JP2002218175A - Image reader and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader and an image forming apparatus that can prevent itself from being damaged due to traveling of a traveling body even when reading an original image by giving priority to the performance. SOLUTION: When transferring image data read by a photoelectric conversion element to an external device while storing the data in an image memory, and when reading of the original image is interrupted depending on the quantity of the image data in the image memory (Y in S14), a read speed at read restart can be adjusted in accordance with the interruption position (S21).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device such as an image scanner used in connection with a host machine such as a personal computer or an external device such as a printer, or a scanner section of a digital copying machine or a facsimile machine. The present invention relates to an image forming apparatus including a reading device.

[0002]

2. Description of the Related Art Conventionally, for example, a document and a light source are relatively moved in a sub-scanning direction by a stepping motor to optically read a document image exposed and scanned by a CCD, and read the read image data through an interface. There is an image reading apparatus which transfers the image data to an external device.

In such an image reading apparatus, the reading speed of a document image is uniquely determined in advance. Further, the transfer speed at which the read image data is transferred to the external device is fixed according to the processing speed of the external device.

Therefore, when a predetermined number of image data determined by the reading density and the reading area is transferred from the image reading device to the external device, the transfer speed at which the image data is transferred is relatively higher than the reading speed at which the document is read. If the image data is transferred to an external device without delay in the image reading device, the transfer speed for transferring the image data is relatively lower than the reading speed for reading the original image. An image memory such as a DRAM is provided in the image reading apparatus, image data is temporarily stored in the image memory, and the stored image data is transferred according to the transfer speed of the external device.

Generally, transfer of image data from an image reading device to an external device is performed by the following processes (1) and (2). (1) Store the read image data in an image memory such as a DRAM. (2) Transfer image data stored in an image memory such as a DRAM to an external device. The above processes (1) and (2) are performed simultaneously.

Here, if the speed of storing the image data in the image memory is relatively faster than the speed of transferring the image data stored in the image memory to an external device,
The image data gradually accumulates in the image memory.

On the other hand, since the capacity of the image memory is limited, when a document image is read at a high reading density,
If a predetermined amount or more of image data is accumulated in the image memory even when a large-capacity image memory such as a RAM is used, the stepping motor is stopped to stop reading the original image, and the image data in the image memory is stopped. Is reduced to a predetermined amount or less, the stepping motor is driven again to resume reading of the document image.

In the intermittent operation, a control method for gradually changing the drive speed of the stepping motor called a through-up and a through-down is adopted for the functional reason of the stepping motor.

The intermittent operation executed by the image reading apparatus as described above includes a normal intermittent operation for reading an original image even during execution of the step-up motor through-up and through-down control, and a through-up operation and a through-operation of the stepping motor. During the down control, there is an intermittent return operation in which the reading of the document image is executed only when the stepping motor is at a constant speed without reading the document image.

[0010] The normal intermittent operation is as shown in FIG.
In the section where the stepping motor is driven at a constant speed, the document image is read at a constant interval, and in the section where the stepping motor is through-up and through-down, the original image is read at a constant speed according to the acceleration or deceleration of the stepping motor. Also, the original image is read at an interval with a reduced frequency.

The intermittent return operation is as shown in FIG.
The document image is not read at all during the step-up and through-down sections of the stepping motor, and is read only during the section in which the stepping motor is driven at a constant speed. In the intermittent return operation, when reading of the original image is interrupted according to the amount of image data in the image memory,
A process of returning the original or the light source by a distance corresponding to the through-up and through-down sections of the stepping motor is performed so that the reading can be resumed from the position where the reading was interrupted.

When the original image is read by the normal intermittent operation, the return operation such as the return intermittent operation is not necessary to read the original image at all times when the stepping motor is driven. Even during execution, there is a limit to increasing the speed of reading a document image in order to read the document image satisfactorily without generating jitter.

For this reason, there is an image reading apparatus in which the driving speed of the stepping motor at the time of the return intermittent operation is higher than that of the normal intermittent operation. Thereby, the reading speed of the original image in the return intermittent operation is faster than the reading speed of the original image in the normal intermittent operation,
Performance can be improved.

[0014]

However, in the above-described image reading apparatus, the reading speed of the original image in the intermittent return operation can be made faster than that in the normal intermittent operation. Is set higher than the constant speed in the normal intermittent operation, the through-up and through-down sections are longer than the through-up and through-down sections in the normal intermittent operation due to the function of the stepping motor.

For this reason, when an original image is read by a return intermittent operation near the original image reading end position,
There is a concern that the device may be damaged due to the running body colliding with the wall because the through-up and through-down sections are insufficient.

