Light-emitting devices and display devices

Abstract

This application discloses a light-emitting device, including a substrate, a plurality of reflective cups on the substrate, a plurality of light-emitting diodes (LEDs) located on the substrate and respectively within the reflective cups, and a light-deflecting element located on the reflective cups. The light-deflecting element has a plurality of Fresnel lenses, each covering one of the LEDs, and the optical axes of the Fresnel lenses are respectively translated by a distance X from the center line of the LED, and the translation distance X conforms to θ = tan θ. ‑1 (X / F), where θ is the deflection angle of the light from each LED through one of the Fresnel lenses, and F is the focal length of the Fresnel lens.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a light-emitting device and a display device having the light-emitting device. Background Technology

[0002] A panoramic head-up display (P-HUD) for automobiles projects an image onto the windshield using a display device placed on the upper trim panel. This image is reflected through the windshield and into the driver's eyes, creating a virtual image in front of the vehicle so that the image seen by the driver is located at the lower edge of the windshield. To achieve this, such a P-HUD display device needs to project the image onto the windshield at an angle.

[0003] In conventional display devices, the backlight module illuminates the LCD panel perpendicularly, thus the backlight module is positioned parallel to the LCD panel. However, to accommodate the projection onto a windshield, the P-HUD display device requires an angled backlight module, creating an angle between the backlight module and the LCD panel. This allows the light to illuminate the LCD panel at an angle, enabling the P-HUD display to project images onto the windshield at an angle. However, compared to a design where the backlight module is parallel to the LCD panel, the angled backlight module results in a significantly larger display device, hindering the pursuit of a thinner design. Summary of the Invention

[0004] Therefore, it is necessary to provide a light-emitting device and a display device to facilitate thinner design.

[0005] According to one aspect of this application, an embodiment of this application provides a light-emitting device.

[0006] According to some embodiments of this application, a light-emitting device includes a substrate, a plurality of reflective cups located on the substrate, a plurality of light-emitting diodes located on the substrate and respectively within the reflective cups, and a light-deflecting element located on the reflective cups. The light-deflecting element has a plurality of Fresnel lenses, each covering one of the light-emitting diodes, and the optical axes of the Fresnel lenses are respectively translated by a distance X from the centerline of the light-emitting diode, and the translation distance X conforms to:

[0007] θ = tan -1 (X / F);

[0008] Where θ is the deflection angle of the light from each LED through one of the Fresnel lenses, and F is the focal length of the Fresnel lens.

[0009] In some implementations, the light-emitting diodes and reflectors are arranged in a two-dimensional array.

[0010] In some embodiments, the light-emitting device further includes a controller electrically connected to a plurality of light-emitting diodes and configured to independently dim, turn on, or turn off each light-emitting diode.

[0011] In some embodiments, the light-emitting device further includes at least one optical film located on the surface of the light deflecting element opposite to the light-emitting diode.

[0012] In some embodiments, the optical film is a diffuser plate, diffuser sheet, diffuser film, brightness enhancement film (BEF), double-layer brightness enhancement film (DBEF), or privacy screen.

[0013] In some implementations, the reflector cup is a rectangular composite parabolic light collector.

[0014] According to another aspect of this application, an embodiment of this application provides a display device.

[0015] According to some embodiments of this application, a display device includes a light-emitting device and a liquid crystal panel. The light-emitting device includes a substrate, a plurality of reflective cups located on the substrate, a plurality of light-emitting diodes (LEDs) located on the substrate and respectively within the reflective cups, and light-deflecting elements located on the reflective cups. The light-deflecting elements have a plurality of Fresnel lenses, each covering one of the LEDs, and the optical axes of the Fresnel lenses are respectively shifted by a distance X from the centerline of the LED, conforming to the following:

[0016] θ = tan -1 (X / F);

[0017] Where θ is the deflection angle of the light from each LED through one of the Fresnel lenses, and F is the focal length of the Fresnel lens. The LCD panel is located above the light deflection elements of the light-emitting device.

[0018] In some embodiments, the light-emitting device further includes at least one optical film located on the surface of the light deflecting element opposite to the light-emitting diode, and the optical film is a diffuser plate, diffuser sheet, diffuser film, brightness enhancement film, double-layer brightness enhancement film, or privacy screen.

[0019] In some implementations, the light-emitting device and the liquid crystal panel are parallel.

[0020] In some embodiments, the light-emitting device further includes a controller electrically connected to a plurality of light-emitting diodes and configured to independently dim, turn on, or turn off each light-emitting diode.

