JPS60242437A - Program shutter device - Google Patents

Abstract

PURPOSE:To reflect easily and properly photographer's intention on an exposure photographic condition determined by a program by shifting the shifting manually the photographic conditions determined by the program. CONSTITUTION:The output-side switch Sw of a comparing circuit 16 is closed at the initial stage of depression of a shutter release button to start setting circuits 8 and 6 for arguments alpha and beta, and an aperture value Av and an exposure time value Tv which are calculated are stored in storage circuits 17 and 18. Switches S1 and S2 are operated to vary exposure factors determined by the program. With the switches S1 and S2, an up/down counter 22 counts up and down and the contents of the counter are set to a subtracting circuit 24 and an adding circuit 25 and added to the Av and Tv stored in the storage circuits 17 and 18 to change combinations. The final values Tv and Av are displayed on a display device 20 and sent to an aperture controller 19 and a two-curtain controller 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a program shutter device that enables photographing of subjects that are most frequently photographed from a photographic perspective with the least number of failures.

In photography, it is necessary to set various photography conditions in consideration of various factors, and in recent years attempts have been made to automate photography, particularly automation of exposure control, and various methods have been proposed. One of them is the so-called program diagram method, in which only the film sensitivity is determined according to the photographer's will, and a predetermined combination of exposure time and aperture value is selected according to the brightness of the photographic field. However, in the program diagram method, the exposure time and aperture value are fixed depending on the brightness of the subject, and the intention of the photographer is hardly reflected.

As a method that can more or less reflect the photographer's intention, there is a method in which the program itself is made variable, which is described in Japanese Patent Laid-Open No. 5'l-6545. FIG. 1 shows a program diagram (a diagram showing the relationship between aperture and exposure time with respect to subject brightness) in this method. That is, the longest exposure time and the maximum aperture of the lens are used as the origin, and an appropriate one can be selected from among several program lines that pass through this point and have different slopes. By appropriately selecting the slope of this program straight line, you can freely select the combination of exposure time and aperture value for the same subject. It is not possible to predict the program straight line (aperture value), and the only thing that can be predicted is that if a program straight line with a tendency to have a large slope is selected, the photograph will be taken with a relatively small aperture; Since there is no clear correlation with the camera shake limit or the depth of field, it is quite difficult for the photographer to select an appropriate program tilt before shooting.

Generally, when using an automatic exposure control camera in aperture priority A mode or exposure time priority S mode, when changing the combination of aperture value and exposure time, if you manually change one by a predetermined amount, the other will be changed by the same amount in the opposite direction. However, such a relationship does not exist in the conventional example described above, making it difficult for photographers who are accustomed to using A or S mode cameras to use the camera.

The present invention aims to eliminate the inconvenience of the program correction function of the conventional program shutter as described above, and to make it possible to easily and appropriately reflect the photographer's intention in the exposure conditions determined by the program.

In order to achieve this long-distance objective, in the present invention, when an arbitrary correction value is added or subtracted to either the aperture value or the exposure time by manual operation to the exposure conditions determined by the program, the other is automatically adjusted by the same amount. An arithmetic mechanism is added to the programmed shutter device for subtracting or adding and shifting the photographing conditions determined by the program while satisfying the conditions for proper exposure.

According to the present invention, instead of selecting the slope of the program as in the previously proposed program shutter described above, the aperture value and exposure time are shifted based on the exposure conditions determined by an arbitrary program over the appropriate exposure conditions. Therefore, it is very easy to set appropriate exposure conditions at a desired aperture value or exposure time.

Note that although the embodiment described below is an example using an 8-bit μmcom, it is also possible to use a 4-bit μmcom with essentially no change, and in FIG. If the number of data is small, almost the same operation can be performed by using registers in RAM.

The present invention will be explained in detail below with reference to Examples.

FIG. 2 is a block diagram showing one embodiment of the present invention. 1 is a photometer installed in the camera, which measures the amount of light incident through the photographic lens plus the film sensitivity, that is, Bv
- Outputs the AVO+SV signal. Here, Bv is the subject brightness, AVO is the open aperture value of the photographing lens, and Sv is the apex value of the film sensitivity. Blocks 2 and 4 are the apex value Avo and maximum F of the shooting lens at maximum aperture, respectively.
This is a circuit that outputs a signal of the apex value Avc (minimum aperture aperture), and is mechanically input and set from the lens when the photographic lens is attached to the camera. Block 5 is a circuit that outputs the apex value Tvmax of the maximum shutter speed, and block 10 is a circuit that outputs the apex value Tvh of the shutter speed that limits camera shake.The camera performance 1 is a fixed value, for example, Tvmax is a value equivalent to 1/1000 seconds, Tvh is set to a value equivalent to 1/60 second. These blocks will now be described according to their functions. Output Bv of photometry section 1
-A? o+Sv and the output AVO of block 2 are added in adder circuit 3 to output Kv=Bv+sv.

On the other hand, the outputs Avc and Tvmax of blocks 4 and 5 are sent to subtraction circuits 7 and 9, respectively, by argument setting circuits 6. The output of 8 is subtracted to obtain Av' = AVC - β and Tv' = T
vmax-α is output from the subtraction circuits 7 and 9, and these two values are added by the addition circuit 13 to obtain Av' + TV' = (
Avc-β)+(Tv' max-a) is output.

This output value and the output Bv of the adder circuit 3 = BV+
When the comparison circuit 16 compares the SV with the comparison circuit 16, a signal is output from the comparison circuit 16 and the same signal is output when the two do not match.)11
．． 15 to the argument α1 β setting circuits 6 and 8.
The value of 2β is changed in the direction in which the two forces of the comparison circuit 16 match, and it is determined by the outputs α and β of the circuits 6 and 8 when the two forces of the comparison circuit 16 match and the output of the same circuit becomes 0. A that can be done
v'=Avc-β and Tv'=TVmaX-α are stored in the storage circuit 1'7.18 as the aperture value A'v and the exposure time-varying Tv, respectively, which are the calculation results. Here is the argument α.

β is initially set to O, and while a mismatch signal is output from the comparison circuit 16, it is gradually increased to open the aperture value from the minimum aperture value Avc, and the shutter speed value is changed to the maximum speed value T.
Change it to the one slower than vmax and get Av' + Tv'
is made to match Ev. In this case, α and β may be increased simultaneously, or the mismatch signal from the comparison circuit 16 may be switched and alternately sent to block 6.8, and α and β may be increased alternately. Further, the ratio of increase in α and β may be changed by the same apex value or at different ratios, either simultaneously or alternately, or the ratio may be changed as appropriate, thereby making it possible to realize various programs. In this way α
, β is increased from O to a value determined by the brightness of the field, but the time required for this operation can be made extremely short by using a microcomputer.

If the exposure is controlled based on the AV value and Tv value stored in the memory circuits 'l'i' and 1B as described above, it can function as a program shutter. One of the features of the present invention is that the program is set so that it can appropriately deal with cases where the Av value and Tv value are out of coordination with the exposure control function or the camera shake limit is reached. gate 11
．． 15 serves to so define the program.

The gate 11 compares the calculation result AV'=Av-β and the open aperture value Avo in the magnitude comparison circuit 12, and calculates Avo(A
It is opened by a signal output from a park opening circuit called v' and sends a mismatch signal from the comparison circuit 16 to the argument β setting circuit. The gate 15 also outputs an inverted signal of the output of the comparison circuit 12 or Tv' = Tv-α and the camera shake limit value setting circuit 10.
It is opened by the output of the comparison circuit 14 which compares the output Tvh of Generally, the program starts from the minimum aperture and maximum shutter speed and gradually moves to the lower exposure value, and when the shutter speed reaches the limit of camera shake, the shutter speed is fixed and only the aperture is opened. When the aperture reaches the maximum aperture, the aperture is fixed there, the gate 15 is opened again, and the shutter speed is again changed to a slower speed.The specific form of this program will be explained with reference to FIG.

FIG. 3 shows an example of the program in the embodiment shown in FIG.
Set to 0. The horizontal axis is Tv, the vertical axis is Av, and the solid line in the figure is focal length 50mIn open FnO,? 2 minimum Fno, F2
2. The dashed line is the same <28mm, F2. F16. The dashed line is 400mm, F5.6. It is an F32 photographic lens. Now, the focal length of the solid line of these three lenses is 50mm, and the open Fno.
.

The graph for a lens with an F2 minimum Fno of F22 will be explained by dividing it into three parts.

(A) Part of Rv 'l 9 to K v 11 e.g. B
v-1-8v; Taking 13 as an example, Av, , Tv are both Av
Since o and Tvh are not reached, Av and Tv are Avc = 9
(F22) Point AV=6 which gradually decreases from Tvmax=10 (1/1000) to Av-4-Tv de Ev=13
(7B) TV=7 (1/125) is the output.

(B) Part of Evll to Ev8, e.g. Bv-4-8
Taking v=9 as an example, Tv=Tvh(1
/6O), so only AV was gradually decreased and AV+
The point where Tv=Ev==9, that is, Av=3 (F2.8
) TV-6 (1/60) output.

(C) K v = 8 or less, for example B v -1-S
Taking v = 2 as an example, since Av = Avo (F2) has been reached, only Tv is gradually decreased this time to Av-1 - Tv
The point where =Ev==2, that is, AV, =2(F2)TV
= O (1 second) output.

FIG. 4 is another embodiment of FIG. 3, and the slope of the part (A) is different. Generally, there is a correlation between the minimum aperture value and the focal length of a photographic lens, such that the larger the minimum aperture F n O, the more telephoto; the smaller the value, the wider the angle.

In Figure 4, taking this point into consideration, the slope is steeper for telephoto lens groups where there is a greater risk of camera shake, that is, those with a large F n O of the minimum aperture, and wide-angle lens groups that are less likely to have such concerns, that is, those with a large F n O aperture of the minimum aperture. For small values of F n 'o, a programming method is constructed in which the slope is made gentler.

Note that this slope can be changed by changing the ratio of the bi-dimensional increases of α1β described above.

As described above, under normal conditions, for example, regarding the solid line graph in FIG. 3, it is possible to purchase a program that is free from camera shake up to Fiv=8. Also, by making the slope in the region (A) steeper and eliminating the region (B), from (A) to (C
) is also possible.

Next, an embodiment of variable combination operation of programs, which is another function of the present invention, will be described. As mentioned above, with this program there is no need to worry about camera shake, but depending on the shooting conditions you may want to make the depth of field shallower or deeper. In this case, the T v (!:
The combination of A and y must be changed. For this purpose, switches Sl, S2 . ,
, F13 are provided on the camera body.

(1, 1, FpTV +IEv Av -IEV(2)
down Tv -IBv Av +IEv (3)
reθat Return to TvAv in the original program operation These three switches are for up-counting, down-counting, and resetting the separately provided up-down counter 22, respectively, and the contents of the counter are transferred to the subtraction circuit 24.
The combination can be changed by sending the signal to the adder circuit 25 and performing an addition operation on Av and Tv which are programmed and stored in the storage circuit 'l'7.18. The sum and difference between Tv and Av is the final Tv value, A
The v value is displayed on the display device 20, and this value is sent to the well-known aperture control device 19 and second curtain control device 21. To explain the above operation in a little more detail by taking an example, let's consider the case where the camera is equipped with a photographic lens with a focal length of 50 mm F2-22 as shown in Fig. 3. At Ev13, the aperture is set to F8 and the shutter speed is set to F8 by the above program calculation. is 1/125
are the shooting conditions and are displayed in the viewfinder. At this time, when the photographer intends to make the depth of field a little shallower, such as when taking a portrait of a person, by pressing the ``up'' switch once while visually checking the viewfinder display, the combination of Av and Tv is set to F5.゜6. Changes from 1/250 to F2, 8, and 1/1000 with three operations.

If you want to return to your parents, press “Reset” and the FB will be sent to you immediately.
Return to 1/125.

This makes it extremely easy to incorporate the photographer's intentions.

Each block in the embodiment shown in FIG. 2 is implemented in an analog manner using well-known circuits. The open aperture value Avo setting circuit 2 and the minimum aperture aperture value Avc setting circuit 4 are potentiometers operated by the lens attachment, and the circuit 5 for setting the minimum exposure time Tvmax is also a potentiometer and adds up.

Each subtraction circuit is an analog addition circuit using an operational amplifier, the comparison circuit 121 14.16 is a differential amplifier, and the circuits 6 and 8 that provide arguments α and β integrate the constant input applied through the gate 11.15. By making the time constant of the integrating circuit switchable, the slope of the program straight line on the program diagram can be changed. Although the counter 22 is a digital counter, its output is DA-converted (not shown) and applied to a subtraction circuit 24 and an addition circuit 25. The device starts operating by turning on the power switch.
At the initial stage of pressing the shutter button, the switch Sw on the output side of the comparator circuit 16 is closed and the circuit for setting the arguments α and β is started. The calculation is completed instantly and the memory circuit 17.
Av and Tv stored in 18 are displayed. If you press the shutter button like this, Program E will be activated.
Shooting is completed as E. If you want to change the exposure factor determined by the program, release the shirt starter button once. At this time, since the exposure factors determined by the program are stored in the memory circuits 17 and 18, the switches S1, 82, etc. are operated without looking at the display, and then the shutter button is pressed again to release the shutter. In this case, when the shutter button is pressed again, the memory circuit: L7,1
The memory content of B may be different from the previous time (due to a change in the subject), or the shooting will be performed based on this new combination of Av and Tv, changed by the amount operated by switches S1, 82, etc. Become. Furthermore, Sl.

