JPH0112254Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shutter for a camera, and more particularly to a high-speed time stabilizer for a shutter.

In camera shutters, in order to stabilize high-speed seconds, there is a method to minimize the gap between the shutter blades, blade actuating members, etc., and to quickly transition from static friction to dynamic friction at the start of operation. Although it is known to provide a separate accelerating force, in recent years, especially in the case of photographing using a motor drive, etc., it has become necessary to perform one cycle of photographing at a considerably high speed. For this reason, in the operating cycle of the shutter, it has become necessary to extremely shorten the time from when the shutter is completely charged until when the shutter is released. As a result, if the shutter release operation is started before the blades come to rest, that is, while the blades are vibrating, the blades will start operating while the blade position remains unstable.
The time from the start of blade operation to the opening of the shutter was unstable, causing variations in exposure time.
Also, after the exposure operation is complete, the shutter may be charged while the blades are vibrating, so if you charge the blades when the vibration direction of the blades is opposite to the charging direction, the blades will not vibrate. Two forces, power and charge force, are applied, which significantly reduces durability and requires an increase in the driving force for charging the shutter in order to operate the shutter at high operating cycles.

The present invention provides a high-speed time stabilization device for a shutter, which is particularly effective for motor drives and the like, by means of a timing determination method that utilizes viscous damping.

The details will be explained below with reference to the drawings.

FIG. 1 is a diagram showing the effect of blade vibration on exposure time, where the horizontal axis represents elapsed time and the vertical axis represents the traveling position of the blade edge relative to the shutter opening. After the shutter charge is completed, the vibration of the blade has not converged, and if the shutter is released when the vibration direction of the blade vibrates in the opposite direction to the exposure operation travel, as shown in Figure 1a, for example, the solid line The operating diagram will be as shown. However,
If the vibrations of the blades have converged, the time from shutter release to shutter opening is t, and the time for the blades to cross the shutter opening is T in the normal operation diagram shown by the broken line B. Therefore, compared to the normal operation diagram B, the time t from the shutter release to the shutter opening becomes longer as _t1 , and the time T for the blade to cross the shutter opening also becomes longer as _T1 .
Further, when the shutter release is performed when the vibration direction of the blade and the traveling direction match as shown in FIG. 1B, the operation diagram C becomes as shown by the solid line. In this case as well, if the vibrations of the blades have converged, the normal operation diagram B will be as shown by the broken line, so compared to the normal operation diagram B, the time t from shutter release to shutter opening will be t ₂ At the same time, the time T for the blade to cross the shutter opening also becomes short as _T2 . Therefore, compared to the operating diagram B, which is normal when the vibrations have converged, the operating diagram becomes significantly different as shown in A or C depending on the vibration direction. Next, the second
The figure shows the effect of the stop position of the blade on the exposure time. Figure 2a shows the case where the distance l ₁ from the stop position of the blade to the shutter opening is short, and the time t from the shutter release to the shutter opening is ₃ becomes short, and when the distance _l2 is long as shown in FIG. 2b, the time _T4 from shutter release to shutter opening becomes long. The difference between t ₃ and t ₄ becomes the variation in exposure time. Furthermore, since the relationship between the traveling distance of the blade and the time is not a linear function, there is also a difference in the times T ₃ and T ₄ during which the blade crosses the shutter opening.

FIG. 3 is a plan view of the first embodiment of the present invention, showing the focal plane shutter in a charged state. In the figure, reference numeral 1 denotes a substrate having a shutter opening 1a for film exposure. Reference numeral 3 denotes a group of opening blades for opening the opening 1a during the exposure operation, which consists of an opening slit forming blade 3a and shielding blades 3b, 3c, 3d, and 3e, and the opening slit forming blade 3a is rotatably mounted on the substrate 1. The open arm 4 and the auxiliary opening arm 5 supported by the shafts 4e and 5e constitute a link mechanism that performs parallel movement utilizing the properties of a parallelogram. has been done. The shielding blade 3b has a groove and is rotatably supported coaxially with the shaft 5a of the open arm 5, and the shielding blade 3c,
3d and 3e each have a groove and are rotatably supported by the shaft 5e. The open arm 4 is provided with stops 4g and 4h. 6 is the opening 1a at the end of exposure.
The closing slit forming blade 6a is a group of closing blades for closing the substrate 1, and consists of a closing slit forming blade 6a and shielding blades 6b, 6c, 6e, 6f. The closing arm 7 and the closing auxiliary arm 8 are pivotally supported on the front sides of the arms 7 and 8, respectively. Shielding blades 6b, 6c, 6d, 6e, 6f
each has a groove and is rotatably supported by the shaft 8e. The closing arm 7 is provided with stops 7g and 7h. Reference numeral 9 denotes an opening drive lever for opening the shutter blade, which is coaxially supported with the shaft 4e, and a pin 9f protruding from the back side connects the hole 4f of the opening arm 4 with the shielding blades 3b, 3c, 3d, and 3e. are inserted into the respective grooves. Reference numeral 10 denotes a closing drive lever for closing the shutter blade, and a shaft 7e
A pin 10f, which is coaxially supported with and protrudes from the back side, is fitted into each groove of the shielding blades 6b, 6c, 6d, 6e, and 6f and the hole 7f of the closing arm 7.
11 is a flexible measuring plate. In addition, in the charging state shown in FIG. 3, the stop portion 4g of the open arm 4
Since the stop portion 7g of the closing arm 7 and the stop portion 7g of the closing arm 7 sandwich the dialing plate 11 facing each other, the open arm 4 and the closing arm 7 are slightly pressed in the clockwise direction by the dialing plate 11. has been done.

