JP3961638B2 - Lighting method and apparatus for electronic component recognition - Google Patents

Description

・記憶手段１２ｂであらかじめ記憶されるコードｂに準じた関係関数

・記憶手段１２ｎであらかじめ記憶されるコードｎに準じた関係関数
Ｌｎ／（Ｌａ＋Ｌｂ＋…＋Ｌｎ）＝１／｛１＋（Ｌａ＋Ｌｂ＋…＋（Ｌｎ−１））／Ｌｎ｝＝１／（１＋Ｍｎ）
となる。
【００２６】
したがって、各記憶手段１２ａであらかじめ記憶されるコードに準じた関係関数は、１／（１＋Ｍ） （Ｍは変数）
と表すことができる。（コードとは：例えば、２進数で構成される数値列を示す）。
【００２７】
なお、調光データＤａｔａａ，Ｄａｔａｂ…Ｄａｔａｎにより、各記憶手段１２ａ，１２ｂ…１２ｎであらかじめ記憶されるコードに準じた関係関数が算出されることになる。
【００２８】
ここでいう調光データＤａｔａａ，Ｄａｔａｂ…Ｄａｔａｎとは、デジタル／アナログコンバータ６ａ，６ｂ…６ｎの各出力電圧に対する各々の量子化した値であって、この各出力電圧によって明るさを制御できる。
【００２９】
例えば、５Ｖを２⁸ ＝２５６で量子化すると、２⁰ ＝１あたりの電圧の重み付け１９．５ｍＶとなり、逆に２⁵ ＝３２のコードで表される電圧は、６２５ｍＶになって、０〜２５５まで任意の値をデータとして与えると、その数値に１９．５ｍＶを乗じた電圧がデジタル／アナログコンバータ６ａ，６ｂ…６ｎから出力される。
【００３０】
また、調光データによって指定される光源１ａ，１ｂ…１ｎの明るさは、調光データと比例関係にあり、この比例関係が、時系列的に変化変動がないときのデジタル／アナログコンバータ６ａ，６ｂ…６ｎの出力電圧を基準値とする。
【００３１】
一方、検出手段２に入る光は各個別の光源１ａ，１ｂ…１ｎの和であるから、これを電圧に変換すると基準値より高くなってしまう。
【００３２】
この電圧の何割かがある光源の明るさであるため、この割合を各乗算型デジタル／アナログコンバータ１３ａ，１３ｂ…１３ｎで乗じて、それぞれの光源１ａ，１ｂ…１ｎに合わせた基準値に戻す。
【００３３】
ここまでは、あくまでもそれぞれの光源１ａ，１ｂ…１ｎが基準値に基づく明るさとしているため、その明るさに対する各光源１ａ，１ｂ…１ｎの割合は調光データによって一義的に決まることとなり、この割合は、各乗算型デジタル／アナログコンバータ１３ａ，１３ｂ…１３ｎの入力コードによって決定される。
【００３４】
したがって、入力コードと調光データも一義的に決まるため、この関係を記憶手段１２ａ，１２ｂ…１２ｎへ保存しておけば、各光源１ａ，１ｂ…１ｎの調光データが決まることで、各々の光源１ａ，１ｂ…１ｎの基準値，入力コードも一義的に決定され各部へ出力されることとなる。
【００３５】
前記した比較手段４は、関係関数置換手段３によって求められた個々の光源１ａ，１ｂ…１ｎの明るさの算出値と、前記基準値とを比較するもので、二つの入力信号の差に比例した出力を出す演算増幅器等の差動増幅器１４ａ，１４ｂ…１４ｎが用いられる。
【００３６】
前記した照明光量調整演算手段５は、比較手段４の比較によって得られた比較差分値を演算して、照明光量のフィードバック値としてデジタル／アナログコンバータ６ａ，６ｂ…６ｎの電圧に加算するもので、例えば、加算増幅器１５ａ，１５ｂ…１５ｎを用いる。
【００３７】
前記のように構成される本発明実施例の電子部品認識用照明方法およびその装置Ａは、以下に示す作用を奏するもので、図５に示すフローチャートにしたがって説明する。
【００３８】
