JPS6296827A - Multiplex light measuring apparatus - Google Patents

Abstract

PURPOSE:To obtain an adequate exposure data, which is not affected by high and low luminances, by blocking outputs exceeding a threshold value among measured light outputs, which are obtained by dividing an object field into a plurality of regions and measuring light, to an output circuit, and transmitting the outputs, when the blocked measured light outputs exceed a specified number, to the output circuit. CONSTITUTION:A blocking circuit 101 controls analog switches 103, 105 and 107 based on a threshold level, which is set by the presence of the sun on an image plane during the day or at the sunset. Thus, transmission of the photoelectric outputs to circuits 11-13 is blocked. A blocking circuit 103 compares the output with the threshold level corresponding to a lower measured light limit. When the photoelectric output lower than the threshold value is present, analog switches 104, 106 and 108 are controlled, and the transmission of the photoelectric output to the circuits 11-13 is blocked. A flag l, which indicates whether the number of blockings is higher or lower than a specified value, is generated and applied to a classifying circuit 20. The circuit 20 receives a flag (n) and the flag l and classifies the inputs into five categorires. Based on the output of the circuit 20, an apex operating circuit 24 generates an output corresponding to an adequate exposure value and applies the value to an exposure control circuit 25 and an exposure display circuit 26.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention measures light by dividing a field into a plurality of regions, and extracts a proper light metering output for determining the proper exposure of the entire screen from a plurality of photoelectric outputs corresponding to the regions. This paper relates to improvements to multi-photometering devices.

The reason for dividing the field into multiple areas and metering is as follows.
It is also possible to obtain proper exposure even when shooting in backlit conditions. However, when high-brightness areas such as the sun enter the screen, conventional equipment results in significantly underexposed images. This is because even if the high-brightness area is only in one part of the screen, the absolute amount of brightness is greater than that of the main subject, and even if the brightness of both is averaged, the average value will be considerably larger than the brightness of the main subject.

On the other hand, when obtaining a plurality of photoelectric outputs corresponding to a plurality of areas, a part of the screen may be below the photometry lower limit, but photometry may be possible for the remaining part. For example, this is the case when the subject is illuminated by a spotlight. In contrast, conventional equipment is almost powerless.

Furthermore, when the contrast in the screen is high, controlling the exposure for high-brightness or low-brightness areas can result in a photograph in which the low-brightness or high-brightness areas are crushed, making it unpleasant to view. be.

The purpose of the present invention is to analyze the situation of the photographic field based on the photoelectric output, and to obtain an appropriate photometric output even for the photographic field under the above-mentioned special conditions, especially when the screen has a high load resistance. It is an object of the present invention to provide a multi-side optical device.

According to the present invention, the field is divided into a plurality of areas and photometry is performed,
A photometric circuit that generates a plurality of photoelectric outputs corresponding to the plurality of regions, and when the maximum value of the plurality of photoelectric outputs is PflgGIj, the average value is 1111141%, and the minimum value is Pll,
P s a g '> PH”:) P % # a s
The first photometric output PM is
The second photometric output PM becomes Pvm # a s 〉P
A third photometric output PL such that L>P m i s;
A fourth photometric output of PHM = PH 10 PII/2,
an appropriate photometric output generation circuit that generates a fifth photometric output of PLM=PM+PL/2; based on the average value;
a standardization circuit for standardizing the plurality of photoelectric outputs;
Using the maximum value and minimum value as input, pmaz-P s i
a determination circuit that generates an output when n≦T (where T is a constant); a first category that extracts at least the first sub-light output from the combinational logic of the output of the normalization circuit; When the third photometric output is extracted into a second category, and the output of the judgment circuit is manually classified into the first category, the output of the judgment circuit is input. , the fourth photometric output is calculated and extracted, and when the output of the determination circuit is input when the combinational logic is classified into the second category, the fifth
A multi-photometering device is obtained, characterized in that it includes an extraction circuit for calculating and extracting the photometering output of.

This makes it possible to obtain a good photograph in which the high-brightness side or the low-brightness side is not blurred even when the contrast of the screen is high. Note that standardization here refers to the average value of multiple photoelectric outputs, for example, detecting the magnitude relationship of each photoelectric output with respect to the average value, and replacing each photoelectric output with a specific signal according to the magnitude. be. This standardization makes it possible to determine where on the screen the main subject is located.

Hereinafter, the present invention will be explained with reference to FIG. 1, which represents the screen and the brightness of each part of the screen as a three-dimensional figure, with the field of view (hereinafter referred to as the screen) as the bottom and the brightness of each part of the screen as the vertical axis). Describe the basic idea. When considering a screen as shown on the bottom surface 8o in FIG. 1(a), the brightness of the screen determines one curved surface 8K. In fact, since (( is photometered with a photoelectric element on the finite side, the curved surface that can be captured is a set of planes with the same number or less than the number of photoelectric elements.For example, if the screen is divided into vertical, horizontal, and horizontal parts with a 4110 photoelectric element, the brightness of one screen The curved surface indicating
When comparing 2 and 84, the absolute level of the brightness that makes up the quantization surface is the same, but their positions on the screen are different, so it is difficult to judge which brightness to obtain the appropriate exposure. different. Also, quantization surface 8. and 8. When compared, the level difference between adjacent luminances is the same, but since the absolute value of the luminance between both quantization planes is different, the determination to obtain the appropriate exposure will also be different.

