JP2023162177A - vehicle - Google Patents

Abstract

To provide a light source device which can be manufactured in a small size at a low cost and is suitable as an illumination light source of a display device of an electronic device such as a HUD and a microminiature projector.SOLUTION: A light source device comprises: a solid-state light source; a collimating optical system which converts light emitted from the solid-state light source into substantially-parallel light; and a light guide body on which light emitted from the collimating optical system is incident and which emits the light in a different direction from the incident direction. The light guide body comprises: an incident part on which light is incident; a reflection part which reflects the incident light; and an emission part which emits the light reflected by the reflection part. The reflection part includes a plurality of reflection surfaces that reflects the incident light and a plurality of connection surfaces that connects the plurality of reflection surfaces with each other. The incident part has an action of deflecting the light in the direction in which the incident angle of the light incident on the reflection surface of the reflection part becomes larger.SELECTED DRAWING: Figure 4

Description

The present invention relates to a light source device that can be used as a planar light source, and particularly to a planar light source device that is suitable for use in an electronic device equipped with an image display device aimed at miniaturization.

2. Description of the Related Art A compact and highly efficient light source device is desired as a light source for illuminating a display device such as a head up display (hereinafter referred to as "HUD") or an ultra-compact projector.

Heretofore, a light source device that utilizes a light guide in which a predetermined texture is formed on a transparent resin is already known from Patent Document 1 below, in order to realize a small and highly efficient light source device. The light guide illumination device described in this patent document allows light to enter from the end of the light guide and scatter the incident light with a texture formed on the surface of the light guide, thereby creating a thin and highly efficient light source device. It describes what can be achieved.

Japanese Patent Application Publication No. 11-224518

In recent years, with the improvement in the luminous efficiency of LEDs, which are solid-state light sources, it is effective to use LEDs as the light source of a light source device. However, in an optical system using an LED and an LED collimator that converts the light into approximately parallel light, the shape of the optical system disclosed in the above-mentioned conventional technology (Patent Document 1) does not have light utilization efficiency characteristics or uniform illumination characteristics. It was found that this was still insufficient.

Therefore, in the present invention, specifically, by further improving the light utilization efficiency characteristics and uniform illumination characteristics of laser light from an LED light source, the light source device can be downsized, and it can be manufactured at low cost. The object of the present invention is to provide a light source device suitable as a light source for illumination in a display device of an electronic device such as a HUD or a micro-projector, and furthermore, to provide an electronic device equipped with an image display device using the light source device. .

According to an embodiment of the present invention, the present invention includes a solid-state light source, a collimating optical system that converts light emitted from the solid-state light source into substantially parallel light, and a collimating optical system that converts light emitted from the solid-state light source into substantially parallel light. A light source device is provided with a light guide that receives light incident thereon and outputs the light in a direction different from the incident direction, the light guide including an entrance part that enters the light, and a reflection part that reflects the incident light. a part, an emitting part that emits the light reflected by the reflecting part, and the reflecting part includes a plurality of reflecting surfaces that reflect the incident light and a plurality of connecting surfaces that connect the plurality of reflecting surfaces. and the incident part is provided with a light source device and a vehicle using the light source device, the light source device having a structure that deflects the light in a direction in which the incident angle of the light incident on the reflective surface of the reflective part becomes larger. be done.

Further, according to the present invention, an electronic device using the above-described light source device as an image display device includes a HUD and a projector.

According to the present invention described above, it is possible to realize a light source device that can be manufactured at low cost, is small in size, and has high efficiency.