まず、各光源１ａ，１ｂ…１ｎの明るさの基準値Ｌａ，Ｌｂ…Ｌｎ、および、前記した関係関数１／（１＋Ｍａ），１／（１＋Ｍｂ）…１／（１＋Ｍｎ）を、それぞれ該当する記憶手段１２ａ，１２ｂ…１２ｎへ設定しておく。
【００３９】
そして、各光源１ａ，１ｂ…１ｎの調光データであるＤａｔａａ，Ｄａｔａｂ…Ｄａｔａｎを、各デジタル／アナログコンバータ６ａ，６ｂ…６ｎへ印加すると、これら各デジタル／アナログコンバータ６ａ，６ｂ…６ｎにより電圧が発生する。
【００４０】
これら電圧を、各光源１ａ，１ｂ…１ｎごとに設けた三角波発生回路７ａ，７ｂ…７ｎと各光源１ａ，１ｂ…１ｎごとに設けたコンパレータ（比較器）８ａ，８ｂ…８ｎとによりパルス波に変換する。
【００４１】
これらパルス波は、各光源１ａ，１ｂ…１ｎごとに設けたドライブ回路９ａ，９ｂ…９ｎへ伝えて、当該パルス波形にならった電流を、各光源１ａ，１ｂ…１ｎから引き込み発光させる。
【００４２】
各光源１ａ，１ｂ…１ｎが発光する総光量を、単一からなるフォトダイオード等の検出手段２によって検出し、増幅回路１１により所定電圧となるように増幅させる。
【００４３】
この増幅された電圧は、各光源１ａ，１ｂ…１ｎに対応する関係関数置換手段３である各乗算型デジタル／アナログコンバータ１３ａ，１３ｂ…１３ｎのリファレンス電圧に印加される。
【００４４】
一方、各乗算型デジタル／アナログコンバータ１３ａ，１３ｂ…１３ｎに関係する各記憶手段１２ａ，１２ｂ…１２ｎへ関係関数１／（１＋Ｍａ），１／（１＋Ｍｂ）…１／（１＋Ｍｎ）を記憶させてあるので、各記憶手段１２ａ，１２ｂ…１２ｎの出力を各乗算型デジタル／アナログコンバータ１３ａ，１３ｂ…１３ｎに印加させる。
【００４５】
すると、各乗算型デジタル／アナログコンバータ１３ａ，１３ｂ…１３ｎにおいて、関係関数１／（１＋Ｍａ），１／（１＋Ｍｂ）…１／（１＋Ｍｎ）を前記リファレンス電圧に乗ずることで、各光源１ａ，１ｂ…１ｎの明るさが算出される。
【００４６】
そして、光源１ａ，１ｂ…１ｎの明るさの基準値Ｌａ，Ｌｂ…Ｌｎと、前記において算出された算出値を比較手段４における差動増幅器１４ａ，１４ｂ…１４ｎにより比較して、両者において差を生じたそれぞれの差分値をフィードバック値として、各デジタル／アナログコンバータ６ａ，６ｂ…６ｎの電圧に照明光量調整手段５である加算増幅器１５ａ，１５ｂ…１５ｎを介して加算する。
【００４７】
更に詳述すれば、前記した光源１ａ，１ｂ…１ｎの明るさの基準値Ｌａ，Ｌｂ…Ｌｎとして、単一の検出手段２において検出される光量Ｇは、
Ｇ＝Ｌａ’＋Ｌｂ’＋…＋Ｌｎ’＝Ｋ（Ｌａ＋Ｌｂ＋…＋Ｌｎ）
＝ＫＬａ（Ｌａ＋Ｌｂ＋…＋Ｌｎ／Ｌａ） …（１）
と求めることができる。
【００４８】
次に、関係関数置換手段３である乗算型デジタル／アナログコンバータ１３ａと記憶手段１２ａにおいて、該記憶手段１２ａに対して、デジタル／アナログコンバータ６ｂ…６ｎの調光データＤａｔａｂ…Ｄａｔａｎにしたがって、あらかじめ記憶されたコードａを出力する。
【００４９】
このコードａは乗算型デジタル／アナログコンバータ１３ａに印加され、該乗算型デジタル／アナログコンバータ１３ａがこのコードａに準じた関係関数
Ｌａ／（Ｌａ＋Ｌｂ＋…＋Ｌｎ）を前記した式（１）に乗ずることにより、単一の検出手段２において検出される光量Ｇにうち、光源１ａ分の検出光量Ｇａが以下のように算出されることになる。
【００５０】
Ｇａ＝ＫＬａ（Ｌａ＋Ｌｂ＋…＋Ｌｎ／Ｌａ）×｛Ｌａ／（Ｌａ＋Ｌｂ＋…＋Ｌｎ）｝
＝ＫＬａ
＝Ｌａ’ …（２）
となる。
【００５１】
