JPS59148035A - Exposure controller of camera - Google Patents

Abstract

PURPOSE:To obtain an exposure device with a simple mechanism by driving a blade which has plural stop apertures of different size and a cam turning a blade which has an aperture for exposure in a simple exposure controlle of a small-sized camera. CONSTITUTION:The 1st blade 3 where the exposure aperture 2 of a substrate 1 is supported 5 pivotally in an opening/closing state is provided with an opn- aperture stop 3a and a small stop 3b, and the 2nd blade 4 is provided with the exposure hole 4a. The 1st blade has a raised part 3c abutting on an external surface cam 7 and the 2nd blade has a pin 4b abutting on an internal surface cam 8. When a motor turns the external surface cam and internal surface cam counterclockwise in one body, the 2nd blade swivels to left firstly beyond the aperture, and then the 2nd blade has the stop aperture overlapping with the aperture successively, so the stop aperture is held selectively by a locking means which is not shwon in a figure, and the 2nd blade turns up to a right swivel position to return to its original state. Therefore, complicate reciprocating motion is reallized only by a unidirectional rotating mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure control device for a small portable camera.

Conventional technologyRecently, with the progress of photosensitive materials and the development of their processing technology, 3
Multifunctional cameras that use roll film smaller than 5-width roll film (J 135) and have ultra-small screen sizes are being actively developed.

The photographic lenses used in these cameras generally tend to be somewhat wide-angle and have a small screen size, so their focal length is usually very short. Furthermore, these cameras use a built-in strobe to take pictures in places with relatively little light, such as when taking pictures indoors, so the photographic lens does not need to be very bright. Therefore, taking a disk camera with a focal length of 12J as an example, the aperture of the photographing lens is usually extremely small, with a diameter of about 3.5H at the aperture position even when the aperture ratio is F2.8.

Also, because these cameras are not used for shooting that requires various exposure conditions due to the nature of the camera, they are generally
The function is limited to controlling the exposure amount in two low steps.

Because the aperture of the photographic lens is small and exposure control is simple, these cameras have a light-shielding blade with an exposure hole that is moved to open and close the photographic lens aperture to adjust the exposure. A so-called guillotine-type shutter is often used.However, in this guillotine-type shutter, when accumulating energy in a spring or other member that operates the shutter, the exposure hole of the light-shielding blade crosses the opening of the photographic lens, causing unnecessary damage. Requires the ability to close the exposure hole to prevent exposure.

As a means of this, 1,220 light-shielding blades with exposure holes in different positions are set at the same time so as to close each other, and energy is stored.
After the exposure hole of the preceding light-shielding blade is aligned with the aperture of the photographing lens by the release, the exposure is performed using the exposure hole of the following light-shielding blade, or alternatively, the light-shielding member and the exposure hole are closed by the release. A method has been proposed in which the light-shielding blades are set together to store energy, and at the end of the release, only the light-shielding blades are released and returned to their original positions to perform exposure.

However, in all of these means, the stored energy is released immediately before exposure, which may cause an impulse, which may cause camera shake or the like.

It also has the disadvantage of a large number of parts (and a somewhat complex structure).

OBJECTS OF THE INVENTION It is an object of the present invention to provide an exposure control device for a camera that does not require a special member to close the exposure hole of a light-shielding blade, has a simple structure, and requires less impulse.

Structure of the Invention The present invention provides a light-shielding blade having an aperture hole for controlling the aperture of a photographic lens, a light-shielding blade having an exposure hole for opening and closing the aperture, and a light-shielding blade having an exposure hole for opening and closing the aperture. It consists of a first and second two blades that rotate around the same axis, and a separate cam with the same axis to perform two-stage exposure. This is achieved by an exposure control device of a camera configured such that the first blade has a small aperture and a wide aperture.

Embodiment 1 and 2 show two aspects of an embodiment according to the present invention. 94Z Figure 1 shows the state after exposure has been completed, and Figure 2 shows the state in which the exposure is completed, and the figure 2 shows the state with a small aperture. It shows a closed state.

In FIG. 1, the first blade 3 has a closing part that covers the aperture 2 of the photographing lens provided on the substrate 1, and has an open aperture 3a on its extension and a small aperture 3b on the opposite side. A second blade 4 having a closing part that covers the opening 2 and an exposed hole 4a on the extension thereof, and a second blade 4 and a second blade 4 having an exposure hole 4a on the extension thereof, are rotatably mounted as a common shaft on the shutter substrate 1, and a fixed bin Tension springs 3e and 4d are stretched across rivers 3d and 4c, respectively, so that the first blade is biased counterclockwise and the second blade is biased clockwise.

On the other hand, an outer cam 7 and an inner cam 8 are integrally and rotatably coupled to another fixed shaft 6 on the /Yakuta board I, and the outer cam 7 is attached to the bending of the first blade 3. The portion 3C and the inner cam 8 are in contact with the bottle 4b on the front B and second blade 4, respectively.

Next, we will explain its operation. When the release button (not shown) is pressed in the state shown in Figure 1, the outer cam and inner cam of the front unit become one body due to the action of the motor (not shown). The first blade 3 can remain stationary for a period of time defined by the arcuate surface 7a of the outer cam 7.
It rotates counterclockwise against the tension spring 4d by the inclined surface 8aK, and its exposure hole 4a occupies a position to the left beyond the opening 2t. Next, the protrusion 7b of the outer cam 7
Force - The first blade 3 moves by pushing the bent part 3C of the first blade 3, so the first blade 3 rotates in the 6 direction against the tension 3e, and its opening diaphragm 3a reaches the opening 2. Then, when the outer cam 7 rotates counterclockwise, the first blade 3 rotates counterclockwise again, and the first blade 3 contacts the stop bottle 9, causing the /J% aperture 3b to reach the front stand. The bottle 4b of the second blade 4 reaches the position where it coincides with the opening 2.
abuts near the end of the inclined surface 8a of the inner cam 8,
The state is shown in FIG.

From the state shown in FIG. 2, the outer cam 7 and the inner cam 8 are
0 When the counterclockwise rotation continues, the bottle 4 of the second blade 4
b is the stepped portion 8 of the inner cam 8 due to the action of the tension spring 4d.
b and rotates the second blade 4 nine times clockwise, so that the exposure hole 4a crosses the opening 2 formed by the small diaphragm 3b of the first blade 3 and moves to the right of the opening 2. Ends exposure at aperture.

Even after the exposure is completed, the outer cam 7 and the inner cam 8 continue to rotate, reach a positive rotational pressure, and return to the initial state shown in FIG. 1.

Note that when the open aperture 3a of the first blade 3 reaches the opening 2, another member (not shown) maintains the first blade 3 at that position, thereby opening the opening 28. It is also possible to perform exposure using an aperture.

Effects of the Invention As is clear from the above explanation, according to the present invention, there is no need for a specific light shielding member to close the exposed hole of the light shielding blade, so the structure is extremely simple, and furthermore, the operation can be controlled by a cam. It has become possible to provide a useful camera exposure control device that can perform two-step exposure switching with less shock and no camera shake.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing the state before shutter operation. FIG. 2 is a configuration diagram with the aperture set to a small aperture and the shutter set. 1...7 PCB 2...Photo lens opening 3...
...First blade 3a...Open aperture 3b...
...Small aperture 4...Second blade 4b.
...Exposure hole 5.6...Fixed shaft 7.
......Outer cam 8...Inner cam 9...Stop pin agent Kuwabara
Yi beauty 1 figure 62 figure

Claims (1)

[Claims] (1) In an exposure control device that performs two-step exposure using first and second two blades whose rotation axis is the same axis, and a separately provided cam of the same axis, the first blade includes An exposure control device for a camera, wherein a closing part is provided between a small aperture and an open aperture, and the second blade performs a winding operation while the closing part of the first blade is in a closed position of the optical axis. . C) The second blade is wound up by a shirt release operation, the first blade is moved to a small aperture position or an open aperture position, and then the second blade operates a shutter. 2. The camera exposure control device according to item 1.