Display device

Abstract

To provide a display device which is improved in productivity.SOLUTION: A head-up display 1 which is an example of a display device according to the present invention includes: a screen 60 on which a video is displayed by receiving the display light L, a projector 10 for projecting the display light L on the screen 60; a field lens 50 which refracts and transmits the display light L therethrough; a case 18 which holds the field lens 50; and a plurality of springs 71, 72 which energize the field lens 50 toward the case 18 and have the same shape as each other in a no-load state.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a display device. [Background technology]

[0002] Display devices such as head-up displays are installed in vehicles and display various information necessary for driving to the driver as virtual images via a transmissive / reflective surface such as the windshield. This allows the head-up display to display information (images) superimposed on the view ahead of the vehicle, allowing the driver to grasp the necessary information without making large eye movements while driving.

[0003] Display light showing an image is generated, for example, by a projector. The generated display light is displayed as an image on a screen. A hot mirror is provided to prevent external light, such as sunlight, incident from outside the head-up display from being directed toward the screen. The hot mirror is also installed at an angle to the screen surface to suppress the occurrence of moire (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-122059 [Patent Document 2] Japanese Patent Application Publication No. 2019-101185 Summary of the Invention [Problem to be solved by the invention]

[0005] In particular, in Patent Document 2, the screen holder 70 is a single thin metal plate with a large opening in the center. This type of screen holder 70 is inefficient in terms of the number of units that can be produced, and assembling the screen 60 and field lens 50 as a single unit to the main holder 100 also makes assembly difficult.

[0006] Therefore, even in such a display device, there is still room for improvement in terms of manufacturability. The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a display device with improved manufacturability. [Means for solving the problem]

[0007] The display device according to the present invention comprises: A screen on which the image is displayed by receiving projection light, a projector that projects the projection light onto the screen; a lens that refracts and transmits the projection light; a housing for holding the lens; a plurality of springs that bias the lens toward the housing and have the same shape when in a no-load state; Equipped with Each of the springs is a first biasing unit that biases the projection light in a traveling direction; a second biasing portion that biases in a plane direction intersecting with the traveling direction of the projection light; a fixed portion fixed to the housing; a buffer section that connects the first biasing section and the second biasing section and that deforms the relative positions of the first biasing section and the second biasing section in response to stress received from the housing; It has. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing an embodiment of a head-up display 1 according to the present invention, particularly showing the configuration of an optical system. [Figure 2] FIG. 2 is an explanatory diagram showing the configuration of an optical system of the projector 10. [Figure 3] FIG. 2 is a perspective view of a main part of the head-up display 1. [Figure 4] FIG. [Figure 5] FIG. [Figure 6]1 is a cross-sectional view of a field lens 50, a lens holder 182, and springs 71 and 72. FIG. [Figure 7] FIG. 10 is a perspective view of the spring 73 fixed to the lens holder 182. [Figure 8] 18 is a diagram showing a mirror holder 183 attached to a lower case 181 and a lens holder 182. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A head-up display, which is an example of a display device according to the present invention, will be described as an embodiment in the following order with reference to the accompanying drawings. 1. First embodiment <1-1. About the composition> <1-2. About Spring 70> <1-3. Assembly Procedure> 2. Variations

[0010] [1. First embodiment] <1-1. About the composition> 1 is an explanatory diagram showing an embodiment of a head-up display, particularly showing the configuration of an optical system. The head-up display is mounted on a vehicle such as an automobile.

[0011] A head-up display 1 (hereinafter referred to as HUD1), which is an example of a display device, is disposed within the instrument panel of an automobile. HUD1 mainly includes a projector 10, a first plane mirror 13, a second plane mirror 14, a screen unit 15, a first concave mirror 16, a second concave mirror 17, and a case 18 (housing). HUD1 reflects display light L representing a display image (image) generated by projector 10 by first and second plane mirrors 13, 14 and first and second concave mirrors 16, 17, which constitute a relay optical system, and irradiates the light onto the automobile's windshield 2, which is an example of a transmissive-reflector. A viewer (primarily the driver) can view a virtual image V of the display image superimposed on the scenery (real scenery) ahead of the vehicle by placing a viewpoint 4 within an eyebox 3, which is the visible area of ​​the image generated by HUD1.

