Display device

Abstract

Display device with: a conductive housing that is electrically connected to a ground; one or more optical elements housed within the casing; a conductive frame that sandwiches the optical element with the housing, with part of the frame being in direct or indirect contact with the housing; a liquid crystal section arranged along a surface of the frame; and a control circuit which is connected to and designed to control the liquid crystal section, wherein the frame and the control circuit are separate.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a display device. TECHNICAL BACKGROUND

[0002] Patent literature 1 discloses a liquid crystal device comprising a liquid crystal display field, a first support element, and a shielding element. The liquid crystal display field has an installation area for installing a driver IC, which is an example of an electronic component. The first support element is conductive, accommodates the liquid crystal display field, and is electrically connected to a reference potential V. GNDe.g., 0 V, connected. The shielding element comprises an insulating layer and a conductive layer. The driver IC is attached through the insulating layer of the shielding element via an adhesive or similar material, and the conductive layer is electrically connected to the first carrier element. Accordingly, noise generated by the driver IC or similar, or from external sources, is conducted to the first carrier element via the shielding element and finally to the reference potential V. GND derived. QUOTE LIST PATENT LITERATURE

[0003] Patent Literature 1: JP2010-072272A SUMMARY OF THE INVENTIONAL PROBLEM

[0004] Providing a shielding element that blocks electromagnetic noise can be difficult due to structural limitations, manufacturing process constraints, and the like. In such cases, it is necessary to prevent electromagnetic noise leakage through a method different from providing a shielding element.

[0005] One objective of the present disclosure is to prevent the emission of electromagnetic noise in a display device. SOLUTION TO THE PROBLEM

[0006] A display device according to one aspect of the present disclosure comprises: a conductive housing electrically connected to a ground; one or more optical elements housed in the housing; a conductive frame sandwiching the optical element with the housing, wherein part of the frame is in direct or indirect contact with the housing; a liquid crystal section arranged along a surface of the frame; and a control circuit connected to the liquid crystal section and configured to control the liquid crystal section, wherein the frame and the control circuit are separate. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0007] According to the present disclosure, the emission of electromagnetic noise in a display device can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view showing a configuration example of a display device according to one embodiment. Fig. Figure 2 is a perspective exploded view showing the configuration example of the display device according to the present embodiment. Fig. Figure 3 is a cross-sectional view of the display device in Fig. 1 along a line A-A'. Fig. Figure 4 is a cross-sectional view of the display device in Fig. 1 along a line B-B'. Fig. Figure 5 shows EMI noise from the display device according to the present embodiment. DESCRIPTION OF THE EXECUTION FORMS

[0008] An embodiment of the present disclosure is described in detail below with reference to the drawings. An overly detailed description can be omitted. For example, a detailed description of already known facts and a redundant description of essentially identical embodiments can be omitted. This serves to avoid redundancy in the following description and to facilitate understanding by persons skilled in the art. The accompanying drawings and the following description are intended to provide persons skilled in the art with a sufficient understanding of the present disclosure and are not meant to limit the subject matter described in the claims. (Present embodiment)<Konfiguration der Anzeigevorrichtung>

[0009] Fig. Figure 1 is a perspective view showing a configuration example of a display device 1 according to an embodiment. Fig. Figure 2 is a perspective exploded view showing the configuration example of the display device 1 according to the present embodiment. Fig. Figure 3 is a cross-sectional view of the display device 1 in Fig. 1 along a line A-A'. Fig. Figure 4 is a cross-sectional view of the display device 1 in Fig. 1 along a line B-B'. The sizes and positions of the elements forming the display device 1 shown in the drawings are examples, and the sizes and positions of the elements forming the display device 1 according to the present embodiment are not limited to those shown in the drawings.

[0010] The display device 1 according to the present embodiment is a device for displaying an image and is mounted in a vehicle, for example as one of the devices that form an in-vehicle infotainment system (IVI system). As in Fig. As shown in Figure 1, the display device 1 has a flat rectangular parallelepiped shape and includes a screen 2 that can display an image on a main surface.

