment of the present invention includes a light source device (light source) 10, a collimating lens 20, a scanning optical system 40, and focusing. An optical system 50, a light diffusing element 60, and a projection optical system 70 are provided. Among these, the projection optical system 70 has an optical path variable member VP for changing the optical path of the passing light.

  The light source device 10 is formed of, for example, a laser diode (LD) capable of emitting laser light of red, green and blue light in a time-division or combined state, and generates a necessary amount of light in the laser projector 100 Light source. The collimating lens 20 collimates the light emitted from the light source device 10.

  The scanning optical system 40 is a light transmission type light modulation device, and two-dimensionally scans red light, green light and blue light sequentially emitted from the light source device 10 to generate red, green and blue color images A device to That is, the scanning optical system 40 emits each color light as scanning light scanned on the screen SC which is an illuminated surface. In the present embodiment, the light transmission type scanning optical system is applied to the scanning optical system 40 as an example, but it is also possible to configure the scanning optical system using a light reflection type element such as a MEMS mirror, for example. It is possible.

  The condensing optical system 50 condenses the light incident from the scanning optical system 40, and forms an image on an imaging plane IF which occupies a predetermined range in the area of the light diffusing element 60 located at the rear stage of the light path. As described above, the light diffusion element 60 is disposed at a position where the light collected by the light collection optical system 50 forms an image. Therefore, an intermediate image MI is formed on the imaging plane IF of the light diffusing element 60. In other words, the condensing optical system 50 is an imaging optical system in which a predetermined region on the light diffusing element 60 is an imaging plane IF and an intermediate image MI is formed on the imaging plane IF. The light diffusion element 60 is formed of a diffusion plate, a microlens array, or the like, and is an axis parallel to the optical axis AX of the condensing optical system 50 by the drive mechanism 61 and an optical path of the image light (image light) GL. It is provided so as to be rotatable about a central axis XX which is at a position away from. The light diffusing effect of the light diffusing element 60 makes the light distribution of the light projected onto the screen SC uniform and reduces speckle noise. The angle of the light emitted from the light diffusing element 60 may be made larger than the collection angle of the light incident from the light collection optical system 50.

  The projection optical system 70 projects the intermediate image MI formed on the light diffusing element 60 by the condensing optical system 50 on the screen SC. That is, the projection optical system 70 is an imaging optical system that re-forms the intermediate image MI in the irradiated region on the screen SC, and is a projection lens (projection lens) that projects the light from the scanning optical system 40. The projection optical system 70 has a zoom mechanism and a focus mechanism as needed. An image of light emitted from each point of the intermediate image MI formed on the light diffusing element 60 is imaged by the projection optical system 70 in the projection area PA of the screen SC.

  Here, FIG. 1B is a view showing a configuration of the projection optical system 70 in the laser projector 100 and a state of image projection. As shown, the projection optical system 70 is scanning optical in synchronization with scanning by the scanning optical system 40, in addition to a plurality of (six in the illustrated example) lenses 71 to 76 for performing normal image projection. The light path variable member VP for changing the light path of the light from the system 40 is placed at or near the position of the stop through which the components of the image light (image light) GL from the light diffusion element 60 overlap. It is provided at a certain pupil position. The light path variable member VP is a member which is light transmissive and variable in shape, and is configured, for example, by making a lens made of a gel-like variable material deformable by a drive mechanism (not shown) or the like. There is. The projection optical system 70 functions as an aberration correction element that suppresses the generation of aberration by changing the optical path of the light from the scanning optical system 40 in synchronization with the scanning timing by having the optical path variable member VP on the optical path. It has become. In the above case, since the light path variable member VP is disposed in the projection optical system 70, it is disposed downstream of the light path of the scanning optical system 40.

  The lenses 71 to 76 constituting the projection optical system 70 are shown as an example of various aspects, but here, from the object side (light path downstream side), the lenses 71 to 73 on the light path downstream side from the stop position. The lenses 74 to 76 are disposed on the upstream side of the optical path from the position of the stop. Among these, the lenses 72 and 73 are cemented lenses that can function as achromatic lenses, and similarly, the lenses 74 and 75 are cemented lenses that can function as achromatic lenses. The lenses 71 to 76 as a whole have a so-called Gaussian lens configuration.

  Referring back to FIG. 1A, the control unit 80 receives image information from an external device such as a PC and controls each of the units. That is, the control unit 80 generates an electrical signal to be supplied to the light source device 10 based on the gradation value of each pixel of the two-dimensional image indicated by the image information and the display timing, and the light source device 10 emits light at each timing. The scanning optical system 40 is controlled so that the pixels displayed by the respective color lights correspond to predetermined positions in the two-dimensional image defined in the image information. Furthermore, in the present embodiment, the control unit 80 controls the deformation operation of the light path variable member VP in the projection optical system 70 in synchronization with the scanning by the scanning optical system 40 as described above.

  Hereinafter, the image projection operation by the laser projector 100 according to the present embodiment will be described in detail. First, as described above, the laser projector 100 is a scanning projector, and as shown in FIGS. 1 (C) to 1 (E), the image height position of the point where display is performed in time division based on the display timing. Is changing. That is, at a certain timing, light is emitted from a position at an image height of 0% which is the position of the optical axis AX as shown in FIG. 1C, but at other timings as shown in FIG. Light is emitted from a position where the image height is slightly high (for example, a position of 70% image height), and at another timing, the position where the image height is the highest (for example, 100% image position) as shown in FIG. Light is emitted from).

  In the case of image projection as described above, the amount of aberration generated varies with the image height position. In the laser projector 100 according to the present embodiment, the light path variable member VP in the projection optical system 70 is synchronized with the image height position of the image light GL changing with the movement of the projection position due to the scanning as described above. It is deformed. That is, by changing the shape of the light path variable member VP in a time division manner according to the image height position as shown in FIG. 1 (B) and FIGS. 1 (C) to 1 (E) By changing the refracting action by the light path variable member VP when the component of the light GL passes, the light path of the light is changed according to the image height position, and as a result, aberration correction suitable for each component of each image light GL is performed It can be an aspect. In particular, since the light path variable member VP is disposed at the pupil position in the projection optical system 70, as shown in FIG. 1 (B) and FIGS. 1 (C) to 1 (E), from which image height position Also for the ray bundle (image light GL), the refracting action can be changed for the whole ray bundle. The amount of change in the change of the light path variable member VP is sufficient as long as it is sufficient for aberration correction, and may not be so large.

  Further, as shown in FIG. 1B, among the lenses 71 to 76 constituting the projection optical system 70, the first lens 71 to the third lens 73 disposed on the object side from the stop ST have lens surfaces L1 to L7. It has L5. The light path variable member VP disposed at the pupil position, that is, at or near the stop ST, has a first surface L6 and a second surface L7. The fourth lens 74 to the sixth lens 76 disposed on the image side of the stop ST have lens surfaces L8 to L12. In the surface representing the position of the aperture stop ST, the light path variable member VP is equal to the first surface L6.

Example 1
Hereinafter, an example of the projection optical system of the projector according to the present embodiment will be described. The symbols used in the examples are summarized below.
R: radius of curvature of lens surface
D: Distance between lens surfaces
nd: index of refraction dd for d-line of optical material: Abbe number radius of d-line: aperture radius

Data of optical surfaces constituting the projection optical system of Example 1 are shown in Table 1 below. FIG. 1 also shows the lens of Example 1. FIG. Also, in the upper column of Table 1, "surface number" is a number assigned to each lens surface etc. in order from the object side. That is, they correspond to the surfaces L1 to L12 shown in FIG. The objects and images in the table indicate the positions of the screen and the light diffusing element, respectively. The middle column and the lower column are data indicating parameters for determining the curved surface shape of the light path variable member disposed at the pupil position (the position of the diaphragm surface in the upper column) and changing corresponding to the image height position.
[Table 1]
RD nd dd radius object Infinity Infinity
1 61.61729283 8.75 1.622294 53.2737 30.23825513
2 151.6957732 0.5 28.92832761
3 35. 13459544 12.5 1.607381 56.6501 25
4 Infinity 3.8 1.60342 38.0299 23.92741932
5 24.30063858 18 17.92625521
Aperture plane Infinity 1 1.5168 64.1673 16.36248805
7 Infinity 18 16.41562742
8-28.10817378 3.8 1.60342 38.0299 18.10524858
9 Infinity 11 1.62041 60.32360001 22.22848126
10 -36.25645449 0.5 23.23636076
11 134.0939552 7 1.62041 60.32360001 25
12-108.8169261 60.00494152 25.16998223
Statue of Infinity -0.468660893 25.677203088

Pupil position plate shape
Image height 0% Image height 50% Image height 70%
Order coefficient order coefficient order coefficient
X ^ 2 1.124E-04 X ^ 2 7.539E-05 X ^ 2 4.326E-05
X * Y -1.826E-14 X * Y 4.770E-13 X * Y 6.338E-12
Y ^ 2 1.124E-04 Y ^ 2 8.828E-05 Y ^ 2 6.578E-05
X ^ 3 -3.335E-12 X ^ 3 1.445E-12 X ^ 3 -5.261E-13
X ^ 2 * Y 2.235E-12 X ^ 2 * Y 1.265E-06 X ^ 2 * Y 1.241E-06
X * Y ^ 2 2.235E-12 X * Y ^ 2 -1.440E-12 X * Y ^ 2 -5.808E-13
Y ^ 3 -3.335E-12 Y ^ 3 1.805E-06 Y ^ 3 2.226E-06
X ^ 4 -6.726E-07 X ^ 4 -6.009E-07 X ^ 4 -5.341E-07
X ^ 3 * Y -8.345E-15 X ^ 3 * Y -2.079E-14 X ^ 3 * Y -7.405E-14
X ^ 2 * Y ^ 2 -1.304E-06 X ^ 2 * Y ^ 2 -1.138E-06 X ^ 2 * Y ^ 2 -9.946E-07
X * Y ^ 3 -8.345E-15 X * Y ^ 3 -8.038E-15 X * Y ^ 3 -1.407E-13
Y ^ 4 -6.726E-07 Y ^ 4 -5.745E-07 Y ^ 4-4.902E-07
X ^ 5 2.396E-14 X ^ 5 -8.871 E-15 X ^ 5 9.931 E-15
X ^ 4 * Y -2.525E-14 X ^ 4 * Y -1.075E-08 X ^ 4 * Y -1.383E-08
X ^ 3 * Y ^ 2 1.865E-14 X ^ 3 * Y ^ 2 2.091E-14 X ^ 3 * Y ^ 2 6.681E-15
X ^ 2 * Y ^ 3 1.864E-14 X ^ 2 * Y ^ 3 -2.567E-08 X ^ 2 * Y ^ 3 -3.336 E-08
X * Y ^ 4 -2.525E-14 X * Y ^ 4 9.881E-15 X * Y ^ 4 1.032E-14
Y ^ 5 2.396E-14 Y ^ 5-1.470E-08 Y ^ 5 -1.897E-08
X ^ 6 1.096E-09 X ^ 6 1.187E-09 X ^ 6 1.273E-09
X ^ 5 * Y -1.189E-16 X ^ 5 * Y -5.150E-17 X ^ 5 * Y 1.106E-16
X ^ 4 * Y ^ 2 3.078E-09 X ^ 4 * Y ^ 2 3.278E-09 X ^ 4 * Y ^ 2 3.428E-09
X ^ 3 * Y ^ 3 6.327E-16 X ^ 3 * Y ^ 3 7.650E-16 X ^ 3 * Y ^ 3 9.142E-16
X ^ 2 * Y ^ 4 3.078E-09 X ^ 2 * Y ^ 4 3.191E-09 X ^ 2 * Y ^ 4 3.200E-09
X * Y ^ 5 -1.189E-16 X * Y ^ 5 -1.874E-16 X * Y ^ 5 4.538E-16
Y ^ 6 1.096E-09 Y ^ 6 1.096E-09 Y ^ 6 1.026E-09
X ^ 7 -4.421E-17 X ^ 7 1.320E-17 X ^ 7 -2.697E-17
X ^ 6 * Y 7.106E-17 X ^ 6 * Y 1.774E-11 X ^ 6 * Y 2.574E-11
X ^ 5 * Y ^ 2 -7.133E-17 X ^ 5 * Y ^ 2 -3.017E-17 X ^ 5 * Y ^ 2 -4.391E-17
X ^ 4 * Y ^ 3 -5.012E-17 X ^ 4 * Y ^ 3 6.878E-11 X ^ 4 * Y ^ 3 1.021E-10
X ^ 3 * Y ^ 4 -5.013E-17 X ^ 3 * Y ^ 4 -1.521E-16 X ^ 3 * Y ^ 4 -4.057E-17
X ^ 2 * Y ^ 5 -7.132E-17 X ^ 2 * Y ^ 5 8.236E-11 X ^ 2 * Y ^ 5 1.225E-10
X * Y ^ 6 7.106E-17 X * Y ^ 6 -1.294E-18 X * Y ^ 6 -3.560E-17
Y ^ 7 -4.420E-17 Y ^ 7 3.131E-11 Y ^ 7 4.678E-11

Image height 90% Image height 100%
Order coefficient order coefficient
X ^ 2 4.775E-06 X ^ 2 -1.570E-05
X * Y -1.511E-12 X * Y -4.291E-12
Y ^ 2 3.615E-05 Y ^ 2 1.870E-05
X ^ 3 -1.359E-11 X ^ 3 1.818E-12
X ^ 2 * Y 5.060E-07 X ^ 2 * Y -2.192E-07
X * Y ^ 2 2.740E-12 X * Y ^ 2-2.907E-12
Y ^ 3 2.001E-06 Y ^ 3 1.700E-06
X ^ 4 -4.368E-07 X ^ 4 -3.758E-07
X ^ 3 * Y 9.498E-14 X ^ 3 * Y 4.291E-14
X ^ 2 * Y ^ 2 -8.061E-07 X ^ 2 * Y ^ 2 -7.099E-07
X * Y ^ 3 -7.281E-14 X * Y ^ 3 1.221E-13
Y ^ 4 -3.997E-07 Y ^ 4 -3.656E-07
X ^ 5 1.279E-13 X ^ 5 -1.861E-14
X ^ 4 * Y -1.397E-08 X ^ 4 * Y -1.279E-08
X ^ 3 * Y ^ 2 9.781E-14 X ^ 3 * Y ^ 2 2.021E-14
X ^ 2 * Y ^ 3 -3.293E-08 X ^ 2 * Y ^ 3 -3.026E-08
X * Y ^ 4 -3.640E-14 X * Y ^ 4 4.976E-14
Y ^ 5 -1.786E-08 Y ^ 5 -1.724E-08
X ^ 6 1.352E-09 X ^ 6 1.378E-09
X ^ 5 * Y -4.737E-16 X ^ 5 * Y -6.330E-17
X ^ 4 * Y ^ 2 3.424E-09 X ^ 4 * Y ^ 2 3.371E-09
X ^ 3 * Y ^ 3 5.250E-16 X ^ 3 * Y ^ 3-6.829E-16
X ^ 2 * Y ^ 4 3.008E-09 X ^ 2 * Y ^ 4 2.863E-09
X * Y ^ 5 3.703E-16 X * Y ^ 5 -5.480E-16
Y ^ 6 8.830E-10 Y ^ 6 8.106E-10
X ^ 7-2.791E-16 X ^ 7 4.319E-17
X ^ 6 * Y 2.950E-11 X ^ 6 * Y 2.944E-11
X ^ 5 * Y ^ 2 -6.415E-16 X ^ 5 * Y ^ 2 -4.962E-18
X ^ 4 * Y ^ 3 1.108E-10 X ^ 4 * Y ^ 3 1.070E-10
X ^ 3 * Y ^ 4 -1.302E-16 X ^ 3 * Y ^ 4 -2.177E-16
X ^ 2 * Y ^ 5 1.370E-10 X ^ 2 * Y ^ 5 1.398E-10
X * Y ^ 6 9.686E-17 X * Y ^ 6 -2.212E-16
Y ^ 7 4.964E-11 Y ^ 7 5.330E-11

  The state of aberration correction in the present embodiment will be described in detail below with reference to FIG. First, FIG. 2 is a diagram for explaining how aberration correction is performed at a position where the image height is 0% (see FIG. 1 (B) or 1 (C)), and shows a lateral aberration view of the projection optical system. Specifically, FIG. 2A shows a lateral aberration view in the Y direction (vertical direction), and FIG. 2B shows a lateral aberration view in the X direction (horizontal direction). In particular, in FIGS. 2A and 2B, the aberration is minimized when the image light GL (a light beam indicated by a solid line in FIG. 1B) is emitted from a position at which the image height is 0%. It is an aberrational figure which shows the mode of the aberration for every image height position in the state which controlled (deformed) optical path variable member VP. FIG. 2C is a spot diagram showing how light is condensed at each image height position, and shows the spot shape at the defocus position and the image height position. The horizontal axis is the defocus position, and the vertical axis is the image height. In this case, as shown by the broken line frame FL1, the aberration is suppressed at the position of 0% of the image height. On the other hand, large aberrations occur at positions other than the image height of 0%. However, at this timing (that is, the timing at which the light path variable member VP is shaped to be optimized to a position of 0% image height), the image light GL is not emitted from a position other than 0% image height. There is no problem even if the condition occurs.

  Similarly, FIG. 3 is a view for explaining the state of aberration correction at a position with an image height of 50% (see FIG. 1 (B)). Specifically, in FIGS. 3A and 3B, aberration occurs when the image light GL (a light beam indicated by a broken line in FIG. 1B) is emitted from the position where the image height is 50%. FIG. 6 is an aberration diagram showing how aberrations at different image height positions are obtained in a state where the light path variable member VP is controlled (deformed) so as to be minimum. FIG. 3C is a spot diagram showing how light is condensed at each image height position. In this case, as indicated by the broken line frame FL2, the aberration is suppressed with respect to the position of 50% of the image height. On the other hand, large aberrations occur at positions other than 50% of the image height. However, at this timing (that is, the timing when the light path variable member VP is shaped to be optimized to the position of 50% of the image height), the video light GL is not emitted from the position other than 50% of the image height. There is no problem even if the condition occurs.

  FIG. 4 is a diagram for explaining the state of aberration correction at a position of 70% of the image height (see FIG. 1 (B) or 1 (D)). Specifically, in FIGS. 4A and 4B, the image light GL (a light beam indicated by a two-dot chain line in FIG. 1B) is emitted from the position of 70% of the image height, FIG. 7 is an aberration diagram showing how aberration is caused at image height positions in a state where the light path variable member VP is controlled (deformed) so as to minimize the aberration. FIG. 4C is a spot diagram showing how light is condensed at each image height position. In this case, as indicated by the broken line frame FL3, the aberration is suppressed at the position of 70% of the image height. On the other hand, large aberrations occur at positions other than 70% of the image height. However, at this timing (that is, the timing at which the light path variable member VP is shaped to be optimized to the position of 70% of the image height), the image light GL is not emitted from the position other than 70% of the image height. There is no problem even if the condition occurs.

  FIG. 5 is a diagram for explaining the state of aberration correction at the position of 90% of the image height (see FIG. 1B). Specifically, in FIGS. 5A and 5B, aberration occurs when the image light GL (a light beam indicated by a dotted line in FIG. 1B) is emitted from the position of 90% of the image height. FIG. 6 is an aberration diagram showing how aberrations at different image height positions are obtained in a state where the light path variable member VP is controlled (deformed) so as to be minimum. FIG. 5C is a spot diagram showing how light is condensed at each image height position. In this case, as shown by the broken line frame FL4, the aberration is suppressed at the position of 90% of the image height. On the other hand, large aberrations occur at positions other than 90% of the image height. However, at this timing (that is, the timing at which the light path variable member VP is shaped to be optimized to the position of 90% of the image height), the image light GL is not emitted from the position other than 90% of the image height. There is no problem even if the condition occurs.

  FIG. 6 is a diagram for explaining how aberration correction is performed at a position where the image height is 100% (see FIG. 1 (B) or 1 (E)). Specifically, in FIGS. 5A and 5B, aberration occurs when the image light GL (a light beam indicated by an alternate long and short dash line in FIG. 1B) is emitted from the position of 90% of the image height. It is an aberrational figure showing the situation of the aberration for every image height position in the state where the light path variable member VP was controlled (deformed) so as to minimize. FIG. 6C is a spot diagram showing how light is condensed at each image height position. In this case, as indicated by the broken line frame FL5, the aberration is suppressed at the position of 100% of the image height. On the other hand, large aberrations occur at positions other than 100% of the image height. However, at this timing (that is, the timing when the light path variable member VP is shaped to be optimized to the position of 100% of the image height), the video light GL is not emitted from the position other than 100% of the image height. There is no problem even if the condition occurs.

  FIG. 7 shows a state of aberration generation in the case where the aberration correction by the light path variable member VP is not performed in the laser projector 100 of the present embodiment as the projector of the comparative example. Specifically, FIGS. 7A and 7B are aberration diagrams showing the state of aberration at each image height position when image light is emitted from each image height position. FIG. 7C is a spot diagram showing how light is condensed at each image height position. Here, in the state where there is no correction by the light path variable member VP, for example, the aberration at each image height position is balanced so that a large difference does not occur. For this reason, it can be seen that the performance is not very high at all image heights.

  FIG. 8 compares the data of the comparative example of FIG. 7 with the data of the present example. 8 (A) -8 (C) are equal to FIGS. 7 (A) -7 (C), and FIGS. 8 (D) -8 (F) are the frames shown in FIGS. The parts FL1 to FL5 are joined together, and show the state of aberration as a whole in this modification. By comparing FIGS. 8A to 8C with FIGS. 8D to 8F, it can be seen that the aberration is significantly improved in this example.

  As shown in FIGS. 2 to 6 and the like, in the present embodiment, the light path variable member VP changes according to the image height position of the image light GL, and in particular, the aberration increases or decreases according to the image height position. It has changed according to the amount. That is, while the image height changes from 0% to 100%, the correction amount can be increased or decreased by changing the degree of shape change of the light path variable member VP, and the best aberration correction can be made at each image height. Since this correction amount is determined for each image height position, for example, at the time of optical design (simulation), the control unit 80 uses table data on the relationship between the shape change amount of the light path variable member VP and the image height position. Pre-input enables appropriate aberration correction. The generation of the table data as described above is not limited to the optical design time (simulation time), and may be performed after measuring the aberration of the manufactured projector.

  In the above, the light path variable member VP of this embodiment changes according to the image height position of the light from the scanning optical system 40, and particularly changes according to the amount of aberration that increases or decreases according to the image height position. . As a result, the correction amount can be adjusted according to each image height position, and the best aberration correction can be performed at all the image height positions. The light path variable member VP may be configured to adjust the change degree of the light path for each irradiation area unit on the screen SC by the scanning optical system 40. That is, by adjusting the change timing of the shape change of the light path variable member VP with respect to the scan timing of the scanning optical system 40 in the control unit 80, it is possible to determine the degree of change of the light path of the image light GL with respect to the irradiation area.

  As described above, in the projector according to the present embodiment, the light path variable member VP adjusts the light path of the light from the scanning optical system 40 in synchronization with the scanning of the scanning optical system 40 according to the scanning position. This makes it possible to adjust the degree of aberration correction. Therefore, highly accurate aberration correction becomes possible at all image height positions, and high-performance image formation becomes possible. In this case, the aberration can be suppressed without increasing the number of lenses simply by providing the light path variable member VP at the pupil position of the projection optical system 70. Therefore, the enlargement of the projection optical system 70 can be suppressed Can be implemented.

Second Embodiment
Hereinafter, the projector according to the second embodiment of the present invention will be described in detail with reference to FIG. 9 and the like. In the present embodiment, the structure other than the optical path variable member is the same as the case shown in FIG. FIG. 9 is a ray diagram showing a state of image projection by the projector of this embodiment, and is a diagram corresponding to FIG. 1 (B) of the first embodiment.

  In the laser projector 100 including the projection optical system 270 shown in FIG. 9, the optical path variable member VP disposed at the pupil position of the projection optical system 270 has a refractive index to light from the scanning optical system 40 (see FIG. 1A). The laser projector differs from the laser projector of the first embodiment in that it is configured of a refractive index distribution variable panel 30 that changes the distribution of the light source. Here, as described later, the refractive index distribution variable panel 30 is configured of a liquid crystal panel, and each image light GL is polarized in a specific polarization direction when entering the refractive index distribution variable panel 30. It is light (or polarized by disposing a polarizing plate in the front stage of the variable refractive index distribution panel 30 or the like).

  The refractive index distribution variable panel 30, which is the light path variable member VP, is a non-light emitting, light transmissive liquid crystal panel, and is configured of a transmissive liquid crystal matrix. The refractive index distribution variable panel 30 can change the refractive index with respect to light passing therethrough (polarized light) by changing the state of liquid crystal molecules in units of regions constituting the liquid crystal matrix. That is, the variable-refractive-index distribution panel 30 changes the refractive index in area units according to the passing area of the light emitted from the scanning optical system 40, thereby two-dimensionally changing the refractive index for the light from the scanning optical system 40. Distribution can be changed. The resolution of the region constituting the refractive index distribution variable panel 30 can be appropriately determined according to the required accuracy of the optical path change.

  Hereinafter, with reference to FIG. 10, a specific example of the refractive index distribution variable panel 30 will be described in more detail. FIG. 10 is a diagram for explaining a liquid crystal device constituting the refractive index distribution variable panel 30. As shown in FIG.

  As shown in FIG. 10A, the liquid crystal device 82a which is the main body of the refractive index distribution variable panel 30 has the first substrate 72a on the incident side and the second substrate 73a on the emission side with the liquid crystal layer 71a interposed therebetween. And vertically oriented.

  The substrates 72a and 73a constituting the liquid crystal device 82a are both flat, and are disposed such that the normal to the incident / exit surface is parallel to the optical axis AX, that is, the Z axis. For example, in the liquid crystal device 82a of vertical alignment type, in the case where the liquid crystal layer 71a is formed of liquid crystal having positive refractive index anisotropy and negative dielectric anisotropy, the alignment films 76a and 78a It has a role of arranging the liquid crystal compound constituting the liquid crystal layer 71a in a state substantially parallel to the optical axis AX, that is, the Z axis in the absence state (see FIG. 10B). Then, as shown in FIG. 10B, when an electric field is applied in the direction along the Z axis, the liquid crystal compound constituting the liquid crystal layer 71a is, for example, from a state substantially parallel to the optical axis AX, that is, the Z axis. It is tilted toward a predetermined orientation in the XY plane. As a result, an electric field non-perpendicular in which the refractive index in the specific polarization direction (the predetermined direction in the XY plane) is the smallest with respect to the incident light on the liquid crystal device 82a, that is, the incident light on The refractive index increases in accordance with the magnitude of the applied electric field from the state of application.

  As described above, in the projector according to this embodiment, the distribution of the refractive index of the variable refractive index distribution panel can be changed in units of regions according to the pixel position at which the image light is scanned. Therefore, aberration correction can be appropriately performed by inserting the refractive index distribution variable panel into the projection optical system as the optical path variable member.

Third Embodiment
Hereinafter, the projector according to the third embodiment of the present invention will be described in detail with reference to FIG. In the present embodiment, the structure other than the projection optical system including the optical path variable member is the same as the case shown in FIG. 1 of the first embodiment, so the illustration and description of the entire optical system will be omitted. FIG. 11 is a ray diagram showing an aspect of image projection by the projector of the present embodiment, which corresponds to FIG. 1 (B) etc. of the first embodiment.

  In the laser projector 100 including the projection optical system 370 shown in FIG. 11, the light path variable member VP disposed at the pupil position of the projection optical system 370 reflects the light from the scanning optical system 40 (see FIG. 1A) by reflection. It differs from the laser projector of the first embodiment etc. in that it is configured to include a deformable mirror DM that changes the optical path. In the example of FIG. 11, the deformable mirror DM, which is the main body of the light path variable member VP, has a surface shape, for example, by providing a piezoelectric element or the like on the back surface side of the mirror surface (reflection surface of the image light GL) MM. It is a deformable member. That is, the deformable mirror DM reflects the light on the mirror surface MM while changing its shape in synchronization with the scanning by the scanning optical system 40, so that the optical path of the image light GL passing through the projection optical system 370 corresponds to the image height position. Can be changed.

  In the laser projector 100 of the present embodiment, as shown in the figure, in the projection optical system 370, the deformable mirror DM constituting the light path variable member VP has the mirror surface MM inclined 45 ° with respect to the optical axis AX. The arrangement is such that the optical axis AX is bent 90 ° at the pupil position, but the other configurations (configurations of the lenses 71 to 76, etc.) are the same as in the projection optical system 70 of FIG. That is, when the optical path of the projection optical system 370 shown in FIG. 11 is developed, it has the same configuration as that of FIG. 1 (B). Therefore, the description of the lens configuration and the like will be omitted.

  Also in the present embodiment, by inserting the deformable mirror constituting the light path variable member into the projection optical system, it becomes possible to change the optical path of the light from the scanning optical system to appropriately perform the aberration correction.

(Example 2)
Hereinafter, an example of the projection optical system of the projector according to the present embodiment will be described. Data of optical surfaces constituting the projection optical system of Example 2 are shown in Table 2 below. FIG. 11 also shows the lens of the second embodiment. Further, in Table 2, "surface number" corresponds to a number assigned to each lens surface etc. in order from the object side. The objects and images in the table indicate the positions of the screen and the light diffusing element, respectively. Further, in Table 2, the item of “refractive mode” indicating the action on reflection and refraction of the optical system is added.
[Table 2]
RD nd d d Refraction mode radius Object Infinity Infinity Refraction
1 97.77025838 8.75 1.743972 44.8504 Refraction 25.20278693
2 191.6074514 0.5 Refraction 23.43514875
3 47.03271646 12.5 1.743972 44.8504 Refraction 26
4 8.89E + 01 3.8 1.754583 28.1687 Refraction 17.97363641
5 36. 9893 5721 35 Refraction 15.64622506
Aperture plane Infinity 0 reflection 11.22824288
7 Infinity -35 Refraction 6.816360526
8 38.35902691-3.8 1.755201 27.5795 Refraction 19.39209782
9 1.97E + 03 -11 1.737124 34.5325 Refraction 25.31879743
10 46.85174642 -0.5 Refraction 27.05142146
11 -4070.974899 -7 1.743972 44.8504 Refraction 26
12 140.173352 -113.2528129 Refraction 33.95761657
Image Infinity 0.278540735 Refraction 27.79556423

Fourth Embodiment
Hereinafter, a projector according to a fourth embodiment of the present invention will be described in detail with reference to FIG. 12 and the like. In the present embodiment, the case where an optical path variable member is provided in a relay optical system that relays an image will be described. Here, as described above, the projection optical system is an imaging optical system that re-forms an image formed in the projector on the screen, and can be regarded as the same type as a relay optical system. The following contents can be regarded as one aspect of the projection optical system. On the other hand, in the projector, from the viewpoint of correction of various aberrations, for example, an aspect in which relay is performed inside the device using an optical system such as a double Gaussian lens is also assumed. In this embodiment, the case where an optical path variable member is provided in a relay optical system that can be used in a projector is considered from various viewpoints.

  FIG. 12 is a ray diagram showing a relay optical system RM as an imaging optical system applied to the laser projector 100 of the present embodiment, and corresponds to FIG. 1 (B) etc. of the first embodiment.

  The relay optical system RM includes a double Gaussian lens DG, a pair of meniscus lenses MSa and MSb, and an optical path variable member VP. The relay optical system RM has a symmetrical shape on the upstream side and the downstream side of the optical path with reference to the double Gaussian lens DG. In addition, this relay optical system RM is a both-side telecentric optical system. That is, the lenses constituting the relay optical system RM which is an imaging optical system constitute a telecentric optical system.

  The double Gaussian lens DG comprises, in order from the object side (left side in the drawing), a first lens (convex lens) LL1, a first achromatic lens AL1, a second achromatic lens AL2 and a second lens (convex lens) LL2. It is configured to have. The first achromatic lens AL1 and the second achromatic lens AL2 are configured by combining two lenses. That is, the first achromatic lens AL1 is configured by bonding the lens AL1a and the lens AL1b, and the second achromatic lens AL2 is configured by bonding the lens AL2a and the lens AL2b. Therefore, the first achromatic lens AL1 and the second achromatic lens AL2 each have a total of three lens surfaces of the front and back surfaces and the bonding surface. By arranging the double Gaussian lens, it is possible to enhance the correction of the aberration in the relay optical system RM.

  Here, the light path variable member VP is disposed at a pupil position which is a central position in the relay optical system RM having a symmetrical shape along the light path. Here, the light path variable member VP can be applied to any of the light transmission type light path variable members shown in the above embodiments. That is, by the light path variable member VP installed at the pupil position of the relay optical system RM, it is possible to change the light path of the light passing through the light path variable member VP by transmission to appropriately perform the aberration correction.

  FIG. 13 is a view for explaining a modification of a relay optical system as an imaging optical system applied to the projector of the present embodiment. In the case of illustration, it differs from the case of FIG. 12 in that an optical path variable member of light reflection type is used in the relay optical system RM. Specifically, the relay optical system RM shown in FIG. 13 includes an achromatic lens AL1 in which two convex lenses MS1 and MS2, one convex lens LL1, and two lenses AL1a and AL1b are combined. Have. Further, the relay optical system RM includes a deformable mirror DM as a reflection type optical path variable member VP. Furthermore, between the relay optical system RM and the imaging plane IF, a polarization separation prism PP is provided, in which the polarization separation film PM is sandwiched so as to be inclined 45 ° with respect to the optical axis AX. A quarter-wave plate QR is provided on the surface of the PP facing the relay optical system RM. Hereinafter, the optical path of light passing through the relay optical system RM will be briefly described. First, the image light GL emitted from the imaging surface IF passes through the polarization splitting prism PP, passes through the relay optical system MR, and then relays By being reflected by the deformable mirror DM of the optical system MR, it is emitted again toward the polarization separation prism PP, and while passing through the quarter wave plate QR twice during this, the polarization separation film of the polarization separation prism PP is made this time It is reflected by PM and re-imaged. Here, when the optical path of the deformable mirror DM which is a reflection type mirror element is expanded, the relay optical system RM is the same as the relay optical system RM shown in FIG. 12 except for the number of meniscus lenses and the polarization splitting prism PP. It can be seen that the configuration is similar. Also in the case shown in FIG. 13, it is possible to change the optical path of the light from the scanning optical system and appropriately perform the aberration correction by inserting the deformable mirror constituting the light path variable member into the projection optical system.

  The present invention is not limited to the above embodiments or examples, and can be implemented in various modes without departing from the scope of the invention.

  First, in each of the above embodiments, the shape change of the optical path variable member and the change of the refractive index distribution have various modes, and can be made according to, for example, the nature of the generated aberration. More specifically, for example, when the lateral aberration diagram of the generated aberration is quadratic or linear, it is possible to generate a distribution of the shape and the refractive index difference as integrated. Aberration can be efficiently suppressed by changing to (ie, a high cubic function or quadratic function of the first order).

  The light path variable member to be changed in shape is, for example, a disc-like one as in the configuration of the light diffusion element 60 of FIG. 1A instead of the one as shown in FIG. It is also possible to arrange something that rotates in synchronization with the scanning, and to change the shape by making the shape of the disk different depending on the location.

  In addition, the configuration of the projector may not be telecentric in the imaging optical system.

  In addition, the arrangement position of the optical path changing member may be other than the pupil position as long as it is possible to change the optical path sufficiently for aberration correction, and for example, it may be a position distant to some extent from the pupil position.

  Further, the focus position may be adjusted in addition to the aberration correction by changing the optical path by the optical path variable member.

  In the above description, although the light path variable member is applied to the projector, aberration correction in the image pickup apparatus may be performed by applying the light path variable member to the imaging lens of the image pickup apparatus (camera).

  Further, for example, various types of liquid crystal panels can be applied to the liquid crystal panel applied to the refractive index distribution variable panel as the optical path variable member in the second embodiment, and for example, the optical axis direction according to the required refractive index difference. A plurality of liquid crystal panels may be stacked or the thickness may be appropriately set. It is also possible to apply a panel with a reaction rate which is sufficient.

  In the second embodiment, the vertical alignment type panel is described as an example of the refractive index distribution variable panel, but a liquid crystal panel of another type may be adopted.

  Further, although the LD is used as the illumination optical system in the above description, the present invention is not limited to this. For example, a self-luminous element such as an organic EL or an LED light source may be used.

  AL1, AL2: lens, AL1a, AL1b: lens, AX: optical axis, DG: double gauss lens, DM: deformable mirror, FL1-FL5: frame, GL: image light, IF: imaging plane, L1-L12: Surface, LL1: convex lens, MI: intermediate image, MM: mirror surface, MR: relay optical system, MS1, MS2: convex lens, MSa, MSb: meniscus lens, PA: projection area, PM: polarization separation film, PP: polarization separation Prism, QR ... wavelength plate, RM ... relay optical system, SC ... screen, VP ... light path variable member, XX ... central axis, 71-76 ... lens, 10 ... light source device, 20 ... collimate lens, 30 ... refractive index distribution variable Panel, 40: Scanning optical system, 50: Focusing optical system, 60: Light diffusing element, 61: Driving mechanism, 70: Projection optics , 71a ... liquid crystal layer, 72a, 73a ... substrate, 76a, 78a ... orientation film 80 ... control unit, 82a ... liquid crystal device, 100 ... laser projector 270 ... projection optical system, 370 ... projection optical system

Claims (8)

A light source for emitting light,
A scanning optical system for emitting light emitted from the light source as scanning light to be scanned on a surface to be illuminated;
A projection optical system for projecting light from the scanning optical system;
Wherein arranged in the optical path downstream of the scanning optical system, and an optical path varying member for varying the optical path of the light from the scanning optical system in synchronization with scanning by the scanning optical system,
Projector the optical path variable member, that will be placed at the pupil position of the projection optical system.   A light source for emitting light,
  A scanning optical system for emitting light emitted from the light source as scanning light to be scanned on a surface to be illuminated;
  A projection optical system for projecting light from the scanning optical system;
  An optical path variable member disposed downstream of the optical path of the scanning optical system and changing an optical path of light from the scanning optical system in synchronization with scanning by the scanning optical system;
  And relay optics for relaying the image;
  The projector according to claim 1, wherein the light path variable member is disposed at a pupil position of the relay optical system. The optical path variable member changes the distribution of the refractive index for the light from the scanning optical system by changing the refractive index in pixel units according to the passing area of the light emitted from the scanning optical system a panel, projector according to claim 1 or 2. The projector according to any one of claims 1 to 3, wherein the light path variable member changes the light path of the light from the scanning optical system by changing its shape. The projector according to claim 4 , wherein the light path variable member includes a deformable mirror that reflects light while changing its shape in synchronization with scanning by the scanning optical system. The light path variable member changes in accordance with the image height position of light from the scanning optical system.
The projector according to any one of to 5 . The projector according to claim 6 , wherein the light path variable member changes in accordance with an amount of aberration that increases or decreases in accordance with an image height position. The light path variable member adjusts the change degree of the light path for each predetermined irradiation area unit.
The projector according to any one of to 7 .

Images