JP2006337777A - Optical component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To relieve the variance in the emitting direction of light due to sinks caused on the light emitting surface of an optical component equipped with a light incident surface and a light emitting surface. <P>SOLUTION: A recessed part 4 for preventing sinks is formed nearly in the center of the light emitting surface 3 of the optical component 1, and the shape of the light incident surface 2 positioned on the optical path of light made incident on the recessed part 4 is formed corresponding to the shape of the recessed part 4 so that the emitting direction D1 of the light in the recessed part 4 is nearly the same as the emitting direction D2 of the light on the light emitting surface 3 positioned on the outside of the recessed part 4. Since the recessed part 4 is formed nearly in the center of the light emitting surface 3 where the sinks are easily caused, a shape error due to the sinks is hardly caused, and the shape of the light incident surface 2 is formed corresponding to the shape of the recessed part 4, so that the variance in the emitting direction of the light is restrained, and the occurrence of glare and the lowering of emitting efficiency are prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical component such as a lens.

  Conventionally, in order to efficiently emit light from a light source in a predetermined direction, a solid optical device having a curved light incident surface 102 and a planar light emitting surface 103 as shown in FIG. Part 101 is used. In the optical component 101 having such a shape, since the light emission surface 103 is flat and has no large unevenness, dust and dust do not easily accumulate on the light emission surface 103, and the emission efficiency is lowered even when used for a long time. There is an advantage that it is difficult.

  On the other hand, as shown in FIG. 5, such an optical component 101 is prone to sink on the planar light exit surface 103 during manufacture. 110 is likely to occur. When sink marks are generated on the light emitting surface 103, light from the light emitting surface 103 is excessively spread or light is emitted in an unexpected direction, which may cause glare and decrease in emission efficiency.

By the way, sink marks generated on the light emitting surface 103 can be prevented by taking a longer solidification time of the molten resin or the like in injection molding or adjusting the pressure distribution when the molten resin or the like is solidified (for example, Patent Document 1).
Japanese Patent No. 2957614

  However, the method of adjusting the solidification time and pressure distribution in injection molding to prevent sink marks generated on the light exit surface has a problem that the manufacturing cost of the optical component increases. Therefore, there is a demand for an optical component that can alleviate the variation in the light emission direction due to sink marks generated on the light emission surface, and prevent the occurrence of glare and the decrease in emission efficiency, regardless of such a method. .

  The present invention has been made in view of such a point, and an object of the present invention is to provide an optical component that can alleviate variations in the light emission direction due to sink marks generated on the light emission surface.

  In order to achieve the above object, the invention according to claim 1 is an optical component having a light incident surface and a light output surface, wherein a concave portion or a convex portion for preventing sink marks is formed at substantially the center of the light output surface, The shape of the light incident surface located on the optical path of the light incident on the concave portion or the convex portion is the same as the light on the light emitting surface where the light emission direction in the concave portion or the convex portion is located outside the concave portion or the convex portion. It is characterized in that it is formed so as to correspond to the shape of the concave portion or convex portion so as to be substantially the same as the emission direction.

  According to the optical component of the first aspect, since the concave portion or the convex portion for preventing the sink is formed at the approximate center of the light emitting surface where the sink is likely to occur, a shape error due to the sink is unlikely to occur. Further, the shape of the light incident surface located on the optical path of the light incident on the concave portion or the convex portion is formed corresponding to the shape of the concave portion or the convex portion, and the light emission direction in the concave portion or the convex portion is the concave portion or the convex portion. Since it is made to be substantially the same as the light emission direction on the light emission surface located outside the convex part, it is possible to suppress variations in the light emission direction, and to prevent the occurrence of glare and the reduction of the emission efficiency. Can do.

  The optical component according to the first embodiment of the present invention will be described below with reference to FIGS. The optical component of the present embodiment is disposed at a predetermined position with respect to an LED (Light Emitting Diode) 10 formed on the printed circuit board 20, and is used for efficiently emitting light from the LED 10 in a predetermined direction. The actual lens 1 includes a curved light incident surface 2 and a planar light emitting surface 3. The light exit surface 3 is disposed substantially perpendicular to the optical axis A. The light incident surface 2 may not be curved over the entire area, and may include a substantially planar light incident surface 5 on the side of the curved light incident surface 2 as shown in FIG. Good. 1 to 5, the hatching of each member is omitted, and a state where no sink marks are generated on the light emitting surface 3 is indicated by a two-dot difference line. The optical path is indicated by a solid line with an arrow.

  In the present embodiment, the recess 4 for preventing the sink is formed in the approximate center of the light emitting surface 3 where the sink is most likely to occur. The shape of the concave portion 4 is preferably formed in accordance with the shape of the sink that occurs when the concave portion 4 is not formed on the light emitting surface 3, and the cross section of the concave portion 4 perpendicular to the light emitting surface 3 has a substantially suspended curve. It is preferable to form it so as to draw a (catenary curve). In this way, by forming a part of the planar light emitting surface 3 in a curved shape, a shape error due to sink marks is unlikely to occur. For example, in the case of the lens 1 having the shape shown in FIG. 1, if the diameter is 20 mm and the thickness in the direction of the symmetric axis (optical axis) is about 12 mm, the diameter is about 8 mm, depending on the material and manufacturing conditions. A concave sink having a maximum direction depth of about 0.3 mm may occur in the approximate center of the light exit surface 3. In this case, the recess 4 is formed in accordance with the shape of this sink mark.