[0021] In the above embodiments of this application, since the optical axis of the Fresnel lens of the light-emitting device's light-deflecting element is shifted from the center line of the light-emitting diode, the illumination light emitted by the light-emitting element can be deflected by the light-deflecting element, allowing the light to illuminate the liquid crystal panel obliquely, without the need for the light-emitting device to be tilted. This reduces the size of the display device, facilitating thinner designs. Furthermore, since the light-emitting device uses multiple light-emitting diodes as the light source, and these diodes can be individually adjusted in their on / off state and brightness, such a light-emitting device, when used in a P-HUD display device, can also provide local dimming functionality. Attached Figure Description

[0022] When read in conjunction with the accompanying illustrations, all aspects of this application can be best understood from the embodiments described below. Note that, according to standard practice in this industry, the various features are not drawn to scale. In fact, the dimensions of the various features may be increased or decreased arbitrarily for clarity of explanation.

[0023] Figure 1 A top view of a display device according to an embodiment of this application is shown.

[0024] Figure 2 It shows Figure 1 The cross-sectional view of the display device along line segment 2-2.

[0025] Figure 3 It shows Figure 1 A 3D view of the light-emitting device below the LCD panel.

[0026] Figure 4 It shows Figure 2 A partial magnified view of the reflector, light-emitting diode, and light-deflecting element, in which the light-emitting diode emits light.

[0027] Figure 5 It shows Figure 2 A schematic diagram of the light path when the light-emitting diode of a display device emits light.

[0028] Figure 6 It shows Figure 5 The display device is used in the schematic diagram of the vehicle.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100: Light-emitting device

[0031] 110: Substrate

[0032] 120: Reflector Cup

[0033] 130: Light Emitting Diode

[0034] 140: Light deflecting element

[0035] 141: Fresnel lens

[0036] 150: Optical film

[0037] 160: Controller

[0038] 200: Display device

[0039] 210: LCD panel

[0040] 300: Vehicles

[0041] 310: Upper trim panel

[0042] 320: Windshield

[0043] 400: virtual image

[0044] 2-2: Line Segment

[0045] C: Centerline

[0046] L, L1, L2, L4: Light rays

[0047] O: Optical axis

[0048] X: Translation distance

[0049] θ: Angle Detailed Implementation

[0050] The following disclosure of embodiments provides many different implementations, or examples, of various features for achieving the provided objectives. Specific examples of elements and arrangements are described below to simplify this application. Of course, these examples are merely illustrative and are not intended to be limiting. Furthermore, element symbols and / or letters may be repeated in various examples. This repetition is for simplicity and clarity and does not in itself specify the relationship between the various embodiments and / or configurations discussed.

[0051] Spatial relative terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein for descriptive purposes to describe the relationship between one element or feature and another, as shown in the accompanying drawings. Spatial relative terms are intended to cover different orientations of the apparatus in use or operation other than those shown in the accompanying drawings. The apparatus may be oriented in other ways (rotated 90 degrees or otherwise), and the spatial relative descriptors used herein shall be interpreted accordingly.

[0052] Figure 1 A top view of a display device 200 according to some embodiments of this application is shown. Figure 2 It shows Figure 1The display device 200 in the middle Figure 1 The cross-sectional view of line segment 2-2 in the diagram. Also refer to... Figure 1 and Figure 2 The display device 200 includes a light-emitting device 100 and a liquid crystal panel 210. The light-emitting device 100 is the backlight module of the display device 200. The liquid crystal panel 210 is located on and covers the light-emitting device 100, and the light-emitting device 100 and the liquid crystal panel 210 are parallel to each other. The light-emitting device 100 includes a substrate 110, a plurality of reflective cups 120, a plurality of light-emitting diodes 130, and a light deflecting element 140. The reflective cups 120 and the light-emitting diodes 130 are located on the substrate 110, and the light-emitting diodes 130 are respectively located in the reflective cups 120. The light deflecting element 140 is located on the reflective cups 120, so the light-emitting diodes 130 can be covered by the light deflecting element 140. Figure 1 Although the diagram shows nine light-emitting diodes 130 and nine reflectors 120 arranged in a 3×3 matrix, this is not a limitation of the present application; other array arrangements are also possible. The component configuration of the light-emitting device 100 will be described in detail below.

[0053] Figure 3 It shows Figure 1 A perspective view of the light-emitting device 100 below the LCD panel 210. See also... Figure 2 and Figure 3 The light deflecting element 140 includes a plurality of Fresnel lenses 141, which are respectively covering the reflector cup 120. In some embodiments, the reflector cup 120, the light-emitting diodes 130 located in the reflector cup 120, and the Fresnel lenses 141 covering the reflector cup 120 can be arranged in a two-dimensional array, such as a checkerboard arrangement with multiple rows and columns.

[0054] In some embodiments, the reflector cup 120 is a rectangular compound parabolic concentrator. Furthermore, the light-emitting diodes 130 may be located at the focal points of the plurality of reflector cups 120 to improve light utilization.

