JPH1021722A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lgihting system for a liquid crystal display element capable of optionally controlling the luminance distribution and/or spectral distribution on the light emitting surface of a back light, and displaying a full color image with uniform brightness, high contrast, and high chroma. SOLUTION: In a device, light from a light source is incident on a light transmitting body 1, a light flux from a plurality of openings of a mask 2 arranged on one surface of the light transmitting body 1 is incident in a hologram element having a plurality of unit holograms 4-i through an array-shaped light collecting element, the light flux is spectrally diffracted in a plurality of light fluxes having different wave length with the unit hologram, and collected in the desired position at a predetermined spatial cycle. The light source has a light emitting element group comprising a plurality of light emitting elements having the central wave length of light emission in the central wave length of a plurality of light fluxes produced by the spectral diffraction of the unit hologram 4-i.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device, and more particularly, to an illuminating device suitable for displaying an image in full color using a liquid crystal display element and for imaging a light transmitting object or a light reflecting object.

[0002]

2. Description of the Related Art Hitherto, most liquid crystal display devices have been illuminated with a white light backlight. For full-color display with a liquid crystal display device, a red (R), green (G), and blue (B) filter is provided for each pixel constituting the liquid crystal display device, and this is illuminated with a white light backlight. And had obtained a full-color image.

However, in the method of extracting R, G, and B colors from white light using this color filter, the transmitted color component is limited to one color, and other complementary color components are wasted. In addition, this method has a problem that the illumination efficiency is extremely poor because of the loss due to absorption in each color filter.

A technique for solving this problem is disclosed in Japanese Patent Laid-Open No. 6-308332.
No. 6,086,045. FIG. 11 is a schematic view of a main part of a lighting device disclosed in the publication. In the figure, 45 is a light source. Emit white light. 48 is a waveguide (light guide),
It consists of a transparent box-shaped hollow housing or a transparent plate. 49
Is a reflector provided on the bottom surface of the waveguide, and irregularly reflects light reaching the bottom surface. Reference numeral 46 denotes an opening mask (mask) having a number of small openings 47, which is provided on the upper surface of the waveguide 48, that is, on the surface facing the reflection plate 49.

[0005] Reference numeral 41 denotes a minute convex lens array (array-like light condensing element), which is composed of a number of minute convex lenses, and converts a light beam from each aperture into collimated light. This is the backlight. A hologram array (hologram element) 43 has one unit hologram corresponding to one convex lens. This unit hologram is a transmission hologram formed in a Fresnel zone plate shape, and separates incident white light into three colors of R, G, and B to form images at predetermined positions. Reference numeral 44 denotes a liquid crystal display element, which displays an image using a large number of pixels (liquid crystal cells) 50.

The operation of the lighting device will be described. The white light emitted from the light source 45 enters the waveguide from the side wall of the waveguide 48 and is repeatedly reflected, and a part of the light is irregularly reflected by the reflector 49 and enters the opening 47 of the aperture mask 46. The light beam from the opening 47 is converted into a substantially parallel light beam by the convex lens of the convex lens array 41 and enters the unit hologram forming the hologram array 43. The unit hologram has a specific wavelength (R, G, B)
Of the liquid crystal display element 44, that is, the liquid crystal cell 50, which is to display R, G, and B of the liquid crystal display element 44, is disposed at that position. , A desired full-color image can be displayed.

That is, in this lighting device, light from a light source is made incident on a light guide, and light beams from a plurality of openings of a mask provided on one surface of the light guide are passed through an array-like light-collecting element. A hologram element having a unit hologram, diffracting the light beam into a plurality of light beams having different wavelengths by the unit hologram, condensing the light beam at a desired position with a predetermined spatial period, and a liquid crystal display provided at that position. The pixels of the element are illuminated to display a full-color image.

FIG. 12 is a schematic view of a main part of a conventional illuminating device used for imaging a light transmitting object or a light reflecting object. This illuminating device is of a direct type in which a light source is provided inside a light-emitting unit, and is used for imaging a transmissive object such as a negative film or a positive film and imaging a light reflecting object such as a photograph printed on printed matter or photographic paper. Used for

In the figure, 103A and 103B are diffusion plates, 104A and 104B are fluorescent lamps, and 105A and 105B are reflecting mirrors for reflecting the light of the fluorescent lamp, which fix the fluorescent lamp and the diffusion plates 103A and 103B. At the same time, the structure can be rotated by the hinges 102A and 102B. 106 is a camera such as a silver halide film camera or a digital camera, and 109 is a mounting plate. The diffusion plate 103
A, the fluorescent lamp 104A, the reflecting mirror 105A, and the like constitute one element of the light emitting unit 101A, and the diffusion plate 103B, the fluorescent lamp 104B, the reflecting mirror 105B, and the like constitute one element of the light emitting unit 101B.

