WO2008029347A2

WO2008029347A2 - Light guide

Info

Publication number: WO2008029347A2
Application number: PCT/IB2007/053557
Authority: WO
Inventors: Serdar Ayten
Original assignee: Grundig Elektronik Anonim Sirketi
Priority date: 2006-09-08
Filing date: 2007-09-04
Publication date: 2008-03-13
Also published as: WO2008029347A3

Abstract

The invention is related to a light guide (1) providing dispersion of light uniformly on aureoles generated around the button (6) and comprising at least one carrier cap (2).

Description

Description LIGHT GUIDE

[I] Technical Field

[2] The invention is related to a light guide providing dispersion of light uniformly on aureoles generated around the button.

[3] Prior Art

[4] In some special button designs, aureoles are generated around the button. Aureoles generated around the button highly impress the user visually and make great contributions to the esthetical design of the product. These kinds of button structures are used in a wide range of area from televisions to elevators.

[5] In these structures, light is generally transmitted into a transparent light guide made of plastic. Light dispersed in the ring-shaped light guide generates aureole around the button. In general, LED is used as a source of light.

[6] Problem faced in these button designs is that light does not dispersed uniformly in the light guide. It is undesired that light does not disperse uniformly but becomes intense in certain areas because a full ring shape image is not generated around the button when looked from afar.

[7] Producers have used various methods in the state of the art in order to overcome this problem. The most known one is to increase the number of LED around the annular light guide. Although 4, 8 even 16 LED are used in elevator embodiments to achieve a uniform light dispersion, it cannot be achieved. Light becomes intense around the LEDs. Producers generally prefer increasing number of LEDs in order to maintain a uniform dispersion. It is obvious that dispersion is getting uniform as the number of LED increases. However, this process increases cost of product significantly.

[8] One of the light guides enabling dispersal of light in circular way in the state of the art is disclosed in Patent No JP2004235153. The light guide according to the said application is of circle shape, one part of which is removed and a cylindrical extension is provided on one of the open ends. Source of light is mounted at the end of this extension and transmitted into the light guide. In said illumination panel a uniform structure cannot be achieved.

[9] A similar structure is described in the Patent No JP2004134323. In this structure, periphery of the circle is produced in indented way in order to provide equal dispersion of light around a clock. The said illumination is required additional equipment and makes difficult to mount the product.

[10] Brief Description of the Invention

[I I] The object of the invention is to provide a light guide enabling dispersion of light in the ring uniformly by means of at least an extension placed on at least one end of the ring and at least a source of light to be placed on the end of said extension. [12] Another object of the invention is to provide a light guide to be lifted from the mould easily together with its extensions to enable use of one or two source of light and to manufacture a low cost light guide. [13] Another object of the invention is to provide a light guide to be used in all the button structures.

[14] Detailed Description of the Invention

[15] The light guide developed to attain the object of the invention is shown in the accompanying drawings.

[16] Figure 1 - is top view of the double capped embodiment according to the invention.

[17] Figure 2 - is the perspective view of the double capped embodiment according to the invention. [18] Figure 3 - is the view of the double capped embodiment according to the invention together with the parts to be mounted with. [19] Figure 4 - is the beam direction graph when a single LED with 1.5 mm exterior outlet radius is used in a double capped embodiment according to the invention. [20] Figure 5 - is the beam direction graph when a single LED with 2 mm exterior outlet radius is used in a double capped embodiment according to the invention. [21] Figure 6 - is the beam direction graph when a single LED with 1 mm exterior outlet radius is used in a double capped embodiment according to the invention. [22] Figure 7 - is the view from different aspects of an embodiment of the light guide according to the invention with a convex tipped cap. [23] Figure 8 - is the perspective view of the single capped embodiment according to the invention. [24] Figure 9 - is the beam direction graph when a single LED with 2 mm exterior outlet radius is used in a single capped embodiment according to the invention. [25] The parts in the figures are each given reference numerals as follows:

[26] 1. Light guide

[27] 2. Cap

[28] 3. Ring

[29] 4, 104 Texture surface

[30] 5. Source of light

[31] 6. Button

[32] 7. End

[33] The light guide (1) according to the invention comprises basically at least a cap (2), a ring (3) and texture surfaces (4, 104) on the front and back side of the ring (3). The ring (3) has thickness and breadth. Said thickness forms the texture surfaces (4, 104) on the front and back surface of the ring (3). [34] The cap (2) extending from the ring (3) shaped light guide (1) and providing carrying of the light through the ring (3) functions as a carrier enabling uniform dispersion. Light transmitted from the source of light (5) proceeds with refractions in the ring (3) by passing through the cap (2) and provides illumination uniformly at each point by dispersing uniform beam at each point of the ring (3).

[35] In one of the embodiments according to the invention, there exists a cap (2) on the one side of the ring (3). The cap (2) begins from the texture surface (104) on the back side of the ring (3). It has a wider structure on the end point compared to the beginning point. The source of light (5) is made close to the end (7) which is the widest part of the cap (2). The cap (2) is preferably of cylindrical structure; therefore, it enables light to be directed into the ring (3) with less loss. This increases the light density in the ring (3) (Figure 8).

[36] In another embodiment according to the invention, there are caps (2) extending symmetrically on the opposite direction on both sides of the ring (3). Caps (2) begin from the texture surface (4, 104) on one side of the ring (3) and extend on the opposite directions, preferably in the triangle prism shape. The source of light (5) is made close to the ends (7) which are the widest part of the caps (2). The caps (2) on the both sides of ring (3) shaped light guide (1) providing carrying of the light into the ring (3) are the carrier extensions enabling uniform dispersion due to their symmetrical shape. Light emitted from the source of light (5) enters from these caps (2), proceeds in the ring (3) with the refractions and enables uniform illumination at each point by dispersing lights uniformly at each point of the ring (3) (Figure 2).

[37] The ends (7) which are the widest part of the caps (2) are of planar structure in the preferred embodiment according to the invention. However, the ends (7) which are the widest part of the caps (2) can be of convex structure. The convex end (7) collects lights better in some special LED types used as the source of light (5) and enables lights to enter into the carrier caps (2) with less loss (Figure 7), which increases the density of the light in the ring (3).

[38] In another embodiment according to the invention, LEDs used as the source of light

(5) have ring-shaped structure, the light outlet radius is 1.5 mm, the radiation angle is 25 degree and it has such a type that radiating 25 beams in total. In the exemplary embodiment, "α" angle is 140 degree, "α" is the angle of LED to the floor (Figure 1).

[39] In another embodiment according to the invention, LEDs have ring-shaped structure, the light outlet radius is 2 mm, the radiation angle is 30 degree and they have such a type that radiating 20 beams in total (Figure 9). It is obvious that LEDs having different structures can be used with the light guide (1) according to the invention.

[40] In a study related to the embodiment with double caps (2) according to the invention, the light guide (1) according to the invention is used with a LED whose exterior outlet radius is 1.5 mm and radiation angle is 25°. In the embodiment, a LED radiating 25 beams in total is used (Figure 4). Reflection of the light can be observed in various densities by changing this number. The other LED to be used in the same way is placed symmetrically to the LED used in the embodiment.

[41] In another study related to the embodiment with double caps (2) according to the invention, the light guide (1) is used with a LED whose exterior outlet radius is 2 mm and light radiation angle is 25°. In embodiment, a single LED radiating totally 25 beams is used (Figure 5). Reflection of light can be observed in different densities by changing the number. The other LED to be used in the same way is placed symmetrically to the LED used in the embodiment.

[42] In another study related to the embodiment with double caps (2) according to the invention, the light guide (1) is used with a LED whose exterior outlet radius is 1 mm and light radiation angle is 25°. In embodiment, a single LED radiating totally 25 beams is used (Figure 6). Reflection of light can be observed in different densities by changing the number. The other LED to be used in the same way is placed symmetrically to the LED used in the embodiment.

[43] It is clear that modifications can be made in the structure of the light guide (1) according to LED type to be used and its values, providing that the basic form of the light guide including ring (3) and caps (2) of the light guide (1) is reserved.

[44] When the texture surfaces (4, 104) of the light guide (1) are textured, reflection is enabled to focus into the light guide (1) and light density is enabled to be increased.

[45] The light guide (1) according to the invention can be made of various materials; however, it is preferably produced from the polycarbonate material.

[46] The light guide (1) can be manufactured easily due to its specific structure and has a structure to be removed easily from the mould. It decreases the cost significantly as it allows dispersion of light uniformly using one or two LEDs.

[47] The light guide (1) is of structure to be used in several embodiments such as in elevator, oven, television and refrigerator. Component surrounding of which is illuminated through the light guide (1) is placed in the middle of the light guide (1). In an embodiment according to the invention, this component is a button (6) (Figure 3).

[48] In different embodiments according to the invention, the cap (2) can begin from any part o the ring (3) with any angle and extend to any direction. Moreover, cap (2) can be manufactured in the geometry of polygon such as quadrangle and pentagon or prism.

[49] In the light of this basic concept, it is possible to develop a great variety of embodiments of the light guide (1) according to the invention and the invention is described essentially in the claims and cannot be limited to the examples discloses herein.

Claims

[1] A light guide (1) comprising a ring (3) illuminating the component placed in the middle of the ring and having thickness and breadth, characterized with

- the texture surface (4, 104) on the front and back side of the ring (3),

- at least a carrier cap (2) directing the light beams into the ring (3), extending by getting wide from the point where it is projecting from the ring (3) to the end (7) point.

[2] A light guide (1) according to Claim 1 characterized in that it comprises a cap (2) beginning from any surface of the ring in any angle and proceeding with any inclination rate.

[3] A light guide (1) according to Claim 1 characterized in that it comprises two caps

(2) on the both side of the ring (3) on the opposite directions but symmetrical which begin from the texture surface (4) on the one side of the ring (3) and extend by getting wide in opposite directions in polygon prismatic geometry such as triangle, quadrangle and pentagon.

[4] A light guide (1) according to any one of the proceeding claims which is made of polycarbonate material.

[5] A light guide (1) according to any one of the proceeding claims characterized in that the end (7) which is the widest point of the cap (2) has convex structure.

[6] A light guide (1) according to the any one of the Claims 1 to 4 characterized in that the end (7) which is the widest point of the cap (2) has planar structure.

[7] A light guide (1) according to the any one of the proceeding claims characterized in that the source of light (5) are used being made close to the widest end (7) points of the caps (2).

[8] A light guide (1) according to the any one of the proceeding claims characterized in that light density in the light guide (1) is increased by texturing the texture surfaces (4, 104).