JPH0611198B2 - Step motor controller for paper sheet transport - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a paper sheet conveying step motor control device that drives a step motor that conveys a paper sheet such as a document or a recording sheet.

[Prior Art] Conventionally, in a recording apparatus such as a facsimile apparatus, an image reading apparatus, or the like, an original document or recording sheet conveying apparatus using a step motor is known. In a thermal recording device or a reading device using a CCD, such as used in a facsimile machine, sub-scanning is performed by transporting a recording paper or a read document in units of one scanning line, and a step motor is used as a driving means for this sub-scanning. To be

As such an apparatus, there is widely known an apparatus configured so that the scanning line density can be changed according to the type of original, the transmission mode, and the like. Generally, the scanning line density used in the recording or reading system of a facsimile machine is (1) 7.7 lines / mm (2) 3.85 lines / mm (3) 6.16 lines / mm (4) 3.08 lines / Mm is well known. The densities of (3) and (4) are densities often used especially when reduction is performed in a reading system. In a facsimile machine using these four types of densities, the recording paper or original document conveyance system must be able to perform conveyance with these four types of conveyance densities.

When attempting to carry out this conveyance by a drive system using the same step motor, it is general that the minimum step amount of the motor via the reduction system is the greatest common divisor of the scanning line densities.

Recently, in order to have multiple communication modes in the same device, a step motor with a small step angle is used.
In many devices, multi-step driving of about 8 to 8 steps is performed to obtain a plurality of scanning line densities by a single mechanism. However, in this method, a step motor having a small step angle is expensive, and since it is driven in multiple steps, noise is large and power consumption is large.

[Purpose] The present invention has been made in view of the above points, and it is possible to easily obtain a plurality of conveyance densities with low power consumption, low noise, and a simple and inexpensive structure. An object of the present invention is to provide a step motor control device for conveying a paper sheet.

[Examples] Hereinafter, the present invention will be described in detail based on examples shown in the drawings. However, in the following embodiments, an operating device which realizes the above-mentioned four scanning line densities in the reading or recording system of the facsimile machine is used as an embodiment.

When the drive system is set so that 7.7 lines / mm, which has the highest density among the above scanning line densities, can be driven in one step, the number of steps for realizing each of the above scanning line densities is It looks like the following table.

Of these, a, c, and d 1, 2, and 2.5 step driving can be performed by 1 and 2 phase excitation as in the prior art, while b 1.25 step driving is conventional 1. It cannot be done with two-phase excitation.

To obtain a scanning line density of 6.16 lines / mm under the above conditions, the intervals between the scanning lines 11 to 18 must be 1.25 steps each, as shown in FIG.
However, since such driving is impossible as described above, in the present invention, as shown in FIG. 2, 1-step driving and 1.5-step driving are alternately repeated to average 1.
The scanning lines 21 to 28 having a pitch of 25 steps are obtained. In this method, an error of ± 0.25 steps is generated for each scanning, and this error is about 0.03 mm in length, and it is possible to obtain sufficient image quality without any perceptual problem.

In order to perform the drive control as described above, the control means as shown in FIG. 3 (A) is used. That is, the control device 31 gives a scanning line synchronization signal and a drive signal to the drive circuit 32, and the drive circuit 32 accordingly generates an excitation signal for exciting each phase of the step motor 33 at a predetermined timing and time width. Output to 33.

More specifically, as shown in FIG. 3 (B), the control device 3
A mode signal is given to 1 via the signal line 34 together with the synchronization signal S. This mode signal commands which step number step motor 33 in the above table is driven. The control device 31 outputs a drive signal C composed of 0.5 step pulses of the step motor 33 to the drive circuit 32 via the signal line 35 in accordance with the mode signal and the synchronization signal. The excitation signal formed by the drive circuit 32 is output to the step motor 33 via the signal line 36.

The control operation of the control device 31 is performed as shown in the flowchart of FIG. In step S1 in FIG. 4, the state of the signal line 34 is read to determine how many steps the step motor 33 should be driven.

Next, in step S2, the input of the synchronization signal S is waited, and when the synchronization signal S is received here, the process proceeds to step S3 and 1
The line feed is performed by the number of steps determined in step S1. If the feed is completed, step S2
Return to and repeat the feeding operation.

Next, with reference to FIGS. 5A to 5D, the drive control according to the mode will be described in more detail among the above controls.
Any number of phases may be used for the step motor 33,
The embodiment shown in FIGS. 5A to 5D shows the control operation when a four-phase stepping motor is used.

FIG. 5 (A) shows a scanning line density of 7.7 lines / mm in a) in the previous table (1 step drive), and FIG. 5 (B) shows 6.16 lines / mm in the previous table b). To obtain the scanning line density of (1.2
(5 step drive), a synchronous signal, a drive signal, and an excitation signal of each phase φ1 to φ4 of the step motor 33 are shown (here, the 2 and 2.5 step drive methods in the previous tables c and d are known. Therefore, detailed description is omitted).

