JP3358730B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to carriage control in an image reading apparatus.

[0002]

2. Description of the Related Art FBS (Flatbed Scanning)
2. Description of the Related Art There is known an image reading apparatus that performs two readings of a document on a flat platen and an ADF (automatic document feeding, using original feeding by an automatic document feeder) using a common carriage. ing. In such an image apparatus, a start position of image reading by the FBS is indicated by a home sensor or the like, and a reading end position is indicated by an end sensor or the like.

In order to reduce the size of the image reading apparatus, it is necessary to arrange the ADF section and the FBS section close to each other. Here, the inventor has stated that the end sensor is A
Since it interferes with a device or the like arranged on the DF side, there is a problem that the end sensor must be arranged before the reading range in the FBS ends.

[0004]

SUMMARY OF THE INVENTION It is a basic object of the present invention to reduce the size of an apparatus by allowing an image to be read by an FBS beyond an end sensor. An additional problem with the present invention is that FBS beyond the end sensor
An object of the present invention is to make it possible to accurately travel to the reading position of the ADF even when the image is read by the ADF. An additional object of the present invention is to enable a vehicle to quickly and accurately travel to a reading position on an ADF after reading an image on an FBS.

[0005]

According to the present invention, the reading of an image by the ADF and the reading of the image by the FBS are performed by a common carriage, the reading of the image by the FBS is started from the side opposite to the ADF section, and the end sensor side. In the apparatus configured to terminate the reading, the end sensor is arranged within the readable range of the FBS, and when the document length exceeds the end sensor, the reading is continued beyond the end sensor, and then the carriage is moved. Means for estimating the position from the running history of the carriage and terminating the reading when the position of the carriage reaches the reading limit length;
After the reading limit is reached and the reading is completed, the carriage is inverted to run to the end sensor, the carriage is again inverted to confirm the position by the end sensor, and then the number of pulses applied to the carriage driving motor The carriage travels at a low speed to the reading position on the ADF based on the position from the end sensor estimated from the rotation speed of the traveling motor or the traveling time of the traveling motor and the planned speed, and A means for controlling is provided (claim 1).

Here, whether or not the document length exceeds the end sensor can be determined by means of an input to the operation unit of the image apparatus, a sensor using a sensor for determining the document size, or the like. In addition, the traveling history of the carriage may be any as long as the position can be estimated using the traveling record of the carriage, using the rotation speed of the traveling motor, the traveling time, and the like.

Preferably, when the document length does not exceed the end sensor, reading is completed at the end sensor position, the carriage is decelerated and positioned, and the travel control means is further provided to the carriage drive motor. Based on the position from the end sensor estimated from the number of pulses added, the number of revolutions of the traveling motor, or the traveling time of the traveling motor and the planned speed, control to travel at a low speed to the reading position on the ADF based on the position from the end sensor. (Claim 2).

[0008]

According to the present invention, the end sensor is set to F
The image can be read beyond the end sensor even if it is located within the reading range of the BS.
The image reading apparatus can be miniaturized because the parts can be arranged close to each other.

Further, according to the present invention, even if an image is read beyond the end sensor, the carriage is reversed to the end sensor side to confirm the position, so that the vehicle can travel accurately to the reading position on the ADF.

According to the second aspect of the present invention, when the document length does not exceed the end sensor, the image reading device scans the image at high speed to the end sensor, reads the image, decelerates the image, and performs positioning using the end sensor. Since the vehicle travels to the reading position, the vehicle can quickly and accurately travel to the reading position on the ADF.

[0011]

1 to 6 show an image reading apparatus according to an embodiment, and FIG. 1 shows a mechanical configuration thereof. The image reading device of the embodiment is an image reading unit of the image device 2 such as a facsimile with a copying function. The image device 2 transmits and receives image data via a communication line, and prints out the read or received image. Reference numeral 4 denotes a document cover, 6 denotes a platen glass for FBS (flat bed scanning), 8 denotes a document feeder for ADF (automatic document feeding), and 10 denotes a platen glass for ADF reading.

Reference numeral 12 denotes a carriage of a scanner for reading a document. As shown in an enlarged manner at the bottom of FIG. 1, a light source 16 such as a fluorescent lamp and a shield 18 for preventing light from being diffused from the light source 16 are provided. And a CCD sensor 20 for reading image data on a document. An arbitrary sensor other than the CCD sensor 20 can be used as the image sensor. Although one carriage 12 is used here, the carriage is divided into a light source carriage and a mirror carriage, and the light source carriage and the mirror carriage are divided into two parts:
The vehicle may be run synchronously at a speed ratio such as one. In this case, the carriage for the light source is replaced with the carriage 12 in the embodiment.
, It can be controlled similarly.

