JP3138686B2 - Facsimile signal output device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a facsimile signal output device for transmitting input facsimile image data to another facsimile terminal device or the like.

[0002]

2. Description of the Related Art For conversion of data transmission speed, etc., a facsimile which performs a flow control of temporarily taking encoded facsimile image data into a buffer memory and transmitting the image data from the buffer memory to another facsimile terminal device or the like. In the signal output device, control must be performed so that underflow of the buffer memory does not occur and image data is transmitted with high transmission efficiency.
If an underflow occurs in the buffer memory, the continuity of the facsimile image data sent cannot be maintained,
This is because accurate decoding cannot be performed in a facsimile terminal device on the receiving side or the like. Further, if the efficient control is not performed, there is a disadvantage that the communication time becomes long.

Japanese Patent Application Laid-Open No. 4-156768 discloses that the number of lines stored in a buffer memory is managed, and the number of lines of image data stored in the buffer memory (1 line = 1 main scanning line) decreases. A facsimile signal output device that inserts a fill bit (hereinafter, referred to as FILL) before an EOL code (hereinafter, referred to as EOL) added to each line is disclosed. JP-A-6-62070 also discloses a facsimile that manages the number of lines of image data stored in a buffer memory, divides the buffer memory into a plurality of blocks, variably controls the block length, and controls image data transmission. A signal output device is disclosed.

[0004]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No.
In the method of performing FILL insertion based on the management of the number of lines as disclosed in Japanese Patent No. 56768, the input and output of the buffer memory cannot be synchronized well, and as a result, excessive FILL is inserted. Transmission efficiency may be reduced. Further, in the method disclosed in Japanese Patent Application Laid-Open No. 6-62070, in which the block length of the buffer memory is variably controlled, the control becomes complicated.

SUMMARY OF THE INVENTION The present invention provides a facsimile signal output device capable of maintaining input / output synchronization during input / output control of encoded image data, preventing overflow and underflow, and performing efficient flow control. The purpose is to:

[0006]

SUMMARY OF THE INVENTION A facsimile signal output device according to the present invention uses both the capacity and the number of lines of image data stored in an image data storage unit to input image data to an image data storage unit. An image data management unit for controlling output of image data from the image data storage unit is provided. So
Then, the image data management unit stores the image data in the image data storage unit.
Image data capacity is below the fill insertion capacity threshold
Of the image data stored in the image data storage unit.
If the number of lines falls below the fill insertion line threshold,
Insert FILL into image data output from data storage unit
It is configured to

[0007] After the input of the image data to the image data storage section is started, the image data management section determines whether the capacity of the image data stored in the image data storage section reaches the output capacity threshold or When the number of lines of the image data stored in the image data storage unit reaches the output line number threshold, the output of the image data from the image data storage unit is started. Note that the number of lines of image data stored in the image data storage unit is equal to the number of EOLs in the image data storage unit.

The image data management unit determines whether the capacity of the image data stored in the image data storage unit reaches the input stop capacity threshold value or the number of lines of the image data stored in the image data storage unit is smaller. When the input stop line number threshold is reached, the input of image data to the image data storage unit is stopped. Also, the image data management unit determines that the capacity of the image data stored in the image data storage unit falls below the input stop capacity threshold value and that the number of lines of the image data stored in the image data storage unit stops inputting. When the number of lines falls below the threshold value, input of image data to the image data storage unit is restarted.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a facsimile signal output device according to the present invention. In the figure, a data control unit 1 inputs encoded image data and transfers it to an image data management unit 2. Image data management unit 2
Stores the input image data in the image data storage unit 5. The data capacity detection unit 3 detects the capacity of the image data stored in the image data storage unit 5. Line management unit 4
Manages the number of lines of image data stored in the image data storage unit 5. Then, the image data transmission unit 6 inputs the image data stored in the image data storage unit 5 via the image data management unit 2, and transmits the image data. The transmission destination may be a line or another terminal device. Further, the input source of the encoded image data may be an encoding unit in the facsimile machine, a memory storing the output of the encoding unit, or another terminal device.

Next, the operation will be described with reference to the flowchart of FIG. 2 and the explanatory diagrams of FIGS. When the encoded image data is input to the data control unit 1, the image data management unit 2 starts storing the image data in the image data storage unit 5. The line management unit 4 detects the EOL in the image data stored in the image data storage unit 5 and the image data output from the image data storage unit 5, and detects the EOL in the image data storage unit 5.
Manages the number of lines of image data stored in the. The data capacity detection unit 3 detects the capacity of the image data stored in the image data storage unit 5 and the capacity of the image data output from the image data storage unit 5, and manages the storage capacity of the image data storage unit 5. .

Then, the storage capacity managed by the data capacity detection unit 3 reaches m2, or the line management unit 4
When the number of lines managed by has reached n2 lines, the image data management unit 2 starts outputting image data in the image data storage unit 5 (steps S1, S2, S3). The image data output from the image data storage unit 5 is output from the image data transmission unit 6 to the outside of the facsimile signal output device.

When the storage capacity managed by the data capacity detection unit 3 reaches m1 or the number of lines managed by the line management unit 4 reaches n1 lines, the image data management unit 2 executes data control. It requests the unit 1 to stop inputting image data (steps S4, S5, S6). The data control unit 1 stops inputting image data according to the request.
When the storage capacity is less than m1 and the number of storage lines is less than n1, the image data management unit 2 requests the data control unit 1 to cancel the input stop of the image data (Step S).
4, S5, S7). The data control unit 1 restarts the input of the image data according to the request.

When the storage capacity is less than m2 and the number of storage lines is less than n2, the image data management unit 2 inserts a predetermined number of FILLs before EOL in the image data output from the image data storage unit 5. (Steps S7, S8, S
9). The number of FILLs is predetermined in accordance with the image data output speed and the image data input speed, for example, within a range where the transfer speed of one line does not exceed 5 seconds. When the image data output speed is relatively fast, a larger FILL is inserted, and when the image data output speed is relatively slow, a smaller FILL is inserted. If the storage capacity is m2 or more, or the number of storage lines is n2 or more,
The image data management unit 2 outputs the image data without inserting the FILL (steps S7, S8, S10).

In this embodiment, m1 corresponds to the input stop capacitance threshold value, and n1 corresponds to the input stop line number threshold value. Further, m2 corresponds to the output capacity threshold value and the fill insertion capacity threshold value, and n2 corresponds to the output line number threshold value and the fill insertion line number threshold value.

Here, a specific example will be described with reference to the explanatory diagrams of FIGS. In this example, as shown in FIG.
This is an example of 7 lines, n2 = 3 lines, and m1 = m2 = 10 kbytes. Therefore, when the storage capacity becomes 10 kbytes or more, or the number of storage lines becomes 7 lines or more,
The input of the image data to the image data storage unit 5 is stopped. When the storage capacity becomes 10 kbytes or more, or when the number of storage lines becomes 3 or more, the image data storage unit 5
Output image data. And the storage capacity is 10k
When the number of storage lines is less than 3 bytes and the number of storage lines is less than 3, a predetermined number of FIs are output before EOL of the output image data.
LL is inserted.

FIG. 4 shows an example in which the storage capacity of the image data storage unit 5 is 4 kbytes and the number of storage lines is five. In this case, the storage capacity is less than 10 kbytes, but since the number of storage lines is three or more, image data is output without FILL insertion. Since the storage capacity is less than 10 Kbytes and the number of storage lines is less than 7, the input of image data to the image data storage unit 5 is continued.

FIG. 5 shows an example in which the storage capacity of the image data storage unit 5 is 4 kbytes and the number of storage lines is two. In this case, since the storage capacity is less than 10 kbytes and the number of storage lines is less than three, the image data management unit 2 sets the FILL before the EOL in the image data output from the image data storage unit 5. Is transferred to the image data transmitting unit 6. Also,
Since the storage capacity is less than 10 kbytes and the number of storage lines is less than 7, input of image data to the image data storage unit 5 is continued.

FIG. 6 shows an example in which the storage capacity of the image data storage unit 5 is 10 kbytes and the number of storage lines is two. In this case, the number of storage lines is 3
Although it is less than the line, the storage capacity is 10 kbytes or more, so the image data is output without FILL insertion. Further, since the storage capacity is 10 kbytes or more, input of image data to the image data storage unit 5 is stopped.

According to this embodiment, the input and output of image data in the image data storage unit 5 are controlled based on both the storage capacity and the number of storage lines. Underflow is prevented. As a result, a decoding error does not occur in a terminal storage or the like for inputting data from the facsimile signal output device.

Further, since input / output of image data in the image data storage unit 5 is controlled based on both the storage capacity and the number of storage lines, effective FILL insertion control can be performed. When the FILL insertion control is performed based only on the number of accumulation lines, even when the accumulation capacity is large, if the number of accumulation lines is small, the FILL is inserted. If the storage capacity is large, there is no danger of underflow, so F
It is not necessary to insert ILL, but unnecessary FIL
The effective data transmission time is reduced by the L insertion. Also, the image data storage unit 5 is based on only the storage capacity.
Try to control the input / output of image data in
Since L detection is not performed, FILL insertion control cannot be performed. That is, there is a risk that an underflow occurs in the image data storage unit 5.

[0021]

As described above, according to the present invention, a facsimile signal output device can be used to store an image in an image data storage unit by using both the capacity and the number of lines of image data stored in the image data storage unit. The system is configured to control data input and image data output from the image data storage unit, so input / output synchronization is maintained when input / output of encoded image data is controlled, and overflow and underflow are prevented to improve efficiency. This has the effect of enabling efficient flow control. In particular, the capacity of the image data stored in the image data storage unit falls below the fill insertion capacity threshold value, and the number of lines of the image data stored in the image data storage unit decreases the fill insertion line number threshold value. If the number of FILLs is less than the FILL value in the image data output from the image data storage unit,
The disadvantage that the data transmission time is reduced by the insertion of the ILL is solved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a facsimile signal output device according to the present invention.

FIG. 2 is a flowchart showing an operation of the facsimile signal output device.

FIG. 3 is an explanatory diagram showing each threshold value.

FIG. 4 is an explanatory diagram showing an example of the capacity and the number of lines of image data stored in an image data storage unit.

FIG. 5 is an explanatory diagram showing another example of the capacity and the number of lines of image data stored in an image data storage unit.

FIG. 6 is an explanatory diagram showing still another example of the capacity and the number of lines of image data stored in the image data storage unit.

[Explanation of symbols]

 Reference Signs List 1 Data control unit 2 Image data management unit 3 Data capacity detection unit 4 Line management unit 5 Image data storage unit 6 Image data transmission unit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-24160 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/21

Claims (4)

(57) [Claims] 1. A facsimile signal output device for temporarily storing encoded image data in an image data storage unit and outputting image data from the image data storage unit, wherein the image data stored in the image data storage unit is An image data management unit that controls input of image data to the image data storage unit and output of image data from the image data storage unit using both the capacity and the number of lines, wherein the data management unit Stored in the storage unit
The image data capacity is below the fill insertion capacity threshold
Line of image data stored in the image data storage
If the number falls below the fill insertion line number threshold, the image data
Insert fill bit into image data output from storage unit
Facsimile signal output apparatus characterized by that. 2. An image data management unit, comprising: after inputting image data to an image data storage unit, determining whether a capacity of the image data stored in the image data storage unit reaches an output capacity threshold value; 2. The facsimile signal output device according to claim 1, wherein output of image data from the image data storage unit is started when the number of lines of image data stored in the image data storage unit reaches the output line number threshold. 3. The image data management unit stores the image data in an image data storage unit.
The capacity of the stored image data is
Image reached or stored in the image data storage
Number of data lines reaches input stop line number threshold
3. The facsimile signal output device according to claim 1 , wherein input of image data to the image data storage unit is stopped . 4. An image data management unit stores the image data in an image data storage unit.
The capacity of the loaded image data
Image data that is lower than and that is stored in the image data storage
If the number of lines in the
4. The facsimile signal output device according to claim 1 , wherein input of image data to the image data storage unit is restarted .