Method for forming light shielding film

Abstract

A liquid crystal display device and a method of forming a light blocking film are disclosed. The liquid crystal display device includes a plurality of liquid crystal display panels juxtaposed and a backlight that emits light toward the plurality of liquid crystal display panels. Each of the plurality of liquid crystal display panels includes a light blocking film on a side surface opposite a side surface of an adjacent liquid crystal display panel, the light blocking film blocking light from the backlight.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Japanese Patent Application No. 2023-090744, filed on June 1, 2023, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This application generally relates to liquid crystal display devices and methods for forming light-shielding films. Background Technology

[0004] In related technologies, liquid crystal display devices in which multiple liquid crystal display panels are arranged to configure a screen are known. For example, unexamined Japanese Patent Application Publication No. 2017-009770 describes a liquid crystal display device that includes a first light shield covering a frame region on the front surface side of the joint portion of adjacent liquid crystal display panels, and a light shield plate arranged in the gap formed between adjacent liquid crystal display panels.

[0005] In the liquid crystal display device of unexamined Japanese patent application publication number 2017-009770, light leakage is suppressed by a first light shield covering the frame area and a light shield disposed in the gap. However, in the liquid crystal display device of unexamined Japanese patent application publication number 2017-009770, the spacing between the liquid crystal display panels is not narrow enough because the light shield is disposed between them. Furthermore, an adhesive must be used to bond the liquid crystal display panels and the light shield to each other.

[0006] This disclosure is made in view of the above circumstances, and the object of this disclosure is to provide a liquid crystal display device in which the spacing of the liquid crystal display panels is very narrow and light leakage is suppressed. Summary of the Invention

[0007] The liquid crystal display device for achieving the above-mentioned objectives disclosed herein includes:

[0008] Multiple LCD panels placed side by side; and

[0009] Backlight, which emits light toward the plurality of liquid crystal display panels, wherein

[0010] Each of the plurality of liquid crystal display panels includes a light-shielding film on a side surface opposite to the side surface of its adjacent liquid crystal display panel, the light-shielding film blocking light from the backlight.

[0011] It should be understood that the above general description and the following detailed description are exemplary and explanatory, and are not intended to limit this disclosure.

[0012] According to this disclosure, each liquid crystal display panel includes a light-shielding film on its side surface opposite to the side surface of its adjacent liquid crystal display panel to block light from the backlight. This allows for a narrower spacing between the liquid crystal display panels and suppresses light leakage. Attached Figure Description

[0013] A more complete understanding of this application can be obtained by considering the following detailed description in conjunction with the accompanying drawings, wherein:

[0014] Figure 1 This is a plan view showing a liquid crystal display device according to Embodiment 1;

[0015] Figure 2 yes Figure 1 The cross-sectional view of the liquid crystal display device shown is taken along line AA;

[0016] Figure 3 This is a schematic diagram showing a cross-section of the liquid crystal display panel according to Embodiment 1;

[0017] Figure 4 This is a schematic diagram showing the side surface of the liquid crystal display panel according to Embodiment 1;

[0018] Figure 5 This is a schematic diagram illustrating the light blocked by the light-shielding film according to Example 1;

[0019] Figure 6 This is a schematic diagram illustrating the method for forming the light-shielding film according to Example 1;

[0020] Figure 7 This is a schematic diagram showing a cross-section of the liquid crystal display device according to Embodiment 2;

[0021] Figure 8 This is a schematic diagram showing a cross-section of the liquid crystal display panel and the joint filler according to Embodiment 2;

[0022] Figure 9 This is a schematic diagram showing a cross-section of the liquid crystal display panel and the joint filler according to Embodiment 3;

[0023] Figure 10 This is a schematic diagram illustrating a liquid crystal display panel according to a modified example; and

[0024] Figure 11 This is a schematic diagram showing a cross-section of a liquid crystal display panel and a joint filler according to a modified example. Detailed Implementation

[0025] In the following description, a liquid crystal display device according to various embodiments is described with reference to the accompanying drawings.

