JPS63103221A - Mirror controller for single lens reflex camera - Google Patents

Abstract

PURPOSE:To eliminate such an accident that a film is exposed to external light when a photographic lens begins to be detached with a mirror and a light shield plate up by detecting its initial operation by a switching means and returning the mirror and light shield plate to their down positions instantaneously and automatically. CONSTITUTION:When a lens unit 8 is detached, a switch 42 is turned off in the beginning of the sliding operation of a release lever 40 provided to a hook 7. The moment its signal is inputted, a mirror control circuit 61 operates and the mirror 27 and light shield plate 31 are moved to their down positions by a motor 28 and a mirror driving mechanism 30. Namely, when the start of the lens detaching operation is detected while the mirror 27 and light shield plate 31 are at their up positions, the mirror 27 and light shield plate 31 are moved down urgently even if a mirror-up button 34 is set at a mirror-up operation position. Consequently, the film 11 is prevented securely from being exposed to the external light.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a single-lens reflex camera with a photographic lens and a film magazine that can be freely attached and detached. This invention relates to a mirror control device for controlling the operation of a mirror.

[Conventional technology]

Lens-shutter type single-lens reflex cameras with large screen sizes are known for commercial photographers and semi-professional photographers. Generally, this type of single-lens reflex camera is
It consists of a camera body, a photographic lens with a built-in shutter, and a magazine containing film, which is attached to the camera body, and by connecting the photographic lens and camera body through a bellows, it is possible to take pictures with added tilt. Some are like this.

The body of a single-lens reflex camera is provided with a mirror that opens a photographing optical path when raised, closes the photographing optical path when lowered, and simultaneously forms a finder optical path. In addition, in the lens-shutter type single-lens reflex camera mentioned above,
In order to completely close the photographing optical path when the mirror is lowered, the camera body is usually provided with a light shielding plate that moves up and down in conjunction with the mirror.

By the way, in an eye-reflex camera, the mirror rapidly moves to the hip position just before exposure starts, so vibrations at this time can be a problem, especially when demanding 1111 degrees are required. There is Narukoshichi. Additionally, special photography lenses with long flange backs may not be able to be attached to the camera body because the mirror gets in the way. In order to solve such problems, apart from the normal shooting sequence,
Can you raise the mirror manually? A mirror-up device that can hold a mirror while moving it to a certain position is known.

[Problem that the invention seeks to solve]

However, when attempting to provide the above-mentioned mirror up device in a lens shutter type single-lens reflex camera, the following problems arise. In other words, in this type of single-lens reflex camera, the shutter is built into the photographic lens that is attached to and removed from the camera body, so it is difficult to raise the mirror and light shielding plate with the photographic lens removed, or to raise the mirror and light shielding plate with the photographic lens removed. If an attempt is made to remove the photographic lens while it is still raised, external light will enter the camera body through the opening of the mounting portion of the photographic lens, and the film will be exposed by this light.

In order to eliminate this inconvenience, when attempting to remove the photographic lens with the mirror and light-shielding plate raised, the mirror and light-shielding plate are forcibly moved to the lowered position, or the photographic lens is not attached. When there is not,
It has been proposed to configure the mirror and the light shielding plate to be prohibited from moving to the raised position. According to this, it is possible to reliably prevent the film from being inadvertently exposed during a lens exchange operation.

However, if the position of the mirror and light shielding plate is simply controlled as described above, it becomes impossible to raise the mirror and light shielding plate when the photographic lens is removed. Problems arise in that lenses, such as special lenses with a long flange back, cannot be used, or that demonstration operations of the mirror alarm device cannot be performed without a photographic lens attached.

The present invention has been made in view of the above-mentioned prior art, and is intended to prevent the film from being inadvertently exposed by a mirror up device attached to a lens-shutter type eye reflex camera, and to reduce the risk of such exposure. It is an object of the present invention to provide a mirror control device for a single-lens reflex camera in which a mirror up device can be operated freely to take various photographing modes when the camera is not in use.

