JP2000138799A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the intermittent operation occurrence of vertical scanning by performing relative displacement of original image information reading in accordance with a reading speed and reading linear density in the direction of vertical scanning of an original, outputting successively stored image information in the order stored, according to a read request and controlling a reading speed in accordance with an image information processing speed. SOLUTION: A CPU 13 makes a scanner 2 read original image information at a decided reading speed and to store it in a buffer memory 3 with set read linear density but repeats processing in which it reads the image information stored in the memory 3 by one line at a time in the order stored, binarizes it in accordance with a reading mode, encodes and compresses it and transmits it to an encoding and decoding part 14 until reading an original set to the scanner 2 is finished. The slower the communication speed decided by the device of the other party and the CPU is, the slower the reading speed of the scanner 2 becomes. Consequently, opportunities in which the memory 3 is filled with unprocessed image information are reduced substantially, and opportunities in which vertical scanning of the scanner 2 is stopped are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus applied to a facsimile machine, a copying machine, and the like.

[0002]

2. Description of the Related Art In an image reading apparatus, a reading means such as a line image sensor or a contact image sensor for reading document image information in units of main scanning lines, and the reading means are relatively moved with respect to the document in the sub-scanning direction. In general, the image information of the entire document is read and output in cooperation with a sub-scanning means driven by a step motor. And
The output image information is processed by a subsequent processing unit.

[0003] However, the image processing speed of the subsequent processing unit,
That is, the number of lines of image information that can be processed per unit time is not always constant, and varies due to various factors. Since the reading unit cannot output the image information for the next line even though the processing unit of the subsequent stage has not completed the processing of the image information for the previous line, in such a case, the reading unit Stop reading the original image information. If the sub-scanning unit continues the sub-scanning while the reading unit stops reading the original image information, the reading of the original image information is lost. Therefore, the sub-scanning unit must also stop the sub-scanning. .

However, when the subsequent processing section completes the processing of the image information for the previous line and the reading means resumes reading the original image information, the sub-scanning means also resumes the sub-scanning. Although it is necessary to stop and restart such sub-scanning, the amount of sub-scanning per step of the step motor is affected by the inertia of the sub-scanning mechanism. Are different, and image information is degraded.

[0005] By reducing the chance of stopping and restarting the sub-scanning due to such fluctuations in the processing speed of the subsequent processing section,
It is common in an image reading apparatus to interpose a buffer memory between the reading unit and a subsequent processing unit in order to reduce image information deterioration.

The buffer memory is a FIFO memory having a capacity capable of storing image information for a plurality of lines. The buffer memory sequentially stores the image information output from the reading means in units of lines, while responding to a read request from the subsequent processing unit. In response, the image information of the oldest line stored in the buffer memory is read and output to the subsequent processing unit.

By interposing the buffer memory in this way, the reading speed of the reading means (the number of lines of image information to be output per unit time) within the range of the number of lines of the buffer memory and the image information of the subsequent processing unit It is possible to cope with a certain degree of inconsistency with the processing speed (the number of lines of image information processed per unit time).

However, if the mismatch between the reading speed of the reading means and the image information processing speed of the subsequent processing unit is too large to be absorbed only by the buffer memory, the buffer memory is full and the capacity of one line is reduced. Are repeated, and the sub-scanning means frequently performs intermittent operations in the sub-scanning, resulting in image information deterioration.

Thus, as in the technique disclosed in Japanese Patent Application Laid-Open No. 5-219326, the read line density is changed in accordance with the occupancy of the image information in the buffer, and the amount of image information input to the buffer per unit time is changed. In which the intermittent operation of the sub-scanning is less likely to occur, and Japanese Patent Application Laid-Open No. 10-75340.
As in the technology shown in Japanese Patent Publication No.
In some cases, the reading speed is determined so that an intermittent operation in the sub-scanning hardly occurs.

[0010]

However, Japanese Patent Application Laid-Open No. Hei 5-21
According to the technology described in Japanese Patent No. 9326, the reading speed is changed depending on the occupancy of the buffer, so that the reading speed is not severe until intermittent, but the image information also deteriorates at the time of speed conversion, and especially when the buffer capacity is small, the speed conversion is not performed. There are problems that are likely to occur. Further, in the technique described in Japanese Patent Application Laid-Open No. H10-75340, the reading speed is determined by the size of the memory to be added, and intermittent operation is unlikely to occur. However, this technique cannot be applied to a device having a small memory size and cannot be added. There is.

As described above, in the prior art, the intermittent operation in the sub-scanning caused by the mismatch between the reading speed of the reading means and the image information processing speed of the subsequent processing section cannot be sufficiently suppressed, and the image information cannot be suppressed. There is a problem that deterioration occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and minimizes inconsistency between the reading speed of a reading unit and the image information processing speed of a subsequent processing unit, and greatly reduces the occurrence of intermittent operations in sub-scanning. It is an object of the present invention to provide an image reading device that can reduce the number.

[0013]

According to a first aspect of the present invention, there is provided an image reading apparatus for reading original image information and outputting the read original image information to a subsequent processing means. Reading means for reading and sequentially outputting document image information in main scanning line units as far as possible, and, while the reading means is reading, moving the reading means in the sub-scanning direction with respect to the document in accordance with the reading speed and the reading line density. And a buffer memory for a plurality of lines for sequentially storing line-by-line image information sequentially output from the reading unit, and outputting the image information in the order of storage in response to a read request from the subsequent processing unit. And reading speed control means for controlling the reading speed of the reading means in accordance with the image information processing speed of the subsequent processing means.

In the image reading apparatus according to the present invention, the transmission speed is determined based on a predetermined transmission control procedure with a destination apparatus via a line, and the determined transmission is performed while reading the original image information. An image reading device provided with image information transmitting means for transmitting data to the destination device via the line at a speed, reading means for reading original image information in units of main scanning lines and sequentially outputting the image information as long as a buffer memory is available, A sub-scanning unit for relatively moving the reading unit in the sub-scanning direction with respect to the document according to the reading speed and the reading linear density while the reading unit is reading; and a line unit sequentially output from the reading unit. And a buffer memory for a plurality of lines, which are sequentially output in the order in which they are stored in response to a read request from the image information transmitting means, and each transfer that can be determined between the counterpart device. A reading speed correspondence table in which a reading speed corresponding to a speed is stored in advance, and a reading speed of the reading means controlled to a reading speed corresponding to the transmission speed determined with the destination apparatus in the reading speed correspondence table. Reading speed control means.

According to a third aspect of the present invention, there is provided an image reading apparatus for reading original image information and outputting the read original image information to a second-stage binarizing unit.
A binarization method setting means for setting either a character mode for simply binarizing image information or a halftone mode for pseudo-halftone processing of image information; Reading means for reading and outputting sequentially in units of main scanning lines; and sub-scanning which, when the reading means is reading, relatively moves the reading means relative to the document in the sub-scanning direction in accordance with the reading speed and reading line density. Means,
A buffer memory for a plurality of lines for sequentially storing line-by-line image information sequentially output from the reading unit and outputting the image information in the order of storage in response to a read request from the binarizing unit; And a reading speed corresponding to each of the above, and a reading speed of the reading unit corresponding to the reading speed corresponding to the binarization method set by the binarization method setting unit in the reading speed correspondence table. And reading speed control means for controlling the reading speed.

According to a fourth aspect of the present invention, there is provided an image reading apparatus for reading original image information and outputting the original image information to a subsequent processing means, as long as there is a space in a buffer memory to be described later, in a unit of a main scanning line. Reading means for sequentially outputting, sub-scanning means for relatively moving the reading means in the sub-scanning direction with respect to the document in accordance with the reading speed and reading linear density while the reading means is reading, A buffer memory for a plurality of lines that sequentially stores the line-by-line image information that is sequentially output, and that outputs the lines in the order in which they are stored in response to a read request from the processing unit at the subsequent stage; A reading speed correspondence table in which reading speeds corresponding to the respective parallel processing degrees are stored in advance,
A reading speed control unit configured to control a reading speed of the reading unit to a reading speed corresponding to the current parallel processing degree of the subsequent processing unit and another processing unit in the reading speed correspondence table. .

According to a fifth aspect of the present invention, in the image reading apparatus of the second aspect, the reading speed stored in the reading speed table is changed according to an operation input. And a reading speed changing means for changing the reading speed.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described in detail.

FIG. 1 shows a block diagram of a facsimile apparatus 1 to which an image reading apparatus according to an embodiment of the present invention is applied.

In FIG. 1, a facsimile apparatus 1 includes a scanner 2, a buffer memory 3, a plotter 4, an operation display unit 5, an image memory 6, a parameter memory 7, a battery 8,
Clock circuit 9, PC interface 10, RAM 11,
It comprises a ROM 12, a CPU 13, an encoding / decoding unit 14, a communication control unit 15, a modem 16, a network control unit 17, and a system bus 18.

As long as there is free space in the buffer memory 3, the scanner 2 can read 3.85 lines / mm (normal), 7.7 lines / mm.
a line image sensor (not shown) as reading means for reading original image information in units of main scanning lines at a predetermined reading line density such as mm (small characters) and 15.4 lines / mm (fine characters) and sequentially outputting the read image data to the buffer memory 3 And a sub-scanning mechanism (not shown) that moves the line image sensor relative to the document in the sub-scanning direction according to the reading speed and the reading line density while the line image sensor is reading. The sub-scanning mechanism includes a pulse generator 2b.
Are driven one step at a time by a step motor 2a driven by a pulse output from.

