JP3716038B2 - Focal plane shutter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, the leading blade driving member and the trailing blade driving member, which are controlled by the respective electromagnets when the operation is started, are sequentially operated by the respective driving springs to cause the leading blade and the trailing blade to perform exposure travel. The present invention relates to a focal plane shutter for a camera.
[0002]
[Prior art]
This kind of focal plane shutter can be roughly divided into two types according to the difference in the interlocking configuration of each electromagnet and each drive member. In general, one is called a locking type and the other is called a direct type. . The present invention relates to the direct type, and in this type, each drive member is provided with an iron piece member, and prior to photographing, the electromagnet resists the iron piece member against the force of the drive spring described above. Thus, it is directly adsorbed and held. Therefore, this type of shutter has no room for adjusting the relative relationship between the drive member and the electromagnet in the assembled state because no interlocking member is interposed, and if the positioning of these members is not appropriate, the shutter must be reassembled. Things will happen. For this reason, this type of shutter is required to be designed in advance to prevent such a situation.
[0003]
Therefore, a conventional example of this type of shutter will be described with reference to an exploded perspective view shown in FIG. 2 and a plan view shown in FIG. The shutter base plate 1 is formed with an opening 1a for exposure and two arc-shaped holes 1b and 1c, and three shafts 1d, 1e and 1f are erected. Of these, the shafts 1d and 1e also protrude from the rear side of the shutter base plate 1, and can rotate a known leading blade main arm A and trailing blade main arm B pivotally supporting a plurality of blades, respectively. It is designed to pivot.
[0004]
These shafts 1d, 1e, and 1f all have a spacer portion, a shaft portion with a large diameter, and a shaft portion with a small diameter on the surface side of the shutter base plate 1. Screw holes are formed. And the front blade drive member 2, the rear blade drive member 3, and the set member 4 made of synthetic resin are rotatably attached to the shaft portion having a large diameter. The drive pins 2a and 3a of the leading blade driving member 2 and the trailing blade driving member 3 pass through the holes 1b and 1c and connect to the main arms A and B described above on the back side of the shutter base plate 1 as is well known. It fits in the formed holes A1 and B1. In addition, iron members 2b and 3b and rollers 2c and 3c are attached to these drive members 2 and 3, but their mounting configurations are well known, and thus description thereof is omitted. Although not shown, a drive spring is applied to each of the drive members 2 and 3 to urge the drive members 2 and 3 counterclockwise.
[0005]
The set member 4 has pushing portions 4a and 4b. When the shutter is set, the rollers 2c and 3c are pushed by them, and the drive members 2 and 3 are rotated clockwise against the urging force of the drive spring. To rotate. The mounting plate 5 has a two-stage configuration, two holes 5a and 5b are formed in the upper stage, holes 5c are formed in the lower stage, and two bent portions 5d and 5e having elasticity are formed in the upper stage. Is formed. The holes 5a, 5b, and 5c are fitted with shafts having small diameters of the shafts 1d, 1e, and 1f, and screws (not shown) are screwed into the shaft 1f from above.
[0006]
The leading blade electromagnet 6 and the trailing blade electromagnet 7 are composed of iron core members 6a and 7a and coil bobbins 6b and 7b, respectively. Although not clearly shown, the iron core members 6a and 7a are substantially U-shaped, and the two magnetic pole portions can adsorb the iron piece members 2b and 3b described above by their front end surfaces. Further, these iron core members 6a and 7a are configured such that their base portions are pushed by the bent portions 5d and 5e of the mounting plate 5 described above. On the other hand, the coil bobbins 6b and 7b have two protrusions 6b ₁ and 7b ₁ , respectively, and are fitted to one magnetic pole part of the iron core members 6a and 7a.
[0007]
Holes 8a and 8b are formed in the printed wiring board 8, and are fitted to shaft portions with small diameters of the shafts 1d and 1e. In addition, a pair of holes 8c and 8d are formed, respectively, so as to be fitted into the protrusions 6b ₁ and 7b ₁ of the coil bobbins 6b and 7b. Then, the electromagnets 6 and 7 place the coil bobbins 6b and 7b on the lower stage of the mounting plate 5, and screw the screws (not shown) from the upper side of the printed wiring board 8 to the tips of the shafts 1d and 1e. It is attached.