Also, as shown in FIG.
It comprises a frame 107 connecting the hinges 102A, 102B of 1A, 101B, and a plurality of legs 108 attached to the frame and fixing the lighting device on a horizontal plane. The operation of this lighting device will be described. FIG. 12 (A) is an explanatory diagram of a case where a transmission object N is imaged using the present illumination device. At this time, the light emitting unit 10
1A and the light emitting portion 101B are arranged horizontally, and the transmission object N is
3 illuminate the transparent object N with both light-emitting parts, and
The transmission object N is imaged from above by 106.

FIG. 12B is an explanatory diagram in the case where an image of a light reflecting object is picked up using the present illumination device. At this time, the reflecting object P is placed on the mounting plate 109, and the light-emitting unit 101A and the light-emitting unit 101B are opened in a C-shape to illuminate the reflecting object P from the side.
6, the reflection object P is imaged from above.

[0012]

The illuminating device for full color display uses a white light source as a light source. At this time, since the white spectrum is used by dispersing it into R, G, and B, it is desirable to completely cut off the spectrum other than B, G, and R in order to increase the contrast and saturation. However, it is difficult to cut this, and long wavelength light
Short wavelength light will crosstalk to the R wavelength and to the B wavelength.

[0013] Further, since the above-mentioned illumination device for imaging the light transmitting object and the light reflecting object uses a fluorescent lamp, there is a problem that the thickness of the light emitting portion becomes large. Further, in particular, when an image of a light transmitting object is taken, there is a problem that even though there is a diffusion plate, brightness unevenness is large from the viewpoint of a camera and uniform illumination cannot be obtained.

According to the present invention, there are provided three types of illuminating devices for illuminating pixels of a liquid crystal display element with R, G, B illumination light obtained by dispersing light from a light source using a hologram. By using a light emitting element group composed of light emitting elements of
The brightness distribution and / or spectral distribution on the light emitting surface of the backlight can be freely controlled by reducing the crosstalk of each R, G, B illumination light and controlling the brightness of each light emitting element constituting the light emitting element group. It is an object of the present invention to provide a lighting device for a liquid crystal display device which can display a full-color image with uniform brightness, good contrast and good saturation.

Further, the uniformity of the illumination is good, and it is thinner and more compact than the conventional one when it is stored. An object of the present invention is to provide a lighting device suitable for imaging a light-transmitting object and a light-reflecting object that skillfully uses a space by illuminating the light from the left and right and photographing the light-reflecting object through an open space with double doors. .

Further, at this time, a light-transmitting object and a light that can control the uniformity of the illumination surface and the spectral characteristics of the illumination by adjusting the brightness of the individual light-emitting elements by using a light-emitting element group of three colors as a light source. An object of the present invention is to provide a lighting device suitable for imaging a reflective object.

[0017]

According to the present invention, there is provided an illumination apparatus comprising: (1-1) light from a light source is incident on a light guide, and light from a plurality of openings of a mask provided on one surface of the light guide is provided. A light beam is made incident on a hologram element having a plurality of unit holograms through an array-shaped light condensing element, and the light beam is diffracted and divided into a plurality of light beams having different wavelengths by the unit hologram, and a desired position is obtained at a predetermined spatial period. The light source is characterized in that the light source has a light-emitting element group including a plurality of light-emitting elements each having a central wavelength of light emission at a central wavelength of a plurality of light beams diffracted and divided by the unit hologram.

In particular, there is provided (1-1-1) adjusting means for individually adjusting the luminance of the light emitting element. (1-1-2) The light emitting element is a light emitting diode. (1-1-3) It has a concave mirror that reflects light from the light emitting element group. (1-1-4) The light emitting elements of the light emitting element group are arranged in one direction along one surface of the light guide, and the concave mirror includes one cylindrical reflecting surface having a generatrix in the direction. (1-1-5) The light emitting elements of the light emitting element group are arranged in one direction along one surface of the light guide, and the concave mirror has a concave reflecting surface group, and the concave reflecting surface group is A plurality of concave reflecting surfaces corresponding to one or a plurality of light emitting elements of the light emitting element group are arranged in the direction. (1-1-6) The concave mirror has a focal point, and the light emitting element is installed at a position deviated from the focal point and at a position where light rays from the light emitting element are reflected by the concave mirror to form a parallel light flux. doing. (1-1-7) The two concave mirrors are provided in a direction orthogonal to the direction in which the light emitting elements are arranged, and a part of the light beam from the light emitting element is converted into a parallel light beam by one concave mirror, and is converted in the first direction. Another part of the light beam from the light emitting element is converted into a parallel light beam by the other concave mirror and directed in a second direction different from the first direction. (1-1-8) The light emitting element group includes a plurality of light emitting units, and the light emitting units emit red light, light emitting green light, and light emitting blue light. And an element. (1-1-9) The light emitting element group is provided corresponding to at least one side surface of the light guide. (1-1-10) The light guide is plate-shaped, and at least a surface of the light guide facing the surface on which the mask is provided is a scattering surface. It is characterized by

Further, the lighting device of the present invention may further comprise: (1-2) a light source provided on at least one side surface of a rectangular flat light guide having a diffuse reflection surface and / or made of a light scattering material; The light guide has two edge lights that scatter light incident on the light guide from the light source by the irregular reflection surface of the light guide and / or a light scattering material to emit scattered light from one surface of the light guide. The two edge lights are rotatable about hinges connected by a frame, respectively, the surfaces of the two light guides that emit scattered light are arranged on substantially one plane, and the ends of the two light guides are arranged. The first is to illuminate the upper part with two edge lights by bringing the parts into close proximity to each other.
And a second state in which the two edge lights are rotated and tilted in a C-shape with each other to illuminate a lower portion between the two edge lights, and the like.

In particular, (1-2-1) the light source is a fluorescent lamp. (1-2-2) the light source is an L-shaped fluorescent lamp,
The fluorescent lamps are respectively provided along two side surfaces of the light guide, and are arranged so that the two fluorescent lamps do not interfere in the first state. (1-2-3) The light source includes a light-emitting element group including a plurality of light-emitting elements, and includes adjustment means for individually adjusting the luminance of the light-emitting elements. (1-2-4) The light emitting element is a light emitting diode. (1-2-5) The light emitting element group includes a plurality of light emitting units, and the light emitting units emit red light, light emitting green light, and light emitting blue light. And an element. It is characterized by

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a lighting device according to a first embodiment of the present invention. The present embodiment is an illumination device that uses a light emitting element (light emitting diode) as a light source, disperses light emitted from the light source by a hologram, and condenses the dispersed light onto pixels constituting a liquid crystal display element. .

In FIG. 1, reference numeral 13 denotes a light source composed of a plurality of light emitting elements. In this embodiment, a light emitting diode is used as a light emitting element.
(Hereinafter referred to as “LED”). Reference numeral 14 denotes a reflecting mirror (concave mirror) having a cylindrical reflecting surface, which reflects light from a light source. Numeral 1 is a transparent plate-shaped light guide having a square or rectangular surface when viewed from the front. Each surface of the light guide 1 is a mirror surface or a rough surface, that is, a scattering surface. The surface 1A facing the light source is a surface on which light from the light source 13 is incident. Surface 1B of light guide 1
Has been subjected to reflection mirror treatment. A mask 2 is provided on the surface opposite to the surface 1B. The mask 2 has a plurality of pinholes (openings) 2-1 to 2-m, and a surface in contact with the light guide 1 is subjected to a reflection mirror treatment. The other surface of the light guide 1 is subjected to a reflecting mirror treatment so that light is efficiently reflected inside the light guide 1. FIG. 2 is a perspective view of a light source 13 and a reflecting mirror 14. The light source 13 of the present embodiment has a generatrix direction (longitudinal direction) of a cylindrical reflecting surface parallel to one side surface of the light guide 1.
A light emitting element group in which a plurality of LEDs 13-1, 13-2, 13-3,..., 13-n are arranged (hereinafter, referred to as an “LED group”), which emits red light. LED (hereinafter referred to as “red LED”),
LED that emits green light (hereinafter referred to as "green LED")
And a plurality of light emitting units composed of LEDs emitting blue light (hereinafter, referred to as “blue LEDs”).

FIG. 3 is an explanatory diagram of the control of the light source 13 of the present embodiment. Power is supplied to each LED via the leads 17-1 to 17-n, but the controller (adjustment means) 1000
The brightness of D is individually adjusted to control the brightness distribution in the light guide 1.

Returning to FIG. 1, reference numeral 3 denotes a first convex lens array.
(Array-shaped condensing element), and has a first convex lens 3-i corresponding to each pinhole 2-i. Reference numeral 4 denotes a hologram element, which includes unit holograms 4-i corresponding to the respective first convex lenses 3-i. The unit hologram 4-i splits the incident light beam into red (R), green (G), and blue (B) light by the diffraction grating effect (color separation), and converts it into parallel light beams traveling in different directions. .

Reference numeral 5 denotes a second convex lens array having a second convex lens 5-i corresponding to each unit hologram 4-i. The second convex lens 5-i condenses each light beam split from the unit hologram 4-i at a predetermined position. Reference numeral 7 denotes a liquid crystal display element, which has a number of pixels (liquid crystal cells) 8, and displays an image by making these pixels 8 transparent or opaque. The liquid crystal display element 7 of the present embodiment is a pixel illuminated with red light to display an image in full color.
8 _R , pixels 8 _G illuminated with green light, and pixels 8 _B illuminated with blue are regularly arranged. Then, each pixel 8 _R is located at a position where the second convex lens 5-i collects the R, G, and B light fluxes.
The liquid crystal display element 7 is arranged so that 8 _G and 8 _B are located.

The operation of this embodiment will be described. The light source 13 is turned on by the controller 1000, and a red LED constituting the light source 13
The light of each wavelength is emitted from the green LED and the blue LED, and the light of three colors enters the light guide 1 directly or is reflected by the reflecting mirror 14. These lights mix and become substantially white light. Then, the light is repeatedly reflected in the light guide 1 and a part of the light passes through the pinhole 2-i to form the first convex lens array.
Inject in the direction of 3. The light beam incident on the first convex lens 3-i is converted into a substantially parallel light beam by the lens, and is incident on the unit hologram 4-i of the hologram array 4.

