JPS5911885B2 - A camera capable of compensating guide numbers based on differences in film sensitivity - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a camera equipped with a distance one stop interlock (also called a flash automatic mechanism).

10 In the case of flash photography, it is necessary to change the aperture aperture depending on the shooting distance (hereinafter simply referred to as distance), so a mechanism called a distance-one-stop linkage device is often used, but this device does not work with flash photography. It is designed to mechanically guarantee the relationship of guide number = distance x F number based on the guide number of the device, so if the sensitivity of the film you are using differs from the standard pool unevenness 0 sensitivity value, use It was necessary to recalculate the aperture aperture converted to the film sensitivity value.

In other words, assuming that a flashlight with a guide number of 14 is used in ASAIOO, and the sensitivity of the film used is ASAIOO and the shooting distance is 2 m, this distance-aperture linkage device naturally When the number becomes 7, proper exposure can be obtained, but for example, ASA5
If you use ASA 200 film, even at a distance of 2 meters, you will need to set the F number to about 5 in order to get the proper exposure. Proper exposure could only be obtained by changing the exposure, and calculations had to be made each time according to the sensitivity value of the film being used. The present invention was developed in order to eliminate these troubles, and its novel feature is that the camera's distance and aperture linkage device is linked to the film sensitivity value setting operation, which is essentially essential for photographing operations. The second feature is that the distance and one aperture interlocking device is made to work independently of the aperture adjustment by a manual or automatic exposure adjustment device.

The present invention will be explained below based on an embodiment applied to a camera with an automatic exposure adjustment device.

Reference numeral 1 indicates a camera, and reference numeral 2 indicates a strobe that is installed so as to be able to enter and exit the camera.In the case of normal photography, it is placed in a recessed position within the camera 1 as shown in the first figure, but when taking flash photography, As shown in FIG. 2, it is constructed with spring means, restricting means, etc. so as to be located at a protruding position on the top surface of the camera.

2a and 2b are limit pins fixed to the strobe 2;
is an intermediate lever rotatably supported by its shaft 4,
One end thereof is inserted between the restriction pins 2a and 2b of the strobe 2, and an interlocking pin 5 is implanted in the other end.

6 is an insulating switch pin protruding from the back side of the center of the left arm of the intermediate lever 3, and when the intermediate lever 3 is in the position shown in the first figure (i.e., the lever position when the strobe 2 is in the retracted position). When the pin 6 opens the operating switches 7, 8 of the strobe circuit, which are known per se, and the intermediate lever 3 is in the position shown in the second figure (i.e. the lever position when the strobe 2 is in the extended position). , the relative positions of the operating switches 7 and 8 are set in advance so as to close them.

Reference numeral 9 denotes an automatic exposure adjustment/flash photography switching member (hereinafter simply referred to as switching member) which is rotatably installed around the imaging optical axis 0, and has a radially extending member on its periphery that engages with the interlocking pin 5. A long hole 9a and a switching cam 9b are formed.

Reference numeral 10 denotes a film sensitivity compensating member which is rotatably provided above the switching member 9 about the optical axis 0 and works in cooperation with the ASA sensitivity setting member. A mating protrusion 10a and a film sensitivity compensating cam 10b are formed to compensate for the correspondence between photographing distance and aperture due to differences in film sensitivity values.

When the ASA sensitivity value to be set differs from the reference sensitivity value, the compensation cam 10b changes the position of the moving shaft 14, which will be described later, so that the aperture driving member 15 for interlocking the distance aperture forms one rotation center. Rotate around the second pin 17, thereby changing the aperture aperture that should be the reference (for example, the aperture aperture when setting the infinite distance) to the reference aperture when the reference sensitivity value is set. The shape is determined in advance so that it can be changed by the aperture correction amount. Reference numeral 11 denotes a swing lever that is swingably supported by a shaft 12, and is always biased clockwise by a spring 13.

Reference numeral 14 denotes a moving shaft installed at the free end of the lever 11, which serves as the other rotational center of the aperture drive member 15, and is moved by the force of the spring 13 to the film sensitivity compensating cam 10b of the film sensitivity compensating member 10. It is designed to be in constant contact.

The aperture drive member 15 for interlocking one aperture distance is rotatably supported by the moving shaft 14 on the swing lever 11, and its tip 15a can engage with an aperture pin 20, which will be described later, during flash photography. , its relative position is determined.

Reference numeral 16 denotes a first pin implanted on the aperture drive member 15, which can engage only with the switching cam 9b of the switching member 9 when the switching member 9 is placed in the normal photographing position shown in the first figure. It is set in advance.

That is, the first pin 16 engages with the switching cam 9b, but is limited in height so that it cannot engage with the film sensitivity compensation cam 10b. The second pin 17 is installed on the aperture drive member 15 in parallel with the first pin 16, and is attached to the outer periphery of the photographic lens barrel only when the switching cam 9b is placed in the flash photographing position shown in the second figure. The relative position thereof is selected in such a way that it can engage a distance and aperture control cam 18 formed on a rotatably mounted focusing operating member (not shown), which is known per se.

