JP3975303B2 - Light emitting diode unit and its lighting method - Google Patents
Light emitting diode unit and its lighting method Download PDFInfo
- Publication number
- JP3975303B2 JP3975303B2 JP23911997A JP23911997A JP3975303B2 JP 3975303 B2 JP3975303 B2 JP 3975303B2 JP 23911997 A JP23911997 A JP 23911997A JP 23911997 A JP23911997 A JP 23911997A JP 3975303 B2 JP3975303 B2 JP 3975303B2
- Authority
- JP
- Japan
- Prior art keywords
- light emitting
- light
- emitting diode
- emitting diodes
- lighting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Non-Portable Lighting Devices Or Systems Thereof (AREA)
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Led Device Packages (AREA)
- Fastening Of Light Sources Or Lamp Holders (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は画像認識用ＣＣＤカメラ等の照明用光源に用いられる発光ダイオードユニット及びその点灯方式の改良に関する。
【０００２】
【従来の技術】
従来、画像認識用光源の照射方法として、複数の又は／及び複数色の発光ダイオードを集合させて電子部品などの被対象物に照射することが提案されており、特開平４−３６５１７８号公報に開示されている、図３に示すような照射方法がある。
図中３１はＣＣＤカメラ部、３２は被対象物、３３は多色搭載された発光ダイオードユニット、３４は被対象物用台である。
これは、単に被対象物の位置や姿勢を各色での反射率の違いを利用して被対象物に最適な発光色を選択して電子部品の位置補正をしようとういうものである。
【０００３】
また、被対象物の物体色を認識する場合、従来からある赤色、緑色、青色の各色のレンズ型（砲弾型）発光ダイオードを配列、集合させて白色のスポット光源を得ているが、実用上は色ムラが大きくて充分な識別が難しいという問題がある。
【０００４】
更に、物体色を色分解する際の手法として赤色、緑色、青色の単色で被対象物を照射する点灯方式が考えられているが、単色点灯をすることによって白色点灯時と異なり、より一層色ムラが大きくなり、色分解機能が低下してしまったり、被対象物における照度不足が生じることから画像認識する際に誤認識となり実用に供することができないという問題がある。
【０００５】
【発明が解決しようとする課題】
前記のように多色の発光ダイオードを多数個配列して被対象物に光を照射する装置として画像認識用光源が挙げられる。しかし、１つの光源（ユニット）の中に多色の発光ダイオードを配列すると色ムラが発生し、特に多色配列されたユニットにおいて、単色点灯する場合発光ダイオードの配列及び発光ダイオード単体の配光ムラによってより一層色ムラが大きいものとなり実用上の問題点がある。
【０００６】
また、従来のレンズ型発光ダイオードを多数個配列した場合、その製造方法に起因する個々の配光バラツキが大きいことから、全ての発光ダイオードを一点に集光させるような場合の光学的な光軸合わせを行うことが困難であり、かつ配光ムラが大きい等の問題がある。
【０００７】
更に、発光ダイオードを直流点灯による順次点灯する場合、被対象物の形状や物体色を認識するのに照度が不足して充分に明るく照射することができない。
一方、発光ダイオードへの入力電力を増加させることによって、照度をある程度改善することは可能であるが、発光素子が温度上昇することとなり照度改善にも限界が生じてしまう。
【０００８】
本発明者等は、多色の発光ダイオードを一つのユニットとして配列したような光源の色ムラ、特に単色点灯による色分解を行なう場合の色ムラを解決する手段を見出した。
本発明は、前記に鑑みなされたもので、発光ダイオードとして反射型発光ダイオードを用い、その配列を工夫することによって、多色の発光ダイオードを一つのユニットに配列したような白色の照射が可能な照明用光源を提供することを目的とし、又、単色発光させた場合の色ムラや照度不足もなく、かつ光軸合わせも容易な発光ダイオードユニット及びその点灯方式を提供することを目的とする。
【０００９】
【課題を解決するための手段】
本発明は、赤色、緑色、青色を発する複数の各色発光ダイオードからなり、各発光ダイオードは発光素子と対向して反射面が設けられ、かつ発光素子から発した光を反射面で反射した後に、該発光素子の背面側の放射面から外部に放射される反射型発光ダイオードよりなり、該発光ダイオードを集合して配列させ、各発光ダイオードからの放射光が少なくとも一点に収束させるように配列させることを特徴とする。
又、前記各赤色、緑色、青色発光ダイオードの集合体は、収束点において、収束点を中心軸として少なくとも軸対称的に配列されてなる。
更に、前記発光ダイオード集合体は、各色を順送りパルス点灯方式により単色放射を可能としてなり、また、前記発光ダイオード集合体は、点灯サイクルを１／４０〜１／１０のデューティ比で点灯し、かつ点灯時間を１０ｎｓ以上と設定することを特徴とする。
【００１０】
上記した構成の発光ダイオーユニットを採用することによって、特に、赤色、緑色、青色の特定された点灯条件下における順次発光による色分解時においても認識性が低下せずに優れた色識別可能な画像認識用光源となる。
【００１１】
【発明の実施の形態】
以下、本発明を図示の実施例に基づき説明する。
図１は本発明の一実施形態である発光ダイオードユニットの概略正面図、図２は該ユニットのＡ−Ａ矢視方向概略断面図である。
図１，２に示す発光ダイオードユニットは１５２個の発光ダイオード１と、保持具１０とを備えるものである。また、２１は被照射物であり、各発光ダイオードは順次点灯用電源に電気的に接続されている。
なお、本実施形態では複数の発光ダイオード１を環状に配列した光源を得る場合について説明する。
【００１２】