The unit hologram 4-i splits the incident substantially white light beam into red, green and blue light beams and directs them in different directions to form the second convex lens array 5.
These three light beams are condensed at a desired position with a predetermined spatial period via the second convex lens 5-i, and the pixels 8 _R , 8 _G , and 8 _{G of} the liquid crystal display element 7 located at the respective light condensing positions Illuminate 8 _B.

In this embodiment, all the pixels of the liquid crystal display element 7 are illuminated as described above, each pixel is made transparent or opaque by a control means (not shown), and the transparent pixels are converted into red, green or blue pixels. Display and recognize color images.

The light source 13 of the present embodiment is originally composed of a red LED, a green LED, and a blue LED each having a central wavelength of light emission at the central wavelength of a plurality of light beams diffracted by the unit hologram 4-i.
, There is almost no occurrence of crosstalk when spectrally separated by the unit hologram 4-i, and the separation of red light, green light and blue light is good. Therefore, in this embodiment, a full-color image with high contrast and high saturation can be displayed.

Further, the light source 13 of this embodiment has a plurality of red LEDs, green LEDs, and blue LEDs, each of which is arranged.
By controlling the brightness of the LED, the brightness of the light emitting surface of the backlight (the brightness of the pinholes 2-1 to 2-m) is partially controlled, or the amounts of red light, green light, and blue light are controlled. To control the spectral distribution.

In this embodiment, the light beam from the pinhole is condensed in a spot shape on each pixel by two convex lenses and unit holograms. When the pixels to be displayed and the pixels to display blue are respectively arranged on a straight line, a slit-shaped opening parallel to the straight line and two convex lenses 3-i and 5-i are used instead of the pinhole 2-i. Instead, a cylindrical lens and a unit hologram having a generatrix parallel to the straight line may be used as a unit hologram having a stripe shape long in the direction of the straight line, and red light, green light and blue light may be respectively condensed in a line shape.

In the present embodiment, a light source is
Some light from 13 was reflected, but in some cases the light source
A plurality of LEDs constituting the light guide 13 may be directly attached along the longitudinal direction of the side surface of the light guide 1.

FIG. 4 is a schematic view of a main part of a lighting device according to a second embodiment of the present invention. In this embodiment, light is incident on the light guide.
Embodiment 2 differs from Embodiment 1 in that two sets of LEDs are provided and illumination light is made incident from two surfaces of the light guide, and that the hologram element separates and condenses light into three colors of light. Is the same. Elements having the same functions as in the first embodiment are denoted by the same reference numerals.

In the drawing, 13 _A and 13 _B are light sources each composed of a plurality of LEDs. 14 _A and 14 _B are reflecting mirrors (concave mirrors) each having a cylindrical reflecting surface, and reflect light from a light source. Numeral 1 is a transparent plate-shaped light guide having a square or rectangular surface when viewed from the front. Each surface of the light guide 1 is a rough surface. Surface 1A and 1C facing the light source is a plane of incidence of the light from the light source 13 _A or 13 _B. The surface 1B of the light guide 1 is subjected to a reflection mirror treatment. A mask 2 is provided on the surface opposite to the surface 1B. The mask 2 has a plurality of pinholes (openings) 2-1 to 2-m, and a surface in contact with the light guide 1 is subjected to a reflection mirror treatment. The other surface of the light guide 1 is subjected to a reflecting mirror treatment so that light is efficiently reflected inside the light guide 1.

The light sources 13 _A and 13 _B of the present embodiment are each a light emitting element group (hereinafter referred to as a light emitting element group) in which a plurality of LEDs are arranged in the generatrix direction (longitudinal direction) of the cylindrical reflecting surface parallel to the two side surfaces of the light guide 1. , “LED group”), and the LED group is configured by arranging a plurality of light emitting units each including a red LED, a green LED, and a blue LED. The brightness of these LEDs can be individually adjusted by a controller (adjustment means) 1000 (not shown), and the brightness distribution in the light guide 1 can be controlled.

Reference numeral 3 denotes a first convex lens array (array-like condensing element), which includes a first convex lens 3-i corresponding to each pinhole 2-i. 9 is a hologram element,
A unit hologram 9-i corresponding to each first convex lens 3-i is provided. The unit hologram 9-i is a transmission-type hologram having a Fresnel lens function, and splits an incident light beam into red (R), green (G), and blue (B) light (color separation) by a diffraction grating effect. The light beams are directed in different directions, and the separated light beams are condensed at desired positions at a predetermined spatial period. 7 is a liquid crystal display element,
(Liquid crystal cell) 8, and an image is displayed by making these pixels 8 transparent or opaque. The liquid crystal display element 7 of the present embodiment has a pixel 8 _R illuminated with red light to display an image in full color, a pixel 8 _G illuminated with green light,
The pixels 8 _B that illuminates in blue is configured by arranging regularly.
The liquid crystal display element 7 is arranged so that the pixels 8 _R , 8 _G , and 8 _B are located at positions where the unit hologram 9-i condenses the R, G, and B light fluxes.