[0026] Example 1

[0027] Reference Figures 1 to 6 The liquid crystal display device 10 according to this embodiment is described. In one example, the liquid crystal display device 10 is mounted on a vehicle. In this embodiment and the following embodiments, the liquid crystal display device 10 is mounted on a vehicle as an example for description. The passengers of the vehicle correspond to users (observers).

[0028] like Figure 1 and Figure 2 As shown, the liquid crystal display device 10 is arranged on the opening 510 of the vehicle's dashboard 500. In one example, the dashboard 500 is formed of resin. Note that in this specification, for ease of understanding, the following description is given: wherein... Figure 1 In this context, the vertical direction (rightward direction on the paper) of the liquid crystal display device 10 is referred to as the "+X direction," the horizontal direction (upward direction on the paper) is referred to as the "+Y direction," and the direction perpendicular to the +X and +Y directions (the front direction on the paper, passenger side) is referred to as the "+Z direction." Furthermore, in... Figure 2 The section lines of the shell 230 are omitted.

[0029] The liquid crystal display device 10 includes a display 100 and a protective element 300. The display 100 displays text, images, etc. The protective element 300 protects the liquid crystal display panels 110A and 110B of the display 100 (described later).

[0030] The display 100 of the liquid crystal display device 10 includes two liquid crystal display panels 110A and 110B, a backlight 200, and a housing 230. The liquid crystal display panels 110A and 110B display text, images, etc. The backlight 200 is the light source for the liquid crystal display panels 110A and 110B. The housing 230 houses the liquid crystal display panels 110A and 110B and the backlight 200.

[0031] The liquid crystal display panels 110A and 110B of the display 100 are juxtaposed in the XY plane. In one example, the liquid crystal display panels 110A and 110B are implemented as known transmissive lateral electric field liquid crystal display panels. The liquid crystal display panels 110A and 110B are active matrices driven by thin-film transistors (TFTs). The liquid crystal display panels 110A and 110B modulate light from the backlight 200 to display text, images, etc. In one example, the liquid crystal display panel 110A is used as a center information display (CID). In one example, the liquid crystal display panel 110B is used as an instrument panel display. Alternatively, it is also possible to configure the liquid crystal display panels 110A and 110B as a single CID or an instrument panel display.

[0032] The liquid crystal display panels 110A and 110B include a display area 111 and a periphery 112. The display area 111 is the area in which pixels are arranged in a matrix. The display area 111 can display text, images, etc. The periphery 112 is the area in which wiring, driving circuits, etc. are arranged.

[0033] like Figure 3 As shown, each of the liquid crystal display panels 110A and 110B includes a TFT substrate 122, an opposing substrate 124, a liquid crystal LC, an incident-side polarizing plate 126, and an exit-side polarizing plate 128. Furthermore, as... Figure 2 and Figure 3 As shown, each of the liquid crystal display panels 110A and 110B includes a light-shielding film 150.

[0034] In one example, the TFT substrate 122 is implemented as a glass substrate. The TFT substrate 122 is located on the -Z side. A TFT for selecting pixels, a common electrode, a pixel electrode, a driving circuit, and an alignment film for aligning the liquid crystal LC are disposed on the main surface 122a of the TFT substrate 122 on the liquid crystal LC side (all not shown in the figures). An incident-side polarizer 126 is disposed on the main surface 122b of the TFT substrate 122 on the side opposite to the main surface 122a.

[0035] The opposing substrate 124 is located on the +Z side and is opposite to the TFT substrate 122. The opposing substrate 124 is attached to the TFT substrate 122 by a sealing material 132. In one example, the opposing substrate 124 is implemented as a glass substrate. A color filter (not shown in the figure), a black matrix BM, an alignment film for aligning with the liquid crystal LC are provided on the main surface 124a of the opposing substrate 124 on the side opposite to the main surface 124a. The emission-side polarizer 128 is provided on the main surface 124b of the opposing substrate 124 on the side opposite to the main surface 124a.

[0036] A liquid crystal LC is sandwiched between a TFT substrate 122 and an opposing substrate 124. In one example, the liquid crystal LC is implemented as a positive nematic liquid crystal. Initially, the liquid crystal LC is aligned in a direction parallel to the main surface 122a of the TFT substrate 122 by an alignment film. Furthermore, by applying a voltage, the liquid crystal LC rotates in a plane parallel to the main surface 122a of the TFT substrate 122.

