JP2002204339A - Image communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image communication apparatus which is capable of implementing reading at a high speed and with a uniform speed without being influenced by a processing speed of an encoder, thus capable of shortening the read time of one page of an original and preventing irregularities in an image caused by interrupted reading. SOLUTION: The image communication apparatus has a read buffer having a capacity in which image data of one page or more of the original image can be accumulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to reading in an image communication apparatus such as a facsimile apparatus.

[0002]

2. Description of the Related Art In a conventional facsimile apparatus, the capacity of a read buffer is about 10 lines.

In the above conventional example, a read buffer for 10 lines is used, and when the read buffer becomes full, the reading motor is stopped, reading is stopped, and half of the read buffer capacity of 10 lines is reduced to 5/5. When the capacity equal to or more than the line capacity is available, control is performed to restart reading.

[0004]

In the above conventional example,
Since reading is stopped every time the read buffer becomes full, there is a problem that the read image is likely to be disturbed.

[0005] When a photographic original is read, the load of encoding is large and the encoding processing time is prolonged. A photographic original has a problem in that reading is stopped easily, which is a cause of image disorder, even though the user demands image quality.

In addition, the longer the encoding takes time, the more frequently the reading stops due to the read buffer full, resulting in a longer image reading time for one page,
There is a problem of making the user wait.

[0007] This problem occurs in image communication apparatuses other than facsimile apparatuses such as personal computers having an image communication function.

According to the present invention, high-speed and constant-speed reading can be realized without being affected by the processing speed of the encoder, thereby shortening the reading time of one page of the original and stopping the image reading. It is an object of the present invention to provide an image communication device capable of preventing the disturbance of the image.

[0009]

SUMMARY OF THE INVENTION The present invention is an image communication apparatus having a read buffer having a capacity capable of storing image data of one page or more of a raw image.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 shows a facsimile apparatus FS1 according to one embodiment of the present invention.
FIG.

In the facsimile apparatus FS1, the CPU
(Central control unit) 1 controls the entire facsimile apparatus FS1 according to the contents of a program stored in the ROM 2. Further, the setting of the operator is registered in the SRAM 3, and the CPU 1 looks at the registered contents of the SRAM 3,
The entire facsimile apparatus FS1 is controlled.

ADF (Auto Document F)
The original set on the feeder (reader)
The image data read by the contact sensor (CS) 9 while being fed to the MTR (MTR) 14 is encoded through a read buffer (R_BUF) 10 and stored in an image memory (DRAM) 13.

The stored image is stored in a write buffer (W_
BUF) 11, and is decoded and printed out on a recording sheet by the printer 12. Or, the modem MOD
After PM-AM modulation by EM4, NCU5
Through to the line.

The received image data is input to the MODEM 4 through the NCU 5, demodulated and decoded, inspected for image errors, coded if correct, and stored in the DRAM 13. The stored image is a write buffer (W_B
The data is decrypted through the UF) 11 and printed out on recording paper by the printer 12.

The operator can perform various instructions / settings by pressing a key (KEY) 8, and the contents are stored and held in the SRAM 3 and confirmed on the display unit (LCD) 7. it can. The CPU 1 detects key input data through the panel control gate array (OP_CNT) 6 and causes the LCD 7 to display necessary data.

Next, the reading motor 14 in the above embodiment is described.
Will be described.

FIG. 2 shows the reading motor 1 in the above embodiment.
FIG. 4 is a diagram illustrating a driving method of No. 4;

The reading motor 14 is a stepping motor. When a current flows through the stepping motor and the A-phase is excited, the motor turns to the A-phase. When the reverse current flows, the motor turns in the opposite direction to the A-phase. The operation in the B phase is the same as the above operation in the A phase.

When the same current is applied to the phases A and B, the phases A and B
The motor faces midway between the phases. As described above, the motor can be directed to a total of eight phases, and (1) → (2) →
(3) → (4) → (5) → (6) → (7) → (8) →
The reading motor 14 is driven by exciting so that (1) → (2) →.

The reading resolution is STD (3.85 li).
ne / mm), FINE (7.7 line / mm), S
In a facsimile apparatus capable of selecting one of UPERFINE (15.4 line / mm), motor control for reading a document at each resolution is performed as follows.

The ADF has a mechanical structure in which the original is fed (1 / 15.4) mm when the reading motor 14 is driven by one pulse.

