JPH0557529B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to an apparatus for photographing by emitting light from a flash light source (hereinafter referred to as an auxiliary light source) in constant light. BACKGROUND OF THE INVENTION Generally, an auxiliary light source is used in ambient light to adjust the contrast between different parts of a photographic screen to a desired level. For example, when the main subject is dark compared to the background due to backlighting, etc., an auxiliary light source is used to increase the brightness of the main subject to achieve a desired contrast with the background. However, no photometry device has yet been proposed that is suitable for adjusting the contrast between various parts of the photographic screen as desired by the photographer using an auxiliary light source. In the past, photographers with extensive shooting experience would adjust the lighting based on their experience to obtain the shots they desired, and this was done only qualitatively to control the contrast. However, quantitative control was not carried out. Furthermore, it is extremely difficult for a typical photographer to even qualitatively control the contrast. Purpose/Summary of the Invention The object of the present invention is to propose a novel photometric device suitable for photographing with contrast between parts of a photographic screen as desired by the photographer using an auxiliary light source. The feature of this invention is that photometry is performed for each of multiple parts of the shooting screen, and a signal corresponding to the amount of light received by each light receiving element when the auxiliary light source is emitting light and a signal corresponding to the amount of light received by each light receiving element when the auxiliary light source is not emitting light are measured. In addition to obtaining a signal corresponding to the amount of light received by the element,
A desired exposure time is set, and based on the signal corresponding to this exposure time and the above two types of signals, the portion of the shooting screen that each light receiving element receives light during actual shooting using an auxiliary light source is determined. This method calculates a signal corresponding to the amount of light that contributes to the exposure of the corresponding photoreceptor portion, and by calculating the difference between the calculated amounts of light, the contrast between each portion is obtained. be. It is also possible to obtain various average exposure amounts for the signal, or to obtain the difference between this average exposure amount and the exposure amount to each portion. As described above, according to the photometric device of the present invention, the contrast between each part of the subject can be obtained from the intensity of the stationary light, the amount of flash light emission, and the set exposure time. In addition, the contrast calculated by changing the set exposure time or changing the flash emission amount at the time of scheduled shooting to a different one from the flash emission amount at the time of measurement and inputting the number of change steps also corresponds to this. and change. Therefore, by changing the conditions as described above and performing photographing using a combination of exposure time and flash light emission amount when the desired contrast is calculated, it is possible to photograph as intended. In this way, by using the photometric device according to the present invention, it becomes possible to perform photography with quantitative control of contrast, which was previously impossible. Embodiments The basic idea of the present invention is to control the contrast in a photographic screen by using an auxiliary light source such as a flash light emitting device. That is, if the luminances of the two parts are 2 ^Bv1 and 2 ^Bv2 , the amount of light reflected from the two parts by the auxiliary light is 2 ^Qvf1 and 2 ^Qvf2 , and the exposure time is 2 ^-Tv , then the exposure by the two parts is The ratio of the amount of light contributing to the exposure of the body is (2 ^Bv1-Tv +2 ^Qvf1 )/(2 ^Bv2-Tv +2 _Qvf2 )...(1). Here, if we define 2 ^Bv1-Tv +2 ^Qvf1 ≡2 ^Qvt1 ……(2-1) 2 ^Bv2-Tv +2 ^Qvf2 ≡2 ^Qvt2 ……(2-2), the contrast between the two parts reproduced on the photoreceptor is is 2 ^Qvt1 /2 ^Qvt2 = 2〓 ^C ... (3-1), and in the apex system, Qvt ₁ - Qvt ₂ = ΔC ... (3-2). Therefore, contrast can be controlled by controlling the exposure time and the amount of light emitted from the auxiliary light source. Furthermore, the exposure level may be controlled by an aperture. Here, Qvt ₁ and Qvt ₂ correspond to the values in the apex system of the amount of light contributing to the exposure of the photoreceptors of the two objects. FIG. 1 is a block diagram showing a first embodiment of the invention. 1 and 2 are photometering circuits each having a light receiving element that measures different parts; 3 and 5 are integration circuits that output a signal corresponding to the logarithmic compression value of the amount of received light;
Sample and hold circuits 4 and 6 sample and hold the outputs of the photometric circuits 1 and 2. FL is
It is a flash light emitting device. S ₁ and S ₂ are changeover switches, which are normally connected to terminals A ₁ and A ₂ respectively, and are switched between terminals F ₁ and F ₂ for a certain period of time by a photometry start signal (not shown).
connected to. S ₃ is a flashlight device that is normally open and is closed for a certain period of time when the photometry start signal is received.
This is an FL trigger switch. 7 is an analog multiplexer, 8 is an AD converter, and 9 is a digital multiplexer. Note that a signal line with diagonal lines indicates a multi-bit digital signal. 10 is a register in which digital data corresponding to the signal Ov ₁ from the integrating circuit 3 is set; 11
12 is a register in which digital data corresponding to the signal Qv ₂ from the integrator circuit 5 is set, 12 is a register in which digital data corresponding to the signal Bv ₁ from the sample and hold circuit 4 is set, and 13 is a sample and hold circuit 6. This register is set with digital data corresponding to the signal _Bv2 from 14 is a fixed data output circuit that outputs fixed data corresponding to the apex value Tvc of the integral time;
3 is a change amount data output circuit that outputs data corresponding to the change amount Δf in the apex system from the set flash light emission amount during photometry, and 26 is a change amount data output circuit that outputs data corresponding to the apex value Tvs of the set exposure time. This is an exposure time data output circuit. 15 to 22, 24, 25, and 27 to 39 are calculation blocks, which are shown in this configuration to make it easier to understand the calculation contents. Instructions can be created using a computer based on the flow of operations shown in the block diagram. Also, switch
Blocks that control the switching of S ₁ , S ₂ , and S ₃ , sample-and-hold timing, multiplexer and demultiplexer data selection signals and signal switching, A-D conversion timing, etc. are not shown, but the operations below are as follows. It is easy for a person skilled in the art to create a timing controller that controls each block at the timing shown in the explanation, so the explanation is omitted. Note that this can also be easily implemented using a microcomputer. First, when the measurement button (not shown) is operated, the apex value is
Tvc) The switch _S1 is connected to the terminal _F1 , and the switch _S2 is connected to the terminal _F2 , and the switch _S3 is closed to cause the flash light emitting device FL to emit light. This integration time is longer than the maximum light emission time of the flash light emitting device FL. After a certain period of time, the switches S ₁ and S ₂ are connected again to the terminals A ₁ and A ₂ , respectively, so that the input signals to the integrating circuits 3 and 5 disappear, and the integrated output is sampled and held. Then, the sample and hold circuit 4,
When the circuit 6 performs sample and hold, the outputs of the photometric circuits 1 and 2 are sampled and held in this circuit.
By the way, the integrating circuits 3 and 5 output a logarithmically compressed value of the integrated value of the current corresponding to the output current of the light receiving element in the photometric circuit, and the photometric circuits 1 and 2 output the apex value of the subject brightness. A concrete example of this circuit is shown in FIG. If the analog output of integrating circuit 3 is Qv ₁ and the output of sample and hold circuit 4 is Bv ₁ , then Qv ₁ = lOg ₂ (2 ^Bv1-Tvc + 2 ^Qvfm1 ) ... (4-1), and the output of integrating circuit 5 is When Qv ₂ and the output of the sample-and-hold circuit 6 are Bv ₂ , Qv ₂ =lOg ₂ (2 ^Bv2-Tvc +2 ^Qvfm2 ) (4-2). Here, Qvfm ₁ and Qvfm ₂ are the amount of light reflected only by the flash light emitting device during photometry. That is,
The sample and hold circuits 4 and 6 output the brightness apex values of the portions photometered by the photometry circuits 1 and 6, respectively, and the integrator circuits 3 and 5 output the amount of light from the two portions when the flash is emitted. That will happen. When the sample-and-hold circuits 4 and 6 perform sampling, the signal from the integrating circuit 3 is first output from the multiplexer 7, and is converted from A to D by the A to D converter 8. When the A to D conversion is completed, This digital data is demultiplexed by 9
is set in the register 10 via. Next, the signal from the integrating circuit 5 is outputted from the multiplexer 7, which is subjected to AD conversion, and this data is set in the register 11. Similarly, the A-D converted data output from the sample-and-hold circuit 4 is set to the register 12, and the A-D converted data output from the sample-and-hold circuit 5 is set to the register 13. Therefore, register 10 contains 11
Data corresponding to Qv ₂ , Bv ₁ to 12, and Bv ₂ to 13 are set, and the following circuit performs calculations based on this data. The subtraction circuit 15 calculates Bv ₁ −Tvc based on the data from the register 12 and the fixed data output circuit 14.
Similarly, the subtraction circuit 16 outputs the data of
Data of Bv ₂ −Tvc is output. Then, in the subtraction circuit 17, Qv ₁ - (Bv ₁ - Tvc) = Δ ₁₁ (5-1), and in the subtraction circuit 18, the calculation of Qv ₂ - (Bv ₂ - Tvc) = Δ ₁₂ (5-2) is performed. . The calculated data of Δ ₁₁ and Δ ₁₂ are stored in the data conversion ROMs 19 and 2.
ROM19, 2 as address specification data for 0.
0, and log ₂ (2〓 ¹¹ −
1), log ₂ (2〓 ¹² -1) data is output. Data from this ROM19, 20 and subtraction circuit 1
The data of Bv ₁ -Tvc and Bv ₂ -Tvc from 5 and 16 are sent to adder circuits 21 and 22, and (Bv ₁ -Tvc) + log ₂ (2〓 ¹¹ -1) = Qvfm ₁
...(6-1) (Bv ₂ - Tvc) + log ₂ (2〓 ¹² -1) = Qvfm ₂
...(6-2) is performed, and the amounts of reflected light Qvfm ₁ and Qvfm ₂ due to light emission from the flashlight emitting device during photometry are calculated. By equations (6-1) and (6-2), Qvfm ₁ ,
Explain why Qvfm ₂ is calculated. (4-1),
Rewriting equation (4-2), 2 ^Qv1 = 2 ^Bv1-Tvc + 2 ^Qvfm1 ... (4'-1) 2 ^Qv2 = 2 ^Bv2-Tvc + 2 ^Qvfm2 ... (4'-2), and this (4' -1), (4'-2) to (5-
Based on equations 1) and (5-2), Qv ₁ and Qv ₂ are eliminated and rearranged, 2 ^Bv1-Tvc (2〓 ¹¹ -1) = 2 ^Qvfm1 2 ^Bv2-Tvc (2〓 ¹² -1) = 2 ^Qvfm2 , and taking log ₂ of both sides of both equations, (6-1),
Equation (6-2) is obtained. Data Qvfm ₁ and Qvfm ₂ from the adder circuits 21 and 22 and data Δf from the change amount data output circuit 23 are input to the subtraction circuits 24 and 25, and Qvf ₁ =Qvfm ₁ −Δf (7-1) Qvf ₂ = Qvfm ₂ -Δf (7-2) The following calculation is performed. As mentioned above, Δf is the number of steps to change the light emission amount of the flash device during photometry to the light emission amount during shooting, so (7-1), (7-
Qvf ₁ and Qvf ₂ calculated by formula 2) correspond to the amount of reflected light from flashlight emission during photographing. The subtraction circuits 27 and 28 receive the data Bv ₁ and Bv ₂ from the registers 12 and 13 and the apex value of the set exposure time from the exposure time data output circuit 26.
Tvs data is input. And from each husband
Data of Bv ₁ −Tvs and Bv ₂ −Tvs is output.
The subtraction circuits 29 and 30 receive data Qvf ₁ and Qvf ₂ from the subtraction circuits 24 and 25 and data Bv ₁ -Tvs and Bv ₂ -Tvs from the subtraction circuits 27 and 28, and Qvf ₁ - (Bv ₁ -Tvs). =ΔL ₁ ...(8-1) Qvf ₂ =(Bv ₂ −Tvs)=ΔL ₂ ...(8-2) The following calculations are performed. The calculated data ΔL ₁ and ΔL ₂ correspond to the ratio of the contribution amounts of the flash light and steady light of the two parts to the exposure, or the difference in the contribution amounts in the apex system, and this is usually the lighting contrast. It is called. The lighting contrast data ΔL ₁ and ΔL ₂ from the subtraction circuits 29 and 30 are for data conversion.
It is sent as the address data of ROM31, 32, and from ROM31, 32, log ₂ (2〓 ^L1 +1), log ₂
Data of (2〓 ^L2 +1) is output. This ROM3
Data from 1, 32 log ₂ (2〓 ^L1 +1), log ₂ (2〓 ^L2
+1) and the data from the subtraction circuits 27 and 28 (Bv ₁
-Tvs) and (Bv ₂ -Tvs) are input to adder circuits 33 and 34. (Bv ₁ − Tvs) + log ₂ (2〓 ^L1 + 1) = Qvt ₁
...(9-1) (Bv ₂ −Tvs) + log ₂ (2〓 ^L2 +1) = Qvt ₂
...(9-2) is performed, and data Qvt ₁ and Qvt ₂ in the apex system of the amount of light contributing to the exposure of the photoreceptor during flash photography by the two parts are calculated. (9-1),
The reason why the apex system data of the amount of light contributing to exposure is determined by equation (9-2) will be explained.
Using equations (8-1) and (8-2), (2-1) and (2
−2) Eliminating Qvf ₁ and Qvf ₂ from the equation, 2 ^Bv1-Tvs (1+2〓 ^L1 )=2 ^Qvt1 2 ^Bv2-Tvs (1+2〓 ^L2 )=2 ^Qvt2 , and taking the log ₂ of both sides of both equations, ( 9-1), (9
-2) Equation is obtained. Also (9-1), (9-2)
As is clear from the formula, the data log ₂ (2〓 ^L1 +1) and log ₂ (2〓 ^L2 +1) from the ROMs 31 and 32 are the exposure of the respective parts when the flashlight emitting device FL is emitted and when it is not emitted. This corresponds to the ratio of the amount of light contributing to this, or the difference in the apex system, and is called the step number difference Δd. And this is Δd ₁ = log ₂ (2〓 ^L1 + 1) = Qvt ₁ − (Bv ₁
-Tvs)...(10-1) Δd ₂ = log ₂ (2〓 ^L2 +1) = Qvt ₂ - (Bv ₁
-Tvs)...(10-2). The data Qvt ₁ and Qvt ₂ from the adder circuits 33 and 34 are input to the adder circuit 35, and the data of Qvt ₁ +Qvt ₂ is calculated.This data is input to the divider circuit 36, where = (Qvt ₁ + Qvt ₂ )/ 2...(11) is calculated. This is the average of the light amounts of two parts in the apex system, and the light amounts 2 ^Qvt1 and 2 ^Qvt2
Corresponds to the geometric mean of √2 ^Qvt1・2 ^Qvt2 = 2 ^Qvt . Note that this is the density average when focusing on the image reproduced on the photoreceptor. The subtraction circuit 37 receives data Qvt ₁ and Qvt ₂ from the addition circuits 33 and 34, and calculates Δc ₂₁ =Qvt ₂ -Qvt ₁ (12-1). This corresponds to the contrast between the two parts. In the subtraction circuit 38, based on the data from the division circuit 36 and the data Qvt ₁ from the addition circuit 33, the following calculation is performed: Δca ₁ =-Qvt ₁ (12-2). This data corresponds to the ratio of the average light amount to the light amount of the first portion, or the difference or contrast between the average density and the density of the first portion. Similarly, the subtraction circuit 39 calculates Δca ₂ =−Qvt ₂ (12−3), which corresponds to the contrast between the average and the second portion. As explained above, in the embodiment shown in FIG. 1, the contrast of two parts and the average and contrast of each part at the time of flash emission can be obtained. Then, the set exposure time Tvs or the set change amount Δf of the flash light emission amount
By changing these values, the calculated contrast will also change, and by changing these set values, the exposure factor that will give the desired contrast can be found. Although blocks on the display device are omitted in FIG. 1, the calculated contrast and various data obtained in the process of calculating this contrast may be input to the display device and displayed. Further, when photometric calculation is performed without causing the flash light emitting device FL to emit light, the following procedure is performed. At this time,
The output data of the subtraction circuits 17 and 18 becomes 0. That is, Qv ₁ =Bv ₁ −Tvc Qv ₂ =Bv ₂ −Tvc. At this time, data corresponding to -∞ (minus infinity) is output from the ROMs 19 and 20, and this data is affected by the calculations in the subtraction circuits 24 and 25 and the subtraction circuits 29 and 30. The data is input to the ROMs 31 and 32 without any interference. To actually perform such processing, for example, set bits that are not necessary for the operation to “1”.
