Patent Publication Number: US-2022229351-A1

Title: Fixing device, projection optical device, and projector

Description:
The present application is based on, and claims priority from JP Application Ser. No. 2021-006964, filed Jan. 20, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a fixing device, a projection optical device, and a projector. 
     2. Related Art 
     There has been known a projector including a light source, a light modulating device that modulates light emitted from the light source and forms an image corresponding to image information, and a projection optical device that enlarges and projects the formed image onto a projection surface. 
     In the projection optical device, when an optical distance from a fixing section to the projector to an end portion on a light emission side of the projection optical device is long, it is likely that the positions of optical components move because of the influence of a bend due to the weight of the projection optical device or vibration from the outside and optical performance of the projection optical device is deteriorated. Therefore, a firmer fixing structure has been desired. 
     To cope with such a problem, there has been known a projector including a projection lens unit in which a convergence optical system, a reflection mirror, and a diffusion optical system are integrally assembled to a common holding member having high rigidity (see, for example, JP-A-2008-180749 (Patent Literature 1)). 
     There has been known a projector including a lens holding mechanism provided on the outside of the projector and holding an interchangeable lens while suppressing tilt and collapse (see, for example, JP-A-2019-211639 (Patent Literature 2)). 
     In the projector described in Patent Literature 1, since high rigidity is required of the holding member to which the convergence optical system, the reflection mirror, and the diffusion optical system are assembled, the weight of the holding member and the protection lens unit tends to be large. Since the holding member needs to be accurately configured, manufacturing difficulty of the projection lens unit is high and manufacturing cost of the projection lens unit is also high. 
     In the projector described in Patent Literature 2, since it is necessary to separately provide the lens holding mechanism, it is troublesome to attach the lens holding mechanism to the projector. Besides, it is necessary to adjust disposition of the lens holding mechanism according to a setting direction of the projector. For example, in a reverse placement posture in which the projector is placed vertically reversely from a normal placement posture, it is likely that the interchangeable lens cannot be held by the lens holding mechanism. 
     Therefore, there has been a desire for another configuration that can fix the projection optical device to the projector. 
     SUMMARY 
     A fixing device according to a first aspect of the present disclosure fixes, to a light emitting device that emits light, a lens barrel included in a projection optical device and holding a plurality of lenses, and the fixing device includes: a first tube member; a contact section provided on an outer side of the first tube member and in contact with a holding section included in the light emitting device; and a pressing mechanism provided to be opposed to the contact section and configured to press the holding section toward the contact section when the fixing device is attached to the light emitting device. 
     A projection optical device according to a second aspect of the present disclosure includes: the fixing device according to the first aspect; a plurality of lenses; and a lens barrel holding the plurality of lenses and attached to the fixing device. 
     A projection optical device according to a third aspect of the present disclosure is detachably attached to a light emitting device that emits light, and the projection optical device includes: a plurality of lenses; a lens barrel holding the plurality of lenses; a contact section in contact with a holding section included in the light emitting device; and a pressing mechanism provided to be opposed to the contact section and configured to press the holding section toward the contact section when the projection optical device is attached to the light emitting device. 
     A projector according to a fourth aspect of the present disclosure includes: a light emitting device configured to emit light; and the projection optical device according to the third aspect. The light emitting device includes: a light source; a light modulating device configured to modulate light emitted from the light source; and an attachment mechanism including a holding section, the projection optical device being attached to the attachment mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing the configuration of a projector according to an embodiment. 
         FIG. 2  is a perspective view showing a projection optical device according to the embodiment. 
         FIG. 3  is a perspective view showing the projection optical device according to the embodiment. 
         FIG. 4  is a sectional view showing a fixing device according to the embodiment. 
         FIG. 5  is a diagram of an attachment mechanism in a release state according to the embodiment viewed from an emission side of image light. 
         FIG. 6  is a view of the attachment mechanism in the release state according to the embodiment viewed from an incident side of the image light. 
         FIG. 7  is a diagram of the attachment mechanism in a lock state according to the embodiment viewed from the emission side of the image light. 
         FIG. 8  is a diagram of the attachment mechanism in the lock state according to the embodiment viewed from the incident side of the image light. 
         FIG. 9  is a perspective view of the attachment mechanism and the projection optical device in the lock state according to the embodiment viewed from the incident side of the image light. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     An embodiment of the present disclosure is explained below with reference to the drawings. 
     Schematic Configuration of a Projector 
       FIG. 1  is a schematic diagram showing the configuration of a projector  1  according to this embodiment. 
     The projector  1  according to this embodiment modulates, according to image information, light emitted from a light source  41  and enlarges and projects the modulated light onto a projection surface such as a screen. The projector  1  includes, as shown in  FIG. 1 , a light emitting device  11  and a projection optical device detachably attached to the light emitting device  11 . 
     Configuration of the Light Emitting Device 
     The light emitting device  11  emits image light, which is light for forming an image. The light emitting device  11  includes an exterior housing  2 , a control device  3 , and an image generating device  4 . Besides, the light emitting device  11  includes an attachment mechanism  5  (see  FIG. 5 ) for attaching the projection optical device  6  and further includes, although not shown in  FIG. 1 , a power supply device that supplies electric power to electronic components configuring the projector  1  and a cooling device that cools cooling targets configuring the projector  1 . 
     The configuration of the attachment mechanism  5  is explained in detail below. 
     Configuration of the Exterior Housing 
     The exterior housing  2  houses the control device  3  and the image generating device  4  on the inside. The exterior housing  2  includes a front surface  21 , a rear surface  22 , a left side surface  23  and a right side surface  24 , and a top surface and a bottom surface not shown in  FIG. 1  and is formed in a substantially rectangular parallelepiped shape. In the exterior housing  2 , although not shown in  FIG. 1 , an operation panel, a light receiving section, and a connection terminal coupled to the control device  3  are disposed in the exterior housing  2 . 
     On the front surface  21 , an opening section  211 , through which the projection optical device  6  is inserted, is provided. The attachment mechanism  5  (see  FIG. 5 ) is provided on the inner side of the front surface  21 . 
