JPS62115429A - Manual stopping-down mechanism for camera - Google Patents

Abstract

PURPOSE:To prevent improper photographing due to misoperation of a manual stopping-down mechanism by providing an inhibiting means which inhibits the exposure control doe to depression of a release button on the way of the operation of the manual stopping-down mechanism. CONSTITUTION:If a manual preview lever 1 is turned counter-clockwise to set a rotation angle theta of a contacting part in the front end of a sliding brush 9 to a range between angles theta1 and theta2, the output of a terminal part 10A goes to the high level and that of a terminal part 11A goes to the low level because a slide contact 9A is not brought into contact with a conductor pattern 10 put a slide contact 9B is brought into contact with a conductor pattern 11 and is made conductive through a conductor pattern 12. Since outputs of an AND gate AND 31 and a NOR gate NOR 31 which are two inputs of an OR gate OR 31 are in the low level together, the output of the gate OR 31 goes to the low level. Consequently, the output of and AND gate AND 32 goes to the low level and a release means 102 is not operated through the release button in depressed to close a release switch SW1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a manual aperture mechanism for a camera that prevents inappropriate photographing due to erroneous operation of the manual aperture mechanism for checking depth of field.

(Background of the Invention) Light that has passed through the wide-open aperture of the photographic lens is detected by a light-receiving element, and the appropriate exposure is calculated based on the output to perform automatic exposure control or display the appropriate exposure value, that is, the TTL wide-open photometry method. Cameras equipped with a manual aperture mechanism capable of narrowing down the aperture to an aperture value preset by an aperture ring of a photographic lens in order to check the effect of depth of field are already known.

On the other hand, a camera is equipped with a position detection switch for the manual aperture mechanism, detects the operation of the manual aperture mechanism by opening and closing the switch, and when the manual aperture mechanism is operating, switches to aperture metering mode and performs /jin for proper exposure. has also been proposed.

However, even in such a camera, while the manual aperture mechanism is in operation, it is not known whether the aperture has been stopped down to the set value by the aperture ring of the one-shade lens, and it is difficult to switch to aperture metering mode. This had the disadvantage that proper exposure could not be obtained because the exposure was not reflected.

(Objective of the Invention) An object of the present invention is to make it impossible to take pictures while the manual aperture mechanism is operating, and to ensure that the manual aperture mechanism completes its operation and stops down to the aperture value set with the aperture ring of the photographic lens. To provide a manual aperture mechanism for a camera that enables photography when

(Summary of the Invention) The technical point of the present invention is to apply a release lock when there is a possibility that the aperture has not been stopped down to the aperture value set by the aperture ring of the photographic lens during operation of the manual aperture mechanism. There is.

(Example) Fig. 1 is a circuit diagram showing a first embodiment of the present invention, Fig. 2 is a plan view showing a specific example of a manual diaphragm mechanism used in the first embodiment, and Fig. 3 is a sectional view taken along the line nn in FIG. 2;

This manual diaphragm mechanism is installed in the above-mentioned TTL open metering camera, and is configured so that the diaphragm mechanism of the photographic lens can be operated manually to confirm the depth of field.

(a) First, the configuration of the manual narrowing down mechanism will be explained using FIGS. 2 and 3.

The manual aperture lever 1 can be operated externally on the camera body 2.
It is arranged on the outside of the camera body 2 and is fixed to a rotatable rotation shaft 3 provided in the camera body 2 with a machine screw 4. The aperture drive lever 6 is fixed to the rotating shaft 3 inside the camera body 2, and is always biased clockwise in FIG. 2 by a coil spring 5 disposed around the rotating shaft 3.

Therefore, the manual aperture lever l rotates integrally with the aperture drive lever 6, and since the aperture drive lever 6 is regulated by the limit pins 7 and 8 implanted in the camera body 2, the limit pin 7 Rotates within the regulation range of and 8. In addition, since the manual aperture drive lever 6 is biased clockwise by the coil spring 5, the manual aperture lever 1 is always prevented from rotating by the restriction pin 7 at the position shown by the solid line in FIG. is recieving. and,
When the manual aperture lever 1 is rotated counterclockwise, the aperture drive lever 6 rotates integrally, and the manual aperture lever 1 is prevented from rotating counterclockwise by the restriction pin 8.

The aperture drive lever 6 has two arms 6A and 6B,
A sliding swing 9 is fixed to one arm 6A, and a bending projection 6C is fixed to the other arm 6B. The sliding brush 9 is configured to slide on a conductive pattern 10.1i 12 on an insulating substrate 13 fixed to the camera body 2. This sliding brush 9 has three sliding contact pieces 9A.
, 9B, and 9C, the sliding contact piece 9A slides on the conductor pattern 101, the sliding contact piece 9B slides on the conductor pattern 11, and the sliding contact piece 9C slides on the conductor pattern 12. The conductor pattern 10 is pulled-amplified to a voltage tXvcc (high level) through a resistor (R1° in FIG. 1) via the terminal portion 10A, and the conductor pattern 11 is pulled-amplified to tXvcc (high level) through the resistor (R1 in FIG. 1) via the terminal portion 11A. 1 source Vcc (high level), and the conductor pattern 12 is grounded via the terminal portion 12A.

The sliding brush 9 and conductor pattern 10.12 constitute a first manual filter switch (5WZ in Figure 1), and the slide brush 9 and conductor pattern 10.12 constitute a second manual filter switch (5WZ in Figure 1). SW,) is configured.

The aperture drive lever 14 is provided on the camera body so as to rotate counterclockwise around a rotation wheel 16 on the camera body side, and has a retaining pin 15 at one end and an engaging portion 14A at the other end.
have. This engagement pin 15 is inserted into the aperture drive lever 16 during rotation of the aperture drive lever 16 (at a position corresponding to when the rotation angle θ of the contact portion of the sliding brush 9 is θ-01).
This retaining portion 14A engages with the bending protrusion 6C of the
It engages with the aperture lever 18 on the photographing lens side.