したがって、次段の比較手段４である差動増幅器１４ａにより、比較差分値として、Ｌａ−Ｌａ’を検出し、照明光量調整手段５である加算増幅器１５ａにより、該比較差分値（Ｌａ−Ｌａ’）分がフィードバック値としてデジタル／アナログコンバータ６ａの電圧に加算される。
【００５２】
このようにして、このフィードバック経路により、他の光源１ｂ…１ｎの影響を除去し、該光源１ａの光量のバラツキを抑えて安定した光量を得ることができる。
【００５３】
以下、他の光源１ｂ…１ｎに対して、同様に、
単一の検出手段２において検出される光量Ｇにうち、

と算出できることとなる。
【００５４】
これによって、各差動増幅器１４ｂ…１４ｎにより比較差分値として、
（Ｌｂ−Ｌｂ’）…（Ｌｎ−Ｌｎ’）
と検出され、それぞれの加算増幅器１５ｂ…１５ｎにより、上記の比較差分値｛（Ｌｂ−Ｌｂ’）…（Ｌｎ−Ｌｎ’）｝分がフィードバック値としてデジタル／アナログコンバータ６ｂ…６ｎの各電圧にそれぞれ加算されることになる。
【００５５】
したがって、Ｄａｔａａ，Ｄａｔａｂ…Ｄａｔａｎによる光源１ａ，１ｂ…１ｎの光量を一つの検出手段２によって安定化させることができる。
【００５６】
また、本発明に係る実施例は、電子部品ｂの種類に応じて、各光源１ａ，１ｂ…１ｎの基準値Ｌａ，Ｌｂ…Ｌｎに基づいた各コード（例：２進数）を各光源１ａ，１ｂ…１ｎに対応した調光データとしてあらかじめ、Ｄａｔａａ，Ｄａｔａｂ…Ｄａｔａｎと設定することにより、関係関数置換手段３の各記憶手段１２ａ，１２ｂ…１２ｎに記憶されているコードに準じた関係関数を自動的に変えることができるので、電子部品ｂに照射する光量が安定し、画像処理の安定化を図ることができる。
【００５７】
【発明の効果】
前述したように本発明の電子部品認識用照明方法は、照明手段の複数の光源から照射されるそれぞれの光量に対して、単一からなる検出手段によって検出することができるので、設置される検出手段の数を減らすことができて大幅なコスト低減となると共に、検出手段の設置スペースを取ることなく該スペースの有効利用となる。
【００５８】
複数の光源からなる照明手段において、それぞれの光源の光の干渉があっても各光源の明るさを安定化させることができ、それにより、撮像手段により撮像された画像の処理が安定化する。
【００５９】
画像の明るさを精度よく調整することができ、外部光が相違する場合（他の光源の影響）や、照明が経年変化した場合などにも検出する画像の明るさを適正に保つことができる。
等の格別な効果を奏するものである。
【図面の簡単な説明】
【図１】本発明に関する電子部品認識用照明方法を採用した電子部品認識用照明装置の一実施例の概略を示す正面図である。
【図２】図１の装置における方法の回路図である。
【図３】図２において関係関数置換手段を拡大して示す回路図である。
【図４】図２において検出手段を拡大して示す回路図である。
【図５】本発明実施例方法を示すフローチャート図である。
【符号の説明】
ｂ 電子部品
ｃ 保持手段
１ 照明手段
１ａ，１ｂ…１ｎ 光源
２ 検出手段
３ 関係関数置換手段
４ 比較手段
５ 照明光量調整演算手段
１０ 撮像手段
１２ａ，１２ｂ…１２ｎ 記憶手段[0001]
[Industrial application fields]
The present invention relates to an illumination method for recognizing an electronic component used in an industry for assembling or mounting an electronic component, and an apparatus therefor.
