JP6282946B2 - Light guide and illumination device - Google Patents

Description

  The present invention relates to a light guide and an illumination device that include a light blocking portion that can prevent unnecessary light leakage.

  A device having a light guide sheet (light guide) for illuminating an operation key of an operation panel is known. The light guide sheet is made of a light transmissive material and is attached on a circuit board provided in the operation panel. Further, a light source is disposed in the vicinity of the end portion of the light guide sheet, and light emitted from the light source enters the sheet from the end surface of the light guide sheet. The light incident on the sheet is diffused by an illumination pattern formed so as to correspond to the operation keys of the operation panel, and the operation keys are lit from the inside. In the light guide sheet, a light shielding portion that shields light traveling in the sheet is formed.

  For example, Patent Document 1 discloses a sheet with a contact spring that suppresses light leakage between divided illumination regions.

  FIG. 9 is a diagram showing the relationship between the irradiation range by the light source unit and the slit arrangement position in the sheet with contact springs described in Patent Document 1. It is explanatory drawing of the light-shielding part by the permeation printing in the conventional sheet | seat with a contact spring.

  As shown in FIG. 9, the light guide sheet 904 is divided into three illumination areas A901-A903 by slits S901, S902. In addition, the holding sheet laminated on the lower surface of the light guide sheet 904 is formed with a plurality of accommodating portions for the contact spring 912. The accommodating parts 931c and 931d are respectively positioned. The light source unit 907 is disposed so as to include an illumination pattern located above the contact spring 912 within the irradiation range.

  The slits S901 and S902 are substantially V-shaped grooves processed into the light guide sheet 904 by laser processing or the like, and are formed leaving a slight thickness on the light guide sheet 904 as shown in FIG. In the slits S901 and S902, a light shielding part 933 that prevents light incident on the illumination areas A901 and A902 from leaking to other illumination areas by the light shielding printing liquid 932 attached to the surfaces of the slits S901 and S902. Is formed.

  For example, as illustrated in FIG. 10, the light shielding portion 933 is formed by allowing a part of the printing liquid 932 to penetrate into the light guide sheet 904. In this case, after the sublimable printing liquid 932 is applied to the surfaces of the slits S901 and S902, the printing liquid 932 is infiltrated into the light guide sheet 904 by heating the printing liquid 932 and the light guide sheet 904. Thereby, compared with the structure which apply | coats the printing liquid 932 to the surface of slit S901, S902, effective light-shielding performance can be obtained.

Japanese Patent No. 4910056

  However, although grooves having an inclined surface are formed as the slits S901 and S902, it is difficult to form an inclined surface in a short time because it is dug deeply by laser processing to obtain this cross-sectional shape. Met. For this reason, the width and depth of the inclined surface are insufficient in a practical processing time, and the printing liquid cannot be infiltrated in a practical heating time. In this case, the light shielding performance varies, and light leakage cannot be reliably prevented.

  The present invention solves the above-described problems, and an object of the present invention is to provide a light guide and an illuminating device including a light shielding portion that can reliably prevent unnecessary light leakage.

The light guide of the present invention is a light guide comprising: a plate body that emits light incident from a light source to an illumination region; and a light shielding portion that is disposed at an outer edge portion of the plate body. The surface is provided with a plurality of dot-shaped concave portions that are dark color paint storage portions along the outer edge portion in a plan view, and the light shielding portion is applied to a region including the plurality of concave portions. The dark paint has a penetration layer that penetrates to the other surface of the plate.

  According to this configuration, since the permeation layer is formed in a region including a plurality of dot-shaped concave portions provided on one surface of the plate, the paint can be reliably permeated to the other surface of the plate. Therefore, light leakage can be prevented.

  In the light guide of the present invention, the plurality of concave portions are formed in at least two rows along the outer edge portion in a plan view, and are formed in a staggered shape between the two rows. .

  According to this configuration, the dot-shaped concave portions can be arranged with high density, the gaps between the dot-shaped concave portions are reduced, and a penetrating layer of paint can be efficiently formed.

