JP2007017581A - Shutter system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shutter system capable of arranging a brake mechanism without being enlarged. <P>SOLUTION: The magnet holding type shutter system where light shielding blade groups are connected by a link mechanism, and are made to run between an expanded state and a superposed state, so as to perform exposure includes: a driving member 7 of driving the light shielding blade group via the link mechanism; a brake mechanism 38 arranged at the outside of the working region of the driving member; and a link lever 43 for a brake in which one end is rotatably fitted to a brake lever as a constitutive element of the brake mechanism and the other end is engaged with the driving member. Also, the other end of the link lever for a brake is guided for working by a guiding means 46 along the working orbit of the driving member. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shutter device that causes a light shielding blade group to travel between a deployed state and a superimposed state.

The focal plane shutter used in optical equipment such as cameras exposes the film and the like while moving the exposure slit formed on the aperture by sequentially moving the front blade group and the rear blade group that are the light blocking blade group. It is. The light shielding blade group is configured by connecting a plurality of divided shutter blades to a parallel link mechanism constituent member. In such a focal plane shutter, the blade speed has been increased in order to increase the stability at the time of high-speed exposure and increase the strobe tuning speed. On the other hand, the higher blade speed leads to the generation of impact and impact noise generated at the running end of the leading blade group and the trailing blade group, and the large impact is the durability of the caulking portion of the shutter blade against the link mechanism component. It is related to such problems. For this reason, conventionally, a brake lever and a friction plate, which are urged by an elastic member such as a leaf spring, are arranged on a passage path of a drive lever that is a drive member of a link mechanism constituent member. In general, the brake lever is rotated by contact with the drive lever, and the kinetic energy of the shutter blade and the drive lever is absorbed by the friction between the brake lever and the friction plate. These techniques are also disclosed in, for example, Patent Document 1 by the present applicant.
Japanese Patent Publication No. 7-46191

  In a so-called magnet holding type shutter, the drive levers for driving the leading blade group and the trailing blade group are held by the charge lever in a state where the camera charge is completed. When the shutter travels, the charge lever escapes and the drive lever is held by attracting the leading blade group and the trailing blade group by holding type magnets. At the travel start timing of the front blade group and the rear blade group, the attracting state of the magnet is released, and the travel of the front blade group and the rear blade group is started. In such a so-called magnet holding type shutter, a charge lever is disposed in the traveling direction of the drive lever of the rear blade group, and a magnet is disposed on the upper surface. Therefore, there is a problem that the brake mechanism cannot be arranged due to space restrictions.

(Object of invention)
An object of the present invention is to provide a shutter device that enables the arrangement of a brake mechanism without increasing the size.

  In order to achieve the above object, the present invention provides a magnet holding type shutter device in which a light shielding blade group is connected by a link mechanism and travels between an unfolded state and a superimposed state to perform exposure. A drive member that drives the light shielding blade group, a brake mechanism that is disposed outside the operating region of the drive member, and a brake lever that is a component of the brake mechanism, one end of which is rotatably attached to the other end. Has a brake link lever that engages with the drive member, and the other end of the brake link lever is operated and guided by guide means so as to follow the operation locus of the drive member. This is a shutter device.

  According to the present invention, it is possible to provide a shutter device capable of arranging a brake mechanism without increasing the size.

  The best mode for carrying out the present invention is as shown in the following examples.

  1 to 5 are plan views showing a focal plane shutter which is a shutter device according to an embodiment of the present invention. First, each component will be described with reference to FIG.

  In FIG. 1, reference numeral 1 denotes a shutter base plate, and an opening 1a is provided at a substantially central portion of the plane. Reference numeral 2 denotes a leading blade drive lever, which is attached to be rotatable about a shaft 3. A leading blade driving pin 4 is connected to a leading blade driving arm 5 of a leading blade group (not shown) and is known by a spring 6. It is urged to rotate clockwise in the figure via a link mechanism. Reference numeral 7 denotes a rear blade drive lever, which is attached so as to be rotatable about the shaft 8. The blade driving pin 9 at the tip is connected to a rear blade driving arm 10 (not shown) and is urged to rotate clockwise by a spring 11 via a known link mechanism. Reference numerals 12 and 13 denote armatures which are slidably attached to the leading blade driving lever 2 and the trailing blade driving lever 7 by armature shafts 14 and 15, respectively, in the longitudinal direction of the armature shafts 14 and 15. And it is urged | biased by the springs 16 and 17 at the upper left direction in the state of FIG. Reference numerals 18a and 18b denote buffer rubbers.

  Reference numerals 19 and 20 denote coils constituting the electromagnet, and reference numerals 21 and 22 denote yokes disposed inside the coils 19 and 20, respectively. The armatures 12 and 13 are connected to the coils 19 and 20 by energization from a control circuit (not shown). It is configured to adsorb. A charge lever 23 is rotatably attached to the shaft 24, and its cam portion 23 a charges the leading blade drive lever 2 via the charge pin 25 of the leading blade drive lever 2. The cam portion 23 b charges the rear blade drive lever 7 via the charge pin 26 of the rear blade drive lever 7. A leading blade brake lever 27 is rotatably attached to a shaft 28 described later.

  Here, the configuration of the brake mechanism will be described with reference to the cross-sectional view of FIG. The friction generating structure of the brake mechanism is the same for both the rear blade group and the front blade group.

  The leading blade brake lever 27 (numbers in parentheses in FIG. 5 indicate a trailing blade brake lever described later, and the same applies hereinafter) is provided with friction sheets 29 and 30 above and below. And it is the structure which generate | occur | produces the frictional force when this leading blade brake lever 27 rotates by pressing with the spring force of the leaf | plate spring 32 via the rotation stopper 31. FIG. 33 is a collar for adjusting the amount of deformation of the leaf spring 32, and 34a is a screw. The rotation stopper 31 is attached to the shaft 28 as shown in FIG. 5, and its rotation is restricted by a dowel 35 shown in FIG. Reference numeral 36 (see FIG. 1) denotes a stopper for the leading blade brake lever 27, and reference numeral 37 denotes a spring for applying a clockwise rotational force to the leading blade brake lever 27.

  Reference numeral 38 denotes a rear blade brake lever, which is rotatably attached to a shaft 42 shown in FIG. 5 and is configured to generate a frictional force during rotation in the same configuration as the front blade brake lever 27. The rotation bias is applied. Reference numeral 40 denotes a rotation stopper, 41 denotes a dowel for restricting the rotation of the rotation stopper 40, and 34b denotes a screw. A brake link lever 43 is rotatably attached to the rear blade brake lever 38 by a shaft 44. A pin 45 for engaging the rear blade drive lever 7 is fixed to the tip of the brake link lever 43. In addition, a guide cam portion 43a is provided at an intermediate portion thereof, and is engaged with a guide shaft 46 attached to the main plate 1. When the rear blade drive lever 7 is rotated from the state shown in FIG. 3 described later to the state shown in FIG. 4, the pin 45 is substantially equal to the operation locus of the engaging portion 7 a (FIG. 3, FIG. 4) of the rear blade drive lever 7. It is configured to operate. Reference numeral 47 denotes a stopper for the brake link lever 43.

  Next, the operation of the focal plane shutter having the above configuration will be described with reference to FIGS.

  In FIGS. 2 to 4, the coils 19 and 20 and the yokes 21 and 22 are omitted so that the operation related to the lever can be easily understood. FIG. 2 shows a state where the charging is completed. When the photographing operation is started, first, the coils 19 and 20 shown in FIG. 1 are energized from a camera control circuit (not shown), and the armatures 12 and 13 are in the suction state.

  Next, when a camera mirror up mechanism (not shown) is operated, the charge lever 23 is rotated counterclockwise. The leading blade driving lever 2 and the trailing blade driving lever 7, which are restricted by the cam portions 23 a and 23 b of the charge lever 23, try to rotate clockwise by the springs 6 and 11, respectively. However, since the armatures 12 and 13 are in the adsorbed state, the rotation is restricted via the buffer rubbers 18a and 18b and the armature shafts 15 and 14 after rotating for the overcharge.

  Next, when the mirror up of the camera (not shown) is completed, first, the power supply to the coil 19 on the leading blade drive lever 2 side is cut off, and the armature 12 is opened. As shown in FIG. 3, the leading blade drive lever 2 rotates clockwise by the bias of the spring 6 to actuate a leading blade group (not shown) to open the shutter. In the leading blade driving lever 2, the blade driving pin 4 comes into contact with the cam portion 27a of the leading blade brake lever 27 at the end of its operation, and rotates the leading blade brake lever 27 counterclockwise. Thereby, braking is applied by the frictional force and the biasing force of the spring 37, and the impact force to the front blade group (not shown) is reduced. The leading blade brake lever 27 rotates and stops until its arm portion 27b comes into contact with the stopper 36, whereby the leading blade driving lever 2 also stops rotating.

  Next, after the specified time has elapsed, the power supply to the coil 20 on the rear blade drive lever 7 side is cut off, the armature 13 is opened, and the rear blade drive lever 7 is rotated clockwise by the bias of the spring 11. Then, the rear blade group (not shown) is operated to close the shutter. As shown in FIG. 3, the rear blade drive lever 7 abuts the pin 45 fixed to the brake link lever 43 at the end of its operation. Therefore, the rear blade brake lever 38 is rotated counterclockwise via the brake link lever 43, and braking is applied by the frictional force and the biasing force of the spring 39.