Incidentally, Japanese Patent Application Laid-Open No. Hei 5-22531 discloses that
In order to enable selection between reading for preventing loss of image data and reading for speeding up, when reading an original, a first speed and a first reading speed set in advance are set. There is disclosed an image reading apparatus in which either one of the fast second speed is selectively set, and the speed at which the stepping motor is driven can be adjusted in two stages. Problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus and an image forming apparatus which can prevent a traveling body from colliding with a wall even when reading a document image in which performance is prioritized.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus and an image forming apparatus which can prevent damage to the apparatus due to the traveling of a traveling body even when reading a document image in which performance is prioritized.

[0019]

According to a first aspect of the present invention, there is provided an image reading apparatus for exposing an original image, and relatively moving the exposure optical system and the original image in the sub-scanning direction. A moving device, speed managing means for managing a relative moving speed between the exposure optical system and the document image by the moving device, and exposure scanning in a range where at least the speed managing means manages the moving speed at a constant speed A photoelectric conversion unit for reading the image data of the original image by a photoelectric conversion element, a memory unit for temporarily storing the image data read by the photoelectric conversion unit in an image memory, and the memory unit for temporarily storing the image data in the image memory. A data transfer unit for transferring the image data to an external device; a speed at which the memory unit stores the image data in the image memory; A reading suspending unit that suspends the image data reading by the photoelectric conversion unit according to the image data amount in the image memory due to a speed difference from a speed at which the image data is transferred to the external device; Interruption position judging means for judging whether the interruption position where the reading of the document image by the photoelectric conversion means is interrupted is on the reading start side or on the reading end side from a predetermined position set within the movable range in the sub-scanning direction. And speed setting means for setting the moving speed managed by the speed management means according to the interruption position judged by the interruption position judgment means.

Therefore, the photoelectric conversion means is provided at least within a range where the speed management means manages the moving speed at a constant speed.
The image data of the original image scanned and exposed by the exposure optical system is read by the photoelectric conversion element. The scanned image data is
The image data is temporarily stored in the image memory by the memory unit, and is transferred to the external device by the data transfer unit. When the reading interrupting unit interrupts the reading of the image data according to the image data amount in the image memory due to the speed difference between the storage speed of the image data and the transfer speed to the external device, the interruption position determined by the interruption position determining unit The moving speed managed by the speed management means is set by the speed setting means in accordance with. This makes it possible to set the moving speed at the time of resuming reading according to the position where reading of the document image was interrupted.

According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, when the interrupt position determining means determines that the interrupt position is closer to the reading end side than the predetermined position, the speed setting means is provided. Sets the moving speed lower than the moving speed before the reading of the document image is interrupted.

Therefore, when the interruption position is judged by the interruption position judging means to be on the reading end side from the predetermined position, the speed is set to be lower than the moving speed before the interruption of the reading of the original image by the speed setting means. The moving speed is set. As a result, even when the exposure optical system or the like collides with the wall and the reading is interrupted at a position where there is a possibility of damage to the apparatus due to the lack of the through-up and the through-down sections at the normal moving speed, the traveling body can be held on the wall. It is possible to prevent collision.

The invention according to claim 3 is the invention according to claim 1 or 2
In the image reading device described in the above, the data transfer means,
SC as an interface between the device and the external device
It uses SI.

Therefore, since the SCSI which is a general-purpose interface is used for the data transfer means, it is not necessary to newly develop a dedicated interface.

The invention described in claim 4 is the first or second invention.
In the image reading device described in the above, the data transfer means,
IE as an interface between the device and the external device
EE1394 is used.

Therefore, since IEEE1394 which is a general-purpose interface is used for the data transfer means,
There is no need to develop a dedicated interface.

According to a fifth aspect of the present invention, there is provided an image forming apparatus comprising: the image reading apparatus according to any one of the first to fourth aspects;
A printer device for forming an image read by the image reading device on a sheet.

Therefore, an image read by the image reading device according to any one of claims 1 to 4 is formed on a sheet by the printer device. Thereby, claim 1
To (4).

[0029]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. In this embodiment, an image reading apparatus is applied to a color image scanner.

FIG. 1 is a side sectional view showing a color image scanner according to a first embodiment of the present invention. The color image scanner 1 includes a scanner body 2 and a scanner body 2.
ARDF (automatic double-sided document feeder) 3
Consists of

On the upper surface of the casing 4 of the scanner body 2, a document table glass 5 on which a document is placed when reading a document image in the book mode, and an ADF (Automatic Document).
and a DF (Document Feeder) glass 6 used when reading a document image in the (t Feeder) mode.

Here, the book mode is an operation mode for reading an original image placed on the original platen glass 5, and the ADF mode is for automatically feeding an original by the ARDF3 and automatically feeding the original. This is an operation mode for reading the original image when the original passes through the DF glass 6.