  In the light guide of the present invention, the plurality of recesses are formed so that adjacent ones do not overlap in a plan view.

  According to this configuration, since the concave portions are formed so as not to overlap with each other, when applying the paint, the paint easily enters each concave portion, the amount of the paint in each concave portion is stabilized, and the concentration of the penetrated paint Stable and reliable light shielding.

  In the light guide of the present invention, the plurality of recesses are formed in a thickness direction of the plate body at a depth of not more than a half of the plate thickness and not less than a quarter.

  According to this configuration, if the recess is too deep, there is a risk of tearing during handling such as sticking at the time of manufacture, and if it is too shallow, the penetration time of the paint will be long. Appropriate depth to the extent that it is not broken.

  The illumination device of the present invention includes any one of the above light guides and a substrate on which the light source is provided, and the light guide is disposed on the substrate such that a light incident portion of the light guide corresponds to the light source. It is arranged above.

  According to this structure, it can be set as the illumination device which can reduce the light leakage from an outer edge part.

  According to the present invention, a plurality of dot-like recesses are provided on one surface of a plate body that emits light incident from a light source to an illumination region, and a permeation layer is formed in a region including the plurality of recesses. The paint can be surely penetrated to the other surface of the body. Therefore, it is possible to provide a light guide and an illumination device that can prevent light leakage.

It is a top view which shows the illuminating device of embodiment of this invention. It is sectional drawing cut | disconnected by the II-II line | wire of FIG. It is sectional drawing which shows the process of providing a dot-shaped recessed part in one surface of a board. It is sectional drawing which shows the process of apply | coating a coating material to the area | region containing a some recessed part. It is sectional drawing which shows the process of making a coating material osmose | permeate in a board body by heating. It is an enlarged plan view explaining the A section of FIG. It is an enlarged plan view of the 1st modification. It is an enlarged plan view of the 2nd modification. It is a figure which shows the relationship between the irradiation range by the light source unit in the conventional sheet | seat with a contact spring, and the arrangement position of a slit. It is explanatory drawing of the light-shielding part by the permeation printing in the conventional sheet | seat with a contact spring.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For easy understanding, the dimensions of the drawings are appropriately changed.

  FIG. 1 is a plan view showing an illumination device 100 according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG.

  The illumination device 100 according to the present embodiment includes a light source 40 and a light guide 1, and is disposed on the substrate 50 so that the light incident portion 1 a of the light guide 1 corresponds to the light source 40 as illustrated in FIGS. 1 and 2. Is arranged.

  The light source 40 is an LED (light emitting diode), is mounted on the substrate 50, and is controlled to be turned on by a control circuit (not shown) via wiring (not shown) provided on the substrate 50.

  In the light guide 1 of this embodiment, a plate body 10 formed in a rectangular shape in plan view with a transparent film having a translucent property of polyurethane resin (PU) is attached to a holding sheet 11 via an adhesive portion 15. Is formed. An opening 10 d formed in the plate 10 in a rectangular shape in plan view is a light incident portion 1 a of the light guide 1 and is provided corresponding to the light source 40. In the present embodiment, the light incident portion 1 a is in the X2 direction when viewed from the light source 40. One surface of the plate 10 is an illumination region 10a from which light is emitted, and the other surface is a light reflecting surface. The light incident on the light incident portion 1a of the light guide 1 from the light source 40 propagates while being repeatedly reflected on one surface and the other surface of the plate 10, and is in a substantially uniform diffused state, so that the illumination region 10a. Is emitted in the Z1 direction.

  In the light guide 1, a light shielding portion 20 is disposed so as to be along the outer edge portion 10 b of the plate body 10 in a plan view. In the light shielding part 20, a plurality of dot-like recesses 10 c are provided on one surface of the plate body 10, and a paint layer 21 is formed by applying paint to a region including the plurality of recesses 10 c. In the light shielding part 20, the dark paint applied to one surface of the plate 10 penetrates to the other surface of the plate 10 to form a permeation layer 22 as shown in FIG. The permeation layer 22 is formed by heat treatment after the coating is applied. By forming the permeation layer 22 from one surface of the plate body 10 to the other surface, the light incident on the light incident portion 1a is prevented from leaking sideways from the outer edge portion 10b of the plate body 10. Yes.