When the aperture drive lever 14 is rotated to the position indicated by the two-dot chain line in FIG. The aperture can be narrowed down to a set aperture diameter (for example, the minimum aperture diameter). This aperture drive lever 14 is linked to a known mirror drive mechanism (not shown) and rotates counterclockwise around a rotation shaft 16 prior to the shutter opening operation, and the aperture lever 18 on the photographing lens side The aperture aperture of the photographic lens is moved downward in FIG. 2 by the biasing force of a tension spring 17 provided inside the photographic lens, and the aperture aperture of the photographic lens is moved to the aperture value preset with the aperture ring of the photographic lens or an aperture value calculated inside the camera. Narrow down. After the shirt closure is closed, the aperture drive lever 14 rotates clockwise against the biasing force of the tension spring 17 to return the aperture lever 18 of the photographing lens to the solid line position at the top of the figure and open the aperture. It is configured to return to the aperture aperture.

(b) Next, the operation of the manual narrowing down mechanism will be explained.

The manual narrowing down mechanism shown in FIGS. 2 and 3 is constructed as described above.

[When 0≦θ<θ1, that is, when the manual diaphragm mechanism is inactive] If the manual diaphragm lever 1 is not rotated, or when the manual diaphragm lever 1 is rotated counterclockwise, the sliding brush 9 A case will be explained in which the rotation angle θ of the contact portion at the tip of is set within the range of 0 and θ1.

In this case, even if the manual aperture lever 1 is rotated counterclockwise in FIG. 2, the aperture of the photographic lens will not be narrowed down as long as the aperture drive lever 14 is not rotated (i.e., 0≦θ<θ1). , the manual aperture mechanism is inactive. At this time, the contact part of the sliding brush 9 and the conductor part of the conductor pattern 1O111 do not come into contact with each other, and the conductor pattern 12 which is grounded
Since the terminals 10A and IIA are not connected to each other, the outputs of the terminals 10A and IIA are at a high level.

[When θ1≦θ<θ2, that is, when the manual diaphragm mechanism is in operation] Rotate the manual diaphragm lever l counterclockwise to set the rotation angle θ of the contact portion at the tip of the sliding brush 9 to θl and 02. We will explain the case where it is within the range of . In this case, in conjunction with the rotation operation of the manual aperture lever 1, the aperture drive lever 6 integrally rotates counterclockwise, and during the rotation (
The aperture drive lever 14 is rotated from θ=θ1). In conjunction with this aperture drive lever 14, an aperture lever 18 on the photographing lens side is also biased by a biasing spring 17 and moved downward. At this time, the manual aperture lever l is not rotated to the position l shown by the two-dot chain line, and for example, if the aperture of the photographic lens is set to the minimum aperture with the aperture ring of the photographic lens, the aperture is stopped down to the minimum aperture. Therefore, there is a possibility that the aperture will not be stopped down to the aperture value set by the aperture ring on the photographic lens, and the manual aperture mechanism is still in operation. Then, the sliding contact piece 9A of the sliding brush 9 does not contact the conductive pattern 10, and the sliding contact piece 9B contacts the conductive pattern 11.
2, the output of the terminal section 10A becomes high level, and the output of the terminal section 11A becomes low level.

[When θ2≦θ, that is, when the operation of the manual diaphragm mechanism is completed] Rotate the manual diaphragm lever 1 counterclockwise to set the rotation angle θ of the contact portion at the tip of the sliding brush 9 to 02 or θ2. If the manual aperture lever l is rotated counterclockwise to the position 1° indicated by the two-dot chain line, or further counterclockwise, the aperture drive lever rotates in unison with the manual aperture lever l. 6 is in the middle of its rotation (θ=θ
The aperture drive lever 14 is rotated from 1) to the position 14' indicated by the two-dot chain line in the figure, or further counterclockwise. In conjunction with this, the aperture lever 1 on the shooting lens side
8 is also biased by the biasing spring 17, resulting in two points.

The aperture is moved to the position indicated by the chain line 18°, and the aperture aperture is reliably narrowed down to the aperture value set by the aperture ring of the photographic lens. At this time, the conductor portion of the conductor pattern 10111 and the sliding contact pieces 9A, 9B of the sliding brush 9 come into contact and are electrically connected via the conductor pattern 12, so that the terminal portions 10A, 1I
The outputs of A each become low level.

The following operations are summarized in Table 1. In this table, the high level is expressed as "1j" and the low level is expressed as "0".

(c) An electric circuit that operates in conjunction with the manual diaphragm mechanism will be explained.

Next, the sliding brush 9 is positioned within the three ranges by the operation of the manual aperture lever 1 described above. How the electric circuit of the camera operates at this time will be explained.

[Electrical circuit configuration]

The release means 102 is a means for starting the camera, such as a release magnet or a motor, and has a power source ■ce(
Transistor 1 connected to the high level) and with its emitter common
The collector load is 03. Release means 102
The high level output of the AND gate AND32 is connected to the resistor R.
When inputted to the base terminal of the transistor 103 via the transistor 14, the signal is activated and starts the camera.

Here, Antogame-1-AND32 is inverter INV3
1 and the output of OR gate 0R31 are input.

The warning display circuit 202 receives the output of the OR gate 0R31 and is composed of a resistor R16, a light emitting diode +04, a transistor 105, a resistor R11, and an inverter 1NV32.

Here, it is preferable that the lighting of the light emitting diode 104 is displayed in the viewfinder, and furthermore, the light emitting diode 104 may be exposed and placed on a part of the external surface of the camera.

