CN112782912A

CN112782912A - Projector with a light source

Info

Publication number: CN112782912A
Application number: CN202011161854.XA
Authority: CN
Inventors: 北野博史; 北冈信一; 山内健太郎
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2019-11-01
Filing date: 2020-10-27
Publication date: 2021-05-11
Also published as: JP7373741B2; JP2021071670A

Abstract

A projector is provided so that projected light is not blocked by a housing. A projector (1) is provided with a projection unit (30) that enlarges light emitted from a light emitting unit (20) and projects the light onto a projection object (80), and a housing (10) having an opening (12). The projection unit (30) has a projection lens (32) and is disposed so as to pass through the opening (12). The tip (32a) of the projection lens (32) in the light projection direction (p1) of the projection unit (30) is positioned closer to the projection target (80) than the opening (12).

Description

Projector with a light source

Technical Field

The present invention relates to a projector that projects light.

Background

Conventionally, a projector including a projection unit that projects light is known. As an example of such a projector, patent document 1 discloses a projector that projects projection light from an opening provided in a housing. In this projector, after the projector is installed on the ceiling of a building, the posture of the projection unit is adjusted using an adjustment mechanism such as a cam plate, and the projection direction of the projection light is changed.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-173574

However, in the conventional projector, for example, when the projection unit is tilted to project the projection light, a part of the projection light may be blocked by the case around the opening.

Disclosure of Invention

The invention aims to provide a projector which can prevent projection light from being shielded by a shell.

A projector according to an aspect of the present invention includes a projection unit that projects light emitted from a light emitting unit onto a projection target by enlarging the light, and a housing having an opening; the projection unit has a projection lens disposed so as to pass through the opening; the projection lens has a tip end located closer to the projection target than the opening in a light projection direction of the projection unit.

According to the projector of the present invention, the projection light can be prevented from being blocked by the housing.

Drawings

Fig. 1 is a cross-sectional view showing a projector of a comparative example.

Fig. 2 is a diagram schematically showing an example of a usage mode of the projector according to the embodiment.

Fig. 3 is a view of the projector according to the embodiment viewed from an obliquely upper side.

Fig. 4 is a view of the projector according to the embodiment viewed from an obliquely lower side.

Fig. 5 is a cross-sectional view of the projector according to the embodiment taken along the V-V line shown in fig. 2 (a).

Fig. 6 is a cross-sectional view of the projector according to the embodiment taken along line VI-VI shown in fig. 5.

Fig. 7 is a block diagram showing a control configuration of the projector according to the embodiment.

Fig. 8 is a sectional view of a projector according to a modification of the embodiment.

Fig. 9 is a diagram showing another use mode of the projector according to the embodiment.

Description of the marks

1. 1A projector

10 casing

12 opening

13 open face

14 gap

15 exhaust port

20 light emitting part

30 projecting part

32 projection lens

32a front end

40 rotary moving part

41 rotating shaft

50. 50a, 50b airflow generating part

80. 81, 82 projected body

91 ceiling

92 ceiling

a1 optical axis

L projected light

p1 projection direction

Detailed Description

(pass to reach the invention)

The process of achieving the present invention will be described with reference to a projector of a comparative example.

Fig. 1 is a cross-sectional view showing a projector 101 of a comparative example.

The projector 101 of the comparative example includes a housing 110 embedded in a ceiling 191 of a building, a projection unit 130 that enlarges and projects image light emitted from the light emitting unit 120, and a posture changing mechanism (not shown) that changes the posture of the projection unit 130.

The housing 110 has a box shape and has an opening 112 through which light projected from the projecting part 130 passes. Fig. 1 shows a case where the projecting unit 130 inclined by the posture changing mechanism projects the projection light L onto a projection target 180 provided on a wall of a building.