前記発光ダイオード１は発光素子と、リードと、光透過性材料と、凹面状反射面と、放射面とよりなる反射型の発光ダイオードよりなる。
前記凹面状反射面は光透過性材料の一方の面上にメッキや金属蒸着等により鏡面加工したものであり発光素子の発光面に対向する側に形成されている。又、凹面状反射面を発光素子の発光パターンにあわせた回転放物面に近い形状に形成し、その焦点に発光素子の発光面の中心を配置する。一方、放射面は発光素子の背面側に形成されている。
かかる反射型発光ダイオード１は、発光素子が発する光を凹面状反射面の中心軸に対して平行な光として効率よく取り出し、有効に利用することができる。
【００１３】
また、発光ダイオード１は、赤色発光ダイオード（Ｒ）２、緑色発光ダイオード（Ｇ）３、青色発光ダイオード（Ｂ）４の三原色よりなり、 図示するように規則的に配列されている。なお、各発光ダイオード２，３，４は、凹面状反射面の端部が中心軸に垂直な平面で左右対称に切断されており、凹面状反射面の切断面が隣り合うように各発光ダイオードを環状に配列する場合、各発光ダイオードの間隔を狭くすることができる。このように発光ダイオードを密に配列することにより、照射密度の向上を図ることができる。
【００１４】
このように構成された反射型の発光ダイオードユニットにおいて、保持具１０は各発光ダイオード２，３，４が光学的に一点に集光できるような放射面に合わせて発光ダイオードの取り付け穴１１が形成されている。
そして、該穴に各光ダイオードの放射面を嵌合し、各発光ダイオードが集光軸に対して対照的に配置されるように発光ダイオードの端部を接着剤にて固定する。
【００１５】
また、このように構成された各発光ダイオードのリード間を各色毎に点灯できるように電気的に独立させて配線して接続する。
そして、これら各色毎に配線された電線を種々デューティ比及び点灯時間を変化させてパルス順次点灯を行ったところ、色分解が可能で認識率が優れ、かつ寿命特性も低下しない、発光出力の安定した画像認識用光源が得られた。
【００１６】
本発明の一実施例として、反射型発光ダイオードを用いて複数の多色発光ダイオードを一体的に密着するように配列してユニットを構成し、その点灯方式として発光ダイオードの寿命特性を低下させないで、かつ被対象物への照度を高める条件としてデューティ比が１／４０〜１／１０の範囲内で点灯し、かつ点灯時間を１０ｎｓ以上とすることにより１パルス毎の発光強度が安定した発光特性が得られる。
【００１７】
なお、前記デューティ比が１／４０未満の場合、寿命特性を考慮すると、発光素子への通電電流を大幅に高められないことから被対象物への照度が低下すると共に画像情報量も低下して実用上問題が生じる。
また、デューティ比が１／１０を超えるとＣＣＤカメラの時定数とのマッチングが取れなくなり画像が乱れてしまい、実用上問題が発生する。
さらに、点灯時間が１０ｎｓ未満になると、発光素子自体の応答速度の面から照度が不安定となり、実用上問題が発生する。
【００１８】
なお、本発明は上記実施形態に限定されるものではなく、その要旨の範囲内において種々の変更が可能である。
上記実施形態では、凹面状反射面の端部を左右対称に切断し凹面状反射面の切断面が隣り合うように発光ダイオードを環状に配列した場合について説明したが、発光ダイオードを密に配列する必要がない場合は、凹面状反射面の端部を切断しなくてもよい。
【００１９】
【発明の効果】
以上説明したように、本発明は発光ダイオードとして反射型発光ダイオードを用い、その配列を工夫することにより、多色の発光ダイオードを一つのユニットに配列した白色の照明用光源が得られる。
又、単色発光させる場合もその色ムラや照度不足もなく、かつ光軸合わせも容易な発光ダイオードユニット及びその点灯方式が得られるとの利点がある。
【図面の簡単な説明】
【図１】本発明の一実施形態である発光ダイオードランプの概略正面図である。
【図２】同じく図１のＡ−Ａ矢視方向概略断面図である。
【図３】従来の画像認識用光源を示す説明図である。
【符号の説明】
１ 発光ダイオード
１０ 保持具[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light emitting diode unit used for an illumination light source such as an image recognition CCD camera and an improvement of a lighting system thereof.
[0002]
[Prior art]
Conventionally, as an irradiation method of a light source for image recognition, it has been proposed to irradiate a target object such as an electronic component by gathering a plurality of or / and a plurality of colors of light emitting diodes, as disclosed in JP-A-4-365178. There is a disclosed irradiation method as shown in FIG.
In the figure, 31 is a CCD camera unit, 32 is an object, 33 is a light emitting diode unit mounted in multiple colors, and 34 is a table for the object.
This is simply to correct the position of the electronic component by selecting the optimum emission color for the object by using the difference in reflectance between the colors of the position and orientation of the object.
[0003]
Also, when recognizing the object color of an object, a conventional spot-type (bullet-type) light emitting diode of each color of red, green, and blue is arranged and assembled to obtain a white spot light source. Has a problem that color unevenness is large and sufficient identification is difficult.
