JP5370037B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus in which an image projection unit including a light source, an optical member, and the like is incorporated in a housing.

  2. Description of the Related Art Conventionally, there is a projection display device that scans a laser beam to form a projected image. For example, the retinal scanning display device described in Patent Document 1 emits image light and forms an image by irradiating the retina. Specifically, a plurality of image lights respectively emitted from a plurality of laser light sources are combined by a combining device. An example of the synthesizer is a dichroic mirror. The synthesized image light is collected by the coupling optical system and is incident on the optical fiber. The image light emitted from the optical fiber is scanned by the vibrating mirror, enters the pupil of the eyeball, and forms an image on the retina. In order to reduce the size of the retinal scanning display device, the laser light source and the synthesis device are fixed to the housing in close proximity. In general, the thickness of the casing is uniform with respect to the thickness near the laser light source.

JP 2008-209653 A

  A part that generates heat may be disposed in the housing of the image forming apparatus. When a laser light source is used as a light source, the laser light source is also a heat source. When the heat generated from these heat sources is transmitted to the housing, the housing is deformed by thermal expansion. When the housing is deformed, the positional relationship between a light source such as a laser light source and an incident portion such as an optical fiber changes. When the positional relationship between the light source and the incident portion changes, the optical axis of the image light incident on the incident portion from the light source is shifted. Even when the light source and the synthesizer are closely fixed on the housing and heat is transmitted from the light source to the housing, the housing has a structure in which the incident position of the image light with respect to the incident portion is not affected by thermal deformation. The body is desired.

  The present invention has been made to solve the above-described problems. The object of the present invention is to prevent thermal deformation in the positional relationship between the optical member supported by the casing, the light source section, and the incident section even when the casing is thermally deformed due to heat transmitted from the light source section. An object of the present invention is to provide an image forming apparatus capable of reducing the influence.

The image forming apparatus according to claim 1 is generated from at least one light source unit that generates heat when light is generated, an incident unit into which light generated from the light source unit is incident, and the light source unit. The light source and the optical member are fixedly supported so that the optical axis of the optical member is arranged on the optical path of the optical member for guiding the incident light to the incident portion and the light source portion, and the light source A light source supporting region for fixing and supporting the light source unit, and a light source support for the light source unit. A proximity region located in the vicinity of the region, and a region other than the proximity region and an optical member support region that supports at least the optical member, and the thickness of the casing in the proximity region is the optical thickness rather thick than the thickness of the housing member supporting area Thickness of the housing of the optical member support region, farther from the light source unit, and the housing of the features that is thinner than the thickness of the neighboring region.

The image forming apparatus according to claim 2 is generated from at least one light source unit that generates heat when light is generated, an incident unit into which light generated from the light source unit is incident, and the light source unit. The light source and the optical member are fixedly supported so that the optical axis of the optical member is arranged on the optical path of the optical member for guiding the incident light to the incident portion and the light source portion, and the light source A light source supporting region for fixing and supporting the light source unit, and a light source support for the light source unit. A proximity region located in the vicinity of the region, and a region other than the proximity region and an optical member support region that supports at least the optical member, and the thickness of the casing in the proximity region is the optical thickness Thicker than the thickness of the housing in the member support area The light source unit generates a plurality of types of light having different wavelengths, the optical member includes a plurality of types of mirror which reflects specific light generated by said light source unit, the optical member supporting region, the Each of the plurality of types of mirror units and the incident unit is a region that supports the plurality of types of mirror units at different positions, and the optical member support region that supports the plurality of types of mirror units. The thickness of the casing is characterized by being thinner than the thickness of the casing in the vicinity region as the distance from the light source unit increases.

The image forming apparatus according to claim 3 , wherein the housing includes a heat release unit that releases heat generated by the light source unit in the light source support region and the vicinity region, and the heat release unit has a surface. It is characterized by having unevenness.

  According to the image forming apparatus of the first aspect, the thickness of the casing in the vicinity area close to the light source unit is thicker than the thickness of the casing in the optical member support area. The heat capacity in the vicinity region is increased, and the amount of heat conducted to the optical member support region is suppressed. Therefore, even if the heat generated from the light source unit is high, a large amount of heat is stored in the vicinity region, so that the temperature rise in the optical member support region is reduced, and the housing is localized in the optical member support region. It is possible to reduce the deformation. As a result, the influence of the heat from the light source unit on the positional relationship between the optical member supported on the housing, the light source unit, and the incident unit is reduced.

Furthermore, the thickness of the casing of the optical member support region becomes thinner as the distance from the light source unit increases. The amount of heat generated from the light source unit conducted to each part of the housing gradually decreases as the distance from the light source unit increases. As a result, even if the housing is heated by the heat from the light source unit, the vicinity of the thick wall has a large heat capacity so that the temperature rise is suppressed, and the amount of heat conducted to the thin optical member support region is small. As a result, the temperature rise can be suppressed, so that the temperature of each part of the housing becomes substantially uniform. Since the temperature of each part of the housing becomes substantially uniform, the influence of the heat from the light source unit on the positional relationship between the optical member supported on the housing and the light source unit and the incident unit is reduced. .