It goes without saying that the exposure factor set by the operation in S2 may be maintained and the shutter released by pressing the shutter button a second time. The entire circuit is reset upon completion of exposure. Additionally, a manual reset switch may be provided separately. Also switch S1
. .2B and 29.30, the open aperture value Avo output circuit 2. Minimum aperture aperture value Avc output circuit 4. Maximum shutter speed Tv value Tvmax output circuit 5
and Tv value corresponding to the longest exposure time. If the manually changed exposure control value exceeds the limit value set by each circuit 2, 4.5.23, each comparison The gates 26 and 26' are closed by the outputs of the circuits 27 to 30 so that no signal is sent to the counter 22 even if the switch S1.82 or the like is operated. The operator can know that his or her setting operation has reached its limit when the display in the finder does not change even if the switch S1, 82, etc. is pressed. Of course, a separate warning display may be provided.

In the embodiment shown in Fig. 2, each block can be implemented as a digital circuit, but when using a digital system, the addition/subtraction circuit, comparison circuit, counter, etc. are shared by one arithmetic circuit by switching, and the maximum aperture value is If the AVO, other information setting section, and storage circuit are inputted by giving respective addresses in the memory, the circuit configuration as a whole becomes very simple and compact. An embodiment of this type can be implemented particularly advantageously using a microcomputer.

FIG. 5 is an example of a circuit in which the programmable exposure control circuit of FIG. 2 is implemented using a microcomputer. 200 is carry flag CY, zero flag ZF, 8-bit accumulator A CC, '8-bit register + OR, 4,
13R, a pair of registers 40PR, ≠1-2PR, etc., which perform the function of a 16-bit register with two registers.The central processing unit (hereinafter referred to as CPU) operates this detailed arithmetic unit, timing controller 1 stack,
There are a stack pointer, a program counter, an instruction register, an instruction decoder, etc., but they are omitted because they are not directly related to the operation of this invention. 300 is a read-only memory (FjOM read-only memory) in which instructions and data are stored, and 400 is a write-readable memory (RAM random access memory) in which data is temporarily stored. OPI, OF2. OP3 is an output port, and lP'l and IF5 are input ports. IC
II is a photographing lens of the camera, 102 is an aperture, FD is a light receiving element, and ES is a variable voltage source that sets film sensitivity and adjusts the output level of a photometric circuit. D is a logarithmic compression diode, and OP is an operational amplifier. 100 is a DA converter, and AC is an analog comparator. 2 and 4 are the maximum aperture value Avo and minimum aperture value Avc of the interchangeable lens.
1.05 is a switch that is closed when the first step of the release button is pressed, 106 is a switch that is closed when the second step of the release button is pressed, and 107 is a switch that is closed when the film winding is completed. 108 is a switch that opens in synchronization with the start of running of the 1st act, and 109, 110, 111 are "up" switches for changing the combination of Av and Tv mentioned above.
``reset'''''down'' switch.1
12 is a magnet circuit for an electromagnetic release, and 19 is a magnet circuit for controlling an aperture. Both magnets have a permanent magnet as a core. 21 is a magnet for controlling the second shutter curtain.

6-1.6-2 is a flow chart showing the operation of the circuit of FIG. 5. The table at the end of the text shows an example of the code used in the circuit shown in FIG. The conventional apex value is converted into a hexadecimal code, and the minimum unit is 1/8 FiV °C.

Therefore, in 8-bit numerical data, the upper 5 bits are integer data and the lower 3 bits are decimal data. Note that even when this code is used, hexadecimal numbers are selected so that Bv+S v=Tv+SV holds true, so hereinafter these apexes will be assumed to correspond to hexadecimal numbers.

