JPH0663835B2 - Camera photometer - Google Patents
Camera photometerInfo
- Publication number
- JPH0663835B2 JPH0663835B2 JP27439287A JP27439287A JPH0663835B2 JP H0663835 B2 JPH0663835 B2 JP H0663835B2 JP 27439287 A JP27439287 A JP 27439287A JP 27439287 A JP27439287 A JP 27439287A JP H0663835 B2 JPH0663835 B2 JP H0663835B2
- Authority
- JP
- Japan
- Prior art keywords
- receiving element
- subject brightness
- photometric
- light receiving
- brightness
- 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
Landscapes
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Exposure Control For Cameras (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、カメラの測光装置に係わり、特にCdS等の被
写体よりの受光光量によって電気抵抗値が変化する受光
素子を用い、マイクロコンピュータを内蔵して露光制御
を行うようにしたカメラの測光装置に関するものであ
る。Description: TECHNICAL FIELD The present invention relates to a photometric device for a camera, and in particular, it uses a light receiving element whose electric resistance value changes according to the amount of light received from a subject such as CdS, and incorporates a microcomputer. The present invention relates to a photometric device for a camera that controls exposure.
マイクロコンピュータを内蔵して自動露光制御（AE）を
行うカメラでは、一般に安価なCdSやCdSe等光エネルギ
ーを吸収すると電気抵抗が変化する受光素子を用い、被
写体の輝度情報をデジタル信号に変換して処理を行って
いる。In a camera with a built-in microcomputer for automatic exposure control (AE), a light receiving element whose electric resistance changes when light energy is absorbed, such as inexpensive CdS or CdSe, is used to convert the brightness information of the subject into a digital signal. It is processing.
CdS等の受光素子の前面にはコンデンサレンズＬを設
け、測光範囲の光を受光素子面に集光して測光し、これ
をデジタル信号に変換するが、従来の被写体の輝度測光
を行う測光装置としては第７図（ａ）に示すような測光
回路が用いられていた。即ち回路はCdSの外にコンパレ
ータComp、コンデンサＣ、トランジスタTr、マイクロコ
ンピュータＭＣ等から構成されて、その動作は第７図
（ｂ）に示すようにしてなされていた。まずマイクロコ
ンピュータＭＣの出力端子AEOをONとしてトランジスタT
rにより一旦電位ＶCdSを放電したのち出力端子AEOをOFF
としてコンデンサＣの充電を開始させ、電位ＶCdSが所
定のレベルに回復した時点の信号をコンパレータCompに
よって得るようにし、この信号を入力端子AEIが受け
て、充電に要した時間を演算し、その値から測光値を得
る方法がとられていた。A condenser lens L is provided on the front surface of a light receiving element such as CdS to collect light in the light measuring range on the light receiving element surface for photometry and convert the light into a digital signal. For this, a photometric circuit as shown in FIG. 7 (a) was used. That is, the circuit is composed of a comparator Comp, a capacitor C, a transistor Tr, a microcomputer MC, etc. in addition to CdS, and its operation is performed as shown in FIG. 7 (b). First, turn on the output terminal AEO of the microcomputer MC and turn on the transistor T.
After discharging the potential VCdS by r, the output terminal AEO is turned off.
As a result, the capacitor C is started to be charged, and a signal at the time when the potential VCdS is restored to a predetermined level is obtained by the comparator Comp, and this signal is received by the input terminal AEI to calculate the time required for charging, and the value thereof is calculated. The method of obtaining the photometric value from was taken.
このような回路をもった測光装置では回路構成を複雑と
し、また複雑な回路構成にも拘わらず測定結果は必ずし
も高精度のものではなかった。The photometric device having such a circuit has a complicated circuit structure, and the measurement result is not always highly accurate despite the complicated circuit structure.
本発明は、前記問題点を解決して簡単なかつきわめて安
価な回路によって、しかも精度のよい被写体の輝度測光
を行うことができるようにした、カメラの測光装置を提
供することを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a photometric device for a camera which solves the above-mentioned problems and is capable of performing accurate brightness photometry of a subject with a simple and extremely inexpensive circuit.
前記目的は、受光量により抵抗値の変化する受光素子
と、下記に示す範囲の予め設定したバイアス抵抗Ｒ２と
を直列に接続し、該受光素子と該バイアス抵抗との接続
点の出力信号をＡ／Ｄ変換することにより被写体輝度を
デジタル情報に変換することを特徴とするカメラの測光
装置 ここで、 Ｒ０：被写体輝度ＬＶ０における受光素子の抵抗値 γ：受光素子のガンマ値 LV0：基準被写体輝度（EV） LV1：測光範囲下限被写体輝度（EV） LV2：測光範囲上限被写体輝度（EV） 被写体輝度は感度IS0100の感光材料を用いたとき適正露
出が得られる露出値（EV）で表示する。The purpose is to connect in series a light receiving element whose resistance value changes according to the amount of received light and a preset bias resistor R 2 in the range shown below, and to output an output signal at the connection point between the light receiving element and the bias resistor. Camera photometric device characterized by converting subject brightness into digital information by A / D conversion here, R 0 : Resistance value of light receiving element at subject brightness LV 0 γ: Gamma value of light receiving element LV 0 : Reference subject brightness (EV) LV 1 : Lower limit of metering range subject brightness (EV) LV 2 : Upper limit of metering range subject brightness (EV) ) The subject brightness is displayed as an exposure value (EV) that gives the proper exposure when a photosensitive material with sensitivity IS0100 is used.
ΔＸ：測光ステップ幅（EV） Ｐ：実用最小分解能 によって達成される。ΔX: Photometric step width (EV) P: Achieved by practical minimum resolution.
第１図は本発明の一実施例を示す測光回路図で、図にお
いて、Ｒ１は受光素子CdSの抵抗値、Ｒ２は受光素子CdS
と直列でアース側に接続されたバイアス抵抗、ＭＣはA/
D変換機能を有するマイクロコンピュータ、ＶCdSは受光
素子CdSとバイアス抵抗Ｒ２との接続点に発生する出力
電圧、ＶDDは電源電圧である。受光素子CdSの受光面
は、コンデンサレンズによるなどして被写体輝度に比例
した照度になっている。それで前記接続点に発生する電
圧ＶCdSは被写体輝度に応じて変化する、この電圧ＶCdS
をマイクロコンピュータＭＣによってA/D変換して、直
接被写体輝度信号を得ることができる。かかる測光方法
においては、被写体輝度に対応する電圧ＶCdSの変化率
を大きくし測定精度を高くするには、測光する輝度範囲
に亙り受光素子CdSの特性に適合した抵抗値を有するバ
イアス抵抗を選択しなければならない。FIG. 1 is a photometric circuit diagram showing an embodiment of the present invention. In the figure, R 1 is the resistance value of the light receiving element CdS, and R 2 is the light receiving element CdS.
Bias resistance connected to the ground side in series with, MC is A /
A microcomputer having a D conversion function, VCdS is an output voltage generated at a connection point between the light receiving element CdS and the bias resistor R 2, and VDD is a power supply voltage. The light receiving surface of the light receiving element CdS has an illuminance that is proportional to the brightness of the subject, such as by a condenser lens. Therefore, the voltage VCdS generated at the connection point changes according to the brightness of the subject.
Can be A / D converted by the microcomputer MC to directly obtain the subject luminance signal. In such a photometric method, in order to increase the rate of change of the voltage VCdS corresponding to the subject brightness and improve the measurement accuracy, a bias resistor having a resistance value that matches the characteristics of the light receiving element CdS over the brightness range to be measured is selected. There must be.
いま、受光面照度Ｉ０のときの受光素子CdSの抵抗値を
Ｒ０、ｘEVだけ異なる受光面照度Ｉｎのときの抵抗値を
Ｒｎとすると、受光素子CdSのガンマ値の定義より であるから logRn＝logR0−γ（logIn−logI0） ２を底に取ると Ｒｎ＝Ｒ０×２−γ(logIn-IogI0) ここでｘｎ＝IogIn-IogI0 とすると Ｒｎ＝Ｒ０×２−γXn となる。それで第１図の回路に当てはめると 従って この関数f(x)をグラフに表すと第２図のようになり、バ
イアス抵抗Ｒ２の値によりグラフの形状が変化する。Now, assuming that the resistance value of the light receiving element CdS when the light receiving surface illuminance is I 0 is R 0 and the resistance value when the light receiving surface illuminance In is different by xEV is Rn, the gamma value of the light receiving element CdS is defined as follows. Therefore, if logRn = logR 0 −γ (logIn−logI 0 ) 2 is taken as the base, then Rn = R 0 × 2 −γ (logIn-IogI 0 ) where xn = IogIn-IogI 0 , then Rn = R 0 × 2- γXn . So if you apply it to the circuit in Figure 1, Therefore The graph of this function f (x) is as shown in FIG. 2 , and the shape of the graph changes depending on the value of the bias resistance R 2 .