[0004]
Furthermore, as a method of separating the object color, a lighting method that irradiates the object with single colors of red, green, and blue is considered, but by turning on single color, it is different from white lighting and even more color There is a problem that unevenness increases, the color separation function deteriorates, and insufficient illuminance occurs on the object, so that the image is erroneously recognized and cannot be put into practical use.
[0005]
[Problems to be solved by the invention]
As described above, an image recognition light source is an example of an apparatus that irradiates a target object with a large number of multicolor light emitting diodes. However, when multi-color light emitting diodes are arranged in one light source (unit), color unevenness occurs. In particular, in a multi-color array unit, when the single color lighting is performed, the arrangement of light emitting diodes and uneven light distribution of the light emitting diodes alone As a result, the color unevenness is further increased and there is a practical problem.
[0006]
In addition, when a large number of conventional lens type light emitting diodes are arranged, there is a large variation in individual light distribution due to the manufacturing method, so the optical optical axis in the case of condensing all the light emitting diodes at one point. There are problems such as difficulty in matching and large light distribution unevenness.
[0007]
Further, when the light emitting diodes are sequentially turned on by direct current lighting, the illuminance is insufficient for recognizing the shape and object color of the object, and it is not possible to irradiate sufficiently brightly.
On the other hand, it is possible to improve the illuminance to some extent by increasing the input power to the light-emitting diode, but the temperature of the light-emitting element rises and the illuminance improvement is limited.
[0008]
The present inventors have found a means for solving the color unevenness of a light source in which multicolor light emitting diodes are arranged as one unit, particularly when performing color separation by single color lighting.
The present invention has been made in view of the above, and by using a reflection type light emitting diode as a light emitting diode and devising its arrangement, it is possible to irradiate white light as if multicolor light emitting diodes are arranged in one unit. An object of the present invention is to provide a light source for illumination, and to provide a light emitting diode unit and a lighting system thereof that are free from color unevenness and insufficient illuminance when monochromatic light is emitted, and easy to align the optical axis.