As shown in FIGS. 5 (A) and 5 (B), the drive circuit 32 inputs φ2 phase excitation → φ1 phase demagnetization → φ3 phase demagnetization every time the drive signal C (pulse) is input through the signal line 35. → φ
2-phase demagnetization → φ4 phase demagnetization → φ3 phase demagnetization → φ1 phase φ excitation → 4
It is assumed that the excitation phases are switched in the order of phase demagnetization (which may start from anywhere, but the order shown is shown here).

When it is determined in step S1 in FIG. 4 that stepwise driving is to be performed, the control device 31 inputs a synchronization signal to the drive circuit 2 at a cycle T as shown in FIG. 5 (A). Two drive pulses C for 0.5 steps are given to the signal line 35 each time (steps S2 to S in FIG. 4).
3). As a result, excitation and demagnetization are performed in the above order,
The 1st and 2nd layer excitation is performed step by step in synchronization with the synchronization signal.

On the other hand, when the drive control is performed in 1.25 steps, the control device 31 drives two or three 0.5 steps each time a synchronization signal is input, as shown in FIG. 5 (B). Alternate pulses. As a result, the step motor 33 is alternately stepped by one step and 1.5 steps in the same manner as described above, so that the line feed as shown in FIG. 2 becomes possible.

As described above, the line feed with the scanning line densities of 7.7 lines / mm and 6.16 lines / mm can be performed by repeating the step by step, or by repeating the step by 1 step and 1.5 steps. it can. To obtain a scan line density of 6.16 lines / mm to 3.08 lines / mm, 2 to 2.
In the case of driving by 5 steps at a time, in the same manner as described above, 4 or 5 sync signals are provided for each sync signal by the control device 31.
The individual drive pulses are output, and the step motor 33 is stepped for the step.

In the above embodiment, a predetermined number of drive pulses are output to the drive circuit 32 each time the synchronization signal is received, the feed is completed in the shortest possible period, and the image is read or recorded in the stop period. 5 (C),
As shown in (D), the output of the drive pulse C may be equally spaced within the cycle T of the synchronization signal.

FIGS. 5 (C) and 5 (D) are views corresponding to FIGS. 5 (A) and 5 (B), respectively, and are 7.7 lines / mm and 8.18, respectively.
Synchronous signal and drive signal C to obtain a scanning line density of lines / mm
And the excitation signals of each phase are shown. In the case of FIG. 5 (C), the drive signal C is given to the drive circuit 32 in a cycle of ½ of the cycle of the synchronization signal, and in the case of FIG. 5 (D), the drive signal C is T / T. It is given by alternating repetitions of a period of 2 to T / 3. For other steps, the driving pulse may be similarly given in the cycle of T / 4 and T / 5.

In this way, one step or 1
By repeating step and 1.5 steps, the step motor 33 is driven on average. This embodiment is not limited to a facsimile machine, but is suitable for a reading or recording apparatus that performs reading or recording while feeding a document or recording paper.

In the above, 7.7 and 6.1 that are often used in facsimile machines
Although the scanning line density of 6, 3.85 to 3.008 lines / mm is illustrated, other densities, for example, the scanning line density of 5.78 lines / mm used in a special facsimile machine can be obtained by the above method. it can. In the case of 5.78 lines / mm, one step drive may be performed once and one 1.5 step drive may be performed twice for each synchronization signal.

According to the above embodiments, even a step motor having a relatively large step angle can obtain a plurality of scanning line densities from a large one to a fine one with the same motor, thereby reducing power consumption and noise, and reducing the cost of the apparatus. Can be realized.

[Effect] As is apparent from the above description, according to the present invention, a step motor that conveys a paper sheet such as a document or a recording sheet,
The driving means for driving the step motor in units of a predetermined step angle, and a plurality of driving modes for driving the driving means at different integral multiples of the predetermined step angle per scanning line are used in an arbitrary periodic combination. Since a configuration is adopted in which the driving means is controlled to obtain a predetermined scanning line density as an average value, a large number of conveyance densities can be easily obtained with a simple and inexpensive structure. It is possible to provide a sheet motor conveying step motor control device which is expensive, low in power consumption, and low in noise.

[Brief description of drawings]

1 and 2 are explanatory views for explaining the outline of scanning in the method of the present invention, FIG. 3 (A) is a block diagram showing a schematic configuration of a scanning device according to the method of the present invention, and FIG. 3 (B).
Is a block diagram showing the configuration of the scanning device according to the present invention in more detail, FIG. 4 is a flow chart showing the control procedure in the device of FIG. 3 (B), and FIGS. Timing chart showing driving timing of the step motor in the invention, FIGS. 5 (C) and 5 (D)
FIG. 8 is a flow chart showing a modified example of FIGS. 5 (A) and 5 (B). 31 ... Control device, 32 ... Drive circuit 33 ... Step motor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location B65H 29/00 8709-3F G03G 15/00 107 8530-2H 108 7369-2H H04N 1/00 108 K 7046-5C

Claims (1)

[Claims] 1. A step motor for conveying a paper sheet such as a document or a recording sheet, driving means for driving the step motor in units of a predetermined step angle, and an integral multiple different from the predetermined step angle per scanning line. A paper sheet provided with a control means for controlling the drive means by an arbitrary periodic combination of a plurality of drive modes for respectively driving the drive means and obtaining a predetermined scanning line density as an average value. Conveyor step motor controller.