Optical refractive member, optical system, illumination system, display system, and moving body

Abstract

The present disclosure provides a light refracting member, an optical system, an illumination system, a display system, and a moving body. The light refracting member (8) includes: an incident surface (6) on which a planar light (9) is incident; a plurality of refracting portions (81) that refract the planar light (9); and an emission surface (7) from which the planar light (9) is emitted as an emitted light (14) after being refracted by the plurality of refracting portions (81). The plurality of refracting portions (81) are arranged along a first direction on at least one of the incident surface (6) and the emission surface (7), and each of the plurality of refracting portions (81) has a region in which the direction of the planar light (9) is changed along a second direction that intersects the first direction.

Description

Technical Field

[0001] This disclosure generally relates to light refraction components, optical systems, lighting systems, display systems, moving bodies, and molds. More specifically, this disclosure relates to light refraction components, optical systems, lighting systems, display systems, moving bodies, and molds for forming light refraction components that control light incident from an incident surface and causes it to exit from an exit surface. Background Technology

[0002] Patent Document 1 discloses an image display device (display system) that projects a virtual image into an object space. This image display device is an automotive HUD (Head-Up Display) device. The projected light, which serves as image light, emitted from the automotive HUD device (optical system) within the dashboard is reflected by the windshield and directed towards the driver, who is the visual observer. Thus, the user (driver) can visually recognize images such as navigation images as virtual images and perceive that the virtual image overlaps with a background such as the road surface.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-142491 Summary of the Invention

[0006] One aspect of this disclosure relates to a light-refracting component comprising: an incident surface for incident planar light; a plurality of refractive portions for refracting the planar light; and an exiting surface from which the planar light is refracted by the plurality of refractive portions and emitted as emitted light. The plurality of refractive portions are arranged along at least one of the incident surface and the exiting surface along a first direction, and each of the plurality of refractive portions has a region along a second direction intersecting the first direction that causes the direction of refraction of the planar light to change.

[0007] One aspect of this disclosure relates to a mold for forming a light-refracting component, the mold comprising: a first mold portion having a cavity; a second mold portion that closes with the first mold portion; and a supply path for supplying molten resin into the cavity. The cavity has a shape for forming the light-refracting component. The light-refracting component comprises: an incident surface for incident planar light; a plurality of refractive portions for refracting the planar light; and an exit surface from which the planar light is refracted by the plurality of refractive portions and emitted as emitted light. The plurality of refractive portions are arranged along at least one of the incident surface and the exit surface along a first direction, and each of the plurality of refractive portions has a region along a second direction intersecting the first direction for changing the direction of refraction of the planar light. Attached Figure Description

[0008] Figure 1AThis is a schematic cross-sectional view illustrating the optical system involved in the embodiment.

[0009] Figure 1B It is Figure 1A The enlarged sectional view of area A1.

[0010] Figure 2 This is a schematic three-dimensional view of the aforementioned optical system.

[0011] Figure 3 This is a schematic top view of the aforementioned optical system.

[0012] Figure 4A The diagram schematically shows a top view and a side view of the light-refracting components of the aforementioned optical system.

[0013] Figure 4B yes Figure 4A Sectional view along line F1-F1.

[0014] Figure 5 This is an explanatory diagram of a display system that uses the aforementioned optical system.

[0015] Figure 6 This is an explanatory diagram of a mobile body equipped with the aforementioned display system.

[0016] Figure 7A This is a top view of the aforementioned optical system.

[0017] Figure 7B This is the front view of the aforementioned optical system.

[0018] Figure 7C This is a bottom view of the aforementioned optical system.

[0019] Figure 7D This is a side view of the aforementioned optical system.

[0020] Figure 8A It is Figure 7C The diagram of region A1 is enlarged.

[0021] Figure 8B yes Figure 8A Sectional view along line B1-B1.

[0022] Figure 9 This is a top view schematically showing the light distribution of the optical system of the comparative example.

[0023] Figure 10 This is a top view schematically illustrating the light distribution of the optical system according to an embodiment.

[0024] Figure 11 This is a schematic perspective view of the mold involved in the embodiment.

[0025] Figure 12 This is a schematic cross-sectional view of the above-mentioned mold in the YZ plane.

[0026] Figure 13 This is a schematic XZ plan sectional view of the cavity of the mold described above.

[0027] Figure 14 This is a top view schematically showing a variation of the aforementioned optical system.

[0028] Symbol Explanation

[0029] 1. Light guide component

[0030] 3 prisms

[0031] 4. Light source

[0032] 5. Monitors

[0033] 6. Incident surface

[0034] 7. Injection surface

[0035] 8. Light refracting components

[0036] 81 Refractive section

[0037] 82 trench

[0038] 9. Planar light

[0039] 10. Light source incident surface

[0040] 11 Page 1

[0041] 12 Page 2

[0042] 14. Emitting light

[0043] 17 Molds

[0044] 171 Module 1

[0045] 172 Module 2

[0046] 173 Supply Path

[0047] 174 cavities

[0048] 100 Optical System

[0049] 200 Lighting System

[0050] 300 Display System

[0051] B1 Moving body

[0052] B11 Mobile Body

[0053] h depth

[0054] L1 direct optical path Detailed Implementation

[0055] The purpose of this disclosure is to provide a light refraction component, an optical system, an illumination system, a display system, a moving body, and a mold capable of controlling the light distribution of emitted light.

[0056] The embodiments and modifications described below are merely examples of this disclosure, and this disclosure is not limited to these embodiments and modifications. Even outside of these embodiments and modifications, changes can be made according to design, etc., as long as they do not depart from the technical concept of this disclosure.

[0057] (1) Summary

[0058] First, refer to Figures 1A to 3 The optical system 100 and the illumination system 200 using the optical system 100 will be described in this embodiment.

[0059] The optical system 100 involved in this embodiment (refer to...) Figure 1A as well as Figure 1B The optical system 100 has the function of controlling the light source incident from the light source incident surface 10 so that it is emitted from the emission surface 7. The optical system 100 includes a light refraction member 8, a light guide member 1, and a prism 3. In addition, the optical system 100 may also include a light control body 2.

[0060] The optical system 100 and the light source 4 together constitute the illumination system 200. In other words, the illumination system 200 according to this embodiment includes the optical system 100 and the light source 4. The light source 4 emits light that is incident on the light source incident surface 10. Details will be described later. When the optical system 100 includes the light control body 2, the light from the light source 4 does not directly incident on the light guide member 1, but passes through the light control body 2 and is incident on the light guide member 1. That is, the light source 4 emits light onto the light source incident surface 10 through the light control body 2.

[0061] Thus, in this embodiment, the optical system 100 includes a light control unit 2 in addition to the light refraction member 8, the light guide member 1, and the prism 3. The light control unit 2 is located between the light source 4 and the light source incident surface 10 of the light guide member 1, and controls the light emitted from the light source 4 and incident on the light source incident surface 10. Specifically, in this embodiment, the light guide member 1 and the light control unit 2 are integrally molded. That is, in this embodiment, the light guide member 1 and the light control unit 2 are integrally molded and inseparable. In other words, the light control unit 2 is seamlessly continuous with respect to the light source incident surface 10 of the light guide member 1, and the light guide member 1 and the light control unit 2 are seamlessly integrated. Therefore, in this embodiment, the light source incident surface 10 in the light guide member 1 is an "imaginary surface" defined inside the integrally molded light guide member 1 and the light control unit 2, and does not have a physical form. Furthermore, the light control unit 2 can also be formed separately from the light guide member 1. Moreover, the light control unit 2 is not a necessary structure in the optical system 100 and can be appropriately omitted.

[0062] In this embodiment, the light guide member 1 has a light source incident surface 10 from which light from the light source 4 is incident, and a first surface 11 and a second surface 12 facing each other. A prism 3 is disposed on the first surface 11. The prism 3 reflects the light from the light source passing through the interior of the light guide member 1 toward the second surface 12.

