Backlight module

Abstract

A backlight module includes a circuit board, a light emitting unit, a reflection plate, a light guide plate, and a light shielding sheet. The light emitting unit is disposed on the circuit board. The reflection plate is disposed above the circuit board. The light guide plate is disposed above the reflection plate and includes a single-key light guide area. The single-key light guide area includes a receiving hole and a light blocking structure. The receiving hole penetrates the single-key light guide area and receives the light emitting unit. The light blocking structure is arranged with the light emitting unit in a direction. The light shielding sheet is disposed above the light guide plate. Thus, the problem of uneven brightness of different areas of the key can be effectively solved.

Description

Technical Field

[0001] This disclosure relates to a keyboard device, and more particularly to a backlight module used in a keyboard device. Background Technology

[0002] Traditional keyboards often have a rather monotonous and dull appearance, so computer peripheral manufacturers have developed backlit keyboards with excellent visual effects. One known type of backlit keyboard has a backlight module. The backlight module mainly uses a light guide plate to propagate the light emitted by the light source, so that all areas of the keyboard can be illuminated.

[0003] To allow individual control of each button's illumination, multiple light sources are placed under each button. However, the placement of these light sources directly affects the light distribution, leading to uneven brightness across different areas of each button. Furthermore, light sources can be categorized as monochromatic or mixed-color. Mixed-color light sources are made by encapsulating multiple differently colored chips, which can mix to produce white light when emitting light simultaneously. However, on either side with only a single chip, the higher light energy of the chip results in color distortion.

[0004] Therefore, how to propose a backlight module that can solve the above problems is one of the issues that the industry is currently eager to invest research and development resources to address. Summary of the Invention

[0005] In view of this, one purpose of this disclosure is to propose a backlight module that can solve the above problems.

[0006] To achieve the above objectives, according to one embodiment of this disclosure, a backlight module includes a circuit board, a light-emitting unit, a reflector, a light guide plate, and a light-shielding sheet. The light-emitting unit is disposed on the circuit board. The reflector is disposed above the circuit board. The light guide plate is disposed above the reflector and includes a single-key light-guiding area. The single-key light-guiding area includes a receiving hole and a light-blocking structure. The receiving hole penetrates the single-key light-guiding area and accommodates the light-emitting unit. The light-blocking structure and the light-emitting unit are arranged in one direction. The light-shielding sheet is disposed above the light guide plate.

[0007] In one or more embodiments disclosed herein, the single-bond light-guiding region further includes a first microstructure portion. The light-shielding sheet has a cutout portion. The first microstructure portion is configured to guide light emitted by the light-emitting unit to the cutout portion.

[0008] In one or more embodiments disclosed herein, the light-blocking structure is a second microstructure portion. The second microstructure portion is composed of multiple microstructure units.

[0009] In one or more embodiments disclosed herein, the first microstructure portion is composed of multiple microstructure units. The area ratio of the microstructure units of the second microstructure portion per unit area is greater than the area ratio of the microstructure units of the first microstructure portion per unit area.

[0010] In one or more embodiments disclosed herein, the backlight module further includes a light-absorbing layer. The light-absorbing layer is disposed on one side of the light-shielding sheet facing the light guide plate and is opposite to the second microstructure portion in the stacking direction of the light-shielding sheet and the light guide plate.

[0011] In one or more embodiments disclosed herein, the light guide plate further includes a light guide structure. The light guide structure is disposed around the single-bond light guide region and configured to guide the light emitted by the light-emitting unit to the light-shielding sheet.

[0012] In one or more embodiments disclosed herein, the first microstructure portion and the light guide structure are each composed of multiple microstructure units. The area ratio of the microstructure units of the light guide structure per unit area is greater than the area ratio of the microstructure units of the first microstructure portion per unit area.

[0013] In one or more embodiments disclosed herein, the backlight module further includes a reflective layer. The reflective layer is disposed between the light-shielding sheet and the light-emitting unit, and completely covers the upper opening of the receiving hole.

[0014] In one or more embodiments disclosed herein, a reflector is disposed on an area of ​​the circuit board not occupied by the light-emitting unit and extends into the area within the inner edge of the receiving hole.

[0015] In one or more embodiments disclosed herein, the light-emitting unit includes a red light chip, a green light chip, and a blue light chip. The red light chip, green light chip, and blue light chip are arranged sequentially along the aforementioned direction.

[0016] In one or more embodiments disclosed herein, the light-emitting unit includes a blue light chip and a phosphor covering the blue light chip.

[0017] In one or more embodiments disclosed herein, the light-blocking structure includes two through holes. The through holes are respectively arranged on both sides of the light-emitting unit in the aforementioned direction.