[0009]
[Means for Solving the Problems]
The present invention comprises a plurality of light emitting diodes that emit red, green, and blue, each light emitting diode is provided with a reflective surface facing the light emitting element, and after reflecting light emitted from the light emitting element on the reflective surface, It consists of a reflective light emitting diode radiated to the outside from the radiation surface on the back side of the light emitting element, the light emitting diodes are assembled and arranged, and the emitted light from each light emitting diode is arranged to converge at least at one point. It is characterized by.
In addition, the aggregate of the red, green, and blue light emitting diodes is arranged at the convergence point at least axisymmetrically with the convergence point as the central axis.
Furthermore, the light emitting diode assembly enables each color to emit a single color by a progressive pulse lighting system, and the light emitting diode assembly lights a lighting cycle with a duty ratio of 1/40 to 1/10, and The lighting time is set to 10 ns or more.
[0010]
By adopting the light emitting diode unit configured as described above, an excellent color distinguishable image without deterioration in recognizability even at the time of color separation by sequential light emission under specified lighting conditions of red, green and blue. A light source for recognition.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on illustrated embodiments.
FIG. 1 is a schematic front view of a light-emitting diode unit according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view in the direction of arrow AA of the unit.
The light emitting diode unit shown in FIGS. 1 and 2 includes 152 light emitting diodes 1 and a
In the present embodiment, a case where a light source in which a plurality of light emitting diodes 1 are arranged in an annular shape is obtained will be described.
[0012]
The light emitting diode 1 includes a reflective light emitting diode including a light emitting element, a lead, a light transmissive material, a concave reflecting surface, and a radiation surface.
The concave reflecting surface is mirror-finished by plating or metal vapor deposition on one surface of a light transmissive material, and is formed on the side facing the light emitting surface of the light emitting element. Further, the concave reflecting surface is formed in a shape close to a rotating paraboloid matched to the light emitting pattern of the light emitting element, and the center of the light emitting surface of the light emitting element is arranged at the focal point. On the other hand, the radiation surface is formed on the back side of the light emitting element.
Such a reflective light-emitting diode 1 can efficiently extract light emitted from the light-emitting element as light parallel to the central axis of the concave reflecting surface and use it effectively.
[0013]
The light emitting diodes 1 are composed of three primary colors of a red light emitting diode (R) 2, a green light emitting diode (G) 3, and a blue light emitting diode (B) 4, and are regularly arranged as shown. In addition, each light emitting diode 2, 3, 4 is cut | disconnected symmetrically by the plane perpendicular | vertical to a central axis at the edge part of a concave reflective surface, and each light emitting diode so that the cut surface of a concave reflective surface may adjoin. When the are arranged in a ring shape, the interval between the light emitting diodes can be reduced. Thus, by arranging the light emitting diodes densely, the irradiation density can be improved.
[0014]
In the reflection type light emitting diode unit configured as described above, the
And the radiation | emission surface of each photodiode is fitted to this hole, and the edge part of a light emitting diode is fixed with an adhesive agent so that each light emitting diode may be arrange | positioned with respect to a condensing axis | shaft.
[0015]
Further, the leads of the respective light emitting diodes configured as described above are electrically wired and connected so as to be lit for each color.
Then, when the electric wires wired for each color are subjected to pulse sequential lighting with various duty ratios and lighting times changed, the color separation is possible, the recognition rate is excellent, and the life characteristics are not deteriorated. A light source for image recognition was obtained.
[0016]
As one embodiment of the present invention, a reflection type light emitting diode is used to form a unit by arranging a plurality of multicolor light emitting diodes so as to be in close contact with each other. In addition, as a condition for increasing the illuminance to the object, the light emission characteristics are achieved such that the light is lit within the range of a duty ratio of 1/40 to 1/10 and the light emission intensity for each pulse is stabilized by setting the lighting time to 10 ns or more. Is obtained.
[0017]
When the duty ratio is less than 1/40, considering the life characteristics, the current applied to the light emitting element cannot be significantly increased, so the illuminance to the object is reduced and the amount of image information is also reduced. Problems arise in practice.
