JPH04339Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention has a built-in automatic focus adjustment device that automatically advances the photographic lens to the in-focus position, and is activated after the photographic lens is set at the in-focus position by the automatic focus adjustment device. The present invention relates to the structure of an AF (abbreviation for autofocus) winding mechanism in the automatic focus adjustment device of a camera equipped with a shutter mechanism that performs exposure control.

Traditionally, automatic focus adjustment devices built into cameras
The AF winding mechanism is always provided with an AF governor so that the automatic focus adjustment device operates at a reasonably low speed and approximately constant speed in order to accurately detect the position of the subject.

However, when raising the automatic focus adjustment device, an excessive load of the AF governor is applied to the AF raise lever, and because of this load, it is necessary to manually operate the shutter mechanism using the camera's raise lever, for example. If you raise the shutter at the same time as the camera's shutter lever, the camera's shutter lever may be heavier than necessary and make the camera feel uncomfortable, or even if you use an electric motor to do the winding automatically, the electric motor may In addition, the AF governor's escape gear and ankle lever caused the characteristic sound of the AF governor to resonate with the camera body, producing a fairly loud and unpleasant sound.

The present invention has been made in view of the above-mentioned problems, and includes a gear that rotates integrally with at least the escape gear that constitutes the AF governor in question, and an ankle lever that meshes with the escape gear. A connection connecting the AF ring and the AF lifting lever to a gear that is rotatably supported on the shaft of a lever that can be suppressed by the lever, and rotates integrally with the escape gear only when the shutter mechanism is in the lifting state. By configuring the AF governor to be able to be skillfully switched depending on the state of the shutter lifting lever of the shutter mechanism so as to mesh with the gear,
When the automatic focus adjustment device is rolled up, the engagement between the gears is disengaged, so that the load of the AF governor is not applied to the AF raising lever as in the past, and the conventional problem can be solved. Its main purpose is to provide a mechanism.