Now, if we classify the shooting screen under all conditions into multiple categories, including information about brightness and information about position, and perform exposure control for which brightness in each category, we can obtain the correct exposure overall. Attach a corresponding response. Then, on a screen under certain conditions, the brightness at which exposure control should be performed can be obtained from the information regarding the brightness and the information regarding the position.

In fact, as a result of making the above correspondences for screens under various conditions, it has been found that the brightness at which exposure control should be performed in order to obtain photographs with proper exposure converges to the following three levels. That is, the first brightness level exists between the maximum value of a plurality of photometric outputs and the average value of these secondary light outputs, and the @2 brightness level is approximately equal to the average value of these photometric outputs. It has been found that a third luminance level exists between the minimum value of these photometric outputs and the average value of these photometric outputs. This average value can be approximated by an average value, a median value, or a mode value.

From the above, if we compare the average value of multiple photoelectric outputs with each photoelectric output and standardize the brightness of each divided screen, we can simultaneously obtain information on the position and brightness of each screen. You will be able to do this. Therefore, if the state of the screen is detected by pattern analysis based on this normalized output, and this detection result is correlated experimentally or empirically with the above three brightness levels, exposure control for the screen under various conditions can be performed. Brightness level can be selected.

On the other hand, the brightness level to be controlled by KJII output may be determined regardless of pattern analysis and Vi. The difference between the maximum brightness and the minimum brightness is within a predetermined range, there is little variation in brightness within the screen, and the maximum brightness is within a predetermined range. This is a case in which it can be determined that such artificial brightness does not exist.

At this time, it has been found that good results can be obtained by adjusting the exposure of K to the second brightness level.

In addition, if there is a high brightness area represented by the sun or a low brightness area below the photometry lower limit in the screen, when setting the levels of the first to third brightness levels described above, the maximum value corresponding to the high brightness area and the photometry By ignoring the minimum value corresponding to the low brightness area below the lower limit and converting these maximum and minimum values to other brightness Kf existing in the screen, it is possible to obtain a photometry report with proper exposure that is not affected by extreme high and low brightness. . That is, new first to third brightness levels are obtained.

Furthermore, the first and third brightness levels VCg! When the difference between the maximum brightness and the minimum brightness exceeds a predetermined value when aligning the outputs, by correcting both R degree levels toward the second 181Ill level, the high f4 degree part or the low f14 degree part is crushed. You can also prevent photos from being taken.

The present invention will be explained below based on examples.

FIG. 2 is a block diagram showing an embodiment of the present invention. In the figure, a photometering circuit 1a includes a photoelectric conversion element for photometering each region of the field divided into a plurality of regions, and outputs an independent analog photoelectric output Po-P corresponding to each region of the field. . This photoelectric output P, , Pn is the film sensitivity (8V)
Therefore, the photoelectric output is expressed as an EV value. First maximum value detection circuit 11
is the photoelectric output P via analog switches 103 and 104
0~P? I is input, and from these, the maximum value Pα2
Detect. The average value detection port j312 inputs the photoelectric outputs Po to Pn via the analog switches 105 and 106, and detects the average value of these, for example, the average value PWLeeL%.
Detect. Photoelectric output Po, P via the first maximum/J% value detection circuit 13Vi analog switch 107°108
% is input, and the minimum value P min is detected from these. The arithmetic circuit 14 calculates the maximum value P and the average value P
First photometric output PM (EV) using m #αn as input
, that is, PM:':kl Pmaz+(1ks)Pmaan
”(1).The arithmetic circuit 15 generates the second photometric output P.
M (EV), that is, PM = P - αn ・・・・・・・・・・・・・・・
Although it generates (2), it can actually be used as the average value detection circuit 12. The arithmetic circuit 16 calculates the minimum value Pm
Using i% and average value ptgaa1% as input, the third photometric output PL (EV), that is, PL=2Pmin+(1-kz)Pmgan...-
−(3) is generated. The circuits 11 to 16 described above constitute an appropriate photometric output generation circuit. The arithmetic circuit 110 is applied with the photometric output PM and PM from the circuits 14 and 15, and the fourth
The photometric output of, ie, PH1, ..., PH Tomachi PE (where wl l wl is a weighting constant for the measurement output) is output. The arithmetic circuit 111 receives the photometric outputs PM and PL from the circuits 15 and 16, and outputs the fifth side light output, that is, PL.
M=g, , PJI+w4. PL (where w3°w4 are weighting constants for photometric output) is output.

The binarization circuit 1T has photoelectric outputs P0 to F, and the average value puma
% is input, and the reference output generated based on the average value Pnaan K is compared with the photometric output PO~p9s to convert each photoelectric output into a logical output. Here, since the level for standardizing the photoelectric output is only the average value Pmea%, standardization and binarization are performed at the same time.

The first determination circuit 18 receives the maximum value P&α2 as input.