In the projector 101 of the comparative example, since all of the projecting parts 130 including the distal ends 132a of the projecting parts 130 are disposed inside the housing 110, there is a possibility that a part of the projection light L projected from the projecting parts 130 is blocked by the housing 110 around the opening and the projection light L cannot be appropriately projected.

In contrast, the projector according to the present embodiment has a structure in which projection light projected from the projector is not blocked by the housing.

The embodiments are specifically described below with reference to the drawings. The embodiments described below are all specific examples of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, steps, order of the steps, and the like shown in the following embodiments are examples and are not intended to limit the present invention. Further, among the constituent elements of the following embodiments, constituent elements that are not described in the independent claims showing the implementation form of the aspect of the present invention are described as arbitrary constituent elements. The embodiments of the present invention are not limited to the current independent claims, and may be expressed by other independent claims.

The drawings are schematic and are not necessarily strictly illustrated. In the drawings, substantially the same components are denoted by the same reference numerals, and redundant description may be omitted or simplified.

(embodiment mode)

The projector 1 according to the embodiment will be described with reference to fig. 2 to 7.

Fig. 2 is a diagram schematically showing an example of a usage mode of the projector 1 according to the embodiment. The z-axis shown in fig. 2 is an axis extending in the vertical direction, and the x-axis and the y-axis are axes extending in the horizontal direction.

The projector 1 is installed in a ceiling 91 of a building, for example. Fig. 2 (a) shows a case where projection light L emitted from the projector 1 is projected onto a wall of a building. Fig. 2 (b) shows a case where projection light L emitted from the projector 1 is projected onto the floor of a building. The wall and floor of the building are examples of the object 80 to be projected that projects the light L. The object 80 to be projected is not limited to a wall or a floor, and may be a structure such as a screen or a table.

Fig. 3 is a view of the projector 1 viewed from an obliquely upper side. Fig. 4 is a view of the projector 1 viewed from an obliquely lower side. Fig. 5 is a cross-sectional view of the projector 1 taken along the V-V line shown in fig. 2 (a). Fig. 6 is a cross-sectional view of the projector 1 taken along line VI-VI shown in fig. 5. In fig. 3, the airflow generation unit 50 described later is not shown.

As shown in fig. 3 to 6, the projector 1 is embedded in a ceiling 91 that separates an indoor space s1 of a building from a space s2 on the rear side of the ceiling.

As shown in fig. 5 and 6, the projector 1 includes a box-shaped housing 10, a light emitting portion 20 that emits image light, and a projecting portion 30 that enlarges and projects the image light emitted from the light emitting portion 20 to the outside. The projector 1 further includes a rotating unit 40 that can rotate the projecting unit 30, and an airflow generating unit 50 and an exhaust duct 55 that cool the inside of the housing 10.

The housing 10 is fitted into and fixed to a ceiling opening 93 formed in the ceiling 91. The case 10 is, for example, rectangular parallelepiped and is formed of resin or metal. The outer shape of the housing 10 is not limited to a rectangular parallelepiped shape, and may be a cylindrical shape.

The housing 10 is composed of a lower housing 11 and an upper housing 18.

Lower case 11 has a convex shape protruding toward the opposite side of the floor, i.e., the rear side of the ceiling with respect to ceiling surface 92 of ceiling 91. Specifically, the lower case 11 includes a rectangular base portion 11a, a plurality of side leg portions 11b extending downward from the outer edge of the base portion 11a, and a plurality of flange portions 11c connected to the respective side leg portions 11 b. The lower case 11 is fixed to the ceiling 91 with the flange portion 11c in contact with the ceiling surface 92.

The lower case 11 is formed of a flat plate made of metal, for example. However, the lower case 11 is not limited to a flat metal plate, and may be formed of a resin decorative panel. The base portion 11a of the lower case 11 may be formed of a louver in which a plurality of louvers are arranged in parallel.

