Display element, display device and vehicle

Abstract

The utility model relates to a display element (11). The utility model further relates to a display device comprising the display element (11) and a vehicle comprising the display device. The display element (11) has a display panel (110) and at least one heat sink (111) for the display panel (110). The at least one heat sink (111) is in contact with the display panel (110) and covers only a partial region (112) of the display surface (113) of the display panel (110).

Description

Technical Field

[0001] The utility model relates to a display element, which comprises a heat sink, a display device comprising the display element and a vehicle / transportation vehicle comprising the display device. Background Art

[0002] A head-up display (also called HUD) is understood to mean a display system in which the observer can maintain his viewing direction as the content to be presented is inserted into his field of vision. Although such systems were initially used mainly in the aviation sector due to their complexity and cost, they are now also used on a large scale in the automotive sector.

[0003] A head-up display generally consists of a picture generating unit (PGU), an optical unit and a reflector unit. The picture generating unit generates an image and uses at least one display element for this purpose. The optical unit directs the image to the reflector unit. The reflector unit is a partially mirror-reflective, light-transmissive piece of glass. As a result, the observer sees what is presented by the picture generating unit as a virtual image and at the same time sees the real world behind the glass. In the automotive field, the windshield is often used as a reflector unit, the curvature of which must be taken into account during the presentation. Due to the interaction between the optical unit and the reflector unit, the virtual image is an enlarged presentation of the image generated by the picture generating unit.

[0004] An important topic in head-up displays is thermal management. In particular, the heat input caused by incident sunlight must be taken into account. Especially the liquid crystal display (LCD) used in head-up displays is a thermally critical component. Current thermal management solutions include optically bonding a transparent heat sink, such as cooling glass, to the LCD.

[0005] In this context, WO 2020 / 166293 A1 describes a head-up display comprising a bisected housing. A display device is arranged on the bottom area of ​​the lower housing portion. The display device comprises a display panel and a backlight. The display panel is tilted relative to the bottom area and has a transparent plate for heat dissipation. At least a portion of the backlight is arranged in a tubular heat-conducting element, which is connected to the display panel and conducts heat to the lower housing portion.

[0006] JP 2013-174855 A describes a head-up display having a heat mirror with a glass substrate, which dissipates heat from incident sunlight to a heat sink.

[0007] However, due to the necessary transparency and bonding quality, the cooling glasses currently used are relatively poor thermal conductors. In addition, the application process (ie bonding) is very complex and expensive. Utility Model Content

[0008] The object of the present invention is to provide an improved solution for thermal management of display elements.

[0009] This object is achieved by a display element having the features described below and by a display device as described below.

[0010] According to a first aspect of the present invention, a display element has:

[0011] - a display panel; and

[0012] - at least one heat sink for the display panel, wherein the at least one heat sink is in contact with the display panel and covers only a partial area of ​​the display face of the display panel.

[0013] In the solution according to the utility model, a partial area of ​​the display surface of the display panel is used for heat dissipation. For this purpose, a material with good thermal conductivity is arranged directly on the top side or bottom side of the display panel, or on both the top side and the bottom side. The specific partial area that can be used for heat dissipation depends on the planned use or installation of the display element. Since the remaining area of ​​the display surface remains free, the optical performance of the image displayed in this remaining area will not be adversely affected. At the same time, the heat dissipation from the display panel can be greatly improved. In addition, the solution according to the utility model is significantly more advantageous than the previous solution based on cooling glass.

[0014] According to one aspect of the utility model, the heat sink is designed as an opaque component. In order to ensure particularly high heat dissipation, preferably a material with high thermal conductivity is used. These materials are usually opaque. Suitable materials are, for example, metal plates or metal films, graphite films or films based on silicone elastomers.

[0015] According to one aspect of the utility model, the heat sink is bonded to the display panel. In this case, the heat sink and the display panel are preferably bonded to each other by means of a thermally conductive adhesive. The bonding leads to further improved heat dissipation. However, at the same time, the bonding can also contribute to the stability of the system. Suitable thermally conductive adhesives are, for example, synthetic resins rich in thermally conductive fillers. The fillers can be, for example, metal fillers, inorganic fillers, ceramic fillers or mineral fillers. Here, a particularly good thermal conductivity coefficient can be achieved with metal fillers, for example with silver or graphite.