A keyboard having various keys such as a start key and an abort key is provided outside the casing 4.
(Not shown) and a main body operation panel 7 (see FIG. 2) provided with a display (not shown). Further, the keyboard is provided with a mode key for receiving a setting instruction of a reading mode in an image reading process described later when operated. The mode key is a normal mode key for setting a normal mode for executing a normal intermittent operation,
And a high-speed mode key for setting a high-speed mode for performing a return intermittent operation.

Inside the casing 4, a first traveling body 10 having an illumination lamp 8 and a mirror 9 and capable of traveling along the original table glass 5, and mirrors 11 and 12 are provided along the original table glass 5. A movable second traveling body 13, a lens 14, and a color CCD (Charge Co.) as a photoelectric conversion element.
SBU (Sensor BoardUn
it) 16 are provided. Illumination lamp 8, mirrors 9, 11, 12, first traveling body 10, and second traveling body 13
Thus, an exposure optical system 17 is formed. The first and second traveling bodies 10 and 13 are driven by a stepping motor 18 as a moving device, and travel from left to right in FIG. 1 at a speed ratio of 2: 1.

Although the detailed description is omitted because it is a known technique, the stepping motor 18 cannot be driven instantaneously at a constant speed due to the function of the stepping motor 18. Through-up control in which the number is gradually increased until the number reaches a preset predetermined number of pulses, and through-down control in which the number of drive pulses is gradually decreased until the number reaches a predetermined number of pulses is taken. .

In the casing 4, an SCU (Scanner C) equipped with an electrical system for controlling the operation of the color image scanner 1 including the scanner body 2 and the ARDF 3 is mounted.
ontrol Unit) 19 is provided. Further, inside the casing 4, a document size sensor (width) 20 for detecting the size of a document placed on the platen glass 5 when reading a document image in the book mode, and a document size sensor (length) 21 are provided (see FIG. 2).

The ARDF 3 has a document table 22 on which a document is placed when reading a document in the ADF mode, a discharge section 23 from which the read document has been discharged, and a discharge section 23 from the document table 22 to the discharge section 23. A communicating guide path 24 and a reversing unit 25 for reversing the original in the duplex reading mode are provided.

Here, the duplex reading mode is an ARDF3
In this operation mode, the document is automatically fed and the front side image is read, and then the document is turned over and the back side image is read.

The document table 22 is provided with a document guide 26 for guiding both sides of the document when the loaded document is transported to the guide path 24. The platen 22 has A
When reading a document in the DF mode, a set sensor 27 that detects whether a document is placed on the document table 22 or not.
A width size detection sensor 28 for detecting the size of the original placed on the original platen 22, original length sensors 29 and 30,
A document trailing edge sensor 31 for detecting the trailing edge of the document is provided. In the present embodiment, the set sensor 27,
Width size detection sensor 28, document length sensors 29, 30,
The document trailing edge sensor 31 is a reflection type optical sensor. In the ADF mode, the size of the document placed on the platen 22 is automatically designated by these sensors even when the size of the document is not designated by operating the paper designation key or the number key. You.

On the document table 22 side of the guide path 24, the documents placed on the document table 22 are separated one by one into
Caller roller 32 and separation roller 3 for feeding
3. A paper feed belt 35 wound around a transport roller 34 that transports the document in the guide path 24 to the paper discharge unit 23, a first and a second belt
A transport unit 39 formed by transport rollers 36 and 37, a paper discharge roller 38, and the like is provided.

The reversing section 25 includes a reversing path 40 having one end communicating with a branch point P branching from the middle of the guide path 24 and a reversing table 41 continuously attached to the other end of the reversing path 40. Is provided. The reversing table 41 is provided with a reversing roller 42 driven by a sheet feeding / reversing motor 52a (see FIG. 2) to be rotatable forward and backward. A branch claw 44 that is rotatable around a support shaft 43 is attached to the reversing path 40. The reversing path 40 is opened and closed by the rotation of the branch claw 44.

The reading of the document image and the reversing operation of the document in various modes such as the book mode, the ADF mode, and the double-side reading mode are well-known techniques, and thus the description thereof is omitted.

Next, referring to FIGS. 2, 3 and 4, an outline of the electrical connection and operation of each unit included in the color image scanner 1 will be described. FIG. 2 is a block diagram showing the electrical connection of each unit included in the color image scanner 1, FIG.
FIG. 4 is a block diagram schematically showing the flow of image data.

Color CC on which reflected light from the original is incident
In D15, the input reflected light is converted into analog image data of each color of RGB having a voltage value corresponding to the intensity of the light.