The buffer memory 3 sequentially stores line-by-line image information sequentially output from the scanner 2 and
3 to several tens or hundreds of lines in order of storage in response to a read request from a subsequent process such as image processing by the PC interface 10, transfer processing by the PC interface 10, and image information transmission processing by the communication control unit 15. Minute F
It is composed of an IFO memory.

The plotter 4 records and outputs the received image information according to the line density, and records and outputs the image information read by the scanner 2 according to the line density (copy operation).
It is for doing.

The operation display unit 5 includes a numeric keypad for designating a destination facsimile number, a transmission start key, a one-touch dial key, and various other keys. It displays the operating state of the device to be notified to the user and various messages.

FIG. 2 shows an example of the arrangement of the operation display unit 5, which is not shown except for parts related to the present embodiment.
In the figure, a numeric keypad 5a is used to directly specify a transmission destination telephone number or the like, or to specify by a speed dial. [Yes] key 5b and [N
The o] key 5c is a key for allowing the user to make various selections of determination or cancellation. [Stop] key 5d is for instructing forcible stop of various operations.
The [Start] key 5e is for instructing the start of a facsimile transmission operation, a copy operation, and the like. The [Function] key 5f is used to register a one-touch dial, abbreviated dial, a user parameter setting function, and a function other than the function of the facsimile machine 1 as a standard facsimile machine, such as time-specified transmission, department code-specified transmission, and the like. The function key 5f is depressed to call an extended function of the keypad 5a.
Thus, by inputting a number corresponding to each function, each function can be called and executed.

The cursor key group 5g includes a [down arrow] key 5
gd, [left arrow] key 5gl, [right arrow] key 5gr,
And an [up arrow] key 5gu.
The [DOWN ARROW] key 5gd and the [UP ARROW] key gku are used to scroll the display contents displayed on the display 5h up and down in response to the depression of each key. [Left arrow]
The key 5gl and the [right arrow] key 5gr are used to select items, functions, and the like displayed on the display 5h in accordance with the depression of each key. The display 5h displays the operating state of the device to be notified to the user and various messages.

A [character mode] key 5i is a key for setting a character mode in which the read image information is simply binarized. When the character mode is set, the indicator lamp 5ii is turned on to switch to the character mode. Indicates that it has been set. A [photo mode] key 5j is a key for setting a photo mode (halftone mode) in which read image information is binarized by pseudo halftone processing. When the photo mode is set, the indicator lamp 5j is used.
i lights up to indicate that the character mode is set.
The [Normal] key 5k is used to output 3.85 lines / m of original image information.
A key for setting a normal mode for reading at a line density of m. When the mode is set to the normal mode, the indicator lamp 5ki lights up to indicate that the mode is set to the normal mode. The [small character] key 51 is a key for setting a small character mode for reading original image information at a line density of 7.7 lines / mm. When the small character mode is set, the indicator lamp 5li is turned on. Indicates that the mode is set to small character mode. The [fine character] key 5m is a key for setting a fine character mode for reading original image information at a line density of 15.4 lines / mm. When the fine character mode is set, the indicator lamp 5mi is turned on. Indicates that the mode is set to the fine character mode.

Returning to FIG. 1, the image memory 6 stores image information read by the scanner 2 and received image information in a compressed state. The parameter memory 7 is backed up by a battery 8 and stores user parameters such as system setting status and registered contents of one-touch dial. The stored contents are retained even when the apparatus is powered off. The clock circuit 9 is for counting the current date and time.

The PC interface 10 exchanges control signals and transfers image information with a personal computer (PC) 30. PC30 is
Under the control of the facsimile application, it requests the facsimile apparatus 1 to transmit image information, requests the facsimile apparatus 1 to record and output the image information, and transmits the received image information from the facsimile apparatus 1 via the PC interface 10. By receiving the transfer, the facsimile machine 1 is used.

The RAM 11 is a random access memory used as a work area of the CPU 13. ROM1
Reference numeral 2 denotes a read-only memory in which a control program for controlling each unit of the apparatus by the CPU 13 is stored. C
The PU 13 uses the RAM 11 as a work area in accordance with the control program written in the ROM 12,
In addition to controlling each unit of the apparatus, it also performs image information processing such as binarization of image information.

The encoding / decoding unit 14 converts the transmission image information into G
While encoding and compressing is performed using a predetermined coding method such as an MH coding method, an MR coding method, or an MMR coding method, which conforms to 3 facsimile, the received image data is subjected to the MH coding method,
The decoding is performed by a predetermined decoding method corresponding to the R coding method, the MMR coding method, or the like. Communication control unit 15
Is for controlling the modem 16 and the network control unit 17 to control G3 facsimile communication. Modem 16
Is for modulating data to be transmitted to the line via the network controller 17 and demodulating a communication signal received from the line via the network controller 17. The modem 16 also sends a DTMF signal corresponding to the dial number. The network control unit 17 is connected to the line, and under the control of the communication control unit 15, closes / releases the DC loop of the line, detects the polarity reversal of the line, detects the release of the line, detects the dial tone, and sets the busy tone ( It controls connection to a line, such as detection of a tone signal (such as busy), detection of a call signal, etc., and generation of a dial pulse. The system bus 18 is a signal line through which the above components exchange data.

