Head-up display

Abstract

The present invention provides a HUD system and a light source device for HUD that are small and can be manufactured at low cost. The head-up display device includes: an image display device for generating image light to be projected; an optical system for performing a predetermined correction on the image light from the image display device; and a concave reflector that reflects the image light corrected by the optical system and projects it onto the windshield or the combiner, the image display device includes an illumination optical system and a display device, wherein the illumination optical system includes a solid light source, a collimating optical system that converts the light from the solid light source into approximately parallel light, and an optical component that deflects the direction of the light beam converted by the collimating optical system and expands the light beam at the same time, and the image display device is arranged opposite to the concave reflector on the optical axis of the concave reflector in a manner that the optical system is sandwiched therebetween.

Description

[0001] This application is a divisional application of the invention patent application with application number 201780047425.X, application date 2017.3.28, and name “Head-up display device and image display device thereof”. Technical Field

[0002] The present invention relates to a head-up display device (Head Up Display: hereinafter referred to as "HUD") that projects an image onto a windshield of a vehicle or a combiner that is a transparent or semi-transparent plate-shaped display component arranged in front of the windshield to display information to the driver using a virtual image, and more particularly to a small and efficient image display device that can be used as a light source module for generating planar image light in a HUD device. Background Art

[0003] In a HUD device, image light is projected onto a vehicle windshield and a combiner to generate a virtual image. An image display device for generating such image light is generally assembled in a narrow space such as a vehicle dashboard, and therefore a small and efficient device is desired.

[0004] In addition, as a related technology of the HUD, for example, Japanese Patent Gazette No. 2015-90442 (Patent Document 1) describes a display device, which includes a device for displaying an image and a projection optical system for projecting the image displayed on the device, which can reduce the image distortion in the entire viewing angle area of ​​the observer while achieving miniaturization. In addition, in this prior art, the projection optical system has a first reflector and a second reflector in the optical path from the display device to the observer. The relationship between the incident angle of the image in the long axis direction in the first reflector and the incident angle of the image in the short axis direction in the first reflector, the interval between the image display surface of the display device and the first reflector, and the horizontal width of the virtual image seen by the observer satisfies a prescribed relationship, thereby achieving miniaturization of the HUD device.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-90442 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In recent years, as the luminous efficiency of LEDs as solid light sources has increased, it has become effective to use LEDs as light sources. However, the shape of the optical system disclosed in the above-mentioned prior art (Patent Document 1) using LEDs and an LED collimator that converts the light from the LEDs into approximately parallel light still has shortcomings in terms of miniaturization and modularization of the device.

[0010] Therefore, an object of the present invention is to provide a small and efficient image display device that can be used for a light source module to generate planar image light constituting a HUD device, and also to provide a HUD device that utilizes the image display device and is suitable for assembly and maintenance in a narrow space such as a vehicle dashboard.

[0011] Technical solutions to solve problems

[0012] As an embodiment for achieving the above-mentioned purpose, the present invention provides a head-up display device, which projects image light onto a windshield of a vehicle or a combiner arranged in front of the windshield, and provides an image to a driver using a virtual image formed by the reflected light thereof, the head-up display device comprising: an image display device for generating the image light to be projected; an optical system for performing a prescribed correction on the image light from the image display device; and a concave reflector that reflects the image light corrected by the optical system and projects it onto the windshield or the combiner, the image display device comprising an illumination optical system and a display device, wherein the illumination optical system comprises a solid light source, a collimating optical system for converting the light from the solid light source into substantially parallel light, and an optical component for deflecting the direction of the light beam converted by the collimating optical system and simultaneously expanding the light beam, and the image display device is arranged opposite to the concave reflector on the optical axis of the concave reflector in a manner that sandwiches the optical system.

[0013] Effects of the Invention

[0014] According to the present invention, a small-sized, highly efficient, and low-cost image display device can be realized, and a HUD device can be provided which can be easily installed and maintained in a narrow space such as an instrument panel by using the image display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a diagram showing the overall appearance of a head-up display (HUD) device according to the first embodiment of the present invention.

[0016] Figure 2 It is a diagram showing the appearance and internal structure of the image display device in the HUD device of Example 1.

[0017] Figure 3 This is a diagram showing the appearance of a light source device in the image display device of Example 1.

[0018] Figure 4 This is a diagram for explaining the internal structure of the light source device in the image display device of Example 1.

[0019] Figure 5 This is a diagram for explaining the details of the collimator in the image display device of Example 1.

[0020] Figure 6 The diagrams are a stereoscopic view, a cross-sectional view, and an enlarged cross-sectional view showing the detailed shape of the light guide in the image display device of Example 1.

[0021] Figure 7 This is a diagram showing the operation of the internal optical system in the image display device of Example 1.

[0022] Figure 8 This is a diagram for explaining the details of the light guide in the image display device of Example 1.

[0023] Fig. 9 This is a diagram for explaining a comparative example of the light guide in the image display device of Example 1.

[0024] Fig.10 This is a diagram showing the detailed shape of a light guide in an image display device as a modified example of Example 1.

[0025] Fig.11 This is a diagram showing the detailed shape of a light guide in an image display device as a modified example of Example 1.

[0026] Fig.12 This is a diagram for explaining a processing method of a mold used for molding a light guide member which is a component of the optical system of the image display device of Example 1.

[0027] Fig.13 This is a diagram showing the detailed shape of a light guide in an image display device as a modified example of Example 1.

[0028] Fig.14 Yes means Fig.13 The characteristic diagram of the spatial frequency distribution of the surface roughness of the light guide in the image display device shown.

[0029] Fig.15 Yes means Fig.13 A schematic diagram of light scattering on the surface of a light guide in an image display device shown.

[0030] Fig.16 This is a plan view showing the shape of the surface of a light guide in an image display device as a modified example of Example 1.

[0031] Fig.17 This is a diagram for explaining the details of a collimator and a synthetic diffusion block in a light source device.

[0032] Fig.18 This is a partially enlarged cross-sectional view illustrating details of a synthetic diffusion block in the light source device.

[0033] Fig.19This is a diagram showing the structure of an image display device as a modified example of Example 1.

[0034] Fig. 20 This is a diagram showing the structure of an image display device as a modified example of Example 1.

[0035] Fig.21 It is a diagram showing the overall appearance of an image display device according to another embodiment of the present invention.

[0036] Fig. 22 It is a diagram showing the appearance of the internal structure of the optical system of the image display device according to another embodiment of the present invention.