FIG. 1 is a developed perspective view showing the overall appearance of a light source device according to an embodiment of the present invention. FIG. 2 is a perspective view showing an overview of the internal configuration of an optical system in the light source device. FIG. 6 is a diagram including a perspective view and a partially enlarged cross section for explaining details of a light guide in the light source device. It is a side view explaining the details of operation of the light guide in the above-mentioned light source device. FIG. 7 is a top view and a side view illustrating details of the operation of a light guide in the light source device. It is a figure which shows the comparative example for demonstrating the operation|movement of the light guide in the said light source device. FIG. 3 is a perspective view illustrating details of a collimator and a synthetic diffusion block in the light source device. FIG. 3 is a partially enlarged cross-sectional view illustrating details of a composite diffusion block in the light source device. It is a figure explaining the processing method of the metal mold|die used for shaping|molding the light guide which is a component of the optical system of the said light source device. FIG. 3 is an external perspective view showing an overall overview of a light source device that is a modified example of the light source device according to an embodiment of the present invention. FIG. 3 is a perspective view showing an overview of the internal configuration of an optical system of a light source device that is a modified example of a light source device according to an embodiment of the present invention. FIG. 7 is an external perspective view showing the overall appearance of a light source device that is another modification of the light source device according to an embodiment of the present invention. It is a perspective view which shows the shape of another form of the collimator and the synthetic|combination diffusion block in the light source device based on one Example of this invention. 1 is a diagram showing the configuration of a HUD using a light source device according to an embodiment of the present invention as a light source for illuminating its display device. 1 is a diagram showing the configuration of a projector that uses a light source device according to an embodiment of the present invention as a light source for illuminating its display device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an exploded perspective view showing an overview of a light source device according to an embodiment of the present invention. As is clear from the figure, the light source device (main body) 10 is made of, for example, plastic, and houses therein an LED, a collimator, a synthetic diffusion block, a light guide, etc., which will be described in detail later. It is composed of a light source device case 11. A liquid crystal display element 50 is attached to its top surface, and an LED board 12 on which an LED (Light Emitting Diode) element, which is a semiconductor light source, and its control circuit are mounted is attached to one side thereof. At the same time, a heat sink 13 is attached to the outer surface of the LED board 12 for cooling the heat generated by the LED elements and the control circuit.

Furthermore, the liquid crystal display element 50 attached to the upper surface of the light source device case 11 includes a liquid crystal display panel frame 51, a liquid crystal display panel 52 attached to the frame, and an FPC (FPC) electrically connected to the panel. (flexible wiring board) 53. That is, as will be described in detail later, the liquid crystal display panel 52 is controlled by a control signal from a control circuit (not shown here) constituting the electronic device.

FIG. 2 shows the configuration of an optical system housed inside the light source device 10, that is, inside the light source device case 11.

A plurality of (in this example, four) LEDs 14a to 14d (in FIG. 2, only two LEDs 14a and 14b are shown) constituting the light source have a conical convex outer shape obtained by rotating a substantially parabolic line. A rectangular synthetic diffusion block 16 is provided on the light output side of the collimator. That is, the laser light emitted from the LED 14a or 14b is reflected by the parabolic boundary surface of the LED collimator 15, becomes parallel light, and enters the synthesis diffusion block 16.

Furthermore, a rod-shaped light guide 17 with a substantially triangular cross section is provided on the exit surface side of the synthetic diffusion block 16 via a first diffusion plate 18a, and a second diffusion plate is provided on the upper surface of the rod-shaped light guide 17. 18b is attached. Thereby, the horizontal light from the LED collimator 15 is reflected upward in the figure by the action of the light guide 17 and guided to the incident surface of the liquid crystal display element 50. At this time, the strength is made uniform by the first and second diffusion plates 18a and 18b.

<Detailed structure of light guide>
Next, details of the light guide 17 constituting the light source device 10 will be described below with reference to the drawings. Note that FIG. 3(a) is a perspective view showing the entire light guide 17, FIG. 3(b) is a cross-sectional view thereof, and FIGS. 3(c) and (d) are detailed views of the cross-section. It is a partially enlarged sectional view shown.

