JP2006310549A - Lighting apparatus and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED lighting apparatus for controlling uneven color and luminance, and fading of contour. <P>SOLUTION: The lighting apparatus comprises a base substrate (50) fixing a power supply member, an LED (11) mounted to the base substrate (50), a diffusing sheet (30) allocated in the opposite side of the base substrate (50) in this LED (11), a first condensing lens (20) in the non-spherical shape allocated in the opposite side of the LED (11) for the diffusing sheet (30), and a second condensing lens (40) of the non-spherical shape allocated in the opposite side of the diffusing sheet (30) for the first condensing lens (20). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lighting device technology, and more particularly to a lighting device technology using LEDs.

There are high expectations for LEDs (Light Emitting Diodes) from the standpoint of power saving and low running costs compared to incandescent and fluorescent lamps, and not using harmful substances such as mercury unlike fluorescent lamps.
However, when used in a lighting device, although high illuminance can be realized, there is a problem that uneven color occurs on the irradiated surface.

With respect to the above problem, Patent Document 1 discloses a technique for reducing color unevenness.
In other words, since all the emitted light from a plurality of light emitting diodes is concentrated on a predetermined part of the lens part and then emitted to the outside, it can be sufficiently mixed in the lens part, resulting in color unevenness It is a technology that can prevent.

JP 2003-16808 A

  On the other hand, white light is highly demanded as a lighting device. In order to obtain this white light, a method of obtaining white light by aligning and emitting all RGB LEDs at the same time, and using a blue LED and a phosphor capable of converting the blue LED light into yellow light are used. A method for obtaining white light is known.

  There is also some demand for appliances that illuminate illuminated items that dislike ultraviolet light. For example, museums, museum exhibits, and hospitals. Since the LED generates almost no ultraviolet light, expectations in this field are great.

Now, in order to use white LED as an illuminating device, what can implement | achieve white light only with blue LED and fluorescent substance is preferable. This is because the structure is simple and the cost can be reduced.
However, the technique described in Patent Document 1 is based on the premise that a plurality of LEDs are used, and is not suitable as a technique for suppressing the occurrence of color unevenness in a lighting device that includes only blue LEDs. This is because a plurality of LEDs must be used and cannot be used in a lighting device that is configured with a single blue LED.

In addition, in the case of an illuminating device that employs a single blue LED, there has been a problem that in addition to color unevenness, illuminance unevenness or outline blurring occurs. Therefore, it has not been suitable for lighting fixtures for works of art and products that require a clean illumination with a clear boundary between the illumination surface and the non-illumination surface.
Illumination with a clear boundary between the illumination surface and the non-illumination surface is in demand for reading lights that scatter light to the surroundings. However, in a lighting device that uses a single blue LED, The request could not be met.

As is apparent from the above, it is a lighting fixture that can realize white light only with a blue LED and a phosphor, and a lighting fixture in which unevenness in color and illuminance is suppressed and the edge is clear has not been realized.
The problem to be solved by the present invention is to provide a lighting-related technique in which white light can be realized only by a blue LED and a phosphor, and color unevenness, illuminance unevenness, and contour blur are suppressed. .

An object of the invention described in claim 1 and claim 2 is to provide an LED lighting device that can suppress color unevenness, illuminance unevenness, and outline blur and can be downsized.
Another object of the present invention is to provide an imaging apparatus using an illumination device that suppresses color unevenness, illuminance unevenness, and outline blurring.

(Claim 1)
The invention according to claim 1 relates to an illuminating device for condensing and irradiating a light beam emitted from an LED (11) by means of two condenser lenses (20, 40).
That is, a base substrate (50) to which a power supply member is fixed, an LED (11) mounted on the base substrate (50), and a diffusion disposed on the opposite side of the LED (11) from the base substrate (50) A sheet (30), an aspherical first condenser lens (20) disposed on the opposite side of the LED (11) with respect to the diffusion sheet (30), and the first condenser lens (20) In contrast, the LED illumination device includes an aspherical second condenser lens (40) disposed on the opposite side of the diffusion sheet (30).

(Glossary)
The angle of “light collection” is 0 to 90 degrees or less, preferably 5 to 50 degrees.
The “diffusion sheet” has a performance of diffusing to a predetermined angle (for example, 60 degrees) when parallel light enters. The material is polycarbonate, for example.
“LED” is not limited to a blue light emitting diode. For example, a composite LED in which RGB is packaged is also included.

(Claim 2)
The invention according to claim 2 limits the LED lighting device according to claim 1.
That is, a holder (a lens holder in the figure) that is located between the diffusion sheet (30) and the first condenser lens (20) and that separates the diffusion sheet (30) and the first condenser lens (20) by a predetermined distance. 70), and the inner wall surface of the holder (70) is black.

It has been found that the illuminance unevenness and the outline blur can be suppressed by making the inner wall surface of the holder (70) black.
Note that all the holders (70) may be black for the convenience of manufacturing.

(Claim 3)
A third aspect of the present invention is an imaging device that employs the LED lighting device according to the first aspect.
In other words, the LED illumination device is an illumination device that irradiates a direction to be photographed by a camera constituting the imaging device,
A base substrate (50) to which a power supply member is fixed, an LED (11) mounted on the base substrate (50), and a diffusion sheet (on the opposite side of the base substrate (50) in the LED (11)) ( 30), an aspherical first condenser lens (20) disposed on the opposite side of the LED (11) with respect to the diffusion sheet (30), and the first condenser lens (20) The LED illumination device includes an aspherical second condenser lens (40) disposed on the side opposite to the diffusion sheet (30).

Examples of the “imaging device” include a digital camera and a mobile phone with a camera function.
The imaging apparatus according to the present invention contributes to improving the quality of an image to be captured because an illumination device with little color unevenness and illuminance unevenness can be used as auxiliary light.

(Claim 4)
A fourth aspect of the present invention is an imaging device that employs the LED lighting device according to the second aspect.
That is, a holder (a lens holder in the figure) that is located between the diffusion sheet (30) and the first condenser lens (20) and that separates the diffusion sheet (30) and the first condenser lens (20) by a predetermined distance. 70), and the inner wall surface of the holder (70) is black.

According to the first and second aspects of the invention, it is possible to provide an LED lighting device that can suppress color unevenness, illuminance unevenness, and outline blur and can be miniaturized.
According to the invention of Claim 3 and Claim 4, the imaging device using the illuminating device which suppressed color unevenness, illumination intensity unevenness, and outline blurring was able to be provided.

  Hereinafter, the present invention will be described in more detail based on embodiments and drawings. The drawings used here are FIGS. 1 to 4. 1 is a perspective view showing the lighting device, FIG. 2 is a side sectional view showing the lighting device, FIG. 3 is a top view showing the lighting device, and FIG. 4 is an exploded perspective view showing the lighting device. FIG.

(overall structure)
As shown in FIG. 1, the illuminating device 10 condenses the incident light beam from the LED 11 (light source) by a plurality of condensing lenses 20 and 40 having different spherical shapes, and forms an emitted light beam having different light distributions. It is the illuminating device which radiates to.
Hereinafter, the illuminating device according to the present embodiment will be described on the assumption that the irradiated surface is located on the lower side of the illuminating device.

The illumination device 10 is fixed to the base substrate 50 on which a connector 100 (power supply member) for causing the LED 11 to emit light is mounted, and condenses the light flux from the LED 11, and the condensed light flux. The diffusion sheet 30 can be diffused at a predetermined angle, the LED holder 60 that holds the diffusion sheet 30, and the end surface 63 c of the LED holder 60 on the side opposite to the base substrate 50. The lens holder 70, the first bottom surface portion 73 and the second bottom surface portion 74 formed on the inner wall of the lens holder 70 along the shape of the condenser lens, and the first bottom surface portion 73 of the lens holder 70. The first condenser lens 20, the second condenser lens 40 disposed on the second bottom surface portion 74 of the lens holder 70, and the lens holder 70 are disposed within the first condenser lens 20. A cylindrical inner sleeve 80 for holding the lens 20, and a cylindrical outer sleeve 90 disposed in the lens holder 70 for holding the first condenser lens 20. The condensing lens 40 is arranged at a predetermined interval from the first condensing lens 90 and is formed so as to have a spherical shape different from that of the first condensing lens 20.
Details of each member will be described below.

(Base substrate)
The base substrate 50 is a substrate member formed as a base of the lighting device 10 having an outer shape of a so-called handle mirror type old tomb with a rectangular parallelepiped attached to a disk when viewed from above. As shown in FIG. 4, the base substrate 50 includes a disk part 51 formed in a disk shape and a rectangular parallelepiped part 52 continuous to the disk part 51, and the connector 100 is provided on an upper surface 52 a of the rectangular part 52. The LED 11 is placed on the upper surface 51 a of the disk portion 51. The upper surface 51 a includes two positioning portions 54 and 54 for fixing the LED holder 60 to the base substrate 50 so as to be sandwiched from both ends of the LED 11. The bottom surface of the LED holder 60 is brought into contact with the positioning portion 54 and fixed using a predetermined connecting member.

The material of the base substrate 50 is made of a metal material such as metal. For this reason, it is a material that achieves a heat radiation promoting effect such that the heat stored inside by the LED 11 is efficiently radiated to the outside.

(LED)
The LED 11 employs a 1 W high power LED. The LED 11 has a rectangular parallelepiped outer shape of 2.8 mm in length, 3.4 mm in width, and 1.15 mm in height. Further, light beams having substantially the same light distribution angle (for example, directivity (2θ 1/2) standard value of about 120 °) are emitted toward the diffusion sheet 30 side. The installation location is disposed substantially at the center of the upper surface 51 of the base substrate 50.
Note that the LED 11 in the present embodiment employs a blue LED, and is formed as an LED capable of realizing white light using only the blue LED and a phosphor (not shown). For this reason, the irradiated light is white light.

(LED holder)
The LED holder 60 projects from an LED holder main body 61 having a cylindrical outer shape with a first opening 69, and an outer peripheral wall 61b of the LED holder main body 61, and can be fixed by a bolt 110 (see FIG. 3). Two connecting members 62 formed are provided.
The inner wall 63 of the LED holder 60 is contacted when the lens holder 70 is placed on the LED holder 60, and the first step 63 b that is brought into contact with the diffusion holder 30. And two step portions 63c.

The connection member 62 has a connection hole 62b on the outer side on the side opposite to the LED holder main body 61, and the bolt 110 can be slid from the connection hole 62b to be connected.
Although illustration is omitted, the illumination device 10 according to the present embodiment has a small size of 16.87 mm in length × 20.94 mm in width × 11 mm in height. Accordingly, the bolt 110 can be used to fix to another device, for example, a member forming a reading lamp.

  The material of the LED holder 60 is made of a metal material such as aluminum. For this reason, the heat stored inside by the LED 11 is efficiently dissipated to the outside.

(Lens holder, inner sleeve, outer sleeve)
The lens holder 70 includes a lens holder body 79 having a cylindrical outer shape having a second opening 77 positioned on the LED holder 60 side and a third opening 78 positioned on the condenser lenses 20 and 40 side, and the lens. A first inner peripheral wall 71 formed inside the holder main body 79 and a second inner peripheral wall 72 continuous with the first inner peripheral wall 71 are provided. The condensing lenses 20 and 40 are held by an inner sleeve 80 and an outer sleeve 90 formed in a cylindrical shape.
The lens holder 70 is a black integrally molded product. The inner wall surface on the diffusion sheet 30 side needs to be at least black.

The inner sleeve 80 has a cylindrical outer shape, and includes an inner sleeve outer wall 81, an inner sleeve bottom surface portion 82 continuous with the inner sleeve outer wall 81, and an inner sleeve upper surface portion 83 disposed to face the inner sleeve bottom surface portion 82. Become. As shown in FIG. 2, the inner sleeve 80 is formed so that the thickness of the inner sleeve outer wall 81 decreases from the inner sleeve bottom surface portion 82 toward the inner sleeve upper surface portion 83. More specifically, the height of the inner sleeve 80 is 2.4 mm, the width of the inner sleeve bottom surface portion 82 is 1.35 mm, and the width of the inner sleeve upper surface portion 83 is 0.52 mm.
It is sufficient that the “angle X = 68.8 °” shown in FIG.
By doing so, the emission angle from the first condenser lens 20 is adjusted, and the optimum light flux can be emitted to the second condenser lens 40.

