JPH073530B2 - Variable metering mode camera - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photometric operation using a plurality of photometric sensitivity distributions (hereinafter,
A metering mode variable camera in which the metering mode is selectable, and in particular, A / D conversion of the metering value at a predetermined cycle is performed.
The present invention relates to a metering mode variable camera that performs exposure calculation based on converted data.

Conventional technology In this type of metering mode variable camera, an exposure control device that A / D converts only the metering value corresponding to the selected metering mode and performs the exposure calculation based on this A / D converted data. , For example, in JP-A-59-123824. Generally, in the case of A / D converting a photometric value, the A / D conversion cycle is set so that fluctuations in the photometric value due to, for example, illumination of a subject by a fluorescent lamp that is lit by alternating current are reduced. That is, at least the A / D conversion cycle time is required from the switching of the photometric mode to the calculation of the exposure control value based on the photometric value in the photometric mode.

Problems to be Solved However, the A / D conversion cycle is relatively long, and the following problems arise when continuous shooting is performed by, for example, a motor drive. That is, if the A / D conversion cycle is long,
In some cases, when the shooting mode is switched during continuous shooting, the exposure calculation value based on the photometric value in the photometric mode is not obtained at the time when the next shutter release should be performed. Therefore, in this case, shooting cannot be performed in that shooting mode.

The present invention is intended to provide a variable metering mode camera that solves the above-mentioned problems and can immediately respond to the switching of the metering mode even if the A / D conversion cycle is long, and that can perform the exposure control based on the metering value in the metering mode. To do.

Means for Solving the Problems The present invention relates to a photometric mode variable camera, and storage means for A / D-converting each photometric value corresponding to each photometric mode in a first cycle and repeatedly storing the same, and the storage means. A reading / calculating means for repeating the operation of reading the A / D converted data of the designated photometric mode out of the A / D converted data and performing the exposure calculation based on the data in a second cycle shorter than the first cycle. It is characterized by that.

Action According to the above configuration, each metering value corresponding to each metering mode is
It is stored in a batch after A / D conversion, and when switching the photometric mode is specified, the corresponding data is read and exposure calculation is performed.

Embodiments FIG. 1 is a plan view of a single-lens reflex camera body having a focal plane shutter to which the present invention is applied, as seen from above, and FIG. 2 is a block diagram showing a circuit configuration of the camera body of FIG. Is. In FIG. 1, a main switch (2), a release button (3), an up key (4), a down key (5), an AE lock switch (6), a liquid crystal display ( 7) and an accessory shoe (8) are provided. Here, in the vicinity of the up key (4), a flash tuning limit speed (for example, 1/250
The symbol X indicating the second) is printed, and the symbol B indicating the valve exposure is printed near the down key (5). Also, the AE lock switch (6) controls the exposure from the non-AE lock position where AE lock is not possible when exposure control is performed based on the photometric value when it is operated prior to the shutter release operation (so-called AE lock shooting). It is possible to switch to the lockable AE lock position, but at the AE lock position, the letters “AEL” indicating that AE lock is possible, in addition to the letters “SPOT” indicating partial metering, and in the non-AE lock position indicating that AE lock is not possible In addition to “OFF”, the letters “AVE” indicating average metering are printed.

In FIG. 2, the camera body (1) mainly includes a microcomputer (11), a film information reading section (12), a photometry section (13), an exposure control section (14) and a display control section (15).
Composed of. Here, the film information reading section (12)
It is a circuit unit that reads film information formed in the form of an electric code signal (hereinafter referred to as a DX code) on the outer peripheral surface of the film cartridge and outputs it to a microcomputer (hereinafter referred to as a microcomputer). The photometry section (13) includes an average photometry light receiving element (16) and a spot photometry light receiving element (17), and outputs the photometric output of the light receiving element to the microcomputer (11). Incidentally, these light receiving elements (16) and (17) are, for example, outside of the photographing optical path capable of receiving the light from the subject which has passed through the semi-transparent portion of the photographing lens and the reflection mirror and reflected by the shutter curtain surface or the film surface. It is located in the position. An exposure control section (14) controls the shutter speed and aperture according to the output of the microcomputer (11). The display control unit (15) displays the display unit (18) in the finder according to the output of the microcomputer (11).
And driving control of the external display unit (7). When the main switch (2) is in the "LOCK" position, control is performed to turn off all the display elements of the two display sections as shown in FIG. 12 described later.