  The light shielding portion 20 is a state in which the paint layer 21 remains on the permeation layer 22 in which the paint has penetrated into the plate body 10, and as shown in FIG. 2, the surface of the paint layer 21 in the region including the plurality of recesses 10 c. Has irregularities corresponding to the recesses 10c.

  Note that the microscopic structure of the plate 10 in the illumination region 10a is devised so that light incident on the light incident portion 1a is emitted uniformly.

  Directly above the illumination area 10a, for example, an operation key of the operation panel is arranged, and a character portion of the operation key can be illuminated from the inside. Since the illumination device 100 according to the present embodiment can reduce unnecessary light leakage from the outer edge portion 10b, the operation keys can be illuminated more easily.

  The adhesive portion 15 is provided by applying an adhesive to the other surface of the plate body 10. The holding sheet 11 is made of polyethylene terephthalate resin (PET). The light guide 1 is stuck on the substrate 50 via the adhesive portion 16. The adhesive part 16 is provided by applying an adhesive in the same manner as the adhesive part 15.

  The light guide 1 of this embodiment can be manufactured by the process example shown in FIGS. FIG. 3 is a cross-sectional view showing a process of providing a dot-like recess 10 c on one surface of the plate body 10. FIG. 4 is a cross-sectional view showing a process of applying a paint to a region including a plurality of recesses 10c. FIG. 5 is a cross-sectional view showing a step of allowing the paint to penetrate into the plate 10 by heating. FIG. 6 is an enlarged plan view for explaining a part A of FIG. FIG. 7 is an enlarged plan view of the first modification. FIG. 8 is an enlarged plan view of a second modification.

  As shown in FIG. 3, the dot-shaped recessed part 10c is formed in one surface along the outer edge part 10b of the board 10 by laser processing. The size of the recess 10c in plan view is adjusted by the laser intensity and the laser irradiation diameter at the time of laser processing. The plurality of recesses 10c are formed by performing laser processing for each position while scanning the laser processing positions at a predetermined pitch. Unlike this embodiment, when forming a line-shaped groove, the laser processing is performed so as to connect the dots, so that the processing time becomes long. Compared to this, dot-shaped laser processing can be processed in a shorter time.

  Next, as shown in FIG. 4, a paint is applied to a region including the plurality of dot-shaped recesses 10 c to form a paint layer 21.

  Subsequently, the paint is infiltrated into the plate body 10 by heating, so that the infiltration layer 22 is formed as shown in FIG. According to this configuration, since the permeation layer 22 is formed in a region including a plurality of dot-shaped concave portions 10c provided on one surface of the plate body 10, the other side of the plate body 10 is not lengthened without increasing the heating time. The paint can be surely penetrated to the surface. Therefore, light leakage can be prevented.

  3 to 5 show a cross section within a range cut by the outer edge portion 10b of the plate body 10, it is preferable to obtain the outer shape shown in FIGS. 3 to 5 by performing a cutting process. 3 to 5, the opening 10 d is formed in advance corresponding to the light source, but the opening 10 d may be formed after the penetration layer 22 is formed. For example, in the process of manufacturing a plurality of light guides 1 in the form of a large sheet, a cutting process for separating the plurality of light guides 1 is performed, and the process of forming the opening 10d is continuously performed in this cutting process. Is preferred.

  By heating, the coating material of the coating layer 21 penetrates into the plate body 10 to form the permeation layer 22. Therefore, if the concave portion 10c is too shallow, the penetration time of the coating becomes long. For this reason, it is preferable to set it as an appropriate depth so that the board 10 may not be broken.

  In the light guide 1 of the present embodiment, the dot-shaped recess 10 c has a diameter equal to the plate thickness in plan view and is formed at a depth half the plate thickness in the thickness direction of the plate body 10. Adjacent recesses 10c are arranged at a distance that does not contact each other.