The outer sleeve 90 has a cylindrical outer shape, and includes an outer sleeve outer wall 91, an outer sleeve bottom surface portion 92 continuous with the outer sleeve outer wall 91, and an outer sleeve upper surface portion 93 disposed to face the outer sleeve bottom surface portion 92. Become. The outer sleeve outer wall 91 is formed in substantially the same thickness. More specifically, the height of the outer sleeve 90 is 2.05 mm, and the width of the bottom portion 92 is 1.3 mm.
Thereby, since the emission angle of the light beam emitted from the second condenser lens 40 is adjusted, a round and beautiful irradiation is realized on the irradiated object.

The lens holder 70 includes a first bottom surface portion 73 continuous with the first inner peripheral wall 71 and a second bottom surface portion 74 continuous with the second inner peripheral wall 72 and the first inner peripheral wall 71. The lens holder 70 is fixed to the ground on the inner peripheral wall 63 of the LED holder 60 and the diffusion sheet 30.
The lens holder 70, the inner sleeve 80, and the outer sleeve 90 are each formed of a metal material such as aluminum. For this reason, it is a material that achieves a heat radiation promoting effect such that the heat stored inside by the LED 11 is efficiently radiated to the outside.

The first condenser lens 20 is placed on the first bottom surface portion 73 of the lens holder 70. In this state, the inner sleeve 80 is fitted so that the inner sleeve outer wall 81 is in contact with the first inner peripheral wall 71 and the inner sleeve bottom surface portion 82 is in contact with the first condenser lens 20. Similarly, the second condenser lens 40 is placed on the second bottom surface portion 74. In this state, the outer sleeve 90 is fitted so that the outer sleeve outer wall 91 is in contact with the second inner peripheral wall 72 and the outer sleeve bottom surface portion 92 is in contact with the second condenser lens 40. That is, the second condenser lens 40 is placed on the first condenser lens 20 via the inner sleeve upper surface portion 83 of the inner sleeve 80.

(Condenser lens)
As shown in FIG. 2, the first condenser lens 20 is formed by integrally forming a continuous hemispherical first spherical surface 22 on a disk-shaped base end portion 21, and has a symmetric cross-sectional shape with respect to the optical axis O as a reference. It is formed to make. The radius of curvature of the first spherical surface 22 is 2.083 mm, the height is 2.9 mm, the diameter is φ8.6 mm, and the circumference is 27.02 mm.

The second condenser lens 40 is formed so that a continuous hemispherical second spherical surface 42 is integrally formed on a disc-shaped base end portion 41 and has a symmetric sectional shape with respect to the optical axis O as a reference. . The second spherical surface 42 is formed as a shape whose spherical angle is gentler than the spherical shape of the first spherical surface 22. More specifically, the radius of curvature is 3.125 mm, the height is 2.7 mm, the diameter is 10.9 mm, and the circumference is 34.24 mm.
Examples of the material of the first condenser lens 20 and the second condenser lens 40 include translucent resins such as acrylic and heat-resistant resins having translucency such as COP (cycloolefin polymer) and COC (cycloolefin copolymer). Etc. can be used.

(Diffusion sheet)
The diffusion sheet 30 is configured in a disk shape, and the material thereof can be, for example, polycarbonate, polyester, acrylic, glass, or the like.
The height of the diffusion sheet was about 0.25 mm, the diameter was 8.4 mm, and the circumference was 26.39 mm.
The diffusion sheet 30 in the present embodiment uses a sheet that diffuses and exits at about 60 ° when the incident light beam from the LED 11 is incident as parallel light.

(Position relationship)
Next, an example of the distance relationship when installing each of the LED 11, the diffusion sheet 30, the first condenser lens 20, and the second condenser lens 40 in the illumination device 10 will be described.
The distance from the LED 11 to the diffusion sheet 30 is 0.95 mm.
The distance from the upper surface of the diffusion sheet 30 to the bottom of the inner lens 20 is 0.68 mm.
The distance from the top of the inner lens 20 to the bottom of the outer lens 40 is 0.1 mm.