[0002]
[Prior art]
As a pre-process for mounting electronic components on a printed circuit board, the holding state of the electronic components sucked by the suction nozzle in advance and the recognition of the electronic components themselves are detected by a camera sensor. If any inconvenience occurs, correction is made so that accurate component mounting can be performed through a predetermined correction means.
[0003]
At the time of imaging by this camera sensor, the electronic component surface is always illuminated by illumination means having a constant light quantity so as to obtain a predetermined imaging accuracy.
[0004]
This illumination means is generally irradiated using a plurality of light sources so that a uniform illumination result can be obtained on the electronic component surface.
[0005]
However, each light source gradually deteriorates over time and attenuates the amount of light.Therefore, the amount of attenuation of each light amount also varies, so that the above-mentioned constant light amount value is sequentially corrected to obtain the above-mentioned constant light amount. There must be.
[0006]
Conventionally, in this light quantity correction, a dedicated light receiving sensor for detecting the brightness of each light source is provided for each of the plurality of light sources, so that the number of light receiving sensors corresponding to the number of light sources is required. .
[0007]
Therefore, each light receiving sensor not only detects light from a predetermined light source, but also detects light from other light sources, and further, so-called disturbance light that interferes with each light source. As a result, the measured value becomes unstable, and it becomes difficult to stabilize the constant light quantity of the light source.
[0008]
In addition, a plurality of light receiving sensors increases the cost, and an extra installation place is required, which increases the size of the apparatus.
Etc. have various problems.
[0009]
[Problems to be solved by the invention]
The present invention has been made to solve the above-described problems. Light emitted from illumination means having a plurality of light sources is detected by a single detection means, and brightness of each predetermined light source is determined. Based on the reference value, the brightness value of each light source is calculated by multiplying by a relational function, the calculated value is compared with the reference value, and the comparison difference value is added as a feedback value of the illumination light amount. An object of the present invention is to provide an illumination method for recognizing an electronic component which can always adjust the brightness of the image of the component with high accuracy and can keep the brightness of the image of the electronic component constant.
[0010]
[Means for Solving the Problems]
The means of the present invention for achieving the above-mentioned object is as follows:
In the illumination of the electronic component surface for imaging the electronic component held by the holding unit and detecting the electronic component by the imaging unit, the illumination unit for illuminating the electronic component surface has a plurality of light sources, In an illumination method for recognizing an electronic component that illuminates the surface of the electronic component so as to obtain a certain brightness combined by a light source,
The ratio value of the brightness of each light source based on the reference value of the brightness of each individual light source is stored in the storage means in advance,
Illumination light from the illumination means to the electronic component surface is detected by a single detection means, and the brightness of each light source is calculated from the detected value using the relation function by the storage means. The calculated value of the brightness of the light source is compared with the reference value, and the comparison difference value obtained by this comparison is subjected to calculation correction for each light source as a feedback value of the illumination light quantity, and the image of the electronic component There is an illumination method for recognizing electronic components that keeps the brightness of the lamp constant.
[0011]
Then, an illuminating means comprising a plurality of light sources for illuminating the electronic component held by the holding means, a single detecting means for detecting the brightness of the image of the electronic component imaged by the imaging means, and the brightness of the image A relational function replacing means for calculating the brightness of each light source having a storage means for storing a ratio value of the brightness of each light source based on a predetermined reference value of the brightness of each light source; Comparing means for comparing the calculated value of the brightness of each light source obtained by the relation function replacing means and the reference value, and the illumination light quantity for calculating the comparison difference value obtained by this comparison as a feedback value of the illumination light quantity Adjustment calculation means;
It is in the structure of the illuminating device for electronic component recognition provided with.
[0012]
【Example】
Next, an example of an embodiment of the illumination method for recognizing electronic parts and the apparatus thereof according to the present invention will be described with reference to the drawings.
[0013]
In FIG. 1, A is an illumination device for recognizing electronic components, and holding means such as suction nozzles before mounting electronic components b such as chip components and IC components on a printed circuit board of an electronic component mounting machine (not shown). When detecting the holding state of the electronic component b attracted to c, the electronic component b is illuminated. The illumination unit 1, the detection unit 2, the relational function replacing unit 3, the comparison unit 4, and the illumination unit It is basically configured by the light amount adjustment calculation means 5.
[0014]
The holding means c such as a suction nozzle is attached to a mounting head that is arbitrarily controlled to move in the X and Y axis directions by an XY unit (not shown), and can be attached to and detached from the mounting head. Hold freely.
[0015]
The illumination unit 1 includes a plurality of light sources 1a, 1b,... 1n that illuminate the surface of the electronic component b held by the holding unit c.
[0016]
The configuration is applied to digital / analog converters (DACs) 6a, 6b,... 6n provided for the respective light sources 1a, 1b... 1n, and voltages generated by the digital / analog converters 6a, 6b. , 1b... 1n are converted into pulse waves by triangular wave generation circuits 7a, 7b... 7n and comparators (comparators) 8a, 8b. ... Are transmitted to drive circuits 9a, 9b... 9n provided for each 1n, and these drive circuits 9a, 9b... 9n draw light from the light sources 1a, 1b.
[0017]
Each of the light sources 1a, 1b,..., 1n has a different light emission amount due to a change in voltage value by the digital / analog converters 6a, 6b,. By arranging a plurality of sets different from each other, the illumination on the surface of the electronic component b is best, and the image of the imaging means 10 can be obtained satisfactorily.
[0018]
Each of the light sources 1a, 1b,..., 1n is composed of, for example, three sets of an illumination group (1), an illumination group (2), and an illumination group (3). Yes.
[0019]
The detecting means 2 described above is a single unit for each of the light sources 1a, 1b... 1n, and detects the brightness of the image of the electronic component b picked up by the image pickup means 10 such as a CCD camera sensor.
[0020]
That is, the light emitted from each of the light sources 1a, 1b,..., 1n is captured by the photodiode 2 serving as detection means, and the detected weak voltage is amplified by the amplifier circuit 11 so as to become a predetermined voltage. In the circuit shown in FIG. 4, when light hits the detection means 2, a current I flows in proportion to the amount of light (brightness), and a corresponding voltage is generated.
[0021]
The relational function replacing means 3 described above is based on the brightness of the image detected by the detecting means 2 and a predetermined reference value of the brightness of the individual light sources 1a, 1b... 1n. ... through the storage means 12a, 12b ... 12n provided for each light source 1a, 1b ... 1n in which the brightness ratio value of 1n is stored, the brightness of each light source 1a, 1b ... 1n is calculated, The outputs of the storage means 12a, 12b,... 12n are applied to multiplication type digital / analog converters (DACs) 13a, 13b,.
