JP7357515B2 - image projection device - Google Patents

Description

The present invention relates to an image projection device such as a projector that projects an image onto a screen or the like.

In an image projection device such as a projector, a projected image is generally projected symmetrically around a projection unit of the image projection device (see Patent Document 1).

Japanese Patent Application Publication No. 2010-160476

However, depending on the application and the installation location, it may be desired to project the projected image only to the left or right from the center of the projection section of the image projection device.

An object of the present invention is to provide an image projection device capable of projecting a projected image only to either the left or right side of the image projection device.

In order to solve the above problems, a first aspect of the present invention includes an illumination optical system that generates illumination light, an image display element that modulates the illumination light to create projection light, and an image display element that magnifies the projection light. and a projection optical system, wherein the image display element divides an orthogonal plane perpendicular to the optical axis of the projection optical system into four quadrants by two straight lines perpendicular to the optical axis. Provided is an image projection device that is arranged in one of the quadrants, and that projection light projected from the image projection device is projected to one side of the optical axis on which the one quadrant is located. do.

The image display element is rectangular, the short side of the image display element is parallel to one of the two straight lines, and the long side of the image display element is parallel to the other of the two straight lines. It is preferable that the line be parallel to the line, not intersect with the one straight line, and be on either side of the one straight line in the direction in which the other straight line extends.

a prism that reflects the projection light created by the image display element and makes it enter the projection optical system; a second optical axis that coincides with the first optical axis, the orthogonal plane is orthogonal to the second optical axis, and the one straight line is a plane that includes the first optical axis and the second optical axis. Preferably, it extends above.

The projection light created by the image display element directly enters the projection optical system, and the one straight line is orthogonal to a plane in the image projection device in which an opening for irradiating the projection light is provided. It is preferable to extend the length.

Preferably, the image display element does not extend beyond the one quadrant of the four quadrants.

In order to solve the above problems, a second aspect of the present invention includes an illumination optical system that generates illumination light, an image display element that modulates the illumination light to create projection light, and an image display element that magnifies the projection light. An image projection apparatus comprising a projection optical system, the illumination optical system, the image display element, and a casing that covers the projection optical system and is provided with an exit window, the image display element comprising: When the image projection device is viewed from the side of the casing where the exit window is provided, with the enlargement side of the projection optical system up and the reduction side down, the optical axis of the projection optical system is An image projection device is arranged on either the left or right side of the image projection device, and the projection light projected from the image projection device is projected on the one side on which the image display element is arranged with respect to the optical axis. provide.

It is preferable that the image display element has a rectangular shape, and a long side of the image display element is disposed on one side of the optical axis.

Preferably, the entire projection light is projected further toward the one side than the one side surface of the image projection device.

The projection optical system includes a housing that covers the illumination optical system and is provided with an adjustment hole, and the projection optical system is arranged on a fixed tube and on the inner diameter side of the fixed tube, and is movable in the optical axis direction with respect to the fixed tube. a focus group holding tube, and a focus adjustment section that is operable from the adjustment hole and moves the focus group holding tube in the optical axis direction with respect to the fixed tube by operation, and the focus adjustment section and It is preferable that the adjustment hole is provided on a side opposite to the side on which the projection light is projected with respect to the optical axis.

According to the present invention, it is possible to provide an image projection device capable of projecting a projection image only to either the left or right side of the image projection device.

1 is a perspective view of an image projection device 1 according to an embodiment. 1 is a block diagram of an image projection device 1. FIG. FIG. 2 is a front view of the image projection device 1 with a front housing 2F removed. 1 is an exploded perspective view of an image projection device 1. FIG. 5 is a schematic diagram illustrating the arrangement and optical path of an image display element 51 in an image display section 5. FIG. FIG. 2 is a schematic perspective view illustrating the arrangement and optical path of an image display element 51 when the image projection device 1 is viewed from the left side. FIG. 2 is a schematic perspective view illustrating the arrangement of an image display element 51 and an optical path when the image projection device 1 is viewed from the front side. FIG. 2 is a schematic perspective view illustrating the arrangement of an image display element 51 and an optical path when the image projection device 1 is viewed diagonally from the front left side. (a) and (b) show, as an installation example of the image projection device 1, a case where the image projection device 1 is attached to an automatic ticket gate K at a station. Another installation example of the image projection device 1 will be shown. Another installation example of the image projection device 1 will be shown. It is a sectional view of the projection optical system 6 and the front housing 2F on a plane passing through the focus adjustment section 61 and the optical axis OA. FIG. 6 is a diagram showing an adjustment jig 66 for adjusting the position of the focus group in the optical axis OA direction with respect to the fixed barrel 63, in which (a) is a view seen from one side in the longitudinal direction, and (b) is a view seen from a direction perpendicular to (a). This is a diagram. FIGS. 3A and 3B are diagrams illustrating a method of adjusting the focus group using the adjustment jig 66, in which (a), (b), and (c) show the focus group holding cylinder 62 at different positions in the optical axis OA direction with respect to the fixed cylinder 63; Indicates a certain state.

