Front light module with light guide strip and electronic reader

Abstract

The utility model relates to a front light module with a light guide strip and an electronic reader. A front light module with a light guide strip comprises a point light source, the light guide strip and a front light plate. The light guide strip comprises a light incident surface, a reflecting surface connected with the light incident surface, a light emergent surface connected with the light incident surface and opposite to the reflecting surface, and a plurality of first microstructures arranged on the reflecting surface, and the first microstructures are asymmetric microstructures. The front light plate is provided with a reference surface facing the light emitting surface of the light guide strip and a plurality of second microstructures arranged on the reference surface. Light rays of the point light source form a line light source after passing through the light guide strip and then form an area light source after passing through the front light plate, and the first microstructures of the light guide strip are matched with the second microstructures of the front light plate, so that the light mixing distance can be reduced, the display range can be enlarged, and the requirement of a narrow frame is met. The utility model also provides an electronic reader comprising the front light module.

Description

Technical Field

[0001] The utility model relates to an optical component, in particular to a front light module and an e-reader. Background Art

[0002] Currently, in order to enable users to clearly see the content presented on the e-reader in both dark or bright light environments, a front-lit display is adopted in the e-reader. The front-lit display includes a front light module and a display panel. The front light module includes a front light plate and a light-emitting unit arranged adjacent to each other. The front light plate has a light-emitting surface, and the light emitted by the light-emitting unit enters one end of the front light plate and is emitted to the display panel through the refraction of the front light plate. The display panel then emits the light from the light-emitting surface to the user's eyes. The front-lit display forms an image by reflecting light, thereby avoiding the interference of light in a bright light environment on the display imaging.

[0003] With the development of technology, portable electronic products not only increasingly emphasize the design of narrow borders to increase the display area, but also must ensure the uniformity of the light-emitting surface and avoid the problem of bright spots (hotspots) at the edge of the light-emitting surface on the premise of achieving narrow borders. Therefore, how to improve the internal structure of existing products to increase the display range and provide better light-emitting uniformity is an important research and development goal for related manufacturers. Summary of the Utility Model

[0004] Therefore, the purpose of the present utility model is to provide a front light module that can reduce the light mixing distance to increase the display range and improve the light-emitting uniformity at the edge.

[0005] A front light module with a light guide bar includes a point light source, a light guide bar for receiving the light of the point light source, and a front light plate for receiving the light emitted from the light guide bar. The light guide bar includes a light incident surface, a reflection surface connected to the light incident surface, a light-emitting surface connected to the light incident surface and opposite to the reflection surface, and a plurality of first microstructures arranged on the reflection surface. Each of the first microstructures is an asymmetric microstructure. The front light plate has a reference surface facing the light-emitting surface of the light guide bar, and a plurality of second microstructures arranged on the reference surface.

[0006] Another technical means of the present utility model is that each of the first microstructures of the light guide bar has a light-facing surface for reflecting light, and the included angle θ between the light-facing surface and the reflection surface is 3 to 25 degrees, including the end values.

[0007] Another technical means of the present utility model is that the first microstructures of the light guide bar are asymmetric convex points, and the distribution density of the first microstructures is denser along the direction away from the point light source.

[0008] Another technical means of the present utility model lies in that the cross-sectional shape of each of the second microstructures on the front light plate is an isosceles triangle.

[0009] Another technical means of the present utility model lies in that the cross-sectional shape of each of the second microstructures on the front light plate is a non-isosceles triangle, and has a first acting surface and a second acting surface connected thereto. The first acting surface is farther from the point light source relative to the second acting surface. There is a first included angle θ1 between the first acting surface and the reference plane, and a second included angle θ2 between the second acting surface and the reference plane. The first included angle θ1 is less than the second included angle θ2.

[0010] Another technical means of the present utility model lies in that the size of the first included angle θ1 is 50 to 70 degrees, and the size of the second included angle θ2 is 70 to 90 degrees, including the end values.

