Image display device

Abstract

An image display device (10) is provided with: a display unit (11) that displays a first image and a second image; and a projection optical system (12) that emits light (L1) of the first image and light (L2) of the second image toward the windshield (3). The display unit (11) displays the first image and the second image in different display regions (DA1, DA2) on the same plane. The projection optical system (12) sets an image point of the light (L1) of the first image and an image point of the light (L2) of the second image such that a first virtual image (IM1) and a second virtual image (IM2) are formed at positions at different distances from a viewpoint (E) within the viewing region (SA).

Description

[0001] This application is a divisional application of the applicant’s patent application No. 201680091588.3 (PCT / JP2016 / 087393) entitled “Image Display Device”, filed on December 15, 2016. Technical Field

[0002] This invention relates to image display devices such as head-up displays, and more particularly to image display devices that visually recognize virtual images through transparent components such as windshields. Background Technology

[0003] Head-up displays (HUDs) used in automobiles project images onto the windshield, combiner, and display various information as virtual images in front of the driver's field of vision. In recent years, various types of these products have been put into practical use.

[0004] In a typical head-up display, an intermediate image formed on a screen such as a diffuser is projected onto the windshield or synthesizer via a projection optical system (such as a magnifying glass). Therefore, even if the position of the projection optical system is fixed, the position of the virtual image visible to the driver can be changed by altering the position of the screen on which the intermediate image is formed.

[0005] In the head-up display device described in Patent Document 1 below, images are displayed on three screens, and these images are reflected by mirrors and projected onto the front glass (Patent Document 1). Figure 3 The three screens are at different distances from the mirrors that serve as projection units, so the three virtual images corresponding to the images on each screen appear to be in different positions in the front and rear directions when observed by the driver.

[0006] Furthermore, in the head-up display device described in Patent Document 2 below, images are displayed on two screens, and these images are reflected by a concave mirror in the optical section and projected onto the front glass (Patent Document 2). Figure 1 , Figure 5 In this head-up display device, the two virtual images corresponding to the images on the two screens appear to be positioned differently in the front-to-back direction when viewed by the driver.

[0007] Prior art literature

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2009-150947

[0010] Patent Document 2: Japanese Patent Application Publication No. 2015-34919 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] When an intermediate image is formed on a screen by scanning light, a smaller beam diameter results in higher resolution. Therefore, optical systems are typically used to converge the light incident on the screen. Since the light is converged by the optical system, the beam diameter varies depending on the distance from the optical system. If there is only one screen, the optical system is configured to focus on that screen (minimizing the beam diameter), thus achieving good resolution. However, when there are multiple screens, if the light is focused on any one screen, the beam diameter will increase on the other screens. Therefore, in the head-up display device described in Patent Document 1, when the light is focused on one screen, the resolution decreases on the other two screens. If the optical system is configured to make the light nearly parallel, the difference in beam diameter caused by the screen position will be smaller, but this method cannot sufficiently reduce the beam diameter, thus reducing the resolution of each screen.

[0013] On the other hand, in the head-up display device described in Patent Document 2, a MEMS mirror capable of changing the curvature of a concave mirror is used as the focus-changing unit for scanning light, enabling the focus to be aligned on both screens (Patent Document 2). Figure 5 However, in controlling the curvature of a concave mirror in a MEMS mirror, there are problems such as increased computational load and difficulty in accurately focusing light rays with small spot diameters on the screen due to the need for complex curvature control.

[0014] Furthermore, in the aforementioned conventional head-up display devices, multiple screens used for imaging intermediate images need to be positioned in different locations relative to the optical system, thus resulting in a problem of large device size.

[0015] The present invention was made in view of such circumstances, and its purpose is to provide an image display device that, although simple in structure, can form multiple virtual images at different distances from the viewpoint.

[0016] Methods for solving problems

[0017] This invention relates to an image display device in which light from a first image and light from a second image are emitted toward a light-transmitting member, and the light from the first image and the light from the second image are reflected from the light-transmitting member toward a visual recognition area. When viewed from the visual recognition area, a first virtual image corresponding to the first image and a second virtual image corresponding to the second image are displayed at positions separated from the light-transmitting member. The image display device includes: a display unit for displaying the first image and the second image; and a projection optical system for emitting light from the first image and the second image toward the light-transmitting member. The display unit displays the first image and the second image in different display areas on the same plane. The projection optical system sets the image points of the light from the first image and the second image respectively, such that the first virtual image and the second virtual image are formed at positions at different distances from a viewpoint within the visual recognition area.

[0018] According to this structure, the first image and the second image are displayed in different display areas on the same plane in the display unit. Therefore, compared with the case where the display areas are not on the same plane, the structure becomes simpler and the size of the device becomes smaller.

[0019] Preferably, the display unit may have a display surface for displaying the first image and the second image.

[0020] According to this structure, two images (image 1 and image 2) are displayed on one display surface, thus the display units of the two images can be made common, and the structure of the display section becomes simple.

[0021] Preferably, the display unit may also have a display surface for displaying the first image and a display surface for displaying the second image.

[0022] Based on this structure, an image (image 1 and image 2) is displayed on each of the two display surfaces. Therefore, it is possible to set up an independent display unit for each image, making it easy to set different display characteristics (resolution, brightness, etc.) for each image.

