JPS63262961A - System for controlling speed of facsimile equipment - Google Patents

Abstract

PURPOSE:To obtain stable picture quality, by controlling speed by monitoring the memory quantity of a buffer memory until the speed reaches to the minimum speed when it is decreased from the maximum speed and it reaches to the maximum speed when it is increased from the minimum speed. CONSTITUTION:An original 6 is placed on an original placing table 4, and the original 6 is read by either moving an optical board 1 on which an image pickup element 3 is loaded above the original placing table 4, or moving the original placing table 4. At this time, the speed is controlled by monitoring the memory quantity of the buffer memory 8 until the speed reaches to the minimum speed when the speed is decreased from the maximum speed surely, and it reaches to the maximum speed when it is increased from the minimum speed surely. Since no steep change occurs at speed, it is possible to obtain a picture superior in picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a facsimile machine, and is sometimes used in a continuously variable sub-scanning method in which the sub-scanning speed changes continuously, such as in the case of a stationary original facsimile transmitter. This relates to a scanning speed control method.

2. Description of the Related Art Generally, a document 6 is placed on a document tray as shown in FIG. The sub-scanning method in the original stationary facsimile transmitter starts by reading 6.

In order to prevent unevenness in image quality due to vibrations of the optical table or document table due to rapid speed changes such as stops, a continuously variable sub-scanning method in which the speed changes continuously is often adopted.

Conventionally, continuously variable sub-scanning control has a control block configuration as shown in FIG.

When the optical bench/on which the image sensor 3 is mounted moves and reads the original 6 shown in FIG. The data is compressed by the data compression section 7 and stored in the line buffer memory section j.

The image signal data stored in the line buffer memory section t is 1
Line transmitter? The image signal is output from the primary to the next.
- Since image signal data is inputted from the image compression section 7, the image signal data stored in the one-line buffer memory section j repeatedly increases and decreases. Speed 1tIIJII part 10 is 1
While monitoring the memory amount of the line buffer memory section S, if the memory amount increases, a speed down command is output to the speed switching section 11.

When the amount of memory decreases, a speed-up command is output to the speed switching section // to control the amount of memory to be constant, thereby controlling the amount of memory and speed in a well-balanced manner.

Problems to be Solved by the Invention Regarding the continuously variable sub-scanning as described above, conventionally the control as shown in Figure 1 has been performed.In other words, the speed control in the amount of memory shown in Figure When the amount is less than the memory amount ila, it is used as a speed-up area, and when it is larger than the memory amount a, it is used as a speed-down area.

However, in this case, depending on class 81 of the manuscript,
As shown in the diagram (F3), there is a case where the speed up/down b changes rapidly for the memo IJia. In such a case, as shown in Figure 3 (0), the speed does not change between the highest speed and the lowest speed, but the speed changes rapidly by repeatedly going up and down in the middle. Therefore, since the speed of the optical bench changes rapidly, there is a drawback that image quality, such as uneven feeding, is affected.

The present invention has been made in view of the above-mentioned conventional circumstances, and therefore, an object of the present invention is to provide a new speed control method for facsimile machines that makes it possible to eliminate the above-mentioned drawbacks inherent in the conventional technology. It's about doing.

Means for Solving the Problems In order to achieve the above object, the speed IIIum method of the facsimile apparatus according to the present invention is based on a continuously variable sub-scanning method in a stationary original type facsimile IJ transmitter, which has two buffers for one-line transmission. This method controls the speed by the amount of memory, and when speeding down from the maximum speed, it always returns to the minimum speed, and when increasing the speed from the minimum speed, it always returns to the maximum speed. By monitoring.

Configured to control speed, however.

By always going up and down between the highest and lowest speeds, it is possible to obtain stable image quality without rapid speed changes.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to FIGS. 1 and 3.

The control block for continuously variable sub-scanning control of the present invention is the first
It is the same as shown in the figure. The main point of the invention is the first
Speed 1rIlIK1 section 10 that monitors the buffer memory amount of line buffer memory g in the figure and controls the speed
of? t11 is one type. FIG. 3 is an explanatory diagram relating to the control of the present invention. According to the present invention, FIG.
As shown in A), the monitoring memory raw point of the buffer memory amount is y
In preparation for points a and 5 in Figure a3 (2), if there are more memory hands than b, there is a speed down area, and if memo IJ-&t is between b and a, there is a speed change prohibited area, or if the memory amount is If it is less than a, it is a speedup area,
The speed control unit IO performs control.

In addition, the line buffer memory section t, the amount of memory between b and a stores the maximum amount of data generated during the time from the highest speed to the lowest speed, or from the lowest speed to the highest speed. Set to a sufficient amount of memory.

When the above settings are made, the speedup starts from the speedup area as shown in C in Figure 3, and continues to speed up until the buffer memory amount exceeds b. is at its maximum speed. or.

As shown in d in Figure 2, the speed begins to slow down from the speed down area, and continues to slow down until the buffer memory amount exceeds a, and at the time the buffer memory amount exceeds a, the speed is sufficiently low. .

As described in detail, according to the present invention, the sub-scanning speed of the continuously variable sub-scanning is controlled as described above, so that the speed can be adjusted between the maximum speed and the minimum speed, as shown in Figure 0. I will have to go back and forth between the two.

Continuously variable sub-scanning speed control that does not cause rapid speed changes as in the conventional method can be obtained. Due to this,
Since rapid speed changes do not occur, a good image can be obtained in one image quality, and it is possible to provide a speed control method for a facsimile IJ device that is sufficiently improved compared to the conventional one.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of a stationary original facsimile transmitter to which the present invention is applied, FIG. 1 is a control block configuration diagram of continuously variable sub-scanning TtllJm to which the present invention is applied, and FIG. ~0 is an explanatory diagram of the speed system (2) system according to the present invention, and Figures (8) ~ 0 are conventional speed city IJ m
FIG. 2 is an explanatory diagram of the method.

Claims (1)

[Claims] In the continuously variable sub-scanning method of a stationary type facsimile transmitter, the original is placed on a document stand and an optical table equipped with an image sensor moves above the document stand, or the document stand moves to read the original. This method controls the speed by the amount of buffer memory stored in the buffer memory, and when speeding down from the highest speed, it always reaches the minimum speed, and when speeding up from the lowest speed, it always controls the speed until it reaches the highest speed. A speed control method for facsimile machines that is characterized by controlling the speed by monitoring.