[0011] To simplify the description, in the present embodiment, as in Fig. Figure 1 shows that the longitudinal direction of the screen 2 of the display device 1 is defined as the X-axis, the transverse direction of the screen 2 as the Z-axis, and a direction perpendicular to the screen 2 as the Y-axis. For the sake of simplicity, a positive direction of the Z-axis can be referred to as "top," a negative direction of the Z-axis as "bottom," a positive direction of the X-axis as "left," a negative direction of the X-axis as "right," a positive direction of the Y-axis as "front," and a negative direction of the Y-axis as "back." For the sake of simplicity, a surface on a positive side of the Y-axis in a ZX-plane can be referred to as the front surface, and a surface on a negative side of the Y-axis in the ZX-plane can be referred to as the back surface.Expressions relating to these directions are used for the sake of simplicity and are not intended to restrict the structure's actual use. For example, the display device 1 can be used in a position where the longitudinal direction of the screen 2 is vertical and the transverse direction of the screen 2 is horizontal (i.e., in a vertical orientation).

[0012] As in Fig. 2, Fig. 3 and Fig. As shown in Figure 4, the display device 1 comprises a housing 11, a light-emitting unit 14, a reflective film 15, a light guide plate 16, a diffusion film 17, a prism film 18, a brightness enhancement film 19, a front frame 20, a first double-sided adhesive tape 21, a damper 22, a first polarizing plate 31, a liquid crystal section 32, a second polarizing plate 33, a drive circuit 34, a flexible substrate 35, a printing board 36, a binding section 37, a cover glass 38 and a second double-sided adhesive tape 39.

[0013] The housing 11 comprises a rectangular main surface 12 and walls 13a, 13b, 13c, and 13d extending forward (in the positive direction of the Y-axis) from four sides of the main surface 12. The housing 11 includes a conductive element (e.g., a metal element). An example of the metal element enclosed in the housing 11 is a magnesium alloy. The housing 11 is electrically connected to a ground 50, which has a reference potential (0 V). The housing 11 can be replaced by a rear frame or a die-cast part.

[0014] As in Fig. As shown in Figure 2, the light-emitting unit 14 has a narrow, elongated shape extending in a left-right direction and is, as in Fig. 3 or Fig. Figure 4 shows the light emitting unit 14, which is located on the lower wall 13a of the housing 11 and emits light upwards. The light emitting unit 14 is, for example, a light-emitting diode (LED).

[0015] The reflective foil 15 is a thin rectangular foil and is arranged along a front surface of the main surface 12 of the housing 11 (e.g., in close contact with the front surface of the main surface 12 of the housing 11). The reflective foil 15 reflects light emitted by the light-emitting unit 14 and light exiting from the light guide plate 16 to the rear.

[0016] The light guide plate 16 is a thin rectangular plate and is arranged along a front surface of the reflection plate 15 (e.g., in close contact with the front surface of the reflection plate 15). The light guide plate 16 scatters light received from the light-emitting unit 14 over its entire surface. Accordingly, the entire surface of the light guide plate 16 emits light.

[0017] The diffusion film 17 is a thin rectangular film and is arranged along a front surface of the light guide plate 16 (e.g., in close contact with the front surface of the light guide plate 16). The diffusion film 17 scatters light emitted by the light guide plate 16 and ensures a uniform luminance.

[0018] The prism foil 18 is a thin rectangular foil and is arranged along a front surface of the diffusion plate 17 (e.g., in close contact with the front surface of the diffusion plate 17). The prism foil 18 improves the luminance of light emitted by the diffusion plate 17.

[0019] The brightness-enhancing film 19 is a thin rectangular film and is arranged along a front surface of the prism foil 18 (e.g., in close contact with the front surface of the prism foil 18). The brightness-enhancing film 19 increases the brightness of light emitted by the prism foil 18.

[0020] As in Fig. As shown in Figure 2, the front frame 20 has a rectangular frame shape (i.e., a shape with only a square frame and no central part) and surrounds the brightness-enhancing film 19, the prism foil 18, the diffusion plate 17, the light guide plate 16, and the reflective foil 15 in a sandwich-like manner with the main surface 12 of the housing 11. At least one of the elements, namely the brightness-enhancing film 19, the prism foil 18, the diffusion plate 17, the light guide plate 16, and the reflective foil 15, which are arranged between the front frame 20 and the main surface 12 of the housing 11, can be called an optical element. The front frame 20 includes a conductive element (e.g., a metal element). An example of the metal element included in the front frame 20 is stainless steel (SUS).

