1. A projector is characterized by comprising:

a light source;

a light modulation device that modulates light emitted from the light source;

a projection optical system that projects the light modulated by the light modulation device;

a sensor that acquires information on an image projected by the projection optical system;

a housing that houses the light source, the light modulation device, and the sensor; and

a sensor holding portion that holds the sensor,

the projection optical system includes a lens barrel that houses a lens therein, through which light modulated by the light modulation device passes,

the lens barrel is held by the housing via a lens barrel holding portion,

the sensor holding portion is held by the lens barrel holding portion.

2. The projector as claimed in claim 1,

the projector further includes a housing for optical components that holds the light modulation device,

the lens barrel holding portion is held by the optical component housing,

the optical component housing is held by the housing.

3. The projector according to claim 2,

the sensor holding portion is of a cantilever structure held by the lens barrel holding portion.

4. The projector as claimed in claim 3,

the sensor holding portion includes a sensor mounting portion connected to the sensor,

the sensor mounting portion and the sensor are separated from the housing.

5. The projector according to any one of claims 2 to 4,

the optical component holds the light source with a housing.

6. The projector according to any one of claims 2 to 4,

the lens barrel holding section and the optical component housing are integrated by one member.

7. The projector according to any one of claims 2 to 4,

the sensor holding portion includes:

a 1 st sensor holding member that holds the sensor; and

a 2 nd sensor holding member that holds the 1 st sensor holding member,

the 2 nd sensor holding member is held by the barrel holding portion.

8. The projector as claimed in claim 7,

the 1 st sensor holding member has a linear expansion coefficient smaller than that of the housing.

9. The projector as claimed in claim 7,

the 2 nd sensor holding member has a linear expansion coefficient smaller than that of the housing.

10. The projector as claimed in claim 7,

the 1 st sensor holding member is made of metal.

11. The projector as claimed in claim 7,

the 2 nd sensor holding member is made of metal.

12. The projector according to any one of claims 2 to 4,

the sensor holding portion is integrated with the lens barrel holding portion.

13. The projector according to claim 2,

the sensor holding unit includes:

a 1 st part connected to the barrel holding part;

a 2 nd portion connected to the sensor; and

a connecting portion connecting the 1 st part and the 2 nd part,

the 1 st portion has a width larger than that of the connection portion.

14. The projector according to any one of claims 2 to 4,

the sensor is an image sensor.

15. The projector according to any one of claims 2 to 4,

the sensor is a ranging sensor.

Background

Conventionally, a projector that adjusts an image projected onto a screen based on information obtained from a sensor is used. Such a projector is disclosed in patent document 1. The projector disclosed in patent document 1 includes a projection optical system that projects an image toward the front of the apparatus and a monitoring camera disposed in front of the apparatus, and performs focus adjustment, zoom adjustment, and pitch adjustment of the projection optical system and keystone adjustment of the projected image based on information obtained by processing an input image input from the monitoring camera.

Patent document 1: japanese patent laid-open publication No. 2000-241874

Conventionally, in a projector including a sensor (for example, a monitoring camera or a distance measuring sensor) for acquiring information necessary for projection of an image, many components are present between a projection optical system for projecting an image and the sensor. For example, the projection optical system is attached to a housing of the projector via a holding member made of resin, while the sensor is attached to the housing via a sensor holding member different from the holding member holding the projection optical system. Therefore, dimensional tolerances of a large number of parts between the sensor and the projection optical system are accumulated, and the relative positional accuracy of the sensor and the projection optical system is lowered. Further, when the distortion of each member due to heat or the distortion due to aging is accumulated, the relative positional accuracy between the sensor and the projection optical system may be further degraded. If the relative positional accuracy between the sensor and the projection optical system is low, there is a problem that the projected image cannot be adjusted with high accuracy.

Disclosure of Invention

The projector of the present invention includes: a light source; a light modulation device that modulates light emitted from the light source; a projection optical system that projects the light modulated by the light modulation device; a sensor that acquires information on an image projected by the projection optical system; a housing that houses the light source, the light modulation device, and the sensor; and a sensor holding portion that holds the sensor, wherein the projection optical system includes a lens barrel that houses a lens therein and through which light modulated by the optical modulation device passes, the lens barrel is held by the housing via the lens barrel holding portion, and the sensor holding portion is held by the lens barrel holding portion.

