JPH10319873A - Light source unit and display device, display and illumination device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source unit which reduces dispersion caused by the directivity characteristics of plural light source means in the display characteristics of individuals and supplies high-illuminance image light to a desired visual field. SOLUTION: A light source unit 1 is provided with a substrate means 5, the light emitting diode elements 21, 22 which are arranged on this substrate means 5, a substrate material 8 disposed in front of these light emitting diodes 21, 22, a holographic optical element 7 formed on one side of this substrate material 8 and a housing means 6 which supports this holographic optical element 7 and the substrate material 8. And the light radiated from the light emitting elements 21, 22 is incident on the holographic optical element 7, deflected and made to diffuse to be radiated to specified directions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a plurality of types of light-emitting elements (for example, light-emitting elements that emit red, green, and blue light) that emit light of different wavelengths are arranged at predetermined positions on a substrate. A light emitting screen is formed by arranging the unit units regularly, and a color image display is realized by controlling the light emission thereof, and an image display device and its application device, for example, displaying a fixed pattern. And a lighting device.

[0002]

2. Description of the Related Art In recent years, displays have become key devices not only for information devices but also for many electronic devices. Full color L using light emitting diode element (hereinafter referred to as LED element) in addition to CRT and discharge tube method
ED displays are entering the market. This is due not only to the mass production of blue LED elements in addition to pure green LED elements, but also to the large expansion of the color reproduction range. The need for public signboards that provide various information to humans has increased. Such a large-screen display is generally used in a place where strong ambient light such as the sun exists, except in a case where the ambient light amount is relatively low, such as indoors or under special lighting. Therefore, compared to a small display device made by assuming one to several observers, the brightness is extremely high, a means for suppressing the reduction in contrast due to external light is provided, and particularly in the horizontal direction. It is required to have a wide viewing angle. Further, strict conditions are required for weather resistance, service life, maintainability, and the like.

For example, in an LED display, a display screen is formed by laying out a matrix of LED devices such as a pilot lamp type LED or a chip type LED in a matrix, and has a longer service life than other large screen displays.
A display excellent in price, weight, and the like can be realized. In addition, a plurality of LEDs corresponding to one pixel to several pixels
There is also a method in which elements are modularized and the unit units are arranged in a matrix to constitute the entire screen. In such a method of arranging ready-made light-emitting elements, since the light distribution of the display device largely depends on the performance of the light-emitting elements constituting the unit unit, various methods are required to obtain a desired viewing angle and brightness as a whole device. A device is devised.

For example, FIG. 20 is an enlarged sectional view showing a part of a conventional typical LED display device. In the figure, reference numeral 1 denotes a unit constituting a display device. Reference numeral 2 denotes an array of LED elements. Here, LED elements 25, 26, 27, and 28 are arranged on the substrate 5. In the case of performing full-color display, LED elements of display colors of red, green, and blue (hereinafter, referred to as R, G, and B, respectively) are used. Also, in order to balance the intensity of each color, the required number of LEDs for each of R, G, B
The elements are arranged to form a unit. Reference numeral 90 denotes a normal line of the display device.
6, 27 and 28 are arranged so as to be parallel to the normal 90. Reference numerals 62 and 63 denote light shielding means arranged between the units along the horizontal direction of the display.
This prevents strong external light such as sunlight from entering the display surface of the display device. In the figure, external light is conceptually indicated by solid arrows.

[0005] The viewing angle of a conventional LED display device as shown in FIG. 20 greatly depends on the directivity determined by a resin lens provided at the tip of the LED element or a dispersant which causes light to diffuse. For example, when an LED element having high directivity and high front luminance is used, the front luminance of the display device can be increased, but the viewing angle becomes narrow. On the other hand, by using an LED element with reduced directivity by increasing the diffusivity, a display device with a wide viewing angle can be realized, but the front luminance decreases. Thus, LED
Since there is a trade-off between the viewing angle and the brightness of the element, either one of them is sacrificed or a compromise value between the two is obtained depending on the required performance of the display. As described above, the viewing angle of the display device can be determined by determining the characteristics of the LED elements.
The viewing angle may be further limited by display components other than LED elements, such as 2, 63 and the like.

According to the light-shielding means 62 and 63, it is possible to suppress a decrease in contrast of a displayed image caused by external light entering the display surface. When the display device is permanently installed outdoors, since the angle or intensity of external light entering the display surface can be roughly predicted, a desired viewing angle,
The unit unit is configured so that display performance such as brightness and contrast can be obtained, and light shielding means is arranged. However, the vertical viewing angle is restricted by the light shielding means 62 and 63 as compared with the horizontal direction. This is again shown in FIG.
0 will be described. In the figure, the lower limit of the vertical viewing range with respect to the display device is determined as shown by a broken line in the figure from the relationship between the shape and arrangement of the light shielding means and the arrangement of the LED elements. That is, the viewing angle below the reference axis of the unit can be defined by the angle A in the figure. When the light-shielding members 62 and 63 are elongated in the direction of the normal 90 of the device, the light-shielding effect increases, but the angle A decreases and the vertical viewing range is narrowed. Conversely, to widen the viewing range below the display device, the light blocking means must be short, but it is difficult to suppress the reduction in contrast due to external light. Such a trade-off is irrespective of the type of light-emitting element constituting the display device, and may occur even when a light-emitting element other than the LED element is used.

[0007]

In the case of a large-screen display device, the display device is relatively higher than an observer for the purpose of providing an image to a large number of people, that is, providing an image over a wide visual field. In general, the positional relationship that the display is installed at a position and the observer visually recognizes the display from below the screen is increased. For example, a situation in which a display device installed on a wall surface of a building is looked up from the road corresponds to this. In such a case, the upward light from the display may be less important than the downward light. In other words, if it is possible to have a light distribution characteristic that is wide in the horizontal direction and enhanced downward in the vertical direction, light can be efficiently collected to the area where the observer exists,
A bright display can be provided in this limited area.

[0008] As a device for solving such a disadvantage that light is wasted unnecessarily to an area where no observer exists, LE is used.
By making the cross-sectional shape of the resin lens of the D element elliptical to give anisotropy to the directional characteristics, for example, to give a wider directivity in the horizontal direction than in the vertical direction, and to effectively emit light to the region where the observer is present You can also. However, directivity control using such a flat lens shape has an angular limit, and it is also difficult to control the directivity in the vertical direction. further,
In practice, the positional accuracy of the LED pellets and the processing accuracy of the lens shape required to obtain an appropriate lens effect are low, and the directional characteristics of each element have optically non-negligible variations. There is a problem that it is significantly damaged. For example, when displaying an all-white image, when observing from a position facing the screen, and when a highly uniform image can be observed, move to a position outside of this and move the display from an oblique direction. When observed, a spot pattern due to the above-described directional characteristic variation appears. Such deterioration of image uniformity is caused by the flat lens LED.
The problem is not limited to the case where an element is used, but is generally a problem common to all display devices using an LED element.

Further, fine particles called a dispersant may be kneaded near the resin lens portion of the LED element to increase the viewing angle, or a diffusion plate containing the dispersant may be disposed in front of the LED element. However, in such diffusion means, the physical quantity contained and the diffusion effect obtained are almost proportional,
In order to diffuse widely, the amount of the dispersant and the thickness of the diffusion plate must be increased. As a result, the light transmittance is reduced, and as a result, the brightness must be sacrificed in order to increase the viewing angle.

When a display device is constructed by arranging the unit units 1 as described above, the arrangement of the plurality of light emitting elements constituting each unit unit and the geometrical relationship between the light shielding member cause the display device to have a different shape. There is a problem that the display color changes depending on the estimated angle. FIG. 21 is a diagram schematically showing a configuration of a conventional typical LED display. In the figure, symbols R, G, and B are red,
These are LED elements having green and blue display colors. Other symbols and symbols are the same as in FIG. The area surrounded by the dashed rectangle is the unit unit 1 and is composed of two green LED elements and one red and one blue LED element, for a total of four LED elements. Further, between the unit units, the light blocking members 62 are arranged only in the vertical direction. The light-shielding member 62 is generally formed to be longer than the LED element in the direction of the normal 90 of the display in order to prevent external light such as the sun from illuminating the LED element.

