JPS6235098B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a power supply voltage warning device for a single-lens reflex camera, and more particularly, to a power supply voltage warning device for a single-lens reflex camera. The present invention relates to a power supply voltage warning device that warns when the voltage is not performed.

[Problems to be Solved by the Invention] In an electric shutter camera with a built-in power supply voltage, if the power supply voltage is low or the battery is forgotten to be loaded and the specified electrical operation is not performed,
This must be communicated to the user by some means. Otherwise, all the photos you intended to take when you press the shutter button will be wasted. For this reason, some cameras are designed to prevent the shutter button from being pressed if the power supply voltage is insufficient or the power switch is open, but with this method, for example, if the exposure meter is out of range or the film is Since the shutter button cannot be pressed before or during winding, the user is confused as to why the shutter button cannot be pressed and may force the shutter button, causing a malfunction.

In addition, when the power supply voltage is higher than the specified voltage, there is a method that notifies the user in advance by lighting a lamp to indicate this while pressing down the shutter button, but this also requires the user to take pictures. I'm so obsessed with this that I almost never check it each time. There are also models that incorporate a shutter lock mechanism that operates when there is no power supply voltage, but this not only makes the mechanism complicated, but once it is locked, it will not work even if the power supply voltage is normalized. Since the shutter is locked, a separate release mechanism is required, making it more complicated and expensive.

[Means and effects for solving the problem] In view of the above points, an object of the present invention is to skillfully use an electromagnet that operates when the power supply voltage is above a specified value, so that the voltage of the built-in power supply battery exceeds the specified value. This is an extremely simple and effective power supply voltage warning device for single-lens reflex cameras that prevents the movable mirror from jumping up midway if it is not maintained, thereby warning that there is no power supply voltage. is to provide.

According to this invention, when the power supply voltage has dropped below a specified voltage, when the user presses the shutter button, the movable mirror moves slightly and stops at that position, and the inside of the viewfinder is opened. Since the light becomes dim, photographing can be stopped immediately, and unnecessary photographing is prevented. Furthermore, when the battery is replaced and the power supply voltage returns to normal, the movable mirror is automatically unlocked and rotated to the normal position, so no special release mechanism is required and the structure is simple. It is also possible to provide a warning device that is simple and can exhibit remarkable effects.

[Example] This invention will be explained based on the illustrated example. FIG. 1 is a perspective view of essential parts of a single-lens reflex camera showing an embodiment of the present invention. As is well known, a single-lens reflex camera is equipped with a movable mirror 1 located in front of the film surface and inclined at 45 degrees with respect to the photographing optical path O. The upper ends of the left and right walls 2a and 2b are rotatably supported by support shafts 3a and 3b attached to the left and right walls 2a and 2b. When the shutter button is pressed, the mirror 1 rotates around support shafts 3a and 3b and flips up to expose photographic light onto the film surface through the shutter. The shutter is arranged just in front of the film surface, and the shutter leading curtain 4 and trailing curtain 5 are driven by a winding drum 7 for driving the leading curtain and a winding drum 9 for driving the trailing curtain, respectively, to perform the exposure operation. This is a focal plane type electric shutter, and reference numeral 6 is a drum for winding up the leading curtain, and reference numeral 8 is a drum for winding up the trailing curtain.

The drive mechanism of the movable mirror 1 is disclosed in Japanese Patent Application No. 47-65484 (Japanese Patent Application Laid-open No. 49-27219) filed by the present applicant.
Since it is as disclosed in Utility Model Application No. 47-77493 (Utility Model Application No. 49-49916) etc., a detailed explanation will be omitted, but the outline is as follows. That is, mirror moving pins 10a and 10b are symmetrically protruded near the upper end of the left and right sides of the mirror 1,
These pins 10a, 10b are connected to the left and right side walls 2a, 2b.
The guide holes 11a and 11b are loosely fitted into arc-shaped guide holes 11a and 11b, respectively. The tip of the pin 10b passes through the elongated hole 11b of the right side wall 2b, and is loosely fitted into the elongated hole 13 provided at the free end of the mirror drive lever 12.

The mirror drive lever 12 has a pin 14 implanted at its base end that is loosely fitted into an elongated hole 16 drilled in a support plate 15, and rotates counterclockwise about the pin 14 as an axis.
The mirror 1 is flipped up by rotating the mirror moving pin 10b clockwise through a long hole 13 provided at the free end.

