Backlight module and illuminated keyboard

Abstract

The present invention discloses a backlight module and an illuminated keyboard. The backlight module includes a shading sheet, a light guide plate, a reflective sheet, a main circuit board, a light emitting unit, a flexible circuit board and an electrical connector. The shading sheet has a light exit area. The light guide plate is arranged below the shading sheet and has a slot and a through hole. The reflective sheet is arranged below the light guide plate and includes a protrusion and an opening. The protrusion protrudes into the through hole. The main circuit board is arranged below the reflective sheet. The light emitting unit is arranged on the main circuit board and is accommodated in the slot through the opening. The light emitting unit is configured to emit light toward the light guide plate. The light reaches the light exit area via the light guide plate. The flexible circuit board is located below the reflective sheet and is configured to receive an external power supply. The electrical connector electrically connects the flexible circuit board and the main circuit board, and is aligned with the through hole or further protrudes into the through hole. In this way, the main circuit board and the flexible circuit board that are in contact with the reflective sheet can be limited in the horizontal direction relative to the light guide plate.

Description

Technical Field

[0001] The invention relates to a backlight module and a luminous keyboard. Background Art

[0002] The appearance of traditional keyboards is usually monotonous and dull, so computer peripheral manufacturers have developed luminous keyboards with excellent visual effects. Illuminated keyboards have backlight modules. In the known backlight modules, the implementation of luminous circuit boards can be mainly divided into two types, one is a flexible material circuit board structure, and the other is a rigid material circuit board structure.

[0003] The flexible material circuit board structure includes an integrally formed circuit board body and a flexible circuit strip. A light source is provided on the circuit board body. The flexible circuit strip is connected to a power source to transmit power to the circuit board body. The light-emitting diodes receiving power can emit light from the inside of the illuminated keyboard to present a beautiful visual effect. However, although its soft / bendable / integrated characteristics make it particularly suitable for keyboard modules with complex circuit layouts, its irregular appearance will increase manufacturing costs.

[0004] The rigid circuit board structure is to weld the flexible circuit strip on the flexible circuit board or rigid circuit board with light source. However, the welding point between the flexible circuit strip and the flexible circuit board is exposed to the outside, which is easy to be broken by external force, or affected by static electricity and hinder the operation of the flexible circuit strip. In addition, if the flexible circuit strip is welded on the rigid circuit board, its size will be significantly increased, affecting the overall volume of the luminous keyboard.

[0005] Therefore, how to propose a backlight module that can solve the above problems is one of the problems that the industry is eager to invest research and development resources to solve. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a backlight module and an illuminated keyboard that can solve the above problems.

[0007] In order to achieve the above-mentioned purpose, according to one embodiment of the present invention, a backlight module includes a shading sheet, a light guide plate, a reflective sheet, a main circuit board, a light-emitting unit, a flexible circuit board and an electrical connector. The shading sheet has a light-emitting area. The light guide plate is disposed below the shading sheet and has a slot and a through hole. The reflective sheet is disposed below the light guide plate and includes a protrusion and an opening. The protrusion protrudes into the through hole. The main circuit board is disposed below the reflective sheet. The light-emitting unit is disposed on the main circuit board and is accommodated in the slot through the opening. The light-emitting unit is configured to emit light toward the light guide plate. The light reaches the light-emitting area via the light guide plate. The flexible circuit board is located below the reflective sheet and is configured to receive an external power source. The electrical connector electrically connects the flexible circuit board and the main circuit board, and is aligned with the through hole or further protrudes into the through hole.

[0008] In one or more embodiments of the present invention, the backlight module further comprises an adhesive layer, which is adhered between the reflective sheet and the main circuit board and covers the electrical connection member.