  If the concave portion 10c is too deep, the light guide 1 may be broken during handling such as sticking when the light guide 1 is manufactured. In the light guide 1 of the present embodiment, the plate body 10 is formed to an appropriate depth so as not to be broken. In addition, when a line-shaped groove portion is formed instead of the dot-shaped concave portion 10c, it is known that the amount of paint that accumulates in the groove portion when the paint is applied is reduced. Similarly, if adjacent recesses 10c are in contact with each other, the amount of paint that accumulates in the recesses 10c when coating is applied is reduced.

  Since the light guide 1 according to the present embodiment is formed so that the plurality of dot-shaped recesses 10c do not overlap each other, when applying paint, the paint easily enters each recess 10c, and the paint in each recess 10c. The amount of the coating is stable, the concentration of the infiltrated paint is also stable, and reliable light shielding is possible. From these facts, if the dot-like recesses 10c are formed at an optimal depth and at a distance that does not allow the adjacent recesses 10c to contact each other, the amount of paint that accumulates in the recesses 10c is stabilized. . Therefore, it is preferable that the concave portion 10 c is formed in the thickness direction of the plate body 10 so as to be not more than half of the plate thickness and at a depth of not less than ¼.

  Further, as shown in FIG. 1, at least one row of the dot-shaped recesses 10c is arranged next to each other in the Y1-Y2 direction so as to be along the outer edge portion 10b of the plate body 10 in a plan view. The columns are offset by a half pitch in the Y1-Y2 direction. That is, it is formed in a staggered pattern between two rows. For example, as shown in FIG. 6, the concave portion 10c is set so that the pitch P1 in the Y1-Y2 direction is 1.25 times the plate thickness of the plate 10 and the pitch P2 in the X1-X2 direction is 1.085 times the plate thickness. Are formed in a dense staggered pattern. That is, three adjacent recesses 10c arranged in a staggered manner can be arranged most efficiently corresponding to the vertices of the equilateral triangle. According to this configuration, the dot-shaped concave portions 10c can be arranged with high density, and the gaps between the dot-shaped concave portions 10c are reduced, so that the permeation layer 22 of the paint can be efficiently formed.

  The dot-shaped recess 10c can be formed on the entire area outside the illumination area 10a. From the viewpoint of the processing time for forming the recess 10c, it is preferable that light leakage can be prevented by processing in 5 rows or less. In the light guide 1 of the present embodiment, light leakage can be prevented if the recesses 10c are arranged in three rows even on the X2 side where light leakage is particularly likely to occur. Further, the Y1 side and the Y2 side in FIG.

  When the dot-like recess 10c is formed by laser processing, the periphery of the recess 10c may melt and rise. However, if there is no problem in the process of applying the paint, the amount of paint accumulated in the recess 10c tends to increase, and this does not cause a problem.

  Hereinafter, the effect by having set it as this embodiment is demonstrated.

  The light guide 1 of the present embodiment includes a plate body 10 that emits light incident from an external light source to an illumination region 10a, and a light shielding portion 20 that is disposed on an outer edge portion 10b of the plate body 10. . A plurality of dot-like recesses 10c are provided on one surface of the plate body 10 along the outer edge portion 10b in a plan view, and the light shielding portion 20 is applied to an area including the plurality of recesses 10c. The dark paint has a permeation layer 22 that has penetrated to the other surface of the plate 10.

  According to this configuration, since the permeation layer 22 is formed in a region including a plurality of dot-shaped concave portions 10c provided on one surface of the plate body 10, as compared with the case where a line-shaped groove is formed by laser processing. The laser processing time is short. Moreover, compared with the case where a recessed part is not formed, a coating material can be osmose | permeated reliably to the other surface of the board 10 by heat processing for a short time. Therefore, unnecessary light leakage can be surely prevented.

  Further, in the light guide 1 of the present embodiment, the plurality of concave portions 10c are formed in at least two rows along the outer edge portion 10b in a plan view, and are formed in a staggered shape between the two rows. To do. According to this configuration, the dot-shaped concave portions 10c can be arranged with high density, and the gaps between the dot-shaped concave portions 10c are reduced, so that the permeation layer 22 of the paint can be efficiently formed.