In the image forming apparatus according to claim 2, a plurality of mirror portions reflecting the specific light, the distance between the incident portion are disposed at different positions. The thickness of the part that supports the plurality of mirror parts varies depending on the distance from the light source part. Even when the plurality of mirror units are arranged at different positions from the light source unit, the plurality of mirror units support the plurality of mirror units by changing the thicknesses of the portions supporting the plurality of mirror units, respectively. The temperature of the part becomes substantially uniform, and the influence of the heat from the light source part on the positional relationship between the plurality of mirror parts is reduced. As a result, each mirror part can accurately reflect light so as not to affect the light incident on the incident part.

In the image forming apparatus according to claim 3, wherein the heat discharging part having irregularities in the light source support region and the adjacent region is provided. Even when heat is transmitted from the light source unit to the housing, the surface area in the light source support region and the vicinity region is increased, and heat is efficiently released. As a result, the temperature rise in the light source support region and the vicinity region is suppressed, and it is further reduced that the heat from the light source unit affects the positional relationship between the optical member supported on the housing and the light source unit and the incident unit. Is done.

1 is a perspective view showing an appearance of an image forming apparatus 1 according to Embodiment 1 of the present invention. 2 is a perspective view showing an external appearance of a single housing 30 of the image forming apparatus 1 as viewed from the front. FIG. 2 is a perspective view showing an external appearance of a single housing 30 of the image forming apparatus 1 as viewed from the rear. FIG. FIG. 2 is a longitudinal sectional view of the image forming apparatus 1 shown in FIG. 1 cut along a horizontal plane including an AA line and extending in the left-right direction and the front-rear direction and viewed in the upward direction as indicated by an arrow A. FIG. 5 is a longitudinal sectional view for explaining the arrangement of optical paths in the image forming apparatus 1 shown in FIG. 4. FIG. 5 is a longitudinal sectional view showing the thickness of thick portions 40A1 to 40A12 of a housing 30 in the image forming apparatus 1 shown in FIG. FIG. 3 is a front view of the housing 30 as viewed from the front with the dichroic mirror 42C and the like of the image forming apparatus 1 removed. With the laser light source 21C and dichroic mirror 42C of the image forming apparatus 1 removed, the image forming apparatus 1 shown in FIG. 7 is cut along a vertical plane including the GG line and extending in the front-rear direction and the up-down direction. It is the cross-sectional view seen toward the left direction which is a direction. It is explanatory drawing which shows the relationship between expansion of the housing | casing 330 with the uniform thickness of the conventional thick part 340, and the position of the dichroic mirror 342. FIG. It is explanatory drawing which shows the relationship between expansion of the thick part 40A2, 40A5, 40A8 of the said housing | casing 30, and the position of the dichroic mirror 42A. FIG. 3 is a schematic diagram illustrating a usage mode of the image forming apparatus 1 according to the first embodiment. It is a perspective view which shows the external appearance of the housing | casing 430 single-piece | unit provided with many radiation fins 431 on the surface 431A of the housing | casing 430 which concerns on Embodiment 2 of this invention. It is a longitudinal cross-sectional view for demonstrating the modification which varied the thickness of 40 A of thickness parts of the housing | casing 30 in this Embodiment 1 according to the areas 231-233.

  Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.

<Embodiment 1>
The configuration of the image forming apparatus 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a perspective view showing an appearance of the image forming apparatus 1. Hereinafter, the left-right direction, the up-down direction, and the front-rear direction in the first embodiment are defined as shown in FIG. For other drawings, the directions are determined in the same manner as in FIG. The image forming apparatus 1 includes an emission unit 11, a housing unit 12, and a fiber unit 13. The emission unit 11 includes three laser light sources 21A to 21C and light source support portions 22A to 22C described later. The casing unit 12 includes a casing 30, three lenses 41A to 41C, which will be described later, and three dichroic mirrors 42A to 42C. The lenses 41A to 41C and the dichroic mirrors 42A to 42C are fixed to the housing 30 and installed. The fiber part 13 includes a fiber 51, a first fiber support part 52, a second fiber support part 53, and a condenser lens 54 described later. The first fiber support 52 supports the fiber 51. The second fiber support portion 53 supports the first fiber support portion 52. The condenser lens 54 is fixedly installed on the second fiber support portion 53. Specific configurations of the emission unit 11, the housing unit 12, and the fiber unit 13 will be described later. The second fiber support 53 is formed by a known mold casting method using stainless steel as a constituent material.