The light guide 17 is, for example, a rod-shaped member with a substantially triangular cross section (see FIG. 3(b)) made of a translucent resin such as acrylic, and as is clear from FIG. 3(a). a light guide light incident part (surface) 171 facing the output surface of the synthetic diffusion block 16 via the first diffuser plate 18a, and a light guide light reflection part (surface) 172 forming a slope; A light guide light emitting portion (surface) 173 is provided that faces the liquid crystal display panel 52 of the liquid crystal display element 50 via the second diffusion plate 18b.

As shown in FIGS. 3(c) and 3(d), which are partially enlarged views, the light guide light reflecting portion (surface) 172 of the light guide 17 has a large number of reflecting surfaces 172a and connecting surfaces 172b. are formed in alternating serrations. The reflective surface 172a (line segment sloping upward to the right in the figure) forms αn (n: a natural number, for example, 1 to 130) with respect to the horizontal plane indicated by the dashed line in the figure. As an example, here αn is set to 52 degrees or less (however, 44 degrees or more).

On the other hand, the connecting surface 172b (a line segment downward to the right in the figure) forms an angle βn (n: a natural number, for example, 1 to 130) with respect to the reflecting surface 172a. In other words, the connecting surface 172b of the reflecting portion is inclined at an angle with respect to the incident light so as to form a shadow within the range of the half-value angle of the scatterer, which will be described later. As will be explained in detail later, α1, α2, α3, α4... form the elevation angle of the reflecting surface, and β1, β2, β3, β4... form the relative angle between the reflecting surface and the connecting surface. , is set to 90 degrees or more (but not more than 180 degrees). In this example, β1=β2=β3=β4=...=β122=...β130.

4 and 5 are schematic diagrams in which the size of the reflective surface 172a and the connecting surface 172b are relatively enlarged with respect to the light guide 17 for explanation. At the light guide entrance part (surface) 171 of the light guide 17, the main light beam is deflected by δ in the direction where the angle of incidence becomes larger with respect to the reflective surface 172a (see FIG. 5(b)). That is, the light guide entrance portion (surface) 171 is formed in a curved convex shape inclined toward the light source side. According to this, the parallel light from the output surface of the composite diffusion block 16 is diffused and incident through the first diffusion plate 18a, and as is clear from the figure, the light guide entrance part (surface) 171 As a result, it reaches the light guide light reflecting portion (surface) 172 while being slightly bent (deflected) upward (see the comparative example in FIG. 6).

The light guide light reflecting portion (surface) 172 has a large number of reflecting surfaces 172a and connecting surfaces 172b alternately formed in a sawtooth shape, and the diffused light is totally reflected on each reflecting surface 172a. The light is directed upward, and further enters the liquid crystal display panel 52 as parallel diffused light via the light guide light output portion (surface) 173 and the second diffuser plate 18b. Therefore, the reflective surface elevation angles α1, α2, α3, α4... are set such that each reflective surface 172a has an angle greater than the critical angle with respect to the diffused light, and on the other hand, the reflective surface 172a and the connecting surface 172b The relative angles β1, β2, β3, β4, etc. are fixed angles as described above, and although the reason will be explained later, they are preferably set to angles of 90 degrees or more (βn≧90°). .

With the above-described configuration, each reflective surface 172a is configured to always form an angle greater than or equal to the critical angle with respect to the diffused light. Reflection becomes possible, and a low-cost light source device can be realized. On the other hand, as shown in FIG. 6, which is a comparative example, when there is no bending (polarization) of the main light beam at the light guide entrance part of the light guide 17, a part of the diffused light 31b is directed toward the reflective surface 172a. As a result, the angle becomes less than the critical angle, and sufficient reflectance cannot be ensured, making it impossible to realize a light source device with good characteristics (bright).

Further, the reflecting surface elevation angles α1, α2, α3, α4, etc. have values that slightly increase as they move from the lower part to the upper part of the light guide light reflecting part (surface) 172. This is because the light that has passed through the liquid crystal display panel 52 of the liquid crystal display element 50 has a certain degree of divergence angle. This is to realize a configuration in which the light rays at the periphery are slightly deflected in the direction of the central axis, as shown by the light ray 30 in FIG. 4, in order to prevent so-called peripheral dimming caused by the periphery of the mirror.