The operation of this embodiment will be described. Light source 13 _A and 13 _B are turned on by the controller 1000, the red LED constituting the light source, a green LED and is reflected directly or reflector 14 _A or 14 _B guiding light of a wavelength of each is emitted from the blue LED Light of three colors is incident on the light body 1. These lights mix and become substantially white light. Then, while the light is repeatedly reflected in the light guide 1, a part of the light is emitted toward the first convex lens array 3 through the pinhole 2-i. First convex lens 3-
The light beam incident on i is converted into a substantially parallel light beam by the lens, and is incident on the unit hologram 9-i of the hologram element 9.

The unit hologram 9-i disperses the incident substantially white light beam into red, green, and blue light beams and directs them in different directions, and transfers these three light beams to a desired position at a predetermined spatial period. To illuminate the pixels 8 _R , 8 _G , and 8 _B of the liquid crystal display element 7 located at the respective light condensing positions.

In this embodiment, all the pixels of the liquid crystal display element 7 are illuminated as described above, each pixel is made transparent or opaque by a control means (not shown), and the transparent pixels are converted into red, green or blue pixels. Display and recognize color images.

The light source 13 _A and 13 _B of this embodiment is a red LED with a central wavelength of each light emission center wavelength of the plurality of light beams originally units hologram 9-i diffracted spectral, constituted by a green LED and a blue LED Crosstalk when splitting with the unit hologram 9-i, there is almost no
Good separation of green light and blue light. Therefore, in this embodiment, a full-color image with high contrast and high saturation can be displayed.

[0041] Further, the light source 13 _A and 13 _B are red LED of the present embodiment, a green LED and a blue LED have been respectively arranging a plurality, luminance of the light emitting surface of the backlight by controlling the brightness of each LED (The brightness of the pinholes 2-1 to 2-m) or the amount of red light, green light and blue light can be controlled to control the spectral distribution.
In the present embodiment, the light beam from the pinhole is condensed in a spot shape on each pixel by one convex lens and a unit hologram, but the pixel of the liquid crystal display element 7 that should display red and the pixel that should display green. When the pixels and the pixels for displaying blue are arranged on a straight line, instead of the pinhole 2-i, a slit opening parallel to the straight line and the first convex lens 3-i are used.
Instead of i, a cylindrical lens having a generatrix parallel to the straight line, a unit hologram may be formed as a striped unit hologram long in the direction of the straight line, and red light, green light and blue light may be respectively condensed in a line shape.

Further, in this embodiment, the light sources are provided on the two side surfaces of the light guide 1, but the light sources may be provided on the other two side surfaces.

In the present embodiment, the light source is
Some light from 13 was reflected, but in some cases the light source
_A plurality of LEDs constituting 13 _A and 13 _B are connected to light guides 1 and 2 respectively.
It may be mounted directly along the longitudinal direction of one side.

FIG. 5 is a schematic view showing Embodiment 3 of the lighting device of the present invention. In this embodiment, instead of the reflecting mirror having the cylindrical reflecting surface of the first embodiment, a rotationally symmetric minute concave mirror 14-i is made to correspond to one or more LEDs of the LED group,
The concave mirror is constituted by a concave reflecting surface group in which a plurality (k) of the concave mirrors are arranged. The reflecting surfaces of the concave mirrors 14-1 to 14-k are spherical, parabolic, elliptical, or the like. Note that such a group of LEDs and a group of concave mirrors may be provided on all side surfaces of the light guide 1.

FIG. 6 is a schematic view showing Embodiment 4 of the lighting device of the present invention. This embodiment is an embodiment of a more preferable arrangement of the concave mirror and the LED in the third embodiment. Fig. 6 (A)
Fig. 6 (B) is a cross-sectional view of the principal part of the operation explanatory view.

In FIGS. 6A and 6B, a reflecting mirror (concave mirror) for reflecting the light beam from the LED 13-i is a first and a second reflecting mirror (concave mirror) in a direction orthogonal to the direction in which the LEDs 13 are arranged. ) 14-i ₁ ,
Has a 14-i _2, has installed LED 13-i to the midpoint of a line connecting the focal point of each of the reflector _{14-i 1, 14-i} 2. Light guide 1
Are rough surfaces as described above.

Therefore, the LED 13-i is decentered with respect to each of the reflecting mirrors 14-i ₁ and 14-i ₂ , and a part of the light beam diverging from the LED 13-i is reflected by the reflecting surface 14-i ₁ and the parallel light beam 18c And is directed upward in the diagonal direction (first direction),
The other portion of the light beam diverging from i is reflected by the reflecting surface 14d, converted into a parallel light beam 18d, and directed downward in a diagonal direction (second direction).