The operation of the circuit shown in FIG. 5 will be described in detail below in accordance with the flowchart shown in FIG. First, in the first step when the release button is pressed down, the switch 105 is closed, a 1 high" signal is input to the reset terminal RE of the CPU 200, the CPU 200 is reset, and the program starts. First, (1)
48R, which is used as an up/down counter for changing the combination of program EE, is set to (00)H. Here, the subscript H indicates that the numbers in parentheses are hexadecimal digits. Next, in (2) and (3), input the outputs of the maximum aperture AVO and minimum aperture Avc of the photographing lenses 2 and 4.
) After inputting from UPI and converting it to the code shown in the table at the end of the text, Avo is 1% OR and AVC is +4R.
Hess door. (For example, if the output of 4 is (11)B (B indicates a binary number), use F32 as Avc = (6B)
H to 4 a R) In (4), camera shake limit seconds Tvh
=1/6 o=(50) Set H to +1R. (5)
is the maximum shutter speed determined by the camera's performance (
(denoted as Tvmax below) Here, 1/'1000=(7
0) Set H to +5R. In (6), the analog signal corresponding to the output Bv-AVO+SV from the photometric circuit is converted into a digital signal. Examples of this method include: First, set (FF)H to +2R, subtract 1 from this value, output it to OPI, and compare the levels of the photometry circuit and the D-A converter via the D-A converter Bg1oo.The output k of the comparator AC is Determine whether it has become 1 high", and if it is 10-", subtract l from the contents of +2R and repeat this until the comparator output is inverted.
The content of +2R when inverted becomes a digital signal corresponding to BV+5V-Avo. Next, in (7), 2
Add the content of ≠OR to the content of R and get B y −4−S v
= Create an EV and set it to +3R. In (9), both the Av argument color Tv argument α corresponding to 6.8 in FIG. 2 are initialized to (00)H. Next, +6 in (10)] - Content EV of 43H converted from A-D in (8)
Determine whether the exposure exceeds the exposure control range. Tsumari Avc + Tvmax (When Bv-1-8v, exposure control is not possible, so Ovθr is displayed with υ, (6)
Depressed, I repeated the photometry again. By doing this, there is no need to release when the ball is over. When the exposure is below the upper limit that can be controlled, add (0'l)H to β and α for a powder and α powder, respectively. In other words, add 17 BKv each. Then, in α9, set the new α1 β to Tvmax, Avc
The content of 3R, which is the sum of the less than each other, By-1-
Compare with 8v. Written as a formula, BV + Sv ((Tvmax - (ri + (Avc
−β)−−−−−−+1), and when Bv+Sv matches the right side or becomes larger than the right side, the Tv at that time
max-α.

Since AVC-β becomes Tv and Av for proper exposure (
16) According to (2), when the left side is smaller than the right side, it is still necessary to make the right side smaller, and α and β are reduced to 1/8 again.
In other words, Ev is decreased by 1/4EV and the comparison of equation (1) is performed.

In (17), this looseness is regulated by T V = T v h up to the camera shake limit. In other words, (Tvmax-α)
<Tvh-(50)H, the comparison of equation (1) becomes (18
), (191) as shown below.

Bv + 5v (Tvh + (Avc-β)...-
・−・Formula 2+(2) leaves Tv as Tvh and reduces only the aperture by increasing β, and the left side is the same as the loop of a9 going to C>
When it comes to the right-hand side, (jumps to 2~). This loop is also regulated by Cυ with an open aperture, and Avc-β (Av cannot be reduced any further when it comes to Avo, so +22
), as shown in (23), equation (2) becomes as follows.

Bv+5v((Tvmax-a) +AvO----
--(3) Equation (3) is Tv when the aperture remains at the aperture value AVO.
This indicates that the comparison is to be made by subtracting . (25
1 is the maximum exposure time Tvmin(
In this case, when Tvmax-a reaches 8 seconds (=(08)H), under is displayed at (26), and the process returns to (6) as in the case of over - the variable temperature light can be released repeatedly. I try not to. In the process of this flow, tl+
, +2c When the left side > the right side in any of the equations (3),
Tvmax-α, Avc- calculated using α and β at that time
The TV and AV values become negative as described above.

That is, the programming method shown in FIG. 3 can be realized with the above steps.

(281 to (49) are for changing the combination of the programmed Av and Tv values just obtained according to the photographer's intention. (28J, I2gI, (3
0) is the above-mentioned up 109. Down 111. This is a test to see if the reset 110 button has been pressed by the photographer.The specific method is, for example (281, converts the 8-bit input data from P2 to integer data (04
) By taking an AND with H and masking, the bit of the zero flag ZF is 111" or ll01', and e becomes '1'.
There are methods to test whether it is "or '0". Here e,
If either g or f is 1", C31), C35
), (3■ detects that the button has been released and presses C
Contents of counterna 8R for up/down reset from C
has the following effect on

(1) IEv (08
)Add H C+(08)H→C (2) From the contents of down 06)su8R, 'IBV(08)
)H (C-(08)H-+C 13) Reset (34) + Set the contents of 8R to (00)H (00)H→C (37), (38) up to (27) Adding the amount of change (+8R) to the Tv and Av values obtained for the program exposure, °C1AvC-βC=Av...
・・・・・・・・・(4) Tvmax −a 10C= Tv
------------- (Set 51 as new AV and Tv values and store them in ($1OR) and (≠11R). (39)
～(In 4 cases, Av and Tv obtained from (1)～C2 force are C
AVO<AV<Avc, Tvmin(Tv
(Tvmax), is tested to see if it is out of the range. If T V ) T V m a
(48) subtracts IFiv from Tv, adds IE to Av, and subtracts IKV from C.