[0022]
The applied voltage to the digital / analog converters 6a, 6b,... 6n is set so that the brightness ratio values of the light sources 1a, 1b,. Have a predetermined functional relationship, and this relationship function is also set in advance for the pulse wave applied to each of the light sources 1a, 1b,.
[0023]
Therefore, the ratio value is set for each of the multiplying digital / analog converters 13a, 13b,.
[0024]
This relational function is obtained by the following equation, for example. (See Fig. 2 and Fig. 3)
First,
The reference value of the brightness of the light source 1a in the illumination means 1 is La
The reference value of the brightness of the light source 1b in the illumination means 1 is Lb
・
・
The reference value of the brightness of the light source 1n in the illumination means 1 is Ln
And
[0025]
-Relational functions according to code a stored in advance in the storage means 12a

A relational function according to the code b stored in advance in the storage means 12b

Relational function Ln / (La + Lb +... + Ln) = 1 / {1+ (La + Lb +... + (Ln-1)) / Ln} = 1 / (1 + Mn) according to the code n stored in advance in the storage means 12n
It becomes.
[0026]
Therefore, the relational function according to the code stored in advance in each storage means 12a is 1 / (1 + M) (M is a variable).
It can be expressed as. (A code is a numeric string composed of binary numbers, for example).
[0027]
It should be noted that a relational function according to a code stored in advance in each storage means 12a, 12b,..., 12n is calculated from the dimming data Dataa, Datab,.
[0028]
The dimming data Dataa, Data... Data here is a quantized value for each output voltage of the digital / analog converters 6a, 6b... 6n, and the brightness can be controlled by each output voltage.
[0029]
For example, when 5V is quantized with 2 ⁸ = 256, the voltage weighting per 2 ⁰ = 1 becomes 19.5 mV, and conversely, the voltage represented by the code of 2 ⁵ = 32 becomes 625 mV, and becomes 0-255. If an arbitrary value is given as data, a voltage obtained by multiplying that value by 19.5 mV is output from the digital / analog converters 6a, 6b,.
[0030]
In addition, the brightness of the light sources 1a, 1b... 1n specified by the dimming data is proportional to the dimming data, and this proportional relationship is digital / analog converter 6a when there is no change variation in time series. The output voltage 6b... 6n is set as a reference value.
[0031]
On the other hand, since the light entering the detection means 2 is the sum of the individual light sources 1a, 1b... 1n, if this is converted into a voltage, it becomes higher than the reference value.
[0032]
Since the brightness of the light source has a percentage of this voltage, this ratio is multiplied by each of the multiplying digital / analog converters 13a, 13b,... 13n to return the reference value to the light source 1a, 1b,.
[0033]
Up to this point, since the light sources 1a, 1b,... 1n have brightness based on the reference value, the ratio of the light sources 1a, 1b, .. 1n to the brightness is uniquely determined by the dimming data. The ratio is determined by the input code of each multiplying digital / analog converter 13a, 13b... 13n.
[0034]
Therefore, since the input code and the dimming data are also uniquely determined, if this relationship is stored in the storage means 12a, 12b... 12n, the dimming data for each light source 1a, 1b. The reference values and input codes of the light sources 1a, 1b... 1n are also uniquely determined and output to each unit.
[0035]
The comparison means 4 compares the calculated brightness values of the individual light sources 1a, 1b... 1n obtained by the relation function replacement means 3 with the reference value, and is proportional to the difference between the two input signals. Differential amplifiers 14a, 14b,... 14n such as operational amplifiers that output the output are used.
[0036]
The illumination light quantity adjustment calculation means 5 calculates the comparison difference value obtained by the comparison of the comparison means 4, and adds it to the voltages of the digital / analog converters 6a, 6b,. For example, summing amplifiers 15a, 15b... 15n are used.
[0037]
The electronic component recognition illumination method and apparatus A according to the embodiment of the present invention configured as described above have the following operations, and will be described with reference to the flowchart shown in FIG.