     Configuration of the Control Device 
     The control device  3  includes an arithmetic processing device such as a CPU (Central Processing Unit) and controls the projector  1 . For example, the control device  3  causes the projector  1  to operate based on an operation signal input from the operation panel and an operation signal of a remote controller received by a light receiving section. When an imaging device is coupled to the projector  1 , the control device  3  is capable of carrying out, based on a captured image input from the imaging device, adjustment of a projected image projected onto the projection surface by the projection optical device  6 . For example, the control device  3  executes, based on the captured image captured by the imaging device, adjustment processing such as keystone correction for correcting trapezoidal distortion of the projected image and color correction for the projected image. 
     Configuration of the Image Generating Device 
     The image generating device  4  generates image light corresponding to image information (including an image signal) input from the control device  3  and emits the Generated image light to the projection optical device  6 . The image generating device  4  includes a light source  41 , a uniformizing device  42 , a color separating device  43 , a relay device  44 , an image forming device  45 , and an optical component housing  46 . 
     The light source  41  emits illumination light to the uniformizing device  42 . As the configuration of the light source  41 , for example, a configuration including a solid-state light source that emits blue light, which is excitation light, and a wavelength conversion element that performs wavelength conversion for converting a part of the blue light emitted from the solid-state light source into fluorescent light including green light and red light can be illustrated. As other configurations of the light source  41 , a configuration including a light source lamp such as an ultra-high pressure mercury lamp as a light source can be illustrated and a configuration including solid-state light sources that individually emit blue light, green light, and red light can be illustrated. 
     The uniformizing device  42  uniformizes illuminance of a light beam made incident from the light source  41 . The uniformizing device  42  includes a first lens array  421 , a second lens array  422 , a polarization conversion element  423 , and a superimposition lens  424 . 
     The color separating device  43  separates the light beam made incident from the uniformizing device  42  into red light LR, green light LG, and blue light LB. The color separating device  43  includes dichroic mirrors  431  and  432  and a reflection mirror  433 . 
     The relay device  44  is provided in an optical path of the red light LR longer than an optical path of the blue light LB and an optical path of the green light LG and suppresses a loss of the red light LR. The relay device  44  includes an incident side lens  441 , a reflection mirror  442 , a relay lens  443 , and a reflection mirror  444 . Color light having an optical path longer than optical paths of the other color lights may be assumed to be the blue light LB and the relay device  44  may be provided in the optical path of the blue light LB. 
     The image forming device  45  modulates the blue light LB, the green light LG, and the red light LR made incident thereon and combines the modulated color lights to form image light. The image forming device  45  includes a field lens  451 , an incident-side polarizing plate  452 , a light modulating device  453 , and an emission-side polarizing plate  454  provided for each of the color lights LB, LG, and LR and one light combining device  455 . 
     The light modulating device  453  modulates, according to image information, light emitted from the light source  41 . The light modulating device  453  includes a light modulating device for blue  453 B that modulates the blue light LB, a light modulating device for green  453 G that modulates the green light LG, and a light modulating device for red  453 R that modulates the red light LR in this embodiment, the light modulating device  453  is configured by a transmission-type liquid crystal panel. A liquid crystal light valve is configured by the incident-side polarizing plate  452 , the light modulating device  453 , and the emission-side polarizing plate  454 . 
     The light combining device  455  combines the color lights modulated by the light modulating devices  453 B,  453 G, and  453 R to form image light. The light combining device  455  emits the formed image light to the projection optical device  6 . The light combining device  455  can be configured by a cross dichroic prism. However, not only this, but the light combining device  455  can also be configured by, for example, a plurality of dichroic mirrors. 
     The optical component housing  46  holds the devices  42  to  44  and the field lens  451 . An illumination light axis Ax, which is an optical axis in design, is set in the image generating device  4 . The optical component housing  46  holds the devices  42  to  44  and the field lens  451  in predetermined positions on the illumination light axis Ax. The light source  41 , the image forming device  45 , and the projection optical device  6  are disposed in predetermined positions on the illumination light axis Ax. 
     In the following explanation, three directions orthogonal to one another are represented as a +X direction, a +Y direction, and a +Z direction. The +Z direction is assumed no be a direction from the rear surface  22  to the front surface  21  and an emitting direction of image light by the image generating device  4 . The +Y direction is assumed to be a direction from a bottom surface to a top surface. A left direction in the case in which the projector  1  is viewed from the +Z direction such that the +Y direction is on the upper side is assumed to be the +X direction. 
     The opposite direction of the +X direction is represented as a −X direction, the opposite direction of the +Y direction is represented as a −Y direction, and the opposite direction of the +Z direction is represented as a −Z direction. 
     Orthogonal indicates crossing at a right angle. 
     Configuration of the Projection Optical Device 
       FIGS. 2 and 3  are perspective views showing the projection optical device  6 . Specifically,  FIG. 2  is a perspective view of the projection optical device  6  viewed from an incident side of image light.  FIG. 3  is a perspective view of the projection optical device  6  viewed from an emission side of the image light. 
     The projection optical device  6  projects light emitted from the light emitting device  11 . That is, the projection optical device  6  projects image light made incident from the image generating device  4  onto the projection surface. 
     The projection optical device  6  includes, as shown in  FIGS. 2 and 3 , a plurality of lenses  61 , a lens barrel  62 , and a fixing device  7  that fixes the lens barrel  62  to the light emitting device  11 . 
     The plurality of lenses  61  enlarges and projects image light emitted from the light emitting device  11 . The plurality of lenses  61  may include a focus lens and a zoom lens. The focus lens is provided in the lens barrel  62  to be capable of moving along the optical axis of the focus lens. The focus lens adjusts a focus state of an image based on the image light projected onto the projection surface. The zoom lens is provided in the lens barrel  62  to be capable of moving along the optical axis of the zoom lens. The zoom lens adjusts a zoom state of the image based on the image light projected onto the projection surface. 
