JP4191755B2 - Focal plane shutter for camera - Google Patents

Description

  The present invention relates to a focal plane shutter for a camera having one or two shutter blades.

  In the focal plane shutter for a camera, two blade chambers are formed between three plate members called a shutter base plate, an intermediate plate, and an auxiliary base plate. Two shutter blades, each of which is referred to as `` I '', are arranged separately, and one shutter blade is arranged in the blade chamber formed between the shutter base plate and the auxiliary base plate. It has been. The former focal plane shutter can be adopted for both a silver salt film camera and a digital camera, while the latter focal plane shutter can be adopted only for a digital camera.

  Also, in any focal plane shutter, the configuration of the shutter blades is substantially the same, a plurality of arms having one end in the length direction rotatably attached to the shutter base plate, and pivotally supported by these arms. It is composed of at least one blade. One of these arms is connected to a drive pin of a drive member rotatably attached to the shutter base plate, and is reciprocally rotated by the drive member so that the exposure opening is opened and closed by the blade. . In addition, as described in Patent Documents 1 and 2 below, the drive member is rotated to one side by a biasing force of a drive spring, and the other is a set that is rotatably attached to a shutter base plate. It is common to be configured to be rotated by a member. However, recently, as described in Patent Document 3 below, it is also known to use an electromagnetic actuator as a drive source, and in that case, a member integrated with a permanent magnet rotor. As a drive member, the drive pin is provided there.

  As described above, in any focal plane shutter, the shutter base plate is provided with a plurality of mounting shafts that rotatably support various rotating members in addition to the above-described arm, driving member, and set member. ing. And it is conventionally known that a lubricant such as grease is applied to these mounting shafts as necessary in order to smoothly rotate the rotating member. Among them, the drive member is required to rotate at a high speed and stably, and the set member is required to rotate with a low torque at the time of setting. As is well known, the drive member mounting shaft and the set member are required. Since a large force is applied to the mounting shafts in the radial direction, the mounting shafts are made much thicker than the other mounting shafts. Therefore, in order to reduce the friction between these members and their mounting shafts and improve the durability, a lubricant is often applied between them. Patent Document 1 describes a configuration in which an oil sump groove is formed in an annular shape on a drive member mounting shaft and a blade mounting shaft that is integrally provided on the drive member mounting shaft.

  By the way, the mounting shaft of the drive member described in Patent Document 1 is obviously made of metal, although the material is not specified. Therefore, the mounting shaft is erected on the shutter base plate by caulking or the like. However, recently, the use of synthetic resin for shutter parts has progressed, and most of the shutter base plate has been made of synthetic resin as well as important parts such as drive members and set members. Therefore, mounting shafts such as drive members and set members are also made of synthetic resin. In Patent Document 2, it is proposed to manufacture these mounting shafts together with a shutter base plate by a synthetic integral material using a synthetic resin material. ing.

Japanese Patent Laid-Open No. 2000-2907 Japanese Patent Laid-Open No. 1-280739 JP 2004-101860 A

  As described above, the mounting shafts of various rotating members have recently been made of a synthetic resin material together with the base plate, or have been formed of a synthetic resin material on a metal base plate. However, if the mounting shaft is made of synthetic resin in this manner, as described in Patent Document 1, it is extremely difficult to form the oil sump groove in an annular shape. For example, as described in Patent Document 2, when the mounting shafts are manufactured by simultaneous integral molding with the shutter base plate, usually, two main molds are injected after the synthetic resin material is injected into the cavity. Is released in the thickness direction of the shutter base plate (the axial direction of the mounting shaft). Therefore, when it is desired to form the annular groove as described above, at least two slide dies are provided. They need to be slid relative to each other in a direction perpendicular to the mold release direction of the two main molds.

  As a result, the number of mold parts increases and the overall structure of the mold becomes complicated, and it becomes difficult to process a plurality of products (multiple production) in one shot, or a high-grade molding machine is required. As a result, there is a problem that the cost becomes high. In addition, when such a slide mold is used, the mark of the dividing line is formed in the axial direction of the formed mounting shaft by the joint of the two slide molds, and the drive member or the set member There is a problem that the mounting shaft for smoothly rotating a rotating member such as the above becomes unsuitable. This also applies to the case where the shutter base plate and the mounting shaft are manufactured by the two-color molding method.

  The present invention has been made in order to solve such problems. The object of the present invention is to provide a synthetic resin mounting shaft to which a rotating member such as a driving member is attached to a lubricating oil reservoir. It is an object of the present invention to provide a focal plane shutter for a camera in which a groove can be suitably formed at low cost.

To achieve the above object, a focal plane shutter for a camera according to the present invention includes at least one shutter base plate having an opening for a subject optical path and at least one shutter base plate having an opening for the subject optical path. An auxiliary base plate that forms a blade chamber, a plurality of arms and at least one blade pivotally supported by the arms, and a plurality of blade mounting shafts erected on the shutter base plate, At least one shutter blade, one end of which is rotatably mounted, and a drive member mounting shaft erected on the shutter base plate, which is rotatably mounted and reciprocally rotates one of the arms. A focal plane shutter comprising: at least one driving member that causes the shutter blade to open and close the opening; At least one of the mounting shaft of the plurality of mounting shaft which is erected on the shutter base plate for attaching the rotating member including a mounting shaft is formed in the vane chamber outer surface made of a synthetic resin The portion to be fitted to the rotating member is composed of a plurality of portions formed such that the diameter on the front end side is gradually reduced from the shutter base plate side with respect to the stepped surface as a boundary. At least one peripheral surface portion of the plurality of portions is provided with an oil sump groove that has one end opened to the stepped surface and the other end closed in the middle of the portion that fits the rotating member. It should be formed in the axial direction of the shaft .