[0063] Here, the light guide component 1 includes a direct optical path L1 (see reference). Figure 1A as well as Figure 1B The direct light path L1 is a light path in which the light source light incident from the light source incident surface 10 is directly reflected by the prism 3, causing it to exit as planar light 9 from the second surface 12. Furthermore, the planar light 9 referred to here means light whose exit range at the second surface 12 is larger than its incident range at the light source incident surface 10 due to reflection by the prism 3. Further, the light guide member 1 includes a light path (direct light path L1) that causes light source light incident from the light source incident surface 10 into the light guide member 1 to exit from the second surface 12 within the light guide member 1 after only one reflection by the prism 3. If the light source light passing through the direct light path L1 enters the light guide member 1 from the light source incident surface 10, it reaches the second surface 12 without being reflected by any component other than the prism 3, and exits from the second surface 12 as planar light 9.

[0064] In this embodiment, most of the light from the light source incident surface 10 that is incident on the light guide member 1 and emitted from the second surface 12 is guided inside the light guide member 1 through the direct light path L1. Therefore, in this embodiment, most of the light incident on the light guide member 1 from the light source incident surface 10 is not reflected by components other than the prism 3, and is emitted from the second surface 12 to the outside of the light guide member 1 after being reflected only once by the prism 3.

[0065] In addition, such as Figure 1A As shown, in the optical system 100 of this embodiment, the optical axis Ax1 of the light incident from the light source incident surface 10 is inclined relative to the first surface 11 in such a way that the distance from the light source incident surface 10 to the first surface 11 is smaller. That is, in this embodiment, the optical axis Ax1 of the light source light incident from the light source incident surface 10 is not parallel to the first surface 11 and is inclined, and due to this inclination, the distance from the light source incident surface 10 is closer to the first surface 11.

[0066] Therefore, the further the light source light incident from the light source incident surface 10 is from the light source incident surface 10, the closer it is to the first surface 11. That is, as it advances inside the light guide member 1, it becomes closer to the first surface 11 and is more likely to be incident relative to the first surface 11 (including the prism 3). Thus, most of the light source light incident from the light source incident surface 10 is likely to be incident on the first surface 11 before reaching the end face 13 of the light guide member 1 opposite to the light source incident surface 10. In other words, most of the light source light incident from the light source incident surface 10 is unlikely to reach the end face 13 of the light guide member 1 opposite to the light source incident surface 10, so the light source light is less likely to leak from the end face 13. As a result, the proportion of the planar light 9 that passes through the direct light path L1 and is emitted from the second surface 12 to the outside of the light guide member 1 becomes higher in the light source light incident from the light source incident surface 10, thereby improving the extraction efficiency of the light source light.

[0067] In addition, such as Figures 1A to 4B As shown, the optical system 100 according to this embodiment includes a light refraction member 8. The light refraction member 8 controls the light distribution of the light source light (planar light 9) drawn from the second surface 12. In addition, the term "light distribution" here refers to the intensity distribution of light in a plane intersecting the optical axis of the direction of light illumination.

[0068] like Figures 1A to 4B As shown, the light refraction member 8 includes an incident surface 6, a plurality of refraction portions 81, and an exit surface 7. Planar light 9 emitted from the second surface 12 of the light guide member 1 is incident on the incident surface 6. The plurality of refraction portions 81 refract the planar light 9 incident on the incident surface 6. The light refracted by the plurality of refraction portions 81 is emitted from the exit surface 7 as emitted light 14. Here, the plurality of refraction portions 81 are arranged along at least one of the incident surface 6 and the exit surface 7 along a first direction.

[0069] In this embodiment, the light refraction member 8 is configured such that the incident surface 6 faces the second surface 12 of the light guide member 1. Furthermore, a plurality of refractive portions 81 are located on the incident surface 6 along a direction parallel to the exit surface 7, i.e., the depth direction of the light guide member 1 (in the longitudinal direction). Figure 1AThe light source light is arranged in the direction in which the optical axis Ax1 extends. In other words, the light source light is incident on the light source incident surface 10 of the light guide member 1 along the direction in which the multiple refractive parts 81 are arranged on the incident surface 6 of the light refraction member 8. The multiple refractive parts 81 are curved lenses that have curvature in the depth direction of the light guide member 1 and have a shape that is concave relative to the incident surface 6.

[0070] As a result, the planar light 9 incident on the incident surface 6 is refracted by multiple refractive parts 81 and emitted from the exit surface 7 as the emitted light 14.

[0071] In addition, such as Figure 4A as well as Figure 4B As shown, each of the plurality of refractive portions 81 is located in the width direction of the light guide member 1 (in Figure 3 In the direction in which multiple light sources 4 are arranged, there is a region that changes the direction of refraction of planar light 9. In addition, multiple refractive parts 81 are continuous along the width direction of the light guide member 1, and the width direction of the light guide member 1 intersects the depth direction of the light guide member 1 perpendicularly.

[0072] That is, each of the multiple refractive sections 81 of the curved lens has a region in which the direction of the optical axis of the emitted light 14 continuously changes when the light incident on the light refraction member 8 moves along the width direction of the light guide member 1 while maintaining the direction of the optical axis. In addition, the term "optical axis" as used here refers to an imaginary ray that represents the light beam passing through the entire system.

[0073] (2) Details

[0074] The following is for reference Figures 1A to 13 The light refraction member 8, the optical system 100 using the light refraction member 8, the lighting system 200 using the optical system 100, the display system 300 using the lighting system 200, the movable body B1, and the mold 17 for forming the light refraction member 8 will be described in detail in this embodiment.

[0075] (2.1) Prerequisites

[0076] In the following description, the width direction of the light guide member 1 (in...) Figure 3 The direction in which multiple light sources 4 are arranged is set as the "X-axis direction", and the depth direction of the light guide component 1 (in the direction of the arrangement of multiple light sources 4) is set as the "X-axis direction". Figure 1A The direction in which the optical axis Ax1 extends is defined as the "Y-axis direction". Furthermore, in the following description, the thickness direction of the light guide member 1 (where...) is... Figure 1A The direction of the arrangement of face 11 and face 22 is designated as the "Z-axis direction". The X, Y, and Z axes of these directions are defined as orthogonal to each other. Furthermore, the arrows in the attached diagram representing the "X-axis direction", "Y-axis direction", and "Z-axis direction" are for illustrative purposes only and do not constitute a physical entity.

[0077] Furthermore, the "extraction efficiency" mentioned in this disclosure refers to the proportion of the amount of light 9 emitted from the second surface 12 of the light guide member 1 relative to the amount of light incident on the light source incident surface 10 of the light guide member 1. That is, if the relative ratio of the amount of light emitted from the second surface 12 of the light guide member 1 to the amount of light incident on the light source incident surface 10 of the light guide member 1 increases, then the light extraction efficiency increases. As an example, if the amount of light incident on the light source incident surface 10 of the light guide member 1 is "100", and the amount of light 9 emitted from the second surface 12 of the light guide member 1 is "10", then the light extraction efficiency of the light guide member 1 becomes 10%.

[0078] Furthermore, the term "parallel" as used in this disclosure refers to two things that are roughly parallel, that is, in addition to the case where the two things are strictly parallel, it also refers to a relationship in which the angle between the two things converges to a range of several degrees (e.g., less than 5 degrees).

[0079] Furthermore, the term "orthogonal" as used in this disclosure refers to two objects that are approximately orthogonal, meaning that, apart from the case where the two objects are strictly orthogonal, it also refers to a relationship in which the angle between the two objects converges within a range of a few degrees (e.g., less than 5 degrees) with 90 degrees as a reference.

[0080] (2.2) Display System

[0081] First, refer to Figure 5 as well as Figure 6 The display system 300 is described below.