Below, the camera according to the present invention will be explained with reference to the drawings.
An embodiment of the AF winding mechanism will be described. Figure 1 shows an exploded perspective view of the camera's AF winding mechanism and its vicinity. In the figure, 10 is a photographic lens,
Crab claws 11 and helicoid screws 12 are formed. Reference numeral 20 denotes an AF ring, which includes a connecting pin 22 that fits into the crab claw 11 of the photographic lens 10 and extends the photographic lens 10 to the focusing position, and a detection claw tooth portion 23.
, the governor gear connecting tooth portion 24 and the focus detection pawl receiving portion 2
1, and a spring 25 provides a constant rotational habit in the clockwise direction. 30
is an AF electromagnet, which is energized with the release of the camera and demagnetized when the energization is cut off by a focus signal from an automatic focus detection circuit (not shown). Reference numeral 40 denotes a focus detection pawl lever, which engages an iron piece 41 attracted by the AF electromagnet 30 and a focus detection pawl receiving portion 21 of the AF ring 20 that extends and maintains the photographing lens 10 at the in-focus position. Detection claw 43 and release arm 44
A rotation shaft 45 is formed, and a spring 42 provides a constant rotational tendency in the counterclockwise direction. 50 is
In the AF governor, the first gear 5 meshes with at least the governor gear connecting teeth 24 of the AF ring 20.
1, and a second gear 5 that meshes with the first gear 52.
2, a third gear 53 that meshes with the first gear 51, an escape gear 54 that rotates integrally with the third gear 53, and an ankle lever 55 that meshes with the escape gear 54. 3
Gear 53, escape gear 54, and ankle lever 5
5 is given the habit of constantly rotating counterclockwise by a spring 57, and is rotatably supported by pins implanted on a lever 56 forming an arm 58, so that the shutter mechanism is in the rolled-up state. It is configured to mesh with the first gear 51 (or the second gear 52) only at certain times. 60 is an AF winding lever, which is connected to the third gear 52 of the AF governor 50.
, an arm 62 for rolling up by a winding cam of a camera (not shown), and elongated holes 63 and 64 for sliding, respectively. 70 is a shutter blade that also serves as an aperture; hole 71;
72 and elongated holes 73 and 74, respectively.
Reference numeral 80 denotes a shutter release lever, which has a shaft hole 81, a pin 82 that fits into the elongated holes 73 and 74 of the shutter blade 70 that also serves as an aperture, and opens the shutter blade 70 that also serves as an aperture, and pins 83 and 84. , spring 8
5 gives it a habit of always rotating clockwise. Reference numeral 90 denotes a locking lever, and the release arm 44 of the focus detection claw lever 40 is constantly pressed so that the focus detection claw 45 of the focus detection claw lever 40 locks into the AF ring 2.
A pin 91 for rotating the locking lever 90 clockwise by the spring 42 when the position is held at 0, a locking pawl 92, a shaft hole 93, and a balance arm 94 are respectively formed, and The spring 95, which has a weaker spring force than the spring 42 of the focus detection claw lever 40, always provides a counterclockwise rotational habit. 100
1 is a shutter lifting lever of a shutter mechanism, which includes a slope portion 101, a tooth portion 102, a pin 84 of the shutter release lever 80 that comes into contact with an aperture opening amount suppressing step portion 103 that suppresses the amount of aperture opening, and a photometering portion (not shown). A hole 105 for a contact piece 104 that switches the operating characteristics of the circuit, a locking portion 106 that is locked by the locking claw 92 of the locking lever 90, and a locking portion 106 for the AF governor 50 in the rolled up state. lever 56
The lever 56 is rotated clockwise against the spring 57, and the first gear 51 and the second gear 5 are rotated.
A bent portion 107 for meshing the third gear 53 with a connecting gear consisting of two gears, and a side surface 108 that is rolled up by the same winding cam simultaneously with the winding up of the AF winding lever 60 are formed, and a spring 109 is formed. This gives a habit of always sliding towards the left in the drawing. 110 is the EE governor, and the AF
Similar to the governor 50, the shutter lifting lever 10
This is to make the drive of 0 constant. 120
The lock lever is formed with a lock portion 121 at one end, supports an iron piece 122 at the other end, and is always given the habit of rotating counterclockwise by a spring 123. Reference numeral 130 denotes a shutter closing lever, which collides with the pin 83 of the shutter opening lever 80, rotates the shutter opening lever 80 counterclockwise against the spring 85, and closes the opened shutter blade which also serves as an aperture. 131, and a bent portion 13 that is locked to the lock portion 121 of the lock lever 120.
2, and a pin 133 that is pressed against the slope portion 101 of the shutter lifting lever 100 and rotates counterclockwise against a spring 134 is implanted.
140 is an exposure control electromagnet which is controlled by an exposure control circuit (not shown). 150 is a light receiving element that detects the brightness of external light. Also, Figure a in the figure mainly shows the operating status of the AF winding mechanism part of the automatic focus adjustment device.
Figure b shows the operating state of the shutter mechanism, which corresponds to the state shown in figure a.

Next, the series of operations in FIG. 1 will be explained with reference to FIGS. 2 to 5. First, in the initial state before winding up shown in FIG. By rolling up the lever, a winding cam (not shown) is also rotated, and the arm 62 of the AF winding lever 60 in the figure and the side surface 108 of the shutter winding lever 100 are pressed together, and almost at the same time, the winding cam (not shown) is rotated to the right in the drawing. 25 and the spring force of the spring 109, the AF winding mechanism a and the shutter mechanism b are respectively rolled up and moved to the third position.
Roll up the figure. At this time, the gear 53 of the AF governor 50 in the AF lifting mechanism a is disengaged from the connecting gears 51 and 52, and is interlocked with the displacement operation of the AF lifting lever 60.
Only the connecting gears 51 and 52 of the AF governor 50 are rotated, and the AF ring 20 is rolled up so that the photographing lens is at an infinite distance or short distance position, and the focus detection claw 43 of the focus detection claw lever 40 is turned to AF. It falls into the focus detection pawl receiving part 21 of the ring 20, and maintains the AF ring 20 in the rolled up state as shown in FIG. 3a.
On the other hand, due to the displacement of the shutter lifting lever 100 of the shutter mechanism b, the slope portion 101 first presses the pin 133 of the shutter closing lever 130 against the spring force of the spring 134, causing the shutter closing lever 130 to move against the spring force of the spring 134.
counterclockwise and release the shutter close lever 13.
The lock portion 12 of the lock lever 120 in which the bent portion 132 of the lock lever 120 is rotated counterclockwise by the spring 123.
1, and is given a clockwise rotational habit by the spring force of the spring 85 by the upper surface 103' of the aperture opening amount suppressing step 103 of the shutter lifting lever 100. The rotational movement of the lever 80 is prevented, the contact pressure between the arm 131 of the shutter closing lever 130 and the pin 82 of the shutter opening lever 80 is released under the condition shown in FIG. The bent portion 107 of the lifting lever 100 is the lever 56 of the AF governor 50 in the AF lifting mechanism a.
The lever 56 is rotated clockwise against the force of the spring 57, and the gear 53 and the gear 51, which had been in a disengaged state until then, are engaged with each other.
The state is made operable as the AF governor 50. Furthermore, the focus detection claw 43 of the focus detection claw lever 40 and
The engagement of the focus detection pawl receiver 25 of the AF ring 20 causes the locking lever 90 to rotate clockwise against the spring force of the spring 42 of the focus detection pawl lever 40.
is rotated by a spring 95, and the locking pawl 92 of the locking lever 90 engages the shutter lifting lever 10.
The lever 100 falls into the locking portion 106 of 0 and holds the shutter winding lever 100 in the raised state shown in FIG. 3b. Therefore, in the rolled-up state shown in Fig. 3, the photographer decides on the object to be photographed and presses the release lever (not shown) of the camera to bring it into the first pressed state.
First, necessary switches such as an autofocus control circuit (not shown) and a photometry circuit (not shown) of the camera are closed. Furthermore, by pressing the release rod a second time, the AF of the AF winding mechanism a is activated.
When a current is supplied to the electromagnet 30 to magnetize it and attract the iron piece 41 of the focus detection claw lever 40 clockwise against the spring force of the spring 42, the focus detection claw lever 4
The focus detection claw 43 of the AF ring 20 is detached from the focus detection claw receiving part 21 of the AF ring 20, and the AF ring 20 is attached to the spring 2.
5, the automatic focus detection device starts operating. Then, when the photographic lens 10 is extended to the in-focus position by the connection between the pin 22 of the AF ring 20 and the crab claw 11 of the photographic lens 10,
A focusing signal is outputted by a well-known method from an automatic focus detection circuit (not shown) of the automatic focus adjustment device, and the current that had been supplied to the AF electromagnet 30 is cut off to demagnetize the AF electromagnet 30. Therefore, the focus detection claw lever 40 is rotated counterclockwise by the spring 42, and the focus detection claw 43 engages with the detection claw tooth portion 23 of the AF ring 20, stopping the rotation of the AF ring 20 and holding it. Then, the photographing lens 10 is maintained at the in-focus position as shown in FIG. 4a. At this time, the AF lift lever 60 and the AF ring 20 are driven at a low and substantially constant speed by the AF governor 50. On the other hand, the release arm 44 of the focus detection claw lever 40 rotates the pin 91 of the locking lever 90 of the shutter mechanism clockwise against the spring force of the spring 95, so that the locking lever 90 in FIG.
The engagement between the locking pawl 92 and the locking portion 106 of the shutter lifting lever 100 is released, resulting in the state shown in FIG. 4b. Subsequently, in the shutter mechanism activation state shown in FIG. 4b, the shutter lifting lever 100 is driven by the spring 109 at a low and almost constant speed by the EE governor and starts sliding back toward the left in the drawing, and the shutter is activated. The pin 84 of the release lever 80 rotates clockwise by sliding down the stepped slope of the aperture opening amount suppressing step 103 of the shutter lifting lever 100, and the pin 82 of the shutter release lever 80 rotates the shutter which also serves as an aperture. The blade 70 is opened and exposure is started. On the other hand, a resistance value previously set according to a certain correlation with the opening amount of the shutter blade 70 which also serves as an aperture is switched by the contact piece 104 of the shutter winding lever 100, and a photograph is taken using the resistance value and the light receiving element 150. A measuring circuit (not shown) detects the brightness at the time, and when the shutter lifting lever 100 returns to a position where an appropriate amount of exposure can be obtained, the exposure control electromagnet 14 receives an output signal from the measuring circuit.
By cutting off and demagnetizing the current that has been supplied since the start of the shutter mechanism of
The suction action of the iron piece 122 of the lock lever 120 disappears, and the shutter closing lever 130, which had been locked by the lock lever 120, momentarily moves the lock lever 120 clockwise by the spring force of the spring 134 against the spring force of the spring 123 of the lock lever 120. Rotate,
The lock part 121 of the lock lever 120 is released by itself, the shutter close lever 130 is rapidly rotated clockwise by the spring 134, and the shutter open lever 80 is pinned by the arm 131 of the shutter close lever 130. 83, the shutter release lever 80 is rotated counterclockwise against the spring force of the spring 85, and the pin 82 of the shutter release lever 80 rapidly rotates in the direction of closing the shutter blade 70 which also serves as an aperture, thereby exposing the shutter. is completed and the series of shooting operations ends.

