WO2013128869A1

WO2013128869A1 - Lighting device

Info

Publication number: WO2013128869A1
Application number: PCT/JP2013/001045
Authority: WO
Inventors: 藤田　勝; 雄介日下; 栄成菊池; 喜彦金山; 由田　宏史
Original assignee: パナソニック株式会社
Priority date: 2012-02-29
Filing date: 2013-02-25
Publication date: 2013-09-06
Also published as: JP6028230B2; JPWO2013128869A1

Abstract

In a light source in which LEDs are arranged in a straight line, the luminance difference between the part of the LEDs having light of a strong directionality and the part of the LEDs having light that is not of a strong directionality is increased, and irregularity is emphasized. In addition, the light from each LED light source, said light being strongly directional LED light, can cause shadows to occur in multiple layers. In the lighting device of the present invention, an optical component (1) comprises an inner-side optical surface having a convex section that faces the light sources of a plurality of LEDs and a thickness (T) on the back surface of the inner-side optical surface, and forms an outer-side optical surface that has a convex section. The lighting device is characterized in that, by means of the optical component (1), the image from the light sources of the plurality of LEDs is divided into multiple images by multi-layer reflection on the inner side optical surface and the outer side optical surface, and exists indefinitely in the direction of the convex shape that exists on the inner-side optical surface and the convex shape that exists on the outer-side optical surface.

Description

Lighting device

The present invention relates to a lighting device using a light emitting diode as a light source.

Instead of lighting devices using fluorescent tubes, replacement with lighting devices using light emitting diodes (LEDs) as light sources is progressing.

One reason for this is that there is a problem during disposal in terms of environmental friendliness due to the small amount of mercury contained in fluorescent lamps. When a fluorescent lamp is replaced with an LED, a completely mercury-free lighting device can be realized.

The second reason is that the fluorescent lamp needs an inverter and a ballast, but it is not necessary for the lighting device using the LED, and the power consumption can be reduced.

On the other hand, incandescent bulbs do not have problems such as mercury and inverters, but their luminous efficiency is low and their lifetime is short compared to fluorescent lamps, so power consumption can be reduced and lifetime can be reduced by replacing them with lighting devices using LEDs. Can be extended.

From such a background, lighting devices using various LEDs have been proposed and put into practical use. However, the illumination device using the LED has a problem that the front of the LED is bright but the surrounding portion is dark because the directivity of light emitted from the LED as the light source is strong.

In addition, even if a plurality of LEDs are arranged, this tendency remains, the distance between the LEDs becomes dark, and if the LEDs are not arranged closely, there is a problem that unevenness of dot-like brightness easily occurs according to the arrangement. It was.

Also, due to the influence of directivity of strong light of the LED, in the lighting device arranged with the LED, the shadow is divided into as many as the number of the light sources of the LED, and multiple shadows are generated. For this reason, there existed a subject of giving a user's discomfort.

Patent Document 1 for solving this problem will be described with reference to FIGS. 25A and 25B. FIG. 25A shows a perspective view of the lighting device body 20 in which an opening is provided in at least a part of the bottom surface. A Fresnel lens 21 having a plurality of linear prisms on the surface is installed in the opening.

FIG. 25B is a cross-sectional view of FIG. 25A and shows a state in which the lighting device body 20, the Fresnel lens 21, the LED 39, and the substrate 3 are configured. The instrument of Patent Document 1 is characterized in that the light of the LED 39 can be dispersed by the Fresnel lens 21.

Meanwhile, the case of Patent Document 2 which is a conventional optical component will be described with reference to FIG. In the conventional optical component, the sheet-like prism sheet 31 is arranged with respect to the plurality of arranged LEDs 37, and the light of the LEDs 37 is scattered.

The prism sheet 31 includes a sheet-like main body 32, a main body 32, a light diffusion layer 33, and a prism layer 34.

The prism layer 34 has a plurality of convex portions 36 protruding outward.

In the light diffusing layer 33, granular materials made of light diffusing particles alone or aggregates are dispersed in a resin binder. The surface of the light diffusion layer 33 on the prism layer 34 side is a rough surface. The refractive index of the resin binder and the refractive index of the prism layer 34 are different.

The main body 32 is a sheet that supports the light diffusion layer 33.

This prism sheet 31 has both a light collecting function by a plurality of convex portions 36 and a light diffusion function by internal roughening.

As a result, the brightness in the front direction is bright due to the condensing function, and it is possible to prevent the light source image from being seen brightly in a dot shape due to the light diffusion function.

In FIGS. 25A and 25B of Patent Document 1, a Fresnel lens 21 is provided on the front surface to make light distribution characteristics uniform. However, although the Fresnel lens 21 has an effect of condensing light in a certain direction, it cannot be expected to have an effect of spreading to the surroundings, and the uneven brightness of the illumination light cannot be resolved. In addition, since directivity of each LED 39 cannot be uniformly distributed, multiple shadows cannot be eliminated.

In FIG. 26 of the conventional Patent Document 2, the light source light emitted from the LED 37 passes through the prism sheet 31 and becomes illumination light. At this time, the light diffusion layer 33 in the inside functions to diffuse light. However, the positional relationship between the resin binder in the light diffusion layer 33 and the prism layer 34 is uneven, and the directivity of strong light from the LED 37 cannot be erased.

As a result of the verification, the luminance difference between the light with strong directivity of the LED 37 and the portion not so is large, and unevenness is emphasized. In the prism sheet 31, when the pitch interval of the LEDs 37 is widened, it cannot be further uniformed.

JP 2008-218186 A JP 2011-1224023 A

In order to solve the above-mentioned problem, it is composed of LEDs arranged at regular intervals on a flat substrate and an optical member that covers the upper surface of the LED, and the optical member has a convex portion on the inner surface facing the LED surface, A lighting device is used, which has a convex portion on the outer surface opposite to the above.

The highly directional light of the LED is dispersed by the convex portions located on both sides of the optical component of the illumination device of the present invention, and uniform light is provided to the periphery.

FIG. 1A is a perspective view of the lighting apparatus according to Embodiment 1 of the present invention. FIG. 1B is a cross-sectional view perpendicular to the Y axis of the lighting apparatus according to Embodiment 1 of the present invention. FIG. 1C is a cross-sectional view taken along line ab of the illumination device according to the first embodiment of the present invention. FIG. 1D is a partially enlarged view of FIG. 1C. FIG. 1E is a partially enlarged perspective view of a dotted line portion in FIG. 1A. FIG. 2A is a cross-sectional view in the Y-axis direction of a modification of the illumination device according to Embodiment 1 of the present invention. FIG. 2B is a cross-sectional view in the X-axis direction of the lighting apparatus according to Embodiment 1 of the present invention. FIG. 3A is a luminance distribution graph of a light emission state of a preferred example (Example 1 of the present invention). FIG. 3B is a luminance distribution graph of a light emission state of an unfavorable example (conventional example). FIG. 3C is a diagram illustrating the contrast of the luminance distribution. FIG. 4A is a cross-sectional view of the optical surface of the optical component according to Embodiment 1 of the present invention. FIG. 4B is a partial cross-sectional view of the optical surface of the optical component according to Embodiment 1 of the present invention. FIG. 4C is a partial cross-sectional view of the optical surface of the optical component according to Embodiment 1 of the present invention. FIG. 5A is a luminance distribution graph of the light emission state of the illumination device using the optical component of Comparative Example 1. FIG. 5B is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to the second embodiment of the present invention. FIG. 6A is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to the third embodiment of the present invention. FIG. 6B is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to Example 4 of the present invention. FIG. 7A is a cross-sectional view of the optical surface of another example of the optical component according to Examples 3 and 4 of the present invention. FIG. 7B is a partial cross-sectional view of the optical surface of the optical component according to Examples 3 and 4 of the present invention. FIG. 8A is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to Example 5 of the present invention. FIG. 8B is a graph of the luminance distribution in the light emission state of the illumination device using the optical component of Comparative Example 2. FIG. 9 is a graph of an allowable region of the luminance distribution in the light emission state of the illumination device using the optical component according to the sixth embodiment of the present invention. FIG. 10 is a partial cross-sectional schematic view of the optical surface of the optical component of the present invention. FIG. 11A is a cross-sectional view of an optical surface of an optical component according to Example 7 of the present invention. FIG. 11B is a partial cross-sectional view of the optical surface of the optical component according to Embodiment 7 of the present invention. FIG. 11C is a cross-sectional view of the optical surface portion of the optical component according to Embodiment 7 of the present invention. FIG. 12A is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to Example 7 of the present invention. 12B is a graph of the luminance distribution in the light emission state of the illumination device using the optical component of Comparative Example 3. FIG. FIG. 13A is a cross-sectional view of the optical surface of the optical component according to Embodiment 8 of the present invention. FIG. 13B is a partial cross-sectional view of the optical surface of the optical component according to Example 8 of the present invention. FIG. 13C is a partial cross-sectional view of the optical surface of the optical component according to Example 8 of the present invention. FIG. 14 is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to the eighth embodiment of the present invention. FIG. 15A is a cross-sectional view of the optical surface of the optical component according to Embodiment 9 of the present invention. FIG. 15B is a partial cross-sectional view of the optical surface of the optical component according to Embodiment 9 of the present invention. FIG. 15C is a partial cross-sectional view of the optical surface of the optical component according to Embodiment 9 of the present invention. FIG. 16 is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to the ninth embodiment of the present invention. FIG. 17A is a cross-sectional view of the optical surface of the optical component according to Embodiment 10 of the present invention. FIG. 17B is a partial cross-sectional view of the optical surface of the optical component according to Example 10 of the present invention. FIG. 17C is a partial cross-sectional view of the optical surface of the optical component according to Example 10 of the present invention. FIG. 18 is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to the tenth embodiment of the present invention. FIG. 19A is a cross-sectional view of an optical surface of an optical component according to Example 11 of the present invention. FIG. 19B is a partial cross-sectional view of the optical surface of the optical component according to Example 11 of the present invention. FIG. 19C is a partial cross-sectional view of the optical surface of the optical component according to Example 11 of the present invention. FIG. 20 is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to the eleventh embodiment of the present invention. FIG. 21A is a cross-sectional view of the optical surface of the optical component according to Embodiment 12 of the present invention. FIG. 21B is a partial cross-sectional view of the optical surface of the optical component according to Example 12 of the present invention. FIG. 21C is a partial cross-sectional view of the optical surface of the optical component according to Example 12 of the present invention. FIG. 22 is a graph of the luminance distribution in the light emission state of the illumination device using the optical component according to the twelfth embodiment of the present invention. FIG. 23 is a perspective view of an illumination device using an optical component according to Example 14 of the present invention. FIG. 24 is a perspective view of an illumination device using an optical component according to Example 15 of the present invention. FIG. 25A is a perspective view of the illumination device of Patent Document 1 of the related art. FIG. 25B is a cross-sectional view of the illumination device of Patent Document 1 of the related art. FIG. 26 is a cross-sectional view of the illumination device of Patent Document 2 of the prior art.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings. An illumination device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1A to 1E.