Further, the taking lens (19) and the electronic flash (20) are detachably attached to the camera body (1). Here, the taking lens (19) outputs lens-specific data regarding its optical and mechanical characteristics, aperture value, etc. to the microcomputer (11) of the camera body (1), and the microcomputer (11) uses this lens information and the above-mentioned information. Exposure control information is calculated based on film information, photometric information, and the like. Similarly, the electronic flash unit (20) outputs flash information such as its mounting signal and charge completion signal to the microcomputer (11). The microcomputer (11) has input terminals (IP ₀ ) to (IP ₉ ), output terminal (OP ₀ ), interrupt terminal (INT), clear terminal (CLR), and signals to the interrupt terminal (INT). The falling edge starts the interrupt operation described later, and the rising edge of the signal to the clear end (CLR) starts the reset operation described later. Switch (S ₀ ) (Su), (S
d) and (Sa) are the main switch (2) and
These switches are operated by the up key (4), the down key (5), and the AE lock switch (6). The switch (S ₀ ) is closed when the main switch (2) is in the “ON” position, the switches (Su) and (Sd) are closed by pressing the up key (4) and the down key (5), and the AE lock switch ( The switch (Sa) is closed at the "AEL" position of 6). The switches (S ₁ ) and (S ₂ ) are the release buttons (3) described above.
Of association with the pressing operation, the initial photometric switch (S ₁₎ is closed pressing action, the photometric switch (S ₁₎ at the final stage is still the release switch (S ₂₎ is closed to close.

Switch (S ₀₎ is connected directly to the input terminal of the microcomputer (11) (IP _0), the one-shot circuit (21), the AND gate (AN _1), an interrupt terminal via the OR gate (OR ₁₎ It is connected to (INT). The other input terminal of the AND gate (AN ₁ ) is connected to the outputs of the switches (S ₁ ) and (Sa) and an OR gate (OR ₂ ) described later, and the OR gate (OR ₁ )
The inverted output of the output terminal (OP ₀ ) of the microcomputer (11) and the switch (S ₀ ) are connected to the other input terminal of the. The switches (S ₁ ), (Sa), (Su), (Sd) are directly connected to the input terminals (IP ₂ ), (IP ₄ ), (IP ₅ ), (IP ₆ ) of the microcomputer (11), The switch (S ₂ ) is connected to the input terminal (IP ₃ ) of the microcomputer (11) via the OR gate (OR ₂ ). The outputs of the switches (S ₁ ) and (Sa) and the OR gate (OR ₂ ) are input to the AND gate (AN ₂ ), and the outputs are connected to the input end (IP ₂ ) of the microcomputer (11). This input terminal (IP ₂ ) is in the photometric state for a predetermined period after one of the switches (S ₁ ), (S ₂ ), (Sa) is closed when the switch (S ₃ ) described later is closed. Is provided (hereinafter, referred to as a photometric hold).

The camera of this embodiment has a program mode in which the combination of shutter speed and aperture is uniquely determined based on a predetermined program diagram. It should be noted that the program mode includes a program mode for natural light photography (hereinafter, referred to as P mode) and a program mode for flash photography (hereinafter, referred to as P mode).
There are two types available: FP mode). Further, in each mode, it is possible to shift the combination according to the predetermined program diagram while maintaining the proper exposure in accordance with the manual operation (hereinafter, referred to as P shift or FP shift). In addition to these automatic exposure controls, it also has a manual mode in which the shutter speed and aperture can be set manually.

The switch (S ₃ ) is a switch that opens when the exposure control operation of the exposure control section (14) is completed and closes when the film winding operation is completed. This switch (S ₃ ) is directly connected to the input terminal (IP ₇ ) of the microcomputer (11) and is connected to the OR gate (OR ₂ ).
Connected to the other input end of the. Therefore, when film winding is not completed, even if the release button (3) is pressed and the release switch (S ₂ ) is closed, the OR gate (OR ₂ )
Since the output of is still "High", the microcomputer (11) does not shift to the exposure control operation. Further, the microcomputer (11) stops the exposure control operation when it determines that the switch (S ₃ ) is opened by the input terminal (IP ₇ ).

The switch (Sx) is a so-called X contact for synchronized flash emission of the flash, and is a contact (b) from the completion of traveling of the shutter front curtain to the completion of traveling of the shutter rear curtain, and otherwise (a). )It is connected to the. While the switch (Sx) is connected to the contact (a), the integral operation of integrating the reflected light from the film surface in the photometry section (13) is prohibited, and when the contact (b) is switched, the integral operation is performed. As it started
The electronic flash (20) starts to emit light.