The base portion 11a has an opening 12 having a long hole shape and a rectangular exhaust port 15. As described above, since the lower case 11 has the convex shape, when the case 10 is installed on the ceiling, the opening 12 and the exhaust port 15 are provided on the opposite side of the object 80 with respect to the ceiling surface 92.

The base portion 11a is provided with a light emitting portion 20, a projecting portion 30, a rotating/moving portion 40, an airflow generating portion 50, and an exhaust duct 55.

The upper case 18 has a cylindrical shape having a top surface portion. The upper case 18 is disposed on the lower case 11 so as to cover the light emitting unit 20, the projecting unit 30, the rotating and moving unit 40, the airflow generating unit 50, and the exhaust duct 55. The upper case 18 has a hermetic property to prevent dust in the space s2 on the rear side of the ceiling and to prevent the invasion of living things such as insects and mice.

As shown in fig. 5 and 6, the light emitting portion 20, the projecting portion 30, the rotational movement portion 40, the airflow generating portion 50, and the exhaust duct 55 are accommodated in an inner space s3 surrounded by the lower case 11 and the upper case 18. Further, most of the projecting part 30 is accommodated in the case inner space s3, but a part of the projecting part 30 is located outside the case inner space s 3. This will be described in detail later.

The light emitting unit 20 includes a light source 21 that emits light, a light modulation element 22 that modulates the light emitted from the light source 21 and emits image light, an optical system 23, a prism 24, and a housing 25. The light source 21, the light modulation element 22, the optical system 23, and the prism 24 are housed in a case 25.

The light source 21 is, for example, a mercury lamp, an led (light Emitting diode), an ld (laser diode), or the like. The light source 21 may include a plurality of light sources that emit red light, blue light, and green light, respectively. The light emitted from the light source 21 is guided to the light modulator 22 by an optical system 23 such as a lens or a mirror.

The light modulation element 22 is, for example, a transmissive liquid crystal element, a reflective liquid crystal element, a dmd (digital Micromirror device), or the like. The light modulation element 22 of the present embodiment is a DMD. The image light generated by the light modulator 22 is emitted to the projector 30 via the prism 24.

The projection unit 30 enlarges the image light emitted from the light emitting unit 20 and projects the projection light L. The projection unit 30 includes a cylindrical lens barrel 31 connected to the light emitting unit 20, and a projection lens 32 provided in the lens barrel 31. In the lens barrel 31, a plurality of lenses including a projection lens 32 may be provided.

The projection portion 30 is disposed so as to pass through the opening 12 of the lower case 11. The elongated hole-shaped opening 12 is formed up to the lower side of the case 25 so that the case 25 of the light emitting portion 20 does not interfere with the base portion 11a of the lower case 11.

Opening 12 of lower housing 11 has a width larger than the diameter of lens barrel 31, and gap 14 is provided between opening 12 and lens barrel 31. A part of barrel 31 of projector 30 protrudes downward from opening 12. Specifically, the tip 32a of the projection lens 32 in the light projection direction p1 of the projection unit 30 is positioned closer to the object 80 than the opening 12. With this configuration, in the projector 1 of the present embodiment, the projection light L is prevented from being blocked by the housing 10.

The rotational movement unit 40 is a head swing mechanism that changes the projection direction p1 of the light projected from the projection unit 30. The rotating and moving unit 40 includes a pair of rotating shafts 41 extending in the horizontal direction, a pair of support columns 42 supporting the light emitting unit 20 and the projecting unit 30 via the pair of rotating shafts 41, and a driving unit 43 (see fig. 6) capable of rotating the light emitting unit 20 and the projecting unit 30 via the pair of rotating shafts 41. The driving unit 43 is, for example, a stepping motor or a servo motor. The driving unit 43 is not limited to the motor, and may be a rotational position holding mechanism that holds a position when manually rotated by friction or a link mechanism, for example. When the projecting part 30 is rotationally moved by the rotational movement part 40, the lens barrel 31 of the projecting part 30 moves along the long hole direction of the opening 12.

