Display device

Abstract

Provided is a display device having excellent transmission performance capable of displaying an aerial image. A display device 1 according to the present embodiment comprises: a display unit 10 having a display surface 15 on which an image to be viewed by a viewer located in front is displayed; at least one microlens array 40 that displays, as an aerial image V1 floating in front of the display surface 15, the image displayed on the display surface 15 disposed so as to be superimposed in the rear; and a case 20 that accommodates the display unit 10 and supports the microlens arrays 40 such that regions having different distances from the display surface 15 are formed in front of the display surface 15.

Description

display device

[0001] The present disclosure relates to a display device mounted on a vehicle or the like.

[0002] A technology has been known in the past that allows users to view a real image of a 3D image by placing a microlens array in front of a display, and this technology has also been applied to display devices mounted on vehicles.

[0003] Japanese Patent Application Laid-Open No. 2003-098479

[0004] Vehicle display devices that display information necessary for driving are required to be highly visible and allow the driver, who is the viewer, to immediately grasp the content of the information. Therefore, there is a demand for displays that take advantage of the three-dimensional images provided by microlens arrays, which cannot be obtained by viewing the flat images provided by conventional displays.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a display device that can display an aerial image with excellent transmittance.

[0006] In order to solve the above-mentioned problems, the display device of the present disclosure comprises a display unit having a display surface that displays an image to be viewed by a viewer positioned in front, at least one microlens array that displays the image displayed on the display surface that is superimposed at the rear as an aerial image floating in front of the display surface, and a case that houses the display unit and supports the microlens array so that areas are formed in front of the display surface at different distances from the display surface.

[0007] The display device of the present disclosure can display an aerial image with excellent transmittance.

[0008] 11 is an external perspective view showing an embodiment of a display device according to the present disclosure. A front view of the display device of FIG. 1. A cross-sectional view taken along line III-III of FIG. 2. A diagram showing an example display when the aerial image is an arrow indicating a right turn. A front view of another embodiment of a display device according to the present disclosure. A cross-sectional view taken along line VI-VI of FIG. 5. A diagram showing an example display when the aerial image is an indicator showing engine RPM. A diagram showing an example image display on a display surface. An explanatory diagram showing the relationship between the viewer's line of sight and MLA. Another explanatory diagram showing the relationship between the viewer's line of sight and MLA. A front view of yet another embodiment of a display device according to the present disclosure. A cross-sectional view taken along line XII-XII of FIG.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a display device according to the present disclosure will be described with reference to the accompanying drawings. The display device according to the present disclosure can be mounted on vehicles such as automobiles, motorcycles, ships, agricultural machinery, and construction machinery.

[0010] Fig. 1 is an external perspective view showing an embodiment of a display device 1 of the present disclosure. Fig. 2 is a front view of the display device 1 of Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III of Fig. 2.

[0011] In the following description, "front (front face)", "rear (rear face)", "upper", "lower", "right", and "left" follow the definitions of "Fr.", "Re.", "To.", "Bo.", "R", and "L" in Figures 1 to 12. Note that the side of the display device 1 that is visible to the user is defined as "front".

[0012] The display device 1 is disposed, for example, on an instrument panel of a vehicle so that a display surface 15 of the display unit 10 is visible to a viewer such as a driver. The display device 1 includes the display unit 10, a case 20, a microlens array 40 (hereinafter simply referred to as "MLA 40"), and a cover 50.

[0013] The display unit 10 includes a liquid crystal display 11 and a substrate 12. The liquid crystal display 11 is a well-known display device that includes a liquid crystal display element and an LED (light-emitting diode). The liquid crystal display element is, for example, a thin-film transistor (TFT) liquid crystal display panel formed by sealing liquid crystal molecules between a pair of glass substrates. The LED illuminates the liquid crystal display element. The liquid crystal display 11 also includes necessary components, such as a light guide plate for distributing the LED light across the entire surface of the liquid crystal display element, a reflector plate provided behind the light guide plate, and a diffuser plate provided in front of the light guide plate. The liquid crystal display 11 (display unit) has a display surface 15 on its front surface that displays an image to be viewed by a viewer positioned in front of the liquid crystal display 11. The substrate 12 is disposed behind the liquid crystal display 11 and controls the liquid crystal display element and the LED.

[0014] The case 20 has a display unit case 21, a rear endpaper 25, and a front endpaper 31.

[0015] The display unit case 21 is made of, for example, a light-blocking resin and houses the display unit 10. The case 20 has an opening 22 through which the display surface 15 of the liquid crystal display 11 is exposed.

[0016] The rear endpaper 25 is a tubular member made of, for example, a light-blocking resin. The rear endpaper 25 has an axial direction along the front-to-rear direction and an outer edge that fits along the opening 22 of the display unit case 21. The rear endpaper 25 has a rear end 26 and a front end 27 opposite the rear end 26. The rear endpaper 25 is positioned in front of the display unit case 21, with the outer edge of the rear end 26 attached to the opening 22 of the display unit case 21. The rear endpaper 25 has a partition wall 28 on the right side that divides the space formed by the inner circumferential surface of the rear endpaper 25 into four rectangular sections in the vertical direction from the rear end 26 to the front end 27.

[0017] The partition wall 28 has a rear MLA support portion 29 formed on the front end 27 side so that its position in the front-to-rear direction changes rearward in a stepped manner from bottom to top. The rear MLA support portion 29 supports the outer edge 41 of the MLA 40 so that the MLA 40 is parallel to a plane along the left-right and up-down directions.

[0018] The front endpaper 31 is a tubular member made of, for example, a light-blocking resin. The front endpaper 31 has an axial direction along the front-to-rear direction and an outer edge that follows the outer edge of the front end 27 of the back endpaper 25. The front endpaper 31 has a rear end 32 and a front end 33 opposite the rear end 32. The front endpaper 31 is positioned in front of the rear endpaper 25, with the outer edge of the rear end 32 attached to the outer edge of the front end 27 of the back endpaper 25. Like the rear endpaper 25, the front endpaper 31 has a partition wall 34 on the right side that divides the space formed by the inner circumferential surface of the front endpaper 31 into four rectangular sections in the vertical direction from the rear end 32 to the front end 33. As a result, the partition walls 28 and 34 form four partitioned spaces along the axial direction along the front-to-rear direction.

[0019] The partition wall 34 has a front MLA support portion 35 formed on the rear end 32 side so that its position in the front-to-rear direction changes rearward in a stepped manner from bottom to top. The front MLA support portion 35 is formed according to the front-to-rear height of the rear MLA support portion 29, and supports the MLA 40 by sandwiching the MLA 40 together with the rear MLA support portion 29 at its outer edge 41. The front-to-rear height of the rear MLA support portion 29 is set according to the display position of the aerial image V1, the focal length of the MLA 40, etc.

[0020] The rear endpaper 25 and front endpaper 31 function as a case 20 that supports the multiple MLAs 40 so that regions of varying distance from the display surface 15 are formed in front of the display surface 15. The rear endpaper 25 and front endpaper 31 also support the multiple MLAs 40 parallel to the display surface 15 so that the distance from the display surface 15 gradually decreases from below to above (in the first direction).

[0021] The MLAs 40 are arranged to display an image displayed on the display surface 15, which is arranged superimposed behind the display surface 15, as an aerial image V1 floating in front of the display surface 15. The MLAs 40 have microlenses, which are multiple miniaturized convex lenses, arranged two-dimensionally. A microlens is provided for each of the multiple display pixels of the display unit 10. The MLAs 40 are supported via their outer edges 41 by four pairs of rear MLA support members 29 and front MLA support members 35. As a result, each MLA 40 is positioned a predetermined distance forward from the display surface 15. Each microlens projects light from an image displayed on the display surface 15, which is superimposed in the front-to-rear direction, onto a predetermined image plane in front of the display device 1. That is, an aerial image V1, in which an image displayed on the superimposed display surface 15 is floating, is displayed in the right region of the display device 1.

[0022] The cover 50 is a plate-like member having, for example, a smoke color (transparent black). The cover 50 has an outer shape corresponding to the outer edge of the front end 33 of the front endpaper 31 and is positioned to cover the front end 33. The cover 50 improves the appearance by shielding the inner surfaces of the back endpaper 25 and front endpaper 31 and the MLA 40 so that they are not visible from the front. The cover 50 also prevents dust from entering the inside of the case 20.