     The lens barrel  62  holds the plurality of lenses  61 . The lens barrel  62  is formed in a substantially columnar shape. 
     Configuration of the Fixing Device 
       FIG. 4  is a sectional view showing the fixing device  7 . Specifically,  FIG. 4  is a diagram showing a cross section of the fixing device  7  extending along a YZ plane and including a center axis CX of a first tube member  71 . 
     The fixing device  7  reinforces coupling of the projection optical device  6  and the light emitting device and attaches the projection optical device  6  to the attachment mechanism  5  of the light emitting device  11 . As shown in  FIGS. 2 and 3 , a portion on an incident side of image light in the lens barrel  62  is fit in the fixing device  7  and the lens barrel  62  is attached to the fixing device  7  such that the portion of the lens barrel  62  is covered, whereby the fixing device  7  couples the projection optical device  6  to the light emitting device  11 . That is, the fixing device  7  fixes the lens barrel  62  included in the projection optical device  6  to the light emitting device  11 . 
     The fixing device  7  includes, as shown in  FIGS. 2 to 4 , a first tube member  71 , a frame member  72 , a pressing mechanism  73 , a locking member  76  and a meshing member  77 . 
     Configuration of the First Tube Member 
     The first tube member  71  is a tubular member functioning as a main body of the fixing device  7 . A portion in the −Z direction of the lens barrel  62  is fit in the first tube member  71 . The lens barrel  62  is attached to the first tube member  71 . The center axis CX of the first tube member  71  coincides with the center axis of the lens barrel  62 . Since the projection optical device  6  is disposed along the +Z direction, the center axis CX of the first tube member  71  and the center axis of the lens barrel  62  extend along the +Z direction. 
     The first tube member includes a through-opening  711 , a restricting section  712 , and a projecting section  713 . 
     The through-opening  711  pierces through the first tube member  71  along the +Z direction. The through-opening  711  is formed in a substantially circular shape when viewed from the +Z direction. A portion in the −Z direction in the lens barrel  62  is inserted into the inside of the through-opening  711 . 
     The restricting section  712  projects to a radial direction outer side centering on the center axis CX. The restricting section  712  restricts a turn centering on the center axis CX of a second tube member  74  explained below. In this embodiment, the restricting section  712  is configured by a screw fixed to the outer circumferential surface of the first tube member  71 . 
     The projecting section  713  is provided in a ring shape at the end portion in the +Z direction in the first tube member  71 . That is, the projecting section  713  projects from the end portion in the +Z direction in the first tube member  71  to the radial direction outer side centering on the center axis CX. The frame member  72  is fixed to the projecting section  713 . 
     Configuration of the Frame Member 
     The frame member  72  is a member formed in a plate shape and is provided on the outer side of the first tube member  71  and includes an opening section  721  through which the lens barrel  62  is inserted. The frame member  72  is fixed to the projecting section  713  of the first tube member  71  by fixing members FM 1  such as screws. As shown in  FIG. 2 , the frame member  72  is formed in a substantially rectangular shape when viewed from the +Z direction and extends to the outer side from the lens barrel  62 . 
     A part in the −Z direction in the frame member  72  is a contact section  722  in contact with a holding section of the attachment mechanism  5  included in the light emitting device  11  explained below. That is, the frame member  72  includes the contact section  722  in a position opposed to the pressing mechanism  73  in the frame member  72 . Specifically, the contact section  722  is opposed to, in the +Z direction, a pressing section  742  included in the second tube member  74  of the pressing mechanism  73 . In other words, the contact section  722  is disposed in the +Z direction with respect to the pressing section  742 . When the frame member  72  is not disposed in the −Z direction with resect to the projecting section  713 , the surface in the −Z direction in the projecting section  713  may be used as a contact section in contact with the holding section  57 . 
     Configuration of the Pressing Mechanism 
     The pressing mechanism  73  is provided to be opposed to the contact section  722 . When the fixing device  7  is attached to the light emitting device  11 , the pressing mechanism  73  presses the holding section  57  (see  FIG. 8 ) of the attachment mechanism  5  of the light emitting device  11  toward the contact section  722 . That is, the pressing mechanism  73  is provided to be opposed to the contact section  722 . When the projection optical device  6  is attached to the light emitting device  11 , the pressing mechanism  73  presses the holding section  57  (see  FIG. 8 ) toward the contact section  722 . The pressing mechanism  73  sandwiches the holding section  57  between the pressing mechanism  73  and the contact section  722 . 
     The pressing mechanism  73  includes the second tube member  74  and an urging section  75  as shown in  FIGS. 2 to 9 . 
     Configuration of the Second Tube Member 
     As shown in  FIGS. 3 and 4 , the second tube member is a tubular member provided concentrically with the first tube member  71  on the outer side of the first tube member  71 . That is, the center axis of the second tube member  74  coincides with the center axis CX of the first tube member  71 . 
     The second tube member  74  includes a long hole  741 , a pressing section  742 , and a disposing section  743 . 
     The long hole  741  is a long hole long in the +Z direction. The long hole  741  pierces through the second tube member  74  along a radial direction centering on the center axis CX. A plurality of long holes  741  are provided at equal intervals in a circumferential direction centering on the center axis CX. Specifically, six long holes  741  are provided in the second tube member  74 . The restricting section  712  is inserted through the long hole  741 , whereby a turn of the second tube member  74  centering on the center axis CX is restricted and a slide of the second tube member  74  along the center axis CX is allowed. That is, the second tube member  74  is movable along the center axis CX. 
     The pressing section  742  is a projecting portion projecting to the radial direction outer side centering on the center axis CX from a portion in the +Z direction in the second tube member  74 . A plurality of pressing sections  742  are provided at equal intervals in the circumferential direction centering on the center axis CX. In this embodiment, four pressing sections  742  are provided. When the projection optical device  6  attached to the attachment mechanism  5  of the light emitting device  11 , the pressing section  742  comes into contact with the holding section  57  and presses the holding section  57  to the contact section  722  side. The surface in the +Z direction in the pressing section  742  includes a pressing surface  742 A and a guide surface  7425 . 