  The structure of the housing 30 will be described with reference to FIGS. FIG. 2 is a perspective view showing an appearance of the housing 30 as viewed from the front. FIG. 3 is a perspective view showing an appearance of the housing 30 as viewed from the rear. The casing 30 is formed by a known mold casting method using stainless steel as a constituent material.

  The housing 30 includes a rear side surface 31A, an upper side surface 31B, a lower side surface 31C, a left side surface 31D, a right side surface 31E, and a front side surface 31F. The rear side surface 31A is parallel to the left and right vertical surfaces extending in the left and right direction and the up and down direction. The upper side surface 31B is parallel to a horizontal plane extending in the left-right direction and the front-rear direction. The lower side surface 31C is parallel to the upper side surface 31B and is located on the opposite side of the upper side surface 31B. The left side surface 31D is parallel to the front-rear vertical plane extending in the up-down direction and the front-rear direction. The right side surface 31E is parallel to the left side surface 31D and is located on the opposite side of the left side surface 31D. The front side surface 31F is parallel to the rear side surface 31A and is located on the opposite side of the rear side surface 31A. On the rear surface 31AA of the rear side surface 31A shown in FIG. The rear side surface 31 </ b> A is provided with three laser light emission holes 32 </ b> A to 32 </ b> C that allow light emitted from the emission unit 11 to pass therethrough. Three circular lens installation regions 33A to 33C are provided on the rear rear surface 31AB of the rear side surface 31A shown in FIG. The lens installation areas 33A to 33C are areas for installing the lenses 41A to 41C around the laser light emission holes 32A to 32C.

  The upper side surface 31B shown in FIG. 2 has three spaces 34A to 34C, and first mirror installation areas 35A to 35C in the vicinity of the spaces 34A to 34C, respectively. Similar to the upper side surface 31B, the lower side surface 31C has three spaces 36A to 36C, and has second mirror installation regions 37A to 37C in the vicinity of the spaces 36A to 36C, respectively. The first mirror installation areas 35A to 35C and the second mirror installation areas 37A to 37C are arranged side by side in the vertical direction. The fiber portion 13 is installed on the left side surface 31D. The left side surface 31D has a laser light incident hole 38 through which light incident on the fiber portion 13 passes.

  A procedure and method for installing the lenses 41A to 41C and the dichroic mirrors 42A to 42C in the housing 30 will be described with reference to FIG. FIG. 4 is a longitudinal sectional view as seen from the direction of arrow A cut along a horizontal plane including the line AA shown in FIG. First, the circular lenses 41A to 41C are respectively fixed to the lens installation areas 33A to 33C on the rear back surface 31AB by an adhesive. Next, the dichroic mirrors 42A to 42C are fixed to the first mirror installation regions 35A to 35C on the three upper side surfaces 31B and the second mirror installation regions 37A to 37C on the three lower side surfaces 31C with an adhesive. Installed. The dichroic mirrors 42 </ b> A to 42 </ b> C have a rectangular parallelepiped shape and have a reflection surface that reflects light emitted from the laser light source. The reflecting surfaces of the dichroic mirrors 42A to 42C are positioned in contact with the first mirror installation areas 35A to 35C and the second mirror installation areas 37A to 37C. The reflection surfaces of the dichroic mirrors 42A to 42C are installed with the side end portion on the left side surface 31D side inclined 45 degrees forward with respect to the rear side surface 31A. In the first embodiment, the lens installation areas 33A to 33C, the first mirror installation areas 35A to 35C, and the second mirror installation areas 37A to 37C are examples of the optical member support area of the present invention.

  A procedure and a method for fixing the laser light sources 21A to 21C of the emitting unit 11 to the light source support units 22A to 22C and installing the laser light sources 21A to 21C on the housing 30 will be described with reference to FIGS. In FIG. 4, laser light sources 21A to 21C are fixed to cylindrical laser light source support portions 22A to 22C. Laser light source support portions 22A to 22C to which the laser light sources 21A to 21C are fixed are fixedly supported on the rear surface 31AA. The laser light sources 21A to 21C are fixed to the laser light source support portions 22A to 22C with an adhesive, and the laser light source support portions 22A to 22C are fixed to the rear surface 31AA with an adhesive. In FIG. 3, the rear side surface 31 </ b> A of the housing 30 has three light source support regions 50 </ b> A to 50 </ b> C indicated by two-dot chain lines. Laser light source support portions 22A to 22C are fixed to the light source support regions 50A to 50C.

  The procedure and method for installing the fiber 51 and the condensing lens 54 of the fiber part 13 on the housing 30 via the first and second fiber support parts 52 and 53 will be described with reference to FIG. In FIG. 4, the condensing lens 54 is fixed to the second fiber support portion 53 with an adhesive. The second fiber support 53 to which the condenser lens 54 is fixed is fixed to the housing 30 by the two screws 39 shown in FIG. The fiber 51 is supported and fixed to the first fiber support portion 52 by an adhesive. The first fiber support 52 is supported by being fixed to the second fiber support 53 with an adhesive. The fiber 51 and the first fiber support 52 are positioned by a jig so that the optical axis of the condensing lens 54 fixed to the second fiber support 52 matches the optical path of the light incident from the housing 30. Is done.