Conversely, when Tv (Tvmin, Av) Avc, (431
, (44), (45) IEV glasses from Tv, IB from Av? Inasu, lKv is added to C. In the process so far, the final Av and Tv values are each (≠1OR)
and (suIIR).

In (49), the Av and Tv values are decoded and output to OF2, and displayed in the finder. For this method, for example, if we take the LED DOT display as an example, the number of dots, including over-display and under-display, is required in this case to be 12 dots with an aperture of 16 dots, as shown at the end of the article. In order to control the lighting of 16 IKDs, 8
Using the bit output ports, it is possible to assemble a 4x4 LED matrix. Therefore, 16 types of output data from under to over to this 4 x 4 matrix are output from ROM 300 (7) (DOTO) address to (DOT
Extract only the integer part from the Tv data (11R) stored up to address o+'15), shift it 3 bits to the right, and add this value to (DOTO). There is a method that outputs data to an output port for displaying the shutter speed that also determines the content. Note that in the above method, the decimal part is ignored, but for example, the decimal part (010)B to (1
01) At the time of B, it is determined that 2 lights are lit, and the output data to the 4x4 matrix for 2 lights is stored in the ROM 300 as described above, and this is used as both the decimal part data and the integer part data. It is easy to turn on two lights by decoding and calling them.

Next, in (50) and (51), it is checked whether the switch 106, which is closed in the second stage of the release button, and the switch 107, which is closed in the winding photon, are both closed, and if not, in ◇9. (6) Jump back and repeat photometry again.

If both are closed (b=c='l) then 02
1 sets h to 1" and activates the release magnet circuit 112 to perform the release. Next, in (53) ≠
When the contents of IIR are set to ACC and this value is output to OPl, the DA converter 100 outputs Tv, that is, Bv-4-
An analog signal compatible with 8v-AV is output. When the aperture starts to stop down, the photometry circuit outputs BV+.
An analog signal compatible with 5V-Avo is output.
(BV+5V-Avo))(Bv+5v-Av), so the output of the =+7 palator AC is 1 no.

When the aperture diaphragm 102 is narrowed down to the predetermined aperture Av, the output level of the photometric circuit gradually decreases when the aperture 102 is narrowed down to the predetermined aperture Av. By inputting this signal, ◇ sets the terminal 1 to 1 high'' and operates the diaphragm control magnet circuit 19 to stop the diaphragm operation and determine the diaphragm.

In c30, j is also set to 1 high at the same time to operate the 2nd curtain control magnet circuit 21 and energize the 2nd curtain locking magnet.In order to save power, the 2nd curtain locking magnet should be energized at this timing. is desirable.

Subsequently, the reflecting mirror is raised by a well-known mechanical operation, and when the raising ends, the first curtain starts running, and in synchronization with this, the switch 108 opens and the counting of the exposure time begins. This count is made up of time digits corresponding to (su), lR). This can be done in the following ways. First, T for ≠IIR
Fourteen sets of the following data corresponding to the upper five bits of the integer data part of the v data are stored, with two addresses in the ROM 300 as one set, from 1/1 OOO to 8 seconds. For example, Tv is (70)H=(・011100O
O) If B, then (01110) 2 mi (ooo) corresponding to B
'ooooo) (ooooooool), (6Fl)H=
(0110111'l)B to (68)H-(0110
Between 1000) and (7), 2 corresponds to (01101)B.
==(Ooooooooo)(00000010), below 2 =(oooooooo)(ooooolo.

), , , , , , , , 2 = (ooloooo-
o) (oo.

16-bit data such as ``ooooo'' is shifted to the left by 1 bit each time the integer data of Tv increases by 1. Next, for the decimal part, l / 8 corresponding to the 3 bits (000)B to (I'1l)B
Geometric numerical sequence (Ao, 2'
8A0, 2%AO, ... Song..., 27/8AO
) = A is stored in the same location (in ROM 300). For example, (000)B has 64 or (40)Hl(001
)B has 59, i.e. (34)H, (010)B has 5
4 i.e. (35)H・・・・・・・・・・・・・・・
(111)B can be 35, that is, (23)H.

