Backlight module and input device
By designing light guides with curved sides and smooth profiles, the problems of illumination light not easily reflected and uneven brightness in the prior art are solved, and better light mixing benefits and uniform brightness are achieved.
Patent Information
- Application Number
- CN202310999239.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-09
- Publication Date
- 2025-02-18
AI Technical Summary
The light guide plate design in the prior art results in the illumination light being less likely to produce secondary reflection, lacks the benefit of mixing light, and is uneven brightness.
A light guide with arc-shaped sides is adopted, and its contour shape is changed to smooth lines, increasing the number of reflections of the light of the light emitting component in the light guide, and improving the reflection efficiency of the light through a virtual elliptical arc design.
It effectively improves the brightness uniformity of the edges and corners of the light guide, improves the light mixing benefits of the backlight module, and provides a backlight module and input device with uniform brightness.
Smart Images
Figure CN119471888A_ABST
Abstract
Description
Technical Field
[0001] The present invention provides a backlight module and an input device, and more particularly, a backlight module and an input device capable of providing uniform brightness. Background Art
[0002] See also Figure 6 , Figure 6 FIG. 6 is a schematic diagram of a light guide plate 60 and a light emitting unit 62 in the prior art. The light guide plate 60 is generally designed to be rectangular, and the light emitting unit 62 is disposed on one side of the light guide plate 60. The illumination light output by the light emitting unit 62 enters the light guide plate 60 and is transmitted to other positions of the light guide plate 60 by total internal reflection. Figure 6 As shown, the rectangular light guide plate 60 will make it difficult for the illumination light to generate secondary reflection, the illumination light cannot be effectively utilized and lacks light mixing effect, and the light guide plate 60 will have the disadvantage of uneven illumination brightness. Summary of the invention
[0003] In view of the problems in the prior art, the present invention provides a power conversion system to solve the above problems.
[0004] Therefore, the technical problem to be solved by the present invention is to provide a backlight module for illuminating the symbols of the input interface, and the backlight module comprises: a light emitting component; and A light guide having a first end edge, a second end edge and a third end edge connected to each other, and the light guide also has a top surface and a bottom surface that are relatively positioned, the first end edge is close to the light-emitting component, the second end edge and the third end edge are respectively arc-shaped and respectively connected to the first end edge, and at least one of the top surface and the bottom surface is provided with a light extraction structure, which guides the light output by the light-emitting component to the symbol of the input interface.
[0005] As an optional technical solution, the second end edge is an arc segment of a virtual ellipse, and the light-emitting component is located at a focal position of one of two elliptical foci of the virtual ellipse.
[0006] As an optional technical solution, the first end edge is located between the two foci of the ellipse and adjacent to the light-emitting component.
[0007] As an optional technical solution, the third end edge is connected to an end of the first end edge relative to the second end edge, and the arc-shaped second end edge increases the amount of light reflected to the third end edge.
[0008] As an optional technical solution, the third end edge is the same as or different from the arc shape of the second end edge.
[0009] As an optional technical solution, the light guide also has a fourth end edge, which is connected between the second end edge and the third end edge, and the fourth end edge is opposite to the first end edge, the second end edge and the third end edge are two arc segments of the virtual ellipse on the major axis, and the first end edge and the fourth end edge are located between the two elliptical foci of the virtual ellipse.
[0010] As an optional technical solution, the fourth end edge is arc-shaped or straight-line-shaped.
[0011] As an optional technical solution, the virtual ellipse has an image focus at the position of the fourth end side relative to one of the two ellipse foci, and the light is focused on the image focus through reflection from the second end side and the fourth end side.
[0012] As an optional technical solution, the second end edge is a portion of a conic curve, a hyperbola or an aspherical curve; or The first end edge is in a straight line shape. The backlight module further comprises a shading component. The shading component forms an escape space in a region adjacent to the first end edge for accommodating the light emitting component.
[0013] The present invention further provides an input device capable of providing uniform brightness. The input device comprises the backlight module and the input interface as described above.
[0014] Compared with the prior art, the backlight module and input device of the present invention are designed with a light guide having curved sides, and the contour shape of the light guide is changed to a smooth line, which can prevent the light guide from being displaced when the waste material is removed. Furthermore, the two curved sides of the light guide can be symmetrical or asymmetrical to each other, which is used to increase the number of reflections of the light of the light-emitting component in the light guide, which can effectively improve the brightness uniformity of the edges and corners of the light guide, thereby improving the light mixing effect of the backlight module.