[0008]
[Problems to be solved by the invention]
However, according to the conventional configuration as described above, the corresponding positions of the iron core members 6a and 7a can be properly positioned with respect to the iron piece members 2b and 3b of the drive members 2 and 3 attached to the shafts 1d and 1e. Extremely difficult. That is, first, an error occurs in the fitting relationship between the three holes 5a, 5b, and 5c of the mounting plate 5 and the shafts 1d, 1e, and 1f, and the protrusions 6b ₁ and 7b _{1 of the} coil bobbins 6b and 7b. And an error occurs in the fitting relationship between the holes 8c and 8d of the printed wiring board 8, and further, an error occurs in the fitting relationship between the holes 8a and 8b of the printed wiring board 8 and the shafts 1d and 1e. As described above, according to the conventional configuration, the cause is that the number of fitting portions involved in the positioning of the iron core members 6a and 7a is extremely large. For this reason, there has been a problem that the machining accuracy of each component has to be increased.
[0009]
The present invention has been made to solve such problems. The object of the present invention is to replace the iron core members of the leading blade electromagnet and the trailing blade electromagnet with the leading blade drive member and the trailing blade driving member. It is an object of the present invention to provide a focal plane shutter having a configuration that can be suitably positioned at a predetermined appropriate position in correspondence with each iron piece member of a blade driving member.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a focal plane shutter according to the present invention is provided with an iron piece member, is rotatably attached to a shutter base plate, and causes the leading blade to open and close the exposure opening by rotating the leading blade shutter. A drive member and an iron piece member are provided, which are rotatably attached to the shutter base plate. The rear blade drive member which causes the rear blade to open and close the opening for exposure by rotating, and a coil bobbin is attached to the shutter base plate. An iron core member of a leading blade control electromagnet that is attached to a standing first shaft and attracts and holds an iron piece member of the leading blade driving member, and a second shaft that is installed on a shutter base plate and is equipped with a coil bobbin. An iron core member of a rear blade control electromagnet attached to and attached to the iron piece member of the rear blade drive member, and a third shaft erected on the shutter base plate is rotatable. And a setting member for setting the trailing blade driving member and with is leading blade driving member Ri.
In the focal plane shutter according to the present invention, preferably, the mounting plates are attached to the first shaft and the second shaft, and then the two iron core members are mounted on the mounting plates, respectively. It is attached to the first shaft and the second shaft.
Further, in the focal plane shutter according to the present invention, preferably, the mounting plate is provided with a restricting portion for restricting the two iron core members from rotating on the first shaft and the second shaft.
In the focal plane shutter according to the present invention, preferably, one of the first axis and the second axis is the same axis as the third axis.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described with reference to the embodiment shown in FIG. FIG. 1 is an exploded perspective view shown in the same manner as FIG. In FIG. 1, substantially the same parts and parts as those shown in FIG. Therefore, detailed descriptions of those configurations are omitted, and only different configurations are described. In this embodiment, the shaft 1f erected on the shutter base plate 1 has a spacer portion, a shaft portion having a large diameter, and a shaft portion having a small diameter, as in the conventional example, but has a small diameter. The shaft portion is formed longer than the conventional example. Further, the shutter base plate 1 is newly provided with a shaft 1g, and this shaft 1g also has a spacer portion, a shaft portion having a large diameter, and a shaft portion having a small diameter, which are not clearly shown. However, a screw hole is formed at the tip. Recently, since the shutter base plate 1 may be made of synthetic resin, in that case, the shafts 1d, 1e, 1f, and 1g may be erected by integral molding.
The iron piece members 2b and 3b of the leading blade driving member 2 and the trailing blade driving member 3 are attached in a posture in which the conventional one is rotated 90 degrees. The mounting plate 15 of the present embodiment also has a two-stage configuration, with two holes 15a and 15b formed in the upper stage and two holes 15c and 15d formed in the lower stage. The shafts 1d, 1e, 1f, and 1g having small diameters are fitted in the holes 15a, 15b, 15c, and 15d, respectively. Also, two bent portions 15e and 15f and two escape portions 15g and 15h are formed in the lower stage.
[0013]
The leading blade electromagnet 16 and the trailing blade electromagnet 17 of this embodiment are composed of iron core members 16a and 17a and coil bobbins 16b and 17b, respectively. Each iron core member 16a, 17a is substantially U-shaped, and the two magnetic pole portions can adsorb the iron piece members 2b, 3b described above by their front end surfaces. Further, holes 16a ₁ and 17a ₁ are formed in the base portions of the respective iron core members 16a and 17a, and these are fitted to shaft portions having small diameters of the shafts 1f and 1g, respectively. Furthermore, the iron core members 16a and 17a are configured such that one of the respective magnetic pole portions can be brought into contact with the bent portions 15e and 15f of the mounting plate 15 described above. On the other hand, the coil bobbins 16b and 17b are fitted to the other magnetic poles of the iron core members 16a and 17a, and the lower part of the coil bobbins 16b and 17a enters the clearances 15g and 15h of the mounting plate 15 described above. Yes.
[0014]
The printed wiring board 18 is formed with four holes 18a, 18b, 18c, and 18d, and these are fitted to shafts with small diameters of the shafts 1d, 1e, 1f, and 1g. Then, four screws (not shown) are screwed into the tips of the shafts 1d, 1e, 1f, and 1g from above, so that the electromagnets 16 and 17 are placed between the lower stage of the mounting plate 15 and the printed wiring board 18. It is attached.
[0015]
As described above, in this embodiment, the fitting portion involved in the positioning accuracy of each of the iron core members 16a and 17a is one place with the shafts 1f and 1g, respectively. There is no significant deviation from the predetermined position, and the positions in the rotational direction of the shafts 1f and 1g are also regulated by the bent portions 15e and 15f, so that accurate positioning is possible.
[0016]
Next, the operation of this embodiment will be briefly described. When the set member 4 is rotated counterclockwise from the initial position after the photographing is finished, the pushing portions 4a and 4b push the rollers 2c and 3c so that the drive members 2 and 3 are moved against the drive springs (not shown). Rotate clockwise. Accordingly, the driving pins 2a and 3a move the front and rear blades (not shown) to the set position. This set operation stops when the iron piece members 2b and 3b of the drive members 2 and 3 are in contact with the tips of the magnetic pole portions of the iron core members 6a and 7a.
[0017]
When the release button is pressed during photographing, the electromagnets 16 and 17 are first energized to attract the iron piece members 6a and 7a and magnetically hold the drive members 2 and 3 at the set position. In this state, the set member 4 is immediately returned to the initial position. Thereafter, when the electromagnet 16 is de-energized, the leading blade drive member 2 is rapidly rotated counterclockwise by a drive spring (not shown) to open the exposure opening 1a. When the energization of the electromagnet 17 subsequent to the electromagnet 16 is cut off, the trailing blade driving member 3 is also rapidly rotated counterclockwise by a driving spring (not shown), and the exposure opening 1a is closed, so that photographing is performed. finish.
[0018]
In the present embodiment, the iron core member 16a is attached to the shaft 1f common to the set member 4. However, in the present invention, another independent shaft is erected on the shutter base plate 1, and the iron core member is provided on the shaft. It is possible to attach 16a. Further, when the iron core member 16a is attached to another independent shaft as described above, the iron core member 17a may be attached to the common shaft 1f with the set member 4.
[0019]
【The invention's effect】
As described above, according to the present invention, the iron core members of the respective electromagnets are directly attached to the shafts erected on the shutter base plate, so that the position of the iron core member is hardly affected by errors. It becomes possible to carry out appropriately.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of the present invention.
FIG. 2 is an exploded perspective view showing a conventional example.
FIG. 3 is a plan view showing a conventional blade support configuration.
[Explanation of symbols]
1 shutter base plate _{5a~5c, 8a~8d, 15a~15d, 16a 1} , 17a 1, 18a~18d hole 1d, 1e, 1f, 1g shaft 2 leading blade driving member 2a, 3a drive pin 2b, 3b iron piece member 3 Rear blade drive member 4 Set members 4a, 4b Pushing portions 5, 15 Mounting plates 5d, 5e, 15e, 15f Bending portions 6, 16 Lead blade electromagnets 7, 17 Rear blade electromagnets 6a, 7a, 16a, 17a Iron core members 6b, 7b, 16b, 17b Coil bobbins 8, 18 Printed wiring board

Claims (4)

An iron piece member is provided, which is rotatably attached to the shutter base plate. The leading blade driving member which causes the leading blade to open and close the opening for exposure by rotation thereof, and an iron piece member which is provided and rotatably attached to the shutter base plate. And a rear blade drive member that causes the rear blade to open and close the opening for exposure and a coil bobbin that is attached to a first shaft that is erected on the shutter base plate to rotate the rear blade. After the iron core member of the front blade control electromagnet for attracting and holding the iron piece member and the coil bobbin and attached to the second shaft erected on the shutter base plate to attract and hold the iron piece member of the rear blade drive member An iron core member of a blade control electromagnet, and a set member that is rotatably attached to a third shaft standing on the shutter base plate and sets a leading blade driving member and a trailing blade driving member Focal plane shutter, characterized by that example. After attaching a mounting plate to the first shaft and the second shaft, the two iron core members are mounted on the first shaft and the second shaft, respectively, so as to be placed on the mounting plate. The focal plane shutter according to claim 1. The focal plane shutter according to claim 2, wherein the mounting plate is provided with a restricting portion that restricts the two iron core members from rotating about the first shaft and the second shaft. 4. The focal plane shutter according to claim 1, wherein one of the first axis and the second axis is the same axis as the third axis. 5.

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