[0011] According to the above arrangement, the light shielding means blocks part or all of the light traveling from the element arranged at the lower stage to the observer among the light emitting elements constituting the unit. The phenomenon occurs. This will be described with reference to FIG. 21. An angle A formed by a boundary line of a vertically lower visual field range indicated by a broken line and a normal line 90 of the display device.
If the user looks up at the display at a larger angle, the above-mentioned "kettle" phenomenon starts. As the angle becomes larger than the angle A, the lower display color constituting the unit unit, that is, light of G and B is blocked, and G and B
Will see the reduced display color. In other words, even if all of the R, G, and B LEDs emit light to display a white image, the user will see an image with a yellow tint due to the “kernel”.

[0012] Furthermore, this "blur" phenomenon causes a disadvantage that the color balance is lost in the vertical direction of the display device even when the observer is stationary. That is,
The higher the unit unit on the screen, the greater the amount of light that is blocked, resulting in uneven color at the top and bottom of the screen. For example, even if the number of light-emitting elements constituting a unit unit is increased and the display area corresponding to one pixel is increased to relatively reduce the influence of “gazing”, the light-shielding means must be increased accordingly. Therefore, it is difficult to obtain a desired effect. After all, such a phenomenon is caused by the action of the light shielding means and the place where the respective color lights are not sufficiently mixed on the display surface of the unit unit, regardless of the arrangement and quantity of the LEDs of each color in the unit unit. Therefore, it is difficult to suppress the influence of the "blur" unless the priority is given to the installation conditions in which strong external light such as the sun does not directly enter and the desired contrast is obtained even if the light shielding means is reduced. Met.

FIG. 22 is a cross-sectional view schematically showing light emitted from LEDs of a conventional full-color LED display disclosed in Japanese Patent Application Laid-Open No. 8-202292.
In the figure, 2R is a red LED, 2G is a green LED, 2R
B is blue LED, 3R, 3G, 3B is LED pellet,
4R, 4G, 4B are resin lenses, 40 is a cylindrical concave lens, 70 is a lenticular lens, k is an optical axis, P
Is one pixel. Next, the operation will be described. Of the red, green and blue LEDs forming one pixel, red and blue LED pellets 3R and 3B are provided outside the optical axis of the resin lens to converge principal rays emitted from the LEDs of each color. Further, the principal ray of each color is refracted by the refraction means into parallel light having a pitch smaller than the pitch of the LED, and is diffused in the horizontal direction by the diffusion means. According to such a configuration, the chief rays emitted from the LEDs of each color forming one pixel appear to be mixed in a short distance, so that it is possible to prevent the display quality from deteriorating due to the arrangement structure of the LEDs. .

In this conventional example, since the directivity of the display is controlled by the lens action of the cylindrical lens 40 and the lenticular lens 70, the direction in which the effects of both lens shapes cannot be expected, that is, the direction in which the lens shapes are repeated, is considered. A large diffusion angle cannot be expected in the orthogonal direction. In order to sufficiently obtain the effect of the directivity control by the cylindrical lens 40 and the lenticular lens 70, each LED element needs to have a strong directivity. Reflection reduces the viewing angle. Therefore, for example, even if the horizontal viewing angle can be widened, the light is distributed only in a very narrow viewing range in the vertical direction. Furthermore, since there is no means for averaging the variation in the directional characteristics of each LED element, it is difficult to avoid the occurrence of the above-mentioned mottled pattern that occurs when the display is observed from an oblique direction.

Further, in this conventional example, there is no component for actively suppressing the contrast reduction caused by the external light component directly entering the display surface. FIG.
According to the method, light other than the main light emitted from the LED of each color enters the concave lens portion corresponding to the adjacent pixel, and as a result, such light has a disadvantage of deteriorating display performance such as resolution and contrast. Since the LED chip itself is a light source having a finite volume that generates incoherent light, it is inevitable that unnecessary light that cannot be controlled only by the lens function of the resin that molds the chip is generated.

FIG. 23 is a view schematically showing the configuration of a conventional full-color LED display disclosed in Japanese Patent Application Laid-Open No. 8-202291. The right side is a sectional view, and the left side is a view of the display as viewed from the front. . 4a is a lens matrix, 4b is a plano-convex lens, 6a is a light shielding means, 6b is an opening, and D is a light emitting diode having a narrow viewing angle lens.
P is an LED pellet, and R is a reflector for mounting the LED pellet P. At a position corresponding to the lens portion of the light emitting diodes D arranged in a matrix, a plano-convex lens 4b having a light-shielding means formed on a plane portion is arranged so that the convex surface portion faces the lens portion. An opening 6b for transmitting the light condensed by the convex portion is formed to constitute an LED display device.

According to such a configuration, the light emitted from the lens portion of each LED element is condensed by the refraction of the lens portion and the plano-convex lens 4b disposed opposite to the lens portion, so that the minute aperture 6b Is efficiently transmitted, and external light is blocked by the large-area light-shielding means 6a, so that both brightness and high contrast can be achieved. However, in this conventional example, similarly to the previous conventional example, it is not possible to completely prevent light emitted from a certain LED element from entering the plano-convex lens 4b corresponding to the adjacent LED element. Such ineffective light repeats multiple reflections between the plano-convex lens 4b and the lens portion of the LED element that are arranged to face each other. Thus, the number of effective light rays passing through the minute opening 6b is reduced, and in order to obtain brightness, the diameter of the opening 6b must be increased. As a result, there is a disadvantage that the contrast is reduced. Further, it is the refraction effect of the plano-convex lens 4b that determines the directivity of the light passing through the opening 6b, but in order to sufficiently widen the viewing angle of the display, a large power for refracting the light beam from the LED element is required. It is necessary to have the plano-convex lens 4b. For example, a complicated process of forming a complicated aspherical shape into a small plano-convex lens is required. Further, similarly to the above-mentioned conventional example, there is no means for averaging the directional characteristic variation of each LED element, so that when the display is observed from an oblique direction, each of the LEs constituting the display is obstructed.
It is unavoidable that a spot pattern due to uneven brightness of the D element appears.

The present invention is not limited to the above-described LED display device, but a large-screen display device in which light-emitting elements that emit light having different wavelengths are arranged in a matrix, and in particular, a large-screen image can be simultaneously displayed by many people. The present invention relates to a light source unit of an indoor or outdoor display device to be provided, and a display device using the same, or an applied device such as a lighting device. The first object is to average the dispersion of the directional characteristics of a plurality of light emitting elements. It is an object of the present invention to provide a light source unit in which the variation in characteristics among individuals is small. It is another object of the present invention to efficiently guide light to a desired viewing area and realize light emission with sufficient luminance in the viewing area.

A second object is to average out variations in the directional characteristics of the light emitting element by this light source unit,
An object of the present invention is to provide a display having high display uniformity in an observation area. Furthermore, the light emitting surface of this light source unit,
Alternatively, an object is to suppress a decrease in contrast caused by external light such as sunlight or indoor illumination light entering a display surface of a display including a light source unit. It is still another object of the present invention to reduce inconveniences such as brightness and color unevenness depending on a viewing angle, which are caused by a structure such as a light shielding member or an arrangement of a light source unit.

Further, a third object is to deflect light in a predetermined direction by the light source unit and display a good fixed pattern in a desired visual field range, and an illuminating device for efficiently illuminating a desired area. And the like to provide an applied device.

[0021]

In a light source unit according to the present invention, a substrate means, a light emitting diode element disposed at a predetermined position on the substrate means, and a holographic element disposed in front of the light emitting diode element. It consists of an optical element.

In the light source unit, the substrate means, the light emitting diode element arranged at a predetermined position of the substrate means, the holographic optical element arranged in front of the light emitting diode element, and the vicinity of the light emitting diode element And a light shielding means for supporting the holographic optical element.

In the light source unit, the holographic optical element is made of a transparent substrate material in which prism means are formed on a light incident surface and a hologram surface is arranged on the other surface.

In the light source unit, the transparent substrate material is formed of an optical filter that selectively transmits a specific range of wavelength components.