[0015] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a top view of the structure of the input device according to an embodiment of the present invention.
[0017] Figure 2 for Figure 1 Side view along section line AA'.
[0018] Figure 3 FIG. 1 is a schematic diagram of a light emitting component and a light guide member according to a first embodiment of the present invention.
[0019] Figure 4 FIG. 4 is a schematic diagram of a light emitting component and a light guide member according to a second embodiment of the present invention.
[0020] Figure 5 FIG. 4 is a schematic diagram of a light emitting component and a light guide member according to a third embodiment of the present invention.
[0021] Figure 6 FIG. 1 is a schematic diagram of a light guide plate and a light emitting unit in the prior art. Implementation
[0022] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.
[0023] See also Figure 1 to Figure 2 , Figure 1 A top view of the structure of an input device according to an embodiment of the present invention; Figure 2 For along Figure 1 The input device 10 is a side view drawn by the section line A-A'. The input device 10 may be a touch panel or a touch device with similar functions. The input device 10 may include a backlight module 12 and an input interface 14. The input interface 14 may be various types of touch interfaces, which are not described in detail herein. The backlight module 12 may include a circuit board 16, a light emitting component 18, a light guide 20 and a shading component 22. The light emitting component 18 may be disposed on the circuit board 16. The light guide 20 is located on the side of the light emitting component 18 to provide a side-entry backlight function. The light guide 20 may have a top surface 201 and a bottom surface 202 that are positioned opposite to each other. The top surface 201 or the bottom surface 202 may be selectively provided with a light extraction structure 203 (that is, at least one of the top surface 201 and the bottom surface 202 may be provided with a light extraction structure 203) to guide light to the symbol 141 on the input interface 14; Figure 1 The illustrated embodiment places the light extraction structure 203 on the bottom surface 202, but the light extraction structure 203 may also be located on the top surface 201. The light extraction structure 203 may be a micro-prism or white dot printing, but the actual application is not limited thereto.
[0024] The shading component 22 forms an escape space 23 in the area adjacent to the light emitting component 18. It can also be considered that in the area adjacent to the light emitting component 18, the shading component 22 and the light guide 20 cooperate to form an escape space 23 for accommodating the light emitting component 18, and the distance between the light emitting component 18 and the first end edge 28 of the light guide 20 can be approximately between 0.1 mm and 0.5 mm, depending on the overall size of the backlight module 12. The edge profile of the light guide 20 can be relatively smooth, without obvious convex and concave shapes, so that when the waste of the light guide 20 is removed, the displacement of the light guide 20 due to the traction of the waste can be effectively avoided. In addition, a reflective layer 24 can be selectively set between the light guide 20 and the circuit board 16, and between the shading component 22 and the circuit board 16. A shielding layer 26 can also be selectively set between the backlight module 12 and the input interface 14. Generally speaking, the shielding layer 26 has a light-transmitting area 261 and a light-shielding area 262. The light-transmitting area 261 corresponds to the input interface 14, and specifically, may correspond to the symbol 141 on the input interface 14. The main body of the shielding layer 26 may be a transparent film, and black or dark ink may be printed on the upper or lower surface of the transparent film to form the light-shielding area 262. The area of the transparent film without the black or dark ink printed is the light-transmitting area 261. In this embodiment, corresponding to part of the light-shielding area 262, black or dark ink is printed on the lower surface of the transparent film, and corresponding to another part of the light-shielding area 262, black or dark ink is printed on the upper surface of the transparent film, but the actual application is not limited thereto. The diaphragms of the input device 10 are not limited to the above-mentioned embodiments, and it depends on the design requirements.
[0025] See also Figure 3 , Figure 3Schematic diagram of the light emitting component 18 and the light guide 20 according to the first embodiment of the present invention. The light guide 20 can be aligned with the light emitting component 18 to guide the light outputted by the light emitting component 18. The light guide 20 can include a first end edge 28, a second end edge 30, a third end edge 32 and a fourth end edge 34 connected to each other. The first end edge 28 faces and is close to the light emitting component 18. In one embodiment, the distance between the light emitting component 18 and the first end edge 28 of the light guide 20 can be approximately between 0.1 mm and 0.5 mm, depending on the overall size of the backlight module 12. The second end edge 30 and the third end edge 32 are arc-shaped and are connected and disposed at two opposite ends of the first end edge 28, respectively. The arc curvature of the second end edge 30 can be the same or different from the arc curvature of the third end edge 32, so that the shapes of the second end edge 30 and the third end edge 32 can be the same or different. The two opposite ends of the fourth end side 34 are respectively connected to the second end side 30 and the third end side 32, and the positions thereof are relative to the first end side 28. That is, the first end side 28, the second end side 30, the fourth end side 34 and the third end side 32 are sequentially connected, the first end side 28 and the fourth end side 34 are arranged opposite to each other, and the second end side 30 and the third end side 32 are arranged opposite to each other. In the first embodiment, the first end side 28 and the fourth end side 34 are designed as a straight line, but the actual application is not limited thereto.