1A is a perspective view of the lighting device, and FIG. 1B is a cross-sectional view perpendicular to the Y axis of the lighting device of FIG. 1A. 1C is a cross-sectional view of the ab plane of the lighting device of FIG. 1A. FIG. 1D is a partially enlarged view of the optical component 1 of FIG. 1C. FIG. 1E is a perspective view of an upper surface of a portion surrounded by a dotted-line square in FIG. 1A, viewed from the X direction.

The illumination device includes an LED 2 that is a light source, a substrate 3 on which the LED 2 is mounted, and an optical component 1. The LEDs 2 are arranged in a straight line in the Y direction at a substantially constant interval PL.

As shown in FIG. 1A and FIG. 1B, the optical component 1 is half the shape of a hollow cylinder.

As shown in FIG. 1C, FIG. 1D, and FIG. 1E, the outer optical surface 1B on the outer side of the optical component 1 and the inner optical surface 1A on the inner side have wavy convex portions.

As shown in FIG. 1E, the wavy convex portion indicates a state like a mountain range with protrusions connected in a straight line. Waves in the direction of LED2 alignment. The direction in which the LEDs 2 are arranged and the linear direction of the protrusion are perpendicular to each other. The direction in which the LEDs 2 are arranged is parallel to the wave traveling direction of the convex portion. The optical component 1 is made of a transparent resin that transmits light such as an acrylic resin or a polycarbonate resin. The substrate 3 is made of aluminum. Here, the wavy convex portions have the same height in FIG. 1E, but the conical convex portions may be adjacent to each other. That is, the top may be uneven. However, it is not good if the conical convex portions do not overlap and are separated. Hereinafter, the height of the convex portion is defined as the height when the height is the same, and the average height when the height is uneven.

At this time, as shown in FIG. 1B, the optical component 1 has a cylindrical inner diameter of R10 mm. The inner optical surface 1A and the outer optical surface 1B are formed on the entire front and back surfaces of the semicylindrical optical component 1.