[0037] Fig.23 It is a diagram showing the overall appearance of an image display device according to another embodiment of the present invention.

[0038] Fig.24 This is a diagram showing an example of the structure of the optical system of the image display device according to the second embodiment of the present invention.

[0039] Fig.25 This is a diagram for explaining the optical system of the image display device of Example 2.

[0040] Fig.26 These are a plan view and a side view for explaining the details of the light guide in the image display device of the second embodiment.

[0041] Fig. 27 This is a diagram showing an example of the structure of an LED collimator and a polarization conversion prism as components of the optical system of the image display device of Example 2.

[0042] Fig.28 These are a plan view and a side view for explaining the details of a light guide in an image display device as a modified example of the second embodiment.

[0043] Fig.29 These are a plan view and a side view for explaining the details of a light guide in an image display device as a modified example of the second embodiment.

[0044] Fig.30 These are a plan view and a side view for explaining the details of a light guide in an image display device as a modified example of the second embodiment. DETAILED DESCRIPTION

[0045] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. In all the drawings used to illustrate the embodiments, the same parts are marked with the same reference numerals in principle, and their repeated descriptions are omitted. On the other hand, for the positions marked with reference numerals in a certain figure for explanation, they are no longer shown in the figure when explaining other figures, but sometimes they are marked with the same reference numerals for reference.

[0046] Figure 1 (a) is a diagram showing an overview of an example of the concept of operation of a head-up display (HUD) device using an image display device according to an embodiment of the present invention. In the HUD device 1 according to an embodiment of the present invention, the image light emitted by the image display device 30 disposed in its housing passes through an optical system 43 such as a correction lens, is reflected by a concave reflector 41, and is projected onto the windshield 3 of the vehicle 2 or onto a combiner (not shown) disposed in the front. The image light reflected by the windshield 3 is as shown in FIG. Figure 1 As shown in (a), the image light enters the field of vision of the driver 5. As a result, the driver 5 sees the image light projected onto the windshield 3 and reflected, and sees the image in front of him in the form of a virtual image.

[0047] In addition, in the HUD device 1, in particular, the image display device 30 generally has the following Figure 1 (b) shows the internal structure, here, the image display device 30 is a projector, and the image display device 30 includes, for example, a light source 301, an illumination optical system 302, and a display element 303. In more detail, the illumination light generated in the light source 301 is collected and uniformed by the illumination optical system 302, and then irradiated to the display element 303. The light includes the display element 303 as an element that generates projection light to form a projected image on its display surface.

[0048] It is obvious to those skilled in the art that the light emitted from the image display device 30 is also projected onto the windshield 3 of the vehicle 2 through the display distance adjustment mechanism 400 and the reflector drive unit 500. In addition, by adjusting the angle of the concave reflector 41, the position where the image is projected onto the windshield 3 is adjusted, thereby adjusting the display position of the virtual image seen by the driver 5 up and down. In addition, there is no particular limitation on the content displayed as a virtual image, for example, vehicle information and navigation information, and images of the situation ahead captured by camera images (surveillance cameras and full vehicle monitoring, etc.) not shown in the figure, etc. can be appropriately displayed.

[0049] Figure 2 (a) is a perspective view showing the appearance of the HUD device 1 . Figure 2(b) is an expanded stereoscopic view in which its various parts are decomposed. As can be seen from these figures, the image display device 30 constituting the HUD device 1 is generally housed inside an outer shell 55 as its shell, and the image display device 30, the concave reflector 41, and the distortion correction lens 43 are stored. An opening for projecting image light toward the windshield is formed on the upper surface of the outer shell 55, and the opening is covered by an anti-glare plate 54 (anti-glare plate). In addition, Figure 2 Reference numeral 42 in the figure denotes a concave reflecting mirror driving unit composed of a motor or the like for adjusting the position of the concave reflecting mirror 41 .

[0050] Next, use Figure 3 The image display device 30 constituting the HUD device 1 is described in detail. The image display device 30 is composed of, for example, an LED, a collimator, a synthetic diffusion block, a light guide, etc., which are stored in a light source device housing 11 formed of resin or the like, and will be described in detail later. A liquid crystal display element 50 (with a Figure 1 The LED circuit board 12 has a display element 303 corresponding to the display element 303, and an LED (Light Emitting Diode) element as a semiconductor light source and an LED circuit board 12 on which a control circuit is installed are installed on one side thereof. In addition, a heat sink 13 for cooling the heat generated in the above-mentioned LED element and the control circuit is installed on the outer side of the LED circuit board 12.

[0051] Furthermore, as can be seen from the above description, since the HUD device is assembled in a narrow space such as the dashboard of a vehicle, it is particularly suitable for modularizing the image display device 30 in the HUD device 1, and it is obviously expected that the device will be smaller and more efficient.

[0052] (Example 1)

[0053] Figure 3 1 is a perspective view showing the appearance of the image display device constituting the HUD device of the first embodiment of the present invention. Figure 3 It can be seen that the image display device (main body) 30 is formed of resin, etc., and is composed of a light source device housing 11 that accommodates LEDs, collimators, synthetic diffusion blocks, light guides, etc., which will be described in detail later. In addition, a liquid crystal display element 50 is installed on its upper surface, and a semiconductor LED (Light Emitting Diode) element as a solid light source and an LED circuit board 12 encapsulating its control circuit are installed on one side. At the same time, a heat sink 13 for cooling the heat generated in the above-mentioned LED element and the control circuit is installed on the outer side of the LED circuit board 12.

[0054] In addition, the liquid crystal display device 50 mounted on the upper surface of the light source device housing 11 is composed of the following parts: a liquid crystal display panel frame 51, a liquid crystal display panel 52 mounted on the frame, and an FPC (flexible wiring circuit board 53) electrically connected to the panel. That is, as will be described in detail later, the liquid crystal display panel 52, together with the LED element as a fixed light source, controls the image light displayed thereon based on a control signal from a control circuit (not shown here) constituting the HUD device.

[0055] Figure 4 1 shows the structure of the optical system contained in the light source device housing 11, which is a part of the internal structure of the image display device 30. That is, a plurality of (four in this example) LEDs 14a and 14b (only two are shown here) constituting the light source are installed at a predetermined position relative to the LED collimator 15.

