JPS6386958A - Reader/recorder for picture information - Google Patents

Abstract

PURPOSE:To execute stable reading and recording with higher accuracy by setting a timing of reading and recording of picture information, based on a stop time point as a reference. CONSTITUTION:In case of recording one line in the course of rotation of one step of a pulse motor 6, it is executed so that the last pulse of a picture signal pulse 5 is inputted immediately before a stop, and also, by setting an input time of the picture signal pulse 5 to a shorter time than a time (M), a recording start time point is set. In this way, recording is executed as avoiding an area where the pulse motor 6 executes a non-linear driving. This control is executed under a suitable control by a CPU 8, by using a program and a fixed data of a ROM 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an image information reading/recording device, and more particularly to a device applicable to a scanner unit/) section or a plotter unit section of a facsimile machine.

BACKGROUND OF THE INVENTION In general, image information reading and recording devices for facsimile machines read and record image information while intermittently feeding a document or recording paper using a pulse motor.

This is because when image signals are transmitted after band compression processing, the encoded information for one line in the main scanning direction differs depending on the amount of information in the document, so there is a difference in the amount of transmission for each line. On the other hand, since the transmission speed is constant, the time required for transmission for each line differs, and as a result, it is necessary to change the feeding speed of the document in the sub-scanning direction depending on the amount of information. By performing such intermittent feeding in the sub-scanning direction, the transmission time is reduced.

By the way, a pulse motor is driven by inputting a step pulse, and its response characteristics, as shown by the dotted line in FIG. Ideally, it would start rotating, rotate a predetermined angle while maintaining that rotational speed, and at that point the speed would drop to zero all at once.

However, the actual response characteristics of a pulse motor are
It becomes as shown by the solid line in the figure.

In other words, due to the influence of inertia of the rotor of the pulse motor,
Even if the l step pulse is applied, uniform rotation does not occur immediately, but the rotational angular velocity increases, and it takes several m S e C until the rotational angular velocity becomes stable. Furthermore, even when the motor stops, there is a tendency that the rotational speed gradually decreases as the motor stops.

Due to these actual response characteristics of a pulse motor, when transitioning from a stopped state to a driven state or from a driven state to a stopped state, the document or recording paper enters a state with a non-linear feed speed, and the feed rate increases. If reading and recording are performed with the speed as the ideal response characteristic, the reading of the - line on the document overlaps with the next line on the scanner unit side of the facsimile machine, which impedes reading accuracy, and the plotter unit side reads Overlaps and gaps occur in the plots, resulting in poor recorded image quality.

Therefore, in consideration of the actual response characteristics of the pulse motor, image signals should be read and recorded in the linear rotational speed region of the pulse motor, that is, Ta in Fig. 5, so as not to use the nonlinear feed speed region of the pulse motor. A means has been devised to match the timing of reading and recording image signals to the time period within the approximate linear region shown (Japanese Patent Application Laid-Open No. 52-155007).
).

When looking at the plotter unit side of a facsimile machine, this means inputs the image signal and recording enable signal to the recording unit via a delay circuit, thereby delaying the step pulse signal to the pulse motor in the sub-scanning direction. The timing with which the recording paper is fed is controlled so that the recording time period falls within the above-mentioned approximate linear region.

However, if the pulse width of the image signal for recording differs, or if the pulse width changes due to temperature control of the thermal plotter, the input time period of the image signal will change.
It may happen that the recording falls into a non-linear feed region outside the approximate linear region, or that recording is performed while the pulse motor is stopped.

Therefore, there is a drawback that it cannot be guaranteed that proper recording will always be performed using the approximate straight line area.

- The present invention has been made in view of the drawbacks of the prior art, and the response wait for the step pulse in the above-mentioned actual pulse motor is that the rotational speed of the motor increases as the transition from the stopped state to the driving state increases. We focused on the fact that the change is not non-linear and is in a surprisingly linear region, and that the stopping point is very stable, and we set the timing for reading and recording image information based on that stopping point. It was created with the aim of providing a device that can perform more accurate and stable reading and recording.

Configuration The configuration of the present invention will be described below based on examples.