[0021] As in Fig. 3 or Fig. As shown in Figure 4, the front frame 20 has an end section near its outer circumference that is bound to the walls 13a, 13b, 13c, and 13d of the housing 11 by the first double-sided adhesive tape 21, which is an example of a binding element. The end section of the front frame 20 near the outer circumference can be a part outside the main surface 12 of the housing 11 (i.e., a part facing the walls 13a, 13b, 13c, and 13d). The first double-sided adhesive tape 21 includes a conductive element.

[0022] An element in which the housing 11, the light-emitting unit 14, the reflective film 15, the light guide plate 16, the diffusion film 17, the prism film 18, the brightness enhancement film 19, the front frame 20 and the first double-sided adhesive tape 21 are assembled can be referred to as a backlight module 10.

[0023] The damper 22 is an example of an elastic body, has a rectangular frame shape (i.e., a shape with only a square frame and no middle section), and is arranged on a front surface of the front frame 20. The damper 22 can be arranged on the entire front surface of the front frame 20. The damper 22 can include a conductive element. The damper 22 can have a thickness of, for example, 0.5 mm to 1.0 mm.

[0024] The first polarizing plate 31 is a thin rectangular plate and is arranged along a front surface of the brightness-enhancing film 19 (e.g., parallel to the front surface of the brightness-enhancing film 19) and along a front surface of the attenuator 22 (e.g., in close contact with the front surface of the attenuator 22). The first polarizing plate 31 transmits light polarized in a prescribed first direction from the light emitted by the brightness-enhancing film 19 and blocks light polarized in other directions.

[0025] The liquid crystal section 32 is a thin rectangular device and is arranged along a front surface of the first polarizing plate 31 (e.g., in close contact with the front surface of the first polarizing plate 31). The liquid crystal section 32 comprises one liquid crystal molecule for each subpixel and controls the polarization when a light output from the first polarizing plate 31 passes through each subpixel based on voltage control.

[0026] The second polarizing plate 33 is a thin rectangular plate and is arranged along a front surface of the liquid crystal section 32 (e.g., in close contact with the front surface of the liquid crystal section 32). The second polarizing plate 33 transmits light polarized in a second direction orthogonal to the first direction of the light from the light emitted by the liquid crystal section 32 and blocks light polarized in other directions.

[0027] As in Fig. As shown in Figure 3, the driver circuit 34 is located on a lower front surface of the liquid crystal section 32. The driver circuit 34 controls pixels (or subpixels) of the liquid crystal section 32. The driver circuit 34 can control a touch on the screen 2 of the liquid crystal section 32. The driver circuit 34 can be located in a position that overlaps the front frame 20 or the damper 22 when viewed from a direction perpendicular to a surface of the liquid crystal section 32 (i.e., when viewed along the Y-axis). The driver circuit 34 can be a touch display driver integration (TDDI) circuit. Two or more driver circuits 34 can be provided.

[0028] The flexible substrate 35 is connected at one end to the control circuit 34 and extends downwards. The flexible substrate 35 can be replaced by a flexible printed circuit (FPC). Two or more flexible substrates 35 can be provided.

[0029] The flexible substrate 35 is connected at one end to the printboard 36. The printboard 36 is located on the rear side of the housing 11. The printboard 36 can be replaced by a printed circuit board (PCB). Two or more printboards 36 can be provided.

[0030] As in Fig. As shown in Figure 3, the flexible substrate 35 is bent in a U-shape, passes along a lower side of the housing 11 and connects the control circuit 34 to the printing board 36.

[0031] An element in which the first polarizing plate 31, the liquid crystal section 32, the second polarizing plate 33, the control circuit 34, the flexible substrate 35 and the printing board 36 are assembled can be provided as a so-called open cell.

[0032] The bonding section 37 is located along a front surface of the second polarizing plate 33 (e.g., in close contact with the front surface of the second polarizing plate 33). The bonding section 37 can be an optically clear resin (OCR) or an optically clear adhesive (OCA).

[0033] The cover glass 38 is arranged along a front surface of the bonding section 37 (e.g., in close contact with the front surface of the bonding section 37). As shown in the Fig. 2 and Fig. As shown in Figure 4, the cover glass 38 has end sections near its sides which are bound to the walls 13a, 13b, 13c and 13d of the housing 11 by the second double-sided adhesive tape 39, which is an example of a binding element.

[0034] An element in which the first polarizing plate 31, the liquid crystal section 32, the second polarizing plate 33, the control circuit 34, the flexible substrate 35, the printing board 36, the binding section 37, the cover glass 38 and the second double-sided adhesive tape 39 are assembled can be called a liquid crystal module 30.

[0035] This means that the display device 1 is formed by assembling the liquid crystal module 30 with the backlight module 10, with the damper 22 positioned between them. The damper 22 absorbs shocks to the liquid crystal module 30 and prevents foreign objects from penetrating between the backlight module 10 and the liquid crystal module 30. <EMI-Rauschen Gegenmaßnahme>

[0036] Fig. Figure 5 shows the EMI noise of the display device 1 according to the present embodiment.

[0037] As in Fig. As shown in Figure 5, the liquid crystal section 32 comprises an active surface 61 (i.e., the screen 2), which is a surface implemented by a plurality of pixels and capable of displaying an image; gate circuits 62 arranged on the left and right sides of the active surface 61; and a DEMUX circuit 63 located below the active surface 61. The DEMUX circuit 63 can be positioned to overlap the front frame 20 or the damper 22 when viewed from a direction perpendicular to a surface of the liquid crystal section 32 (i.e., when viewed along the Y-axis). The gate circuits 62 control the pixels of the active surface 61 based on a gate control signal. The DEMUX circuit 63 controls the DEMUX of an image displayed on the active surface 61 based on a MUX signal.

[0038] The control circuit 34 is connected to the DEMUX circuit 63 via a signal line 64 and transmits the MUX signal via the signal line 64. The control circuit 34 is connected to the gate circuit 62 via a signal line 65 and transmits the gate control signal via the signal line 65. The control circuit 34 is connected to the print board 36 via the flexible substrate 35 and the signal line 66, the print board 36 is connected to the gate circuit 62 via the flexible substrate 35 and the signal line 66, and the control circuit 34 and / or the print board 36 transmit VGH and / or VGL via the flexible substrate 35 and the signal line 66.

[0039] In the following, a circuit comprising at least one of the drive circuit 34 and the DEMUX circuit 63 is referred to as the control circuit. During the drive operation, the control circuit generates electromagnetic noise (including line noise and radiated noise). Hereinafter, the electromagnetic noise generated by the control circuit is referred to as EMI noise. EMI noise can cause electromagnetic interference with other electronic devices. For example, if the EMI noise escapes from the outside of the display device 1, which is mounted in a vehicle, it can interfere with the radio waves used in the vehicle or affect the behavior of other electronic devices mounted in the vehicle.Examples of devices that handle radio waves used in vehicles include car radios that receive AM and FM waves, car televisions that receive broadcast waves, and wireless communication devices that perform wireless communication such as 4G, 5G, Wi-Fi, or Bluetooth.

[0040] The display device 1 according to the present embodiment prevents the emission of EMI noise. This is described in detail below.

[0041] As described above, the front frame 20, the first double-sided adhesive tape 21, and the housing 11 comprise conductive elements, and the housing 11 is connected to ground 50. Therefore, the front frame 20 has a reference potential (0 V). The front frame 20 and the control circuit (the drive circuit 34 or the DEMUX circuit 63) are separated by a first gap 51A (see Fig. 3) Accordingly, a gap between the front frame 20 and the control circuit acts as a virtual capacitor, creating a capacitance. Therefore, the EMI noise is attracted more strongly to the front frame 20, where the capacitance is created, than to the cover glass 38. This prevents the EMI noise from escaping from the display device 1.