ここでマイクロコンピュータＭＣのA/Dコンバータの実
用最小分解能をＰとすると（例えば８bitA/Dコンバータ
で温度特性による誤差も含め３LSBの誤差が考えられる
ときはＰ＝３／256となる）、測光すべき被写体輝度範
囲LV1〜LV2全域に亙り、最小測光ステップΔｘ（EV）の
輝度変化に対する（１）式の変化量がＰより大きけれ
ば、精度よく測光できることとなる。Let P be the practical minimum resolution of the A / D converter of the microcomputer MC (for example, P = 3/256 when an error of 3 LSB including the error due to the temperature characteristic is considered in the 8-bit A / D converter). If the amount of change in the equation (1) with respect to the change in brightness of the minimum photometric step Δx (EV) is larger than P over the entire subject brightness range LV 1 to LV 2 , photometry can be performed accurately.
（１）式よりｘ＝ｘｎにおいてΔｘだけ変化したときの
f(x)の変化量を求めると であり、よって となる。f(x)は単調増加関数であるから f(Xn＋ΔＸ）−f(Xn)＞Ｐ であればよいことになる。From the equation (1), when x = xn is changed by Δx,
When the variation of f (x) is calculated And therefore Becomes Since f (x) is a monotonically increasing function, it suffices if f (Xn + ΔX) −f (Xn)> P.
従って Ｐを左辺に移して整理すると 両辺に−１を乗じて この不等式の解Ｒ２は、左辺をg(R2)とし、 この方程式（３）の２根をα，β（α＜β）とすると、 α＜Ｒ２＜β となる。Therefore Moving P to the left side and rearranging Multiply both sides by -1 The solution R 2 of this inequality is g (R 2 ) on the left side, If the two roots of this equation (3) are α and β (α <β), then α <R 2 <β.
ところで、第２図に見られるように測光範囲全域に亙り
平均して増加率を高くするようにバイアス抵抗Ｒ２の値
を選ぶと（第２図のＲ２がほぼ中間の値の場合）、測光
範囲の最小輝度と最大輝度における出力電圧の変化量が
最小となる。それでこの２点における（２）式を満足す
るＲ２の値（範囲）を求め、二つの範囲に共通する値を
求めれば良いことになる。また受光面照度Ｉは被写体輝
度に比例し、ｘｎは基準照度Ｉ０と任意照度Ｉｎの２を
底とした対数の差であるから、被写体輝度をEV単位のLV
で表すと、 ｘｎ＝log2In−log2I0＝LVn−LV0 となる。By the way, as shown in FIG. 2 , when the value of the bias resistance R 2 is selected so as to increase the rate of increase on average over the entire photometric range (when R 2 in FIG. 2 is a substantially intermediate value), The amount of change in the output voltage at the minimum and maximum brightness in the photometric range is minimized. Therefore, it suffices to find a value (range) of R 2 that satisfies the equation (2) at these two points and find a value common to the two ranges. The light-receiving surface illuminance I is proportional to the subject brightness, and xn is the logarithmic difference of the reference illuminance I 0 and the arbitrary illuminance In from the base 2. Therefore, the subject brightness is LV in EV units.
When expressed by, xn = log 2 In−log 2 I 0 = LVn−LV 0 .
そこで測光範囲の最小被写体輝度をLV1、最大被写体輝
度をLV2とすると、最小輝度点のｘ１及び最大輝度点の
ｘ２は ｘ１＝LV1−LV0 ｘ２＝LV2−LV0 となる。Therefore, if the minimum subject brightness in the photometric range is LV 1 and the maximum subject brightness is LV 2 , x 1 of the minimum brightness point and x 2 of the maximum brightness point are x 1 = LV 1 −LV 0 x 2 = LV 2 −LV 0 Becomes
（３）式のｘｎに前記ｘ１及びｘ２を代入した方程式を
ｇ１（Ｒ２），ｇ２（Ｒ２）とし、それぞれの根を求
め、α１，β１（α１＜β１）及びα２，β２（α２＜
β２）とすると、ｇ１（Ｒ２），ｇ２（Ｒ２）のグラフ
は第３図に示すようになる。従って であるから ここで、 である。Let g 1 (R 2 ) and g 2 (R 2 ) be equations in which x 1 and x 2 are substituted for xn in the equation (3), find respective roots, and obtain α 1 , β 1 (α 1 <β 1 ) And α 2 , β 2 (α 2 <
β 2 ), the graph of g 1 (R 2 ), g 2 (R 2 ) becomes as shown in FIG. Therefore Because here, Is.
第４図は下記に示す実際例について、第１図のバイアス
抵抗Ｒ２を、前記計算によって求めた範囲の値にした場
合の被写体輝度に対する出力信号の関係を示す図であ
る。縦軸は出力電圧をA/D変換したbit数を示し、横軸は
被写体輝度をEV単位で表したLVである。FIG. 4 is a diagram showing the relationship of the output signal with respect to the subject brightness when the bias resistance R 2 of FIG. 1 is set to a value in the range obtained by the calculation in the practical example shown below. The vertical axis represents the number of bits obtained by A / D converting the output voltage, and the horizontal axis is the LV representing the subject brightness in EV units.
即ち、CdSの抵抗； 基準被写体輝度LV15において５ｋΩ（カメラに組み込ん
だもの） CdSのガンマ値；γ＝0.53 測光範囲；LV6〜LV17 測光ステップ幅；Δｘ＝1/3EV 実用最小分解能；Ｐ＝３／256 である場合の適合バイアス抵抗Ｒ２は 15.4ＫΩ＜Ｒ２＜18.8ＫΩ となり、Ｒ２＝18ＫΩとしたものである。That is, CdS resistance; 5kΩ at reference subject brightness LV15 (incorporated in camera) CdS gamma value; γ = 0.53 photometric range; LV6 to LV17 photometric step width; Δx = 1 / 3EV practical minimum resolution; P = 3 / When 256, the adapted bias resistance R 2 is 15.4 KΩ <R 2 <18.8 KΩ, and R 2 = 18 KΩ.
第５図は本発明の他の実施例を示す測光回路図で、符号
CdS，ＭＣ，ＶCdS，ＶDDは、第１図に示す部分または電
圧と同一で、Ｒ３及びＲ４は分割したバイアス抵抗、Tr
はトランジスタ、AECはトランジスタTrを制御する制御
端子である。この実施例は測光輝度範囲が広すぎるか、
受光素子CdSのガンマ値などが不適当で、適当なバイア
ス抵抗値Ｒ２の解が得られなかった場合、あるいは更に
高分解能を有し高精度の測光を必要とする場合に用いら
れる測光回路である。FIG. 5 is a photometric circuit diagram showing another embodiment of the present invention.
CdS, MC, VCdS and VDD are the same as the parts or voltages shown in FIG. 1, and R 3 and R 4 are divided bias resistors, Tr
Is a transistor, and AEC is a control terminal for controlling the transistor Tr. In this example, if the photometric brightness range is too wide,
With a photometric circuit used when the gamma value of the light receiving element CdS is not appropriate and a suitable bias resistance value R 2 cannot be obtained, or when high resolution and high precision photometry are required. is there.
Ｒ３及びＲ４は次ぎのようにして求められる。まず測光
輝度範囲をほぼ中央で２分割し、低輝度範囲に適合する
バイアス抵抗値Ｒ２をもとめ、次ぎに高輝度範囲に適合
するバイアス抵抗値Ｒｂを求める（Ｒａ＞Ｒｂ）、そう
して Ｒ３＝Ｒａ−Ｒｂ Ｒ４＝Ｒｂ とする。R 3 and R 4 are obtained as follows. First, the photometric brightness range is roughly divided into two at the center, and the bias resistance value R 2 suitable for the low brightness range is obtained, and then the bias resistance value Rb suitable for the high brightness range is obtained (Ra> Rb). 3 = and Ra-Rb R 4 = Rb.
次ぎに前記第５図に示した測光回路の動作について説明
する。低輝度範囲における測光時には、マイクロコンピ
ュータＭＣの制御端子AECはOFFになっていてトランジス
タTrはOFF状態になっているので、回路のバイアス抵抗
値は、Ｒ３＋Ｒ４＝Ｒａとなり低輝度範囲に適合したバ
イアス抵抗となる。また高輝度範囲における測光時に
は、前記制御端子AECはONになりトランジスタTrはON状
態になるので、Ｒ３は短絡されてバイアス抵抗値は、Ｒ
４＝Ｒｂとなり高輝度範囲に適合した値となる。この場
合の被写体輝度に対する出力信号の関係を第６図に示
す。Next, the operation of the photometric circuit shown in FIG. 5 will be described. During photometry in the low brightness range, the control terminal AEC of the microcomputer MC is off and the transistor Tr is off, so the bias resistance value of the circuit is R 3 + R 4 = Ra and is suitable for the low brightness range. It becomes the bias resistance. Further, during photometry in the high luminance range, the control terminal AEC is turned on and the transistor Tr is turned on, so that R 3 is short-circuited and the bias resistance value is R.
4 = Rb, which is a value adapted to the high luminance range. The relationship of the output signal with respect to the subject brightness in this case is shown in FIG.
なおこの場合、低輝度範囲と高輝度範囲の境界輝度をLV
mとし、LVmにおける低輝度範囲でのA/D変換された出力
信号をｎ１、同じく高輝度範囲での出力信号をｎ２とす
るとき、高輝度範囲の出力信号には、常に（ｎ１−
ｎ２）が加えられるように、マイクロコンピュータＭＣ
のプログラムを変更することなどが行われる。In this case, the boundary brightness between the low brightness range and the high brightness range is set to LV.
m, and the output signal A / D converted in the low brightness range in LV m is n 1 and the output signal in the high brightness range is n 2 , the output signal in the high brightness range is always (n 1-
n 2 ) is added so that the microcomputer MC
The program is changed and so on.
このように測光範囲を２分割して極めて高精度の測光回
路を得ることができる。In this way, the photometric range can be divided into two to obtain a highly accurate photometric circuit.
本発明によれば以上説明したように、受光量により抵抗
値の変化する受光素子と、適合する範囲の予め設定した
バイアス抵抗Ｒ２とを直列に接続し、該受光素子と該バ
イアス抵抗との接続点の出力信号をA/D変換するように
したので、簡単なかつきわめて安価な回路によって、極
めて精度の高い測光回路を得ることができる。According to the present invention, as described above, a light receiving element whose resistance value changes according to the amount of received light and a preset bias resistor R 2 in a suitable range are connected in series to connect the light receiving element and the bias resistor. Since the output signal at the connection point is A / D converted, an extremely accurate photometric circuit can be obtained with a simple and extremely inexpensive circuit.
第１図は本発明の一実施例を示す測光回路図、 第２図は前記第１図に示した回路による被写体輝度と出
力電圧の関係を示す図、 第３図は方程式ｇ１（Ｒ２）及びｇ２（Ｒ２）を示すグ
ラフ、 第４図は実施例について、前記第１図のバイアス抵抗Ｒ
２を計算により求めた適合値にした場合の、被写体輝度
に対する出力信号の関係を示す図、 第５図は本発明の他の実施例を示す測光回路図、 第６図は前記第５図の測光回路によって得られる出力信
号を示す図、 第７図（ａ）は従来の測光回路を示す図、 第７図（ｂ）は前記第７図（ａ）に示す測光回路の動作
を説明するための図である。 AEC……制御端子、Ｃ……コンデンサ CdS……受光素子、Comp……コンパレータ Ｌ……コンデンサレンズ ＭＣ……マイクロコンピュータ Ｒ２，Ｒ３，Ｒ４……バイアス抵抗 ＶCdS……出力電圧、ＶDD……電源電圧FIG. 1 is a photometric circuit diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the relationship between subject brightness and output voltage by the circuit shown in FIG. 1, and FIG. 3 is the equation g 1 (R 2 ) And g 2 (R 2 ), and FIG. 4 shows the bias resistance R of FIG.