Further, the automatic aperture lever 21 is rotatably supported by a shaft 19, and a clockwise rotational force is applied by a spring 28.
9 (see Figure 2).

In the above configuration, when the locking lever 29 is driven in the direction of the arrow by pressing down the shutter release button, the automatic aperture lever 21 is moved as shown in FIG.
The mirror 1 is rotated clockwise by a spring 28 to narrow down the diaphragm and flip up the mirror 1 via the mirror drive lever 12.

Next, the power supply voltage warning device according to the present invention will be explained in more detail with reference to FIGS. 4 to 6. As shown in Fig. 4, this warning device consists of a release type electromagnet 7 that operates when the power supply voltage is higher than a specified voltage.
1, and a mirror blocking mechanism 70, which is made up of a blocking control member 72 formed of a three-arm rod and also serves as mirror control.

The mirror blocking control member 72 is rotatably supported at its central fulcrum by a shaft 73;
The end of the first arm 72a that extends in front of the camera (to the right in FIG. 4) serves as a suction portion 72d for the electromagnet device 71. And this adsorption part 7
A movable member 71a, which is attracted to the attraction surface of the electromagnet 71, is swingably attached to 2d by a pin 74. The movable member 71a is of a sandwich type in which a permanent magnet 75 is sandwiched between upper and lower plates 76a and 76b made of soft iron pieces, and its central mounting portion is attached to the adsorption portion 72d by the mounting pin 74, so that it can be used for a lifetime. A permanent magnet 7 is attached to the attraction surface of the electromagnet consisting of the excitation coil 77b and the yoke 77a.
It is adsorbed by the suction force of 5.

The second arm 72b of the mirror blocking control member 72 is directed toward the movement path of the mirror driving pin 10a provided on the left side of the movable reflecting mirror 1 on the opposite side of the first arm 72a. The blocking portion 72c, which extends out and is formed at the tip thereof, comes to rest at a position a certain distance away from the pin 10a when the attracting portion 72d is attracted to the electromagnet 71. ing.

The mirror blocking control member 72 is wound around a support shaft 73, and has one end attached to a fixing pin 78 and the other end attached to a torsion spring 79 attached to a downwardly extending third arm 72e for backward movement. A clockwise (in FIG. 4) rotational behavior is thus provided. However, in normal life, the rotation due to this habit is such that the movable member 71a is moved by the permanent magnet 75 to the yoke 77.
This is prevented by adsorption to a.

In addition, the reference numeral 80 is a stopper member of the movable member 71a, and the reference numeral 81 is a stopper of the movable reflecting mirror 1.

In this embodiment configured as described above, when the power supply battery has a predetermined voltage, when the power switch is closed, the electromagnet 71 is excited, and the electromagnet 71 is energized. The above permanent magnet 7
The movable member 71a is repelled by the magnetic force with the polarity opposite to that of the attracting magnetic force of No. 5, and the movable member 71a loses its attracting force to the electromagnet 71. The movable member 71 rotates clockwise due to its habit, as shown in FIG.
a comes into contact with the stopper member 80 and stops. In this state, the blocking portion 72c of the second arm 72b moves to a position evacuated from the movement path of the mirror drive pin 10a, so the mirror blocking control member 72 prevents the movable reflecting mirror 1 from jumping up. There is nothing to do, moveable reflector 1
performs normal jumping motion.

However, when the power supply voltage is lowered, as shown in FIG. 6, the electromagnet 71 is not excited, so the movable member 71a is not repelled by the electromagnet 71, and the attraction part 72d of the first arm 72a is connected to the electromagnet device. 71 remains adsorbed. Therefore, the mirror blocking control member 72 does not rotate, and the blocking portion 7 of its second arm
2c prevents the movable reflecting mirror 1 from jumping up midway. Therefore, the interior of the viewfinder becomes dimly lit, which can provide a warning that the power supply voltage is dropping.

As described above, by configuring the mirror blocking mechanism 70 with a single mirror blocking control member 72 having a mirror blocking function and a locking control function, the object of the present invention is successfully achieved despite the simple configuration. be able to.

Further, in the above embodiment, the electromagnet is energized directly from the power source, but it may be energized via a voltage determination circuit in the middle.

