JP4789026B1 - Mixed color lighting device - Google Patents

Abstract

An illumination device having excellent color rendering properties is realized by mixing light sources provided in a plurality of directions with high efficiency and controlling a radiation angle.
A right triangular prism made of a low-refractive-index material having a 45 ° inclined reflecting surface symmetrically arranged on a vertical surface is provided inside the high-refractive-index material, and is irradiated vertically with light incident in a symmetric direction parallel to the reference surface. Total reflection in the direction.
The total reflection triangular prisms are subdivided by the height h of the total reflection surface and the width d of the total reflection surface in the reference plane direction, and are dispersed and arranged in a staircase pattern so as not to interfere with light from other total reflection triangular columns. . The light incident on the reference plane in parallel from the symmetric direction is subdivided by the height h of the total reflection triangular prism, and then both incident lights are alternately arranged in a comb-like arrangement shifted by the width d in the reference plane direction. Total reflection in the vertical direction.
Light in four or more directions is mixed by allowing the reflected light from the total reflection triangular prisms arranged in a separate row to pass between the total reflection triangular prisms arranged in rows in a staircase pattern.
[Selection] Figure 5

Description

  The present invention relates to an illuminating device in which triangular prisms of a low refractive index material are dispersedly arranged in a high refractive index material to form a total reflection surface, and incident light from a plurality of directions is mixed.

Light emitting diodes are used for general lighting such as backlights of liquid crystal display devices and LED bulbs because of their small size and high efficiency. Cross dichroic prisms that are used in liquid crystal projectors as a mixture of the three primary colors are expensive and are not common, so they are mixed in the same package, or the blue light emitted from the blue light-emitting diodes is applied to the phosphor to obtain the complementary fluorescence. White light emitting diodes are used.

Using a white light-emitting diode to separate the three colors with a color filter is absorbed by the color filter and the efficiency is reduced. Therefore, a number of additive color mixing methods using three primary color light-emitting elements without using a color filter have been proposed. Yes.
There is a proposal in which 45-degree grooves are provided in the light guide plate for the number of pixels, three layers of light guide plates that totally reflect light incident from the side face toward the liquid crystal panel at the groove interface, and thick portions of the wedge-shaped light guide plate are alternately arranged. (Patent Document 1, FIG. 20). There has been proposed a liquid crystal display device in which light sources of three colors are installed on three sides of a liquid crystal panel, a quadrangular pyramid is provided in a matrix shape on a light guide plate, and the light is reflected on an inclined surface of the quadrangular pyramid to irradiate predetermined pixels of the liquid crystal panel. (Patent Document 2, FIG. 21).
There has been proposed a light-emitting display device that emits light from four directions vertically upward by providing three total reflection surfaces with a pixel size of 45 ° on the bottom surface of the light guide plate and arranging them in a matrix (Patent Document 3). ). This proposal uses the 45 ° total reflection surface of Patent Document 1 and is considered to be the same operation as the matrix display by the quadrangular pyramid of Patent Document 2.

There has been proposed a color mixing device having a structure in which light from four directions is incident on a plane side of a sheet on which right-angle prisms are arranged and is emitted using a bandpass mirror (Patent Document 4, FIG. 22). The incident light on one prism surface is refracted light mixed in the same direction and emitted, but the incident light on the other prism surface exceeds the critical angle and is totally reflected and incident on the opposite light source. It is the structure which utilizes total reflection light using.

The fluorescent white light emitting diode is a light emitting diode that is recognized as white by a complementary color by irradiating the yellow phosphor with the blue light of the blue light emitting diode. Compared with the mixed color in which the three primary color light emitting elements are provided inside the reflecting mirror, color unevenness is less likely to occur, and therefore, it is used as a backlight of a liquid crystal display device such as a mobile phone, an LED bulb, and the like. The spectrum of the fluorescent white light-emitting diode consists of two peaks of sharp blue and gentle yellow region. For this reason, there is a proposal for improving color rendering properties by mixing red-range phosphors such as Ca _1-x AlSiN ₃ : Eu ²⁺ (Patent Document 5).