[0038]
First, the brightness reference values La, Lb,... Ln of the light sources 1a, 1b,..., 1n and the relational functions 1 / (1 + Ma), 1 / (1 + Mb),. Means 12a, 12b... 12n are set.
[0039]
Then, when Dataa, Dataab,... Datan, which is dimming data of each light source 1a, 1b,... 1n, is applied to each of the digital / analog converters 6a, 6b,. appear.
[0040]
These voltages are converted into pulse waves by triangular wave generation circuits 7a, 7b... 7n provided for each light source 1a, 1b... 1n and comparators (comparators) 8a, 8b. Convert.
[0041]
These pulse waves are transmitted to the drive circuits 9a, 9b,... 9n provided for the respective light sources 1a, 1b,..., 1n, and currents that follow the pulse waveforms are drawn from the light sources 1a, 1b,.
[0042]
The total amount of light emitted from each of the light sources 1a, 1b,..., 1n is detected by the detection means 2 such as a single photodiode, and is amplified by the amplifier circuit 11 to a predetermined voltage.
[0043]
This amplified voltage is applied to the reference voltage of each of the multiplying digital / analog converters 13a, 13b... 13n, which is the relational function replacement means 3 corresponding to each light source 1a, 1b.
[0044]
On the other hand, the relational functions 1 / (1 + Ma), 1 / (1 + Mb)... 1 / (1 + Mn) are stored in the storage means 12a, 12b... 12n related to the multiplication type digital / analog converters 13a, 13b. Therefore, the outputs of the storage means 12a, 12b,... 12n are applied to the multiplying digital / analog converters 13a, 13b,.
[0045]
Then, in each of the multiplying digital / analog converters 13a, 13b,... 13n, the relational functions 1 / (1 + Ma), 1 / (1 + Mb), ..1 / (1 + Mn) are multiplied by the reference voltage, whereby the light sources 1a, 1b,. The brightness of 1n is calculated.
[0046]
Then, the brightness reference values La, Lb... Ln of the light sources 1a, 1b... 1n and the calculated values calculated in the above are compared by the differential amplifiers 14a, 14b. The resulting difference values are added as feedback values to the voltages of the respective digital / analog converters 6a, 6b,... 6n via summing amplifiers 15a, 15b,.
[0047]
More specifically, the light quantity G detected by the single detection means 2 as the reference values La, Lb... Ln of the brightness of the light sources 1a, 1b.
G = La ′ + Lb ′ +... + Ln ′ = K (La + Lb +... + Ln)
= KLa (La + Lb + ... + Ln / La) (1)
It can be asked.
[0048]
Next, in the multiplication type digital / analog converter 13a and the storage means 12a which are the relational function replacing means 3, the storage means 12a is stored in advance according to the dimming data Datab ... Datan of the digital / analog converters 6b ... 6n. The generated code a is output.
[0049]
The code a is applied to the multiplying digital / analog converter 13a, and the multiplying digital / analog converter 13a multiplies the relational function La / (La + Lb +... + Ln) according to the code a by the above-described equation (1). Of the light amount G detected by the single detection means 2, the detected light amount Ga for the light source 1a is calculated as follows.
[0050]
Ga = KLa (La + Lb +... + Ln / La) × {La / (La + Lb +... + Ln)}
= KLa
= La '(2)
It becomes.
[0051]
Therefore, La-La ′ is detected as a comparison difference value by the differential amplifier 14a which is the comparison means 4 at the next stage, and the comparison difference value (La−La ′) is detected by the addition amplifier 15a which is the illumination light quantity adjustment means 5. ) Is added to the voltage of the digital / analog converter 6a as a feedback value.
[0052]
In this way, by this feedback path, the influence of the other light sources 1b... 1n can be removed, and variations in the light amount of the light source 1a can be suppressed to obtain a stable light amount.
[0053]
Hereinafter, for the other light sources 1b.