Moreover, not good at least one mounting axis even as a pre-SL drive member mounting shaft. The drive member is configured to be rotated by an urging force of a drive spring at the time of photographing, and a set member mounting shaft for rotatably mounting the set member is provided on the shutter base plate, The set member starts to rotate from the initial position against the biasing force of the return spring at the time of setting and rotates the drive member to the set position against the biasing force of the drive spring. Prior to the start of rotation, it may be configured to return to the initial position by the urging force of the return spring, and the at least one attachment shaft may be the set member attachment shaft .

Further, among the plurality of mounting shafts erected on the shutter base plate for mounting the rotating member including the drive member mounting shaft, at least one blade mounting shaft erected on the surface on the blade chamber side The blade mounting shaft is made of a synthetic resin and is formed in a cylindrical shape, and its peripheral surface portion has one end portion opened to the front end surface and the other end portion having an axial length. An oil sump groove that is blocked in the middle may be formed.

  When the oil sump groove is formed in plural at predetermined angular intervals of the mounting shaft, or when the mounting shaft is cut perpendicularly to the axial direction, the cross section is V-shaped. When it is formed so that it becomes, it becomes the optimum one.

  In the present invention, when the mounting shaft that is erected on the shutter base plate and to which the rotating member is mounted is made of synthetic resin, a groove for oil sump for the lubricant is formed long in the axial direction on the peripheral surface of the mounting shaft. Since it did, it can manufacture at low cost, and it becomes possible to make the rotation of a rotation member suitable, and to aim at the improvement of durability.

  Embodiments of the present invention will be described with reference to the illustrated examples. As described above, the present invention can be applied to either a focal plane shutter having two shutter blades or a focal plane shutter having one shutter blade. This is applied to a focal plane shutter having shutter blades. Further, as described above, the focal plane shutter having two shutter blades can be used for a silver salt film camera or a digital camera. However, in the embodiment, the focal plane shutter is used for a digital camera. explain.

  1 is a plan view of the state immediately after the end of the exposure operation as viewed from the photographic lens side, and FIG. 2 is a cross-sectional view showing the main part of FIG. 1 in an easy-to-understand manner. 3 is a plan view showing a part of the shutter base plate, FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, and FIG. 5 is a diagram of the shutter base plate shown in FIGS. It is a top view in the middle of manufacture. FIG. 6 is a plan view showing a set state, and FIG. 7 is a plan view showing a state immediately before the start of the exposure operation.

First, the structure of a present Example is demonstrated using FIGS. The shutter base plate 1 is manufactured by adopting a liquid crystal polymer mixed with glass fiber as a synthetic resin material, and as shown in FIG. Has an opening 1a. On the back side of the shutter base plate 1, that is, on the solid-state imaging device side, an intermediate plate (not shown) and an auxiliary base plate 2 (see FIG. 2) are sequentially attached with a predetermined interval. Between the intermediate plate and the auxiliary base plate 2 , the blade chamber of the leading blade is formed. Further, as is well known, the intermediate plate and the auxiliary base plate 2 have substantially the same size as the shutter base plate 1, and a subject having substantially the same size so as to overlap the opening 1a at the substantially central portion thereof. An opening for the optical path is formed, but in the case of this embodiment, the opening 1a regulates the exposure opening.

  The shutter base plate 1 is formed with two large arc-shaped long holes 1b and 1c in the region on the left side of the opening 1a in FIG. 1, and the lower end thereof is made of rubber. A well-known buffer member 3, 4 having a C-shaped planar shape is attached. The auxiliary base plate 2 is also formed with a long hole having a similar shape so as to overlap with the long holes 1b and 1c. In FIG. 2, the long hole formed so as to overlap with the long hole 1b. Only 2a is shown in cross-sectional shape. In addition, the shutter base plate 1 is formed with a smaller arc-shaped elongated hole 1d (see FIG. 3) in the region between the elongated holes 1b and 1c. As can be seen from FIG. 2, the shutter base plate 1 is not penetrated. The elongated hole 1d is not shown in FIGS. 1, 6, and 7.

The shutter base plate 1, as shown in FIG. 4, the mounting shaft 1e, 1f is, they are erected over both surfaces of the sheet Yatta base plate 1, the shaft portion 1e-1,1f-1 of the imaging lens side The shafts 1e-2 and 1f-2 on the blade chamber side are used as the drive member mounting shafts, and the blade mounting shafts 1e and 1f are made of a liquid crystal polymer mixed with glass fiber as a synthetic resin material. Tei Ru. And although the front-end | tip of the shaft parts 1e-2 and 1f-2 by the side of the blade chamber is loosely inserted in the hole formed in the auxiliary base plate 2, in FIG. 2, the shaft part 1e- of the mounting shaft 1e Only the hole 2b for inserting the tip of 2 is shown in cross-sectional shape. Further, on the shutter base plate 1, a set member mounting shaft 1g manufactured by adopting the same liquid crystal polymer as the mounting shafts 1e and 1f is also erected on the photographing lens side.

  In the present embodiment, two flange portions 1e-4, 1e, respectively, with the shaft portions 1e-3, 1f-3, 1g-1 in between the mounting shafts 1e, 1f, 1g. -5, 1f-4, 1f-5, 1g-2, 1g-3 are formed, and the shutter base plate 1 is sandwiched between them, so that the standing state of the mounting shafts 1e, 1f, 1g is stronger In particular, even when the degree of adhesion between the shafts and the shutter base plate 1 is small, the mounting strength in the axial direction of those shafts can be suitably obtained. Further, the flange portions 1e-4, 1f-4, and 1g-2 are adjacent to a base portion that is formed so as to protrude from the shutter base plate 1, but the interval between the shutter base plate 1 and a support plate 5 described later is narrow. If desired, such a base need not be formed.

  As can be seen from FIG. 4, the shaft portions 1e-1 and 1f-1 of the mounting shafts 1e and 1f and the set member mounting shaft 1g each have a large diameter portion, a medium diameter portion, and a small diameter portion. Among them, a large diameter portion and a medium diameter portion formed in the shaft portion 1e-1 of the mounting shaft 1e are portions that are fitted to a leading blade driving member 9 described later, and the circumferential surface thereof has an axial direction. The oil reservoir grooves 1e-6 and 1e-7 are formed in a straight line. Further, as can be seen from FIG. 3, four of these oil sump grooves 1e-6 and 1e-7 are formed on the peripheral surfaces of the large diameter part and the medium diameter part, respectively, at intervals of 90 degrees. When cut perpendicularly to the axial direction of the mounting shaft 1e, the cross section is formed in a V shape that opens in the radial direction. At the time of assembly, the lubricant is applied to the grooves, and thereafter, the lubricant comes out from the leading blade driving member 9 by an appropriate amount as the leading blade driving member 9 rotates. In this way, the leading blade driving member 9 can be suitably rotated and the durability can be improved.

Further, the shaft portion 1f-1 of the mounting shaft 1f and the large-diameter portion and the medium-diameter portion formed on the set member mounting shaft 1g are portions that are respectively fitted to the rear blade drive member 13 and the set member 16 described later. In addition, for the same purpose as described above, four oil reservoir grooves 1f-6, 1f-7, 1g-4, and 1g-5 having the same shape are formed at an angular interval of 90 degrees. Furthermore, since the shaft portion 1e-2 of the mounting shaft 1e is a part that fits into a reinforcing member 30 (see FIG. 2) mounted on the arm 23 described later, the angular interval of 90 degrees is also formed on the peripheral surface. Thus, four grooves 1e-8 having the same cross-sectional shape as described above are formed. Similarly, the shaft portion 1f-2 of the mounting shaft 1f is also a portion that fits into a reinforcing member (not shown) attached to the arm 18 to be described later, and has the same cross section in an angular range of 90 degrees on its peripheral surface. Four grooves 1f-8 having a shape are formed.

  On the surface of the shutter base plate 1 on the blade chamber side, blade attachment shafts 1h and 1i manufactured by adopting a liquid crystal polymer as a synthetic resin material are erected, and as shown in FIG. Is loosely inserted into the holes 2c and 2d of the auxiliary base plate 2. In the case of this embodiment, the mounting shafts 1e and 1f, the set member mounting shaft 1g, and the blade mounting shafts 1h and 1i are erected after the shutter base plate 1 is formed by the two-color molding method. . The blade mounting shafts 1h and 1i of the present embodiment are formed with thin shaft portions 1h-1 and 1i-1 that are erected with respect to the shutter base plate 1, and one flange portion 1h at one end thereof. -2 and 1i-2 are formed, and the flange portions 1h-2 and 1i-2 are configured to sandwich the shutter base plate 1 with shaft portions to which arms 19 and 24 described later are attached. However, two flange portions may be formed as in the mounting shafts 1e, 1f, and 1g, and the shutter base plate 1 may be sandwiched between them.

  In addition, at least two shafts (not shown) are erected on the surface of the shutter base plate 1 on the photographing lens side. As is well known, the support plate 5 shown only in FIG. And the printed wiring board 6 are attached in an overlapping manner, and the small diameter portions of the mounting shafts 1e and 1f and the set member mounting shaft 1g are loosely inserted into the holes provided in them. Further, the front blade electromagnet and the rear blade electromagnet are attached to the support base plate 5 on the shutter base plate 1 side, and since their configurations are well known, in FIG. Only 8 is indicated by a two-dot chain line, and the iron core member 7 of the leading blade electromagnet is also indicated by a two-dot chain line in FIG. Further, as is well known, a part of the support plate 5 is bent to form one spring hook and two ratchet claws having flexibility. In FIG. A hanging portion 5a and one ratchet claw 5b are shown.

  A synthetic resin front blade drive member 9 is rotatably attached to the shaft portion 1e-1 of the mounting shaft 1e. The leading blade drive member 9 includes a driven portion 9a, a drive pin 9b, a mounting portion 9c, a cylindrical portion 9d, and a spring hooking portion 9e. The cylindrical portion 9d is connected to the shaft portion described above. The large diameter part and the medium diameter part of 1e-1 are fitted. Further, the drive pin 9 b passes through the long hole 1 b of the shutter base plate 1 and protrudes into the blade chamber, and the tip thereof is inserted into the long hole 2 a of the auxiliary base plate 2. Further, as can be seen from FIG. 2, the attachment portion 9 c is formed so as to protrude toward the support plate 5, and the iron piece member 10 is attached to the inside thereof. The iron piece member 10 includes an iron piece portion 10a adsorbed to the iron core member 7, a shaft portion 10b, and a flange-shaped head portion 10c. The iron piece part 10a is urged | biased by the spring which is not shown so that it may protrude from the attachment part 9c. FIG. 1 shows a state in which the head portion 10c is in contact with the opposite edge of the attachment portion 9c by the biasing.

  Although not shown in FIG. 1, as shown in FIG. 2, a known ratchet wheel 11 is rotatably attached to the small diameter portion of the shaft portion 1e-1 of the mounting shaft 1e. . The ratchet wheel 11 has ratchet teeth 11a formed on the outer peripheral surface thereof, and the ratchet pawl 5b is engaged therewith. The ratchet wheel 11 is formed with an annular groove 11b, and a slit-like spring hook 11c is formed at a part of the outer peripheral portion. Further, a leading blade driving spring 12 having a strong biasing force is loosely fitted into the cylindrical portion 9d of the leading blade driving member 9. The leading blade drive spring 12 has one end hooked on the spring hooking portion 9e of the leading blade driving member 9 and the other end hooked on the spring hooking portion 11c from the groove 11b side of the ratchet wheel 11 in FIG. The blade drive member 9 is urged to rotate clockwise. The urging force of the leading blade drive spring 12 can be adjusted by rotating the ratchet wheel 11 and changing the engagement position between the ratchet teeth 11a and the ratchet pawl 5b during manufacture.

  A synthetic resin rear blade drive member 13 is rotatably attached to the shaft portion 1f-1 of the attachment shaft 1f. The rear blade drive member 13 includes a driven portion 13a, a drive pin 13b, a mounting portion 13c, a cylindrical portion 13d, and a spring hooking portion 13e. The large diameter part and the medium diameter part of the part 1f-1 are fitted. Further, the drive pin 13 b penetrates the long hole 1 c of the shutter base plate 1 and protrudes into the blade chamber, and the tip thereof is inserted into a long hole (not shown) of the auxiliary base plate 2. Furthermore, the attachment portion 13c is formed so as to protrude toward the support plate 5 as in the case of the attachment portion 9c, and an iron piece member 14 is attached therein. The iron piece member 14 includes an iron piece portion 14a adsorbed by the iron core member 8, a shaft portion 14b, and a flange-shaped head portion 14c. The iron piece part 14a is urged | biased so that it may protrude from the attaching part 13c with the spring which is not shown in figure interposed.

  Although not shown, a ratchet wheel having the same shape as the ratchet wheel 11 is rotatably attached to the small diameter portion of the shaft portion 1f-1 of the mounting shaft 1f. A ratchet claw (not shown) provided on the support plate 5 is also engaged with the ratchet teeth of the ratchet wheel. A rear blade drive spring 15 is loosely fitted in the cylindrical portion 13d of the rear blade drive member 13 in the same manner as the front blade drive spring 12 described above, and one end of the rear blade drive spring 15 is attached to the rear blade drive member 12. 1, the rear blade drive member 13 is urged to rotate in the clockwise direction in FIG. 1 by being hooked on the spring hook portion 13e of 13 and the other end being hooked on the spring hook portion of a ratchet wheel (not shown). . The urging force of the rear blade drive spring 15 can also be adjusted by rotating the ratchet wheel.

  A set member 16 is rotatably mounted on the set member mounting shaft 1g. The set member 16 includes push parts 16a and 16b, a pushed part 16c, a cylinder part 16d, a pin 16e, and a spring hook part 16f, and the cylinder part 16d is connected to a set member mounting shaft. It is fitted to the 1 g large diameter part and the medium diameter part. During the set operation, the pushing portion 16a pushes the pushed portion 9a of the leading blade drive member 9, and the pushing portion 16b pushes the pushed portion 13a of the trailing blade drive member 13. The pin 16e provided on the shutter base plate 1 side is inserted into the long hole 1d. Further, a return spring 17 is loosely fitted on the cylindrical portion 16d of the set member 16, and the return spring 17 has one end thereof as a spring hook portion of the set member 16 as shown in FIG. The other end is hooked on the spring hooking portion 5a of the support member 5 described above to urge the set member 16 to rotate counterclockwise in FIG.

  As described above, the rear blade is arranged in the blade chamber between the shutter base plate 1 and the intermediate plate (not shown), and the front blade is arranged in the blade chamber between the intermediate plate and the auxiliary base plate 2. However, the leading and trailing blades have a well-known configuration. In other words, the rear blade is composed of two arms 18 and 19 and three blades 20, 21, and 22 that are pivotally supported in the length direction in FIG. 1. The arm 18 is attached to one end thereof with a reinforcing member similar to the reinforcing member 30 of the arm 23 described later, and rotates into the shaft portion 1f-2 of the mounting shaft 1f by fitting the hole. It is attached as possible.

  As shown in FIG. 2, one end of the arm 19 is rotatably attached to the blade attachment shaft 1i. The arm 18 is formed with a hole 18a, into which the drive pin 13b is fitted. Therefore, in FIG. 1, when the rear blade drive member 13 rotates counterclockwise, the arm 18 also rotates counterclockwise to superimpose the three blades 20, 21, 22 and then the rear blade drive member. When 13 rotates clockwise, the arm 18 also rotates clockwise to unfold the three blades 20, 21, 22.

  On the other hand, the leading blade is composed of two arms 23, 24 and three blades 25, 26, 27 that are pivotally supported in the length direction in the same manner as the trailing blade. In the blade chamber, the rear blade is placed inside out. Among them, as shown in FIG. 2, one end of the arm 23 is rotatably attached to the shaft portion 1 e-2 of the mounting shaft 1 e via the reinforcing member 30. One end of the arm 24 is rotatably attached to the blade attachment shaft 1h. The arm 23 is formed with a hole 23a, into which the drive pin 9b is fitted. Therefore, in FIG. 1, when the leading blade driving member 9 rotates counterclockwise, the arm 23 also rotates counterclockwise to unfold the three blades 25, 26, 27, and then the leading blade driving member. When 9 rotates in the clockwise direction, the arm 23 also rotates in the clockwise direction so that the three blades 25, 26 and 27 are superposed.

  As shown in FIG. 2, the arms 19 and 24 are fitted to the blade mounting shafts 1i and 1h, and have a smaller biasing force than the drive springs 15 and 12, and are well known. The springs 28 and 29 are hung. Each of the backlash springs 28 and 29 has one end hung on a spring hooking portion (not shown) provided on the shutter base plate 1 and the other end hung on the arms 19 and 24. In FIG. The arms 19 and 24 are urged to rotate counterclockwise. As shown in FIG. 2, the mounting portion of the leading blade arm 23 with respect to the shaft portion 1e-2 has an interval between the shutter base plate 1 and the auxiliary base plate 2 in addition to preventing the arm 23 from wobbling and damage. The reinforcing member 30 is fixed by caulking so that the reinforcing member 30 can be suitably maintained. However, as described above, the reinforcing member having a substantially similar shape is also attached to the arm 18 of the rear blade. . Further, although not attached in the present embodiment, actually, reinforcing members having similar shapes may be attached to the arms 19 and 24 as well. Therefore, in such a case, it is preferable to form a groove for oil sump on the blade mounting shafts 1i and 1h as well as the shaft portions 1f-2 and 1e-2 and apply a lubricant. .

  Next, the operation of this embodiment will be described. FIG. 1 shows a state immediately after the end of the exposure operation. Therefore, in this state, the leading blade driving member 9 is in a stopped state in which the driving pin 9b is in contact with the buffer member 3, and the three blades 25 to 27 of the leading blade overlap each other. The amount is maximized and stored in a position below the opening 1a. On the other hand, the driving member 13 for the rear blade is also in a stopped state in which the driving pin 13b is in contact with the buffer member 4, and the three blades 20 to 22 of the rear blade minimize the overlapping amount of the blades. The unfolded state covers the opening 1a. Furthermore, the set member 16 is in a stopped state in which the pin 16e is in contact with the lower end of the long hole 1d. Hereinafter, for the set member 16, this position is referred to as an initial position.

  First, the set operation performed from this state will be described. When the previous shooting is finished, a member on the camera body (not shown) pushes the driven portion 16c of the set member 16 to rotate the set member 16 clockwise against the urging force of the return spring 17. The rotation is preferably performed. That is, by the rotation, the set member 16 first resists the urging force of the leading blade drive spring 12 by the pushing portion 16 a pushing the pushed portion 9 a of the leading blade drive member 9. The leading blade driving member 9 starts to rotate counterclockwise. After that, when the blade 27 that is the slit forming blade of the leading blade overlaps with the blade 22 that is the slit forming blade of the trailing blade by a predetermined amount, the pushing portion 16b of the set member 16 is covered by the driven member 13 of the trailing blade. By pushing the pushing portion 13a, the rear blade drive member 13 starts to rotate counterclockwise against the urging force of the rear blade drive spring 15. Thereby, the three blades 25 to 27 of the leading blade operate upward while reducing the overlap between the blades, and the three blades 20 to 22 of the rear blade move upward while increasing the overlap between the blades. It works.

  During such a set operation, the springs 12, 15 and 17 fitted to the drive members 9 and 13 and the set member 16 are twisted as the center line of the winding shaft is twisted. The force generated by the twisting causes a part of the inner peripheral surface of the cylindrical portions 9d, 13d, and 16d to be pressed in the radial direction against the shaft portion 1e-1, the shaft portion 1f-1, and the set member mounting shaft 1g. Will act on. However, in the case of the present embodiment, the friction is preferred by the lubricant that has oozed from the grooves 1e-6, 1e-7, 1f-6, 1f-7, 1g-4, and 1g-5 for the oil sump. Therefore, the drive members 9, 13 and the set member 16 are preferably rotated.

  In this way, the set operation is performed, the three blades 25 to 27 of the leading blade cover the opening 1a, and the three blades 20 to 22 of the rear blade are retracted to the position above the opening 1a. In this state, the iron piece portions 10a and 14a of the iron piece members 10 and 14 attached to the driving members 9 and 13 come into contact with the iron core members 7 and 8 of the leading blade electromagnet and the trailing blade electromagnet. However, the set member 16 is rotated slightly thereafter, and the iron piece portions 10a and 14a of the iron piece members 10 and 14 are placed in the attachment portions 9c and 13c of the drive members 9 and 13, respectively. When the heads 10c and 14c of the iron piece members 10 and 14 are separated from the attachment portions 9c and 13c, they are stopped. The stop state is the set state shown in FIG.

  When the release button is pressed at the time of shooting, first, the respective electromagnets (not shown) are energized, and the iron core members 7 and 8 hold the iron piece members 10 and 14 by suction. Thereafter, since the pressing force by a member on the camera body (not shown) on the driven portion 16c of the set member 16 is released, a lubricant is applied between the set member 16 and the set member mounting shaft 1g. Therefore, the urging force of the return spring 17 is quickly rotated counterclockwise from the set position. In the initial stage, the pressing force on the driven parts 9a and 13a of the driving members 9 and 13 by the pressing parts 16a and 16b of the set member 16 is released, so that the driving members 9 and 13 are Due to the urging force of the drive springs 12 and 15, the mounting portions 9c and 13c rotate and stop until they come into contact with the head portions 10c and 14c of the iron piece members 10 and 14, respectively. Further, as is well known, at this time, the drive pins 9b and 13b rotate the arms 23 and 18, whereby the backlash springs 28 and 29 are slightly tensioned, and the slit forming blades 27 and 22 of the leading blade and the trailing blade are formed. Is placed at a predetermined exposure operation start position. And the state which the set member 16 returned to the initial position is the state shown by FIG.

  Thereafter, when the energization of the two electromagnets is sequentially released at time intervals determined by the exposure control circuit, the leading blade driving member 9 and the trailing blade driving member 13 are connected to the shaft portions 1e-1, 1f-1. Furthermore, the lubricant is applied between the reinforcing members attached to the arms 23 and 18 and the shaft portions 1e-2 and 1f-2. Therefore, each of the drive springs 12 and 15 having a strong biasing force is always rapidly rotated clockwise at a stable speed, and between the leading blade slit forming blade 27 and the trailing blade slit forming blade 22. The imaging surface of the solid-state imaging device is exposed by the slit formed in the above.

  Therefore, first, when the energization to the leading blade electromagnet is cut off, the attractive force by the iron core member 7 to the iron piece portion 10a of the iron piece member 10 is lost, and the leading blade driving member 9 is attached to the leading blade driving spring 12. Due to the force, the backlash spring 29 is rapidly rotated clockwise while being tensioned. Therefore, the three blades 25 to 27 of the leading blade operate while increasing the overlap between the blades, and open the opening 1a from the upper region. Immediately after the opening 1a is fully opened, the driving pin 9b of the leading blade driving member 9 comes into contact with the buffer member 3, so that the operation of the leading blade driving member 9 and the leading blade is stopped. The three blades 25 to 27 are overlapped and stored in a position below the opening 1a.

  When energization of the rear blade electromagnet is interrupted after a predetermined time has elapsed since the energization of the leading blade electromagnet is cut off, the attraction force by the iron core member 8 to the iron piece portion 14a of the iron piece member 14 is lost, and the The driving member 13 is rapidly rotated clockwise by tensioning the backlash spring 28 by the urging force of the trailing blade driving spring 15. Therefore, the three blades 20 to 22 of the rear blade operate while reducing the overlap between the blades, and close the opening 1a from the upper region. Then, immediately after the three blades 20 to 22 of the rear blades completely close the opening 1a, the drive pin 13b of the rear blade drive member 13 comes into contact with the buffer member 4, so that the rear blade drive member 13 and the operation of the trailing blades are stopped. Thereafter, the state where the imaging information has been transferred from the solid-state imaging device to the storage device is the state shown in FIG.

  Here, a manufacturing method of the shutter base plate 1 of the present embodiment and the shafts 1e, 1f, 1g, 1h, and 1i standing on the shutter base plate 1 will be described. As described above, in this embodiment, the small-diameter portions of the shafts 1e, 1f, and 1g are loosely fitted into the holes formed in the support plate 5 and the printed wiring board 6 by a slight but only assembly tolerance. ing. The drive springs 12 and 15 and the return spring 17 are torsion coil springs. The drive members 9 and 13 and the cylindrical portions 9d, 13d, and 16d of the set member 16 are connected to their outer peripheral surfaces. The drive springs 12 and 15 are loosely fitted to prevent sliding contact, and one end of each drive spring 12 and 15 is hung on each drive member 9 and 13 and the other end is hung on each ratchet wheel 11 (one ratchet wheel is not shown). The return spring 17 has one end hung on the set member 16 and the other end hung on the support plate 5.

  As is well known, these springs 12, 15, and 17 not only urge the drive members 9 and 13 and the set member 16 in the rotational direction, but also always urge the shutter base plate 1 side. Therefore, the center line of each coil portion is actually spiral. Therefore, the drive springs 12 and 15 are arranged in the radial direction with respect to the shaft portions 1e-1 and 1f-1 of the mounting shafts 1e and 1f by the two drive members 9 and 13 and the two ratchet wheels (11 and the like). A force is applied, and the return spring 17 applies a radial force to the set member mounting shaft 1 g via the set member 16. Then, as can be understood from the above description of the operation, such a radial force is remarkably increased each time a set operation for winding up each spring is performed.

  When the set member 16 returns to the initial position and the pin 16e comes into contact with the lower end of the long hole 1d, a large force acts in the radial direction of the set member mounting shaft 1g due to the impact. When the drive pins 9b and 13b come into contact with the buffer members 3 and 4 at the end of the exposure operation of the drive members 9 and 13, the shaft portions 1e-1 and 1f-1 of the mounting shafts 1e and 1f are caused by the strong impact. A large force also acts in the radial direction of the shaft, and a large force also acts in the radial direction of the shaft portions 1e-2, 1f-2, 1h, and 1i due to the inertia of each shutter blade. Further, since radial forces are directly acting on the blade mounting shafts 1h and 1i by the backlash springs 28 and 29, these radial forces become large during the exposure operation.

  Since these strong radial forces are repeatedly applied every time photographing is performed, the mounting shafts 1e and 1f, the set member mounting shaft 1g, and the like are used as the shutter base plate 1 as in the prior art. In the case where the shafts are erected by simultaneous integral molding, if the shafts are narrowed as the shutter is downsized, the shafts are eventually tilted or broken. In particular, in the case of the shaft portions 1e-1 and 1f-1 of the mounting shafts 1e and 1f, the drive springs 12 and 15 hung on the drive members 9 and 13 have a strong biasing force. Such an influence will be the greatest. However, in the case of the present embodiment, this is not the case, and it is possible to make the mounting shafts 1e, 1f, the set member mounting shaft 1g, etc. thinner than in the past. This will be described next.

