JPS59165074A - Copying machine - Google Patents

Abstract

PURPOSE:To correct the error of magnification in each machine and to reduce the deviation of real magnification by changing a constant for setting vertical magnification and scanning speed setting data to correct the magnificaion. CONSTITUTION:The titled machine is constituted of a photosensitive drum 1, an encoder 2, a main motor 3, a frequency converter 4, a comparator part 5, a servo control circuit 8, an amplifier 9, original scanning systems, and a motor, etc. The vertical magnification (m) of the original scanning carriage 11 is m= K/FD. Provided that K is a constant. When the setting difference between the K and scanning speed setting data FD is small, (m) can be corrected proportionally to the K. If the K is reduced by 5% when real magnification ma is larger than the proposed magnification (m) by 5% [(ma-m)mX100%] in case of determining the K from a design norminal and determining the FD to be used as (m), ma=m is formed. If the K determined by (m) and FD is changed less than the ratio of the real magnification ma to (m), the error of magnification can be corrected in each machine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying machine having a function of correcting the magnification in the scanning direction, that is, the vertical magnification.

Normally, in a copying machine, there is a relationship between the surface speed of the sensitive material Vl, the document scanning speed V8, and the vertical magnification m.

By the way, in conventional document scanning drives, the photosensitive material driving motor is used as the power source, and the document scanning system is also driven by mechanical parts such as gears and boosters. , its vertical magnification m is the above (1
), it was necessary to improve the accuracy of these mechanical power transmission parts, and it was also necessary to take into account the overall variation in the finished copying machine. Therefore, in a copying machine having such a structure,
Regarding the vertical magnification m determined by the sensitive material surface speed Vp7nk and the original scanning speed V8, the set magnification m may be changed due to variations in the mechanical system, etc.
The error is large, and due to deviations in the actual magnification.
The problem is that it has a big impact on image quality.

The present invention has been made in view of the above points, and an object of the present invention is to provide a copying machine that uses a servo function to drive document scanning to reduce magnification errors.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

The figure shows an embodiment of the present invention, in which +11 is a drum-shaped photoreceptor, (2) is a drum encoder, (8) is a main motor that drives the photoreceptor (1), and the photoreceptor (1) is It is driven by a main motor (8) at a drum speed VP/R, and an output at a frequency f+) is taken out from a drum encoder (3). The output frequency fD of this drum encoder (3) is proportional to the above-mentioned drum speed VP/R, and between the two, VP/R f l)°" -
(There is a relationship of 21.

(4) is a frequency converter, which converts the Drano encoder (
The output of step 3) is converted into a signal having a new frequency fxp as shown by the following equation (8), and this is supplied to the comparator section (5) of the servo system.

fHHp = KI X FD X fo
”...(3) (However, K1 is a constant) In the servo system, a carriage motor (6) separate from the main motor (1) is driven so as to scan the document at a speed proportional to the frequency fltgp. That is, the signal of frequency fREF from the frequency converter is applied to the comparator (5), and the output from the carriage encoder (7) provided on the carriage motor (6) is also applied, and the comparison output is is supplied to the servo control circuit (8), and the output of the water control circuit (8) is supplied to the power amplifier (9).
The signal is amplified to drive the carry motor (6). This carriage motor (6) operates a carriage encoder (7) and also drives a document scanning carriage 0] at a scanning speed v8 via a capstan pulley αQ. Therefore, this scanning speed (18) is proportional to the frequency fREP, and there is a relationship as shown in the following equation.

V, cx: f, agp --
(4) According to the above configuration, the above (11 and (2)),
From equations (3) and (4), the vertical magnification m is (however, K2, K3, and K4 are constants), and if we add 4 to the constant in equation (5) as K, m=1... ...(6) It can be expressed as D.

Here, if the setting errors of the constant K and the scanning speed setting data FD are sufficiently small, the vertical magnification m can be corrected in proportion to the constant K.

For example, when K is determined from the anatomical nominal and the FD value for the magnification setting m is determined, the actual magnification ma is 5% (-!!!!!!!!
Assuming that it is large, if K is reduced by 5%, mα=m can be obtained. That is, by changing the value (initial nominal value) determined by the magnification nI and FD value to be less than or equal to the ratio of the actual magnification mα to m, it is possible to correct the magnification error for each machine.

As described above, in the present invention, the magnification can be corrected by changing the constant K, which is the relationship between the longitudinal magnification m to be set and the scanning speed setting data FD, so that magnification errors can be easily corrected on each machine side. Furthermore, since deviations in actual magnification can be reduced, image quality can be improved.

[Brief explanation of drawings]

The figure is a configuration diagram showing an embodiment of the present invention. (4) Frequency converter (6) Carriage motor (8) Servo control circuit

Claims (1)

[Claims] A motor for driving a document, which is provided separately from a motor for driving a sensitive material,
A servo system that controls this document drive motor and a signal with a frequency proportional to the surface speed of the sensitive material obtained when driving the winning drive motor are frequency-converted in accordance with the scanning speed setting data FD. and a frequency conversion means for supplying the frequency converting means, so as to correct the vertical magnification m by changing the design nominal value K determined by the set vertical magnification m and the above-mentioned FD value to a ratio below the ratio of the actual vertical magnification mα to the above-mentioned m. A copying machine characterized by the following.