Just leave it as . This data is ROM31,3
2, the ROMs 31 and 32 output data corresponding to 0 regardless of data from other bits, and the outputs of the adder circuits 33 and 34 are Qvt ₁ = Bv ₁ - Tvs Qvt ₂ = Bv ₂ −Tvs. Therefore, the calculated contrast is a ratio of brightness due to stationary light, and the contrast does not change even if the set value is changed. Furthermore, when Qvf ₁ and Qvf ₂ are −∞, this corresponds to the amount of flash light being 0, the lighting contrast is −∞, and the difference in the number of steps is 0. In the embodiment shown in Fig. 1, the photometric portions of the light receiving elements of the two photometric circuits may be different parts of the photographic screen, for example, one may measure the central area and the other may measure the average value of the remaining area. Alternatively, one may photometer a portion of the upper portion and the other may photometer a portion of the lower portion, and various other modifications are possible. FIG. 2 shows another example for determining the average amount of light. This embodiment calculates a weighted average, and is effective, for example, in a type of photometry system in which one light-receiving element measures the center portion and the other measures the average of the other portions. The principle of this embodiment will be explained. Here, = log ₂ {(2 ^Qvt1 +2 ^Qvt2 ×0.8
)/(1+0.8)}...(13) is the average light amount. (13) log ₂ 0.8≒−0.3log ₂ 1.8
When transformed using ≒0.8 = log ₂ (2 ^Qvt1 + ^Qvt2-0.3 ) −0.8……(13−1
) becomes. Therefore, if Qvt ₁ − (Qvt ₂ −0.3) = α, log ₂ (2 ^Qvt1 + 2 ^Qvt2-0.3 ) = (Qvt ₂ −0.3
) + log ₂ (2〓+1) relationship is obtained. Therefore, the subtraction circuit 40 obtains data of Qvt ₂ -0.3, and then the subtraction circuit 41 obtains Qvt ₁ -(Qvt ₂ -0.3)=α, and this data α is stored in the ROM 42 as log ₂ (2〓 +1), the addition circuit 43 calculates (Qvt ₂ -0.3) + log (2〓+1), and the subtraction circuit 44 calculates = log ₂ (2〓+1) + (Qvt ₂ - 0.3)−0.8= _log2
(2 ^Qvt1 +2 ^Qvt2-0.3 )−0.8……(13−1) =log ₂ {(2 ^Qvt1 +2 ^Qvt2 ×0.8)/(1+0.8)}……(1
3) has been found, and the value of the weighted average light amount in the apex system has been found. FIG. 3 shows still another example for determining the value of the average light quantity in the apex system. This embodiment calculates a harmonic average, and is suitable for a type of photometry system in which, for example, one light-receiving element measures part or all of the upper part, and the other light-receiving element measures part or all of the lower part. This principle will be explained. The harmonic mean is =log ₂ {2/(1/2 ^Qvt1
+1/2 ^Qvt2 )}...(14), and when transformed, it becomes =1-log ₂ (2 ^-Qvt1 +2 ^-Qvt2 )...(14-1). Therefore, using Qvt ₂ −Qvt ₁ =Δc ₂₁ ...(12−1), −log ₂ (2 ^−Qvt1 +2 ^−Qvt2 )=Qvt ₂ −lo
The relationship g ₂ (2〓 ^c21 +1) is obtained. Therefore, in the subtraction circuit 37 in FIG.
-1) The calculation of the formula is performed, and the data of Δc ₂₁ is calculated, and this data is converted into log ₂ by the ROM 46.
It is converted to data of (2〓 ^c21 +1). Based on this data and the data Qvt ₂ from the addition circuit 34, the subtraction circuit 47 calculates Qvt ₂ −log ₂ (2〓 ^c21 +1), and the addition circuit 48 adds 1 to this data.
is added, =1+Qvt ₂ −log ₂ (2〓 ^c21 +1)=1−log ₂ (2 ^−
Qvt1 +2 ^-Qvt2 )...(14-1) = log ₂ {2/1/2 ^Qvt1 +1/2 ^Qvt2 ...(14) was found, and the value of the apetutic system of the average light amount in the harmonic mean was found. It turns out. FIG. 4 is a block diagram for calculating the aperture value for appropriate exposure based on the two portions and the average light amount determined in FIG. 1, FIG. 2, or FIG. 3.
49 is a film sensitivity output circuit for outputting the data of the set film sensitivity Sv, and 50 is a block for outputting the average light amount of blocks 35 and 36 in FIG. 1 or FIG. 2 or 3. The adder circuit 51 receives data from the adder circuit 33.
Data from Qvt ₁ and film sensitivity output circuit 51
Sv is input, and Qvt ₁ +Sv=Av ₁ ... (15-1) is calculated. This is the apex value of the aperture at which the first portion is properly exposed. Further, the adding circuit 52 calculates Qvt ₂ +Sv=Av ₂ . . . (15-2) based on the data Qvt ₂ from the adding circuit 34 and the data Sv from the film sensitivity output circuit 49. This is the apex value of the aperture at which the second portion is properly exposed. Furthermore, the adder circuit 53 receives data from the average value calculation block 50.
Qvt and data Sv from film sensitivity output circuit 49
Based on this, +Sv=...(15-3) is calculated. This is the apex value of the aperture value at which the entire photographic screen is properly exposed. FIG. 5 shows an optical system of a photometric meter to which the present invention is applied, and FIG. 6 is a diagram showing the light receiving portion of each light receiving element. 60 is an objective lens, 61 is a half mirror for splitting light, and one light beam is sent to the photodetector PD ₁ ~
On the PD ₅ side, the other ray is guided into the finder system. Reference numeral 62 is a condenser lens, and 63 is a focusing plate. On this focusing plate, indicators 631 to 635 are provided to allow the observer to see the photometric units P ₁ to _{P 5} . 64 is a penta roof prism, and 65 is an eyepiece. If such an optical system is used, the sixth
As shown in the figure, spot metering is performed on five areas of the shooting screen surrounded by solid lines: center P ₁ , upper left P ₂ , upper right P ₃ , lower left P ₄ , and upper right P ₅ become. FIG. 7 is an external view of a photometric meter to which the present invention is applied. The functions of each operation section and the display section DI will be explained. HS is the hot shoe for attaching the flashlight device, and ST is the terminal for the trigger cord of the flashlight device. MK is the photometry key, and when this key is pressed, the flash device starts emitting light and photometry also starts. TK is the key for setting exposure time, this key and UP key UK or DOWN
When keys DK are pressed at the same time, the set exposure time displayed on the display section DI ₂ changes in units of 1 Ev every fixed time. When the set exposure time reaches the limit value, it stops changing. ASK is a key for setting the ASA sensitivity, and is displayed on the display section DI ₃ when the UP key UK or DOWN key DK are pressed at the same time. ASA sensitivity changes in 1/3Ev steps.
ΔK is the key that sets the amount of change in the amount of light emitted by the flashlight emitting device, and this is also the UP key UK or DOWN key DK.
When pressed at the same time, the setting value displayed on the display section DI ₄ changes in 0.5Ev steps.
Regarding the setting of ASA sensitivity and change amount, when the set value reaches the limit, the data will not change. The UP key UK is pressed to increase the apex value of the setting data, and the DOW key DK is pressed to decrease it. When contrast key CK is pressed, the display
"CONT" of DI ₅ is displayed, and numbers indicating the two parts are displayed on display sections DI ₆ and DI ₇ . Further, the contrast value calculated based on the measured value is displayed on the display section DI ₁ in units of 0.1 Ev. Lighting Contrast Key LCK
When is pressed, "L.CONT" is displayed on display DI ₅ , the number of the photometry section is displayed on display DI ₆ , and
Display section DI ₇ does not display anything. In addition, the display section
DI ₁ displays the calculated lighting contrast value. When FNo. key FNK is pressed,
Display section DI ₅ displays "F No.", display section DI ₆ displays the photometry section number, display section DI ₇ is blank, display section DI ₁ displays the F value, and 1Ev or less is displayed in 1.1Ev units. Is displayed. When F/B key FBK is pressed,
When the slide switch FAS is set to the FLASH side, the display section DI ₅ will display "FLASH",
Display section DI ₆ shows the number of the photometry section, and
DI ₇ is blank, and display section DI ₁ displays the amount of light received by the flash light emitting device as an Ax system value. Also, when the slide switch FAS is set to the AMBI side, “AMBI” will appear on the display DI ₅ .
is displayed, the subject brightness is displayed on the display section DI ₁ , the number of the photometry section is displayed on the display section DI ₆ , and the display section DI ₇ is blank. AVK, 1K to 5K are keys to specify the photometry position of the photometry value to be displayed on the display section DI ₁ , and AVK is the average value of 5 photometry positions,
1K is P ₁ in Figure 6, 2K is P ₂ , 3K is P ₃ , 4K is P ₄ ,
5K designates _P5 . The operation shown in FIG. 7 will be explained. Measuring key MK
When is pressed, the flashlight emitting device emits light and photometry is performed, and then the photometry values are taken in and calculations are performed. Then, the setting values are displayed on DI ₂ , DI ₃ , and DI ₄ , the display mode is displayed on DI ₅ , and the calculated value is displayed.