[0011] Another technical means of the present utility model lies in that the light guide bar further includes a plurality of strip-shaped microstructures disposed on the light-emitting surface, and the strip-shaped microstructures extend along a first direction.

[0012] Another technical means of the present utility model lies in that the second microstructures extend along a second direction, and the first direction is perpendicular to the second direction.

[0013] Another technical means of the present utility model lies in that each of the strip-shaped microstructures is an arc surface with a central angle of 70 to 100 degrees, including the end values.

[0014] Another technical means of the present utility model lies in that the thickness of the light guide bar gradually decreases along the direction away from the point light source.

[0015] Another technical means of the present utility model lies in that the front light module further includes at least one reflector covering the light guide bar, and the reflector covers the area other than the light-emitting surface of the light guide bar.

[0016] Another technical means of the present utility model lies in that the front light module further includes at least one light-shielding member covering the light guide bar, and the light-shielding member covers one end of the light guide bar adjacent to the point light source but does not shield the light-incident surface of the light guide bar.

[0017] Another technical means of the present utility model lies in that the light-shielding member and the reflector do not overlap.

[0018] Another object of the present utility model is to provide an e-reader, including a front light module as described above, and a display panel disposed on the front light module.

[0019] The efficacy of the present utility model lies in that the light of the point light source forms a line light source after passing through the light guide bar, and then forms a surface light source after passing through the front light plate. With the first microstructures on the reflection surface of the light guide bar and in cooperation with the second microstructures of the front light plate, the mixing light distance at the light incident edge of the front light plate can be reduced, and the display range can be increased, meeting the requirements of a narrow-bezel e-reader. Brief Description of the Drawings

[0020] Figure 1 is a schematic diagram, which is a preferred embodiment of the front light module of the present utility model;

[0021] Figure 2 is a schematic diagram, which is Figure 1 with a light-shielding member and a reflecting member that shield a light guide bar in it partially removed;

[0022] Figure 3 is a side cross-sectional view, which is the view of the cutting line III-III in Figure 2 illustrating the relative positional relationship between the reflecting member and the light guide bar;

[0023] Figure 4 is a side schematic diagram, illustrating the relative positional relationship between the light-shielding member and the light guide bar;

[0024] Figure 5 is a top schematic diagram, illustrating the morphology of multiple first microstructures of the light guide bar;

[0025] Figure 6 is a bottom schematic diagram, illustrating the morphology of multiple strip-shaped microstructures of the light guide bar;

[0026] Figure 7 is a schematic diagram, illustrating Figure 2 the partial enlargement of the framed part in

[0027] Figure 8 is a side schematic diagram, which is a preferred embodiment of the e-reader of the present utility model. Detailed Description of the Preferred Embodiment

[0028] Regarding the relevant patented features and technical content of the present utility model, they will be clearly presented in the following detailed description of the preferred embodiment with reference to the drawings. It should be noted before the detailed description that similar elements are denoted by the same reference numerals. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front, back, bottom, top, etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for illustration purposes and not to limit the present utility model.

[0029] Refer to Figure 1 and Figure 2, which is the first preferred embodiment of the front light module of the present utility model, includes a point light source 2, a light guide bar 3 for receiving the light of the point light source 2, and a front light plate 4 for receiving the light emitted from the light guide bar 3. As Figure 2 shown, the light guide bar 3 includes a light incident surface 31, a reflection surface 32 connected to the light incident surface 31, a light exit surface 33 connected to the light incident surface 31 and opposite to the reflection surface 32, and a plurality of first microstructures 34 disposed on the reflection surface 32. Among them, each of the first microstructures 34 is an asymmetric microstructure. The front light plate 4 has a reference surface 41 facing the light exit surface 33 of the light guide bar 3, and a plurality of second microstructures 42 disposed on the reference surface 41. For example, the point light source 2 can be a set of multiple LEDs, and is correspondingly disposed on the light incident surface of the light guide bar 3. In the case where high brightness is not required, the point light source 2 can also be selected as a single LED. Preferably, the light exit surface of the single LED can correspondingly cover the range of the light incident surface 31 of the light guide bar 3. Through the above design, the light of the point light source 2 forms a line light source after passing through the light guide bar 3, and then forms a surface light source after passing through the front light plate 4. With the first microstructures 34 on the reflection surface 32 of the light guide bar 3 and the cooperation of the second microstructures 42 of the front light plate 4, the mixing distance of the light at the light incident edge of the front light plate 4 can be reduced, and the display range can be increased, meeting the requirements of a narrow border e-reader.