<Ratio of distance D to pitch PL>
FIG. 2A is a cross-sectional view of the optical component 1 that is the same as that of FIG. Here, the spread angle of the illuminance of the LED 2 is 60 ° on one side. FIG. 2A shows a light irradiation region LD to which the light of the LED 2 is irradiated. If the light irradiation regions LD do not overlap, the homogeneity of the light will deteriorate. The case of FIG. 2A is the limit positional relationship. In FIG. 2A, the value of distance D / pitch PL is 0.29, and a value larger than that is necessary.

When the distance D is increased, the light overlaps and works to improve the uniformity. However, the lighting device becomes large. If the number of LEDs 2 is increased and the pitch PL is shortened, the light overlaps and becomes homogeneous, but a large number of LEDs 2 are required, and extra power is required.

In the present lighting device, the distance D is small, and in the case of a limited number of LEDs 2, the directivity of the light of the LEDs 2 can be dispersed and made uniform.

<Overall shape of optical components>
FIG. 2B corresponds to FIG. 1B. Similarly to the above, because of the spread of light, the convex portion need not be on the entire surface of the optical component 1 but may be on the upper part of the arc as shown by the arrow. As shown in FIG. It suffices if there is a convex part in the part. It does not have to be in a portion smaller than 30 °. Therefore, as shown in FIG. 2B, the lower part of the optical component 1 may be a straight line instead of an arc.

<Luminance evaluation>
A method for evaluating the luminance distribution of the illumination device by optical simulation will be described. Evaluation was made from the two directions shown in FIG. 1A, that is, from the front E direction and the diagonal F direction of 45 °. The results are shown in FIGS. 3A and 3B. The luminance distribution when viewed from the E direction is indicated by a solid line, and the luminance distribution viewed from the F direction is indicated by a dotted line. The horizontal axis is the Y-axis direction, and the vertical axis is the luminance. The lighting device of FIGS. 1A to 1E is intended. The number of LEDs 2 is 5, the pitch PL is 12 mm, the thickness T is 2 mm, and the distance D is 10 mm. In the luminance evaluation of the following embodiments, evaluation is performed by changing only the surface shape of the optical component 1 with the same verification device. The following example is the same.

FIG. 3A shows the result of a preferable case. It can be seen that the luminance difference between the LED 2 and the portion between the LEDs 2, that is, the contrast value is small, and light is emitted on the line. In addition, as shown in the luminance distribution when viewed from the F direction in the 45 ° direction, it is satisfied that even if the angle is inclined, the light emission is maintained in a linear shape and the luminance is not uneven.

In contrast, FIG. 3B shows the result when it is not preferable. It is the example of the conventional FIG. The number of LEDs 2, the pitch PL, and the distance D were the same as in FIG. 3A. It can be seen that the luminance unevenness in the arrangement direction of the LEDs 2 is large.

This time, as an index of whether or not it becomes uneven, it was evaluated as the following value calculated from the undulation difference of brightness, and the contrast value representing the sharpness of light and shade. FIG. 3C is a schematic diagram illustrating the relationship between the position of the illumination device and the luminance. As shown in FIG. 3C, the contrast calculation formula is Kmax as the luminance undulation of the luminance waveform, and Kmin as the MIN value of the luminance undulation. Calculated by

C (contrast) = (Kmax−Kmin) / (Kmax + Kmin) × 100% (Equation 1)
The smaller the value of the contrast C, the smaller the brightness undulations and the less unevenness.

As the luminance difference, the difference between the average luminance of the five peaks in the E direction in FIG. 3A and the average luminance of the five peaks in the F direction was evaluated. The five peaks correspond to the light from the five LEDs. When the luminance difference is large, the appearance of the lighting device is affected. A difference in luminance occurs in the viewing direction, resulting in poor appearance.

The objective is that the contrast C value is 35% or less, and the luminance difference in the F direction is less than 40% with respect to the luminance in the E direction. In the following evaluations, pass / fail was determined based on the above values.

The contrast of 35% is a limit value that cannot be seen as uneven brightness. A luminance difference of less than 40% is an acceptable level of the appearance of light emission as a product.

<Evaluation of roughness of convex part>
(Examples 1 to 4)
FIG. 4A is an enlarged cross-sectional view of the optical pattern surface of the optical component 1. It is sectional drawing perpendicular | vertical to the X-axis of an illuminating device. It is sectional drawing of the advancing direction of the wave of a convex part. The optical component 1 has a thickness T. Here, the thickness T does not include the height of the convex portion. The same applies to the following embodiments.