Of the light quantity G detected by the single detection means 2,

It can be calculated as follows.
[0054]
As a result, each differential amplifier 14b.
(Lb−Lb ′) (Ln−Ln ′)
Each of the summing amplifiers 15b... 15n detects the comparison difference value {(Lb−Lb ′)... (Ln−Ln ′)} as a feedback value to each voltage of the digital / analog converters 6b. Will be added.
[0055]
Therefore, the light quantity of the light sources 1a, 1b... 1n by Data, Data.
[0056]
Further, according to the embodiment of the present invention, according to the type of the electronic component b, the codes (eg, binary numbers) based on the reference values La, Lb,... Ln of the light sources 1a, 1b,. As the dimming data corresponding to 1b... 1n is set in advance as Dataa, Dataab... Datan, the relational function according to the code stored in each storage means 12a, 12b. Therefore, the amount of light applied to the electronic component b is stabilized, and the image processing can be stabilized.
[0057]
【The invention's effect】
As described above, the illumination method for recognizing an electronic component according to the present invention can detect each light quantity emitted from a plurality of light sources of the illumination unit by a single detection unit, and thus can be installed. The number of means can be reduced, resulting in a significant cost reduction and effective use of the space without taking up a space for installing the detection means.
[0058]
In the illumination means composed of a plurality of light sources, the brightness of each light source can be stabilized even if there is interference of light from each light source, thereby stabilizing the processing of the image captured by the image capture means.
[0059]
The brightness of the image can be adjusted accurately, and the brightness of the detected image can be kept appropriate even when the external light is different (influence of other light sources) or when the illumination changes over time. .
It has a special effect such as.
[Brief description of the drawings]
FIG. 1 is a front view showing an outline of an embodiment of an illumination device for recognizing electronic components that employs an illumination method for recognizing electronic components according to the present invention.
FIG. 2 is a circuit diagram of the method in the apparatus of FIG.
FIG. 3 is an enlarged circuit diagram showing a relational function replacing unit in FIG. 2;
4 is an enlarged circuit diagram showing a detection means in FIG. 2. FIG.
FIG. 5 is a flowchart showing a method according to an embodiment of the present invention.
[Explanation of symbols]
b Electronic component c Holding means 1 Illuminating means 1a, 1b... 1n Light source 2 Detection means 3 Relational function replacing means 4 Comparison means 5 Illumination light quantity adjustment calculating means 10 Imaging means 12a, 12b.

Claims (2)

In the illumination of the electronic component surface for imaging the electronic component held by the holding unit and detecting the electronic component by the imaging unit, the illumination unit for illuminating the electronic component surface has a plurality of light sources, In an illumination method for recognizing an electronic component that illuminates an electronic component surface so as to obtain a certain brightness combined by a light source,
The ratio value of the brightness of each light source based on the brightness reference value of each individual light source is stored in the storage means in advance,
Illumination light from the illumination means to the electronic component surface is detected by a single detection means, and the brightness of each light source is calculated from the detected value using the relation function by the storage means. The calculated value of the brightness of the light source is compared with the reference value, and the comparison difference value obtained by this comparison is subjected to calculation correction for each light source as a feedback value of the illumination light quantity, and the image of the electronic component An illumination method for recognizing electronic components, characterized by maintaining the brightness of the electronic component constant. Illumination means comprising a plurality of light sources for illuminating the electronic component held by the holding means, single detection means for detecting the brightness of the image of the electronic component imaged by the imaging means, brightness of the image, and Relational function replacing means for calculating the brightness of each light source having storage means for storing the ratio value of the brightness of each light source based on the determined reference value of the brightness of each light source, and the relation Comparison means for comparing the calculated value of the brightness of each light source obtained by the function replacement means with the reference value, and an illumination light amount adjustment calculation for calculating the comparison difference value obtained by this comparison as a feedback value of the illumination light amount And a lighting device for recognizing electronic parts.

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