The shape of the distance-aperture control cam 18 is determined so as to ensure the correspondence between the photographing distance and the aperture aperture with respect to the guide number.

19 is a spring for rotating the aperture drive member 15 clockwise with respect to the moving shaft 14 via the second pin 17;
0 is an aperture pin in the aperture mechanism installed in the photographic lens barrel. During normal shooting, it is driven by an automatic exposure adjustment device to automatically set the appropriate aperture aperture, and during flash photography. In some cases, the diaphragm opening can be set mechanically by means of a cam (in the illustrated embodiment, the distance-stop control cam 18) which acts during focusing.

That is, the schematic diagram shown in FIG. 3 is an example, and 1 in the diagram
5a is the tip of the aperture drive member 15, 20 is the aperture pin, 21 is a meter pointer for automatic exposure adjustment (EE), 22 is a pointer holder, and 23 is rotatably supported by its shaft 24. It forms the aperture drive member for automatic exposure adjustment photography.
．． ``This is a stepped tooth member for detecting EE, and can hold the meter pointer 21 between it and the pointer holder 22 and fix it in that position. A biasing spring 26 is connected to the stage 1 tooth member 23 via a pin 27 on the shutter release plate.

Reference numeral 28 denotes an aperture lever rotatably supported by its shaft 29, which is rotated counterclockwise by a relatively weak spring 30.
It is biased in the direction of fully opening the aperture.

31 is a transmission pin, and 32 is an aperture blade supported by a shaft 33 thereof.

When the brightness of the field is high, the meter pointer 21 deviates to the left in the figure (in the direction where the aperture blades are set to the minimum aperture, that is, in the direction of stopping down), and when the field is dark enough to be suitable for flash photography. Set it so that it is displaced to the right (in the direction of fully opening the aperture blades). Now, to briefly touch on the effect in this case, if the subject is bright, the meter pointer 2
1 is located on the left, so when the release plate 26 is pressed down in this state, the stepped tooth member 23 swings a considerable amount counterclockwise by the force of the spring 25, changing the brightness of the subject at that time. The pointer 21 is pressed against the pedestal 22 with a step corresponding to the step. Therefore, the aperture transmission lever 28 also rotates accordingly, and the aperture blades 32 are narrowed down by a predetermined amount via the aperture pin 20. Furthermore, when the subject is dark, the meter pointer 21 is positioned to the right, so during flash photography, the aperture pin 20 is moved by the distance and aperture control cam 18 at the tip 15a of the aperture drive member 15. Therefore, the aperture blades 32 are displaced in the aperture direction, and as a result, the aperture blades 32 are apertured to an aperture corresponding to the photographing distance at that time.

34 is a light receiving part for sending photoelectric information of subject brightness to the exposure meter of the automatic exposure adjustment device; 35 is an ASA sensitivity setting member rotatably provided around the optical axis 0; A droplet-shaped aperture 35a for adjusting the amount of light incident on the portion 34 according to the ASA sensitivity value and a recess 35b for receiving the protrusion 10a of the film sensitivity compensating member 10 are formed.

Next, the operation of the illustrated embodiment will be explained.

[If the subject is sufficiently bright]

In this case, since there is no need to use a strobe, the user can take pictures using normal photographing operations with the strobe 2 immersed in the camera 1.

That is, when the camera is pointed toward the subject after operating the ASA sensitivity setting member 35 to set the sensitivity value of the film being used, the automatic exposure adjustment device operates to adjust the meter pointer 21 according to the subject brightness and the film sensitivity value. Therefore, when the shutter release plate 26 is pushed down in this state, the EE step tooth member 23 swings a predetermined amount as described above, and the aperture blades are moved by an amount commensurate with the angle. 32, and then release the shutter. In this case, the intermediate lever 3, the flash photography switching member 9, the aperture driving member 15 for interlocking the distance and one aperture, etc. are placed in the state shown in FIG. It can be freely displaced in any way.

Further, even if a flash synchronization contact (not shown) in the shutter is closed with the release operation, the strobe 2 does not emit light because the actuation switches 7 and 8 of the strobe light emitting circuit are open as shown.

[When the subject is dark] With ordinary cameras equipped with automatic exposure adjustment devices, various warning displays are normally displayed when the subject is so dark that automatic exposure does not work. If a warning appears, or if you use a strobe for safety even though it is not very dark, such as when shooting indoors, the strobe 2 should be protruded above the camera as shown in the second figure. to set it to a state where flash photography is possible.

That is, when the strobe 2 is made to protrude above the camera by an appropriate means, one of the restriction pins 2 provided on the strobe
b rotates the intermediate lever 3 counterclockwise, the flash photography switching member 9 is rotated clockwise around the optical axis 0 via the interlocking pin 5 and the elongated hole 9a, and the switching cam 9b and the 1 pin 16 is released.

Therefore, the aperture drive member 15 for distance-one-aperture interlocking is rotated by the spring 19 until the second pin 17 implanted therein comes into contact with the distance-one-aperture control cam 18 on the focusing operation member, and as a result, the aperture The tip end 15a of the drive member comes to engage with the aperture pin 20.

If the focusing operation member (not shown) is rotated in this state, the tip 15a of the aperture drive member 15 can narrow down the aperture blades 32 through the aperture pin 20 in proportion to the distance. As a result of the sensitivity setting operation of the ASA sensitivity setting member 35, the moving shaft 14, which is one of the rotational centers, of the diaphragm driving member 15 has already been changed to a position corresponding to the set sensitivity value. When the aperture pin 20 is rotated, the aperture pin 20 narrows down the aperture blades 32 to a predetermined relationship through the cam action of the distance-aperture control cam 18. That is, when loading a film, the ASA sensitivity setting member 35 is rotated to set the ASA sensitivity value of the film to be used. At this time, the recess 35b of the ASA sensitivity setting member and the projection 10a of the film sensitivity compensation member Since the film sensitivity compensating member 10 also rotates at the same time due to the engagement, the film sensitivity compensating cam 10b swings the moving shaft 14 about the shaft 12, thereby displacing it to a position corresponding to the set ASA sensitivity value.

Therefore, the aperture drive member 15 rotates around the second pin 17, which is the other rotation center, while sliding on the aperture control cam 18 by a certain distance, and moves the reference position of the aperture pin 20 at the reference sensitivity value. Displace the position by the difference in sensitivity value.

Therefore, as described above, if the focusing operation member is rotated in this state, an interlocking relationship between the photographing distance and the aperture aperture can be obtained in accordance with the currently set ASA sensitivity value.

Furthermore, if the intermediate lever 3 rotates counterclockwise when the strobe 2 is pulled out, the operating switch 7
, 8 are closed, the strobe light emitting circuit naturally transitions to an operable state.

Therefore, if the shutter release plate 26 is pressed down in this state, the flash tuning contact (not shown) in the shutter will be closed and proper flash photography will be completed. This proper flash photography is done by using the aperture aperture set by the aperture driving member 15 when the subject is so dark that automatic exposure does not work, but when the strobe 2 is used in conditions that are not so dark. In some cases, the aperture aperture set by the step tooth member 23 based on automatic exposure has priority over the aperture aperture set by the distance-stop interlocking device under field conditions where the step tooth member 23 based on automatic exposure narrows down the photograph more. This prevents overexposure from occurring based on the brightness of the field.

As described above, according to the present invention, even when using films with different sensitivities, it is possible to obtain a distance-one-aperture interlock relationship according to the film sensitivity by simply setting the film sensitivity, which is originally necessary. This not only has the effect of eliminating the hassle of conversion calculations and forgetting operations, but also prevents overexposure when taking flash photography when the subject is bright. You can also get some unpleasant effects.

[Brief explanation of drawings]

The figures show an example in which the present invention is applied to a camera with a built-in strobe.Figure 1 is the main diagram showing the state during normal shooting, Figure 2 is the main diagram showing the state during flash photography, and Figure 3 is the automatic exposure adjustment. FIG. 4 is a partial illustration of the apparatus, and FIG. 4 is a partial illustration of the film sensitivity setting mechanism. 1 is the camera, 2 is the strobe, 3 is the intermediate lever, 4 is the shaft,
5 is an interlocking pin, 6 is a switch pin, 7 and 8 are operating switches, 9 is a switching member, 9b is a switching cam, 10 is a film sensitivity compensation member, 10b is a film sensitivity compensation cam, 11 is a swing lever, 12 is a shaft, 13 is a spring, 14 is a moving axis, 15
1 is the aperture drive member, 16 is the first pin, 17 is the second pin, 1
8 is a distance and aperture control cam, 19 is a spring, 20 is an aperture pin, 0 is a photographing optical axis, 21 is a meter pointer, 22 is a pointer holder, 23 is a stepped tooth member, 24 is a shaft, 25 is a spring, 26 is a Shutter release plate, 27 is pin, 28 is aperture transmission lever,
29 is a shaft, 30 is a spring, 31 is a transmission pin, 32 is an aperture blade, and 33 is a shaft.

Claims (1)

[Claims] 1. Normally, the aperture aperture is set using an automatic exposure adjustment device, but in a camera that can use a distance-aperture linkage device to set the aperture aperture according to the shooting distance during flash photography, the automatic exposure adjustment device and the aperture drive member for the distance-aperture interlocking device are installed so that their engagement directions are in the same direction with respect to the aperture device of the photographing lens, and the automatic exposure adjustment is performed. The device is configured to operate without being switched during flash photography, and the aperture drive member for the distance-aperture interlocking device has two cam engaging portions so that one One cam engaging part engages the distance-aperture control cam that is linked to the focusing operation member, and the other cam engaging part engages the film sensitivity compensation cam that works with the film sensitivity setting member to adjust the distance and film. A distance characterized in that the diaphragm aperture setting position is occupied according to the sensitivity.
A camera equipped with an aperture linkage device.