TWI443287B - Light device with well-distributed light guiding - Google Patents

Description

Light-emitting device capable of uniformly guiding light

The invention relates to a light-emitting device, in particular to a light-emitting device capable of uniformly guiding a point light source.

Light emitting diodes (LEDs) have become a common trend as a light source for indicating and illuminating. However, due to the characteristics of the light-emitting diode itself, most of the light emitted from it is concentrated near the optical axis, and thus is generally regarded as a point light source. If a light-emitting diode is used as a short-distance projection light source, the brightness is too concentrated, and the product body using the light-emitting diode cannot visually design the characteristics of uniform light illumination. Usually, these products use the surface of the light source formed by a plurality of light-emitting diodes, and because of the characteristics of the light-emitting of each of the light-emitting diodes, the surface of the entire light source has a little high brightness distribution, so that the entire surface has a very high Obvious phenomenon of uneven brightness.

In order to improve the illuminating characteristics of most of the light-emitting diodes concentrated in the vicinity of the optical axis, there are several methods in the prior art: 1. The distance between the light-emitting diode source and the lamp or the projection surface is enlarged to make the light-emitting diode The effective cone area can cover a larger projected area due to the increased distance. 2. Change the position of the vertically projected light source to the side projection, and use the light to reflect or scatter to project to the luminaire or projection surface. 3. Add a light guide plate medium between the luminaire or the projection surface and the light source, which also increases the distance between the light source and the luminaire or projection surface. Regardless of the above three methods, it is possible to change the light characteristics of the light-emitting diode to produce a uniform light effect in a general application. However, more and more devices currently use LEDs as indicator light sources, such as buttons in mobile phones, illuminated keyboards, control buttons in operation panels, etc., a common feature of these applications is that The space and size of the button of the diode light source to the device are quite narrow, so the above-mentioned method of improving the light-emitting characteristics cannot be used to increase the distance between the light source and the button, or change the projection mode of the light source. Therefore, for the case where the visible area of these products (buttons) is larger than the effective light cone area of the light-emitting diodes, it is necessary to provide another solution that can increase the light-emitting angle of the light-emitting diodes to reduce the local light source excessive phenomenon.

In order to solve the above problem of light-emitting diode point illumination of a small-sized button, the present invention provides a light-emitting device capable of uniformly guiding light, comprising: a light source, a light-scattering element, and a casing. The light source is used to emit light along an exiting optical axis. The astigmatism element includes an astigmatism medium having a first surface and a second surface. The light source is disposed on a side of the first surface of the astigmatism element and the first surface is a conical surface. The outer casing is disposed on a side of the second surface of the astigmatism element, and the outer casing has a recess for accommodating the astigmatism element, the outer casing having a transparent area. Light emitted by the light source is first refracted through the first surface of the astigmatism element to deviate from the exit optical axis, and a uniform light source is formed through the second surface, and the transparent region surrounding the outer casing is emitted.

The light-emitting device of the present invention can make the light source capable of generating a surface light source having a larger exit angle and uniformly covering the surface of the outer casing to exhibit uniform light guiding characteristics without increasing the distance between the light source and the button housing. Provides good visual characteristics of the button housing of the illuminating device.

Please refer to FIG. 1 , which is a schematic diagram of components in an embodiment of a light-emitting device 10 according to the present invention. The illumination device 10 is preferably applied to electronic devices, particularly buttons, buttons, indicator lights, etc. on electronic devices having size limitations. The light emitting device 10 includes a light source 20, a light diffusing element 30, and a casing 40. The astigmatism element 30 is disposed between the light source 20 and the outer casing 40, and the light source 20 is preferably a point light source such as a light emitting diode (LED).

Referring to FIG. 2 together, FIG. 2 is a schematic view of the components of the light-emitting device 10 after assembly, wherein the outer casing 40 has a recess 41, and the astigmatism member 30 is received in the recess 41 of the outer casing 40, and the astigmatism member 30 The material may be polycarbonate or silicone, but the invention is not limited thereto. In addition, in an embodiment of the invention, the outer casing 40 of the light-emitting device 10 has an extension arm 43 that is fixed to the extension arm 43, which is suitable for use in some applications, the light source 20 and the outer casing 40. The size of the space is limited by the application and cannot be expanded (for example, a mobile phone or the like), and when the light source 20 is disposed on the extension arm 43, the light source 20 and a transparent area 42 of the outer casing (ie exposed An exit distance between the viewable area on the applied electronic device (e.g., the viewable area of the button exposed on a surface of the mobile phone) is fixed to match the size constraints of the application. However, the present invention does not For this reason, the light source 20 may not be disposed on the extension arm 43 of the outer casing 40, but may emit light to the transparent region 42 at other positions, so the distance between the light source 20 and the transparent region 42 is not necessarily fixed. of.