The carriage 12 is driven by a traveling motor such as a stepping motor to be described later.
1 and stops at the lower part of the platen glass 10 for reading the ADF when reading with the ADF, and performs reading at the time of FBS, and runs at high speed from right to left in FIG. 1 under the platen glass 6 for FBS at the time of FBS. And scan.
HS is a home sensor and uses a photoelectric sensor or the like. In the embodiment, HS is provided at a standby position for FBS. ES is an end sensor similarly using a photoelectric sensor or the like and is provided closer to the FBS than the reading position of the ADF. Standard paper size (for example, A
This is a sensor for detecting the end of the reading range for 4).

As shown in FIG. 1, the position of the end sensor ES is closer to the home sensor HS than the end of the platen glass 6 for FBS due to mechanical restrictions, and is located on the platen glass 6 beyond the end sensor ES. Can be read. A plurality of end sensors may be arranged in accordance with the type of the document, but it is assumed that the end sensor closest to the ADF unit is within the readable range of the FBS. These sensors HS and ES detect, for example, a light-shielding plate provided on the carriage 12 and
Detect the position of.

FIG. 2 shows a configuration of a control system of the image apparatus 2. 22, a CPU (main controller); 24, a network controller (network controller) for connecting and disconnecting a telephone line and the like; 26, a modem; 28, an image for storing images to be transmitted / received or copied; A memory 30 stores various data and the like in a RAM, and a ROM stores programs and the like in a ROM. Reference numeral 34 denotes a display unit, and 36 denotes an operation unit. These constitute a man-machine / interface.
Is constituted by a liquid crystal display or the like, and the operation unit 36 is constituted by a touch panel, a group of button switches, or the like.

Reference numeral 38 denotes a scanner for scanning and reading an image. The ADF document feeder 8, the carriage 12, a driver 42 for controlling the traveling of the carriage, a traveling motor 44 such as a stepping motor, a home sensor HS and an end sensor. It is composed of ES or the like. The driver 42 has a sensor H
The position of the carriage 12 is confirmed by signals from S and ES. Further, the driver 42 integrates the number of pulses applied to the traveling motor 44, integrates the number of revolutions of the traveling motor 44 by an encoder or the like, or estimates the current position from the traveling time of the traveling motor 44 and a scheduled speed. To estimate the position from the sensors HS and ES. And the driver 42
Determines the traveling pattern in consideration of the document length in response to the traveling command from the CPU 22, estimates the current position, and controls the motor 44. The driver 42 is an example of a travel control unit. A printing unit 40 prints an image by a method such as electrophotography.

The traveling operation of the carriage 12 is as follows: at the time of reading by the FBS, after traveling to the home sensor HS position,
Reading an image while traveling from right to left in FIG. 1 and then moving to a reading position on the ADF and waiting. It should be noted that the carriage 12 can be
It is waiting at the reading position on the ADF. Hereinafter, the traveling operation of the carriage 12 will be described in the order of returning to the home sensor HS position, reading a document, and returning to the reading position on the ADF.

[0018]

[Return to Standby Position for FBS] FIG. 3 shows a return pattern of the carriage to the reading position in the FBS. 3A is a reading position on the ADF, F is a reading start position on the FBS, B is a carriage standby position for the FBS,
P is a deceleration start position. The left limit and the right limit are the left and right travel limits of the carriage. The reset position shown in FIG. 3 is an example of a position at the time of return from a power failure or the like, and it is unknown to the driver or the like for the carriage traveling control at which position the reset was performed.

When the cover 4 of FIG. 1 is opened, F
It is understood that it is necessary to return the carriage to the standby position B for the BS. At this time, designation of a sheet to the operation unit 36 in FIG. 2 or reading by a document sensor (not shown) is performed by the document length detecting means. By using this, the document length (document size) is determined. When the cover 4 is opened,
The CPU 22 instructs the driver 42 to control traveling to the standby position B. At this time, if the position of the carriage is the standby position B, the command has been executed, and if not, the low-speed traveling starts.

