JP2017116896A - Blade drive device, focal plane shutter, and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blade drive device.SOLUTION: A blade drive device drives a blade group conducting an opening/closing operation of an opening part formed in a base plate, and the blade drive device is employed that comprises: a drive spring (d) that generates drive force upon operating; a first drive lever (f) that is coupled to the drive spring to be driven; a second drive spring (g) that is driven by the first drive lever to drive the blade group by a reciprocal operation; and brake levers (l and m) that brake the first drive lever (f).SELECTED DRAWING: Figure 9

Description

  One embodiment of the present invention relates to a blade driving device in a focal plane shutter employed in an imaging device such as a camera (for example, a digital camera).

  2. Description of the Related Art Conventionally, a focal plane shutter for a camera is known that performs exposure on a photosensitive surface by driving one or a plurality of sets of blade groups to open and close an opening for exposure (image frame) during photographing. Some focal plane shutters have a configuration in which an image frame is opened during shooting standby so that images can be captured continuously, and is sometimes referred to as a normally open type. As such a focal plane shutter, there has heretofore been a technique described in, for example, Patent Document 1 or Patent Document 2.

JP 2007-298544 A JP-A-9-236845

  In recent years, in the focal plane shutter as described above, it has been required to increase the traveling speed of the blade group in order to form a large image frame and to shorten the exposure time of an image sensor mounted on a camera or the like. ing. However, since the blade group may be damaged when the traveling speed of the blade group is increased, a braking mechanism for braking the blade group is required. There is a friction brake as one of the braking mechanisms, but since the conventional friction brake is braked by the shaft portion where the drive lever is connected to the blade group, for example, the drive lever unit is a lever that is rotated by the biasing force of the spring, There has been a problem that it is difficult to apply to a focal plane shutter composed of two levers connected to a blade group.

  The present invention adopts the following means in order to solve the above problems. In the following description, in order to facilitate understanding of the invention, reference numerals and the like in the drawings are appended in parentheses, but each component of the present invention is not limited to these appendices. It should be construed broadly to the extent that contractors can technically understand.

One means of the present invention is to
A blade driving device that drives a blade group that opens and closes an opening formed in a base plate,
A driving spring that generates a driving force during operation (first driving spring d);
A first drive lever (first forward drive lever assembly f) coupled to and driven by the drive spring;
A second drive lever (second forward drive lever assembly g) driven by the first drive lever and driving the blade group by a reciprocating operation;
And a brake lever (first front brake lever 1 and second front brake lever m) for braking the first drive lever (first front drive lever assembly f).

  According to the blade drive device having the above-described configuration, a configuration equivalent to a friction brake can be provided without adopting a friction brake in the connecting shaft between the drive lever and the blade group by including a brake lever that brakes the first drive lever. It is possible to configure a blade driving device for a focal plane shutter utilizing the above. As a result, it is possible to mitigate the impact applied to the blades and other components during operation, and to prevent breakage of the blades. This configuration is particularly suitably applied as a blade driving device for a so-called normally-open focal plane shutter that opens an image frame in a standby state.

In the blade driving device, preferably,
The brake levers (first front brake lever 1 and second front brake lever m) are controlled by coming into contact with the first drive lever from an intermediate position of operation of the first drive lever (first front drive lever assembly f). Configure to provide power.

  According to the blade drive device having the above-described configuration, the first drive lever is braked by the frictional force generated between the first drive lever and the brake lever, thereby indirectly braking the operation of the blade group. Accordingly, it is possible to configure a blade driving device including a friction brake in addition to the connecting shaft between the blade group and the drive lever. Further, since the friction brake is configured by the contact between the first drive lever and the brake lever, it is possible to configure a blade driving device having an arbitrary braking characteristic by adjusting the timing and angle of contact. .

Another means of the present invention is as follows:
The blade driving device,
A base plate in which an opening is formed;
A blade group for switching the opening and closing state of the opening,
Is a focal plane shutter.

  According to the focal plane shutter having the above-described configuration, it is possible to configure a focal plane shutter that uses a configuration equivalent to a friction brake without employing a friction brake in the connecting shaft of the drive lever and the blade group.

  Another means of the present invention is an imaging apparatus including the above focal plane shutter.

  According to the imaging apparatus having the above configuration, in a configuration including a focal plane shutter that is driven by the force of a spring, it is possible to achieve a configuration in which durability is improved by appropriately braking a blade group that operates at high speed. Become.

The top view of the focal plane shutter of a 1st state (state before blade | wing driving | running | working). The top view of the focal plane shutter of a 2nd state (state which drive | worked only the front blade | wing). The top view of the focal plane shutter of a 3rd state (image frame open state). The top view of a focal plane shutter of the 4th state (blade driving completion state). The top view of the blade drive device of the 1st state (state before blade driving | running | working). The top view of the blade | wing drive device of a 2nd state (state which drive | worked only the front blade | wing). The top view of the blade | wing drive device of a 3rd state (image frame open state). The top view of the blade drive device of the 4th state (blade running completion state). The enlarged view of the characteristic part of the blade drive device of the 1st state (state before blade driving | running | working). The enlarged view of the characteristic part of the blade drive device of the 2nd state (state which drive | worked only the front blade). The enlarged view of the characteristic part of the blade drive device of a 3rd state (image frame open state). The enlarged view of the characteristic part of the blade drive device of the 4th state (blade driving completion state). The figure which shows the structural example of a set lever assembly. The figure which shows the structural example of a 1st front brake lever. The figure which shows the structural example of a 2nd front brake lever. The figure which shows the structural example of a 1st front drive lever assembly. The figure which shows the structural example of a 2nd front drive lever assembly.

An embodiment according to the present invention will be specifically described according to the following configuration with reference to the drawings. However, the embodiment described below is merely an example of the present invention and does not limit the technical scope of the present invention. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and the description may be abbreviate | omitted.
1. Embodiment 2. FIG. Supplementary matter

<1. Embodiment>
One feature of the focal plane shutter applied to an imaging apparatus such as a camera of the present embodiment is that the operation of the blade group is braked by braking the drive lever. Hereinafter, the focal plane shutter of the present embodiment will be specifically described with reference to the drawings.

  1 to 4 are plan views of the focal plane shutter of the present embodiment. 5 to 8 are plan views of a blade driving device portion in the focal plane shutter of the present embodiment. 9 to 12 are enlarged plan views of characteristic portions of the focal plane shutter according to the present embodiment. In FIGS. 1 to 4 and FIGS. 9 to 12, the display of the upper mechanism unit q shown in FIGS. 5 to 8 is omitted. 1, FIG. 5, and FIG. 9 show a first state (a state before blade traveling). 2, 6 and 10 show the second state (the state where only the leading blade has traveled). 3, 7 and 11 show a third state (image frame open state). 4, 8, and 12 show a fourth state (blade travel completion state). As will be described below, in the characteristic operation of the focal plane shutter according to the present embodiment, the first state (the state before traveling on the blade), the second state (the state where only the leading blade has traveled), the third state ( The state changes in the order of (frame open state). Since the characteristic part of this embodiment is the blade drive device (blade drive mechanism) portion of the focal plane shutter, the following description will be made mainly with reference to FIGS.

  As shown in FIGS. 1 to 4, the focal plane shutter of this embodiment includes a plate a, a leading blade group b, a trailing blade group c, a leading drive spring d, a trailing drive spring e, and a first leading drive lever assembly. f is included.

<Plate a>
The plate a is a ground plane, and various configurations are arranged on the plate a. An opening (image frame) for exposure is formed inside the plate a. The opening / closing state of the opening of the plate a changes depending on the state of the leading blade group b and the trailing blade group c. The leading blade group b and the trailing blade group c are arranged in a blade chamber formed between the plate a and a plate that functions as an auxiliary ground plate.

<Lead feather group b and rear feather group c>
Each of the front blade group b and the rear blade group c is a set of one or a plurality of blades, and functions as a front curtain and a rear curtain, respectively. That is, the leading blade group b and the trailing blade group c operate by being driven by the blade driving device, and change the opening / closing state of the opening. Thereby, exposure is performed with respect to the image pick-up element arrange | positioned ahead of an opening part.

<Previous drive spring d>
The front drive spring d is the drive spring of the present invention, and generates a driving force when the operation is started to drive the front blade group b. The front drive spring d includes an arm portion d1. The front drive spring d is disposed so as to be wound around the shaft f2, and the arm portion d1 applies a biasing force in the clockwise rotation direction to the first front drive lever assembly f.

<Rear drive spring e>
The rear drive spring e generates a driving force when the operation is started by the release, and drives the rear blade group c.

<First drive lever assembly f>
The first front drive lever assembly f is rotatably supported by the shaft f2, and the biasing force in the clockwise rotation direction is applied by the front drive spring d as described above. FIG. 16 is a six-sided view of the first front drive lever assembly f.

  Next, as shown in FIGS. 5 to 8, the focal plane shutter of the present embodiment is divided into an upper mechanism unit q and a lower mechanism unit. The characteristic part in this embodiment is a lower mechanism unit, and the structure of this lower mechanism unit is shown in FIGS. The upper mechanism unit q operates in the same manner as a conventional focal plane shutter blade driving device, but a detailed description of its configuration and operation is omitted here.

  Next, as shown in FIGS. 9 to 12, the focal plane shutter of the present embodiment includes a second front drive lever assembly g, a rear drive lever assembly h, a return spring i, a front locking lever j, and a rear locking. It further includes a lever k, a first front brake lever l, a second front brake lever m, a blade set lever assembly n, a return lever o, and a set lever assembly p.

<Second tip drive lever assembly g>
Similarly to the first front drive lever assembly f, the second front drive lever assembly g is rotatably supported by the shaft f2, and is rotatable about the same central axis as the first front drive lever assembly f. . The leading blade group b is fitted with the shaft g1 of the second leading drive lever assembly g and operates together with the second leading drive lever assembly g. The second forward drive lever assembly g is urged by the return spring i in the clockwise direction opposite to the urging force applied by the forward drive spring d, and the second forward drive lever assembly g is supported by the shaft f3 of the first forward drive lever assembly f. Operation is restricted. FIG. 17 is a six-side view of the second front drive lever assembly g.

<Rear drive lever assembly h>
The rear drive lever assembly h is rotatably supported by the shaft h2.

<Return spring i>
The return spring i is arranged to be wound around the shaft f2. The arm of the return spring i abuts on the second front drive lever assembly g and urges the second front drive lever assembly g in the clockwise rotation direction.

<Previous locking lever j>
The leading locking lever j is configured to lock the first leading drive lever assembly f. When the locking by the first locking lever j is released, the first first driving lever assembly f starts operating.

<Rear locking lever k>
The rear locking lever k is configured to lock the rear drive lever assembly h. When the locking by the rear locking lever k is released, the rear drive lever assembly h starts to operate.

<First front brake lever l, second front brake lever m>
The first front brake lever 1 and the second front brake lever m interfere with the first front drive lever assembly f during operation, thereby braking the operation of the first front drive lever assembly f. The first front brake lever l and the second front brake lever m are rotatably supported on the same shaft. FIG. 15 is a six-side view of the first front brake lever l. FIG. 14 is a six-sided view of the second front brake lever m.

<Blade set lever assembly n, set lever assembly p>
The blade set lever assembly n and the set lever assembly p operate when changing the state from the blade travel completion state (FIGS. 4, 8, and 12) to the set state (FIGS. 1, 5, and 9). It is a member to do. FIG. 13 is a six-side view of the set lever assembly p.

<Operation of blade driving device>
Next, the operation of the blade driving device of this embodiment will be described.

  When trying to travel only the leading blade in the state before traveling of the blade of FIG. 9, first, the leading locking lever j first rotates in the clockwise direction, whereby the first leading drive lever assembly f by the leading locking lever j. And the lock | rock of the 2nd front drive lever g is cancelled | released. Then, the first front drive lever assembly f is rotated in the counterclockwise direction by the biasing force applied by the front drive spring d. At this time, the second front drive lever assembly g is rotated together with the first front drive lever assembly f by being pushed by the shaft f2 formed in the first front drive lever assembly f. Thereby, only the leading blade group b travels. In this way, the blade driving device changes to a state in which only the leading blade (leading blade group b) shown in FIG. 10 (FIGS. 2 and 6) travels.

  When the first front drive lever assembly f rotates as described above, the shaft f4 formed on the first front drive lever assembly f interferes with the first front brake lever l and the second front brake lever m, thereby braking. Is done. As a result, the second leading drive lever assembly g to be rotated together with the first leading drive lever assembly f and the leading blade group b driven by the first leading drive lever assembly f are also braked.

  Next, the operation in which the blade driving device switches from the state in which only the leading blade in FIG. 10 (FIGS. 2 and 6) travels to the image frame open state in FIG. 11 (FIGS. 3 and 7) will be described.

  When the blade set lever assembly n rotates and moves from the position of FIG. 10 to the position of FIG. 11, the roller n1 formed on the blade set lever assembly n moves while contacting the roller h1 of the rear drive lever assembly h. . As a result, the rear blade group c is set to a position before traveling. Further, the roller n2 formed on the blade set lever assembly n moves while contacting the roller f5 of the first front drive lever assembly f, whereby the first front drive lever assembly f is set to the pre-travel position.

  At this time, since the second front drive lever assembly g is biased by the return spring i, it rotates together with the first front drive lever assembly f immediately after the operation is started. Thereafter, the operating portion o1 of the return lever o that rotates about the axis n3 of the blade set lever assembly n interferes with the shaft g2 of the second forward drive lever assembly g, whereby the second forward drive lever assembly g becomes Rotates counterclockwise. When the first front drive lever assembly f is moved to the pre-travel position, the front blade group b is in a position to open the opening (image frame).

  At this time, the first front brake lever 1 and the second front brake lever m are moved to the pre-travel position by the roller f6 and the shaft f4 of the first front drive lever assembly f. Further, the first front drive lever assembly f and the rear drive lever assembly h are locked by the front locking lever j and the rear locking lever k, respectively. As a result, the blade driving device enters the image frame open state shown in FIG. 11 (FIGS. 3 and 7).

  Next, an operation of switching from the image frame open state of FIG. 11 (FIGS. 3 and 7) to the state before blade travel of FIG. 9 (FIGS. 1 and 5) will be described.

  First, the set lever assembly p rotates counterclockwise and changes to the state of FIG. 9 (FIGS. 1 and 5). When the set lever assembly p rotates, the blade set lever assembly n whose rotation is restricted by the set lever assembly p also rotates in the clockwise direction. When the blade set lever assembly n rotates, the return lever o also rotates in the clockwise direction. When the return lever o is rotated, the second front drive lever assembly g whose movement restriction by the return lever o is released is rotated in the clockwise direction by the biasing force of the return spring i, and then the first front drive lever. Stops by interfering with the shaft f3 of the assembly f. Accordingly, the leading blade group b moves to the pre-travel position. As a result, the blade driving device is in a state before the blade traveling in FIG. 9 (FIGS. 1 and 5).

  By the way, FIG. 12 (FIG. 4, FIG. 8) has shown the blade travel completion state. When the release is performed in the state before the blade traveling in FIG. 9, the leading blade group b and the trailing blade group c operate one after another, and the image sensor is exposed. FIG. 12 (FIGS. 4 and 8) shows a state after the leading blade group b and the trailing blade group c have traveled in this way.

  According to the focal plane shutter blade driving device of this embodiment, the first front brake lever l and the second front brake lever m function as a brake lever that brakes the first front drive lever assembly f. By doing so, it is possible to construct a focal plane shutter blade drive device that uses a friction brake equivalent configuration without employing a friction brake in the connecting shaft of the first front drive lever assembly f and the front blade group b. Is possible. As a result, it is possible to mitigate the impact applied to the blades and other components during operation, and to prevent breakage of the blades. This configuration is particularly suitably applied as a blade driving device for a so-called normally-open focal plane shutter that opens an image frame in a standby state. This configuration is applicable not only to the configuration for the leading blade group b but also to the configuration for the trailing blade group c.

  Further, in the focal plane shutter blade driving device of the present embodiment, the friction force generated between the first front drive lever assembly f and the first front brake lever l and the second front brake lever m functioning as a brake lever. The first front drive lever assembly f is braked, whereby the operation of the front blade group b is indirectly braked. Accordingly, it is possible to configure a blade driving device including a friction brake in addition to the connecting shaft of the leading blade group b and the first leading drive lever assembly f. Further, since the friction brake is configured by the first front drive lever assembly f and the brake lever (first front brake lever 1 and second front brake lever m) contacting each other, the timing and angle of contact are adjusted. Thus, it is possible to configure a blade driving device having an arbitrary braking characteristic.

<2. Supplementary items>
The specific description of the embodiment of the present invention has been given above. The above description is merely an embodiment, and the scope of the present invention is not limited to this embodiment, and is broadly interpreted to the extent that a person skilled in the art can grasp based on the same technical idea. is there.

  The shapes of the first front brake lever 1 and the second front brake lever m in the above embodiment are merely examples, and are not limited to such shapes. In particular, when changing the braking force applied to the drive lever (first front drive lever assembly f), another shape may be adopted. Similarly, other configurations such as the first front drive lever assembly f are not limited to the shapes shown in the embodiment.

  The blade driving device of the present invention is suitably applied to, for example, a focal plane shutter.

a ... Plate (base plate)
b ... front blade group c ... rear blade group d ... front drive spring e ... rear drive spring f ... first front drive lever assembly g ... second front drive lever assembly h ... rear drive lever assembly i ... return spring j ... pretend Stop lever k ... Rear lock lever l ... First brake lever m ... Second brake lever n ... Blade set lever assembly o ... Return lever p ... Set lever assembly q ... Upper mechanism unit

Claims (4)

A blade driving device that drives a blade group that opens and closes an opening formed in a base plate,
A driving spring that generates a driving force during operation;
A first drive lever coupled to and driven by the drive spring;
A second drive lever driven by the first drive lever and driving the blade group by reciprocation;
A blade drive device comprising: a brake lever that brakes the first drive lever. The braking lever applies a braking force by contacting the first driving lever from an intermediate position of the first driving lever;
The blade driving device according to claim 1. The blade driving device according to claim 1 or 2,
A base plate in which an opening is formed;
A blade group for switching the open / closed state of the opening, and
Focal plane shutter.   An imaging device comprising the focal plane shutter according to claim 3.

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