  Further, the shape of the light incident surface 2 (substantially the entire area of the curved light incident portion in this embodiment) 2 located on the optical path of the light incident on the concave portion 4 is set so that the light emission direction D1 in the concave portion 4 is the concave portion. 4 is formed so as to correspond to the shape of the recess 4 so as to be substantially the same as the light emission direction D2 on the light emission surface 3 located outside the substrate 4.

  That is, when the light emission direction D1 in the concave portion 4 is controlled to a predetermined direction, the lens 1 of the light incident on the concave portion 4 according to Snell's law based on the emission direction D1, the shape of the concave portion 4 and the material of the lens 1. The optical path inside can be specified. Furthermore, based on the optical path in the lens 1, the position of the LED 10, and the material of the lens 1, the inclination of the interface (light incident surface 2) with respect to the incident light can be calculated according to Snell's law. In this way, the shape of the light incident surface 2 can be determined in accordance with the shape of the recess 4. Although there is a possibility that some sink marks may be generated in the vicinity of the concave portion 4, the shape error due to sink marks is reduced as compared with the case where the entire area of the light emitting surface 3 is flat.

  For example, as shown in FIG. 2, when the emission direction D1 is controlled to be substantially parallel to the optical axis A, there is no concave sink mark on the light output surface 3 (in FIG. The shape of the lens in which no light is generated is indicated by a two-dot chain line, and its optical path is indicated by a dotted line), and the direction of light from the light incident surface 12 toward the light output surface 13 is substantially parallel to the optical axis A. In this embodiment, the direction of light from the light incident surface 2 toward the light emitting surface 3 is a predetermined angle with respect to the optical axis A in consideration of refraction in the recess 4. The light incident surface 2 is formed so as to be inclined outward by α.

  Next, a method for manufacturing the lens 1 described above will be described. The lens 1 is manufactured by an injection molding method or the like using a mold having a molding surface that substantially matches the light incident surface 2 and the light emitting surface 3. The shapes of the light incident surface 2 and the light exit surface 3 of the lens 1 after molding do not need to be completely matched with the shape of the molding surface of the mold, and the concave portion 4 of the lens 1 is considered in consideration of the shape change due to sink marks. The molding surface of the mold may be formed such that the convex portion of the molding surface of the mold corresponding to is slightly smaller than the optically designed value as described above. In this case, the pressure at the time of molding can be reduced, and the molding time can be shortened.

  According to the lens 1 of the present embodiment, the concave portion 4 for preventing sink marks is formed at the approximate center of the light emitting surface 3 where sink marks are likely to occur, so that shape errors due to sink marks are unlikely to occur. Further, the shape of the light incident surface 2 located on the optical path of the light incident on the concave portion 4 is formed corresponding to the shape of the concave portion 4, and the light emission direction D <b> 1 in the concave portion 4 is located outside the concave portion 4. Since the light exit surface 3 is substantially the same as the light exit direction D2, variations in the light exit direction can be suppressed, and the occurrence of glare and the reduction of the exit efficiency can be prevented.

  Next, an optical component according to a second embodiment of the present invention will be described with reference to FIG. In the lens 1 according to the present embodiment, a concave portion 6 is also formed on the light emitting surface 3 located outside the concave portion 4, and the shape of the light incident surface 5 located on the optical path of the light incident on the concave portion 6 is changed to the concave portion 6. Is formed in correspondence with the shape of the recessed portion 6 so that the light emitting direction D3 in FIG.

  According to the lens 1 according to the present embodiment, the same effect as in the first embodiment can be obtained, and the concave portion 6 is formed also on the light emitting surface 3 located outside the concave portion 4. Compared to the case where the light exit surface is flat, a shape error due to sinking is less likely to occur. In addition, since the shape of the light incident surface 5 is formed so as to correspond to the shape of the recess 6 and the emission direction D3 is substantially the same as the emission direction D1, variations in the light emission direction can be suppressed.

  The present invention is not limited to the configurations of the various embodiments described above, and various modifications can be made. For example, instead of the concave portion 4 of the above embodiment, a convex portion for preventing sink marks is formed at the approximate center of the light emitting surface 3, and the shape of the light incident surface 2 located on the optical path of the light incident on the convex portion is You may form corresponding to the shape of a convex part so that the light emission direction in a convex part may become substantially the same as the light emission direction in the light-projection surface located outside a convex part.

1 is a cross-sectional view of an optical component according to a first embodiment of the present invention. Sectional drawing explaining the shape of the light-incidence surface of the same optical component. Sectional drawing of the optical component which concerns on the 2nd Embodiment of this invention. Sectional drawing of the optical component which concerns on a prior art example. Sectional drawing of the same optical component in the state where sink marks were generated on the light exit surface.

Explanation of symbols

1 Lens (optical component)
2 Light entrance surface 3 Light exit surface 4 Recess

Claims (1)

In an optical component having a light incident surface and a light output surface,
Forming a concave or convex portion for preventing sink marks at the approximate center of the light emitting surface;
The shape of the light incident surface located on the optical path of the light incident on the concave portion or the convex portion,
Corresponding to the shape of the concave portion or convex portion so that the light emitting direction of the concave portion or convex portion is substantially the same as the light emitting direction of the light emitting surface located outside the concave portion or convex portion. An optical component characterized by being formed.

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