Further, in the light source unit, a substrate means, a plurality of light emitting diode elements arranged at predetermined positions of the substrate means, and a unit having a different prism shape corresponding to a plurality of main emission wavelengths of the light emitting diode elements. It comprises a prism means having a structure arranged thereon, and a holographic optical element made of a transparent substrate material having the prism means on a light incident surface and having a hologram surface on the other surface.

In the light source unit, the substrate means, the light emitting diode element disposed at a predetermined position of the substrate means, the lens means disposed in front of the light emitting diode element, and the light emitting surface of the lens means And a holographic optical element for forming a hologram surface.

Also, in the light source unit, a substrate means, a plurality of light emitting diode elements arranged at predetermined positions of the substrate means, an array-like lens plate arranged on a first predetermined surface, and a second predetermined It consists of a holographic optical element arranged on the surface.

Further, in the light source unit, the plurality of light emitting diode elements are arranged so that the light beam emitted from each light emitting diode element is condensed on each lens element of the array lens plate.

Further, in the light source unit, a substrate means, a light emitting diode element arranged at a predetermined position of the substrate means, a light pipe for guiding light from the light emitting diode element to a predetermined surface, and a light pipe incident on the predetermined surface It consists of a holographic optical element on which surfaces are arranged.

Further, in the light source unit, a substrate means, a light emitting diode element arranged at a predetermined position of the substrate means, an optical integrator for guiding light from the light emitting diode element to a predetermined surface, and a light incident on the predetermined surface It consists of a holographic optical element on which surfaces are arranged.

In the light source unit, the pellet of the light emitting diode element is disposed at a position off the optical axis of the resin lens of the light emitting diode element.

The light source unit comprises a plurality of light emitting diode elements that emit light having different wavelengths.

In the light source unit, the diffusion means is disposed on the inner surface near the exit end of the light pipe.

In the light source unit, the exit end face of the optical integrator is inclined from a plane perpendicular to the normal line of the light source unit.

In the light source unit, at least one of the entrance surface and the exit surface of the optical integrator is an aspheric lens.

In the light source unit, the holographic optical element is arranged in close contact with the light exit surface of the optical integrator.

In the light source unit, the holographic optical element has both a refraction function of deflecting incident light in one predetermined direction and a diffusion function of diffusing incident light in a predetermined range.

Further, in the light source unit, the distribution of the light diffused by the diffusing action of the holographic optical element has a characteristic that it is wide in the horizontal direction and narrow in the vertical direction.

In the display device, the light source units are arranged in an XY matrix, and the light emission of each light source unit is controlled.

In the display, light source units are arranged and light emission thereof is controlled.

Further, the lighting device is constituted by a light source unit or an aggregate of light source units, and its light emission is controlled.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a light source unit according to an embodiment of the present invention, light radiated from a light emitting diode element arranged at a predetermined position on a substrate means is converted into a hologram arranged in front of the light emitting diode element. The light enters the graphic optical element and acts to diffuse this light in a predetermined direction.

Further, the holographic optical element is supported by a part of the light shielding means and functions so as to be disposed in front of the light emitting diode element.

Further, the light incident on the holographic optical element is refracted by the prism means, and functions to be deflected and diffused on the hologram surface.

Further, of the light incident on the transparent substrate material,
It functions to selectively transmit a specific range of wavelength components.

Light of different wavelengths emitted from a plurality of light-emitting diode elements is incident on prism means in which different prism-shaped unit structures corresponding to respective light emission main wavelengths are arranged, refracted, and further refracted. Work to be deflected and diffused at

Also, the light emitted from the light emitting diode element is refracted by the resin lens of the light emitting diode element and the lens means constituting the synthetic lens system, and is deflected and diffused on the hologram surface formed on the light exit surface of the lens means. Work to be.

Light emitted from the plurality of light emitting diode elements is incident on an array-like lens plate, and the array-like lens plate changes the shape of a first predetermined surface, which is a light emitting surface of the light emitting diode, to a second predetermined surface. The light that forms an image on the surface and exits the array-shaped lens plate acts to be deflected and diffused by the holographic optical element disposed on the second predetermined surface.

Also, the light emitted from the plurality of light emitting diode elements acts to condense on each lens element of the array lens plate.

Further, light emitted from the light emitting diode element is guided to a predetermined surface by repeating specular reflection, and acts to diffuse in a predetermined direction.

Further, the light emitted from the light emitting diode element is guided to a predetermined surface by repeating total reflection, and functions to diffuse in a predetermined direction.

Further, the light emitted from the pellet of the light emitting diode element is refracted on the surface of the resin lens, and works so that the light is directed in a predetermined direction.

Further, the light source unit works so as to emit light of a plurality of different wavelengths.

Further, the light which travels while repeating specular reflection in the light pipe acts to diffuse on the inner surface near the exit end of the light pipe.

Further, the light that has progressed while repeating total internal reflection in the optical integrator is refracted at the exit end face of the optical integrator, and acts so as to be directed in a predetermined direction.

Further, after traveling in the optical integrator, it works to optimize the directivity of light incident on the holographic optical element.

Further, the light that has traveled in the optical integrator acts to efficiently enter the holographic optical element.

Further, the light incident on the holographic optical element is refracted and diffused, and functions so as to have a predetermined directivity.

The light emitted from the holographic optical element works so as to have a directivity that is wide in the horizontal direction and narrow in the vertical direction.

The light source units are arranged in an XY matrix, and function to control the light emission of each light source unit to display an image.

Further, the light source units are arranged and function so as to display a predetermined fixed pattern.

Further, the light emitted from the light source unit or the aggregate of the light source units works so as to be focused on a predetermined area.

Embodiment 1 FIG. 1 is a sectional view schematically showing a configuration of a light source unit according to Embodiment 1 of the present invention. In FIG. 1, 1 is a light source unit, 21 and 22
Denotes a light emitting diode element (hereinafter, referred to as an LED element), 31 and 32 denote pellets, and 41 and 42 denote resin lenses. Reference numeral 5 denotes a substrate on which LED elements 21 and 22 are mounted. 6 is a housing means, 7 is a holographic optical element (hereinafter, HOE (Holographic Optical Element))
, 8 is a substrate material, and HOE 7 is formed on one side thereof. 91 and 92 are LED elements 21,
22 is the optical axis. Further, this substrate material 8 is used for the housing means 6.
Is supported near the opening. Further, the substrate 5 supports the housing means 6 to form the light source unit 1 including a plurality of LED elements.

Next, the operation will be described. LED of Figure 1
The elements 21 and 22 are LED elements which are generally referred to as a cannonball type due to their shape and a pilot lamp type according to the application, and are arranged on reflectors 301 and 302.
Pellets 31 and 32 are molded into a cylindrical shape with resin, and resin lenses 41 and 42 are formed at the tips, respectively. The light emitted from each LED pellet is efficiently guided forward by the reflectors 301 and 302, propagates inside the resin, and has resin lenses 41 and 42 formed at the tips.
Is radiated to the outside with a predetermined directivity by the lens action of. Light emitted from the LED elements 21 and 22 enters the HOE 7 formed on one side of the substrate material 8. HOE7
Has a light deflecting action and a diffusing action, and the incident light is diffused downward. HOE like this
By the action given to 7, it is possible to diffuse the light rays so as to be directed in a desired direction.

Although the shape of the resin lenses 41 and 42 is known to be hemispherical or spheroidal, the shape is not only for determining the directivity of the LED element but also for reducing the loss due to reflection at the interface between the resin and air. The shape that minimizes is often selected. Regarding the directivity, not only the resin lenses 41 and 42 but also the shapes of the reflectors 301 and 302 are design parameters. In addition, the shape of the cross section perpendicular to the optical axis of the resin lens is not a circle but an oval shape, and the radius of curvature of the lens portion along the longitudinal direction is increased to enhance the directivity in a predetermined direction. It is known. On the other hand, there is a type in which a dispersing agent is mixed in the resin lens portion or the entire resin in order to widen the light diffusion range, and a type in which a dye is mixed in for the purpose of changing the emission wavelength or increasing the color purity. As described above, various characteristics of the LED element are known according to the application, but it is of course possible to apply such an LED element in the present invention.

The HOE 7 is an optical element utilizing the basic function of a hologram. For example, the HOE 7 utilizes a wavefront conversion function including a function of converging light, a dispersion and deflection function as a diffraction grating, and a multiple interference inside the hologram. It can be provided with a filter function for the set angle and wavelength. In the present invention, it is effective to have a light diffusion function such as a diffusion plate, a deflection function for directing light in an arbitrary direction, a wavefront conversion function for changing the cross-sectional shape of a light beam, and the like.

FIG. 2 is a diagram conceptually showing a change in the emitted light beam of the light source unit according to the first embodiment of the present invention. In the figure, 21, 22, 23, and 24 are LED elements, 5 is a substrate, Is an HOE, and 80 is an observation surface. Reference numeral 91 denotes an upper left LED element 21 of an LED light source unit arranged in a 2 × 2 arrangement.
Reference numeral 93 denotes an optical axis of a light beam deflected downward by the HOE 7. The cross section of the light beam near the resin lens of the LED element 21, the HOE 7, and the observation surface 80 is indicated by oblique lines so that the deflection of the light beam and the change in the cross-sectional shape are easy to understand. That is, the circular luminous flux emitted from the LED element 21 is
, And arrives at the observation surface as a flat elliptical light beam in the horizontal direction. When the HOE 7 is rotated about the optical axis 91, the elliptical light beam can be easily rotated on the observation surface 80.

FIG. 3 is a diagram conceptually showing the deflection operation of the HOE 7. The solid line indicates the angular distribution of light transmitted through the HOE 7, the broken line indicates the angular distribution of light before entering the HOE 7, and the peak value of the broken line is used as a reference for the observation angle.
The directivity of the original LED element shown by the dashed line has been changed by the action of the HOE, indicating that the light in the direction of the optical axis having the highest intensity has been deflected so as to be directed vertically downward.

As such an HOE, for example, Physic
al Optics Corporation (CA, USA) LSD (Light
Shaping Diffusers) can be used. For the characteristics of LSD, refer to “HOLOGRAPHIC LIGHT SHAPI
NG DIFFUSERS ”(Jeremy M. Lerner, Rick Shie, Joel
Petersen, presented at the Aerospace LightingInsti
tute, Advanced Seminar, February 1994) or `` R.
L. Shie, CWChau, JM Lerner; Surface relief
This is described in detail in "holography for use in display screens", and is omitted here.

This LSD can be formed by applying holographic technology of the same type as the surface relief technology to provide minute irregularities on the surface of the substrate material, and an infinite number of minute micro lenses are randomly arranged on a plane. The same effect is obtained. In addition to the directivity control of the outgoing light by the lens function, a circular, elliptical,
An arbitrary light beam cross-sectional shape such as a rectangular shape can also be obtained.
By arranging such a HOE 7 in front of the LED element, the emitted light can be strongly directed in a predetermined direction.

HOE7 such as LSD is compatible with PMMA and PC
It can be easily formed by transferring a hologram pattern to a resin material such as by embossing. For example, it is possible to further expand the range of directivity control by using a HOE 7 formed on a sheet-like substrate material by bending it, or by using a HOE 7 directly formed on a substrate material having a curved surface. When such a transfer technique is applied, the resin lens portions 41, 4
It is also possible to form HOE 7 directly on the surface of No. 2.

Further, the transmittance of the above-mentioned LSD is as high as 90% or more, and compared with the case where a general diffusing element such as a frosted glass or a diffusing plate containing a diffusing agent is arranged on the optical path, the HOE is not so large. According to this, directivity control can be performed with high light utilization efficiency overall. In a general diffusion element, a trade-off occurs between the overall transmittance and the diffusion effect.
In OE7, it is possible to obtain both a high transmittance and a predetermined diffusion effect. In addition, since the directivity of the LED element can be controlled by a resin lens, by setting the incident light in accordance with the design incident condition of the HOE 7 (for example, substantially parallel incidence),
Sufficient light flux deformation and directivity control effects can be obtained. In addition, because of high transmittance and low absorption, H
The OE 7 has high heat resistance, and if a material having high heat resistance is selected as a substrate material for forming the OE 7, the light source can be arranged sufficiently close to the light source, and the space can be saved.

Further, the LSD has a light beam shaping effect by a diffusion action. FIG. 4 is a diagram conceptually showing the diffusion action of the holographic optical element according to the first embodiment of the present invention. In the case where the LSD is used for a light beam having a large angle-related intensity variation, the intensity distribution has a small angle range. And conceptually shows the effect of obtaining a smooth intensity distribution as a whole. In the figure, the broken line indicates the intensity distribution of the light beam having a large intensity variation with respect to the angle, and the solid line indicates the state after the LSD is arranged in the light beam and the intensity distribution is shaped. According to such a light beam shaping effect, it is possible to reduce the non-uniformity of the intensity distribution with respect to the angle of each LED element.

According to the above-described light source unit, it is possible to efficiently deform and deflect a light beam emitted from a plurality of LED elements constituting the light source unit, and to average the dispersion of the directional characteristics with respect to the angle. However, it is needless to say that the same effect can be obtained even with one LED element constituting the light source unit. In order to obtain sufficient luminous flux deformation and deflection effect,
The optimal design of the overall light source unit including the characteristics of the HOE should be designed, and it is preferable that the optical characteristics of the HOE be designed in relation to the shape of the resin lens or the reflector of the LED element. Further, the light source need not be limited to the LED element, and other light emitting devices can be used as the light source. Further, by controlling the light output of each light source unit or the light emission of the LED elements constituting each light source unit, it is possible to configure a display for displaying an image. Are averaged, and the occurrence of the above-mentioned mottled pattern in the display surface can be suppressed. It is also possible to configure a display in which a plurality of light source units are arranged so as to display a fixed pattern without performing complicated light emission control. Furthermore, if the light source unit or an assembly thereof is used as an illumination device, so-called spot illumination for illuminating a limited desired area can be efficiently performed.

On the other hand, a plurality of LEs constituting the light source unit
When the D elements have different display colors and require a color mixing effect, for example, for the purpose of forming a full-color or multi-color display device, the HOE 7 itself is regarded as a secondary light source surface, and the HOE 7 and the LED element are used. By setting the interval to a predetermined length, it is possible to reduce the light leakage due to the light shielding means. As an application example of such a light source unit, FIG. 5 is an enlarged cross-sectional view of the light source unit when a plurality of light source units are arranged in a matrix to constitute a display device. In the figure, reference numerals 61 and 62 denote light shielding means, and other reference numerals are the same as those in FIG. In addition,
The HOE 7 is formed on a substrate material 8 which is drawn separately in FIG. 1, and assuming that these are integrated, a member consisting of both is re-designated as HOE 7 in FIG. Light shielding means 61,
Reference numeral 62 has both a light shielding function for preventing external light such as sunlight from directly entering the HOE 7 and a housing function for holding the substrate means 5.

According to the above configuration, the secondary light emitting surface of each LED element is changed by the diffusion action of the HOE 7.
Since it is formed on the upper side, the rate at which the light emitted from the LED element disposed at the lower stage of the light source unit is blocked by the light blocking means is reduced. In addition, H
Most of the external light that has entered the OE 7 reaches the lower light-shielding means and is absorbed because the transmittance of the HOE 7 is high. That is, since the external light component reflected on the surface of the HOE 7 and traveling toward the observation region can be reduced, the display performance of the light source unit is not significantly impaired. As described above, not only the above-described color mixing effect, but also a reduction in the contrast of a displayed image due to external light can be reduced, and a light source unit having a simple configuration can be obtained. The shapes of the light shielding units 61 and 62 and the arrangement of the HOEs 7 are not limited to the application example shown in FIG. 4. For example, each of the light shielding units 61 and 62 may be composed of a plurality of members. Of course, it is possible to adopt a structure that is not held by 62 and is arranged by housing means (not shown). Furthermore, as described above, HO
It is also possible to arrange E7 in a curved manner.

