Backlit display device with cone-cup array

Abstract

The invention relates to a backlit display device with a cone-cup array, comprising a light source array (1) consisting of a plurality of light sources (11), a cone-cup array (2) consisting of a plurality of cone cups (21), a diffuser (3), a display module (4) for displaying an image, and an imaging concave mirror (5), wherein the components (1, 2, 3, 4, 5) are arranged sequentially along a light path. The cone cups (21) are inclined at different angles, each corresponding to a light source (11) and thus determining the light emission angle of the light source (11). The light from the light sources (11) passes through the diffuser (3) and then forms a backlight (L). The display module (4) and the backlight (L) are located, respectively, inside and outside the focal length of the imaging concave mirror (5).The backlight (L) illuminates an image light (D) generated from the image, which is projected by the imaging concave mirror (5) onto a single eyebox (E). Each light source (11) illuminates only a portion of the display module (4). The normal (F) of the respective cone cup (21) extends along its light path and then intersects the center of the individual eyebox (E).

Description

Technical area

[0001] The invention relates to a display device equipped with a backlight, in particular to a display device equipped with a backlight and having a conical cup array. State of the art

[0002] In the imaging process of a backlit display device, pixels of a display module are illuminated by a light source module behind the display module (e.g., a TFT panel) so that an image light is projected forward and reaches the viewer's field of vision. The backlight provided by the light source module largely determines the quality of the image light. Therefore, several optical elements are typically arranged between the light from the light source module and the display module to generate uniform light or adjust the light intensity. Object of the invention

[0003] The invention is based on the object of creating a display device with a conical cup array and equipped with a backlight. Technical solution

[0004] This object is achieved according to the invention by a display device equipped with a backlight and having a conical cup array with the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0005] The invention provides a backlit cone-cup array display device. The display device comprises a light source array, a cone-cup array, a diffuser, and a display module. The light source array consists of a plurality of light sources that project light. The cone-cup array consists of a plurality of cone cups. Each cone cup tilts at a different angle and is arranged on a light-exit side of the light source array, wherein each cone cup corresponds to a respective light source and determines the light-exit angle of the corresponding light source. The diffuser is arranged on a light-exit side of the cone-cup array to increase light uniformity and provide backlighting. The display module is used to display an image and is arranged on a light-exit side of the diffuser to receive the backlighting.The backlight illuminates the image to create an image light. An imaging concave mirror is arranged on a light-exit side of the display module, with the display module and the backlight respectively located inside and outside the focal length of the imaging concave mirror. The imaging concave mirror creates a virtual image from the image and a real image from the backlight, i.e., a single eyebox. The light sources are designed such that each light source only illuminates part of the display module. When all light sources are illuminated simultaneously, the display module is fully illuminated. The normal of the respective conical cup extends along its light path and then crosses the center of the individual eyebox.

[0006] Preferably, the conical cup is a hollow cup with a reflective coating on its surface. Alternatively, the conical cup is a cup-shaped, transparent, and solid light guide.

[0007] Preferably, each conical cup is rectangular and conical, in particular rectangular in cross-section and tapered in the longitudinal direction, with the cup edges of the light exit openings of two adjacent conical cups adjacent to one another. The light exit openings of the conical cups are aligned with one another and located on the same plane, thus forming a horizontal light source.

[0008] The display module is preferably a TFT (thin-film transistor) panel.

[0009] Preferably, the diffuser is flat and plate-shaped.

[0010] Preferably, a light entry side of the diffusion disc is arranged at a distance from the light exit side of the conical cups.

[0011] Preferably, a convex lens array is further provided between the light exit side of the diffuser and the light entrance side of the display module to collect the light of the backlight and then project it onto the display module.

[0012] Preferably, the imaging concave mirror and a windshield are provided between the display module and the light path of the individual eyebox, with the imaging concave mirror reflecting the image light projected by the display module onto the windshield. The windshield then reflects the image light onto the individual eyebox.

[0013] Preferably, the display module is arranged within the focal length of the imaging concave mirror, wherein the equivalent distance of the light source array is greater than the focal length of the imaging concave mirror. The light source array generates a real image located within the windshield.

[0014] Preferably, the light source array is an LED array. Short description of the drawings Fig. 1 shows a schematic representation of conical cups according to a first embodiment of a display device according to the invention. Fig. 2 shows a schematic representation of a structure and a light path of the display device according to the invention from Fig. 1. Fig. 3 shows a schematic representation of a structure and a light path of a head-up display device according to the invention. Fig. 4 shows a schematic representation of a second embodiment of the display device according to the invention. Detailed description of preferred embodiments

[0015] Objects, features, and advantages of the present invention will be explained in more detail below with reference to the detailed description of exemplary embodiments and the accompanying drawings. However, the invention is not limited to the description of these exemplary embodiments and their illustration in the accompanying drawings.