[0056] <LED Collimator>

[0057] In addition, the LED collimators 15 are formed of a light-transmitting resin such as acrylic, for example. Figure 5 As shown, it has a conical convex outer peripheral surface 151 obtained by rotating a roughly parabola, and at the same time, it has a concave portion 153 with a convex portion (i.e., a convex lens surface) 152 formed in the central portion at its top. In addition, a convex lens surface (or a concave lens surface recessed inwardly) 154 protruding outward is provided in the central portion of its planar portion. On the other hand, LEDs 14a and 14b are respectively arranged at specified positions on the surface of the so-called LED circuit board 12 which serves as its circuit board. In addition, the parabola forming the conical outer peripheral surface of the LED collimator 15 is set within an angle range that can completely reflect the light emitted from LED 14a to the peripheral direction inside it, or a reflecting surface is formed. In addition, the material forming the LED collimator is not limited to the aforementioned propylene, as long as it is a transparent material. In particular, when the power of the LED is large, polycarbonate, cycloolefin polymer, silicone polymer material, glass, etc. with higher heat resistance are preferred.

[0058] like Figure 5 As shown in FIG. 1 , the LED circuit board 12 is arranged and fixed relative to the LED collimator 15 in such a manner that the LEDs 14a and 14b on the surface are respectively located in the center of the recess 153. According to this structure, according to the LED collimator 15, among the light emitted from the LED 14a, especially from the center thereof toward the upper side ( Figure 5The light emitted in the right direction of the LED collimator 15 is collected by the two convex lens surfaces 152 and 154 forming the outer shape of the LED collimator 15 and becomes parallel light. In addition, the light emitted in the peripheral direction from other parts is reflected by the parabola forming the outer peripheral surface of the conical shape of the LED collimator 15, and is also collected and becomes parallel light. In other words, the LED collimator 15 has a convex lens in its central part and a parabola in its peripheral part, so that basically all the light generated by the LED 14a is obtained as a light beam close to parallel light, which can improve the utilization efficiency of the generated light.

[0059] Furthermore, a rectangular synthetic diffusion block 16 is provided on the light emitting side of the LED collimator 15. That is, the light emitted from the LED 14a or 14b is converted into parallel light by the LED collimator 15 and enters the synthetic diffusion block 16.

[0060] Here, return Figure 4 On the exit surface side of the synthetic diffusion block 16, a light guide 17 having a substantially triangular cross section is provided via a first diffusion plate 18a, and a second diffusion plate 18b is mounted on the upper surface thereof. Thus, the horizontal light of the LED collimator 15 is directed to the Figure 4 At the same time, the longitudinal beam width of the horizontal light is widened by the action of the light guide 17 and is guided to the incident surface of the liquid crystal display element 50. According to the action of the light guide, a thin and small image display device can be realized. At this time, its intensity is uniformed by the first and second diffusion plates 18a and 18b.

[0061] <Detailed structure of light guide>

[0062] Next, refer to Figure 6 The light guide 17 constituting the light source device will be described in detail. Figure 6 (a) is a perspective view showing the entire light guide 17. Figure 6 (b) is its cross-sectional view, Figure 6 (c) and Figure 6 (d) is a partially enlarged cross-sectional view showing the details of the cross section.

[0063] The light guide 17 is formed of a light-transmitting resin such as acrylic and has a substantially triangular cross section (see Figure 6 (b)) of the components, Figure 6 (a) It can be seen that it includes: a light guide light incident portion (surface) 171 opposite to the output surface of the above-mentioned synthetic diffusion block 16 via the first diffusion plate 18a, a light guide reflection portion (surface) 172 forming an inclined surface, and a light guide output portion (surface) 173 opposite to the liquid crystal display panel 52 of the above-mentioned liquid crystal display element 50 via the second diffusion plate 18b.

[0064] On the light guide light reflecting portion (surface) 172 of the light guide 17, as shown in the partially enlarged view thereof, Figure 6 (c) and Figure 6 As shown in (d), the plurality of reflecting surfaces 172a and the connecting surfaces 172b are alternately formed into a sawtooth shape. Figure 6 The upper right line segment in the middle) is relative to Figure 6 The horizontal plane indicated by the dot-dash line forms an angle of αn (n: a natural number, such as 1 to 130 in this example), and as an example, αn is set to be less than 43 degrees (but greater than 0 degrees).

[0065] On the other hand, the connection surface 172b (at Figure 6 The lower right line segment in the figure) forms an angle βn (n: a natural number, for example, 1 to 130 in this example) with respect to the reflecting surface. That is, the connecting surface 172b of the reflecting portion is inclined with respect to the incident light to an angle that becomes a shadow within the half-value angle range of the scatterer described later. This will be described 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. As an example, it is set to be greater than 90 degrees (but less than 180 degrees). In addition, in this example, β1=β2=β3=β4=…=β20=…β130.

[0066] For the sake of convenience, Figure 7 and Figure 8 17 shows a schematic diagram of a light guide 17 in which the sizes of the emitting surface 172a and the connecting surface 172b are relatively increased. In the light guide light incident portion (surface) 171 of the light guide 17, the main light beam is deflected δ in the direction of increasing the incident angle relative to the reflecting surface 172a (refer to Figure 8 (b)). That is, the light-incident portion (surface) 171 of the light guide is formed into a curved convex shape inclined relative to the light source side. In this way, the parallel light from the exit surface of the synthetic diffusion block 16 is diffused and incident on the first diffusion plate 18a. Figure 8 (b) It can be seen that the light incident portion (surface) 171 of the light guide body is slightly bent (deflected) upward and reaches the light reflecting portion (surface) 172 of the light guide body (see Fig. 9 of comparative examples).

[0067] In addition, on the light-guiding body light-reflecting portion (surface) 172, a plurality of reflecting surfaces 172a and connecting surfaces 172b are alternately formed in a sawtooth shape, and the diffused light is completely reflected on each reflecting surface 172a and directed upward, and passes through the light-guiding body light-emitting portion (surface) 173 and the second diffuser 18b, and is incident on the liquid crystal display panel 52 as parallel diffused light. Therefore, the reflecting surface elevation angles α1, α2, α3, α4, ... are set so that each reflecting surface 172a forms an angle greater than a critical angle with the diffused light, and on the other hand, the relative angles β1, β2, β3, β4, ... between the reflecting surface 172a and the connecting surface 172b are set to a certain angle as described above, and the reason for this will be described later, and it is more preferable to set it to an angle greater than 90 degrees (βn≥90 degrees).

