JPS6333215Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electromagnetically driven camera shutter.

In recent years, electromagnetic drive cameras with automatic focus adjustment, that is, A/F, have been developed, but they are complex and expensive in structure, and have the drawback of not being able to operate reliably.

This invention organically links A/F and electromagnetic shutter control, and uses the aperture-priority automatic exposure control, that is, the electromagnetic shutter of the aperture-priority AE device, to combine the A/F lens drive mechanism and the electromagnetic shutter.
The purpose of the present invention is to provide a shutter mechanism for a camera system with a simple structure and reliable operation.

In this invention, lens distance adjustment, aperture setting, and shutter sector opening/closing operation time can be digitally controlled, so there is less influence from temperature, friction, power supply voltage, etc., and highly accurate control can be performed. Since the lens is operated entirely by electromagnetic force, the lens block is connected to the camera body by an electrical conductor, making it suitable for use in cameras with retractable lenses.

High-precision A/F devices currently on the market are extremely expensive, but in this invention, the aperture aperture is prioritized by taking into consideration subject distance, brightness, camera shake limit, etc. through the calculation of a control circuit using pure electrical operation. Set the
The A/F performance is compensated by the depth of field, which is extremely effective in providing an A/F camera that is simple in structure, inexpensive, and has excellent practical performance.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Figure 1 shows the control circuit of an A/F electromagnetic shutter type AE camera suitable for incorporating the present invention.
This circuit is connected to the power supply E and the power switch SW ₁ , which is connected, for example, by opening the camera's dust cover.
and a start switch SW ₂ that is connected when the camera's release button is activated to perform a series of camera operation sequences (if necessary, another switch that is connected when the first step of the release button is activated is provided). As a result, battery check, AE check,
(It can be configured to latch various data such as A/F distance measurement, and perform aperture setting, lens drive, and shutter sector operation in the second stage operation), a central processing unit CPU, and a noise cancellation filter F. , a transistor Tr that is turned on by connecting switch SW ₂ and applies the power supply voltage Vcc to each control circuit system through a filter (this hold is released after the exposure operation is completed), and a transistor Tr that is used to generate a subject brightness information signal. A light receiving circuit AE for AE having a light receiving element Pb,
An A/F distance measuring circuit A/F is connected to a light emitting diode Pe and an A/F light receiving circuit Pd that receives reflected light from the light emitting diode Pe reflected from a subject to generate a subject distance information signal, and a shutter block SB. The shutter block driver circuit SD controls the operation of the shutter block driver circuit SD, and is connected as shown.

By applying the power supply voltage Vcc, the central processing unit
The CPU starts operating, and after a predetermined delay time during which the AE light receiving circuit AE is able to operate normally, the central processing unit CPU receives the subject information signal from the AE light receiving circuit AE and latches it. Preferably, this signal is converted into a digital signal by an analog-to-digital converter.

After latching the above-mentioned AE signal, the central processing unit CPU issues a distance measurement command to the A/F distance measurement circuit A/F, and the light emitting diode Pe emits light.
This reflected light from the subject is the A/F light receiving circuit Pd.
The information is input to the A/F distance measuring circuit A/F for calculation, and the calculation result is input to the central processing unit CPU to latch the A/F information signal. After a predetermined delay time, the central processing unit
The CPU uses the latched AE data and A/F
Calculations are performed based on the data, and this calculation sets an appropriate aperture value that takes into account the depth of field, camera shake limit shutter time, and whether or not strobe flash is necessary, depending on the subject distance and brightness. , the shutter time is determined based on this aperture value. At this time, the shutter sector opening degree is also changed to make the shutter time appropriate, and it functions as a program shutter. In this way, there is no need to worry about blurring due to camera shake, and the depth of field provided by the set aperture makes it possible to take photographs with sufficiently good resolution for practical purposes.

A diaphragm, lens, and shutter sector actuating device incorporating the present invention controlled by the above-described control circuit will now be described with reference to FIGS. 2 and 3.

In FIGS. 2 and 3, the electromagnetic movable element of the electromagnetic shutter includes an aperture and shutter control printed coil board 5 rotatably supported by a shaft 28 embedded in the upper base plate 27, and a printed coil board 5 also embedded in the upper base plate 27. The distance adjusting printed coil board 1 is rotatably supported on a shaft 29, and each of these movers has printed coils 30, 31, 32, 3.
3, and the coil 30 has permanent magnets 34, 35 having magnetic flux in a direction perpendicular to the paper plane of FIG.
(having mutually opposite polarities), the coil 31 likewise cooperates with the permanent magnets 36, 37, and in the same way the coil 32 cooperates with the permanent magnets 38, 3
9 and the coil 33 cooperate with permanent magnets 40 and 41, and when a current is applied to the coil in a predetermined direction, the coil substrates 5 and 1 rotate in a predetermined direction, respectively, but are normally held at the neutral position shown by a spring not shown. Ru.

Yoke 5 to strengthen the magnetic circuit of the permanent magnet
9, 60, 61, and 62 are provided as shown in FIG.

A lens 18 supported by a camera body (not shown) is designed to focus a subject image on a film 42 when a lens aperture 18a is opened.
The lens 18 is adjusted to long distance, normal distance, and short distance by rotating the helicoid 18b, but is normally maintained at the normal distance.

In order to adjust the aperture diameter of the lens aperture 18a, an aperture lever 15 is provided which is pivotally supported on a shaft 44 implanted in the base plate 43. The aperture lever 15 is provided with a large aperture 15b and a small aperture 15c spaced apart from each other by a predetermined distance, which align with the lens aperture 18a when rotated, and are biased counterclockwise by a spring (not shown). The lens is normally held at the maximum lens aperture position shown in the figure by a stopper not shown, giving the maximum lens aperture, but as described later, when rotated clockwise, the large diaphragm 15b and the small diaphragm 15c are sequentially aligned with the aperture 18a. It is designed to be stopped by a stopper (not shown) at a position slightly beyond the point.

A pair of shutter sectors 26, 26 (only one is shown in FIG. 3) is attached to the shaft 4 embedded in the upper base plate 27.
5 and 45, respectively, and a sector opening/closing lever 23, which is pivoted on a shaft 48 implanted in the top plate 27 as will be described later, is connected to a pin 23b at one end of this lever and a pin 23b on the top plate 27. When the shaft 23 attached to the lever 23 is swung counterclockwise against the action of the return spring 24 tensioned between the fixed positions of the
The sectors 26, 26 are opened from the closed position shown in FIG. 2 in conjunction with each other through elongated holes 26a, 26a of the sectors 26, 26, which are slidingly fitted in the sectors 26, 26, respectively.

A pin 15d is implanted in the aperture lever 15 to adjust the aperture diameter, and a shoulder portion 14b abuts against a pin 5a implanted in the printed coil board 5.
The long hole 14c provided near the lower end of the interlocking lever 14, which is pivotally supported by the shaft 28, is slidably engaged with the pin 15d, so that when the printed coil board 5 rotates counterclockwise, the interlocking lever 14 also rotates counterclockwise. direction to rotate the aperture lever 15 clockwise. In order to position the large aperture 15b and the small aperture 15c at positions aligned with the aperture 18a, the aperture lever 15 is provided with a protrusion 15a that passes through the elongated hole 27a of the upper base plate 27. The protrusion 15a is adapted to cooperate with the aperture stop lever 13 which is pivotally supported on the upper base plate 27 by a shaft 46. The aperture stop lever 13 is biased clockwise by a spring (not shown). An inclined cam portion 13a, a stop shoulder portion 13b, a stop shoulder portion 13c, and a stop edge 13d are formed on the lower edge of the aperture stop lever 13, and a pin 13e installed at the left end is installed on the upper base plate 27. axis 4
8 and is biased clockwise by a spring (not shown).
2a and is held at the position shown in the figure, the aperture stop lever 13 resists the action of the spring, and as shown in the figure, the cam part 13a, the stop shoulders 13b, 13c, and the stop edge 13d are held at the protrusion of the pinch lever 15. 15a.

A long hole 12 formed at the lower end of the clutch lever 12
c is an iron piece lever 9 that cooperates with the electromagnetic plunger 10;
The plunger 10 is slidably engaged with a pin 9a provided in the plunger 10.
When the coil 11 is energized and the iron piece lever 9 is attracted to the plunger 10, the clutch lever 12 is swung counterclockwise against the action of the spring, and the first shoulder portion 12a moves upward, causing the aperture stop lever to move. 1
Since the pin 13e of No. 3 is allowed to move upward, the aperture stop lever 13 is rotated clockwise by the action of the spring. When the projection 15a of the aperture lever 15 is in the illustrated position, it is pressed by the clockwise rotation of the aperture stop lever 13 and comes into contact with the inclined cam portion 13a;
The state of the maximum lens aperture shown in the figure is maintained, but when the aperture lever 15 is rotated clockwise as described later with the aperture stop lever 13 being pressed clockwise, the protrusion 15a passes over the cam part 13a and reaches the stop shoulder. 13b and 13c, and the protrusion 15a is stopped by the stopping shoulder 13c, so that the large aperture 1
5b is held in position exactly aligned with aperture 18a. Further, as will be described later, after the aperture lever 15 has rotated to a position where the protrusion 15a exceeds the stop edge 13d of the aperture stop lever 13, the aperture stop lever 13 is rotated clockwise, and then the printed coil board 5 is rotated counterclockwise. When the drive is released and the aperture lever 15 is returned counterclockwise via the interlocking lever 14 by the action of the spring, the protrusion 15a comes into contact with the stopper end 13d and is stopped, and at this position the small aperture 15c is closed to the aperture 18a. Set the aperture in accordance with the In this way, by changing the timing of energizing the plunger coil 11 and energizing the printed coil board 5, it is possible to selectively set the maximum lens aperture, the aperture setting using the large aperture 15b, and the aperture setting using the small aperture 15c. .

A pin 5b is implanted in the printed coil board 5, and this pin 5b engages with the shutter sector drive lever 20 which is pivotally supported on the shaft 28, and the sector drive lever 2
0 rotates together with the printed coil board 5. A locking arm 21a and a locking recess 21b are provided on the shaft 20a installed in the sector drive lever 20.
A sector return lever 21 is pivotally supported and biased counterclockwise by a spring (not shown),
Rotation is restrained by a stopper pin 22 implanted in the upper base plate 27.

The pin 23a at the lower end of the sector opening/closing lever 23, which is pivotally supported on the upper plate 27 by a shaft 48, cooperates with the cam portion 20b of the sector drive lever 20, and when the sector drive lever 20 rotates clockwise, the sector return lever 21 is activated by a spring. The sector lever opening/closing lever 23 is rotated counterclockwise by the action of the locking recess 21b to lock the pin 23a to ensure that the sector lever opening/closing lever 23 is interlocked with the sector drive lever 20, and the sector opening/closing lever 23 is rotated counterclockwise. Pin 23 at the top end
b is moved to the left against the action of the return spring 24. The locking recess 21 of this sector return lever 21
The pin 23a is locked by the sectors 26, 26
The closing operation start timing of the sector drive lever 20 is reliably synchronized with the return operation of the sector drive lever 20. Second
Although not shown in the figure, in conjunction with the leftward movement of the pin 23b, the sectors 26, 26 are opened from the closed position at an opening degree corresponding to the amount of movement of the pin 23b. Sectors 26, 26 are normally held in the closed position by return springs 24.

The amount of leftward movement of the pin 23b mentioned above, and hence the opening degree of the sector 26, is adjusted in relation to the setting of the aperture aperture, and works as a program shutter to obtain an appropriate amount of exposure and depth of focus. ing. For this purpose, the sector opening setting cam lever 25 (second
) is provided, and the protrusion 1 at the upper end of the interlocking lever 14 is provided.
4a, is biased counterclockwise by a spring (not shown), and is stopped by the protrusion 14a.

When the aperture lever 15 is actuated by the counterclockwise rotation of the printed coil board 5 via the interlocking lever 14, and the aperture aperture is set as described above by selecting the timing with the activation of the plunger coil 11. The position of the cam lever 25 is determined by the position of the interlocking lever 14, which is defined in relation to the current position of the aperture lever 15.

The cam edge 25a at the lower end of the cam lever 25 cooperates with the pin 23a of the sector opening/closing lever 23, and when the printed coil board 5 is rotated clockwise, the pin 23a of the sector opening/closing lever 23 is pushed by the cam portion 20b of the sector drive lever 20. When the sector opening/closing lever 23 is swung in the sector opening direction, the cam edge 25a of the cam lever 25 limits the movement of the pin 23a so that the sector opening degree is related to the aperture setting position at that time.

In order to adjust the distance of the lens 18, an interlocking lever 16 that is interlocked with a pin 1a on the printed coil board 1 is pivotally supported on a shaft 29, and a pin 50 is provided at the lower end. When the interlocking lever 16 is slidably engaged with the long groove 17a of the lens drive lever 17 which is pivotally supported on a shaft 51 provided, the lens drive lever 17 is also interlocked and swung in the opposite direction. There is. A pin 17b is installed in this lens drive lever 17, and the pin 17b is held by a pair of opposing neutral position holding levers 53 and 54, which are pivoted on a shaft 52 installed in the upper base plate 27.
7b is held in between, and the opposing levers 53 and 54 are pulled together by a spring 56 by sandwiching a stopper pin 55 installed in the upper base plate 27, so that when the lens drive lever 17 is rotated in any direction, the lever 5
3 and 54, the pin 17b is connected to the stopper pin 55.
The lens drive lever 17 is held in the neutral position by being pulled back to the position determined by the action of the spring 56. Lens drive lever 1
A long hole 17c is formed at the upper end of 7, and a pin 57 implanted in a protrusion formed on the helicoid 18b of the lens 18 is engaged with this long hole 17c, and the printed coil board 1 is rotated clockwise or counterclockwise. When the helicoid 18b rotates, the helicoid 18b is rotated in conjunction with the interlock lever 16 and the lens drive lever 17 to adjust the lens 18 to a long distance or a short distance.
The lens drive lever 17 is held at the neutral position, that is, at the normal distance of the lens, by the neutral position holding levers 53 and 54, which are biased so as to be drawn toward each other so as to come into contact with each other.

In order to clickly hold the helicoid 18b at the lens distance adjustment position, a lens stop lever 19 is provided which is pivoted on a shaft 58 implanted in the upper base plate 27, and this lens stop lever 19 is supported by a spring (not shown). The pin 19a implanted in the lever 19 comes into contact with the second shoulder 12b formed at the upper end of the clutch lever 12 and is stopped, so that the locking pawl 19b of the lens stop lever 19 is normally A long distance click recess 18c and a short distance click recess 1 formed in the helicoid 18b.
8d, the plunger coil 11 is energized and the clutch lever 12 is moved as described above.
is swung counterclockwise, and when the aperture lever 15 is rotated to a predetermined aperture setting position by the operation of the printed coil board 5 that is timed with this, the lens stop lever 19 is moved by the second shoulder portion 12b. The locking of the pin 19a is released and the lens stop lever 19 is allowed to rotate clockwise due to the action of the spring, and the locking pawl 19b engages with the click recess 18c or 18d at the predetermined aperture setting position to set the aperture. It maintains the caliber.

In FIG. 2, illustrations of grooves through which pins and protrusions pass are omitted for clarity.

Furthermore, in the above description, the printed coil board 5 is linked to the aperture setting mechanism, but instead of this, it is also possible to link the lens distance adjustment mechanism.

The operation of the mechanism according to the present invention constructed as described above is as follows.

First, when the dust cover of the camera is opened, the power switch SW ₁ is closed, and when the release button is pressed, the start switch SW ₂ is closed and the control circuit is energized. The AE information signal is input from the AE light receiving circuit AE to the central processing unit CPU and latched.A command is given to the A/F ranging circuit A/F, and the A/F information signal is given to the central processing unit CPU and latched. be done.
Based on this calculation, an optimum aperture diameter that provides an appropriate depth of focus according to the field conditions and an appropriate shutter time taking into account camera shake prevention is calculated and provided to the shutter block drive circuit SD. The output from the shutter block drive circuit SD activates the coils 30 and 31 of the printed coil board 5 in the counterclockwise direction to actuate the aperture lever 15 and the plunger coil 11 to actuate the aperture stop lever 13. The timing is determined, and the aperture lever 15 is operated and held at that position so that a predetermined aperture diameter is set.

Next, when adjusting the lens to a long distance based on the A/F signal, the coils 32 and 33 are energized, and the printed coil board 1 is rotated, for example, clockwise by a command from the control circuit, and The lens drive lever 17 is rotated counterclockwise, the helicoid 18b is rotated clockwise, and the printed coil board 1 is deactivated when the distance is normal, and the printed coil board 1 is rotated counterclockwise when the distance is short. The lens distance is adjusted by rotating the lens, and the lens is locked by the lens stop lever 19.

Next, the coils 30 and 31 of the printed coil board 5 are energized to rotate the printed coil board 5 clockwise in order to open the shutter sectors 26 and 26. In this case, since the pin 5a moves in a direction away from the interlocking lever 14, the aperture lever 15 is maintained at the set aperture aperture position.

The sector opening/closing lever 23 is rotated counterclockwise by the sector drive lever 20 which is interlocked with the clockwise rotation of the printed coil board 5 against the action of the spring 24, thereby opening the sector 26 from the closed position. At this time, the sector return lever 21 rotates counterclockwise around the pin 22 and locks the pin 23a, so that the interlocking of the sector opening/closing lever 23 and the sector driving lever 20 is ensured, and jumping of the sector opening/closing lever 23 is prevented. .

After a predetermined time according to the AE signal, a current in the opposite direction is applied to the coils 30 and 31 of the printed coil board 5, and the sector drive lever 20 is strongly rotated counterclockwise together with the printed coil board 5. The interlocked sector opening/closing lever 23 is also reliably rotated in the sector closing direction.

As mentioned above, the sector opening is adjusted to operate as a program shutter in order to provide the optimum shutter time as determined by the AE and A/F information, and for this purpose the aperture lever 15 which sets the aperture The position of the cam lever 25 is determined by the interlocking lever 14 whose position is regulated, and the amount of rotation of the sector opening/closing lever 23 in the counterclockwise direction is determined by the pin 23a that comes into contact with the cam edge 25a of the cam lever 25. The opening degree is determined.

After a predetermined delay time after exposure, the control circuit is deactivated and the camera is returned to its initial position as shown.

FIG. 4 shows an operation time chart of the camera of the present invention.

As mentioned above, according to the present invention, fully automatic A/F.
The AE camera can be manufactured with a simple structure to ensure highly efficient and accurate operation.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a control circuit of a camera incorporating the present invention. 2 is a bottom view of the aperture setting mechanism according to the present invention, with the base plate omitted and viewed in the direction of arrow A in FIG. 3; FIG. FIG. 3 is a side view of FIG. 2. Figure 4 is an operating time chart of a camera incorporating the present invention. 1, 5... Mover, i.e. printed coil board, 9... Iron piece lever, 10... Plunger, 1
1... Plunger coil, 12... Clutch lever, 13... Aperture stop lever, 14... Interlocking lever, 15... Aperture lever, 15b... Large aperture, 15c... Small aperture, 18a... Lens aperture, 20... Sector drive lever, 21... Sector return lever, 23... Sector opening/closing lever,
25...Cam lever.

Claims (1)

[Scope of utility model registration request] A lens 18 having a helicoid 18b for adjusting the subject distance, and various aperture apertures 15b and 15c, the aperture aperture 15 being selected at a predetermined swing position.
b, 15c to align with the lens aperture 18a,
Alternatively, an aperture lever 15 that can be pivoted to separate from the lens aperture 18a, a sector 26 that can be pivoted between fully open and fully closed positions and set to a selected lens aperture opening, and outputs a subject brightness information signal. an A/F distance measuring circuit A/F that outputs a subject distance information signal;
A central processing unit that inputs these signals and outputs a subject brightness setting signal and a ranging distance setting signal.
An electromagnetic camera shutter comprising a CPU and a shutter block drive circuit SD which inputs an output signal from the central processing unit CPU and outputs an output signal for controlling the shutter block to set a subject distance and perform proper exposure. The shutter block drive circuit SD is energized at a predetermined time and for a predetermined period of time by the output of the shutter block drive circuit SD to selectively pivot in one direction or the opposite direction, and is normally held at an intermediate neutral position. The printed coil board 5 for controlling the aperture and shutter sector, and the output of the shutter block drive circuit SD are energized at a predetermined time and for a predetermined time to selectively pivot in one direction or the opposite direction, and are normally pivoted in the intermediate direction. The printed coil board 1 for adjusting the subject distance tends to be held at a neutral position, and the printed coil board 5 for controlling the aperture and shutter sector is pivoted in the one direction in conjunction with the aperture lever 15. an interlocking lever 14 that can follow and align the selected aperture diameter 15b or 15c with the lens aperture 18a; and an interlocking lever 14 that is interlocked with the sector 26 and adapted to pivot the aperture and shutter sector control printed coil board 5 in the opposite direction. The sector 2 is pivoted accordingly.
Sector opening/closing lever 2 that can be set to a predetermined opening degree
3, the sector opening/closing lever 23 is pivoted by the interlocking lever 14 that follows the one-way pivoting of the aperture and shutter sector control printed coil board 5 and comes into contact with the sector opening/closing lever 23, thereby changing the position of the sector opening/closing lever 23. a cam lever 25 that regulates the opening of the sector 26, and an interlocking lever 1 that pivots in accordance with the pivoting of the subject distance adjusting printed coil board 1 in one direction or the opposite direction.
6, the lens helicoid 18b is interlocked with the lens helicoid 18b and the interlocking lever 16, and is pivoted by the pivoting of the subject distance adjustment printed coil board 1 in one direction or the opposite direction.
a lens drive lever 17 that operates the helicoid 18b to set the intermediate distance of the lens 18 from the intermediate position to an infinite distance or short distance position; Neutral position holding levers 53, 54, which are controlled to return to the neutral position, and the aperture lever 15, the selected aperture aperture 15b or 15c is aligned with the lens aperture 18a, or these aperture apertures are separated from the lens aperture 18a. The aperture lever 1 is
a throttle stop lever 13 operatively connected to 5;
Then, the aperture lever 15 is actuated by the plunger coil 11 which is energized at a predetermined time and for a predetermined time by the output of the shutter block drive circuit SD, and is pivoted to give a predetermined aperture aperture to the lens 18. An electromagnetically driven camera shutter comprising a clutch lever 12 for pivoting the stop lever 13 between a restraining position and a releasing position.