[0016] In Fig. 1 to Fig. Figure 3 illustrates a first embodiment of a backlit cone-cup array display device according to the invention. The display device comprises a light source array 1, a cone-cup array 2, a diffuser 3, a display module 4, and an imaging concave mirror 5.

[0017] The light source array 1 consists of a plurality of light sources 11. For example, the light source array 1 is an LED array attached to an aluminum carrier plate 0. The light source array 1 serves to provide backlighting.

[0018] The conical cup array 2 consists of a plurality of conical cups 21. Each conical cup 21 is tilted at a different angle, with a light entrance side 25 and a light exit side 26 defined on the conical cup 21. Each light source (LED, light-emitting diode) 11 corresponds to a conical cup 21 and is arranged on the light entrance side 25 of the corresponding conical cup 21. The conical cup 21 can be a hollow cup with a highly reflective coating or a cup-shaped, transparent, and solid light guide. When the light inside the conical cup 21 is projected onto the cup wall, it is completely reflected by the cup wall. The conical cup array 2 is arranged on the light exit side 26 of the light source array 1. The point LED light in the conical cup 21 is reflected and then projected onto the light exit side 26.Each conical cup 21 corresponds to a light source 11 and is intended to determine the light exit angle of the light source 11.

[0019] In the embodiment from Fig. 1, each conical cup 21 of the conical cup array 2 is rectangular and conical and has a rectangular light entry side (light entry opening) 25 and a rectangular light entry side (light exit opening) 26, wherein the cup edges of the light exit openings of two adjacent conical cups are adjacent to one another.

[0020] The diffuser 3 has a light entrance side 31 and a light exit side 32, with the light entrance side 31 directed toward the light exit side 26 of the conical cup 21 to increase the light uniformity of the backlight. A gap exists between the light entrance side 31 of the diffuser 3 and the light exit side 26 of the conical cup 21. This means that the diffuser 3 does not completely adhere to the light exit side 26 of the conical cup 21. This prevents a black shadow that occurs in the boundary area between two conical cups 21 from being projected forward.

[0021] The display module 4 is a TFT panel that displays an image. The display module 4 has a light entrance side 41 and a light exit side 42, with the light entrance side 41 of the display module 4 directed toward the light exit side 32 of the diffuser 3 to obtain the backlight and thereby emit an image light D.

[0022] The imaging concave mirror 5 is arranged on the light exit side 42 of the display module 4 such that it is located within the focal length of the imaging concave mirror 5 to generate a virtual image I. The backlight is located outside the focal length of the imaging concave mirror 5. This allows the light of the backlight to be reflected by the imaging concave mirror 5 and then generated into a real image of the backlight, ie, a single eyebox.

[0023] Fig. Figure 2 schematically shows the application of a backlight module in a display device. The conical cup array 2 consists of a plurality of conical cups 21 that are tilted at different angles. The light exit openings of the conical cups 21 are aligned with one another and located on the same plane, so that all light exit sides 26 together provide a horizontal light source. The light exit sides 26 of the conical cups 21, the diffuser 3, and the light entry side 41 of the display module 4 are spaced apart and arranged parallel to one another. The normal F of the respective conical cup 21 extends along the respective light path and then crosses the center of the individual eyebox E. Each light source 11 radiates only a portion of the display module 4. The entire display module 4 can only be fully illuminated when all light sources 11 of the light source array 1 emit light simultaneously. Fig. 2, in particular the imaging concave mirror 5 is omitted.

[0024] In the first embodiment, an LED array is used as the backlight. Each LED is located on the light entrance side 25 of the conical cup. The light exit side 26 of the conical cup forms a light-emitting surface. The light penetrates the diffuser 3 and radiates directly onto the TFT panel, so that the image light D (see Fig. 3). Except for the diffuser 3, there are no optical elements (e.g., multiple reflectors, an imaging concave mirror, or convex lenses) between the light exit side 26 of the conical cup and the light entry side 41 of the display module 4 that are intended to form a folded light path, to converge, or to generate a real image.

[0025] In Fig. Figure 3 illustrates the light path of a backlight used in a head-up display device. In this embodiment, a windshield 6 is further provided. The imaging concave mirror 5 reflects the image light D projected by the display module 4 onto the windshield 6. The windshield 6 then reflects the image light D, so that an image is provided in a driver's eyebox E. The display module 4 is arranged within the focal length of the imaging concave mirror 5, with the equivalent distance of the light source array 1 being greater than the focal length of the imaging concave mirror 5. The display module 4 generates a virtual image I located outside the windshield 6. The light source array 1 generates a real image eyebox E located inside the windshield 6.

