JP2012118124A - Image projection device - Google Patents

Abstract

An image projection apparatus capable of stabilizing operations such as focus adjustment and zoom adjustment is provided.
The image projection apparatus irradiates an image forming element that forms an image in accordance with a modulation signal with illumination light from a light source, and the image formed on the image forming element An image projection apparatus that projects an enlarged projection onto a projection surface by a projection optical system that includes a projection lens having a movable part that can move in a direction, and that houses at least a part of the projection optical system, from the projection optical system And a manual adjustment means for adjusting the position of the movable portion in the optical axis direction, and the projection lens is mounted when the casing is placed. The manual adjustment means includes an adjustment unit that is at least partially exposed from an upper surface or a side surface of the housing, and the adjustment unit includes: The movable part is movable within a plane parallel to the projection surface. Adjusting the position of the optical axis direction.
[Selection] Figure 5

Description

  The present invention relates to an image projection apparatus having a projection optical system.

  In recent years, image projection apparatuses such as so-called close-up projectors, in which the projection distance to the screen is shortened, have been actively developed. The close-up projector is roughly classified into an ultra-short focus projector in which the focal length of the projection lens is simply shortened and an ultra-close-up projector in which the distance between the projector and the screen is further shortened by combining the lens and the reflection mirror.

  An ultra-close projector is one in which the beam emitted from the projection lens is folded back to the projector side using a curved reflecting surface, and the projector can be placed very close to the screen surface or wall, which obstructs human traffic. The projector can be used for a wide range of applications, such as being difficult to see the shadows of people, or being close to the wall, so that it can be easily suspended from the ceiling or attached to the wall.

FIG. 1 is a diagram illustrating an example of a conventional image projection apparatus. Referring to FIG. 1, an image projection apparatus 10 is a so-called very close-up projector, which is roughly a box-shaped housing 20, an image forming element 30, a projection optical system 40 having a projection lens 41 and a curved mirror 43. It has. In the image projection apparatus 10, the light emitted from the image forming element 30 is incident on the curved mirror 43 via the projection lens 41, and the optical path is folded back to the image forming element 30 side by the curved mirror 43.
The light enters the screen 90 that is the projection surface. Thus, since the optical path is folded back toward the image forming element 30, the image projection apparatus 10 cannot be brought closer to the screen 90 than the length of the image forming element 30 and the projection optical system 40. 1, the major axis direction of the screen 90 is X, the normal direction is Y, and the minor axis direction is Z (the same applies to the following drawings).

  FIG. 2 is a diagram illustrating another example of a conventional image projection apparatus. Referring to FIG. 2, in the image projection apparatus 10 </ b> A, the point that the projection optical system 40 is replaced with the projection optical system 40 </ b> A in which the reflection mirror 42 is disposed in the optical path between the projection lens 41 and the curved mirror 43. Different from 10. 10 A of image projection apparatuses can arrange | position the projection lens 41 vertically (Z direction) so that an optical axis may become a vertical direction by arrange | positioning the reflective mirror 42. FIG. That is, the projection lens 41 can be arranged in a direction substantially parallel to the screen 90. As a result, the image projection apparatus 10A can be disposed closer to the screen 90 than the image projection apparatus 10 (see FIG. 1). Further, since the image projection apparatus 10A itself can be shaped to follow the screen 90, the projection of the image projection apparatus 10A from the screen 90 can be extremely reduced.

  By the way, as one problem of an image projection apparatus having a shape along the screen 90, such as the image projection apparatus 10A, there is a problem of focus adjustment (focus adjustment) and zoom adjustment (magnification adjustment). A general image projection apparatus includes an adjustment unit including an adjustment ring for focus adjustment and an adjustment ring for zoom adjustment provided concentrically on a part of a projection lens.

  FIG. 3 is a diagram (part 1) for explaining the adjusting means of the image projection apparatus of FIG. For the sake of convenience, in the image projection apparatus 10A, the surface seen from the front when the screen 90 is viewed from the Y direction is the front surface, the surface opposite to the front surface and the surface facing the screen 90 is the back surface, and the side connecting the front surface and the back surface is oriented. The face that faces up is referred to as the upper face.

  In FIG. 3, in the image projection apparatus 10 </ b> A, a part of the adjustment ring 44 that is concentrically provided in a part of the projection lens 41 and is used for zoom adjustment is exposed from the front surface of the housing 20.

  In FIG. 3, focus adjustment and zoom adjustment can be performed by turning the adjustment ring 44 by hand. However, since the adjustment ring 44 is lightly pressed on the front surface of the image projection apparatus 10A and turned, and the image projection apparatus 10A may move in the direction of the screen 90, the focus adjustment operation cannot be stabilized. An ultra-close projector such as the image projection apparatus 10A is thin in the depth direction (Y direction) and has a small frictional resistance to stop the movement, so that the image projection apparatus 10A itself is very likely to move in the direction of the screen 90. .

  FIG. 4 is a diagram (part 2) for explaining the adjusting means of the image projection apparatus of FIG. In FIG. 4, in order to avoid the above problem, a knob 47 that is linked to the adjustment ring 44 via a gear or the like is disposed on the side surface of the image projection apparatus 10A. Also in this case, since the direction in which the knob 47 is rotated is a direction perpendicular to the screen 90, there is a possibility that the image projection apparatus 10A itself may be moved if the rotation is not smooth, and the focus adjustment and zoom adjustment operations are stabilized. I can't let you. Note that a very close projector such as the image projection apparatus 10A projects on the screen obliquely from the very close distance, and therefore has a very short focal length. Therefore, whether the focus adjustment or the zoom adjustment is good is extremely important.

  The present invention has been made in view of the above, and an object of the present invention is to provide an image projection apparatus capable of stabilizing operations such as focus adjustment and zoom adjustment.

  The image projection apparatus irradiates an image forming element that forms an image in accordance with a modulation signal with illumination light from a light source, and the image formed on the image forming element can be moved in a fixed portion and an optical axis direction. An image projection apparatus that projects an enlarged projection onto a projection surface by a projection optical system including a projection lens having a movable part, and houses at least a part of the projection optical system from the projection optical system to the projection surface. And a manual adjustment unit that adjusts the position of the movable portion in the optical axis direction. The projection lens is mounted when the casing is mounted. The manual adjustment means includes an adjustment unit that is at least partially exposed from an upper surface or a side surface of the housing, and the adjustment unit is disposed on the projection surface. Movable in a parallel plane, the optical axis direction of the movable part It is a requirement to adjust the position.

  According to the disclosed technology, it is possible to provide an image projection apparatus capable of stabilizing operations such as focus adjustment and zoom adjustment.

It is a figure which shows an example of the conventional image projector. It is a figure which shows the other example of the conventional image projector. FIG. 3 is a diagram (part 1) illustrating an adjusting unit of the image projection apparatus in FIG. FIG. 3 is a diagram (part 2) for explaining an adjusting unit of the image projection apparatus of FIG. 1 is a perspective view illustrating an image projection apparatus according to a first embodiment. It is a schematic diagram which illustrates the image projection apparatus which concerns on 1st Embodiment. It is a figure which shows an example of the structure of the projection lens of FIG. 5, and a knob vicinity. FIG. 6 is a diagram (No. 1) illustrating another example of the structure in the vicinity of the projection lens and the knob in FIG. 5; FIG. 6 is a second diagram illustrating another example of the structure in the vicinity of the projection lens and the knob illustrated in FIG. 5; FIG. 6 is a third diagram illustrating another example of the structure in the vicinity of the projection lens and the knob illustrated in FIG. 5; It is a perspective view which illustrates the image projector concerning a 2nd embodiment. It is a figure which shows the example of the structure of the projection lens of FIG. 8, and a knob vicinity. It is a perspective view which illustrates the image projector concerning a 3rd embodiment. It is a figure which shows the example of the structure of the projection lens of FIG.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

<First Embodiment>
First, the outline of the image projection apparatus according to the first embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 is a perspective view illustrating the image projection apparatus according to the first embodiment. FIG. 6 is a schematic view illustrating the image projection apparatus according to the first embodiment. Referring to FIGS. 5 and 6, the image projection apparatus 10B is a so-called very close-up projector, and generally includes a box-shaped casing 20, an image forming element 30, and a projection optical system 40A. The housing 20 accommodates at least a part of the projection optical system 40A and transmits the projection light directed from the projection optical system 40A toward the screen 90 which is a projection surface.

  More specifically, the image projection apparatus 10 </ b> B includes an image forming element 30, a projection optical system 40 </ b> A, an illumination optical system 60, and a separating unit 70 in the housing 20. The image projection apparatus 10B may include an illumination power source (not shown), a modulation unit for the image forming element 30, an image processing unit, and the like. Note that the configuration, arrangement, and the like of the projection optical system 40A are as described in FIG.