An image projection device 1 according to an embodiment of the present invention will be described below.
FIG. 1 is a perspective view of an image projection device 1 according to an embodiment. The image projection device 1 has a substantially rectangular parallelepiped shape and includes a housing 2 and a heat dissipation section 3 disposed outside the housing 2. The housing 2 includes a front housing 2F and a rear housing 2B, each of which is made of metal and has high thermal conductivity. FIG. 2 is a block diagram of the image projection device 1. As shown in FIG. FIG. 3 is a front view of the image projection device 1 with the front housing 2F removed. FIG. 4 is an exploded perspective view of the image projection device 1.

The image projection device 1 includes a housing 2 and a heat dissipation section 3 disposed outside the housing 2. Furthermore, the image projection device 1 includes, inside the housing 2, an illumination optical system 4, an image display section 5, a projection optical system 6, a concave reflecting mirror 7, an interface section 9, and a control section 8 for controlling these. Equipped with.

(Front housing 2F)
The front housing 2F is provided with an opening 25 for irradiating projection light and an adjustment hole 21 for operating a focus adjustment section 61, which will be described later, provided in the projection optical system 6 from the outside.
Hereinafter, as illustrated, the side of the housing 2 where the opening 25 is provided is referred to as the front, the opposite side is referred to as the rear, and the direction in which the projection light of the optical axis OA of the projection optical system 6 travels is the upper (enlargement side). ), the opposite side is defined as the bottom (reduced side), and the left and right sides when viewed from the front with the image projection apparatus 1 disposed vertically are also referred to as left and right in the specification.

As shown in FIG. 1, a transparent member 27 such as a glass plate is attached to the opening 25 of the front housing 2F, and a lid 26 is attached to the adjustment hole 21. The lid part 26 can open and close the adjustment hole 21.

(Rear case 2B)
As shown in FIGS. 3 and 4, a groove 22 is provided on the outer peripheral edge of the rear housing 2B, and an elongated elastic seal member 23 is disposed in the groove 22. An internal space 2Ba having a predetermined depth and in which the projection optical system 6 and the concave reflecting mirror 7 are arranged is provided in the upper part of the rear housing 2B. The lower part of the rear housing 2B has a substantially plate shape, and is provided with a mounting section 2Bb on which the illumination optical system 4 and the image display section 5 are arranged.

With the seal member 23 disposed in the groove 22 of the rear housing 2B, the front housing 2F is placed in front of the rear housing 2B, and when the periphery is fixed with screws 24 so as to bring them into close contact with each other, the front housing The state shown in FIG. 1 is reached in which the 2F and the rear housing 2B are fixed to each other. At this time, the opening 25 of the front casing 2F is sealed with a light-transmitting member 27, and the interface section 9 is also attached to the casing 2 in a dust-proof manner. Therefore, when the adjustment hole 21 closes the lid part 26, there are no other holes in either the front casing 2F or the rear casing 2B, so the inside of the casing 2 is free of dust from the outside. It is sealed to prevent intrusion.

In addition, in the assembled state, the housing 2 is thick at the upper part where the internal space 2Ba is provided (the front and rear widths are large), and thin at the lower part (the front and rear widths are small). A recess P is provided, the rear side of which is recessed to provide a space in which the heat dissipation section 3 can be placed. When the heat dissipation section 3 is placed in the recess P, the housing 2 and the heat dissipation section 3 form a substantially rectangular shape as a whole. Therefore, since the heat dissipation section 3 does not protrude from the housing 2, it does not become an obstacle when installing the image projection device 1.