[0068] According to the above structure, each reflection surface 172a always maintains an angle greater than the critical angle with respect to the diffused light, so even if a metal or other reflective film is not formed on the light guide light reflecting portion (surface) 172, it can be completely reflected, and a low-cost image display device 30 can be realized. On the other hand, as a comparative example, Fig. 9 As shown, in the light guide incident portion of the light guide 17, in the absence of bending (polarization) of the main light rays, a portion of the diffused light forms an angle below the critical angle with the reflecting surface 172a, and sufficient reflectivity cannot be ensured, so a light source device with good (bright) characteristics, i.e., an image display device, cannot be realized.

[0069] In addition, the reflection surface elevation angles α1, α2, α3, α4, etc. are values ​​that slightly increase as they move from the lower part to the upper part of the light guide body light reflecting portion (surface) 172. This is because the light of the liquid crystal display panel 52 that passes through the liquid crystal display element 50 has a certain degree of divergence angle. Therefore, in order to prevent the so-called peripheral dimming phenomenon in which part of the light passing through the peripheral part of the liquid crystal display panel 52 is reduced at the peripheral edge of the reflector arranged downstream, Figure 7 As shown in the light ray L30, a structure is realized in which the light ray in the peripheral part is slightly deflected toward the central axis.

[0070] As mentioned above, β1=β2=β3=β4…βn≥90 degrees. The reason is that Fig.12 As shown, in the processing of the mold 40 for making the light guide 17 by injection molding, the reflective surface 172a and the connecting surface 172b can be processed simultaneously by using a milling cutter with a relative angle β between the bottom surface and the side surface. In addition, the reflective surface 172a and the connecting surface 172b can be processed using a relatively rough tool, thereby greatly shortening the processing time and greatly reducing the processing cost. In addition, the boundary between the reflective surface 172a and the connecting surface 172b can be processed with high precision, thereby improving the light guiding characteristics of the light guide 17.

[0071] in addition, Figure 7 Lr1, Lr2, Lr3, Lr4... represent the projection length of the reflecting surface 172a on the horizontal plane, Lc1, Lc2, Lc3, Lc4... represent the projection length of the connecting surface 172b on the horizontal plane, and Lr / Lc, that is, the ratio of the reflecting surface 172a to the connecting surface 172b, can be changed according to the position. The intensity distribution of the main light L30 incident on the light guide 17 may not be consistent with the expected intensity distribution on the incident surface of the liquid crystal display panel. Therefore, a structure is adopted to adjust the intensity distribution according to the ratio Lr / Lc of the reflecting surface 172a and the connecting surface 172b. In addition, the higher the ratio, the higher the average intensity of the partially reflected light. Generally speaking, the central part of the light L30 incident on the light guide tends to be enhanced, so in order to correct it, the aforementioned ratio Lr / Lc varies with different positions, especially reducing the intensity of the central part. The aforementioned ratio Lr / Lc and the aforementioned reflection surface elevation angles α1, α2, α3, α4, etc. adopt different structures depending on the position. Therefore, the outline 172c representing the approximate shape of the light guide light reflection portion (surface) 172 is as follows: Figure 7 The shape of the curve is shown.

[0072] In addition, Lr1+Lc1=Lr2+Lc2=Lr3+Lc3=Lr4+Lc4…=Lr+Lc≤0.6mm. By adopting this structure, the repetition pitch of the reflection surface seen from the light guide light emitting portion (surface) 173 side of the light guide 17 can be the same. In addition, since this pitch is less than 0.6mm, combined with the function and effect of the diffuser plates 18a and 18b, when observed through the liquid crystal display panel 52, the respective emission surfaces are not separated but appear as a continuous surface, so the spatial brightness through the liquid crystal display panel 52 becomes uniform, and thus the display characteristics are improved. That is, according to this structure, the intensity distribution of the incident light on the liquid crystal display panel 52 can be made uniform. On the other hand, if the value of Lr+Lc is less than 0.2mm, not only will it take time to process, but it will also be difficult to process each reflection surface 172a with high precision, so it is preferably greater than 0.2mm.

[0073] According to the shape of the light guide light reflecting portion (surface) 172 of the light guide 17, the conditions for complete reflection of the main light can be met, and there is no need to set a reflective film such as aluminum on the light guide light reflecting portion (surface) 172, so that light can be effectively reflected, and there is no need for the evaporation of aluminum thin film that increases the manufacturing cost, etc., so that a bright light source can be achieved at a lower cost. In addition, each relative angle β is set to an angle at which the connection surface 172b forms a shadow relative to the main light L30 after being diffused in the synthetic diffusion block 16 and the diffusion plate 18a. In this way, the incident of excess light on the connection surface 172b can be suppressed, and the reflection of excess light can be reduced, thereby realizing an image display device with good characteristics.

[0074] In addition, according to the above-mentioned light guide 17, the following image display device can be realized, that is, by appropriately setting the reflection surface elevation angles α1, α2, α3, α4, ..., and the ratio Lr / Lc of the reflection surface to the connection surface, the length of the light guide light emitting portion (surface) 173 in the optical axis direction can be freely changed, so that for the light guide light incident portion (surface) 171, the size (surface size) of the light guide light emitting portion (surface) 173 can be appropriately changed to a size (surface size) suitable for the above-mentioned liquid crystal display panel 52 and other devices. In addition, the light guide light emitting portion (surface) 173 can be formed into a desired shape without being affected by the configuration shape of the LEDs 14a and 14b constituting the light source, thereby obtaining a planar light source of a desired shape. In addition, according to this structure, the thickness of the LED collimator 15 and the synthetic diffusion block 16 can be made thinner for the size of the liquid crystal display panel 52, so it will also be conducive to the miniaturization of the entire device.

[0075] In addition, according to the above-mentioned light guide 17, Fig.10 As shown, by appropriately setting the connecting surface 172b constituting the light reflecting portion (surface) 172 of the light guide body (in this example, light is not reflected by the reflecting surface 172a, which is a part of the central portion), the ratio Lr / Lc of the reflecting surface 172a and the connecting surface 172b can be greatly changed according to the position in the light guide body light emitting portion (surface) 173 of the light guide body 17. Fig.10 In the example of FIG. 1 , the light emitted from the light guide light emitting portion (surface) 173 of the light guide 17 is divided into two beams on the left and right in the optical axis direction. For example, this structure is very suitable for separating the illumination light from the HUD device up and down or left and right without loss. In addition, by appropriately adjusting the above ratio Lr / Lc, the reflected light can also be partially enhanced or weakened.