The rotating unit 40 can rotate the projecting unit 30 so that the optical axis a1 of the projecting unit 30 swings around the rotating shaft 41. For example, the rotating/moving unit 40 rotates and moves the projecting unit 30 so that the light is projected to the object 81 arranged in the vertical direction as shown in fig. 2 (a) or projected to the object 82 arranged in the horizontal direction as shown in fig. 2 (b). For example, when the angle α of the optical axis a1 of the projector 30 when light is projected onto the projection object 82 is 0 °, the angle α of the optical axis a1 when light is projected onto the projection object 81 is 45 °.

The projector 1 may project light so that the image light moves from the floor to the wall or from the wall to the floor while the projection unit 30 is rotationally moved by the rotational movement unit 40. The angle α of 45 ° is an example, and the projector 1 can project the projection light L in a range where the angle α of the optical axis a1 of the projection unit 30 is 0 ° to 90 °.

The projecting unit 30 is configured to be capable of being rotationally moved by the rotational movement unit 40, but even if rotationally moved, the tip 32a of the projection lens 32 is positioned closer to the object 81 or 82 than the opening 12. That is, the front end 32a of the projection lens 32 is necessarily positioned between the opening 12 and the ceiling surface 92.

The projection light L projected from the projection unit 30 is diffused light having a larger area (area of a surface perpendicular to the optical axis a 1) as the projection unit 30 is separated from the projection unit 30, and in the present embodiment, the projection light L is not shielded from light by the lower case 11. Specifically, the side leg 11b of the lower housing 11 has a height dimension that does not shield the projection light L.

Next, a structure for cooling the casing 10 inside will be described. As described above, the light source 21, the light modulation element 22, the driving unit 43, and the like are provided inside the housing 10. Since the light source 21, the light modulation element 22, and the driving unit 43 generate heat, the housing 10 is provided with an airflow generating unit 50 and an exhaust duct 55 for cooling the air inside the housing 10.

The airflow generating unit 50 includes a1 st airflow generating unit 50a disposed near the opening 12 and a 2 nd airflow generating unit 50b disposed near the exhaust port 15. The 1 st airflow generation unit 50a is, for example, an axial fan, and is fixed to the base unit 11a via a support member 51. The 1 st airflow generating section 50a may be fixed to the light emitting section 20 via a support member different from the support member 51. The 2 nd airflow generation part 50b is, for example, a blower fan or a centrifugal fan, and is provided in the exhaust duct 55. The exhaust duct 55 is a duct for guiding the airflow generated by the 2 nd airflow generating unit 50b to the exhaust port 15. The airflow generating unit 50 takes in air in the indoor space s1 from the gap 14 into the casing 10, and discharges air heated in the casing 10 to the indoor space s1 from the exhaust port 15.

The exhaust port 15 is provided on the same surface as the opening surface 13 of the opening 12. That is, the exhaust port 15 is located on the ceiling rear side of the front end 32a of the projection lens 32. In other words, the tip 32a of the projection lens 32 is positioned closer to the projection target 81 or 82 than the exhaust port 15.

When the exhaust port 15 is viewed from the vertical direction, the exhaust port 15 is provided at a position not overlapping the lens barrel 31 of the projecting part 30 (see fig. 4). The same applies to the case where air vent 15 and lens barrel 31 are in a positional relationship not overlapping when viewed from the vertical direction, and the case where projecting part 30 is rotated and moved. In the projector 1, the exhaust port 15 is provided at a position not overlapping the front end 32a of the projection lens 32, and the high-temperature air discharged from the exhaust port 15 is less likely to enter the optical path of the projection light L emitted from the projection unit 30.

Next, a control structure of the projector 1 will be explained.

Fig. 7 is a block diagram showing a control configuration of the projector 1.