[0023] Next, the operation of the display device 1 in this embodiment will be described.

[0024] In the region of the display surface 15 to the left of the partition wall 28, the display device 1 allows display light relating to an image displayed on the display surface 15 to be viewed as passing through the cover 50. Meanwhile, in the region of the display surface 15 to the right of the partition wall 28 of the display surface 15, the display device 1 has the MLA 40 disposed therein, and therefore allows display light relating to an image displayed by the display unit 10 to be viewed as an aerial image V1 as passing through the MLA 40 and the cover 50. The aerial image V1 is viewed as if it is floating in front of the cover 50.

[0025] Here, the MLAs 40 are supported by the rear endpaper 25 and the front endpaper 31 so that the distance to the viewer increases from below to above. For this reason, for example, when each MLA 40 displays an image of the same size on the display surface 15 as an aerial image V1, the viewer will perceive the aerial image V1 closer as it is displayed lower, and the aerial image V1 displayed higher as it is displayed further away.

[0026] For example, Fig. 4 is a diagram showing a display example in which the aerial image V1 is an arrow 2 indicating a right turn. For the sake of explanation, Fig. 3 shows an image of the arrow 2 displayed on the display surface 15 below the display device 1 and superimposed on the MLA 40.

[0027] When the display device 1 displays the arrow 2 on the display unit 10, the viewer perceives the arrow 2 such that the base end 2a of the arrow 2 displayed at the bottom is closer to the viewer and the tip end 2b of the arrow 2 displayed at the top becomes farther away from the viewer. That is, the display device 1 can easily generate a three-dimensional aerial image V1 with a sense of depth by varying the distance between the MLA 40 and the viewer's viewpoint. This allows the MLA 40 to be positioned without varying its longitudinal position (distance from the display surface 15), and the information to "turn right" can be intuitively conveyed in harmony with the road surface, etc., in front of the vehicle, compared to when a planar image is simply displayed in the air.

[0028] Therefore, the display device 1 of this embodiment can not only simply display an aerial image using the MLA 40, but also display an image that is more intuitive and has excellent information transmission properties.

[0029] In addition, in the display device 1, an example of generating an aerial image V1 in which the lower the image, the closer to the viewer (forward) and the higher the image, the farther away from the viewer (rearward) has been described; however, the aerial image may also be generated so that the center is closer to the viewer and the outside is farther away from the viewer.

[0030] For example, FIG. 5 is a front view showing another embodiment of a display device according to the present disclosure.

[0031] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5. For the sake of explanation, Fig. 6 shows an image of the indicator 5 displayed on the display surface 15 below the display device 101, overlapping with the MLA 40.

[0032] Display device 101 differs from display device 1 in that rear endpaper 125 and front endpaper 131 support multiple MLAs 40 so that the distance of the MLAs 40 from the display surface 15 gradually increases as the distance approaches the center in the left-right direction (second direction), that is, so that the distance of the MLAs 40 disposed further outward in the left-right direction from the center gradually decreases. As the other configurations are the same as those of display device 1, the same reference numerals are used for configurations and parts corresponding to those of display device 1, and redundant explanations will be omitted.

[0033] The display device 101 displays, for example, an indicator 5 that displays the engine speed by lighting a lamp (a so-called rev indicator) as an aerial image V2. Fig. 7 is a diagram showing a display example in which the aerial image V2 is an indicator 5 that indicates the engine speed.

[0034] The indicator 5 is a plurality of rectangular images arranged in the left-right direction. The indicator 5 has a first image 5a that is displayed when the engine speed is equal to or less than a first value, a second image 5b that is displayed when the engine speed is greater than the first value and equal to or less than a second value, and a third image 5c that is displayed when the engine speed is equal to or less than a third value that is greater than the second value and requires a gear change. The first images 5a are displayed one by one on the left-right outer side of the indicator 5, for example, in green. The second images 5b are displayed two by two on the left-right inner side of each first image 5a, for example, in yellow. The third images 5c are displayed two by two in red in the left-right center of the indicator 5, inside each second image 5b. Note that the images of the indicator 5 are merely an example, and the number and shape are not limited to those shown. For example, the indicator 5 is not limited to a rectangle, but may be a circle.