[0016] According to one aspect of the utility model, the partial area of ​​the display surface covered by the heat sink is an area of ​​the display panel that is not used for image display. In particular, when the display element is used for a head-up display, it is possible to utilize the fact that most of the display surface of the display panel does not need to be used for image display at all. The image on the display panel of the head-up display is usually a curved surface / curved area generated by pre-distortion of the content to be displayed, which is adapted to the shape and position of the windshield. The image is never displayed outside this curved surface.

[0017] According to one aspect of the utility model, the display panel is a liquid crystal panel. Liquid crystal panels are particularly heat-critical. Excessive temperature rise in the area of ​​the polarization filter may lead to destruction of the polarization filter, because the temperature rise may impair the optical properties of the polarization filter. The solution according to the utility model can ensure that the liquid crystal panel is cooled as quickly as possible.

[0018] According to one aspect of the present invention, a display device uses a display element according to the present invention. Such a display device is particularly advantageous for applications in the automotive field. In these applications, high heat input may occur due to sunlight. Additional heat input may also be caused by the fact that high-performance lighting units are required for sufficient brightness, in which very high power loss densities may occur.

[0019] According to one aspect of the utility model, the heat sink is thermally coupled to the heat sink. In this way, heat dissipation can be ensured even over a relatively long period of time. The heat sink can be, for example, a metal housing of a display device. Further heat dissipation can be actively achieved by forced convection.

[0020] According to one aspect of the present invention, the display device is a head-up display. Due to the specific position of the head-up display just below the vehicle windshield, sunlight causes high heat input to occur. The solution according to the present invention is particularly suitable for keeping this heat input under control and ensuring that the display panel, which is a key component, dissipates heat as quickly as possible.

[0021] The display device according to the utility model is preferably used in a vehicle. The vehicle can be, for example, a motor vehicle, but alternatively can also be an aircraft, a rail vehicle or a ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features of the present invention will become apparent from the following description and appended claims taken in conjunction with the accompanying drawings.

[0023] Figure 1 A head-up display for a motor vehicle according to the prior art is schematically shown;

[0024] Figure 2schematically shows a cross section through a display element according to the present invention;

[0025] Figure 3 Schematically shows an oblique view of a display element according to the utility model;

[0026] Figure 4 schematically shows a display device including a display element according to the present invention; and

[0027] Figure 5 A vehicle using the display device according to the present invention is schematically shown.

[0028] List of reference numerals:

[0029] 1 Display Device

[0030] 2 mirror units

[0031] 20 Windshield

[0032] 21 Folding reflector

[0033] 22 Curved Mirror

[0034] 23 Mounting parts

[0035] 24 Cover

[0036] 3. Observer

[0037] 4 Eye movement range

[0038] 5 Stray light sources

[0039] 6 Heat sink

[0040] 7 Shell

[0041] 8 backlight parts

[0042] 80 Shell

[0043] 81 Reflector

[0044] 82 Cavity

[0045] 83 Light Source

[0046] 84 Circuit Board

[0047] 85 Optical Plate

[0048] 86 membrane stack

[0049] 87 Connecting elements

[0050] 9 Cover glass

[0051] 10 Image generation unit

[0052] 11 Display components

[0053] 110 Display Panel

[0054] 111 Radiator

[0055] 112 Partial area

[0056] 113 Display surface

[0057] 114 Adhesive

[0058] 115 Top side

[0059] 116 bottom side

[0060] 117 Image area

[0061] 12 Optical unit

[0062] 13 Housing

[0063] 30 Transportation

[0064] 31 Sensor system

[0065] 32 Navigation System

[0066] 33 Data Transmission Unit

[0067] 34 Memory

[0068] 35 Network

[0069] SB, SB' beam

[0070] SL Sunlight

[0071] VB virtual image DETAILED DESCRIPTION

[0072] In order to better understand the principle of the utility model, the embodiments of the utility model will be explained in more detail below with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals are used for the same or functionally equivalent elements, and it is not necessary to re-describe each figure. It goes without saying that the utility model is not limited to the embodiments shown, and the described features may also be combined or modified without departing from the scope of protection of the utility model defined in the attached claims.

[0073] Figure 1The schematic diagram of a first head-up display for a motor vehicle according to the prior art is shown. The head-up display has a display device 1, which includes an image generation unit 10 and an optical unit 12. Light SB is emitted from the display element 11 and is reflected by a folding mirror 21 onto a curved mirror 22, which reflects the light in the direction of the mirror unit 2. The mirror unit 2 is shown here as a windshield 20 of a motor vehicle. From there, the light SB' reaches the eyes of the observer 3.

[0074] The observer 3 sees a virtual image VB outside the motor vehicle, above the bonnet or even in front of the motor vehicle. Due to the interaction between the optical unit 12 and the mirror unit 2, the virtual image VB is an enlarged representation of the image displayed by the display element 11. The speed limit, the current vehicle speed, and navigation instructions are symbolically presented here. As long as the eyes of the observer 3 are located within the eyebox 4 represented by the rectangle, all elements of the virtual image VB are visible to the observer 3. If the eyes of the observer 3 are outside the eyebox 4, the virtual image VB is only partially visible to the observer 3 or not visible at all. The larger the eyebox 4, the less restricted the observer is when choosing his sitting position.

[0075] The curvature of the curved reflector 22 is adapted to the curvature of the windshield 20 and ensures that the image distortion is stable over the entire eye range 4. The curved reflector 22 is rotatably mounted by means of a mounting 23. The rotation of the curved reflector 22 allowed in this way makes it possible to shift the eye range 4 and thus adapt the position of the eye range 4 to the position of the observer 3. The folding mirror 21 serves to ensure that the path traveled by the light SB1 between the display element 11 and the curved reflector 22 is long and at the same time ensures that the optical unit 12 is compact. The picture generation unit 10 and the optical unit 12 are separated from the environment by a housing 13 with a transparent cover 24. The optical elements of the optical unit 12 are thus protected, for example from dust in the vehicle interior. In addition, the cover 24 can be used to reliably absorb light reflected via the contact surface of the cover 24 so that the observer is not dazzled. In addition to the sunlight SL, light from some other stray light sources 5 can also reach the display element 11.

[0076] Figure 2A cross section through a display element 11 according to the utility model is schematically shown. The display element 11 includes a display panel 110 and a heat sink 111 for the display panel 110. For good heat dissipation, the heat sink 111 is in contact with the display panel 110. However, in this case, the heat sink only covers a partial area 112 of a display surface 113 of the display panel 110. The partial area 112 is preferably an area of ​​the display panel 110 that is not used for image display. What area can be used specifically depends on the planned application and / or installation of the display element 11. In this embodiment, the heat sink 111 is designed as an opaque component, which is indicated by hatching. However, it goes without saying that the heat sink can also have a certain light transmittance. For example, the heat sink 111 can be implemented as a metal plate or a metal film, a graphite film or a film based on a silicone elastomer. The heat sink 111 and the display panel 110 are bonded to each other by means of an adhesive 114. Preferably, a thermally conductive adhesive 114 is used for this purpose, such as a synthetic resin rich in suitable fillers. The filler can be, for example, a metal filler, an inorganic filler, a ceramic filler or a mineral filler. A particularly good thermal conductivity can be achieved here with a metal filler, for example with silver or graphite. In this embodiment, the heat sink 111 is arranged on the top side 115 of the display panel 110. However, alternatively, the heat sink can also be arranged on the bottom side 116. Likewise, the heat sink 111 can be arranged on both the top side 115 and the bottom side 116.

[0077] Figure 3 An oblique view of a display element 11 according to the present invention is schematically shown. In this example, the display element 11 is a liquid crystal panel for a head-up display. Here, it is possible to utilize the fact that a large part of the display surface of the display panel 110 does not need to be used for image display at all. The image area 117 required for image display on the display panel 110 of the head-up display is usually a curved surface generated by pre-distortion of the content to be displayed, which is adapted to the shape and position of the windshield. Images are never displayed outside this image area 117, so a large partial area 112 of the display surface 113 can be used for heat dissipation through the radiator 111, which is indicated here by arrows.

[0078] Figure 4A display device 1 including a display element 11 according to the utility model is schematically shown. A cross section through the display device 1 is shown. The display device 1 has a housing 7, in which a display element 11 including a display panel 110 and a heat sink 111 and a backlight 8 for backlighting the display panel 110 are located. The housing 7 is enclosed by a cover glass 9. In this example, the backlight 8 is a matrix backlight arranged in another housing 80. The backlight 8 has a reflector 81, which has a plurality of cavities 82. Each light source 83 (typically a light emitting diode) is arranged in these cavities 82. The light source 83 is arranged on a circuit board 84, which can be bonded to the housing 80 of the backlight 8. In the example shown, an optical plate 85 is located between the backlight 8 and the display panel 110, and a film stack 86 is arranged on the optical plate. The film of the optical film stack 86 is intended to scatter, collect or direct the light from the reflector 81 so as to meet the requirements of the solid angle of the backlight 8. Typical films for light orientation are brightness enhancement film (BEF) and light control film (LCF). The optical plate 85 is a transparent plate that ensures the optical distance between the optical film stack 86 and the light source 83. In addition to the heat input caused by the incident sunlight, the light source 83 also causes a considerable heat input, which needs to be offset by heat dissipation. For this purpose, a heat sink 111 arranged on the display panel 110 is thermally coupled to a housing 7 used as a heat sink 6. The cover glass 9, the housing 7, the optical plate 85, and the housing 80 of the backlight 8 are connected to each other by a suitable connecting element 87 (e.g., an adhesive).

[0079] Figure 5 A vehicle 30 using the display device 1 according to the utility model is schematically shown. In this example, the vehicle 30 is a motor vehicle. In this example, the display device 1 can be arranged in the dashboard. Data about the vehicle's surroundings can be acquired by a sensor system 31. The sensor system 31 can particularly include a surrounding environment recognition sensor, such as an ultrasonic sensor, a laser scanner, a radar sensor, a lidar sensor or a camera. The information acquired by the sensor system 31 can be used to generate the content to be displayed by the display device 1. In this example, other components of the motor vehicle are a navigation system 32 and a data transmission unit 33, through which position information can be provided. With the help of the data transmission unit 33, for example, a connection can be established with the background, for example, to receive software updates of components of the motor vehicle. There is a memory 34 to store data. The data exchange between the various components of the motor vehicle is carried out via a network 35.

Claims

1. A display element (11), comprising: - a display panel (110); as well as - at least one heat sink (111) for the display panel (110), wherein the at least one heat sink (111) is in contact with the display panel (110) and covers only a partial area (112) of a display surface (113) of the display panel (110).

2. The display element (11) according to claim 1, characterized in that The at least one heat sink (111) is designed as an opaque component.

3. The display element (11) according to claim 1 or 2, characterized in that The at least one heat sink (111) is bonded to the display panel (110).

4. The display element (11) according to claim 3, characterized in that The at least one heat sink (111) and the display panel (110) are bonded to each other by means of a thermally conductive adhesive (114).

5. The display element (11) according to claim 1 or 2, characterized in that The partial area (112) of the display surface (113) covered by the at least one heat sink (111) is an area of ​​the display panel (110) that is not used for image display.

6. The display element (11) according to claim 1 or 2, characterized in that The display panel (110) is a liquid crystal panel.

7. A display device (1) comprising a display element (11) as claimed in any one of claims 1 to 6.

8. The display device (1) according to claim 7, characterized in that At least one heat sink (111) is thermally coupled to the heat sink (6).

9. The display device (1) according to claim 7 or 8, characterized in that The display device (1) is a head-up display.

10. A vehicle (30) comprising a display device (1) according to any one of claims 7 to 9.

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