[0012] The projector 10 generates display light L (projection light) related to a display image, and projects the light onto a screen 60 via a field lens 50.

[0013] The first plane mirror 13 reflects the display light L generated and projected by the projector 10. The second plane mirror 14 further reflects the display light L reflected by the first plane mirror 13.

[0014] The screen unit 15 receives the display light L reflected by the second plane mirror 14 and displays an image (real image). Details of the screen unit 15 will be described later. The first concave mirror 16 has a curvature (the reciprocal of the radius) that causes the display light L emitted from the screen unit 15 to cross above and below (cross at cross point C) before reaching the second concave mirror 17, and reflects the display light toward the second concave mirror 17. The second concave mirror 17 reflects the display light L reflected by the first concave mirror 16 toward the windshield 2. The case 18 houses the projector 10, the first and second plane mirrors 13 and 14, the screen unit 15, and the first and second concave mirrors 16 and 17.

[0015] The case 18 has an opening 18a in a portion facing the windshield 2. The opening 18a is covered with a light-transmitting cover 19. The display light L reflected by the second concave mirror 17 passes through the light-transmitting cover 19 and is emitted from the HUD 1. The case 18 includes a lower case 181, a lens holder 182, and a mirror holder 183, which will be described later. The lower case 181 is a case that functions as a lens barrel behind the screen 60 (on the first concave mirror 16 side). The lens holder 182 is a case that holds the field lens 50. The mirror holder 183 is a case that holds the first plane mirror 13 and the second plane mirror 14.

[0016] 2 is an explanatory diagram showing the configuration of the optical system of the projector 10. The projector 10 mainly includes a light source 22, an optical member 23, and a light modulation element 24.

[0017] The light sources 22 are LEDs (Light Emitting Diodes) mounted on a substrate. The light sources 22 include a red light source 22a that emits red light R, a green light source 22b that emits green light G, and a blue light source 22c that emits blue light B. Hereinafter, when there is no need to distinguish between the red light source 22a, the green light source 22b, and the blue light source 22c, they will simply be referred to as light sources 22.

[0018] The optical member 23 includes a mirror 41 , dichroic mirrors 42 and 43 , a reflecting mirror 44 , a convex lens 45 , a prism 46 , and a light projecting lens 47 .

[0019] The red light ray R emitted from the red light source 22a is reflected by the mirror 41 and passes through the dichroic mirrors 42 and 43. The green light ray G emitted from the green light source 22b is reflected by the dichroic mirror 42 and passes through the dichroic mirror 43. The blue light ray B emitted from the blue light source 22c is reflected by the dichroic mirror 43. These light rays R, G, and B are reflected by the reflecting mirror 44, distributed by the convex lens 45, and passed through the prism 46. The transmitted light rays R, G, and B are converted into display light L by the light modulation element 24. The display light L is reflected by the prism 46, passed through the projection lens 47, and projected (emitted).

[0020] The light modulation element 24 is, for example, a reflective display element such as a DMD (Digital Mirror Device) or LCOS (Liquid Crystal On Silicon). The light modulation element 24 is connected to a control board (not shown) and is controlled by this control board.

[0021] Fig. 3 is a perspective view of the main parts of the HUD 1. Specifically, Fig. 3 is a perspective view of the field lens 50, springs 71, 72, 73, lower case 181, and lens holder 182 in an assembled state.

[0022] The field lens 50 adjusts the direction of the display light L. That is, the field lens 50 has a function of guiding the display light L to the screen 60 at a predetermined light distribution angle.

[0023] The screen 60 receives the display light L emitted from the field lens 50 on a rear surface 61 and displays an image on a front surface 62. The screen 60 is made of, for example, polycarbonate resin, and is thin and flexible. The screen 60 has a microlens array surface. The microlens array surface is a surface on which a plurality of convex microlenses are arranged on a substrate.