[0076] In addition, Fig.11 As shown, if a plurality of (two in this example) light source devices including the above-mentioned LEDs 14a, 14b and light guide 17 are combined in a manner opposite to each other in the same plane, an image display device can be realized that includes a light guide light emitting portion (surface) 173 with a greater variety of surface sizes and light amounts.

[0077] Here, the inclination of the main light rays incident on the liquid crystal display panel is generally preferably close to vertical, but according to the characteristics of the liquid crystal display panel, such as Fig.10 That is, among the liquid crystal panels available on the market, the panel with the incident angle tilted by about 5 to 10 degrees has excellent characteristics. In this case, it is preferable to set the above η to 5 to 10 degrees according to its characteristics.

[0078] In addition, instead of tilting the panel at an angle of n, the angle of the reflective surface 172a may be adjusted, so that the main light can be tilted toward the liquid crystal panel. In addition, when the light must be tilted toward the side direction of the light guide, the inclined surface of the triangular texture structure 161 formed on the exit surface of the synthetic diffusion block 16 described in detail below is tilted to be asymmetric on the left and right, or the formation direction of the texture composed of the reflective surface 172a and the connecting surface 172b is changed, so that it can be achieved.

[0079] In addition, in the above-mentioned light guide 17, Fig.13 As shown, the following functional scattering surfaces 175 are respectively given (formed) on the incident surface and the outgoing surface, thereby, the above-mentioned Figure 6 With this structure, the diffuser plates 18a and 18b are not required, and the image display device can be made low-cost.

[0080] This functional scattering surface can reduce unnecessary radiation structure parts by reducing the surface roughness of components with high spatial frequencies (fine components). Fig.14 (b) shows the spatial frequency component of the surface roughness of a typical scattering surface. Fig.14 (a) shows the surface roughness spatial frequency component of the scattering surface having more preferred scattering characteristics. The surface roughness spatial frequency distribution of a conventional scattering surface is as follows: Fig.14 As shown in the figure, it represents the distribution along the inverse of the spatial frequency (1 / f). In contrast, for a more preferred spatial frequency distribution of surface roughness, the values ​​are lower in the low frequency region below 10 / mm and the high frequency region above 100 / mm. The low frequency component of the surface roughness spatial frequency is small, and the mid-frequency component is moderate, so a light source with less scattering unevenness can be realized. In addition, since the high frequency component of the surface roughness spatial frequency is small, the scattering angle of the scattered light will not increase, such as Fig.15 As shown in (a), the direction of light scattered on the surface can be limited to a direction that can be used as a light source, and a bright light source with uniform brightness distribution can be realized. Fig.15 As shown in (b), light is also scattered in directions other than those in which it can be used as a light source, so a bright light source cannot be realized.

[0081] Fig.16 1 is a partial enlarged view showing a specific example of the texture structure 161 formed on the incident surface or the emitting surface of the light guide 17. In this schematic diagram, Fig.16 (a) shows an example in which the boundary between the reflection surface (or the emission surface) and the connection surface is arranged and formed in a straight line. Fig.16(b) shows another example in which the LEDs 14a and 14b as the light source are arranged and formed in a curved shape according to necessity, such as being arranged separately and dispersedly.

[0082] That is, if the above-mentioned functional scattering surface is adopted, the control freedom of the light incidence and emission in the incident surface and the output surface of the light guide 17 will be increased, the uneven brightness of the light from the light source device can be reduced, and detailed control can be performed according to the characteristics of the device of the optical system arranged on its downstream side (in this case, the liquid crystal display device 50), which will also be conducive to the low cost of the device.

[0083] <Details of synthetic diffusion block>

[0084] Next, refer to Fig.17 as well as Fig.18 The synthesis diffusion block 16 as another component of the image display device 30 is described. Fig.17 represents a synthetic diffusion block 16 integrated with the above-mentioned LED collimator 15, Fig.18 (a) and Fig.18 (b) shows a partially enlarged cross section of the synthetic diffusion block 16 .

[0085] Depend on Fig.18 (a) It can be seen that a plurality of texture structures 161 having a substantially triangular cross section are formed on the emission surface of the synthetic diffusion block 16 formed into a square column shape using a light-transmitting resin such as acrylic, and the light emitted from the LED collimator 15 is diffused in the vertical direction of the light guide light incident portion (surface) 171 of the light guide 17 according to the effect of the texture structures 161. Due to the interaction between the substantially triangular texture structures 161 and the diffusion plates 18a and 18b, even if the LED collimators 15 are dispersedly arranged, the intensity distribution of the light emitted from the light guide light exit portion (surface) 173 of the light guide 17 can be made uniform.

[0086] In particular, according to the texture structure 161, since the diffusion direction is limited to the side direction of the light guide body and the diffusion in the side direction can be controlled, the isotropic diffusion of the first and second diffusion plates 18a and 18b can be weakened. As a result, the light utilization efficiency is improved, and an image display device with good characteristics can be realized. In addition, in this example, as an example of a texture structure 161 in a roughly triangular shape, an example with an angle γ = 30 degrees and a formation spacing α = 0.5 mm is shown. However, the texture structure 161 can also be used in the above description. Figure 13 to Figure 16In addition, the texture structure formed on the diffusion block is not limited to being roughly triangular, for example, it can also be a concentric circle shape consistent with the central axis of each LED collimator according to the dispersed configuration of the LED collimators 15.

[0087] In addition, the synthetic diffusion block 16 can also replace the above-mentioned square column shape, such as Fig.19 The bent member 16' is a so-called wedge-shaped triangular prism. In this way, the light from the LED collimator 15 including the LEDs 14a and 14b as the light source is directed in the desired direction ( Fig.19 Thus, the flat incident surface facing the light guide 17 can be incident at a desired angle. Figure 5 to Figure 7 As shown, the light guide light incident portion (surface 171) of the light guide 17 is not formed into a curved convex shape inclined toward the light source side, and complete reflection on the reflection surface 172a can be ensured, so it is a structure that is easier to manufacture.

[0088] In addition, Fig. 20 As shown, the above-mentioned synthetic diffusion block 16 is not provided, but the configuration angle of the LED collimator 15 including the LEDs 14a and 14b as the light source is tilted, thereby ensuring complete reflection in the reflection surface 172a and obtaining a bright light source. In addition, since the light L30 emitted from the LED is refracted in the light guide light incident portion (surface) 171 of the light guide 17, the tilt angle δ' of the LED collimator 15 may not be consistent with the tilt angle δ of the light inside the light guide 17 (δ'≠δ), so this point should be paid special attention to.