[0023] Preferably, in the first invention relating to the above-described image display device, the optical path length of the first optical path may be different from that of the second optical path. The first optical path extends from the display area of ​​the first image in the display unit to the incident area of ​​the light of the first image in the light-transmitting member, and the second optical path extends from the display area of ​​the second image in the display unit to the incident area of ​​the light of the second image in the light-transmitting member.

[0024] According to this structure, the optical path length of the first optical path is different from that of the second optical path. Therefore, when viewed from a viewpoint within the visual recognition area, the positions of the first virtual image corresponding to the first image and the second virtual image corresponding to the second image are different.

[0025] Preferably, in the first invention described above, the projection optical system may also include at least one of a first plane mirror and a second plane mirror, wherein the first plane mirror is disposed only in the first optical path and the second plane mirror is disposed only in the second optical path.

[0026] According to this structure, by providing at least one of the first and second plane mirrors, the optical path becomes longer compared to the case where these plane mirrors are not provided. Therefore, the optical path lengths of the first and second optical paths can be set independently.

[0027] Preferably, in the first invention described above, the projection optical system may also include: at least one common curved mirror, which is commonly disposed in the first optical path and the second optical path to concentrate or diverge the reflected light.

[0028] According to this structure, the characteristics (focal distance, etc.) of the projection optical system are set by concentrating or diverging the reflected light in the common curved mirror.

[0029] Preferably, in the first invention described above, the projection optical system may also include: a first common curved mirror that reflects light from the first image and the second image toward the light-transmitting member, thereby concentrating or diverging the reflected light; and a second common curved mirror that reflects light from the first image and the second image toward the first common curved mirror, thereby concentrating or diverging the reflected light. At least one of the first plane mirror and the second plane mirror may also be disposed in the optical path between the display unit and the second common curved mirror.

[0030] According to this structure, the focal distance and other characteristics of the projection optical system are set by concentrating or diverging the reflected light in the first and second common curved mirrors. Furthermore, when the image is magnified in the first and second common curved mirrors, the size of the image (first image, second image) in the optical path (first optical path, second optical path) between the display unit and the second common curved mirror is relatively small. Therefore, the plane mirrors (first plane mirror, second plane mirror) can be made smaller.

[0031] Preferably, in the second invention relating to the above-described image display device, the projection optical system may include: a first optical system forming a first optical path that extends from the display area of ​​the first image in the display unit to the incident area of ​​the light of the first image in the light-transmitting member; and a second optical system forming a second optical path that extends from the display area of ​​the second image in the display unit to the incident area of ​​the light of the second image in the light-transmitting member. The first optical system and the second optical system may have different composite focal distances.

[0032] According to this structure, the first optical system forming the first optical path and the second optical system forming the second optical path have different composite focal distances. Therefore, when viewed from a viewpoint within the visual recognition area, the positions of the first virtual image corresponding to the first image and the second virtual image corresponding to the second image are different.

[0033] Preferably, in the second invention described above, the projection optical system may include at least one of a first curved mirror and a second curved mirror, wherein the first curved mirror is disposed only in the first optical path and concentrates or disperses the reflected light, and the second curved mirror is disposed only in the second optical path and concentrates or disperses the reflected light.

[0034] According to this structure, by providing at least one of the first curved mirror and the second curved mirror, the combined focal distance of the first optical system and the combined focal distance of the second optical system can be independently set, making it easier to form the difference between their combined focal distances. By forming the difference in the combined focal distances in the two optical systems (the first optical system and the second optical system), the plane mirror used to form the difference between the optical path lengths of the first optical path and the second optical path can be omitted.

[0035] Preferably, in the second invention described above, the projection optical system may include: at least one common curved mirror, which is commonly disposed in the first optical path and the second optical path to concentrate or diverge the reflected light.

[0036] According to this structure, the characteristics (combined focal distance, etc.) of the projection optical systems in the first and second optical systems are set by concentrating or diverging the reflected light in the common curved mirror. The structure is simplified by using the common curved mirror.

[0037] Preferably, in the second invention described above, the projection optical system may also include: a first common curved mirror, commonly disposed in the first optical path and the second optical path, reflecting light of the first image and light of the second image toward the light-transmitting member, thereby concentrating or diverging the reflected light; the first curved mirror reflecting light of the first image toward the first common curved mirror; and the second curved mirror reflecting light of the second image toward the first common curved mirror.

[0038] According to this structure, the composite focal distance of the first optical system is set in the first curved mirror and the first common curved mirror, and the composite focal distance of the second optical system is set in the second curved mirror and the first common curved mirror. Since the composite focal distance is set separately in the two optical systems (the first optical system and the second optical system), it becomes easy to form the difference between their composite focal distances. By forming the difference in composite focal distances in the two optical systems (the first optical system and the second optical system), the plane mirror used to form the difference between the optical path length of the first optical path and the optical path length of the second optical path can be omitted.

[0039] Furthermore, according to this structure, the light from both images (first image and second image) is reflected towards the first common mirror through the two curved mirrors (first curved mirror and second curved mirror). As a result, the light paths (first light path and second light path) between the display unit and the first common curved mirror are reflected back, thus making the device smaller.

[0040] Preferably, in the second invention described above, the image display device may also include: an actuator that moves the first common curved mirror to change the position of the visual recognition area.