  The illumination optical system 60 includes a light source 61. For example, the illumination optical system 60 is reflected by the reflector 62 (may be integrated with the light source 61), the relay lenses 63 and 64, and the reflector 62 disposed in the vicinity of the light source 61 and has directivity. The illuminance uniformizing means 65 or the like called an integrator optical system for uniformizing the illuminance of the luminous flux is obtained so that a uniform illumination distribution can be obtained on the surface of the image forming element 30. As the light source 61, a halogen lamp, a xenon lamp, a metal halide lamp, an ultrahigh pressure mercury lamp, an LED, or the like is used.

  Further, the color light may be projected by using the color wheel 66 to color the illumination light and controlling the image of the image forming element 30 in synchronization therewith. When a reflection type liquid crystal image forming element is used as the image forming element 30, more efficient illumination is possible by using the separating means 70 that separates the illumination optical path and the projection optical path. When a micromirror device type (DMD) is used as the image forming element 30, optical path separation using a total reflection prism or the like is employed. As described above, an appropriate optical system may be employed according to the type of the image forming element 30.

  In addition, by using a plurality of image forming elements 30 such as red, green, and blue, irradiating illumination light that has passed through the color filters, and making the light synthesized by the color synthesizing unit enter the projection optical system 40A. A color image can be projected on the screen 90.

  In the image projection apparatus 10B, the image forming element 30 forms an image according to the modulation signal. Illumination light from the light source 61 is applied to the image forming element 30, and an image formed on the image forming element 30 is enlarged and projected onto the screen 90 by the projection optical system 40A.

  In FIG. 5, the reflection mirror 42 and the curved mirror 43 protrude out of the housing 20, but the reflection mirror 42 and the curved mirror 43 are configured to be movable, and when the image projection apparatus 10B is used, FIG. The structure is housed in the housing 20 when not in use.

  Next, focus adjustment of the image projection apparatus according to the first embodiment will be described with reference to FIGS. 5 and 7A. FIG. 7A is a diagram showing an example of the structure in the vicinity of the projection lens and the knob in FIG. With reference to FIGS. 5 and 7A, a knob 47 is disposed on the side surface of the housing 20, and at least a part of the knob 47 is exposed from the side surface of the housing 20. The knob 47 is a typical example of the adjustment unit according to the present invention.

  The projection lens 41 has a movable part 41a and a fixed part 41b. An adjustment ring 44 is fixed to a part of the side surface of the movable portion 41a. The movable portion 41a is configured to be movable with respect to the fixed portion 41b. When the adjustment ring 44 rotates, the movable portion 41a moves in the direction of the optical axis A of the projection lens 41 with respect to the fixed portion 41b. The adjustment ring 44 is connected to a knob 47 via a spur gear 45 and a worm gear 46. In the present application, the projection lens 41 is installed such that the optical axis A is substantially perpendicular to the placement surface when the housing 20 is placed on a placement surface such as the upper surface of the table. Yes.

  The adjustment ring 44 is a substantially annular member, and a tooth row is formed on a side surface thereof. The adjustment ring 44 having a tooth row formed on the side surface meshes with a spur gear 45. The worm gear 46 includes a screw gear 46a (worm) meshing with each other and a helical gear 46b (worm wheel), and the spur gear 45 meshes with the helical gear 46b. The knob 47 is concentrically fixed to the screw gear 46a, and is configured to be rotatable integrally with the screw gear 46a. In the present embodiment, the knob 47 is provided on the side surface of the housing 20 and is configured to be rotatable within a plane parallel to the screen 90.

  The adjustment ring 44, the spur gear 45, and the helical gear 46b are configured so as to be rotatable about a rotation axis that is substantially parallel to the optical axis A of the projection lens 41 through the respective center portions. The screw gear 46a is configured to be rotatable about a rotation axis that passes through a substantially central portion of the screw gear 46a and is substantially orthogonal to the screen 90. That is, in the worm gear 46, the rotation axis of the screw gear 46a and the rotation axis of the helical gear 46b are orthogonal to each other.

  Thus, the adjustment ring 44 having a tooth row on the side surface, the spur gear 45, the helical gear 46b, and the screw gear 46a constitute a gear row, and the adjustment ring 44 and the knob 47 are connected. ing. For example, when the knob 47 is manually rotated in a plane parallel to the screen 90, the screw gear 46 a fixed concentrically with the knob 47 rotates integrally with the knob 47. When the screw gear 46a rotates, the helical gear 46b rotates in conjunction with it. At this time, since the rotation shaft of the screw gear 46 a and the rotation shaft of the helical gear 46 b are orthogonal to each other, the rotation direction is orthogonally converted, and the helical gear 46 b rotates in a plane perpendicular to the screen 90.