[0089] As described in detail above, the image display device 30 according to the first embodiment of the present invention can further improve the utilization efficiency of light from the LED light source and its uniform lighting characteristics, and at the same time, can manufacture a small and low-cost modular image display device.

[0090] <Other Examples>

[0091] in addition, Fig.21 as well as Fig. 22 The overall appearance of the image display device 300 and its internal structure are shown in another embodiment of the present invention. In this other embodiment, a synthetic diffusion block 16b having a substantially trapezoidal cross section is used to install a LED collimator 15 having a plurality of conical convex shapes on which LEDs are mounted at an inclined position below the device. Fig.21 Reference numeral 13b denotes a heat sink for cooling heat generated in the LED element and the control circuit.

[0092] in addition, Fig.23 The overall appearance of the image display device 300 of another embodiment of the present invention is shown in a three-dimensional diagram. In this embodiment, the heat generated in the LED circuit board 12 is cooled by the heat transfer plate 13d in the heat sink 13c disposed at the lower part of the device. According to this structure, a light source device with a short overall length can be realized.

[0093] (Example 2)

[0094] <Light source device with polarization function>

[0095] Next, refer to Figures 24 to 30 Embodiment 2 of the present invention is described in detail. In this embodiment 2, unlike the above-mentioned embodiment 1, it is an image display device that emits light from a light source device as polarized light of S polarization or P polarization, but it is the same as the above-mentioned point that a small and efficient planar light source that can be used as a modular light source is realized.

[0096] Figure 24 to Figure 26 The structure of the optical system, which is particularly characteristic of the image display device of the second embodiment, is shown. That is, in the second embodiment, in the structure of the first embodiment, as an example, the number of LEDs 14a and 14b constituting the light source is half that of the first embodiment, i.e., two, and a polarization conversion element 21 is provided between each LED collimator 15 and the synthetic diffusion block 16. In addition, the other structures in the figure are marked with the same reference numerals as those in the first embodiment, and their detailed description is omitted here to avoid repetition.

[0097] In addition, from these drawings, especially Fig.26 (a) It can be seen that a translucent component with a parallelogram-shaped column (hereinafter referred to as a parallelogram column) extending in a direction perpendicular to the drawing paper and a translucent component with a triangular column (hereinafter referred to as a triangular column) in cross section are combined so that a plurality of them are arranged in a matrix in parallel with a plane orthogonal to the optical axis of the parallel light from the LED collimator 15 (in this example, the vertical direction on the drawing paper) to form a polarization conversion element 21. In addition, polarization beam splitter (hereinafter referred to as "PBS") films 211 and reflection films 212 are alternately provided at the interface between these adjacent translucent components arranged in a matrix. In addition, a 1 / 2λ phase plate 213 is provided on the exit surface from which the light incident on the polarization conversion element 21 and passing through the PBS film 211 is emitted.

[0098] As described above, the polarization conversion element 21 is constructed symmetrically with respect to a plane formed by the optical axis of the parallel light from the LED collimator 15 and the extending direction of the light-transmitting member of the parallelogram column (a vertical plane extending vertically on the paper of the drawing), the so-called optical axis plane of the parallel light, and the parallelogram column and the triangular column of the light-transmitting member as its constituent elements are inclined at an angle of 45 degrees to the optical axis plane. For the parallel light from the two LED collimators 15, the polarization conversion element 21 is composed of polarization conversion elements divided into two groups in the vertical direction of the drawing.

[0099] According to the polarization conversion element 21 constructed in the above manner, Fig.26 (a) For example, the S polarization wave in the incident light that is emitted from the LED 14a and becomes parallel light in the LED collimator 15 (see Fig.26 The P polarized wave (see the symbol (×)) is reflected by the PBS film 211, and then further reflected by the reflective film 212 and reaches the incident surface of the synthetic diffusion block 16. Fig.26 After passing through the PBS film 211, the light (indicated by the upper and lower arrows) is converted into an S-polarized wave by the 1 / 2λ phase plate 213 and reaches the incident surface of the synthetic diffusion block 16.

[0100] As described above, according to the polarization conversion element 21, all the light emitted from the (multiple) LEDs and converted into parallel light by the LED collimator 15 is converted into S polarized waves and incident on the incident surface of the synthetic diffusion block 16. Then, the light emitted from the emission surface of the synthetic diffusion block 16 is incident on the light guide body 17 described in detail above via the first diffusion plate 18a, and is directed to the light source 17 by the action of the light guide body 17. Fig.26 (b) is reflected from above and guided to the incident surface of the liquid crystal display element 50, which is the same as the case in the above-mentioned embodiment 1. In addition, the function of the light guide 17 has been described in detail above, and its description is omitted here to avoid repetition.

[0101] also, Fig. 27 2 is a perspective view showing the two LED collimators 15 mounted on the polarization conversion element 21. Fig.29 1 is a diagram showing the appearance structure of a synthetic diffusion block 16 installed on the exit surface side of a polarization conversion element. Fig.30 1 is a side view and a partially enlarged cross-sectional view showing the detailed structure of the synthetic diffusion block 16. As can be seen from these figures, in the second embodiment, a plurality of texture structures 161 having a substantially triangular cross-section are formed on the emission surface of the synthetic diffusion block 16. However, the details have been described above and are omitted here. In addition, in the synthetic diffusion block 16, the above-mentioned Figure 13 to Figure 16It will be obvious to those skilled in the art that the functional scattering surface shown as having a texture structure 161 formed on its surface can also achieve the same effect.

[0102] As described above, according to the image display device of the second embodiment, the polarization conversion element 21 is used to convert the light incident on the liquid crystal display panel 52 constituting the liquid crystal display element 50 into a desired polarized wave (in this case, an S polarized wave), thereby achieving effects such as improving the transmittance of the light in the liquid crystal display panel based on the polarization characteristics of the emitted image light, and thus, fewer light sources (LEDs) can be used to achieve a smaller and more efficient modular image display device at a lower cost. In addition, in the above description, the case where the polarization conversion element 21 is installed behind the LED collimator 15 is described, but the present invention is not limited to this, and the same function and effect can be obtained by setting it in the light path reaching the liquid crystal display element, which is obvious to those skilled in the art.