(Illumination optical system 4)
The illumination optical system 4 includes, for example, three-color LEDs of RGB as a light source. However, the light source is not limited to this, and may be, for example, an ultra-high pressure mercury lamp or a laser. Light including R light, G light, and B light generated from a light source in the illumination optical system 4 enters the image display section 5 .

(Image display section 5)
FIG. 5 is a schematic diagram illustrating the arrangement of the image display elements 51 in the image display section 5 and the optical path of projection light. The image display section 5 includes an image display element (light modulation element) 51 and a prism 52 (only the reflective surface is displayed).

(Image display element 51)
The image display element 51 is rectangular, and is, for example, a DMD (digital micromirror device). The DMD has a substantially rectangular mirror surface made up of a plurality of micromirrors, and based on data received from the control unit 8, each micromirror is driven in a time division manner, and the illumination light generated in the illumination optical system 4 is driven. When reflected, the light is modulated to create a predetermined projection light, which is then incident on the projection optical system 6.
In the embodiment, a DMD is used as the image display element 51, but the present invention is not limited to this, and a liquid crystal panel, a light emitting element array in which minute light emitting elements are arranged in a two-dimensional array, etc. can be used as appropriate.

(Prism 52)
Although the prism 52 is a TIR (Total Internal Reflection) prism or an RTIR (Reverse Total Internal Reflection) prism in the embodiment, it may be a cross dichroic prism. The prism 52 directs the illumination light generated by the illumination optical system 4 toward the image display element 51 and reflects the projection light created by the image display element 51 to the projection optical system 6.

(Projection optical system 6)
Although not shown in FIG. 5, the projection optical system 6 includes a plurality of lens groups. Note that details of the projection optical system 6 will be described later. The lens group is arranged along the optical axis OA with the optical axis OA as the center, and magnifies the image generated by the image display element 51.

(Concave reflector 7)
The concave reflecting mirror 7 reflects the projection light magnified by the projection optical system 6, changes the optical path, and guides the projection light through the light-transmitting member 27 to the projection surface. This makes it possible to project images or videos with an ultra-wide angle.

(Heat radiation part 3)
As shown in FIG. 4, the heat radiation section 3 includes one intake fan 31, two exhaust fans 32, and a heat sink 33, and is arranged in a recess P outside the housing 2. However, the number of intake fans 31 and exhaust fans 32 is not limited to this. Further, in the embodiment, the intake fan 31 is attached to the left and the exhaust fan 32 is attached to the right, but the present invention is not limited to this, and the opposite may be used.
The heat sink 33 includes a plurality of plate-shaped fins 33a arranged in parallel with each other. The heat sink 33 is arranged between the intake fan 31 and the exhaust fan 32 so that the fins 33a are arranged along the direction from the intake fan 31 to the exhaust fan 32 (extending left and right) so that air flows between the plurality of fins 33a. ) is located.

In FIGS. 1 and 4, the flow of air exhausted from the heat radiating section 3 is indicated by arrows. Further, the arrow shown on the light-transmitting member 27 in FIG. 4 is the direction in which the projection light travels. The air in the heat dissipation section 3 flows in a twisted direction different from the direction in which the projection light is irradiated, and does not intersect with the projection light. Therefore, the projection light is not disturbed by the high temperature air flowing from the heat radiating section 3.

(Interface part 9)
The interface section 9 is provided with a connection terminal section 91 for connection with the outside. An interface board 92 extends from these connection terminals 91 into the housing 2, and provides power and input to the control unit 8 via the interface board 92 and a flexible board 94 and other interface boards 95 that further extend from the interface board 92. A signal is sent, and further power and control signals are sent from the control section 8 to the illumination optical system 4, image display section 5, and heat dissipation section 3.

(Control unit 8)
The control unit 8 is provided on a main board disposed on an interface board 95 that further extends from the interface board 92. The main board is arranged at the bottom of the internal space 2Ba of the rear housing 2B.

The control section 8 controls the illumination optical system 4 , the image display element 51 , and the heat dissipation section 3 based on the signal received from the interface section 9 . The control section 8 operates the illumination optical system 4 and also drives the intake fan 31 and exhaust fan 32 of the heat radiation section 3 . Then, the control section 8 drives the image display element 51 based on the signal received via the interface section 9. The image display element 51 generates projection light based on the control of the control section 8.