4B is an enlarged cross-sectional view of the outer optical surface 1B of the optical component 1. FIG. As shown to FIG. 4B, a convex part is the pitch PB and the front-end | tip is R shape (arc). It consists of a part of a circle (R part) and a straight line part (H part) extending as a tangent at its end. An angle formed by two straight lines extending in the tangential direction is an angle ∠TB. It has the height HB of the convex part. That is, a convex part consists of R part and a linear part (tangent). Hereinafter, the shape of the convex part of FIG. Here, the height is the average height of the protrusions.

FIG. 4C is an enlarged cross-sectional view of the inner optical surface 1A. Surfaces having an R-shaped (arc) cross section are continuously arranged in a convex shape at a pitch PA. The convex shape is the height HA. That is, there is no straight part and it consists only of the R part of a part of the circle. An angle formed by a straight line extending in the tangential direction at the end is an angle ∠TA. Hereinafter, it is assumed as an R shape. The R shape means a shape of a part of a circle.

In Examples 1 to 4 and Comparative Example 1, evaluation was performed by changing the pitch PA, height HA, and radius R of the inner optical surface 1A. The conditions are shown in Table 1. The shape of the outer optical surface 1B is constant. Table 1 shows the shape of the protrusion and the evaluation results.

Results of evaluating the luminance distribution of Examples 1, 2, 3, 4 and Comparative Example 1 are shown in FIGS. 3A, 5B, 6A, 6B, and 5A.

Here, there is no interaction between the shape of the outer optical surface 1B and the shape of the inner optical surface 1A. Since the thickness T is 2 mm and the height HA and the height HB are 0.3 mm or less, the thickness is larger than the height of the convex portion, and there is no mutual influence. Therefore, the shape of the outer optical surface 1B is constant.

When at least the total height of the convex portions of the outer optical surface 1B and the inner optical surface 1A is less than half of the thickness T, there is almost no interaction between the shapes of the two convex portions.

Also, consider the pitch PA / height HA. In this PA / HA, the pitch is divided by the height, and thus represents the roughness and fineness of the convex portion. Larger numbers are coarser, smaller numbers are finer. It greatly affects the homogeneity of light.

Furthermore, the shape of the outer optical surface 1B and the shape of the inner optical surface 1A are the difference in whether light is incident or emitted, and the preferred shape is the same.

From Table 1, the preferred range is the range of the following formula 2 based on this result.

PA / HA <10 ... (Formula 2)
Similarly for the outer optical surface 1B,
PB / HB <10 .................. (Formula 3)
It becomes.

Here, consider the case of Example 3.

FIG. 7A is a diagram showing a cross section of the optical component 1 of Examples 3 and 4, and FIG. 7B is an enlarged view of the shape of the inner optical surface 1A. As can be seen in FIG. 7B, the convex portions do not overlap, and a flat portion is located between the convex portions. However, the result of evaluation has passed. Therefore, there may be a flat portion. However, when the pitch is further widened, for example, when the pitch is 1 mm, the luminance unevenness is recognized at that pitch.

That is, in this case, the pitch PA is 1.00 mm, the radius of the circle of the R-shaped convex portion is 0.20 mm, and the diameter is 0.40 mm. Therefore, the ratio of the convex portion on the surface of the optical component 1 needs to be larger than 40% of the pitch PA from 0.40 / 1.00. The case of Example 4 is preferable. That is, in Example 4, since the pitch is 0.80 mm and the diameter of the circle of the R-shaped convex portion is 0.40 mm, the convex portion is the pitch PA on the surface of the optical component 1 from 0.40 / 1.00. It is necessary to occupy 50% or more.

<Evaluation of top angle of convex part>
(Examples 1, 5 and 6)
Next, the angle ∠TB (FIG. 4B) of the outer optical surface 1B was evaluated. As shown in Table 2, in Examples 1, 5, 6 and Comparative Example 2, the evaluation was performed by changing the angle ∠TB of the outer optical surface 1B. The inner optical surface 1A has the same shape. The results of evaluating Examples 1, 5, 6 and Comparative Example 2 are shown in Table 2. The results of the luminance distribution evaluated in Examples 1, 5, 6 and Comparative Example 2 are shown in FIGS. 3A, 8A, 9, and 8B, respectively.

From the results of Table 2, the preferred angle of the angle ∠TB of the outer optical surface 1B is Equation 4.

35 ° ≦ ∠TB ≦ 120 ° (Equation 4)
The above is the outer optical surface 1B, but the inner optical surface 1A surface can be considered to have the same result.