[0055] Figure 4 It shows Figure 2A partially enlarged view of the reflector cup 120, the light-emitting diode 130, and the light-deflecting element 140 is shown, wherein the light-emitting diode 130 emits light L. The light-emitting diode 130 is located in the reflector cup 120, and a Fresnel lens 141 covers the reflector cup 120. The Fresnel lens 141 has a focal length F, and there is a translational distance X between the optical axis O of the Fresnel lens 141 and the center line C of the light-emitting diode 130. In some embodiments, the focal length F is between 2 mm and 4 mm (e.g., 2.6 mm), and the translational distance X is between 0.15 mm and 1.5 mm (e.g., 0.6 mm). The light L is emitted by the light-emitting diode 130 located at the focal point of the reflector cup 120, and thus, after being reflected by the cup wall of the reflector cup 120, forms a light ray L1 that travels in a first direction, which is perpendicular to the light-deflecting element 140 and points upward.

[0056] After light ray L1 passes through the Fresnel lens 141 of the light deflection element 140, it is refracted by the Fresnel lens 141 to form light ray L2 that travels in the second direction. The second direction forms an angle θ with the first direction, and the angle θ satisfies the following:

[0057] θ = tan -1 (X / F);

[0058] In other words, the angle θ is equal to the arctangent function of the ratio of the translation distance X between the optical axis of the Fresnel lens 141 and the center line of the light-emitting diode 130 to the focal length F of the Fresnel lens 141. In some embodiments, the angle θ is between 5 degrees and 25 degrees (e.g., 13 degrees).

[0059] Figure 5 It shows Figure 2 A schematic diagram of the optical path when the light-emitting diode 130 of the display device 200 emits light L. The light L emitted by the light-emitting diode 130 of the light-emitting device 100 is reflected and collected by the reflector cup 120 to form light L1. Then, the light L1 is refracted into light L2 by the Fresnel lens 141 of the light deflection element 140, so that the light L2 can obliquely illuminate the liquid crystal panel 210. The reflector cup 120, the light-emitting diode 130 and having the aforementioned translation distance X (see...) form a two-dimensional array. Figure 4 The Fresnel lens 141 of the light-emitting device 100 enables the light-emitting device 100 to fully illuminate the entire liquid crystal panel 210, and is used as the light source (i.e., backlight module) of the display device 200.

[0060] See also Figure 4 and Figure 5Specifically, because the optical axis O of the Fresnel lens 141 of the light-emitting device 100's light-deflecting element 140 is shifted from the center line C of the light-emitting diode 130, the illumination light emitted by the light-emitting diode 130 can be deflected by the light-deflecting element 140 (i.e., light L1 is refracted into light L2), so that light L2 illuminates the liquid crystal panel 210 at an angle, without the need for the light-emitting device to be tilted. In this way, the size of the display device 200 can be reduced, which is beneficial for thinner design.

[0061] In this embodiment, the light-emitting device 100 may further include at least one optical film 150. The optical film 150 is located on the surface of the light deflecting element 140 facing away from the reflector cup 120 and the light-emitting diode 130, and the liquid crystal panel 210 is located on the optical film 150, that is, the optical film 150 is located between the light deflecting element 140 and the liquid crystal panel 210. In some embodiments, the optical film 150 may be a diffuser plate, diffuser sheet, diffuser film, brightness enhancement film, double-layer brightness enhancement film, privacy screen, or a combination thereof, but this is not intended to limit the present application. The optical film 150 can enhance the light transmission efficiency in the display device 200, improve the light emission efficiency, and the optical film 150 with corresponding functions can be provided according to the design needs of the display device 200.

[0062] Furthermore, the light-emitting device 100 may also include a controller 160. The controller 160 is electrically connected to the light-emitting diodes 130 via the substrate 110. The controller 160 can independently dim, turn on, or turn off each light-emitting diode 130. Since the light-emitting device 100 uses the light-emitting diodes 130 as its light source, and these light-emitting diodes 130 can individually adjust their on / off state and brightness, such a light-emitting device 100, when used in a P-HUD display device (such as display device 200), can also have a local dimming function.

[0063] Figure 6 It shows Figure 5 A schematic diagram of a display device 200 applied to a vehicle 300. A light-emitting device 100 serves as an oblique illumination source for the display device 200, and the display device 200 can be mounted below the windshield 320 of the vehicle 300. In some embodiments, the display device 200 is disposed on the upper trim panel 310 of the vehicle, and because the light-emitting device 100 in the display device 200 provides oblique illumination L4 (i.e., Figure 5The light beam L2, after illuminating the liquid crystal panel 210, produces light beam L4. The display device 200 can obliquely project the light beam L4 of the image onto the windshield 320. In this way, the image light beam L4 emitted by the display device 200 is reflected through the windshield 320 to the viewer's eyes, and a virtual image 400 is formed in front of the vehicle 300, allowing the viewer to see the image at the lower edge of the windshield 320. Since the light-emitting device 100, which serves as the backlight module in the display device 200, uses a light deflecting element 140 to deflect the illumination light, the light-emitting device 100 and the liquid crystal panel 210 can be arranged parallel to each other (e.g., Figure 5 As shown in the figure, compared with the traditional tilted backlight module design, it is smaller in size and more conducive to thinner design.

[0064] In some embodiments, the light-emitting device 100, through the controller 160, allows the light-emitting diodes 130 forming a two-dimensional array to have different switching states and brightness, thereby enabling the light-emitting device 100, the illumination source of the display device 200, to have different brightness in different areas, making it suitable for application in the field of P-HUD display devices.

[0065] The foregoing outlines features of several embodiments to enable those skilled in the art to better understand various aspects of this application. Those skilled in the art will understand that this application can be readily used as a basis for designing or modifying other methods and structures for achieving the same purposes and / or obtaining the same advantages of the embodiments introduced herein. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of this application, and that various changes, substitutions, and modifications can be made herein without departing from the spirit and scope of this application.

Claims

1. A light-emitting device, characterized in that, include: substrate; Multiple reflective cups are located on the substrate; Multiple light-emitting diodes are located on the substrate and are respectively located within the multiple reflective cups; as well as A light deflecting element is located on the plurality of reflective cups. The light deflecting element has multiple Fresnel lenses, each covering one of the plurality of light-emitting diodes (LEDs). Multiple incident rays emitted from each LED are reflected by the reflective cups to form multiple reflected rays. Each of these reflected rays is perpendicular to the light deflecting element, and the optical axes of the multiple Fresnel lenses are respectively shifted by a distance from the centerline of the multiple LEDs, and meet the following conditions: θ=time -1 (X / F); Wherein, θ is the deflection angle of each of the plurality of reflected rays as it passes through one of the plurality of Fresnel lenses, X is the translation distance, and F is the focal length of each of the plurality of Fresnel lenses.

2. The light-emitting device as described in claim 1, characterized in that, The plurality of light-emitting diodes and the plurality of reflective cups are arranged in a two-dimensional array.

3. The light-emitting device as described in claim 1, characterized in that, The light-emitting device further includes: A controller, electrically connected to the plurality of light-emitting diodes, is configured to independently dim, turn on, or turn off each of the plurality of light-emitting diodes.

4. The light-emitting device as described in claim 1, characterized in that, The light-emitting device further includes: At least one optical film is located on the surface of the light deflecting element opposite to the plurality of light-emitting diodes.

5. The light-emitting device as described in claim 4, characterized in that, The optical film is a diffuser plate, diffuser sheet, diffuser film, brightness enhancement film, double-layer brightness enhancement film, or privacy screen.

6. The light-emitting device as claimed in claim 1, characterized in that, The multiple reflector cups are rectangular composite parabolic light collectors.

7. A display device, characterized in that, The display device includes: Light-emitting device, the light-emitting device comprising: substrate; Multiple reflective cups are located on the substrate; Multiple light-emitting diodes are located on the substrate and respectively within the multiple reflective cups; and A light deflecting element is located on the plurality of reflective cups. The light deflecting element has multiple Fresnel lenses, each covering one of the plurality of light-emitting diodes (LEDs). Multiple incident rays emitted by each LED are reflected by the reflective cups to form multiple reflected rays. Each of these reflected rays is perpendicular to the light deflecting element, and the optical axes of the multiple Fresnel lenses are respectively shifted by a distance from the centerline of the multiple LEDs, and satisfy the following conditions: θ=time -1 (X / F); Where θ is the deflection angle of each of the plurality of reflected rays as it passes through one of the plurality of Fresnel lenses, X is the translation distance, and F is the focal length of the plurality of Fresnel lenses; and The liquid crystal panel is located above the light deflecting element of the light-emitting device.

8. The display device as claimed in claim 7, characterized in that, The light-emitting device further includes: At least one optical film is located between the liquid crystal panel and the light deflecting element, and the optical film is a diffuser plate, diffuser sheet, diffuser film, brightness enhancement film, double-layer brightness enhancement film or privacy screen.

9. The display device as claimed in claim 7, characterized in that, The liquid crystal panel is parallel to the light-emitting device.

10. The display device as claimed in claim 7, characterized in that, The light-emitting device further includes: A controller, electrically connected to the plurality of light-emitting diodes, is configured to independently dim, turn on, or turn off each of the plurality of light-emitting diodes.

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