[0035] When the display device 101 displays rectangular images of the same dimensions as the indicator 5 on the display unit 10, the indicator 5 is perceived as follows: the aerial image V2 of the first image 5a, displayed on the outer left-right sides, is farther from the viewer; the aerial image V2 of the second image 5b, displayed inside the first image 5a, and the aerial image V2 of the third image 5c, displayed in the center, are gradually closer to the viewer. As a result, the first image 5a, displayed when the current engine speed is a first value below a value requiring a gear change, is perceived as closer to the viewer and larger; the second image 5b, displayed when the engine speed is greater than the first value but less than a second value, is perceived as closer to the viewer and larger. Furthermore, the third image 5c, displayed when the engine speed approaches a third value requiring a gear change, is perceived as closer to the viewer and larger. In other words, the display device 101 can easily generate a three-dimensional aerial image V2 with a sense of depth by varying the distance between the MLA 40 and the viewer (viewpoint). This allows the viewer to intuitively understand the engine speed value compared to when the MLA 40 simply displays a planar image in the air.

[0036] With the recent increase in the size of display surfaces 15, the display surface 15 may be wide in the horizontal direction, as shown in FIG. 8 . From the viewpoint of information transmission, a display device is required to display an aerial image with good visibility. The MLA 40 is a thin plate on which microlenses, which are miniaturized convex lenses, are arranged. Therefore, due to its structure, unless the viewpoint is directly facing the convex direction of the microlenses and on the optical path of light passing through the microlenses, i.e., on a line perpendicular to the MLA 40 as shown in FIG. 9 (i.e., unless the lines of sight 8 a and 8 b are perpendicular to the MLA 40), a clear aerial image cannot be seen. In other words, the more the viewer 8's line of sight 8 a is inclined relative to the direction approximately perpendicular to the MLA 40, the more blurred the aerial image the viewer 8 will perceive. As a result, taking Figure 8 as an example, the image displayed in area 15C visible to line of sight 8a is perceived as a clear aerial image V3, but the images displayed in areas 15R and 15L visible to line of sight 8b are perceived as a blurred, unclear aerial image V4.

[0037] Therefore, in the display device of the present disclosure, the MLA 40 transmits an image in which the line of sight 8b is tilted in a direction approximately perpendicular to the MLA 40, i.e., an image at a position relatively far from the viewer 8 who is expected to be located near the center of the display surface 15, and the MLA 40 is arranged on the left and right outer sides of the display surface 15, and is supported at an angle so that the MLA 40 is non-parallel to the display surface 15, so that the lines of sight 8a, 8b are approximately perpendicular to the MLA 40, as shown in Figure 10.

[0038] Here, Fig. 11 is a front view showing still another embodiment of a display device according to the present disclosure, and Fig. 12 is a cross-sectional view taken along line XII-XII in Fig. 11 .

[0039] Display device 201 differs from display device 1 in that rear endpaper 225 and front endpaper 231 support right MLA 241 and left MLA 242 at an angle non-parallel to display surface 15 so that line of sight 8b of expected viewer 8 is approximately perpendicular to MLA 40. As the other configurations are the same as those of display device 1, the same reference numerals are used for configurations and parts corresponding to those of display device 1, and redundant explanations will be omitted.

[0040] The back endpaper 225 and the front endpaper 231 (case) support the MLAs 240, 241, and 242 so that they are arranged along the left-right direction (third direction). The MLAs 240, 241, and 242 include a central MLA 240 arranged in the center in the left-right direction, a right MLA 241 arranged to the right of the central MLA 240, and a left MLA 242 arranged to the left of the central MLA 240. The back endpaper 225 and the front endpaper 231 support the right MLA 241 and the left MLA 242 so that the outer edges of the right MLA 241 and the left MLA 242 (the MLAs arranged outward in at least the third direction) are inclined away from the display surface 15 in the front-to-back direction. Meanwhile, the back endpaper 225 and the front endpaper 231 support the central MLA 240 so that it is parallel to the display surface 15.