[0018] In one or more embodiments disclosed herein, the through holes respectively constitute portions of the two heat dissipation channels penetrating the backlight module.

[0019] In summary, in the backlight module disclosed herein, the single-key light-guiding area of ​​the light guide plate includes a light-blocking structure arranged on the side of the light-emitting unit. This allows for adjustment of the light distribution emitted by the light-emitting unit, effectively solving the problem of uneven brightness in different areas of the key. Furthermore, in embodiments where the light-emitting unit includes different colored light chips, the light-blocking structure can also effectively solve the problem of color distortion caused by uneven light mixing. In embodiments where the light-blocking structure is a microstructure, light blocking is achieved by placing a light-absorbing layer on one side of the light-guiding plate and opposite the light-blocking structure. In embodiments where the light-blocking structure is a perforation, in addition to achieving the same light-blocking purpose, the light-blocking structure can also serve as a heat dissipation hole. By providing a light-guiding structure surrounding the single-key light-guiding area on the light guide plate, the proportion of light emitted by the light-emitting unit that propagates outside the single-key light-guiding area can be effectively reduced. By arranging the brightest chip (e.g., a green light chip) in the center of the light-emitting unit, the effect of solving the color distortion problem can be further improved.

[0020] The above description is only used to illustrate the problem to be solved by this disclosure, the technical means to solve the problem, and the effects produced, etc. The specific details of this disclosure will be described in detail in the following implementation method and related drawings. Attached Figure Description

[0021] To make the above and other objects, features, advantages and embodiments disclosed herein more apparent and understandable, the accompanying drawings are described below:

[0022] Figure 1 A perspective view of a keyboard device according to an embodiment of the present disclosure is provided.

[0023] Figure 2 A partial cross-sectional view of a backlight module according to an embodiment of the present disclosure is provided.

[0024] Figure 3 For illustration Figure 2 A partial bottom view of the light guide plate in the image;

[0025] Figure 4 For illustration of a partial cross-sectional view of a backlight module according to another embodiment of this disclosure;

[0026] Figure 5 For illustration Figure 4 A partial bottom view of the light guide plate in the image;

[0027] Figure 6 A partial cross-sectional view is shown for illustrating another embodiment of the backlight module according to this disclosure.

[0028] [Symbol Explanation]

[0029] 100: Keyboard device

[0030] 110: Base Plate

[0031] 120: Button assembly

[0032] 200, 300, 400: Backlight module

[0033] 210, 310: Circuit board

[0034] 211: Second through hole

[0035] 220, 420: Light-emitting unit

[0036] 221: Red light chip

[0037] 222: Green light chip

[0038] 223,421: Blue optical chip

[0039] 230, 330: Reflectors

[0040] 231: Fourth through hole

[0041] 240, 340: Light guide plate

[0042] 241, 341: Single-bond light guide area

[0043] 241a: Receiving hole

[0044] 241b, 341b: Light-blocking structure

[0045] 241c: First microstructure part

[0046] 242: Light guide structure

[0047] 250, 350: Light-blocking sheet

[0048] 251: Third through hole

[0049] 252: Openwork section

[0050] 260, 360: Light absorption layer

[0051] 261: Fifth through hole

[0052] 270: Reflective layer

[0053] 422: Phosphor

[0054] A1: Direction

[0055] A2: Stacking direction Detailed Implementation

[0056] The following describes several embodiments of this disclosure with reference to the accompanying drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this disclosure. That is, in some embodiments of this disclosure, these practical details are not essential. Furthermore, for the sake of simplicity, some known and conventional structures and elements will be shown in the drawings in a simple schematic manner.

[0057] Please refer to Figure 1 This is a perspective view illustrating a keyboard device 100 according to an embodiment of the present disclosure. Figure 1 As shown, in this embodiment, the keyboard device 100 includes a base plate 110, a plurality of key assemblies 120, and a backlight module 200 (see [link to documentation]). Figure 2 The key assembly 120 is disposed above the base plate 110 and configured for user pressing. A backlight module 200 is disposed between the base plate 110 and the key assembly 120 and configured to emit light toward the key assembly 120, thereby making the keyboard device 100 a backlit keyboard. Furthermore, the keyboard device 100 of this embodiment can be an external keyboard for desktop computers (e.g., a PS / 2 interface keyboard or a USB interface keyboard) or an input device including keys, but is not limited thereto. In other words, the concept of the keyboard device 100 disclosed herein can be applied to any electronic product that uses pressing as an input method.

[0058] Please refer to Figure 2 as well as Figure 3 . Figure 2 A partial cross-sectional view of a backlight module 200 according to an embodiment of the present disclosure is shown. Figure 3 For illustration Figure 2 A partial bottom view of the light guide plate 240. (See attached image.) Figure 2 and Figure 3 As shown, in this embodiment, the backlight module 200 includes a circuit board 210, a light-emitting unit 220, a reflector 230, a light guide plate 240, and a light-shielding sheet 250. The light-emitting unit 220 is disposed on the circuit board 210. The reflector 230 is disposed above the circuit board 210. The light guide plate 240 is disposed above the reflector 230 and includes a single-key light guide area 241. The single-key light guide area 241 corresponds to one of the key components 120. For example, the single-key light guide area 241 is defined by the orthographic projection of the aforementioned key component 120 onto the light guide plate 240 (e.g., the orthographic projection of the keycap onto the light guide plate 240), but this disclosure is not limited thereto. The single-key light guide area 241 includes a receiving hole 241a. The receiving hole 241a penetrates the single-key light guide area 241 and receives the light-emitting unit 220. The light-shielding sheet 250 is disposed above the light guide plate 240.

[0059] like Figure 2 and Figure 3As shown, in this embodiment, the light emitted by the light-emitting unit 220 can enter the light guide plate 240 through the inner wall of the receiving hole 241a, and propagate within the light guide plate 240 after total internal reflection on the upper and lower surfaces of the light guide plate 240. The reflector 230 can prevent light from leaving the lower surface of the light guide plate 240, thus avoiding light loss. Furthermore, as... Figure 3 As shown, the single-key light guide area 241 further includes a first microstructure portion 241c. The first microstructure portion 241c is disposed at the bottom of the single-key light guide area 241. The light shield 250 has a cutout portion 252 (shown as dashed lines). The first microstructure portion 241c is configured to guide the light emitted by the light-emitting unit 220 to the cutout portion 252. In other words, when the light propagating in the light guide plate 240 reaches the first microstructure portion 241c, it is scattered upward by the first microstructure portion 241c, and then shines on the upper key assembly 120 through the cutout portion 252 of the light shield 250.

[0060] like Figure 2 As shown, in this embodiment, the reflector 230 is disposed on the area of ​​the circuit board 210 not occupied by the light-emitting unit 220, and extends into the area within the inner edge of the receiving hole 241a. In this way, the light emitted downwards by the light-emitting unit 220 within the receiving hole 241a can be reflected upwards by the reflector 230, thus further ensuring that light energy enters the light guide plate 240 from the inner wall of the receiving hole 241a.

[0061] like Figure 2 and Figure 3 As shown, in this embodiment, the single-key light-guiding area 241 further includes two light-blocking structures 241b. The light-blocking structures 241b and the light-emitting unit 220 are arranged in direction A1. With this structural configuration, the distribution of light emitted by the light-emitting unit 220 can be adjusted by using the light-blocking structures 241b, thereby effectively solving the problem of uneven brightness in different areas of the key assembly 120. In practical applications, the distance between the light-blocking structure 241b and the light-emitting unit 220 can be adjusted based on the aforementioned purpose.

[0062] like Figure 2 As shown, in this embodiment, the light-emitting unit 220 includes a red light chip 221, a green light chip 222, and a blue light chip 223. The red light chip 221, green light chip 222, and blue light chip 223 are arranged sequentially along the aforementioned direction A1. Therefore, one of the light-blocking structures 241b is located on the side of the red light chip 221 away from the green light chip 222, while the other of the light-blocking structures 241b is located on the side of the blue light chip 223 away from the green light chip 222. With this structural configuration, the light-blocking structure 241b can disrupt the light propagation of the red light chip 221 and the blue light chip 223 in the aforementioned direction A1, thereby effectively solving the color difference problem caused by uneven light mixing.

[0063] In some embodiments, the green light chip 222 has the highest brightness compared to the red light chip 221 and the blue light chip 223. By arranging the brightest green light chip 222 between the less bright red light chip 221 and the blue light chip 223, the effect of solving the color discrepancy problem can be further improved.

[0064] like Figure 2 and Figure 3 As shown, in this embodiment, the backlight module 200 further includes a light absorption layer 260. The light absorption layer 260 is disposed on one side of the light shield 250 facing the light guide plate 240, and is located above the light blocking structure 241b in the stacking direction A2 of the light shield 250 and the light guide plate 240. By absorbing the unevenly mixed light guided by the light blocking structure 241b through the light absorption layer 260, the effect of solving the color difference problem can be further improved.

[0065] like Figure 2 As shown, in this embodiment, the backlight module 200 further includes a reflective layer 270. The reflective layer 270 is disposed between the light-shielding sheet 250 and the light-emitting unit 220. Thereby, the light emitted upwards by the light-emitting unit 220 can be reflected downwards by the reflective layer 270, thereby re-mixing the light and improving the uniformity of the white light. Furthermore, the reflective layer 270 completely covers the upper opening of the receiving hole 241a to prevent the light emitted by the light-emitting unit 220 from leaving through the upper opening of the receiving hole 241a, thus ensuring that light energy enters the light guide plate 240 through the inner wall of the receiving hole 241a.

[0066] like Figure 2 and Figure 3 As shown, in this embodiment, the light-blocking structure 241b consists of two first through holes. These first through holes are arranged on both sides of the light-emitting unit 220 in the aforementioned direction A1. Additionally, the circuit board 210 has two second through holes 211. The light-blocking sheet 250 has two third through holes 251. The reflector 230 has two fourth through holes 231. The light-absorbing layer 260 has two fifth through holes 261. Each first through hole, together with its corresponding second through hole 211, third through hole 251, fourth through hole 231, and fifth through hole 261, forms a heat dissipation channel. This prevents heat accumulation from affecting the performance of the keyboard device 100.

[0067] like Figure 3As shown, in this embodiment, the light guide plate 240 further includes a light guide structure 242. The light guide structure 242 is disposed around the single-key light guide area 241 and configured to guide the light emitted by the light-emitting unit 220 to the light shield 250. Specifically, when light in the single-key light guide area 241 that is not guided by the first microstructure portion 241c propagates to the light guide structure 242, it will be guided by the light guide structure 242 toward the light shield 250 and will not be able to continue propagating to the single-key light guide areas 241 corresponding to other button components 120. In this way, the light guide structure 242 can effectively avoid the problem of mutual interference between the light emission effects of adjacent single-key light guide areas 241.

[0068] In some embodiments, the first microstructure portion 241c and the light guide structure 242 are each composed of multiple microstructure units. For example... Figure 3 As shown, the microstructure units of the first microstructure portion 241c and the light guide structure 242 are mesh microstructures, but this disclosure is not limited to this. In some embodiments, the area ratio of the microstructure units of the light guide structure 242 per unit area is greater than the area ratio of the microstructure units of the first microstructure portion 241c per unit area. For example, such as Figure 3 As shown, the spacing of the mesh microstructures in the light guide structure 242 is smaller than the spacing of the mesh microstructures in the first microstructure portion 241c. This structural configuration further enhances the effect of blocking light propagation to the adjacent single-bond light guide region 241.

[0069] Please refer to Figure 4 as well as Figure 5 . Figure 4 A partial cross-sectional view of a backlight module 300 according to another embodiment of the present disclosure is shown. Figure 5 For illustration Figure 4 A partial bottom view of the light guide plate 340 in the image. Figure 4 and Figure 5 As shown, in this embodiment, the backlight module 300 includes a circuit board 310, a light-emitting unit 220, a reflector 330, a light guide plate 340, a light-shielding sheet 350, a light-absorbing layer 360, and a reflective layer 270. The stacking order and relative positions of these components are the same or similar. Figure 2 The corresponding components in the illustrated embodiment. The backlight module 300 of this embodiment is for... Figure 2 The light-blocking structure 241b in the single-bond light-guiding region 341 is modified. Specifically, in this embodiment, the light-blocking structure 341b in the single-bond light-guiding region 341 is a second microstructure. The second microstructure is composed of multiple microstructure units. For example... Figure 5As shown, the microstructure units of the first microstructure portion 241c and the second microstructure portion are mesh microstructures, but this disclosure is not limited to this. In some embodiments, the area ratio of the microstructure units of the second microstructure portion per unit area is greater than the area ratio of the microstructure units of the first microstructure portion 241c per unit area. For example, such as Figure 5 As shown, the spacing of the mesh microstructures in the second microstructure section is smaller than that in the first microstructure section 241c. With this structural configuration, the distribution of light emitted by the light-emitting unit 220 can also be adjusted using the light-blocking structure 341b, thereby effectively solving the problem of uneven brightness in different areas of the button assembly 120.

[0070] In addition, compared to Figure 2 In the embodiment shown, the backlight module 300 eliminates the heat dissipation channel. In this structural configuration, the light absorption layer 360 faces the second microstructure in the stacking direction A2 of the light-shielding sheet 350 and the light guide plate 340. By absorbing the unevenly mixed light guided by the light-blocking structure 341b, the effect of solving the color difference problem can be further improved.

[0071] Please refer to Figure 6 This is a partial cross-sectional view illustrating a backlight module 400 according to another embodiment of this disclosure. Figure 6 As shown, in this embodiment, the backlight module 400 includes a circuit board 210, a light-emitting unit 420, a reflector 230, a light guide plate 240, a light shield 250, a light absorption layer 260, and a reflective layer 270. The circuit board 210, reflector 230, light guide plate 240, light shield 250, light absorption layer 260, and reflective layer 270 are identical to... Figure 2 The embodiments shown are described above, and therefore, the relevant descriptions of these components are not repeated here. The backlight module 400 of this embodiment is for... Figure 2 The light-emitting unit 220 in this embodiment is modified. Specifically, the light-emitting unit 420 in this embodiment includes a blue light chip 421 and a phosphor 422 covering the blue light chip 421. The phosphor 422 is configured to convert a portion of the blue light emitted by the blue light chip 421 into yellow fluorescence, and this yellow fluorescence, when mixed with the unconverted blue light, can produce white light.

[0072] From the detailed description of the specific embodiments disclosed above, it is clear that in the backlight module of this disclosure, the single-key light guide area of ​​the light guide plate includes a light-blocking structure arranged on the side of the light-emitting unit. Therefore, the distribution of light emitted by the light-emitting unit can be adjusted, thereby effectively solving the problem of uneven brightness in different areas of the key. In addition, in embodiments where the light-emitting unit includes different colored light chips, the light-blocking structure can also effectively solve the problem of color difference caused by uneven light mixing. In embodiments where the light-blocking structure is a microstructure, the purpose of light blocking can be achieved by placing a light-absorbing layer on one side of the light guide plate and opposite to the light-blocking structure. In embodiments where the light-blocking structure is a perforation, in addition to achieving the same purpose of light blocking, the light-blocking structure can also serve as a heat dissipation hole. By providing a light guide structure around the single-key light guide area on the light guide plate, the proportion of light emitted by the light-emitting unit that propagates outside the single-key light guide area can be effectively reduced. By arranging the brightest chip (e.g., a green light chip) in the center of the light-emitting unit, the effect of solving the color difference problem can be further improved.

[0073] Although the present disclosure has been described above with reference to embodiments, it is not intended to limit the present disclosure. Any person skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the scope defined in the appended claims.

Claims

1. A backlight module, characterized in that, Include: A circuit board; A light-emitting unit is disposed on the circuit board; A reflector is positioned above the circuit board; A light guide plate is disposed above the reflector and includes a single-key light guide area, which includes: A receiving hole extends through the single-bond light-guiding area and houses the light-emitting unit; A first microstructure is disposed at the bottom of the single-bond light-guiding area; and A light-blocking structure is arranged in one direction with the light-emitting unit. The light-blocking structure is a second microstructure, which is composed of multiple microstructure units. A light-shielding sheet is placed above the light guide plate.

2. The backlight module according to claim 1, characterized in that, The light-shielding sheet has a cutout portion, and the first microstructure portion is configured to guide the light emitted by the light-emitting unit to the cutout portion.

3. The backlight module according to claim 2, characterized in that, The first microstructure is composed of multiple microstructure units, and the area ratio of the multiple microstructure units in the second microstructure is greater than the area ratio of the multiple microstructure units in the first microstructure.

4. The backlight module according to claim 2, characterized in that, Further includes: A light-absorbing layer is disposed on the side of the light-shielding sheet facing the light guide plate, and is opposite to the second microstructure portion in a stacking direction of the light-shielding sheet and the light guide plate.

5. The backlight module according to claim 2, characterized in that, The light guide plate further includes a light guide structure arranged around the single-bond light guide area and configured to guide the light emitted by the light-emitting unit to the light shield.

6. The backlight module according to claim 5, characterized in that, The first microstructure and the light guide structure are each composed of multiple microstructure units, and the area ratio of the multiple microstructure units of the light guide structure per unit area is greater than the area ratio of the multiple microstructure units of the first microstructure.

7. The backlight module according to claim 1, characterized in that, Further includes: A reflective layer is disposed between the light-shielding sheet and the light-emitting unit, and completely covers the upper opening of the receiving hole.

8. The backlight module according to claim 1, characterized in that, The reflector is disposed on an area of ​​the circuit board not occupied by the light-emitting unit, and extends into the area within the inner edge of the receiving hole.

9. The backlight module according to claim 1, characterized in that, The light-emitting unit includes a red light chip, a green light chip, and a blue light chip, and the red light chip, the green light chip, and the blue light chip are arranged sequentially along the direction.

10. The backlight module according to claim 1, characterized in that, The light-emitting unit includes a blue light chip and phosphor covering the blue light chip.

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