  The arrangement of the optical path in the image forming apparatus 1 according to the first embodiment will be described with reference to FIG. The laser light emitted from the laser light sources 21 </ b> A to 21 </ b> C is transmitted through the lenses 41 </ b> A to 41 </ b> C installed in the housing 30, reflected by the dichroic mirrors 42 </ b> A to 42 </ b> C, and incident on the fiber 51. A predetermined optical path indicated by a chain line is formed. Each lens is positioned so that the optical axes of the lenses 41A to 41C coincide with a predetermined optical path, and each lens forms a part of the optical path of the light emitted by each of the laser light sources 21A to 21C. The dichroic mirrors 42 </ b> A to 42 </ b> C are positioned so as to reflect the light transmitted through the lenses 41 </ b> A to 41 </ b> C and reflect the light on a predetermined optical path, and each dichroic mirror also forms a part of the predetermined optical path. . The optical axis of the condensing lens 54 coincides with a predetermined optical path so that the light reflected by the dichroic mirrors 42 </ b> A to 42 </ b> C is collected by the condensing lens 54 installed on the second fiber support portion 53. The condenser lens 54 also forms a part of a predetermined optical path. In FIG. 5, the optical paths of the light emitted from each of the laser light sources 21 </ b> A to 21 </ b> C and reflected by the dichroic mirrors 42 </ b> A to 42 </ b> C are the optical paths 61 </ b> A to 61 </ b> C, reflected by the dichroic mirrors 42 </ b> A to 42 </ The optical paths of the emitted light are the optical paths 62A to 62C. In the first embodiment, the optical paths 61A to 61C are set to have substantially the same length. The optical paths 61A to 61C in the first embodiment are an example of an optical path between the light source unit and the optical member of the present invention. The light condensed by the condenser lens 54 enters the fiber 51. Each of the laser light sources 21 </ b> A to 21 </ b> C includes a structure that emits laser light and dissipates heat generated by light emission. The laser light sources 21A to 21C in Embodiment 1 are an example of the light source unit of the present invention. The housing | casing 30 and the 2nd fiber support part 53 in this Embodiment 1 are examples of the housing | casing of this invention. The fiber 51 in the first embodiment is an example of the incident portion of the present invention. The lenses 41 </ b> A to 41 </ b> C, the dichroic mirrors 42 </ b> A to 42 </ b> C, and the condensing lens 54 in Embodiment 1 are examples of the optical member of the present invention.

  The laser light sources 21A to 21C generate laser beams of different colors. The laser light source 21A generates red laser light, the laser light source 21B generates blue laser light, and the laser light source 21C generates green laser light. The laser light sources 21A to 21C generate heat at different temperatures in order to emit light having different wavelengths. Each laser light source generates high-temperature heat in the order of the laser light source 21A, the laser light source 21B, and the laser light source 21C. Each laser light source has a structure having a high heat dissipation capability in the order of the laser light source 21A, the laser light source 21B, and the laser light source 21C. As a result, even if the three laser light sources generate heat at different temperatures, the amount of heat transferred from the three laser light sources to the housing 30 is substantially the same. Heat is transmitted to the housing 30 from the laser light sources 21A to 21C. Heat is transmitted from the rear surface 31AA to which the laser light sources 21A to 21C are fixed to the housing 30 and gradually propagated to the front side surface 31F.

  The dichroic mirror 42A reflects red light emitted from the laser light source 21A. The dichroic mirror 42B reflects blue light emitted from the laser light source 21B and transmits red light. The dichroic mirror 42C reflects green light emitted from the laser light source 21C and transmits blue and red light. The dichroic mirrors 42A to 42C have a function of combining red, blue, and green light and transmitting the combined light. The light transmitted through the dichroic mirror travels on a predetermined optical path. The synthesized light synthesized by the dichroic mirror 42 </ b> C is incident on the fiber 51 through the condenser lens 54.

[Case thickness]
The thickness of the housing 30 according to the first embodiment will be described with reference to FIGS. 6, 7, and 8. In the first embodiment, the thickness of the casing 30 is the thickness of the casing 30 in the left-right direction orthogonal to the optical paths 61A to 61C. The thickness of the case 30 in the left-right direction orthogonal to the optical paths 61A to 61C in Embodiment 1 is an example of the thickness of the case of the present invention. FIG. 6 is an enlarged longitudinal sectional view of the housing 30 for explaining the thickness of the housing 30 of the image forming apparatus 1 shown in FIG. FIG. 7 is a view of the external appearance of the housing 30 from the front. FIG. 7 is a diagram showing the housing 30 with the laser light sources 21A to 21C, the lens 32C, and the dichroic mirror 42C of the image forming apparatus 1 shown in FIG. 1 removed. FIG. 8 is a cross-sectional view taken along a horizontal plane including the line GG shown in FIG. 7 and extending in the vertical direction and the front-rear direction, as viewed from the direction of the arrow G toward the left. FIG. 8 is a view showing the housing 30 in a state where the fiber 51, the first fiber support portion 52, and the second fiber support portion 53 are further removed from the image forming apparatus 1 shown in FIG. In the first embodiment, the thicknesses 40A1 to 40A12 of the casing 30 in the left-right direction indicated by arrows in FIG. 6 and the thicknesses 40B1 and 40B2 of the casing 30 in the vertical direction indicated by arrows in FIG. It is thick.