When the _contrast display is displayed, the measurement point is displayed using DI ₆ and DI _7. When the display is other than contrast, the measurement point is displayed using DI ₆ .
Displayed only by Note that when it is an average value, it is displayed as “〓”. After the display is performed, all DI displays will disappear if no key operations are performed for a certain period of time.
You can also use TK, ASK,
Pressing either ΔK and UK or DK changes the setting value and also changes the value displayed on the display section DI ₁ . After a certain period of time after this key operation,
All DI displays disappear. When the photometry key MK is held down, measurement values using ambient light continue to be captured, and the displayed value on the display section DI ₁ changes in accordance with changes in subject brightness.
In addition, CK, LCK,
When operating FNK, FBK, or AVK, 1K to 5K to change the metering point, the display contents will also change, and if no key operations are performed after a certain period of time, the display will disappear altogether. When photometry is performed without using a flashlight emitting device, display is performed using only constant light. FIG. 8 is an internal circuit diagram of the photometric meter shown in FIG. 7. E is the power battery, and the micro
Power is constantly supplied to a computer (hereinafter referred to as a microcomputer) section 100, and power is supplied to the circuit section surrounded by a broken line via a power supply transistor _BT1 . This power supply transistor BT ₁ is μ-com10
0 output terminal OT ₂ and an inverter IN ₁ . A specific circuit example of the photometric circuit 80 and multiplexer 81 is shown in FIG. In FIG. 9, PD ₁ to PD ₅ are photodetecting elements corresponding to the photometric sections P ₁ to P ₅ , respectively, D ₁ to _{D 5} are diodes for logarithmic compression,
OA ₁ to _{OA 5} are operational amplifiers, which output potentials corresponding to logarithmic compression values of the light receiving intensities of the light receiving elements PD ₁ to _{PD 5} . BT ₁₁ to _{BT 15} are logarithmic expansion transistors, and BT ₂₁ to _{BT 25} are current mirror transistors. Diode D ₁₁ ~
The circuit composed of D ₁₅ , D ₂₁ to D ₂₅ and capacitors C ₁₁ to C ₁₅ is a circuit known in Japanese Patent Publication No. 50-28038,
A voltage obtained by logarithmically compressing the integral value of the current flowing into this circuit is output across the capacitors C ₁₁ to _{C 15} . FT ₁₁ to _{FT 15} , FT ₂₁ to _{FT 25} are FETs for analog switches, FT ₄₁ to _{FT 45} are FETs for sample and hold analog switches, FT ₃₁ to _{FT 35} are FETs for resetting capacitors C ₁₁ to C ₁₅ . FET, _C21 to _C25
is a sample/hold capacitor.
The analog switch FETs and decoder DE shown as FT ₅₁ to FT ₅₅ and FT ₆₁ to _{FT 65} constitute a multiplexer 81 in FIG. Decoder DE
is based on the data from the output port OP ₁ of the microcomputer 100, sets one of the output terminals to High, and outputs the corresponding FT ₅₁ to FT ₅₅ and FT ₆₁ to _{FT 65.}
When one of the FETs is turned on, the capacitor
One of the analog signals C ₁₁ to C ₁₅ and C ₂₁ to _{C 25} is input to the A-D converter 82 . output port
Table 1 shows the relationship between OP ₁ data and input data.

[Table] The configuration of FIG. 8 will be explained again. 100 is a one-chip microcomputer. Inside this, there is a power-on clear circuit 101, a clock generator 102, a RAM 103, an address controller 104 for the RAM 103, and an accumulator 10.
5. Carry flag 106, ALU 107, divider 108, ROM 110, ROM address controller 109, input flip-flop IF ₁ , input port INP ₁ , INP ₂ , output port
OUP ₁ , OUP ₂ , OUP ₃ , etc. are provided. The feature of this microcomputer 100 is that when power is supplied to the microcomputer 100 by replacing the power supply battery E, etc., the power-on clear circuit 101 operates.
The operation starts from a specific address in the ROM 110.
In addition, when the clock is in the clock end (CEND) state, no command is executed, and the clock generator 102 and divider 108 operate, and when a 1 second sec signal from the divider 108 or a key input is received, the command is not executed. executes an instruction from a specific address in ROM 110. Next, the functions of each labeled register and flag in the RAM 103 will be explained. SFJ is a flag for determining whether to output the light emission signal of the flash device, IFJ is a flag for determining completion of importing all photometric data, MCJ is a flag for determining whether photometry is in progress, DFJ is a flag for determining whether photometry is in progress. Flag for determining whether calculation of display data is complete, QJF
is a flag for determining whether the light emission amount Qvfm of only the flash light emitting device is calculated. DIR is a register for selecting data to be captured, and the contents of this register are output from output port _OP1 . Table 1' shows the relationship between the contents of this register and the captured data. COR is a register that counts the time from the end of a key operation until the display turns off. DSR is a register where the data of the change value Δf of the flash light emission amount is set, and TVR is the set exposure time Tvs.
SVR is the register where the setting film sensitivity is set. BDR is a register in which data corresponding to the display mode is set, and the relationship between the contents and the display mode (display contents) is shown in Table 2.

[Table] NDR1 and NDR2 are registers in which data indicating the photometry sections corresponding to the photometry sections P ₁ to _{P 5} and the average are set, and in cases other than contrast, the portion corresponding to the contents of NDR1 is set as the photometry section. Moreover, in the case of contrast, it is the contrast between parts corresponding to the contents of NDR1 and NDR2. NDR1, NDR2
Table 3 shows the relationship between the contents and the photometry section.

【table】

【table】

[Table] DPR ₁ is a register in which the display data to display unit DI ₁ is set. DPR2 is the data obtained by decoding register BDR, that is, the register in which display data to display unit DI ₅ is set. DPR3 is the contents of register NDR1. DPR4 is the data that is decoded from the contents of register _NDR2 ;
That is, it is a register in which display data to be displayed on the display section DI ₇ is set. DPR5 is a register in which data decoded from the contents of register TVR is set. This data is output from output port _OP3 , and DRP6
DPR7 is a register in which the data decoded from the contents of register SVR is set, and this data is output from output port OP ₄ , and DPR7 is set to the data decoded from the contents of register DFR, and this content is output from output port OP ₅ . be done. QVR1～QVR
5 and BVR1 to BVR5 are registers in which photometric data taken in from the A-D converter 82 is set, QVR1 has Qv ₁ , QVR2 has Qv ₂ ,
Qv ₅ for QVR5, Bv ₁ for BVR1, BVR4
Data of Bv ₅ is set in Bv ₄ and BVR5.
QFR1 to QFR5 and QFRA are registers where the light intensity of only the flash light emitting device during photometry is set.
Qvfm ₁ for , Qvfm 2 for QFR2 , Qvfm ₂ for QFR5
Qvfm ₅ , QFRA is set. In addition, the RAM 103 includes registers for calculations, registers for temporary storage of other data, and the like. The output terminal OT ₁ of the output port OUP ₁ serves as an A-D conversion start signal for the A-D converter 82 . terminal
OT ₂ is connected to the input terminal of the one-shot circuit OS and to the base of the transistor BT ₁ via the inverter IN ₁ , and serves as a reset signal for the integrating capacitors C ₁₁ to _{C 15} and a power supply control signal to the circuit surrounded by the broken line. It's summery. The terminal OT ₃ is connected to the photometry circuit 80 via the inverter IN ₂ , and further to the trigger circuit 83 of the flashlight emitting device, and is connected to a switching signal for integration during flashlight emission and photometry for ambient light, and a flashlight emission signal. It's summery. Terminal OT ₄ is connected to photometric circuit 80 and serves as a sample/hold signal. As described above, the contents of the input data selection register DIR are output to the output port OUP ₂ . From the output port OUP ₃ , display data is output from OP ₂ to _{OP 3} , and strobe signals for display and key scanning are output from OP ₉ . The input port INP ₁ is a port for taking in digital data from the A-D converter 28, and the input port INP ₂ is a port for inputting a key signal. The relationship between the key switch and the key buttons in Figure 7 is as follows: TS becomes TK,
ASS to ASK, US to UK, DS to DK, CS to
CK, LCS to LCK, FNS to FNK, FBS to
FBK, 1S to 1K, 2S to 2K, 3S to 3K, 4S
becomes 4K, 5S becomes 5K, AVS becomes AVK, MS becomes MK
, ΔS corresponds to ΔK, respectively. FAS is the 7th
This is a switch linked to the slide switch FAS shown in the figure, and when it is on the "FLASH" side, it is connected to the terminal FL, and "AMBI"
When it is on the side, it is connected to terminal AM. Figure 10-a, b, Figure 11-a, b, Figure 12
-a, b, c, FIG. 13, and FIG. 14 are flow charts showing the operation of the microcomputer 100. Based on this, the operations in FIGS. 8 and 9 will be explained below. Figures 10-a and 10-b are flow charts showing the overall operation. When a 1sec signal or key signal is input in the CEND state, the microcomputer 100
The operation starts according to an instruction from a specific address in the ROM 110. In step #1, determine whether the 1sec signal is a key signal, and if it is a 1sec signal, as shown in Figure 13.
Performs 1sec operation. If it is a key signal, next, determine whether the photometry switch MS is on,
When the photometering switch MS is not ON, the 12th-a,
After performing the key discrimination operations shown in Figures b and c, the process moves to step #5. When photometry switch MS is ON, set terminal OT ₂ to High. Then, a high pulse is output from the one-shot circuit OS for a certain period of time, turning on FETs FT ₃₁ and FT ₃₂ , and turning on the capacitor.
C ₁₁ to C ₁₅ are reset. Also, inverter
The output of IN ₁ becomes Low and power supply by transistor BT ₁ starts. At this time, terminal OT ₃ is
Since it is Low, the FETs FT ₂₁ to FT ₂₅ are non-conductive and the capacitors C ₁₁ to C ₁₅ are not charged. In step #4, the light emission determination flag SFJ is set to 1, and the data import determination flag IFJ, photometry status determination flag MCJ, display data completion determination flag DFJ, and Qvfm calculation completion determination flag QJF are set to 0. Set. Next, in step #5, it is determined whether or not the photometry data has been captured.However, since the capture has not yet been completed when the photometry switch MS is pressed, the process moves to step #6, and the data is displayed for display. Determine whether data calculation is complete. If the display data calculation has not been completed, proceed to step #7 to set the display register DPR.
Blank data (data for erasing the display) is set in DPR1 to DPR7, and then it is determined whether or not to emit a flash. When the photometering switch MS is closed, it is necessary to make the flash light emitting device emit light, so proceed to step #9 and set the terminal OT ₃ to High.
As a result, the trigger signal of the flashlight emitting device is output from the trigger circuit 83, and at the same time, the trigger signal of the flashlight emitting device is outputted from the trigger circuit 83, and at the same time,
FETs FT ₁₁ to FT ₁₅ become non-conductive, FT ₂₁ to _{FT 25} become conductive, and charging of capacitors C ₁₁ to C ₁₅ begins. Then, after counting a certain period of time _T1 and setting the flag SFJ for light emission determination to 0, the terminal _OT3 is set to Low again. By this,
The FETs FT ₂₁ to FT ₂₅ become inactive, and charging to the capacitors C ₁₁ to C ₁₅ is stopped, and the integral value at this time is sampled and held. The time required from step #3 to step #9 after the photometry switch MS is closed is longer than the time it takes for the photometry circuit 80 to start being supplied with power and for the circuit to stabilize. Further, the time required from step #9 to step #12 is longer than the time required for a normal flash light emitting device to emit all light, and this time corresponds to the apex value Tvc. In step #13, set the terminal OT ₄ to High and the 9th
FETs FT ₄₁ to FT ₄₅ in the figure are turned on for a certain period of time T ₂
count. Then, in step #15, turn terminal OT ₄ low again and turn FT ₄₁ to FT ₄₅ OFF.
Therefore, the operational amplifier OA ₁ is connected to the capacitors C ₂₁ to C ₂₅
~The output of OA ₅ is sampled and held. At step #16, it is determined whether this step has been reached by closing the photometric switch MS, and when this step is reached by the key determination operation as described later, it jumps to step #20. do. In step #17, the contents of the register DIR for specifying the data to be taken in are output from the output port _OP1 and sent to the multiplexer 81. At the time when the photometry switch MS is pressed, the contents of the register DIR are 0110 as described later, and the decoder DE in Fig. 9 sets the terminal d ₁ to High, makes the FET FT ₅₁ conductive, and integrates the capacitor C ₁₁ . Voltage Qv ₁ is A-D
It is input to converter 82. By steps #18 and #19, a high pulse is output from the terminal _OT1 , and the conversion operation of the A/D converter 82 is started. Then, in step #20, display register DPR1
~Output the contents of DPR7 to output ports _OP2 ~ _OP8 . At this time, if the key discrimination operation described later or the calculation of display data has been completed, the display device
A predetermined display is performed on DI ₁ to DI ₇ , and as described above, when this step is reached after passing through step #7, nothing is displayed on the display devices DI ₁ to _{DI 7} . Note that the output ports _OP2 to _OP7 have a latch function, and hold the current output data until the output data is changed. In step #21, it is determined whether photometry is in progress, and if it is not in step #28, the display time count register is reset and the CEND state is entered. When it is determined in step #21 that photometry is in progress, data from the A-D converter 82 is taken in from the input port _IP1 . The time required from step #18 to step #22 is longer than the time required for AD conversion. In step #23, it is determined whether the photometry switch MS is closed, and if it is not, it is determined in step #24 whether or not data acquisition is complete. When data acquisition is complete, set terminal OT ₂ to Low, turn off power supply transistor BT ₁ , set 0 to flag MCJ for photometry determination, and specify Qv ₁ to acquisition data selection register DIR. Set data 0110 to reset the counter register COR and enter the CEND state. If the photometry switch MS is closed in step #23 or #24, or if the data acquisition is not completed, the process moves to step #29. In step #29, the contents of the register DIR are determined, and based on this, the fetched data is set in the register corresponding to this data. That is, if the contents of DIR are
If 0110, the data is Qv ₁ and register QVR
1), 1001 is Qv ₄ and register (QVR4), 1101 is Bv ₃ and register BVR ₃ , 1111 is Bv ₅ and register
Set to BVR ₅ . And Carrie Flag 1
Determine whether 06 has become 1 (whether the calculation result has become 10000 or not), and if it is not 1, set the data import determination flag IFJ to 0 and
Proceed to step #5 in Figure 0-a. When carry flag 106 becomes 1, the contents of register DIR before being added in step #30 are
1111, which means that 10 pieces of data have been imported. Therefore, set the capture completion flag IFJ to 1, then set the register DIR to 1011, and in steps #36 to #37, as in steps #13 to #15, perform the steps shown in FIG. The output of operational amplifier OA ₁ ~ _{OA 5} is connected to capacitor C ₂₁ ~ C ₂₅
sample and hold and return to step #5. To explain once again how to take in photometric data, when the photometric switch MS is closed, the first time a flash is emitted and an integral operation is performed, and then the photometric value of the stationary light is sampled and held. Next, output the contents of register DIR 0110 and convert Qv ₁ to A-D.
Convert, import, and set to QVR1. next
Add 1 to 0110, output this data, and convert Qv ₂ to A
−D conversion and set in register QVR2, 0111
1 is added to , and the same operation as described above is repeated, and when the result of adding 1 to register DIR overflows (carry is 1), all data has been taken in. Then, in order to follow the changes in the ambient light, the photometric values of the ambient light are sampled and held again, and the register DIR is set to 1011 so that only the data of the ambient light will be taken in below. Then, return to step #5 and step 11-
After performing the calculation operations shown in figures a and b, Bv ₁ is returned again.
Converts A-D and displays the calculated value.
Import the data of Bv ₁ , and at this time set the metering switch.