[Means for solving problems]

In order to achieve the above object, the present invention has a mirror-up operation means operated when performing a mirror-up operation, a switching means operated by an initial operation when removing a photographic lens from a camera body, and a switching means operated on the back of the camera body. A light-shielding lid detection means is used to detect whether or not the exposure opening on the front surface of the mounted film magazine is completely shielded by a removable light-shielding lid. When the exposure opening of the film magazine is shielded by the light-shielding lid detection means, the film stored in the magazine will not be exposed to light, so that the mirror is raised regardless of the switching operation of the switching means. The mirror-up operation can be performed freely by operating the operation means, and when the light-shielding lid detection means identifies that the exposure opening is open, regardless of the operation of the mirror-up operation means,
The mirror and light shielding plate located at the photographing position and the optical path opening position are moved to the finder observation position and the optical path blocking position, respectively.

Further, in a preferred embodiment of the present invention, the switching means is configured to maintain the switching operation state unless a photographic lens is attached to the camera body, and the exposure opening of the film magazine is opened.
When the photographic lens is not attached, the operation of the mirror drive mechanism is prohibited even if the mirror up operation means is operated, and the mirror and the light shielding plate are maintained in the lowered position. Further, a motor is used to move the mirror and the light shielding plate between the raised position and the lowered position, and these movements can be easily performed by electrically controlling the drive of the motor. It has become.

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

〔Example〕

In FIG. 1, which schematically shows a lens shutter type eye reflex camera using the present invention, a pair of guide tubes 3 are provided protruding forward from a camera body 2. A feeding unit 4 is attached. This feeding unit 4 is provided with a lens board 6 to which a bellows 5 is connected. The lens unit 8 is attached to the lens board 6 in a light-tight manner by means of a hook 7 provided on the upper part of the lens board 6. A knob 9 provided at the base of the feeding unit 4
When the lens unit 8 is rotated, the lens unit 8 moves forward and backward in the optical axis direction together with the lens board 6, thereby enabling focus adjustment. Further, a magazine 12 in which a film 11 is stored is attached to the back side of the camera body 2.

In addition to the photographic lens 13, the lens unit 8 includes a shutter blade 14 and a shutter control circuit 15 for controlling the drive thereof. It has a built-in shutter blade drive mechanism 16 (FIG. 1). By attaching the lens unit 8 to the lens board 6, the electrodes (
(not shown) is connected, and the lens unit 8 and camera body 2 are also electrically connected via a flexible cord 17.

On the other hand, when the magazine 12 is also attached to the camera body 2, the two are electrically connected via the contacts 18. The magazine 12 includes a film winding motor 20, a winding control circuit 21 (FIG. 1) for controlling its drive, and a winding drive mechanism 22, and these operations are controlled by electrical signals from the camera body 2. It looks like this. Magazine 12 to camera body 2
In order to prevent the film 11 from being exposed to external light when removed from the magazine 12, a light-shielding lid 25 that can be pulled out and inserted is provided on the front surface of the magazine 12. In addition,
A liquid crystal display panel 23 is provided on the top surface of the magazine 12, and is used to display the number of films and warnings.

The camera body 2 is provided with a mirror 27 that is movable between a lower position shown by a solid line and an upper limit position shown by a two-dot chain line. The mirror 27 is driven by a motor 28 for driving the mirror.
and a mirror control circuit 29 (Fig. 1) that controls its drive.
, is operated by the mirror drive mechanism 30. This mirror drive mechanism 30 also operates a light shielding plate 31 movably installed behind the mirror 27. The light shielding plate 31 functions to close an opening 32 formed on the back surface of the camera body 2 and prevent light from entering the magazine 12 side. When the mirror 27 is in the lowered position, the opening 32 is completely closed, and when the mirror 27 is moved to the raised position, it is moved up in conjunction with this, and the opening 32 is completely opened. The operation of the mirror 27 and the light shielding plate 31 is controlled according to the normal photographing sequence executed by operating the release buttons 3-10 = 3, and is also manually moved to the raised position by operating the mirror up button 34. be able to. Of course, in this case as well, the motor 28. The mirror drive mechanism 30 is now activated.