[0037] An incident-side polarizer 126 is disposed on the main surface 122b of the TFT substrate 122. An exit-side polarizer 128 is disposed on the main surface 124b of the opposing substrate 124. One of the transmission axes of the incident-side polarizer 126 and the exit-side polarizer 128 is arranged parallel to the initial alignment direction of the liquid crystal LC. The transmission axes of the incident-side polarizer 126 and the exit-side polarizer 128 are orthogonal to each other. In this embodiment, the main surface 128a of the +Z side of the exit-side polarizer 128 corresponds to the display surface 113 of the liquid crystal display panels 110A and 110B.

[0038] like Figure 2 and Figure 3 As shown, a light-shielding film 150 is disposed on each of the opposing side surfaces 135 of the liquid crystal display panel 110A and the liquid crystal display panel 110B. In this embodiment, the side surface 135 of the liquid crystal display panel 110A is the entire side surface of the liquid crystal display panel 110A. Figure 4 As shown, the side surface 135 includes not only the side surface 122c of the TFT substrate 122, the side surface 124c of the opposing substrate 124, the side surface 126c of the incident-side polarizer 126, the side surface 128c of the exit-side polarizer 128, the side surface 132c of the sealing material 132, and the side surface BMC of the black matrix BM, but also the main surfaces 122a and 122b of the TFT substrate 122 and the main surfaces 124a and 124b of the opposing substrate 124 exposed on the side of the liquid crystal display panel 110A. The side surface 135 of the liquid crystal display panel 110B is the same as that of the liquid crystal display panel 110A. In this embodiment, the light-shielding film 150 covers the entire side surface 135 of both the liquid crystal display panel 110A and the liquid crystal display panel 110B.

[0039] Note that, for ease of understanding, in Figure 4 The light-shielding film 150 is omitted. Furthermore, no components are arranged between the light-shielding film 150 of liquid crystal display panel 110A and the light-shielding film 150 of liquid crystal display panel 110B. A gap 152 is provided between the light-shielding film 150 of liquid crystal display panel 110A and the light-shielding film 150 of liquid crystal display panel 110B.

[0040] The light-shielding film 150 blocks light from the backlight 200. In one example, the light-shielding film 150 absorbs light from the backlight 200. Specifically, as... Figure 5As shown, the light-shielding film 150 blocks light L1 from the backlight 200 that enters the liquid crystal display panel 110A (liquid crystal display panel 110B), is reflected at the interface between the side surface of the opposing substrate 124 (TFT substrate 122) and the gap 152 (air layer), and is emitted to the observer side. Additionally, the light-shielding film 150 blocks light L2 from the backlight 200 that is emitted from the TFT substrate 122 of the liquid crystal display panel 110B (liquid crystal display panel 110A), reflected at the side surface of the TFT substrate 122 of the liquid crystal display panel 110A (liquid crystal display panel 110B), re-enters the liquid crystal display panel 110B (liquid crystal display panel 110A), and is emitted from the liquid crystal display panel 110B (liquid crystal display panel 110A) to the observer side. Furthermore, the light-shielding film 150 blocks light L3 from the backlight 200 that is reflected at the side surface of the opposing substrate 124 (TFT substrate 122) in the gap 152 and emitted to the observer side without entering the liquid crystal display panel 110A and liquid crystal display panel 110B. As a result, the light-shielding film 150 can suppress light leakage from the liquid crystal display device 10. In addition, the light-shielding film 150 is provided on each of the opposing side surfaces 135 of the liquid crystal display panel 110A and liquid crystal display panel 110B, thereby reducing the gap S1 between the liquid crystal display panel 110A and liquid crystal display panel 110B. Figure 3 It is very narrow.