Suppose that the angle of ∠TB is 35 °. FIG. 10 schematically showing FIG. 4B will be described. The height HB = 0.25 / TAN (17.5 °) = 0.793 of the convex portion of the triangular prism when the angle ∠TB is 35 ° and the pitch (PB) is 0.5 mm. The height HB of the convex portion is 0.793 mm, and at this time, PB / HB = 0.5 / 0.793 = 0.63. From this result, the preferable estimation range of the region where the value of PB / HB is small is The following formula 5 is obtained.

0.63 ≤ PB / HB (5)
When combined with Equation 3 above, Equation 6 is obtained.

0.63 ≦ PB / HB <10 (Equation 6)

<Evaluation when convex part is RR shape>
(Examples 7 and 8)
Examples 7 and 8 are embodiments in which the shape of the optical component 1 shown in FIGS. 4A to 4C of Example 1 is different. Both the convex portions of the inner optical surface 1A and the outer optical surface 1B are R-shaped patterns.

11A to 11C are those of the seventh embodiment, and FIGS. 13A to 13C are those of the eighth embodiment.

11A and 13A are cross-sectional views of the optical pattern surface of the optical component 1. 11B and 13B are enlarged sectional views of the outer optical surface 1B of the optical component 1. FIG. 11C and 13C are enlarged cross-sectional views of the inner optical surface 1A. The convex portions of both the inner optical surface 1A and the outer optical surface 1B have an R shape. Examples 7 and 8 and Comparative Example 3 have the above shapes, and were evaluated by changing the shape of the convex portion of the outer optical surface 1B. Table 3 shows the shape conditions and the evaluation results. The luminance distributions of Examples 7 and 8 and Comparative Example 3 are shown in FIGS. 12A, 14 and 12B, respectively.

Since the time of Comparative Example 3 is the limit of the good range, the preferable region of PB / HB is PB / HB <7.49.

Here, in Comparative Example 3, the C value in the E direction is 37.58%, which is close to 35% of the reference, and can be estimated to pass to the very vicinity of PB / HB = 7.49 of Comparative Example 3. Therefore,
PB / HB <7.49 (7)
When combined with (Equation 6),
0.63 ≦ PB / HB <7.49 (Equation 8)
It becomes. Similarly, 0.63 ≦ PA / HA <7.49 (Equation 9)
It becomes.

In FIG. 13B, there is a flat portion between the convex portions, but the flat portion is not large and allowed as in the case of FIG. 7B.

<Evaluation when the convex part is triangular and RH shape>
Example 9
Example 9 is a different embodiment of the optical component 1 shown in FIGS. 4A to 4C of Example 1. FIG. This will be described with reference to FIGS. 15A to 15C. The convex part is a triangle and RH shape.

FIG. 15A shows a cross-sectional view of the optical component 1. FIG. 15B is an enlarged sectional view of the outer optical surface 1B, and FIG. 15C is an enlarged sectional view of the inner optical surface 1A.

As shown in FIG. 15C, the convex shape of the inner optical surface 1A is a convex shape having a triangular apex angle ∠TA, a pitch PA, and a convex portion height HA.

As shown in FIG. 15B, the convex shape of the outer optical surface 1B has a pitch PB, an R-shaped cross section, the height of the convex portion is HB, and the angle ∠TB. Evaluation was performed under the shape conditions shown in Table 4. The results are shown in FIG. This is an acceptable level for the optical component 1. In addition, as for the shape, the angle ∠TA was 90 °, the angle ∠TB was 40 °, and R was 0.2 mm.

<Evaluation when the convex part is trapezoidal and R-shaped>
(Example 10)
Example 10 is a different embodiment of the optical component 1 shown in FIGS. 4A to 4C of Example 1. FIG. The tenth embodiment will be described with reference to FIGS. 17A to 17C.

FIG. 17A is a cross-sectional view of the optical pattern surface of the optical component 1. FIG. 17B is an enlarged cross-sectional view of the outer optical surface 1B of the optical component 1. FIG. 17C is an enlarged cross-sectional view of the inner optical surface 1A.

The inner optical surface 1A has a triangular apex angle ∠TA as shown in FIG. 17C. The convex shape (D shape, trapezoid) having a flat surface at the tip is a pitch PA. An inner optical surface 1A having a convex portion height HA and an outer optical surface 1B having an R-shaped cross section with a pitch PB and a convex portion height HB on the back side of the inner optical surface 1A. Formed on the wall.