In the embodiment, the projection light created by the image display element 51 is reflected by the reflective surface of the prism 52 and enters the projection optical system 6. In this case, the image display element 51 extends upward perpendicularly to the optical axis (first optical axis) OA of the projection optical system 6, and when the direction is turned by 90 degrees at the prism 52, the image display element 51 extends upwardly, and when the direction is changed by 90 degrees at the prism 52, It is arranged on an element arrangement surface S1 perpendicular to the two optical axes OA1.
Furthermore, the image display element 51 is arranged in one quadrant (quadrant III in the embodiment) when the element arrangement surface S1 is divided into four quadrants by two straight lines X and a straight line Y that are orthogonal to the second optical axis OA. It is located in Here, the straight line Y is a straight line extending on a plane including the optical axis OA and the second optical axis OA. The image display element 51 is located only in the III quadrant and does not extend to any quadrant other than the III quadrant.

The image display element 51 is rectangular, and its short side is parallel to the straight line Y. The long side is parallel to the straight line X and is on either side of the straight line Y in the X-axis direction. That is, the long side does not straddle the straight line Y.

Unlike the embodiment, when the projection light created by the image display element is not reflected by the prism 52 and directly enters the projection optical system, the image display element 51 is perpendicular to the optical axis OA (first optical axis). The device is placed on the element placement surface S2.
Furthermore, the image display element 51 is arranged in one quadrant (quadrant III in the embodiment) when the element arrangement surface S2 is divided into four quadrants by two straight lines X and a straight line Y perpendicular to the optical axis OA. has been done. Here, the straight line X is a straight line extending parallel to the surface of the image display device 1 in which the opening 25 for irradiating projection light is provided. The image display element 51 is located only in the III quadrant and does not extend to any quadrant other than the III quadrant.
The image display element is rectangular, the long side is parallel to the straight line X, the short side is parallel to the straight line Y, and the long side is on either side of the straight line Y in the X-axis direction. That is, the long side does not straddle the straight line Y.

Furthermore, if the two straight lines X and Y are expressed in another way, they are parallel to the sides of the image projection device 1 in both the reflective type and the transmissive type. The straight line X is parallel to the left and right sides of the image projection device 1. In the case of the reflective type of the embodiment, the straight line Y is parallel to the vertically extending sides. In the case of a transmission type, the straight line Y is parallel to the side edges extending back and forth.
Furthermore, in both the reflective type and the transmissive type, the image display element 51 is substantially fixed so that it cannot move beyond the straight line Y.

FIG. 6 is a schematic perspective view illustrating the arrangement of the image display element 51 and the optical path of projection light when the image projection device 1 is viewed from the left side. FIG. 7 is a schematic perspective view illustrating the arrangement of the image display element 51 and the optical path of projection light when the image projection device 1 is viewed from the front side. FIG. 8 is a schematic perspective view illustrating the arrangement of the image display element 51 and the optical path of projection light when the image projection device 1 is viewed from the diagonally front left side.

In the following description, for ease of explanation, even in the reflective image display element 51 of the embodiment, the image display element 51 is placed on the second element arrangement surface S2 at an equivalent position to the element arrangement surface S1. Explain as if it exists.

6 and 8 are diagrams of the image display element 51 viewed from the short side. The image display element 51 is arranged on the second element arrangement surface S2 in front of the optical axis OA. The projection light from the image display element 51 travels to the rear side while passing through the projection optical system 6, is reflected by the concave reflecting mirror 7, and is irradiated onto the front side of the image projection device 1 on the projection plane G.
Note that in the embodiment, the entire short side of the image display element 51 is arranged in front of the optical axis OA on the second element arrangement surface S2; Accordingly, the position of the short side with respect to the optical axis OA can be changed as appropriate.

7 and 8 are diagrams of the image display element 51 viewed from the long side. The entire long side of the image display element 51 is placed on the left side of the optical axis OA on the second element placement surface S2. The projection light from the image display element 51 travels to the right side while passing through the projection optical system 6, is reflected by the concave reflecting mirror 7, and is irradiated to the left side of the image projection device 1 on the projection plane G.
Note that the present invention is not limited to this, and if the long side of the image display element 51 does not intersect with the optical axis OA (unless it straddles the optical axis OA), the purpose of the image projection device 1 is determined on the second element arrangement surface S2. It can be on either the left or right side depending on the situation.

