JP2016014761A - Reflection type projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection type projection device that is entirely made small and compact and is reduced in weight by simplification of a basic structure, improves the storage property, installation property, handleability, and low cost performance, improves the wide angle performance while securing a sufficient image quality, and can flexibly handle various applications.SOLUTION: An optical processing system S includes a refracting optical system 3 disposed on the rear side in the optical axis direction (optical travel direction) Fs and a reflecting optical system 4 disposed on the front side in the optical axis direction Fs. The refracting optical system 3 and reflecting optical system 4 are formed of a coaxial system. The reflecting optical system 4 includes one or more refractive surface units La and Lb through which the light coming from the refracting optical system 3 passes, and one reflective surface unit Lr on which the light coming from the refractive surface units La and Lb is reflected. As the optical condition of the reflecting optical system 4, -0.5<Pr*|fr|<0.1 (where, Pr: Petzval sum of reflecting optical system, and fr: focal distance of reflecting optical system) is set.

Description

  The present invention relates to a reflective projection apparatus suitable for use in a projector or the like that projects light from a light source unit via a predetermined optical processing system.

  Conventionally, a projector that projects an image on a screen is known, but in this type of projector, in order to shorten the projection distance, it is usually possible to use a wide-angle lens and adjust the zoom function. . However, since the reduction in projection distance and the increase in screen size are contradictory, it is not easy to achieve a large screen size while securing a short projection distance. Even if you zoom in, there are limits to meeting these requirements. On the other hand, Patent Documents 1 and 2 also propose a reflection type optical system capable of obtaining a large screen size with a short projection distance.

  The reflection-type imaging optical system disclosed in Patent Document 1 is a wide-angle reflection-type imaging optical system that can be applied to a wide range by optimizing the shape, arrangement, and materials of the three reflecting mirrors. Is intended to provide a low-cost, high-performance, wide-angle reflective imaging optical system, and specifically has an image forming element or imaging element on its imaging surface. The first reflecting mirror having a rotationally symmetric surface shape with the concave surface facing the imaging surface from the imaging surface side, and the second having a rotationally symmetric aspherical shape with the convex surface facing the light beam from the l-th reflecting mirror. And a third reflecting mirror having a rotationally symmetric aspherical shape with a convex surface facing the light beam from the second reflecting mirror.

  The reflective imaging optical system disclosed in Patent Document 2 is intended to provide a reflective imaging optical system that can achieve both bright FNO and a short optical path length. Specifically, In order from the imaging surface side, a first reflecting mirror having a rotationally symmetric surface shape with a concave surface facing the imaging surface, and a second having a rotationally symmetric aspherical shape with a convex surface facing the light beam from the lth reflecting mirror. Reflective imaging optical system having an imaging system composed of three reflecting mirrors, a third reflecting mirror having a rotationally symmetric aspherical shape with a convex surface facing the light beam from the second reflecting mirror. When the power of the entire system of the reflective imaging optical system is φ, the powers of the first, second, and third reflecting mirrors are φ1, φ2, φ3, and the Petzval sum is P, the conditional expression 0. 01 <(φ1 / φ) <0.1 (1), conditional expression φ3 / φ <φ2 / φ <0 (2), 0.1 <| P / φ | <0.5... (3) is satisfied.

JP-A-10-111458 JP 2003-344772 A

  However, the above-described conventional reflection type projection apparatus (reflection type imaging optical system) has the following problems.

  First, since the basic structure is a structure in which three or more reflecting mirrors are combined, it is difficult to realize a compact and lightweight design with respect to the optical system and the entire projection apparatus. Accordingly, it is difficult to increase the size, specifically, it is inferior in storability, installation and handling, and requires a large cabinet, which is disadvantageous in terms of cost.

  Secondly, since it is basically constituted by a combination of reflecting mirrors, there is a limit to improving the wide-angle performance while ensuring image quality. Therefore, in a case where a projector using a conventional reflective imaging optical system is placed on a table in a room and projected onto a screen installed on a wall surface, a large screen with a projection distance of 1 [m] or less It is not easy to meet the demand of projecting to size, and even if it is realized, it is difficult to ensure good image quality (optical characteristics).

  An object of the present invention is to provide a reflective projection apparatus that solves the problems in the background art.