Please refer to FIG. 3, which is a schematic diagram of the outer casing 40 of the light-emitting device 10. As described above, the light-emitting device 10 is applied to a button, a button, an indicator light number, etc. having a size limitation on the electronic device, and has the same effect as the front cover 40 in order to generate an effect that the button is illuminated and lit. The transparent region 42, wherein the transparent region 42 can be at least a pattern of words to be displayed (as shown in FIG. 3) or a region of a specific area on the surface of the casing, and in other embodiments, the light-emitting device 10 The outer casing 40 can also be made of a transparent material, and the transparent area is a visible area that is visible to the human eye and exposed to the electronic device.

Please refer to FIG. 4 and FIG. 5 , wherein FIG. 4 is a schematic diagram of an angle of the astigmatism element 30 of the illuminating device 10 , and FIG. 5 is a schematic diagram of another angle of the astigmatism element 30 . As shown, the astigmatism element 30 has a first surface 31 and a second surface 32. The light source 20 is disposed on a first surface 31 facing the astigmatism element 30 in an opposing configuration with other elements of the illumination device 10. The side, while the second surface 32 of the astigmatism element 30 faces the recess 41 of the outer casing 40 (or the outer casing 40 is disposed on the side facing the second surface 32 of the astigmatism element 30). In order to make the light-emitting device 10 have uniform light guiding and can effectively increase the exit angle of the light source 20, in the embodiment of the present invention, the astigmatism element 30 uses a non-transparent material, which can be achieved by including a astigmatism medium. When the outgoing light of the light source 20 enters the astigmatism element 30, the light is homogenized through the astigmatism medium.

In order to effectively increase the exit angle of the light source 20, the first surface 31 of the astigmatism element 30 is designed as a conical surface (eg, a conical surface having an elliptical, hyperbolic or parabolic cross section), while the second surface 32 of the astigmatism element 30 is planar or The circular curved surface is a perfect circular curved surface in the embodiments of Figs. 4 and 5. Since the astigmatism element 30 is received in the recess 41 of the outer casing 40, the contour of the second surface 32 can also conform to the contour of the recess 41.

Please refer to FIG. 6. FIG. 6 is a partial side elevational view of the light emitting device 10. Since the light source 20 is a point source, most of the light is concentrated near the exiting optical axis R, so that the astigmatism element 30 can increase the exit angle of the light of the light source 20. When the light emitted by the light source 20 along the exit optical axis R enters the first surface 31 of the astigmatism element 30, the light is first refracted by the first surface 31 to deviate from the exit optical axis R. It is mentioned that the first surface 31 is designed as a conical surface, and the conical surface has a characteristic that the outer normal line rapidly approaches horizontally (relative to the outgoing optical axis R), so that the light emitted by the light source 20 enters the first surface 31. It will be refracted for the first time away from the exiting optical axis R and dispersed outward. As previously mentioned, the source 20 has an exit distance L from the transparent region 42 of the outer casing 40, and the area of the transparent region 42 is defined as a viewable area. When the astigmatism element 30 in the illuminating device 10 is removed, the light emitted by the light source 20 along the exiting optical axis R is not directly refracted and is directly emitted to the transparent region 42 (as indicated by the dashed line in FIG. 6), and at a distance The exit distance L covers an original area A ₁ on the transparent area 42 . If the original area A _{1 is} smaller than the visible area of the transparent area 42 and there is no astigmatism medium in which the astigmatism element 30 can homogenize the light, on the transparent area 42 It will show a clear central highlight.