[0041] The light-shielding film 150 is implemented as a blackened film formed of metal oxide, a black coating formed of black paint, etc. In one example, the light-shielding film 150 is formed by sputtering of a metal oxide. Figure 6 As shown, a light-shielding film 150 can be formed by clamping multiple liquid crystal display panels 610 in a fixture 620 with the protective film 129 attached to the incident-side polarizer 126 and the exit-side polarizer 128, and forming a blackening film on the side surface 135. In one example, the thickness of the light-shielding film 150 is from 35 nm to 50 nm. Note that... Figure 6 Sealing material 132, etc., is omitted. Furthermore, the protective film 129 is removed after the light-shielding film 150 is formed.

[0042] like Figure 2 As shown, the backlight 200 of the display 100 is arranged on the back side (-Z side) of the liquid crystal display panels 110A and 110B. The backlight 200 is the light source for the liquid crystal display panels 110A and 110B. The backlight 200 emits white light towards the liquid crystal display panels 110A and 110B. The backlight 200 includes a white light-emitting diode (LED) element, a reflector, a diffuser, an illumination circuit, etc. (none of which are shown in the figures).

[0043] The housing 230 of the display 100 houses the liquid crystal display panels 110A and 110B and the backlight 200. The housing 230 includes a base frame 232 and a bezel 236.

[0044] The base frame 232 has a box-like shape. The base frame 232 is formed of resin or metal. The base frame 232 houses the liquid crystal display panels 110A, 110B and the backlight 200.

[0045] The bezel 236 has a box-like shape and includes an opening in its bottom 237. In one example, the bezel 236 is formed of metal. The bezel 236 faces the +Z side with its bottom 237 and covers the base frame 232. The liquid crystal display panels 110A and 110B are exposed through the opening. In this embodiment, the side panels 239 of the bezel 236 are bonded to the inner wall 510a of the opening 510 of the dashboard 500 by an adhesive (not shown). As a result, the liquid crystal display device 10 is fixed to the opening 510 of the dashboard 500.

[0046] like Figure 2 As shown, a protective member 300 of the liquid crystal display device 10 is disposed on the display surface (+Z side surface) 113 of the liquid crystal display panels 110A and 110B. The protective member 300 protects the liquid crystal display panels 110A and 110B. In one example, the protective member 300 is formed into a rectangular shape from a light-transmitting resin. The protective member 300 is attached to the display surface 113 of the liquid crystal display panels 110A and 110B by an adhesive 320. In one example, the adhesive 320 is implemented as an optically clear adhesive (OCA).

[0047] When viewed from above, the protective element 300 includes a light shield 302 that covers the gap 152 between the liquid crystal display panels 110A and 110B. In one example, the light shield 302 is formed of black ink. The light shield 302 blocks light emitted through the gap 152 between the liquid crystal display panels 110A and 110B to the observer's side. Therefore, the liquid crystal display device 10 is able to further suppress light leakage.

[0048] As described above, a light-shielding film 150 is provided on each of the opposing side surfaces 135 of the liquid crystal display panel 110A and the liquid crystal display panel 110B to block light from the backlight 200, thereby enabling the liquid crystal display device 10 to suppress light leakage. Furthermore, the spacing between the liquid crystal display panels 110A and 110B can be made very narrow, allowing for a unified display between the liquid crystal display panels 110A and 110B. In addition, the light-shielding cover 302 of the protective member 300 covers the gap 152 between the liquid crystal display panels 110A and 110B, thereby further suppressing light leakage in the liquid crystal display device 10.

[0049] Example 2

[0050] In Embodiment 1, a gap 152 is formed between liquid crystal display panel 110A and liquid crystal display panel 110B. Additionally, the protective member 300 includes a light shield 302 covering the gap 152. A configuration in which a portion of the gap 152 is filled by a joint filling member can be used. A configuration in which the protective member 300 does not include the light shield 302 can also be used.

[0051] Similar to the liquid crystal display device 10 of Embodiment 1, the liquid crystal display device 10 of this embodiment includes a display 100 and a protective member 300. Furthermore, the display 100 includes two liquid crystal display panels 110A and 110B, a backlight 200, and a housing 230. In this embodiment, as... Figure 7 and Figure 8 As shown, the display 100 also includes a joint filler 350.