Pα≦P cap I≦Pβ ・・・・・・・・・・・・・・・
. . . (4) (where Ptx and Pβ are constants) is determined, and a logical output representing the determination result is generated. Of course, the first determination circuit 1B includes a circuit that generates reference outputs corresponding to Pα and Pβ. This judgment operation is the maximum value P1α.

This is done to identify whether the light is caused by a bright light source, including the sun, or an artificial light source, such as a spotlight.

The second determination circuit 19 determines the maximum value pmam and the minimum value Pth.
With i s as input, ΔPmPsa g-7" s 4 s -= = =
= - Perform the calculation of (5), then a≦ΔP≦β ・・・・・・・・・・・・・・・・・・
. . . (6) (where %' tβ is a constant) is determined, and a logical output representing the determination result is generated. Of course, the circuit 13 that generates the reference output corresponding to the constants a and β is included in the second determination circuit 19. This judgment operation judges the brightness distribution of the screen, and for example, when the brightness distribution is large, the main subject is on the low brightness side, but the high brightness side is crushed, or vice versa, the main subject is on the high brightness side. This is done in order to prevent the phenomenon of the low brightness side being crushed even though there is a certain brightness.

Using the classification circuit 20fl, logic outputs from circuits 17, 18, and 19, 5 flags from a third determination circuit 100 (described later), and t flag from a second blocking circuit 102 (described later) as inputs, a combinational logic of these logical outputs is generated. determine which of the predetermined categories belongs to. That is, classify.

This predetermined category is divided into three, and a control output corresponding to each category is selectively generated. Circuit 14.
15.16, 110°111 and apex calculation circuit 24
Analog switches 21.2 connected respectively to
2.23, 112, and 113 select the output corresponding to the classified category from among the first to fifth photometric outputs according to the control output of the classification circuit 20, and transmit it to the apex calculation circuit 241C.

The apex calculation circuit 24 generates an output corresponding to an appropriate exposure value (shutter speed and aperture value) K based on the selected photometric output and other exposure factors from the information setting section 2T, and outputs this output to a known exposure control circuit 25. and is applied to the exposure display circuit 26.

Second minimum value detection circuit 99, second maximum value detection circuit 10
0 takes the photoelectric output Po%F as input, and from these, the minimum value Psi%ortgtsα1 maximum value Psamortg
Detect each i*al.

The third judgment circuit 17G determines the maximum value Pmaso pre-5saj.
Ptm4 duck origtn from the second minimum value detection circuit 99
Pmagorigivsal-Pm(*origina
It is determined that l ≦r (where T is a constant). Of course, this judgment circuit 110 uses the constant r
It includes a circuit that generates a reference output corresponding to K and a comparison circuit. This determination operation is for determining whether to extract the fourth or fifth photometric output. The output of this circuit is n
It is applied to the classification circuit 20 as a flag.

The first blocking circuit 101 receives the photoelectric outputs P0 to Pn and compares them with two threshold levels.

! The threshold level P t Al of @1 is set to approximately 16 hv assuming that the daytime sun is present on the screen, and the second threshold level Pth2 is set on the assumption that the dusk sun is present on the screen. It is set to approximately 151:V. First, if there is a charging output equal to or higher than the threshold level pth1.

Analog switch 103 is controlled to prevent transmission of its photoelectric output to circuit 11% 12.13. However, when all the photoelectric outputs are equal to or higher than the threshold level Pt11, the analog switch 103 is controlled so that any one photoelectric output can be transmitted to the next stage circuit. The reason for this will be explained later. Next, when there is a photoelectric output equal to or higher than the threshold level pth, the analog switch 103 is controlled to block the transmission of the photoelectric output to the circuits 11, 12, and 13, but the number of blocks is kept below a certain number. . This is because when photographing at dusk, the sun itself may be the object of the photograph, and if all that information is blocked, the photographer's intentions may not be reflected.

The second blocking circuit 102 inputs the photoelectric output PO-Pn and compares it with a threshold level Ptk corresponding to the lower limit of photometry.

When there is a photoelectric output equal to or less than Pth, the analog switch 104 is controlled to output the photoelectric output circuits 11, 12 .
Prevent transmission to 13. Then, the classification circuit 20 generates a t flag indicating whether the number of inhibitions is above or below a certain value.
to be applied.

1st. The second blocking circuits 101 and 102 transmit the number of blocked transmissions to the next stage circuit to the average value detection circuit 12,
Not included in average value calculation.

Next, the operation and the classification mode of the classification circuit 20 are shown on the screen 11:3.
The cases of division and five divisions will be explained. Third (a
) (6) The figure shows how the screen is divided and the photoelectric output of each divided area.

(1) 3rd (In the cLJ diagram, the screen is the central area assuming a 6x6 camera, and the upper area l)s
, the lower region DtK is divided, and each photoelectric output is Po,
It is represented by P.

Each photoelectric output Po~p is the average value pmaα3 (=Po +
Pt+F! /3), and each region is Po,
When P, ≧Pmg6%, it is expressed as a logical value l, and P, ,P! When ≦Pmma%, it is represented by a logical value of 0. The classification circuit 20 determines whether the combination of logical values is (1) when the central region Dl is O, or when the lower region Dl is O (
At this time, since there is a high possibility that the main subject exists in the area Dc or DtVc), the analog switch 23 is turned on and the third photometry output PL is transmitted to the apex calculation circuit 24. (11) When the center area is 1 (at this time, the main subject is area Dc) (because there is a high possibility that it exists), turn on the analog switch 21 and transmit the first photometric output PM to the apex calculation circuit 24. . (For combinations other than the above, K turns on the analog switch 22 and transmits the second photometric output PJI to the apex calculation circuit 24. When QJ n 7 lag is 1, that is, P-αz o
When riginαl≦γ, if the screen is in the state (1), the fifth photometric output Pi is substituted for the third photometric output PL.
Turn on the analog switch to extract +PL/2, and if the screen is in (1), turn on the analog switch to extract the fourth photometric output PJI + PH72 in place of the first photometric output PM. do.

This is the maximum value Pmarg and minimum value Pmarg of the photoelectric output when the first or third photometric output is extracted.
-<% If the difference is large, the high-brightness side or low-brightness side may be distorted, so to prevent this, the first or third metering output is leveled toward the average value. It is being corrected.

On the other hand, when the first determination circuit 18FiPα≦PH≦Pβ, K generates an output with a logical value of 1, and otherwise generates an output with a logical value of 0. The second determination circuit 19 is α≦ΔP
When ≦β, K generates an output of logical value 1, and otherwise generates an output of logical value 0. And the first. When a logical value of 1 is applied from the second judgment circuit 18 or 19, the classification circuit 20 turns on the analog switch 22 with priority even if the screen is in the above states (1) and (II). and transmits the second photometric output PM to the apex calculation circuit 24.

(2) In Fig. 3(b), assuming a squid-sized camera with a screen that crawls, the central area Dc, the upper right area Df%,
Upper left area D1%, lower right area Dr1. % Lower left area Dtt IIc is divided, and each photoelectric output is Po%
It is represented by P4.

Each photoelectric output P, .about.P4 is compared with the average value P''1% as described above, and each region is represented by a logical 1 or 0. The classification circuit 20 calculates the following combinations: (1) When the central region is 0, when the left and right lower regions DrL and DrL are 0, when the upper left region DLs and the lower left region Dtt are 0, when the upper right region is 0, % and the lower right area DrL are 00, or when some area KO is missing and 1 does not exist (at this time, the main subject is likely to exist in the 0 area), turn on the analog switch 23. and transmits the third photometric output PL to the apex calculation circuit 24.

(II) (ilD (lψ is the same operation as described in section (1)).

This five-division example takes into consideration the fact that there are vertical and horizontal photographing positions, such as in a Leica camera.

Now, in the above-mentioned item (1-2), if there is a high brightness part above the threshold level Pth1 in a certain area of the screen, the photoelectric output of that area, for example, Pl, is blocked and the average value is
Dew' =Po+P! /2 or ij P starvation
=P6 +P2 +Ps +P4 /4.

Therefore, using this average value, circuit 17. Arithmetic circuit 14.
15% 16Vi operation means K.

That is, the circuit 17 calculates this new average value Pmaan'
, K, each photoelectric output is converted into a logical output, and the arithmetic circuit 1
4, 15, and 16 generate corrected photometric outputs PH1PM and PL based on this Pmaas'K. This modified photometric output is selectively extracted by the classification circuit 20 in the same manner as described above.

By the way, when the entire screen has high brightness, for example when photographing clouds, only one maximum photoelectric output p m aπ is applied to the circuits 11, 12, and 13. Then,
The maximum value, average value, and minimum value all match PtnaygVc. At this time, the screen state becomes the OiD state described in (1) and (2) above, and the second photometric output PJI is selected, but since PJ = Pm a z , exposure control is not performed for high brightness. K will be done so that it will be done.

Next, the photoelectric outputs above the threshold level pth2 are prevented from being transmitted to the circuit 11, 12, 13 within a certain number, and the average value Pm
aan also has a constant average value P11% depending on the number of inhibitions.
It drops to $a%#. And this average value PtK
It operates in the same way as the previous stage based on etL%#.

As described above, correction is performed when generating side light output for the presence of a high brightness area.

On the other hand, if there is a photoelectric output below the threshold level Pthx, this photoelectric output, e.g. P t Fi, circuit It, 12
．． ．． Since the transmission to 13 is blocked, the absolute level of the average value increases, and pm g a tt””Po +P* /
2 or In P m a a n”'=Po1F,
10P30P4/4. Therefore, new first to fifth photometric outputs P that ignore photoelectric outputs below the photometric lower limit
M, PJf%PL%PHM%PLM is obtained. This photometric output is selected by the classification circuit 20 in the same manner as described above.

In this manner, correction is performed when a low brightness portion exists within the screen.

The configuration of each block will be explained below.

Figure 4 shows an example of a light element, in which multiple photoelectric elements are lined up, such as a photodiode, 7-ray, or Fi(,)C.
It can be configured by D, etc. However, it is not necessarily necessary to form a matrix. The photoelectric output in the above-mentioned divided area is obtained by combining the outputs of the photoelectric elements.

FIG. 5 shows an example of a receiving optical system. 31Fi Figure 4 shows a plurality of light IL elements, 32l- is a photographing lens, 33 is a mirror, 34 is a film surface, 35 is a finder screen, and 36 is a subject image formed on the finder screen. This lens is used to re-image the light on the light-receiving surface.

With the above configuration, the brightness of each part of the scene to be photographed can be measured, and a plurality of independent photometric information can be output.

lit 6 (a) Figure Fi + large value reading detection circuit, 100
An example of the circuit in FIG. 6(b) #i minimum value detection circuit 13
0 circuit examples are shown respectively. These circuits are known per se, using OP amplifiers and ideal diodes.

FIG. 7 shows an average value detection circuit 12 configured with a resistor r% r/n and an OF7 amplifier AL, and the output of the UP amplifier is P, +P1...Pn/n=, IJm-
An output αn is obtained.

FIG. 8 is a circuit example of arithmetic circuits 14, 15, and 16,
It is composed of followers "10 to '14, and voltage dividing resistors R, -R, and the first to fifth photometric outputs pm%PM%PL%
PHJf.

PLM can achieve the above (1)% (2), (
3) can be obtained to satisfy the equation.

FIG. 9 shows an example of the first blocking circuit, in which the number of blocking circuits described above is two. In the same figure; comparator 0100
%AND gate AND100, ANDlol, flip-flop FIPIQ%FF11. Inverter INV10
0, analog switch j, and 9100 are prepared in correspondence with the number of photoelectric outputs. Here, five blocks are prepared corresponding to the photoelectric ratio Po-P4VC, and block B is representatively shown. However, 7nd gate AND99, AND9γ, diode D100
．． Resistor 100, flip-flop FF1'l, FF13
is exclusive to block B1.

Now, the ring counter AC is applied with a clock pulse of a constant period, and the output terminal (IosQl, qs%Qs%qγ
Outputs are sequentially generated on s fs and lo according to the number of clock pulses. The terminals Ql-Q* are provided every other bit, and a time lag of one bit is provided between each output.

Binary counter Bυ1 is 90 of ring counter Rσ
The output is input, and a pulse is generated every two cycles of the Qo output obtained by dividing the to output by h. And the Q output is 1
At this time, the Q output outputs 0, turns off the transistor rr, and applies a voltage corresponding to the above-mentioned threshold level pth to the inverting input terminal of the comparator of each block. Further, when the Q output is 0, the i output of K becomes 1, the transistor Tr is turned on, and the inverting input terminal of the comparator of each block is connected to the above-mentioned threshold level Pth! <The corresponding voltage is applied. These comparators are PN'>Pth (where Pli is each photoelectric output, Pth is Pth! or P
th2), outputs 1. Next, the operation will be described.

(2) When the Q output of the binary counter BC1 is 1; in this case, the mode is for detecting PN>P g Al.

Since it is the output Fil of the off-gate OR110, block B! When the AND gate AND I Q Q receives the 91 output of the ring counter RU, the comparator σ10
Apply an output of 0 to the 8-man power of the flip 70 tube FFjQ. Here, if Po>V t At , the comparator Utoo outputs l, so the flip 70 tube F
Output 1 to the FIQFiQ1 output. At the same time, 7 lip-flop FF1j is Q! It outputs a specific output of 1 and turns off the analog switch /1.9100 so that Po is not transmitted to the next stage circuit. This operation is performed by the ring counter R(j's q1~
It is time-divided based on the q meeting output and sequentially moves to the block that receives the photoelectric output P4 as an input. As a result, P
From the block inputting the photoelectric output of N > P t h t, the photoelectric output is sent to the next stage circuits, namely the aforementioned first maximum value detection circuit 11, average value detection circuit 12, and first minimum value detection circuit. 13 is not transmitted.

On the other hand, α of AND gate, 4#D100. The output is input to an AND gate AND1101 which closes the qs ratio output input of the ring counter IIC, and α. When the output and the qIth output are both Kl, the 7nd gate/1ND110 outputs l, which is input to the binary counter BC2Vc via the off gate 0B111. Similarly, the C1, α2% C3, a4 outputs of the AND gate of each block are Qss
In synchronization with qss err and C1 output, respectively,
It is input to the binary counter EC'l. Therefore, the binary counter BC2 is α. ~G, count the output 1s.

However, since Q output #ii, OR gate 0R
The output of 11G is 1 regardless of the count value of counter B (72). Therefore, P.

~P4) Pg le! When K means that all photoelectric outputs are blocked from being transmitted to the next stage circuit, the count value of binary counter BC2 is 5, that is, '1' in binary code.
01', K is binary counter B (QIO of j2
The output and QIt output become 1, and the AND gate AND9
8 outputs 1, 1 enters the set input of flip-flop FF12, output Q becomes 1, and flip-flop /
1 is input to the set input of Fi 3, and the output Q becomes IK and Q becomes OIC. (Reset timing relationship F-1F
(Similar to F10.7'/11) Therefore, the output of the 7nd gate AND99 is OK and the analog switch j8100 is turned on. As a result, the photoelectric output P0 is transmitted to the next stage circuit. Here, if the 7-node terminal of the diode D100 is raised by the variable resistor B100 from Pth, the equivalent voltage by the amount lowered by the diode, the photoelectric output Po is limited to the Pth equivalent voltage. This is based on the FIK principle, which states that when the entire screen is bright, overexposure can produce more realistic photos. Same, binary counter BU
When the count value of 2 is 5 or less, Noah Gate N0E100
The output of is l, and the AND gate AND 99ij flip-flop! Connect the Q2 output of F12 to that analog switch, f, 9100'V? :Den El.

Moreover, when the count value of binary counter BC2 becomes 2 or more, Qll output, Q1! Output or 7nd gate AN
If the output of D115 is 1, then NOR gate #0.
#1g□ outputs 0. Then and gate A#Dl
15 resets the binary counter Bσ1 when the ring counter IIC reaches the to ratio output IK.
When the q1 output becomes IK again, the Q output becomes 1, and as a result, PN>P i &.

does not shift to a mode that detects

■ When the Q output of binary counter BU1 is 0; in this case, PH>P g A! This is the mode for detecting. When the output of the NOR gate NORI Q is 1, the output of the OR gate OR110 is 1. In other words, when the count value of binary counter Bσ2 is 2 or less, that is, QIO
This is when the output is 1 or the Q-th output is 1.

Now, if the count value of counter BC2 is 0, NOR gate N0I1100 and off gate OR110 output 1, so the comparator of each block is set to threshold level pth2.
and the photoelectric outputs P0 to P4, respectively. and,
When there is a photoelectric output of P th = or more, for example, P o
, P 1 , F * > P tA x then s”
os”1α output becomes 1. Then, Ql, Qss
By applying the qs ratio output, each AND gate AND110 ~
J#D112 outputs 1, which is counted by counter BC2. Therefore, %'21G, Q11 output is 1, so AND gate AND115 outputs 1 and NOR gate #0
R100 and off-gate 0R110 output 0. As a result, if two or more photoelectric outputs are blocked, K is set so that no more are blocked. In other words, blocks operating successively in chronological order do not perform blocking operations. Note that due to restrictions on the blocking operation, there is a possibility that a photoelectric output of Pth2 or more will be transmitted to the next stage circuit, but this is due to the diode D100 and resistor R100.
Since the voltage is limited to the voltage equivalent to pth2 by the action of , this does not pose a problem.

Similarly, AND gate 4A'Ji1γ and AND118 generate reset pulses for flip-flops FFjQ and FF11, and after AND11γ generates output l,
ND l l Let f3 generate a crab, and F
The reset timing of I'10 and FF11 is adjusted.

FIG. 10 shows a circuit example of the second blocking circuit, in which the number of blocking circuits is set to the constant number of blocking circuits described above. In the figure, a voltage corresponding to the threshold level Pt is generated by a resistor R200 and applied to the common-mode input terminals of the comparators C200 to C0204. The inverting input terminals KVi of the comparators C200 to C2O4 are applied with photoelectric outputs Po to P4, and each comparator has a voltage of PH<Pth6 (where PN is an arbitrary P,
~P4), output 1 is generated. Analog switch A32 provided corresponding to each comparator
The output 1 of the comparators corresponding to 00 to A3204 blocks the transmission of the photoelectric output to the next stage circuit. Analog switch lit 200~18204kFi respectively Analog switch for each block described in the figure, l5100~A
B104CAB 101-A8104 I, -, Tef
l! It is omitted in Figure 9. ) are connected in series. Analog switch block B10. B11 is the second
Circuits 103, 105, 107 and circuits 104, 106 in the diagram
．． 108, respectively.

The ring counter R020G sequentially changes Qos Q1* QssqS% 9m% by applying a clock pulse.
Generates flo output. q! ~Q output is output with a time lag of one bit of the counter. Now, when the 90 output of the ring counter Bσ200 becomes 1, the binary counter B (73 is reset.q! output becomes IK
Then, the AND gate, 4#D2QQ gate opens, and the output of comparator σ200 becomes OR gate 0R200II.
C communicate. At this time, the output 1 of the comparator σ200 (
If Po<Ptho), the binary counter EO3 counts this output 1. Below, ring counter Rc2o
As the q1 to q9 outputs of o sequentially become 1, a similar operation moves to Antogame ND201 to AND 204, and if there is one among the photoelectric outputs p, to P4 that satisfies ps<p thO, the number only binary counter B
Continue counting σ3t-. Then, when the count value of binary counter EC3 becomes 3, Q! The o output, Q, and 1 output all become 1, the output of the AND gate AND205 becomes 1, and the Q output of the 7 lip-flop FF'lQ, that is, the t flag becomes 1 due to the output IK of the OR gate 011201. Similarly, the count value of binary counter Bσ3 is 4.5
This is also the t flag F'i1.

As the operation progresses and the qIo output of the ring counter 5c2aa becomes 1, when the count value of the binary counter Bσ3 is 3 or more, the output of the AND gate AND 206 to which the output O is applied from the inverter lNV2O0 is O. Since flip-flop FF20 is not reset,
The t flag is maintained at 1. If the number of blockages is 2 or less in the next cycle, the output of the inverter I tV V 2Q Q is 1, so the t flag becomes 0.