[0042] As described above, the damper 22, which is in contact with the front frame 20, can include a conductive element. In this case, the damper 22 has a reference potential (0 V). The damper 22 and the control circuit (the drive circuit 34 or the DEMUX circuit 63) are separated by a second gap 51B (see Fig.3) The damper 22 is positioned closer to the control circuit than to the front frame 20, and therefore the second distance 51B is shorter than the first distance 51A. Consequently, the space between the damper 22 and the control circuit acts as a virtual capacitor, creating a larger capacitance than in the case of the first distance 51A. Therefore, the EMI noise is more strongly attracted to the damper 22 and is thus more effectively prevented from escaping from the display device 1.

[0043] The control circuit (the control circuit 34 or the DEMUX circuit 63) can be positioned in a location that overlaps the front frame 20 or the damper 22 when viewed from a direction perpendicular to the surface of the liquid crystal section 32 (i.e., when viewed along the Y-axis). Accordingly, the control circuit and the front frame 20 or the damper 22 are positioned facing each other, thus enabling the creation of a larger capacity.

[0044] As described above, according to the display device 1 in the present embodiment, it is possible to prevent electromagnetic noise from escaping from the display device 1 to the outside without providing electromagnetic shielding.

[0045] Although the case in which the display device 1 is a liquid crystal display (LCD) has been described above, the display device 1 can also be an organic electroluminescence diode (OLED). The configuration described above for preventing EMI noise from escaping is also applicable to the OLED display. (Summary of the present embodiment)

[0046] The following techniques are disclosed based on the description of the present embodiment described above. <Technik 1>

[0047] The display device 1 according to the present embodiment comprises: the conductive housing 11, which is electrically connected to ground 50; one or more optical elements (e.g., at least the reflective film 15, the light guide plate 16, the diffusion film 17, the prism film 18, and / or the brightness enhancer film 19) housed in the housing 11; a conductive frame (e.g., the front frame 20) sandwiching the optical element with the housing 11, with part of the frame in direct or indirect contact with the housing 11; the liquid crystal section 32 arranged along a surface of the frame; and a control circuit (e.g., the control circuit 34 or the DEMUX circuit 63) connected to the liquid crystal section 32 and configured to control the liquid crystal section 32, the frame and the control circuit being separate from each other. <Technik 2>

[0048] In the display device 1 according to technology 1, a capacitance is created between the control circuit and the frame.

[0049] According to techniques 1 and 2, the conductive frame is electrically connected to ground 50 via the housing 11, and the frame and the control circuit are isolated. Consequently, a capacitance is created between the frame and the control circuit. Therefore, electromagnetic noise (EMI noise) generated by the control circuit is attracted to the frame and thus prevented from escaping the display device 1. <Technik 3>

[0050] The display device 1 according to Technology 1 or 2 further comprises a conductive elastic body (e.g. the damper 22) which is arranged between the frame and the liquid crystal section 32 and is in contact with the frame, wherein the elastic body and the control circuit are separate. <Technik 4>

[0051] In the display device 1 according to technology 3, a capacitance is created between the control circuit and the elastic body.

[0052] According to techniques 3 and 4, the conductive elastic body is electrically connected to ground 50 via the frame and housing 11, and the elastic body and the control circuit are separated. Consequently, a capacitance is created between the elastic body and the control circuit. Therefore, electromagnetic noise (EMI noise) generated by the control circuit is attracted to the elastic body and can thus be prevented from escaping the display device 1. The separation distance (second distance 51B) between the elastic body and the control circuit is shorter than the separation distance (first distance 51A) between the frame and the control circuit, and thus a greater capacitance is created.Therefore, electromagnetic noise generated by the control circuit is more strongly attracted to the elastic body, and thus the escape of electromagnetic noise to the outside of the display device 1 can be more effectively prevented. <Technik 5>

[0053] The display device 1 according to one of techniques 1 to 4 further comprises a conductive binding element (e.g. the first double-sided adhesive tape 21) which is provided on the part of the frame which is in contact with the housing 11 and which binds the frame to the housing 11.