As shown in FIGS. 2 and 3, the hook 7 for attaching the lens unit 8 is pivoted to the lens board 6, and is attached by a spring 38 in the counterclockwise direction, that is, in the direction in which the lens unit 8 is attached. Forced. Then, by engaging the lower part of the lens unit 8 with a support hook (not shown) protruding from the lower part of the lens board 6, and inserting the tip of the hook 7 into a locking hole 8a formed in the lens unit 8. The lens unit 8 is tightly attached to the lens board 6. In this engaged state, the release lever 40 slidably provided on the hook 7 is moved to the left by the bias of the spring 41, and the distal end hook 40a touches the stepped portion 6a formed on the lens board 6. Since they are engaged, the release 11 of the hook 7 is prevented from moving in one direction. Further, when the release lever 40 is moved to the illustrated position, the switch 42 is turned on.

When removing the lens unit 8, first slide the release lever 40 to the right and release the tip hook 40a and the stepped portion 6.
Release the bond with a. Thereafter, the lens unit 8 can be removed by holding the hook 7 as shown in FIG. In addition, at the beginning of the operation for removing the lens board l-8, the release lever 40 is slid as described above, but at this time, the switch 42 is
is turned off, by monitoring the signal from the switch 42, it is possible to detect the preparatory operation of the lens unit 8 before it is actually removed.

When the hook 7 is held in the position shown in FIG.
It rotates under the bias of the spring 44, and its tip 43a protrudes from the mounting surface 45. As a result, the pin 47 implanted in the lens attachment detection lever 43 also moves. Therefore, even if the lifting of the hook 7 is subsequently released, the tip of the pin 47 supports the bottom surface of the hook 7, so that the hook 7 is held in the position shown in FIG. 3. Also, at this time, the tip hook 40a of the release lever 40 comes into contact with the stepped portion 6a, so the switch 42 is turned off.
It remains in the F state.

When attaching the lens unit 8, as described above, the lower side of the lens unit 8 is first engaged with the lens board 6, and then the lens unit 8 is pushed into the lens board 6. As a result, the flange rear surface 48 of the lens unit 8 presses the tip 43a of the lens attachment detection lever 43 protruding from the mount surface 45. Then, when the lens attachment detection lever 43 rotates against the spring 44 and the tip of the pin 47 comes directly below the fitting hole 49 formed on the bottom surface of the hook 7, the hook 7 is rotated to the left by the spring 38. The lens unit 8 is now tightly attached to the lens board 6.

An exposure frame 50 is formed on the front surface of the magazine 12, as shown in FIG. Then, the light shielding lid 25 can be inserted into the magazine 12 so that the exposure frame 50 can be completely shielded. In order to detect insertion and withdrawal of the light-shielding lid 25, switches 52 and 53 are built into the magazine 12. When the light shielding i25 is completely inserted, the switch 52 is set to 0FFL, and conversely, when the light shielding lid 25 is completely pulled out, the switch 52 is set to 0FFL.
3 turns OFF.

In FIG. 5, which shows the circuit configuration used in the above camera, block A shows the part built into the camera body 2, block B shows the part built into the lens unit 8, and block C shows the part built into the magazine 12. The contacts B and C are each connected to contact 18.
．． It is electrically connected to block Δ via 55. Block A is a microprocessor unit (hereinafter referred to as body MI) 6 that is included in the camera body 2.
0. A mirror control circuit 61 for controlling the operation of the mirror drive motor 28, and an up operation detection circuit 6 for detecting that the mirror up button 34 has been operated.
2 and a buzzer 63 for alarm. The body MPU 60 sends and receives electrical signals to and from blocks B and C, executes sequences necessary for photographing, and monitors whether each part is operating normally.

Block B includes a shutter control circuit 15, which controls driving of a motor 64 for operating a shutter blade drive mechanism 16. Also,
ON/O by the release lever 40 provided on the hook 7
A signal from the switch 42 that is turned OFF is input to the body MPU 60 via the connector 55.

Block C is a microprocessor unit (hereinafter referred to as magazine MP) that controls electrical signals of 12 magazines.
65 and the winding control circuit 21, a liquid crystal driver 66 for driving the liquid crystal display panel 23, a light shielding lid detection circuit 68 for detecting the presence or absence of the light shielding lid 25 via the switches 52 and 52, and a film The film 11
It includes a film detection circuit 69 for detecting the presence or absence of the film.

According to the above configuration, a normal photographing sequence is performed as follows. First, in the viewfinder observation state shown in FIG. The light shielding plate 31 is placed in the lowered position, and the shutter blade 14 is open. Therefore, the subject light flux that has passed through the photographic lens 13 is reflected by the mirror 27 and formed into an image on the focusing glass 35'. When the operation of the release button 33 is detected by the body MPU 60, a closing signal is input from the body MPU 60 to the shutter control circuit 15, the motor 64 is driven, and the shutter blade 14 is closed. This shutter blade 1
When the closing signal No. 4 is fed back to the body MPU 60, the motor 28 is driven via the mirror control circuit 61, and the mirror 27 and the light shielding plate 31 are respectively raised by the operation of the mirror drive mechanism 30 and retreated from the photographing optical path.

Thus mirror 27. When it is confirmed that the light shielding plate 3 has moved to the raised position, the body MPU 60 outputs an exposure start signal to the shutter control circuit 15. As a result, motor 6
4. Shutter blade 1 via shutter blade drive mechanism 16
4 opens and closes to perform exposure. When the exposure is completed, an exposure completion signal is fed back from the shutter control circuit 15 to the body MPU 60. Upon receiving this exposure end signal, the body MPU 60 outputs a film winding signal to the magazine MPU 65.

When a film winding signal is input to the magazine MPU 65, the motor 20 is driven by the winding control circuit 21, and the film 11 is wound through the winding drive circuit 22. When the film 11 has been wound by exactly one frame, a winding completion signal is returned to the magazine MPU 65, and the operation of the winding control circuit 21 is stopped. The winding completion signal is body M
When input to the PU 60, the motor 28 is reversed by the mirror control circuit 61, and the mirror 27. The light shielding plate 31 moves to the lowered position. When it is detected that these have reached the fully lowered position, the body MPU 60 operates the shutter control circuit 15 to open the shutter blade 14 again. As a result, the -th photographing sequence is completed and the viewfinder observation state shown in FIG. 1 is restored.

By the way, in the above-mentioned normal viewfinder observation state, that is, in the finder observation state during shooting, the light shielding plate 31 is in the lowered position and completely shields the aperture 32, so even if the lens unit 8 is removed, the film cannot be seen. 1
Since the lens unit 1 will not be exposed to light, the lens unit 8 can be replaced at will. In addition, when moving the mirror 27 and the light shielding plate 31 to the raised position with the lens unit 8 attached, press the mirror up button 34.
All you have to do is operate.

When the mirror up button 34 is operated, the mirror up switch 72 is turned on, and the up operation detection circuit 6 is turned on.
2, a shutter close signal is first output from the body MPU 60 to the shutter control circuit 15. When the shutter blade 14 is completely closed, this closing completion signal is fed back to the body MPU 60, and after receiving this signal, the mirror control circuit 61 is activated, and the mirror 27 and light shielding plate 31 are moved to the raised position. will be done. Therefore, in this case, since the light is blocked by the shutter blade 14, the film 11 is not exposed. From this state, press the mirror up button 34.
Return to the normal position and turn the mirror up switch 72 OFF.
In the case of F, the shutter blade 14 is opened after the mirror 27 and the light-shielding plate 31 have reliably returned to the lowered position, contrary to the mirror-up operation.