SBU 1 equipped with this color CCD 15
Reference numeral 6 denotes an LSYNC (main scanning line synchronization signal) output from the RIPU 45 mounted on the SCU 19 and an LGA
By the TE (main scanning line data output period), the color CC
The analog image data of each color of RGB, which has been photoelectrically converted in D15, is divided into odd bits and even bits, and is divided into two parts.
Having the function of relaying the power supply of electrical components used for
VIOB 47 to which DU (ADF Driving Unit) 46 is connected
Are output sequentially.

The VIOB 47 removes the dark potential portion from the input analog image data by the analog processing circuit 48, combines the odd bits and the even bits, and adjusts the gain to a predetermined amplitude. (Analog / Digital)
The converter 49 performs a process of converting the digital signal. A /
The digital image data converted into a digital signal by the D converter 49 is a shading ASIC (Application Speci
fic Integrated Circuit) 50 to the SCU 19.

The digital image data input to the SCU 19 is subjected to shading correction, gamma correction, MTF correction, and the like by the RIPU 45, and then binarized, and output together with a page synchronization signal, a line synchronization signal, and an image clock.

Although the description is omitted because it is a known technique, in the shading correction executed in the SCU 19, the line memory 45a connected to the RIPU 45 is used.
Of the original image is corrected based on the white reference data stored in.

By the way, on the SCU 19, a CPU 51 (see FIG. 4) for centrally controlling and driving each unit, a ROM (not shown) for storing fixed data in advance, and a variable data for rewritably stored. A microcomputer (not shown) including a RAM (not shown) and the like is mounted.

The ROM stores the traveling speeds of the first and second traveling bodies 10 and 13 during an image reading process described later.
A speed data file storing speed data relating to the number of drive pulses per unit time of the stepping motor 18 for determining (moving speed) is stored.

For example, the speed data corresponding to the high-speed mode indicates that the traveling speeds of the first and second traveling bodies 10 and 13 are the first and second traveling bodies 10 and 13 under the setting of the normal mode.
Is the number of drive pulses per unit time of the stepping motor 18 for driving the stepping motor 18 so as to be faster than the traveling speed of the stepping motor 18.

In an image reading process to be described later, a stepping motor 18 that is driven from the start of reading to the interruption of reading of the original image by detecting near full upon reading and exposure of a single original image is described in the RAM. However, an interruption position information storage area for temporarily storing the interruption position information is secured. Also,
In the RAM, a set pulse number storage area for storing the number of drive pulses for driving the stepping motor when reading a document image is secured. In the set pulse number storage area, an operation mode set by an operator's operation and optimal speed data are appropriately updated and stored in an image reading process described later.

The CPU 51 includes a stepping motor 18,
It also controls the timing of the feed / reverse motor 52a and the transport motor 52b of the ARDF3. In particular, the CPU 51
When the stepping motor 18 is driven, the stepping motor 18 is driven with an appropriate number of drive pulses based on the currently set speed data with reference to the set pulse number storage area. Here, a function as a speed management unit is executed.

Although not shown, the main body operation panel 7 is connected to an input port connected to the CPU 51 via a VIOB 47. When each key provided on the keyboard of the main body operation panel 7 is operated, the CPU 51
Detects that each key has been operated through the input port.

The digital image data output from the RIPU 45 is stored in an OIPU (Optio) connected to the SCU 19.
n Image Process Unit) 54.

The OIPU 54 performs predetermined image processing on the input digital image data, and again executes the SCU.
Output to # 19.

The digital image data input to the SCU 19 is input to the video input switching circuit 55 again. The video input switching circuit 55 is provided with digital image data supplied from the RIPU 45 to the other input, and is formed so as to select whether or not to undergo image processing by the OIPU. Video input switching circuit 5
The output signal from SIBC (Scanner Image Buffer)
Controller) 56, 57 or an NIC that is an expansion board for adding a communication function for connecting the color image scanner 1 to a LAN (Local Area Network).
(Network Interface Card) 58 and transferred to a host computer (not shown) which is an external device.

The SIBC 56 converts the digital image data output from the video input switching circuit 55 into an SDRAM
(Synchronous DRAM) image memory (not shown)
Temporarily, and then SCSI (Small Computer Syst
em Interface) sequentially output to the controller 59.

The SCSI controller 59 is provided with the SIBC5
6. The image data input from 6 is transferred to an external device.

The SIBC 57 is provided on the IEEE 1394 board, and sequentially outputs the digital image data output from the video input switching circuit 55 to the LINE 60 provided on the IEEE 1394 board. LIN
E60 outputs the input image data to PIEY61 provided in IEEE1394. PIEY61 is
The input image data is transferred to an external device. SIBC
57, LINE60, IEEE13 by PIEY61
A 94 controller 62 is formed.