Next, its operation will be explained. From the shutter charging state shown in FIG. 3, when the shutter is released by a known method in conjunction with depression of the camera's release button, the release drive lever 9 is released from its lock (not shown) and the spring force (not shown) is released. The projecting pin 9f causes the open blade group 3 to travel downward in the drawing, and the opening 1
Open a and start exposure. When the opening slit forming blade 3a reaches almost the full opening area, the opening arm 4
The side portion 4h of is in contact with the metering plate 11. After the opening drive lever 9 is released, the closing drive lever 10 is unlocked (not shown) after a desired exposure time by a known device, and the closing drive lever 10 is moved by a spring force (not shown). A right turn is started, and the protruding pin 10f causes the closing blade group 6 to travel downward in the drawing, thereby closing the opening 1a and completing the exposure. When the closing slit forming blade 6a almost reaches the closing region, the stop portion 7h of the closing arm 7 contacts the determining plate 11, and the stopping portion 7h and the stopping portion 4h of the open arm 4 contact the flexible determining plate 11. Place them facing each other.

Next, when charging the shutter, the opening drive lever 9 and the closing drive lever 10 are respectively turned to the left against spring force (not shown) and locked (not shown). At this time, the charge state shown in FIG. 3 is reached, and the stop part 4g of the open arm 4 and the stop part 7g of the close arm 7 are in a charging state with the flexible metering plate 11 facing each other, similar to when the exposure operation is completed. Insert.

In addition, in FIG. 3, the opening arm 4 and the closing arm 4 are configured to sandwich the flexible adjustment plate 11 facing each other, but the opening auxiliary arm 5 and the closing auxiliary arm 8 It may be configured so that the plates 11 are sandwiched in opposite directions. Also, open blade group 3 and closed blade group 6
The design of at least one or more of the blades, the blades, the respective arms, etc. may be changed as appropriate.

FIG. 4 is a plan view showing a charged state of the lens shutter in a second embodiment of the present invention. In the figure, reference numeral 1 denotes a substrate having a shutter opening 1a for film exposure. Reference numeral 16 denotes a drive lever for opening and closing the blades, and is rotatably supported on the base plate 1 by a shaft 16e. Reference numeral 14 denotes a group of blades for opening and closing the opening 1a during the exposure operation, and a pair of blades 12 and 13 is rotatably supported on the base plate 1 by a shaft 14e, and a drive lever is provided in each long hole of the blade. A protruding pin 16f is fitted into the pin 16. The blades 12 and 13 have a stop portion 12.
g, 12h, 13g, 13h. 11
is a flexible measuring plate. In the state shown in FIG. 4, the flexible metering plate 11 is sandwiched between the stop portion 12g of the blade 12 and the stop portion 13g of the blade 13, so that each blade 12 is held in the operating direction. , 13 are pressed.

Next, its operation will be explained. In the state shown in FIG. 4, when the shutter is released in conjunction with the depression of the camera's release button, the drive lever 16 is turned to the right in a known manner, and the blade 1
2 and 13 are opened to start exposure. When the blades 12 and 13 reach almost the full opening range, the stop portions 12h and 13h of the blades sandwich the flexible adjustment plate 11 facing each other. After the desired exposure time has elapsed, the drive lever 16 is turned to the left using a known device to close the blades 12 and 13, thereby completing the exposure. When the blades 12 and 13 reach the end of exposure area,
The stop portions 12g, 13g of the blades 12, 13 sandwich the flexible metering plate 11 facing each other.

In Fig. 4, the blades 12 and 13 are configured to be coaxial, but even when the blades are operated not coaxially by a ring or the like, the blades can be sandwiched oppositely to a flexible dial plate. It goes without saying that the structure may be configured in such a way that it is crowded.

According to the present invention as described above, before or after the focal plane shutter is actuated, and before or after the blade is fully opened in the case of a lens shutter, the flexible adjustment means is configured to control each blade or the blade actuating member before or after the blade is fully opened. Since the stop parts are provided at positions sandwiched between each other in the terminal region of each operation, it is possible to reduce the vibration of the blade in a geometric progression by using the viscous damping of the flexible determining means. ,
Compared to conventional solid friction damping alone, it is possible to converge blade vibrations much faster.

Further, according to the present invention, since the blades can be displaced in a fixed direction by the flexible determining means before and after the shutter is operated, it is possible to eliminate the gap between the fitting of the operating member, and improve the precision of the parts. The blade can always be stopped at a fixed position without raising the height. Furthermore, since the flexible determining means can also be used as a driving force when the blade is activated and released, it can be used as an auxiliary driving force at the transition point from static friction to dynamic friction, reducing the charging force of the shutter. , it is possible to provide a shutter that is more suitable for motor drives, etc., and the benefits are great.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the influence of blade vibration on exposure time, Figure 2 is a diagram showing the influence of blade stopping position on exposure time, and Figure 3 is a diagram showing the first embodiment of the present invention. FIG. 4 is a plan view showing the case of a focal plane shutter, and FIG. 4 is a diagram showing the case of a lens shutter according to a second embodiment of the present invention. 1... Board, 3... Open blade group, 4... Open arm, 5... Open auxiliary arm, 6... Closed blade group, 7... Closed arm, 8... Closed auxiliary arm,
9... Opening drive lever, 10... Closing drive lever, 11... Determining plate, 14... Vane, 16... Drive lever.

Claims (1)

[Scope of utility model registration request] In a camera shutter of the type in which exposure is performed by a pair of blades that operate to open and close, a blade or blade actuation having a flexible determining means and a stop portion that contacts the determining means at the end region of the operation. The determining means is provided at a position where it is sandwiched between the stop portion of one of the blades or the blade actuating member and the stop portion of the other blade or the blade actuator. Shutter for camera.