[0041] According to this structure, the number of actuators is reduced and the structure becomes simpler compared to the case where multiple mirrors are moved to change the position of the visual recognition area.

[0042] Preferably, in the second invention described above, the optical path length of the first optical path and the optical path length of the second optical path in the projection optical system may be different. For example, the projection optical system may also include at least one of a first plane mirror and a second plane mirror, wherein the first plane mirror is disposed only in the first optical path and the second plane mirror is disposed only in the second optical path.

[0043] According to this structure, in addition to the difference in the composite focal distance between the two optical systems (first optical system and second optical system), the difference in the optical path length of the first optical path and the optical path length of the second optical path is also set, thus making it easy to form the difference in distance between the position where the first virtual image is formed and the position where the second virtual image is formed.

[0044] Invention Effects

[0045] According to the present invention, although the structure is simple, it is able to form multiple virtual images at different distances from the viewpoint. Attached Figure Description

[0046] Figure 1 This diagram illustrates the state in which the image display device according to an embodiment of the present invention is mounted on a vehicle.

[0047] Figure 2 This is a diagram used to illustrate a virtual image displayed by an image display device according to an embodiment of the present invention.

[0048] Figure 3 This is a diagram illustrating an example of the structure of the image display device according to the first embodiment.

[0049] Figure 4A and 4B This is a diagram showing an example of the display surface and display area in a display unit. Figure 4A This example shows two display areas set on a single display surface. Figure 4B This example shows a display area set on two separate display surfaces.

[0050] Figure 5 This is a diagram showing a modified example of the display section.

[0051] Figure 6 This is a diagram illustrating an example of the structure of the image display device according to the second embodiment.

[0052] Figure 7 This is a diagram illustrating an example of the structure of the image display device according to the third embodiment.

[0053] Figure 8 Observing from the direction of arrow A Figure 7 A diagram of the projection optical system in the image display device shown.

[0054] Figure 9 This is a diagram illustrating an example of the structure of the image display device according to the fourth embodiment.

[0055] Figure 10 This is a diagram illustrating an example of the structure of the image display device according to the fifth embodiment. Detailed Implementation

[0056] <First Implementation>

[0057] Hereinafter, an image display device according to the first embodiment of the present invention will be described with reference to the accompanying drawings.

[0058] The image display device involved in this embodiment is a device that forms virtual images at multiple positions at different distances from the viewpoint, such as a head-up display device for a vehicle that forms virtual images at close range and far range in front of the driver.

[0059] Figure 1 This diagram illustrates the state in which the image display device 10 according to this embodiment is mounted on the vehicle 1. Figure 1 In this example, the image display device 10 is embedded inside the instrument panel 2, which is located further forward than the steering wheel 4.

[0060] The image display device 10 emits light L1 of a first image toward the first incident area PA1 of the windshield 3, and emits light L2 of a second image toward the second incident area PA2 of the windshield 3. The windshield 3 is equivalent to the light-transmitting member in this invention. The windshield 3 functions as a semi-reflective surface, whereby these lights (L1, L2) are reflected from the windshield 3 toward the visual recognition area SA of the driver 5 and reach the eyes of the driver 5. The driver 5 visually recognizes the first virtual image IM1 through the light L1 of the first image and visually recognizes the second virtual image IM2 through the light L2 of the second image.

[0061] Figure 2 This is a diagram used to illustrate the virtual image displayed by the image display device 10 according to this embodiment. For example... Figure 1 as well as Figure 2 As shown, the virtual images (IM1, IM2) observed by the driver 5 are formed in front of the driver through the windshield 3. In the example shown, the first virtual image IM1 is formed at a position farther than the second virtual image IM2.

[0062] Figure 3 This is a diagram illustrating an example of the structure of the image display device 10 according to the first embodiment. Figure 3 In the example, the image display device 10 includes a display unit 11, a projection optical system 12, an actuator 15, and a control unit 16.

[0063] Display unit 11 displays a first image and a second image corresponding to the first virtual image IM1 and the second virtual image IM2. Display unit 11 displays the first image and the second image in different display areas on the same plane. For example, display unit 11 includes a device (liquid crystal display) that displays an image on a planar display surface by transmitting or reflecting light from a light source such as an LED through a liquid crystal panel.

[0064] Figure 4 is a diagram showing an example of the display surface and display area in the display unit 11. Figure 4AIn the example, the display unit 11 has a display surface 111, and two display areas (DA1, DA2) are provided on the display surface 111. The display unit 11 displays a first image in the first display area DA1 and a second image in the second display area DA2. Figure 4A In the case where there is only one display surface, the display unit 11 is constructed using a single display unit (such as a liquid crystal display).

[0065] On the other hand, Figure 4B In the example, the display unit 11 has two display surfaces 111A and 111B. A first display area DA1 for displaying a first image is provided on display surface 111A. A second display area DA2 for displaying a second image is provided on display surface 111B. In such a case... Figure 4B In the case where there are two display surfaces, the display unit 11 is constructed using two display units (such as liquid crystal displays).

[0066] The projection optical system 12 emits light L1, which is the first image, and light L2, which is the second image, which are displayed on the display unit 11, toward the windshield 3. The projection optical system 12 sets the image point of the light L1 of the first image and the image point of the light L2 of the second image, so that the first virtual image IM1 and the second virtual image IM2 are formed at different distances from the viewpoint E of the visual recognition area SA.