Drawings

Fig. 1 is a schematic configuration diagram showing a main part of a projector to which the present invention is applied.

Fig. 2 is a perspective view showing a holding structure of the image sensor.

Fig. 3 is a side view showing a holding structure of the image sensor.

Fig. 4 is a plan view showing a holding structure of the image sensor.

Fig. 5 is a partial sectional view showing the arrangement of the front surface portion of the housing and the image sensor.

Fig. 6 is an explanatory diagram schematically showing a holding structure of the image sensor shown in fig. 2 to 4.

Fig. 7 is an explanatory view schematically showing a modification 1 of the holding structure of the image sensor.

Fig. 8 is an explanatory view schematically showing a modification 2 of the holding structure of the image sensor.

Description of the reference symbols

1: a projector; 2: a housing; 3: an image light generating device; 4: a projection optical system; 5: an image sensor; 6: a housing for an optical component; 7: a lens barrel holding section; 8: a sensor holding section; 8A: part 1; 8B: part 2; 8C: a connecting portion; 21: a front surface portion; 22: an opening for projection; 23: an opening for a sensor; 24: a cover glass; 25: a sensor cover; 26: a cover opening part; 30: a light source; 31. 31R, 31G, 31B: a light modulation device; 32: an illumination light guide optical system; 33: a homogenizing optical system; 34: a color separation optical system; 35: a relay optical system; 36: an incident-side polarizing plate; 37: an exit-side polarizing plate; 39: a cross dichroic prism; 40: a 1 st lens; 41: a lens barrel; 42: a large-diameter cylindrical portion; 43: a flange portion; 80: a sensor mounting portion; 81: 1 st sensor holding member; 82: a 2 nd sensor holding member; 83: 1 st plate-like portion; 84: a 2 nd plate-like portion; 85: a 3 rd plate-like portion; 86: a convex portion; 107: a lens barrel holding section; 108: a sensor holding section; 200: a holding member; 207: a lens barrel holding section; 208: a sensor holding section; 331: a 1 st lens array; 332: a 2 nd lens array; 333: a polarization conversion element; 334: a superposed lens; 341. 342: a dichroic mirror; 343: a mirror; 351: an incident-side lens; 352. 354: a mirror; 353: a relay lens; l: the direction of the optical axis; w1: the width of part 1; w2: the width of the connecting portion.

Detailed Description

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the present specification, for convenience of explanation, X, Y, and Z axes are illustrated as 3 axes orthogonal to each other, and one side in the X axis direction is defined as the + X direction and the other side is defined as the-X direction. In addition, one side in the Y-axis direction is set as the + Y direction, the other side is set as the-Y direction, one side in the Z-axis direction is set as the + Z direction, and the other side is set as the-Z direction.

(Overall Structure)

Fig. 1 is a schematic configuration diagram schematically showing a main part of a projector 1 to which the present invention is applied.

As shown in fig. 1, the projector 1 includes a housing 2, a video light generation device 3, a projection optical system 4, and an image sensor 5. The image light generation device 3, a part of the projection optical system 4, and the image sensor 5 are housed in the case 2. In addition to the above, the case 2 houses a control unit, a power supply device, a fan, and the like, which are not shown. The projector 1 enlarges and projects the image light emitted from the image light generation device 3 on a screen (not shown) through the projection optical system 4. Further, the image sensor 5 captures an image projected by the projection optical system 4, and performs a process of correcting keystone distortion of the projected image based on information obtained from the captured image.

Hereinafter, the optical axis direction of the image light emitted from the projection optical system 4 is set to L, one (emission side) of the one and the other sides of the optical axis direction L, which emits light from the projection optical system 4, is set to L1 direction, and the side (incidence side) on which light is incident on the projection optical system 4 is set to L2 direction. The optical axis direction L is parallel to the Y-axis direction.

The + Y direction coincides with the L1 direction, and the-Y direction coincides with the L2 direction. The Z-axis direction is a direction that is oriented in the vertical direction when the projector 1 is set in a normal set state. The + Z direction is the upper side and the-Z direction is the lower side. The X-axis direction is the device width direction of the projector 1.