Furthermore, rather than a light emitting element such as a light emitting diode,
A sound warning may be displayed using a sounding element such as a piezoelectric buzzer. The light emitting diode 104 is pull-amplified to 'l1litVcc (high level) via a resistor R.

Inverter INV32 inverts the output of OR gate 0R31 and passes it through tmiffRls to transistor 10-
Output to the base terminal of 5. The emitter of the transistor 105 is grounded, and the light emitting diode 104 is used as a collector load.
has.

Here, the operation of the warning display circuit 202 will be explained. When a high level is input to the warning display circuit 202, it is inverted by the inverter INV32, and the low level becomes 1°.
1 to the base terminal of the transistor 105, the transistor 105 is turned off, and no current flows to the light emitting diode 104, so it does not light up. When a low level is input to the warning display circuit 202, the inverter INV
32 and the high level is applied to the base terminal of the transistor 105 through the resistor R+s, so the transistor 105 is in the on state and the light emitting diode 1
04, current flows and lights up to display a warning.

The release switch SW1 is closed by pressing a release button (not shown). One end of this switch is grounded and the other end is biased to the source Vce (high level) via the resistor R1□, so when the release switch SW1 is closed by pressing the release button, a low level is output and the inverter outputs a low level. 1NV3] and the high level is input to AND32. When the release button is not pressed, the release switch SWI is open, so a high level is output, which is inverted by the inverter INV31, and the low level is output by the AND gate AND.
32, the output of the AND gate AND32 will be at a low level regardless of other inputs, and the release means 102 will not operate.

Block 201 is first and second manual narrowing switches SWt and SW3 that are opened and closed by rotating the manual narrowing lever 1 shown in FIGS. 2 and 3.

As described above, the terminal section IOA is pulled up to the power supply vcc (high level) via the resistor RIG, the terminal section 11A is pulled up to the power supply vcc (high level) via the resistor Rz, and the terminal section 12A is grounded.

Therefore, the first and second manual narrowing switches sw, , S
W:l outputs a high level when opened, and outputs a low level when closed. The output of the first manual diaphragm switch S W t is input as a photometry mode detection signal 301 to the arithmetic circuit 11.2. Photometry mode detection signal 3
01 is at a low level, the manual aperture lever 1 is rotated and the aperture drive lever 6 interlocked with it is rotated so that the aperture drive lever 6
In the case of ≧02, the first manual aperture switch S W z is closed, that is, when photographing is performed and the aperture value is surely stopped down to the aperture value set by the Hell's aperture ring. Further, the photometry mode detection signal 301 is at a high level in cases other than those described above. The output of this switch SW2 is input to an AND gate AND31 and a NOR gate N0R31. The output of the second manual filter switch SW is AND gate A
ND31. It is input to NOR gate N0R31. The outputs of the AND gate AND31 and the NOR gate N0R31 are input to the OR gate 0R31, and the output of the OR gate 0R31 is input to the AND31 and the warning display circuit 202.
(internal inverter INV32).

The shutter speed setting means 106 is, for example, a shutter speed setting means.

The shutter speed set by the digital dial is converted into a digital signal and input to the arithmetic circuit 112.

The stop-down step number detecting means 107 detects how many steps the field lens has been stopped down from the open aperture value, converts it into a digital signal, and inputs the digital signal to the arithmetic circuit 112 .

The exposure control mode setting means 108 converts the exposure control mode set by, for example, a mode selector into a digital signal and inputs the digital signal to the arithmetic circuit. In this embodiment, manual exposure control mode (hereinafter referred to as M mode), aperture priority exposure control mode (hereinafter referred to as A mode), shutter speed priority exposure control mode (hereinafter referred to as S mode), and program exposure control mode (hereinafter referred to as S mode) are used. (hereinafter referred to as P mode).

The open aperture value detection means 109 detects the aperture calibration value signal provided in the TI shadow lens, converts it into a digital signal, and inputs it to the arithmetic circuit 112 .

The film sensitivity setting means 110 converts, for example, the film sensitivity set by a dial or the film sensitivity information provided on the surface of the film cartridge into a digital signal and inputs the digital signal to the arithmetic circuit 112 .

The TTL light amount detection means 111 detects and amplifies the output of the light receiving means that receives the light that has passed through the photographic lens, converts it into a digital signal, and inputs it to the arithmetic circuit 112 .

The arithmetic circuit 112 calculates the open photometry mode when the photometry mode detection signal 301 is at a high level, that is, when the aperture drive lever 6 interlocked with the manual aperture lever l is 0≦θ and θ2, and also calculates the photometry mode detection signal 301. When 301 is at a low level, that is, when the aperture drive lever 6 interlocked with the manual aperture lever 1 is θ≧02, the aperture photometry mode is calculated.

The display circuit 113 inputs the signal output from the arithmetic circuit 112 and operates a display 114 provided in, for example, a finder. Note that the display circuit 113 stores the manually input signal from the arithmetic circuit 112 until the next signal is input, and operates the display 114 using this stored signal.

The gloss control circuit 115 inputs the shutter speed signal converted into a digital signal output from the /11 calculation circuit 112, and stores this shutter speed signal until the next shutter speed signal is input.

Here, the shutter control circuit 115 prohibits the manual input of the output signal from the arithmetic circuit 112 after the second release port is pressed and the release switch SW1 is closed, and after the adjustment is completed, the shutter control circuit 115 prohibits the manual input of the output signal from the arithmetic circuit 112. is configured to be entered again. Then, the front curtain of the shutter 116 is run after a certain period of time from the time when the release means 102 is activated and the aperture of the lens is narrowed down to the minimum aperture, and the rear curtain of the shutter 116 is run after the time of the stored gloss speed. to control the shutter 116.

The aperture control circuit 117 stores the appropriate aperture stage number signal converted into a digital signal output from the arithmetic circuit 112 until the next aperture stage number signal is input. Here, the aperture control circuit 117 prohibits input of the output signal of the arithmetic circuit 112 after the release switch SWI is closed, and inputs the output signal from the /jix circuit again after photographing is completed. Then, the detected aperture step number signal converted into a dinotal signal detected by the aperture control device 118 when the release means 102 starts operating is compared with the stored appropriate aperture step number signal, and when they match, the aperture control device 118 is locked. The aperture is controlled by means. Note that when the aperture stop number signal is not output from the arithmetic circuit 112, the aperture control circuit 117 does not operate and the aperture is not controlled, and the aperture is stopped down to the aperture value set by the aperture ring of the photographic lens.

[Operation of electric circuit] (When 0≦θ<θ1) As mentioned above, when the manual aperture lever 1 is not rotated, or even if it is rotated, the aperture drive lever 14 is not rotated, that is, when the manual aperture lever 1 is not rotated. When the squeezing mechanism is inactive (the rotation angle θ of the contact part at the tip of the sliding brush 9 is 0≦θ
<The case of θ1> will be explained. In this case, as shown in Table 1, the first and second manual narrowing switches sw,
, sw3 are both at high level. Since these two outputs are both high level, the AND gate AN
The output of D31 becomes high level. The OR gate 0R31 receives the high level output of the AND gate AND31 as an input, and since at least one input is at a high level, the output is at a high level.

At this time, the high level of the OR gate R31 input to the warning display circuit 202 is inverted by the inverter TNV32 and becomes a low level, so the light emitting diode 104 does not light up and no warning is displayed.

Further, since the high level of the photometry mode detection signal 301, which is the output of the first manual aperture switch S W t, is input to the arithmetic circuit 112, the open photometry mode is set, and the exposure control set by the exposure control mode setting means 108 is performed. In this mode, calculations are performed and controlled by the calculation circuit 112. The arithmetic circuit 112 outputs a display value signal to the display circuit 113 for display. The operation of this arithmetic circuit 112 will be described later with reference to a flowchart.

At this point, press the release button and press the release switch SW.
When the switch is closed, the low level output of the release switch sw1 is inverted to a high level by the inverter 1NV31 and input to the AND gate AND32. However, the OR gate 0R31 which is the other input of AND32
Since the output of is at a high level, both inputs are at a high level, and the output of the AND gate AND32 is at a high level. Then, the transistor 103 is turned on, the release means 102 is activated, and the camera is activated. When the shutter 116 is controlled and the aperture control mode (P mode or S mode) is set by the exposure control mode setting means 10, the aperture of the photographing lens is set to the aperture control device 118 before shutter control. Photographing is performed under the control of

(When θ1 ≦ θ × θ2) Next, even if you rotate the manual aperture lever 1 and rotate the aperture drive lever 14, there is a possibility that the aperture will not be narrowed down to the aperture value set with the aperture ring of the photographic lens. A certain case, that is, a case where the manual narrowing mechanism is in operation (a case where the rotation angle θ of the contact portion at the tip of the sliding brush 9 is θ, ≦θ<θ2) will be described.

In this case, as shown in Table 1, the output of the first manual filtering switch SW2 is at a high level, and the output of the second manual filtering switch SW is a low level.

Since one input of the AND gate AND31 is at a low level, the output is at a low level. Since one input of the NOR gate NoR31 is at a high level, the output is at a low level. The output of the OR gate 0R31 is at a low level because the outputs of the two human-powered computer games AND31 and the NOR gate N0R31 are both at a low level. At this time, since the input to the warning display circuit 202 is at a low level, the light emitting diode 104 lights up as described above, indicating that the manual aperture lever 1 has not been completely rotated to the end and the aperture is incomplete. A warning will be displayed.

At this point, press the release button and release the release button.
Even if the gate AND32 is closed, the output of the OR gate ○R31, which is one input of the AND gate AND32, is at a low level.
The output of the AND gate AND32 is at a low level regardless of other inputs (the output of the inverter INV31, which is caused by the opening and closing of the release switch SW1, that is, whether the release button is pressed or not), and the release means 102 does not operate.

In other words, the release is locked. However, since the photometry mode detection signal 301 is at a high level, the calculation circuit 112 performs calculations for the open photometry mode and displays only on the display 114, and since the release is locked, the shutter control circuit 115 and the aperture control circuit 117 doesn't work.

(If θ2≦θ) Next, rotate the manual aperture lever 1 to rotate the aperture drive lever 14 to the 14° position or further counterclockwise to adjust the aperture set with the aperture ring on the photographic lens. A case where the aperture has been reliably narrowed down to the aperture value, that is, a case where the manual aperture mechanism has completed its operation (a case where the rotation angle θ of the contact portion at the tip of the sliding brush 9 satisfies θ2≦θ) will be described.

In this case, as shown in Table 1, the outputs of the first and second narrowing down switches sw, , sw are both low level, so the output of the NOR gate N0R31 is high level. OR gate 0R31 receives the high level output of NOR gate N0R31 as an input, and since at least one input is at high level, the output of OR gate 0R31 becomes high level.

At this time, since a high level is input to the warning display circuit 202, the light emitting diode 104 does not light up as described above and no warning display is performed.

Further, since the low-level stop-down photometry mode detection signal 301 is input to the arithmetic circuit 112, the stop-down photometry mode calculation is performed as described above. This calculation will be explained using an apex display.

That is, if the shutter speed is Tv, the aperture value is Av, the film sensitivity is Sv, and the subject brightness is Bv, then under the conditions for proper exposure, AV + TV = Bv + Sv ---
1 is true. Here, when the shadow lens is narrowed down, the TTL light amount detection means 111 outputs (Bv
Av) is detected.

Therefore, the light amount (Bv-AV) detected by the TTL light amount detection means 111 and stored manually as a digital signal
), the appropriate shutter speed Tv can be obtained by transforming the formula (■) as follows: Tv = (BV Av ) + SV ---1■
It is determined by This appropriate shutter speed is output to the display circuit 113 as a digital signal.

Note that Sv is the film sensitivity set by the film sensitivity setting means 11O.

Here, if the exposure control mode setting means 108 sets the automatic exposure control mode to A mode, S mode, or P mode, the calculation circuit 112 performs automatic exposure calculation with aperture priority in all these modes. , outputs the appropriate shutter speed calculated by equation (2) to the shutter control circuit 115 as a digital signal. When the first release port is pressed to close the release switch SWI, the output becomes low level, inverted to high level by the inverter INV31, and input to the AND gate AND32.

On the other hand, since the output of OR31 (OR game) is at a high level, the two inputs of AND gate AND32 are both at high level, so its output becomes high level and is input to the base terminal of transistor 103 via resistor R24. . At this time, the transistor 103 is turned on, and the release means 102 is activated. The camera is activated by the operation of the release means 102, and the setting is made with the aperture ring of the photographic lens.
With the aperture value already narrowed down by the rotation of the manual aperture lever l, the shutter 116 is controlled to the appropriate shutter speed calculated in 20, and photography is performed. Photographing using this exposure control is referred to as photographing using the stop-down type A mode.

On the other hand, when the M mode is set by the exposure control mode setting means 108, the calculation circuit 112 outputs the set gloss speed set by the shutter degree setting means 106 to the shutter control circuit 115 as a digital signal. When the release button is pressed to close the release switch SW, the output of the OR game OR31 and the output of the inverter INV31 are both at a high level, so the output of the AND gate AND32 becomes a high level. At this time, a high level is input to the base terminal of the transistor 103 via the resistor R54, and the transistor 1
03 is turned on, and the release means 102 is activated. Then, the camera is started, and the shutter 116 is controlled at the aperture value of the photographic lens that has already been narrowed down by rotating the manual aperture lever 1, and at the set shutter speed set by the shutter speed setting means 106. Photography will take place. Photographing using this exposure control mode is narrowed down to photographing using the 2M mode.

The operation of the arithmetic circuit 112 at this time will be explained in detail below.

(d) Operation of the arithmetic circuit 112 The arithmetic circuit 112 shown in FIG. 1 is composed of a microcomputer, and the operation of the arithmetic circuit 112 will be explained based on the flowchart of FIG. 4.

[Explanation of main routine]

It starts when the camera is turned on. Step S
1, the arithmetic circuit 112 first detects the TTL light amount detection means 1.
The amount of light detected by step 11 and converted into a digital signal is input and stored, and then in step S2, the film sensitivity set by film sensitivity setting means 110 and converted into a digital signal is manually stored.

In step S3, it is determined whether the aperture metering mode is selected. This determination is determined by whether the manual aperture lever l is rotated and the photometry mode detection signal 301, which is the output of the first manual aperture switch S W z, is at a low level or a high level. That is, if the photometry mode detection signal 301 is at a low level, it is determined that the manual aperture lever 1 has been operated to the end and the operation of the manual aperture mechanism has been completed, and the aperture photometry mode is entered, and the photometry mode detection signal 3
If 01 is a high level, it is determined that the manual aperture lever 1 has not been operated, the open metering mode is entered, and the process proceeds to subroutine A. At this time, we will explain the calculation of the appropriate exposure using the Apex display.9 In step S4, set the shutter speed to Tv and the aperture value to AV.
, where the film sensitivity is Sv and the subject brightness is Bv, under conditions for proper exposure, Av + Tv = By +
Sv ----- ■ holds true. Here, when the photographing lens is stopped down, the TTL light amount detection means 111 detects Bv Av.

In step S5, the appropriate shutter speed Tv is obtained by transforming the equation (2) as Tv-+(BV*v)+SV--'■. Incidentally, Sv is the film sensitivity setting means 110
is the film speed set by . From the above, the appropriate gloss speed is determined. The calculated appropriate gloss speed is output to the display circuit 113, and the display 114 is activated to display the appropriate gloss speed.

Next, in step S6, it is detected whether the mode is M mode or not. If the answer is negative, the process advances to step S7.

Regardless of which automatic exposure control mode, P, SSA mode, is set in step S7, the gloss speed calculated in 2) is output as a digital signal to the gloss control circuit 115 to perform aperture-priority automatic exposure control. Then, the process returns to step Sl to repeat the calculation as a state in which photography is possible.

On the other hand, if the M mode is set, step S
In step S8, the shutter speed set by the shutter speed setting means 106 is input and memorized, and in step S9, the set gloss speed is converted into a digital signal and the shutter speed is set as a digital signal.
I[1] is output to the circuit 115 to enable photography in M mode, and the process returns to step Sl to repeat the calculation.

In step S3, when the 4111 optical mode detection signal 301 is at a high level, the process advances to subroutine A, that is, when the aperture value of the photographing lens is maintained at the open aperture without operating the manual aperture mechanism, Calculations in each exposure control mode are performed in a known open metering mode.

[Description of subroutine A]

In step SIO, it is determined whether the mode is M mode or not. If the M mode is set by the exposure control mode setting means 10B, the aperture set by the aperture ring of the photographing lens is determined by the aperture step number detection means 107 in step Sll. Detects how many stops the value is narrowed down from the open aperture value,
The number of narrowing stages is converted into a digital signal, input, and stored.

In the aperture metering mode, if the apex display of the aperture value of the photographing lens is Avo, the TTL light amount detection means 111
The amount of light detected is (Bv Ava),
The number of refinement stages detected by the refinement stage number detection means 107 is (Ay Avo). Then, in step S12, when formula (■) is transformed, Tv = (By-Avo) + Sv (Av
Avo)-1--■, and an appropriate shutter speed is determined. Then, the display circuit 1 displays the appropriate shack speed calculated in step S13.
13 as a digital signal.

Next, in step 314, the shutter speed setting means 106
The set shutter speed set by is converted into a digital signal and stored, and in step 315 this set shutter speed is output as a digital signal to the shutter control circuit 115 to enable photography in M mode, and in step 31 Return to and repeat the calculation.

In step S16, it is determined whether or not the mode is A, and if the mode is set, in step S17, the number of stops detected by the number of stops detecting means 107 and converted into a digital signal is input and stored. , In step 318, the appropriate shutter speed is calculated using 2〇, and in step 319, the display circuit 113 and the shutter control circuit 1 are
15, the appropriate shutter speed is output as a digital signal, and the process returns to the main routine to repeat the flow.

In step S20, it is determined whether or not the S mode is set. If the S mode is set, the open aperture value is detected by the open aperture value detection means 107 in step S21, and this converted into a digital signal is detected. The open aperture value is input and stored, and the gloss speed setting means 106 is set in step S22.
A set shutter speed signal set by and converted into a digital signal is input and stored.

At step 323, by transforming the formula ■, AV = (Bv Avo) +
to Sv + , -T.

−1−−■ is obtained, and an appropriate calibration value is determined.

Then, in step S24, this appropriate calibration value is output to the display circuit 113 as a digital signal.

Next, in step S25, by transforming 2〇, Av Avo= (Bv Avo) + Sv
Tv---■ is obtained, and the appropriate number of refinement stages is determined.

In step S26, the set shutter speed is output as a digital signal to the shutter control circuit 115, the appropriate number of aperture stops is output as a digital signal to the aperture control circuit 117, and the process returns to the main routine to repeat the flow.

In step S27, it is determined whether the mode is P mode, and if the mode is set, in step 828, the maximum aperture value signal detected by the maximum aperture value detection means 107 is input and stored.

In step 329, the subject brightness By is By −
(Bv Awo) +Avo --- Since it is determined by 10, the subject brightness Bv and film sensitivity S
A program function f that uniquely determines the shutter speed TV and the aperture value Av based on v.

(BV,, SV), f2 (B,, sv) using T
v = f, (Bv, Sv) -----■Av
= rz (By −Sv ) −−−− ■ However, Bv + Sv −f + (By ,
Sv ) + [, (By ,, sv) --- Find the appropriate shutter speed and appropriate calibration value that are 1.

Then, in step S30, the appropriate shutter speed and the appropriate comparison value are output as digital signals to the display circuit 113.

Next, in step S31, 2〇 is transformed into Av A
vo= f z (Bv, Sv) Av.

-111 [phase] to find the appropriate number of aperture steps, and in step 332, output the appropriate shutter speed as a digital signal to the shutter control circuit 115, output the appropriate number of aperture steps as a digital signal to the aperture control circuit 117, and then proceed to the main routine. Go back and repeat the flow. The above is the operation of the arithmetic circuit 112.

To summarize the above operation, the manual narrowing mechanism is not activated (
In the case of 0≦θ×θ1), the exposure control mode setting means 1
Photographing is performed according to the exposure control mode set by 08. The manual aperture mechanism is in operation (θ1≦θ
In 2), if there is a possibility that the aperture has not been stopped down to the aperture value set with the aperture ring of the photographic lens, the release lock is applied. The operation of the manual aperture mechanism is completed (θ2≦
θ), and the aperture value is actually stopped down to the aperture value set by the aperture ring of the photographic lens by rotating the manual aperture lever 1, the automatic exposure control mode (A, S,
P mode), the manual aperture lever I
The aperture value is narrowed down by the rotating operation of the aperture value, and the shutter speed that provides the appropriate exposure for this aperture value is used to shoot, that is, the aperture type A mode. Also, when set to the M mode, excessive lens Photographing is performed at the aperture value set by the aperture ring and narrowed down by rotating the manual aperture lever 1 and at the shutter speed set by the shutter speed setting means 106, that is, in the aperture 2M mode. This is summarized in Table 2.

FIG. 5 is a circuit diagram of a second embodiment of the present invention;
The same parts as in the figure are omitted.

(e) Description of the electric circuit that operates in conjunction with the manual diaphragm mechanism.

[Electrical circuit configuration]

The input terminal of OR gate ○R31 is an AND gate AND
31 and the NOR gate N0R31 are input, and the output signals of the inverter INV31 and the off gate 0R31 are input to the input terminal of the AND32.

The warning display circuit 202 is the same as that shown in FIG. 1, and a warning display is performed only when a low level is input. The arithmetic circuit 112' includes a shutter speed setting means 106, a stop-down step number detection means 107, an exposure control mode setting means 108, an open aperture value detection means 109, a film sensitivity setting means 110, and a TTL light amount detection means 111, as in FIG. A digital signal is inputted to the display circuit 113, a shutter control circuit 115, and an aperture control circuit 117, but these are not shown in the figure. Also, the arithmetic circuit 11
2゛ is the 1st manual aperture switch S as in Fig. 1.
Input the photometry mode detection signal 301 which is the output of W2,
A release blocking signal 302 not shown in FIG. 1 is output. Release inhibit signal 302 is normally kept high and goes low when attempting to prevent release. Specifically, the lens blocking signal is at a low level when the photometry mode detection signal 301 is at a low level and the exposure control mode setting means 107 is set to the aperture control mode (P mode or S mode); is kept at a high level. In other words, when the aperture control mode is set like this, the aperture of the photographic lens is set to the minimum aperture position by the aperture ring, and at this time the manual aperture mechanism is activated to adjust the aperture of the photographic lens. Even if an attempt is made to check the depth of field, the aperture of the photographic lens is stopped down to the minimum aperture, and the depth of field cannot be checked.
2 is set to a low level to prevent release.

Further, the release prevention signal 302 is generated by the AND gate AND
33 and an AND gate AND34. The output of the AND gate AND34 is input to the warning display circuit 202, and the output of the AND gate AND33 is input to the base of the transistor 103 via a resistor R4. The transistor 103 has a release means 102 as a collector load, and its emitter is grounded. Here, one end of the release means 102 is connected to a power supply VCC (high level). In the description of FIG. 5 above, the same numbers as in FIG. 1 are given to the same parts as in FIG. 1.

[Operation of electric circuit]

Next, the operation shown in FIG. 5 will be explained.

(Case of 0≦θ<θ1) First, as in the first embodiment, a case where the manual narrowing mechanism is inactive (O≦θ<θ1) will be described.

In this case, as described in the explanation of FIG. 1, since the photometry mode detection signal 301, which is the output of the first manual diaphragm switch SW2, is at a high level, the open photometry mode is set.
The calculation is performed in the exposure control mode set by the exposure control mode setting means 108, and the calculation result is displayed on the display circuit 113.

Furthermore, as described in the explanation of FIG. 1, since the first and second manual aperture switches SWz and SW3 are open, the output of the OR gate 0R31 is kept at a high level, and the release blocking signal 302 is kept at a high level. Therefore, the output of the AND gate AND34 with both inputs at high level becomes high level, and the warning display circuit 202 does not operate and no warning display is performed.If the release button is pressed now, the explanation shown in FIG. As described above, since the output of the AND gate AND32 is at a high level and the release prevention signal 302 is also at a high level, the output of the AND gate AND33 is at a high level, the release means 102 is activated, and the camera is activated. Then, calculation is performed in the exposure control mode set by the exposure control mode setting means 108, and the excess is performed.

(When θ, ≦θ×θ2) Next, similarly to the first embodiment, a case where the manual narrowing mechanism is in operation (θ1≦θ×θ2→) will be described.

In this case, as mentioned in the explanation of Fig. 1, OR gate 0R
The output of 31 is low level. Therefore, Antogame)A
ND34 outputs a low level regardless of other inputs. Therefore, since a low level is input to the warning display circuit 202, the light emitting diode 104 in the warning display circuit 202 shown in FIG. 1 lights up to display a warning.

At this point, press the release button to close the release switch SW as described above, and press the AND gate AND32.
Even if a high level output is input to one side of the AND gate AN
Since the output of the OR gate 0R31, which is the other input of D32, is at a low level, the output of the AND gate AND32 remains at a low level. Therefore, the AND gate AND3
The output of No. 3 is also at a low level, and the release means 102 does not operate regardless of whether the release button is pressed or not. In other words, the release is locked.

At this time, the arithmetic circuit 112'' detects the photometry mode (No. 8 3).
Since 01 is at a high level, calculation is performed in the open metering mode and a digital signal is output to the display 114, but since the release is locked, the shutter 115 and the aperture control circuit 117 do not operate.

(Case of θ2≦θ) Next, as in the first embodiment, a case where the manual narrowing mechanism has completed its operation (θ2≦θ) will be described.

In this case, as described in the explanation of FIG. 1, the photometry mode detection signal 301 is at a low level, and therefore the aperture photometry mode is set. At this time, the exposure control mode setting means 1 is set to either the aperture control mode (S mode, P mode).
08, the release blocking signal 302 is at a low level, so the AND gate AND33
, and both outputs of the AND gate A N D34 are at a low level because one of the inputs is at a low level. Therefore, since a low level is input to the warning display circuit 202, the light emitting diode 104 in the warning display circuit 202 shown in FIG. 1 lights up to display a warning. on the other hand,
Since the low level output of the AND gate AND33 is also input to the release means 102, even if an attempt is made to perform a release operation by pressing the release button, the release operation is disabled.

In other words, the release is locked.

Furthermore, when the exposure control mode setting means 10B sets the exposure control mode to either the A mode or the M mode, the release prevention signal 302 is kept at a high level. Further, since the output of the OR gate 0R31 is at a high level, the output of the AND gate AND34 is at a high level, and this output is input to the warning display circuit 202.
will not operate and no warning will be displayed. On the other hand, arithmetic circuit 1
At step 12', the photometry mode detection signal 301 becomes low level, so the aperture photometry mode is set. Using the light amount (Bv Av) detected by the TTL light amount detection means 111, the arithmetic circuit 112 calculates Tv'' (By Av).
+SV −−−−■ calculates the appropriate shutter speed,
This is output to the display circuit 113 as a digital signal. Here, if the A mode is set, the appropriate shutter speed calculated by equation (2) is output to the shutter control circuit 115 as a digital signal.

Then, when the release button is pressed, as mentioned in the explanation of FIG. level,
Transistor 103 is turned on and release means 102 is activated. By the operation of the release means 102, the camera is started and reaches the appropriate shooting speed calculated by the formula The shutter 116 is controlled and photographing is performed in the aperture 2A mode.

On the other hand, when set to M mode, the arithmetic circuit 1
12 outputs the set shutter speed set by the gloss speed setting means +06 to the shutter control roller circuit 115 as a digital signal.

Then, when the opening of the release 15 is pressed, the output of the AND gate AND32 goes to a high level as described above, and since the release blocking signal 302 is at a high level, the output of the AND gate A'ND33 goes to a high level and the transistor 103 goes to a high level. It is turned on and the release means 102 is activated. The camera is activated by the operation of the release means 102, and the aperture value that has already been narrowed down by the rotating operation of the manual aperture lever 1 is set to the glossy speed setting means 106.
Photographing is performed in the aperture 2M mode at the set shutter speed set by .

[Operation of arithmetic circuit]

Next, the operation of the arithmetic circuit 112', which is composed of a microcomputer similar to the arithmetic circuit 112 of FIG. 1, will be explained using the flowchart of FIG. 6.

First, the camera starts when the power is turned on, and in step S40, the light intensity detected by the TTL light intensity detection means 11 and converted into a digital signal is input and stored, and in step S41, the light intensity is input to the film sensitivity setting means 110. The film sensitivity set by and converted into a digital signal is input and stored.

In step S42, it is determined whether the photometry mode detection signal 301, which is the output of the manual aperture switch SW2, is in the aperture photometry mode.

If the photometry mode detection signal 301 is at a high level and it is determined that the open photometry mode is in effect, this is a normal state and the process jumps to subroutine A in FIG. 4(B), which is the same as the explanation in FIG. 1.

On the other hand, when the aperture photometry detection signal 301 is at a low level, the aperture ff1ll light mode is determined.

In step S43, it is determined whether the exposure control mode is set to the aperture control mode (S mode, P mode). If the exposure control mode setting means 108 sets the exposure control mode to either the S mode or the P mode, that is, the aperture control mode, the release prevention signal 302 is set to a low level in step S44 to prohibit the operation of the release means 102. and activates the warning display circuit 202. Then return to the start and repeat the flow.

The release prevention signal 302 is kept at a high level except when it is determined that the aperture metering mode is selected and the aperture control mode is selected. When the mode is other than the aperture control mode, that is, when the exposure control mode setting means 108 sets the mode to either A mode or M mode, the explanation is the same as that of FIG. 4, but will be briefly explained.

Based on the light intensity and film sensitivity that have already been input and stored in step S45, an appropriate shutter speed is calculated by the formula ■Tv - (By Av) +Sv -----■, and is sent as a digital signal to the display circuit 113 in step S46. Output to.

In step S47, it is determined whether the mode is M mode.

When the M mode is set by the exposure control mode setting means 108, the set shutter speed set by the shutter speed setting means 106 is inputted and stored as a digital signal in step 348, and the shutter control is performed in step 349. The set shutter speed is output as a digital signal to the circuit 115, and the process returns to the start and repeats the flow.

If the A mode is set by the exposure control mode setting means 108, in step S50, the appropriate shutter speed calculated by equation (2) is output as a digital signal to the shutter control circuit 115, and the process returns to the start and repeats the flow.

The operation of the second embodiment described above can be summarized as follows. When the manual aperture mechanism is not activated (0≦θ×θl)
In this case, the exposure control mode setting means 108 is set in the open metering mode.
Photographing is performed according to the exposure control mode set by .

Also, if the manual aperture mechanism is in the middle of operation (θ1 ≦θ
θ2), the release lock is applied, making photography impossible.

Also, when the manual aperture mechanism completes operation (θ≦θt
), the aperture metering mode is set, and in A mode, shooting is performed at a shutter speed that achieves a proper exposure at the aperture value set on the photographic lens, and in M mode, the aperture value set on the photographic lens is used. Photography is performed at the shutter speed set with the shutter dial, and in S and P modes other than A mode, the aperture of the photographic lens is normally set to the minimum aperture, and when stopped down, If you use too much, the aperture will be stopped down to the minimum aperture, which is different from the intention of checking the depth of field by stopping down, so multiply the release by 0.7 to make it impossible to use too much. The above is summarized in Table 3.

(Effects of the Invention) As described above, according to the present invention, when the manual aperture mechanism is in the middle of operation, that is, the aperture is halfway done and there is a possibility that the aperture value has not reached the aperture value set with the aperture ring of the photographic lens. Since it is not possible to obtain the proper exposure, locking the release has the advantage of allowing the person possessed to confirm the situation, prompting them to operate the camera again, and then taking a picture with the proper exposure.

According to the embodiment, when the manual aperture lever is not operated and the aperture of the ↑excess lens is not narrowed down, photography is performed in the open metering mode, and when the manual aperture lever is half-heartedly operated, photography is disabled. When the manual aperture lever is operated all the way to the end, the aperture value set with the aperture ring on the lens is used to stop the camera in metering mode. Proper exposure may not be obtained.

In addition, in the case of aperture control modes such as P mode and S mode, as a general rule, -C should be set with the aperture ring of the Yang Ying lens at the minimum aperture aperture of the photographing lens or at a position corresponding to the minimum aperture aperture. If you operate the manual aperture mechanism, the aperture will be narrowed down to the minimum aperture, which is often not the purpose of checking the brightness of the subject.
When the aperture control mode is selected and the manual aperture mechanism is operated, the release lock is applied.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a first embodiment of the present invention Fig. 2 is a plan view showing a manual narrowing mechanism Fig. 3 is a sectional view of Fig. 2 Fig. 4 (A) and (B) are FIG. 5 is a circuit diagram showing a second embodiment of the present invention; FIG. 6 is a flow chart explaining the operation of the arithmetic circuit shown in FIG. 5. FIG. ε Description of symbols of main parts] 1: Manual aperture lever 6: Aperture drive lever 14: Aperture drive lever 18 Double aperture lever 102 Release means 112: Arithmetic circuit 201: Manual aperture switch 202: Warning display circuit 301; Aperture metering mode detection Signal 302 Ni release prevention signal

Claims (2)

[Claims] (1) In an open metering camera having a manual aperture mechanism that can manually operate the aperture mechanism of the photographic lens, the camera is characterized by having a prohibition means for prohibiting exposure control by pressing the release button during operation of the manual aperture mechanism. A camera's manual aperture mechanism. (2) The prohibiting means prohibits exposure control by pressing the release button even if the manual aperture mechanism has completed operation in an automatic exposure control mode of aperture control. Manual aperture mechanism of the camera described in (1).