[0082] like Figure 5 As shown, the lighting system 200 and the display 5 together constitute a display system 300 according to this embodiment. In other words, the display system 300 according to this embodiment includes a lighting system 200 and a display 5. The display 5 receives emitted light 14 emitted from the lighting system 200 to display an image. Here, "image" refers to an image displayed by a user U1 (refer to...). Figure 6 Images displayed in a visually recognizable manner can be graphics, symbols, text, numbers, patterns, photographs, or combinations thereof. Images displayed by the display system 300 include moving images (moving pictures) and still images (still pictures). Furthermore, "moving images" include images composed of multiple still images obtained through time-lapse photography or the like.

[0083] In addition, such as Figure 6As shown, the display system 300 and the mobile body B11 together constitute a mobile body B1, such as a car. In other words, the mobile body B1 according to this embodiment includes the display system 300 and the mobile body B11. The display system 300 is mounted on the mobile body B11. In this embodiment, as an example, the mobile body B1 is set as a car (passenger vehicle) driven by a person. In this case, the user U1 who visually recognizes the image displayed by the display system 300 is a passenger of the mobile body B1. In this embodiment, as an example, it is assumed that the driver of the car that is the mobile body B1 is the user U1.

[0084] In this embodiment, the display system 300 is, for example, a head-up display (HUD) mounted on the mobile body B1. The display system 300 is used, for example, to display driving support information associated with the mobile body B1, such as speed information, status information, and driving information, within the user U1's field of vision. Driving information for the mobile body B1 includes, for example, navigation-related information such as displaying the driving route, and ACC (Adaptive Cruise Control)-related information that maintains a constant driving speed and inter-vehicle distance.

[0085] like Figure 5 as well as Figure 6 As shown, the display system 300 includes an image display unit 310, an optical system 320, and a control unit 330. Furthermore, the display system 300 also includes a housing 340 that houses the image display unit 310, the optical system 320, and the control unit 330.

[0086] The housing 340 is made of, for example, a molded synthetic resin. An image display unit 310, an optical system 320, and a control unit 330 are housed within the housing 340. The housing 340 is mounted on the dashboard B13 of the main body B11. Light reflected by the second reflector 322 of the optical system 320 (described later) passes through an opening on the upper surface of the housing 340 and is emitted towards the reflective member (windshield B12). The light reflected by the windshield B12 is focused within the eye box C1. The reflective member is not limited to the windshield B12; for example, it can be implemented using a synthesizer or the like mounted on the dashboard B13 of the main body B11.

[0087] According to such a display system 300, the user U1 visually recognizes a virtual image projected onto the space in front of the moving body B1 (outside the vehicle) through the windshield B12. The term "virtual image" as used in this disclosure refers to an image formed by light emitted from the display system 300 and reflected by a reflective member such as the windshield B12, appearing as if it were an actual object. Therefore, the user U1 driving the moving body B1 visually recognizes the image projected by the display system 300 as a virtual image, overlapping with the real space extending in front of the moving body B1. In summary, the display system 300 of this embodiment displays virtual images as images. The images (virtual images) that the display system 300 can display include a virtual image E1 superimposed along the driving surface D1 of the moving body B1, and a virtual image drawn three-dimensionally along a plane PL1 orthogonal to the driving surface D1.

[0088] The image display unit 310 includes a housing 311. The image display unit 310 has the function of displaying stereoscopic images using a light field method, which reproduces light emitted from an object in the image in multiple directions to make the object appear stereoscopically. However, the method by which the image display unit 310 displays a stereoscopically drawn virtual image of an object is not limited to the light field method. The image display unit 310 may also employ a parallax method, which projects images with parallax to the left and right eyes of the user U1 respectively, allowing the user U1 to visually recognize the stereoscopically drawn virtual image of the object.

[0089] The image display unit 310 includes a display 5 and an illumination system 200 including an optical system 100. The display 5, such as a liquid crystal display, receives light emitted from the illumination system 200 to display an image. That is, the illumination system 200 emits light from behind the display 5 toward the display 5, and the light from the illumination system 200 passes through the display 5, thereby displaying an image. In other words, the illumination system 200 functions as a backlight for the display 5.

[0090] The image display unit 310 is housed within a housing 311, which contains an illumination system 200 including an optical system 100 and a light source 4, and a display 5. The illumination system 200 and the display 5 are held within the housing 311. Here, the display 5 is positioned along the upper surface of the housing 311, with one side of the display 5 protruding from the upper surface of the housing 311. The illumination system 200 is positioned below the display 5 within the housing 311, emitting light from below the display 5. Thus, the upper surface of the housing 311 forms a display surface 312 for displaying images.

[0091] The image display unit 310 is housed inside the housing 340 with its display surface 312 facing the first reflector 321 (described later). The display surface 312 of the image display unit 310 has a shape (e.g., rectangular) that matches the range of the image projected onto the user U1, i.e., the shape of the windshield B12. Multiple pixels are arranged in an array on the display surface 312 of the image display unit 310. The multiple pixels of the image display unit 310 emit light under the control of the control unit 330, and an image is displayed on the display surface 312 by the light emitted from it.

[0092] The image displayed on the display surface 312 of the image display unit 310 is projected onto the windshield B12, and the light reflected by the windshield B12 is focused within the visual field C1. That is, the image displayed on the display surface 312 is visually recognized by the user U1, whose viewpoint is within the visual field C1, through the optical system 320. At this time, the user U1 visually recognizes the virtual image projected in the space in front of the moving body B1 (outside the vehicle) through the windshield B12.

[0093] The optical system 320 focuses the light emitted from the display surface 312 of the image display unit 310 within the visual range C1. In this embodiment, the optical system 320 includes, for example, a first reflecting mirror 321 as a convex mirror, a second reflecting mirror 322 as a concave mirror, and a windshield B12.

[0094] The first reflector 321 reflects the light output from the image display unit 310 and directs it to the second reflector 322. The second reflector 322 reflects the light incident from the first reflector 321 toward the windshield B12. The windshield B12 reflects the light incident from the second reflector 322 and directs it into the field of vision C1.

[0095] The control unit 330 may include, for example, a computer system. The computer system is primarily structured with one or more processors and one or more memories as hardware. The functions of the control unit 330 (e.g., drawing control unit 331, image data generation unit 332, and output unit 333, etc.) are implemented by executing programs recorded in one or more memories or storage units 334 of the computer system via one or more processors. The programs are pre-recorded in one or more memories or storage units 334 of the computer system. The programs can be provided via electrical communication lines or recorded on non-volatile recording media such as computer system readable memory cards, optical discs, or hard disk drives.

[0096] The storage unit 334 is implemented, for example, using a non-volatile recording medium such as a rewritable non-transitory semiconductor memory. The storage unit 334 stores programs executed by the control unit 330. Furthermore, as described, the display system 300 is used to display driving support information of the moving body B1, such as speed information, status information, and driving information, in the user U1's field of vision. Therefore, the type of virtual image displayed by the display system 300 is predetermined. Moreover, image data for displaying virtual images (a virtual image E1 as a planar object and a virtual image as a three-dimensional object) is pre-stored in the storage unit 334.

[0097] The drawing control unit 331 receives detection signals from various sensors 350 mounted on the mobile body B1. The sensors 350 are, for example, sensors used to detect various information used by advanced driver assistance systems (ADAS). The sensors 350 include, for example, at least one of sensors for detecting the state of the mobile body B1 and sensors for detecting the state of the environment surrounding the mobile body B1. Sensors for detecting the state of the mobile body B1 include, for example, sensors that measure the vehicle speed, temperature, or remaining fuel of the mobile body B1. Sensors for detecting the state of the environment surrounding the mobile body B1 include image sensors that capture images of the environment surrounding the mobile body B1, millimeter-wave radar, or LiDAR (Light Detection and Ranging).

[0098] The rendering control unit 331 acquires one or more image data from the storage unit 334 based on the detection signal input from the sensor 350, for displaying information related to the detection signal. Here, when the image display unit 310 displays multiple types of information, the rendering control unit 331 acquires multiple image data for displaying multiple types of information. Furthermore, based on the detection signal input from the sensor 350, the rendering control unit 331 calculates position information related to the position of the virtual image displayed in the object space. Then, the rendering control unit 331 outputs the image data and position information of the virtual image of the displayed object to the image data generation unit 332.

[0099] The image data generation unit 332 generates image data for displaying a virtual image of a display object based on the image data input from the drawing control unit 331 and the position information.

[0100] The output unit 333 outputs the image data generated by the image data generation unit 332 to the image display unit 310, so that an image based on the generated image data is displayed on the display surface 312 of the image display unit 310. By projecting the image displayed on the display surface 312 onto the windshield B12, the display system 300 displays the image (virtual image). In this way, the image (virtual image) displayed by the display system 300 is visually recognized by the user U1.

[0101] (2.3) Optical System

[0102] Next, refer to Figures 1A to 4B as well as Figures 7A to 10 The optical system 100 will be described.

[0103] In this embodiment, the optical system 100 includes a light refraction member 8, a light guide member 1, multiple light control elements 2, and multiple prisms 3. That is, the optical system 100 according to this embodiment includes multiple light control elements 2 and also multiple prisms 3.

[0104] Furthermore, in this embodiment, the optical system 100 together with the plurality of light sources 4 constitutes the lighting system 200. That is, the lighting system 200 according to this embodiment includes the optical system 100 and the plurality of light sources 4.

[0105] Since the multiple light control bodies 2 share a common structure, the structure described below for one light control body 2 is the same for the other light control bodies 2 unless otherwise stated. Similarly, since the multiple prisms 3 share a common structure, the structure described below for one prism 3 is the same for the other prisms 3 unless otherwise stated. Furthermore, since the multiple light sources 4 share a common structure, the structure described below for one light source 4 is the same for the other light sources 4 unless otherwise stated.

[0106] The light source 4 is, for example, a solid-state light-emitting element such as a light-emitting diode (LED) or an organic electroluminescence (OEL) element. In this embodiment, as an example, the light source 4 is a sheet-shaped LED element. While such a light source 4 actually emits light over a certain area of ​​its surface (light-emitting surface), it can ideally be considered a point light source emitting light from a single point on its surface. Therefore, the following description assumes that the light source 4 is an ideal point light source.

[0107] In this embodiment, the light control unit 2 and the light guide member 1 are integrated. The term "integrated" in this disclosure refers to a form in which multiple elements (parts) can be physically treated as a single unit. That is, multiple elements integrated means that multiple elements can be assembled into one and treated as a single component. In this case, the multiple elements can be inseparable, like a single molded article, or they can be multiple separately manufactured elements mechanically joined, for example, by welding, bonding, or riveting. In short, the light guide member 1 and the light control unit 2 can be integrated as long as it is done in a suitable manner.

[0108] More specifically, in this embodiment, as described above, the light guide member 1 and the light control body 2 are integrated as a single molded product. That is, in this embodiment, the light guide member 1 and the light control body 2 are integrally molded products and are inseparable. Therefore, as described above, the light source incident surface 10 in the light guide member 1 is an "imaginary surface" defined inside the integral molded product of the light guide member 1 and the light control body 2, and does not have a solid form.

[0109] Here, as Figure 2 As shown, multiple light sources 4 are arranged with a given interval along the X-axis. Each of the multiple light sources 4 corresponds one-to-one with a multiple light control body 2. That is, the multiple light control bodies 2 are also arranged along the X-axis in the same way as the multiple light sources 4. Here, the spacing between the multiple light sources 4 in the X-axis direction is equal to the spacing between the multiple light control bodies 2.

[0110] The light guide member 1 is a component that guides light from the light source 4 from the light source incident surface 10 into the light guide member 1, through the light guide member 1, and towards the second surface 12; that is, it is a light guiding component. In this embodiment, as an example, the light guide member 1 is a molded product of a light-transmitting resin material such as acrylic resin, and is formed into a plate shape. That is, the light guide member 1 is a light guide plate with a certain thickness.

[0111] As described above, the light guide member 1 has a light source incident surface 10 and a first surface 11 and a second surface 12 facing each other. Furthermore, the light guide member 1 has an end surface 13 facing the light source incident surface 10.

[0112] Specifically, in this embodiment, such as Figures 7A to 7DAs shown, the light guide member 1 is a rectangular plate, with two opposing surfaces in the thickness direction being surface 11 and surface 12. Furthermore, one of the four end faces (circumferential surfaces) of the light guide member 1 is the light source incident surface 10. That is, the light guide member 1 is rectangular in shape when viewed from above (from the Z-axis direction). Here, as an example, the light guide member 1 is formed as a rectangle with a dimension in the Y-axis direction smaller than that in the X-axis direction. Moreover, the two surfaces in the thickness direction (Z-axis direction) of the light guide member 1 constitute surface 11 and surface 12, respectively. Furthermore, the two surfaces in the short side direction (Y-axis direction) of the light guide member 1 constitute the light source incident surface 10 and end face 13, respectively.

[0113] Thus, one of the two end faces of the light guide component 1 that are opposite each other in the Y-axis direction ( Figure 1A The left side (in the image) is the light source incident surface 10, where light emitted from multiple light sources 4 passes through multiple light control bodies 2 and enters the light source. The first surface 11 of the light guide member 1 is... Figure 1A The lower surface of the middle, the second surface 12 is Figure 1A The upper surface of the light guide member 1. Furthermore, the second surface 12 emits planar light 9 from the inside of the light guide member 1 to the outside. Therefore, with respect to the light guide member 1, the light source is incident from one end face of the light source incident surface 10, thereby the second surface 12 emits surface light.

[0114] Furthermore, in this embodiment, the second surface 12 is a plane parallel to the XY plane. Similarly, the light source incident surface 10 is a plane parallel to the XZ plane. The "XY plane" referred to here is a plane including the X and Y axes, and is orthogonal to the Z axis. Likewise, the "XZ plane" referred to here is a plane including the X and Z axes, and is orthogonal to the Y axis. In other words, the second surface 12 is a plane orthogonal to the Z axis, and the light source incident surface 10 is a plane orthogonal to the Y axis. Therefore, the second surface 12 and the light source incident surface 10 are orthogonal to each other.

[0115] On the other hand, the first surface 11 is a plane that is not parallel to the XY plane but is inclined relative to it. That is, the first surface 11 and the light source incident surface 10 are not orthogonal to each other. Specifically, the first surface 11 is inclined relative to the XY plane in such a way that it approaches the second surface 12 as it moves away from the light source incident surface 10. That is, in this embodiment, the first surface 11 and the second surface 12 are inclined relative to each other.

[0116] A light control unit 2 is disposed between the light source 4 and the light source incident surface 10 of the light guide member 1. The light control unit 2 controls the light source light output from the light source 4 and incident on the light source incident surface 10. In this embodiment, the light control unit 2 has a collimation function that brings the light source light output from the light source 4 closer to parallel light. That is, the light control unit 2 is a collimating lens that, if radially diffused light source light is incident from the light source 4, focuses the light source light toward the light source incident surface 10 to bring the light closer to parallel light. Here, the light source light emitted from the light source 4 passes through the light control unit 2 and is incident on the light source incident surface 10 of the light guide member 1. Therefore, the light source light from the light source 4 is controlled by the light control unit 2, which has a collimator function, to narrow the diffusion angle and be emitted toward the light source incident surface 10 of the light guide member 1. In this embodiment, it is assumed that the light source light from the light source 4, which is an ideal point light source, is controlled by the light control unit 2 to be ideally parallel light for explanation.

[0117] In this embodiment, such as Figure 1A As shown, the optical axis Ax1 of the light source light incident from the light source incident surface 10 of the light guide member 1 is inclined relative to the first surface 11 in such a way that the distance to the first surface 11 decreases the further away from the light source incident surface 10. Therefore, the parallel light emitted from the light control body 2 to the light source incident surface 10 of the light guide member 1 becomes parallel light inclined relative to the first surface 11 in such a way that the distance to the first surface 11 decreases the further away from the light source incident surface 10. Furthermore, the dashed arrows in the accompanying drawings conceptually represent light rays (or light paths) and do not have a physical form.

[0118] In this embodiment, such as Figure 2 As shown, multiple light control elements 2 are arranged along the X-axis at the end of the light source incident surface 10 constituting the light guide member 1. That is, in this embodiment, the light control elements 2 and the light guide member 1 are integrated. Furthermore, as already described, each of the multiple light control elements 2 corresponds to one of the multiple light sources 4. Therefore, each of the multiple light control elements 2 controls the diffusion angle of the light emitted by the corresponding light source 4, causing it to be incident on the light source incident surface 10.

[0119] A prism 3 is disposed on the first surface 11, reflecting the light from the light source passing through the interior of the light guide member 1 toward the second surface 12. In this embodiment, multiple prisms 3 are disposed on the first surface 11. The prism 3 is configured to perform total internal reflection of the incident light source. Of course, the prism 3 is not limited to performing total internal reflection of all the incident light source; it may also include a configuration where a portion of the light source is not completely reflected and passes through the prism 3.

[0120] In the light guide member 1, most of the light from the light source incident surface 10 is not reflected by any part of the first surface 11 or the second surface 12 except for the prism 3, but is reflected by the prism 3 and emitted from the second surface 12. That is, the light guide member 1 includes a direct light path L1 in which the light from the light source incident surface 10 is directly reflected by the prism 3 and emitted from the second surface 12.

[0121] In this embodiment, the prism 3 is formed on the first surface 11 in such a way that its cross-section, when viewed from one side along the X-axis, is triangular in shape. The prism 3 is formed, for example, by machining the first surface 11 of the light guide member 1. Figure 1B As shown, the prism 3 has a reflecting surface 30, which reflects the light source light that passes through the interior of the light guide member 1 toward the second surface 12. Figure 1B It is Figure 1A The schematic end face view of region A1 is enlarged.

[0122] The angle θ1 between the reflecting surface 30 and the first surface 11 (i.e., the tilt angle of the reflecting surface 30) is such that the incident angle θ0 of the light source incident on the reflecting surface 30 becomes a critical angle or higher. That is, the reflecting surface 30 is tilted relative to the first surface 11, such that the incident light source light is totally internally reflected. Furthermore, the tilt angle θ1 of the reflecting surface 30 is set such that the light source light totally internally reflected by the reflecting surface 30 is incident in a direction perpendicular to the second surface 12.

[0123] In this embodiment, such as Figure 8A as well as Figure 8B As shown, viewed from one side along the Z-axis, the multiple prisms 3 are arranged in a zigzag pattern on the first surface 11. Here, Figure 8A It is Figure 7C The schematic top view of area A1 is enlarged. Figure 8B It is a schematic representation Figure 8A The attached diagram shows the cross-section of line B1-B1. Figure 8A In the image, only a portion of the first face 11 is shown, but in reality, multiple prisms 3 are formed over a roughly whole area of ​​the first face 11.

[0124] Specifically, each prism 3 is formed to have a length along the X-axis direction, and multiple prisms 3 are arranged with gaps in their long side direction (X-axis direction). Furthermore, the multiple prisms 3 are also arranged with gaps in the Y-axis direction. Moreover, when the columns of the multiple prisms arranged along the X-axis direction are designated as column 1, column 2, column 3, etc., counting from the light source incident surface 10 side in the Y-axis direction, the multiple prisms 3 included in the even-numbered columns and the multiple prisms 3 included in the odd-numbered columns are positioned offset from each other in the X-axis direction. Here, the multiple prisms 3 included in the even-numbered columns and the multiple prisms 3 included in the odd-numbered columns are configured such that the ends of their respective long side directions (X-axis direction) overlap each other in the Y-axis direction. According to this configuration, when viewed from the light source incident surface 10, the multiple prisms 3 are arranged without gaps along the X-axis direction, and the light from the light source incident surface 10 that enters the interior of the light guide member 1 is reflected by any one of the multiple prisms 3.

[0125] In this embodiment, as an example, the plurality of prisms 3 are all identical in shape. Therefore, as... Figure 8B As shown, among the multiple prisms 3 arranged along the Y-axis, the tilt angle θ1 of the reflecting surface 30 is the same. Furthermore, the size of the prism 3, such as its length along its long side and the depth d of its recess (in other words, the height of the prism 3), is also the same across the multiple prisms 3. That is, in this embodiment, multiple prisms 3 are arranged in the direction (Y-axis direction) in which the light source is incident on the light source incident surface 10. Here, the multiple prisms 3 have the same shape. Therefore, if the incident angle θ0 of the light source incident on the reflecting surface 30 is constant, the direction of the light source reflected by the reflecting surface 30 of any one of the multiple prisms 3 is the same. Therefore, all the light source reflected by the multiple prisms 3 can be incident perpendicularly to the second surface 12.

[0126] Furthermore, as an example, the depth d of the concave portion of prism 3 (in other words, the height of prism 3) is more than 1 μm and less than 100 μm. Similarly, as an example, the spacing between the multiple prisms 3 in the Y-axis direction is more than 1 μm and less than 1000 μm. As a specific example, the depth d of the concave portion of prism 3 is several tens of μm, and the spacing between the multiple prisms 3 in the Y-axis direction is several hundred μm.

[0127] like Figure 1A As shown, the light refraction member 8 introduces the planar light 9, which is drawn from the second surface 12 of the light guide member 1, into the light refraction member 8 from the incident surface 6. The planar light 9 is refracted by the multiple refraction portions 81 provided by the light refraction member 8 and emitted as emitted light 14 from the emission surface 7. In this embodiment, as an example, the light refraction member 8 is a molded product of a light-transmitting resin material such as acrylic resin, and is formed into a plate shape.

[0128] As described above, the light refraction member 8 has an incident surface 6, a plurality of refraction portions 81 and an exit surface 7, and the incident surface 6 is configured to face the second surface 12 of the light guide member 1.

[0129] Specifically, in this embodiment, such as Figure 1A as well as Figures 2 to 4B As shown, the light refraction member 8 is a rectangular plate. The two opposing surfaces of the light refraction member 8 in the thickness direction (Z-axis direction) are the incident surface 6 and the exit surface 7. In addition, the incident surface 6 and the exit surface 7 are parallel planes, both of which are set to be parallel to the XY plane.

[0130] In this embodiment, a plurality of refractive elements 81 are arranged along the Y-axis direction on the incident surface 6.

[0131] Furthermore, the plurality of refractive portions 81, for example, have grooves 82 extending along the X-axis direction. In this embodiment, each of the plurality of refractive portions 81 is a groove 82 extending along the X-axis direction. That is, the plurality of refractive portions 81 are a plurality of grooves 82. Figure 3 as well as Figure 4A As shown, each refractive portion 81 (one groove 82) includes two peaks 83 extending along the X-axis and one valley 84 disposed between the two peaks 83. The two peaks 83 and the valley 84 are arranged parallel to each other in the Y-axis direction. Here, the peaks 83 are the portions in the plurality of refractive portions 81 (plural grooves 82) where the thickness of the light refractive member 8 in the Z-axis direction changes from increasing along the Y-direction to decreasing along the Y-direction. Similarly, the valleys 84 are the portions in the plurality of refractive portions 81 (plural grooves 82) where the thickness of the light refractive member 8 in the Z-axis direction changes from decreasing along the Y-direction to increasing along the Y-direction.

[0132] Furthermore, in this embodiment, the incident surface 6 is an imaginary plane where the multiple peaks 83 of the multiple refractive portions 81 (multiple grooves 82) are connected. Alternatively, a portion of the multiple peaks 83 may not be connected to the incident surface 6.

[0133] Furthermore, the multiple refractive sections 81 are also curved lenses, each with curvature along the Y-axis. That is, as... Figure 4A As shown, viewed from the X-axis direction, a peak 83 and a valley 84 of a refractive section 81 (a groove 82) are connected by a continuous curve, and the portion of this curve becomes a curved lens. Thus, the light refraction member 8 equipped with multiple refractive sections 81 functions as a lens, an optical element for refracting, diverging, or focusing planar light 9 incident on the incident surface 6.

[0134] Furthermore, in this embodiment, the depth h of the trench 82 varies linearly along the X-axis direction. Here, as... Figure 4AAs shown, the depth h of the groove 82 refers to the distance between the incident surface 6 and the valley 84 along the Z-axis. That is, as... Figure 4B As shown, when the depth h of the groove 82 varies linearly along the X-axis, the valley 84 becomes a straight line inclined relative to the incident surface 6 in a cross-section parallel to the XZ plane. Furthermore, Figure 4B It is a schematic representation Figure 4A The attached diagram shows the cross-section of line F1-F1.

[0135] On the other hand, the peak 83 becomes a straight line parallel to the incident plane 6 in a cross-section parallel to the XZ plane. Furthermore, in this embodiment, the plurality of refractive portions 81 are continuous surfaces along the X-axis direction.

[0136] Therefore, in this embodiment, the curvature of the refractive portion 81 between the peak 83 and the valley 84 in the Y-axis direction is either continuously increasing or decreasing in one direction along the X-axis. Consequently, the angle at which the planar light 9 incident from the incident surface 6 is refracted by the plurality of refractive portions 81 is either increasing or decreasing in one direction along the X-axis.

[0137] By controlling the structure of these light refraction components 8, the angle at which the planar light 9 incident from the incident surface 6 is refracted is controlled, thereby enabling the emission light 14 with the desired light distribution to be obtained at the emission surface 7.

[0138] Furthermore, the depth h of the groove 82 is set such that the emitted light 14 achieves the desired light distribution on the emission surface 7, preferably satisfying 0.01mm ≤ h ≤ 5mm, and more preferably satisfying 0.05mm ≤ h ≤ 1mm. As an example, the shallowest part of the depth h of the groove 82 is formed to be 0.1mm, and the deepest part is formed to be 0.2mm. That is, in this embodiment, as... Figure 4A as well as Figure 4B As shown, the depths h1 and h2 of the grooves 82 in the end faces 15 and 16 in the X-axis direction of the light refraction member 8 are 0.1 mm and 0.2 mm, respectively.

[0139] In addition, such as Figure 4A As shown, in this embodiment, the width w of each groove 82 in the plurality of refractive portions 81 (plural grooves 82) is different. Here, the width w of the groove 82 refers to the distance in the Y-axis direction between the two peaks 83 of one refractive portion 81 (one groove 82). Furthermore, the different widths w of the grooves 82 are not limited to the case where all the grooves 82 in the plurality of refractive portions 81 (plural grooves 82) have different widths w, but also include the case where some grooves have different widths.

[0140] In this embodiment, the curvature of the plurality of refractive portions 81 of the light refraction member 8 in the Y-axis direction is set respectively, so that the planar light 9 incident on the incident surface 6 diverges. In other words, the light refraction member 8 has a negative refractive power relative to the planar light 9 incident on the incident surface 6. As a result, the emission range of the emitted light 14 on the emission surface 7 becomes larger than the incident range of the planar light 9 on the incident surface 6.

[0141] The following uses Figure 1A as well as Figure 1B The light emission principle of the optical system 100 in this embodiment will be explained.

[0142] First, such as Figure 1A As shown, the light emitted from the light source 4 passes through the corresponding light control body 2, thereby controlling the diffusion angle. Then, the light emitted from the light control body 2 with the diffusion angle controlled is emitted from the light control body 2 toward the light source incident surface 10 of the light guide member 1. In this embodiment, the light emitted from the light control body 2 becomes parallel light parallel to the second surface 12 and is incident perpendicularly to the light source incident surface 10.

[0143] Furthermore, as already described, the optical axis Ax1 of the light source incident from the light source incident surface 10 of the light guide member 1 is inclined relative to the first surface 11 in such a way that the distance to the first surface 11 decreases the further away from the light source incident surface 10. Therefore, most of the light source incident on the light source incident surface 10 does not reach the second surface 12 and the end face 13 opposite to the light source incident surface 10 of the light guide member 1, but reaches the first surface 11.

[0144] Moreover, such as Figure 1B As shown, most of the light source light incident on the light source incident surface 10 is not reflected by the first surface 11 and the second surface 12, but is totally reflected by the reflecting surface 30 of any one of the plurality of prisms 3 provided on the first surface 11. That is, the light guide member 1 includes a direct light path L1 in which the light source light incident from the light source incident surface 10 is directly reflected by the prism 3 and emitted from the second surface 12. Furthermore, in this embodiment, the direct light path L1 includes the light path of the light source light that is totally reflected by the prism 3. The light that is totally reflected by the reflecting surface 30 of the prism 3 travels along the light path orthogonal to the second surface 12 and is emitted from the second surface 12 as a planar light 9.

[0145] In this embodiment, as described above, the tilt angle θ1 of the reflecting surface 30 is the same in all the plurality of prisms 3. Since parallel light parallel to the second surface 12 is incident on these prisms 3, the incident angle θ0 of the light incident on the reflecting surface 30 also becomes constant. Therefore, in any one of the plurality of prisms 3, the direction of the light reflected by the reflecting surface 30 also becomes the same. Thus, in this embodiment, all the light source light reaching the second surface 12 via the direct light path L1 is incident at the same angle relative to the second surface 12. The term "same angle" here includes not only strictly identical angles but also an error of 2 or 3 degrees. Ideally, all the light source light reaching the second surface 12 via the direct light path L1 is incident at 90 degrees relative to the second surface 12, that is, incident in an orientation orthogonal to the second surface 12.

[0146] In this embodiment, since multiple prisms 3 are arranged throughout the entire area of ​​the first surface 11, the light source light passing through the direct light path L1 as described above is emitted from the second surface 12 of the light guide member 1, covering the entire area of ​​the second surface 12. As a result, the second surface 12 emits surface light as a whole, emitting a planar light 9 that is parallelized in the Z-axis direction.

[0147] The planar light 9, which is parallelized along the Z-axis direction and emitted from the second surface 12, is incident on the incident surface 6 of the light refraction member 8, which is disposed opposite to the light guide member 1. In this embodiment, the second surface 12 of the light guide member 1 and the incident surface 6 of the light refraction member 8 are arranged parallel to each other in the Z-axis direction, and the planar light 9 emitted orthogonally to the second surface 12 is also orthogonally incident relative to the incident surface 6.

[0148] Planar light 9, incident orthogonally to the incident surface 6, is refracted by a plurality of refractive parts 81 disposed on the incident surface 6, changing the plane light 9 from a state parallel along the Z-axis to a state inclined relative to the Z-axis. As described above, the light refraction member 8 has a negative refractive power relative to the plane light 9, thus the plane light 9 is refracted such that the emission range of the emitted light 14 on the emission surface 7 is greater than the incident range of the plane light 9 on the incident surface 6. In this way, the light distribution of the emitted light 14 is controlled by the plurality of refractive parts 81 of the light refraction member 8.

[0149] The following is for reference Figure 9 as well as Figure 10 The advantages of the optical system 100 of this embodiment, which has a light refraction member 8 that changes the direction of refraction of planar light 9 along the X-axis, will be explained.

[0150] In a typical optical refractive element such as a linear Fresnel lens 18 (hereinafter referred to as the optical refractive element of the comparative example), the curvature of the lens in the Y-axis direction is constant along the X-axis direction, thus making the direction of refraction of the planar light 9 constant along the X-axis direction. That is, as Figure 9As shown, the diffusion of the emitted light 14, controlled by the linear Fresnel lens 18, in the light distribution range AR1 on the emission surface 7 along the X-axis direction is constant. Furthermore, Figure 9 as well as Figure 10 The light distribution ranges AR1 and AR2 shown schematically illustrate the light distribution of the emitted light 14 on the emission surface 7.

[0151] However, in the case of an optical system including a light refraction member used in a head-up display mounted on a mobile body B1, as in the display system 300 of this embodiment, for the light refraction member 8, it is required to properly control the diffusion of the emitted light 14 in the Y-axis direction along the X-axis direction for the following reasons.

[0152] The image display unit 310 of the head-up display receives emitted light 14 from the light refraction member 8 to display an image. The display surface 312 is shaped (e.g., rectangular) to match the range of the image projected onto the user U1, i.e., the shape of the windshield B12. The emission surface 7 of the light refraction member 8 is also configured to match the shape of the display surface 312.

[0153] Here, the image displayed on the display surface 312 undergoes a change in light distribution before it is reflected by the windshield B12 and perceived by the user U1. Therefore, it is necessary to pre-distribute the emitted light 14 from the light refraction member 8, which functions as the backlight of the display surface 312, to the light distribution required to achieve the optimal image for the user U1's visual perception.

[0154] For example, in this embodiment, regarding the image displayed on the rectangular display surface 312, before the user U1 visually recognizes it, the light intensity decreases along the top of the windshield B12 from the user U1's perspective, particularly at the left and right ends of the windshield B12. This is because the length of the light path between the display surface 312 and the windshield B12 increases towards the top and left and right ends of the windshield B12, resulting in stronger light scattering. Furthermore, in this embodiment, regarding the vertical direction of the windshield B12 from the user U1's perspective, the light intensity decreases. Figure 9 as well as Figure 10 The X-axis direction is reversed to correspond to the left and right directions observed from user U1 regarding the windshield B12, and the Y-axis direction is reversed to correspond to the left and right directions.

[0155] Therefore, as Figure 10 As shown, by setting the curvature of the multiple refractive parts 81 of the light refraction member 8, the light distribution range AR2 of the emitted light 14 on the emission surface 7 expands further along the Y-axis as it moves downward in the X-axis direction. This allows correction of the decrease in light intensity along the upper left and right ends of the windshield B12, enabling the user U1 to visually recognize an appropriate image.

[0156] (2.4) Molds used to form light-refracting components

[0157] For the mold 17 used in this embodiment to form the light refraction component 8, the following is used: Figures 11-13 This will be explained in more detail. Additionally, the arrows in the attached diagram representing the "X-axis direction," "Y-axis direction," and "Z-axis direction" are for illustrative purposes only and do not constitute a physical entity.

[0158] like Figure 11 as well as Figure 12 As shown, mold 17 includes a first mold portion 171, a second mold portion 172, and a supply path 173. The first mold portion 171 includes a cavity 174, which is a space for supplying molten resin. The cavity 174 has a shape for forming the light-refractive member 8. The second mold portion 172 closes with the first mold portion 171. The supply path 173 supplies molten resin into the cavity 174.

[0159] The first mold 171 and the second mold 172 are, for example, made of stainless steel alloy, and nickel alloy plating is applied to the stainless steel alloy.

[0160] like Figure 13 As shown, a protrusion 175 is provided in the cavity 174 of the first mold portion 171. The protrusion 175 is used to form multiple grooves 82 of multiple refractive portions 81, which serve as light refractive members 8. The surface forming the protrusion 175 is shaped to a mirror finish.

[0161] The supply path 173 is configured to pass through the second mold section 172 and reach the cavity 174 of the first mold section. With the first mold section 171 and the second mold section 172 fixed under pressure, molten acrylic resin is filled into the cavity 174 through the supply path 173. After the acrylic resin filled into the cavity 174 solidifies by cooling, it is removed from the mold 17 and, after finishing processes such as grinding, becomes the light-refracting component 8.

[0162] (3) Variations

[0163] The above-described embodiments are merely one example of various embodiments of this disclosure. Various modifications can be made to the above embodiments based on design, etc., as long as they achieve the objectives of this disclosure. Furthermore, the figures described in the above embodiments are schematic diagrams, and the size and thickness ratios of the constituent elements in the figures are not necessarily intended to reflect actual dimensional ratios.

[0164] Hereinafter, variations of the above embodiments are listed. However, for components common to the above embodiments, the same reference numerals are used, and their descriptions are omitted where appropriate. Furthermore, the structures of the variations described below can be appropriately combined with the structures described in the above embodiments.

[0165] (3.1) Variation Example 1

[0166] In the optical system 100 of the above embodiment, the light source light is incident on the light source incident surface 10 of the light guide member 1 along the direction in which the plurality of refractive parts 81 are arranged on the incident surface 6 of the light refraction member 8. On the other hand, the optical system 100 of Modified Example 1 differs from the above embodiment in that the light source light is incident on the light source incident surface 10 of the light guide member 1 along a direction that intersects the direction in which the plurality of refractive parts 81 are arranged on the incident surface 6 of the light refraction member 8.

[0167] That is, in variation example 1, such as Figure 14 As shown, multiple refractive portions 81 (multiple grooves 82) are arranged on the incident surface 6 along the width direction (X-axis direction) of the light guide member 1. That is, the planar light 9 incident on the incident surface 6 is refracted by the multiple refractive portions 81 arranged along the X-axis direction and emitted from the emission surface 7 as emitted light 14.

[0168] The advantages of the optical system 100 of Modified Example 1 will be explained below.

[0169] For example, consider the following situation: before the user U1 visually recognizes the image displayed on the rectangular display surface 312, the light intensity decreases along the left side of the windshield B12 and at the upper and lower ends of the windshield B12. In this case, by setting the curvature of the plurality of refractive sections 81 arranged along the X-axis direction in Modified Example 1, the light distribution range of the emitted light 14 in the X-axis direction is expanded to the right along the Y-axis direction. Therefore, the decrease in light intensity along the left side of the windshield B12 can be corrected, allowing the user U1 to visually recognize the appropriate image.

[0170] (3.2) Other variations

[0171] Other variations of the implementation are listed below. These variations can also be implemented by appropriate combinations.

[0172] Multiple refractive elements 81 can also be provided on the ejection surface 7, or on both the incident surface 6 and the ejection surface 7.

[0173] The multiple refractive sections 81 may also have points of discontinuity in the width direction of the light guide member 1 that intersect perpendicularly with the depth direction of the light guide member 1. That is, since the multiple refractive sections 81 are curved lenses, when the light incident on the multiple refractive sections 81 moves along the width direction of the light guide member 1 while maintaining the direction of the optical axis, the direction of the optical axis of the emitted light 14 changes, and there may be points of discontinuity in this change.

[0174] The depth h of the plurality of refractive portions 81 (plural grooves 82) can also vary non-linearly along the X-axis direction. For example, the depth h can increase or decrease non-linearly along one direction of the X-axis. That is, the curvature of the plurality of refractive portions 81 in the Y-axis direction can increase or decrease non-linearly along one direction of the X-axis, and the angle at which the planar light 9 incident from the incident surface 6 is refracted by the plurality of refractive portions 81 can also increase or decrease non-linearly along one direction of the X-axis.

[0175] (4) Summary

[0176] As explained above, the light refraction member (8) of the first type includes: an incident surface (6) on which planar light (9) is incident; a plurality of refraction portions (81) for refracting the planar light (9); and an exit surface (7) on which the planar light (9) is refracted by the plurality of refraction portions (81) and emitted as emitted light (14). The plurality of refraction portions (81) are arranged along at least one of the incident surface (6) and the exit surface (7) along a first direction, and each of the plurality of refraction portions (81) has a region along a second direction intersecting the first direction in which the direction of refraction of the planar light (9) changes.

[0177] According to the first method, the light distribution of the emitted light (14) can be controlled.

[0178] In the second type of light refraction member (8), in the first type, multiple refraction parts (81) are continuous along the second direction.

[0179] According to the second method, the light distribution of the emitted light (14) can be controlled.