[0052] In this embodiment, except that the protective member 300 does not include the light shield 302 and the display 100 includes the joint filler 350, the configuration of the liquid crystal display device 10 (the configuration of the liquid crystal display panels 110A, 110B, backlight 200, etc.) is the same as in Embodiment 1. Therefore, the joint filler 350 of the display 100 will be described next.

[0053] The joint filler 350 fills a portion of the gap 152 between the liquid crystal display panel 110A and the liquid crystal display panel 110B. In this embodiment, the joint filler 350 fills the observer-side portion of the gap 152.

[0054] The joint filler 350 has light-shielding properties. The light-shielding joint filler 350 fills a portion of the gap 152, thereby enabling the liquid crystal display device 10 of this embodiment to block light emitted through the gap 152 to the observer side without providing a light shield 302 on the protective member 300. Furthermore, since the protective member 300 does not include a light shield 302, the display of the liquid crystal display panel 110A and the display of the liquid crystal display panel 110B can have a unified appearance.

[0055] In one example, the joint filler 350 is formed of an acrylic adhesive containing carbon black. In one example, the joint filler 350 is formed by pouring the acrylic adhesive containing carbon black into the gap 152 and then curing the acrylic adhesive containing carbon black.

[0056] In this embodiment, a light-shielding joint filler 350 fills a portion of the gap 152 between the liquid crystal display panel 110A and the liquid crystal display panel 110B, thereby blocking light emitted through the gap 152 to the observer's side. Furthermore, light emitted through the gap 152 to the observer's side can be blocked without providing a light shield 302 on the protective member 300, thus giving a unified appearance to the displays of the liquid crystal display panel 110A and the liquid crystal display panel 110B. Additionally, as in Embodiment 1, a light-shielding film 150 is provided on each of the opposing side surfaces 135 of the liquid crystal display panels 110A and 110B to block light from the backlight 200, thereby suppressing light leakage in the liquid crystal display device 10 and allowing for a very narrow spacing between the liquid crystal display panels 110A and 110B.

[0057] Example 3

[0058] In embodiment 2, both liquid crystal display panel 110A and liquid crystal display panel 110B include an emission-side polarizer 128. However, a configuration in which liquid crystal display panel 110A and liquid crystal display panel 110B share the emission-side polarizer 128 can be adopted.

[0059] In this embodiment, as Figure 9 As shown, liquid crystal display panels 110A and 110B share a single emission-side polarizing plate 128. Furthermore, a joint filler 350 is disposed on the gap 152 of the emission-side polarizing plate 128 on the side opposite to the observer (-Z side) (for example, between the opposing substrate 124 of liquid crystal display panel 110A and the opposing substrate 124 of liquid crystal display panel 110B). Other configurations of the liquid crystal display device 10 in this embodiment are the same as in Embodiment 2.

[0060] In this embodiment, liquid crystal display panels 110A and 110B share a single emission-side polarizing plate 128, and the joint filler 350 is located on the side of the emission-side polarizing plate 128 opposite to the observer (-Z side). As a result, the reflectivity of the liquid crystal display device 10 to external light becomes uniform. Consequently, for the liquid crystal display device 10 of this embodiment, the joint filler 350 (gap 152) can be made inconspicuous.

[0061] As described above, liquid crystal display panels 110A and 110B share a single emission-side polarizing plate 128, and the joint filler 350 is located on the side of the emission-side polarizing plate 128 opposite to the observer (-Z side). This makes the joint filler 350 inconspicuous. Furthermore, similar to Embodiment 1, the liquid crystal display device 10 can suppress light leakage, and the spacing between liquid crystal display panels 110A and 110B can be very narrow.

[0062] Modify Example

[0063] Embodiments have been described, but various modifications may be made to this disclosure without departing from the spirit and scope thereof.

[0064] For example, the display 100 of the liquid crystal display device 10 may be configured to include a plurality of backlights 200.

[0065] The configuration in which the light-shielding film 150 extends to the display surface 113 of the liquid crystal display panels 110A and 110B can be adopted. Alternatively, the configuration in which the light-shielding film 150 is formed by spraying black paint can be adopted. When the light-shielding film 150 is formed, the exposed terminals, wiring, etc. of the liquid crystal display panels 110A and 110B can be covered.

[0066] In embodiments 1 to 3, the light-shielding film 150 covers all side surfaces 135 of the liquid crystal display panels 110A and 110B. However, it is sufficient for the light-shielding film 150 to cover at least a portion of the side surfaces 135. For example, a configuration can be adopted in which the light-shielding film 150 does not cover all or a portion of the main surfaces 122a and 122b of the TFT substrate 122 exposed on the side of the liquid crystal display panel 110A, the main surfaces 124a and 124b of the opposing substrate 124, the side surface 132c of the sealing material 132, and the side surface BMc of the black matrix BM. Preferably, the light-shielding film 150 covers the side surface 122c of the TFT substrate 122 and the side surface 124c of the opposing substrate 124.

[0067] In embodiments 1 to 3, the liquid crystal display device 10 includes two liquid crystal display panels 110A and 110B. However, it is sufficient for the liquid crystal display device 10 to include multiple liquid crystal display panels. For example, a configuration in which the liquid crystal display device 10 includes four liquid crystal display panels 110A to 110D can be adopted. In this case, as Figure 10 As shown, a configuration in which each of the liquid crystal display panels 110A to 110D includes a light-shielding film 150 on two side surfaces 135 opposite to the side surfaces 135 of the adjacent liquid crystal display panels 110A to 110D.

[0068] Alternatively, at least two adjacent liquid crystal display panels 110A to 110D can be configured to share a single emission-side polarizer 128.

[0069] In embodiments 2 and 3, the joint filler 350 fills the observer-side portion of the gap 152. However, as... Figure 11 As shown, a configuration in which the joint filler 350 is filled in the portion of the gap 152 on the backlight 200 side can be adopted.

[0070] Some exemplary embodiments have been described above for illustrative purposes. Although specific embodiments have been given in the discussion above, those skilled in the art will recognize that changes in form and detail may be made without departing from the broader spirit and scope of the invention. Therefore, the specification and drawings are to be considered illustrative rather than restrictive. Consequently, this detailed description is not limiting, and the scope of the invention is defined only by the included claims and the full scope of their equivalents.

Claims

1. A method for forming a light-shielding film, the method comprising: Protective films are disposed on a first polarizing plate and a second polarizing plate of a plurality of liquid crystal display panels. Each of the plurality of liquid crystal display panels includes a first substrate, a second substrate opposite to the first substrate, and liquid crystal sandwiched between the first substrate and the second substrate. The first polarizing plate is disposed on a main surface opposite to the main surface of the liquid crystal side of the first substrate, and the second polarizing plate is disposed on a main surface opposite to the main surface of the liquid crystal side of the second substrate. In a plurality of liquid crystal display panels having protective films applied, the protective films of one liquid crystal display panel overlap with the protective films of another liquid crystal display panel. The plurality of liquid crystal display panels with protective films are then bundled together. A light-shielding film is formed on the side surface of multiple bundled liquid crystal display panels that have protective films. After the light-shielding film is formed, multiple bundled liquid crystal display panels, each individually fitted with the protective film, are separated. The protective film is removed from a plurality of liquid crystal display panels on which a light-shielding film is formed on their side surfaces and a protective film is disposed.

2. The forming method according to claim 1, wherein During the formation process, the light-shielding film is formed on the entire side surface.

3. The forming method according to claim 1, wherein During the formation process, the light-shielding film is formed on the side surface by means of sputtering a film formed from metal oxide.

4. The forming method according to claim 1, wherein During the formation process, the light-shielding film is formed on the side surface by applying a black coating to the side surface.

5. A liquid crystal display device, comprising: Multiple liquid crystal display panels having a light-shielding film formed on their side surface by the method for forming a light-shielding film according to claim 1; and A backlight that emits light onto the plurality of liquid crystal display panels, wherein the plurality of liquid crystal display panels have a light-shielding film formed on the side surfaces of the plurality of liquid crystal display panels, wherein With the side surfaces on which light-shielding films are formed facing each other, the plurality of liquid crystal display panels, on which light-shielding films are formed, are arranged side by side. The light-blocking film blocks light from the backlight.

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