     The pressing surface  742 A is provided in a position opposed to the contact section  722  in the pressing section  742 . The pressing surface  742 A comes into contact with the holding section  57  and presses the holding section  57  with an urging force of the urging section  75 . The pressing surface  742 A is parallel to an XY plane orthogonal to the center axis CX. 
     The guide surface  7425  is adjacent to the pressing surface  742 A in the circumferential direction centering on the center axis CX and is provided continuously to the pressing surface  742 A. Specifically, the guide surface  742 B is provided continuously to the pressing surface  742 A in a counterclockwise position with respect to the pressing surface  742 A when viewed from the +Z direction. The guide surface  7425  is inclined with respect to the circumferential direction centering on the center axis CX to further separate from the contact section  722  as being further away, from the pressing surface  742 A. That is, the guide surface  742 B is inclined to be further located in the −Z direction as further separating from the pressing surface  742 A in the circumferential direction of the center axis CX when viewed from the +Z direction. When an operation section  59  explained below is operated and the holding section  57  is turned clockwise when viewed from the +Z direction, the guide surface  742 B guides the holding section  57  to between the pressing surface  742 A and the contact section  722 . That is, the guide surface  742 B guides the holding section  57  to the pressing surface  742 A. 
     The disposing section  743  is a pin-like section projecting in the −Z direction from the surface in the −Z direction in the second tube member  74 . A plurality of disposing sections  743  are provided at equal intervals in the circumferential direction centering on the center axis CX. The disposing section  743  is inserted into the inside of the urging section  75 , whereby the urging section  75  is disposed in the disposing section  743 . At this time, the end portion in the +Z direction in the urging section  75  is in contact with an end face  74 A in the −Z direction in the second tube member  74 . 
     In this embodiment, six disposing sections  743  are provided. 
     Configuration of the Urging Section 
     The urging section  75  urges the second tube member  74  in the +Z direction. That is, the urging section  75  urges the pressing section  742  of the second tube member  74  to the contact section  722  side. In this embodiment, six urging sections  75  are provided in the fixing device  7 . The urging section  75  is a compression coil spring. The end portion in the +Z direction in the urging section  75  is in contact with the end face  75 . The end portion in the −Z direction in the urging section  75  is in contact with the locking member  76 . That is, the urging section  75  is disposed between the second tube member  74  and the locking member  76 . 
     Configuration of the Locking Member 
     The locking member  76  locks the urging section  75  disposed in the disposing section  743 . The locking member  76  is a tubular member concentric with the first tube member  71  and provided on the outer side of the first tube member  71 . An end face  76 A in the +Z direction in the locking member  76  locks the end portion in the −Z direction in the urging section  75 . 
     As shown in  FIG. 4 , the locking member  76  includes, in a part in the −Z direction, a meshing section  761  that meshes with the meshing member  77 . The meshing section  761  is a spiral screw groove extending along the circumferential direction centering on the center axis CX. 
     Configuration of the Meshing Member 
     In a state in which the meshing member  77  meshes with the locking member  76 , the meshing member  77  is fixed to a surface  71 A in the −Z direction in the first tube member  71  by fixing members FM 2  such as screws. The meshing member  77  is a cylindrical member centering on the center axis CX and is concentric with the first tube member  71  and is disposed on the outer side of the first tube member  71 . The meshing member  77  includes a meshing section  771 , an attaching section  772 , and a plurality of hole sections  773 . 
     The meshing section  771  is provided on the outer circumferential surface of a part in the +Z direction in the meshing member  77 . The meshing section  771  is a spiral screw thread extending along the circumferential direction centering on the center axis CX. In a state in which the meshing section  771  and the meshing section  761  are meshed, the meshing member  77  is turned clockwise when viewed from the −Z direction, whereby the meshing member  77  moves in the direction. On the other hand, in a state in which the meshing section  771  and the meshing section  761  are meshed, the meshing member  77  is turned counterclockwise when viewed from the −Z direction, whereby the meshing member  77  moves in the −Z direction. 
     The attaching section  772  configures the end portion in the −Z direction in the meshing member  77 . The attaching section  772  projects to the radial direction inner side centering on the center axis CX from the end portion in the −Z direction in the meshing section  771 . 
     The plurality of hole sections  773  pierce through the attaching section  772  along the +Z direction. The fixing member FM 2  such as a screw is inserted through each of the plurality of hole sections  773  along the +Z direction. The fixing members FM 2  inserting through the hole sections  773  are fixed to the surface  71 A, whereby the meshing member  77  meshing with the locking member  76  is fixed to the first tube member  71 . 
     The urging section  75  adopted in the fixing device is a compression coil spring having relatively large repulsion. Therefore, it is not easy to attach the urging section  75  to the fixing device  7  while keeping the urging section  75  in contact with the second tube member  74  to cause an urging force to act on the second tube member  74 . 
     In contrast, the locking member  76  in contact with the end portion in the −Z direction in the urging section  75  and the meshing member  77  meshing with the locking member  76  are provided in the first tube member  71  and, in a state in which the meshing member  77  is turned clockwise when viewed from the −Z direction and the position of the meshing member  77  is adjusted, the meshing member  77  is fixed to the tube member  71  by the fixing members FM 2 . 
     Consequently, the urging section  75  having relatively large repulsion can be provided in the fixing device  7  in a state in which an urging force acts on the second tube member  74 . 
     It is possible to adjust the urging force of the urging section  75  acting on the second tube member  74  by adjusting the position of the locking member  76  at the time when the meshing member  77  is fixed to the first tube member  71 . 
     Configuration of the Attachment Mechanism 
       FIG. 5  is a diagram of the attachment mechanism  5  in a release state viewed from an emission side of image light.  FIG. 6  is a diagram of the attachment mechanism  5  in the release state viewed from an incident side of the image light.  FIG. 7  is a diagram of the attachment mechanism  5  in a lock state viewed from the emission side of the image light.  FIG. 8  is a diagram of the attachment mechanism  5  in the lock state viewed from the incident side of the image light. 