(effect)
According to the present embodiment, by forming the inner sleeve 80 and the outer sleeve 90 into a shape, a predetermined aperture is generated in the light distribution angle, and the spot of light irradiated to the irradiated object and its edge Becomes a very “clear” spot light. In addition, since the light distribution can be uniformly controlled by the diffusion sheet 30, color unevenness and illuminance unevenness are reduced.
Therefore, it is possible to simultaneously solve the problem of color unevenness that occurs when the light flux is diffused from each of the condenser lenses 20 and 40 and the problem of enlargement of equipment that occurs when the color unevenness problem is solved. Therefore, it is possible to meet the demand for downsizing even when a lighting device as a photographing auxiliary lamp such as a mobile phone or a digital camera is mounted.

In addition, each component size mentioned above and the installation distance between each component are an example to the last, and are not limited to the above.
Moreover, although LED11 in this embodiment has shown the example which employ | adopted 1W high power LED, it is not limited to this. For example, it may be 3 W, 5 W or more, and can be applied even when other wattage is used.

Since the present invention does not include ultraviolet rays, it is most suitable as illumination in an object that dislikes ultraviolet light (for example, exhibits in museums and art galleries) and hospitals. In addition, since there is very little color unevenness and illuminance unevenness, it is also suitable for beautifully illuminating artworks and products.
Moreover, since the boundary (edge) between the illumination surface and the non-illumination surface enables clear illumination, it is also suitable for a reading lamp in which scattered light is a problem.
In addition, since it is small and light, it is a technology that can also be used for auxiliary lighting for photographing such as a mobile phone with a camera and a digital camera.

It is a perspective view which shows an illuminating device. It is side surface sectional drawing which shows an illuminating device. It is a top view which shows an illuminating device. It is a disassembled perspective view which shows an illuminating device.

Explanation of symbols

10 Lighting device 11 LED
DESCRIPTION OF SYMBOLS 20 1st condensing lens 21 Base end part 22 1st spherical surface 30 Diffusion sheet 40 2nd condensing lens 41 Base end part 42 2nd spherical surface 50 Base board 51 Disk part 51a Upper surface 52 Rectangular part 52a Upper surface 54 Positioning part 60 LED holder 61 LED Holder Body 61b Outer Wall 62 Connection Member 62b Connection Hole 63 Inner Wall 63b First Step 63c Second Step 69 First Opening 70 Lens Holder 71 First Inner Wall 72 Second Inner Wall 73 First Bottom 74 Second bottom surface portion 77 Second opening portion 78 Third opening portion 79 Lens holder main body 80 Inner sleeve 81 Inner sleeve outer wall 82 Inner sleeve bottom surface portion 83 Inner sleeve upper surface portion 90 Outer sleeve 91 Outer sleeve outer wall 92 Outer sleeve bottom surface portion 93 Outer sleeve Top surface 100 Connector 110 Bolt

Claims (4)

An illumination device for condensing and irradiating a light beam emitted from an LED with two condenser lenses,
A base substrate to which a power supply member is fixed;
LEDs mounted on the base substrate,
A diffusion sheet disposed on the opposite side of the LED from the base substrate;
An aspherical first condenser lens disposed on the opposite side of the LED with respect to the diffusion sheet;
An LED illumination device comprising: an aspherical second condensing lens disposed on the opposite side of the first condensing lens from the diffusion sheet. The holder is located between the diffusion sheet and the first condenser lens, and includes a holder that separates the diffusion sheet and the first condenser lens by a predetermined distance.
The LED lighting device according to claim 1, wherein the inner wall surface of the holder is black. An imaging device including an LED illumination device,
The LED illumination device is an illumination device that irradiates a direction to be photographed by a camera constituting an imaging device,
A base substrate to which a power supply member is fixed;
LEDs mounted on the base substrate,
A diffusion sheet disposed on the opposite side of the LED from the base substrate;
An aspherical first condenser lens disposed on the opposite side of the LED with respect to the diffusion sheet;
An imaging apparatus comprising: an LED illumination device including an aspherical second condenser lens disposed on the opposite side of the first condenser lens from the diffusion sheet. An imaging apparatus comprising a holder that is positioned between a diffusion sheet and a first condenser lens and that separates the diffusion sheet and the first condenser lens from each other by a predetermined distance, and an inner wall surface of the holder is black.

Images