Here, when the end sensor ES detects the carriage, specifically, when the end sensor signal detects an edge that changes from off to on or from on to off, the driver sets the current position to the end sensor position. Then, start high-speed driving. A solid line in FIG. 3 shows a pattern for shifting to high-speed running by detecting an edge from the on state to the off state of the end sensor, and a chain line in FIG. 3 shows a pattern for shifting to high-speed running at an edge from off to on. Then, the number of drive pulses applied to the travel motor is integrated, and when the position estimated from the travel history of the travel motor reaches the deceleration start position P, the vehicle decelerates and shifts to creep travel (travel at a very low speed that can be stopped instantaneously). Then, as shown in an enlarged manner at the lower right of FIG. 3, the arrival at the standby position B is detected by the signal of the home sensor HS, and the operation is immediately stopped.

If the current position of the carriage is reset due to a power failure or the like, if the initial position is closer to the ADF than the end sensor ES, the end sensor ES can detect the carriage and calibrate the position. Can run at high speed. When the vehicle is reset closer to the FBS than the end sensor ES, the vehicle travels at a low speed until it reaches the home sensor ES. Therefore, even if the initial position is unknown, the vehicle can stop at the standby position B without overrun even if the initial position is unknown.

FIG. 4 shows an algorithm of traveling control to the standby position for FBS. In step S1, the image apparatus 2 detects that the cover has been opened, shifts to the FBS reading mode, and in step S2, instructs the carriage to travel to the FBS standby position. Step S3
To check the initial position of the carriage. If the initial position is the home sensor position (standby position for FBS), traveling is unnecessary and the process jumps to step S10.

When the initial position is other than the home sensor position,
In step S4, the vehicle starts traveling at a low speed. In step S5, it is checked whether the vehicle has passed the end sensor. If the vehicle has passed the end sensor, the vehicle shifts to high speed traveling in step S6.
In step S7, it is determined whether or not a predetermined distance from the home sensor has been reached. If the distance has been reached, the speed is reduced in step S8,
It stops when the signal of the home sensor changes from off to on (steps S9 and S10).

When a command to return to the reading position in the FBS is issued from a state where the initial position of the carriage is unknown due to a power failure or the like, it is determined in step S3 that the initial position is other than the home sensor position. After the start, since the end sensor cannot be detected in step S5, the low-speed traveling is continued in step S11, and the low-speed traveling is continued until the home sensor is turned on in step S12.

[0025]

[Reading of Images with FBS] FIGS. 5 and 6 show reading of images with FBS. FIG. 5 shows a traveling pattern of the carriage. The carriage stopped at the standby position B travels from right to left in FIG. 5, and completes acceleration to the reading start position F and shifts to high-speed constant-speed traveling. I do. The document length is obtained by an input switch for specifying the type of the document on the operation unit 36 or a unit for obtaining the document length such as a document sensor. When the document length is normal, as shown in FIG. 5A, when the end sensor ES is turned on, the speed is low (constant speed).
Slow down. Here, the end sensor ES has a width of several mm or more from on to off, completes deceleration by the end of passing through the end sensor ES, shifts to low speed traveling, and when the end sensor ES changes from on to off, The current position is set at the left end of the end sensor ES in FIG. 5, the distance to the reading position on the ADF is set, and thereafter the vehicle runs at a constant speed at a low speed. The travel to the reading position of the ADF is detected by the number of input steps to the travel motor, the signal of an encoder connected to the output shaft of the travel motor, and the like, and stopped.

The fact that the original has a special original length and that the end of the original is closer to the reading position of the ADF than the end sensor ES is due to the input to the operation unit when the original is set or the original sensor when the cover is closed. It has already been detected by checking the size of. In this case, as shown in FIG. 5B, the signal of the end sensor ES is ignored and the document is read to the end of the document readable range (the end of the platen glass for FBS on the ADF side). Then, after stopping, it reverses and passes through the end sensor ES at a low speed. When it has passed through the end sensor ES, it reverses again and enters the ON range of the end sensor ES. When the signal of the end sensor ES changes from ON to OFF, the current position is recognized as the left end of the end sensor ES, the remaining travel distance is set to the reading position on the ADF, and the vehicle travels at a low speed and stops.

FIG. 6 shows A from the start of reading by the FBS.
4 shows an algorithm for controlling the travel of the carriage up to the reading position in the DF. When the start of reading is instructed in step S20, the traveling motor is started in step S21, accelerated to a constant speed until the reading start position, and reading is started in step S22, and the carriage travels at high speed. At the same time, monitoring of the end sensor is permitted in step S23, and when the end sensor changes from off to on in step S24, if the document length is normal, reading is terminated in step S26, and the speed is reduced to the minimum speed.
If it is detected in step S27 that the end sensor has changed from ON to OFF, the current position is recognized as the end of the end sensor near the ADF in step S28, and the stop position is set. In step S29, the reading position of the ADF is read. When it is detected that the vehicle has traveled to
30).

If the original length is the special length, the process branches off from step S25 to continue reading up to the limit reading length (steps S31 and S32), and stops reading when the limit length is reached (step S33). Whether or not the limit length has been reached is determined from the travel distance and travel time from the home sensor, or the travel distance and travel time after passing through the end sensor. At the time when the limit length is reached, as shown in FIG. 5, the carriage has finished passing through the end sensor, and the end sensor is off.

Next, the carriage is stopped and inverted, and the carriage is caused to travel toward the end sensor at a low speed (step S3).
4). When it is detected that the sheet has passed the end sensor again (step S35), the carriage is stopped and turned over again, and is moved to the reading position on the ADF at the lowest speed (step S36). Returns to the flow of processing in the normal case, in step S27, detects that the end sensor has changed from ON to OFF, sets a stop position, and stops at the reading position on the ADF.

In the embodiment, even in the case of the special document length, the stop position is set by detecting the change of the end sensor from on to off in step S27, but the end sensor is turned off between step S36 and step S27. The stop position may be set using the change from ON to ON. In the case of the special document length, the detection of the end of the passage at the end sensor in step S35 is omitted, and while the end sensor is turned on after the first reversal, the reversal of step S36 is performed, and the process is stopped in step S27. The position may be set.

As described above, in the embodiment, even if the end sensor is arranged within the readable range of the FBS, the image can be read beyond the end sensor, so that the apparatus can be downsized. If the document length does not exceed the end sensor, scanning is performed at a high speed to the end sensor, deceleration is completed before the end sensor is turned off, the position is confirmed when the end sensor is turned off, and the vehicle runs at low speed. Quickly and accurately move to a position. Even when the document length exceeds the end sensor, the carriage is inverted twice, the position is confirmed by the end sensor, and the document is moved to the reading position on the ADF, so that the document can be moved accurately.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an image reading apparatus according to an embodiment from a mechanical aspect.

FIG. 2 is a block diagram showing the image reading apparatus according to the embodiment in terms of the configuration of a control system.

FIG. 3 is a characteristic diagram showing a sensor output and a carriage speed pattern in the embodiment.

FIG. 4 is a flowchart showing an algorithm of carriage traveling control in the embodiment.

5A and 5B are characteristic diagrams illustrating a relationship between a carriage traveling pattern and a sensor output according to a document length in the embodiment, and FIG.
Shows the case where the document length does not reach the end sensor, and (b) shows the case where the document length exceeds the end sensor.

FIG. 6 is a flowchart illustrating carriage traveling control according to a document length in the embodiment.

[Explanation of symbols]

 2 Imager 4 Cover 6 Platen glass for FBS 8 Document feeder for ADF 10 Platen glass for ADF reading 12 Carriage 14 Carriage running rail 16 Light source 18 Shield 20 CCD sensor 22 CPU 24 Network control unit (NCU) 26 Modem 28 Image Memory 30 RAM 32 ROM 34 Display unit 36 Operation unit 38 Scanner 40 Printing unit 42 Driver 44 Traveling motor HS Home sensor ES End sensor

Claims (2)

(57) [Claims] An ADF and an FBS read an image on a common carriage.
In an apparatus in which reading of an image by the FBS is started from the side opposite to the F section and reading is completed by the end sensor, the end sensor is arranged within a readable range of the FBS, and a document length is set. When the scanning exceeds the end sensor, the reading is continued beyond the end sensor, the position of the carriage is estimated from the traveling history of the carriage, and when the position of the carriage reaches the reading limit length, the reading is terminated. Means, after the reading limit length has been reached and reading has been completed, the carriage is turned over and run to the end sensor, the carriage is turned over again and the position is confirmed by the end sensor, and then the carriage is turned on by the motor for running. From the number of pulses, the number of revolutions of the traveling motor, or the traveling time of the traveling motor and the planned speed. It was based on the position of the end sensor, so as to travel at a low speed to the reading position in the ADF, characterized in that a means for controlling the travel of the carriage, the image reading apparatus. 2. The method according to claim 1, further comprising: when the document length does not exceed the end sensor, terminates reading at the end sensor position, decelerates and positions the carriage, and adds the carriage to the carriage drive motor. Number of pulses,
Based on the rotation speed of the traveling motor, or the position from the end sensor estimated from the traveling time of the traveling motor and the planned speed, control is performed so as to travel at a low speed to the reading position in the ADF based on the position from the end sensor. The image reading device according to claim 1, wherein: