JPS584131A - Mirror box for single-lens reflex camera - Google Patents

Abstract

PURPOSE:To completely remove delay by jumping up a mirror at the reception of a stop closing completion signal. CONSTITUTION:By releasing, current is supplied to electromagnets 2, 3, an adsorption piece 11 is adsorbed and an adsorption piece 7 is released. A lever 5 is rotated in the counterclockwise direction by a spring 6, a locking lever 25 is rotated in the clockwise direction and a lever 13 and a lever 18 both of which are united with a lever 9 are unlocked. The stop lever 18 is rotated in the counterclockwise direction by a spring 21, a stop is closed by making a lens stop pin 51 follow to the rotation of the stop lever 18, a sector gear 17 is rotated in the counterclockwise direction an a latchet gear 28 is rotated also in the counterclockwise direction. Subsequently pulses generated in a magnetism to electricity converting element 29 by the rotation of the latchet gear 28 are counted up and, when the counted value coincides with the number of pulses operated from the photometric value, the current to an electromagnet 3 is interrupted, the levers 9, 13 are rotated in the clockwise direction to cease the stop closing and unlock the mirror driving mechanism, so that the mirror is jumped up.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mirror box structure for a single-lens reflex camera that minimizes the time lag from release operation to shutter activation and eliminates aperture delay.

Conventionally, in most eye reflex cameras, the diaphragm 9 and the mirror start operating independently at almost the same time in connection with the release operation, and there is no relationship between the two.

Therefore, for lenses with large aperture diameters such as large-diameter lenses and telephoto lenses, the aperture time is long υ,
Even after the mirror has finished rising and the shutter has started running, the aperture is often not completed, which may result in uneven exposure.

Further, in order to avoid such aperture delay, the mirror rise time is lengthened in advance, which causes a large time lag at the time of release, making it impossible to obtain an accurate shutter opportunity when photographing a moving object or the like.

This invention has been made in view of the above points, and the first invention is 1. - A first electromagnet that always attracts and a second electromagnet that attracts when energized are installed in the mirror box of an eye reflex camera so that they can attract the attracting pieces attached to one end of the first lever and the second lever, respectively. Regarding the operation, see the above 2. The first electromagnet is energized in this order, and the energization of the first electromagnet causes the first lever to move to the detached position by its own springing force, thereby releasing the aperture lever to perform the narrowing, and when the narrowing is completed, the second electromagnet is de-energized. To provide a mirror box for a single-lens reflex camera in which a second lever is brought to a disengagement position by its own springing force, thereby releasing a mirror lifting lever and lifting up the mirror, thereby eliminating aperture delay.

Furthermore, in addition to the above, the second lever is mechanically driven to return to the suction position at the end of the forward movement of the mirror raising lever, and the second lever is mechanically driven at the end of the backward movement of the charge lever. By driving the mirror and returning it to the suction position, the movement of the mirror is controlled at the final stages of raising and returning to reduce the impact and impact noise associated with mirror operation. Due to the early return of the second lever to the suction position, the first lever. The second electromagnet and the first electromagnet. To provide a mirror box for a single-lens reflex camera that is reliable in operation and quiet, which prevents dirt and the like from intervening between the suction pieces of a second lever.

Hereinafter, the present invention will be described in detail with reference to all the accompanying drawings, but in order to avoid complicating the drawings, members that are not necessary for the explanation of each drawing will be omitted as appropriate.

FIG. 1 is a perspective view of the mirror box 1 in a fully charged state, with the lower surface side turned to earth. Most of the aperture and mirror drive mechanisms are provided on the lower surface, and only a part of the mirror drive mechanism is shown. It is provided on the left side surface in the figure, and there is no mechanism section on the right side surface (not shown).

Figure 2 shows the bottom surface of the mirror box in the charging state.
FIG. 6 shows the state in which the upper member has been removed.

A first electromagnet 2 and a second electromagnet 6 are arranged on the left and right sides of the lower surface of the mirror box 1, respectively, and the first electromagnet 2 normally has an attractive force due to a permanent magnet, but is applied with a magnetic force so as to cancel the magnetic force when energized. The second electromagnet 6 is of the constant attraction type, which is combined with a permanent magnet that generates an electric current and loses the attraction force, and the second electromagnet 6 is an attraction type that generates an attraction force when energized, and loses the attraction force when the energization is stopped. After the second electromagnet 6 is energized, the first electromagnet 2 is energized.

A third lever 5 is pivotally connected to the bottom surface of the mirror box 1 by a shaft 4, and a left rotation behavior is imparted by a spring 6.
A first adsorption piece 7 is swingably attached to one end of the electromagnet 2 so as to face the first electromagnet 2.

Similarly, the shaft 8 moves the second lever 9 to the mirror box 1.
The second lever 9 is pivotally attached to the bottom surface of the second lever 9, and is provided with right-handed rotation by a spring 10. A second adsorption piece 11 is swingably attached to one end of the second lever 9 facing the second electromagnet 6, and a pin 12 is attached to the other end of the second lever 9. It is planted.

As shown in FIG. 6a, the diaphragm stop lever 13 and the mirror latching lever 14 are both pivotally connected to the same shaft 8 as the second lever 9, and a spring 15 is engaged between the levers 13 and 14. The stop lever 13 is given a left-handed rotation behavior, and the mirror locking lever 14 is given a right-handed rotation behavior, so that the pin 12 is held between the levers 13 and 14.

1 sector gear 17. Aperture lever 18.
Mirror raising lever 19. The charge levers 20 are stacked and pivoted in order from the bottom as shown in the figure, and the aperture spring 21 is placed between the aperture lever 18 and the charge lever 20, and the mirror lift lever 19 is placed between the aperture lever 18 and the charge lever 20.
A mirror raising spring 22 is engaged between the charge lever 20 and the charge lever 20, and a return spring 26 is engaged between the charge lever 20 and the fixed part, and the bent part 18ak of the aperture lever 18 is engaged with the side surface of the sector gear 17. Raise the mirror that is in reserve state.
The bent portion 19ak of the mirror locking lever 14 is locked with the claw portion 14a of the mirror locking lever 14, and the side cam portion 2 of the charge lever 20 is locked.
0ae Enables engagement with the bin 12.

As mainly shown in FIG. 25• locks the second lever L step portion 9• so that the second suction piece 11 is in the suction position, and at the same time, the claw portion 25b locks the bent portion 18d of the aperture lever 18 in the energized state. possible, one end 2
5c'! It is made to face one end 5a of the i-th lever 5.

Next, the rotation of the sector gear 17 is increased by the speed increasing gear train 27 and transmitted to the ratchet gear 28 having right-handed rotation, and its teeth are engaged with the tip bent portion 13a of the throttle stop lever 13. The ratchet gear 28 is made removable, and a magnetoelectric transducer 29 is disposed close to the teeth of the ratchet gear 28.
A pulse signal is generated by the magneto-electric conversion element 29 when the lens rotates, and the aperture p value is controlled by counting the pulse signal.

Further, the base of the mirror intermediate lever 31 is pivotally connected to the shaft 60 in FIG.
A pin 37 implanted in the side surface of the mirror frame 36 is engaged with the forked portion 34a of the mirror drive lever 34.

Furthermore, as shown in Figure 1, the shaft 3 on the side of the mirror box
A small locking lever 69 is pivoted at 8, and a spring 40 imparts left-turning behavior, and its bent portion 39aTh can be engaged and detached from the mirror drive lever 34. A shutter release lever 42 is pivoted at a shaft 41 to drive the mirror. A two-way spring 43 is engaged between the lever 34, a charge release lever 44 is pivoted on the same shaft 41 as the shutter release lever 42, and one end of the charge release lever 44 is connected to one end of an auxiliary lever 46 by a pin 45. This auxiliary lever 4
The other end of 6 is attached to the pin 47 and the elongated hole 46a so as to be slidable up and down.

The bent portion 44a (Fig. 2) of the charge release lever 44 is
A shaft 48 is attached to the lower surface of the mirror box so that it can be slid up and down, and a spring 49 (Fig. 1) is engaged between the shaft 48 and the bent portion 44a to press the bent portion 44a against the lower surface of the mirror box. A locking portion 44be capable of locking the charge lever 20 even in the energized state is provided at one end of the curved portion 44a. Further, a charge pin 50 is installed in the charge lever 20.

This embodiment has the above-described configuration, and FIGS. 1, 2, and 6 all show the charging completed state.

In this state, the first. The second electromagnets 2 and 6 are in a non-energized state, and the second lever 5. The second lever 9 is at the suction position, the charge lever 20 is at the left rotation end, and the charge release lever 44
is locked by the locking portion 44b of the diaphragm 9 spring 21. Mirror raising spring 22. All of the return springs 26 are kept in a charged state.

When a release operation is performed on the camera side from this state, a mechanism (not shown) first energizes the second electromagnet 3.
After the second attraction piece 9 is in the attraction state, the first electromagnet 2 is energized to eliminate its attraction force, and the second lever 9 is rotated to the left by the force of the spring 6, so that one end 5a of the second lever 9 is connected to one end of the locking lever 25. 25c'e is driven and this locking lever 2 is moved against the spring 26.
5 to the right, the second lever 9 is completely unlocked by the stepped portion 25a and becomes rotatable, and at the same time, the locking of the aperture lever 18 by the claw portion 25b is released, so the aperture bar 18 is rotated.
is rotated to the left by the diaphragm spring 21, and the lens-side diaphragm pin 51, which was restrained by the bent portion 18b at its tip, follows due to its own biasing force, and the diaphragm is narrowed down to the state shown in FIGS. 4 and 5. becomes.

Prior to this, the photometry circuit on the camera side is turned on with the first stroke of the release operation, and a photocurrent is generated in the light receiving element depending on the brightness of the subject, the film sensitivity used, the set shutter speed, and the opening of the lens. An appropriate aperture value is calculated from the aperture value and is stored as a pulse number.

By turning the aperture lever 18 to the left, its bent portion 18a (fifth
) presses and rotates the sector gear 17 in the counterclockwise direction, and causes the ratchet gear 28 to rotate at an increased speed in the same direction via the speed increasing gear train 27. As the ratchet gear 28 rotates, its teeth sequentially pass near the magnetoelectric transducer 29, thereby generating a periodic signal.

This is converted into a rectangular wave pulse through a full waveform shaping circuit, the number of pulses is counted by an exposure determining circuit, and when the counted pulse number matches the previously stored number of pulses, the power to the second electromagnet 6 is cut off. dripping

As a result, the second lever 9 is rotated to the right by the force of the spring 10, and the aperture stop lever 16, which is integrated with the second lever 9 via the pin 12, is also rotated to the right, and its bent portion 16a is rotated to the right.
As shown in the drawings and FIG. 7, the aperture lever 18 and the aperture shear pin 51 are stopped because they engage with the teeth of the two-chip gear 28 to prevent its rotation.

At the same time, the mirror locking lever 14 shown in FIG. The lever 31 is rotated to the left and the state shown in FIGS.
5), and turns the second lever 5 to the right against the spring 6. This applies a brake to the rotation of the mirror raising lever 19, softening the impact caused by the mirror raising. The first attracting piece 7 can be returned to the state where it is pressed against the first electromagnet 2 and held there.

When the mirror intermediate lever 31 is rotated to the left, the forked portion 3 at its tip is rotated to the left.
1b rotates the mirror drive lever 34 on the side of the mirror box fully to the right via the pin 65, and rotates the mirror frame 3 via the pin 37.
Jump up 6. (See Figure 1).

By rotating the mirror drive lever 34 in FIG.
After the directional spring 46 has once expanded and passed the dead center,
The mirror drive lever 64 is slightly contracted again and held in the clockwise rotation position, but at the end of its rotation, the bending part 42b of the shutter release lever 42 is released from the one end 34b and the small locking lever 39 is moved against the spring 40. As a result, the shutter release lever 42 is rotated to the right by the two-way spring 46, and one end 42c is rotated to the right by the two-way spring 46.
A drives a shutter activation member (not shown) to activate the shutter.

At the end of the shutter operation, the bent portion 46b of the auxiliary lever 46 in FIG. rises, the charge lever 20 is released from its lock, and rotates to the right along with the bent portion 19b'e of the mirror raising lever 19 by the return spring 23. By turning the mirror raising lever 19 to the right, the mirror intermediate lever 61 (Fig. 3) turns to the right via the pin 62, and the mirror drive lever 64 shown in Fig. 1 turns to the left, returning the mirror frame 66 to the 45 degree position. When the mirror drive lever 64 is turned left in FIG.
c is locked by the claw portion 39b of the small locking lever 39 and maintained in that state. At the same time, the bent portion 20b (FIG. 2) of the charge lever 20 rotates to the right along with the bent portion 18ce of the aperture lever 18, and its tip bent portion 18b drives the lens-side aperture pin 51 to the left to aperture the aperture. is opened, and the bent portion 18d is locked to the claw portion 25b of the locking lever 25. On the other hand, the speed increasing gear train 27. The ratchet gear 28 causes the sector gear 17 to follow and return to the bent portion 18a of the aperture lever 18 by its own biasing force.

At the same time, at the end of the return of the charge lever 20, the cam portion 20a on its side drives the pin 12 to rotate the second lever 9 to the left against the spring 1o, thereby controlling the movement of the charge lever 20. Reduces the impact when the charge lever returns,
The second suction piece 11 is held in a pressed state against the second electromagnet 3 (see FIGS. 8 and 9).

When the camera winds the film in the photographed state shown in FIGS. 8 and 9, a mechanism (not shown) pushes the pin 5° in the direction of arrow B in FIG. As a result, the charging lever 20 turns to the left and returns to the charging state shown in FIG. 1 to FIG. 6 again.