     The attachment mechanism  5  is provided in the light emitting device  11  and detachably holds the attached projection optical device  6 . That is, the projection optical device  6  is detachably attached to the attachment mechanism  5 . The attachment mechanism  5  includes, as shown in  FIGS. 5 to 8 , a substrate  51  and a turning member  55 . 
     Configuration of the Substrate 
     The substrate  51  supports the turning member  55  to be capable of turning centering on the center axis CX of the projection optical device  6  to be attached. The substrate  51  is formed in a rectangular shape long in the +X direction when viewed from the +Z direction. The substrate  51  includes an opening section  52 , a projecting section  53 , and an inserting section  54 . 
     The opening section  52  is a circular opening section piercing through the substrate  51  along the +Z direction in the center of the substrate  51 . A center C of the opening section  52  when viewed from the +Z direction coincides with the center axis CX at the time when the project on optical device  6  is attached to the attachment mechanism  5 . 
     in the following explanation, a clockwise direction centering on the center C of the opening section  52  viewed from the +Z direction is represented as a +D direction and a counterclockwise direction centering on the center C is represented as a −D direction. In other words, a counterclockwise direction centering on the center C of the opening section  52  viewed from the −Z direction is represented as the +D direction and a clockwise direction centering on the center C is represented as the −D direction. 
     The projecting section  53  projects toward the inner side of the opening section  52  from the inner edge of the opening section  52  when viewed from the +Z direction or the −Z direction. A plurality of projecting sections  53  are provided in the substrate  51 . In this embodiment, four projecting sections  53  are provided at equal intervals along the inner edge of the opening section  52 . 
     The inserting section  54  is provided in each of the plurality of projecting sections  53 . That is, a plurality of inserting sections are provided. The inserting section  54  is a pin inserted into a guide section  58  of the turning member  55  to guide a turn of the turning member  55  centering on the center C. That is, the inserting section  54  guides the turn of the turning member  55  centering on the center axis CX in conjunction with the guide section  58 . 
     A diameter expanded section is provided at the distal end of the inserting section  54 . Consequently, a drop of the turning member  55  from the substrate  51  is suppressed. 
     Configuration of the Turning Member 
     The turning member  55  is formed in a ring shape as shown in  FIGS. 6 and 8 . The turning member  55  is concentric with the opening section  52  and is provided such that the inner edge of the turning member  55  substantially coincides with the inner edge of the opening section  52 . The turning member  55  is supported by the substrate  51  to be capable of turning centering on the center axis CX. The turning member  55  includes an opening section  56 , a holding section  57 , a guide section  58 , and an operation section  59 . 
     The opening section  56  is formed in a substantially circular shape in the center of the turning member  55  when viewed from the −Z direction. The center or the opening section  56  coincides with the center C of the opening section  52  when viewed from the −Z direction. 
     The holding section  57  is a part sandwiched by the fixing device  7  and is a part that holds the fixing device  7  and the projection optical device  6 . The holding section  57  is a projecting section disposed on the surface in the −Z direction in the turning member  55  and projecting to the inner side of the opening section  56  when viewed from the Z direction. In this embodiment, four holding sections  57  are provided at equal intervals in the circumferential direction of the turning member  55 . 
     When a state of the attachment mechanism  5  is the release state, the holding section  57  is disposed in a position overlapping the projecting section  53  when viewed from the −Z direction. On the other hand, when the state of the attachment mechanism  5  is the lock state, the holding section  57  projects in the +D direction from the projecting section  53 . As explained in detail below, the holding section  57  moves along the guide surface  742 B according to a turn of the turning member  55  in the +D direction and is disposed between the pressing section  742  and the contact section  722 . The release state is a state in which the projection optical device  6  attached to the attachment mechanism can be detached among states of the attachment mechanism  5 . The lock state is a state in which the projection optical device  6  attached to the attachment mechanism  5  is locked among the states of the attachment mechanism  5 . 
     An inclined surface  571  along the guide surface  742 B is provided at the distal end portion in the +D direction in the holding section  57 . 
     The guide section  58  is an arcuate long hole centering on the center C. A plurality of guide sections  58  are provided. When the turning member  55  is attached to the substrate  51 , the inserting sections  54  corresponding to the guide sections  58  are inserted into the guide sections  58  from the +Z direction. The guide section  58  guides a turn of the turning member  55  in the +D directions centering on the center C. 
     When the inserting section  54  is located at the end portion in the +D direction in the guide section  58 , the holding section  57  is disposed in a position overlapping the projecting section  53  when viewed from the +Z direction or the −Z direction. A state of the attachment mechanism  5  at this time is the release state. On the other hand, when the inserting section  54  is located at the end portion in the −D direction in the guide section  58 , the holding section  57  is disposed in a position projecting in the +D direction from the projecting section  53 . A state of the attachment mechanism  5  at this time is the lock state. The holding section  57  is disposed between the contact section  722  and the pressing surface  742 A and is urged to the contact section  722  side by the pressing section  742 . 
     The operation section  59  is a part operated by a user in the turning member  55 . The operation section  59  is a columnar portion provided at the end portion in the +Y direction in the turning member  55  and extends in the +Z direction. The operation section  59  is turned in the +D direction to thereby move the turning member  55  including the holding section  57  in the +D direction and dispose the holding section  57  between the contact section  722  and the pressing mechanism  73 . 
     The turning member  55  is urged in the +D direction by a not-shown urging member such that the lock state is maintained. 
     Attachment of the Projection Optical Device to the Light Emitting Device 
     Attachment of the projection optical device  6  to the light emitting device  11  is explained below. 
     First, the operation section  59  is operated to turn the turning member  55  in the −D direction and set the state of the attachment mechanism  5  to the release state in which the holding section  57  overlaps the projecting section  53 . 
     Thereafter, the projection optical device  6  is disposed with respect to the attachment mechanism  5  such that the pressing sections  742  of the fixing device  7  are located among the four projecting sections  53  in the circumferential direction centering on the center C. 