[0026] The arc-shaped features of the second edge 30 and the third edge 32 can increase the number of reflections of light in the light guide 20 to improve the edge brightness, so that the backlight module 12 provides uniform brightness. Therefore, the second edge 30 and the third edge 32 can be designed as virtual ellipses (such as Figure 3 The second end side 30 and the third end side 32 are usually two arc sections of the virtual ellipse on the major axis, but the actual application is not limited thereto; for example, the second end side 30 and / or the third end side 32 may be partial sections of a conic curve, a hyperbola or an aspheric curve. The first end side 28 is located between the two ellipse foci F1 and F2 of the virtual ellipse and is adjacent to the light emitting component 18, and the fourth end side 34 is also located between the two ellipse foci F1 and F2 of the virtual ellipse; that is, the ellipse foci F1 and F2 are located outside the light guide 20, and the light emitting component 18 is arranged at the ellipse focus F1 to transmit light into the light guide 20.
[0027] The virtual ellipse may have a mapping focus F2' relative to the ellipse focus F2. In one embodiment, the ellipse focus F2 and the mapping focus F2' are symmetrical relative to the fourth end edge 34. Since the arc design of the second end edge 30 can increase the amount of light reflected to the third end edge 32, and the arc design of the third end edge 32 can increase the amount of light reflected to the second end edge 30, the light emitted by the light emitting component 18 enters the light guide 20 through the first end edge 28, and can be converged at the mapping focus F2' of the virtual ellipse (such as the fourth end edge 34) through multiple reflections of the second end edge 30, the third end edge 32 and the fourth end edge 34. Figure 3 The light guide 20 is preferably arranged in a direction of the arrow shown in the figure, thereby improving the brightness of the second end side 30 and the third end side 32 of the light guide 20, so that the entire light guide 20 can have a uniform brightness distribution.
[0028] The backlight module of the present embodiment has a light guide 20 with curved sides. Furthermore, the light guide 20 has two curved sides. The curved second end side 20 and the third end side 32 can be symmetrical or asymmetrical to each other, so as to increase the number of reflections of the light of the light emitting component 18 in the light guide 20, and can effectively improve the brightness uniformity of the edges and corners of the light guide 20, thereby improving the light mixing effect of the backlight module.
[0029] See also Figure 4 , Figure 4 Schematic diagram of the light emitting component 18 and the light guide 20A of the second embodiment of the present invention. In the second embodiment, the components with the same number as the first embodiment have the same structure and function, and will not be repeated here. In the first embodiment, the light guide 20 has two arc-shaped side edges. In this embodiment, the light guide 20A may include a first end edge 28A, a second end edge 30A, a third end edge 32A and a fourth end edge 34A connected to each other. Specifically, the first end edge 28A, the second end edge 30A, the fourth end edge 34A and the third end edge 32A are connected in sequence and have corresponding ellipse foci F1 and F2. The second end edge 30A and the third end edge 32A may be two arc-shaped sections of the virtual ellipse on the major axis, or partial sections of a conic curve, a hyperbola, or an aspheric curve, and may be two arc-shaped sections that are the same or different from each other. The first end side 28A is generally still designed as a straight line; while the fourth end side 34A may be designed as an arc, which may be the same as or different from the arc of the second end side 30A or the third end side 32A.
[0030] The light emitting component 18 may be disposed at the position of the ellipse focus F1. A portion of the light emitting component 18 may pass through the ellipse focus F2 via reflection from the second end edge 30A, and another portion of the light emitting component 18 may pass through the ellipse focus F2 via reflection from the third end edge 32A, thereby passing through most areas of the light guide 20A, which may effectively improve the brightness uniformity of the edges and corners of the light guide 20A and enhance the overall brightness distribution of the light guide 20A.