The long axis direction of the strip-shaped reflecting surface is arranged on the horizontal plane so as to be orthogonal to the traveling direction of the parallel light from the light source, and the short axis direction of the strip-shaped reflecting surface is alternately inclined by ± 30 ° to form a triangular wave shape. And a structure in which a parallel light source is provided at a symmetrical position in an obliquely upward 30 ° direction has been proposed (Patent Document 6). Since the reflecting surfaces forming the pair of each parallel light source and the triangular wave lattice are parallel, they cannot enter the reflecting surface arranged on the side of the parallel light source forming the pair, and the parallel light source 30 ° above the horizontal plane. Parallel light from both sides is incident along the light source direction reflecting surface of the triangular wave reflector, and any light incident from both sides is reflected vertically upward.

Patent Document 6 also proposes a color mixing device using a refractive grating. When the refractive index n2 of the constituent material and the refractive index n1 of the surrounding medium are set, and the light incident on the inclined surface from the refractive grating constituent material at an angle α is refracted at an angle β, the inclined surface angle of the V-shaped groove is relative to the center line. Therefore, the right side light source light is incident only on the right inclined surface, and the inclined surface and the incident light are symmetrical. By setting the inclined surface angle γ of the V-shaped groove by the difference between β and α, both refracted lights are emitted parallel to the center line. A four-way color mixing device is shown by combining the refraction grating and the reflection grating in the previous section (FIG. 23).

Japanese Patent No. 3131034 JP 2006-323221 A JP 2007-264148 A JP 2008-218154 A Japanese Patent No. 4405298 Japanese Patent No. 4399678

The proposal in which a 45 ° groove is provided in the light guide plate of Patent Document 1 and three layers of light guide plates that totally reflect in the direction of the liquid crystal panel at the interface of the groove constitute a subpixel with a 45 ° total reflection surface. The thickness of one light guide plate needs to be 1/3 of the display surface length. Since three of these are stacked, even if wedge-shaped alternating arrangement is performed, a very thick and heavy display device is obtained. For this reason, there is a problem that the material cost is remarkably increased. Since the display device of Patent Document 3 is also a 45 ° total reflection surface, a flat portion is provided in between, but it is thicker and heavier than Patent Document 1. Since there is a flat portion for thinning, there is also a problem that uneven brightness occurs. Thus, simply laminating a 45 ° total reflection surface has a problem that is not practical in terms of thickness, mass, cost, and the like.

  The proposal of Patent Document 3 in which a large number of quadrangular pyramid reflectors are provided on the bottom surface of the light guide plate, and the three primary colors from three directions are reflected on the pixels and mixed, is only reflected by the inverted V-shaped reflected light by the front pyramid. I can't get it. When oblique parallel light is irradiated onto the quadrangular pyramid, it also hits the side surface, so that it is reflected obliquely to become scattered light as shown in FIG. 21 and becomes blurred when incident on other pixels.

A white light-emitting diode with a complementary color obtained by irradiating a yellow phosphor with blue light from a blue light-emitting diode has a sharp spectrum of blue light and a gentle yellow light spectrum. The lighting is low in color rendering before and after.
As the compounding ratio of the phosphor is increased, the blue light peak decreases and the fluorescence increases. However, when it hits another yellow phosphor, the phosphor is colored and opaque and absorbs because the fluorescence conversion rate is low for the fluorescence wavelength. There is a problem that the efficiency is lowered.

In order to improve the color rendering, it is necessary to increase the amount of long wavelength phosphor such as red. In the red region, the relative luminous sensitivity is low, so it is necessary to mix a large amount of phosphor. However, the light emitted from the long wavelength phosphor is not absorbed and converted by the short wavelength phosphor, and the yellow fluorescence is converted into the yellow phosphor. And the probability that the red fluorescence hits the red phosphor also increases and the efficiency is lowered.

In the proposal of Patent Document 4 in which light is refracted by one inclined refracting surface of a right-angle prism and is emitted in the vertical direction, since the incident angle to one refracting surface is greater than the critical angle, the ratio of total reflection and incidence on the opposite light source side is Occupies half. In order to avoid the loss of the totally reflected light incident on the opposite light source side, it is re-reflected by a band pass mirror and used, but it is complicated and expensive.