[0009] In order to achieve the above-mentioned purpose, according to one embodiment of the present invention, an luminous keyboard includes a key, a shading sheet, a light guide plate, a reflective sheet, a main circuit board, a light emitting unit, a flexible circuit board and an electrical connector. The key has a light-transmitting character area. The shading sheet has a light-emitting area aligned with the light-transmitting character area. The light guide plate is arranged below the shading sheet and has a slot and a through hole. The reflective sheet is arranged below the light guide plate and includes a protrusion and an opening. The protrusion protrudes into the through hole. The main circuit board is arranged below the reflective sheet. The light emitting unit is arranged on the main circuit board and is accommodated in the slot through the opening. The light emitting unit is configured to emit light toward the light guide plate. The light sequentially passes through the light guide plate and the light-emitting area to reach the light-transmitting character area. The flexible circuit board is located below the reflective sheet and is configured to receive an external power supply. The electrical connector electrically connects the flexible circuit board and the main circuit board and is aligned with the through hole or further protrudes into the through hole.

[0010] In one or more embodiments of the present invention, the luminous keyboard further comprises an adhesive layer, which is adhered between the reflective sheet and the main circuit board and covers the electrical connector.

[0011] In one or more embodiments of the present invention, the adhesive layer completely covers the upper surface of the electrical connector and extends outward from the periphery of the upper surface.

[0012] In one or more embodiments of the present invention, the adhesive layer is further adhered to the flexible printed circuit board.

[0013] In one or more embodiments of the present invention, the adhesive layer is composed of a pressure-sensitive adhesive.

[0014] In one or more embodiments of the present invention, the electrical connector is a thermocompression welding structure.

[0015] In one or more embodiments of the present invention, the light shielding sheet further has a light-proof area, and the through hole is aligned with the light-proof area.

[0016] In one or more embodiments of the present invention, the opaque area corresponds to the central area of ​​the key, and the transparent character area is adjacent to the edge area of ​​the key.

[0017] In summary, in the backlight module of the present invention, since the electrical connector is directly covered and protected by the adhesive layer adhered between the reflective sheet and the main circuit board, it can have a smaller thickness than the known method of applying glue on the electrical connector. Relatively speaking, the area of ​​the reflective sheet relative to the through hole of the light guide plate can be free from the need to set a hole, which can not only avoid the problem of light in the light guide plate leaking downward through the reflective sheet, but also avoid the light guide plate scratching the main circuit board and the flexible circuit board under the reflective sheet. In addition, by the raised portion of the reflective sheet protruding into the through hole, the main circuit board and the flexible circuit board that are in contact with the reflective sheet can be limited in the horizontal direction relative to the light guide plate. In the luminous keyboard of the present invention, since the opaque area of ​​the shading sheet corresponds to the central position of the key, the light transmitted from the translucent character area of ​​the key can have better character uniformity.

[0018] The above description is only used to illustrate the problems to be solved by the present invention, the technical means to solve the problems, and the effects produced, etc. The specific details of the present invention will be introduced in detail in the following implementation methods and related drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the above and other objects, features, advantages and embodiments of the present invention more clearly understood, the accompanying drawings are described as follows:

[0020] Figure 1 FIG. 4 is a three-dimensional diagram illustrating a luminous keyboard according to an embodiment of the present invention.

[0021] Figure 2 FIG. 1 is an exploded view of a backlight module according to an embodiment of the present invention.

[0022] Figure 3 To illustrate Figure 2 A cross-sectional view of the backlight module after assembly.

[0023] Figure 4 To illustrate Figure 1 A partial top view of the illuminated keyboard in FIG.

[0024] Description of main reference numerals:

[0025] 100-luminous keyboard; 110-keyboard module; 111-key; 111a-translucent character area; 200-backlight module; 210-shading sheet; 211-light emitting area; 212-opaque area; 220-black shielding material; 230-light guide plate; 231-slot; 232-through hole; 233-microstructure; 240-reflective sheet; 241-raised portion; 242-opening; 250-main circuit board; 260-light emitting unit; 270-flexible circuit board; 280-electrical connector; 290-adhesive layer; B1, B2-dashed box. DETAILED DESCRIPTION

[0026] The following will disclose multiple embodiments of the present invention with the accompanying drawings. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. That is, in some embodiments of the present invention, these practical details are not necessary. In addition, in order to simplify the drawings, some well-known and commonly used structures and elements will be depicted in a simple schematic manner in the drawings.

[0027] Please refer to Figure 1 , which is a three-dimensional diagram of a luminous keyboard 100 according to an embodiment of the present invention. Figure 1 As shown, the luminous keyboard 100 is a keyboard that can emit light and has low cost, good structural strength and antistatic properties, and is thin. The luminous keyboard 100 includes a keyboard module 110 and a backlight module 200. The keyboard module 110 includes a plurality of keys 111 for a user to press to trigger corresponding commands. The backlight module 200 is disposed below the keyboard module 110. The backlight module 200 is used to provide light with sufficient brightness and uniform distribution.

[0028] Please refer to Figure 2 as well as Figure 3 . Figure 2 FIG. 2 is an exploded view of a backlight module 200 according to an embodiment of the present invention. Figure 3 To illustrate Figure 2 The cross-sectional view of the backlight module 200 after assembly. Figure 2 and Figure 3 As shown, the backlight module 200 includes a light shielding sheet 210, a light guide plate 230, a reflective sheet 240, a main circuit board 250, a light emitting unit 260, a flexible circuit board 270 and an electrical connector 280. The structures, functions and connections between these components will be described in detail below.

[0029] like Figure 3As shown, the shading sheet 210 has a light exiting area 211. The light guide plate 230 is disposed below the shading sheet 210 and has a slot 231 and a through hole 232. The reflective sheet 240 is disposed below the light guide plate 230 and includes a protrusion 241 and an opening 242. The protrusion 241 protrudes into the through hole 232. The main circuit board 250 is disposed below the reflective sheet 240. The light emitting unit 260 is disposed on the main circuit board 250 and is accommodated in the slot 231 of the light guide plate 230 through the opening 242 of the reflective sheet 240. The light emitting unit 260 is configured to emit light laterally toward the inner wall of the light guide plate 230 at the slot 231. The light entering the light guide plate 230 is repeatedly reflected in the light guide plate 230 to be transmitted in the horizontal dimension, and is reflected upward by the microstructure 233 formed on the lower surface of the light guide plate 230 and leaves from the upper surface of the light guide plate 230 and reaches the light shielding sheet 210. The position of the microstructure 233 is substantially located directly below the light exit area 211. The flexible circuit board 270 is located below the reflective sheet 240 and is configured to receive an external power source. The electrical connector 280 electrically connects the flexible circuit board 270 and the main circuit board 250 and is aligned with the through hole 232. In other embodiments, the electrical connector 280 will further protrude into the through hole 232, which is not separately illustrated here.

[0030] According to the above structural configuration, since the protrusion 241 of the reflective sheet 240 protrudes into the through hole 232, the reflective sheet 240 can be limited in the horizontal direction (e.g., X direction and Y direction) relative to the light guide plate 230, and the main circuit board 250 and the flexible circuit board 270 attached to the reflective sheet 240 can also be limited, thereby effectively improving the product reliability of the backlight module 200. In addition, since the reflective sheet 240 is only provided with the protrusion 241 and no broken hole in the area relative to the through hole 232 of the light guide plate 230, it can not only prevent the light in the light guide plate 230 from leaking downward through the reflective sheet 240, but also prevent the burrs of the light guide plate 230 from scratching the main circuit board 250 and the flexible circuit board 270 below the reflective sheet 240. Furthermore, the reflective sheet 240 with an isolation effect can also isolate the static electricity at the system end and the temperature generated by the operating chip, so as to further improve the product reliability of the backlight module 200.

[0031] In one embodiment, the light emitting unit 260 is a light emitting diode, but the invention is not limited thereto.

[0032] In one embodiment, the electrical connector 280 is a thermocompression welding structure (such as solder). That is, the electrical connector 280 is formed by heat-melting welding and is disposed on the main circuit board 250. Figure 3As shown, the backlight module 200 further includes an adhesive layer 290. The adhesive layer 290 is adhered between the reflective sheet 240 and the main circuit board 250, and covers the electrical connector 280. More specifically, the adhesive layer 290 completely covers the upper surface of the electrical connector 280 (see FIG. Figure 3 ), and extends outward from the periphery of the upper surface. The adhesive layer 290 is further adhered to the flexible circuit board 270. On the other hand, the electrical connector 280 is surrounded by the adhesive layer 290, the main circuit board 250 and the flexible circuit board 270. In other words, the purpose of the adhesive layer 290 is not only to adhere the reflective sheet 240 and the main circuit board 250, but also to protect the electrical connector 280 to prevent foreign matter from causing a short circuit in this area.

[0033] According to the above structural configuration, since the electrical connector 280 is directly covered and protected by the adhesive layer 290 adhered between the reflective sheet 240 and the main circuit board 250, it can have a smaller thickness than the conventional method of dispensing glue on the electrical connector 280, and this is also the reason why the reflective sheet 240 does not need to be provided with a hole. In addition, the method of extending the adhesive layer 290 to cover the electrical connector 280 can not only maintain the original product reliability of the backlight module 200, but also further improve the pull-out resistance.

[0034] In some embodiments, the adhesive layer 290 is made of pressure-sensitive adhesive, but the invention is not limited thereto.

[0035] In some embodiments, the main circuit board 250 is made of a hard material (e.g., PCB). The main circuit board 250 is used to obtain power from an external power source (not shown) via the flexible circuit board 270, and transmit the power to the light-emitting unit 260, so that the light-emitting unit 260 emits light. Since the main circuit board 250 is made of a hard material, its manufacturing and assembly costs are cheaper than those of the flexible circuit board 270. Furthermore, since the main circuit board 250 and the flexible circuit board 270 each have a simple shape (e.g., a rectangle), they can have a lower manufacturing cost than the conventional flexible material circuit board having an irregular shape composed of an integrally formed circuit board body and a flexible circuit strip.

[0036] like Figure 2 and Figure 3As shown, a black shielding material 220 is provided on the light shielding sheet 210, so the light shielding sheet 210 can be divided into a light exit area 211 not covered by the black shielding material 220 and a light-proof area 212 covered by the black shielding material 220. In this way, the light transmitted from the light guide plate 230 from below will be shielded by the black shielding material 220 and only continue to be transmitted upward to the outside from the light exit area 211. In addition, the through hole 232 is aligned with the light-proof area 212. It can be seen that the light shielding sheet 210 is not provided with a broken hole in the area relative to the through hole 232 of the light guide plate 230, so that the static electricity caused by the friction between the keyboard module 110 and the iron parts can be isolated, thereby further protecting the area of ​​the electrical connection 280.

[0037] In some embodiments, the black masking material 220 is, for example, a black tape or black ink, but the invention is not limited thereto.

[0038] Please refer to Figure 4 , which is a drawing Figure 1 A partial top view of the luminous keyboard 100 in FIG. Figure 4 As shown, at least one key 111 of the keyboard module 110 has a light-transmitting character area 111a. The area between the dotted frames B1 and B2 is the light-emitting area 211 of the light-shielding sheet 210, and the area within the dotted frame B1 and the area outside the dotted frame B2 are the opaque area 212 of the light-shielding sheet 210. The opaque area 212 of the light-shielding sheet 210 within the dotted frame B1 corresponds to the central area of ​​the key 111, and the light-transmitting character area 111a is adjacent to the edge area of ​​the key 111. The light-transmitting character area 111a is aligned with the four corners of the light-emitting area 211, respectively. The light guide plate 230 is provided with a microstructure 233 corresponding to the area directly below each light-transmitting character area 111a, so that the light reflected upward by the microstructure 233 can be transmitted to the outside through the light-transmitting character area 111a. Since the light guide plate 230 has the through hole 232 , it may cause light leakage and thus deteriorate the uniformity of characters. The design of the opaque area 212 can shield the light and maintain a better uniformity of characters.

[0039] In some embodiments, the opaque area 212 of the light shielding sheet 210 may correspond to the area below the space bar, but the present invention is not limited thereto.

[0040] From the above detailed description of the specific implementation of the present invention, it can be clearly seen that in the backlight module of the present invention, since the electrical connector is directly covered and protected by the adhesive layer adhered between the reflective sheet and the main circuit board, it can have a smaller thickness than the known method of dispensing glue on the electrical connector. Relatively speaking, the area of ​​the reflective sheet relative to the through hole of the light guide plate can be free from the need to set a broken hole, which can not only avoid the problem of light in the light guide plate leaking downward through the reflective sheet, but also avoid the light guide plate scratching the main circuit board and the flexible circuit board under the reflective sheet. In addition, by the protrusion of the reflective sheet protruding into the through hole, the main circuit board and the flexible circuit board that are in contact with the reflective sheet can be limited in the horizontal direction relative to the light guide plate. In the luminous keyboard of the present invention, since the opaque area of ​​the shading sheet corresponds to the central position of the key, the light transmitted from the translucent character area of ​​the key can have better character uniformity.

[0041] Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Any technician in the field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A backlight module, characterized in that: Include: A shading sheet having a light exiting area; A light guide plate, disposed below the light shielding sheet, and having a slot and a through hole; A reflective sheet, disposed below the light guide plate, comprising a protruding portion and an opening, wherein the protruding portion protrudes into the through hole; A main circuit board is arranged below the reflective sheet; A light emitting unit is disposed on the main circuit board and passes through the opening and is accommodated in the slot, wherein the light emitting unit is configured to emit light toward the light guide plate, and the light reaches the light exiting area via the light guide plate; A flexible circuit board is located below the reflective sheet and is configured to receive an external power source; An electrical connector electrically connects the flexible circuit board and the main circuit board and is aligned with the through hole or further protrudes into the through hole; as well as The adhesive layer is adhered between the reflective sheet and the main circuit board and covers the electrical connector. The adhesive layer completely covers the upper surface of the electrical connector and extends outward from the periphery of the upper surface.

2. The backlight module according to claim 1, wherein: The adhesive layer is further adhered to the flexible circuit board.

3. The backlight module according to claim 1, wherein: The adhesive layer is composed of pressure-sensitive adhesive.

4. The backlight module according to claim 1, wherein: The electrical connector is a hot pressing welding structure.

5. The backlight module according to claim 1, wherein: The shading sheet also has a light-proof area, and the through hole is aligned with the light-proof area.

6. A luminous keyboard, characterized in that: Include: Keys, with light-transmitting character areas; A light shielding sheet having a light emitting area, wherein the light emitting area is aligned with the light-transmitting character area; A light guide plate, disposed below the light shielding sheet, and having a slot and a through hole; A reflective sheet, disposed below the light guide plate, comprising a raised portion and an opening, wherein the raised portion protrudes into the through hole; A main circuit board is arranged below the reflective sheet; A light emitting unit is disposed on the main circuit board and is received in the slot through the opening. The light emitting unit is configured to emit light toward the light guide plate. The light sequentially passes through the light guide plate and the light exiting area to reach the light-transmitting character area. A flexible circuit board is located below the reflective sheet and is configured to receive an external power source; An electrical connector electrically connects the flexible circuit board and the main circuit board and is aligned with the through hole or further protrudes into the through hole; as well as The adhesive layer is adhered between the reflective sheet and the main circuit board and covers the electrical connector. The adhesive layer completely covers the upper surface of the electrical connector and extends outward from the periphery of the upper surface.

7. The luminous keyboard according to claim 6, characterized in that: The adhesive layer is further adhered to the flexible circuit board.

8. The luminous keyboard according to claim 6, characterized in that: The adhesive layer is composed of pressure-sensitive adhesive.

9. The luminous keyboard according to claim 6, characterized in that: The electrical connector is a hot pressing welding structure.

10. The luminous keyboard according to claim 6, characterized in that: The shading sheet also has a light-proof area, and the through hole is aligned with the light-proof area.

11. The luminous keyboard according to claim 10, characterized in that: The opaque area corresponds to the central area of ​​the key, and the translucent character area is adjacent to the edge area of ​​the key.

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