[0024] The springs 71, 72, and 73 are members that urge the field lens 50 toward the case 18. The springs 71, 72, and 73 may also urge and position the screen 60. The springs 71, 72, and 73 are formed from thin metal plates. The springs 71, 72, and 73 each have the same shape when no load is applied (unloaded state). Specifically, they are configured as springs 70 as shown in FIGS. 4 and 5.

[0025] <1-2. About Spring 70> Spring 70 will be described with reference to Figures 4 to 7. The longitudinal direction of field lens 50 is defined as direction X, the lateral direction as direction Y, and the thickness direction as direction Z. Spring 70 has a fixed portion 701, a first biasing portion 702, a second biasing portion 703, a buffer portion 704, and a positioning portion 705.

[0026] The fixing portion 701 is a portion for fixing the spring 70 to the case 18 (lens holder 182). The fixing portion 701 is a U-shaped portion formed on the spring 70 by bending. The fixing portion 701 determines a reference position for the spring 70 by firmly clamping the protrusions 182a and ribs formed on the case 18. It is desirable that the fixing portion 701 has a shape such as a barb 701a that can prevent the spring 70 from falling off the case 18. A plurality of fixing portions 701 are formed in a first direction D1, and clamp the case 18 in a second direction D2 that is perpendicular to the first direction D1.

[0027] The first biasing portion 702 is a portion that biases the field lens 50 and the screen 60 in the traveling direction of the display light L (the thickness direction of the field lens 50, direction Z, direction D3). Specifically, the spring 70 performs the biasing force as the leg portion 702a elastically deforms. The biasing portion may bias a non-optical portion such as a flange portion 51 (protrusion) provided on the field lens 50. In other words, the leg portion 702a functions as an elastic portion of the first biasing portion 702.

[0028] The second biasing portion 703 is a portion that biases the field lens 50 in a plane direction (XY plane direction, D1-D2 plane) that intersects with the traveling direction (thickness direction of the field lens 50, direction Z, direction D3) of the display light L. Specifically, the second biasing portion 703 elastically deforms, causing the spring 70 to bias the field lens 50.

[0029] Buffer portion 704 is a portion that connects first biasing portion 702 and second biasing portion 703, and that changes the relative position of first biasing portion 702 and second biasing portion 703 in response to stress received from case 18. Specifically, as shown in Figures 6 and 7, for example, the buffer portion undergoes different elastic deformations, thereby changing the mounting posture of each spring. With this configuration, even if each spring has the same shape, the mounting posture can be changed depending on the mounting location on case 18, and the function (presence or absence of biasing action, etc.) can be adjusted according to each mounting location. Also, by changing the mounting posture, each spring can be modified to fit into the space available for mounting, depending on the limitations of the available mounting space.

[0030] Because buffer portion 704 is elastically deformable in this manner, it is desirable that the spring constant of buffer portion 704 be smaller than that of first biasing portion 702 and second biasing portion 703. Buffer portion 704 may be guided, for example, by groove 182d so that the position of spring 70 relative to case 18 does not shift in direction D1.

[0031] The positioning portion 705 is a guide for installing the field lens 50 and the screen 60 in the correct position relative to the spring 70 and the case 18, for example.

[0032] The spring 70 configured in this manner is assembled into the lens holder 182 as springs 71, 72, and 73.

[0033] Spring 71 functions as a first spring, and spring 72 functions as a second spring. Specifically, second biasing portion 713 provided on first spring 71 biases, but second biasing portion 723 provided on second spring 72 does not bias field lens 50. In this way, the presence of buffer portion 74 allows first spring 71 and second spring 72, which have the same shape, to perform different functions. Note that, as shown in FIG. 3, field lens 50 is not biased by second spring 72, but is instead positioned relative to receiving portion 182c.

[0034] <1-3. Assembly Procedure> Next, the assembly procedure for the screen unit 15 will be described.