FIG. 5 is a diagram showing the relationship of the output signal with respect to the luminance of the subject when 2 is a suitable value obtained by calculation. FIG. 5 is a photometric circuit diagram showing another embodiment of the present invention. FIG. 7 (a) is a diagram showing a conventional photometric circuit, FIG. 7 (b) is for explaining the operation of the photometric circuit shown in FIG. 7 (a). FIG. AEC ...... control terminal, C ...... capacitor CdS ...... light receiving element, Comp ...... comparator L ...... condenser lens MC ...... microcomputer R 2, R 3, R 4 ...... bias resistor VCdS ...... output voltage, VDD ... …Power-supply voltage
Claims (3)
と、下記に示す範囲の予め設定したバイアス抵抗Ｒ２と
を直列に接続し、該受光素子と該バイアス抵抗との接続
点の出力信号をA/D変換することにより被写体輝度をデ
ジタル情報に変換することを特徴とするカメラの測光装
置。 ここで、 Ｒ０：被写体輝度ＬＶｏにおける受光素子の抵抗値 γ：受光素子のガンマ値 LV0：基準被写体輝度（EV） LV1：測光範囲下限被写体輝度（EV） LV2：測光範囲上限被写体輝度（EV） 被写体輝度は感度IS0100の感光材料を用いたとき適正露
出が得られる露出値（EV）で表示する。 Δｘ：測光ステップ幅（EV） Ｐ：実用最小分解能1. A light-receiving element whose resistance value changes depending on the amount of light received and a preset bias resistor R 2 in the range shown below are connected in series, and an output signal at a connection point between the light-receiving element and the bias resistor is connected. A photometric device for a camera, characterized in that the subject brightness is converted into digital information by A / D conversion of. here, R 0 : Resistance value of light receiving element at subject brightness LV o γ: Gamma value of light receiving element LV 0 : Reference subject brightness (EV) LV 1 : Lower limit of metering range subject brightness (EV) LV 2 : Upper limit of metering range subject brightness (EV) ) The subject brightness is displayed as an exposure value (EV) that gives the proper exposure when a photosensitive material with sensitivity IS0100 is used. Δx: Photometric step width (EV) P: Practical minimum resolution
輝度の場合にはその抵抗値を小さくするようにしたこと
を特徴とする特許請求の範囲第１項記載のカメラの測光
装置。2. The photometric device for a camera according to claim 1, wherein the bias resistor R 2 is adapted to reduce its resistance value when the subject brightness is high.
する特許請求の範囲第１項又は第１項記載のカメラの測
光装置。3. The photometric device for a camera according to claim 1, wherein the light receiving element is CdS.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27439287A JPH0663835B2 (en) | 1987-10-28 | 1987-10-28 | Camera photometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27439287A JPH0663835B2 (en) | 1987-10-28 | 1987-10-28 | Camera photometer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01114726A JPH01114726A (en) | 1989-05-08 |
| JPH0663835B2 true JPH0663835B2 (en) | 1994-08-22 |
Family
ID=17541029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27439287A Expired - Fee Related JPH0663835B2 (en) | 1987-10-28 | 1987-10-28 | Camera photometer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0663835B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0540838U (en) * | 1991-11-07 | 1993-06-01 | 株式会社精工舎 | Photometric device for camera |
-
1987
- 1987-10-28 JP JP27439287A patent/JPH0663835B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01114726A (en) | 1989-05-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3703130A (en) | Electronic shutter control device | |
| US4176955A (en) | Exposure meter | |
| US3843249A (en) | Exposure correction factor setting indicator for cameras | |
| US4245900A (en) | Electronic exposure control apparatus | |
| US4306807A (en) | Light measuring system | |
| JPH0587812B2 (en) | ||
| US4275953A (en) | Exposure parameter information generating circuit in a single lens reflex camera | |
| JPH0663835B2 (en) | Camera photometer | |
| US4324462A (en) | Exposure time control circuit for camera | |
| US4630917A (en) | Exposure control device of a camera | |
| US5023647A (en) | Automatic status discriminator | |
| US4721976A (en) | AE lock device for camera | |
| JP2007232864A (en) | Light emission control circuit for flashing device | |
| US4433914A (en) | Exposure meter | |
| US4331401A (en) | Exposure control system for a photographic camera | |
| JPS622294B2 (en) | ||
| US4166696A (en) | Photometer | |
| JP3286859B2 (en) | Automatic light control strobe | |
| US5097262A (en) | Analog-to-digital converter for camera | |
| US3675548A (en) | Exposure time indicating device for photographic cameras equipped with an electronically controlled shutter | |
| JP2524347B2 (en) | Exposure control device | |
| US3765312A (en) | Exposure control device | |
| JP2660052B2 (en) | Photometric circuit | |
| JPS628774B2 (en) | ||
| SU1651112A1 (en) | Calorimeter probe for color photographic printing |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |