JPH0748790B2 - Speed control system for fascinator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile apparatus, and more particularly, in a continuously variable sub-scanning method in which the sub-scanning speed continuously changes in the case of a stationary original facsimile machine or the like. The present invention relates to a scanning speed control method.

2. Description of the Related Art Generally, a manuscript 6 is placed on a manuscript table 4 as shown in FIG. 1, and the optical table 1 equipped with the image pickup device 3 moves over the manuscript table 4 or the manuscript table 4 moves. The sub-scanning method in the document stationary type facsimile transmitter for reading the document 6 is to prevent unevenness in image quality due to vibration of the optical table or the document table in response to rapid speed changes such as start and stop. A continuous variable sub-scanning method in which the speed changes continuously is often adopted.

Conventionally, a control block configuration as shown in FIG. 2 has been adopted for the continuously variable sub-scanning control.

When the optical table 1 equipped with the image pickup device 3 reads the document 6 shown in FIG. 2 while moving by the sub-scan feed motor 12, the image signal data of the document read by the image pickup device 3 is the image signal. The data is compressed by the data compression unit 7 and stored in the line buffer memory unit 8.

The image signal data stored in the line buffer memory unit 8 is
Although the image signal data is output from the line transmission unit 9, but the image signal data is input from the image signal data compression unit 7 one after another, the image signal data stored in the line buffer memory unit 8 is repeatedly increased and decreased. The speed control unit 10 monitors the memory amount of the line buffer memory unit 8 and outputs a speed down command to the speed switching unit 11 when the memory amount increases,
When the memory amount becomes small, a speed-up command is output to the speed switching unit 11 so that the memory amount is controlled to be constant and the memory amount and the speed are well balanced.

Problems to be Solved by the Invention In the continuously variable sub-scan as described above, conventionally, the control as shown in FIG. 4 (A) was performed. That is, the speed control in the memory amount shown in FIG. 4 (A) is set as the speed-up region when the memory amount is smaller than the memory amount a and as the speed-down region when the memory amount is larger than the memory amount a.

However, in this case, depending on the type of the original, there may occur a case where the speed up b changes rapidly with respect to the memory amount a as shown in FIG. 4 (B).
In such a case, the speed does not change between the highest speed and the lowest speed as shown in FIG. 3 (C),
The speed will change rapidly with repeated ups and downs at the midway speed. Therefore, there is a drawback in that the image quality of the optical table 1 is affected because the optical table 1 changes speed rapidly.

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 novel speed control system for a facsimile machine capable of eliminating the above-mentioned drawbacks inherent in the conventional technology. To provide.

Means for Solving the Problems In order to achieve the above object, a speed control system of a facsimile machine according to the present invention is a continuously variable sub-scanning system in a document stationary type facsimile machine, in which a speed is controlled by a buffer memory amount for line transmission. It is a method of controlling, and when speeding down from the maximum speed,
It is configured to control the speed by monitoring the amount of memory in the above buffer memory until it reaches the minimum speed, or when the speed is always increased from the minimum speed to the maximum speed. By surely turning up and down, you can obtain stable image quality without a rapid speed change.

Embodiment Next, the present invention will be specifically described with reference to FIGS. 2 and 3 as a preferred embodiment thereof.

The control block of the continuously variable sub-scan control according to the present invention is the second control block.
The same as shown in the figure. Second point of the present invention
This is a control system of the speed control unit 10 for controlling the speed by monitoring the buffer memory amount of the line buffer memory 8 in the figure. FIG. 3 is an explanatory diagram related to the control of the present invention. According to the present invention, as shown in FIG. 3 (A), monitoring memory amount points of buffer memory amount are provided at points a and b in FIG. 3 (A), and when the memory amount is larger than b, the speed is increased. The speed controller 10 performs control so that it is a down area, a speed change inhibition area when the memory amount is between b and a, and a speed up area when the memory amount is less than a.

In addition, the line buffer memory unit 8 is sufficient to store the maximum amount of data generated during the time from the maximum speed to the minimum speed of the intermediate memory amount between b and a and from the minimum speed to the maximum speed. Set the amount of memory.

When set as above, speed-up starts from the speed-up area as shown by c in FIG. 3 (B), and speed-up is continued until the buffer memory amount exceeds b. When the buffer memory amount exceeds b, the speed is increased. Is fast enough. Also, as shown by d in FIG. 3 (B), the speed starts to slow down from the speed down area and continues to slow down until the buffer memory amount exceeds a. At the time when the buffer memory amount exceeds a, the speed is sufficiently the minimum speed. ing.

As described above, according to the present invention, by controlling the sub-scanning speed of the continuously variable sub-scanning as described above, the speed is the maximum speed as shown in FIG. 4 (C). Since it reciprocates between the minimum speeds, it is possible to obtain continuously variable sub-scanning speed control that does not cause a rapid speed change as in the past. As a result, since a rapid speed change does not occur, a good image in image quality can be obtained, and it is possible to provide a speed control system of a facsimile device which is sufficiently improved as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of a stationary document type facsimile transmitter to which the present invention is applied, and FIG. 2 is a control block configuration diagram of continuously variable sub-scanning control to which the present invention is applied, and FIG. 3 (A). (C) is an explanatory view of the speed control system according to the present invention, and FIGS. 4 (A) to (C) are explanatory views of the conventional speed control system. 1 ... Optical table, 2 ... Optical table moving direction, 3 ... Imaging element, 4 ... Original table, 5 ... Original table moving direction, 6 ...
Manuscript, 7 ... Image signal data compression unit, 8 ... Line buffer memory unit, 9 ... Line transmission unit, 10 ... Speed control unit,
11 …… Speed switching unit, 12 …… Sub-scan feed motor

Claims (2)

[Claims] 1. A continuously variable sub-scan in a stationary document type facsimile transmitter in which a document is placed on a document table and an optical table having an image pickup device is moved over the document table or the document table is moved to read a document. In the method, the speed is controlled by the buffer memory amount for line transmission, and when the speed is increased when the buffer memory amount is smaller than the first memory amount, the sub-scanning speed is changed from the minimum speed to the buffer memory. When the amount reaches the maximum speed at which the second memory amount is reached, or when the buffer memory amount is slower than the second memory amount, the sub-scanning speed is changed from the maximum speed to the first Speed is controlled by monitoring the amount of memory in the buffer memory until it reaches the minimum speed that is the amount of memory. Speed control system of the facsimile apparatus which is characterized in that. 2. An intermediate memory amount between the first memory amount and the second memory amount in the buffer memory unit for storing the buffer memory amount for the line transmission is from the maximum speed to the minimum speed, and is the minimum speed. The speed of the facsimile apparatus according to claim (1), further comprising setting a memory amount sufficient to store a maximum amount of data generated during the time from speed to maximum speed. control method.