The software control of the reading motor 14 generates an interrupt periodically, and generates four motor drive pulses at the same interval according to the interrupt signal. One line reading is performed for each periodic interrupt.

In the case of reading with STD (3.85 line / mm), the motor is driven for 4 steps by one periodic interruption, such as 1, 2, 3, and 4, and in the next periodic interruption, 4 steps, like 5, 6, 7, 0
Minutes, drive the motor.

In the case of reading with FINE (7.7 line / mm), the motor is driven for two steps by one periodic interruption, such as 1, 1, 2, and 2, and in the next periodic interruption, 2 steps like 3, 3, 4, 4
Drive the motor.

SUPERFINE (15.4 line /
mm), read 1, 1, 1, 1, etc.
The 1-step motor is driven by one periodic interrupt, and the 1-step motor is driven by the next periodic interrupt, such as 2, 2, 2, 2.
Drive the p-motor.

FIG. 3 is a diagram showing the driving speed of the reading motor 14 when the periodic interruption period is 5 ms in the above embodiment.

For example, as shown in FIG. 3, if the period of the periodic interrupt is 5 ms and the STD (3.85 line
/ Mm), 800 pps (step)
/ Sec) and the FINE (7.7 l)
line / mm), 400 pps (s)
step / sec) and the SUPERF
Reading at INE (15.41 line / mm) results in a reading speed of 200 pps (step / sec).

FIG. 4 is a diagram showing the driving speed of the reading motor when the periodic interruption period is 3 ms in the above embodiment.

As shown in FIG. 4, in order to speed up the reading operation, the reading speed is reduced by using the reading motor 14 driven at a period of 5 ms for the periodic interruption and shortening the period of the periodic interruption. Raising is possible with software control.

Assuming that the period of the periodic interrupt is 3 ms, the reading speed is 1333 pps (step / sec) when reading STD (3.85 line / mm), and 666 pps when reading FINE (7.7 line / mm). (Step / sec) reading speed, SUPERFINE (15.4 line / m)
m) When reading, 333 pps (step / sec)
The reading speed can be increased by software control.

However, when reading the STD, 800 pps
The reading motor 14 that was reading at the reading speed of
, When turning at 1333 pps during STD reading, depending on the reading motor 14,
I can't spin at 33 pps, so I step out. In addition, FINE
(7.7 line / mm) at reading, 666 pps
There is no problem to drive the motor at a reading speed of (step / sec), and the SUPERFINE (15.4)
333 pps (steel) when reading (line / mm)
There is no problem in driving the motor at a reading speed of (p / sec).

FIG. 5 shows a case where 1333p
FIG. 9 is a diagram illustrating an acceleration control operation required to perform reading in ps.

In the above case, as shown in FIG. 5, an acceleration control is provided to drive the motor at a higher speed, and reading is started when the maximum speed is reached.
High-speed reading can be realized.

First, the periodic interrupt cycle is set to 6 ms.
The motor drive is started at 666 pps, and the motor is driven in a predetermined step. Next, the periodic interrupt cycle is set to 4 ms, and 1
The speed is increased to 000 pps and a predetermined step drive is performed. Subsequently, the periodic interrupt cycle is set to 3 ms, and 133
Accelerate stepwise to a speed of 3 pps. In this case, the motor may be driven at a high speed of 1333 pps.

Next, the acceleration control operation in the above embodiment will be described.

FIG. 6 is a flowchart showing the acceleration control operation in the above embodiment.

When a document is set on the ADF and a transmission or copy operation is started by an operation of an operator.
To start reading, the reading resolution is checked (S1).

When the reading resolution is STD (3.85 line /
mm), the periodic interruption cycle for driving the reading motor 14 is set to 6 ms, and the document is fed at a predetermined step at 666 pps (S2).

After driving this predetermined step, a periodic interruption period for driving the reading motor 14 is set to 4 ms.
The document is fed at a predetermined step at 1000 pps (S3). After the predetermined step driving, the reading motor 1
4 is set to 3 ms,
The document is fed at a predetermined step at 1333 pps (S
4). When the leading edge of the document reaches the reading start point, STD
(3.85 line / mm) resolution, 1333 pps
To start document reading (S5).

The reading resolution is FINE (7.7 line /
mm), without changing the periodic interrupt cycle.
An original feed is performed (S6). When the leading edge of the document reaches the reading start point, document reading is started at 666 pps with a resolution of LINE (7.7 line / mm) (S
7).