[0030] For example, in this embodiment, a single LED4 is used as the light source of the front light module, and no bright spot distribution similar to that of a conventional e-reader will be generated at its edge. In particular, the use of the second microstructures 42 can further evenly disperse the light in the front light plate 4. It should be noted that the front light plate 4 includes a light exit surface 43 connected to the reference surface 41, and a plurality of reflection microstructures 44 are provided on the light exit surface 43, similar to the first microstructures 34 of the light guide bar 3, and the reflection microstructures 44 (shown in Figure 8 ) are arranged on the light exit surface 43 in a manner of being sparse to dense along the light traveling direction (the third direction D3). More specifically, after the front light plate 4 receives the light from the light guide bar 3, the light traveling along the Y direction (such as the third direction D3) inside the front light plate 4 can be reflected by the reflection microstructures 44 on the light exit surface 43 and turned to the Z direction (the second direction D2), and hits the display panel 5 located on the bottom surface as shown in Figure 8 , and is reflected and then emitted from the light exit surface 43 of the front light plate 4. For example, the reflection microstructures 44 are microstructures recessed in the light exit surface 43, and their shapes can be symmetric or asymmetric.

[0031] The front light module further includes at least one reflector 35 covering the light guide bar 3 and at least one light shield 36 covering the light guide bar 3. For the convenience of explaining the detailed structure and the traveling direction of the light, in Figure 2 , a part of the reflector 35 and the light shield 36 are removed. Among them,Figure 3 is Figure 2 a sectional view at the position of the center cutting line III-III, as Figure 3 shown, the reflector 35 covers the area other than the light-emitting surface 33 of the light guide bar 3. Refer to Figure 2 and Figure 4 shown, the light-shielding member 36 covers one end of the light guide bar 3 adjacent to the point light source 2 but does not shield the light-incident surface 31 of the light guide bar 3. As Figure 2 shown, in this embodiment, the covering positions of the reflector 35 and the light-shielding member 36 do not overlap each other. It should be noted that the light-shielding member 36 is to prevent the light of the point light source 2 from directly emitting light after entering the light guide bar 3 and forming light leakage. Therefore, it covers one end of the light guide bar 3 adjacent to the point light source 2 but does not shield the light-incident surface 31, ensuring that the light of the point light source 2 can enter through the light-incident surface 31 and continue to travel in the light guide bar 3, and at the same time, it can also provide a sufficient light mixing distance. Since most of the light in the light guide bar 3 is reflected by the first micro-structure 34 and then turns to emit light from the light-emitting surface 33, and a small part of the light will be emitted from the reflecting surface 32 of the light guide bar 3. Therefore, the reflector 35 is used to reflect the light in the light guide bar 3 that is not reflected by the first micro-structure 34 back into the light guide bar 3 after being reflected by the reflector 35, and then emit light from the light-emitting surface 33. In this way, the light utilization rate can be improved. Therefore, except for the light-emitting surface 33 of the light guide bar 3 and the area covered by the light-shielding member 36, almost all of the light guide bar 3 is shielded by the reflector 35.

[0032] Refer to Figure 5 , which is a top view of the light guide bar 3 after removing the reflector 35. The first micro-structure 34 of the light guide bar 3 is an asymmetric convex point, and the distribution density of the first micro-structure 34 is denser along the direction away from the point light source 2. That is to say, the arrangement density of the first micro-structure 34 increases as the distance from the point light source 2 increases. By arranging the first micro-structure 34 with different densities, the light emission can be made more uniform. It should be noted that the first micro-structure 34 is an integrally formed structure of the light guide bar 3, so there is no physical boundary line between the first micro-structure 34 and the reflecting surface 32 on the light guide bar 3.

[0033] Refer to Figure 6 and Figure 7 , the light guide bar 3 further includes a plurality of strip-shaped micro-structures 37 disposed on the light-emitting surface 33, and the strip-shaped micro-structures 37 extend along a first direction D1. The first direction D1 is parallel to the optical axis of the point light source 2. Among them, as Figure 3As shown, each of the strip-shaped microstructures 37 is an arc surface with a central angle of 70 to 100 degrees, including the end values. In this embodiment, the light traveling along the X direction inside the light guide bar 3 is reflected by the first microstructure 34 on the reflecting surface 32 to form a directional light. Then, the strip-shaped microstructure 37 on the light-emitting surface 33 can expand the light that has been turned to the Y direction along the YZ plane formed by the Y direction and the Z direction, which is beneficial for the second microstructure 42 of the lower front light plate 4 to receive the light. Further, it is explained that the extending direction of the strip-shaped microstructure 37 intersects with the extending direction of the second microstructure 42, which is beneficial to expand the directional direction along different planes, such as the YZ plane and the XY plane, to increase the breadth of the light path. More specifically, each of the strip-shaped microstructures 37 has an arc-shaped periphery in a second direction D2, and the shape and length of the arc-shaped periphery correspond to the arc shape and length with a central angle of 70 to 100 degrees, wherein the first direction D1 is perpendicular to the second direction D2.

[0034] Referring to Figure 7 , which is Figure 2 an enlarged view of the framed area A in [reference], each of the first microstructures 34 of the light guide bar 3 is an asymmetric microstructure, and each of the first microstructures 34 has a light-facing surface 341 for reflecting light. The included angle θ between the light-facing surface 341 and the reflecting surface 32 is 3 to 25 degrees, including the end values.

[0035] The second microstructure 42 of the front light guide plate 4 extends along the second direction D2. Wherein, the cross-sectional shape of each of the second microstructures 42 of the front light guide plate 4 along the first direction D1 is a non-isosceles triangle, and has a connected first working surface 421 and a second working surface 422. The first working surface 421 is farther from the point light source 2 than the second working surface 422. The first working surface 421 and the second working surface 422 of each of the second microstructures 42 extend along the second direction D2. There is a first included angle θ1 between the first working surface 421 and the reference surface 41, and there is a second included angle θ2 between the second working surface 422 and the reference surface 41, and the first included angle θ1 is less than the second included angle θ2. The size of the first included angle θ1 is 50 to 70 degrees, and the size of the second included angle θ2 is 70 to 90 degrees, including the end values. Thus, by using the second microstructures 42 arranged along the X direction and being asymmetric to receive the light from the light guide bar 3, especially when the included angle between these lights and the Y direction is about 60 to 75 degrees, so each first included angle θ1 with a smaller angle can efficiently receive the aforementioned oblique light from the light guide bar 2 and can effectively reflect the aforementioned light in the Y direction and travel. In some embodiments, the cross-sectional shape of each of the second microstructures 42 can also be an isosceles triangle, which has the advantage of being easy to fabricate. It should be noted that the second microstructure 42 is a microstructure for refracting and reflecting light on the reference surface 41 of the front light guide plate 4, and the second microstructure 42 is an integrally formed structure on the front light guide plate 4, and there is no physical boundary line between the second microstructure 42 and the reference surface 41 on the front light guide plate 4.

[0036] Refer to Figure 2 and Figure 7 , since the light guide bar 3 is covered by the light shielding member 36 and the reflecting member 35, when the light of the point light source 2 enters the light guide bar 3 from the light incident surface 31, it will be reflected in the light guide bar 3 and exit from the area of the light exit surface 33 not covered by the light shielding member 36 and the reflecting member 35. Wherein, the asymmetric first microstructures 34 are formed on the reflecting surface 32 of the light guide bar 3, and the light will be reflected by the reflecting surface 32 and the light incident surface 341 of each of the first microstructures 34 and exit from the light exit surface 33. Through the angle design of the included angle θ between the light incident surface 341 and the reflecting surface 32, the light can be reflected in the direction of the light exit surface 33. It should be noted that the reflecting member 35 has the characteristic of specular reflection, which can ensure no light leakage and improve the light reuse rate. In addition, due to the characteristic of specular reflection of the reflecting member 35 being parallel reflection, and the first microstructures 34 on the light guide bar 3 all have high light directivity, it is beneficial for the subsequent front light guide plate 4 to receive light at the correct angle.

[0037] Next, in cooperation with the arc-shaped surface with a central angle of 70 to 100 degrees of the strip-shaped microstructures 37 on the light-emitting surface 33, the light-emitting angle is further concentrated, so that when the light passes through the light-emitting surface 33 of the light guide bar 3, it has a light-emitting angle of 60 to 75 degrees. By using the above-mentioned structural design of the light guide bar 3, the light of the point light source 2 can be transformed into a uniform linear light source, and the design of the first microstructures 34 can make the luminous intensity at each position in the linear light source equal. In addition, in this embodiment, the thickness of the light guide bar 3 tapers along the direction away from the point light source 2, and the area of the reverse light-incident surface is smaller than that of the light-incident surface, so that the light guide bar 3 forms a wedge shape, and its shape design is to improve the light utilization rate. For example, the light emitted by the LED has a specific angle range. For easier understanding, only the light rays L1, L2, and L3 presented in Figure 2 are used for illustration. The light ray L1 that first hits the first microstructures 34 in the front section will be reflected and redirected earlier than the light ray L2, and the light ray L2 will be reflected and redirected earlier than the light ray L3. In this way, light rays at different angles can be diffusely reflected along the first direction D1, so that the effect of improving the light utilization rate can be achieved. However, if the size of the point light source 2 is small, the light guide bar 3 can also be a long strip with a uniform thickness, not limited to what is disclosed in this embodiment.

[0038] After the light of the point light source 2 is transformed into a linear light source and emitted through the light guide bar 3, it then enters the front light plate 4. At this time, the light will be refracted through the second acting surface 422 of each of the second microstructures 42, and then reflected through the first acting surface 421 to redirect the light in a direction perpendicular to and away from the reference surface 41, so that the front light plate 4 forms a surface light source. Refer to Figure 8 A display panel 5 is disposed at an interval from the bottom surface of the front light plate 4 opposite to the light-emitting surface 43, which is a preferred embodiment of the electronic reader of the present invention.

[0039] To sum up, the front light module of the present invention uses the structural design of the light guide bar 3 to make the light of the point light source 2 form a linear light source after passing through the light guide bar 3, and then form a surface light source after passing through the front light plate 4. By means of the first microstructures 34 on the reflecting surface 32 of the light guide bar 3 and in cooperation with the second microstructures 42 of the front light plate 4, the mixing distance at the light-incident edge of the front light plate 4 can be reduced, and the display range can be increased, meeting the requirements of a narrow-bezel electronic reader, and indeed achieving the purpose of the present invention.

[0040] However, the above are only the preferred embodiments of the present invention, and the scope of implementation of the present invention cannot be limited thereby. That is, all simple equivalent changes and modifications made according to the description of the present invention and the content of the utility model description still fall within the scope covered by the patent of the present invention.