The reflection grating and the refraction grating in Patent Document 6 mix parallel light from two directions and emit it as parallel light. When light in four directions or more is mixed, a thick structure is necessary because a total of three refracting gratings that mix two colors or two reflecting gratings and one refracting grating that mixes four colors are combined into a triangle.

When incident light parallel to the reference surface is irradiated onto the 45 ° inclined reflection surface with respect to the reference surface, the light is reflected in the vertical direction with respect to the reference surface, so the 45 ° inclined reflection surface is symmetric with respect to the vertical direction of the reference surface. In this case, both light beams that are parallel to the reference plane and incident from a symmetric direction are reflected in the vertical direction. If a low-refractive-index material space having a triangular prism shape with an inclination of 45 ° is provided inside the high-refractive-index material, total reflection can be used. If the inclined reflection surface of 45 ° is arranged symmetrically with respect to the vertical plane, a right-angled triangular prism is formed, and this will be referred to as a total reflection triangular prism 1.
The total reflection triangular prisms are subdivided by the height h of the total reflection surface and the width d of the total reflection surface in the reference plane direction, and are dispersed and arranged in a staircase pattern so as not to interfere with light from other total reflection triangular columns. . Light incident in a symmetric direction parallel to the reference plane is subdivided by the height h of the total reflection triangular prism, and then both incident lights are shifted by a width d in the reference plane direction in a comb-like arrangement and totally reflected in the vertical direction. To do. For this reason, the light incident from the symmetric direction is alternately arranged with the width d in the reference plane direction of the total reflection surface and is emitted in the same direction. FIGS. 1 and 3 show the state of this structure and action. Since it is a 45 ° inclined surface, h and d have the same value.
The critical angle θc at the interface between the refractive index n1 of the high refractive index material and the refractive index n2 of the low refractive index material is expressed by Equation 1.

When the refractive index of air is a refractive index of about 1 as a low refractive index material and the refractive index of the high refractive index material is 1.41 or more, the critical angle can satisfy the total reflection condition of 45 ° or less. Table 1 shows examples of the refractive index n and the critical angle θc of polymethyl methacrylate, cycloolefin resin, polycarbonate, and copolyester.

If the width d in the reference plane direction of the total reflection surface is set to be equal to or less than a width that cannot be visually recognized, the additive color mixture is performed. In Patent Documents 1 and 3 and the like, a light guide plate having a unidirectionally incident component is simply laminated, so three layers are displayed in three colors. In the present invention, incident light in a symmetric direction is divided into two colors by one total reflection triangular prism. Since they can be mixed, they can be mixed at twice the density.

In FIG. 2, every other triangular prism constituting the total reflection surface is arranged in the reference plane direction, and light in four directions is mixed by allowing the reflected light from the lower triangular column to pass between the upper triangular columns. It is sectional drawing which showed the state. The triangular prism row is an arrangement in which triangular prisms paired with incident light from symmetrical directions are inclined up. As shown in FIG. 2, there are two rows of triangular prisms in the four-color mixing. However, since the number of triangular prisms is half of the number of mixed colors, for example, there are three rows for six-color mixing and four rows for eight-color mixing.

Providing a triangular prism-shaped low refractive index material space inside a high refractive index material can be realized by combining two high refractive index materials provided with a triangular prism-shaped low refractive index material space. Since the positions of the triangular prisms are arranged in a step-like manner, it is necessary to provide a joint surface along the row of triangular prisms.
FIG. 3 is a cross-sectional view in the case where six rows of total reflection triangular prisms are stacked to mix six colors, and has a structure in which an interface perpendicular to incident light or reflected light is used except for the total reflection surface. Even if an air layer enters the joined interface, total reflection does not occur, and assembly is facilitated. Since it is a vertical interface, it has a large unevenness as shown in FIG. Even if an air layer enters the vertical interface, total reflection does not occur, but interface reflection of about 4% occurs. Therefore, the transmittance can be increased by interposing a bonding agent.