[0067] In this embodiment, in the projection optical system 12, the optical path length of the first optical path OP1 is different from that of the second optical path OP2. The first optical path OP1 is the optical path of light L1 of the first image from the first display area DA1 of the display unit 11 to the first incident area PA1 of the windshield 3. The second optical path OP2 is the optical path of light L2 of the second image from the second display area DA2 of the display unit 11 to the second incident area PA2 of the windshield 3. Because the optical path lengths of the first optical path OP1 and the second optical path OP2 are different, a deviation occurs between the image point of light L1 of the first image and the image point of light L2 of the second image, resulting in a difference between the distance from the viewpoint E to the first virtual image IM1 and the distance from the viewpoint E to the second virtual image IM2.

[0068] exist Figure 3 In the example, the projection optical system 12 has a first plane mirror 121, a second plane mirror 122, a first common curved mirror 131, and a second common curved mirror 132.

[0069] A first common curved mirror 131 and a second common curved mirror 132 are commonly disposed in the first optical path OP1 and the second optical path OP2, causing the reflected light to be concentrated or diffused. The first common curved mirror 131 reflects light L1 of the first image and light L2 of the second image toward the windshield 3. The second common curved mirror 132 reflects light L1 of the first image and light L2 of the second image toward the first common curved mirror 131.

[0070] A first plane mirror 121 is disposed in the first optical path OP1 between the display unit 11 and the second common curved mirror 132, reflecting light L1 of the first image incident from the display unit 11 toward the second common curved mirror 132. A second plane mirror 122 is disposed in the second optical path OP2 between the display unit 11 and the second common curved mirror 132, reflecting light L2 of the second image incident from the display unit 11 toward the second common curved mirror 132.

[0071] The actuator 15 is a mechanism that moves the first common curved mirror 131 according to the control of the control unit 16 so as to change the position of the visual recognition area SA. For example, it is constructed using an electric motor, a piezoelectric element, etc.

[0072] The control unit 16 is a circuit that controls the overall operation of the image display device 10, and is configured, for example, using a computer that executes processing according to program command codes. The control unit 16 generates the image displayed on the display unit 11 and controls the position, posture, tilt, etc. of the first common curved mirror 131 using the actuator 15.

[0073] exist Figure 3In the image display device 10 shown, a first image and a second image are displayed in different display areas (DA1, DA2) on the same plane in the display unit 11. Light L1 of the first image displayed in the first display area DA1 is incident on the first plane mirror 121, reflected from the first plane mirror 121 toward the second common curved mirror 132, reflected from the second common curved mirror 132 toward the first common curved mirror 131, and reflected from the first common curved mirror 131 toward the windshield 3, thereby incident on the first incident area PA1 of the windshield 3. Similarly, light L2 of the second image displayed in the second display area DA2 is incident on the second plane mirror 122, reflected from the second plane mirror 122 toward the second common curved mirror 132, reflected from the second common curved mirror 132 toward the first common curved mirror 131, and reflected from the first common curved mirror 131 toward the windshield 3, thereby incident on the second incident area PA2 of the windshield 3. Light L1 of the first image and light L2 of the second image, incident on the windshield 3, are reflected toward the visual recognition area SA and reach the eyes of the driver 5, which is located within the visual recognition area SA. From the driver 5's viewpoint E, a first virtual image IM1 based on light L1 of the first image and a second virtual image IM2 based on light L2 of the second image are formed at a position in front of the windshield 3. Figure 3 As shown, the first optical path OP1 of the light L1 in the first image is longer than the second optical path OP2 of the light L2 in the second image. Therefore, the image point of the light L1 in the first image has a longer optical path from the first common curved mirror 131 compared to the image point of the light L2 in the second image. Consequently, the first virtual image IM1 is formed at a position farther from the viewpoint E compared to the second virtual image IM2.

[0074] As explained above, the image display apparatus 10 according to this embodiment displays a first image and a second image in different display areas (DA1, DA2) on the same plane in the display unit 11. The image points of light L1 of the first image and light L2 of the second image are separately set in the projection optical system 12, thereby forming a first virtual image IM1 and a second virtual image IM2 at positions with different distances from the viewpoint E. Therefore, compared with the case where the display areas of the first image and the second image are not on the same plane (such as the case of different screens arranged in staggered positions), the structure can be simplified and the size of the device can be made smaller.

[0075] Furthermore, according to the image display device 10 of this embodiment, by displaying two images (a first image and a second image) on a display surface 111, the display units of the two images can be made common, thereby further simplifying the structure of the display unit 11.

[0076] Furthermore, according to the image display device 10 of this embodiment, by displaying two images (a first image and a second image) on two display surfaces 111A and 111B, it is possible to set an independent display unit for each image, and thus it is easy to set different display characteristics (resolution, brightness, etc.) for each image.

[0077] Furthermore, according to this embodiment, by concentrating or diverging the reflected light using the first common curved mirror 131 and the second common curved mirror 132, the characteristics such as the focal distance of the projection optical system 12 can be set with a simple structure. When the two images (first image and second image) in the first common curved mirror 131 and the second common curved mirror 132 are magnified, the size of each image is relatively small in the optical path (first optical path OP1 and second optical path OP2) between the display unit 11 and the second common curved mirror 132. Therefore, by providing plane mirrors (first plane mirror and second plane mirror) between the display unit 11 and the second common curved mirror 132, the size of the plane mirror can be made smaller.

[0078] Furthermore, according to this embodiment, the first common curved mirror 131 that reflects the light (L1, L2) of the two images toward the windshield 3 is driven by the actuator 15, thereby changing the position of the visual recognition area SA. As a result, compared to the case where multiple mirrors are moved to change the position of the visual recognition area SA, the number of actuators can be reduced, thus simplifying the structure.

[0079] Figure 5 This is a diagram showing a modified example of the display unit 11. Figure 5 In a modified example, the display unit 11 includes: a light source 112 such as a laser, a scanner 113 that reflects light rays LS from the light source 112, and a screen 114 that images (a first image and a second image) by scanning the light rays LS reflected in the scanner 113. The scanner 113 is, for example, a MEMS element having a mirror with an angle that varies according to the control of the control unit 16. The control unit 16 controls the light intensity of each color of the light rays LS generated in the light source 112 and the angle of the scanner 113, thereby imaging a given image onto the screen 114. According to this embodiment, two images (a first image and a second image) are imaged in different areas on the same plane of the screen 114, so it is not necessary to adjust the beam diameter of the light incident on the screen 114 for each image.

[0080] In addition to the above-described variations, the display unit 11 may also use, for example, a display device that displays an image by shining light onto a MEMS element arranged in an array of tiny mirrors and reflecting it, or a display device that arranges multiple self-emissive elements such as organic EL elements in an array.

[0081] <Second Implementation Method>

[0082] Next, the second embodiment of the present invention will be described. Figure 6 This is a diagram illustrating an example of the structure of the image display device 10 according to the second embodiment. Figure 6 The image display device 10 shown is omitted. Figure 3 The actuator 15 in the image display device 10 shown replaces the projection optical system 12 with the projection optical system 12A, and the other structures are the same. Figure 3 The image display device 10 shown is identical. The image display device 10 according to the second embodiment incident light L1 of the first image and light L2 of the second image onto a synthesizer 3A. The synthesizer 3A is, for example, disposed in front of the windshield 3, and the driver 5 visually recognizes the first virtual image IM1 and the second virtual image IM2 via the synthesizer 3A. The synthesizer 3A corresponds to the light-transmitting member in this invention.

[0083] The projection optical system 12A includes a first plane mirror 121A and a second plane mirror 122A. The first plane mirror 121A reflects light L1 of a first image incident from the display unit 11 toward the first incident area PA1 of the synthesizer 3A. The second plane mirror 122A reflects light L2 of a second image incident from the display unit 11 toward the second incident area PA2 of the synthesizer 3A.

[0084] like Figure 6 As shown, the first optical path OP1 of the light L1 in the first image has a longer optical path length than the second optical path OP2 of the light L2 in the second image. Therefore, the first virtual image IM1 based on the light L1 in the first image is formed at a position farther away from the viewpoint E than the second virtual image IM2 based on the light L2 in the second image.

[0085] In this embodiment, the same effect as in the first embodiment can be achieved.

[0086] <Third Implementation Method>

[0087] Next, the third embodiment of the present invention will be described. Figure 7 This is a diagram illustrating an example of the structure of the image display device 10 according to the third embodiment. Figure 8 Observing from the direction of arrow A Figure 7 A diagram of the projection optical system 12B in the image display device 10 shown. Figure 7 as well as Figure 8 The image display device 10 shown will Figure 3 The projection optical system 12 in the image display device 10 shown is replaced with a projection optical system 12B, and the other structures are the same. Figure 3 The image display device 10 shown is the same.

[0088] The projection optical system 12B has a first plane mirror 121B and 121C, a first common curved mirror 131B, and a second common curved mirror 132B.

[0089] The first common curved mirror 131B and the second common curved mirror 132B are commonly disposed in the first optical path OP1 and the second optical path OP2, so that the reflected light is concentrated or diffused. The first common curved mirror 131B reflects the light L1 of the first image and the light L2 of the second image toward the windshield 3. The second common curved mirror 132B reflects the light L1 of the first image and the light L2 of the second image toward the first common curved mirror 131B.

[0090] The first plane mirrors 121B and 121C are connected in series in the first optical path OP1 between the display unit 11 and the second common curved mirror 132. For example, Figure 8 As shown, the first plane mirror 121B reflects the light L1 of the first image incident from the display unit 11 toward the first plane mirror 121C. The first plane mirror 121C reflects the light L1 of the first image incident from the first plane mirror 121B toward the common curved mirror 132B.

[0091] The actuator 15 moves the first common curved mirror 131B under the control of the control unit 16 so that the position of the visual recognition area SA changes.

[0092] exist Figure 7 In the image display device 10 shown, light L1 of a first image displayed in the first display area DA1 is incident on the first plane mirror 121B, reflected from the first plane mirror 121B toward the first plane mirror 121C, reflected from the first plane mirror 121C toward the second common curved mirror 132B, reflected from the second common curved mirror 132B toward the first common curved mirror 131B, and reflected from the first common curved mirror 131B toward the windshield 3, thereby incident on the first incident area PA1 of the windshield 3. Furthermore, light L2 of a second image displayed in the second display area DA2 is directly incident on the first common curved mirror 131B, reflected from the second common curved mirror 132B toward the first common curved mirror 131B, and reflected from the first common curved mirror 131B toward the windshield 3, thereby incident on the second incident area PA2 of the windshield 3. The light L1 of the first image and the light L2 of the second image incident on the windshield 3 are reflected toward the visual recognition area SA and reach the eyes of the driver 5, which is located within the visual recognition area SA. Figure 7 As shown, the first optical path OP1 of the light L1 in the first image is longer than the second optical path OP2 of the light L2 in the second image. Therefore, the optical path from the first common curved mirror 131 is longer for the image point of the light L1 in the first image compared to the image point of the light L2 in the second image. Consequently, the first virtual image IM1 is formed at a position farther from the viewpoint E compared to the second virtual image IM2.

[0093] In this embodiment, the same effect as in the first embodiment can be achieved.

[0094] <Fourth Implementation Method>

[0095] Next, the fourth embodiment of the present invention will be described. Figure 9 This is a diagram illustrating an example of the structure of the image display device 10 according to the fourth embodiment. Figure 9 The image display device 10 shown will Figure 3 The projection optical system 12 in the image display device 10 shown is replaced with a projection optical system 12C, and the other structures are the same. Figure 3 The image display device 10 shown is the same.

[0096] The projection optical system 12C comprises two optical systems (12C-1 and 12C-2) with different composite focal distances. The first optical system 12C-1 forms a first optical path OP1 from the first display area DA1 of the display unit 11 to the first incident area PA1 of the windshield 3. The second optical system 12C-2 forms a second optical path OP2 from the second display area DA2 of the display unit 11 to the second incident area PA2 of the windshield 3. The composite focal distance of the first optical system 12C-1 is longer than that of the second optical system 12C-2. Because of this difference in composite focal distances, the image point of the light L1 of the first image deviates from the image point of the light L2 of the second image, resulting in a difference between the distance from the viewpoint E to the first virtual image IM1 and the distance from the viewpoint E to the second virtual image IM2.

[0097] exist Figure 9 In the example, the projection optical system 12C has a first curved mirror 141, a second curved mirror 142, and a first common curved mirror 131C. The first optical system 12C-1 includes the first curved mirror 141 and the first common curved mirror 131C, and the second optical system 12C-2 includes the second curved mirror 142 and the first common curved mirror 131C.

[0098] The first common curved mirror 131C is commonly disposed in the first optical path OP1 and the second optical path OP2 to concentrate or diverge the reflected light. The first common curved mirror 131C reflects the light L1 of the first image and the light L2 of the second image toward the windshield 3.

[0099] A first curved mirror 141 is disposed in the first optical path OP1 between the display unit 11 and the first common curved mirror 131C, causing the reflected light to be concentrated or diffused. The first curved mirror 141 reflects light L1 of the first image incident from the display unit 11 toward the first common curved mirror 131C. A second curved mirror 142 is disposed in the second optical path OP2 between the display unit 11 and the first common curved mirror 131C, causing the reflected light to be concentrated or diffused. The second curved mirror 142 reflects light L2 of the second image incident from the display unit 11 toward the first common curved mirror 131C.

[0100] The actuator 15 moves the first common curved mirror 131C under the control of the control unit 16 so that the position of the visual recognition area SA changes.

[0101] exist Figure 9 In the image display device 10 shown, light L1 of a first image displayed in the first display area DA1 is incident on the first curved mirror 141, reflected from the first curved mirror 141 toward the first common curved mirror 131C, and reflected from the first common curved mirror 131C toward the windshield 3, thereby incident on the first incident area PA1 of the windshield 3. Furthermore, light L2 of a second image displayed in the second display area DA2 is incident on the second curved mirror 142, reflected from the second curved mirror 142 toward the first common curved mirror 131C, and reflected from the first common curved mirror 131C toward the windshield 3, thereby incident on the second incident area PA2 of the windshield 3. The light L1 of the first image and the light L2 of the second image incident on the windshield 3 are reflected toward the visual recognition area SA, respectively, reaching the eyes of the driver 5 located within the visual recognition area SA. Compared to the second optical system 12C-2 forming the second optical path OP2, the first optical system 12C-1 forming the first optical path OP1 has a longer composite focal distance. Therefore, the first virtual image IM1 is formed at a position farther away from the viewpoint E compared to the second virtual image IM2.

[0102] According to the image display device 10 of this embodiment, the composite focal distance of the first optical system 12C-1 is set in the first curved mirror 141 and the first common curved mirror 131C, and the composite focal distance of the second optical system 12C-2 is set in the second curved mirror 142 and the first common curved mirror 131C. Since the composite focal distance is set in the two optical systems (first optical system 12C-1 and second optical system 12C-2) respectively, it becomes easy to form the difference between the two composite focal distances. By forming the difference between the composite focal distances in the two optical systems (first optical system 12C-1 and second optical system 12C-2), the plane mirror (e.g., used to form the difference between the optical path length of the first optical path OP1 and the optical path length of the second optical path OP2) can be omitted. Figure 3(The first plane mirror 121 and the second plane mirror 122 in the middle). Therefore, the overall structure can be further simplified, and the size of the device can be further miniaturized.

[0103] Furthermore, according to the image display device 10 of this embodiment, the light from both images (first image and second image) is reflected towards the first common curved mirror 131C by two curved mirrors (first curved mirror 141 and second curved mirror 142). As a result, both optical paths (first optical path OP1 and second optical path OP2) between the display unit 11 and the first common curved mirror 131C are reflected back, thus making the device smaller.

[0104] <Fifth Implementation>

[0105] Next, the fifth embodiment of the present invention will be described. Figure 10 This is a diagram illustrating an example of the structure of the image display device 10 according to the fifth embodiment. Figure 10 The image display device 10 shown will Figure 3 The projection optical system 12 in the image display device 10 shown is replaced with a projection optical system 12D, and the other structures are the same. Figure 3 The image display device 10 shown is the same.

[0106] Projection optical system 12D and the already described projection optical system 12C ( Figure 9 Similarly, it has two optical systems (12D-1 and 12D-2) with different composite focal distances.

[0107] exist Figure 10 In the example, the projection optical system 12D has a first plane mirror 121D, a second plane mirror 122D, a first curved mirror 141D, a second curved mirror 142D, and a first common curved mirror 131D. The first optical system 12D-1 includes the first plane mirror 121D, the first curved mirror 141D, and the first common curved mirror 131D. The second optical system 12D-2 includes the second plane mirror 122D, the second curved mirror 142D, and the first common curved mirror 131D.

[0108] The first common curved mirror 131D is commonly disposed in the first optical path OP1 and the second optical path OP2 to concentrate or diverge the reflected light. The first common curved mirror 131D reflects the light L1 of the first image and the light L2 of the second image toward the windshield 3.

[0109] The first curved mirror 141D is positioned in the first optical path OP1 between the first plane mirror 121D and the first common curved mirror 131D, causing the reflected light to be concentrated or diverged. The first curved mirror 141D reflects the light L1 of the first image incident from the first plane mirror 121D toward the first common curved mirror 131D.

[0110] The second curved mirror 142D is positioned in the second optical path OP2 between the second plane mirror 122D and the first common curved mirror 131D, causing the reflected light to be concentrated or diverged. The second curved mirror 142D reflects the light L2 of the second image incident from the second plane mirror 122D toward the first common curved mirror 131D.

[0111] The first plane mirror 121D is disposed in the first optical path OP1 between the display unit 11 and the first curved mirror 141D, and reflects the light L1 of the first image incident from the display unit 11 toward the first curved mirror 141D.

[0112] The second plane mirror 122D is disposed in the second optical path OP2 between the display unit 11 and the second curved mirror 142D, and reflects the light L1 of the first image incident from the display unit 11 toward the second curved mirror 142D.

[0113] exist Figure 10 In the image display device 10 shown, light L1 of a first image displayed in the first display area DA1 is incident on a first plane mirror 121D, reflected from the first plane mirror 121D toward a first curved mirror 141D, reflected from the first curved mirror 141D toward a first common curved mirror 131D, and reflected from the first common curved mirror 131D toward the windshield 3, thereby incident on the first incident area PA1 of the windshield 3. Furthermore, light L2 of a second image displayed in the second display area DA2 is incident on a second plane mirror 122D, reflected from the second plane mirror 122D toward a second curved mirror 142D, reflected from the second curved mirror 142D toward the first common curved mirror 131D, and reflected from the first common curved mirror 131D toward the windshield 3, thereby incident on the second incident area PA2 of the windshield 3. The light L1 of the first image and the light L2 of the second image incident on the windshield 3 are reflected towards the visual recognition area SA and reach the eyes of the driver 5, which are located within the visual recognition area SA. The first optical system 12C-1 forming the first optical path OP1 has a longer composite focal distance than the second optical system 12C-2 forming the second optical path OP2. Furthermore, as in... Figure 10 As shown, the optical path length of the first optical path OP1 is longer than that of the second optical path OP2. Therefore, the first virtual image IM1 is formed at a position farther from the viewpoint E compared to the second virtual image IM2.

[0114] According to this embodiment, in addition to the difference in the composite focal distance between the two optical systems (first optical system 12D-1 and second optical system 12D-2), the difference in the optical path length of the first optical path OP1 and the optical path length of the second optical path OP2 is also set, thus making it easier to construct the difference in distance between the position where the first virtual image IM1 is formed and the position where the second virtual image IM2 is formed. Furthermore, even when the range of composite focal distances that can be set in each optical system is limited, by setting the difference in the optical path length of the first optical path OP1 and the optical path length of the second optical path OP2, the difference in distance between the position where the first virtual image IM1 is formed and the position where the second virtual image IM2 is formed can be set to a wider range. Moreover, the relationship between the distance between the position where the first virtual image IM1 is formed and the position where the second virtual image IM2 is formed and the projection magnification of each virtual image can be adjusted independently.

[0115] The above describes several embodiments of the present invention, but the present invention is not limited to the above embodiments and includes various modifications.

[0116] For example, the number of plane mirrors, curved mirrors, and common curved mirrors in the projection optical system listed in the above embodiments are just one example; the number of these mirrors can be arbitrary. Furthermore, the shape and arrangement of each mirror in the above embodiments are also just one example; other shapes and arrangements are also possible.

[0117] Furthermore, in the above embodiments, examples of forming two virtual images at different distances from the viewpoint are given, but in other embodiments of the present invention, three or more virtual images at different distances from the viewpoint may also be formed.

[0118] In addition, Figure 9 as well as Figure 10 In the example, the two curved mirrors (141 and 142, 141D and 142D) are physically separate, but these curved mirrors can also be formed into one.

[0119] The light-transmitting component in this invention is a component that has the property of allowing light to pass through, and the degree of transparency can be arbitrarily selected according to the application.

[0120] Symbol Explanation

[0121] 1…Vehicle 1, 2…Dashboard, 3…Windshield, 3A…Synthesizer, 4…Steering wheel, 5…Driver, 10…Image display device, 11…Display unit, 111, 111A, 111B…Display surface, 112…Light source 112, 113…Scanner 113, 114…Screen 114, 12…Projection optical system, 12C-1, 12D-1…First optical system, 12C-2, 12D-2…Second optical system, 121, 121A, 121B, 121C, 121D…First plane mirror, 122, 122A, 122D…Second plane mirror, 131, 131B, 131C, 131D… First common curved mirror, 132, 132B… Second common curved mirror, 141, 141D… First curved mirror, 142, 142D… Second curved mirror, 15… Actuator, 16… Control unit, DA1… First display area, DA2… Second display area, PA1… First incident area, PA2… Second incident area, IM1… First virtual image, IM2… Second virtual image, OP1… First optical path, OP2… Second optical path, L1… Light of the first image, L2… Light of the second image, SA… Visual recognition area, E… Viewpoint.

Claims

1. An image display device, wherein the image display device emits light of a first image and light of a second image from a display unit toward a light-transmitting member via a projection optical system; The image display device causes light from the first image and light from the second image to be reflected from the light-transmitting member toward the visual recognition area. Viewed from the visual recognition area, a first virtual image corresponding to the first image and a second virtual image corresponding to the second image are displayed at a position separated from the light-transmitting member. The image display device includes: The display unit displays the first image and the second image; and The projection optical system emits light from the first image and light from the second image toward the light-transmitting component. The display unit displays the first image and the second image in different display areas on the same plane of the display unit, wherein the display unit has a first display area for displaying the first image and a second display area for displaying the second image; The projection optical system sets the image points of the light from the first image and the second image, respectively, so that the first virtual image and the second virtual image are formed at positions with different distances from the common viewpoint within the visual recognition area. The projection optical system includes a first optical path and a second optical path. The first optical path extends from the display area of ​​the first image in the display unit to the incident area of ​​the first image in the light-transmitting member. The second optical path extends from the display area of ​​the second image in the display unit to the incident area of ​​the second image in the light-transmitting member. The optical path lengths of the first and second optical paths are different. The projection optical system includes a first plane mirror and a second plane mirror. The first plane mirror is disposed only in the first optical path, and the second plane mirror is disposed only in the second optical path. The first plane mirror is configured to receive light from the first image in the first display area of ​​the display unit, and the second plane mirror is configured to receive light from the second image in the second display area of ​​the display unit, or... The projection optical system includes a first curved mirror and a second curved mirror. The first curved mirror is disposed only in the first optical path and concentrates or diverges the reflected light. The second curved mirror is disposed only in the second optical path and concentrates or diverges the reflected light. The first curved mirror is configured to receive light from the first image in the first display area of ​​the display unit. The second curved mirror is configured to receive light from the second image in the second display area of ​​the display unit.

2. The image display device according to claim 1, wherein, The projection optical system includes at least one common curved mirror, which is commonly disposed in the first optical path and the second optical path to concentrate or diverge the reflected light.

3. The image display device according to claim 2, wherein, The at least one common curved mirror includes: A first common curved mirror reflects light from the first image and the second image toward the light-transmitting member, causing the reflected light to concentrate or diverge; and The second common curved mirror reflects the light from the first image and the light from the second image toward the first common curved mirror, causing the reflected light to concentrate or diverge. At least one of the first plane mirror and the second plane mirror is disposed in the optical path between the display unit and the second common curved mirror.

4. The image display device according to claim 1, wherein, The projection optical system includes: A first optical system forms a first optical path that extends from the display area of ​​the first image in the display unit to the incident area of ​​the light on the first image in the light-transmitting member; and A second optical system forms a second optical path that extends from the display area of ​​the second image in the display unit to the incident area of ​​the light on the second image in the light-transmitting member. The first optical system and the second optical system have different composite focal distances.

5. The image display device according to claim 1, wherein, The projection optical system includes at least one common curved mirror, which is commonly disposed in the first optical path and the second optical path to concentrate or diverge the reflected light.

6. The image display device according to claim 5, wherein, The image display device includes a first curved mirror disposed only in the first optical path and a second curved mirror disposed only in the second optical path; The at least one common curved mirror includes a first common curved mirror, which reflects light from the first image and light from the second image toward the light-transmitting member, thereby concentrating or diverging the reflected light; The first curved mirror reflects the light of the first image toward the first common curved mirror; and The second curved mirror reflects the light of the second image toward the first common curved mirror.

7. The image display device according to claim 3 or 6, wherein, The image display device includes an actuator that moves the first common curved mirror to change the position of the visual recognition area.

8. The image display device according to any one of claims 4 to 6, wherein, In the projection optical system, the optical path length of the first optical path is different from that of the second optical path.

9. The image display device according to claim 8, wherein, The projection optical system includes at least one of a first plane mirror and a second plane mirror, wherein the first plane mirror is disposed only in the first optical path and the second plane mirror is disposed only in the second optical path.

Images