       FIG. 9  is a perspective view of the attachment mechanism  5  and the projection optical device  6  in the lock state viewed from the incident side of the image light. 
     In this state, when the operation section  59  is operated to turn the turning member  55  in the +D direction, the holding sections  57  move in the +D direction along the guide surfaces  742 B of the pressing sections  742  corresponding to the holding sections  57 . Consequently, as shown in  FIG. 9 , the holding sections  57  are disposed between the pressing surfaces  742 A of the pressing sections  742  and the contact section  722 . At this time, the second tube members  74  including the pressing sections  742  are urged to the contact section  722  side by the urging sections  75 . Therefore, the holding sections  57  are sandwiched between the contact section  722  and the pressing sections  742 . The fixing device  7  and the projection optical device  6  are fixed to the attachment mechanism  5 . A state of the attachment mechanism  5  at this time is the lock state as explained above. As long as the turning member  55  is not turned in the −D direction, detachment of the projection optical device  6  from the attachment mechanism  5  is restricted. 
     Detachment of the Projection Optical Device from the Light Emitting Device 
     Detachment of the projection optical device  6  from the light emitting device  11  is explained. 
     In the attachment mechanism  5  in the lock state, when the operation section  59  is operated to turn the turning member  55  in the −D direction, the holding sections disposed between the pressing sections  742  and the contact section  722  move in the −D direction and are disposed in positions overlapping the projecting sections  53  when viewed from the −Z direction. In this state, since the holding sections  57  are not sandwiched between the pressing sections  742  and the contact section  722 , the projection optical device  6  can be moved in the +Z direction with respect to the attachment mechanism  5 . The projection optical device  6  can be detached from the attachment mechanism  5 . A state of the attachment mechanism  5  at this time is the release state as explained above. 
     Effects of the Embodiment 
     The projector  1  according to this embodiment explained above achieves effects explained below. 
     The projector  1  includes the light emitting device  11  and the projection optical device  6 . The light emitting device  11  includes the light source  41 , the light modulating device  453  that modulates light emitted from the light source  41 , and the attachment mechanism  5  to which the projection optical device  6  is attached. The attachment mechanism  5  includes the holding section  57 . 
     The fixing device  7  configuring the projection optical device  6  fixes, to the light emitting device  11  that emits light, the lens barrel  62  configuring the projection optical device  6  and holding the plurality of lenses  61 . The fixing device  7  includes the first tube member  71 , the contact section  722 , and the pressing mechanism  73 . The contact section  722  is provided on the outer side of the first tube member  71  and is in contact with the holding section  57  included in the light emitting device  11 . The pressing mechanism  73  is provided to be opposed to the contact section  722 . When the fixing device  7  is attached to the light emitting device  11 , the pressing mechanism  73  presses the holding section  57  toward the contact section  722 . 
     With such a configuration, the holding section  57  configuring the attachment mechanism  5  of the light emitting device  11  is sandwiched by the contact section  722  and the pressing mechanism  73 . Consequently, the fixing device  7  can be attached to the light emitting device  11 . Consequently, the fixing device  7 , to which the lens barrel  62  is coupled, can be fixed to the light emitting device  11 . Therefore, it is possible to cause the light emitting device  11  to stably hold the projection optical device  6 . 
     In the fixing device  7 , the pressing mechanism  73  includes the pressing section  742  that comes into contact with the holding section  57  and the urging section  75  that urges the pressing section  742  to the contact section  722  side. 
     With such a configuration, since the pressing section  742  in contact with the holding section  57  can be urged to the contact section  722  side by the urging section  75 , the holding section  57  can be pressed to the contact section  722  side. Therefore, the holding section  57  can be stably sandwiched between the contact section  722  and the pressing section  742 . 
     In the fixing device  7 , the pressing section  742  includes the pressing surface  742 A and the guide surface  742 B. The pressing surface  742 A is provided in the position opposed to the contact section  722  and presses the holding section  57 . The guide surface  7423  is adjacent to the pressing surface  742 A in the circumferential direction centering on the center axis CX of the first tube member  71  and provided continuously to the pressing surface  742 A. The guide surface  7423  is inclined with respect to the circumferential direction to further separate from the contact section  722  as being further away from the pressing surface  742 A and Guides the holding section  57  to the pressing surface  742 A. 
     With such a configuration, when the fixing device  7  is attached to the attachment mechanism  5  of the light emitting device  11 , the holding section  57  moves along the guide surface  742 B, whereby the holding section  57  can be guided to between the pressing surface  742 A and the contact section  722 . Therefore, it is possible to smoothly attach the fixing device  7  and the lens barrel  62  to the light emitting device  11 . 
     In the fixing device  7 , the plurality of pressing sections  742  are provided in the circumferential direction centering on the center axis CX of the first tube member  71 . 
     With such a configuration, the holding sections  57  can be sandwiched by the plurality of pressing sections  742 . Therefore, the fixing device  7  can be stably to the light emitting device  11 . Further, the lens barrel  62  can be stably fixed to the light emitting device  11 . 
     In the fixing device  7 , the pressing mechanism  73  includes the second tube member  74 . The second tube member  74  is provided on the outer side of the first tube member  71  and is capable of moving along the center axis CX of the first tube member  71 . The pressing section  742  projects to the outer side from the second tube member  74 . The urging section  75  urges the second tube member  74  to the contact section  722  side. 
     With such a configuration, the second tube member  74  can be moved along the first tube member  71  by an urging force of the urging section  75 . The holding section  57  can be pressed by the pressing section  742  provided in the second tube member  74 . Therefore, the pressing section  742  can be stably moved. A pressing force can be stably applied to the holding section  57 . 
     The projection optical device  6  includes the fixing device  7 , the plurality of lenses  61 , and the lens barrel  62  holding the plurality of lenses  61  and attached to the fixing device  7 . 