With the above configuration, the facsimile machine 1
The setting processing procedure shown in FIG.

In the figure, the CPU 13 has a [character mode] key 5i and a [photo mode] key 5i of the operation display unit 5.
j, the [ordinary character] key 5k, the [small character] key 5l, or the [fine character] key 5m is monitored to be pressed (No in judgment 101, No in judgment 102, judgment 10)
No. 3; No. of judgment 104; No. loop of judgment 105).

When the [character mode] key 5i is pressed (Yes in decision 101), the character mode is set (step 106), and when the [photo mode] key 5j is pressed (step 102). (Yes), the mode is set to the photograph mode (process 107), and when the [ordinary character] key 5k is pressed (Yes in decision 103), the reading linear density is set to 3.85.
Set to book / mm (processing 108), and [small character] key 5
If 1 is pressed (Yes in decision 104), the reading linear density is set to 7.7 lines / mm (processing 109), and if the [fine] key 5m is pressed (Y in decision 105).
es) The read linear density is set to 15.4 lines / mm (process 110).

The setting states are stored in the parameter memory 7.
Is stored as a predetermined flag value, and by reading out the flag value of the CPU 13, it is possible to determine whether the binarization method is currently set to the character mode or the photograph mode, and the currently set reading linear density. Come to know.

In the scanner 2, a stepping motor 2a for driving the sub-scanning mechanism one step at a time is such that the line image sensor per step (1 / 30.8) mm moves relative to the document by two-phase excitation. The sub-scanning mechanism is driven. 3.85 reading line density / mm (normal character)
, The image information for one line corresponds to a sub-scanning width of only (1 / 3.85) mm. Therefore, step motor 2
When a is rotated 8 pulses by two-phase excitation, 3.85 lines / m
The image information for one line is read at a reading line density of m. When the reading line density is 7.7 lines / mm (small characters), image information for one line corresponds to a sub-scanning width of only (1 / 7.7) mm. Therefore, when the step motor 2a is rotated four pulses by two-phase excitation, one line of image information is read at a read line density of 7.7 lines / mm. At a reading line density of 15.4 lines / mm (fine characters),
The image information for one line corresponds to a sub-scanning width of only (1 / 15.4) mm. Therefore, the step motor 2a is
When two pulses are rotated by phase excitation, one line of image information is read at a read line density of 15.4 lines / mm.

The shortest period for reading one line of image information, that is, the shortest period for outputting one line of image information from the scanner 2 is a line period (line sync).
In this embodiment, 2.5 msec
c.

When reading original image information at the highest speed (the number of lines of image information output from the scanner 2 per unit time) at a reading line density of 3.85 lines / mm (normal character), FIG. As shown in a), the scanner 2 outputs image information for one line per 2.5 msec by rotating the step motor 2a for 8 pulses per two-phase excitation per 2.5 msec. 3.85 lines / mm (normal character)
When reading the original image information at half the maximum speed at a reading line density of 5 msec, as shown in FIG.
By rotating the stepping motor 2a per pulse by 8 pulses with two-phase excitation, image information for one line is output from the scanner 2 per 5 msec.

Similarly, when reading original image information at the highest speed with a reading line density of 7.7 lines / mm (small characters),
By rotating the stepping motor 2a for 4 pulses by two-phase excitation per 2.5 msec, 1 step per 2.5 msec
The image information for the line is output from the scanner 2 and 15.4
When reading original image information at the highest speed with a reading line density of book / mm (fine characters), the step motor 2a is rotated by two pulses with two-phase excitation per 2.5 msec to obtain one line per 2.5 msec. The image information of the minute is output from the scanner 2.

However, the image information is output in line units from the scanner 2 only when the buffer memory 3 has an empty space when the subsequent processing is delayed and the buffer memory 3 is full of the image information. , The output of the image information from the scanner 2 is stopped, and the sub-scanning is also stopped.

When reading at the highest reading speed, for example, the time required to read one page of an A4 size document is (297 mm · 3) at a reading line density of 3.85 lines / mm (normal character). .85 / mm · 2.5m
sec) = 2.86 seconds, and a reading linear density of 7.7 lines / mm (small characters) is (297 mm · 7.7 lines / mm · 2.
5 msec) = 5.72 sec, and a reading linear density of 15.4 lines / mm (fine characters) is (297 mm · 15.4 lines / m).
m · 2.5 msec) = 11.44 seconds, and even if the reading speed (the number of lines of image information output from the scanner 2 per unit time) is the same, the time required to read a constant sub-scanning width is , Which is proportional to the read linear density.