(image light generating device)

As shown in fig. 1, the image light generation device 3 includes a light source 30 and a light modulation device 31. The projector 1 of the present embodiment is an LCD type projector, and the light modulation device 31 is a liquid crystal panel. The light modulation device 31 modulates light emitted from the light source 30 based on image information input from the outside. As the light source 30, a halogen lamp, a metal halide lamp, a high-pressure mercury lamp, or a solid-state light source such as LD or LED may be used.

In the present embodiment, the light modulation device 31 includes a light modulation device 31R for modulating red light (hereinafter, referred to as "R light"), a light modulation device 31G for modulating green light (hereinafter, referred to as "G light"), and a light modulation device 31B for modulating blue light (hereinafter, referred to as "B light"). The image light generation device 3 further includes: an illumination light guide optical system 32 that separates light emitted from the light source 30 into 3 color light beams of R light, G light, and B light and makes the light incident on the light modulation devices 31R, 31G, and 31B; and a cross dichroic prism 39 that combines the R light, the G light, and the B light modulated by the light modulation devices 31R, 31G, and 31B.

The illumination light guide optical system 32 includes a uniformizing optical system 33, a color separation optical system 34, and a relay optical system 35. The uniformizing optical system 33 includes a 1 st lens array 331, a 2 nd lens array 332, a polarization conversion element 333, and a superimposing lens 334. The uniformizing optical system 33 superimposes the light flux from the light source 30 on the liquid crystal panel as the light modulation device 31. The color separation optical system 34 includes 2 dichroic mirrors 341 and 342 and a reflecting mirror 343, and separates the light flux emitted from the uniformizing optical system 33 into R light, G light, and B light. The relay optical system 35 includes an incident side lens 351, a relay lens 353, and mirrors 352 and 354. The relay optical system 35 guides the R light separated by the color separation optical system 34 to the light modulation device 31R.

An incident-side polarizing plate 36 and an exit-side polarizing plate 37 are disposed on the incident side and the exit side of the light modulation devices 31R, 31G, and 31B, respectively. In the cross dichroic prism 39, the light incident side end face on which the modulated G light is incident is directed in the L2 direction, the light incident side end face on which the modulated R light is incident is directed in the-X direction, and the light incident side end face on which the modulated B light is incident is directed in the + X direction. The cross dichroic prism 39 reflects the R light and the B light modulated by the light modulation devices 31R and 31B, transmits the G light modulated by the light modulation device 31G, and combines the color lights of 3 colors. The full-color image light synthesized by the cross dichroic prism 39 is emitted from the cross dichroic prism 39 in the direction L1, and enters the projection optical system 4.

Each optical component constituting the video light generation device 3 is held by a resin optical component case 6, and is held by a case 2, which is an outer case of the projector 1, via the optical component case 6. As shown in fig. 1, in the present embodiment, the lens barrel holding portion 7, which is a resin member separate from the optical component case 6, is arranged in the L1 direction with respect to the optical component case 6. The cross dichroic prism 39 and the light modulation devices 31R, 31G, and 31B are held by the barrel holding portion 7, and are held by the optical component case 6 via the barrel holding portion 7.

The image light generation device 3 of the present embodiment uses a transmissive liquid crystal panel as the light modulation device 31, but other types of light modulation devices may be used. For example, a reflective liquid crystal panel or a DMD (digital micromirror device) may also be used.

The light source 30 and the illumination light guide optical system 32 are not limited to the above configuration. For example, the relay optical system 35 may be configured to guide the B light to the light modulator 31B instead of the R light. Further, the following configuration may be adopted: instead of separating the light emitted from the light source 30 into 3 color lights of R light, G light, and B light, light sources emitting R light, G light, and B light are disposed corresponding to the light modulation devices 31R, 31G, and 31B, respectively.

(projection optical System)

The projection optical system 4 is disposed on the L1 side of the cross dichroic prism 39, and magnifies and projects the full-color image light emitted from the cross dichroic prism 39. The projection optical system 4 includes a plurality of lenses including a 1 st lens 40 disposed on the most enlarged side (emission side) and a lens barrel 41 housing the plurality of lenses. The lens barrel 41 holds a plurality of lenses in a state of being arranged on the optical axis. A large-diameter tube 42 surrounding the outer periphery of the 1 st lens 40 is disposed at an end of the lens barrel 41 in the L1 direction. The lens barrel 41 is held by the housing 2 of the projector 1 via a barrel holding portion 7. As described above, the barrel holding portion 7 is held by the optical component housing 6. Thus, the lens barrel 41 is held in the housing 2 via the lens barrel holding portion 7 and the optical component housing 6. The lens barrel 41 is fixed to the barrel holding portion 7 by a flange portion 43 provided at an end in the L2 direction.

(case)

As shown in fig. 1, the entire housing 2 of the projector 1 has a substantially rectangular parallelepiped shape. The front surface 21 of the housing 2 is provided with a projection opening 22 for projecting the end of the projection optical system 4 in the L1 direction to the outside of the housing 2. Further, a sensor opening 23 is provided in the front surface 21 of the housing 2. The image sensor 5 captures an image projected by the projection optical system 4 through the sensor aperture 23. In the present embodiment, the end portion of the projection optical system 4 in the L1 direction protrudes outside the housing 2, but the present invention is not limited to this, and the entire projection optical system 4 may be housed in the housing 2 without protruding the projection optical system 4 outside the housing 2.

(holding structure of image sensor)

Fig. 2 is a perspective view showing a holding structure of the image sensor 5. Fig. 3 is a side view showing a holding structure of the image sensor 5. Fig. 4 is a plan view showing a holding structure of the image sensor 5. The projector 1 includes a sensor holding unit 8 that holds the image sensor 5. In the present embodiment, the sensor holding portion 8 is held by the barrel holding portion 7. As shown by a broken line in fig. 1, the sensor holding portion 8 is connected to the lens barrel holding portion 7 arranged in the L2 direction of the lens barrel 41. The sensor holding portion 8 extends from the barrel holding portion 7 to the L2 side of the sensor opening 23 formed in the front surface portion 21 of the housing 2.

The sensor holding portion 8 has a smaller linear expansion coefficient than the case 2. In the present embodiment, the case 2 is made of resin, and the sensor holding portion 8 is made of aluminum. The sensor holding portion 8 may be made of a metal other than aluminum. In the case of using aluminum, the weight is light and the strength can be ensured. Therefore, the impact resistance of the sensor holding portion 8 can be improved. As shown in fig. 2 to 4, in the present embodiment, the sensor holding portion 8 is configured by two members, i.e., a 1 st sensor holding member 81 that holds the image sensor 5 and a 2 nd sensor holding member 82 that holds the 1 st sensor holding member 81. The 1 st sensor holding member 81 and the 2 nd sensor holding member 82 are each made of aluminum, and have a smaller linear expansion coefficient than the case 2. The material constituting the 2 nd sensor holding member 82 is not limited to aluminum, and may be iron, stainless steel, or the like.

The sensor holding portion 8 includes a 1 st portion 8A connected to the barrel holding portion 7, a 2 nd portion 8B connected to the image sensor 5, and a connecting portion 8C connecting the 1 st portion 8A and the 2 nd portion 8B. As shown in fig. 2 to 4, the 1 st section 8A is arranged above the lens barrel 41 and the barrel holding portion 7 (+ Z direction), extending in the optical axis direction L. The connecting portion 8C extends from the 1 st portion 8A in the + X direction of the lens barrel 41. The connection portion 8C is bent substantially at right angles to the + Z direction in the middle of extending in the + X direction, and then bent substantially at right angles to the + X direction.

The 2 nd portion 8B extends from the + X direction end of the connection portion 8C in the L1 direction. As shown in fig. 2 to 4, a sensor mounting portion 80 curved in the-Z direction is provided at the tip of the 2 nd portion 8B. As shown in fig. 3, the sensor mounting portion 80 is inclined in the direction L1 as it goes to the-Z direction. The image sensor 5 is connected to the sensor mounting portion 80 and faces the sensor opening 23.

The 1 st sensor holding member 81 is a metal plate member that is bent at a plurality of positions. The 1 st sensor holding member 81 includes: a 1 st plate-like portion 83 extending in the optical axis direction L above the lens barrel 41 and the barrel holding portion 7 (+ Z direction); a 2 nd plate-like portion 84 extending in the + X direction from an end of the 1 st plate-like portion 83 in the L1 direction; and a 3 rd plate-like portion 85 extending from the + X direction end of the 2 nd plate-like portion 84 in the L1 direction (+ Y direction). The end of the 1 st plate-like portion 83 in the L2 direction overlaps the 2 nd sensor holding member 82 from the + Z direction, and is fixed to the 2 nd sensor holding member 82 by a fixing member such as a screw. The 2 nd sensor holding member 82 is a flat plate-like metal plate member. The 2 nd sensor holding member 82 is fixed to the end of the barrel holding portion 7 in the + Z direction. The 2 nd sensor holding member 82 covers the end of the cross dichroic prism 39 in the L1 direction from the + Z direction.

The 1 st part 8A of the sensor holding portion 8 is constituted by the 1 st plate-like portion 83 and the 2 nd sensor holding member 82 of the 1 st sensor holding member 81. The connecting portion 8C is formed by the 2 nd plate-like portion 84 of the 1 st sensor holding member 81, and the 2 nd portion 8B is formed by the 3 rd plate-like portion 85 of the 1 st sensor holding member 81. As described above, the 2 nd plate-like portion 84 includes the bent portion bent substantially at right angles to the + Z direction and the bent portion bent substantially at right angles to the + X direction. The 2 nd plate-like portion 84 has a plurality of convex portions 86 formed by embossing, and some of the convex portions 86 are disposed in the bent portion. The 3 rd plate-like portion 85 is bent in the-Z direction at the tip in the L1 direction (+ Y direction) to form the sensor mounting portion 80.

Fig. 5 is a partial cross-sectional view showing the arrangement of the front surface portion 21 of the housing 2 and the image sensor 5, and is a partial cross-sectional view at a position a-a in fig. 1. A cover glass 24 is disposed in the sensor opening 23 provided in the front surface portion 21. As shown in fig. 5, the image sensor 5 and the sensor mounting portion 80 are disposed at positions separated from the housing 2, and the image sensor 5 and the sensor mounting portion 80 do not contact the front surface portion 21 of the housing 2. In the present embodiment, a sensor cover 25 is disposed between the front surface portion 21 of the housing 2 and the image sensor 5. The sensor cover 25 is separated from the front surface part 21 without contacting the front surface part 21. The sensor cover 25 has a cover opening 26 facing the image sensor 5. The image sensor 5 captures an image projected by the projection optical system 4 through the cover opening 26 and the sensor opening 23. In the present embodiment, the cover glass 24 using glass is used as the cover member of the sensor opening 23, but the present invention is not limited thereto, and a cover made of resin having light transmittance may be used.

As shown in fig. 4, in the sensor holding portion 8, the width W1 of the 1 st part 8A connected to the barrel holding portion 7 is larger than the width W2 of the connecting portion 8C. The width W1 of the 1 st portion 8A is the width of the 1 st plate-like portion 83 of the 1 st sensor holding member 81, and the width of the connecting portion 8C is the width of the 2 nd plate-like portion 84 of the 1 st sensor holding member 81. As shown in fig. 2 to 4, the 1 st part 8A of the sensor holding portion 8 is connected to the barrel holding portion 7, and the image sensor 5 is connected to the 2 nd part 8B. As described above, the sensor mounting portion 80 and the image sensor 5 provided at the 2 nd part 8B do not contact the housing 2. Therefore, the sensor holding portion 8 supports the image sensor 5 in a cantilever structure.

(main effects of the present embodiment)

As described above, the projector 1 of the present embodiment includes: a light source 30; a light modulation device 31 for modulating light emitted from the light source 30; a projection optical system 4 that projects the light modulated by the light modulation device 31; an image sensor 5 that acquires information on the image projected by the projection optical system 4; a housing 2 that houses the light source 30, the light modulation device 31, and the image sensor 5; and a sensor holding portion 8 that holds the image sensor 5. The projection optical system 4 includes a lens barrel 41 in which lenses are housed and through which light modulated by the light modulation device 31 passes. The lens barrel 41 is held by the housing 2 via the lens barrel holding portion 7, and the sensor holding portion 8 is held by the lens barrel holding portion 7.

As described above, in the present embodiment, the sensor holding portion 8 that holds the image sensor 5 and the lens barrel 41 that holds the projection optical system 4 are both held by the lens barrel holding portion 7. The barrel holding portion 7 is a member interposed between the barrel 41 and the housing 2. Therefore, in the connection structure in which the housing 2 is not interposed between the sensor holding portion 8 and the lens barrel 41, the number of components interposed between the image sensor 5 and the projection optical system 4 is small. Accordingly, since a decrease in the accuracy of the relative position between the image sensor 5 and the projection optical system 4 can be suppressed, when the keystone distortion is corrected based on the information acquired from the image captured by the image sensor 5, a decrease in the accuracy of the correction caused by the decrease in the accuracy of the relative position between the image sensor 5 and the projection optical system 4 can be suppressed. Therefore, the keystone distortion in the projector 1 can be corrected with high accuracy.

In the above embodiment, the barrel holding portion 7 and the optical component case 6 are separate members, but the barrel holding portion 7 may be integrated with the optical component case 6.

In the present embodiment, the sensor holding portion 8 includes the 1 st sensor holding member 81 that holds the image sensor 5 and the 2 nd sensor holding member 82 that holds the 1 st sensor holding member 81, and the 2 nd sensor holding member 82 is held by the barrel holding portion 7. By dividing the sensor holding portion 8 into two parts in this way, the influence of foreign matter generated at the time of assembly can be suppressed. For example, the 2 nd sensor holding member 82 is attached to the barrel holding portion 7 in advance, and then the barrel 41 and the optical component housing 6 are connected by the barrel holding portion 7. Then, the 1 st sensor holding member 81 is fixed to the 2 nd sensor holding member 82. As described above, the 2 nd sensor holding member 82 has a shape covering the upper side (+ Z direction) of the end portion of the cross dichroic prism 39 in the L1 direction. Therefore, by connecting the sensor holding portion 8 and the barrel holding portion 7 in this order, the possibility of foreign matter generated by the work such as screwing of the components falling onto the cross dichroic prism 39 can be reduced.

In the present embodiment, the linear expansion coefficient of the 1 st sensor holding member 81 is smaller than the linear expansion coefficient of the housing 2. In addition, the linear expansion coefficient of the 2 nd sensor holding member 82 is smaller than the linear expansion coefficient of the housing 2. Thus, by using a member having a small linear expansion coefficient, thermal deformation of the sensor holding portion 8 can be reduced. Therefore, when used in a high-temperature environment, the image sensor 5 can be prevented from deviating from the design position, and therefore, the accuracy of the relative position between the image sensor 5 and the projection optical system 4 can be prevented from being lowered.

In the present embodiment, the 1 st sensor holding member 81 is made of metal such as aluminum. The 2 nd sensor holding member 82 is made of metal such as aluminum. When a resin member is used as the sensor holding portion 8, the deformation with time due to the load increases even at normal temperature, but when a metal member is used, the deformation with time due to the load is less likely to occur if the metal member is not used in a high-temperature environment. Therefore, in the present embodiment, the image sensor 5 can be prevented from being displaced from the design position at normal temperature. Therefore, a decrease in the relative positional accuracy of the image sensor 5 and the projection optical system 4 can be suppressed. The 1 st and 2 nd sensor holding members 81 and 82 according to the present embodiment are metal plate members obtained by machining a metal plate, but cast or forged members may be used.

In the present embodiment, the sensor holding portion 8 includes: a 1 st part 8A connected to the barrel holding part 7; a 2 nd portion 8B connected to the image sensor 5; and a joint 8C connecting the 1 st segment 8A with the 2 nd segment 8B, the 1 st segment 8A having a width W1 greater than a width W2 of the joint 8C. Therefore, the strength of the 1 st portion 8A connected to the barrel holding portion 7 can be ensured, and the weight saving of the sensor holding portion 8 can be achieved. Therefore, since the deformation of the sensor holder 8 can be suppressed, the deterioration of the relative positional accuracy between the image sensor 5 and the projection optical system 4 can be suppressed. As described above, in the present embodiment, the sensor holding portion 8 supports the image sensor 5 in a cantilever structure. Therefore, by making the width W1 of the 1 st portion 8A connected to the barrel holding section 7 larger than the width W2 of the connecting section 8C, the strength of the portion to which the maximum load is applied can be secured, and the weight of the sensor holding section 8 can be reduced. Therefore, deformation of the sensor holder 8 can be suppressed, and a decrease in the accuracy of the relative position between the image sensor 5 and the projection optical system 4 can be suppressed.

In the present embodiment, the sensor holding portion 8 has a sensor mounting portion 80 connected to the image sensor 5, and the sensor mounting portion 80 and the image sensor 5 are separated from the housing 2. Therefore, the housing 2 is not present in the connection structure of the image sensor 5 and the lens barrel 41, and the relative positional accuracy of the image sensor 5 and the lens barrel 41 can be made unaffected by the housing 2.

In the present embodiment, the image sensor 5 is held by the sensor holding portion 8. Therefore, various adjustments can be made based on information obtained from the image captured by the image sensor 5. For example, in the present embodiment, the keystone distortion is corrected based on information obtained from an image captured by the image sensor 5. As described above, in the present embodiment, a decrease in the relative positional accuracy between the image sensor 5 and the projection optical system 4 can be suppressed. Accordingly, a decrease in the accuracy of correction due to a decrease in the accuracy of the relative position of the image sensor 5 and the projection optical system 4 can be suppressed.

(modification 1)

Fig. 6 to 8 are explanatory views schematically showing a holding structure of the image sensor. Fig. 6 is an explanatory diagram schematically showing a holding structure of the image sensor 5 shown in fig. 2 to 4. As shown in fig. 6, in the above-described aspect, the sensor holding portion 8 is constituted by two members, i.e., the 1 st sensor holding member 81 and the 2 nd sensor holding member 82, and in the connection structure of the image sensor 5 and the projection optical system 4, the number of members interposed therebetween is three members, i.e., the 1 st sensor holding member 81, the 2 nd sensor holding member 82, and the barrel holding portion 7.

Fig. 7 is an explanatory view schematically showing a modification 1 of the holding structure of the image sensor 5. As shown in fig. 7, the sensor holding portion 108 of modification 1 is formed of one member. One end of the sensor holding portion 108 is connected to the barrel holding portion 107, and the image sensor 5 is connected to the other end of the sensor holding portion 108. The lens barrel 41 of the projection optical system 4 is connected to the barrel holding portion 107.

For example, the sensor holding portion 108 of modification 1 may be the same as the 1 st sensor holding member 81 of the above-described embodiment, or may be a member in which the 1 st sensor holding member 81 and the 2 nd sensor holding member 82 of the above-described embodiment are integrated. In the case where the 1 st sensor holding member 81 is used as the sensor holding portion 108, a member obtained by integrating the 2 nd sensor holding member 82 with the barrel holding portion 7 may be used as the barrel holding portion 107.

In the configuration of modification 1, as in the above-described embodiment, in the connection structure of the sensor holding portion 108 and the lens barrel 41, the housing 2 is not interposed therebetween, and both the sensor holding portion 108 and the lens barrel 41 are held by the lens barrel holding portion 107. Therefore, the number of components interposed between the image sensor 5 and the projection optical system 4 is two components, i.e., the sensor holding portion 108 and the lens barrel holding portion 107, and is smaller than that in the above-described embodiment, and therefore, a decrease in the accuracy of the relative position between the image sensor 5 and the projection optical system 4 can be further suppressed as compared with the above-described embodiment. Therefore, the keystone distortion can be corrected with high accuracy.

(modification 2)

Fig. 8 is an explanatory diagram schematically showing a modification 2 of the holding structure of the image sensor 5. As shown in fig. 8, in modification 2, the image sensor 5 is held by a holding member 200 in which a sensor holding portion 208 and a barrel holding portion 207 are integrated. For example, the holding member 200 is a member in which the 1 st sensor holding member 81 and the barrel holding portion 7 of the above-described embodiment are integrated. In modification 2, the lens barrel 41 and the image sensor 5 are both connected to the holding member 200. Accordingly, in the connection structure between the image sensor 5 and the projection optical system 4, the number of components interposed therebetween is 1 component and is smaller than that in modification 1, and therefore, a decrease in the accuracy of the relative position between the image sensor 5 and the projection optical system 4 can be further suppressed as compared with the above-described embodiment and modification 1. Therefore, the keystone distortion can be corrected with high accuracy.

(other embodiments)

The present invention can be applied to a system in which the sensor held by the sensor holding unit 8 is a sensor other than an image sensor. For example, in the above-described embodiment and modifications 1 and 2, the sensor held by the sensor holding portion 8 may be a distance measuring sensor using light such as infrared rays or laser beams or ultrasonic waves. The distance to the image projected by the projection optical system 4 can be detected by the distance measuring sensor, and various adjustments such as focus adjustment of the projection optical system 4 can be performed based on the detected distance.