JP2698137B2 - Lens homing control method for copier - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for positioning a moving member, and more particularly to a method of scanning a document by relatively moving a document and an optical system and providing a variable magnification copy function. The present invention relates to a lens homing control method for a copier provided with the camera.

[Conventional technology]

As one of the additional functions of recent copying machines, there is a variable magnification function for obtaining an enlarged or reduced copy having an image size different from the size of the document image.

As means for making the copy magnification variable, there are a means for processing a scanning signal of a document, a means for changing a magnification of an optical system for scanning a document, and the like.

An analog type copying machine is generally configured to change the magnification by changing the position of an optical system, that is, the position of a lens.

Since this type of copying apparatus is well known, no particular reference is given.

[Problems to be solved by the invention]

In the above-mentioned conventional technology, a sensor for detecting a lens position (homing position) of a 1: 1 copy is provided, and a lens position for enlarged copy or reduced copy is set based on the detected position of the lens by this sensor. .

The movement of the lens for zooming is usually performed by mechanical means such as a motor-driven pulley, wire, and the like.
Even if the sensor detects the same-size copy position of the lens, play on the mechanism of the mechanical means, play, wire elongation,
Due to the inertia or the processing time of the CPU that performs signal processing, the response time is delayed and the lens goes too far, resulting in a shift in the actual lens stop position.

The lens position of the enlarged copy or reduced copy is set based on the same-magnification copy position of the lens, and the distance from this reference position to a predetermined magnification copy position is set, for example, as the number of drive pulses to the pulse motor of the lens moving means. It is usual to move the lens.

For this reason, it is difficult to correctly position the lens at the desired enlarged copy position and reduced copy position unless the position accuracy of the same-size copy position of the lens serving as the reference position, that is, the lens homing position, cannot be accurately determined. There's a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens homing control method for a copying machine which solves the above-mentioned problems in the prior art and enables the lens to be accurately positioned at a 1: 1 copy position, that is, a reference position (homing position). Is to do.

[Means for solving the problem]

The object is to detect that the lens has come to the same-size copy position when the lens moves from the enlarged copy position or the reduced copy position at a normal speed in the direction of the same-size copy position serving as a reference for zooming, that is, the lens homing position. After the sensor detects the lens, the lens is slightly moved in the reverse direction, and then moved again at the lower speed than the normal speed in the same direction as the moving direction at the normal speed, so that the sensor is moved. This can be achieved by detecting the lens again and moving the lens to the same-size copy position at normal speed and controlling the lens to move to the homing position.

[Action]

Move the lens at low speed to detect the position of the home sensor corresponding to the 1: 1 copy position of the lens with high accuracy, and accurately determine the lens movement reference to the enlarged copy or reduced copy position. It is possible to accurately set the position and the scaled copy position.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view of a main part of a lens moving mechanism of a copying machine, wherein 1 is a lens carriage, 10 is a lens, 2 is a lens home sensor composed of a photocoupler or the like, and 3 is a light shield that moves together with the lens carriage 1. Reference numeral 4 denotes a lens driving motor, 5 and 50 denote pulleys, 6 denotes a guide rod, 7 denotes a gear for drivingly connecting the lens driving motor and the pulley, and 8 denotes a wire connected to the lens carriage.

In FIG. 1, a lens carriage 1 holds a lens 10 and moves from an enlarged copy position to a reduced copy position beyond an equal-magnification copy position, and stops at a set position for obtaining a copy at a desired magnification. Is controlled as follows.

This movement is guided by a guide rod 6 from a lens drive motor 4 (generally, a pulse motor is used) via a gear 7, a lens carriage moving mechanism composed of a wire 8 stretched between the pulleys 5 and 50. .

A lens home sensor 2 for detecting a lens position (the position of the lens carriage 1) corresponding to the equal-magnification copy position is provided on the main body side of the copying machine, and the lens home sensor 2 is fixed to the lens carriage 1 and fixed to the lens carriage 1. A light-shielding plate 3 that moves together with the carriage 1 is installed so as to block optical coupling of the lens home sensor 2 at the same-magnification copy position.

In such a configuration, when the lens carrier 1 moves from the enlarged copy or reduced copy position to the equal-size copy position and the light-shielding plate 3 reaches the lens home sensor 2, the drive of the lens carriage moving mechanism is stopped. Thus, the lens carriage 1 is positioned at the same-size copy position.

FIG. 2 is a block diagram for explaining the outline of the control means in the present invention, wherein 20 is a CPU, 21 is a ROM, 22 is a RAM, and 23, 24.
Is an I / O port, 25 is an operation unit, 251 is an operation input unit, 252 is an operation display unit, 2 is a lens home sensor, and 4 is a lens drive motor, which is the same as that shown in FIG. is there.

In the figure, a CPU 20 controls a lens drive motor 4 based on a magnification designation operation input from an operation unit 25 and a detection signal state of a lens home sensor 2 to move a lens carriage 1 () to a designated magnification position. (Fig. 1).

The operation display unit 252 displays the magnification setting value and the operation state input from the operation input unit 251.

FIG. 3 is an explanatory diagram of an example of lens homing control according to the present invention, wherein a is a detection signal of the lens home sensor 2, S is a set position of the lens home sensor 2, H is a 1: 1 copy position of the lens, and FIG. 4 conceptually shows the movement path of the lens carriage 1 for zooming.

In the figure, the same-size copy position H and the installation position S of the lens home sensor 2 are set to 14 drive pulses of the lens drive motor, but the present invention is not limited to this.

When the light receiving plate 3 of the lens carriage 1 interrupts the light reception, the lens home sensor 2 goes to the high level "H" as shown in a, and in the light receiving state, outputs the low level "L". Shall be shown.

Hereinafter, the operation of various homing movement modes of the lens carriage 1 will be described.

First, when the lens home sensor 1 moves from the enlarged copy position to the same-size copy position (A), the CPU 20 drives the lens drive motor 4 at a normal rotation speed in accordance with the designation from the operation input unit 251 of the operation unit 25. Let's make a lens carriage 1
At the normal speed to the right of the figure.

When the light-shielding plate 3 installed on the lens carriage 1 reaches the sensor 2, the sensor 2 outputs "H" which is a detection output.
Output level.

Accordingly, the driving of the lens carriage 1 is stopped. Actually, due to the delay of the signal processing, the inertia of the driving mechanism, the play of the driving mechanism, etc.
Is slightly too far from the point of detection of the sensor.

The lens carriage 1 is returned in the reverse direction by a predetermined pulse in response to the detection signal of the sensor 2, and then moved again in the sensor direction, this time at the low speed SL lower than the normal speed in the sensor direction.

Thereby, when the lens carriage 1 is detected by the sensor 2 again, its position is determined accurately.

Then, when the detection at the low speed is performed, from this point, the copy is moved at the normal speed in the direction of the 1: 1 copy position (to the left in the figure).

The drive pulse at this time is set, for example, to 14 pulses from the point at which the sensor 2 stops detecting the lens carriage 1 to the motor 4 as described above, and is set as an excess of the lens carriage 1 due to the above-mentioned reason. After returning by five pulses, the copying operation is stopped at the exact same-size copy position, that is, the home position H.

Next, when the lens carriage 1 is moved from the reduced copy position to the same-size copy position (b), as described above, the lens carriage 1 is first moved at a normal speed until the sensor 2 detects it. When the lens carriage 1 is detected for the first time, the lens carriage 1 is moved in the reverse direction at a low speed SL, and when the sensor 2 detects the lens carriage 1 again, the direction is reversed. Move to double copy position.

In the case of movement within the enlarged copy area (c) and movement within the reduced copy area (d), since the lens carriage 1 is set from the same-size copy position (reference position), the operation input unit 251 A value corresponding to the current position of the lens carriage 1 is calculated with respect to the magnification setting value from, and the motor 4 is driven by the number of pulses of the calculation result to move the lens to a desired magnification position.

Note that when the lens carriage 1 moves in the enlarged copy area or the reduced copy area, the lens carriage 1 goes too far from the set position due to its inertia, play of the drive mechanism as described above, or the like. In the case where the lens carriage is moved in a direction opposite to the moving direction), a predetermined magnification position may be set by a return operation of, for example, five pulses in the same manner as the position adjustment at the same-magnification copy position. Done.

In addition, the number of drive pulses corresponding to the distance between the above-described sensor position and the same-size copy position, and the number of drive pulses for adjusting overshoot of the lens carriage can be changed to adjust the position of the lens carriage. You can do it.

〔The invention's effect〕

As described above, according to the present invention, it is possible to precisely home the lens carriage position to the same-size copy position as a reference for moving and setting the lens carriage to a predetermined enlarged or reduced copy position. It is possible to correctly position the lens at the position of the specified magnification,
A copy without a focus shift can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a main part of a lens moving mechanism of a copying machine, FIG. 2 is a block diagram illustrating an outline of control means in the present invention, and FIG. 3 is an explanatory view of an example of lens homing control according to the present invention. . 1 ... Lens Carriage, 10 ... Lens, 2 ... Home Sensor, 3 ... Light Shielding Plate, 4 ... Lens Drive Motor, 5,
50 ... pulley, 6 ... guide rod, 7 ... gear, 8 ...
…wire.

Claims (1)

(57) [Claims] A lens homing control of a copying machine having a function of obtaining a copy of an image having a magnification different from the image size of the original by changing the position of a lens for scanning the original with respect to the original. In the method, a lens moving means for moving the lens between an enlarged copy area and a reduced copy area across a 1: 1 copy position, a home sensor for detecting a home position of the lens, and a detection signal of the home sensor Control means for positioning the lens at the home position, and when the lens is positioned at the same magnification copy position from the enlarged copy area or the reduced copy area, the home sensor moves in the direction of the home sensor at normal speed. The lens moving means is determined by a first detection signal that has detected that the lens has moved in the first direction. Move in the direction opposite to the first direction only by separation, and when the predetermined distance is reached, move again in the first direction at a low speed lower than the speed in the first direction, and at this low speed A lens homing control method for a copying machine, wherein the lens is controlled so as to be positioned by moving the lens to the same-size copy position at the normal speed by a second detection signal detected by the home sensor.