Furthermore, in the camera configured as described above, even if an inadvertent operation is performed as described below, the process shown in Figure 6 that is performed after the power is turned on, and the process that is performed subsequently. By the process shown in FIG. 7, accidents such as the film 11 being exposed to external light can be completely prevented.

In the initial state when the power switch is turned on, the mirror 27.degree. light-shielding plate 31 is placed in the lowered position by the power-off processing described later. When the lens unit 1-8 is removed from the lens board 6 for replacement, for example, after the power is turned on, the switch 42 detects the removal. And the light-shielding lid detection circuit 68
When it is detected that the light shielding lid 25 is pulled out and the film detection circuit 69 detects that the film 11 is loaded, as shown in step 75, even if the operation of the mirror up button 34 is detected. However, the body MPU 60 does not output a signal to the mirror control circuit 61 to raise the mirror 27, but instead sounds the buzzer 63 and displays a warning on the liquid crystal display panel 23, causing the mirror 27 and The light shielding plate 31 maintains the lowered state.

In other words, if the mirror is raised when the lens unit 1-8 is removed, the fill 1.11 will be directly exposed to external light. You will receive a warning if you attempt to do so.

Note that when the light-shielding lid detection circuit 68 detects that the light-shielding lid 25 is completely inserted into the magazine 12,
Alternatively, when the film 11 is not detected by the film detection circuit 69, the mirror 27 and the light-shielding plate 31 can be freely raised and lowered by operating the mirror up button 34, regardless of whether the lens unit 8 is attached or not. Also, by operating the mirror up button 34, the mirror 27. When the power switch of the camera is turned off with the light shielding plate 31 raised, the hold on the power is cut off after the mirror 27 and the light shielding plate 31 are lowered. Therefore, in the initial state when the power switch is turned on, each of the mirror 27 and the light shielding plate 31 always maintains a lowered state.

While the power switch is maintained in the ON state, the processing shown in FIG. 7 continues to be executed. According to this process, when a mirror-up operation at the time of removing the lens unit 8 is detected in step 76, the operation is prohibited and a warning is issued, as described above. Furthermore, mirror 27. When it is detected in step 77 that the lens removal operation is started while the light shielding plate 31 is in the 2-up position, the mirror 27. 2. The light shielding plate 31 is closed. It will now work down.

That is, when removing the lens unit 8, the release lever 40 provided on the hook 7 is first slid to the right, and at the beginning of the sliding operation, the switch 42 is
is turned off. The moment the OFF signal of this switch 42 is input to the body MP tJ 60, the mirror control circuit 6I is activated, and the motor 28. The mirror 27° light shielding plate 31 is moved to the lowered position by the mirror drive mechanism 30.

At the moment when this switch 42 is turned off, the lens unit 8 has not yet been removed from the lens board 6.

Therefore, the moment the switch 42 is turned off, the light shielding plate 3
1 to the lowered position, even if you continue to remove the lens unit 8, the film 1
1 can be reliably prevented from being exposed to external light.

Furthermore, when the light-shielding lid 25 is completely inserted into the magazine 12, the mirror 27. Each of the light shielding plates 31 can be operated in accordance with the operation of the mirror up button 34. Therefore, by inserting the light shielding i25 and turning off the switch 52, it is possible to demonstrate mirror-up and mirror-down regardless of whether the lens unit 8 is attached or not. Furthermore, when using a photographic lens that is not systematized as an interchangeable lens, for example, a photographic lens with a long flange back, first insert the light-shielding lid 25 and then remove the mirror 27. The light shielding plate 31 is held in the raised position, and then the photographing lens is attached. To attach this photographic lens, an adapter having a common mount part with the lens unit 8 is used, and when the attachment is completed, the lens attachment detection lever 43 is rotated.
Even if the light shielding cover 25 is pulled out after this installation, the mirror 27
And since the light shielding plate 31 remains held at the upper limit position according to the operation of the mirror up button 34,
In this way, it becomes possible to take pictures by manually operating the shutter of the attached photographic lens.

Further, the process shown in FIG. 7 is repeatedly executed until the power switch is turned off. Therefore, for example, when the light-shielding lid 25 is inserted and the lens unit 8 is removed, and the switch 52 is turned on to pull out the inserted light-shielding lid 25, the mirror 27 and the light-shielding plate 31 in the raised position is forcibly moved to the lowered position, and inadvertent film exposure is prevented.

Note that step 75 in FIG. Step 76 in FIG.
When the processes after 77 are performed, taking into consideration that the operation position of the mirror up button 34 and the positions of the mirror 27 and the light shielding plate 31 will conflict with each other and become unnatural, when these processes are performed, an electromagnet etc. It is desirable to forcefully return the mirror up button 34 to the normal position by using the .

〔Effect of the invention〕

As described above, according to the mirror control device of the present invention, even if the operation to remove the photographic lens is started while the mirror and the light shielding plate remain raised, the switching means detects the initial operation and removes the mirror and the light shielding plate. Since the light-shielding plate is instantly and automatically returned to the lowered position, even if the photographing lens is removed, accidents such as the film being exposed to external light can be reliably prevented. Moreover, this safety function is automatically released when the exposure opening of the film magazine is covered by the light-shielding lid, that is, when there is no risk of the film being exposed to external light. By inserting the lid into the film magazine, attaching various photographic lenses, and then pulling out the light-shielding lid, you will be able to use lenses other than the systemized interchangeable lenses for photography. - Very useful as a mirror control device for an eye reflex camera.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the structure of a camera using the present invention. FIG. 2 is a sectional view of the main part of the hook for attaching the lens with the lens unit attached. FIG. 3 is a sectional view of the main part of the hook for attaching the lens with the lens unit removed. FIG. 4 is a partially cutaway view schematically showing the structure of the front side of the magazine. FIG. 5 is a block diagram showing the circuit configuration used in the present invention. FIG. 6 is a flowchart showing a process for prohibiting the mirror and the light-shielding plate from moving to the "2-up" position. FIG. 7 is a flowchart showing the process of 26 when the mirror and the light shielding plate are urgently moved to the lowered position when the lens unit is removed. 2...Camera body 7...Hook 8...Lens unit 12...Magazine 25...Shading lid 27...Mirror 31...Shading plate 34...Mirror up button 40...Release lever 42...Switch 43...Lens attachment detection lever. 27-1

Claims (1)

[Claims] (1) A mirror is moved between the viewfinder observation position and the photographing position, and in conjunction with the movement of the mirror, a light shielding plate is installed between the optical path blocking position, which blocks the photographing optical path, and the optical path opening position, which opens the photographing optical path. In a single-lens reflex camera consisting of a camera body equipped with a mirror drive mechanism that moves the camera body, a photographic lens and a film magazine detachably attached to the camera body, switching is performed by an initial operation when removing the photographic lens from the camera body. switching means to be operated;
a mirror-up operation means operated when moving the mirror and the light-shielding plate to a photographing position and an optical path open position via the mirror drive means; and a light-shielding lid for opening and closing an exposure opening formed in the film magazine. is provided with a light-shielding lid detection means for detecting that the exposure aperture is blocked, and when the light-shielding lid detection means does not detect that the light-shielding lid is shielding the exposure aperture, When the initial operation is detected by the switching means, the mirror and the light shielding plate located at the photographing position and the optical path opening position are forcibly moved to the finder observation position and the optical path blocking position, respectively, regardless of the operation of the mirror up operation means. When the mirror driving means is operated and the light shielding lid detecting means detects that the light shielding lid is shielding the exposure aperture, the mirror up operation means is operated regardless of the signal from the switching means. A mirror control device for a single-lens reflex camera, characterized in that the mirror drive mechanism is operated to move a mirror and a light shielding plate to positions corresponding to the following.