If the MS is open, it will go through steps #24 and below to enter the CEND state. At this time, the photometry switch
If the MS is closed, the imported data will be
Set BVR to 1, add 1 to DIR, further set IFJ to 0, return to step #5, and repeat the same operation as above. Therefore, if the photometry switch MS is open when the first data capture is completed, calculations and display will be performed based on the data captured at this time. If the photometry switch MS is left open, the display will remain as before until the second measurement of steady light is completed, and once that is completed, calculations and display will resume using the second data. It will be fixed. In addition,
When the first data acquisition loop is started, even if the photometry switch MS is released during this time, the acquisition will be repeated until the data acquisition is completed, at which point the system will enter the CEND state. Figures 11-a and 11-b are flowcharts of the calculation operation shown in Figure 10-a. In step #41, it is determined whether calculation of the light emission amount Qvfm of only the flash light emitting device during photometry has been completed. When the first import is completed, the calculation is not yet complete, so move on to step #42, and when the second and subsequent imports are completed or when step #41 is reached due to key discrimination operation, go to step #45. Transition. In step #42, the following calculation is performed. The photometric data set in the QVR1 to QVR5 registers are: Qv ₁ 〓 Qv ₅ = log ₂ (2 ^Bv1-Tvc + 2 ^Qvfm1 ) 〓 = log ₂ (2 ^Bv1-Tvc + 2 ^Qvfm5 ...(4-1) 〓 ...( 4-5) So, this data and register
Based on the data of BVR ₁ to BVR ₅ and the fixed data Tvc, Qv ₁ 〓 Qv ₅ − (Bv _{1 −} Tvc) − (Bv _{5 −} Tvc) = Δ ₁₁ 〓 = Δ ₁₅ …… (5− 1) Calculate 〓 (5-5) and convert this calculated data Δ ₁₁ to _{Δ 15} into log ₂
(2〓 ¹¹ −1) ~ log ₂ (2〓 ¹⁵ −1) and convert this data into (Bv ₁ −Tvc) ~ (Bv ₅ −Tvc)
_By ^adding _{to the data of _} ^_ −1) 〓 (6-5) is calculated. In step #43, the average value is calculated based on the data Qvfm ₁ to Qvfm ₅ calculated in step #42.
This is the step to obtain Qvfm data. In this embodiment, a case of weighted average will be explained. Here, the weighting of the photometric value of the P ₁ part is set to 1,
The weighting of the part P ₂ to P ₅ is set to 0.4. Therefore,
Corresponds to center-weighted average metering. is shown by the following formula; = log ₂ {2 ^Qvfm1 +0.4 (2 ^Qvfm2 +2 ^Qvfm3 +2
^Qvfm4 +2 ^Qvfm5 )/1+0.4×4}...(16-1) Transforming this = log ₂ (2 ^Qvfm1 +2 ^Qvfm2-1.3 +2 ^Qvfm3-1.3 +2 ^Q
vfm4-1.3 +2 ^Qvfm5-1.3 )−0.7……(16−2). Here, the relationships of log ₂ 0.4 = -1.3 and log ₂ 2.6 = 0.7 are used. Next, find Qvfm ₁ - (Qvfm ₂ -1.3) = α ₁ , convert it to log ₂ (2d ₁ + 1), and calculate Qvfm ₁₂ = (Qvfm _{2 -} 1.3) + log ₂ (2d ₁ + 1). Do this to find Qvfm ₁₂ , which is 2 ^Qvfm12 = 2 ^Qvfm1 + ^{2 Qvfm2-1.3} . Next, find Qvfm ₁₂ - (Qvfm ₃ - 1.3) = α ₂ , convert it to log ₂ (2〓 ² + 1), and then calculate Qvfm ₁₃ = (Qvfm ₃ - 1.3) + log ₂ (2〓 ² + 1). Perform the calculation to find Qvfm ₁₃ , which is 2 ^Qvfm13 = 2 ^Qvfm12 + ^{2 Qvfm3-1.3} . Similarly, Qvfm ₁₅ = log ₂ (2 ^Qvfm1 +2 ^Qvfm2-1.3 +2 ^Qvfm3-1.3 +
2 ^Qvfm4-1.3 + 2 ^Qvfm5-1.3 ) Find Qvfm ₁₅ , and subtract 0.7 from this data, as is clear from equation (16-2). Note that when performing photometry without firing the flash device, when the object to be measured is far away, or when the amount of light emitted is very small compared to the amount of steady light, the amount of flash light 2 ^Qvfm is set to 0. , and Qv−(Bv−Tvc)=Δ ₁ =0. In this case, Qvfm becomes −∞, but when Δ ₁₁ to _{Δ 15} become data corresponding to a predetermined value or less (for example, 0.1), data corresponding to −∞ is set in the register where Qvfm is set. .
In addition, in the process of calculating , when α becomes data corresponding to a predetermined value or less (for example, -3.8), the minuend is output as is. That is, for example, when α ₂ −3.8, Qvfm ₁₂ =
Qvfm ₁₃ . Furthermore, for example, when Qvfm ₂ is data corresponding to -∞, Qvfm ₁ =Qvfm ₁₂ . The change amount data Δf set in the register DFR in step #45 and the calculated light emission amount data
From Qvfm ₁ to Qvfm ₅ , calculate Qvf ₁ = Qvfm ₁ −∆f 〓 Qvf ₅ = Qvfm ₅ −∆f ......(7-1) 〓 ...(7-5) = -∆f ......(7-6) flash output Qvf ₁ ~
Calculate Qvf ₅ . At this time, when the Qvfm data corresponds to −∞, Qvf is left as the data corresponding to −∞. Next, in step #46, an average value is calculated based on the photometric data Bv 1 to Bv 5 taken into the registers BVR ₁ to BVR ₅ . Here, as in =log ₂ {2 ^Bv1 +0.4(2 ^Bv2 +2 ^Bv3
+2 ^Bv4 +2 ^Bv5 )/1+0.4×4}...(17) This is calculated in the same way as the calculation in step #43. In step #47, registers BVR1 to BVR5
Based on the contents Bv ₁ to BV ₅ , the exposure time data Tvs set in the register TVR, and the data calculated in step #46, calculate Bv ₁ −Tvs 〓 〓 Bv ₅ −Tvs −Tvs do. Next, in step #48, Qvf ₁ Qvf ₅ − 〓 − − (Bv _{1 −} Tvs) = (Bv _{5 −} Tvs) = (−Tvs) Δ 〓 Δ ΔL ₁ L ₅ La……(8-1) 〓 ...(8-5) ...(8-6) Data ΔL ₁ to ΔLa corresponding to the lighting contrast are calculated by performing the following calculations. At this time, when Qvf is data corresponding to -∞, ΔL is also set to data corresponding to -∞. Next, convert the calculated data into data corresponding to log ₂ (2〓 ^L1 +1) ~ _{log 2} (2〓 ^La +1), and add this data to (Bv ₁ − Tvs) ~ (Bv ₅ − Tvs). Therefore, Qv 〓 Qvt ₁ = (Bv _{1 −} Tvs) t ₅ = (Bv ₁ − Tvs) + 〓 +log ₂ (2〓 ^L1 +1) 〓 log ₂ (2〓 ^L5 +1) …(9-1) 〓 …( 9-5) Calculate. In other words, the amount of light due to steady light and flash light at the time of photographing has been calculated. Here, when the data corresponds to ΔL equal to or less than a predetermined value (for example, −3.8) or the data corresponds to −∞, Qvt=Bv−Tvs. Next, in step #49, based on the data of Qvt ₁ to Qvt ₅ calculated in step #48,
Calculate the average value. =log ₂ {2 ^Qvt1 +0.4(2 ^Qvt2 +2 ^Qvt3
+2 ^Qvt4 +2 ^Qvt5 )/1+0.4×4}(18) This calculation is performed in the same manner as steps #43 and #46. In step #50, it is determined whether the content of register BDR for display mode determination is 1 or not. When it is 1, it is a mode for displaying contrast. In step #51, data Qvt corresponding to register NDR2 is subtracted from Qvt corresponding to register NDR1, where data corresponding to the photometry section is set.
The contrast between the photometric section corresponding to the data of NDR1 and the photometric section corresponding to the data of NDR2, Δc=Qvt(NDR1)−Qvt(NDR2)...(3), is calculated. This calculated data Δc (indicated by COD in the flowchart) is converted to display data and set in register DPR1,
Furthermore, the data in register ND2 is also decoded and set in register DPE4. If register BDR is not 1 in step #50, it is determined whether BDR is 2 in step #54. 2 is the lighting contrast display mode as shown in Table 2, and in step #55, the display mode corresponds to the content of NDR1 based on the lighting contrast ΔL found in the calculation process of #48. The lighting/contrast data of the photometry section (indicated by LCD (NDR1) in the flowchart) is decoded into display data and set in register DPR1. Note that when the writing contrast ΔL data corresponds to -∞, for example, display data such that -□□ is displayed on the display section DIi is registered.