In the embodiment, as shown in FIGS. 7 and 8, the projection light is irradiated further to the left of the left surface of the image projection device 1. Further, when the image projection device 1 is attached to a pillar Q of a building, etc., the position of the image display element 51 may be adjusted so that the light is irradiated to a position further leftward than the end face of the pillar Q.

FIGS. 9A and 9B show an example of how to use the image projection device 1, and show a case where the image projection device 1 is attached to an automatic ticket gate K at a station. The image projection device 1 is attached to the lower part of the automatic ticket gate K on one or both sides in the passage direction. The image projection device 1 projects projection light indicating a guide sign to guide passengers passing through the automatic ticket gate K, and this projection light is irradiated onto one side of the image projection device 1 on the passageway as the projection surface G. be done.
The projected light is then projected to the outside of the gap between the automatic ticket gates K. For example, as shown in FIG. 9(a), when the automatic ticket gates K can be passed through, a blue arrow is displayed as the projected light of the guidance sign. do. As shown in FIG. 9(b), if the passage is impossible, a red cross mark is displayed as the projected light of the guidance sign.

Unlike the embodiment, in a general image projection device, projection light is irradiated evenly on both sides of the image projection device. In this case, if you try to illuminate a guidance sign at a position that is offset from the automatic ticket gate at a station ticket gate as described above, the image projection device will need to be placed away from the automatic ticket gate, which will obstruct traffic. .
In addition, when a general image projection device is attached to an automatic ticket gate, the projection light is emitted evenly on both sides of the image projection device, so at least half of the projected image is illuminated between the automatic ticket gates. This makes the projected image difficult to see.

However, according to the image projection device 1 of the embodiment, the projected light of the guidance sign is displayed not in front of the image projection device 1, but in a diagonal direction, shifted to the left or right from the automatic ticket gate K, so that the guide sign can be used easily. Guidance signs are easy to see for people.
Furthermore, the projected image is bright and clear in areas near the image projection device 1, and darker in areas farther away because the magnification is increased. In this case, the projected image becomes brighter as the user approaches the automatic ticket gate K, making it easier to recognize the direction in which the user is being guided.

FIG. 10 shows another usage example of the image projection device 1, in which the image projection device 1 is installed near a door that is an entrance/exit of a store, and a message welcoming customers entering the store through the door 100 is projected. show.
In the illustrated example as well, since the door 100 is in front of the desired message projection position, the image projection device 1 cannot be placed on the door 100, which moves when opening and closing. Therefore, the image projection device 1 is placed at a position diagonal to the desired projection position, which is the front of the door 100.
According to the embodiment, the image projection device 1 can project a message at a desired projection position diagonally in front, so that the message can be displayed in front of a customer who enters the store through the door 100.

FIG. 11 shows still another usage example of the image projecting device 1, in which the image projecting device 1 projects, for example, a course indicating an exit onto a crossroad such as a hallway.
In the illustrated example as well, the image projection device 1 cannot be placed in front of the location where the message is desired to be projected because the passageway 101 is located in front of the location. Therefore, the image projection device 1 is disposed at a position diagonal to the intersection of the paths, which is the desired projection position.
According to the embodiment, the image projection device 1 can project a message at a desired projection position diagonally in front, and therefore can display a message in the center of a crossroads.

(Focus adjustment section 61)
Returning to FIG. 3, the projection optical system 6 of the image projection device 1 is provided with a focus adjustment section 61 at a position shifted from the optical axis OA in the circumferential direction (to the right in the figure) in the front view. The direction of deviation in the circumferential direction is opposite to the projection direction. That is, since the projection light is projected to the left in the embodiment, the focus adjustment section 61 is shifted to the right in the circumferential direction from the optical axis OA in the front view.
FIG. 10 is a cross-sectional view of the projection optical system 6 and the front housing 2F on a plane passing through the focus adjustment section 61 and the optical axis OA. As shown in FIGS. 10 and 1, an adjustment hole 21 is provided in the front housing 2F.

As shown in FIG. 12, the projection optical system 6 includes a plurality of lens groups. The lens group includes a focus lens group L. The focus lens group L is held as one body by a focus group holding cylinder 62. A fixed barrel 63 is arranged on the outer diameter side of the focus group holding barrel 62. The focus group holding cylinder 62 is movable in the optical axis OA direction with respect to the fixed cylinder 63.

The fixed tube 63 is provided with a fixed tube elongated hole 63A and a fixed tube round hole 63B that extend in the optical axis OA direction. The focus group holding tube 62 is provided with a circular holding tube screw hole 62A and a holding tube elongated hole 62B.
The holding cylinder screw hole 62A is provided at a position overlapping the fixed cylinder long hole 63A, and the diameter of the holding cylinder screw hole 62A is approximately equal to the short diameter of the fixed cylinder long hole 63A. The holding cylinder long hole 62B is provided at a position overlapping the fixed cylinder round hole 63B, and the long diameter of the holding cylinder long hole 62B is approximately equal to the diameter of the fixed cylinder round hole 63B.

A screw 65 is screwed into the holding cylinder screw hole 62A of the focus group holding cylinder 62 from the fixed cylinder elongated hole 63A side of the fixed cylinder 63.
The diameter of the threaded portion 65a of the screw 65 is approximately equal to the short diameter of the fixed barrel elongated hole 63A, and the screw 65 is inserted into the holding barrel threaded hole 62A of the focus group holding barrel 62, and the threaded portion 65a is screwed together. Then, the focus group holding barrel 62 does not rotate relative to the fixed barrel 63 and can move in the optical axis OA direction.

FIG. 13 is a diagram showing an adjustment jig 66 for adjusting the position of the focus group in the optical axis OA direction with respect to the fixed barrel 63, in which (a) is a view seen from one side in the longitudinal direction, and (b) is a view orthogonal to (a). FIG. The adjustment jig 66 is a round bar, and a cylindrical protrusion 66A is provided at the tip. The diameter of the protrusion 66A is approximately equal to the short diameter of the holding cylinder elongated hole 62B.

FIG. 14 is a diagram illustrating a method of adjusting the focus group using the adjustment jig 66, and (a), (b), and (c) show that the focus group holding cylinder 62 is in the optical axis OA direction with respect to the fixed cylinder 63. It shows the state in different positions of.
For example, in state (a), the adjustment jig 66 is inserted into the fixed cylinder round hole 63B so that its protrusion 66A enters the holding cylinder elongated hole 62B. Then, when the adjustment jig 66 is rotated within the fixed cylinder round hole 63B, the position of the protrusion 66A of the adjustment jig 66 changes within the fixed cylinder round hole 63B. ) is shifted in the direction of the arrow shown in (b). If the adjustment jig 66 is further rotated from the state of (b), the position of the protrusion 66A of the adjustment jig 66 in the fixed cylinder round hole 63B will further change, so the focus group holding cylinder 62 (holding cylinder long hole 62B ) is shifted in the direction of the arrow shown in (c).
In this way, the focus can be adjusted by using the adjustment jig 66 to change the position of the focus group holding cylinder 62 (holding cylinder long hole 62B) with respect to the fixed cylinder 63 in the optical axis OA direction.

Here, unlike the embodiment, in a general image projection device, projection light is projected equally on the left and right sides of the main body. In this case, if the focus adjustment section is provided on the outer surface of the projection optical system as in the embodiment, the operator will block the projection light when adjusting the focus adjustment section. This makes it difficult for the operator to work while observing the focused state of the projection light.
There is also a conventional technique in which a focus lever or the like is attached to the side of the lens unit, which allows the operator to adjust the focus without blocking the projection light. However, in this case, it is necessary to provide a lever or the like on the housing side, making the configuration complicated.

However, in the embodiment, the focus adjustment section 61 and the adjustment hole 21 are provided on the opposite side of the optical axis OA to the side on which the projection light is projected. Therefore, the operator can adjust the focus without blocking the projection light.
For example, in the case of FIG. 9, the operator enters between the automatic ticket gates K and operates the focus adjustment unit 61 while observing the image formation state of the projection light irradiated on the left passageway (projection surface G). This makes it easier to work without complicating the configuration.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and various changes can be made within the scope of the invention. For example, the up and down, left and right, and front and back arrangements described in the specification are not limited to these, and the up and down, left and right, and front and rear positions may be reversed.