Figure 1 is a mechanical diagram and an electric circuit diagram of a plotter unit in a facsimile machine.

1 is a thermal head, 2 is a platen roller, 3 is a recording paper, and 12 is a thermal head. 12 is a recording paper 3 that passes through the outer circumferential surface of the platen roller 2 while a constant pressing force is applied by a spring 4 to the recording paper. Record in step 3.

The image signal pulse 5 reproduced as image information based on the received signal is selectively input to each resistor arranged on the recording surface of the thermal head l at a predetermined timing.
Recording will be performed in the main scanning direction, but the recording paper 3
is transferred in the sub-scanning direction by a platen roller 2 driven by a pulse motor 6 that intermittently applies rotational force.

The electric circuit that creates the image signal pulse 5 and the step pulse signal 7 to the pulse motor 6 includes the CPUB, ROM 9,
RAM (image storage memory) 10, and I10 port 1
1, which are connected by a data bus 12, an address bus 13, and a control line 14.

When the received signal 15 is input to this circuit through the I10 port 11, it is processed by the CPU 8 into a predetermined image signal,
It is stored in RAM10.

At the same time, the pulse motor 6 is
A step pulse 7 is outputted, the platen 2 is rotated by the rotation of the pulse motor 6, and the recording paper 3 is fed.

In this case, the image signal stored in RAM10 is
The problem is the timing of outputting the image signal pulse 5 to the thermal RAD 1 through the baud) 11, but this timing and the pulse repetition period of the image signal pulse 5 are set by the CPU 8 using the program and fixed data in the ROMQ.
This is done under the control of

In Figure 2, (L) shows the response characteristics of the pulse motor 6, and (b)
The step pulse 7 that drives the pulse motor 6 to (
C) shows the image signal pulse 5, and the times are made to correspond to each other.

In this embodiment, a case is shown in which one step of the pulse motor 6 feeds the recording paper 3 by one line.

As clarified in the above-mentioned prior art, the actual response characteristics of the pulse motor 6 are that even when the step pulse 7 is input, its rotational angular velocity is slow, and the speed gradually increases until it rotates at a constant angular velocity (region 16). ), the rotational angular velocity is gradually reduced and stopped even when stopping (area 17), but at this stopping, unlike the driving state at the time when step pulse 7 was input, a phenomenon of relatively rapid angular velocity is exhibited. Also, the time (CM) required for one step of rotation is very stable.

Therefore, when one line is recorded during one step of rotation of the pulse motor 6, the final pulse of the image signal pulse 5 is inputted immediately before stopping, and the image signal pulse 5 is
input time is shorter than time (M) (preferably time (
By setting the recording start time as the time (time corresponding to area 16) from M), it becomes possible to perform recording while avoiding area 16 where the pulse motor 6 performs nonlinear drive. That is, a means is adopted for setting the recording start time to a time retroactive by the input time of the image signal pulse 5 with reference to the stop time of the pulse motor 6.

However, if such a means is adopted, the image signal pulse 5
It is necessary to always control the input time to be shorter than the time CM), but this control can be performed using the program and fixed data in the ROM 9 and under appropriate control by the CPU 8.

Now, as shown in Figure 2(c), divide the l line into N parts,
Suppose that recording is performed using N image signal pulses 5, and image signal pulse 5
Each preset pulse repetition period of T
A control flowchart of the image signal pulse 5 in the case indicated by n is shown in steps ① to ＠ in FIG.

First, if the sum of the pulse repetition periods Tn is longer than the time (M) required for one step of rotation, all of the image signal pulses 5 will not be received within the time M, so it is necessary to shorten Tn. In order to change the pulse repetition period to Ts n (=M/N) and output the final pulse of the image signal pulse 5 immediately before the stop time of the pulse motor 6, the recording start time is changed to −Σn=1 Ts n) [Steps ■ to ■].

On the other hand, if the sum of each Tn is less than or equal to time CM),
Since all of the image signal pulses 5 will be input within the time M, the problem is that the final pulse of the image signal pulses 5 is the pulse motor 6.
The only thing to do is to set the recording start time so that the output is output just before the stop time, and the recording start time is set as (M-ΣT n
) It is sufficient to set n=1 [Step [stock] ~ 0]
.

In this way, the pulse width of the image signal stored in the RAM 10 is controlled, and the image signal 4 is output as the image signal 5 at the optimum timing, so that the pulse motor 6 is always within the linear drive range. It becomes possible to perform recording.

11) This embodiment relates to a plotter unit similar to the first embodiment described above, but is concerned with the case where the recording paper 3 is fed by two lines in one step of the pulse motor 6.

FIG. 3(a) shows the response characteristics, and FIG. 3(b) shows the image signal pulse 5, with time correspondence.

In this embodiment, each line is divided into N parts, each is recorded with N image signal pulses 5, and the first line and the second line are divided into N parts.
A non-recording time zone of time (A) is provided between the line and the line.

In this case as well, the pulse repetition period of the image signal pulse 5 and the means for controlling the recording start time are essentially the same as in the first embodiment, with the only difference being the calculation formula.

That is, the sum ΣTm of the pulse repetition periods of the image signal pulses 5 of the first embodiment is equal to the sum 2Σ of the pulse repetition periods of the image signal pulses 5 of the first line and the second line ms+°.
Just changing the sum of Tm and non-recording time A results in m.

Therefore, the control flowchart also has the same configuration as in the first embodiment, as shown in steps [stock] to θ in FIG.

By performing such control, it is possible to always record both lines in the linear drive range of the pulse motor 6.

In addition, as shown in steps ■, ■, and @ in Fig. 4, whether only one line is recorded in one step of the pulse motor 6 or two
It is also possible to have the user automatically select whether or not to record a line.

The above embodiment relates to a plotter unit of a facsimile machine, but the means for controlling the image signal pulse and recording timing for the response characteristics of the pulse motor is as follows.
In principle, it can also be applied to the reading section of a scanner unit.

That is, if the platen for feeding the original is driven by a pulse motor, and the timing for reading the image information by the reading unit is determined based on the same means,
It is possible to prevent redundant reading of different lines and improve reading accuracy.

Class 1 As described above, the present invention does not require the use of special delay circuits as in the prior art, and can be applied even when the pulse width of the image signal is different or when the pulse width fluctuates due to temperature control of the thermal plotter. Moreover, it is possible to always perform recording in the linear feed region of the response characteristic of the pulse motor, thereby making it possible to realize an image information recording apparatus with high recording accuracy.

Further, the present invention can be applied to an image information reading device, and allows highly accurate reading.

[Brief explanation of the drawing]

Figure 1 shows the mechanical diagram and electric circuit diagram of the plotter unit in a facsimile machine, and Figure 2 (a) shows the response characteristics of the pulse motor, with time on the horizontal axis and rotation angle of the pulse motor on the vertical axis. Graphs, Figure 2(b) is a time chart of step pulses, Figure 2(C) is a time chart of image signal pulses, and Figure 3(a) is the response characteristic of a pulse motor similar to Figure 2(a). Figure 3(b) is a time chart of image signal pulses, Figure 4 is a control flowchart of image signal pulses, and Figure 5 shows the response characteristics of the pulse motor similar to Figure 2(a). Figure 2 shows a graph and a time chart of step pulses. 1... Thermal plotter 2... Platen 3...
・Recording paper 4... Spring 5... Image signal pulse 6...
・Pulse motor 7...Step pulse 8...CP
U 9...ROM 10...RAM11...
I10 baud) 12...Data bus 13...Address bus 14...Control line 15...Received image signal

Claims (3)

[Claims] (1) In an image information reading/recording device that uses a pulse motor to feed a document or recording paper step by step, the final signal of the image signal is read or recorded by inputting and outputting it just before the pulse motor stops in one step response operation. An image information reading/recording device characterized by: (2) The image according to claim (1), wherein the pulse repetition period of the image signal is controlled, and the reading or recording start point of the image signal is set after the nonlinear response operation region after the start of driving the pulse motor. Information reading/recording device. (3) Reading and recording of image information according to claim (1) or (2), in which reading or recording of two lines is performed by one step response operation of the pulse motor.
Recording device.