[0041] In this way, by arranging the MLAs 240, 241, and 242 in consideration of the optical path of the microlenses and the position of the viewer 8, it is possible to maintain the visibility of the aerial images V3 and V4 while creating a sense of three-dimensionality and depth between the multiple aerial images V3 and V4. That is, by arranging the right MLA 241 and the left MLA 242 at an angle non-parallel to the display surface 15 so that the viewer is positioned on the optical path of light passing through the microlenses, even the aerial image V4 corresponding to the image displayed in regions 15R and 15L, which are relatively far from the viewer, can be clearly viewed, and a difference in three-dimensionality from the aerial image V3 corresponding to the image generated by the central MLA 240 and displayed in region 15C can also be created. Furthermore, the aerial image V4 itself generated by the tilted right MLA 241 and left MLA 242 can also create a sense of three-dimensionality and depth depending on the aspect of the displayed image.

[0042] Although several embodiments of the invention of this disclosure 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.

[0043] For example, the display devices of the present disclosure have been described using an example in which the display device 1 has multiple MLAs 40 arranged at different front-to-back distances from the display surface 15 in the up-down direction, and the display device 101 has multiple MLAs 40 arranged at different front-to-back distances from the display surface 15 in the left-to-right direction. However, the arrangement directions of the multiple MLAs 40 and the way in which the distances from the display surface 15 are varied are merely examples and are not limited to these. Furthermore, even in the case of the display devices 1 and 101, the MLAs 40 may be arranged at an angle non-parallel to the display surface 15 if a visual effect can be obtained.

[0044] Furthermore, the example in which the display device 201 has a plurality of MLAs 240, 241, and 242, and some of the MLAs 241 and 242 are arranged at an angle non-parallel to the display surface 15, has been described. However, the display device 201 may have only one MLA, and the MLA may be arranged at an angle non-parallel to the display surface 15.

[0045] Although the display devices 1, 101, and 201 have been described as having the cover 50 for the purpose of improving visibility, the cover 50 may be omitted if the improved visibility and dustproof effect are not required.

[0046] Furthermore, if the MLAs 40, 240, 241, 242 can be fixed to the back endpapers 25, 125, 225 by adhesive or by integrally forming them by two-color molding or the like, the front endpapers 31, 131, 231 may be omitted.

[0047] 1, 101, 201 Display device 2 Arrow 2a Base end 2b Tip end 5 Indicator 8 Viewer 8a, 8b Line of sight 10 Display unit 11 Liquid crystal display element 12 Light source substrate 15 Display surface 15C, 15R, 15L Area 20 Case 21 Display unit case 22 Opening 26, 32 Rear end 27, 33 Front end 28, 34 Partition wall 29 Rear MLA support portion 35 Front MLA support portion 40 Microlens array (MLA) 41 Outer edge 50 Cover 240 Central microlens array (MLA) 241 Right microlens array (MLA) 242 Left microlens array (MLA) V1, V2, V3, V4 Aerial image

Claims

1. A display device comprising: a display unit having a display surface that displays an image to be viewed by a viewer positioned in front; at least one microlens array that displays the image displayed on the display surface, which is positioned superimposed at the rear, as an aerial image floating in front of the display surface; and a case that houses the display unit and supports the microlens array so that areas are formed in front of the display surface at different distances from the display surface.

2. The display device according to claim 1, wherein the microlens array is a plurality of microlens arrays, and the case supports the plurality of microlens arrays on the display surface such that the distances of the plurality of microlens arrays from the display surface are different from one another.

3. The display device according to claim 2, wherein the case supports the plurality of microlens arrays such that the distance of each of the plurality of microlens arrays to the display surface gradually decreases in a first direction.

4. The display device according to claim 2, wherein the case supports the plurality of microlens arrays such that the distance of each of the plurality of microlens arrays to the display surface gradually increases toward the center in the second direction.

5. The display device according to claim 1, wherein said case supports said microlens array so as to be non-parallel to said display surface.

6. The display device of claim 5, wherein the microlens array is a plurality of microlens arrays, and the case supports the plurality of microlens arrays so that they are arranged along a third direction, and supports the plurality of microlens arrays by tilting at least the outer edge side of the microlens arrays arranged on the outside in the third direction so that the outer edge side is positioned away from the display surface.

Images