G: projection plane, OA: optical axis, P: recess, S1: element arrangement surface, S2: element arrangement equivalent surface, S3: plane, 1: image projection device, 2: housing, 2B: rear housing, 2Ba: Internal space, 2Bb: Placing section, 2F: Front housing, 3: Heat dissipation section, 4: Illumination optical system, 5: Image display section, 6: Projection optical system, 7: Concave reflector, 8: Control section, 9 : Interface section, 21: Adjustment hole, 22: Groove section, 23: Seal member, 25: Opening section, 26: Lid section, 27: Transparent member, 31: Intake fan, 32: Exhaust fan, 33: Heat sink, 51: Image display element, 52: Prism, 61: Focus adjustment section, 62: Focus group holding cylinder, 62A: Holding cylinder screw hole, 62B: Holding cylinder long hole, 63: Fixed cylinder, 63A: Fixed cylinder long hole, 63B: Fixed Cylindrical round hole, 66: Adjustment jig, 66A: Protrusion, 91: Connection terminal section, 92: Interface board

Claims (8)

an illumination optical system that generates illumination light;
an image display element that modulates the illumination light to create projection light;
An image projection device comprising: a projection optical system that magnifies the projection light;
The image display element is
When an orthogonal plane perpendicular to the optical axis of the projection optical system is divided into four quadrants by two straight lines perpendicular to the optical axis, the projection optical system is arranged in one quadrant;
Projection light projected from the image projection device is projected to one side where the one quadrant is located with respect to the optical axis ,
A casing that covers the illumination optical system and is provided with an adjustment hole,
The projection optical system is
A fixed tube,
a focus group holding barrel disposed on the inner diameter side of the fixed barrel and movable in the optical axis direction with respect to the fixed barrel;
a focus adjustment section that is operable from the adjustment hole and that moves the focus group holding tube in the optical axis direction with respect to the fixed tube by operation;
The focus adjustment unit and the adjustment hole are provided on a side opposite to the side on which the projection light is projected with respect to the optical axis.
Image projection device. The image display element is rectangular;
The short side of the image display element is parallel to one of the two straight lines,
The long side of the image display element is parallel to the other of the two straight lines, does not intersect with the one straight line, and is in either direction in which the other straight line extends with respect to the one straight line. on the side of
The image projection device according to claim 1. comprising a prism that reflects the projection light created by the image display element and makes it enter the projection optical system,
The optical axis includes a first optical axis of the projection optical system and a second optical axis that coincides with the first optical axis when the direction is changed in the prism, and the orthogonal plane includes the second optical axis. and the one straight line extends on a plane including the first optical axis and the second optical axis,
The image projection device according to claim 2. The projection light created by the image display element directly enters the projection optical system,
The one straight line extends perpendicularly to a plane in which an opening for irradiating projection light in the image projection device is provided.
The image projection device according to claim 2. The image display element does not extend beyond the one quadrant of the four quadrants,
An image projection device according to any one of claims 1 to 4. an illumination optical system that generates illumination light;
an image display element that modulates the illumination light to create projection light;
a projection optical system that magnifies the projection light;
An image projection device comprising: a casing that covers the illumination optical system, the image display element, and the projection optical system and is provided with an exit window;
The image display element is
When the image projection device is viewed from the side of the casing where the exit window is provided, with the enlargement side of the projection optical system up and the reduction side down, the optical axis of the projection optical system is It is placed on one side of the left and right,
Projection light projected from the image projection device is projected to one side on which the image display element is arranged with respect to the optical axis,
A casing that covers the illumination optical system and is provided with an adjustment hole,
The projection optical system is
A fixed tube,
a focus group holding barrel arranged on the inner diameter side of the fixed barrel and movable in the optical axis direction with respect to the fixed barrel;
a focus adjustment section that is operable from the adjustment hole and that moves the focus group holding tube in the optical axis direction with respect to the fixed tube by operation;
The focus adjustment unit and the adjustment hole are provided on a side opposite to the side on which the projection light is projected with respect to the optical axis.
Image projection device. The image display element is rectangular;
The long side of the image display element is arranged on either the left or right side with respect to the optical axis,
The image projection device according to claim 6. The entire projection light is projected further to the one side than the one side surface of the image projection device.
An image projection device according to any one of claims 1 to 7.

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