  In order to solve the above-described problems, the reflective projection apparatus 1 according to the present invention is configured to construct an optical projection system that projects the light Co from the light source unit 2 through a predetermined optical processing system S. S is provided with a refractive optical system 3 disposed on the rear side of the optical axis direction (light traveling direction) Fs and a reflective optical system 4 disposed on the front side of the optical axis direction Fs, and the refractive optical system 3 and the reflective optical system 4 are provided. While being constituted by a coaxial system, the reflection optical system 4 reflects one or more refractive surface portions La and Lb through which the light Co emitted from the refractive optical system 3 is transmitted and the light Co emitted from the refractive surface portions La and Lb. One reflecting surface portion Lr is provided, and the optical condition of the reflecting optical system 4 is −0.5 <Pr · | fr | <0.1 (where Pr is the Petzval sum of the reflecting optical system, fr is the reflecting optical system (Focal distance).

  In this case, according to a preferred aspect of the invention, the optical condition of the entire optical processing system S is −0.1 <P · f <0.2 (where P: Petzval sum of the entire system, F: total system (Focal length) is desirable. Further, the optical axis Km of the optical processing system S can be offset with respect to the optical axis Kc of the light source unit 2. On the other hand, the refracting surface portions La and Lb can be constituted by a refracting lens 5 having a negative power, and the reflecting optical system 4 can be provided with at least one aspheric surface portion 5c. Furthermore, a convex mirror 6p, a plane mirror 6h, or a concave mirror 6i can be used for the reflective surface portion Lr. The reflective surface portion Lr is configured by an integrated back surface mirror 6r or a separate independent mirror 6m with respect to the refractive surface portion Lib. can do.

  According to the reflection type projection device 1 according to the present invention having such a configuration, the following remarkable effects can be obtained.

  (1) The optical processing system S is provided with the refractive optical system 3 disposed on the rear side of the optical axis direction (light traveling direction) Fs and the reflective optical system 4 disposed on the front side of the optical axis direction Fs. And the reflection optical system 4 are constituted by a coaxial system, and the reflection optical system 4 is emitted from one or more refractive surface portions La and Lb through which the light Co emitted from the refractive optical system 3 is transmitted and from the refractive surface portions La and Lb. Since the reflection light system L is provided with one reflection surface portion Lr and the optical condition of the reflection optical system 4 is set to −0.5 <Pr · | fr | <0.1, the basic structure is simplified. Can be achieved. As a result, it is possible to reduce the overall size and weight of the reflective projection apparatus 1 and to further improve storage, installation, handling, and cost.

  (2) Since the present invention is not limited to the conventional combination of reflecting mirrors, wide-angle performance can be further enhanced while ensuring good image quality. Therefore, for example, even when the reflective projection apparatus 1 (projector) is placed on a table in a room and projected onto a screen installed on a wall surface, the required large screen size while setting the projection distance within 1 [m]. It is possible to flexibly respond to various uses, such as being able to ensure the above.

  (3) According to a preferred embodiment, if the optical condition of the entire optical processing system S is set to −0.1 <P · f <0.2, in addition to the optimization of the Petzval sum in the reflective optical system 4, Since the Petzval sum in the entire optical processing system S can be optimized, the basic operational effects when the reflective projection apparatus 1 according to the present invention is configured can be further enhanced.

  (4) According to a preferred embodiment, if the optical axis Km of the optical processing system S is offset with respect to the optical axis Kc of the light source unit 2, the function similar to the lens shift function can be exhibited, so that the screen position In particular, the screen position in the vertical direction can be shifted to an optimal position.

  (5) If the refracting surface portions La and Lb are constituted by the refracting lens 5 having negative power, it can be implemented by a single and general-purpose concave lens, which can contribute to ease of implementation and reduce the number of components. And it can contribute to the cost reduction based on this.

  (6) If the reflecting optical system 4 is provided with at least one aspherical portion 5c, in particular, the refractive lens 5 can be optimized, which can contribute to the improvement of the optical performance of the entire optical processing system S.

  (7) In constructing the reflective surface portion Lr, the convex mirror 6p, the plane mirror 6h, or the concave mirror 6i can be selected and used. Therefore, the design when constructing the optical processing system S by combining with the refractive surface portions La and Lb. The degree of freedom can be increased, and the optimum design according to the purpose and grade can be easily and flexibly performed.