As described in detail above, according to the present invention, the first electromagnet is always attracted and the second electromagnet is attracted when energized. The first lever of the second lever. The second suction piece is placed facing the opposite side, and when released, the aperture lever is released and the lens is tightened by setting the second lever to the detached position.
With the lever in the release position, the aperture lever is locked and the mirror raising lever is released at the same time, and the shutter is released at the end of the rotation of the mirror raising lever, so there is no aperture delay no matter what lens is used. Become.

Also, when photographing a fast-moving subject and trying to freeze the image using a high shutter speed and a high shutter speed, the aperture is often set close to wide open due to the amount of exposure. The time lag between release and shutter operation is also extremely short, making it possible to grasp photo opportunities extremely accurately.

Furthermore, according to the second invention, when the mirror raising lever moves forward and when the charge lever moves backward, the second lever and the
The first lever is mechanically returned to the suction position. The second suction piece is always attached to the cylinder 1. Since it is held in close contact with the second electromagnet, these parts are in an adsorbed state in conjunction with conventional winding, and compared to the case where they are normally in the detached position, the electromagnet can become stuck due to dust etc. attached to the magnetic pole. In addition to eliminating the risk of deterioration in performance, the brake is applied at the end of the mirror lever's forward movement and the end of the charge lever's return.
It also has the excellent effect of significantly alleviating the impact and noise associated with return.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a mirror box of a single-lens reflex camera according to the present invention in a charged state, with the bottom side facing up; Fig. 2 is a bottom view of the mirror box also in a charged state; Fig. 3 is a bottom view of the mirror box in a charged state; , a bottom view of the mirror box in the charging state with the upper part partially removed, Figure 3a is an explanatory diagram showing details of the aperture lever locking mechanism, and Figure 4 is the mirror in the aperture state. A bottom view of the box. Figure 5 is a bottom view of the mirror box in the squeezed state with the upper part partially removed. Figure 6 is a bottom view of the mirror box in the mirror flip-up state. , Fig. 7 is a bottom view of the mirror box in the same mirror-up state with the upper part removed, Fig. 8 is a bottom view of the mirror box in the fully activated state, and Fig. 9 is FIG. 2 is a bottom view of the mirror box in the fully operated state, with the upper member partially removed. 1...Mirror box 2...First electromagnet 6...Second electromagnet 5...
・Second lever 9...First suction piece 9...
...Second lever 11...Second suction piece
16...Aperture stop lever 17...Sector gear 18...Aperture lever 19...
...Mirror raising lever 20...Charge lever 21...Aperture 9 spring 22...
Mirror raising spring 23...Return spring 27...
... Speed-up gear train 28 ... Ratchet gear 2
9...Magnetoelectric conversion element 64...Mirror drive lever 66...Mirror frame Applicant: Mamya Koki Co., Ltd. Daiichi Misaki IJ 2 Figure 3 Figure 728 4am Fig. 5 Fig. 6m Fig. 7 Fig. 8 Fig. 9 Fig. 11'.

Claims (1)

[Scope of Claims] 1. A first electromagnet of a constant attraction type that is instantaneously energized in connection with a release operation, a second electromagnet of an attraction type when energized that is maintained in an energized state before the first electromagnet, and A first suction piece attached to one end of the first electromagnet moves to a detached position and an adsorption position when the first electromagnet is energized and de-energized; and a second suction piece attached to one end of the second electromagnet when the second electromagnet is energized and de-energized. a second lever that is in an adsorption position and a detachment position; an aperture lever that is released from a stored state in connection with the detachment of the second lever; and an aperture lever that energizes the second electromagnet when the aperture is completed. a mirror raising lever which is released from the stored state in connection with the disengagement of the second lever, raises the mirror and releases the shutter at the end of rotation; and the aperture lever and the mirror in connection with winding. A mirror box for a single-lens reflex camera, which is characterized by having a charge lever for accumulating a raising lever. 2. A first electromagnet of a constant attraction type that is instantaneously energized in connection with a release operation, a second electromagnet of an attraction type when energized that is kept in an energized state before the first electromagnet, and energization and energization of the first electromagnet. When the first lever is stopped, the first suction piece attached to one end becomes the detachment position and the suction position, and when the second electromagnetic conductor is energized and de-energized, the second suction piece attached to the one end becomes the suction position and the detachment position. a second lever, an aperture lever that is released from the energized state in connection with the detachment of the second lever, and means for stopping energization to the second electromagnet when the aperture lever completes the aperture tightening; A mirror raising lever which is released from the charged state in connection with the detachment of the second lever, raises the mirror and releases the shutter at the end of rotation, and the aperture lever and the mirror raising lever are charged in relation to winding. and a mechanism for mechanically driving the first lever to return it to the suction position at the end of forward movement of the mirror raising lever;
A mirror box for a single-lens reflex camera, comprising a mechanism for mechanically driving the second lever to return it to the suction position at the end of the backward movement of the charge lever.