As mentioned above, β1=β2=β3=β4...βn≧90°, but this is because the mold 40 for producing the light guide 17 by injection molding is set as shown in FIG. This is because the reflective surface 172a and the connecting surface 172b can be simultaneously processed by the end mill 35 whose relative angle between the bottom surface and the side surface is β. Furthermore, since the reflective surface 172a and the connecting surface 172b can be machined with a relatively thick tool, the machining time can be significantly shortened and the machining cost can be significantly reduced. Further, the boundary edge between the reflective surface 172a and the connecting surface 172b can be processed with high precision, and the light guiding characteristics of the light guide 17 can be improved.

In addition, Lr1, Lr2, Lr3, Lr4, . . . in the figure represent the projected length of the reflective surface 172a on the horizontal plane, and Lc1, Lc2, Lc3, Lc4, . . . represent the projected length of the connecting surface 172b on the horizontal surface, respectively. In addition, Lr/Lc, that is, the ratio of the reflective surface 172a to the connecting surface 172b, can be changed depending on the location. The intensity distribution of the main light beam 30 incident on the light guide 17 does not necessarily match the intensity distribution desired at the incident surface of the liquid crystal display panel. Therefore, a configuration was adopted in which the intensity distribution is adjusted by the ratio Lr/Lc between the reflective surface 172a and the connecting surface 172b. Note that the higher this ratio is, the higher the average intensity of reflected light in that portion can be. Generally, the light ray 30 incident on the light guide tends to be strong at the center, so to correct this, the ratio Lr/Lc is configured differently depending on the location. I made it. Since the ratio Lr/Lc is different depending on the location and the above-mentioned reflecting surface elevation angles α1, α2, α3, α4, etc. are different depending on the location, the envelope 172c representing the general shape of the reflecting part 172 is as shown in FIG. It shows a curved shape like this.

Furthermore, Lr1+Lc1=Lr2+Lc2=Lr3+Lc3=Lr4+Lc4...=Lr+Lc≦0.6mm. By employing such a configuration, the repeating pitch of the reflective surfaces viewed from the light exit surface 173 of the light guide 17 can be made the same. In addition, since the pitch is 0.6 mm or less, combined with the action and effect of the diffusion plates 18a and 18b, when viewed through the liquid crystal display panel 52, the individual emission surfaces do not separate and appear as a continuous surface. Therefore, the spatial brightness across the liquid crystal display panel 52 can be made uniform, thereby improving display characteristics. That is, with this configuration, it is possible to make the incident light intensity distribution on the liquid crystal display panel 52 uniform. On the other hand, if the value of Lr+Lc is smaller than 0.2 mm, it not only takes time to process, but also makes it difficult to process each reflective surface 172a with high precision, so it is desirable that the value is 0.2 mm or more.

Furthermore, although not shown here, the above-mentioned value of Lr+Lc (sum of lengths) is, in whole or in part, Lr1+Lc1>Lr2+Lc2>Lr3+Lc3>Lr4+Lc4... or Lr1 +Lc1=Lr2+Lc2=Lr3+Lc3=Lr4+Lc4....= Lr90+Lc90> Lr91+Lc91= Lr92+Lc92> Lr93+Lc93...> Lr130+Lc130 or Lr1+Lc1≧ A configuration such as Lr2+Lc2≧Lr3+Lc3≧Lr4+Lc4…Lr1+Lc1>Lr130+Lc130 may also be used. By employing this configuration, the repetition pitch of the reflective surfaces 172a viewed from the output surface 173 of the light guide 17 becomes finer as it approaches the output surface 173. Furthermore, with this configuration, the repetition pitch of the reflective surface 172a seen from the diffuser plate 18b of the light guide 17 becomes finer as it approaches the diffuser plate 18b. The repeating structure of the reflective surface 172a increases visibility as it approaches the diffuser plate 18b, impairing the uniformity of light intensity, so the diffuser plate 18b needs to have some degree of diffusivity. Since the repeating pitch of the reflective surfaces arranged close to 18b becomes fine, uniformity of light intensity can be ensured even if the diffusivity of the scattering plate is small, and as a result, the light utilization efficiency can be improved. Further, the value of Lr+Lc is desirably set within the range of 0.2 mm or more and 0.6 mm or less, as described above.

According to the shape of the light guide light reflecting portion (surface) 172 of the light guide 17 described above, the condition for total reflection of the main light can be satisfied, and there is no need to provide a reflective film such as aluminum on the reflecting portion 172. It becomes possible to reflect light efficiently, and there is no need to evaporate aluminum thin films, which increases manufacturing costs, making it possible to create a brighter light source at a lower cost. Further, each relative angle β was set to such an angle that the connecting surface 172b casts a shadow on the light that the main light ray 30 diffused by the composite diffusion block 16 and the diffusion plate 18a. Thereby, by suppressing the incidence of unnecessary light on the connecting surface 172b, reflection of unnecessary light can be reduced, and a light source device with good characteristics can be realized.

Generally, it is desirable that the main rays of light incident on the liquid crystal display panel be close to perpendicular, but depending on the characteristics of the liquid crystal display panel, it may be tilted by an angle η as shown in FIG. 5(b). It is also possible. In other words, some commercially available liquid crystal display panels have better characteristics when the incident angle is tilted by about 5 to 10 degrees. It is desirable to set the angle to ~10°.

Furthermore, instead of tilting the panel by η, by adjusting the angle of the reflective surface 172a, it is also possible to tilt the main beam of light to the liquid crystal display panel. Furthermore, if it is necessary to incline the light beam toward the side surface of the light guide, the slope of the triangular texture 161 formed on the exit surface of the composite diffusion block 16 may be made asymmetrical or reflective. This can be realized by changing the direction in which the texture formed by the surfaces 172a and 172b is formed.

Next, the synthesis diffusion block 16, which is another component of the light source device 10, will be explained with reference to FIGS. 7 and 8. Note that FIG. 7 shows a composite diffusion block 16 integrated with the LED collimator 15, and FIGS. 8(a) and 8(b) show partially enlarged cross sections of the composite diffusion block 16.

As is clear from FIG. 8(a), a large number of textures 161 having a substantially triangular cross section are formed on the output surface of the composite diffusion block 16, and due to the action of the textures 161, the light is emitted from the LED collimator 15. The light is diffused in the direction perpendicular to the plane of the drawing of the incident part (surface) 171 of the light guide 17. Due to the interaction between the substantially triangular texture 161 and the diffusers 18a and 18b, even if the LED collimators 15 are arranged discretely, the individual intensity distribution of the light emitted from the light emitting part 173 of the light guide 17 can be controlled. It becomes possible to make it uniform. In particular, the texture 161 makes it possible to limit the diffusion direction to the side surface of the light guide, and furthermore, to control the diffusivity in the side direction. It becomes possible to weaken the directional diffusivity, and as a result, the light utilization efficiency improves, and a light source device with good characteristics can be realized. In this example, as an example of the substantially triangular texture 161, the angle γ=30 degrees and the formation pitch a=0.5 mm.

As detailed above, according to the light source device 10 of the present invention, the light utilization efficiency of the laser light from the LED light source and its uniform illumination characteristics can be further improved, and at the same time, the light source device can be miniaturized and the cost can be reduced. Since the present invention can be manufactured using the same method, it is possible to provide a light source device that is particularly suitable as a light source for illumination in a display device of an electronic device such as a HUD or a micro-projector.

