Optical element and projection device using the same

Abstract

An optical element and a projection apparatus using the same are provided. In an optical element disposed between a light source and an optical deflector that reflects incident light and deflects the incident light in two dimensions, the reduction of a projection angle and optical aberration caused by the optical element are solved. An optical element that is disposed between a light source and a light deflector that reflects incident light and deflects the incident light in two dimensions, the optical element including: a first region on which light from the light source is incident and emitted toward the light deflector; and a second region different from the first region, the light reflected and two-dimensionally deflected by the light deflector being incident on the second region and being emitted to the outside. Optical surfaces having different optical effects are provided on at least one of an incidence side and an emission side of the first region and an incidence side and an emission side of the second region.

Description

[0001] This application is based on and claims the benefit of priority of Japanese patent application No. 2023-119401 filed on July 21, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to an optical element and a projection device using the optical element. Background Art

[0003] There is known a projection device including a light source, a light deflector for two-dimensionally deflecting incident light, and an optical element (prism) disposed between the light source and the light deflector (for example, refer to Japanese Patent No. 6457185).

[0004] However, Japanese Patent No. 6457185 considers measures to counter stray light using optical elements, but does not fully consider the reduction in projection angle of view and optical aberrations caused by the optical elements. Summary of the invention

[0005] The present invention is completed in order to solve such a problem, and its purpose is to provide an optical element which can well suppress various aberrations, easily obtain a high-quality projection image, and suppress the reduction of the viewing angle caused by the optical element, and a projection device using the optical element.

[0006] According to the present invention, the optical element is arranged between a light source and a light deflector, which reflects incident light and deflects it two-dimensionally, wherein the optical element includes: a first area, light from the light source is incident on the first area and emitted toward the light deflector; and a second area different from the first area, light reflected and two-dimensionally deflected by the light deflector is incident on the second area and emitted toward the outside, and optical surfaces with different optical effects are provided on at least one of the incident side and the emission side of the first area and the incident side and the emission side of the second area.

[0007] In the above optical element, the optical surface may be an optical surface having refractive power.

[0008] Furthermore, in the above optical element, an optical surface having a refractive power may be provided at least on the emission side of the second region.

[0009] Furthermore, in the above optical element, an optical surface having a refractive power may be provided at least on the incident side of the first region.

[0010] Furthermore, in the above optical element, at least the optical effects of the incident side of the first region and the optical effects of the emission side of the second region are different from each other.

[0011] Furthermore, the optical element may be formed using at least two or more materials.

[0012] The projection device of the present invention comprises: a light source; a light deflector for reflecting incident light and deflecting it two-dimensionally; and the above-mentioned optical element.

[0013] According to the present invention, it is possible to provide an optical element capable of satisfactorily suppressing various aberrations, easily obtaining a high-quality projection image, and suppressing a reduction in the viewing angle caused by the optical element, and a projection device using the optical element.

[0014] The above and other objects, features and advantages of the present invention will be more fully understood from the detailed description given below and the accompanying drawings, which are given by way of example only and thus should not be construed as limiting the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 2 is a schematic structural diagram of the projection device 10 .

[0016] Figure 2 It is a perspective view of the projection device 10 .

[0017] Figure 3 yes Figure 2 AA section view.

[0018] Figure 4 This is Modification 1 of the optical element 50 .

[0019] Figure 5A This is a second modification of the optical element 50 .

[0020] Figure 5B This is a third modification of the optical element 50 .

[0021] Fig. 6A This is Modification 4 of the optical element 50 .

[0022] Figure 6B This is Modification 5 of the optical element 50 .

[0023] Figure 7 This is a sixth modification of the optical element 50 .

[0024] Figure 8 This is Modification 7 of the optical element 50 .

[0025] Fig. 9 This is Modification 8 of the optical element 50 . DETAILED DESCRIPTION

[0026] Hereinafter, a projection device 10 to which an optical element 50 according to an embodiment of the present invention is applied will be described with reference to the drawings. In each of the drawings, the same reference numerals are given to corresponding components, and duplicate descriptions are omitted.

[0027] Figure 1 is a schematic structural diagram of the projection device 10, Figure 2 is a perspective view of the projection device 10, Figure 3 yes Figure 2 AA section view.

[0028] The projection device 10 is a laser scanning projector (or a micro projector) that forms (projects) an image on a screen S using a two-dimensionally deflected (two-dimensionally scanned) laser beam.

[0029] like Figure 1 , Figure 2 As shown, the projection device 10 includes a light source 20, a reflecting surface 30 ( Figure 1 ), light deflector 40, optical element 50, control device 60. The light source 20, the reflecting surface 30, the light deflector 40, the optical element 50, and the control device 60 are arranged in a housing 70. The housing 70 is a rectangular parallelepiped housing, and a light outlet 71 is formed on one side (side) thereof, from which the laser beam Ray2 reflected by the light deflector 40 and deflected in two dimensions is emitted.

[0030] The light source 20 is a light source module that emits a laser beam Ray1 (light beam) obtained by synthesizing (combining) three primary color (RGB) laser beams. The laser beam Ray1 emitted by the light source 20 is reflected by the reflection surface 30, passes through the optical element 50, and enters the light deflector 40 (mirror 41).

[0031] The reflecting surface 30 is disposed on the optical path of the laser beam Ray1 emitted from the light source 20 , but is not an essential structure and may be omitted when not necessary.

[0032] like Figure 3 As shown, the light deflector 40 is disposed on the side of the optical element 50 opposite to the light emission port 71. At this time, the light deflector 40 is disposed so that the laser beams Ray1 and Ray2 transmitted through the optical element 50 do not overlap.

[0033] The distance L1 between the light deflector 40 and the optical element 50 is preferably as short as possible, and the light deflector 40 is preferably arranged with a gap near the optical element 50. In this way, the optical element 50 can be miniaturized, and the projection device 10 can be miniaturized.

[0034] The optical element 50 is made of a transparent resin such as acrylic or polycarbonate or glass. The optical element 50 is formed by, for example, bonding a trapezoidal prism and a lens portion with refractive power, which are marked as 51a and 51b in the figure. The trapezoidal prism includes a first surface 51 and a second surface 52 that are not parallel to each other, and a transparent body 53 between the first surface 51 and the second surface 52. The optical path of the light guided to the light deflector 40 and guided from the light deflector 40 to the projection surface can be realized by one optical element 50, so that the projection device 10 can be miniaturized. In addition, the optical element 50 is not limited to a trapezoidal prism and a lens portion with refractive power, and the two can also be integrally formed.

[0035] Hereinafter, the portion of the optical element 50 into which the laser beam (the laser beam Ray1 reflected by the reflecting surface 30) from the light source 20 is incident and emitted from the light deflector 40 is referred to as the first region 50a, and the portion different from the first region 50a is referred to as the second region 50b into which the laser beam Ray2 reflected by the light deflector 40 and two-dimensionally deflected is incident and emitted to the outside. The first region 50a is composed of Figure 3 The optical element portion of the range surrounded by the dotted line shown by the reference numeral 50a in the figure. Similarly, the second region 50b is composed of Figure 3 The optical element portion is enclosed by a dashed line indicated by reference numeral 50b.

[0036] The first surface 51 includes a first optical surface 51 a and a second optical surface 51 b disposed therebelow. However, the arrangement of the first optical surface 51 a and the second optical surface 51 b varies depending on the position and emission direction of the light source 20 , and therefore does not necessarily have to be in the up-and-down direction.

[0037] The first optical surface 51a is an optical surface having refractive power on the incident side of the optical element in the first region 50a. Figure 3 The first optical surface 51a is a surface having a positive refractive power. The first optical surface 51a is provided in the area of ​​the first surface 51 where the laser beam Ray1 reflected by the reflecting surface 30 is incident. The first optical surface 51a is provided, for example, to allow the laser beam Ray1 reflected by the reflecting surface 30 and transmitted through the optical element 50 (first area 50a) to be incident on the light deflector 40 (mirror 41) with a desired light spot and optical performance. By incidenting the optimal light on the light deflector 40 (mirror 41), the projected image can be improved.

[0038] On the other hand, the second optical surface 51b is an optical surface having refractive power on the optical element emission side of the second region 50b. Figure 3The second optical surface 51b is a surface with negative refractive power. The second optical surface 51b is arranged below the first optical surface 51a in the first surface 51, that is, the area where the laser beam Ray2 reflected and two-dimensionally deflected by the light deflector 40 and transmitted through the optical element 50 (the second area 50b) is emitted. The second optical surface 51b has the effect of expanding the emitted light and enlarging the projected image. In addition, by using an aspherical surface, etc., distortion, trapezoidal correction, etc. can also be performed.

[0039] As described above, according to the present embodiment, by making the first area 50a of the optical element 50 through which the laser beam from the light source 20 is transmitted and the second area 50b of the optical element 50 through which the laser beam reflected by the light deflector 40 and two-dimensionally deflected is transmitted have different optical functions, various aberrations can be well suppressed, a high-quality projection image can be easily obtained, and the reduction of the viewing angle caused by the optical element 50 can be suppressed. In addition, a good projection image and a wide viewing angle can be ensured.

[0040] Next, modified examples will be described.

[0041] In the above embodiment, an example of using one material to constitute the optical element 50 is described, but the present invention is not limited thereto. For example, in order to reduce chromatic aberration, two or more materials may be used to constitute the optical element 50. For example, different materials may be used for the prism parts 53, 51a, and 51b, respectively, and the optical element 50 may be constituted by combining them via bonding surfaces.

[0042] Figure 4 This is Modification 1 of the optical element 50 .

[0043] like Figure 4 As shown, both the first optical surface 51 a and the second optical surface 51 b may be optical surfaces having positive refractive power, and by configuring appropriate refractive powers for each, various aberrations can be corrected, light from the light source 20 can be shaped, and the like.

[0044] Figure 5A is a second modification of the optical element 50, Figure 5B This is a third modification of the optical element 50 .

[0045] like Figure 5A As shown, the second optical surface 51b of the second region 50b may also be omitted. Figure 5B As shown, the first optical surface 51 a on the incident side of the first region 50 a may also be a surface having a negative refractive power.

[0046] Fig. 6A is a modification example 4 of the optical element 50, Figure 6B This is Modification 5 of the optical element 50 .

[0047] like Fig. 6AAs shown, a third optical surface 52a having a refractive power may be provided on the light deflector side of the first region 50a. In addition, a fourth optical surface 52b having a refractive power may be provided on the light deflector side of the second region 50b. As described above, the optical surface having a refractive power may be provided on at least one of the incident side and the emission side of the first region 50a and the incident side and the emission side of the second region 50b.

[0048] like Figure 6B As shown, the third optical surface 52a of the first area 50a and the fourth optical surface 52b of the second area 50b do not necessarily need to have an area boundary. If possible, they can also be as shown in FIG. Figure 6B The optical surface 52a has a continuous surface like the optical surface 52b.

[0049] In the above-mentioned embodiment and each of the above-mentioned variations, the example of using a convex lens surface (or a concave lens surface) as the first optical surface 51a to the fourth optical surface 52b is described, but it is not limited to this. That is, the first optical surface 51a to the fourth optical surface 52b can be any optical surface as long as it has different optical effects. For example, the first optical surface 51a to the fourth optical surface 52b can also be a lens surface with positive refractive power, a lens surface with negative refractive power, or a diffusion surface. In addition, the first optical surface 51a to the fourth optical surface 52b can also be a free-form surface, a curved surface, a microlens, or a Fresnel lens. In addition, the first optical surface 51a to the fourth optical surface 52b can be a spherical lens or an aspherical lens. In addition, different optical effects refer to optical effects different from simple refraction. For example, different optical effects refer to optical effects different from the first surface 51 as a base surface on which the first optical surface 51a and the second optical surface 51b are provided, for the first optical surface 51a and the second optical surface 51b. Similarly, third optical surface 52a and fourth optical surface 52b refer to optical functions different from second surface 52 as a base surface on which third optical surface 52a and fourth optical surface 52b are provided.

[0050] Figure 7 This is a sixth modification of the optical element 50 . Figure 8 This is Modification 7 of the optical element 50 . Fig. 9 This is Modification 8 of the optical element 50 .

[0051] like Figure 7 As shown, the emission side optical surface 51b of the second region 50b may be a shape extending in one direction (see Figure 7 The shape can also be rotationally symmetrical about the optical axis (see Figure 7 This deformation can be appropriately selected according to the manufacturing difficulty of the optical element, and is also effective for miniaturization.

[0052] In this case, the second optical surface 51b of the second region 50b on the emission side and extending in one direction may be arranged in parallel with the optical element 50 (see Figure 7 The optical element 50 may also be arranged in a tilted state relative to the optical element 50 (see Figure 8 ).

[0053] In addition, if Fig. 9 As shown, the second optical surface 51b of the emission side of the second region 50b and extending in one direction may be one (refer to Figure 7 middle and upper section, Figure 8 ), or multiple (see Fig. 9 ).

[0054] In addition, if Figure 8 , Fig. 9 The deformation shown is not limited to the emission side of the second area 50b, and can also be applied to any area of ​​the incident side, the emission side, and the incident side of the first area 50a, the second area 50b. Through this deformation, it is easy to guide the light regardless of the incident direction and the emission direction of the light. In addition, in the above embodiment, an example of using a light source module that emits a laser beam Ray1 obtained by synthesizing (combining) laser beams of three primary colors (RGB) as the light source 20 is described, but it is not limited to this. For example, a light source module that emits a monochromatic laser beam can also be used as the light source 20.

[0055] In addition, in the above-mentioned embodiment, an example of applying the optical element of the present invention and the projection device using the optical element to a laser scanning projector (or micro projector) is described, but it is not limited thereto. For example, the optical element of the present invention and the projection device using the optical element may also be applied to smart glasses, ultra-small projectors, interactive projectors, and laser radars.

[0056] The numerical values ​​shown in the above-mentioned embodiments are all examples, and it is of course possible to use appropriate numerical values ​​different from them.

[0057] The above-mentioned embodiments are merely illustrative in all aspects. The present invention cannot be interpreted restrictively by the description of the above-mentioned embodiments. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

Claims

1. An optical element disposed between a light source and a light deflector, the light deflector reflecting incident light to deflect it two-dimensionally, wherein: The optical element includes: a first region into which light from the light source is incident and emitted toward the light deflector; and a second region different from the first region into which light reflected by the light deflector and two-dimensionally deflected is incident and emitted toward the outside, An optical surface having a different optical function is provided on at least one of the incident side and the emission side of the first region and the incident side and the emission side of the second region.

2. The optical element according to claim 1, wherein The optical surface is an optical surface having refractive power.

3. The optical element according to claim 1, wherein An optical surface having refractive power is provided at least on the emission side of the second region.

4. The optical element according to claim 1, wherein An optical surface having refractive power is provided at least on the incident side of the first region.

5. The optical element according to claim 1, wherein At least the optical effects of the incident side of the first region and the exit side of the second region are different from each other.

6. The optical element according to claim 1, wherein: The optical element is formed of at least two or more materials. 7 . A projection device comprising: a light source; a light deflector for reflecting incident light to deflect it two-dimensionally; and the optical element according to claim 1 .

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