[0026] Reference is made to Fig.4. While the diffuser 3 increases the light uniformity of the backlight L, the divergence angle is correspondingly increased. For this reason, the display device is further provided with a convex lens array 7. The diffuser 3 is flat and plate-shaped. The convex lens array 7 is arranged on the light exit side 32 of the diffuser 3 and serves to reduce the divergence angle of the horizontal light source spread by the diffuser 3 and to adjust the divergence angle to a desired angle. The backlight is then projected onto the rear side (the light entry side 41) of the display module 4.

[0027] In the second embodiment, the convex lens array 7 consists of a plurality of convex lenses. Each convex lens has a light entrance side 71 that is directed toward the light exit opening of the respective conical cup 21 and covers this light exit opening.

[0028] Although the present invention has been described in detail using exemplary embodiments, it will be understood by those skilled in the art that the invention is not limited to these exemplary embodiments. Rather, modifications are possible such that individual features can be omitted or other combinations of features can be implemented, as long as the scope of the appended claims is not exceeded. The disclosure of the present invention includes all combinations of the individual features presented. List of reference symbols 0 aluminum carrier plate 1 light source array 11 light sources 2 cone cup array 21 reflective cone cup 25 Light entry side 26 Light exit side 3 Diffuser 31 Light entry side 32 Light exit side 4 Display module 41 Light entry side 5 imaging concave mirror 6 Windshield 7 Convex lens array 71 Light entry side D Image light E Eyebox F Normal L Backlight I virtual image

Claims

[1] A backlit cone-cup array display device comprising - a light source array (1) consisting of a plurality of light sources (11) that project light; - a conical cup array (2) consisting of a plurality of conical cups (21), each conical cup (21) being inclined at a different angle and being arranged on a light exit side of the light source array (1), each conical cup (21) corresponding to a respective light source (11) and determining the light exit angle of the corresponding light source (11), a light entry side (25) and a light exit side (26) being defined on the conical cup (21); - a diffuser (3) arranged on a light exit side of the conical cup array (2) to increase the light uniformity and to form a backlight (L), the diffuser (3) having a light entrance side (31) and a light exit side (32); and - a display module (4) for displaying an image and arranged on the light exit side (32) of the diffuser (3) to receive the backlight (L), the backlight (L) illuminating the image to generate an image light (D), the display module (4) having a light entry side (41) and a light exit side (42), characterized by , - an imaging concave mirror (5) is arranged on the light exit side of the display module (4), wherein the display module (4) is located within the focal length of the imaging concave mirror (5), wherein a virtual image (I) is generated from the image with the imaging concave mirror (5), wherein the background illumination (L) is located outside the focal length of the imaging concave mirror (5), wherein a real image of the background illumination (L), ie a single eyebox (E), is generated with the imaging concave mirror (5); that the light sources (11) are constructed in such a way that each light source (11) illuminates only a part of the display module (4), whereby when all light sources (11) are illuminated simultaneously, the display module (4) is completely illuminated; and that the normal (F) of the respective conical cup (21) extends along the respective light path and then crosses the center of the individual eyebox (E). [2] Display device according to claim 1, characterized by , that the conical cup (21) is a hollow cup whose surface is provided with a reflective coating, or is a cup-shaped, transparent and solid light guide. [3] Display device according to claim 1, characterized by that each conical cup (21) is rectangular and conical, the cup edges of the light exit openings of two adjacent conical cups (21) being adjacent to one another, the light exit openings of the conical cups (21) being aligned with one another and being located on one and the same plane, thereby forming a horizontal light source. [4] Display device according to claim 1, characterized by that the display module (4) is a TFT panel. [5] Display device according to claim 1, characterized by that the diffuser (3) is flat and plate-shaped. [6] Display device according to claim 1, characterized bythat the light entry side (31) of the diffuser (3) is arranged at a distance from the light exit side (26) of the conical cup (21). [7] Display device according to claim 1, characterized by that a convex lens array (7) is further provided between the light exit side (32) of the diffuser (3) and the light entry side (41) of the display module (4) in order to collect the light of the backlight (L) and then project it onto the display module (4). [8] Display device according to claim 1, characterized by that a windshield (6) is further provided between the display module (4) and the light path of the individual eyebox (E), wherein the imaging concave mirror (5) reflects the image light (D) projected by the display module (4) onto the windshield (6) and the windshield (6) reflects the image light (D) onto the individual eyebox (E). [9] Display device according to claim 8, characterized bythat the display module (4) is arranged within the focal length of the imaging concave mirror (5), wherein the equivalent distance of the light source array (1) is greater than the focal length of the imaging concave mirror (5), wherein the light source array (1) produces a real image which is located within the windshield (6). [10] Display device according to claim 1, characterized by that the light source array (1) is an LED array.

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