As shown in FIG. 6B, the LED 13-i and the reflecting mirror 14
Since -i ₁ and 14-i ₂ are provided on the side surfaces of the light guide 1, the parallel light fluxes 18c and 18d pass through the inside 200 of the light guide 1 and have upper surfaces 1D and 1D, respectively.
At least one of the upper surface 1D and the lower surface 1B is scattered toward the lower surface 1B, and some light beams are radiated directly above, while other light beams propagate inside the light guide 1 to the right.

According to this embodiment, it is possible to efficiently propagate the light beam diverging from the LED group through the inside of the light guide for forming the surface light source.

In some cases, there is only one reflecting mirror (concave mirror) that reflects the light beam from the LED 13-i in the direction orthogonal to the direction in which the LEDs 13 are arranged, and the LED 13-i is located at a position shifted from the focal point of the reflecting mirror. In addition, the object is achieved even if the light from the LED is installed at a position where it is reflected by the reflecting mirror to form a parallel light beam.

FIG. 7 is an explanatory diagram showing an example of the arrangement of the LED groups of the lighting device of the present invention. The figure shows red LED, green LED, blue LED
1 shows a form of arrangement. In FIG. 7, R, G, and B denote a red LED, a green LED, and a blue LED, respectively, provided on the side surface of the light guide 1. Fig. 7 (A) shows blue LED, green LED, red LED
Embodiments 1 and 2 correspond to an example in which a plurality of light emitting units are arranged in the longitudinal direction of the side surface of the light guide. Fig. 7
(B) shows an example in which the LED groups of FIG. 7 (A) are arranged in two rows in the longitudinal direction of the side surface, and FIG. 7 (C) shows two rows of the LED groups in FIG. 7 (A) in the longitudinal direction of the side surface.
This is an example in which the LED groups are shifted by half the array pitch.

FIG. 8 is a schematic view (plan view) of a main part of a fifth embodiment of the lighting device of the present invention. FIG. 9 is a schematic view (side view) of a main part of the fifth embodiment, and shows a cross-sectional view along line AA in FIG. FIG. 9 illustrates a state (first state) in which a light transmitting object N such as a negative film or a positive film is imaged by a camera according to the present embodiment. FIG. 10 is a schematic view (side view) of a main part of the fifth embodiment.
FIG. FIG. 10 shows a state (second state) in which a light-reflecting object P such as a photograph printed on printed matter or photographic paper is imaged by a camera according to the present embodiment.

In the figure, 23A and 23B are fluorescent lamps as light sources,
A and 25B are the ends of the fluorescent lights, while fluorescent lights 23A and 23B are respectively
It is L-shaped and is arranged so that the ends 25A and 25B do not interfere in the state of FIG. 27A and 27B are reflecting mirrors each having a cylindrical surface having a generating line in the longitudinal direction of the fluorescent lamp. Reference numerals 24A and 24B denote rectangular plate-shaped light guides, each surface of which is a mirror surface or a rough surface (diffuse reflection surface). In FIG. 9, the surface on the opposite side to the camera is subjected to reflection mirror processing. 22A, 22
B is the upper surface of the light guides 24A and 24B.

The light guides 24A and 24B may be made of a material that scatters light itself, for example, a milky white material.

The light guide, the light source, the reflecting mirror and the like make light incident from the side surface of the light guide, and scatter the light by the irregular reflection surface of the light guide or / and the light scattering material to form one of the light guides. It constitutes one element of an edge light that emits scattered light from two surfaces.

The light guides 24A and 24B are mounted on plates 28A and 28B, respectively, and the plates 28A and 28B are mounted on the frame 32, respectively.
Hinges 26A, 26B connected by (only shown in FIG. 10)
It is mounted so that it can rotate around the axis. That is, the two light guides 24A and 24B rotate around the hinges 26A and 26B,
It can be in the state of one upward illuminating flat plate, or in the double door state in which the lower part is illuminated.

The operation of the present embodiment will be described. First, a case where the light transmitting object N is imaged in the present embodiment will be described with reference to FIG. The surfaces 22A and 22B for emitting scattered light of the two light guides 24A and 24B of the present embodiment are arranged on a substantially
The ends of the two light guides are opposed to each other and fixed to each other by fixing means (not shown), and a first state of illuminating the upper side with two edge lights is set. Next, the light transmitting object to be imaged is placed on the upper surfaces of the two edge lights. (In some cases, it is placed on a transparent glass plate). A silver halide camera or digital camera 30 is fixed above the light transmitting object.

When the light source is turned on in this state, the fluorescent lamp 23A
And 23B from the light guide 24A or 24B
The light enters the respective light guides through the side surfaces of the light guide, and is scattered by the rough surface or the scattered object in the light guides, and light of substantially uniform brightness is scattered upward from the surfaces 22A and 22B and emitted.

The image of the light transmitting object N illuminated by the light scattered and emitted from the surfaces 22A and 22B is picked up by the film of the camera 30 or the sensor 31.