  (8) The reflective surface portion Lr can be implemented by selecting various forms, such as an integrated back surface mirror 6r or a separated independent mirror 6m with respect to the refractive surface portion Lb. Can increase diversity.

The block diagram of the whole optical system of the reflective projection apparatus which concerns on suitable embodiment of this invention, Action explanatory diagram of the optical system of the reflection type projection device, The block diagram of the whole optical system which concerns on the change embodiment of the reflection type projector of this invention, Use explanatory drawing of the reflection type projection device concerning the present invention, Schematic configuration diagram clearly showing a reflective optical system according to another modified embodiment of the reflective projection device of the present invention, Schematic configuration diagram clearly showing a reflective optical system according to another modified embodiment of the reflective projection device of the present invention, Schematic configuration diagram clearly showing a reflective optical system according to another modified embodiment of the reflective projection device of the present invention,

  Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.

  First, an example of a projector 1p to which the reflective projection apparatus 1 according to this embodiment is applied will be described with reference to FIG.

  In FIG. 4, 21 indicates a room, 22 indicates a wall surface in the room, and 23 indicates a table placed in the room. The wall surface 22 is viewed from a person sitting on a chair (not shown) placed around the table 23. The screen 31 having a relatively large screen size is installed at a height (position) where the projector 1p can be mounted, and the projector 1p (the reflective projection device 1) is disposed on the upper surface of the table 23 on the end on the screen 31 side. ) Indicates the state of being placed.

  In the case of the example, the projector 1 p includes a cabinet 7, and light Co (video) emitted from a projection port 7 e provided in the cabinet 7 is projected (projected) on the screen 31. In this case, it is possible to secure a projection distance within 1 [m] and a screen size of 60 inches or more. Further, as shown in FIG. 4, the projection position (projection height) is positioned above the projector 1p itself. In addition, while satisfying such a demand, the original necessary projector performance such as image quality is secured. The reflective projection apparatus 1 according to the present embodiment is intended to meet such a demand for the projector 1p.

  Next, the configuration of the main part of the reflective projection apparatus 1 (projector 1p) according to this embodiment will be described with reference to FIGS.

  As shown in FIG. 1, the main configuration (optical system configuration) of the reflective projection apparatus 1 includes a light source unit 2, a refractive optical system 3, and a reflective optical system 4. The refractive optical system 3 and the reflective optical system 4 constitute an optical processing system S in the reflective projection apparatus 1. The optical processing system S includes a refractive optical system 3 disposed on the rear side of the optical axis direction (light traveling direction) Fs and a reflective optical system 4 disposed on the front side of the optical axis direction Fs.

  Furthermore, the refractive optical system 3 and the reflective optical system 4 in the optical processing system S are configured by a coaxial system having a common optical axis Km, and the optical axis Kc of the light source unit 2 is the optical axis Km of the optical processing system S. Is offset by Do width. As described above, if the optical axis Km of the optical processing system S is offset with respect to the optical axis Kc of the light source unit 2, the same function as the lens shift function can be exhibited. There is an advantage that the screen position in the direction can be shifted (set) to the optimum position. Thereby, as shown in FIG. 4, the projection position (projection height) can be positioned above the projector 1p itself.

  The light source unit 2 has a function of emitting light Co (see FIG. 2) forward in the optical axis direction Fs (light traveling direction) as a basic function. In the illustrated example, since the projector 1p is assumed, the illustration of the light emitting source (lamp) is omitted, and one transmissive liquid crystal panel 11 disposed in the output portion that emits the light Co is representatively shown. Therefore, light Co from a light emitting source (lamp) (not shown) is transmitted through the liquid crystal panel 11 and emitted forward.

  The refractive optical system 3 is constituted by a wide-angle lens system 3w. The illustrated wide-angle lens system 3w is a super-wide-angle lens unit, and from the front side to the rear side in the optical axis direction Fs (light traveling direction), a negative meniscus lens L1, a convex lens L2f, a compound lens L2 of a concave lens L2r, a convex lens L3f, A compound lens L3 of a concave lens L3r, a positive meniscus lens L4, and a negative meniscus lens L5 are sequentially arranged. In this way, if the refractive optical system 3 is constituted by the wide-angle lens system 3w, it can be handled by a wide-angle lens design, so that an optical processing system S effective for the reflective projection apparatus 1 according to the present invention can be easily and reliably constructed. .

  The reflecting optical system 4 has, as a basic configuration, one or more refracting surface portions La and Lb through which the light Co emitted from the refracting optical system 3 is transmitted and one reflecting surface portion through which the light Co emitted from the refracting surface portions La and Lb is reflected. The reflective optical system main part 4m which has Lr is provided. If necessary, the reflecting optical system 4 can be provided with various optical elements such as a lens, a filter, and a mirror in addition to the reflecting optical system main portion 4m.

Further, the refracting surface portions La and Lb are constituted by a refracting lens 5 in which one surface, that is, the front surface in the light traveling direction Fs is the refracting surface portion La and the other surface (rear surface) is the refracting surface portion Lb. . The illustrated refracting lens 5 is an aspherical lens having one surface formed on the aspherical surface portion 5c, and a single lens having negative power is used. As for the aspherical portion 5c, when the length of the optical axis is x, the height from the optical axis is y, the radius of curvature is R, and the aspherical coefficient is C, the general formula is x = R− { Since R ² − (1 + C) · y ² } ^0.5 holds, the shape of the aspherical surface portion 5c can be obtained based on this.

  As described above, if the refracting lens 5 having the refracting surface portions La and Lb is added to the wide-angle lens system 3w in the refracting optical system 3, the wide-angle can be increased in addition to the wide-angle lens system 3w. It becomes. Further, when configuring the refracting surface portions La and Lb, if the refracting surface portions La and Lb are configured by the refracting lens 5 having a negative power, it can be implemented by a single and general-purpose concave lens. There is an advantage that it is possible to contribute to the reduction of the score and the cost reduction based thereon. Further, since the refractive lens 5 is provided with the aspherical surface portion 5c, the refractive lens 5 can be optimized in particular, and there is an advantage that the optical performance of the entire optical processing system S can be improved.

  On the other hand, a plane mirror 6h is used for the reflection surface portion Lr, and the plane mirror 6h (reflection surface portion Lr) is configured as an independent mirror 6m separated from the refraction surface portions Lb and La (refractive lens 5). As a result, the light Co that has passed through (refracted) the refractive surface portions La and Lb in the refractive lens 5 in order is reflected on the reflective surface portion Lr and retransmitted (rerefracted) from the opposite direction with respect to the refractive surface portions Lb and La. Projected outside.

In this case, the optical condition of the reflective optical system 4 is
−0.5 <(Pr · | fr |) <0.1 (100)
Set to. Note that Pr is the Petzval sum of the reflective optical system 4, and fr is the focal length of the reflective optical system 4.

The optical conditions of the entire optical processing system S including the refractive optical system 3 and the reflective optical system 4 are as follows:
−0.1 <(P · f) <0.2 (101)
Set to. P is the Petzval sum of the entire system, and F is the focal length of the entire system.

  The conditional expressions (100) and (101) indicate the Petzval sum, that is, the degree of curvature of the image plane, and the inverse of the Petzval sum (numerical value) is the radius of curvature of the image plane. Therefore, when the Petzval sum is 0 (zero), the radius of curvature is infinite, and the image plane is imaged on a flat plane. On the other hand, when this numerical value is large, the curvature of the image surface becomes intense, and even if the image is formed at the center, the focus is shifted at the periphery. If the Petzval sum is positive, the peripheral portion bends to the lens side, and if it is negative, the peripheral portion bends to the opposite side. Therefore, in the entire optical processing system S, if the Petzval sum P is suppressed to a numerical value of about 0.1, when the focal length f is 22 [mm], 0.1 / 22 = 0.0045, that is, When the curvature of field with a radius of 222 [mm] occurs and the outermost part of the liquid crystal panel 11 (the part farthest from the optical axis Km) is 20 [mm], the focus deviation is 0.9 [mm]. Thus, if it exceeds 0.9 mm, an acceptable field curvature cannot be obtained.

  As described above, when conditional expressions (100) and (101) are set as optical conditions, the projection distance is within 1 [m], preferably around 80 [cm], and the screen size is 60 inches or more. In addition, it is possible to easily ensure the original projector performance such as image quality. In particular, by setting the conditional expression (100), it is possible to optimize the reflective optical system 4 that is a main part of the reflective projection apparatus 1 according to the present embodiment. In addition to optimizing the Petzval sum in the reflective optical system 4, the present invention can optimize the Petzval sum in the entire optical processing system S if the conditional expression (101) is set, as well as the operational effects can be secured. The basic operational effects when the reflective projection apparatus 1 is configured can be further enhanced. FIG. 2 shows the traveling direction of the light Co (light beam) in the reflective projection apparatus 1 shown in FIG. 1 by arrows.

  Next, with reference to Table 1, the validity as the invention of the reflective projection apparatus 1 shown in FIG. 1 will be verified. Table 1 shows optical data of the reflective projection apparatus 1 shown in FIG. In particular, the optical data surrounded by the dotted line in Table 1 is the optical data in the reflection optical system 4.

  As described above, it is assumed that the projector 1p (reflective projection apparatus 1) shown in FIG. 4 secures a projection distance of 1 [m] or less and a screen size of 60 inches or more. . In addition, in order to ensure the originally necessary projector performance such as image quality, it is ideal that the value of Petzval sum Pet (s) is made as close to zero as possible.

  In the case of the refracting lens 5 constituting the refracting surface portions La and Lb, the Petzval sum Pet (s) can be obtained by an arithmetic expression of Formula 1.

  Note that n is the refractive index, ra is the radius of curvature of the refractive surface portion La, and rb is the radius of curvature of the refractive surface portion Lb.

  In addition, with respect to the focal length f of the refraction lens 5, the formula 2 is established.

  Therefore, the arithmetic expression of Expression 1 can be rewritten to the arithmetic expression of Expression 3 by using the arithmetic expression of Expression 2.

  On the other hand, from the optical data in Table 1, n is “1.51680”, ra is “838.0349”, rb is “−78.77631”, and the aspherical coefficient of the refracting surface portion Lb is “−5”. Accordingly, the focal length f of the entire optical processing system S is 22.66 [mm], and the Petzval sum Pet (s) is 0.0018. The value of Petzval sum Pet (s) is ideally as close to zero as possible, but a value less than 0.01 is sufficiently acceptable in practice.

  Next, a reflective optical system 4 according to a modified embodiment of the reflective projection apparatus 1 of the present invention will be described with reference to FIG.

  The reflection optical system 4 shown in FIG. 1 uses a plane mirror 6h for the reflection surface portion Lr, and the plane mirror 6h is an independent mirror 6m spaced from the refraction surface portions Lb and La (refractive lens 5). Although configured, the reflecting optical system 4 shown in FIG. 3 is configured such that the reflecting surface portion Lr is configured by the convex mirror 6p and the back surface mirror 6r is integrated with the refracting surface portions Lb and La (refractive lens 5). It is.

  Therefore, the basic configuration relating to the refractive surface portions La and Lb is the same as that of the embodiment shown in FIG. That is, the refractive lens 5 has one surface serving as a refracting surface portion La and the other surface serving as a refracting surface portion Lb, and a single lens is provided with an aspheric surface portion 5c. The point which has power is the same as embodiment shown in FIG.

  As described above, the reflecting surface portion Lr can be implemented by selecting various forms such as an integrated back surface mirror 6r or a separated independent mirror 6m with respect to the refracting surface portion Lb. Diversity of forms can be increased. Further, as the reflecting surface portion Lr, the convex mirror 6p shown in FIG. 3 may be used, the flat mirror 6h shown in FIG. 1 may be used, and a concave mirror 6i may be used as shown in FIG. Is possible. Thus, in constructing the reflective surface portion Lr, the convex mirror 6p, the plane mirror 6h, or the concave mirror 6i can be selected and used. Therefore, when the optical processing system S is constructed by combining with the refractive surface portions La and Lb, The degree of design freedom can be increased, and the optimum design according to the purpose and grade can be easily and flexibly performed.

  Next, with reference to Table 2, the validity as the invention of the reflective projection apparatus 1 shown in FIG. 3 will be verified. Table 2 shows optical data of the reflective projection apparatus 1 shown in FIG. In particular, the optical data surrounded by the dotted line in Table 2 is the optical data in the reflection optical system 4. The wide-angle lens system 3w in FIG. 3 is the same as the wide-angle lens system 3w shown in FIG. Therefore, in Table 2, the surface numbers “7” to “19” and “light source part” are the same as the numerical values of the surface numbers “7” to “19” and “light source part” in Table 1 described above. The corresponding part of the optical data in Table 2 is omitted.