The color image scanner 1 of the present embodiment
As a data transfer means for transferring image data to a host computer, a general-purpose interface SCS
I and IEEE1394 are used freely.

More specifically, based on the control program stored in the ROM, in the original image reading processing executed by the CPU 51 under the setting of the book mode which is the original fixed mode, the CPU 51 The driving of the stepping motor 18 for driving the traveling bodies 10 and 13 is controlled via a motor driver, and the transfer of image data to a host computer, which is an external device, is controlled by S.
It is controlled via the CSI controller 59 or the IEEE 1394 controller 62.

Next, a data transfer method using SCSI as an interface between the color image scanner 1 and an external device (not shown) such as a personal computer or a printer will be described.

The data transfer methods on the SCSI are classified into basic asynchronous transfer and synchronous transfer which can be performed at a high speed in terms of transfer rate.

Asynchronous transfer is the basis of the transfer method, and information transfer other than data transfer (for example, message,
Status) is also transmitted by this transfer method. Specifically, R
This is based on handshaking by EQ / ACK. In this transfer mode, transfer of about 1.5 Mbytes / sec is possible.

On the other hand, synchronous transfer is a mode for high-speed data transfer, and can be used only in the data phase. Use of this synchronous transfer mode for data transfer requires agreement between the target initiators. This consent is for the Synchronous Data Transfer Request
"REQ / ACK"
This is performed by arranging two values of “offset value” and “minimum transfer synchronization”. In this transfer mode, 10
High-speed transfer up to Mbytes / sec is possible.

Next, a data transfer method and a data transfer speed when the IEEE 1394 is used as an interface between the color image scanner 1 and an external device (not shown) such as a personal computer or a printer will be briefly described.

IEEE 1394 is 100M / 200M
And hardware and software standards for 400 Mbps data transfer. It has a unique function for plug-and-play and multimedia data transfer, a function that secures a band for transferring data such as video and audio, and enables real-time transfer (isochronous data transfer, isochronous )have. The data transfer systems on IEEE 1394 are classified into two types: isochronous transfer and asynchronous transfer.

The isochronous transfer has an advantage that the data transfer speed is guaranteed. Specifically, at least one packet can be sent every 125 μsec per channel, talkers and listeners can be set up to 64 channels per node, and 10
The maximum packet size is determined by the data transfer rate of 0M / 200M or 400Mbps.

Asynchronous transfer can be performed only after all isochronous transfers have been completed.
An isochronous transfer is point-to-point, whereas an isochronous transfer has the concept of a channel and is somewhat similar to a broadcast where talkers and listeners are defined. Each transaction has an ID of the destination and destination associated with it.

Next, an image reading process executed by the CPU 51 based on the control program stored in the ROM will be described with reference to FIGS. FIG. 5 is a flowchart schematically showing the image reading process in the book mode. Although the image reading process in the book mode is described in the present embodiment, the same applies to other operation modes such as the ADF mode.

In the image reading process, first, the VIOB 47
And waits until it detects that the operator has operated the start key by determining the presence or absence of a signal input to the SCU 19 (S1).

When it is determined that the start key has been operated by determining that a signal has been input to the input port of the CPU 51 (Y in S1), the reading mode is set to the normal mode or the high-speed mode. Is determined (S2).

In the color image scanner 1 of the present embodiment, the reading mode corresponding to the mode key operated by the operator is not changed until the start of the image reading process is instructed by the operation of the start key by the operator. Set.

In the color image scanner 1 according to the present embodiment, the operation of the start key
If no special mode key operation is performed, the normal mode is set as a default.

If it is determined that the reading mode is set to the normal mode (Y in S2), the stepping motor 18 is driven based on the speed data in the normal mode by referring to the set pulse number storage area, and The illumination lamp 8 is turned on (S3).

Thus, with the illumination lamp 8 turned on, the first and second traveling bodies 10 and 13 travel in the sub-scanning direction, and the original image is exposed and scanned.

The color CCD 15 receives the reflected light from the document image that has been exposed and scanned, and performs photoelectric conversion to obtain analog image data.

The analog image data is supplied to the analog processing circuit 48 of the VIO 47B, the A / D converter 49, the shading ASIC 50, the RIPU 45 of the SCU 19, the OI
When the signal passes through the PU 54, the video input switching circuit 55, and the like, the above-described predetermined processing is performed, the image data is converted into digital image data, and the image data is sequentially temporarily stored in the image memory.
(S4).

The digital image data stored in the image memory is sequentially processed by the data transfer process shown in FIG.
The data is transferred to an external device via the CSI controller 59 and the like.

Since the capacity of the image memory is limited, the speed of temporarily storing digital image data in the image memory in step S4 exceeds the speed of transferring the digital image data stored in the image memory to an external device. In this case, even when a large-capacity image memory such as an SDRAM is used, digital image data in the image memory gradually accumulates. When digital image data in the image memory is accumulated for a predetermined amount or more (hereinafter, referred to as
It is assumed that “memory near full”), and a memory near full interrupt signal is output as shown in FIG.

When it is determined that the memory is nearly full (Y in S5), the drive of the stepping motor 18 is stopped by the through-down control (S6).

When it is determined that the number of drive pulses of the stepping motor 18 has become 0 by performing the through-down control (Y in S7), the illumination lamp 8 is turned off (S7).
8) Only transfer of digital image data is performed.

As a result, the amount of image data in the image memory gradually decreases. When the digital image data amount in the image memory becomes equal to or less than a predetermined amount smaller than the previously set near full (hereinafter referred to as “memory empty”), as shown in FIG. Is output.

As a result, when it is determined that the memory is empty (Y in S9), the process returns to step S3.

Under the setting of the normal mode, which is the reading mode in which the normal intermittent operation is performed from step S3 to step S9, the original image exposed when the driving speed of the stepping motor 18 is accelerated or decelerated is partially changed. By reading the thinned image data by the color CCD 15, the original image is read even during the through-up and through-down of the stepping motor 18, and the stepping motor 18 stops when the reading of the original image is completed.

Thus, under the setting of the normal mode,
Regardless of the position within the movable range in the sub-scanning direction where the reading of the document image is interrupted, the first and second traveling bodies 1
0, 13 can be prevented from colliding with the casing 4 and being destroyed.

FIG. 7 is a flowchart schematically showing the data transfer process. The data transfer process is executed in parallel with the image reading process shown in FIG.

In the data transfer processing, the presence or absence of digital image data in the image memory is determined, and the process waits until it is determined that digital image data is present in the image memory (S3).
1).

If it is determined that there is digital image data in the image memory (Y in S31), the preset S
The digital image data is transferred by the CSI controller 59 or the IEEE 1394 controller 62.
(S32). Here, a function as a data transfer unit is executed.

If it is determined that the memory is empty based on the amount of digital image data in the image memory (Y in S33), a memory empty interrupt signal is output (S34).

On the other hand, if it is determined in step S2 in FIG. 5 that the reading mode is set to the high-speed mode (S2).
2) N, referring to the set pulse number storage area, the above-described through-up control is performed until it is determined that the number of drive pulses of the stepping motor 18 has reached the predetermined number of drive pulses (Y of S11). Is performed (S10).

When it is determined that the number of drive pulses of the stepping motor 18 has reached the predetermined number of drive pulses (Y in S11), the illumination lamp 8 is turned on.
(S12).

As a result, the first and second traveling bodies 1
The reference numerals 0 and 13 travel in the sub-scanning direction to expose and scan the original image, and the reflected light from the original image is received by the color CCD 15. The color CCD 15 photoelectrically converts reflected light from the received document image to obtain analog image data. Here, a function as a photoelectric conversion unit is executed.

The analog image data is subjected to predetermined image processing to obtain digital image data, and the digital image data is stored in the image memory in parallel with the data transfer processing (see FIG. 7) (S13). Here, the function as the memory means is executed.

When it is determined that the memory is near full,
(Y of S14), the illumination lamp 8 is turned off, the stepping motor 18 is stopped by the through-down control, and the interruption position information where the reading of the document image is interrupted is stored in the interruption position information storage area (S15).

When it is determined that the reading of the original image has been interrupted by determining that the number of driving pulses of the stepping motor 18 has become 0 by performing the through-down control (Y in S16), the stepping is performed by the through-up control. After driving the motor 18 in the reverse direction (S17),
By stopping the stepping motor 18 by the through-down control (S18), the first traveling body 13 is moved backward from the first stop position. Here, a function as a reading interruption unit is executed.

In this embodiment, the stepping motor 1
Although the traveling body is moved backward by performing the through-up and the through-down control of 8, the vehicle is not limited to this, and may return at a low speed and a constant speed.

In any case, by retreating the first traveling body 10, when reading the original image is resumed, the first traveling body 10 is advanced by the through-up control until the stepping motor 18 reaches a constant speed. Enough runway distance is ensured. In the present embodiment, the first traveling body 10 is retracted by 30 mm from the initial stop position, but the distance by which the first traveling body 10 is retracted is not limited to this.

Referring to the position information storage area, when reading a single document image, drive pulse number data is obtained, and the obtained drive pulse number data is compared with the limit pulse number stored in the ROM ( S19), it is determined whether the driving pulse number is larger or smaller than the limit pulse number (S2).
0). Here, the function as the interruption position determination means is executed.

If the number of drive pulses is larger than the limit pulse number (Y in S20), the number of drive pulses per unit time of the stepping motor is currently set with reference to the speed data file and the set pulse number storage area. Set to a value smaller than the number of drive pulses per unit time (S
21). Here, a function as speed setting means is executed.

Thus, when the reading of the document image is restarted, the moving speed is set to be lower than the moving speed at the time when the near full is detected and the reading is stopped in step S14.

If the number of drive pulses is smaller than the limit pulse number (N in S20), the process proceeds to step S22 with the drive pulse number data per unit time as it is.

In step S22, the process waits until it is determined that the memory is empty by outputting a memory empty interrupt signal (N in S22). If it is determined that the memory is empty (Y in S22), the process proceeds to step S22. Proceed to S10.

In the present embodiment, step S10
Each processing executed from step S19 to step S19 is a return intermittent operation (see FIG. 9B).

The number of drive pulses per unit time of the stepping motor 18 under the high-speed mode setting stored in the speed data file is larger than the number of drive pulses per unit time of the stepping motor 18 under the normal mode setting. Therefore, the traveling speed of the first and second traveling bodies 10 and 13 in the high-speed mode setting is higher than that in the normal mode setting.

Thus, even when the high-speed mode is set, the moving speed at the time of resuming the reading is appropriately set according to the position where the reading was interrupted. Even if the reading is interrupted at a position where breakage of the apparatus due to collision of the first and second traveling bodies 10 and 13 with the wall due to lack of the through-up and through-down sections at the speed as it is, the traveling body Can be prevented from colliding with the wall.

Thus, even when reading the original image in the intermittent return operation in which performance is prioritized, the first
Further, it is possible to prevent breakage due to the collision of the second traveling bodies 10 and 13 with the casing 4.

In the present embodiment, the data relating to the driving speed of the stepping motor 18 is set in two stages. However, the present invention is not limited to this. The speed data is associated with each of a plurality of interruption position data. A file may be provided, and the speed data to be updated may be adjusted in a plurality of stages according to the position where the reading is interrupted. As a result, the performance and the reliability can be more effectively improved.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment shows an example of application to an electrophotographic copying machine as an image forming apparatus.

FIG. 8 is a side sectional view showing a copying machine according to the second embodiment. The copier 63 includes the color image scanner 1 described in the first embodiment and a printer unit 64 as a printer provided below the color image scanner 1.

Although the image scanner 1 has the same configuration as the image scanner 1 of the first embodiment, in the present embodiment, a read document image is obtained as monochrome image data.

In the printer unit 64, a paper transport path 69 is formed from a tray 65 for laminating the paper to an output stacker 68 via an electrophotographic printer 66 and a fixing device 67. Around a photoconductor 70 provided substantially at the center of the printer unit 66, a charger 71 for uniformly charging the surface of the photoconductor 70, a color image scanner 1
An exposure device 72 for exposing the image of the document read on the photoconductor 70 on the surface of the document; a developing device 73 for developing the latent image formed on the surface of the photoconductor 70 by exposing the toner to a visible image; The transfer unit 74 is formed by a transfer unit 74 that transfers a visible image onto a sheet conveyed in the conveyance path 69.

In the copying machine 63 of this embodiment, an image forming operation for forming an image of a read document on a sheet by the printer unit 66 in accordance with the reading mode of the color image scanner 1 set by the operator. The operation mode is set. Specifically, the image forming operation in each image forming operation mode executed by the printer unit 64 is the same, but when the normal mode is set for the color image scanner 1, the normal image forming mode is set. When the high-speed mode is set, the high-speed image forming mode is set.

In such a configuration, the image of the original read by the color image scanner 1 is
As a result, the toner image is formed on the paper conveyed with the timing adjusted in the paper conveyance path 69, and is fixed by the fixing device 67.

According to the copying machine 63 of this embodiment, when the high-speed image forming mode is set in the image forming operation for forming the image of the original read by the color image scanner 1 on the paper by the printer section 66, Also,
Since the moving speed at the time of resuming the reading is appropriately set according to the position where the reading in the color image scanner 1 is interrupted, the performance is prioritized, and the first and second traveling bodies 10 and 13 collide with the wall. The device can be prevented from being damaged.

As a result, a copying machine 63 which is highly convenient for the operator can be provided.

In this embodiment, the printer section 66 is of the electrophotographic type. However, the present invention is not limited to this. For example, the present invention may be applied to an ink jet printer having an ink jet.

Further, in the present embodiment, an example in which the image forming apparatus is applied to the copying machine 63 has been described. However, the present invention is not limited to this, and may be applied to, for example, a facsimile.