Next, the case of imaging the light reflecting object P in this embodiment will be described with reference to FIG. Light guide 24A or 24B
Are rotated in the shape of a triangle and the mutual relationship is fixed by fixing means, and a second state of illuminating the lower part between the two edge lights is set. At this time, the light guides 24A and 24B are positioned at appropriate heights by the four legs 33 (only shown in FIG. 10) attached to the frame 32. The light reflecting object P is placed on a lower mounting plate 29 between the two light guides, and the camera 30 is set above it.

When the light source is turned on in this state, the light guides 24A, 24A
The scattered light exits from the surfaces 22A and 22B of B to illuminate the light reflecting object P below the two edge lights substantially uniformly. An image of the illuminated light reflecting object is captured by a film of the camera 30 or the sensor 31.

When the present embodiment is stored, the two light guides 24A and 24B are brought together as shown in FIG.
The four legs are also stored along the frame 32 in FIG.

In the present embodiment, the uniformity of illumination is good because of the edge light type, and furthermore, the edge light is adopted, so that the storage is thinner and more compact than the conventional one when stored, so that the light reflection object can be imaged. Has two edge lights with double doors and illuminates them from the left and right above the light reflecting object, and can shoot the light reflecting object through the open space with double doors, achieving a lighting device that skillfully utilizes the space. .

In the present embodiment, two edge lights are used. However, in some cases, more edge lights may be used. In this embodiment, an L-shaped fluorescent lamp is used. Alternatively, two linear fluorescent lamps may be used, and light sources are provided on the three side surfaces of the light guide within a range that does not cause interference. It may be arranged.

In this embodiment, two fluorescent lamps are used as the light source. However, the LED group and the controller used in the first to fourth embodiments are used as the light source and the adjusting means, and the individual LED is used.
By adjusting the luminance of the light, the uniformity of the illumination surface and the spectral characteristics of the illumination can be further controlled.

Further, in this embodiment, the entire surface 22A, 22B is used as a light-emitting surface, and scattered light is emitted from this surface. However, as in the previous embodiment, a mask having a large number of small holes is provided on this surface. If a convex lens array composed of a large number of convex lenses corresponding to the small holes and having the small holes as focal points is arranged above the mask, illumination light having high directivity can be obtained.

At this time, if the surface of the mask on the light guide side is subjected to a reflecting mirror treatment, light rays that have not entered the small holes of the mask are effectively reflected, and the reflection is repeated in the light guide. Thus, the amount of light passing through the small hole can be increased.

[0068]

According to the present invention, there is provided an illumination device for illuminating pixels of a liquid crystal display device with R, G, and B illumination light obtained by dispersing light from a light source using a hologram. By using a light-emitting element group composed of three types of light-emitting elements that emit light, crosstalk between each of the R, G, and B illumination lights is reduced, and the luminance of each light-emitting element that constitutes the light-emitting element group is reduced. By controlling, the luminance distribution and / or the spectral distribution on the light emitting surface of the backlight can be freely controlled, so that a lighting device for a liquid crystal display element capable of displaying a full-color image with uniform brightness and good contrast and saturation. To achieve. Also, the uniformity of illumination is good, and it is thinner and more compact than the conventional one when it is stored, and when imaging a light-reflecting object, the two edge lights are opened from the left and right above the light-reflecting object. By illuminating the object and photographing the light reflecting object through the open space of the double door, a lighting device suitable for imaging a light transmitting object and a light reflecting object that skillfully utilizes the space is achieved.

Further, at this time, by using a light emitting element group of three colors as a light source and adjusting the luminance of each light emitting element, a light transmitting object and a light which can control the uniformity of the illumination surface and the spectral characteristics of the illumination can be controlled. A lighting device suitable for imaging a reflective object is achieved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part of a lighting device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a light source part according to the first embodiment.

FIG. 3 is an explanatory diagram of light source control according to the first embodiment.

FIG. 4 is a schematic diagram of a main part of a lighting device according to a second embodiment of the present invention.

FIG. 5 is a schematic view showing Embodiment 3 of the lighting device of the present invention.

FIG. 6 is a schematic diagram showing Embodiment 4 of the lighting device of the present invention.

FIG. 7 shows an example of an arrangement of LED groups in the lighting device of the present invention.

FIG. 8 is a schematic diagram of a main part of a fifth embodiment of the lighting device of the present invention.
(Plan view)

FIG. 9 is a schematic view of a main part of a fifth embodiment of the lighting device of the present invention.
(Side view) Explanatory drawing of light transmission object imaging

FIG. 10 is a schematic diagram of a main part of a lighting device according to a fifth embodiment of the present invention (side view).

FIG. 11 is a schematic diagram of a main part of a lighting device for illuminating a conventional liquid crystal display element.

FIG. 12 is a schematic view of a main part of a conventional lighting device.