When Tv data based on these preparations is given, the above-mentioned 1 corresponding to it is calculated from its upper integer part 51) 1t.
The 6-bit data 2 is taken out from the ROM 300 to the COH register, the corresponding 8-bit data A is taken out from the ROM 300 from the decimal part, and the count of 2 is repeated A times (repeat) in synchronization with the count switch.

In other words, if one count time is T, the time t until all counts are completed is t=A.2.T.

For example, T = l/12 B m B as T
If v data (61) H,, = (01100001) B, 16-bit data is (00000000) (00000100) from integer data (01100) B, that is, 2
, from decimal data (001) B, A=59, so t=1
7'128・23・59=3.69m5, which is 1/8 from (60)Hmari 1/250]! iv
The exposure time is short. That is, logarithmic expansion is performed by counting the time of the doubling sequence A times at intervals of 178 Ev.

When the exposure time count is completed, the terminal j is set to ``-2'' to start the running of the C2 curtain.When the running of the 2nd curtain is completed and the switch 107 is opened and C becomes 10-'', one flow is completed. , and jumps to C(6) to start new photometry in preparation for the next photograph.

With the above configuration, it is possible to have a program exposure method with the least failures according to various shooting conditions, and to change the combination of exposure time and aperture value with a simple operation, depending on the photographer's intention to select the field temperature and exposure time. An exposure control device that can do this can be realized.

To explain in more detail how to supply power to each circuit section, in FIG. 5, the analog photometry circuit (OF, AC),
Display circuit 20. CPU200, ROM300. RAM4
Power is supplied to the switch 106, which is turned on by the second step operation of the release button, and power is further supplied to the above circuit, the electromagnetic release circuit 112, the aperture control circuit 19, and the second curtain control circuit 21 to hold them.

This holding is released by opening the winding interlock switch 107 upon completion of the second curtain run. With this purchase, the power is maintained even if you take your finger off the release button before exposure control ends after metering the light with the first step of the release button and releasing the camera with the second step. If you continue to press the release button even after exposure control is finished, winding has not yet been completed, so go to (6) with Q=Q from Figure 6 (51).
u m pL Repeat new photometry for the next photograph.

Alternatively, it is also possible to purchase the coU, RAM, and aoM using elements with low power consumption, such as C-MO8, and to constantly supply power to these elements.

Figures 7, 8, and 9 further improve the above-mentioned embodiment, and add shooting modes to the program mode to include aperture priority mode (hereinafter referred to as A mode) and exposure time priority mode (hereinafter referred to as S mode). It was established.

Figure 7 is a perspective view of the camera seen from the rear, 109°110
．． 111 is the aforementioned up, reset, (1 own) selection button switch, 120 is a newly provided mode change switch, and when it is in the center P position, it performs the exposure control of the aforementioned program mode;
set also performs the operation described above. When 120 is set to S, exposure control is performed in S mode, that is, exposure time priority mode, and when it is set to A, exposure control is performed in A mode, that is, aperture priority mode. It is necessary to set the exposure time or aperture to be prioritized in both S mode and A mode, but this can be done with upl○9 or do
Do it with wnllll. This will be explained by taking A mode aperture priority as an example. First, when power is supplied, the aperture value and exposure time are displayed on the display device 20 according to the program method.The aperture value at this time is set in the camera as the priority aperture value, and only the exposure time is displayed depending on changes in subject brightness, etc. Change. Now, if you want to change this priority aperture value, press np109 once and the priority aperture value will change to the IEv open side.
If you press once, it will depend on the IEv narrowing down side. Similarly, in the S mode, the priority exposure time shifts to the IEv much shorter time side by up'109, and shifts to the longer time side in abwnllll.

In this way, the conventional method of rotating the aperture ring or exposure time control ring is no longer complicated, and exposure control with aperture priority or exposure time priority can be performed with a very simple operation.

8 and 9 show embodiments of the exposure control device equipped with the above-mentioned A mode and S mode, and FIG. 8 shows the mode changeover switch 12.
0 configuration and an example in which this is added to the engineering PI in FIG. 5 are shown. FIG. 9 shows an instruction flow to be added to the instruction flow of FIG. Below, we will explain according to Figure 9. In the figure, (49) is the same as in Figure 6.
])-GLI”l is added.

Now, to explain A mode, in the flow up to (49), AV, TV, IO using the aforementioned program method.
R and 411R, respectively.

('70), these Av and Tv values are stored in Φ12R and '13R, respectively. ctl), if j = Q, that is, the mode selector switch is set to the A side, the flow jumps to lj7, and at this time, priority is given to Av stored in $12H, and the shutter speed is calculated according to the flow below. . In (73) and (74), BV+5V-Avo is AD converted using the same method as described above, and (75)
Then add Avo to this and store Bv+Bv at ≠3R. In Q-ri, the calculated BV+SV is Tvmax-4-A
Determine whether it is between vc and TVmin-) - AVO, and if it is not, ove at (118).
Display r or under r, then jump to 7), judge the mode again, and repeat photometry. When Bv-)-8'v is within the control range, C7'f), C1aJteupl
O9, determine whether downllll is pressed, that is, whether there is no Av value increase/decrease specification that should be given priority,
When aown is pressed, prioritize Av value: 1K
The sum of v(08)H is the same when up ((0
8) Subtract H and store in 12H. el)-
In @4), it is determined whether the prioritized Av value increased or decreased in (7 is also @O) exceeds the range of AVO and AvO, and if it does, it is changed from another AV value to 1. Increase or decrease Ev to keep it within the range of AVO, AV, and AVC.

05), transfer this priority Av value to +IOR and M
BV+5V-Av is calculated to calculate Tv. (B'
f) → q, this calculated Tv value is Tvmax, T
Av.

Shift the combination of 'rv by lEv.

In (91), it is checked whether b = c = 1, that is, whether the winding is completed and the release button is pressed to the second stage. If it is pressed, the process jumps to the above-mentioned (52), and the release operation and Exposure control is performed according to the contents of IOR, , 1411H. If it is not pressed, jump to 1'71) and repeat the above operation again.

With the above configuration, an aperture-priority exposure control method can be realized, and the photographer only needs to select the desired priority aperture with up:LO9 or down'n1ll, and By+S v will automatically control the exposure when the priority aperture cannot control the exposure. The priority aperture is corrected and displayed. Also, the set aperture value is set in registers used for control≠IOR, +11R, and 4P12R, +13H.
Therefore, even if the priority aperture value is corrected once outside the exposure control range, once BV and SV are again within the control range of the initial priority aperture, calculation will be performed using the original priority aperture. It has the advantage of being able to

The flow of S mode is similar to that of A mode, so I will omit the explanation here.In addition, in A mode and S mode, it is often the case that you decide the priority value once and then want to take a number of shots. , CP in A mode, S mode
U200. Power is constantly supplied to the ROM 300 and RAM 400 to store priority setting values, and the display circuit 20 and photometry circuit (O
F, AC). Also, in that case, in order to prevent reset from being applied to the reset terminal RE of the CPU in A mode and S mode, m, /
, a needs to be connected to the RE.

As described above, according to the present invention, it is possible to realize a programming method with the least number of failures in accordance with various shooting conditions, and it is also possible to incorporate the photographer's intention with a simple operation, and it is possible to realize not only the programming method but also the exposure time. It is also possible to add functions similar to the priority aperture El and the aperture priority shutter KFi. Although the example using an 8-bit microcomputer has been described, there is essentially no difference when a 4-bit microcomputer is used.
If the number of registers in the CPU is small in FIG. 5, it can be implemented with almost the same operation by using registers in the RAM.

Data 5 bits 3 bits Integer data Decimal data

[Brief explanation of drawings]

FIG. 1 is an example of a program for a conventional programmable shutter, FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is an example of a program for a programmable shutter of the present invention, and FIG. Another example of FIG. 5 is μmcom
An embodiment of the present invention using the ROM 30 in FIG. 5, FIG.
0 shows a flowchart of instructions stored in
FIG. 7 is an external view showing a configuration example of the present invention, FIG. 8 is a circuit diagram of the main part of the embodiment shown in FIG. 5 with a mode changeover switch added, and FIG. 9 is a flow chart of FIG.
This is a flowchart that should be added when a shutter priority mode is added. Representative Patent Attorney Kosuke Hayashi

Claims (2)

[Claims] (1) A photometric means that measures the brightness of a subject and outputs a photometric value, a manual operation means, a data output means that outputs value change data according to manual operation of the manual operation means, and the photometered value and the change Based on the data, C1 increases one of the combinations of aperture value and exposure time on the predetermined program diagram that is uniquely determined by the above photometric value by an amount equivalent to the APEX value of the above change data, and the other remains the same. 1. A program shutter device comprising: calculation means for calculating an aperture value and exposure time corresponding to a reduction by an amount and outputting the calculated values as an exposure control value. (2) It has a means for storing change data set by the manual operation means, and based on the output of the storing means, a change calculation is performed for the combination of aperture value and exposure time on the program diagram. A program shutter device according to claim 1.