On the other hand, if the duty ratio exceeds 1/10, matching with the time constant of the CCD camera cannot be obtained, and the image is disturbed, causing a problem in practical use.
Furthermore, when the lighting time is less than 10 ns, the illuminance becomes unstable from the viewpoint of the response speed of the light emitting element itself, which causes a practical problem.
[0018]
In addition, this invention is not limited to the said embodiment, A various change is possible within the range of the summary.
In the above embodiment, the description has been given of the case where the light emitting diodes are arranged in an annular shape so that the ends of the concave reflecting surfaces are cut symmetrically and the cut surfaces of the concave reflecting surfaces are adjacent to each other. If not necessary, the end of the concave reflecting surface may not be cut.
[0019]
【The invention's effect】
As described above, the present invention uses a reflection type light emitting diode as a light emitting diode, and by devising its arrangement, a white illumination light source in which multicolor light emitting diodes are arranged in one unit can be obtained.
Further, even when monochromatic light is emitted, there is an advantage that a light-emitting diode unit and its lighting system can be obtained which are free of color unevenness and lack of illuminance and easy to align the optical axis.
[Brief description of the drawings]
FIG. 1 is a schematic front view of a light-emitting diode lamp according to an embodiment of the present invention.
2 is a schematic cross-sectional view taken along the line AA in FIG.
FIG. 3 is an explanatory view showing a conventional light source for image recognition.
[Explanation of symbols]
1
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23911997A JP3975303B2 (en) | 1997-08-21 | 1997-08-21 | Light emitting diode unit and its lighting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23911997A JP3975303B2 (en) | 1997-08-21 | 1997-08-21 | Light emitting diode unit and its lighting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1166918A JPH1166918A (en) | 1999-03-09 |
| JP3975303B2 true JP3975303B2 (en) | 2007-09-12 |
Family
ID=17040082
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23911997A Expired - Fee Related JP3975303B2 (en) | 1997-08-21 | 1997-08-21 | Light emitting diode unit and its lighting method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3975303B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6200002B1 (en) * | 1999-03-26 | 2001-03-13 | Philips Electronics North America Corp. | Luminaire having a reflector for mixing light from a multi-color array of leds |
| JP5254754B2 (en) * | 2008-11-14 | 2013-08-07 | シャープ株式会社 | Light emitting device |
-
1997
- 1997-08-21 JP JP23911997A patent/JP3975303B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1166918A (en) | 1999-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6234646B1 (en) | Vehicular signal lamp having a plurality of light-emitting diodes | |
| EP1024398B1 (en) | Solid state based illumination source for a projection display | |
| US6918693B2 (en) | Light source device for endoscope and assembly method for light source unit | |
| JP5260687B2 (en) | Lighting fixture with reflector | |
| US7347586B2 (en) | LED light bulb | |
| JP5081307B2 (en) | Optical unit positioning device | |
| US7995882B2 (en) | Lighting device comprising a plurality of semiconductor light sources | |
| US7777405B2 (en) | White LED headlight | |
| US8403530B2 (en) | LED spotlight including elliptical and parabolic reflectors | |
| KR101212911B1 (en) | Lighting module and luminaire | |
| JP5650962B2 (en) | Surgical light | |
| EP1503139A2 (en) | LED light source assembly | |
| US20070187710A1 (en) | Led light source | |
| JP2007265964A (en) | Lighting system | |
| JPH06349306A (en) | Lighting fixture of led light source | |
| TW201218436A (en) | LED package device | |
| JP3975303B2 (en) | Light emitting diode unit and its lighting method | |
| JP5225799B2 (en) | Lighting device | |
| WO2009037645A2 (en) | Led package | |
| JPS62108584A (en) | Light-emitting diode lighting appliance | |
| JPS6320132Y2 (en) | ||
| JPH048562Y2 (en) | ||
| JP2007318176A (en) | Light-emitting diode | |
| JP3997124B2 (en) | Illumination device for image reading apparatus | |
| JP2962495B2 (en) | Illumination device for bar code reader |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20040730 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20070523 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070605 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100629 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110629 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110629 Year of fee payment: 4 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110629 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120629 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120629 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130629 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140629 Year of fee payment: 7 |
|
| LAPS | Cancellation because of no payment of annual fees |