Table 4 shows the dimensions of the convex shape of Example 10. In addition, the angle ∠TA of the triangular apex is 90 °, the flat portion length is 0.05 mm, the tip R is 0.20 mm, and the angle ∠TB is 40 °.

In this case, the inner optical surface 1A has a trapezoidal convex portion protruding outward, and a straight line (plane) between the convex portions. The result of evaluating this luminance distribution is shown in FIG. From Table 4, it is a level acceptable as an optical component.

<Evaluation when the convex part is triangular and rounded>
(Example 11)
Example 11 is a different embodiment of the optical component 1 shown in FIGS. 4A to 4C of Example 1. FIG. This will be described with reference to FIGS. 19A to 19C.

FIG. 19A is a cross-sectional view of the optical pattern surface of the optical component 1. FIG. 19B is an enlarged cross-sectional view of the outer optical surface 1B of the optical component 1. FIG. 19C is an enlarged cross-sectional view of the inner optical surface 1A.

The convex part of the inner optical surface 1A of the optical component 1 has an R-shaped cross section as shown in FIG. 19C, has a pitch PA, and the height of the convex part is HA. As shown in FIG. 19B, the convex portion of the outer optical surface 1B of the optical component 1 is a convex shape (T shape) having a triangular apex angle ∠TB cross section, a pitch PB, and a convex portion height. HB.

The details of the shape in this example are shown in Table 4. In addition, the convex portion of the inner optical surface 1A is R0.2 mm, and the angle 三角形 TB of the triangular apex of the convex portion of the outer optical surface 1B is 90 °.

The results of this optical simulation are shown in FIG. This is an acceptable level for the optical component 1 of the present invention. The conditions other than those in Table 4 were as follows: R was 0.2 mm and angle ∠TB was 90 °.

<Evaluation when the convex part is trapezoidal and R-shaped>
Example 12
Example 12 is a different embodiment of the optical component 1 shown in FIGS. 4A to 4C of Example 1. FIG. Example 12 will be described with reference to FIGS. 21A to 21C.

FIG. 21A is a cross-sectional view of the optical pattern surface of the optical component 1. FIG. 21B is an enlarged cross-sectional view of the outer optical surface 1B of the optical component 1. FIG. 21C is an enlarged cross-sectional view of the inner optical surface 1A.

The convex part of the inner optical surface 1A has an R shape as shown in FIG. 21C, has a pitch PA, and the height of the convex part shape is HA.

As shown in FIG. 21B, the convex portion of the outer optical surface 1B has a triangular shape, a cross section with a vertex angle ∠TB, and a convex shape (trapezoidal shape, D shape) having a flat portion at the vertex. At the pitch PB, the height of the convex portion is HB.

The details of the shape in this example are shown in Table 4. In addition, the convex portion of the inner optical surface 1A is R0.2 mm, the convex portion of the outer optical surface 1B has a triangular apex angle ∠TB of 90 °, and the trapezoidal apex side is 0.05 mm. .

In this case, the outer optical surface 1B has a trapezoidal convex portion protruding outward, and the convex portion is a straight line (plane). FIG. 22 shows the result of the luminance distribution, and Table 4 shows the evaluation result. This is an acceptable level for the optical component of the present invention.

(Summary of Examples 9-12)
Table 4 summarizes the convex shape and results of Example 1-12. In Example 1-12, the shape of the convex portion was changed. Also in Example 1-12, the characteristics are satisfied. In Example 9-12, Expressions 8 and 9 of the result of Example 1-8 are satisfied. Therefore, it can be seen that Expressions 8 and 9 can be applied regardless of the convex shape.
<When optical parts are flat>
(Embodiment 2)
Example 13 will be described with reference to FIG. As shown in FIG. 23, the optical component 1, the LED 2, and the substrate 3 are arranged, and the LED 2 is linearly arranged on the substrate 3 with a pitch PL of 12 mm. The difference from the first embodiment is that the optical component 1 is a flat surface.

The inner optical surface 1A is formed on the surface facing the LED 2, and the optical surface of Example 1 shown in FIG. 4C is formed on the inner optical surface 1A. The optical surface of Example 1 shown in FIG. 4B is formed on the outer optical surface 1B.

The optical component 1 has a flat plate shape with a thickness of 2 mm, and is located at a distance D10 mm from the LED 2. Also in the flat optical component 1 of Example 13, the preferable ranges of the convex portions of the inner optical surface 1A and the outer optical surface 1B are the conditions described above.

Also in the flat plate shape of Example 13, similarly, it is possible to emit light uniformly in a planar shape within the range of the shape of the convex portion shown above.

<When LED2 is in multiple rows>
(Embodiment 3)
Example 14 will be described with reference to FIG. As shown in FIG. 24, the illumination device of the present invention includes an optical component 1, an LED 2, and a substrate 3. The difference from the first embodiment is that the optical component 1 is planar, and a plurality of examples of the LEDs 2 are arranged on the substrate 3.

The optical component 1 at this time is formed with convex portions of the inner optical surface 1A and the outer optical surface 1B similar to the above.

The optical component 1 has a thickness T2 mm and is formed in a flat plate shape with a distance D10 mm from the LED 2 so as to cover the light emission range of the LED 2. The pitch of the LEDs 2 is 12 mm.

Also in the flat plate shape of Example 14, it is possible to emit light uniformly in a planar shape within the range of the shape of the convex portion shown above.

As described above, according to the present invention, even if the pitches of the LEDs 2 are arranged apart from each other, light can be emitted in one line shape, and unevenness can be seen from the front direction (E direction) and the oblique direction (F direction). It becomes a linear light source without any. Alternatively, a planar light source can be realized.

In addition, since this optical pattern is configured to create an infinite number of images, an object viewed through the optical component appears as if it is visible through the frosted glass, and also functions as a cover in which the internal organs cannot be seen.

And even if it looks like a frosted glass, it has been confirmed that the optical efficiency maintains a high transmittance of 83% or more. Further, as a function of this optical component, multiple shadows are not generated by creating innumerable images by the light of the highly directional LED 2. With this optical component, it is possible to realize a high-efficiency light source without unevenness in the light emission state with a small number of LEDs 2, and energy saving can be realized in all lighting devices.

Various lighting devices can be used for backlights used for displays, signboards, and the like.

DESCRIPTION OF SYMBOLS 1 Optical component 1A Inner optical surface 1B Outer

optical surface

2,37,39 LED
3 Substrate 20 Lighting Device Body 21 Fresnel Lens 31 Prism Sheet 32 Body Part 33 Light Diffusing Layer 34 Prism Layer 36 Convex Part

Claims

A plurality of LEDs arranged at regular intervals on a flat substrate;
An optical member covering the upper surface of the plurality of LEDs,
The optical member is
An illumination device comprising a convex portion on an inner surface facing the plurality of LEDs and a convex portion on an outer surface facing the inner surface.
The lighting device according to claim 1, wherein the convex portion on the inner surface and the convex portion on the outer surface are wavy convex portions.
The lighting device according to claim 2, wherein a wave traveling direction of the wavy convex portion is parallel to an arrangement direction of the LEDs.
The lighting device according to claim 1, wherein the optical member has a semi-cylindrical shape.
3. The illumination according to claim 2, wherein the convex portion of the inner surface has a circular cross section in the traveling direction of the wave, and the convex portion of the outer surface has a shape in which the cross section in the traveling direction of the wave is an arc and a straight line. apparatus.
The lighting device according to claim 2, wherein the convex portion of the inner surface has a circular cross section in the wave traveling direction, and the convex portion of the outer surface has a circular cross section in the traveling direction of the wave or a trapezoid.
The lighting device according to claim 2, wherein the convex portion on the outer surface has a circular cross section in the wave traveling direction, and the convex portion on the inner surface has a triangular or trapezoidal cross section in the wave traveling direction.
The convex portion of the inner surface has a triangular cross section in the wave traveling direction, and the convex portion of the outer surface has a shape in which the cross section in the wave traveling direction is a combination of an arc and a straight line. Lighting device.
The lighting device according to any one of claims 1 to 8, wherein a relationship between a pitch PA of the protrusions on the inner surface and a height HA of the protrusions is in a range according to the following expression.
0.63 ≦ PA / HA <7.49
The lighting device according to any one of claims 1 to 8, wherein a relationship between a pitch PB of the protrusions on the outer surface and a height HB of the protrusions is in a range according to the following equation.
0.63 ≦ PB / HB <7.49
The lighting device according to claim 5 or 8, wherein a shape obtained by combining the arc and the straight line includes a circular arc at a tip and two straight lines in contact with the arc.
The lighting device according to claim 11, wherein an angle formed between the two straight lines is 35 ° or more and 120 ° or less.
9. The illumination device according to claim 1, wherein the distance between the LEDs is PL, and the distance D between the inner surface and the LED is represented by the following formula.
0.29 ≦ D / PL