  When the rear blade drive lever 7 rotates the rear blade brake lever 38 counterclockwise via the brake link lever 43, the rotating shaft 44 of the brake link lever 43 is rotated as described above. Rotate around 34b. However, the brake link lever 43 controls the posture during operation by the engagement between the guide cam portion 43a and the guide shaft 46 fixed to the main plate 1. The operating locus of the pin 45 that engages with the engaging portion 7a of the rear blade drive lever 7 provided at the tip of the brake link lever 43 on the opposite side of the rotating shaft 44 is centered on the shaft 8 of the rear blade drive lever 7. It is comprised so that it may operate | move substantially the same as the circular arc-shaped operation locus. Therefore, during the period from the state in which the engaging portion 7a of the rear blade drive lever 7 shown in FIG. 3 is in contact with the pin 45 of the brake link lever 43 to the operation end state shown in FIG. The engagement between the engagement portion 7a and the pin 45, which is the engagement portion of the brake link lever 43, is not released. In a state where the engaging portion 7 a of the rear blade drive lever 7 is in contact with the pin 45, the engaging portion 7 a is always located between the shaft 44 and the pin 45.

  Next, as shown in FIG. 4, when the rear blade drive lever 7 rotates to the end, the pin 45 of the brake link lever 43 comes into contact with the stopper 47, the operation of the rear blade drive lever 7 ends, and the shutter. Is closed.

  Finally, the charging operation of the front blade group and the rear blade group is started, the charge lever 23 is rotated clockwise by a charge mechanism (not shown), and the charge cam 23a is connected to the front blade via the charge pin 25 of the front blade drive lever 2. The drive lever 2 is charged counterclockwise. Along with this, the brake charge portion 2a of the leading blade drive lever 2 rotates the leading blade brake lever 27 in the clockwise direction to charge the leading blade brake lever 27. The charging cam 23b of the charging lever 23 charges the trailing blade driving lever 7 counterclockwise via the charging pin 26 of the trailing blade driving lever 7 at a timing slightly delayed. At the same time, the brake charge portion 7b of the rear blade drive lever 7 rotates the rear blade brake lever 38 clockwise to charge the rear blade brake lever 38 and the brake link lever 43. When charging is completed, the state returns to the state shown in FIG.

  The above embodiment has the following effects. In other words, in the magnet holding type focal plane shutter, a brake mechanism is disposed on the drive lever that drives the light shielding blade group in order to suppress an impact or the like generated at the traveling end of the light shielding blade group (the leading blade group or the rear blade group). It is generally done. When the brake mechanism is to be arranged on the drive lever, the brake mechanism of the rear blade drive lever needs to be arranged in the operating region of the charge lever and the magnet for charging the rear blade drive lever, and the focal mechanism. The size of the plain shutter was increased. In order to avoid this, in this embodiment, the brake mechanism (rear blade brake lever 38, etc.) of the rear blade drive lever 7 is disposed outside the operating region of the armature 13 forming a magnet, and the brake link lever 43 is used to The brake mechanism and the rear blade drive lever 7 are connected to each other. The brake link lever 43 is rotatably attached to the rear blade brake lever 38, and the engagement portion (pin 45) with the rear blade drive lever 7 at the tip of the brake link lever 43 is rearward by the guide cam portion 43a. It operates so as to substantially follow the operation locus of the blade drive lever 7.

  Therefore, it is possible to provide a magnet holding type focal plane shutter that enables the arrangement of the brake mechanism without increasing the size of the focal plane shutter.

It is a top view which shows the charge state of the focal plane shutter which is a shutter apparatus concerning one Example of this invention. It is a top view which shows the charge state of the focal plane shutter of FIG. It is a top view which shows the operation | movement middle of the focal plane shutter of FIG. It is a top view which shows the operation completion state of the focal plane shutter of FIG. It is sectional drawing which shows the brake structure of the focal plane shutter of FIG.

Explanation of symbols

1 shutter base plate 2 leading blade driving lever 7 trailing blade driving lever (driving member)
7a engaging portion 7b brake charge portion 23 charge lever 27 leading blade brake lever 29, 30 friction sheet 32 leaf spring 33 collar 38 rear blade brake lever 40 anti-rotation 43 brake link lever 43a guide cam portion 46 guide shaft

Claims (3)

In a magnet holding type shutter device in which a light shielding blade group is connected by a link mechanism, and exposure is performed by running between a deployed state and a superimposed state,
A drive member for driving the light shielding blade group via the link mechanism;
A brake mechanism disposed outside the operating region of the drive member;
One end of a brake lever that is a component of the brake mechanism is rotatably attached, and the other end has a brake link lever that engages with the drive member,
The shutter device is characterized in that the other end of the brake link lever is guided to be operated by guide means along an operating locus of the driving member.   The drive member is positioned between one end and the other end of the brake link lever while the drive member is engaged with the other end of the brake link lever. Shutter device. The shutter device according to claim 1, wherein the drive member has a contact portion that returns the brake lever to a return position when the drive member is returned.

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