Set to DPR1. If the contents of register BDR are not 2 in step #54, then it is determined whether the contents are 4 in step #56. 4, as shown in Table 2, is the display mode of the aperture value that provides appropriate exposure. At this time, based on the light amount data Qvt (NDR1) of the photometering section corresponding to the contents of register NDR1 and the film sensitivity Sv set in register SVR, Qvt (NDR1) + Sv = Av (NDR1) ... (15 ) is calculated, and this calculated data (indicated by AVD in the flowchart) is decoded into the data necessary to display the F value and stored in register DPR.
Set to 1. When the step BDR of #56 is not 4, it is 8 as is clear from Table 2, and this is a mode for displaying the light amount Qvf of the flash light emitting device or the brightness Bv due to constant light. Therefore, in step #59, the switch FAS is connected to the terminal FL and the input flip
Determine whether flop IF ₁ is set. And when connected to terminal FL,
Data Qvf corresponding to the amount of light emitted from the photometric unit corresponding to the contents of register NDR1 is decoded into display data and set in register DPR1. In step #61, blank data is set in the register DPR4 since no display is made on the display section DI7 except in the contrast display mode. In step #62, the contents of register BDR are decoded and this data is set in register DPR2. This is data for display on the display section DI5. Input flip-flop IF at step #59
When it is not set to 1, the switch FAS is connected to terminal AM, which is the mode for displaying the brightness of the copy using ambient light. At this time,
Add 1 to the contents of register BDR to make it 9, and decode the subject brightness data Bv of the photometer corresponding to the contents of NDR1 to register DPR1.
, decode the contents of BDR and set it in DPR2, then subtract 1 from the contents of BDR, set blank data in register DPR4, and write #68.
Move on to the next step. In step #68, the data in register NDR1 is decoded and set in register DPR3. Here, data is set such that the display of the photometric sections P ₁ to _{P 5} is the usual display of 1 to 5, and when the average value is displayed, the display of ⓓ is performed. #69
In step 2, based on the data in the register TVR, it is decoded into data necessary to display the exposure time and set in the register DPR5. #70
In step 2, based on the data in the register SVR, it is decoded into the data necessary to display the ASA sensitivity, and this is set in the register DRP6.
In step #71, based on the data in register DFR, decode it into the data necessary to display Δf, set it in register DPR7, and then use it to determine whether the display data setting is complete. After setting flag DFJ to 1, step 10 of #16
Moving on to Figure 6. To summarize the operation shown in FIG. 11, when this flow is entered for the first time after photometry is performed, the amount of light emission Qvfm ₁ to Qvfm ₅ of the flashlight emitting device during photometry is calculated. Also, if the photometry button MS is held down and the photometry data Bv ₁ to BV ₅ is imported again and this flow is entered, the light emission amount Qvfm ₁ to Qvfm ₅ of the flashlight emitting device will not be calculated. , based on previously calculated data #45
The following calculations are performed. Below, Qvf ₁ ~
Qvf ₅ , , ΔL ₁ ~ ΔL ₅ , ΔLa, Qvt ₁ ~
Qvt ₅ is calculated, and the data corresponding to the set display mode is stored in display registers DPR1 to DPR.
Set to 7. When displaying contrast, register
The difference between Qvt corresponding to the location corresponding to the contents of NDR1 and Qvt corresponding to the location corresponding to the contents of register NDR2 is displayed on display section DI ₁ , and the location corresponding to NDR1 is displayed on display section DI 6, and the difference between Qvt corresponding to the location corresponding to the contents of register NDR2 is displayed on display section DI ₆ . The location is displayed on display DI ₇ , "CON" is displayed on display DI ₅ , the set exposure time is displayed on display DI ₂ , the film sensitivity is displayed on display DI ₃ , and Δf is displayed on display DI 5. ₄ will be displayed. When displaying the lighting contrast, display section DI ₁ displays the lighting contrast at the location corresponding to the contents of register NDR1 as an apex value, and display section DI ₆ displays the lighting contrast at the location corresponding to the contents of NDR1. The display section DI ₇ will not display anything. In addition, the display section DI ₅ shows “L.
CON" is displayed and the set value is displayed on display sections DI ₂ to DI _4. When displaying Qvt, NDR1 is displayed on display section DI ₁ .
Qvt at the location corresponding to is displayed as an apex value, and other displays are the same as for lighting contrast. Also, when displaying the aperture value for appropriate exposure, the aperture value is displayed on display DI ₁ , "FNO" is displayed on display DI ₅ , and other displays are the same as for lighting contrast. be. When displaying the amount of light emitted by a flash or the brightness of steady light, Qvf and Bv are displayed as apex values, and "FLA" or "AMB" is displayed. Here, the displayed values do not have to be apex values, and the contrast, lighting contrast, and Δf may be displayed in a linear system. Alternatively, the light emission amount may be calculated as Qvf+Sv=Avf, and an appropriate aperture value may be displayed based only on the light emission amount. Also, instead of Bv, Ev=Bv
The aperture value corresponding to +Sv or Av=Bv+Sv−Tv may be displayed. Figures 12-a, 12-b, and 12-c are flowcharts showing the key discrimination operation. If the photometric switch MS is not closed at step #2 in FIG. 10-a, the process moves to step #80. Here, it is determined whether the switch ΔS is closed or not, and if it is not closed, the process moves to step #87, and if it is closed, the switch US for up is closed. determine whether If it is closed, determine whether the contents of the Δf setting register DSR are at the upper limit, and if the upper limit is the upper limit, leave it as is; if it is not the upper limit, add data corresponding to 1/2Ev to the contents of DSR and proceed to step #5. Transition. If it is determined in step #81 that the up switch US is not closed, the down switch is turned on in step #84.
Determine whether DS is closed. When this switch DS is closed, it is determined whether the content of DSR is the lower limit or not, and if it is the lower limit, it remains at #5.
Move to step #5 after subtracting the data corresponding to 1/2Ev from the DSR contents if it is not the lower limit.
Move on to the next step. If step #84 determines that DS is also not closed, the process moves to step #28, resets the display time count register COR, and then enters the CEND state. Therefore, if the switches ΔS and US or DS are closed while data is being displayed, Δf is changed and newly calculated data based on this data is displayed. If both switches continue to be closed, Δf is changed at regular intervals, and the calculated value is also changed and displayed. Also, if two switches are closed while not being displayed, DSR
The contents of will be changed but will not be displayed. Steps #87 to #93 are the flow of the exposure time setting operation, and are the same as the Δf setting. Here, the contents of register TVR are changed in units of 1Ev. Steps #94 to #100 are the flow for setting film sensitivity, and are the same as setting Δf.
Here, the contents of register SvR are changed in units of 1/3Ev. If the film sensitivity setting switch SS is not closed at step #94, the process moves to step #101. #101 to #108 are the flow for setting the display mode, and when the switch CS is closed, it is the contrast display mode, and the register
Set BDR to 0001, when LCS is closed, it is lighting contrast display mode, set register BDR to 0010, when FNS is closed, it is aperture value display mode, and BDR is
0100, and when the FBS is closed, set the display mode BDR of luminescence amount or brightness to 1000 and set #5.
The process moves to the next step and a new display is performed. If the switch FBS is not closed in #107, proceed to step #109. Steps #109 to #132 register the data corresponding to the photometry section.
This is the flow for setting NDR1 and NDR2. Here, first, it is determined whether the data at the location corresponding to the closed switch matches the contents of register NDR1, and if they match, the contents of registers NDR1 and NDR2 are left unchanged and #5
If there is no match, proceed to the NDR step.
The contents of step #1 are transferred to NDR2, the data of the location corresponding to the closed switch is set in NDR1, and the process moves to step #5. Then, new data is displayed following step #5. If the switch AS is not closed at step #129, the process moves to step #28, resets the display time count register, and enters the CNED state. FIG. 13 is a flowchart of 1 second operation.
If it is determined at step #1 in FIG. 107-a that the signal is a 1 sec signal, the process moves to step #140. In step #140, it is determined whether the display time count register COR has overflowed, that is, whether a certain period of time has elapsed since the register COR was reset. When there is no overflow, add 1 to COR and enter the CEND state, and when there is overflow, the display will not be displayed even if any key operation (excluding photometering switch MS) is performed from now on. ,
Set the flag IFJ for determining data import completion and the flag DFJ for determining display data calculation completion to 0,
Set blank data to the display register,
Output this and enter the CEND state. Therefore, after the register COR is reset (photometering switch MS is opened or other key operation is performed) and a certain period of time has elapsed, the display disappears and from then on, the photometry switch is
The display remains clear unless the MS is closed and photometric calculations are performed again. Figure 14 shows the μ-
Power on when power supply starts to com100.
This is a flowchart of clearing operation. μ-com1
When power supply to 00 starts, the power on clear circuit 101 causes the microcomputer 100 to clear the ROM 11.
Starts operation according to the command from the specific address 0. At step #150, the register TVR has a specific exposure time Tvsc (e.g. 1/60 seconds) and the SVR has a specific exposure time Tvsc.
(for example, ASA100), DFR is set to Δfc (for example, 0), then data 6 corresponding to the average is set to NDR1, and data 1 corresponding to the center photometry section _P1 is set to NDR2. In step #152, data 0001 corresponding to the contrast display mode is set in the display mode selection register BDR, and data 0110 for capturing Qv ₁ is set in the capture data selection register DIR. Next, in order to prevent the display from occurring when any key operation other than the photometry switch MS is performed, set the import completion determination flag IFJ and the display data calculation completion determination flag DFJ to 0, and set the display data to 0. Set blank data in the data setting register and output it.
Enters CEND state. In this embodiment, an example has been described in which a weighted average is calculated as the average value, but a harmonic average or a geometric average may also be calculated. First, the geometric mean is = log ₂ ( ₅ √2 ^x1・2 ^x2・2 ^x3・2 ^x4・2 ^x5 ), which becomes = x ₁ + x ₂ + x ₃ + x ₄ + x ₅ )/5, and the microcontroller's Calculation is possible with normal computing power. On the other hand, the harmonic mean is = log ₂ (5/1/2 ^x1 +1/2 ^x2 +1/2 ^x3 +1/2 ^x4 +
1/2 ^x5 ) and log ₂ 5 = 2.3, so = 2.3−log ₂ (2 ^-x1 +2 ^-x2 +2 ^-x3 +2 ^-x4 +2 ^-x5 ). Here, if we define 2 ^-x15 ≡2 ^-x1 +2 ^-x2 +2 ^-x3 +2 ^-x4 +2 ^-x5 and find _x15 , we will find =2.3+ _x15 . So, first, if x ₁ −x ₂ ≡β ₁ , then 2 ^-x12 ≡2 ^-x1 +2 ^-x2・(1+2 ^- 〓 ¹ ), and x ₁₂ =x ₂ −log ₂ (1+2 ^- 〓 ¹ ) is found. Next, if x ₁₂ −x ₃ ≡β ₂ , ₁₃ = x ₃ −log ₂ (1+2 ⁻ 〓 ² ) can be found in the same way. Below, x ₁₃ −x ₄ ≡ β ₃ x ₁₄ = x ₄ − log ₂ (1 + 2 ^- 〓 ³ ) x ₁₄ − x ₅ ≡ β ₄ x ₁₅ = x ₅ − log ₂ (1 + 2 ^- 〓 ⁴ ), x ₁₅ is found. This example does not explain the case where the calculated data exceeds the display limit, but when the calculated data exceeds the display limit, for example, as disclosed in Japanese Patent Application No. 154753, When it is determined that the limit value has occurred, the limit value data and blank data may be output alternately to cause the limit value to blink. FIG. 15 shows another display format of this embodiment, in which display parts DP 1 _to DP ₅ at positions corresponding to each photometry part P ₁ to _{P 5} display information based on the photometry value of each photometry part. The data obtained during the test are displayed, and the average value is displayed on the display section _DP6 . In addition, the display section
DP ₇ indicates display mode. These display sections may be made of liquid crystal, for example, and displayed on the viewfinder. Further, when displaying the contrast with this display device, the display section DP ₆ is left blank, and the display sections DP ₁ to _{DP 5} display the contrast between the average and each photometric section. In this way, the contrast between P ₁ to _{P 5} between the photometric units also corresponds to the difference between each display value, so it can be directly read. FIG. 16 shows another embodiment of the photometric circuit. During the integration operation, the output current of transistor BT ₂₁ is converted into a voltage by resistor R ₁₁ , which voltage is varied by a high pass filter formed by capacitor C ₃₁ and resistor R ₂₁ . Only the amount is taken out. That is, a potential corresponding only to the change in the output current of the light receiving element PD ₁ due to light emission from the light emitting device is applied to the + input terminal of the operational amplifier OA ₆ .
This is operational amplifier OA ₆ , transistor BT ₃₁ ,
BT _41. It is converted into a current by the circuit consisting of the resistor R ₃₁ , and this current is passed through the aforementioned diode D ₁₁ ,
D flows into the circuit made up of ₃₂ . Therefore, the integrated voltage of this capacitor C ₁₁ corresponds to Qvfm ₁ , and there is no need to calculate Qvfm ₁ from Qv ₁ and Bv ₁ . The photometric device of the present invention can also be applied to an exposure control device for a camera. For example, before exposure control starts, the light emitting device emits a preliminary light, measures the light, calculates the contrast and exposure control position, displays the contrast, and after the photographer confirms it, performs the actual exposure control. Just do it.
In this case, exposure may be controlled using the calculated exposure control value. Effects As detailed above, with the photometry device according to the present invention, you can change the setting value while looking at the measured and displayed contrast, and if you take a picture with the setting value that makes the contrast the desired value, the contrast will increase. It is now possible to perform photography in which the value of 0 is a desired value, and photography that has been impossible in the past becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of this invention.
Figure 2 is a block diagram for calculating the weighted average, Figure 3 is a block diagram for calculating the harmonic average, Figure 4 is a block diagram for determining the aperture value that gives the appropriate exposure, and Figure 5 is a block diagram for determining the aperture value that provides the appropriate exposure. Optical system, Fig. 6 shows the photometry section of the photometry meter, Fig. 7 shows the external appearance of the photometry meter, Fig. 8 shows the internal circuit of the photometry meter, and Fig. 9 shows the area surrounded by the broken line in Fig. 8. 10-a, b, 11-a, b, 12-a, b, C, and 13 and 14 are flowcharts showing the operation of μ-com in FIG. 8. FIG. 15 shows another embodiment of the display section of the photometric meter. FIG. 16 shows another embodiment of the photometric circuit. P ₁ to _{P 5} ... Multiple light receiving elements, 1 to 13 ... Photometric circuit, 26 ... Exposure time setting device, 15 to 2
2, 24, 25, 27-53...processing circuit, 10
~13...Recording means, 23...Emission amount difference input means.

Claims (1)

[Scope of Claims] 1. A first type of signal corresponding to the amount of light from a plurality of areas within the photographic screen when the auxiliary light source is emitting light is output for each area, and the signal is output from each area when the auxiliary light source is not emitting light. photometric means for outputting a second type of signal corresponding to the intensity from the plurality of regions in each region, and a signal corresponding to one set exposure time for all of the plurality of regions; an exposure time setting means for outputting, and a third type of signal corresponding to the amount of constant light obtained within the exposure time, based on the second type of signal and the signal corresponding to the exposure time, for each area. In addition, based on the first and third types of signals, a second signal corresponding to the amount of light that contributes to exposure of the photoreceptor portion corresponding to each area during actual shooting using an auxiliary light source is calculated. 1. A photometry device for photographing using an auxiliary light, comprising: arithmetic means for calculating four types of signals; 2. The auxiliary light according to claim 1, wherein the calculation means calculates a signal corresponding to an average amount of light contributing to exposure of the photoreceptor, based on the fourth type of signal. Photometering device for photography using. 3. The calculation means calculates the average amount of light contributing to the exposure of the photoreceptor and the amount of light applied to the photoreceptor portion corresponding to each region, based on the fourth type of signal and the signal corresponding to the average amount of light. 3. A photometry device for photographing using an auxiliary light according to claim 2, wherein a signal corresponding to a difference from a light amount contributing to exposure is calculated. 4. Claims characterized in that the calculation means calculates, based on the fourth type of signal, a signal corresponding to a difference in the amount of light contributing to exposure of the photoreceptor portion corresponding to each region. A photometry device for photographing using the auxiliary light according to item 1.