JP2676519B2 - Facsimile machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a facsimile apparatus.

[Prior Art] Generally, when a facsimile apparatus transmits a plurality of pages of transmission originals set on a document table, the originals are pulled out one by one by a platen roller and conveyed through a scanner unit. In the scanner unit, an image is read while each page of the original is passing, and the read image information is transmitted.

By the way, as a document feeding mechanism for reliably pulling out a plurality of pages of transmission originals one by one, a set of protein rollers that directly contact the next page to be pulled and rotate in the forward direction,
It is known that a platen roller that rotates in the opposite direction is provided in contact with another page.

Generally, when conveying a document with a prot roller,
A slip between the platen roller and the original, that is, a so-called original slip may occur, and this slip is particularly likely to occur when the above-described adjustment of the original feeding mechanism is improper.

When such document slip occurs, the document takes a longer time to pass through the scanner unit, and a one-page image is stretched and transmitted.

Then, on the receiving side, when the roll-shaped recording paper is used, an image longer than the actual length is recorded. On the other hand, when the cut-sheet-shaped recording paper is used, one page image is divided into two pages and recorded. There was a problem.

To prevent this, when the receiving side receives an image of each page from the transmitting side, if the number of lines is larger than the number of lines corresponding to the original size of the transmitting side, the receiving side thins out the number of lines and records the received image. The process is known.

Now, for example, as shown in FIG. 6 (a), line i
From a line i + 22 to a line image showing black one dot at a time, the number of lines of the received image is 5 with respect to the document size.
Suppose there was a lot. In this case, the received image is shown in FIG.
As shown in, the line was thinned out every 20 lines for recording.

For this reason, conventionally, there is a problem in that when a document is stretched and transmitted due to a document slip, a straight line is divided in the middle, so that the recorded image is not smooth and the image quality is deteriorated.

[Object] It is an object of the present invention to provide a facsimile apparatus which solves the above problems and improves the image quality of a recorded image.

[Structure] Therefore, according to the present invention, when the image information is received, the original size and the image linear density on the transmitting side are identified, and at the same time, a plotter having a recording linear density higher than the image linear density and at least one received page. And a memory for accumulating image information of each page, converting the received image information of each page into recording image information of the number of lines corresponding to the recording linear density, and receiving the rated number of lines corresponding to the document size and receiving The number of lines for one page of the image information is determined, the recording image information is thinned out in line units at a constant rate based on the rated number of lines and the number of lines for one page, and the plotter is used. It is characterized by being recorded.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a facsimile apparatus according to an embodiment of the present invention. In the figure, a scanner 1 reads an image of a transmission document with a predetermined linear density, and a plotter 2 records a received image with a predetermined linear density. In this embodiment, the recording linear density of the plotter 2 is 16 dots / mm in the main scanning direction and 15.4 dots / mm in the sub scanning direction.
mm.

The encoding / decoding unit 3 encodes image information to be transmitted and decodes received image information. The image memory 4 stores transmitted and received image information in an encoded state, and the page memory 5 decodes the received image information and stores it for one page.

The communication control unit 6 controls the modem 7 and the network control device 8,
The transmission control procedure signal and image information are transmitted. When the recording linear density of the plotter 2 is higher than the image density of the transmitting side, the density converting section 9 converts the received image information into recording image information of the number of lines corresponding to the recording linear density.

As shown in FIG. 2, the density conversion unit 9 includes a P / S conversion circuit 9a for converting image information, which is parallel data read from the page memory 5, into serial data, and a latch circuit for temporarily latching the serial data. 9b, a line memory 9c for storing image information data for one line, and a clock / memory control circuit 9d for activating each of the above parts at a predetermined timing.

The operation display unit 10 displays operation guidance and the like, and an operator performs a predetermined operation. Then, the system control unit 11 controls each of the above units to execute a predetermined transmission / reception operation.

In the facsimile apparatus of this embodiment, when receiving an image with the above configuration, as shown in FIG. 3 (a), when a call is received from the telephone line, the line is first connected (process 101) and a predetermined transmission control procedure is performed. To start. In this procedure, the document size and the image line density of the transmission document on the transmission side are identified (processing
102).

Next, the transmitted image information is received by the communication control unit 6 via the network control device 8 and the modem 7, as shown in FIG. Then, the image information as it is, which has been data-compressed, is sequentially accumulated in the image memory 4 (from N of processing 104 to processing 103
When the reception of all image information is completed, the line is disconnected after executing a predetermined transmission control procedure (process 105).

FIG. 3B shows a recording process executed in parallel with the above-mentioned receiving process. First, the image information accumulated in the image memory 4 is sequentially read out and restored to the original raw data.
The pages are stored in the page memory 5 (process 106). Next, the number of lines Nr of the accumulated image for one page is determined (process 107).

By the way, for example, for example, the transmission document size identified in the process 102 is A4 size, and the image linear density is 3.85.
If it were books / mm, the long side of the rated A4 size is 297 mm
Therefore, the rated number of lines Ns of image information is N = 297 × 3.8
It can be calculated as 5 = 1143. In this way, the rated line number Ns is obtained from the size of the transmission document and the image line density (process 108).

Next, the thinned line interval X is obtained as X = Nr / (Nr-Ns) from the rated line number Ns and the image line number Nr (process 109).

Next, the counter on the control program is reset (process 110), and the image information of the page memory 5 is read for one line (process 111).

Next, when the image linear density and the recording linear density match each other, in the density conversion unit 9, the clock signals Ck ₁ ,
Ck ₂ is output in the same cycle T. As a result, the image information for one line is converted into serial data by the P / S conversion circuit 9a at a constant cycle T, and is latched by the latch circuit 9b at that cycle.

On the other hand, for example, when the image linear density in the main scanning direction is 8 dots / mm, the recording linear density in the main scanning direction of the plotter 2 is 16 dots / mm.
The clock signal Ck ₁ from the clock / memory control circuit 9d is
The clock signal Ck ₂ is output at a constant cycle T and at a cycle T / 2. As a result, the image information for one line is P /
The S conversion circuit 9a converts the data into serial data at a constant period T, and the data is latched by the latch circuit 9b at a period T / 2. Therefore, 1-bit data from the P / S conversion circuit 9a becomes 2 bits and is set in the latch circuit 9b. As a result, the original image information data is set in the latch circuit 9b in a doubled state, and density conversion of the image information in the main scanning direction is performed.

In this way, by adjusting the periods of the clock signals Ck ₁ and Ck ₂ as necessary, the line-density converted image information for recording of one line is stored in the line memory 9c (above,
Process 112).

Then, the value of the counter is checked (process 11
3) When the thinning line interval X does not match (process 113)
N), the image information of one line stored in the line memory 9c is recorded by the plotter 2 (process 114), and the counter is incremented by 1 (process 115).

By the way, when the recording linear density of the plotter 2 is higher than the image linear density, the recording density of the image is converted by recording the same line image a plurality of times.

Therefore, next, the necessity of re-recording is determined from the linear densities of both of them (process 116), and when the recording linear density of the plotter 2 is higher than the image linear density (Y of process 116), the process returns to the process 113. .

Now, on the second line, the value of the counter is 1. Usually, the thinning line interval X is a very large numerical value, so the value of the counter is the thinning line interval X.
And the same one-line image as described above is recorded by the plotter 2.

The recording of the same line image is repeated to determine the recording linear density.
Since it is 15.4 lines / mm, it is executed twice when the image linear density is 7.7 lines / mm and four times when it is 3.85 lines / mm. As a result, one line of the received image is subjected to linear density conversion in the sub scanning direction and recorded.

When the same line image is recorded a predetermined number of times (N in process 116), if the recording process for one page is not completed (process
(N of 117), the image information of the next one line is read from the page memory 5, and the same process is repeated (process 11).
1).

By the way, as described above, when a document slip occurs on the transmitting side of the facsimile apparatus, the actual document image is stretched and received on the receiving side. Now, when the original image is stretched and received, and for example, the thinning line interval X becomes X = 20, when the counter value becomes 20, that is, when 20 lines are recorded (Y in step 113). ), The counter is reset (process 118).

At this time, the recording of the image on the 20th line is not performed, and the same recording process is repeated from the next one line. As a result, assuming that a straight line image showing one dot at a time from line i to line i + 21 at a linear density of 1/2 of the plotter 2 is received from the transmitting side, as shown in FIG. In the plotter 2, as shown in FIG. 3B, one line is thinned and recorded every 20 lines. That is, only one of the two lines corresponding to the lines i + 10 and i + 20 of the received image is recorded.

In this way, when the recording of the image information of one page is completed (Y of end 117) and the entire page is not completed (N of process 119), the recording process of the image information of the next one page is similarly performed (process 106). What). As a result, in each page, the recorded images are thinned by the thinning line interval X thus obtained.

When the recording of all pages is completed (YG of process 119, this recording process is completed.

Even when the image linear density and the recording linear density of the plotter 2 are the same, the thinned recording is similarly performed by the plotter 2 according to the calculated thinning line interval X. in this case,
As shown in FIG. 6, the data is recorded in the same manner as the conventional one.

As described above, according to this embodiment, when the recording linear density of the plotter 2 is higher than the image linear density of the received image,
The density conversion unit 9 converts the density into recording image information according to the recording linear density.

Then, for each page of the received image information, the thinned-out line interval X is calculated from the number of lines Nr for that page and the rated number of lines Ns corresponding to the size of the original document on the transmission side. The image is thinned out in such a manner that one line is not recorded for each thinning line interval X for each line unit of the recording linear density of the plotter 2.

As a result, for example, when the recording linear density of the plotter 2 is twice the image linear density of the received image, as shown in FIG. 4, only one of the two lines corresponding to one line of the received image is When the storage linear density of the plotter 2 is four times the image linear density, only one of the four lines corresponding to one line of the received image is thinned.

Therefore, when the recording linear density of the plotter 2 is higher than the image linear density of the received image, the straight line of the image transmitted by the document slip on the transmitting side is not divided in the middle and the recorded image Since the unnaturalness is improved, the image quality of the recorded image is improved.

In the above embodiment, the recording linear density of the plotter 2 is 16 dots / mm in the main scanning direction and 15.4 dots / mm in the sub scanning direction.
However, the storage linear density must be always higher than the received image linear density to improve the image quality, and the higher the density, the higher the effect. Further, the thinned-out line interval X is calculated from the number of lines Nr and the rated number of lines Ns, and the recorded image is thinned out by one line for each line interval X, but it is not always necessary to have a constant line interval. Of course.

[Effect] As described above, according to the present invention, a memory for accumulating at least one received page of image information and a plotter having a recording linear density higher than the received image linear density are provided.
The received image information of each page is converted into recording image information of the number of lines corresponding to the recording linear density, and the rated number of lines corresponding to the document size and the number of lines of one page of the received image information are converted. Since the recording image information is thinned out in line units at a constant rate based on the above and is recorded by the plotter, when the image is stretched by the document slip and transmitted, the recorded image is smoother and more smooth. It becomes natural and the image quality improves.

[Brief description of the drawings]

FIG. 1 is a block configuration diagram of a facsimile apparatus according to an embodiment of the present invention, FIG. 2 is a block configuration diagram of a density conversion unit,
3A is a flowchart of the image receiving process, FIG. 3B is a flowchart of the image recording process, FIG. 4 is an explanatory diagram showing a flow of image information in the image receiving and recording process, and FIG. 5 is a recording process. FIG. 6 is an explanatory diagram showing an image, and FIG. 6 is an explanatory diagram showing a conventional recorded image. 1 ... Scanner, 2 ... Plotter, 3 ... Encoding / decoding unit, 4 ... Image memory, 5 ... Page memory, 6 ... Communication control unit, 7 ... Modem, 8 ... Network control device, 9 ... Density converter, 9a ... P / S converter, 9b ... Latch circuit, 9c
...... Line memory, 9d …… Clock memory control circuit,
10 …… Operation display section, 11 …… System control section.

Claims (1)

(57) [Claims] 1. When receiving image information, identification means for identifying the original size and image linear density on the transmitting side, a plotter having a recording linear density higher than the image linear density, and an image for at least one received page. A memory for accumulating information, image information density conversion means for converting the received image information of each page into recording image information of the number of lines corresponding to the recording linear density, and the rated number of lines corresponding to the document size are determined. The rated line number determining means, the receiving line number determining means for determining the number of lines of one page of the received image information, and a fixed ratio based on the rated line number and the number of lines of one page. An image thinning means for thinning the recording image information line by line and recording the thinned image information by the plotter.