  Further, in the light guide 1 of the present embodiment, the plurality of recesses 10c are formed so that adjacent ones do not overlap in a plan view. According to this configuration, since the recesses 10c are formed so as not to overlap with each other, when applying a paint, the paint easily enters each recess 10c, and the amount of the paint in each recess 10c is stabilized and penetrated. The concentration of the paint is stable and light shielding is possible.

  Further, in the light guide 1 of the present embodiment, the plurality of recesses 10c are formed in the thickness direction of the plate body 10 so as to have a depth of not more than half of the plate thickness and not less than ¼. According to this configuration, if the concave portion 10c is too deep, there is a possibility that it will be cut off during handling such as sticking at the time of manufacture, and if it is too shallow, the penetration time of the paint will be long. Appropriate depth to the extent that it is not broken.

  The illumination device 100 according to the present embodiment includes any one of the light guides 1 and the substrate 50 provided with the light source 40, and the light guide 1 a of the light guide 1 corresponds to the light source 40. The guide 1 is arranged on the substrate 50. According to this structure, it can be set as the illuminating device 100 which can reduce the light leakage from the outer edge part 10b.

  As described above, the light guide 1 and the illumination device 100 according to the embodiment of the present invention have been specifically described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Can be implemented. For example, the present invention can be modified as follows, and these also belong to the technical scope of the present invention.

  (1) In the present embodiment, the arrangement of the dot-like recesses 10c is different in the pitch P1 and the pitch P2, but may be changed so as to have the same pitch P3. FIG. 7 is an enlarged plan view of the first modification. The pitch P3 in FIG. 7 has the same dimensions as the pitch P1 in FIG. 6, but is larger than the pitch P2. This is effective when it is desired to expand the light shielding portion 20 in the X1-X2 direction without increasing the number of the concave portions 10c.

  (2) In the present embodiment, the plurality of concave portions 10c are formed in at least two rows and formed in a staggered pattern between the two rows, but the arrangement of the concave portions 10c is not limited to the staggered arrangement. Absent. FIG. 8 is an enlarged plan view of a second modification. Since the recesses 10c are arranged at the same interval in the X1-X2 direction and the Y1-Y2 direction, the gap between the dot-like recesses 10c is wide, but there is no problem when the penetration time of the paint is long.

  (3) In the present embodiment, the plate body 10 is formed of a polyurethane resin, but is not limited to this configuration. The plate 10 may be a sheet that can guide light, and may be formed of, for example, a polycarbonate resin.

DESCRIPTION OF SYMBOLS 1 Light guide 1a Light incident part 10 Plate body 10a Illumination area | region 10b Outer edge part 10c Recessed part 10d Opening part 11 Holding sheet 15,16 Adhesive part 20 Light shielding part 21 Paint layer 22 Penetration layer 40 Light source 50 Substrate 100 Illumination device P1, P2, P3 pitch

Claims (5)

In a light guide comprising: a plate that emits light incident from a light source to an illumination region; and a light-shielding portion that is disposed at an outer edge of the plate,
One surface of the plate body is provided with a plurality of dot-shaped concave portions that are reservoirs of dark paint along the outer edge portion in plan view,
The light shielding portion, a light guide, characterized in that it comprises a permeation layer in which the dark paint applied to the region including the plurality of recesses has penetrated to the other surface of the plate member.   The light guide according to claim 1, wherein the plurality of concave portions are formed in at least two rows along the outer edge portion in a plan view, and are formed in a staggered manner between the two rows.   The light guide according to claim 1, wherein the plurality of recesses are formed so that adjacent ones do not overlap in plan view.   The plurality of recesses are formed at a depth of not more than half of the plate thickness and not less than a quarter in the thickness direction of the plate body. Light guide. A light guide according to any one of claims 1 to 4, and a substrate provided with the light source,
The illumination device according to claim 1, wherein the light guide is disposed on the substrate so that a light incident portion of the light guide corresponds to the light source.