FIG. 5 shows the correspondence between each line density and various parameters. In the drawing, in the reading mode “normal”, the line width corresponding to the image information for one line at the line density of 3.85 l / mm is (1 / 3.85) mm / l, and the image for one line is displayed. The number of pulses of the step motor 2a per information is 8p / l, and the maximum number of pulses of the step motor 2a per line sync (cycle) is 8p / 2.5ms.
The maximum reading speed is 400 l / s, and the maximum sub-scanning speed (sub-scanning distance per unit time) is 103.
9 mm / s.

The reading mode "small characters" has a line density of 7.7.
The line width corresponding to the image information for one line at 1 / mm is (1
/7.7) mm / l, the number of pulses of the step motor 2a per image information for one line is 4p / l, and the maximum number of pulses of the step motor 2a per line sync (cycle) is 4p / l. At 2.5 ms, the maximum reading speed is 40
The maximum sub-scanning speed (sub-scanning distance per unit time) is 51.9 mm / s.

In the reading mode "fine characters", the line density
The line width corresponding to the image information of one line at 4 l / mm is
(1 / 15.4) mm / l, the number of pulses of the step motor 2 a per one line of image information is 2 p / l, and
The maximum number of pulses of the step motor 2a per line sync (cycle) is 2p / 2.5ms, the maximum reading speed is 400 l / s, and the maximum sub-scanning speed (sub-scanning distance per unit time) is It becomes 26.0 mm / s.

As described above, the CPU 13 controls the driving pulse supplied from the pulse generator 2b to the step motor 2a, so that the reading speed can be controlled for each reading linear density.

The facsimile apparatus 1 previously stores a reading speed correspondence table 7a shown in FIG.

In the figure, a reading speed correspondence table 7a
Is used when performing facsimile communication with the destination device.
In the pre-transmission procedure of the 3 facsimile protocol, the digital identification signal DIS and the digital transmission command signal DC
S, or each communication speed (14400 bps, 9600 bps, 7200 bp) that can be set by exchanging the non-standard function identification signal NSF and the non-standard function setting signal NSS.
s, 4800 bps, and 2400 bps), the reading speed for each reading mode is set.

In the reading mode, whether the binarization method is the simple binarization of the character mode or the pseudo-halftone processing of the photograph mode at each of the reading linear densities of the normal character, the small character, and the fine character Are classified by The simple binarization processing in the character mode is a method of determining whether the image is white or black by comparing a certain fixed threshold value and the image signal level. Therefore, high-speed binarization processing can be performed. That is, the number of lines of image information that can be binarized per unit time is relatively large, and the number of lines of image information read from the buffer memory 3 per unit time is relatively large.

On the other hand, the pseudo halftone processing in the photograph mode generally includes a dither method and an error diffusion method. Dither method is 8 ×
An error diffusion method is a method of dispersing the density of peripheral pixels by a certain algorithm and binarizing the data by using a binarization threshold matrix dispersed such as 8 pixels or 16 × 16 pixels. Halftone originals such as photographic originals can be read clearly and the processing is relatively complicated, so that the binarization processing cannot be performed at high speed as compared with the simple binarization processing in the character mode. That is, the number of lines of image information that can be binarized per unit time is relatively small.

In the case of so-called direct transmission, in which original image information is read by the scanner 2 and transmitted to the destination apparatus, the higher the communication speed set with the destination apparatus, the higher the communication speed.
The number of lines of image information read from the buffer memory 3 per unit time is relatively large.

Therefore, in the reading speed correspondence table, the communication speed and the reading speed are set to be in a proportional relationship, and the lower the transmission speed, the lower the reading speed. At each communication speed, the reading speed in the photograph mode is set to half the reading speed in the character mode. Note that the reading speed (V) is set as a reduction rate with respect to the highest reading speed (400 l / s) at each reading linear density. For example, in the case of the communication speed (9600 bps) and the reading mode (ordinary character, photograph), The reduction rate is 1/4, indicating that the reading speed is set to 100 l / s.

Next, the procedure of the direct transmission process in the facsimile machine 1 will be described with reference to FIG.

In the figure, the CPU 13 has a scanner 2
It is monitored whether or not the original is set (No loop of judgment 201), and when the original is set (Yes of judgment 201).
s) It is monitored via the operation display unit 5 whether there is a designation input of a transmission destination (No loop of decision 202), and if there is a designation input (Yes of decision 202), a [Start] key for instructing the start of transmission 9e is pressed or not (determination 203).
No loop), when pressed (Ye in decision 203)
s) Instruct the communication control unit 15 to call the destination specified in the judgment 203 (process 204), and perform a pre-transmission procedure based on the G3 facsimile protocol (process 205).
In the pre-transmission procedure, communication parameters are determined within a common range of the capability of the own device including the communication speed and the capability of the partner device, and the communication speed is also determined.

When the pre-transmission procedure of the process 205 is completed, the determined communication speed and the reading mode (character or photo) and the reading linear density set at the present time by the setting processing procedure shown in FIG. Reading speed correspondence table 7
With reference to a, the corresponding reading speed is determined as the reading speed in the scanner 2 (step 206).

The CPU 13 controls the driving pulse supplied from the pulse generator 2b to the stepping motor 2a at the set reading linear density, and
The original image information is read at the determined reading speed and stored in the buffer memory 3, while the image information stored in the buffer memory 3 is read line by line in the order in which the image information was stored. A process (process 207) of binarizing by binarization or pseudo halftone processing, and encoding and compressing and transmitting the encoded data to the encoding / decoding unit 14 is as follows.
The process is repeated until the reading of the document set on the scanner 2 is completed (No loop of the determination 208). When the reading is completed (Yes of the determination 208), the direct transmission process is terminated.

As a result, the lower the communication speed determined with the destination device, that is, the lower the reading speed of image information from the buffer memory 3 (the number of read lines per unit time), the lower the speed in the scanner 2 becomes. Since the reading speed is reduced, the chance that the buffer memory 3 becomes full of unprocessed image information can be greatly reduced, the chance that the sub-scanning of the scanner 2 is stopped can be reduced, and the occurrence of the intermittent operation of the sub-scanning is almost eliminated. Can be eliminated.

When the reading mode is the photograph mode,
That is, when the processing is relatively complicated, the binarization processing speed is slower than in the character mode, and the reading speed of image information from the buffer memory 3 is slow, the reading speed in the scanner 2 is also slow. Opportunities for the memory 3 to be filled with unprocessed image information can be greatly reduced, opportunities for stopping the sub-scanning of the scanner 2 can be reduced, and intermittent operation of the sub-scanning can be almost eliminated.

The CPU 13 controls the communication control unit 15 and reads the plotter 4 in addition to the reading process by the scanner 2.
Recording processing, P via the PC interface 10
While other processing must be performed in parallel during reading, such as image information transfer with the C30, the processing capacity of the CPU 13 has a processing speed limit that is limited by the apparatus cost. Therefore, when performing a plurality of processes at the same time, the processes cannot be performed at the same processing speed as when each process is performed one by one. The speed, that is, the speed at which image information is read from the buffer memory 3 and processed at a subsequent stage is reduced.

For example, a received image received in memory during execution of memory transmission is output by the plotter 4, and the image information stored in the memory is output to the PC via the PC interface 10.
In the case where the image information is read by the scanner 2 while the image information is being transferred to the scanner 30 and the case where the image information is read by operating the scanner 2 alone, the speed of the image information processing is obviously lower in the former case. If the scanner 2 reads original image information at the same reading speed without considering parallel operations with other processes, the buffer memory 3 tends to be full of unprocessed image information, and Intermittent operation is likely to occur.

Therefore, as shown in FIG. 8, a reading speed correspondence table 7b is stored in the parameter memory 7 in advance, and the
The reading speed of the scanner 2 may be determined based on the degree of the parallel processing in U13, and the occurrence of the intermittent operation of the sub-scan of the scanner 2 may be suppressed.

In the figure, the reading speed table 7b
The reading speed in each reading mode is set to be slower as the value of the closing degree is larger. The parallel processing degree 0 is
When the CPU 13 performs only the reading process by the scanner 2, the parallel processing degree n (n = 1, 2, 3, 4) is
This means that the CPU 13 is performing n other processes other than the reading process by the scanner 2.

When reading original image information by the scanner 2, the CPU 13 determines its own parallel processing degree,
The determined parallel processing degree is stored in the reading speed correspondence table 7b.
Then, the reading speed is determined, and the scanner 2 reads the document image information at the determined reading speed.

As a result, the degree of parallel processing increases, and the CP
The amount of time that the image information is read from the buffer memory 3 by the U13 decreases, and the buffer memory 3
The writing speed of the image information to the memory becomes slow. As a result, the buffer memory 3 is less likely to become full, and the intermittent operation of the scanner 2 in the sub-scanning is less likely to occur.

Next, a reading speed change processing procedure performed in the facsimile machine 1 will be described with reference to FIG.

In the figure, the CPU 13 monitors whether there is a combination operation of pressing the [Function] key 5f and inputting the number “80” by the numeric keypad 5a to call the reading speed changing function (No loop of the judgment 301). ), If there is (Yes in decision 301), the display 5h
0 is displayed to prompt the user to input the communication speed, and the reading mode currently set by the setting processing procedure of FIG. 3 is displayed (in the display D01,
(Photograph character: ordinary character)) (Process 302).

When a number sequence indicating a communication speed such as 14400 is input, the input communication speed number sequence is displayed on the display D01 and an input process for storing the input communication speed (process 303). [Ye
s] key 5b is pressed (No in decision 304)
loop).

When the [Yes] key 5b is pressed (Yes in decision 304), the display D shown in FIG.
02 is displayed to prompt the user to input the reading speed reduction rate (process 305), and waits for the [Yes] key 5b to be pressed (No loop of the determination 306).

When the [Yes] key 5b is pressed (Yes in decision 306), the reading speed reduction rate input according to the display D02 of the process 305 is transmitted to the communication input by the process 303 in the reading speed correspondence table 7a. The speed and the corresponding location specified by the reading mode set by the setting process procedure of FIG. 3 are registered (process 307).

Thus, the reading speed set in the reading speed correspondence table 7a can be set to a speed desired by the user. It should be noted that the setting can be similarly changed for the reading speed correspondence 7b.

In the above-described embodiment, the image reading apparatus according to the present invention is applied to a facsimile apparatus. However, the present invention is not limited to this. The present invention is similarly applicable.

[0071]

According to the first aspect of the present invention, the reading speed of the reading unit, that is, the number of lines of image information output per unit time, is changed according to the image information processing speed of the subsequent processing unit. Therefore, if the image information processing speed of the subsequent processing unit is slow, that is, if the number of lines of image information that can be processed per unit time is small, the image information output from the reading unit per unit time is controlled. The number of lines is reduced accordingly. As a result, image information that has not been processed by the subsequent processing means tends to remain in the buffer memory, and the buffer memory frequently becomes full of unprocessed image information. The reading by the reading unit is frequently stopped, and the sub-scanning by the sub-scanning unit is frequently stopped, and the chance of an intermittent operation in which restart is repeated can be greatly reduced. The effect that the deterioration of can be suppressed can be obtained.

According to the second aspect of the present invention, the reading speed of the reading means, that is, the number of lines of image information output per unit time, is controlled according to the image information transmission speed of the image information transmitting means. Therefore, if the image information transmission speed of the image information transmitting means is slow, that is, if the number of image information lines that can be transmitted per unit time is small, the number of image information lines output per unit time from the reading means Is reduced accordingly. As a result, image information that has not been transmitted to the destination apparatus by the image information transmitting means tends to remain in the buffer memory, and the buffer memory frequently becomes full of unprocessed image information. Therefore, it is possible to greatly reduce the chance that intermittent operation in which the reading by the reading unit is frequently stopped and the sub-scanning by the sub-scanning unit is frequently stopped and restarted repeatedly occurs. Thus, the effect that the deterioration of the image information can be suppressed can be obtained.

According to the third aspect of the present invention, the binarizing means is generally faster in a character mode having a small amount of image information per line and slower in a halftone mode having a large amount of image information according to the binarizing processing speed of the binarizing means. Reading speed of reading means,
That is, since the number of lines of image information output per unit time is controlled, if the binarization processing speed of the binarization unit is slow, that is, the number of lines of image information that can be binarized per unit time Is smaller, the number of lines of image information output from the reading unit per unit time is reduced accordingly. As a result, image information that has not been binarized by the binarization means tends to remain in the buffer memory, and the buffer memory often becomes full of unprocessed image information. In addition, the reading by the reading unit is frequently stopped, and the sub-scanning by the sub-scanning unit is frequently stopped. The effect that the deterioration of image information can be suppressed is obtained.

According to the fourth aspect of the present invention, the reading speed of the reading means, that is, the image information output per unit time, depends on the degree of parallel processing of the subsequent processing means with other processing means. Since the number of lines is controlled, other processing means operate simultaneously while the latter processing means is processing image information, and are allocated to the latter processing means of the entire processing capacity of the system. If the processing capacity to be processed is low and the image information processing speed of the subsequent processing unit is low, that is, if the number of lines of image information that can be processed per unit time is small, the image is output from the reading unit per unit time. The number of lines of image information is reduced accordingly. As a result, image information that has not been processed by the subsequent processing means tends to remain in the buffer memory, and the buffer memory frequently becomes full of unprocessed image information.
For this reason, it is possible to greatly reduce the chance that intermittent operation in which the reading by the reading unit frequently stops and the sub-scanning by the sub-scanning unit also frequently stops and restarts occurs. Thus, the effect that the deterioration of the image information can be suppressed is obtained.

According to the fifth aspect of the present invention, the reading speed stored in the reading speed table can be set to an arbitrary speed desired by the user, so that it is possible to widely support the usage pattern of each user. The effect of improving usability is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a block configuration of a facsimile apparatus to which an image reading apparatus according to an embodiment of the present invention is applied.

FIG. 2 is a diagram showing an arrangement configuration of an operation display unit of the facsimile apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a setting processing procedure in the facsimile apparatus according to the embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between a line sync signal and a motor pulse in the scanner of the facsimile apparatus according to the embodiment of the present invention.

FIG. 5 is a diagram showing correspondence between each line density and various parameters.

FIG. 6 is a diagram showing a reading speed correspondence table.

FIG. 7 is a flowchart showing a direct transmission processing procedure in the facsimile apparatus according to the embodiment of the present invention.

FIG. 8 is a diagram showing a reading speed correspondence table, which is different from FIG.

FIG. 9 is a flowchart illustrating a reading speed change processing procedure in the facsimile apparatus according to the embodiment of the present invention.

FIG. 10 is a diagram showing a display example in the processing procedure shown in FIG. 9;

[Explanation of symbols]

1 Facsimile machine 2 Scanner 2a Step motor 2b Pulse generator 3 Buffer memory 4 Plotter 5 Operation display 5a Numeric keypad 5b [Yes] key 5c [No] key 5d [Start] key 5e [Stop] key 5f [Function] key 5g Cursor Key group 5gd [Down arrow] key 5gl [Left arrow] key 5gr [Right arrow] key 5gu [Up arrow] key 5h Display 5i [Character mode] key 5ii, 5ji, 5ki, 5li, 5mi Indicator lamp 5j [Photo mode] ] Key 5k [ordinary character] key 51 l [small character] key 5m [fine character] key 6 image memory 7 parameter memory 8 battery 9 clock circuit 10 PC interface 11 RAM 12 ROM 13 CPU 14 encoding / decoding unit 15 communication control unit 16 Modem 17 Network control unit 18 System bus 30 Personal computer

Claims (5)

[Claims] 1. An image reading apparatus for reading original image information and outputting the read image information to a subsequent processing unit, wherein the reading unit reads the original image information in units of main scanning lines and sequentially outputs the original image information as long as a buffer memory is available. While the unit is reading, a sub-scanning unit that relatively moves the reading unit in the sub-scanning direction with respect to the document in accordance with the reading speed and the reading linear density, and line-by-line image information sequentially output from the reading unit Are sequentially stored, and a buffer memory for a plurality of lines, which is output in the order stored in response to the read request from the subsequent processing unit, and the reading speed of the reading unit according to the image information processing speed of the subsequent processing unit. An image reading apparatus comprising: reading speed control means for controlling. 2. A transmission rate is determined based on a predetermined transmission control procedure with a destination apparatus via a line, and the destination apparatus is connected to the destination apparatus at the determined transmission rate while reading original image information. An image reading apparatus provided with image information transmitting means for transmitting the original image information in units of a main scanning line and sequentially outputting the image information as long as there is a space in a buffer memory to be described later. A sub-scanning unit that relatively moves the reading unit in the sub-scanning direction with respect to the document in accordance with the reading speed and the reading linear density; and sequentially stores line-by-line image information sequentially output from the reading unit. A buffer memory for a plurality of lines, which is output in the order of storage in response to a read request from the image information transmitting means, and a reading speed corresponding to each of the transmission speeds that can be determined between the destination device, A reading speed correspondence table, and a reading speed control means for controlling a reading speed of the reading means to a reading speed corresponding to the transmission speed determined between the destination device and the reading speed correspondence table in the reading speed correspondence table. An image reading apparatus. 3. An image reading apparatus for reading original image information and outputting the read image information to a binarization unit at a subsequent stage, wherein the binarization method in the binarization unit is based on a simple binary
A binarization method setting means for setting either a character mode for digitizing or a halftone mode for pseudo-halftone processing of image information, and original image information in main scanning line units as long as there is a space in a buffer memory to be described later. Reading means for sequentially outputting reading; sub-scanning means for relatively moving the reading means in the sub-scanning direction with respect to the document in accordance with the reading speed and the reading linear density while the reading means is reading; A buffer memory for a plurality of lines for sequentially storing image information in line units sequentially output from the means and outputting the image information in the order of storage in response to a read request from the binarization means; A reading speed correspondence table in which reading speeds corresponding to
An image reading apparatus comprising: a reading speed control unit that controls a reading speed of the reading unit to a reading speed corresponding to the binarization method set by the binning method setting unit in the reading speed correspondence table. 4. An image reading apparatus for reading original image information and outputting the same to a subsequent processing means, wherein the reading means reads original image information in units of main scanning lines and sequentially outputs the original image information as long as a buffer memory is available. While the unit is reading, a sub-scanning unit that relatively moves the reading unit in the sub-scanning direction with respect to the document according to the reading speed and the reading line density, and line-based image information sequentially output from the reading unit. And a buffer memory for a plurality of lines, which is output in the order of storage in response to a read request from the subsequent processing unit, and a degree of parallel processing of the subsequent processing unit and another processing unit. A reading speed correspondence table in which the reading speed is stored in advance, and a reading corresponding to the current parallel processing degree of the subsequent processing means and another processing means in the reading speed correspondence table. An image reading device comprising: a reading speed control unit that controls a reading speed of the reading unit at a speed. 5. The apparatus according to claim 2, further comprising a reading speed changing unit that changes a reading speed stored in the reading speed table in accordance with an operation input. Image reading device.