The photometric section (13) includes a photometric circuit provided for each of the average photometric light receiving element (16) and the partial photometric light receiving element (17), and the outputs of these two photometric circuits, that is, the average photometric value (hereinafter,
A) and A / D conversion are performed by selectively inputting the AVE) and spot metering values (hereinafter referred to as SPOT) in time series.
The microcomputer (11) includes an / D converter and a data output register that sequentially sends the A / D converted data to the microcomputer, and the microcomputer (11) performs an exposure calculation based on the output data. Further, the photometry section (13) further includes a section for reading the film sensitivity data sent from the microcomputer (11), a D / A converter for converting the film sensitivity data into an analog signal, and a photometry circuit for average photometry. Adder circuit that adds the film sensitivity signal from the D / A converter to the output of the switch, and the switch (Sx) is the contact (b)
A circuit that integrates the output of the adder circuit when connected to
When the integrated value reaches the specified value, the electronic flash (2
The light emission amount control unit is composed of a circuit for outputting a signal for stopping the light emission of 0).

In addition, when the Fill-In area is discriminated in the FP mode (described later) and when the P shift is performed in the FP mode, the light emission amount control unit increases the film sensitivity data by, for example, 1 Ev and sends it to the photometry circuit. The amount of light emission is reduced by 1 Ev from the proper exposure level. At the time of flash photography other than the above, the film sensitivity data is output as it is, and the flash emission amount is set to an appropriate exposure level.

The electronic flash device (20) is connected to the microcomputer (11) from the output end (g).
A charge completion signal indicating the completion / non-completion of charging is output to the input terminal (IP ₈ ) of the microcomputer (11) from the output terminal (f).
A mounting signal indicating that the power switch of the electronic flash device (20) is closed is output to the input terminal (IP ₉ ) of.

FIG. 3 is a flowchart showing the operation of the microcomputer (11) in FIG. 2, and the operation of the entire camera will be described based on this flow.

First, when the power supply (22) is loaded into the camera body, the power-up clear circuit (23) momentarily sets the clear terminal (CLR) to the "LOW" level. This enables the microcomputer (11)
Starts the RESET routine, initializes the I / O port and RAM (# 1), and then proceeds to the STOP routine. Since this routine is also called up after the end of the photometry hold, etc., first interrupt the photometry operation (# 2) and set the output port (OP ₀ ) to "High" to interrupt. Is allowed (# 3). Then, the AE lock flag AF is reset and the mounting flag NF is set (# 4). Here, the flag AF is set when the AE is locked, and the flag NF is set when the electronic flash (20) is not attached. By this step # 4, even if the AE lock switch (6) is set to the "AEL" position, the photometry section (13) always performs the photometry operation for the first time.

Next, the manual flag MF is determined (# 5). Here, the flag MF is set when one of the switches (Su) and (Sd) is closed when the main switch (S ₀ ) is closed. By this setting, the exposure control of the camera is switched from the program mode to the manual mode thereafter. Here, when the flag MF is reset, the display portions (7) and (15) perform the standby display shown in FIG. 13 (# 6), and when it is set, as shown in FIG. 14 or FIG. Only the shutter speed is displayed. Although the specific display form will be described later, it is possible to determine whether the display mode is automatic or manual even when the metering state is not reached by changing the display form according to the state of the flag MF. After these displays,
The microcomputer stops operating (# 8).

Next, when the main switch (S ₀ ) of the camera is closed,
The one-shot circuit (21) shown in FIG. 2 causes the interrupt end (INT) of the microcomputer (11) to momentarily "LOW", causing an interrupt. As a result, the microcomputer (11) starts the INT routine. In the INT routine, the output terminal (OP ₀ ) is set to "LOW" to disable the next interrupt (# 9).
Prevents other interrupts from occurring during execution of the T routine.
Then, the input terminal (IP ₁₎ by a switch _{(S 1), (S 2} ),
(Sa) determines whether all are open (# 1
0). If the switches (S ₁ ), (S ₂ ), and (Sa) are all open, the process proceeds to step # 11 to reset the flag MF and determine whether the switches (Su) and (Sd) are closed. It is determined (# 12, # 13). When the switch (Su) is closed, the shutter speed is set to 1/250 seconds (# 14) and the flag MF is set (# 16). When the switch (Sd) is closed, the shutter speed is set to the valve (# The flag MF is set from (15) (# 16). As a result, when the flag MF is set, the shutter speed is set to the set value (1/250
The manual mode is fixed to the second or valve and the aperture is set according to the operation of the up key (4) and the down key (5). On the other hand, switches (Su), (Sd)
If both are open, the flag MF remains reset and the process proceeds to step # 17. Register P in step # 17
Clear R and FR and reset flag FF. Here, the registers PR and FR store the program shift amounts in the program mode for natural light photography and the program mode for flash photography, that is, the P shift amount and the FP shift amount, respectively, and the flag FF.
Is set when the flash mode is set to auto and the aperture is set manually (hereinafter referred to as FL manual mode). That is, by closing the main switch (S ₀ ), P shift, FP shift, and FL manual are all released. Then, the process proceeds to the STOP routine described above, and the microcomputer is stopped.

If any of the switches (S ₁ ), (S ₂ ) or (Sa) is closed during execution or stop of the microcomputer's STOP routine, the microcomputer is interrupted and the microcomputer starts the INT routine. The switches (S ₁ ), (S ₂ ), and (Sa) are collectively referred to as start switches. When executing the INT routine with any of these start switches, the input terminal (IP ₁ ) is "LOW"(# 10), so proceed to the S.LOOP routine,
First, it is determined whether the main switch (S ₀ ) is closed by the input terminal (IP ₀ ) (# 18). If the main switch (S ₀ ) is open, the process proceeds to step # 17 described above to release the P shift, FP shift, and FL manual, execute the STOP routine, and then stop. On the other hand, if the main switch (S ₀ ) is closed, start the photometry operation (# 1
9), every 250 ms, the metering unit (13) changes the AVE and SPOT
The A / D conversion operation is performed and the A / D converted data is stored in the output register. Furthermore, the film information is read from the DX code of the film patrone, and if there is no DX code, ISO
Set the value to 100 (# 20). And electronic flash (2
Read the flash information of installation and charging completion from (0) (# 2
1) Read the lens information such as the maximum aperture value (Av ₀ ) and the minimum aperture value Avmax from the taking lens (19) (# 22), and determine the key switch (Su), (Sa) (# 23). . The exposure calculation is performed based on the above information, and the shutter speed and aperture value for shooting are calculated (# 24) and displayed (# 24).
twenty five).

Next, it is judged from the input terminal (IP ₁ ) whether the start switch is closed (# 26). If any of the start switches is closed, the timer is reset and the timekeeping operation is restarted (# 27). ) To step # 28, and if all are open, immediately go to step # 28. This timer is a timer for determining the photometric hold, and is configured to stop the photometric operation of the photometric section (13) and stop the microcomputer when 10 seconds have elapsed since the activation switches were all opened. next,
If the release switch (S ₂ ) is closed, exposure control is performed with the shutter speed and aperture value obtained in step # 24 (# 29) to determine the timer state (# 30), and switch (S ₂ ) If is open, jump immediately to step # 30 above. Here, if 10 seconds have not elapsed, the above S.LO
If the OP routine is repeated and 10 seconds have passed (that is,
At the end of photometry hold), proceed to the STOP routine and stop. At the end of this photometric hold, unlike when the main switch (S ₀ ) is opened, step # 17 is not executed, so the P shift, FP shift, and FL manual are not released.

The above is the rough movement of the present embodiment. The detailed operation of this embodiment will be described below.

FIG. 4 shows in detail the step # 22 of reading lens information and the step # 23 of KEY determination in the flow of FIG. First, read the lens information of the maximum aperture value Av ₀ and the minimum aperture value Avmax from the lens (# 3
1) Next, it is determined whether or not there is lens information (# 32). If the lens information is not read, such as when the lens is not attached to the camera or a lens without lens information is attached to the camera, the process proceeds to step # 33, and Av ₀ , Avmax Both are set to “0” and register P
R and FR are cleared and the actual aperture calculation described later is performed. The P shift and FP shift are canceled when the lens is removed from the camera body (when the lens information disappears).