[0054] Accordingly, the frame is bound to the housing 11 and electrically connected to ground 50 via the conductive binding element and the housing 11. <Technik 6>

[0055] In the display device 1 according to one of techniques 1 to 5, the control circuit is arranged at a position that overlaps the frame, viewed from a direction perpendicular to the surface of the liquid crystal section 32.

[0056] Accordingly, the control circuit and the frame are arranged in positions facing each other, thus enabling a greater capacity to be generated. <Technik 7>

[0057] In the display device 1 according to one of techniques 1 to 6, the control circuit is a touch display driver integration circuit (TDDI) relating to the liquid crystal section 32.

[0058] Accordingly, it is possible to prevent electromagnetic noise generated by the TDDI from escaping the display device 1. <Technik 8>

[0059] In the display device 1 according to one of techniques 1 to 7, the control circuit is the DEMUX circuit 63, which relates to the liquid crystal section 32.

[0060] Accordingly, it is possible to prevent electromagnetic noise generated by the DEMUX circuit 63 from escaping the display device 1. <Technik 9>

[0061] In the display device 1 according to one of techniques 1 to 8, the housing 11 and the frame comprise a metal element.

[0062] Accordingly, the housing 11 and the frame are conductive.

[0063] Although the embodiment described above has been described with reference to the accompanying drawings, the present disclosure is not limited thereto. It is obvious to a person skilled in the art that various modifications, corrections, substitutions, additions, deletions, and equivalents are conceivable within the scope described in the claims, and it is understood that such modifications, corrections, substitutions, additions, deletions, and equivalents also fall within the technical scope of the present disclosure. Components in the embodiment described above can be freely combined within a certain range without departing from the core of the invention.

[0064] The present application is based on a Japanese patent application (JP2023-053888A) filed on March 29, 2023, the contents of which are incorporated herein by reference. COMMERCIAL APPLICABILITY

[0065] The techniques described in this disclosure are useful for preventing the emission of electromagnetic noise. REFERENCE MARK LIST 1 Display device 2 screens 10 Backlight module 11 cases 12 main area 13a, 13b, 13c, 13d Wall 14 light-emitting units 15 reflective foil 16 Light guide plate 17 Diffusion foil 18 prism foil 19 Brightness enhancement film 20 front frame 21 first double-sided adhesive tape 22 dampers 30 Liquid crystal module 31 first polarizing plate 32 Liquid crystal section 33 second polarizing plate 34 Control circuit 35 flexible substrate 36 Print board 37 Binding section 38 Cover glass 39 second double-sided adhesive tape 50 mass 51A first gap 51B second distance 61 active area 62 gate circuit 63 DEMUX circuit 64, 65, 66 Signal line QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2010-072272A

[0003] JP 2023-053888A

[0064]

Claims

[1] Display device with: a conductive housing that is electrically connected to a ground; one or more optical elements housed within the casing; a conductive frame that sandwiches the optical element with the housing, with part of the frame being in direct or indirect contact with the housing; a liquid crystal section arranged along a surface of the frame; and a control circuit which is connected to and designed to control the liquid crystal section, wherein the frame and the control circuit are separate. [2] Display device according to claim 1, wherein a capacitance is generated between the control circuit and the frame. [3] Display device according to claim 1, further comprising a conductive elastic body that is arranged between the frame and the liquid crystal section and is in contact with the frame, wherein The elastic body and the control circuit are separate. [4] Display device according to claim 3, wherein a capacitance is generated between the control circuit and the elastic body. [5] Display device according to any one of claims 1 to 4, further comprising: a conductive binding element provided on the part of the frame that is in contact with the housing, and which binds the frame to the housing. [6] Display device according to claim 1, wherein the control circuit is arranged in a position which overlaps the frame when viewed from a direction perpendicular to a surface of the liquid crystal section. [7] Display device according to claim 1, wherein the control circuit is a touch display driver integration circuit (TDDI) relating to the liquid crystal section. [8] Display device according to claim 1, wherein the control circuit is a DEMUX circuit relating to the liquid crystal section. [9] Display device according to claim 1, wherein the housing and frame comprise a metal element.

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