  The thickness in the left-right direction of the housing | casing 30 is demonstrated using FIG. The casing 30 has thick portions 40A1 to 40A12 on the right side of the optical paths 61A to 61C of light emitted from the laser light sources 21A to 21C, respectively. In FIG. 6, areas from the light source support areas 50A to 50C of the housing 30 to the lens installation areas 33A to 33C are neighboring areas 71A to 71C, respectively. The housing 30 has thick portions 40A1 to 40A3 in the vicinity regions 71A to 71C. The housing 30 has thick portions 40A4 to 40A6 in the lens installation regions 33A to 33C. The housing 30 has thick portions 40A7 to 40A9 in positions close to the right rear region in the first mirror installation regions 37A to 37C, and the left front region in the first mirror installation regions 37A to 37C. It has thick part 40A10-40A12 in the front position equivalent to. The wall thickness of the housing 30 is thinner in the order of the wall thickness portions 40A1, 40A4, 40A7, and 40A10 on the right side of the optical path 61A. The wall thickness of the housing 30 is thinner in the order of the wall thickness portions 40A2, 40A5, 40A8, and 40A11 on the right side of the optical path 61B. The wall thickness of the housing 30 is thin in the order of the wall thickness portions 40A3, 40A6, 40A9, and 40A12 on the right side of the optical path 61C. The thickness of the housing 30 on the left side of the optical path 61C is thinner from the rear direction toward the front direction. The thickness in the front-rear direction of the housing 30 that is the direction away from the laser light source decreases from the rear direction toward the front direction. In the first embodiment, since the lengths of the optical paths 61A to 61C are set to be substantially the same, the thickness in the left-right direction of the housing 30, for example, the thickness 40A1 to 40A3, is set to be substantially the same. Yes.

  With reference to FIG. 8, the thickness of a vertical plane extending in the vertical direction and the front-rear direction of the housing 30 will be described. In FIG. 8, the housing 30 includes an upper thick portion 40B1 and a lower thick portion 40B2 on the upper side and the lower side, respectively, centering on the laser light emission holes 32A to 32C. As shown in FIG. 8, the upper thick portion 40B1 and the lower thick portion 40B2 are thicker on the rear side 31A side and are thinner toward the front side 31F side.

[Changing expansion of housing during laser emission]
9A and 9B, during the light emission operation of the laser light sources 21A to 21C, the relationship between the expansion change of the thick part due to the heat transmitted from the laser light sources 21A to 21C to the housing 30 and the positions of the dichroic mirrors 42A to 42C. Will be explained. FIG. 9A is a diagram illustrating an example of the thickness of the thick portion 340 in the conventional casing 330 and the arrangement of the dichroic mirror 342. FIG. 9B is a diagram illustrating an example of the thickness of the thick portions 40A2, 40A5, 40A8, and 40A11 in the casing 30 of the first embodiment and the arrangement of the dichroic mirror 42A. The housing 300 includes a space 334 in the vicinity of the dichroic mirror 342. The thickness of the conventional casing 330 shown in FIG. 9A is uniform in the thick portion 340 regardless of the distance from the rear side surface 331A where the laser light source 321 is installed. The thick part 340 of the housing 330 is expanded by the heat transmitted from the laser light source 321. The thickened portion 340 after expansion is shown by a two-dot chain line in FIG. 9A. As shown by a two-dot chain line in FIG. 9A, when the thick portion 340 is thermally expanded, the dichroic mirror 342 moves from the position before expansion. In FIG. 9A, the position of the dichroic mirror 342 after the housing 330 is expanded is indicated by a two-dot chain line. As a result of the change in the installation angle of the dichroic mirror 342, even if light parallel to the optical axis of the lens 341 enters the dichroic mirror 342, it is reflected in a direction different from that before expansion and does not enter the fiber 51 accurately.