When the interface is perpendicular to the incident / exit light, since the irregularities are large as shown in FIG. 3, a simplified shape of the interface is shown in FIG. One of the interfaces in FIG. 5 has a repetitive structure of a gently inclined surface and a plane, and the other interface has a structure in which a right triangular prism-like space is provided. Although FIG. 5 shows a case where six colors are mixed, four or eight colors can be mixed with the same structure. In this shape, when an air layer enters the interface, it is totally reflected in the opposite direction, so it is necessary to interpose a bonding agent layer at the interface. As an optical bonding agent, a balsam resin, an epoxy adhesive, an acrylic adhesive, an ultraviolet curable resin, or the like is used. After the bonding agent is applied to the surface of one transparent material, the other transparent material side can be bonded together. Compared with the interface with many irregularities in FIG. 3, this structure is a structure in which one surface is a repetitively inclined surface and a flat surface, so that the coating and bonding processes are easy. If one of the interfaces is flattened, the coating and bonding steps are further facilitated, but the reference plane side of the triangular prism is inclined, so that a light quantity loss that totally reflects in the opposite direction occurs.

FIG. 6 shows a state in which when the light emitting element chip is provided at the focal point of the parabolic mirror, an error between the parallel light is caused by the ratio of the radius r of the light emitting element chip dimension and the focal length p of the parabolic mirror. When this error angle is ε, it is expressed by Equation 2.

When the focal length p is 10 mm and the radius r is 0.2 mm, the error angle is 1.1 ° at maximum.
The inclination of the total reflection triangular prism is not only a strict 45 °, but is actually an inclination angle in a range having a tolerance. When this error angle is ζ, the error in the emission direction is added to the error of ε.
In the case of a device that emits light as parallel light, ε and ζ need to be kept small. However, since a radiation angle is large in a general lighting device, the influence can be restrained if ε and ζ are smaller than the radiation angle.

The lighting device is evaluated for color rendering in a mixed color state of an object to be irradiated. When the irradiated object is irradiated with completely parallel light, a stripe pattern is generated, so that it is necessary to configure the optical path difference so that the optical path difference cannot be visually recognized. Since the distance from the eyes to the display surface is different for indoor use and outdoor use, the dimension that cannot be visually recognized is greatly different, but for a liquid crystal display viewed from several tens of centimeters, it is about 100 μm. When these arctans are converted into angles, the angle is about 0.01 °. In the case of using as parallel light, the standard of the refractive grating pitch P when the distance L from the eye to the refractive grating is long is expressed by Equation 3.

In general illumination, irradiation is performed with a wider radiation angle, and FIG. 7 shows the action of providing a microlens array on the exit surface to widen the radiation angle. In FIG. 7, a concave lens array is provided for expanding the radiation angle as compared with parallel light. A convex lens is also possible because it diffuses after passing through the focal point.
If each color light is emitted in the same direction and with the same emission angle, the color mixture ratio is constant regardless of the direction. The radiation angle θ of the single lens constituting the microlens is expressed by Equation 4 by the ray height e and the focal length f in the single spherical lens, and the radiation angle becomes maximum at the boundary portion of the microlens.

If the mixed parallel light emission direction is different, only one component will be formed and color spots will occur, so the concave lens pitch is made narrower than the refractive grating pitch, and the mixed parallel light emission angle and direction are aligned to irradiate uniform color mixing light I can do it.
When the diffused light from the microlens array is superimposed, the stripe is relaxed and cannot be recognized. For this reason, compared with the case where it radiate | emits with a parallel light, the dimension which cannot recognize the width | variety d of the reference surface direction of a total reflection surface can be enlarged.

The color rendering index is calculated by the CIE 1964 color matching function from the color difference between the standard light and the reflected light of the 15 color charts. For this reason, it is possible to calculate from the spectral characteristics of the light source without using actual measurement using a color chart. The spectral characteristics due to the color mixture of the present invention are shown in FIGS. In the figure, the spectral characteristics of the individual light emitting elements are indicated by a broken line, the combined spectrum by color mixture is indicated by a thick solid line, and the standard light of 6504K is indicated by a thin solid line. The color rendering property of the light source is calculated from the color difference from standard light such as a color temperature of 6504K, and is calculated from the color difference from black body radiation for a light source of 5000K or less.

By approximating the envelope of the composite curve by color mixing to the spectrum curve of standard light, the color difference can be reduced and the color rendering index can be increased. Table 2 shows the color rendering index of the light source by mixing four colors, six colors, and eight colors in FIGS. R1 to R15 are the color rendering index for each color chart, and Ra is the average color rendering index for R1 to R8. YAG in the table is a comparison of the color rendering index of a conventional fluorescent white LED using a blue LED and a YAG phosphor, and is shown by the spectral characteristics of the thick broken line in FIG. 2PHOS in the table is the color rendering index of the spectral characteristics of FIG. 11 mixed using a plurality of fluorescent white LEDs and total reflection triangular prisms.

In fluorescent white light-emitting diodes, mixing multiple phosphors in a large amount can improve the color rendering index of YAG. However, if multiple phosphors are mixed in a large amount, the converted fluorescence is absorbed by other phosphors. It becomes easy to be done and efficiency falls.
It is also possible to mix colors using a plurality of fluorescent white LEDs having different wavelength characteristics and total reflection triangular prisms. Unlike the case where the wavelength characteristics are improved in a wide band by mixing phosphors, the color is mixed and widened without a decrease in efficiency.

In order to mix three colors of RGB, the method of simply stacking three light guide plates with 45 ° total reflection surfaces significantly increases the thickness, mass, and cost, and there is a problem that is impractical for color mixing of multiple colors. However, if the total reflection triangular prisms of the present invention are arranged in a distributed manner, it is possible to mix many colors easily and at low cost.
A color mixing device that emits oblique parallel light to a quadrangular pyramid hits the side surface and becomes scattered light and becomes unclear when incident on other pixels, but since the present invention is a total reflection triangular prism, the radiation angle is controlled without causing scattered light Thus, it is possible to mix colors with high efficiency.
A four-way color mixing device using a right-angle prism sheet requires a bandpass mirror and is complicated and expensive. However, since the present invention is a mixed color in which total reflection triangular prisms are arranged in a dispersed manner, such a phenomenon does not occur and is highly efficient. Color mixing is possible at low cost.
In order to improve the color rendering properties of fluorescent white light emitting diodes, it is necessary to increase the amount of phosphor such as a long wavelength phosphor. The probability that the converted fluorescence hits the red phosphor also increases and the efficiency decreases. It is highly efficient because it mixes colors regardless of body mixing.
The refraction grating or reflection grating is a mixture of two colors, so when mixing four or more colors, it is combined with a triangle so that a thick structure is necessary. However, the color mixture by the total reflection triangular prism is a structure in which multiple lights pass between the pitches of the total reflection triangular prism. So multi-color mixing is easy. Since a plurality of lights can be easily mixed, it is possible to emit continuous spectrum white light with good color rendering.
Since they are mixed and emitted as parallel light in the same direction, they can be emitted at any radiation angle in combination with other optical systems.
Since total reflection is used, it is possible to mix colors with high efficiency.

Principle diagram of structure that mixes light in two directions by total reflection triangular prism Principle diagram of structure that mixes light in 4 directions by total reflection triangular prism Sectional view of a structure that couples a total reflection triangular prism that mixes light in two directions with a structure perpendicular to the interface Cross-sectional view of a structure in which total reflection triangular prisms that mix light in six directions are coupled in a structure perpendicular to the interface Cross-sectional view of a total reflection triangular prism joined at an interface consisting of a gently inclined surface and a flat surface and an interface including a triangular prism structure Error angle from parallel light due to the size of the light emitting element chip provided on the parabolic mirror The figure which shows the relation of the radiation angle and the ray height with the concave lens and the focal length Spectral characteristic diagram when light in four directions is mixed by total reflection triangular prism Spectral characteristic diagram when light in 6 directions is mixed by total reflection triangular prism Spectral characteristics when mixing light in 8 directions by total reflection triangular prism Spectral characteristics when mixing two types of fluorescent white LED light with total reflection triangular prism Plan view of a structure with a parallel light source using a parabolic mirror using a total reflection triangular prism Sectional view using a total reflection triangular prism having the structure of FIG. 5 and a concave microlens array on the exit surface Cross-sectional view of an LED bulb that mixes light in six directions with a total reflection triangular prism Front perspective view of a vehicle headlamp arranged by changing the curvature of the concave microlens array on the exit surface Radiation range of traveling beam and passing beam by vehicle headlamp of FIG. Sectional view of a conventional liquid crystal display device in which three light guide plates are laminated with 45 ° total reflection grooves Conventional example of irradiating a predetermined pixel with three-color light by an inclined surface of a quadrangular pyramid provided on a light guide plate A conventional example in which light in four directions is incident on a right-angle prism and mixed with a bandpass mirror. Sectional view of a conventional four-color mixing device using a reflective / refractive grating