Note that when both the 92G output and the Qt2 output of the binary counter Bσ3 are 1, the #'i blocking number is 5, and the entire screen is below the lower limit of photometry. Therefore, we define this as AND gate A
If detected by the ND 207, it is possible to indicate that photography is not possible by lighting up the light emitting diode LED.

FIG. 11 shows an example of the average value detection circuit. In the same figure; blocking operation by the first blocking circuit (high brightness side);
Since the blocking operation (low luminance @) by the second blocking circuit cannot occur in normal photographing conditions, the adder circuit is constructed with 40 OR gates.

Each field effect transistor FET is conductive when its gate is at 1.

When the blocking number is O, all the FETs are conductive at all gates 75f1, so the combined feedback resistance R is r15, ie, Patl is the sum of the unblocked photoelectric outputs.

When the blocking number is 1, FET□ is non-conducting, 　　　r When the blocking number is 2, FllTl becomes non-conductive, 　　　T When the number of inhibition is 3, I'ETQ,l becomes non-conducting, When the number of blocking is 4, FET1.2 is connected to the valve groove.

FIG. 12 is a circuit example of the classification circuit 20.

This figure shows an example in which the screen is divided into five parts as shown in Fig. 3(b).

An input corresponding to the constant Pal< is applied to the in-phase input terminal of the comparator υ1, and an input corresponding to the constant Pβ is applied to the inverting input terminal of the comparator C2. On the other hand, an input corresponding to the constant α is applied to the in-phase input terminal of the comparator C3, and an input corresponding to the constant β is applied to the inverting input terminal of the comparator C4. An input corresponding to the constant γ is applied to the in-phase input terminal of the comparator σ5. The inverting inputs of the comparators a7 to σ11, which use the photoelectric outputs P0 to P4 as in-phase inputs, are
A reference input equivalent to L is applied.

This level reduction equivalent to δL is the photoelectric output P.

This is to more reliably perform binarization on the low luminance side of ~P4. A reference input corresponding to the inverted input K 14 Pm aα gastric δH of the comparator C6 which uses the photoelectric output P0 as the in-phase input is applied. This level-up corresponding to δH is intended to more reliably binarize the high-brightness side of the photoelectric output Po.

The maximum value Pmax is input to the inverting input terminal of the comparator U1 and the in-phase input terminal of the comparator C2. The luminance difference ΔP' is input to the inverting input terminal of the comparator C3 and the in-phase input terminal of the comparator C4. Comparator C1
The output of ~C4 is input to the AND gate AND1.

When the output of AND gate AIVD1 becomes 1, the outputs of comparators c1 to C4 all indicate 1, and Pα≦Pα2≦Pβ ・・・・・・・・・・・・・・・
・・・・・・(7)(α) and α≦ΔP′≦β ・・・・・・・・・・・・・・・・・・
...(7) When (b) holds true. AND GATE AN
The output of D1 is set as 1 flag. When the I flag is 1, the output of the OR gate OB1 becomes IK, and the analog switch 22
is turned on to select the second photometric output PM. This is because formula (7) (b) holds true, indicating that there is a certain degree of f4 degree difference, but if formula (7) (cL) holds, that is, the maximum value falls within a certain range. This is because when the subject is exposed to light, there is no backlight and the appropriate exposure level is around the average value. Q. This holds true even if the photoelectric output on the high-brightness side or the low-brightness side is blocked. The photoelectric output Po is input to the in-phase input terminals of the comparators υ6 and CI, and the photoelectric outputs P1, P, . Also, the inverting input terminal KVi of comparator σ6
Output the average value to a certain level up PmaeXn+δH
enters. The output of the comparator σ6 becomes 1 when the photoelectric output Po of the central region DC is higher than the average value ptnean by a discernible amount (by δH), indicating that the central part of the photographic screen is a bright part. . On the other hand, an output PrILgan-δL obtained by lowering the average value by a certain value is input to the inverting input terminals of the converters C7 to U11. When the outputs of the comparators C7 to C11 become OK, the photoelectric output is P. +-P4 is lower than the average value Pgnζαn by a discernible amount (by δL), and the photoelectric output P0~
This shows that the screen corresponding to P4 is a dark area.

AND gate AND 2 has comparator υ5. (,7
9. Output of Ul 0 and inverter INVI of E flag
The output inverted by K is input. AND GATE AN
The output of D2 becomes 1 only when the following holds true and the I flag is O. In such a state, the central region D6 is bright and the upper half region Ddet%D
When t s is dark, it is a spotlight-like state.

Therefore, equation (8) becomes a condition for determining that the main subject is in a bright area. The output of the AND gate AND2 is set as the H flag. When the H flag is l, analog switch 2
1 is turned on and the first photometric output PH is selected.

The output of CI enters inverter IN73.

Now, Po <Pmgan−δL ・・・・・・・・・
If (9) (central area DC is dark) holds, the output of the comparator U1 is O and the output of the inverter INV3 is 1.

Also, the outputs of comparators σ8 and 09 are the NOR gates Nul
Enter l l K.