Further, as described above, the electromagnet 71 in the present invention has a power supply voltage determination function, and
It has a function that temporarily stops the shutter operation immediately before the shutter operation. Therefore, by skillfully utilizing this function, for example, the electromagnet 7
By inserting a delay circuit for a self-timer into the circuit that supplies power to the camera and activating the electromagnetic device after a certain period of time, the camera can easily be provided with a self-timer function.

FIG. 7 is a block diagram showing the configuration of an electric circuit of a self-timer using the power supply voltage warning device according to the present invention. That is, the power source P _W
is led to the voltage judgment circuit _PJ via the power switch SW, where it is judged whether the power supply voltage is above the specified value, and a switch S for self-timer setting is connected to the output terminal of the circuit _PJ . , the same switch S is connected to the electromagnet 71 and a self-timer delay circuit.
It is configured to switch between CR and CR.

The self-timer delay circuit CR is composed of a well-known CR time constant circuit consisting of a capacitor and a resistor, and the self-timer setting changeover switch S is connected to one of the self-timer setting operations. The fixed terminal Sa switches to
The voltage determination circuit P _J is connected to the electromagnet 71 via the self-timer delay circuit CR. Therefore, when the switch S is switched to the fixed terminal Sa, after the predetermined delay time set in the delay rotation CR has elapsed, the electromagnet 7 is turned on by the output of the same circuit.
1 will be energized. However, in normal life, the changeover switch S is switched to the other fixed terminal Sb, so that the electromagnet 71 is directly connected to the output terminal of the voltage determination circuit _PJ .

According to the self-timer configured in this way, you can set the self-timer and turn on the power switch.
Even if the SW is turned on and current is applied to the circuit, the electromagnet 71 is not energized immediately, so the movable reflector 1 (see FIG. 1) is slightly raised by the electromagnet 71 and the mirror blocking mechanism 70. It will be stopped. In this stopped state, a self-timer period of 10 to 15 seconds set in the self-timer delay circuit CR elapses, and the self-timer is activated at this time. When the self-timer elapses, the electromagnet 71 is energized and the electromagnet device operates to normally operate the mirror drive mechanism, so the shutter operates and self-timer photography is performed smoothly.

As described above, by using the power supply voltage warning device of the present invention, a self-timer can be added to a camera simply by adding a changeover switch and a delay circuit.

[Effects of the Invention] According to the present invention, when the power supply voltage has dropped below a specified voltage, the movable reflector rises slightly when the photographer presses the shutter button. Since the camera is stopped at this position and the inside of the viewfinder becomes dimly lit, it is possible to know that there is no power supply voltage and immediately stop photographing, thereby preventing unnecessary photographing. Furthermore, when the battery is replaced with a new one and the power supply voltage returns to normal, the movable reflector will automatically rotate and jump from its stopped position to its normal raised position. It is possible to provide a single-lens reflex camera having a power supply voltage drop warning device that does not require a release mechanism, has a simple configuration, and exhibits a remarkable effect.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a power supply voltage warning device for a single-lens reflex camera, showing an embodiment of the present invention, and FIGS. 2 and 3 show the operation of the movable reflector drive mechanism shown in FIG. 1 above. 4 to 6 are side views of the main parts showing the operation of the power supply voltage warning device of FIG. 1, respectively, and FIG. FIG. 2 is a block diagram of the timer electrical circuit. DESCRIPTION OF SYMBOLS 1... Movable mirror, 10a... Mirror drive pin (engaging part), 70... Mirror blocking mechanism, 71...
...Electromagnet, 72...Mirror blocking control member.

Claims (1)

[Scope of Claims] 1. A movable mirror that is arranged to be movable between a lowered position and a raised position and that performs a shutter release when raised; an engaging portion provided on one side of the movable mirror; Only when the power supply voltage is higher than the specified voltage, there is an electromagnet that is activated by electricity from the power supply, the middle part is pivotally supported, one end is a blocking part located in the movement path of the above-mentioned engaging part, and the other part is The mirror is provided with a mirror blocking control member having an adsorbing portion fixed to the end thereof to be attracted to the electromagnet, and when the power supply voltage is lower than a specified voltage, the mirror is prevented from rising midway by the mirror blocking control member. A power supply voltage warning device for a single-lens reflex camera, characterized in that: