JPS5948367B2 - Exposure adjustment lever in copying machine - automatic return device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic exposure adjustment lever return device in a copying machine.

2. Description of the Related Art Exposure adjustment devices for copying machines are well known, which operate an exposure adjustment lever to change the width of an exposure aperture, thereby adjusting the amount of exposure.

It is also widely known that an exposure adjustment lever automatic return device of the type described above is attached to this exposure adjustment device so that the exposure adjustment lever is automatically returned to an intermediate position between bright and dark after a copying operation is completed. In this case, in the conventional automatic return device, the adjustment lever returns to the intermediate position after copying one document. That is, when obtaining one sheet of copy paper from one sheet of original, the lever returns to the intermediate position after the copying operation is completed, or after copying a predetermined number of sheets in the case of repeat copying. It's getting old. However, when operating in this way, for example, when the same operator copies multiple originals with the same exposure adjustment state, it is necessary to redo the exposure adjustment for each original, which avoids complicating the operation. do not have. The present invention aims to eliminate the above-mentioned drawbacks and provide an exposure adjustment lever automatic return device with a simple structure.Examples of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, an exposure adjustment lever 1 is rotatably supported on a fixed plate 2 of the copying machine body via a shaft configured as a stepped screw 3, and the upper end of this adjustment lever is A knob 4 for adjusting exposure is □crossed.

Further, one end of an aperture thread 6 is moored to a mooring pin 5 protruding from the adjustment lever 1, and the other end of this aperture thread 6 is connected to an aperture lever (not shown) on an exposure aperture plate (not shown). connected via. In FIG. 1, the adjustment lever 1 is located at an intermediate position N where the aperture and aperture of the aperture plate are intermediate.
When the operator moves the knob 4 from this N position to the open position L, the adjustment lever 1 rotates counterclockwise around the screw 3 and pulls the drawing thread 6. This widens the aperture of the diaphragm plate and increases the amount of exposure. Conversely, if the knob is turned to the dark position D, the aperture of the diaphragm plate becomes narrower and the amount of exposure decreases. Since the aperture lever and the aperture plate that operate in this manner are both well known, further explanation will be omitted. Adjustment lever
A first return lever 7 and a second return lever 8 are rotatably supported on the stepped screw 3 supporting the second return lever 1 .

These two return levers 7 and 8 each have a first
A projecting pin 7a and a second projecting pin 8a are provided in a protruding manner, and a spring 9 is tensioned on these projecting pins 7a, 8a. With this configuration, the return levers 7 and 8 are given the tendency to rotate in the direction toward each other, but in the position shown in FIG. Both return levers 7, 8 are stationary because they abut between the levers 7, 8. When the adjustment lever 1 is in the position shown in FIG. 1, that is, in the intermediate position,
Both side surfaces 1a and 1b of the lever 1 are in contact with the first and second projecting pins 7a and 8a, respectively. Two protrusions are provided at the lower end of the adjustment lever 1, and these protrusions form three recesses, namely a first recess 11, a second recess 12, and a third recess 1.
3 is formed.

On the other hand, a release lever 15 is rotatably supported on a support pin 14 protruding from the fixed plate 2, and this release lever 15 is supported by a spring 16.
gives the counterclockwise rotational behavior in FIG. A roller 17 is rotatably supported at one end of the release lever 15, and the roller 17 can be engaged with the three recesses 11, 12, or 13 formed in the adjustment lever. A plunger 19 of a solenoid 18 is pivotally connected to the other end of the release lever 15. This solenoid 1
8 is in the OFF state, the lever 15 is rotated counterclockwise by the action of the spring 16 than in the state shown in FIG. 1, and the roller 17 is disengaged from the recess 11, 12 or 13. However, when the solenoid is turned on, the release lever 15 rotates to the state shown in FIG. 1, and the roller 17 can press into the recess 11, 12 or 134. The ON and OFF states of the solenoid 18 are activated by the ON and OFF states of a power switch (not shown) of the copying machine. The operation of the device according to the present invention will be explained below.

For example, when it is desired to obtain copy paper with high brightness, the knob 4 is moved counterclockwise in FIG. 1 and the adjustment lever 1 is rotated to the bright position L, as described above. Due to this rotation of the adjustment lever, the first projecting pin 7a of the first return lever 7 is pressed by one side surface 1a of the adjustment lever 1, and the first return lever 7 resists the force of the spring 9. and rotated around the screw 3 in the counterclockwise direction in FIG. The second return lever 8 remains stationary (Fig. 3). When the power switch of the copying machine is turned on in this state, the solenoid 1
8 is biased, the roller 17 of the release lever 15 engages with the second recess 12, and the adjustment lever 1 is locked at the bright position L, as shown in FIG. Copying work can continue, but the third
The locked state of the adjustment lever 1 shown in the figure is maintained until the power switch is turned off. That is, even when repeat copying is performed, unless the power switch is turned off after the last repeat copying operation is completed, the adjustment lever 1 remains in the third position.
The state shown in the figure is maintained, so the operator can copy the next document as is without having to adjust the exposure again. For example, the operator turns off the power supply after copying all originals.
When it is FF, the power to the solenoid 18 is cut off, so the release lever 15 is rotated counterclockwise by the force of the spring 16 as shown by the chain line in FIG. 3, and the roller 17 is disengaged from the second recess 12. do. Therefore, the first return lever 7 is pulled by the spring 9 in the direction of the stationary second return lever 8, comes into contact with the stopper pin 10, and stops. At this time,
The first protruding pin 7a of the first return lever 7 is the adjustment lever 1
1, the adjustment lever 1 automatically returns to the position shown in FIG. The person who will use the copying machine next turns the adjustment lever 1 to the desired position. When copying with the adjustment lever in the intermediate position N,
7 engages with the first recess 11, and when the adjustment lever is rotated to the dark position D to copy, the same operation as described above is performed.
Naturally, the roller 17 engages with the third recess 13,
It is easily understood that the operating state in which the adjustment lever 1 returns from the dark position D to the intermediate position N is performed in the same manner as in the above case. It goes without saying that the number of recesses in the adjustment lever 1 is not limited to three, and that two or four or more recesses can be provided to reduce or increase the number of image density stages on the copy paper.

It is also clear that the present invention can be applied to other types of exposure adjustment apparatuses than the type shown. As described above, according to the present invention, conventional drawbacks can be eliminated with a relatively simple configuration.

[Brief Description of the Drawings] Fig. 1 is a perspective view of the exposure adjustment lever return device according to the present invention, with some parts omitted, Fig. 2 is an exploded perspective view of the device, and Fig. 3 is a perspective view of the exposure adjustment lever return device according to the present invention. FIG. 3 is a front view of the return device when the adjustment lever is rotated to the bright position. DESCRIPTION OF SYMBOLS 1... Exposure adjustment lever, 2... Fixed plate, 3... Shaft, 7, 7a, 8, 8a, 9, 10... Returning means, 15
...Release lever, 18...Driving means, N...Intermediate position, L...Bright position, D...Dark position.

Claims (1)

[Claims] 1. In a copying machine that has an exposure adjustment lever that is rotatably supported on a fixed plate and that can change the exposure amount to a desired amount by swinging the lever, the exposure adjustment lever is moved approximately halfway in the swing width. a return means that operates to return the lever to the desired position; a release lever that is engageable with the exposure adjustment lever to lock the exposure adjustment lever at a desired brightness/dark position; and a release lever that is activated when the copying machine is powered on. and a driving means for driving the release lever to engage with the exposure adjustment lever, and the return means is rotatably supported on a shaft supporting the exposure adjustment lever, and is rotated separately by swinging of the exposure adjustment lever. a first return lever and a second return lever to be moved; a spring that provides a rotational habit of the first return lever and the second return lever in a direction toward each other; and a spring located between the two return levers. a stopper pin that is fixed to the fixed plate and that both return levers come into contact with when the exposure adjustment lever returns to the intermediate position;
The exposure adjustment lever automatic return in the copying machine is characterized in that when the power is turned off, the release lever releases the lock of the exposure adjustment lever, and both return levers come into contact with a stopper pin by the action of the spring. Device.