When the reading resolution is SUPERFINE (15.
If it is 4 lines / mm), the document is fed without changing the periodic interrupt cycle (S8). When the leading edge of the document reaches the reading start point, SUPERFINE
Document reading is started at a resolution of (15.4 line / mm) at 333 pps (S9).

Next, in the above embodiment, the operation of the facsimile apparatus in which the capacity of the read buffer 10 is set to one page or more of the image so that the reading operation does not stop during the reading will be described. I do.

FIG. 7 shows the flow of read image data.
It is a figure shown in a conventional example and an example.

The image data read by CS9 is
It is stored in d_buf10. The image data stored in read_buf10 is encoded by the encoder and stored in the image memory. In the case of copying, it is passed to write_buf11 → Printer12. When transmitting, it is sent to the telephone line via the NCU 5.

By the way, in the conventional example, when the acceleration control as shown in FIG. 6 is performed, if the read buffer becomes full during the reading, the reading is stopped. To read it, you have to accelerate again. In this case, since it is necessary to accelerate while reading the image, the control is complicated, and the image quality of the read image is likely to be affected.

As shown in FIG. 7A, in reading by a conventional facsimile apparatus, 10 bytes are used as a read buffer.
When the read buffer becomes full, the reading motor 14 is stopped to stop reading when the read buffer becomes full, and reading is restarted when half or more of the 10 read buffer capacities are free. Was. In such a case, the read buffer is likely to be full, and the reading is stopped every time the read buffer is full, so that the read image is likely to be disturbed.

In the above-mentioned conventional example, in particular, in the case of a photographic original, the load of encoding is large and the encoding process takes a long time. In the case of a photographic original, reading is likely to stop, which is a cause of image disorder, even though the user requires image quality. The longer the encoding takes time, the more frequently the reading stops due to the read buffer full, resulting in a slower image reading time for one page, which causes the user to wait.

Therefore, in the above embodiment, in order to solve this problem, as shown in FIG. 7 (2), the read buffer is provided with a capacity equal to or more than one page of the raw image, so that the read buffer is provided. It is something that does not stop at. By having a read buffer large enough to store one or more pages of raw image data, one page of an image can be read at a constant speed and without stopping during reading, without being affected by encoding. Can be.

As a result, the reading does not stop halfway, so that the reading can be performed at a high speed, and there is an advantage that the image is clear and the image quality is stable without waiting the user.

FIG. 8 is a diagram showing the size of a raw image when an A4 document is read in the above embodiment.

The size of one page of the raw image is specifically as shown in FIG. For the sake of simplicity, the description will be made on an A4 document. The number of main scanning pixels is STD, FINE, SUPER
Each of the FINEs has 1728 pixels, and the number of sub-scanning lines is different.

The sub-scanning resolution of the STD is 3.85 lin.
e / mm, and the sub-scanning length of the A4 document is 297 mm, so the number of sub-scanning lines is 3.85 lines / mm × 2
97 mm = 1144 lines.

The sub-scanning resolution of FINE is 7.7 lin
e / mm, the number of sub-scanning lines is 7.7 lines / mm × 297 mm = 2287 lines.

The sub-scanning resolution of SUPERFINE is 1
Since it is 5.4 line / mm, the number of sub-scan lines is
15.4 lines / mm × 297 mm = 4574 lines.

In the case of the above embodiment, the acceleration control is performed only during the STD mode. Therefore, the size of the read_buf necessary to prevent the document from being stopped during the reading of the original is 1728 pixels in the main scan, Number of sub-scan lines:
3.85 lines / mm × 297 mm = 1144 lines.

[Second Embodiment] Even when the reading control is performed as in the first embodiment, when reading a long document having a sub-scanning length longer than A4, the read buffer 10 may become full. If the read buffer 10 becomes full due to the reading of a long document, the reading must be temporarily stopped. When the read buffer 10 is empty and the read buffer 10 is no longer full, a reading speed that does not require acceleration control, a speed at which reading can be started by self-starting,
Scan at a reduced scanning speed. by this,
Even if the read buffer 10 becomes full during reading, reading can be restarted without performing acceleration control.

Next, the operation of the above embodiment when the read buffer 10 becomes full due to reading of a long document will be described.

FIG. 9 is a flow chart showing the operation when the read buffer 10 becomes full due to reading of a long document in the above embodiment.

The operation up to the start of document reading is the same as the operation of the flowchart shown in FIG.