[0180] In the light refraction member (8) of the third type, in the first or second type, each of the plurality of refraction portions (81) has a groove (82) extending along the second direction, and the depth (h) of the groove (82) varies linearly along the second direction.

[0181] According to the third method, the light distribution of the emitted light (14) can be controlled.

[0182] In the light refraction member (8) of the fourth type, in any one of the first to third types, each of the plurality of refraction parts (81) has a groove (82) extending along the second direction, and the depth (h) of the groove (82) is 0.01mm≤h≤5mm.

[0183] According to the fourth method, the light distribution of the emitted light (14) can be controlled.

[0184] The light refraction member (8) of the fifth mode has a negative refractive power relative to the planar light (9) incident on the incident surface (6) in any one of the modes 1 to 4.

[0185] According to method 5, it is possible to diffuse the surface light (9).

[0186] The optical system (100) of the sixth type includes a light refraction member (8), a light guide member (1), and a prism (3) of any one of the first to fifth types. The light guide member (1) has a light source incident surface (10) on which light from a light source is incident, and a first surface (11) and a second surface (12) opposite to each other. The prism (3) is disposed on the first surface (11) and reflects the light from the light source passing through the interior of the light guide member (1) toward the second surface (12). The light guide member (1) includes a direct light path (L1) by which the light source incident from the light source incident surface (10) is directly reflected by the prism (3) and emitted from the second surface (12) as a planar light (9).

[0187] According to the sixth method, the extraction efficiency of light from the light source incident surface (10) being extracted from the second surface (12) as a planar light (9) can be improved. In addition, the light distribution of the emitted light (14) can be controlled.

[0188] In the seventh optical system (100), in the sixth method, the light source light is incident on the light source incident surface (10) along the first direction.

[0189] According to the seventh method, the extraction efficiency of light from the light source incident surface (10) being extracted from the second surface (12) as a planar light (9) can be improved. In addition, the light distribution of the emitted light (14) can be controlled.

[0190] In the optical system of the eighth mode (100), in the sixth mode, the light source is incident on the light source incident surface (10) in a direction intersecting the first direction.

[0191] According to the eighth method, the extraction efficiency of light from the light source incident surface (10) being extracted from the second surface (12) as a planar light (9) can be improved. In addition, the light distribution of the emitted light (14) can be controlled.

[0192] The ninth type of lighting system (200) includes an optical system (100) of any one of the sixth to eighth types and a light source (4) that emits light from the light source incident surface (10).

[0193] According to the ninth method, the extraction efficiency of light from the light source incident surface (10) being extracted from the second surface (12) as a planar light (9) can be improved. In addition, the light distribution of the emitted light (14) can be controlled.

[0194] The 10th type of display system (300) includes the 9th type of lighting system (200) and a display (5) that receives emitted light (14) to display images.

[0195] According to the 10th method, the extraction efficiency of light from the light source incident surface (10) being extracted from the second surface (12) as a planar light (9) can be improved. In addition, the light distribution of the emitted light (14) can be controlled.

[0196] The mobile body (B1) of the 11th method includes the display system (300) of the 10th method and the mobile body (B11) equipped with the display system (300).

[0197] According to the 11th method, the extraction efficiency of light from the light source incident surface (10) being extracted from the second surface (12) as a planar light (9) can be improved. In addition, the light distribution of the emitted light (14) can be controlled.

[0198] The mold (17) of the 12th type is used to form a light-refracting member (8) and includes: a first mold part (171) having a cavity (174); a second mold part (172) that closes with the first mold part (171); and a supply path (173) for supplying molten resin into the cavity (174). The cavity (174) has a shape for forming the light-refracting member (8). The light-refracting member (8) includes: an incident surface (6) on which planar light (9) is incident; a plurality of refractive parts (81) for refracting the planar light (9); and an ejection surface (7) on which the planar light (9) is refracted by the plurality of refractive parts (81) and emitted as emitted light (14). The plurality of refractive parts (81) are arranged along a first direction at least one of the incident surface (6) and the ejection surface (7), and each of the plurality of refractive parts (81) has a region along a second direction intersecting the first direction in which the direction of refraction of the planar light (9) changes.

[0199] According to the 12th method, a light refraction member (8) can be formed that can control the light distribution of the emitted light (14).

[0200] Furthermore, methods 2 through 5 are not essential structures in the light refraction component (8) and can be appropriately omitted. In addition, methods 7 and 8 are not essential structures in the optical system (100) and can be appropriately omitted.

[0201] In this disclosure, the light distribution of emitted light can be controlled.

Claims

1. A light-refracting component, used in a head-up display mounted on a moving body. The head-up display receives light emitted from the light-refracting component to display images. The light-refracting component includes: The incident surface of planar light; Multiple refracting portions that refract the planar light; and The planar light is refracted by the plurality of refractive parts and serves as the emission surface from which the emitted light is emitted. The plurality of refractive elements are arranged along a first direction at least one of the incident surface and the exit surface. Each of the plurality of refractive elements is a curved lens having curvature along the first direction and a concave shape relative to the incident surface. The curvature of the first direction changes continuously along a second direction intersecting the first direction. Furthermore, each of the plurality of refractive elements has a region along the second direction that causes the direction of refraction of the planar light to change, such that the light distribution range of the emitted light on the emission surface expands further along the first direction as it moves towards the direction corresponding to the top of the image in the second direction.

2. The light refraction component according to claim 1, wherein, The plurality of refractive portions are each continuous along the second direction.

3. The light refraction member according to claim 1 or 2, wherein, Each of the plurality of refractive portions has a groove extending along the second direction. The depth of the trench varies linearly along the second direction.

4. The light refraction member according to claim 1 or 2, wherein, Each of the plurality of refractive portions has a groove extending along the second direction. The depth h of the trench is 0.01mm ≤ h ≤ 5mm.

5. The light refraction member according to claim 1 or 2, wherein, The planar light incident on the incident surface has a negative refractive power.

6. An optical system comprising: The light refraction component according to any one of claims 1 to 5; A light guide component having a light source incident surface from which light from a light source is incident, and a first surface and a second surface facing each other; and A prism, disposed on the first surface, reflects the light source light passing through the interior of the light guide member toward the second surface. The light guide component includes: The prism directly reflects the light from the light source incident on the light source incident surface, so that the light is emitted directly from the second surface as the planar light.

7. The optical system according to claim 6, wherein, The light from the light source is incident on the incident surface of the light source along the first direction.

8. The optical system according to claim 6, wherein, The light from the light source is incident on the incident surface of the light source in a direction that intersects with the first direction.

9. A lighting system comprising: The optical system according to any one of claims 6 to 8; and A light source emits light from the light source onto the incident surface of the light source.

10. A display system comprising: The lighting system of claim 9; and A display receives the emitted light to display an image.

11. A mobile body, comprising: The display system according to claim 10; and The main body of the mobile device is equipped with the display system.

12. A mold for forming a light-reflecting component for use in a head-up display mounted on a moving body. The head-up display receives light emitted from the light-refracting component to display images. The mold has the following features: The first module has a cavity; The second mold part that is molded with the first mold part; and The supply path for supplying molten resin into the cavity. The cavity has a shape for forming the light refraction member. The light-refracting component includes: The incident surface of planar light; Multiple refracting portions that refract the planar light; and The planar light is refracted by the plurality of refractive parts and serves as the emission surface from which the emitted light is emitted. The plurality of refractive elements are arranged along a first direction at least one of the incident surface and the exit surface. Each of the plurality of refractive elements is a curved lens having curvature along the first direction and a concave shape relative to the incident surface. The curvature of the first direction changes continuously along a second direction intersecting the first direction. Furthermore, each of the plurality of refractive elements has a region along the second direction that causes the direction of refraction of the planar light to change, such that the light distribution range of the emitted light on the emission surface expands further along the first direction as it moves towards the direction corresponding to the top of the image in the second direction.

Images