  On the other hand, the wall thickness of the housing 30 of the first embodiment shown in FIG. 9B is thinner in the thick portions 40A2, 40A5, 40A8, and 40A11 as compared with the rear side surface 31A side and closer to the front side surface 31F side. For this reason, the thick portions 40A2, 40A5, 40A8, and 40A11 of the casing 30 are less deformed by thermal expansion than the conventional uniform-thick casing 330 as the position is closer to the front side surface 31F. Thick portions 40A2, 40A5, 40A8, and 40A11 when the casing 30 of the first embodiment is thermally expanded are shown by a two-dot chain line in FIG. 9B. 9B, the thick portions 40A2, 40A5, 40A8, and 40A11 in the casing 30 of the first embodiment are expanded so that the influence on the installation state such as the installation angle of the dichroic mirror 42A is reduced. Therefore, the installation position of the dichroic mirror 42A hardly changes. Further, even when the housing 30 expands due to heat from the laser light source 21A, the space 34A is provided, so that the dichroic mirror 42A maintains the installation angle and is not in contact with other members. It is displaced within 34A. For this reason, the thermal expansion of the housing 30 is suppressed so as to reduce the influence on the installation angle position of the dichroic mirror 42A. That is, even in the case 30 of the first embodiment, even when the laser light source 21A is turned on to emit light and expand due to heat from the laser light source 21A, the installation angle of the dichroic mirror 42A does not change greatly, and the lens 41A The optical path including the optical axis is maintained in the same manner as when the laser light source 21 </ b> A is turned off and is not emitting light, and the light from the laser light source 21 </ b> A enters the fiber 51 accurately. As with the thick portions 40A2, 40A5, 40A8, and 40A11, the thick portions 40B1 and 40B2 of the housing 30 are thinner as the location is closer to the front side 31F than the rear side 31A. Therefore, as for the thick portions 40B1 and 40B2 of the housing 30, the closer to the front side surface 31F, the smaller the amount of deformation due to thermal expansion compared to the conventional uniformly thick housing 330. As with the thick portions 40A2, 40A5, 40A8, and 40A11, the thick portions 40B1 and 40B2 in the casing 30 of the first embodiment also have less influence on the installation state such as the installation angle of the dichroic mirror 42A. Since it expands, the installation angle position of the dichroic mirror 42A hardly changes.

  In the thick portions 40A1 to 40A12 and 40B1 and 40B2 of the casing 30, expansion occurs in the front-rear direction due to heat from the laser light source 21A. Since the fiber 51 and the condensing lens 54 are fixed and supported by the housing 30 by the second fiber support portion 52, when the housing 30 expands in the front-rear direction, the arrangement position of the fiber 51 and the condensing lens 54 Moves along with the movement of the installation position of the dichroic mirror 42A in the front-rear direction, as the thick portion of the casing 30 expands in the front-rear direction. As a result, the relative positional relationship among the dichroic mirror 42A, the fiber 51, and the condenser lens 54 in the front-rear direction does not change. The same relative positional relationship is maintained between the dichroic mirrors 42B and 42C, the fiber 51, and the condenser lens 54. Accordingly, the positional relationship between the optical path formed by the three dichroic mirrors 42 </ b> A to 42 </ b> C and the optical axis of the condenser lens 54 is also maintained, and the light emitted from the laser light sources 21 </ b> A to 21 </ b> C is accurately incident on the fiber 51. The

[Example of use]
A usage example of the image forming apparatus 1 according to the first embodiment will be described. FIG. 10 is a schematic diagram of a retinal scanning display device 130 using the image forming apparatus 1 according to the first embodiment.

  A video signal of an image formed on the retina 151 in the observer's eyeball 150 is input to the video signal supply circuit 131. The video signal supply circuit 131 outputs image signals corresponding to the colors of the laser beams emitted from the laser light sources 21A to 21C to the laser drive circuits 132A to 132C corresponding to the laser light sources 21A to 21C, respectively. The laser drive circuits 132A to 132C output drive signals to the laser light sources 21A to 21C based on the image signals. Each of the laser light sources 21A to 21C modulates the light intensity based on the drive signal and emits the corresponding color laser light. The laser beams emitted from the laser light sources 21 </ b> A to 21 </ b> C are converted into parallel lights by the lenses 41 </ b> A to 41 </ b> C of the image forming apparatus 1, synthesized by the dichroic mirrors 42 </ b> A to 42 </ b> C, and enter the fiber 51 through the condenser lens 54.

  The video signal supply circuit 131 outputs a synchronization signal synchronized with the image signal to the horizontal synchronization signal circuit 133 and the vertical synchronization signal circuit 135. The horizontal synchronization signal circuit 133 outputs a horizontal synchronization signal to the horizontal scanning drive circuit 134. The vertical synchronization signal circuit 135 outputs a vertical synchronization signal to the vertical scanning drive circuit 136. The oscillating mirror unit 137 is oscillated based on the resonance vibration when a driving signal is output from the horizontal scanning driving circuit 134.