     In other words, the projection optical device  6  is detachably attached to the light emitting device  11  that emits light. The projection optical device  6  includes the plurality of lenses  61 , the lens barrel  62 , the contact section  722 , and the pressing mechanism  73 . The lens barrel  62  holds the plurality of lenses  61 . The contact section  722  comes into contact with the holding section  57  included in the attachment mechanism  5  of the light emitting device  11 . The pressing mechanism  73  is provided to be opposed to the contact section  722 . When the projection optical device  6  is attached to the attachment mechanism  5  of the light emitting device  11 , the pressing mechanism  73  presses the holding section  57  toward the contact section  722 . 
     With such a configuration, it is possible to achieve the same effects as the effects of the fixing device Consequently, the projection optical device  6  can be stably fixed to the attachment mechanism  5  of the light emitting device  11 . 
     In the projector  1 , the attachment mechanism  5  includes the operation section  59  that moves the holding section  57  and disposes the holding section  57  between the contact section  722  and the pressing mechanism  73 . 
     With such a configuration, by operating the operation section  59 , it is possible to switch a state in which the holding section  57  is disposed between the contact section  722  and the pressing mechanism  73  and a state in which the holding section  57  is not disposed between the contact section  722  and the pressing mechanism  73 . That is, it is possible to switch a state in which the attachment mechanism  5  holds the projection optical device  6  and a state in which the attachment mechanism  5  does not hold the projection optical device  6 . Consequently, it is possible to detachably attach the projection optical device  6  to the light emitting device  11 . Therefore, it is possible to easily replace the projection optical device  6 . 
     Modifications of the Embodiment 
     The present disclosure is not limited to the embodiment. Modifications, improvements, and the like in a range in which the object of the present disclosure can be achieved are included in the present disclosure. 
     In the embodiment, the first tube member  71  is the cylindrical member. However, the shape of the first rube member  71  may not be a perfect cylindrical shape and may be a part of a cylindrical shape, that is, an arcuate shape when viewed from the +Z direction or the −Z direction. The shape of the first tube member  71  is not limited to the cylindrical shape and may be a polygonal cylindrical shape. 
     In the embodiment, the fixing device  7  includes the frame member  72  provided on the outer side of the first tube member  71 . However, the frame member  72  is not limited to be configured as a separate member from the first tube member  71  and fixed to the first tube member  71  and may be configured integrally with the first tube member  71 . 
     In the embodiment, the contact section  722  is provided in the part opposed to the pressing mechanism  73  in the frame member  72 . However, not only this, but the contact section  722  may be provided separately from the frame member  72 . 
     In the embodiment, the pressing mechanism  73  includes the second tube member  74  including the pressing section  742  that comes into contact with the holding section  57  and the urging section  75  that urges the pressing section  742  to the contact section  722  side. However, not only this, but the configuration of the pressing mechanism  73  can be changed as appropriate if the pressing mechanism  73  can cause a pressing force to the contact section  722  side to act on the holding section  57 . 
     In the embodiment, the pressing section  742  is provided in the second tube member  74  provided on the outer side of the first tube member  71  and concentrically with the first tube member  71 . However, not only this, but the pressing section  742  may not be provided in the second tube member  74  if the urging section  75  can urge the pressing section  742 . 
     The urging section  75  is the compression coil spring. However, not only this, but the urging section  75  may be configured by another urging member such as a tension coil spring or an elastic body if the urging section  75  can cause the urging force to act on the pressing section  742 . 
     In the embodiment, the pressing section  742  includes the pressing surface  742 A and the guide surface  742 B. However, not only this, but the guide surface  742 B may be absent. Similarly, the inclined surface  571  is provided at the distal end portion in the +D direction in the holding section  57 . However, not only this, but the inclined surface  571  may be absent. 
     In the embodiment, the plurality of pressing sections  742  are provided in the circumferential direction centering on the center axis CX of the first tube member  71 . However, not only this, but the number and the disposition of the pressing sections  742  can be changed as appropriate if the holding sections  57  can be sandwiched between the contact section  722  and the pressing sections  742  and the projection optical device  6  can be stably held by the attachment mechanism  5  by sandwiching the holding sections  57 . The projection optical device  6  is more stably held by the attachment mechanism  5  by disposing three or more pressing sections  742  at equal intervals in the circumferential direction centering on the center axis CX. 
     In the embodiment, the projection optical device  6  includes the plurality of lenses  61 , the lens barrel  62  that holds the plurality of lenses  61 , and the fixing device  7 . A part in the −Z direction in the lens barrel  62  is disposed in the first tube member  71  of the fixing device 
     However, not only this, but the fixing device  7  only has to be provided in the lens barrel  62  and may not house a part of the lens barrel  62  on the inside. The fixing device  7  may be provided in the +Z direction from the center in the +Z direction in the lens barrel  62 . In other words, the contact section  722  and the pressing mechanism  73  may be provided in the +Z direction from the center the +Z direction in the lens barrel  62 . In this case, light emitted from the lens barrel  62  may be projected to the outside of the projection optical device  6  passing through the through-opening  711  of the first tube member  71 . 
     In the embodiment, the operation section  59  is operated, whereby the holding section  57  is capable of moving between the position where the holding section  57  is disposed between the contact section  722  and the pressing mechanism  73  and the position where the holding section  57  is not disposed between the contact section  722  and the pressing mechanism  73 . However, not only this, but the state in which the holding section  57  is disposed between the contact section  722  and the pressing mechanism  73  and the state in which the holding section  57  is not disposed between the contact section  722  and the pressing mechanism  73  may be switched by turning the fixing device  7  centering on the center axis CX. That is, the holding section  57  may not always be moved. 
     A moving direction of the holding section  57  is not limited to the +D directions centering on the center C and may be a direction orthogonal to an axis parallel to the center axis CX. For example, the attachment mechanism  5  may be configured such that, when the projection optical device  6  is attached to the light emitting device  11 , the holding section  57  is moved in +Y directions or +X directions, whereby the holding section  57  is disposed between the contact section  722  and the pressing mechanism  73 . 