On the other hand, if there is lens information, the process proceeds to the KEY determination routine, and first, the flag MF is determined (# 34). If the flag MF is reset, then it is determined whether the electronic flash (20) is attached by the input terminal (IP ₉ ) (# 35). If the electronic flash (20) is not attached, it is determined whether the up key (4) or the down key (5) is pressed (# 36, # 38), and these keys are pressed. The P shift amount in the P mode is set by adding or subtracting 1 to or from the register PR for each (# 37, # 39). If the electronic flash device (20) is attached, the process proceeds to step # 40, and the charging completion state is determined by the input terminal (IP ₈ ). If charging is not complete, immediately follow step # in Figure 3
Go to 24 and do not make KEY judgment. That is, electronic flash (20)
Even if is attached, the up key (4) and the down key (5) do not function when charging is not completed. on the other hand,
If the charging is completed, it is determined whether or not the AE lock is made by the flag AF (# 41), and if the AE is locked, the up key and the down key are determined (# 42,
# 44), each time these keys are pressed, 1 is added to or subtracted from the register FR (# 43, # 45) to set the FP shift amount in the FP mode.

If the AE is not locked, the process proceeds to step # 46 when there is no lens information or the flag MF is set, and the photographic aperture value is moved to the setting register Avs. Then, the up key and the down key are determined (# 47, # 49),
Each time these keys are pressed, 0.5EV is added or subtracted to the register Avs (# 48, # 50) and the flag FF is set (# 51). Here, the aperture can be changed only within the range of Av _{0 to} Avmax, and when it becomes Av ₀ or less or Avmax or more,
The content of Avs is fixed to Av ₀ or Avmax, respectively.
If there is no lens information, the content of Avs is automatically 0. With the above processing, the aperture value in the FL manual mode, the manual mode, and the case without lens information is determined.

The calculation routine of step # 24 in FIG. 3 will be described in detail with reference to FIG. First, the mounting of the electronic flash device (20) is determined by the input terminal (IP ₉ ) (# 53). Electronic flash (2
If (0) is not installed, clear register FR,
Reset the flag FF, release the FP shift, FL manual (# 56), set the flag NF and set the electronic flash (20).
Remember that is not attached (# 57). On the other hand, when the electronic flash (20) is attached, the register PR is cleared and the P shift amount in the P mode is reset (#
54). Then, the flag NF is judged (# 55), and if it is not newly mounted, it is judged whether or not the AE lock is made by the flag AF (# 59). If the AE lock is not set, both the AVE and SPOT photometric values are read from the photometric unit (13) and the AVE value is input to the R1 register and the SPOT value is input to the R2 register (# 60). Do not enter the metering value when the AE lock is set. It should be noted that both metering values AVE and SPOT must be read in comparison with the metering cycle in the S.LOOP routine (that is,
This is because the period in which the microcomputer reads the information of the photometry unit) is short. For example, when the switch (Sa) must be closed to lock the spot metering value SPOT, both metering values are always input in this way, so that the metering value can be immediately measured without waiting for the next metering cycle. You can select it, lock it, and perform calculations, display, and exposure control based on that value.

On the other hand, if the flag NF has been set in step # 55, that is, if the electronic flash device (20) has just been installed, the flag NF is reset to store that the electronic flash device (20) has been installed. (# 58), without making the determination of the flag AF, the process immediately proceeds to step # 60 to input the photometric value. This is when the electronic flash (20) is attached with the AE locked,
This is because the shooting conditions are completely different from before, and the photometry value in P mode is measured again so as not to bring it to FP mode.

Next, if the AE lock switch (Sa) is closed, flag AF
Is set (# 62), and if it is open, the register FR is cleared and the flag AF is reset (# 63). Furthermore, depending on whether or not the electronic flash is attached and whether or not the AE lock is set, the photometric value AV
Either E or SPOT is selectively adopted (# 64 to # 67).
That is, when the electronic flash is attached, the average photometric value AVE is adopted regardless of the presence or absence of the AE lock, when the electronic flash is not attached, the spot photometric value SPOT is used with the AE lock and the average photometric value AVE is used with the non-AE lock. . After that, a metered display for displaying the sign of the difference between the set exposure value in manual mode and the proper exposure value.
Clears the manual register and fills in FP mode.
Reset the in-flash flag FI (# 68).

Next, the film sensitivity information Sv obtained in step # 20 of FIG.
Then, the exposure value Ev is calculated by adding the photometric value information Bv obtained in step # 66 or # 67 described above (# 69). Then, the calculation mode is determined according to whether or not the manual flag MF and the electronic flash (20) have been charged (# 70, # 71). That is,
When the flag MF is set, the Tv constant value and the AV set value are set in the manual mode regardless of whether the charging is completed. When the flag MF is reset, the P mode is set when the charging is not completed and the FP mode is set when the charging is completed.

