JP2574302B2 - Sub-scanning control method using pulse motor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sub-scanning control device using a pulse motor.

2. Description of the Related Art Conventionally, a sub-scanning method applied to an image processing apparatus such as a facsimile machine, that is, a continuous sub-scanning method in which each scanning line is drawn in a time-series regulated manner as a scanning line moving format, a scanning line and a next scanning line. An intermittent sub-scanning format in which the scanning line intervals become irregular in the time series or a continuously variable sub-scanning format intermediate between the two is known (Basics and Applications of the New Edition of the IEICE facsimile P47-P49) ).

Problems to be Solved by the Invention Incidentally, the above-described scanning line moving method has the following problems.

(1) In the case of the intermittent sub-scanning type, if the moving distance is large, the light source cannot move within the specified time, and even if the light source attempts to move within the specified time, the light source abnormally vibrates due to step-out or inertia of the motor. In some cases, normal recording cannot be performed.

(2) In the case of the continuous sub-scanning method or the continuously variable sub-scanning method, if different linear densities are recorded, the inclination of recording will be different, and recording unevenness or omission will occur in a portion where different linear densities are adjacent to each other. Also, it takes a long adjustment time to reduce the vibration of the optical system.

 The above problem occurs for the following reasons.

(1) A pulse motor is used to perform intermittent sub-scanning. However, when the inertia moment of the load increases, the self-starting frequency of the motor decreases, and it becomes difficult to perform start and stop control within the time limit.

(2) When the start and stop operations are performed at high speed, the vibration of the optical system becomes large, and this vibration causes judder and uneven feeding.

(3) In order to reduce the above-mentioned vibrations, it is necessary to make fine adjustments mechanically when engaging the lead screw with the optical system part, attaching the light source unit, and the like.

(4) When the input frequency is varied according to the load of the motor (slow-up, slow-down frequency input) or when scanning at a uniform frequency, recording becomes non-uniform and vibration is reduced, but different linear densities are used. When the recordings are mixed, the scanning width of the scanning line varies depending on the line density, and the inclination of the scanning line changes. Therefore, the recording is overlapped or omitted in the portion where the different line densities are adjacent.

The present invention has been made in view of the above-described problems, and can widen the time limit to increase the moving distance, and can move at high speed without generating large vibration, and even in recording at different linear densities. It is an object of the present invention to provide a sub-scanning control device using a pulse motor capable of performing appropriate printing without causing overlap or omission.

Means for Solving the Problems In order to achieve the above object, the present invention divides one scanning time into a certain blanking time and a certain recording time,
Switching means for switching these two times, selecting means for selecting a linear density condition for recording, and a signal having a cycle corresponding to the linear density condition in the blanking time based on the linear density condition selected by the selecting means. A signal control means for generating and generating a signal having a predetermined period in the recording time, a count value corresponding to the linear density condition being set, and setting a signal having a period according to the linear density condition to the blanking time. And a secondary output counter that outputs a signal until a predetermined count value is set irrespective of the linear density condition and a signal of a predetermined cycle is set during the recording time until the count value is reached. An output counter; and signal combining means for combining outputs from the primary output counter and the secondary output counter.

Operation The present invention relaxes the time limit of the input frequency to the drive circuit of the pulse motor by the above-described configuration, enables a smooth self-start of the pulse motor, and reduces the vibration for continuously inputting, and In performing printing, any input can be made in accordance with the inclination of the scanning line, and intermittent sub-scanning can be performed in portions where different linear densities are adjacent without causing printing unevenness or omission.

FIG. 1 is a block diagram showing a sub-scanning control circuit of a sub-scanning control device using a pulse motor according to an embodiment of the present invention.

In FIG. 1, a, b, and c are linear density signals (ALPI, BLPI, and CLPI) having different values set in advance, d is an operation start timing signal (phase signal) output for each line, “e” is a pulse signal finally calculated by the present circuit and output to the drive circuit (motor driver) of the pulse motor.

1 is a crystal (Xtal) as a signal source, 2 is a signal line
A signal generating circuit for dividing the frequency from the crystal 1 connected through the line 12 and generating a signal (clock) of a fundamental frequency, and receives any one of the line density signals a, b and c or a switching signal from the counter control circuit 5. A signal cycle counting circuit 4 counts the fundamental frequency and outputs a signal 34. A signal control circuit 4 sends a signal 46 having a cycle corresponding to the signal 34 to the primary output counter 6 and the secondary output counter 7.