[0031] The backlight module of the present embodiment has a light guide 20A with curved sides. Furthermore, the light guide 20 has three curved sides. The curved second end side 20A, the third end side 32A and the fourth end side 34A can be symmetrical or asymmetrical with each other, so as to increase the number of reflections of the light of the light emitting component 18 in the light guide 20A, and can effectively improve the brightness uniformity of the edges and corners of the light guide 20A, thereby improving the light mixing effect of the backlight module.
[0032] See also Figure 5 , Figure 5 Schematic diagram of the light emitting component 18 and the light guide 20B of the third embodiment of the present invention. In the third embodiment, the components with the same number as the above-mentioned embodiments have the same structure and function, and will not be repeated here. The light guide 20B can be matched with two or more light emitting components 18. The light guide 20B may include a first end 28B, a second end 30B, a third end 32B and a fourth end 34B connected to each other. Specifically, the first end 28B, the second end 30B, the fourth end 34B and the third end 32B are connected in sequence, the first end 28B and the fourth end 34B are arranged opposite to each other, and the second end 30B and the third end 32B are arranged opposite to each other. Figure 5 As shown, in this embodiment, two light-emitting components 18 are arranged on the outer side of the first end edge 28B, and the light output by the light-emitting component 18 close to the third end edge 32B can be reflected from the third end edge 32B and the fourth end edge 34B to the second end edge 30B, wherein the light output by the light-emitting component 18 close to the second end edge 30B can be reflected from the second end edge 30B and the fourth end edge 34B to the third end edge 32B, thereby significantly improving its light mixing efficiency.
[0033] In the backlight module of this embodiment, the light guide has at least two curved sides, which can be symmetrical or asymmetrical to each other, and are used to increase the number of reflections of the light of the light-emitting component in the light guide, which can effectively improve the brightness uniformity of the edges and corners of the light guide, thereby improving the light mixing effect of the backlight module.
[0034] In summary, the backlight module and input device of the present invention are designed with a light guide having curved sides, and the contour shape of the light guide is changed to a smooth line, which can prevent the light guide from being displaced when the waste material is removed. Furthermore, the two curved sides of the light guide can be symmetrical or asymmetrical to each other, which is used to increase the number of reflections of the light of the light-emitting component in the light guide, which can effectively improve the brightness uniformity of the edges and corners of the light guide, thereby improving the light mixing effect of the backlight module.
[0035] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims attached to the present invention.
Claims
1. A backlight module for illuminating a symbol of an input interface, characterized in that: The backlight module includes: a light emitting component; and A light guide having a first end edge, a second end edge and a third end edge connected to each other, and the light guide also has a top surface and a bottom surface that are relatively positioned, the first end edge is close to the light-emitting component, the second end edge and the third end edge are respectively arc-shaped and respectively connected to the first end edge, and at least one of the top surface and the bottom surface is provided with a light extraction structure, which guides the light output by the light-emitting component to the symbol of the input interface.
2. The backlight module according to claim 1, wherein: The second end edge is an arc section of a virtual ellipse, and the light-emitting component is located at a focal position of one of two ellipse foci of the virtual ellipse.
3. The backlight module according to claim 2, wherein: The first end edge is located between the two ellipse foci and is adjacent to the light emitting component.
4. The backlight module according to claim 1, wherein: The third end edge is connected to an end of the first end edge opposite to the second end edge, and the arc-shaped second end edge increases the amount of light reflected to the third end edge.
5. The backlight module according to claim 4, characterized in that: The third end edge is the same as or different from the arc shape of the second end edge.
6. The backlight module according to claim 4, wherein: The light guide also has a fourth end edge, which is connected between the second end edge and the third end edge, and the fourth end edge is opposite to the first end edge. The second end edge and the third end edge are two arc segments of the virtual ellipse on the major axis, and the first end edge and the fourth end edge are located between the two elliptical foci of the virtual ellipse.
7. The backlight module according to claim 6, wherein: The fourth end edge is arc-shaped or straight-line-shaped.
8. The backlight module according to claim 6, wherein: The virtual ellipse has a mapping focus at a position of the fourth end side relative to one of the two ellipse foci, and the light is focused on the mapping focus through reflection from the second end side and the fourth end side.
9. The backlight module according to claim 1, wherein: The second end edge is a portion of a conic curve, a hyperbola or an aspherical curve; or The first end edge is in a straight line shape. The backlight module further comprises a shading component. The shading component forms an escape space in a region adjacent to the first end edge for accommodating the light emitting component.
10. An input device capable of providing uniform brightness, characterized in that: The input device comprises the backlight module and an input interface as claimed in any one of claims 1 to 9.