When the astigmatism element 30 is disposed between the outer casing 40 and the light source 20 as shown in FIG. 6, the light of the light source 20 and the first refraction of the first surface 31 via the astigmatism element 30 as described above are then passed through the astigmatism element 30. The second refraction of the second surface 32, and finally covers an exit area A ₂ on the transparent region 42 at a distance from the exit angle L at a larger exit angle, and the exit area A ₂ will be greater than (at least not less than) the transparent area The visible area of 42 and the astigmatism medium of the astigmatism element 30, the light emitted to the transparent region 42 is homogenized, so that it appears as a uniform light source on the transparent region 42 and will be transparent to the outer casing 40. District 42. Therefore, the light-emitting device 10 of the present invention can display the transparent light region of the outer casing 40 on the outer casing 40 via the action of the astigmatism element 30 under the limited size limitation. 42, increase the texture and effect of the display. For example, when the effective exit angle of the light-emitting diode as the light source 20 is 120 degrees, the original area A ₁ generated by the light source 20 under a design limitation space of a projection distance of only 2 millimeters (mm). For a circular area having a diameter of 6.93 mm, if the area of the transparent region 42 of the outer casing 40 is larger than the circular area having a diameter of 6.93 mm, the light of the light source 20 can be refracted after the astigmatism element 30 is added, and the light source is made The light of 20 can cover the area of the transparent region 42 and the brightness is more uniform.

In the light-emitting device of the present invention, an astigmatism element having an astigmatism medium is disposed between the light-emitting diode light source and the outer casing, and the first surface of the astigmatism element facing the light-emitting diode light source is a conical surface, and the light source can be The light is refracted away from the exiting optical axis to increase the angle of light exit. The astigmatism element is a material that is opaque and has an astigmatism medium, which can further homogenize the light. The light passing through the astigmatism element can be presented on the transparent area larger than the exit area of the visible transparent area of the outer casing and the result of the homogenization, and the point light source can be effectively converted into a uniform surface under the condition of maintaining the finite distance between the light source and the outer casing of the light emitting diode. The light source increases the texture and effect of the display.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10‧‧‧Lighting device

20‧‧‧Light source

30‧‧‧ astigmatism components

31‧‧‧ first surface

32‧‧‧second surface

40‧‧‧ Shell

41‧‧‧ Groove

42‧‧‧Transparent Zone

43‧‧‧Extension arm

R‧‧‧ optical axis

L‧‧‧Output distance

A ₁ ‧ ‧ original area

A ₂ ‧‧‧Outlet area

Fig. 1 is a schematic view showing the components of an embodiment of a light-emitting device of the present invention.

Fig. 2 is a schematic view showing the assembly of the components of the light-emitting device.

Figure 3 is a schematic view of the outer casing of the light-emitting device.

Figure 4 is a schematic illustration of an angle of the astigmatism element of the illumination device.

Figure 5 is a schematic illustration of another angle of the astigmatism element.

Figure 6 is a partial side elevational view of the light emitting device.

10‧‧‧Lighting device

20‧‧‧Light source

30‧‧‧ astigmatism components

31‧‧‧ first surface

32‧‧‧second surface

40‧‧‧ Shell

42‧‧‧Transparent Zone

R‧‧‧ optical axis

A ₁ ‧ ‧ original area

A ₂ ‧‧‧Outlet area

Claims (10)

A light-emitting device capable of uniformly guiding light, comprising: a light source for emitting light along an outgoing optical axis; a light diffusing element comprising an astigmatism medium, the light diffusing element having a first surface and a second surface, the light source And disposed on a side of the first surface of the astigmatism element and the first surface is a conical surface; and a casing disposed on a side of the second surface of the astigmatism element, the casing having a groove to receive the astigmatism component The outer casing has a transparent region; wherein the light emitted by the light source passes through the first surface of the light diffusing element to generate a first refraction to deviate from the exiting optical axis, and a uniform light source is formed through the second surface The transparent area of the outer casing is ejected. The illuminating device of claim 1, wherein the light source has an outgoing distance from the transparent section of the outer casing, and the transparent area of the outer casing has a visible area, and the light emitted by the light source along the outgoing optical axis passes through The astigmatism element covers a exit area after the first refraction to the exit distance, wherein the exit area is not less than the viewable area. The illuminating device of claim 1, wherein the outer casing has an extension arm, and the light source is fixed to the extension arm such that the light source has a fixed exit distance from the transparent section of the outer casing. The illuminating device of claim 1, wherein the second surface is a perfectly circular curved surface or a plane. The illuminating device of claim 1, wherein the second surface conforms to the groove contour of the outer casing. The illuminating device of claim 1, wherein the outer casing is a transparent button on the electronic device. The illuminating device of claim 1, wherein the first surface is an elliptical, hyperbolic or parabolic conical surface. The illuminating device of claim 1, wherein the light source is a light emitting diode light source. The illuminating device of claim 1, wherein the astigmatism element is a non-transparent material. The illuminating device of claim 1, wherein the light emitted by the light source generates a second refraction through the second surface of the astigmatism element, and the uniform light source is formed by the second surface to fill the transparent region of the outer casing Shoot out.