The counter control circuit 5 takes in the output signals 68 and 78 of the primary output counter 6 and the secondary output counter 7, respectively, and outputs a plurality of linear density signals (in this embodiment, linear density signals a, b and c). In advance, a blanking time T1 or a recording signal T2 described later is detected, and a switching signal is output to the signal cycle counting circuit 3, the signal control circuit 4, the primary output counter 6, and the secondary output counter 7 by this detection. That is, the blanking time T1 and the recording time T2 in one scanning time.
It operates as a means for switching between.

Reference numeral 8 denotes a signal synthesizing circuit. The signal synthesizing circuit 8 includes output signals 68, 78 of the primary output counter 6 and the secondary output counter 7.
To generate a pulse signal e.

Here, a count value is set in the primary output counter 6 in accordance with the linear density signal, and the signal 46 having a cycle corresponding to the linear density signal is counted in the blanking time T1. Then, the output signal 68 from the primary output counter 6 is repeatedly output until the count value set in the primary output counter 6 is reached.

Further, a predetermined count value is set in the secondary output counter 7 irrespective of the linear density condition, and the signal 46 of a predetermined cycle is counted in the recording time T2. The output signal 78 from the secondary output counter 7 is repeatedly output until the count value set in the secondary output counter 7 is reached.

The operation of the sub-scanning control circuit configured as described above will be described below by taking as an example a case where three different types of line density signals a, b, and c are applied. FIG. 2 used in the description of the operation shows the moving distance and time of the optical system that performs the sub-scanning by driving the pulse motor. In FIG. 2, T1 is a blanking time, T2 is a recording time, and T1 and T2 are set to be constant times in any of the three types of linear density signals. Switching between blanking and recording is performed.
A ', B', and C 'indicate recording scan widths based on the linear densities A, B, and C, respectively. ΔA′1 is the movement amount within the blanking time T1 at the linear density A, ΔA′2 is the movement amount within the recording time T2 at the linear density A, and ΔB′1 is the movement within the blanking time T1 at the linear density B. ΔB′2 is the amount of movement within the recording time T2 at the linear density B, ΔC′1 is the amount of movement during the blanking time T1 at the linear density C, and ΔC′2 is the amount of movement within the recording time T2 at the linear density C Is shown.

In this case, first, before recording, the line density signal
a, b, c are taken into the counter control circuit 5, the primary output counter 6, and the secondary output counter 7. The counter control circuit 5 firstly outputs a signal having the smallest linear density among the three linear density signals a, b, and c (the linear density signal c corresponds to this signal in this embodiment, and hereinafter, this linear density signal When the signal c is taken as an example), the recording signal T2, the moving amount ΔC'2, and the number of pulses in the linear density signal c are calculated, and the inclination γ of the scanning line is calculated as shown in FIG. Calculate. Then, the counter control circuit 5 sets the inclinations α and β of the scanning lines in the recording signals T2 in the line density signals a and b, respectively, so that the inclinations α and β are equal to the inclination γ. With this setting, the movement amounts ΔA′2, Δ during the recording time T2 of the linear density signals a, b respectively.
B'2 and the number of pulses are also calculated to be equivalent to the movement amount ΔC'2 and the number of pulses.

The blanking time T1 of each of the linear density signals a and b
, And the movement amounts Δ′1 and ΔB′1 are calculated,
The number of pulses required for the movement amounts ΔA′1 and ΔB′1 is calculated in advance. Since the blanking time T1 and the recording time T2 are constant and the respective slopes are calculated, it is needless to say that the blanking time T1 and the recording time T2 are respectively inversely calculated by counting the number of pulses.

After preparing various data, the pulse signal e is output to the drive circuit of the pulse motor and recording is performed as follows.

First, the phase signal d is output, and the operations of the signal generation circuit 2 and the signal cycle counting circuit 3 start.

First, the signal cycle counting circuit 3 counts the clock (basic frequency) from the signal generating circuit 2 in response to the linear density condition from the count control circuit 5, and outputs a signal having a signal 34 having a cycle corresponding to the linear density condition. The signal control circuit 4 passes the signal passed from the signal cycle counting circuit 3 to the primary output count 6 and the secondary output counter 7. The primary output counter 6 counts the signal 46 according to the signal from the counter control circuit 5. At this time, the secondary output counter does not operate and the primary output counter 6
The output 68 of the counter control circuit 5 and the signal synthesis circuit 8
Is input to The counter control circuit 5 detects the blanking time T1 based on the signal 68 and the linear density signal, and outputs a signal cycle count circuit 3, a signal control circuit 4, a primary output counter 6
Then, the setting change is notified to the secondary output counter 7.

Subsequently, the signal cycle counting circuit 3 outputs a signal 34 having a frequency required for the recording time T2, and the secondary output counter 7 outputs the signal 34.
46 is counted and this count value is
And output to the signal synthesis circuit 8. Counter control circuit 5
Detects the recording time T2 based on the signal 78 and the linear density signal, and detects the signal period count circuit 3, the signal control circuits 4 and 2
The next counter 7 is notified, and the output signal 78 is stopped. Then, the signal synthesizing circuit 8 synthesizes the output signals 68 and 78 of the primary output counter 6 and the secondary output counter 7 to generate a pulse signal e, and outputs this to the drive circuit of the pulse motor.

For example, when the linear density signal a is set, the number of pulses corresponding to the moving amount ΔA′1 as the pulse signal e in the blanking time T1 and the moving amount ΔA′2 as the pulse signal e in the recording time T2. A corresponding number of pulses are sent to secure a recording scanning line width (the same as the moving amount) A 'of the line density a. Similarly, when the linear density signal b is set,
The number of pulses corresponding to the movement amount ΔB′1 as the pulse signal e in the blanking time T1 and the number of pulses corresponding to the movement amount ΔB′2 as the pulse signal e in the recording time T2 are transmitted. Is secured. The case where the line density signal c is set is the same as the case where the line density signals a and b are set. At this time,
As described above, ΔA′2 = ΔB′2 = ΔC′2.

In this embodiment, ΔC′1 = 0, but as ΔC′1 increases, ΔC′2 decreases and the overall inclination (the inclination of the scanning line in the recording signal T2) decreases.

In this way, even if the linear density differs, first the recording time T2
Since the moving amount of the blanking time T1 for each line density is calculated by making the inclination of the scanning line the same and the moving amount of the blanking time T1 is calculated, and the pulses corresponding to both are continuously supplied to the drive circuit as a pulse signal, The frequency to be supplied to the drive circuit can be relaxed, smooth self-starting can be obtained, and continuous input is applied, so that vibrations are suppressed to a small extent, and any input can be made according to the inclination of the scanning line, so recording Intermittent sub-scanning can be performed without causing unevenness or omission.

In this embodiment, the blanking time T1 for each linear density is set by hardware as shown in FIG.
The drive pulse for the pulse motor is generated by calculating the recording time T2, and the drive pulse for each linear density is generated during the blanking time T1 by using software using a microcomputer and memory for presetting. It is also possible to realize by generating.

As is clear from the above description, as in the present invention, the present invention divides the time given for one scan into a blanking time and a printing time, and determines the amount of movement to the printing time by a scanning line. And the calculated number of pulses is output to the drive circuit of the pulse motor, so that the time limit of the input frequency to the drive circuit of the pulse motor is relaxed, and the motor can be started smoothly and self-starting. In addition, the vibration is reduced because the input is applied to the scanning line, and any input can be performed in accordance with the inclination of the scanning line during recording. This has the effect of enabling scanning.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a sub-scanning control circuit of a sub-scanning control device using a pulse motor according to one embodiment of the present invention, and FIG. It is a schematic diagram which shows time. 1 ... Xtf1, 2 ... Signal generation circuit, 3 ... Signal cycle counting circuit, 4 ... Signal control circuit, 5 ... Counter control circuit, 6 ... Primary output counter, 7 ... Secondary output counter, 8. Signal synthesis circuit.

Claims (1)

(57) [Claims] 1. A scanning unit which divides one scanning time into a fixed blanking time and a fixed recording time, switches between these two times, a selecting means for selecting a recording linear density condition, and a selecting means for selecting the linear density condition. A signal control unit that generates a signal having a cycle corresponding to the linear density condition during the blanking time and generates a signal having a predetermined cycle during the recording time, based on the linear density condition. A primary output counter that outputs a signal having a cycle corresponding to the linear density condition during the blanking time until the set count value is reached, and a predetermined count value regardless of the linear density condition. Is set, and a secondary output counter that outputs a signal of a predetermined cycle during the recording time until the set count value is reached, the primary output counter and the secondary output counter.
A sub-scanning control device using a pulse motor, comprising: signal synthesizing means for synthesizing an output from a next output counter.