[0035] In the first step, the lens holder 182 is attached to the lower part of the lower case 181 (the side surface facing the direction Dn).

[0036] In the second step, springs 71, 72, and 73 are attached to protrusion 182a. At this time, buffer portion 704 is guided into groove 182d, thereby positioning springs 71, 72, and 73. Furthermore, restricting portion 182b presses the legs, thereby elastically deforming the buffer portion and adopting an attachment posture appropriate for each spring.

[0037] In the third step, the screen 60 is attached to the first biasing portions 712, 722, and 732. At this time, the screen 60 is positioned by the positioning portions 715, 725, and 735.

[0038] In a fourth step, the field lens 50 is placed on top of the second biasing portions 713, 723, and 733. Specifically, the upper slopes of the second biasing portions 713, 723, and 733 come into contact with the slopes of the side surfaces of the flange portion 51, thereby creating a floating state.

[0039] In the fifth step, mirror holder 183 is attached to lower case 181 and lens holder 182. At this time, field lens 50, which was floating in the fourth step, is pressed by mirror holder 183 and moves to the position shown in FIG. 6. At the same time that the position shift of field lens 50 is completed successfully, hook 183a of mirror holder 183 engages with protrusion 182e of lens holder 182. With this configuration, the assembly state of internal field lens 50 can be determined based on the engagement state of hook 183a, which is visible from the outside, making it easy to determine whether it is normal. This ultimately results in a head-up display with improved manufacturability.

[0040] Thereafter, the mirror holder 183 may be fixed to the lower case 181 or the like by screwing. By including a screwing process, the mirror holder 183 can be fixed more firmly, and by being able to perform screwing, it is possible to obtain the effect of being able to confirm that the hook 183a and the field lens 50 have been moved to the correct position.

[0041] Through the above steps, the screen unit 15 is assembled in the state shown in FIGS.

[0042] [Variations] Although embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0043] 1 Head-up display (HUD) 2. Windshield 3 Eye Box 4. Perspective 10 Projector 13 1st plane mirror 14 Second plane mirror 15 Screen Unit 16 1st concave mirror 17 Second concave mirror 18 cases 18a opening 181 Lower case 182 Lens holder 182a Protrusion 182b Regulatory Department 182c Receiving part 183 Mirror Holder 19 Translucent cover 22 Light source 22a Red light source 22b Green light source 22c blue light source 23 Optical Components 24 Light modulation element 41 Mirror 42, 43 Dichroic mirror 44 Reflector 45 Convex Lens 46 Prism 47 Projection lens 50 Field Lens 60 screens 70,73 Spring 71 First Spring 72 Second Spring 701,711,721,731 Fixed part 702,712,722,732 First energizing portion 703,713,723,733 Second energizing section 704,714,724,734 Buffer section 705,715,725,735 Positioning part

Claims

1. A screen on which the image is displayed by receiving projection light, a projector that projects the projection light onto the screen; a lens that refracts and transmits the projection light; a housing for holding the lens; a plurality of springs that bias the lens toward the housing and have the same shape when in a no-load state; Equipped with Each of the springs is a first biasing unit that biases the projection light in a traveling direction; a second biasing portion that biases in a plane direction intersecting with the traveling direction of the projection light; a fixed portion fixed to the housing; a buffer section that connects the first biasing section and the second biasing section and that deforms the relative positions of the first biasing section and the second biasing section in response to stress received from the housing; have Display device.

2. the springs include at least a first spring and a second spring; the first spring biases the lens via the first biasing portion and the second biasing portion when the fixed portion is fixed to the housing; When the fixed portion is fixed to the housing, the first biasing portion of the second spring biases the lens, and the second biasing portion does not bias the lens. The display device according to claim 1 .

3. The buffer section is the relative position is changed by elastically deforming in response to stress received from the housing, The spring constant is smaller than that of the elastic portions formed in the first and second biasing portions. The display device according to claim 1 .

4. The lens is a field lens. The display device according to claim 1 .

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