  The light emitted from the fiber 51 is applied to the vibration mirror unit 137. The vibration mirror unit 137 is driven by the horizontal scanning drive circuit 134 and swings. The light is reflected by the vibration mirror unit 137 and is scanned horizontally. The reflected light irradiates the galvanometer mirror 139 via the relay optical system 138. The galvanometer mirror 139 has its mirror surface oscillated by the fluctuation of the magnetic field, and scans the reflected light in the vertical direction. The reflected light reflected by the galvanometer mirror 139 enters the pupil of the eyeball 150 via the second relay optical system 140 and forms an image on the retina 151.

<Embodiment 2>
Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings. The second embodiment is different from the first embodiment in that the housing is provided with a configuration that dissipates heat generated by the laser light source. Since the second embodiment is the same as the first embodiment in the configuration of the other parts, only the different configuration will be described in detail, and the description of the same configuration as the first embodiment will be omitted.

  FIG. 9 is a perspective view showing an external appearance of the casing 430 used in the second embodiment as viewed from the rear. In FIG. 9, the housing 430 has a large number of heat radiation fins 432 on the rear side surface 431A to which the laser light sources 21A to 21C are fixed. The large number of heat radiation fins 432 extend in the front-rear direction and are arranged at predetermined intervals in the left-right direction. The large number of radiating fins 432 are formed integrally with the main body portion of the housing 430 by a known mold casting method. The rear side surface 431A of the housing 430 has three light source support areas 450AA to 450AC to which the laser light sources 21A to 21C are respectively fixed. These regions 450AA to 450AC are circular regions where no heat radiating fins are formed. Three laser light incident holes 438A to 438C are formed in the regions 450AA to 450AC, respectively, and are configured such that light from the laser light sources 21A to 21C enters toward the inside of the housing 430. Since the rear side surface 431A of the housing 430 has an uneven shape due to the formation of the large number of heat radiation fins 432, the heat radiation area increases, so that the heat generated from the laser light sources 21A to 21C is radiated through the heat radiation fins 432. As a result, the heat conducted from the rear side surface 431A of the housing 430 to the optical member inside the housing 430 is reduced, and the thermal expansion of the region supporting the optical member can be further suppressed. In particular, the thickness of the housing 430 on the rear side surface 431A to which the laser light sources 21A to 21C are fixed is thicker than other parts and has a large heat capacity. As a result, the heat dissipation efficiency of the entire housing 430 can be improved. In the second embodiment, the rear side surface 431A provided with a large number of radiating fins 432 is an example of a heat-dissipating part having irregularities on the surface in the present invention.

[Modification 1]
In the first embodiment, the material of the casing 30 and the second fiber support portion 53 is stainless steel, but is not limited thereto. An aluminum alloy may be used as a material for the housing 30 and the second fiber support portion 53. In this case, the casing and the second fiber support portion can be cast at a lower cost than stainless steel by an aluminum die casting method.

[Modification 2]
In the first embodiment, the thick portions 40A and 40B of the housing 30 are thick on the rear side 31A side and gradually thin toward the front side 31F side, but are not limited thereto. Similarly to the first embodiment, when the housing 30 and the second fiber support portion 53 are fixed, for example, if the housing 30 expands in the front-rear direction, the second fiber support portion 53 is expanded according to the expansion. The position moves back and forth. Therefore, the positional relationship between the housing 30 and the second fiber support portion 53 is maintained regardless of expansion. The thick portions 40A1 to 40A12 and 40B1 and 40B2 of the housing 30 may have a thickness set so that the dichroic mirrors 42A to 42C are not displaced in the left-right direction. A modified example will be described with reference to FIG. 12, taking as an example the internal configuration of the housing 30 that supports the laser light source 21A and the dichroic mirror 42A. FIG. 12 is an enlarged view showing only the internal configuration of the housing 30 that supports the laser light source 21A and the dichroic mirror 42A. In FIG. 12, the thick portion 40A includes a thick portion 231 in a region from the rear side surface 31A to which the laser light source 21A is fixed to a position where the right end 42AA of the dichroic mirror 42A is positioned, and a reflecting surface of the dichroic mirror 42A. And a thick portion 233 in the region from the position where the left end 42AB of the dichroic mirror 42A is located to the front side surface 31F. The thick part 231 is thicker than the thick part 232 and the thick part 233, the thick part 232 is thinner than the thick part 231, and the thick part 233 is thick. The thick portion 40 </ b> A of the housing 30 may be configured to be thinner than the thickness of the thick portion 232 and thicker than the thick portion 232. In this configuration, when heat is transmitted to the housing 30, the deformation amount due to thermal expansion of the thick portion 40 </ b> A of the housing 30 decreases in the order of the thick portion 231, the thick portion 233, and the thick portion 232. The deformation amount of the thick part 232 is smaller than that of the thick part in the other region. Therefore, the dichroic mirror 42 </ b> A can be prevented from being greatly displaced due to the thermal expansion of the thick portion 232. By adopting the same configuration for the dichroic mirrors 42B and 42C, similarly, the displacement of the dichroic mirrors 42B and 42C can be suppressed.