[0041]

Symbol Explanation

[0042] 2 Point light sources

[0043] 3 Light guide bars

[0044] 31 Light incident surface

[0045] 32 Reflective surface

[0046] 33 Light exit surface

[0047] 34 First microstructure

[0048] 341 Light-facing surface

[0049] 35 Reflective member

[0050] 36 Light-shielding member

[0051] 37 Striped microstructure

[0052] 4 Front light plate

[0053] 41 Reference plane

[0054] 42 Second microstructure

[0055] 421 First acting surface

[0056] 422 Second acting surface

[0057] 43 Light exit surface

[0058] 44 Reflective microstructure

[0059] 5 Display panel

[0060] A At the boxed area

[0061] D1 First direction

[0062] D2 Second direction

[0063] θ Angle

[0064] θ1 First angle

[0065] θ2 Second angle.

Claims

1. A front light module with a light guide strip, characterized in that: Include: Point light source; a light guide bar for receiving light from the point light source, the light guide bar comprising a light incident surface, a reflective surface connected to the light incident surface, a light emitting surface connected to the light incident surface and opposite to the reflective surface, and a plurality of first microstructures disposed on the reflective surface, each of the first microstructures being an asymmetric microstructure; and The front light plate is used for receiving the light emitted from the light guide bar. The front light plate has a reference surface facing the light emitting surface of the light guide bar and a plurality of second microstructures arranged on the reference surface.

2. The front light module with light guide strip according to claim 1, characterized in that: Each of the first microstructures of the light guide strip has a light-facing surface for reflecting light, and an angle θ between the light-facing surface and the reflecting surface is 3 to 25 degrees, including end values.

3. The front light module with light guide strip according to claim 1, characterized in that: The first microstructure of the light guide strip is an asymmetric convex point, and the distribution density of the first microstructure becomes denser along the direction away from the point light source.

4. The front light module with light guide strip according to claim 1, characterized in that: The cross-sectional shape of each of the second microstructures of the front light plate is an isosceles triangle.

5. The front light module with light guide strip according to claim 1, characterized in that: The cross-sectional shape of each of the second microstructures of the front light plate is a non-isosceles triangle, and has a first active surface and a second active surface connected, the first active surface is farther away from the point light source than the second active surface, a first angle θ1 is formed between the first active surface and the reference plane, and a second angle θ2 is formed between the second active surface and the reference plane, and the first angle θ1 is smaller than the second angle θ2.

6. The front light module with light guide strip according to claim 5, characterized in that: The first angle θ1 is between 50 and 70 degrees, and the second angle θ2 is between 70 and 90 degrees, including end points.

7. The front light module with light guide strip according to claim 1, characterized in that: The light guide strip further comprises a plurality of strip-shaped microstructures arranged on the light emitting surface, and the strip-shaped microstructures extend along a first direction.

8. The front light module with light guide strip according to claim 7, characterized in that: The second microstructure extends along a second direction, and the first direction is perpendicular to the second direction.

9. The front light module with light guide strip according to claim 7, characterized in that: Each of the strip-shaped microstructures is an arc surface with a central angle of 70 to 100 degrees, including endpoint values.

10. The front light module with light guide strip according to claim 1, characterized in that: The thickness of the light guide strip gradually decreases along a direction away from the point light source.

11. The front light module with light guide strip according to claim 1, characterized in that: It also comprises at least one reflective member covering the light guide bar, and the reflective member covers the area outside the light emitting surface of the light guide bar.

12. The front light module with light guide strip according to claim 11, characterized in that: The invention also comprises at least one light shielding member covering the light guide bar, wherein the light shielding member covers one end of the light guide bar adjacent to the point light source but does not shield the light incident surface of the light guide bar.

13. The front light module with light guide strip according to claim 12, characterized in that: The shading element does not overlap with the reflecting element.

14. An electronic reader, characterized in that: It comprises a front light module with a light guide strip as claimed in any one of claims 1 to 13, and a display panel spaced apart from the front light module.

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