<Modified example of light source device>
Further, FIGS. 10 and 11 show a modification of the light source device according to an embodiment of the present invention, and as a modification, a perspective view of the overall appearance of the light source device 10b and its internal configuration are shown. In this modification, by using a composite diffusion block 16b having a substantially trapezoidal cross section, an LED collimator 15 having a plurality of conical convex shapes to which LEDs are attached is attached at an inclined position below the device. Note that the reference numeral 13b in the figure is a heat sink for cooling the heat generated in the LED elements and the control circuit.

<Other modifications of the light source device>
Furthermore, FIG. 12 shows another modified example of the light source device according to one embodiment of the present invention, and as another modified example, a perspective view of the overall appearance of a light source device 10c is shown. Although details are not shown in this other modification, the structure is such that the heat generated in the LED board 12 is cooled by a heat sink 13c disposed at the bottom of the device through a heat transfer plate 13d. With this configuration, a light source device with a short overall length can be realized.

<Another form of collimator in the light source device>
Furthermore, FIG. 13 shows another form of the collimator 15b in the light source device according to an embodiment of the present invention, and shows an example of the shape including the above-mentioned synthetic diffusion block 16. The collimator shape shown in FIGS. 7 and 8 had a conical convex outer shape obtained by rotating a substantially parabolic section, but this shape is based on a substantially quadrangular pyramidal convex shape, with chamfered corners and It has a curved shape. Considering the efficiency of light emitted from the LED and emitted from the light guide 17, the paraboloid of revolution shape shown in FIGS. Since the boundaries are smoothly connected, a more uniform light intensity distribution can be achieved.

Note that it is obvious that the light source devices 10b and 10c, which are modified examples of the light source device of the present invention described above, also have the same functions and effects as the light source device 10 shown in FIG. 1 above. In addition, according to these light source devices 10, 10b, and 10c, if they are selected appropriately, the interior of electronic devices such as HUDs and micro-projectors that may have various shapes and forms can be improved. It fits into the storage space of the store and can be installed securely.

<Application example of light source device>
In addition, examples will be shown below in which the above-described light source device 10 of the present invention is mounted on a HUD and a micro-projector as a typical example of an electronic device that uses the light source device 10 of the present invention as a light source for a display device.

FIG. 14(a) shows an example in which the light source device according to the embodiment of the present invention described above is applied to a HUD. In this figure, the head-up display device 100 displays an image displayed on an image display device 300 including a projector, an LCD (Liquid Crystal Display), etc. using a mirror 151 and other mirrors 152 (for example, a free-form mirror or a light The light is reflected by a mirror having an axially asymmetrical shape and projected onto the windshield 3 of the vehicle 2. On the other hand, the driver 105 views the image projected onto the windshield 103 and visually recognizes the image as a virtual image in front of the transparent windshield 103.

FIG. 14(b) shows an example of the internal configuration of the head-up display device 100, particularly the video display device 300 thereof. As is clear from this figure, a case is shown in which the video display device 300 is a projector, and the video display device 300 includes various parts such as a light source 301, an illumination optical system 302, and a display element 303, for example. Note that by employing the above-described light source device 10 of the present invention as the light source 301, it is possible to generate good illumination light for projection.

In addition, in this example, an illumination optical system 302 is further added, which is an optical system that collects the illumination light generated by the light source 301, makes it more uniform, and irradiates the display element 303, and an element that generates an image to be projected. It includes a display element 303 which is . However, in the above embodiment, these elements are already used as the composite diffusion block 16, the first diffusion plate 18a, the light guide 17, the second diffusion plate 18b, and further as the liquid crystal display panel 52. It is included in the light source device 10 of the present invention. Therefore, the light source device 10 of the present invention can also be used as the video display device 300 of the head-up display device 100 as it is. According to this, in particular, it becomes possible to realize the head-up display device 100 that can be easily installed in a narrow space such as a dashboard in a car.

It should be noted that it is clear to those skilled in the art that the light emitted from the video display device 300 described above is further projected onto the windshield 103 of the vehicle 102 via the display distance adjustment mechanism 400 and the mirror drive unit 500. Dew.

FIG. 15 shows an example in which the above-described light source device of the present invention is applied to a projector. As is clear from the figure, the projector is composed of a plurality of lens groups indicated by symbols G1 to G3 and one mirror indicated by symbol M13. In addition, in the figure, the projected light is shown by a solid line and a broken line arrow.

Further, in the figure, a light source P0 and an image display element P1 (reflective image display element) are arranged on the opposing surfaces of the prism optical element, and the light source device 10 of the present invention described above as the light source P0 is shown. By adopting this, it becomes possible to generate good illumination light. In this example, these elements have already been used as the composite diffusion block 16, the first diffusion plate 18a, the light guide 17, and the second diffusion plate 18b in the light source device 10 of the present invention. Since it is included as a liquid crystal display panel 52, the light source device 10 of the present invention can be installed in a projector as is. According to this, it can be easily installed in the space inside the projector, and it becomes possible to realize a smaller and cheaper projector.

As described above in detail, by using the light source device 10 of the present invention as a light source for illuminating a display device, it can be easily installed even in a narrow space, and is smaller and cheaper. It becomes possible to realize an electronic device.

Above, planar light source devices suitable for use in electronic devices equipped with image display devices according to various embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, in the embodiments described above, the entire system is explained in detail in order to explain the present invention in an easy-to-understand manner, and the system is not necessarily limited to having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add, delete, or replace a part of the configuration of each embodiment with other configurations.

10... Light source device (main body), 11... Case, 50... Liquid crystal display element, 12... LED board, 13... Heat sink, 14a, 14b... LED, 15... LED collimator, 16... Synthetic diffusion block, 17... Light guide, 171... Light guide light incident part (surface), 172... Light guide light reflection part (surface), 172a... Reflective surface, 172b... Connection surface, 173... Light guide light output part (surface).

Claims (5)

A vehicle,
A solid-state light source made of multiple semiconductor elements,
a collimating optical system that converts the light emitted from the solid-state light source into substantially parallel light;
a reflective optical element that receives the light emitted from the collimating optical system and outputs the light in a direction different from the direction of incidence;
A display element;
a mirror that reflects and projects the image light emitted from the display element,
The plurality of semiconductor elements are arranged in a first direction perpendicular to the direction of the optical axis of the collimating optical system,
the solid-state light source and the collimating optical system are arranged in a second direction parallel to the optical axis;
The reflective portion of the reflective optical element includes a reflective surface made of a plurality of planes and a connecting surface made of a plurality of planes adjacent to the reflective surface,
The reflective optical element reflects the light incident in the second direction in a third direction different from the first direction and the second direction, and is connected to the reflective surface of the reflective section. The area ratio of the projected surface in a direction orthogonal to the first direction and the second direction varies depending on the intensity distribution of light incident on the reflective optical element,
The angle of the reflective surface of the reflective portion with respect to the second direction varies depending on the location, and the apex angle of a convex portion or a concave portion formed of the reflective surface and the connecting surface of the reflective portion is constant regardless of the location. , and a line connecting the vertices of the concave portion as an envelope representing the general shape of the reflective portion consisting of the reflective surface and the connecting surface has a curved shape.
vehicle. The vehicle according to claim 1,
In the vehicle, in the reflective optical element, the angle of the reflective surface of the reflective section increases as the distance from the solid-state light source increases. The vehicle according to claim 1,
A vehicle comprising an LED element as the solid-state light source. The vehicle according to claim 1,
The reflective optical element has a length Lr of the slope projected in the normal direction to the output direction of the plurality of reflective surfaces of the reflective section and an output direction of a connecting surface connected to the opposite side of the light incidence from the reflective surface. The sum Lr+Lc of the length Lc of the slope projected in the normal direction is approximately constant regardless of the location of the vehicle. The vehicle according to claim 4,
The vehicle, wherein the value of the sum Lr+Lc is 0.2 mm or more and 0.6 mm or less.

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