[Modification 3]
In this Embodiment 1, the thickness of the housing | casing 30 is thin as it goes to a front direction from back direction according to the distance with laser light source 21A-21C. The heat generated by the laser light sources 21A to 21C is emitted by the laser light sources 21A to 21C before being transmitted to the housing 30 regardless of the amount of heat. The thickness of the casing 30 is the same as that of the thick portions 40A1 to 40A3, and the thickness of the thick portions 40A4 to 40A6 is the same regardless of the amount of heat generated by the laser light sources 21A to 21C. The thickness of the portions 40A7 to 40A9 is the same, and the thickness of the thick portions 40A10 to 40A12 is the same. The thickness of the casing 30 is a configuration in which the thickness differs only in accordance with the distance from the laser light sources 21A to 21C, but is not limited thereto. When the laser light sources 21A to 21C generate different amounts of heat, the thickness of the casing 30 is made different from the thickness of the thick portions 40A1 to 40A12 according to the arrangement of the laser light sources 21A to 21C. Good. The thick portions 40A2, 40A3, 40A5, 40A6, 40A8, 40A9, 40A11, and 40A12 are thick because the laser light sources 21A and 21B or the laser light sources 21B and 21C generate heat. It may be thicker than the portions 40A1, 40A4, 40A7, and 40A10.

[Modification 4]
In the first embodiment, the thickness of the casing 30 is thinner as it goes from the rear to the front depending on the distance from the laser light sources 21 </ b> A to 21 </ b> C, but is not limited to the casing 30. In the second fiber support portion 53 that supports the condensing lens 54 that is an optical member, the thickness orthogonal to the optical paths 62AB, 62B, and 62C is thick on the right side that is close to the distance from the laser light sources 21A to 21C. A thin configuration may be employed on the left side that is far from 21C.

[Modification 5]
In the first embodiment, the thickest thicknesses of the thick portion 40B1 and the thick portion 40B2 of the housing 30 have different configurations, but are not limited thereto. When strict accuracy is required for the positions in the vertical direction of the dichroic mirrors 42A to 42C, the thickest thickness of the thick portion 40B1 and the thick portion 40B2 may be the same thickness.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 21A-21C Laser light source 22A-22C Laser light source support part 30 Case 33A-33C Lens support area 35A-35C 1st mirror support area 37A-37C 2nd mirror support area 40A1-40A12, 40B1, 40B2 Thickness Part 41A-41C Lens 42A-42C Dichroic mirror 50A-50C Light source support area 51 Fiber 52 First fiber support part 53 Second fiber support part 54 Condensing lens 61A-61C, 62A-C Optical path 71A-71C Neighborhood area 432 Radiation fin

Claims (3)

At least one light source unit that generates heat when generating light;
An incident part into which light generated from the light source part is incident;
An optical member for guiding the light generated from the light source unit to the incident unit;
The light source unit and the optical member are fixed and supported so that the optical axis of the optical member is arranged on the optical path of the light source unit, and the optical path between the light source unit and the optical member A housing having a predetermined thickness in the orthogonal direction,
The housing is a light source support region that fixes and supports the light source unit, a nearby region that is located in the vicinity of the light source support region, and a region other than the nearby region, and at least an optical that supports the optical member A member support region,
The wall thickness of the housing of the neighboring region, the optical member supporting region and the rather thick than the thickness of the housing of,
The image forming apparatus according to claim 1, wherein the thickness of the casing in the optical member support area is thinner than the thickness of the casing in the vicinity area as the distance from the light source unit increases .
At least one light source unit that generates heat when generating light;
An incident part into which light generated from the light source part is incident;
An optical member for guiding the light generated from the light source unit to the incident unit;
The light source unit and the optical member are fixed and supported so that the optical axis of the optical member is arranged on the optical path of the light source unit, and the optical path between the light source unit and the optical member A housing having a predetermined thickness in the orthogonal direction,
The housing is a light source support region that fixes and supports the light source unit, a nearby region that is located in the vicinity of the light source support region, and an area that supports at least the optical member, other than the nearby region. A member support region,
The thickness of the casing in the vicinity region is thicker than the thickness of the casing in the optical member support region,
The light source unit generates a plurality of types of light having different wavelengths,
The optical member includes a plurality of types of mirror units that reflect specific light generated by the light source unit,
The optical member support region is a region that supports the plurality of types of mirror units at positions where the distance between each of the plurality of types of mirror units and the incident unit is different.
The thickness of the casing of the optical member support area that supports the plurality of types of mirror parts is thinner than the thickness of the casing in the vicinity area as the thickness of the casing is further away from the light source section. images forming device.
The housing includes a heat release unit that releases heat generated by the light source unit in the light source support region and the vicinity region,
The image forming apparatus according to claim 1, wherein the heat release portion has irregularities on a surface thereof .

Images