     In the embodiment, the attachment mechanism  5  includes the operation section  59  that turns the turning member  55  and moves the holding section  57  in the +D directions. However, not only this, but the operation section  59  may be absent. In this case, the turning member  55  may be turned, for example, using driving means such as a motor that is driven according to operation by the user. 
     The holding section  57  may be directly moved by the driving means. 
     Further, the holding section  57  may not be provided in the ring-like turning member  55 . A configuration including the holding section  57  can be changed as appropriate. That is, the holding section  57  only has to be provided in the light emitting device  11  to be capable of being disposed between the contact section  722  and the pressing mechanism  73 . 
     In the embodiment, the projector  1  includes three light modulating devices  453 B,  453 G, and  453 R. However, not only this, but the present disclosure is also applicable to a projector including two or less or four or more light modulating devices. 
     In the embodiment, in the image generating device  4 , optical components are disposed in a layout shown in  FIG. 1 . However, not only this, but, in the image generating device  4 , the optical components may be disposed in another layout or the image generating device  4  may include optical components other than the optical components shown in  FIG. 1 . 
     In the embodiment, the light modulating device  453  includes the transmission-type liquid crystal panel, a light incident surface and a light emission surface of which are different. However, not only this, but the light modulating device  453  may include a reflection-type liquid crystal panel, a light incident surface and a light emission surface of which are the same. A light modulating device other than liquid crystal such as a light modulating device making use of a device including a micromirror, for example, a DMD (Digital Micromirror Device) may be used if the light modulating device is capable of modulating an incident light beam and forming an image corresponding to image information. 
     Overview of the Present Disclosure 
     An overview of the present disclosure is noted below. 
     A fixing device according to a first aspect of the present disclosure is a fixing device that fixes, to a light emitting device that emits light, a lens barrel included in a projection optical device and holding a plurality of lenses, the fixing device including: a first tube member; a contact section provided on an outer side of the first tube member and in contact with a holding section included in the light emitting device; and a pressing mechanism provided to be opposed to the contact section and configured to press the holding section toward the contact section when the fixing device is attached to the light emitting device. 
     With such a configuration, the holding section of the light emitting device is sandwiched by the contact section and the pressing mechanism. Consequently, the fixing device can be attached to the light emitting device. Therefore, it is possible to fix the lens barrel to the light emitting device by integrating the fixing device and the lens barrel. 
     In the first aspect, the pressing mechanism may include: a pressing section configured to come into contact with the holding section; and an urging section configured to urge the pressing section to the contact section side. 
     With such a configuration, since the pressing in contact with the holding section can be urged to the contact section side by the urging section, the holding section can be pressed to the contact section side. Therefore, the holding section can be stably sandwiched between the contact section and the pressing section. 
     In the first aspect, the pressing section may include: a pressing surface provided in a position opposed to the contact section and configured to press the holding section; and a guide surface adjacent to the pressing surface in a circumferential direction centering on a center axis of the first tube member and provided continuously to the pressing surface and configured to guide the holding section to the pressing surface, and the guide surface may be inclined with respect to the circumferential direction to further separate from the contact section as being further apart from the pressing surface. 
     With such a configuration, when the fixing device is attached to the light emitting device and the holding section moves to he inserted between the contact section and the pressing section, the holding section can be guided to between the pressing surface and the contact section by moving along the guide surface. Therefore, it is possible to smoothly attach the fixing device and the lens barrel to the light emitting device. 
     In the first aspect, a plurality of the pressing sections may be provided in a circumferential direction centering on a center axis of the first tube member. 
     With such a configuration, the holding section can sandwiched by the plurality of pressing sections. 
     Therefore, the fixing device can be stably fixed to the light emitting device and the lens barrel can be stably fixed to the light emitting device. 
     In the first aspect, the pressing mechanism may include a second tube member provided on an outer side of the first tube member and capable of moving along a center axis of the first tube member, the pressing section may project to the outer side from the second tube member, and the urging section may urge the second tube member to the contact section side. 
     With such a configuration, the second tube member can be moved along the first tube member by an urging force of the urging section. The holding section can be pressed by the pressing section provided in the second tube member. Therefore, the pressing section can be stably moved. A pressing force can be stably applied to the holding section. 
     A projection optical device according to a second aspect of the present disclosure includes: the fixing device according to the first aspect; a plurality of lenses; and a lens barrel holding the plurality of lenses and attached to the fixing device. 
     With such a configuration, it is possible to achieve the same effects as the effects of the fixing device according to the first aspect. Consequently, the projection optical device can be stably fixed to the light emitting device. 
     A projection optical device according to a third aspect of the present disclosure is a projection optical device detachably attached to a light emitting device that emits light, the projection optical device including: a plurality of lenses; a lens barrel holding the plurality of lenses; a contact section in contact with a holding section included in the light emitting device; and a pressing mechanism provided to be opposed to the contact section and configured to press the holding section toward the contact section when the projection optical device is attached to the light emitting device. 
     With such a configuration, it is possible to achieve the same effects as the effects of the projection optical device according to the second aspect. 
     A projector according to a fourth aspect of the present disclosure includes: a light emitting device configured to emit light; and the projection optical device according to the third aspect. The light emitting device includes: a light source; a light modulating device configured to modulate light emitted from the light source; and an attachment mechanism including a holding section, the projection optical device being attached to the attachment mechanism. 
     With such a configuration, it is possible to achieve the same effects as the effects of the projection optical device according to the second aspect and the third aspect. Consequently, it is possible to cause the light emitting device to stably hold the projection optical device. 
     In the fourth aspect, the attachment mechanism may include an operation section configured to move the holding section and dispose the holding section between the contact section and the pressing mechanism. 
     With such a configuration, by operating the operation section, it is possible to switch a state in which the holding section is disposed between the contact section and the pressing mechanism and a state in which the holding section is not disposed between the contact section and the pressing mechanism. That is, it is possible to switch a state in which the attachment mechanism holds the projection optical device and a state in which the attachment mechanism does not hold the projection optical device. Consequently, the projection optical device can be detachably attached to the light emitting device. Therefore, it is possible to easily replace the projection optical device. What is claimed is: