JPS6146944A - Lens moving device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To reduce a cost price of a device by installing a plate having a pattern for showing the reduction and magnification in accordance with a less in parallel to a lens optical axis, driving a lens base by a DC motor, detecting it by a sensor fixed to the base, and releasing the driving at the time of an equal value to the set reduction and magnification. CONSTITUTION:A lens 1 and a sensor 3 are fixed to a base 1A and fed with a screw by a DC motor 5. A frame 6 exists in a copying machine and a stop position setting plate 4 is fixed so as to be opposed to the sensor 3, in parallel to the moving direction of the lens 1. Bar codes 4A-4C are formed on the plate 4 in accordance with the lens 1. The reduction and magnification set in advance are compared with a reduction and magnification code 4 of the present position detected by the sensor 3, the motor is energized in the direction of the same value, and at the time of the same value, the energizing is released, and the position is fixed to the prescribed reduction and magnification. According to this constitution, a lens moving device for an electrophotography which is suitable for setting the reduction and magnification is obtained by using the DC motor without using an expensive pulse motor.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a lens moving device for an electrophotographic copying machine. The present invention relates to a lens moving device for a photocopying machine.

(Prior Art) As is well known, an electrophotographic copying machine having an enlargement/reduction function has a condenser lens (hereinafter simply referred to as a lens) for forming an image of an exposed document surface onto a photoreceptor. A lens moving device is required to move the lens along its optical axis.

Conventional lens moving devices use a pulse motor as a lens drive source. That is, in the conventional lens moving device, the number of pulses corresponding to a set magnification is input to the pulse motor, and the drive shaft of the pulse motor is rotated from a preset reference point according to the number of pulses. By rotating the lens by an angle, the lens can be moved to a desired predetermined position.

The lens moving device uses a pulse motor as the lens drive source.
Because the control system is simple and highly accurate, it has been widely put into practical use.

(Problems to be Solved by the Invention) The above-mentioned conventional technology had the following problems.

That is, since the pulse motor is very expensive, the manufacturing cost of the electrophotographic copying machine also increases.

As mentioned above, the control system of a lens moving device using a pulse motor can be easily constructed, so the manufacturing cost of the control system is low. However, the price of the pulse motor is very high, so it is The overall production cost is also high.

1. The present invention has been made to solve the above-mentioned problems.

(Means and operations for solving the problems) In order to solve the above problems, the present invention uses a DC motor as a lens moving motor, and provides a DC motor that is arranged parallel to the optical axis of the lens and a stop position setting plate having a bit pattern representing each magnification formed at a position corresponding to a position where the lens is arranged to obtain a magnification; and a stop position setting plate arranged to face the stop position setting plate; A sensor detects a pit pattern and determines whether a set magnification factor is larger than a magnification factor corresponding to the current position of the lens, and if it is larger, the lens moves in a direction in which the magnification factor increases. a first comparator circuit that energizes the motor drive circuit so that the lens moves in a direction in which the magnification decreases if the magnification is small; a second comparison circuit that determines whether or not the reduction ratio is equal to the set reduction ratio, and releases the energization of the motor drive circuit if the reduction ratio is equal to the set reduction ratio; A feature of the present invention is that the means for fixing one of the lenses to a lens stand for fixing the lens is provided in a pot, thereby making it possible to manufacture the lens moving device of the electrophotographic copying machine at a low cost. .

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall configuration diagram for clearly showing the development of an embodiment of the present invention.

In the figure, the lens 1 can be moved by a motor 5 together with a sensor 3, which will be described below with respect to FIG.

The motor 5 is a general C motor.

The first memory 11 stores a magnification factor (hereinafter referred to as a magnification factor Δ) corresponding to the current position of the lens 1 before the motor 5 is driven - that is, before a new magnification factor is set. The second memory 12 is a memory that stores a new reduction ratio (hereinafter referred to as reduction ratio B) set by the operator of the electrophotographic copying machine.

The reduction ratios A and B stored in the first memory 11 and the second memory 12 are compared in a first comparison circuit 13. As a result of the comparison, if the reduction ratios A and 8 are not equal, the motor drive circuit 15 is energized.

The motor drive circuit 15 rotates the drive shaft of the motor 5 and moves the lens 1 based on the output signal of the first comparison circuit 13 . The output signal determines the direction of movement of the lens 1, in other words, the direction of rotation of the drive shaft of the motor 5, depending on the magnitude relationship of the reduction ratios A and B.

As the lens 1 moves, the sensor 3 also moves. The sensor 3 detects a magnification factor (hereinafter referred to as a magnification factor C) corresponding to the position of the lens 1, and the detection signal is transmitted to the second memory 12 along with the magnification factor B stored in the second memory 12. The signal is input to the comparison circuit 14.

The second comparison circuit 14 compares the reduction ratios C and B, and when they match, outputs a stop signal @E to the motor drive circuit 15 to stop the rotation of the drive shaft of the motor 5.

Through the above operations, the lens 1 is moved to a position corresponding to a predetermined magnification ratio (reduction ratio B), and the electrophotographic copying machine
It becomes possible to copy.

FIG. 2 is a schematic perspective view showing the main parts of the mechanism of an embodiment of the present invention. In the figure, the same symbols as in Figure 1 are
The same or equivalent parts are hailed.

The lens 1 and the sensor 3 are fixed to the lens stand 1A. The lens stand 1A further includes a nut 1B screwed onto a feed screw 5A connected to the drive shaft of the motor 95.

By rotation of the drive shaft of the motor 5, the lens 1 can be moved in the direction of arrow F or G. In addition,
The arrow indicates the original reflected light that passes through the lens 1.

A frame 6 is arranged inside the electrophotographic copying cabinet, and a part of the frame 6 is arranged parallel to the central axis of the feed screw 5A, that is, parallel to the moving direction of the lens 1, and connected to the sensor 3. Stop position setting plates 4 are fixed so as to face each other.

On the stop position setting plate 4, bit patterns 4A to 4G (barcodes) representing each magnification are formed or drawn at positions corresponding to the positions where the lens 1 is placed at each magnification. ing.

In FIG. 2, the bit pattern is 4A.

Although only three, 4B and 4C, are formed, it is a matter of course that they are formed as many times as there are magnifications that can be copied by the electrophotographic copying machine.

The sensor 3 reads the bit patterns 4A to 4C and outputs the signal only when moved to a position facing the bit patterns 4A to 4G.

FIG. 3 is a schematic diagram showing a concrete groove structure of an embodiment of the present invention. In the figures, the same reference numerals as in FIGS. 1 and 2 refer to the same or equivalent parts.

In FIG. 3, the microcomputer 10 includes CPtJl 0A, ROM 10B, . . . as is well known.

RΔM10C and an input/output interface 10D. Further, each of them is connected by a common bus 10E.

The input/output interface 100 includes an illumination light source 2 for illuminating the stop position setting plate 4, and the stop position ili.
! A motor drive circuit 15 that energizes the sensor 3 for reading the bit patterns 4A to 4C formed on the setting plate 4, and the motor 5 for moving the sensor 3 and the lens 1.
, and an operation g19 for setting the reduction ratio.

The first memory 11 and the second memory 1 shown in FIG.
2 is included in the RAM 10C. Also, the first
The comparison circuit 13 and the second comparison circuit 74 are as follows:
Executed in CPLll 0A.

Next, the operation and motor control of one embodiment of the present invention will be explained in more detail with reference to FIG. 4 and FIG.

FIG. 4 is a flowchart for executing motor control in one embodiment of the present invention.

First, when the power switch of the slave photocopier is turned on, it stops! ! The setting plate 4 is illuminated by the illumination light source 2, and the sensor 3 determines the position of the lens 1 - that is, the magnification A
is detected. The reduction ratio A is stored in the first memory 11 in step S1.

Next, the operator of the electrophotographic copying machine
When the reduction ratio (reduction ratio B) is set, the reduction ratio B
is stored in the second memory 12 in step S2.

Subsequently, in step S3, it is determined whether the scaling factor B is larger than the scaling factor A.

If the niJ written reduction ratio B is larger than the reduction ratio A, the motor drive circuit 15 is energized and the drive shaft of the motor 5 rotates in the normal direction in step S4. By normal rotation of the drive shaft of the motor 5, the lens 1 moves in a direction in which the magnification increases.

During the movement, the sensor 3 detects the bit pattern 4A (reduction ratio C) formed on the stop position setting plate 4 in step S5.

In step S6, the reduction ratio C detected in step S5 is compared with the reduction ratio B.

If the scaling factor C is not the same as the scaling factor B, then 17
(Return to step S4, and if they are the same, step S1
1, the energization of the motor drive circuit 15 is released,
The rotation of the drive shaft of the motor 5 stops.

Then, in step 812, the reduction ratio C is stored as the reduction ratio A in the first memory 11, and then,
The program ends.

If the scaling factor B is not larger than the scaling factor A in step S3, it is determined whether the scaling factor B is smaller than the scaling factor A in step S7.

If the scaling factor B is not smaller than the scaling factor A, -
That is, if the reduction ratio B and the reduction ratio A are equal, the program ends.

If the magnification ratio BIfi is smaller than the magnification ratio A, the motor drive circuit 15 is energized and the drive shaft of the motor 5 is reversely rotated in step S8. By reversing the drive shaft of the motor 5, the lens 1 moves in a direction in which the magnification decreases.

In step S9, similarly to step $5,
The sensor 3 detects the pit pattern (magnification C) formed on the stop position setting plate 4, and in step 810, the magnification C is compared to the magnification B in the second comparison circuit 14. compared to

If the reduction ratio C is not the same as the reduction ratio B, the process returns to step S8, and if they are the same, in step S11,
The bias to the motor drive circuit 15 is released, and the rotation of the drive shaft of the motor 5 is stopped.

Then, in step S12, the scaling factor C is stored as a scaling factor A in the first memory 11, and the role
The program ends.

Note that in step 312, before the program ends, the reduction ratio C is stored in the first memory 11 as the reduction ratio A, so step S1 may be omitted when controlling the motor movement next time. I can do it.

Now, as is clear from the above explanation, the present invention includes J3.
In this case, the position of the lens 1 can be reliably and accurately moved according to the set magnification factor using an inexpensive C motor.

In the above description, as shown in FIG. 2, it is assumed that the stop position setting plate 4 is fixed to the frame 6 and the sensor 3 is fixed to the lens stand 1A, but the present invention is not limited to this. A stop position setting plate 4 is fixed to the lens stand 1A,
Of course, the sensor 3 may be fixed to the frame 6.

(Effects of the Invention) As is clear from the above description, according to the present invention, the following effects are achieved.

That is, since a DC motor is used as the lens drive source, the lens moving device can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram for clearly showing the configuration of an embodiment of the present invention, FIG. 2 is a schematic perspective view showing the main parts of the structure of an embodiment of the present invention, and FIG. FIG. 4 is a schematic diagram showing a specific configuration of an embodiment of the invention. FIG. 4 is a flowchart for controlling a motor in an embodiment of the invention. 1... Lens, 1A... Lens stand, 1B... Nut, 2... Light source for illumination, 3... Sensor, 4... Stop position setting plate, 4A to 4C... Bit pattern , 5・
...Motor, 5A...Feed screw, 6...Frame,
9...Operation console, 10...Microcomputer, 1
1... First memory, 12... Second memory, 13
...First comparison circuit, 14...Second comparison circuit, 1
5...Motor drive circuit agent Patent attorney Michito Hiraki and 1 other person 1 Prisoner 2 Figure 6

Claims (2)

[Claims] (1) A lens moving device for an electrophotographic copying machine that moves a lens that forms an image of reflected light from a document surface onto a photoreceptor in the direction of its optical axis according to a set magnification ratio, the lens moving a lens stand to be fixed; a lens movement mechanism for moving the lens stand in the optical axis direction of the lens; a DC motor for driving the lens movement mechanism; a motor drive circuit for energizing the DC motor; a stop position setting plate arranged parallel to the optical axis and having a bit pattern representing each reduction ratio formed at a position corresponding to a position where the lens is arranged so as to obtain each reduction ratio; and the stop position setting plate. A sensor is arranged to face the plate and detects the bit pattern, and the sensor determines whether the set magnification is larger than the magnification corresponding to the current position of the lens, and if it is larger, the magnification is increased. A first comparison in which the motor drive circuit is energized so that the lens moves in a direction where the magnification increases, and when the magnification is small, the motor drive circuit is energized so that the lens moves in a direction where the magnification decreases. and a second comparison circuit that determines whether or not the magnification ratio detected by the sensor is equal to the set magnification ratio, and releases the energization of the motor drive circuit if they are equal. . A lens moving device for an electrophotographic copying machine, wherein either the sensor or the stop position setting plate is fixed to the lens stand. (2) The lens moving mechanism includes a feed screw arranged parallel to the optical axis of the lens and rotated by the DC motor, and screwed into the feed screw and fixed to the lens stand. 2. The lens moving device for an electrophotographic copying machine according to claim 1, wherein the lens moving device is a nut.