When the light deflecting action is given to a member different from that of the HOE 7, the substrate material on which the HOE 7 is formed may have a prismatic action. FIG. 6 is a cross-sectional view showing a modified example using a prism plate 81 in which a number of micro prisms having the same shape in the vertical direction are arranged as a substrate material. The other reference numerals are the same as those in FIG. FIG. 6 shows a magnified view of a joint portion between the prism plate 81 and the HOE 7 in a circle below. If the HOE 7 is formed on the surface opposite to the surface on which the minute prisms are formed, and the prism plate 81 is disposed on the light incident side, the refraction of the prism can be effectively used, and the prism can be deflected downward. The emitted light can be efficiently diffused by the HOE 7. Further, when LED elements that emit light of a plurality of different wavelengths are arranged, by arranging micro prisms of different shapes optimally designed according to each wavelength at positions corresponding to each LED element. The deflection angle can be controlled for each color. Incidentally, the prism shape does not necessarily have to be sufficiently small with respect to the size of the LED element as shown in FIG. 6, and the shape serving as a basic unit may correspond to the LED element on a one-to-one basis. It is also possible to correspond to the LED element. Further, it is of course possible to dispose, instead of the prism plate 81, a HOE 7 having only a deflection action. Also in this case, the display light can be efficiently deflected and diffused by arranging the HOE having a deflecting action on the incident side and giving the HOE of the next stage a diffusing action.

On the other hand, as a substrate material for forming the HOE 7, a filter means for selectively transmitting only a desired wavelength component can be used. This color filter enhances the color purity of each color.
Since the light component transmitted through E7 can be selectively removed, the contrast can be improved as a result. According to such a method, color display can be performed not only when the light-emitting element emits monochromatic light but also when it emits white light. Of course, such an application is also possible. It is needless to say that the type of the color filter is not limited, and various filter means can be arranged within a range where a desired effect can be obtained. Further, it is not necessary to use a color filter as a substrate material for forming the HOE 7, and it is needless to say that the HOE 7 can be disposed as a separate member in front of the LED element.

In a display such as an LED display in which a light-emitting element is directly viewed, a reduction in the smoothness of an image due to the element shape, in other words, a reduction in display quality that directly affects the resolution degradation. Potentially exists. It can be said that the smaller the distance between the light-emitting regions of adjacent pixels, the higher the apparent resolution is. However, in the case of an LED display in which bullet-shaped elements are arranged, the pixel shape is generally almost circular, and compared to the case of rectangular pixels. Therefore, the pixel interval is felt large. Further, in order to obtain the color mixing effect, it is necessary to observe the object at a sufficient distance where the integrating action of the human eye can effectively work. Therefore,
In order to obtain an effective color mixing effect at a short viewing distance, a screen means having a light diffusing effect by including a dispersing agent is used.
Modifications arranged after E7 will be described with reference to FIG. In the figure, reference numeral 82 denotes a screen means including a dispersant (black spots in the figure), and other reference numerals are the same as those in FIG. As described above, the HOE 7 is connected to the screen means 8.
2 as a single member by molding on the LED element side surface
Of course, it is also possible to arrange in front of the D element.

When the screen means 82 is arranged as in this modification, the amount of transmitted light generally decreases as a whole, but since the screen means 82 is used as a secondary light source surface, a greater color mixing effect can be obtained. it can. The screen means 82 preferably contains a dispersant, but a matte screen having a roughened surface to obtain a diffusion effect may be used. In addition, a coating such as an anti-reflection coating may be applied to the entrance surface or the exit surface of the screen means 82 in order to reduce reflection on the screen surface and improve the amount of transmitted light as a whole.

On the other hand, the resin lenses 41 and 42 of the LED element
In the case where light of sufficient narrow directivity cannot be obtained by only the action of (1), a lens system for collimating the light beam is replaced with an LED element and an HOE.
It is of course also possible to additionally arrange them between 7. In this case, as described above, the HOE 7 capable of forming a curved surface can be formed on the final surface of the additionally disposed lens system. FIG. 8 shows a modification of the light source unit to which one unit lens is added as a lens system. In the figure, 401, 4
Reference numeral 02 denotes an additional unit lens, and reference numerals 71 and 72 denote HOEs formed on the exit surfaces of the unit lenses 401 and 402. Other symbols are the same as those in FIG. Unit lens 40
Reference numerals 1 and 402 denote resin lenses 41 of LED elements,
Although it is arranged corresponding to 42, it is sufficient that a desired lens action can be obtained as a synthesizing action with the resin lens, and the unit lenses 401 and 402 may be plural. Further, a flat lens such as a Fresnel lens can be used as the unit lenses 401 and 402.

The above-described embodiment and its modifications include LE
The case where the array of the D elements is a square array of 2 × 2 is shown.
The action of the OE does not depend on the arrangement of the LED elements, and similar diffusion, deflection and color mixing effects can be obtained for various LED element arrangements such as polygonal, radial, polycyclic, and random arrangements. Also, as for the light beam deformation action of the HOE, not only a conversion action from a circle to an ellipse but also an HOE having a conversion action from a circle to a circle or from a circle to a rectangle can be used. Also, the incident light beam and the outgoing light beam do not need to correspond one-to-one, and the HOE has a function that the light beam arriving from the LED element is split into a plurality of light beams and strongly directed in a plurality of predetermined directions. It is also possible to make it.

FIG. 9 is a conceptual diagram showing, as a modified example of such a light beam splitting type, a state in which a light emitted from a light source unit in which LED elements are arranged in a multi-ring is split into two by an HOE. In the figure, reference numeral 2 denotes an LED element assembly part of the light source unit, 5 denotes a substrate, 7 denotes a HOE, and other reference numerals denote FIG.
Is the same as Further, the cross section of the light beam on the HOE 7 and the observation surface 9 is indicated by oblique lines. FIG. 4 conceptually illustrates a state in which a circular light beam emitted from the LED element assembly unit 2 is branched by the action of the HOE 7 and reaches the observation surface. Of course, as described above, the vertical branching action as shown in FIG. 7 can be easily converted to a horizontal branching action by rotating the HOE 7 about the optical axis.

FIG. 10 is a diagram conceptually showing the optical branching action of the HOE 7. The solid line indicates the angular distribution of light transmitted through the HOE 7, the broken line indicates the angular distribution of light before entering the HOE 7, and the peak value of the broken line is used as a reference for the observation angle. The directivity of the original LED element indicated by the broken line is branched by the action of the HOE, and two strong deflection angles appear. In this modification, each LED
Although the elements form an annular array on the same plane, it is of course possible to provide a three-dimensional element arrangement in which the center of the unit is raised.

As described above, in the first embodiment, the transmission type H
The case where OE is used has been described. But reflective HOE
Of course, it is also possible to use, and similarly to the transmission type, it is possible to obtain a desired diffusion effect, light flux deformation effect, and directivity control effect. Further, in the present embodiment, the case where a known pilot lamp type LED element is used has been described, but in order to effectively increase the directivity control action of the light source unit,
The LED element can be changed to a desired form. FIG.
Reference numeral 1 denotes a modified example of Embodiment 1 of the present invention, and is a cross-sectional view showing an LED element constituting a light source unit. FIG. 12 is a diagram of this as viewed from the front. In FIG.
All the reference numerals are the same as those in FIG. 1, and in FIG. 12, LED elements 23 and 24 and respective LED pellets 33 and 34 are added. The arrows in each figure conceptually show the directivity of light emitted from the LED elements.

In this modification, 2 × 2 LED elements are arranged in a square, and the pellets 31 and 32 of each LED element are L
It is arranged at a position deviated upward from the optical axis of the resin lens of the ED. FIG. 12 shows a state in which the pellets are eccentrically arranged with respect to the optical axis of the resin lens so as to be horizontally symmetrical in the horizontal direction. According to such an arrangement, the radiated light distribution from each LED element has a non-concentric distribution with respect to the optical axis, and the radiated light of the entire light source unit can have wide directivity downward and left and right. It becomes possible. Of course, the arrangement of each pellet is not limited to this. For example, if an LED element having such an eccentric pellet is used and the pellets are arranged so as to be concentrated at the center of the light source unit,
It is also possible to make the directivity of the emitted light of the entire light source unit concentrically wide. On the contrary, the light emitted from the plurality of LED elements constituting the light source unit is, for example, HO
When it is desired to combine the eccentric pellets on the E7 plane, the eccentric pellets may be arranged so as to be dispersed around and the emitted light may be collected at the center. Further, in such a case, it is more effective to arrange each LED element on the substrate at an angle so that the optical axes of the resin lenses intersect on the HOE 7 surface.