[0103] Fig.28 In the above-mentioned image display device, the number of LEDs 14a, 14b, and 14c constituting the light source is three, and a polarization conversion element 21 is provided between each LED collimator 15 and the synthetic diffusion block 16, but an orientation control plate 16c is provided instead of the synthetic diffusion block 16 constituting the orientation control plate. In addition, in this structure, it is characterized in that a larger LED 14 is used relative to the shape of the LED collimator 15. Accordingly, the shape of the light incident portion 155 of the LED collimator 15 is larger than that of other embodiments. Fig.28 (a) is used to explain that the light L301 and L302 emitted from the LED 14a in an oblique direction enters the light incident portion 155 of the LED collimator and is reflected by the side surface 156 to form a roughly convergent light, and reaches the exit surface 157 of the LED collimator. In particular, the outer peripheral portion of the exit surface 157 of the LED collimator forms a concave shape, so in this portion, the light L301 and L302 are refracted and converted into substantially parallel light, and enter the light incident portion 21w of the polarization conversion element. By adopting this structure, even if Fig.28 Even when the width of the light incident portion 21w of the polarization conversion element shown in (a) is narrow, light from the LED can be effectively incident on the polarization conversion element, and an efficient light source can be realized.

[0104] Next, use Fig.28(b) The light emitted from LED 14a and refracted in the light incident portion 155 of the LED collimator is described. Since the light incident portion 155 of the LED collimator is formed in a convex shape, the light L30 emitted from the center of the LED 14a is converted into approximately parallel light there, passes through the polarization conversion element 21, and then passes through the diffuser 18a, the light guide 17, and the diffuser 18b and is incident on the liquid crystal display panel 52. On the other hand, if the light L3001 and the light L3002 emitted from the end of the LED 14a and especially intersecting the central axis are considered, then the light is incident at an angle close to perpendicular to the surface of the light incident portion 155 of the LED collimator, so its refraction angle is small, and the result is as follows. Fig.28 As shown in FIG. 1 , the light is emitted obliquely from the LED collimator 15, and as a result, it is also emitted obliquely from the polarization conversion element. Therefore, if there is no component for controlling the direction of light between the polarization conversion element 21 and the light guide 17, the light will deviate from the light incident portion of the light guide 17 as shown by the dotted line, such as the light L3001c and the light L3002c, so that the light cannot be effectively used. On the contrary, in the present invention, an orientation control plate 16c having a substantially cylindrical convex shape is arranged between the polarization conversion element 21 and the light guide 17, thereby, each light L3001, L3002 will be refracted like the light L3001b, L3002b, and then pass through the diffuser 18a, the light guide 17, and the diffuser 18b to enter the liquid crystal display panel 52, so that an efficient light source can be realized. This structure is particularly suitable when a larger-sized LED is used relative to the width of the light incident portion of the polarization conversion element. In addition, the present structure is not limited to the structure having the polarization conversion element 21, and the orientation control plate 16c may be arranged between the LED collimator 15 and the light guide 17. In addition, in this structure, the diffusion plates 18a and 18b provided on the incident surface and the outgoing surface of the light guide 17 are omitted, and the above-mentioned functional scattering surfaces are added (formed) on the incident surface and the outgoing surface respectively instead (see Figure 13 to Figure 16 ).

[0105] In addition, although it is particularly suitable for small image display devices with a small light source emission surface, it can also be used as Fig.29 As shown in FIG. 1 , a polarization conversion element 21 ′ is directly provided instead of the light guide 17 disposed behind the synthetic diffusion block 16. Fig.29 It can be seen that the light-transmitting component 211' of the combined triangular column and the light-transmitting component 212' of the parallelogram column form an S-polarized wave (see FIG. 1 ) at their boundary that reflects the incident light emitted from the LED 14a and converted into parallel light in the LED collimator 15. Fig.29 symbol (×)) and transmits P polarized waves (refer to Fig.29A PBS film 211 is formed on the upper surface of a parallelogram-shaped light-transmitting member 212', and a reflective film 212 is formed on the side thereof.

[0106] According to the above structure, Fig.29 It can also be seen that the polarization component of the incident light emitted from the LED 14a and converted into parallel light in the LED collimator 15 is converted into S polarization by the polarization conversion element 21' replacing the light guide 17, and is emitted upward from the upper surface of the element. That is, in the above-mentioned structure, especially by removing the light guide 17, it is possible to achieve a significant miniaturization of the device and reduce the manufacturing cost of the device.

[0107] in addition, Fig.30 1 shows a structure in which multiple sets of LEDs 14 and LED collimators 15 as light sources are arranged not only in the horizontal direction but also in the vertical direction in the above manner. That is, in this example, in addition to arranging three sets of LEDs 14 and LED collimators 15 separated from each other in the horizontal direction (see Fig.30 In addition to (a), three sets of LEDs 14 and LED collimators 15 are also arranged adjacent to each other in the longitudinal direction (see Fig.30 (b)). In addition, other structures in the figure are the same as those in the above-mentioned embodiment 2, and their detailed description is omitted here to avoid repetition.

[0108] In addition, according to this structure, the number of LEDs 14 as light sources can be increased, so that a brighter image display device can be realized. In addition, the light emitting surface can be further expanded. In addition, in the case of an image display device equipped with a light emitting surface with a large display area, or in the case of being used in combination with a liquid crystal display panel 52 with a large display area, it is very suitable. In addition, according to this structure, the light emitting surface is divided into a plurality of display areas corresponding to a plurality of LEDs 14, and the so-called Local Dimming can be realized by independently controlling the light output (lighting) of the LEDs 14, etc., and high contrast and low power consumption of the displayed image can also be achieved. In addition, the multi-layer arrangement structure of the light source is not limited to the image display device with polarization function of Example 2, but is also applicable to the image display device of Example 1 above, and of course the same effect can be obtained.

[0109] In addition, in addition to the above-mentioned regional dimming by controlling the LEDs individually, according to the above-mentioned control circuit (for example, mounted on Figure 3 The flexible wiring circuit board 53 is used to control the LEDs individually and at the same time control them in combination with the liquid crystal display panel 52. Thus, a more suitable image display device with lower power consumption can be realized, and a HUD device using the image display device can also be realized.

[0110] In addition, in the area dimming, the vertical arrangement of LEDs is preferably arranged neatly rather than staggered. The neat arrangement makes it easy to control the lighting brightness of each location. In addition, even when a polarization conversion element is used, the vertical arrangement of LEDs is preferably arranged neatly. In the case of a staggered arrangement of the vertical arrangement, the polarization conversion prism must be arranged as a separate element according to each longitudinal position, but in the neat arrangement, the thickness in the vertical direction of a single element can be adjusted according to the arrangement of the LEDs.