  When the helical gear 46b is rotated, the spur gear 45 and the adjustment ring 44 are sequentially rotated in conjunction with the rotation. Since the adjustment ring 44 is fixed to a part of the side surface of the movable portion 41a, when the adjustment ring 44 rotates, the movable portion 41a rotates relative to the fixed portion 41b. Thereby, since the movable part 41a moves in the direction of the optical axis A with respect to the fixed part 41b, the position of the movable part 41a in the optical axis direction is adjusted, and the focus of the projection lens 41 can be adjusted. The adjustment ring 44 is a typical example of the rotating unit according to the present invention. The adjustment ring 44, the spur gear 45, the helical gear 46b, the screw gear 46a, and the knob 47 are typical examples of manual adjustment means according to the present invention. Moreover, the screw gear 46a and the helical gear 46b are a typical example of a pair of gears having orthogonal rotation axes according to the present invention.

  Thus, in the first embodiment, the gear train that connects the adjustment ring that rotates integrally with the movable portion of the projection lens and the focus adjustment knob is a worm gear that orthogonally converts the rotation axis of the gear. Including. Accordingly, the focus of the projection lens can be adjusted by providing the knob on the side surface of the housing and rotating the knob in a plane parallel to the screen. As a result, since there is no possibility that the image projection apparatus moves in the direction of the screen along with the focus adjustment, the focus adjustment work can be stabilized. The focus adjustment has been described above, but the same effect can be obtained when zoom adjustment is performed with the same configuration.

<Variation 1 of the first embodiment>
In the first modification of the first embodiment, an example is shown in which a rotation axis of a gear is orthogonally transformed using a bevel gear in a gear train that connects an adjustment ring and a knob. In the first modification of the first embodiment, the description of the same components as those of the already described embodiment is omitted.

  FIG. 7B is a diagram (part 1) illustrating another example of the structure in the vicinity of the projection lens and the knob in FIG. 7B is different from FIG. 7A in that the worm gear 46 is replaced with a gear 48 and a bevel gear 49.

  In FIG. 7B, the adjustment ring 44 is connected to the knob 47 via a spur gear 45, a gear 48, and a bevel gear 49. The gear 48 has a structure in which a bevel gear and a spur gear are integrated, and the spur gear side of the gear 48 meshes with the spur gear 45. Also, the bevel gear side (conical surface) of the gear 48 meshes with the conical surface of the bevel gear 49 to constitute a bevel gear pair. The knob 47 is concentrically fixed to the bevel gear 49 and is configured to be rotatable integrally with the bevel gear 49. As in the first embodiment, the knob 47 is provided on the side surface of the housing 20 and is configured to be rotatable within a plane parallel to the screen 90.

  The adjustment ring 44, the spur gear 45, and the gear 48 are configured so as to be able to rotate around a rotation axis that is substantially parallel to the optical axis A of the projection lens 41 through the respective substantially central portions. The bevel gear 49 is configured to be rotatable about a rotation axis that passes through a substantially central portion of the bevel gear 49 and is substantially orthogonal to the screen 90. That is, the rotation axis of the gear 48 and the rotation axis of the bevel gear 49 are orthogonal to each other.

  As described above, the adjustment ring 44, the spur gear 45, the gear 48, and the bevel gear 49, each having a tooth row formed on the side surface, constitutes a gear row and connects the adjustment ring 44 and the knob 47. For example, when the knob 47 is manually rotated in a plane parallel to the screen 90, the bevel gear 49 fixed concentrically with the knob 47 rotates integrally with the knob 47. When the bevel gear 49 rotates, the gear 48 rotates in conjunction with it. At this time, since the rotation shaft of the bevel gear 49 and the rotation shaft of the gear 48 are orthogonal to each other, the rotation direction is orthogonally converted, and the gear 48 rotates in a plane perpendicular to the screen 90.

  When the gear 48 is rotated, the spur gear 45 and the adjustment ring 44 are sequentially rotated in conjunction with the rotation of the gear 48. Since the adjustment ring 44 is fixed to a part of the side surface of the movable portion 41a, when the adjustment ring 44 rotates, the movable portion 41a rotates relative to the fixed portion 41b. Thereby, since the movable part 41a moves in the direction of the optical axis A with respect to the fixed part 41b, the position of the movable part 41a in the optical axis direction is adjusted, and the focus of the projection lens 41 can be adjusted. The adjustment ring 44, the spur gear 45, the gear 48, the bevel gear 49, and the knob 47 are typical examples of manual adjustment means according to the present invention. Further, the gear 48 and the bevel gear 49 are typical examples of a pair of gears whose rotating shafts are orthogonal to each other according to the present invention.

  As described above, in the first modification of the first embodiment, the gear train that connects the adjustment ring that rotates integrally with the movable portion of the projection lens and the focus adjustment knob transforms the rotation axis of the gear orthogonally. Includes bevel gear pairs. Thereby, there exists an effect similar to 1st Embodiment.

<Modification 2 of the first embodiment>
Modification 2 of the first embodiment shows an example in which a bevel gear having a rotation axis orthogonal to both the rotation axis of the adjustment ring and the rotation axis of the knob is used. In the second modification of the first embodiment, the description of the same components as those of the already described embodiment is omitted.

  FIG. 7C is a diagram (part 2) illustrating another example of the structure in the vicinity of the projection lens and the knob in FIG. 7C is different from FIG. 7A in that the adjustment ring 44 is replaced with an adjustment ring 51 and the worm gear 46 is replaced with bevel gears 49 and 52.

  In FIG. 7C, an adjustment ring 51 is fixed to a part of the side surface of the movable portion 41a. The movable part 41a is configured to be movable with respect to the fixed part 41b. When the adjustment ring 51 rotates, the movable part 41a moves in the direction of the optical axis A of the projection lens 41 with respect to the fixed part 41b. The adjustment ring 51 is a substantially annular member whose side surface is a conical surface, and a tooth row is formed on the conical surface. That is, the adjustment ring 51 functions as a bevel gear. The bevel gear 52 is a substantially cylindrical member having both ends of a substantially truncated cone shape, and tooth rows are formed on the conical surfaces of both ends. The adjustment ring 51 is connected to the knob 47 via a bevel gear 52 and a bevel gear 49.

  The conical surface of the adjustment ring 51 meshes with the conical surface at one end of the bevel gear 52 to form a bevel gear pair. The conical surface at the other end of the gear 52 meshes with the conical surface of the bevel gear 49 to form a bevel gear pair. The knob 47 is concentrically fixed to the bevel gear 49 and is configured to be rotatable integrally with the bevel gear 49. As in the first embodiment, the knob 47 is provided on the side surface of the housing 20 and is configured to be rotatable within a plane parallel to the screen 90.

  The adjustment ring 51 is configured to be rotatable about a rotation axis that passes through a substantially central portion of the adjustment ring 51 and is substantially parallel to the optical axis A of the projection lens 41. The bevel gear 49 is configured to be rotatable about a rotation axis that passes through a substantially central portion of the bevel gear 49 and is substantially orthogonal to the screen 90. The bevel gear 52 is configured to be rotatable around a rotation axis that is orthogonal to both the rotation axis of the adjustment ring 51 and the rotation axis of the bevel gear 49 (= the rotation axis of the knob 47).

  The adjustment ring 51 is a typical example of the rotating unit and the first gear according to the present invention. The adjustment ring 51, the bevel gear 52, the bevel gear 49, and the knob 47 are typical examples of manual adjustment means according to the present invention. The bevel gear 49 is a typical example of the second gear according to the present invention. The bevel gear 52 is a typical example of the third gear according to the present invention.

  As described above, the adjustment ring 51 functioning as a bevel gear, the bevel gear 52, and the bevel gear 49 constitute a gear train, and the adjustment ring 51 and the knob 47 are connected to each other. For example, when the knob 47 is manually rotated in a plane parallel to the screen 90, the bevel gear 49 fixed concentrically with the knob 47 rotates integrally with the knob 47. When the bevel gear 49 is rotated, the bevel gear 52 is rotated in conjunction with the rotation of the bevel gear 49, and the adjustment ring 51 is further rotated. At this time, the rotating shaft of the bevel gear 52 is orthogonal to both the rotating shaft of the adjusting ring 51 and the rotating shaft of the bevel gear 49 (= the rotating shaft of the knob 47). 51 rotates in a plane perpendicular to the screen 90.

  Since the adjustment ring 51 is fixed to a part of the side surface of the movable portion 41a, when the adjustment ring 51 rotates, the movable portion 41a rotates with respect to the fixed portion 41b. Thereby, since the movable part 41a moves in the direction of the optical axis A with respect to the fixed part 41b, the position of the movable part 41a in the optical axis direction is adjusted, and the focus of the projection lens 41 can be adjusted.

  As described above, in the second modification of the first embodiment, the gear train that connects the adjustment ring that rotates integrally with the movable portion of the projection lens and the focus adjustment knob includes the rotation shaft and the knob of the adjustment ring. A bevel gear having a rotation axis orthogonal to both of the rotation axes. As a result, the rotation axis of the gear is orthogonally transformed, and the same effect as in the first embodiment is obtained.

<Modification 3 of the first embodiment>
In the third modification of the first embodiment, an example is shown in which the rotation axis of the gear is orthogonally transformed using a rack in a gear train that connects the adjustment ring and the knob. Note that in the third modification of the first embodiment, the description of the same components as those of the already described embodiment will be omitted.

  FIG. 7D is a diagram (No. 3) illustrating another example of the structure in the vicinity of the projection lens and the knob in FIG. 5. 7D is different from FIG. 7A in that the spur gear 45 and the worm gear 46 are replaced with a rack 53, a pinion 54, and a screw gear 55.

  In FIG. 7D, the rack 53 is engaged with the pinion 54 and the adjustment ring 44. The pinion 54 meshes with the screw gear 55. The knob 47 is concentrically fixed to the screw gear 55 and is configured to be rotatable integrally with the screw gear 55. As in the first embodiment, the knob 47 is provided on the side surface of the housing 20 and is configured to be rotatable within a plane parallel to the screen 90.

  The pinion 54 is configured to be rotatable about a rotation axis that passes through a substantially central portion of the pinion 54 and is substantially parallel to the optical axis A of the projection lens 41. The screw gear 55 is configured to be rotatable about a rotation axis that passes through a substantially central portion of the screw gear 55 and is substantially orthogonal to the screen 90. That is, the rotation axis of the pinion 54 and the rotation axis of the screw gear 55 are orthogonal to each other. The rack 53 is configured to be capable of reciprocating in the X direction according to the rotation of the pinion 54.

  The adjustment ring 44, the rack 53, the pinion 54, the screw gear 55, and the knob 47 are typical examples of manual adjustment means according to the present invention. The screw gear 55 is a typical example of the fourth gear according to the present invention. The pinion 54 is a typical example of the fifth gear according to the present invention. The rack 53 is a typical example of the sixth gear according to the present invention.

  Thus, the rack 53, the pinion 54, and the screw gear 55 constitute a gear train, and connect the adjustment ring 44 and the knob 47. When the knob 47 is manually rotated in a plane parallel to the screen 90, for example, the screw gear 55 fixed concentrically with the knob 47 rotates integrally with the knob 47. When the screw gear 55 rotates, the pinion 54 rotates in conjunction with it, and the rack 53 moves in the X direction as the pinion 54 rotates. When the rack 53 moves in the X direction, the adjustment ring 44 rotates. At this time, since the rotation axis of the adjustment ring 44 and the rotation axis of the pinion 54 and the rotation axis of the screw gear 55 are orthogonal to each other, the rotation direction is orthogonally converted, and the adjustment ring 44 is within a plane perpendicular to the screen 90. Rotate.

  Since the adjustment ring 44 is fixed to a part of the side surface of the movable portion 41a, when the adjustment ring 44 rotates, the movable portion 41a rotates relative to the fixed portion 41b. Thereby, since the movable part 41a moves in the direction of the optical axis A with respect to the fixed part 41b, the position of the movable part 41a in the optical axis direction is adjusted, and the focus of the projection lens 41 can be adjusted.

  Thus, in the third modification of the first embodiment, the gear train that connects the adjustment ring that rotates integrally with the movable portion of the projection lens and the focus adjustment knob are screws whose rotation axes are orthogonal to each other. Includes gears, pinions, and racks. As a result, the rotation axis of the gear is orthogonally transformed, and the same effect as in the first embodiment is obtained.

<Second Embodiment>
In the second embodiment, an example in which the knob is arranged on the upper surface of the image projection apparatus will be described. In the second embodiment, the description of the same components as those of the already described embodiments is omitted.

  FIG. 8 is a perspective view illustrating an image projection apparatus according to the second embodiment. Referring to FIG. 8, image projection apparatus 10 </ b> C is different from image projection apparatus 10 </ b> B (see FIG. 5) in that knob 47 is arranged on the upper surface.

  FIG. 9 is a diagram showing an example of the structure in the vicinity of the projection lens and the knob in FIG. In FIG. 9, an adjustment ring 51 that functions as a bevel gear is fixed to a part of the side surface of the movable portion 41a. The gear 56 has a structure in which a bevel gear and a spur gear are integrated, and the bevel gear side (conical surface) of the gear 56 meshes with the conical surface of the adjustment ring 51 to constitute a bevel gear pair. Further, the spur gear side of the gear 56 meshes with the spur gear 57. The knob 47 is concentrically fixed to the spur gear 57 and is configured to be rotatable integrally with the spur gear 57. The knob 47 is provided on the upper surface of the housing 20 and is configured to be rotatable within a plane parallel to the screen 90.

  The gear 56 and the spur gear 57 are configured to be rotatable about a rotation axis that passes through the respective substantially central portions and is substantially orthogonal to the screen 90. That is, the rotation axis of the adjustment ring 51 is orthogonal to both the rotation axis of the gear 56 and the rotation axis of the spur gear 57 (= the rotation axis of the knob 47).

  Thus, the adjustment ring 51 that functions as a bevel gear, the gear 56 that forms a structure in which the bevel gear and the spur gear are integrated, and the spur gear 57 constitute a gear train, and the adjustment ring 51 and the knob 47 are connected to each other. is doing. When the knob 47 is manually rotated, for example, in a plane parallel to the screen 90, the spur gear 57 fixed concentrically with the knob 47 rotates integrally with the knob 47. When the spur gear 57 rotates, the gear 56 rotates in conjunction with it, and the adjustment ring 51 further rotates. At this time, since the rotation axis of the gear 56 is orthogonal to the rotation axis of the adjustment ring 51, the rotation direction is orthogonally converted, and the adjustment ring 51 rotates in a plane perpendicular to the screen 90.

  Since the adjustment ring 51 is fixed to a part of the side surface of the movable portion 41a, when the adjustment ring 51 rotates, the movable portion 41a rotates with respect to the fixed portion 41b. Thereby, since the movable part 41a moves in the direction of the optical axis A with respect to the fixed part 41b, the position of the movable part 41a in the optical axis direction is adjusted, and the focus of the projection lens 41 can be adjusted. The adjustment ring 51, the gear 56, the spur gear 57, and the knob 47 are typical examples of manual adjustment means according to the present invention. Further, the adjustment ring 51 and the gear 56 are a representative example of a pair of gears whose rotating shafts are orthogonal to each other according to the present invention.

  Thus, in the second embodiment, the gear train that connects the adjustment ring that rotates integrally with the movable portion of the projection lens and the focus adjustment knob is a bevel gear pair that orthogonally transforms the rotation axis of the gear. including. Accordingly, the focus of the projection lens can be adjusted by providing the knob on the upper surface of the casing and rotating the knob within a plane parallel to the screen. As a result, since there is no possibility that the image projection apparatus moves in the direction of the screen along with the focus adjustment, the focus adjustment work can be stabilized. The focus adjustment has been described above, but the same effect can be obtained when zoom adjustment is performed with the same configuration. It is also possible to provide a knob on the top surface of the housing using the same gear train as in the first embodiment and its modification, and rotate it in a plane parallel to the screen.

<Third Embodiment>
The third embodiment shows an example in which two knobs are arranged on the side surface of the image projection apparatus. In the third embodiment, the description of the same components as those of the already described embodiments is omitted.

  FIG. 10 is a perspective view illustrating an image projection apparatus according to the third embodiment. Referring to FIG. 10, image projection apparatus 10 </ b> D is different from image projection apparatus 10 </ b> B (see FIG. 5) in that knobs 47 and 58 are arranged on the side surfaces.

  FIG. 11 is a diagram showing an example of the structure of the projection lens of FIG. In FIG. 11, adjustment rings 44 and 59 are fixed to a part of the side surface of the movable portion 41a. The adjustment ring 44 is a focus adjustment ring as described above. The adjustment ring 58 is a zoom adjustment ring. That is, the movable part 41a includes a first movable part (not shown) that changes the focus of the projection lens 41 and a second movable part (not shown) that changes the zoom of the projection lens 41. Then, by rotating the adjustment ring 44, the first movable part (not shown) moves along the optical axis A to perform focus adjustment, and by rotating the adjustment ring 59, the second movable part ( The zoom adjustment is performed by moving along the optical axis A (not shown).

  The adjustment ring 44 is connected to the knob 47 via a first gear train (not shown). As the first gear train (not shown), any one of the gear trains exemplified in the first embodiment, its modification, and the second embodiment can be used. The adjustment ring 59 is connected to the knob 58 via a second gear train (not shown). As the second gear train (not shown), any of the gear trains exemplified in the first embodiment, its modification, and the second embodiment can be used.

  As described above, in the third embodiment, the projection lens is provided with the focus adjustment ring and the zoom adjustment ring, and the corresponding focus adjustment knob and zoom adjustment knob are arranged on the side surface of the image projection apparatus. In that case, each ring and each knob are connected via any one gear train illustrated in the first embodiment, its modified example, and the second embodiment. Since this gear train is a transmission mechanism in which the rotation axes of the respective knobs and the respective rings are orthogonal to each other, the respective knobs can be rotated in a plane parallel to the screen. As a result, there is no possibility that the image projection apparatus moves in the direction of the screen in accordance with the focus adjustment or the zoom adjustment, so that the focus adjustment work or the zoom adjustment work can be stabilized.

  Note that, as in the second embodiment, the focus adjustment knob and the zoom adjustment knob may be arranged on the upper surface of the image projection apparatus.

  The preferred embodiment and its modification have been described in detail above, but the present invention is not limited to the above-described embodiment and its modification, and the above-described implementation is performed without departing from the scope described in the claims. Various modifications and substitutions can be added to the embodiment and its modifications.

  For example, in the first embodiment and its modifications, the second embodiment, and the third embodiment, the types of gears constituting the gear train, the number of gear teeth, the number of gears, etc. are as described above. It is not limited to this example, and can be appropriately selected depending on the distance between the projection lens and the knob, the size of the space in which the knob can be placed, and the like.

  Further, the knob is not necessarily limited to the illustrated disk, and may be a lever, for example. In this case, the rotation axis of the lever may be perpendicular to the screen and the movement of the lever may be in a plane parallel to the screen. It is also possible to make the knob a slide type by using a rack and pinion mechanism for the knob. In this case, the knob slide direction may be in-plane direction parallel to the screen.

  Further, the transmission mechanism that makes the rotary shafts of the knobs and the rings orthogonal to each other is not necessarily limited to gears, and belts, chains, cams, and the like can also be used. Or they may be combined.

10, 10A, 10B, 10C, 10D Image projection apparatus 20 Housing 30 Image forming element 40, 40A Projection optical system 41 Projection lens 41a Movable part 41b Fixed part 42 Reflection mirror 43 Curved mirror 44, 51, 59 Adjustment ring 45, 57 Flat Gear 46 Worm gear 46a Screw gear 46b Helical gear 47, 58 Knob 48, 56 Gear 49, 52 Bevel gear 53 Rack 54 Pinion 55 Screw gear 60 Illumination optical system 61 Light source 62 Reflector 63, 64 Relay lens 65 Illuminance uniformizing means 66 Color wheel 70 Separation means 90 Screen A Optical axis

JP 2007-219352 A JP 2010-197874 A

Claims (8)

An image forming element that forms an image according to a modulation signal is irradiated with illumination light from a light source, and the image formed on the image forming element includes a fixed portion and a movable portion that can move in the optical axis direction. An image projection apparatus that projects an enlarged projection onto a projection surface by a projection optical system including a projection lens,
A housing that accommodates at least a part of the projection optical system and transmits projection light from the projection optical system toward the projection surface;
Manual adjustment means for adjusting the position of the movable part in the optical axis direction;
The projection lens is installed such that the optical axis is perpendicular to the placement surface when the casing is placed,
The manual adjustment means includes an adjustment unit that is at least partially exposed from an upper surface or a side surface of the housing,
The adjustment unit is movable in a plane parallel to the projection surface, and adjusts the position of the movable unit in the optical axis direction. The projection lens has a rotation unit that rotates with respect to a rotation axis parallel to the optical axis and moves the movable unit in the optical axis direction.
The image projecting device according to claim 1, wherein the rotating unit and the adjusting unit are connected via a transmission mechanism. The transmission mechanism includes a first gear having a rotation axis parallel to the optical axis, a second gear having a rotation axis orthogonal to the projection surface, the first gear, and the second gear. A third gear connecting the two,
The image projection apparatus according to claim 2, wherein the third gear has a rotation axis that is orthogonal to both the rotation axis of the first gear and the rotation axis of the second gear.   The transmission mechanism includes a fourth gear having a rotation axis orthogonal to the projection surface, a fifth gear having a rotation axis parallel to the optical axis meshing with the fourth gear, and the fifth gear. The image projection apparatus according to claim 2, further comprising: a sixth gear that reciprocates in a direction orthogonal to a rotation axis of the fifth gear according to the rotation of the gear.   The image projection apparatus according to claim 2, wherein the transmission mechanism includes a pair of gears whose rotation axes are orthogonal to each other.   The image projecting apparatus according to claim 1, wherein the movable unit varies a focal point of the projection lens or a magnification of the projection lens. The projection lens includes a plurality of movable parts,
The image projection apparatus according to claim 1, wherein the manual adjustment unit includes a plurality of adjustment units that adjust positions of the plurality of movable units in the optical axis direction.   The image according to claim 7, wherein the plurality of movable parts include a first movable part that varies a focal point of the projection lens and a second movable part that varies a magnification of the projection lens. Projection device.

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