In general, liquid crystal polymers have excellent fluidity because they have a strong orientation that aligns in the direction in which molecular chains flow during molding, and are conventionally widely used as molding materials for precision parts and the like. However, this material, after molding, so resulting in cured remains of the orientation state of flow perturbed, warpage or distortion at the molded article with anisotropic too large occurs. Therefore, in order to reduce anisotropy, a filler such as glass fiber is blended with the liquid crystal polymer. Therefore, conventionally, the mounting shafts 1e and 1f and the set member mounting shaft 1g of the present embodiment are manufactured by simultaneous integral molding using a material such as a liquid crystal polymer mixed with glass fiber or the like in the same manner as the shutter base plate 1. It was. At the time of molding, the molten material mixed with the glass fiber is injected from the gate into the cavity and flows along the cavity region serving as the plate surface of the shutter base plate 1, and the mounting shafts 1 e and 1 f and the set are set. At the base portion of the member mounting shaft 1g and the like, a part of the shaft flows by changing the direction by about 90 degrees. Therefore, at the root of these shafts, the flow direction is disturbed, so that the orientation of molecular chains and glass fibers at the time of curing is not aligned, and the shaft is further narrowed to flow in the mold. become worse, it has become a thing desired strength is not obtained, et al. Therefore, if a strong force is repeatedly applied in the radial direction of the mounting shafts 1e, 1f, the set member mounting shaft 1g, etc., these shafts are inclined or damaged.

  On the other hand, the mounting shafts 1e and 1f and the set member mounting shaft 1g according to the present embodiment are manufactured together with the shutter base plate 1 by using a two-color molding method. That is, first, the shutter base plate 1 is formed of a liquid crystal polymer. At that stage, the shutter base plate 1 has the shape shown in FIG. 5, and the mounting shafts 1 e and 1 f, the set member mounting shaft 1 g and the blade mounting shafts 1 h and 1 i are circular at the site. The holes 1j, 1k, 1m, 1n, and 1p having the above shapes are formed as through holes. After the shutter base plate 1 is formed in this way, the mounting shafts 1e and 1f, the set member mounting shaft 1g, and the blade mounting shafts 1h and 1i are further molded with a liquid crystal polymer. 3 and 4 show the shutter base plate 1 in a state where the shafts 1e, 1f, 1g, 1h, 1i are erected in this way.

  Thus, in the case of the present embodiment, the shafts 1e, 1f, 1g, 1h, and 1i are erected with respect to the shutter base plate 1 by using the two-color molding method. Compared with the case of molding, the flow of the molten material at the time of molding is not disturbed, and the molecular chains and glass fibers of the liquid crystal polymer are aligned in the axial direction. Therefore, even if these shafts are erected by simultaneous integral molding, such a situation does not occur even if they are thinned so as to cause inclination or damage. In addition, the shafts 1e, 1f, 1g, 1h, and 1i of the present embodiment are shaft portions 1e-3, 1f-3, 1g-1, 1h-1, and 1i-1 of the portion standing on the shutter base plate 1. The cross section is circular corresponding to the shape of the holes 1j, 1k, 1m, 1n, and 1p, but when the cross sectional shape is non-circular such as an oval or star shape, Even when the degree of adhesion between the shafts and the shutter base plate 1 is small, the mounting strength in the rotational direction of the shafts can be suitably obtained.

  The shafts 1e, 1f, 1g, 1h, and 1i of this embodiment are manufactured by the two-color molding method together with the shutter base plate 1. At the end of the molding process, the two main molds are The shutter base plate 1 is released in the thickness direction. In that case, the shaft portions 1e-1 and 1f-1 and the set member mounting shaft 1g of the present embodiment are gradually tapered at the tip end side, and each oil sump groove is also linearly formed in the axial direction. Therefore, it is not necessary to provide a slide mold that is slid in a direction perpendicular to the mold release direction of the two molds, so that the mold can be easily released. Therefore, it is possible to manufacture at a low cost without requiring a mold having a complicated configuration or an expensive molding machine.

  In this embodiment, the shafts 1e, 1f, 1g, 1h, and 1i are manufactured together with the shutter base plate 1 by a two-color molding method. However, the shafts 1e, 1f, and 1g are manufactured according to this embodiment. Thus, it is possible to form the groove for oil sump also when manufacturing by simultaneous integral molding as described in Patent Document 2. Further, for example, the shutter base plate 1 as shown in FIG. 5 is manufactured in advance as a molded part or as a metal part, and then the shafts 1e, 1f, 1g, 1h, Even when 1i is molded, the oil sump groove can be easily formed as in this embodiment. Therefore, this invention is applied also to what was manufactured like that.

  The shaft portions 1e-1 and 1f-1 and the set member mounting shaft 1g of the present embodiment have a large diameter portion, a medium diameter portion, and a small diameter portion. It does not prevent the parts from being formed to the same thickness. Even when the large-diameter portion and the medium-diameter portion are formed as in the present embodiment, the oil sump groove may be formed only in one of them. In this embodiment, the four oil sump grooves formed at an angular interval of 90 degrees have the same length. However, for example, every other length may be changed. . Further, the number is not limited to four, and may be one in some cases. However, in practice, it is preferable to form a plurality of grooves at equiangular intervals as in this embodiment. In addition, the oil sump groove of the present embodiment is formed in a V-shaped cross section as an example for facilitating mold release at the time of manufacture, but the present invention is limited to this shape. For example, it may be substantially U-shaped or other shapes.

  Further, in this embodiment, the oil reservoir grooves 1e-8 and 1f-8 are formed in the shaft portions 1e-2 and 1f-2, but the oil reservoirs are formed in these shaft portions 1e-2 and 1f-2. In some cases, it is not necessary to form the grooves 1e-8 and 1f-8. Therefore, in the present invention, as long as the oil sump groove of the present invention is formed on other mounting shafts, the shaft portions 1e-2 and 1f-2 may not be formed. In this embodiment, the oil reservoir grooves 1g-4 and 1g-5 are formed on the set member mounting shaft 1g. However, it is necessary to form the oil reservoir grooves on the set member mounting shaft 1g. In some cases, the set member mounting shaft 1g may be made of metal, or the shutter base plate 1 may not be provided with the set member mounting shaft 1g. For this reason, the present invention does not necessarily form an oil sump groove on the set member mounting shaft 1g.

  In practice, the mounting shafts 1e and 1f may be made of metal. Therefore, in the present invention, if the oil sump groove of the present invention is formed on another mounting shaft, it is not essential to form it on the mounting shafts 1e and 1f. In particular, when a focal plane shutter having only one shutter blade is employed in a camera having a progressive CCD as a solid-state imaging device, the shutter blade closing operation may not be particularly severely restricted. Therefore, in this case, even if the drive member mounting shaft is made of a synthetic resin, it may not be necessary to form an oil sump groove on the drive member mounting shaft. Therefore, the oil sump groove of the present invention may be formed only on any mounting shaft as long as it is a synthetic resin mounting shaft that is erected on the shutter base plate and has a rotating member attached thereto. become.

It is the top view of the Example which looked at the state immediately after complete | finishing exposure operation from the photographing lens side. FIG. 2 is a cross-sectional view showing the main part of FIG. 1 in an easy-to-understand manner. It is the top view which showed a part of shutter base plate of an Example. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3. It is a top view in the middle of manufacture of the shutter base plate shown in FIG.3 and FIG.4. It is the top view of the Example which showed the set state seeing similarly to FIG. It is the top view of the Example which showed the state just before exposure operation start seeing similarly to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shutter base plate 1a Opening part 1b, 1c, 1d, 2a Long hole 1e, 1f Mounting shaft 1e-1 to 1e-3, 1f-1 to 1f-3, 1g-1, 1h-1, 1i-1, 10b, 14b Shaft 1e-4, 1e-5, 1f-4, 1f-5, 1g-2, 1g-3, 1h-2, 1i-2 Flange 1e-6 to 1e-8, 1f-6 to 1f- 8, 1g-4, 1g-5 Oil sump groove 1g Set member mounting shaft 1h, 1i Blade mounting shaft 2 Auxiliary ground plate 2b, 2c, 2d, 18a, 23a Hole 3, 4 Buffer member 5 Support plate 5a, 9e, 11c, 13e, 16f Spring hook portion 5b Ratchet claw 6 Printed wiring board 7, 8 Iron core member 9 Lead blade drive member 9a, 13a, 16c Driven portion 9b, 13b Drive pin 9c, 13c Mounting portion 9d, 13d, 16d Cylinder part 10,14 Iron piece member 1 0a, 14a Iron piece 10c, 14c Head 11 Ratchet wheel 11a Ratchet tooth 11b Groove 12 Lead blade drive spring 13 Rear blade drive member 15 Rear blade drive spring 16 Set member 16a, 16b Pusher 16e Pin 17 Return spring 18, 19, 23, 24 Arm 20, 21, 22, 25, 26, 27 Blade 28, 29 Ruffle spring 30 Reinforcing member

Claims (6)

A shutter base plate having an opening for a subject optical path, an auxiliary base plate having an opening for a subject optical path and forming at least one blade chamber between the shutter base plate, a plurality of arms, and pivotally supported by these arms At least one shutter blade configured to be individually rotatable at one end of each of the arms on a plurality of blade mounting shafts erected on the shutter base plate. At least one drive member that is rotatably attached to a drive member mounting shaft that is erected on a shutter base plate, and causes the shutter blade to open and close the opening by reciprocatingly rotating one of the arms; In the focal plane shutter having the above-described structure, the shutter is erected on the shutter base plate for mounting the rotating member including the driving member mounting shaft. At least one of the mounting shaft of the plurality of mounting shaft is made of synthetic resin is formed in the vane chamber outer surface, a portion fitted to said rotary member, said shutter base plate by a step surface as a boundary The tip side is composed of a plurality of portions formed so that the diameter gradually decreases from the side, and at least one peripheral surface portion of the plurality of portions has one end portion on the step surface. A focal plane shutter for a camera, characterized in that an oil sump groove is formed in the axial direction of the mounting shaft so as to open and close the other end portion in the middle of the portion where the rotating member is fitted .   2. The focal plane shutter for a camera according to claim 1, wherein the at least one attachment shaft is the drive member attachment shaft. The drive member is configured to be rotated by an urging force of a drive spring at the time of photographing, and a set member mounting shaft for rotatably mounting a set member is provided on the shutter base plate. The member starts rotating from the initial position against the biasing force of the return spring at the time of setting to rotate the drive member to the set position against the biasing force of the driving spring, and starts to rotate at the time of photographing. 3. The apparatus according to claim 1, wherein the at least one mounting shaft is the set member mounting shaft. Focal plane shutter for camera. Among the plurality of mounting shafts erected on the shutter base plate for mounting the rotating member including the driving member mounting shaft, at least one blade mounting shaft erected on the surface on the blade chamber side is included. The blade mounting shaft is made of a synthetic resin and is formed in a cylindrical shape. One end of the peripheral surface of the blade mounting shaft is opened at the tip and the other end is in the middle of the axial length. The focal plane shutter for a camera according to any one of claims 1 to 3, wherein a groove for oil sump that is closed is formed . Groove for said oil sump is a camera focal plane shutter according to any one of claims 1 to 4, characterized in that it is formed in a plurality of numbers in a predetermined angular spacing position of the mounting shaft. Groove for said oil sump, when cut perpendicularly the mounting axis relative to the axial direction, cross section according to any one of claims 1 to 5, characterized in that it is formed in a V-shape Focal plane shutter for camera.

Images