[Explanation of symbols]

1 light guide 2 mask 2-i pinhole 3 first convex lens array 3-i first convex lens 4 hologram element 4-i unit hologram 5 second convex lens array 5-i second convex lens 6 _R , 6 _G red to 6 _B condensed, green and pixels 8 _R of the principal ray 7 liquid crystal display device 8 the liquid crystal display device of the blue beam, 8 _G, 8 _B red, and displays the green and blue pixels 9 hologram element 13, 13A, 13B Light source 13-1 ~ 13-n LED 14,14A, 14B Reflector 14-1 ~ 14-k Small concave mirror 17-1 ~ 17-n Lead wire 1000 Controller 22A, 22B Upper surface of light guide 23A, 23B Light source (Fluorescent lamp) 24A, 24B Light guide 25A, 25B End of fluorescent lamp 26A, 26B Hinge 27A, 27B Reflector 28A, 28B Plate 29 Mounting plate 30 Camera 31 Film or sensor 32 Frame 33 Leg 41 Convex lens array 43 Hologram Array 44 Liquid crystal display element 45 Light source 46 Aperture mask 47 Aperture 48 Waveguide 49 Reflector 50 Pixel (liquid crystal cell) 101A, 101B Light emitting part 103A, 103B Diffuser 104A, 104B Light lamps 105A, 105B reflector

Claims (17)

[Claims] A light from a light source is incident on a light guide, and light beams from a plurality of openings of a mask provided on one surface of the light guide are converted into a plurality of unit holograms through an array-shaped light-collecting element. A hologram element having the unit hologram, diffracting the light beam into a plurality of light beams having different wavelengths by the unit hologram, and condensing the light beam at a desired position with a predetermined spatial period. A lighting device, comprising: a light emitting element group including a plurality of light emitting elements each having a central wavelength of light emission at a central wavelength of a plurality of light fluxes to be split. 2. The lighting device according to claim 1, further comprising adjusting means for individually adjusting the luminance of the light emitting elements. 3. The lighting device according to claim 1, wherein the light emitting element is a light emitting diode. 4. The device according to claim 1, further comprising a concave mirror for reflecting light from said light emitting element group.
The lighting device according to any one of the preceding claims. 5. The light-emitting element of the light-emitting element group is arranged in one direction along one surface of the light guide, and the concave mirror has one cylindrical reflection surface having a generatrix in the direction. The lighting device according to claim 4, wherein: 6. The light emitting elements of the light emitting element group are arranged in one direction along one surface of the light guide, the concave mirror has a concave reflecting surface group, and the concave reflecting surface group is the light emitting element. 5. The lighting device according to claim 4, wherein a plurality of concave reflecting surfaces corresponding to one or a plurality of light emitting elements of the group are arranged along the direction. 7. The concave mirror has a focal point, and the light emitting element is installed at a position deviated from the focal point and at a position where light rays from the light emitting element are reflected by the concave mirror to form a parallel light flux. The lighting device according to claim 4, wherein: 8. The two concave mirrors are provided in a direction orthogonal to the direction in which the light emitting elements are arranged. A part of the light beam from the light emitting element is converted into a parallel light beam by one concave mirror and directed in a first direction. The lighting device according to claim 7, wherein another portion of the light beam from the light emitting element is converted into a parallel light beam by the other concave mirror and directed to a second direction different from the first direction. 9. The light emitting element group includes a plurality of light emitting units, the light emitting units emitting red light, the light emitting element emitting green light, and the light emitting element emitting blue light. The lighting device according to any one of claims 1 to 8, further comprising: 10. The lighting device according to claim 1, wherein the light emitting element group is provided so as to correspond to at least one side surface of the light guide. 11. The lighting device according to claim 10, wherein the light guide has a plate shape, and at least a surface of the light guide opposed to a surface on which the mask is provided is a scattering surface. 12. A light source is provided facing at least one side surface of a rectangular flat light guide having a diffuse reflection surface and / or made of a light scattering material, and light incident on the light guide from the light source is provided. The light guide has two edge lights that are scattered by a diffuse reflection surface or / and a light scattering material to emit scattered light from one surface of the light guide, and the two edge lights are respectively connected by a frame. The two light guides can be rotated about an axis, the surfaces of the two light guides that emit scattered light are arranged on substantially one plane, and the ends of the two light guides are opposed to and close to each other. A first state of illuminating the upper side, and a second state of illuminating the lower part between the two edge lights by rotating the two edge lights and inclining each other in a C shape can be selected. Lighting equipment. 13. The lighting device according to claim 12, wherein the light source is a fluorescent lamp. 14. The light source is an L-shaped fluorescent lamp,
14. The lighting device according to claim 13, wherein the fluorescent lamps are provided along two side surfaces of the light guide, respectively, and the two fluorescent lamps are arranged so as not to interfere in the first state. . 15. The lighting device according to claim 12, wherein the light source has a light emitting element group including a plurality of light emitting elements, and further includes adjusting means for individually adjusting the luminance of the light emitting elements. 16. The lighting device according to claim 15, wherein said light emitting element is a light emitting diode. 17. The light-emitting element group includes a plurality of light-emitting units. The light-emitting units include a light-emitting element that emits red light, a light-emitting element that emits green light, and a light-emitting element that emits blue light. The method according to claim 15, further comprising:
6. Illumination device.