Example 1
FIG. 12 is a plan view of an embodiment of a spotlight that mixes six colors, and FIG. 13 is a cross-sectional view thereof. 4 or FIG. 5 in which the shape of one interface is alternately arranged between a gently inclined surface and a plane, and the other interface has a triangular prism-like space and a triangular prism-like low-refractive-index material space provided inside the high-refractive-index material. A structure can be used. In the case of the structure of FIG. 5, the bonding material is applied to the surface of one transparent material and then the other transparent material is bonded to the surface. In the case of FIG. Can function.
The light source unit has an advantage that heat radiation is improved if one of the off-axis parabolic mirrors is used as a heat radiating plate, but a light emitting element can also be provided at the focal point of the rotating parabolic mirror.
A concave microlens array can be provided on the exit surface in accordance with the radiation angle of the spotlight to emit diffused light. If the radiation angle is changed, it can be applied to a downlight, and if it is elongated in the vertical direction from FIG. 12, it can also be applied to linear illumination. In the case of mixing six colors, if an individual light emitting diode having the characteristics shown by the broken line in FIG.

Example 2
A cross-sectional view of an embodiment of an LED bulb that mixes six colors is shown in FIG. FIG. 4 shows the structure of FIG. 4 in which the shape of one interface is alternately arranged between a gently inclined surface and a flat surface, and the other interface has a triangular prism-like low refractive index material space inside the high refractive index material. . It can be formed by applying a bonding agent to the surface of one transparent material and then bonding the other transparent material side together.
The light source part is an off-axis parabolic mirror, and if the outside of the shaft is a heat sink, the heat radiation area can be widened, so heat radiation is good. Since general LED bulbs are provided near the center, the heat radiation fins are large and heavy to reduce the thermal resistance, but this light source is the best heat radiation position because it is provided on the widest and outer periphery of the heat sink on the base side. .
The exit surface can be provided with a concave microlens array in accordance with the radiation angle to emit diffused light. FIG. 17 shows a concave microlens array for radiating also to the side surface. However, when the radiation angle is narrow, the entire surface is composed of only the concave microlens array in the center without providing the side surface concave microlens array. You can also The radiation angle by the concave microlens can be set by Equation 3.
A total reflection surface is provided for conversion to the side surface in order to emit light from the side concave microlens.
In the case of mixing six colors, if an individual light emitting diode having the characteristics shown by the broken line in FIG.

Example 3
FIG. 15 shows a perspective view of an embodiment of a vehicle headlamp that mixes four colors. The structure of FIG. 5 in which the shape of one interface is alternately arranged with a gently inclined surface and a plane, and the other interface is a triangular prism-like space, and a triangular prism-like low-refractive-index material space is provided inside the high-refractive-index material. It can be adopted. It can be formed by applying a bonding agent to the surface of one transparent material and then bonding the other transparent material side together.
The light source part is an off-axis parabolic mirror, and if the outside of the shaft is a heat sink, the heat radiation area can be increased, so that heat radiation is good and the reliability can be improved.
A concave microlens array can be provided on the exit surface in accordance with the radiation angle of the spotlight to emit diffused light. The vehicle headlamp is used by switching between the traveling beam irradiation range and the passing beam irradiation range. In this embodiment, the upper part is set for the traveling beam and the lower part is set for the passing beam. The traveling beam irradiation area is an elliptical concave microlens that irradiates upward as shown in FIG. 16 but has a shorter radius of curvature in the horizontal direction and a longer radius of curvature in order to radiate and expand in the horizontal direction rather than the vertical direction. .
The low beam irradiation area irradiates below the traveling beam, but it is necessary to avoid irradiating oncoming vehicles with a cut-off line of about 15 °. Since there are three areas: a region that illuminates the front of the traveling lane, a region that illuminates the opposite lane, and a region that illuminates the side of the opposite lane, there are three types of curvature in the vertical direction of the concave microlens. The right half of FIG. 15 irradiates the front of the traveling lane, so the radius of curvature is shortened to irradiate the upper part, and the left side of FIG. The oncoming lane irradiation area is set by sequentially changing the radius of curvature according to the cut-off line.
In the case of four-color mixing, if the individual light emitting diodes having the characteristics shown by the broken line in FIG. 8 are used, the combined spectral characteristics will be like a thick solid line, and the average color rendering index will be 96, which is sufficient as a vehicle headlamp. It is color rendering.