If (the left half area Dts%Dtt is 8), the outputs of the comparator 09 and (j9 are both KO and the output ViIK of the NOR gate N0E1. Similarly, K Ps < P m a - r @ - δL (The lower half region Dr4Dlt is the dark part) and P4kuP-αn-δL (If the right half region Dr, , Drl is the dark part, then
Output Vi1 of NOR gate 7voR2 and NOR3, respectively
become. Inverter INV3 and NOR gate NOR1
The output of ~NOR3 is input to the OR gate OR3, and if any of the outputs is 1, the output of the OR gate OR3 becomes 1. That is, if any of the equations (9) to (2) is satisfied, the output of the OR gate OR3 becomes 1. (9
) holds true when the center of the screen, where there is a high probability that the main subject is located, is a dark area, and it is better to set the exposure to the low brightness side. However, even if the center of the screen is bright, it often depends on the brightness K of the background, and it cannot necessarily be determined that the main subject is in the bright area. In fact, in backlit situations, the brightness of the main subject will be close to the brightness of the lower part of the screen. Therefore, if the formula holds true, it is better to determine that the main subject is in a dark area and select the third photometric output PL. If αq, equation (2) holds true, it is considered that the camera is held in a vertical position and the image is taken. As described above, each of formulas (9) to sub-types becomes a condition for determining that the main subject is subject to dark area VC. And at this time, or gate o
The output of x3 becomes IK.

When a certain number of photoelectric outputs are below the lower limit of photometry, the l flag becomes IK. Then, the output tilK of the OR gate 0112 or the first photometric output PM is selected. This is because when there are many photoelectric outputs that are below the photometric lower limit, there is a high probability that photometry is possible due to some bright part of the photoelectric element, and it is better to select the high brightness side. .

ΔP, that is, Pmax orig inal−Pmin
or 1g1nal is input to the inverting input terminal of comparator C5, and ΔP γ ・・・・・・・・・・・・・・・
When α3 (where γ is a constant) holds true, the output of comparator c5 becomes 1. This is a case where the measured luminance difference is relatively small, and correcting it toward the average value will bring the exposure closer to the correct exposure.

The output of the humpator U5 is inverted by the inverter INV2. Inverter NV2 output and l
The flag enters the AND gate A A' D 3 K.

The output of the AND gate AND3 becomes 1 when Equation 9 does not hold and the l flag is 1. That is, this is the case when the high-contact side is selected and the brightness difference is large, and the output of the off-gate OR2 is IK, so the first photometric output PM is selected.

The l flag is input to inverter/N V4 and inverted, and the output of inverter INV4 and comparator C5 and l
The flag is input to the AND gate AND4.The output of the AND gate AND4 is IK because formula 03 is established and l
This is when the flag is 1 and the l flag is 0. That is, when the high brightness side is selected and the f4 degree difference is small, the fourth photometric output PHJ! , for example, (PH+PM)/2 is selected.

The outputs of the AND gate AND7KFi or gate OR3 and the inverters INV1 and INV4 are input. The output of the AND gate AND7 is IK when the t%E flag is O and the output of the OR gate 0113 is 1. That is, this is a case where the low luminance side is selected. Now, let the output of the seventh gate AIVD7 be the L flag.

AND gate AND 5 The KViL flag and the output of comparator C5 are input, the low luminance side is selected, and when the luminance difference is small, the output is l, and the fifth photometric output P LJ
f, for example (PM+PL)/2, is selected.

AND gate AND6 has L flag and inverter INV
'l output is input, the low brightness side is selected, and when the brightness difference is large, 1 output becomes IK, and the third 6All optical output P
L is selected.

The Nant gate NAVDK receives 1% L and l flags, and becomes 1 when both are O.

This is a case where it is determined that the main subject is neither in a bright area nor in a dark area. At this time, off-gate OA
The output of '1 is not 1, and the second side optical output PM is selected.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the brightness distribution of the field (screen), Fig. 2 is a block diagram showing an embodiment of the present invention, Fig. 3 is a diagram showing how the screen is divided, and Fig. 4 is a diagram showing the luminance distribution of the field (screen). Diagram showing an example of an array,
Fig. 5 is a diagram showing an example of the optical receiving system, Fig. 6 is a diagram showing an example of the maximum value and minimum value detection circuit, Fig. 7 is a diagram showing an example of the average value detection circuit, Fig. 8 is a diagram showing an example of the Fi calculation circuit. 9 is a diagram showing an example of the first blocking circuit, FIG. 10 is a diagram showing an example of the second blocking circuit, and FIG. 11 is a diagram showing an example of the average value detection circuit. , and FIG. 12 are diagrams showing examples of classification circuits. [Explanation of symbols of main parts]

Claims (1)

[Scope of Claims] A multi-photometering device comprising a photometering circuit that divides a field into a plurality of areas and measures the light and obtains photoelectric outputs corresponding to the plurality of areas, and a means for generating an appropriate photometering output from the photoelectric outputs. By comparing the photoelectric output with a threshold value, those that exceed the threshold value are not involved in the means for generating appropriate photometric output, and if the number of things that are not involved exceeds a predetermined number, the excess amount is A multi-photometering device that is characterized by replacing it with a fixed value.