As shown in fig. 7, the projector 1 includes a light source 21, a light modulator 22, a rotation/movement unit 40, an airflow generation unit 50, a communication unit 71, and a control unit 70.

The control unit 70 controls the operations of the light source 21, the light modulator 22, the rotation/movement unit 40, the airflow generation unit 50, and the communication unit 71. The control unit 70 includes a CPU, a ROM, a RAM, and the like, and the CPU reads a program stored in the ROM and expands the program into the RAM to execute various processes. The ROM stores image data of an image formed by the light modulator 22. The control unit 70 may have a nonvolatile rewritable memory instead of the ROM. The control unit 70 may acquire image data from an external device such as a smartphone, a PC, or a remote controller, or an external storage device via the communication unit 71.

When the power is turned ON (ON), the control unit 70 drives the light source 21 and the light modulator 22. Thereby, for example, the projection light L from the projection unit 30 is projected toward the object 81 or 82. The control unit 70 may acquire information on the projection direction p1 of the projected light L from a smartphone or the like via the communication unit 71, and control the rotational movement unit 40 to change the projection direction p 1. When the power is turned on, the control unit 70 drives the airflow generating unit 50. Thereby, the inside of the housing 10 of the projector 1 is cooled.

(effects, etc.)

As described above, the projector 1 of the present embodiment includes the projection unit 30 that enlarges the light emitted from the light emitting unit 20 and projects the light onto the projection object 80, and the housing 10 having the opening 12. The projector 30 has a projection lens 32 and is disposed so as to pass through the opening 12. The tip 32a of the projection lens 32 in the light projection direction p1 of the projection unit 30 is positioned closer to the object 80 than the opening 12.

In this way, the tip 32a of the projection lens 32 is positioned closer to the projection target 80 than the opening 12, and the projection light L projected from the projection unit 30 can be emitted from the outside of the housing 10. This can prevent the projection light L from being blocked by the housing 10.

The projector 1 may further include a rotation moving unit 40 that can rotate and move the projecting unit 30.

In this way, the projector 1 includes the rotating and moving unit 40, and can change the projection direction p1 of the light projected from the projecting unit 30. In the present embodiment, since the tip 32a of the projection lens 32 is positioned closer to the projection target 80 than the opening 12, the projection light L can be emitted from the outside of the housing 10 even when the projection unit 30 is rotated. This can prevent the projection light L from being blocked by the housing 10.

The rotating unit 40 may be configured to rotate the projecting unit 30 so that the optical axis a1 of the projecting unit 30 swings about the rotating shaft 41 extending in the horizontal direction.

This allows the projection direction p1 of the light projected from the projection unit 30 to be easily changed around the rotation axis 41. In the present embodiment, since the tip 32a of the projection lens 32 is positioned closer to the projection target 80 than the opening 12, the projection light L can be emitted from the outside of the housing 10 even when the projection unit 30 swings about the rotation shaft 41. This can prevent the projection light L from being blocked by the housing 10.

The rotating/moving unit 40 may be configured to be capable of rotating the projecting unit 30 so as to project light onto the object 81 disposed along the vertical direction or project light onto the object 81 disposed along the horizontal direction.

This makes it possible to project the projection light L onto the projection target 81 such as a wall or a screen, and the projection target 82 such as a floor or a table. In the present embodiment, since the tip 32a of the projection lens 32 is positioned closer to the object 81 or 82 than the opening 12, the projection light L can be emitted from the outside of the housing 10 when the light is projected onto the objects 81 and 82. This can prevent the projection light L from being blocked by the housing 10.

The casing 10 may have an exhaust port 15 for exhausting air heated in the casing 10, and the exhaust port 15 may be provided on the same surface as the opening surface 13 of the opening 12.

By providing the exhaust port 15 on the same surface as the opening surface 13 in this way, the tip 32a of the projection lens 32 can be positioned closer to the object 80 than the exhaust port 15. This makes it difficult for the high-temperature air discharged from the exhaust port 15 to enter the optical path of the projection light L, and the projection light L can be appropriately projected.