[0111] In addition, in the above description, the point that the liquid crystal display panel has good transmittance for S-polarized waves is explained. However, in the case of good transmittance for P-polarized waves, the same function and effect can still be obtained based on a polarization conversion element having the same structure as above, which is obvious to those skilled in the art.

[0112] In addition, as can be seen from the above detailed description, as described above, the modularized small-sized and efficient image display device adopts a structure in which the concave reflector is arranged on the optical axis of the windshield or the combiner after reflecting the image light (however, the correction lens constituting the correction optical system is interposed therebetween), and the volume of the entire HUD device can be further reduced. Therefore, the following effects are exerted: the HUD device can be easily assembled even in a narrow space such as an instrument panel, and the installation and maintenance operations are also easy to perform.

[0113] The image display device of the HUD device applicable to various embodiments of the present invention has been described above. However, the present invention is not limited to the above-mentioned embodiments, but also includes various modified examples. For example, the above-mentioned embodiment is an example of describing the entire system in detail for the convenience of explaining the present invention, and is not limited to including all the structures described. In addition, a part of the structure of a certain embodiment can be replaced with the structure of other embodiments, and the structure of other embodiments can be added to the structure of a certain embodiment. In addition, for a part of the structure of each embodiment, other structures can be added, deleted, and replaced.

[0114] Description of Reference Numerals

[0115] 1…HUD device, 2…vehicle, 3…windshield, 5…driver, 30…image display device, 41…concave reflector, 43…distortion correction lens, 55…exterior casing, 54…anti-glare plate, 11…light source device casing, 12…LED circuit board, 13…heat sink, 50…liquid crystal display device, 51…liquid crystal display panel frame, 52…liquid crystal display panel, 53…FPC (flexible wiring board), 14a, 14b…LED, 15…LED collimator, 17…light guide, 18a, 18b…diffuser, 172a…reflection surface, 172b…connection surface, 16…synthetic diffuser, 161…texture structure, 21…polarization conversion element, 211…PBS film, 212…reflection film.

Claims

1. A head-up display device projects image light onto a windshield of a vehicle or a combiner disposed in front of the windshield, and provides an image to a driver using a virtual image formed by the reflected light, wherein the head-up display device comprises: Solid-state light sources; A collimating optical system including a collimator that converts light emitted from the solid light source into light including substantially parallel light and light emitted in an oblique direction relative to the substantially parallel light; A light guide that receives the light emitted from the collimating optical system and causes the light to be emitted in a predetermined direction; An image display element disposed on the exit surface of the light guide; and a concave reflector for reflecting the image light from the image display element and projecting it onto the windshield or the combiner, wherein: The light guide has an incident portion for light to be incident, a reflecting portion for reflecting the incident light, and an emitting portion for emitting the light reflected by the reflecting portion. The reflecting portion is composed of a plurality of reflecting surfaces for reflecting the incident light and a plurality of connecting surfaces connected between the plurality of reflecting surfaces.

2. The head-up display device according to claim 1, characterized in that: The incident portion has a structure that deflects light in a direction in which an incident angle of light incident on a reflecting surface of the reflecting portion becomes larger.

3. The head-up display device according to claim 2, characterized in that: The deflection structure of the incident surface of the light guide is an inclined surface arranged obliquely with respect to the incident light.

4. The head-up display device according to claim 3, characterized in that: At least a portion of the inclined surface disposed obliquely is a curved surface.

5. The head-up display device according to claim 2, characterized in that: The elevation angle of the reflection surface formed on the reflection part of the light guide body is different depending on the position, and the relative angle between the adjacent reflection surfaces and the connection surface is greater than or equal to 90 degrees.

6. The head-up display device according to claim 5, characterized in that: The relative angle between the adjacent reflecting surfaces and the connecting surface does not change with the position and is a constant value.

7. The head-up display device according to claim 5, characterized in that: The absolute value of the elevation angle of the connection surface does not change with the position and is a constant value.

8. The head-up display device according to claim 1, characterized in that: A ratio Lr / Lc of a length Lr of the plurality of reflecting surfaces of the reflecting portion projected onto the horizontal plane to a length Lc of a connecting surface connecting the reflecting surfaces projected onto the horizontal plane differs depending on the position.

9. The head-up display device according to claim 8, characterized in that: The ratio Lr / Lc is smallest near the center of the reflecting portion.

10. The head-up display device according to claim 8, characterized in that: By partially reducing the ratio Lr / Lc, the outgoing light from the light guide is partially reduced or blocked.

11. The head-up display device according to claim 8, characterized in that: The sum of the lengths Lr+Lc is constant.

12. The head-up display device according to claim 8, characterized in that: The sum of the lengths Lr+Lc is 0.6 mm or less and 0.2 mm or more.

13. The head-up display device according to claim 1, characterized in that: The collimator is disposed on the light emitting surface side of the solid light source, and is composed of a light-transmitting member whose outer circumference is formed by a parabola and whose central portion has a lens surface.

14. The head-up display device according to claim 13, characterized in that: The invention comprises a rectangular synthetic diffusion block arranged on one side of the exit surface of the collimator.

15. The head-up display device according to claim 14, characterized in that: A texture structure for diffusing light is formed on the emission surface of the synthetic diffusion block.

16. The head-up display device according to claim 14, characterized in that: A concentric circular texture structure that is consistent with the central axis of the collimator is formed on the exit surface of the synthetic diffusion block.

17. The head-up display device according to claim 13, characterized in that: A cylindrical convex orientation control plate is arranged between the collimator and the light guide.

18. The head-up display device according to claim 13, characterized in that: A plurality of the solid light sources and the collimators are arranged in a horizontal and vertical direction, and the arrangement method is to arrange them neatly, and control the regional dimming of the output of each solid light source according to the image to be displayed.

19. The head-up display device according to claim 13, characterized in that: A polarization conversion element is arranged between the collimating optical system and the light guide.

20. The head-up display device according to claim 18, wherein: At least a portion of the exit surface of the collimator is a concave surface.

21. The head-up display device according to claim 19, wherein: A plurality of the solid light sources and the collimators are arranged in a neat arrangement in both the horizontal and vertical directions.

22. The head-up display device according to claim 1, characterized in that: Functional scattering surfaces are formed at the incident portion and the emitting portion of the light guide.

Images