When the read buffer is full or the trailing edge of the read document is detected during the STD reading (S11), the reading is stopped. If the reading stop is due to the detection of the trailing edge of the document, the reading is stopped and the reading is completed (S
12). If the reading stop is due to the read buffer being full, the reading is stopped (S13), and the read buffer 10 waits until the read buffer 10 becomes more than a predetermined amount (S1).
4). The standard for resuming the reading depends on the processing speed of the encoder. If the encoder of the system is fast, reading may be resumed when the read buffer becomes empty about 10 lines. Conversely, if the system encoder is slow,
If reading is not resumed when the read buffer 10 becomes half empty or more, the read buffer becomes full → stop reading immediately.

If the read buffer becomes empty beyond a predetermined amount, if the original is read at a periodic interruption period of 3 ms and 1333 pps before the reading is stopped, the interruption period that is longer than the interruption period of 3 ms and is self-started. For example, at 6 ms and 666 pps, the document reading is restarted (S15). Thereafter, when the trailing edge of the document is detected, the reading is terminated.

On the other hand, when the leading edge of the original reaches the reading start point, the resolution of LINE (7.7 line / mm), 6
When reading of the document is started at 66 pps (S7), or when the leading edge of the document reaches the reading start point and SUP
Resolution of ERFINE (15.4 line / mm), 3
When the document reading is started at 33 pps (S9),
When the read buffer is full or the trailing edge of the read original is detected at the time of reading FINE or SUPERFINE (S2
1) Stop reading (S22). If the read stop is due to the read buffer 10 being full (S2
1) Stop reading (S23), and read buffer 10
It waits until a certain amount of space becomes available (S24), and when the read buffer 10 becomes empty beyond a certain amount, the document reading is restarted at the same interrupt cycle and reading speed as before the reading was stopped (S25). Thereafter, when the trailing edge of the document is detected (S21), the reading is terminated (S2).
2).

According to the above embodiment, by having a read buffer having a capacity equal to or more than one page of an image, high-speed reading at a constant speed can be realized without being affected by the processing speed of the encoder. Thus, the reading time of one page of the document can be shortened, and the disturbance of the image due to the stoppage during reading can be prevented.

[0064]

According to the present invention, by having a read buffer for one image page or more, high-speed and constant-speed reading can be realized without being affected by the processing speed of the encoder. This has the effect of shortening the time required to read one page of a document and preventing image disturbance due to stoppage during reading.

[Brief description of the drawings]

FIG. 1 shows a facsimile apparatus FS according to an embodiment of the present invention.
FIG.

FIG. 2 is a diagram illustrating a driving method of a reading motor in the embodiment.

FIG. 3 is a diagram showing a configuration in which the periodic interruption period is 5 m in the embodiment.
FIG. 6 is a diagram illustrating a driving speed of a reading motor when the speed is s.

FIG. 4 is a diagram showing a configuration in which the periodic interruption period is 3 m in the embodiment.
FIG. 9 is a diagram illustrating a reading motor driving speed when the speed is s.

FIG. 5 is a diagram illustrating an acceleration control operation required to perform reading at 1333 pps in the embodiment.

FIG. 6 is a flowchart showing an operation of acceleration control in the embodiment.

FIG. 7 is a diagram illustrating a flow of read image data in a conventional example and an example.

FIG. 8 is a diagram illustrating a size of a raw image when an A4 document is read in the embodiment.

FIG. 9 is a flowchart showing an operation when the read buffer 10 becomes full due to reading of a long document in the embodiment.

[Explanation of symbols]

 FS1 facsimile machine, 1 CPU, 2 ROM, 3 SRAM, 4 modulator / demodulator, 5 NCU, 6 panel control gate array, 7 display unit, 8 key, 9 contact sensor, 10 lead Buffer: 11: write buffer, 12: printer, 13: image memory, 14: reading motor.

Claims (3)

[Claims] 1. An image communication apparatus having a read buffer having a capacity capable of storing image data of one page or more of a raw image. 2. A reading stop means according to claim 1, wherein when the read buffer becomes full due to reading of a long document, reading stop means for temporarily stopping reading; and after the read buffer becomes full, An image communication device comprising: a read resuming unit configured to reduce a reading speed to a speed at which the read buffer becomes available and restart reading when the read buffer becomes empty. 3. The image communication device according to claim 1, wherein the image communication device is a facsimile device.