In the case of the P mode, first in FIG. 6A, the presence or absence of lens information is determined (# 72). If there is no lens information, the actual aperture AE calculation that determines the shutter speed based on the actual aperture of the lens is performed (# 73). In this case, the display of the aperture value is "---". On the other hand, when the lens information is present, the program AE calculation in the P mode for calculating the shutter speed and the aperture value based on a predetermined program diagram is performed (# 74). If the content of the register PR is not "0", a program shift calculation for shifting the shutter speed and the aperture value from the above calculated values is performed according to the value (# 76).

In the FP mode, in FIG. 6B, first, the calculation mode is determined according to the presence / absence of lens information, the presence / absence of AE lock, and the state of the FL manual flag FF. In other words, if there is lens information and AE lock is set, it is compatible with AE lock.
FP mode program AE calculation (details will be described later) is performed to calculate the shutter speed and aperture value (# 79). If the content of register FR is not "0", the shutter speed is calculated from the calculated value according to the value. Shift the aperture value (# 81). If the lens information is present and the FF is not locked and the flag FF is reset, the program AE operation for the FP mode is performed (#
83). If the flag FF is set, as in the case where there is no lens information, the manual mode is set, the shutter speed is fixed at 1/250 second (# 84), and the aperture value is set to the up key (4) or down. It becomes the value set by the key (5) (# 85). The difference between the exposure value and the proper exposure value of this combination is calculated as the metered manual value (#
87).

FIG. 7A shows in detail the program AE calculation for the FP mode in step # 83 of FIG. In this FP calculation, the shutter speed is 1/250 seconds (Tv
= 8), and 1E from the proper exposure value determined only by natural light
v It is for obtaining the aperture value that is under.

First, the shutter speed is set to 1/250 second (# 88) and fixed. Next, 1 Ev is added to the Ev value obtained in step # 69 in FIG. 5 to obtain Ev ′, and at the same time, the fill-in-flash flag FI is set. This is because the control of the light emission amount of the electronic flash device is removed from the proper control and the control is adjusted. Next, subtract Sv from Ev (# 90), and if Bv is 8 or more in APEX value, add 1 to Sv as Av (# 93), and if Bv is less than 8, Ev
The value obtained by subtracting Tv from v ′ is Av (# 92). Note that Av is A
It is determined within a range from a large Av value of v ₀ and F2.8 to Avmax (for example, F2.8 to F22). And (Tv
+ Av) is larger than Ev '(that is, from the proper exposure value Ev to 1E
If it is under v or more), the flag FI is reset. Through the above processing, the shutter speed and aperture value in FP mode can be obtained. FIG. 9 shows this FP mode program diagram. In FIG. 9, the horizontal axis indicates the Ev axis, and the vertical axes indicate the Av value, Tv value, and ΔEv value (deviation amount from the proper exposure level), respectively.

FIG. 7B shows the program AE calculation for the FP mode adapted to the AE lock in step # 79 of FIG. In this FP mode for AE lock, the shutter speed changes according to the brightness of the subject, and so-called slow sync that is slower than 1/250 seconds is also possible. For this reason, the exposure by natural light can be maintained at 1Ev under or more from the proper level even at low brightness, so that it becomes Fill-In at all brightness. In addition, the upper limit of the aperture value set by ISO is also removed. In this FP calculation for AE lock, first the flag
FI is set, and Ev obtained in step # 69 in FIG. 5 is 1
The value obtained by adding is set as Ev ′ (# 97). Next, the shutter speed is set to 1/250 seconds (# 98), Tv is subtracted from Ev ', and Av ₀ ~
The value restricted within the range of Avmax is Av (# 99). At this time, if Av is restricted by Av ₀ , the restricted Av is Ev ′
Is subtracted from Tv. The solid line in Fig. 10 is for this AE lock.
The program diagram in FP mode is shown. As in FIG. 9, the horizontal axis represents Ev value and the vertical axis represents Av value and Tv value, respectively.
Indicates the value and ∆Ev value.

FIG. 7C shows in detail the FP shift calculation in step # 81 of FIG. Here, the FP shift is
The Tv and Av values obtained by the above FP calculation for AE lock are (Tv + Av)
Means changing the combination based on the set shift amount while keeping constant. Figure 10 shows how the program diagram changes due to the FP shift, as indicated by broken lines and dashed lines other than solid lines.
First, the register R3 for counting the number of shift stages is set to 0 (# 103). Next, compare registers R3 and FR (# 10
4) Determine whether or not the shift amount is set by the number of shift stages set according to the contents of the register FR. Where R3
And FR match, the process proceeds to step # 120, and the FP shift ends.

On the other hand, if the shift amount is not equal to the set number of shift steps, it is determined whether the register FR is positive or negative (# 105). If positive, the process proceeds to the overshift routine, and if negative, the process proceeds to the undershift routine. The overshift routine is a routine that shifts Tv in the up direction and Av in the down direction.First, if the shutter speed is higher than 1/250 seconds, the electronic flash will tune when the shutter speed is shifted higher. Since this is not possible, the process proceeds to step # 120, and the shift ends. On the other hand, if the shutter speed is a low speed of 1/250 seconds or less, 1 is added to the shift register R3 (# 107), and Tv
0.5 is added to (# 108). At this time, the shutter speed is 1 /
If it becomes faster than 250 seconds, the shutter speed is fixed to 1/250 seconds (# 110), Av is calculated by subtracting Tv from Ev (# 111),
Av is restricted within the range of Av _{0 to} Avmax, and the process proceeds to step # 120 to end the shift. In addition, the shifted shutter speed
If the speed is lower than 1/250 second, then the aperture value is Av ₀ (that is,
It is determined whether or not the aperture value is the maximum aperture value (# 113), and if the aperture is full, 1 is subtracted from R3 (# 114). This is because Av is already open due to overshift and cannot be shifted to the open side anymore, so the shift counter is decremented by 1. After that, 0.5Ev is subtracted from Av (# 115), and if the shifted Av is Av ₀ or more, the process returns to step # 104 described above,
Continue the shift again. On the other hand, if shifted Av is less than Av _0, to secure the Av in Av ₀ (# 117), subtracts the Av calculates Tv from Ev (# 118), 30 seconds to 1/250 seconds Tv Within the range of, the process proceeds to step # 120 and the shift ends. The broken line in FIG. 10 shows the state of overshifting twice.

The undershift routine is a routine for shifting Tv in the down direction and Av in the up direction. First, if Tv is a speed lower than 30 seconds, it is impossible to shift to a speed lower than this, so proceed to step # 120. The shift ends. On the other hand, Tv
Is faster than 30 seconds, subtract 1 from R3 (# 122)
Subtract 0.5Ev from v (# 123). At this time, if Tv is slower than 30 seconds (# 124), Tv is fixed at 30 seconds (# 12).
5), Av is calculated by subtracting Tv from Ev (# 111), and Av is Av
Limit within the range of ₀ ~ Avmax, proceed to step # 120,
The shift ends. On the other hand, if Tv is faster than 30 seconds,
Next, it is determined whether Av is Avmax (that is, the minimum aperture value) (# 126), and if it is the minimum aperture, 1 is added to R3 (# 127). This is because the Av is already at the minimum aperture due to the undershift, and the shift counter is incremented by 1 because the aperture cannot be further reduced. After that, 0.5Ev is added to Av (# 128). If the shifted Av is less than Avmax, the process returns to step # 104 described above, and the shift is continued again. On the other hand, if the shifted Av is equal to or greater than Avmax, Av is fixed to Avmax (# 130), Av is subtracted from Ev to calculate Tv (# 11
8), limit Tv within 30 seconds to 1/250 seconds, step #
Proceed to 120 to complete the shift. The alternate long and short dash line in FIG. 10 shows a state in which the undershift has been performed twice.

In step # 120, the contents of R3 are stored in FR. This is done by changing the limited shift amount when the subject brightness changes during shift and the shift amount is limited.
This is to replace FR. As a result, when the shift is made in the opposite direction, Tv and Av are immediately changed, and the responsiveness at the time of operating the up key or the down key is improved.

FIG. 11 is a diagram showing a fully lit state of the external display section (7) and the finder display section (15) of this embodiment, and FIG. 12 is a fully lit state when the main switch (S ₀ ) is opened. It is a figure which shows a state. 13 to 15 both show the display in the standby state (when the main switch is closed and not in the photometric state). Fig. 14 shows the case where the main switch (S ₀ ) is closed while closing the up switch (Su), and Fig. 15 shows the case where the main switch (S ₀ ) is closed while closing the down switch (Sd). However, it shows Tv, indicating that it is in manual mode.

FIG. 16 shows the display in each mode during photometry.
Even if the AE lock switch (Sa) is closed, the SPOT display does not appear when the electronic flash is attached, indicating that exposure control is performed by the average photometry value AVE. Also, when the up switch or down switch is closed when the electronic flash is fully charged (that is, in FL manual mode), or when 1/250 seconds is set in manual mode, the symbol Displays the metered manual. 16th
In the data display of these figures, the calculated data are sent in time series to the display control unit (15), and Tv, Av
And metered manual symbols Is displayed, and a photometry / calculation / exposure control mode and a charge completion signal are sent to the display control section (15) to indicate the mode and charge completion. This operation is performed in step # 25 in FIG. 3, but the specific flow will be omitted because it can be easily inferred by those skilled in the art.

In this embodiment, Tv is fixed at 1/250 seconds when the up switch or down switch is closed while the AE lock switch is open when the electronic flash is fully charged, and Av is the FL manual mode that is the set value. Although it is adopted, as another example, Tv is fixed to 1/250 seconds and Av is a value shifted from the value calculated by FP calculation from Bv and Sv by the shift amount determined by the up switch or down switch. You can also
The 17th program diagram for this FL manual shift
Shown in the figure. At this time, Av changes depending on the brightness, and has a difference in the number of shift steps set with respect to Av obtained by FP calculation at all brightness.

Also, at the place where the Fill-In area is switched to the normal area,
When the aperture value reaches the limit, the shutter speed is changed from 1/250 seconds to the low speed side according to the brightness, and when the brightness is lower than the brightness of 1/60 seconds, F2.8 and 1/60 seconds. The Fill-In area may be expanded by fixing the area to the fixed area.

In the above-described embodiment, the two photometry modes that are selectively selected are average photometry and spot photometry. However, in addition to this, the multi-point division in which the photographic screen is divided into a number of regions and the subject brightness is measured in each region. The photometric mode may be used. Further, the switching of the photometric mode may be performed uniquely in response to a manual operation, or depending on the subject luminance distribution measured by the photometric means, the state of the taking lens, the exposure control mode of the camera, the focus adjustment mode, etc. It may be performed automatically.

Effect As described above, according to the present invention, each photometric value corresponding to each photometric mode is A / D converted in the first cycle and stored separately, and in the specified photometric mode in a cycle shorter than that. A / D
Since the conversion data is read and the exposure is calculated, even if the A / D conversion cycle of the photometric value is long, it is possible to quickly respond to the switching of the photometric mode and the exposure control based on the photometric value in that photometric mode can be performed quickly. .

[Brief description of drawings]

1 is a plan view showing the appearance of a camera to which the present invention is applied, FIG. 2 is a block diagram showing the circuit configuration of the camera shown in FIG. 1, and FIGS. 3 to 7 are operations of the microcomputer shown in FIG. 8 is a flowchart showing the exposure control data in each flash photography mode, and FIGS.
11 to 16 are explanatory diagrams showing the display states of the display section in each operating state of the camera, and FIG. 17 is a program diagram showing exposure control data in other flash photography modes. 13,16,17: Photometric means, 13, # 60: Data storage means, # 64, #
65: Designating means, S.LOOP: Reading / calculating means, 14, # 29: Exposure control means.

 ─────────────────────────────────────────────────── --Continued from the front page Examiner Shuji Omoto (56) References JP 59-123825 (JP, A) JP 59-53821 (JP, A) JP 58-223128 (JP, A)

Claims (1)

[Claims] 1. A photometric means for outputting a plurality of photometric values corresponding to each photometric sensitivity distribution, wherein a photometric operation by a plurality of different photometric sensitivity distributions is selectable, and all of the plurality of photometric values in a first cycle. A / D conversion, each A / D
A data storage unit that repeats the operation of separately storing the converted data, a designation unit that designates switching of the photometric sensitivity distribution of the photometric unit, and read each A / D conversion data stored in the storage unit,
A reading / calculating means for repeating a predetermined exposure calculation operation based on A / D converted data corresponding to the photometric sensitivity distribution designated by the designating means in a second cycle shorter than the first cycle; A metering mode variable camera having an exposure control means for performing exposure calculation based on the exposure calculation result.