The projector 1 further includes an airflow generating unit 50 disposed in the housing 10, the opening 12 is provided with a gap 14 with respect to the projecting unit 30, the airflow generating unit 50 takes in external air from the gap 14 into the housing 10, and discharges air heated in the housing 10 from the exhaust port 15.

This enables the air to be taken into the casing 10 and the air to be discharged from the casing 10 with a simple structure, and thus the casing 10 can be easily cooled. By this cooling, the image light formed in the housing 10 can be appropriately formed, and therefore the image included in the projection light L can be appropriately projected.

The housing 10 may be fitted to a ceiling 91 of a building, and the opening 12 may be provided on the opposite side of the object 80 with respect to the ceiling surface 92 of the ceiling 91.

This enables the opening 12 to be arranged on the rear side of the ceiling surface 92, and the opening 12 can be made inconspicuous when the projector 1 is viewed from the lower side.

Further, the front end 32a of the projection lens 32 may be located between the opening 12 and the ceiling surface 92.

This makes it possible to make the projecting section 30 passing through the opening 12 inconspicuous when the projector 1 is viewed from below.

(modification of embodiment)

Next, a projector 1A according to a modification of the embodiment will be described with reference to fig. 8. In this modification, an example will be described in which the lower case of the case 10 is not convex but flat.

Fig. 8 is a sectional view of the projector 1A. The projector 1A is buried in the ceiling 91.

The projector 1A includes a box-shaped housing 10, a light emitting unit 20 that emits image light, and a projecting unit 30 that enlarges and projects the image light to the outside. The projector 1A includes a rotating unit 40 that can rotate the projecting unit 30, and an airflow generating unit 50 and an exhaust duct 55 that cool the housing 10.

The housing 10 is composed of a lower housing 11A and an upper housing 18.

The lower case 11A has a flat shape and is provided along the ceiling surface 92. The lower case 11 is fixed to the ceiling 91 in a state of being in contact with the ceiling surface 92.

The lower case 11A is a flat plate made of metal, for example. However, the lower case 11A is not limited to a flat metal plate, and may be a resin decorative panel, or may be formed of louvers in which a plurality of louvers are arranged in parallel.

The lower case 11A has a rectangular opening 12 and a rectangular exhaust port 15. When the casing 10 is installed on a ceiling, the opening 12 and the exhaust port 15 are provided on the same surface as the ceiling surface 92.

The lower housing 11A is provided with a light emitting unit 20, a projecting unit 30, a rotating unit 40, an airflow generating unit 50, and an exhaust duct 55.

The upper case 18 has a cylindrical shape having a top surface portion. The upper case 18 is disposed on the lower case 11A so as to cover the light emitting unit 20, the projecting unit 30, the rotating and moving unit 40, the airflow generating unit 50, and the exhaust duct 55.

As shown in fig. 8, the light emitting unit 20, the projecting unit 30, the rotating unit 40, the airflow generating unit 50, and the exhaust duct 55 are accommodated in a housing space s3 defined by the lower housing 11A and the upper housing. Further, most of the projecting part 30 is accommodated in the case inner space s3, but a part of the projecting part 30 is located outside the case inner space s 3.

The light emitting unit 20 includes a light source 21 that emits light, and a light modulator 22 that modulates the light emitted from the light source 21 and emits image light.

The projection unit 30 enlarges and projects the light emitted from the light emitting unit 20. The projection unit 30 includes a cylindrical lens barrel 31 and a projection lens 32 provided in the lens barrel 31.

The projection portion 30 is disposed so as to pass through the opening 12 of the lower case 11A. Opening 12 of lower housing 11A has a width larger than the diameter of lens barrel 31, and gap 14 is provided between opening 12 and lens barrel 31. A part of barrel 31 of projector 30 protrudes downward from opening 12. Specifically, the tip 32a of the projection lens 32 in the light projection direction p1 of the projection unit 30 is positioned closer to the object 80 than the opening 12. With this configuration, in the projector 1A of the present embodiment, the projection light L is prevented from being blocked by the housing 10.

Further, the housing 10 may be embedded in the ceiling 91 of the building, and the opening 12 may be provided on the same surface as the ceiling surface 92 of the ceiling 91.

Thereby, the projector 1A can be easily set to the ceiling 91.

(other embodiments)

The projector according to the present invention has been described above based on the above embodiment and modification, but the present invention is not limited to the above embodiment and modification. For example, the present invention may be configured by combining the above-described embodiments and modifications.

For example, in the projector 1 of the above embodiment, the angle α of the optical axis a1 when the light is projected to the projection object 81 is 45 °, but the present invention is not limited to this. For example, as shown in fig. 9, the projector 1 may project light to the other wall-side object 80 facing the other wall-side object 80 with the angle α of the optical axis a1 set to-45 °.

For example, in the above embodiment, the case where the gas flow generating unit 50 includes the 1 st gas flow generating unit 50a and the 2 nd gas flow generating unit 50b has been exemplified, but at least 1 gas flow generating unit 50 may be provided. For example, the airflow generating unit 50 may be only the 2 nd airflow generating unit 50 b.

In the above embodiment, the exhaust port 15 is provided on the same surface as the opening surface 13 of the opening 12, but the present invention is not limited thereto. The exhaust port 15 may be provided between the opening surface 13 and the tip 32a of the projection lens 32.

For example, a dust collecting filter or the like may be provided in the exhaust port 15. In addition, a retractable dust collecting filter may be provided in the gap 14 between the opening 12 and the lens barrel 31.

For example, the projector 1 may include an adjustment mechanism for finely adjusting the posture of the projecting unit 30 with screws or the like after the projector 1 is installed on the ceiling 91 or the like.

In addition, the present invention includes a form obtained by applying various modifications of the embodiments as will occur to those skilled in the art, and a form realized by arbitrarily combining the components and functions of the embodiments within a scope not departing from the gist of the present invention.

Claims

1. A projector is characterized in that a projector body is provided,

the disclosed device is provided with:

a projection unit that projects the light emitted from the light emission unit onto a projection target while enlarging the light; and

a housing having an opening;

the projection unit has a projection lens disposed so as to pass through the opening;

the projection lens has a tip end located closer to the projection target than the opening in a light projection direction of the projection unit.

2. The projector as defined in claim 1,

the projector further comprises a rotating and moving part capable of rotating and moving the projecting part.

3. The projector as defined in claim 2,

the rotating and moving unit can rotate and move the projecting unit so that the optical axis of the projecting unit swings about a rotation axis extending in a horizontal direction.

4. The projector according to claim 2 or 3,

the rotating/moving unit can rotate and move the projecting unit so that the projecting unit projects light to the object arranged in the vertical direction or projects light to the object arranged in the horizontal direction.

5. The projector according to any one of claims 1 to 3,

the housing has an exhaust port for exhausting air heated in the housing;

the exhaust port is provided on the same surface as the opening surface of the opening.

6. The projector as defined in claim 5,

further comprising an airflow generating part disposed in the housing;

the opening is provided with a gap relative to the projection part;

the airflow generating unit takes in external air from the gap into the housing, and discharges air heated in the housing from the exhaust port.

7. The projector according to any one of claims 1 to 3,

the housing is embedded in a ceiling of a building;

the opening is provided on the opposite side of the object to be projected with respect to the ceiling surface of the ceiling.

8. The projector as defined in claim 7,

the front end of the projection lens is located between the opening and the ceiling surface.

9. The projector according to any one of claims 1 to 3,

the housing is embedded in a ceiling of a building;

the opening is provided on the same surface as the ceiling surface of the ceiling.