As a modification of the LED element, it is of course possible to use a known chip type LED element. FIG. 13 is a diagram schematically showing a configuration of a modification of the light source unit according to the first embodiment of the present invention.
1 schematically illustrates a light source combining an ED element and a HOE. In the figure, 3 is a light emitting diode chip, 50 is a housing made of resin or ceramic, 60 is a transparent mold resin, 7 is HOE, and the arrows indicate the directivity of light rays conceptually. The transparent mold resin 60 is slightly raised on the LED element surface, and the light emitting diode chip 3
Has a lens function so that light emitted from the lens is diffused with a predetermined directivity. In general, the transparent mold resin 60 of the chip type LED element is different from the shell type in many cases in a shape giving a wide directivity.
In order to obtain the effect of E7 efficiently, it is preferable that the shape is formed so as to have a small radius of curvature that gives a narrow directivity. Instead of the configuration shown in FIG. 13, the HOE 7 can be formed by bending the HOE 7 directly on the surface of the mold resin as described above. According to the above-described configuration, it is possible to reduce the variation in the intensity distribution with respect to the angle of the LED element as described above, and to provide a desired directivity. Furthermore, as in the case of the bullet type LED element, a plurality of L
It is of course possible to configure the light source unit as a configuration using the common LOE 7 for the ED, and configure the display device by arranging a plurality of light source units in a matrix. Further, the light source unit or an aggregate thereof can be used as a lighting device. It goes without saying that the display device and the lighting device thus obtained can obtain the same effects as those of the above-described example of the bullet-type LED element.

Embodiment 2 FIG. 14 is a diagram schematically showing a configuration of a light source unit according to Embodiment 2 of the present invention. The feature of this embodiment is that, unlike the first embodiment, an eccentric lens system is arranged between the LED element and the HOE. In the figure, 1 is a light source unit, 2 is an LED element assembly part, and a plurality of LED elements 21,
22, 23, and 24 are collectively arranged. 400 is each L
A lens plate having a plurality of unit lenses arranged in a plane perpendicular to the optical axis of the ED element;
404 is a unit lens. Reference numeral 5 denotes a substrate on which a plurality of LED elements are mounted. Reference numeral 6 denotes a housing member forming the light source unit, and reference numeral 7 denotes a HOE. The housing member 6 holds the lens plate 400 and the HOE 7. 9 is an optical axis of the light source unit 1.

Next, the operation in FIG. 14 will be described. Light having a predetermined directivity is radiated forward from the LED elements 21, 22, 23, and 24 by the action of a resin lens formed at the tip. Further, the resin lens has a lens function of emitting a convergent light beam forward. Next, the radiated light from each LED element is applied to the unit lens 40 of the lens plate 400 which is optically arranged.
1, 402, 403, and 404. Further, the unit lens is decentered with respect to the optical axis of the corresponding LED element, so that each incident light is deflected in a predetermined direction and
To reach. The solid line in the figure represents the boundary ray incident on the HOE 7 radiated from the LED pellet.
The subsequent arrows conceptually show how light rays incident on the HOE 7 are radiated toward the observation area after undergoing predetermined deflection and diffusion actions.

Next, FIG. 15 is a view conceptually showing a change in the light beam emitted from the light source unit 1. As shown in FIG. Since the reference numerals in the figure are the same as those in FIG. 14, the description will be omitted. As shown in the figure, the unit lenses of the lens plate 400 are arranged optically corresponding to a plurality of LED elements. For example, a light beam emitted from the upper left LED element enters an optically corresponding upper left unit lens and reaches the HOE 7. According to such a configuration,
The image (hatched portion) in the vicinity of the resin lens of each LED element propagates while being enlarged, and is superimposed to form an image (hatched portion) again on the HOE 7.

FIG. 16 schematically shows a structure of a light source unit according to the second embodiment of the present invention.
The optical correspondence between the images 201 and 202 formed in the vicinity of the resin lens of the element and the illumination area 71 superimposed on the unit lenses 401 and 402 and the HOE 7 is shown. L
1 is the distance from the image formed near the resin lens of the LED element to the unit lens, and L2 is the distance from the unit lens to the HOE 7. Other symbols are the same as those in FIG.
The unit lenses 401 and 402 convert the images 201 and 202 into HO
It is arranged between the LED assembly 2 and the HOE 7 so as to transmit to the E7. In the case of such a correspondence, the positions of the unit lenses 401 and 402 can be determined by the ratio between the sizes of the images 201 and 202 and the size of the illumination area formed on the HOE 7. In addition, since the relationship of L1: L2 = image size: size of the illumination area is established,
When the sizes of the images 201 and 202 and the size of the illumination area of the HOE 7 are determined, the position and the focal length of each unit lens can be determined.

On the other hand, the focal length of the resin lens formed at the tip of the LED element is determined so that light emitted from the pellet inside the LED element is converged on the center of the corresponding unit lens. Also, if the size of the unit lens is larger than the size of the image of the pellet formed at the center of the unit lens by the action of the resin lens, all the light from the resin lens passes through the unit lens and becomes H
It will reach OE7. Further, the LED element and the unit lens are arranged at positions off the optical axis of the light source unit. In such a case, the unit lens must be an eccentric lens whose center of curvature deviates from the lens center.

The sizes of the images 201 and 202 and the HOE
The ratio of the size of the illumination area 7 can take any value. In FIG. 16, the optical axis 9 of the light source unit 1 and the HOE 7
Are arranged so that the central axes are equal, but the position of the illumination area 71 is not limited to this, and may be set at a position deviated from the optical axis 9 as shown in FIGS. No problem. That is, the illumination area of a desired size can be superimposed on a desired position based on the eccentricity of the unit lens formed on the lens plate 400 and the optical relationship between the image and the size of the illumination area.

According to the configuration of the light source unit as described above, the radiated light from each LED element is superimposed and coupled to the HOE.
Therefore, even if there is a characteristic variation among a plurality of LED elements, the variation is averaged by the combination of the light beams, and a light distribution with less intensity unevenness can be obtained on the HOE 7. Furthermore, the LED elements having different wavelengths can be used, and the light source unit 1 having full-color or multi-color display characteristics can be configured according to the number and arrangement thereof. In the first embodiment, the lights of different wavelengths emitted from the respective LED elements are mixed after the HOE 7. In the present embodiment, the colors are mixed on the HOE 7 by combining a plurality of light beams. Good light distribution with less unevenness can be obtained.

Further, such a light source unit is arranged,
When configuring a full-color or multi-color display device,
The characteristics of the light distribution reaching the observation area from one light source unit corresponding to one pixel mainly depend on the characteristics of the HOE 7. Since the colors are already mixed on the light emitting surface of the light source unit, a good image can be observed even with a short viewing distance. Further, similarly to FIG. 5, when a light shielding unit is provided between the light source units to prevent a reduction in contrast due to external light, a change in the color tone of the display device due to the observation position depending on the shading phenomenon by the light shielding unit is eliminated. can do.

Embodiment 3 FIG. 17 is a cross-sectional view illustrating a configuration of a light source unit according to Embodiment 3 of the present invention. The feature of the present embodiment is that the cylindrical member forming the light source unit is constituted by a light pipe.
In the figure, reference numeral 61 denotes a light pipe which is made of metal whose inner surface is finished to an optical mirror surface. The light pipe 61 needs to minimize the light loss at the time of reflection. However, the light pipe 61 may have a configuration in which a reflective coating for realizing this is applied to a cylindrical resin material or the like. Reference numeral 5 denotes a substrate, which is an LED element 21;
22 is mounted. The cross section of the light pipe 61 may be any shape as long as it matches the shape of the substrate 5 or the arrangement of the LED elements. For example, the cross section may be rectangular, for example. Reference numeral 7 denotes a HOE, which is held by an opening of the light pipe 60. The light source unit 1 is constituted by the above elements, and 9 is an optical axis of the light source unit 1.

Light emitted from the plurality of LED elements mounted on the substrate 5 propagates while diffusing, and reaches the HOE 7 surface while repeating specular reflection on the inner surface of the light pipe 61. In order to combine or mix colors of the emitted light from the LED elements, it is possible to dispose a lens system as in Embodiment 2 above. However, if the length of the light source unit 1 can be made sufficiently long, the lens According to the embodiment, it is possible to obtain a favorable combination and color mixing effect. Further, similarly to the first embodiment, the number of components is small, and the complexity of creating the light source unit can be reduced.

Further, when the area of the reflection surface is increased, the color mixing effect is relatively increased. FIG. 18 is a diagram showing a configuration as a modification of the optical unit according to the third embodiment. In the figure, reference numeral 601 denotes a diffuse reflection surface provided on the inner surface near the opening of the light pipe 61. Other reference numerals are the same as in FIG. 17 showing the third embodiment. The diffuse reflection surface 601 may be formed by partially roughening the inner surface of the light pipe 61, or a diffuser may be applied. According to the above-described configuration, sufficient light is synthesized before the light reaches the HOE 7, and the desired display performance as the light source unit 1 is obtained by the light diffusion and deflection functions of the HOE 7. This is the same as described in the second embodiment. Further, it is also possible to extend a part of the opening of the light pipe 61 to function as a light shielding member for external light.

Further, as a modification of the third embodiment,
Instead of the light pipe 61, a rod integrator can be used. FIG. 19 is a cross-sectional view schematically showing a light source unit using a rod integrator as a means for transmitting light emitted from an LED element. In the figure, 6
Reference numeral 02 denotes a rod integrator (shaded portion), which can have an arbitrary cross section, similarly to the modification using the light pipe. Rod integrator 602
Is a bulk optical element using a transparent glass material or a plastic material, and the side surface and the incident / outgoing end face are finished to an optical mirror surface. Other symbols are the same as those in FIG. The emitted light of the LED element incident on the rod integrator 602 propagates while repeating total reflection at the interface between the rod integrator 602 and air.
% Propagation efficiency.

Further, by filling a matching liquid for matching the refractive index between the LED elements 21 and 22 and the incident surface of the rod integrator 602, the incident loss of the rod integrator 602 can be reduced. Therefore, if there is no inconvenience between the packing of the matching liquid and the weight of the light source unit 1, it is possible to realize a higher light use efficiency than the above-described modified example using the light pipe. Note that the emission end face of the rod integrator 602 may be inclined from a state perpendicular to the optical axis 9. In this case, the light deflecting action can be further enhanced in addition to the action of the HOE 7. On the other hand, if at least one of the input end face and the output end face of the rod integrator 602 has an aspheric lens shape, the angle distribution of the incident light on the HOE 7 can be optimized, and the light beam deformation and deflection action of the HOE 7 can be maximized. can do.

Although the present invention has been described in many embodiments and modified examples, the light source constituting the light source unit is not limited to the LED element described here.
A similar effect can be achieved with a light source whose directivity can be controlled by the function of the element itself or additional means. Also, the holographic optical element is not limited to the above-described embodiment and its modifications, and can have various functions without departing from the gist of the present invention.

[0102]

Since the present invention is configured as described in the above embodiment, the following effects can be obtained.

It is possible to provide a light source unit that adjusts the directional characteristics of light emitted from a light emitting diode element and diffuses light in a desired direction with high efficiency.

Further, a light source unit having a holographic optical element for adjusting the directional characteristics of light emitted from the light emitting diode element and diffusing light in a desired direction with high efficiency can be constituted with a small number of components. A light source unit with less loss can be provided.

Also, the efficiency of the diffusion effect by the holographic effect is improved by first refracting the light by the prism means formed on the light incident surface of the holographic optical element and then causing the deflected light to enter the holographic optical element. Since the light source unit can be raised, it is possible to provide a light source unit having a uniform directional characteristic and a small light loss for diffusing light in a desired direction.

Further, since the substrate material of the holographic optical element has the function of a wavelength-selective optical filter, it is possible to provide a light source unit that efficiently emits monochromatic light and has low light loss. Furthermore, even if external light enters the light source unit, a wavelength component in a specific range can be reflected or absorbed by the action of the optical filter, so that a light source unit with reduced external light reflection can be configured.

Further, since the plurality of light emitting diode elements that emit light of different wavelengths correspond to the prism shape formed on the incident surface of the holographic optical element, respectively.
The directional characteristics of the emitted light can be made uniform without depending on a plurality of wavelengths, and a light source unit having a large degree of freedom in arrangement and quantity of a plurality of light emitting diodes having different wavelengths can be provided.

Further, since the control range of the directivity of light can be increased by the resin lens of the light emitting diode element and the lens means constituting the synthetic lens system, a light source unit having a high degree of freedom in the directivity of the light emitting diode can be provided. Can be provided. Further, since the holographic optical element is formed on the light emitting surface of the lens means, a light source unit with small light loss can be configured.

Further, by the superimposed imaging action of the array-shaped lens plate, the radiated light from the plurality of light emitting diode elements can be efficiently synthesized, and the variation in the characteristics of the light emitting diodes can be averaged. Therefore, the allowable range of the variation in the characteristics of the light emitting diodes can be expanded, and an inexpensive light source unit can be provided. Furthermore, since the light of the light emitting diode that emits light of different wavelengths can be efficiently combined, a light source unit having an excellent color mixing effect can be provided. Furthermore, since the light from each light emitting diode can be condensed at substantially the same position on the holographic optical element surface, a light source unit having uniform display characteristics independent of wavelength can be provided.

Further, since the radiated light from the plurality of light emitting diode elements can be efficiently condensed on each lens element of the arrayed lens plate, a light source unit with small light loss can be provided.

Further, since light from a plurality of light emitting diodes is combined by a light pipe, light from a plurality of light emitting diode elements can be efficiently combined with a small number of components. Further, since a light exit surface substantially equal to the opening diameter of the light pipe can be obtained, it is possible to provide a light source unit having a uniform display characteristic independent of a characteristic variation of each light emitting diode element.

Further, since light from a plurality of light emitting diodes is combined by an optical integrator, light from a plurality of light emitting diode elements can be efficiently combined with a small number of components. Further, since a light exit surface substantially equal to the aperture diameter of the optical integrator can be obtained, it is possible to provide a light source unit having uniform display characteristics independent of variations in characteristics of each light emitting diode element.

Also, since the pellet of the light emitting diode element is arranged eccentrically with respect to the optical axis of the resin lens,
The light emitted from the resin lens has a distribution that is deviated with respect to the optical axis according to the amount of eccentricity. Therefore, it is possible to provide a light-emitting diode device having a simple configuration and the directivity of which is inclined off the optical axis.

Further, since the light source means is composed of a plurality of light emitting diode elements which emit light of different wavelengths from each other, light of different wavelengths from the plurality of light emitting diode elements can be efficiently mixed with a small number of components. Therefore, it is possible to provide a light source unit having uniform display characteristics independent of the wavelength of each light emitting diode element.

The light combining and color mixing effects can be enhanced by the diffusing means disposed on the inner surface near the exit end of the light pipe.

Since the exit end face of the optical integrator is inclined from a plane perpendicular to the normal line of the light source unit, light can be deflected in a predetermined direction. Therefore, the deflection effect of the light source unit can be increased with a small number of components.

Further, since at least one of the incident surface and the outgoing surface of the optical integrator is an aspheric lens and the directivity of light incident on the holographic optical element can be controlled, the light is deflected and diffused by the holographic optical element. The action can be obtained more efficiently.

Further, the transmission loss of light from the optical integrator to the holographic optical element can be reduced.
A light source unit with small light loss can be provided.

Further, since the holographic optical element has both a refraction function for deflecting the incident light in a predetermined direction and a diffusion function for diffusing the incident light in a predetermined range, the light source unit has a simple structure and little light loss. Can be provided.

Further, the distribution of light diffused by the diffusing action of the holographic optical element has a characteristic that is wide in the horizontal direction and narrow in the vertical direction, so that a light source unit suitable for display use can be provided.

Further, since the present light source units are arranged in an XY matrix and the light emission of each light source unit is controlled to display an image, a light loss is small and the image light is efficiently provided to a desired observation area. An apparatus can be provided. Furthermore, since the variation in the light emission characteristics of each LED element is averaged, it is possible to suppress the occurrence of spots on the display surface due to the variation in the directional characteristics between individuals, and to provide a display device capable of displaying high-quality images. Can be provided.
Furthermore, it is also possible to suppress a reduction in contrast of a display image due to external light.

Further, since the present light source units are arranged and a predetermined fixed pattern is displayed, it is possible to provide a display device which has a small light loss and efficiently supplies image light to a desired observation region. Furthermore, since the variation in the light emission characteristics of each LED element is averaged, it is possible to suppress the occurrence of spots on the display surface due to the variation in the directional characteristics between individuals, and to display a high-quality image pattern. Can be provided. Furthermore, it is also possible to suppress a reduction in contrast of a display image due to external light.

Further, since the light source unit or the aggregate of the light source units is used, it is possible to provide an illumination device which has a small light loss and efficiently illuminates a desired area.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a configuration of a light source unit according to Embodiment 1 of the present invention.

FIG. 2 is a diagram conceptually showing a change in a light beam emitted from the light source unit according to the first embodiment of the present invention.

FIG. 3 is a diagram conceptually showing a deflecting action of the holographic optical element according to the first embodiment of the present invention.

FIG. 4 is a diagram conceptually showing a diffusion action of the holographic optical element according to the first embodiment of the present invention.

FIG. 5 is a sectional view schematically showing a configuration of an application example of the light source unit according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view schematically showing a configuration of a modification of the light source unit according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view schematically showing a configuration of a modified example of the light source unit according to the first embodiment of the present invention.

FIG. 8 is a sectional view schematically showing a configuration of a modification of the light source unit according to the first embodiment of the present invention.

FIG. 9 is a diagram conceptually showing a light branching action of the holographic optical element according to the first embodiment of the present invention.

FIG. 10 is a diagram conceptually showing a light branching action of the holographic optical element according to the first embodiment of the present invention.

FIG. 11 is a cross-sectional view schematically showing a configuration of a modification of the LED element according to Embodiment 1 of the present invention.

FIG. 12 is a front view schematically showing a configuration of a modification of the LED element according to Embodiment 1 of the present invention.

FIG. 13 is a diagram schematically showing a configuration of a modified example of the light source unit according to the first embodiment of the present invention.

FIG. 14 is a sectional view schematically showing a configuration of a light source unit according to Embodiment 2 of the present invention.

FIG. 15 is a diagram conceptually showing a change in emitted light flux of the light source unit according to the second embodiment of the present invention.

FIG. 16 is a cross-sectional view schematically showing a configuration of a light source unit according to Embodiment 2 of the present invention.

FIG. 17 is a sectional view schematically showing a configuration of a light source unit according to Embodiment 3 of the present invention.

FIG. 18 is a cross-sectional view schematically showing a configuration of a modification of the light source unit according to Embodiment 3 of the present invention.

FIG. 19 is a sectional view schematically showing a configuration of a modification of the light source unit according to Embodiment 3 of the present invention.

FIG. 20 schematically shows the configuration of a unit of a conventional typical LED display.

FIG. 21 is a diagram schematically showing a configuration of a conventional typical LED display.

FIG. 22 shows L of a conventional full-color LED display.
It is sectional drawing which showed the radiation light from ED typically.

FIG. 23 is a diagram schematically showing a configuration of a conventional full-color LED display.

[Explanation of symbols]

1 light source unit, arrangement of 2 LED elements, 21 to 28
LED element, 201, 202 images, 31, 32 LE
D pellet, 301, 302 reflector, 41, 4
2 resin lens, 400 lens plate, 401 to 404
Unit lens, 5 substrate means, 6 housing, 60 transparent mold resin, 61 light pipe, 62, 63 light shielding means, 601 diffuse reflection surface 602 rod integrator, 7, 71, 72 holographic optical element, 8
Substrate material, 80 observation surface, 81 prism plate, 82 screen means, 9, 91, 92, 93 optical axis, 90 normal, distance from image formed near resin lens of L1 LED element to unit lens, L2 unit lens The distance from the hologram diffusion element to.

Claims (21)

[Claims] 1. A light source means comprising a light emitting diode element disposed at a predetermined position on a substrate means, and a light source comprising a holographic optical element disposed in front of the light source means and diffusing light from the light source means in a predetermined direction. unit. 2. A light source means comprising a light emitting diode element arranged at a predetermined position on the substrate means, a holographic optical element arranged in front of the light source means to diffuse light from the light source means in a predetermined direction, and light emission A light source unit, comprising: a light-shielding means arranged near a diode element, wherein the holographic optical element is supported by a part of the light-shielding means and arranged in front of the light-emitting diode element. 3. The holographic optical element according to claim 1, wherein a prism means is formed on a light incident surface and a hologram surface is disposed on another surface of the transparent substrate material. 2. The light source unit according to 2. 4. The light source unit according to claim 3, wherein the transparent substrate material is an optical filter that selectively transmits a wavelength component in a specific range. 5. A light source means comprising a plurality of light emitting diode elements arranged at predetermined positions of a substrate means and emitting light of different wavelengths, and units of different prism shapes corresponding to a plurality of main emission wavelengths of the light emitting diode elements A light source unit comprising: a holographic optical element made of a transparent substrate material having a prism means having a structure arranged on a light incident surface and a hologram surface on the other surface. 6. A light source means comprising a light emitting diode element disposed at a predetermined position on the substrate means, and a lens means disposed in front of the light emitting diode element and constituting a synthetic lens system with a resin lens of the light emitting diode element; A holographic optical element for forming a hologram surface on a light exit surface of the lens means. 7. A light source means comprising a plurality of light emitting diode elements arranged at a predetermined position on the substrate means, and a first predetermined light emitting surface corresponding to each of the plurality of light emitting diode elements and being a light emitting surface of the light emitting diode. An array-like lens plate that transfers an image on a second predetermined surface to form an image on a second predetermined surface, and a holographic optical element disposed on the second predetermined surface and diffusing light from the lens plate in a predetermined direction is provided. A light source unit. 8. The light source unit according to claim 7, wherein the plurality of light emitting diode elements are configured to collect the emitted light beam on each lens element of the array lens plate. 9. A light source means comprising a light emitting diode element disposed at a predetermined position on the substrate means, a light pipe for guiding light from the light source means to a predetermined surface, and an incident surface disposed on the predetermined surface, A light source unit comprising a holographic optical element for diffusing light from a pipe in a predetermined direction. 10. A light source means comprising a light emitting diode element disposed at a predetermined position on a substrate means, an optical integrator for guiding light from the light source means to a predetermined surface, and an incident surface disposed on the predetermined surface, A light source unit comprising a holographic optical element for diffusing light from an integrator in a predetermined direction. 11. The light emitting diode element according to claim 1, wherein the pellet is disposed at a position off the optical axis of the resin lens of the light emitting diode element, and light is directed in a predetermined direction. The light source unit according to any one of the above. 12. The light source means comprises a plurality of light emitting diode elements that emit light of different wavelengths from each other.
The light source unit according to claim 9. 13. The light pipe according to claim 9, wherein a diffusion means is arranged on an inner surface near an exit opening end of the light pipe.
A light source unit as described. 14. The light source unit according to claim 9, wherein an end face of the output opening of the optical integrator is inclined from a plane perpendicular to a normal line of the light source unit. 15. The light source unit according to claim 9, wherein at least one of the entrance surface and the exit surface of the optical integrator is an aspheric lens. 16. The light source unit according to claim 9, wherein said holographic optical element is disposed in close contact with an emission surface of an optical integrator. 17. The holographic optical element according to claim 1, wherein the holographic optical element has both a refraction function for deflecting the incident light in a predetermined direction and a diffusion function for diffusing the incident light in a predetermined range. The light source unit according to any one of the above. 18. The light source unit according to claim 1, wherein the distribution of the light diffused by the diffusion action has a characteristic that is wide in a horizontal direction and narrow in a vertical direction. 19. A display device in which the light source units according to claim 1 are arranged in an XY matrix, and light emission of each light source unit is controlled to display an image. 20. A display configured to arrange the light source units according to claim 1 and displaying a predetermined fixed pattern. 21. A lighting device comprising the light source unit or an aggregate of the light source units according to any one of claims 1 to 18.