[0120]

According to the image reading apparatus of the first aspect of the present invention, at least in a range where the moving speed is controlled at a constant speed, the exposure optical system performs exposure scanning, reads by the photoelectric conversion element, and reads the image into the image memory. When transferring the temporarily stored original image data to an external device, the reading of the image data is interrupted according to the amount of image data in the image memory due to the speed difference between the image data storage speed and the transfer speed to the external device. And
By setting the moving speed according to the interruption position,
Since it is possible to set the moving speed at the time of resuming reading according to the position where the reading of the document image was interrupted, for example, as in the invention according to the second aspect, the determined interruption position starts reading from a predetermined position. By setting the moving speed at the time of resuming reading depending on whether it is on the side or the reading end side, the traveling body may collide with the wall even when reading the original image in the intermittent return operation with priority on performance Can be prevented. As a result, even when reading a document image in which performance is prioritized, it is possible to prevent damage to the apparatus due to the traveling of the traveling body.

According to the second aspect of the present invention, in the image reading apparatus according to the first aspect, when the interruption position is on the reading end side from the predetermined position, the moving speed before the interruption of the original image reading is reduced. By setting the moving speed so as to be slower, at the moving speed that is increased to give priority to performance in the intermittent return operation, the through-up and through-down sections are not enough, and the exposure optical system etc. Even when reading is interrupted at a position where there is a concern that the vehicle may be damaged, it is possible to prevent the traveling body from hitting the wall. As a result, even when reading a document image in which performance is prioritized, it is possible to prevent damage to the apparatus due to the traveling of the traveling body.

The third aspect of the present invention is the first or second aspect.
In the image reading apparatus described above, since the SCSI which is a general-purpose interface is used for the data transfer means, the effects described in claim 1 or 2 can be realized at low cost without newly developing a dedicated interface. .

The invention described in claim 4 is the first or second invention.
In the image reading apparatus described above, since the IEEE 1394, which is a general-purpose interface, is used as the data transfer unit, the effects described in claim 1 or 2 can be realized at low cost without newly developing a dedicated interface. .

According to a fifth aspect of the present invention, there is provided an image forming apparatus including the image reading device according to any one of the first to fourth aspects, wherein the image read by the image reading device is formed on a sheet. An image read by the image reading device according to any one of Items 1 to 4 can be formed.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a color image scanner according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating an electrical connection of each unit included in the color image scanner.

FIG. 3 is a block diagram showing an excerpted part of the information;

FIG. 4 is a block diagram schematically showing a flow of image data.

FIG. 5 is a flowchart schematically illustrating an image reading process.

FIG. 6 is a timing chart in an image reading process.

FIG. 7 is a flowchart schematically showing a data transfer process.

FIG. 8 is a side sectional view showing a copying machine according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating a reading interval of a document image in a normal intermittent operation and a return intermittent operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image reading device 15 Photoelectric conversion element 17 Exposure optical system 18 Moving device 63 Image forming device 64 Printer device

Claims (5)

[Claims] 1. An exposure optical system for exposing a document image, a moving device for relatively moving the exposure optical system and the document image in a sub-scanning direction, the exposure optical system and the document image by the moving device Speed management means for managing a relative moving speed with respect to the image data; and photoelectric conversion means for reading, by a photoelectric conversion element, at least image data of the original image which is exposed and scanned in a range where the speed management means manages the moving speed at a constant speed. Memory means for temporarily storing the image data read by the photoelectric conversion means in an image memory; data transfer means for transferring the image data temporarily stored in the image memory to the external device; and the memory A speed at which the means stores the image data in the image memory and a speed at which the data transfer means transfers the image data to the external device. Reading interruption means for interrupting the reading of the image data by the photoelectric conversion means in accordance with the image data amount in the image memory due to a difference in degree; and the reading interruption means interrupting the reading of the original image by the photoelectric conversion means. An interruption position determining unit that determines whether the interruption position is on a reading start side or a reading end side from a predetermined position set within a movable range in the sub-scanning direction; and the interruption position determined by the interruption position determination unit. Speed setting means for setting the moving speed managed by the speed management means in accordance with the following. 2. The method according to claim 1, wherein the interruption position determination unit determines that the interruption position is closer to the reading end side than the predetermined position, and the speed setting unit sets the moving speed to the value before interrupting the reading of the document image. The image reading device according to claim 1, wherein the image reading device is set to be lower than the moving speed. 3. The image reading apparatus according to claim 1, wherein said data transfer means uses SCSI as an interface between said apparatus and said external apparatus. 4. The image reading apparatus according to claim 1, wherein said data transfer means uses IEEE1394 as an interface between said apparatus and said external apparatus. 5. An image forming apparatus comprising: the image reading device according to claim 1; and a printer device that forms an image read by the image reading device on a sheet.