In this embodiment, the shutter mechanism b is shown in FIG.
However, the AF winding mechanism a continues to be maintained at the point where the operation from FIG. 2 a to FIG. Sometimes the state shown in Fig. 5a is raised to the state shown in Fig. 3a by the camera's winding cam from the middle of the state. Care has been taken to ensure that this does not occur.

As described above, according to the present invention, the action of the AF governor is ensured when the AF lifting mechanism of an automatic focus adjustment device is rolled up, without complicating the structure in order to capture and utilize the rolled up state of the shutter mechanism. Because it can be cut off, it has excellent effects on the quality of the camera, such as the camera's winding up is light and the feeling of winding up is good, and there is no unpleasant sound peculiar to AF governors.
This prevents the governor from being forced to rotate.
It also has a significant effect on durability, such as eliminating damage to the AF governor gear.

[Brief explanation of the drawing]

Figure 1 shows a camera according to an embodiment of the present invention.
2 to 5 are exploded perspective views showing the vicinity of the AF winding mechanism, and show various operating states for explaining the operating states of the present invention in FIG. 1. In the figure, 10... Photographing lens, 20... AF ring, 30... AF electromagnet, 40... Focus detection claw lever, 50... AF governor, 60... AF lift lever, 70... Also serves as aperture. Shaft feather, 80
... Shutter release lever, 90 ... Locking lever,
100...Shutter lift lever, 110...
EE governor, 120... Lock lever, 130...
...Shutter closing lever, 140... Exposure control electromagnet, 150... Light receiving element.

Claims (1)

[Scope of utility model registration request] An AF wind-up mechanism of an automatic focus adjustment device that automatically moves the photographic lens 10 to the in-focus position, and a shutter that is activated to control exposure after the photographic lens 10 is set at the in-focus position by the AF wind-up mechanism. In the AF roll-up mechanism of a camera equipped with a mechanism, the AF roll-up lever 60 of the AF roll-up mechanism and the photographic lens 10 are driven to a focusing position.
Connecting gears 51 and 52 that connect with the AF ring 20
and the shutter lifting lever 1 of the shutter mechanism.
The AF governor 50 of the AF lifting mechanism is composed of an escape gear 54, an ankle lever 55, and a gear 53 that rotates integrally with the escape gear 54, respectively supported by a lever 58 movable by a lever 58. , moving the lever 58 of the AF governor 50 by the shutter raising lever 100 only when the shutter mechanism is in the raised state;
The gear 53 of the AF governor 50 is connected to the gears 51 and 5.
The camera's AF winding mechanism is characterized by having two meshes.