  Further, the Petzval sum Pet (s) and the focal length f can be obtained in the same manner as in the embodiment of FIG. That is, from the optical data in Table 2, n is “1.51680”, rb is “−700”, ra is “72”, and the aspherical coefficient of the refracting surface portion La is “−5”. Accordingly, the focal length f is 22.42 [mm], and the Petzval sum Pet (s) is 0.0001. In particular, the Petzval sum Pet (s) has a better value than the embodiment shown in FIG.

  Next, another modified embodiment of the reflective projection apparatus 1 according to the present invention will be described with reference to FIGS.

  5 and 6 each show a modification based on the embodiment of FIG. FIG. 5 shows an example in which the radius of curvature is changed with respect to the embodiment of FIG. The refracting lens 5 having the relationship of | rb | <| ra | is used as the radius of curvature in the embodiment of FIG. 1, but in the modified embodiment of FIG. 5, the refraction having the relationship of | rb |> | ra | The lens 5 for use was used. The modified embodiment of FIG. 5 is the same as the embodiment of FIG. 1 except for this point. As an example, if n is “1.51680”, ra is “91.7”, rb is “−200”, and the aspherical coefficient of the refractive surface portion La is “−10”, the focal length f is 22 .55 [mm] is obtained, and Petzval sum Pet (s) is obtained as 0.0032.

  In FIG. 6, a negative meniscus lens is used, and the reflecting surface portion Lr is configured as a convex mirror 6p. Therefore, the value on the ra side is a negative sign. The modified embodiment of FIG. 6 is the same as the embodiment of FIG. 1 except for this point. As an example, n is “1.51680”, ra is “−252”, rb is “−85”, the aspherical coefficient of the refractive surface portion Lb is “−5”, and the radius of curvature of the convex mirror 6p is “−300”. Then, the focal length f is 22.87 [mm], and the Petzval sum Pet (s) is 0.0090.

  On the other hand, FIG. 7 shows a modification example based on the modified embodiment shown in FIG. The modified embodiment shown in FIG. 7 is the same in that the reflective surface portion Lr in the reflective optical system 4 is configured as an integrated rear surface mirror 6r with respect to the refractive surface portions Lb and La (refractive lens 5). The difference is that the back mirror 6r is configured as a concave mirror 6i. In this case, the value of ra is a plus sign. Except for this point, the modified embodiment of FIG. 7 is the same as the modified embodiment of FIG. As an example, if n is “1.51680”, ra is “42”, rb is “500”, and the aspherical coefficient of the refracting surface portion La is “−3”, the focal length f is 22.46 [ mm] and Petzval sum Pet (s) can be obtained as 0.0112.

  Thus, the reflective projection apparatus 1 according to the present invention has a basic configuration, that is, the optical processing system S, the refractive optical system 3 disposed on the rear side of the optical axis direction (light traveling direction) Fs, and the optical axis. The reflective optical system 4 disposed in front of the direction Fs is provided, and the refractive optical system 3 and the reflective optical system 4 are configured by a coaxial system, and light Co emitted from the refractive optical system 3 is transmitted through the reflective optical system 4. If one or more refracting surface portions La and Lb and one reflecting surface portion Lr that reflects the light Co emitted from the refracting surface portions La and Lb are provided, the optical condition of the reflecting optical system 4 is relatively easy. The optical condition of 0.5 <Pr · | fr | <0.1 can be satisfied.

  Therefore, according to the reflection type projection apparatus 1 according to the present embodiment, the optical processing system S has the refractive optical system 3 disposed on the rear side of the optical axis direction (light traveling direction) Fs and the optical axis direction Fs. A reflective optical system 4 disposed on the front side is provided, and the refractive optical system 3 and the reflective optical system 4 are configured by a coaxial system, and the light Co emitted from the refractive optical system 3 is transmitted through the reflective optical system 4. The above-described refracting surface portions La and Lb and one reflecting surface portion Lr for reflecting the light Co emitted from the refracting surface portions La and Lb are provided, and the optical condition of the reflecting optical system 4 is −0.5 <Pr · | fr | Since it is set to <0.1, the basic structure can be simplified. As a result, it is possible to reduce the overall size and weight of the reflective projection apparatus 1 and to further improve storage, installation, handling, and cost. Further, since the present invention is not limited to a combination of reflecting mirrors as in the prior art, wide-angle performance can be further improved while ensuring good image quality. Therefore, for example, even when the reflective projection apparatus 1 (projector) is placed on a table in a room and projected onto a screen installed on a wall surface, the required large screen size while setting the projection distance within 1 [m]. It is possible to flexibly respond to various uses, such as being able to ensure the above.

  Although the preferred embodiment has been described in detail above, the present invention is not limited to such an embodiment, and the detailed configuration, shape, material, quantity, technique, and the like do not depart from the gist of the present invention. It can be changed, added, or deleted arbitrarily.

For example, it is desirable to set −0.1 <P · f <0.2 as the optical condition of the entire optical processing system S (refractive optical system 3 and reflective optical system 4), but it is not necessarily an essential constituent requirement. It is not positioned. In addition, the optical axis Kc of the light source unit 2 is substantially the optical axis Kc of the light source unit 2. For example, when the light source unit 2 is composed of a combination of a plurality of light source elements and only a part thereof is used, The light source element used constitutes the substantial light source unit 2. On the other hand, the lens configuration of the illustrated wide-angle lens system 3w is an example, and various other lens configurations can be applied. On the other hand, the refracting lens 5 constituting the refracting surface portions La and Lb is shown as a single lens, but it may be composed of a compound lens in which a plurality of lenses are combined. In addition, although the case where the aspherical lens which has the aspherical part 5c was used for the refractive lens 5 was shown, it does not necessarily need to be an aspherical lens. Even when the aspherical portion 5c is provided, the refractive lens 5 does not necessarily need to be an aspherical lens. That is, it is sufficient if the reflection optical system 4 is provided with at least one aspherical surface portion 5c, and it may be combined with other lenses having the aspherical surface portion 5c.

  The reflection type projection device according to the present invention can be used for various projectors, including various projectors, for the purpose of projecting light from a light source unit at a wide angle.

  DESCRIPTION OF SYMBOLS 1: Reflection type projector, 2: Light source part, 3: Refraction optical system, 4: Reflection optical system, 5: Refractive lens, 5c: Aspherical part, 6p: Convex mirror, 6h: Plane mirror, 6i: Concave mirror, 6r: Back mirror, 6m: Independent mirror, Co: Light, Fs: Optical axis direction (light traveling direction), La: Refraction surface portion, Lb: Refraction surface portion, Lr: Reflection surface portion, Km: Optical axis of optical axis processing system, Kc: Optical axis of light source

Claims (7)

A reflective projection apparatus that projects light from a light source unit through a predetermined optical processing system, the optical processing system including a refractive optical system and an optical axis arranged on the rear side of the optical axis direction (light traveling direction) A reflective optical system disposed on the front side of the direction, and the refractive optical system and the reflective optical system are configured by a coaxial system, and the light emitted from the refractive optical system is transmitted through the reflective optical system. The above refractive surface portion and one reflective surface portion that reflects light emitted from the refractive surface portion are provided, and as the optical conditions of the reflective optical system,
−0.5 <Pr · | fr | <0.1
(Where Pr: Petzval sum of the reflective optical system, fr: focal length of the reflective optical system)
A reflection type projection device, characterized in that it is set to As the optical conditions of the entire optical processing system,
−0.1 <P · f <0.2
(However, P: Petzval sum of the entire system, F: Focal length of the entire system)
The reflection type projector according to claim 1, wherein   The reflective projection apparatus according to claim 1, wherein an optical axis of the optical processing system is offset with respect to an optical axis of the light source unit.   4. The reflective projection apparatus according to claim 1, wherein the refractive surface portion is constituted by a refractive lens having a negative power.   The reflective projection apparatus according to claim 1, wherein the reflective optical system has at least one aspherical portion.   The reflection type projection device according to claim 1, wherein the reflection surface portion is a convex mirror, a plane mirror, or a concave mirror.   The reflection type projection device according to claim 1, wherein the reflection surface portion is constituted by an integrated rear surface mirror or a separate independent mirror with respect to the refracting surface portion.

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