Example 4
An embodiment of an LED bulb that mixes the light of two types of fluorescent white light emitting diodes will be described. Since the total reflection triangular prism to be used is a mixed color in two directions, it is shown in FIG. Since this bonding interface has an acute angle portion of 45 °, it is easier to mold if the width d in the reference plane direction is large. Since the two types of fluorescent white light emitting diodes are similar in color, the stripe of the light source is not noticeable even if the width d in the reference plane direction is large.
A cross-sectional view of the LED bulb is similar to that of FIG. 14 and is omitted, but has the same structure except for the total reflection triangular prism and the light emitting diode. The exit surface can be provided with a concave microlens array in accordance with the radiation angle to emit diffused light. FIG. 17 shows a concave microlens array for radiating also to the side surface. However, when the radiation angle is narrow, the entire surface is composed of only the concave microlens array in the center without providing the side surface concave microlens array. You can also The radiation angle by the concave microlens can be set by Equation 3.
A total reflection surface is provided for conversion to the side surface in order to emit light from the side concave microlens.
If the fluorescent white light emitting diode having the characteristic as shown by the broken line in FIG. 11 is used, the combined spectral characteristic becomes a thick solid line, and the average color rendering index is 97.

1: Total reflection triangular prism 2: Total reflection surface
3: High refractive index material 4: Low refractive index material
5: Reference plane 6: Parabolic mirror
7: Bonding surface 8: Light emitting element
9: concave refractive surface 10: concave mirror
11: Light source 12: Incident light 13: Diffused light 14: Parallel light
15: Reflected light 16: Interface
17: Heat dissipation material 18: Circuit board
19: Cover 20: Traveling beam irradiation area
21: Passing beam irradiation area 22: Cut-off line
23: Center line 24: Road boundary line 25: Total reflection groove 26: Light guide plate
27: Square pyramid 28: Band pass mirror 29: Refraction grating 30: Reflection grating

Claims (5)

A triangular prism made of a low-refractive-index substance with a fixed dimension consisting of a 45 ° inclined surface symmetrical to the vertical direction of the reference plane,
Inside the high refractive index material, disperse and arrange in a staircase pattern shifted from the optical path of other total reflection triangular prisms,
The total reflection triangular prism is irradiated with light incident from a symmetric direction parallel to the reference plane, and both are totally reflected in the vertical direction.
A mixed color lighting device that emits light beams having a constant width in an alternating arrangement. Between the total reflection triangular prisms arranged in rows in a staircase pattern,
2. The mixed color lighting device according to claim 1, wherein light in an even direction is mixed by allowing reflected light from total reflection triangular prisms arranged in separate rows to pass therethrough. 3. Consists of a plurality of high-refractive-index structures with an interface shape that connects between the arrays of total reflection triangular prisms,
2. The color mixing lighting device according to claim 1, wherein a low refractive index material space is formed inside the high refractive index material by joining the plurality of high refractive index structures. 2. The mixed color illumination device according to claim 1, wherein a radiation angle is enlarged and emitted by a structure in which a microlens array is provided on an emission surface of the mixed color illumination device including a total reflection surface triangular prism. It has a structure in which a microlens array in a passing beam irradiation area is provided on the exit surface of a color mixing illumination device composed of a total reflection triangular prism, and the curvature radius of the microlens is changed stepwise to match the cut-off line. The color mixing lighting device according to claim 1.