JP2004246298A - Image reading device and image forming device - Google Patents

Abstract

In a case where the apparatus is activated in advance by a pre-scan start command, if a predetermined condition is satisfied, a scan is started by skipping a homing operation without performing accurate positioning. Get a quick rise.
A light source for illuminating a document, a mirror for guiding reflected light from the document illuminated by the light source, a carriage movable in a scanning direction of the document, and a home position of the carriage for detecting a home position of the carriage. In an image reading device equipped with a sensor and a line sensor that reads the image of the original document from light reflected from a mirror, check whether or not a mode in which a pre-scan is performed when positioning the carriage by performing a homing process. In the case of pre-scanning, when the sensor detects the carriage, the homing operation of step 102 is omitted and the light source is turned on (step 103).
[Selection diagram] Fig. 4

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading device that reads an image by scanning a document placed on a document table by moving a carriage, and an image forming apparatus including the image reading device.
[0002]
[Prior art]
2. Description of the Related Art In an image forming apparatus such as a copying machine, a facsimile, and a scanner, an image reading device (scanner) that scans a document placed on a document table and reads a document image is provided. The image reading apparatus includes a carriage that moves along a predetermined direction of the document (sub-scanning direction) while supporting a light source that illuminates the document and a mirror that guides reflected light from the document in a predetermined direction. When scanning a document, the accuracy of the start position of the carriage is extremely important. Therefore, in the conventional image reading apparatus, a sensor (detection means) for detecting the home position is provided near the home position, which is the reference position of the carriage, and the home position is searched by the detection output of this sensor. This home position search, that is, homing processing (hereinafter referred to as homing processing) is to perform preliminary scanning for copying when a copy button is pressed in a copying machine, or to read a document in a facsimile or scanner. Is performed immediately before the main scan is performed. As described above, since the control that enables the scan to be started after the homing operation for aligning the carriage when the power is turned on is performed, the first copy and the first reading time are increased by the homing process. It was customary.
[0003]
On the other hand, in recent years, due to the increase in energy saving and environmental problems, an operation of automatically turning off the power immediately after unnecessary time has been required. On the other hand, a quick start-up after the power is turned on is also required.
[0004]
Therefore, for example, Japanese Patent Application Laid-Open No. 2003-163,097 proposes that the repetition of the reading operation is speeded up by performing the correction of the position shift of the carriage and the homing process only when the position shift occurs during the return operation of the carriage. . Further, in Patent Document 2, when a black reference value based on a sensor reading output and a moving distance of a carriage at the time of a homing process exceeds a preset upper and lower limit value, a previously detected value exceeds the upper and lower limit value. If not, it has been proposed to improve the positional accuracy of the read image by using the previously detected value as a correction reference value, and to obtain an image with less positional variation.
[0005]
[Patent Document 1]
JP 2001-356428 A
[Patent Document 1]
JP 2002-64683 A
[Problems to be solved by the invention]
In the present invention, similarly to the invention described in the above-mentioned patent document, in the case where the apparatus is started in advance by a pre-scan start command, it is considered that accurate alignment is not required if a certain condition is satisfied. The purpose is to obtain a quick rise by omitting the homing operation and starting the scan.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a first means is equipped with a light source for illuminating the document and a mirror for guiding reflected light from the document illuminated by the light source, and a carriage movable in the sub-scanning direction with respect to the document. An image sensor comprising: detecting means for detecting a home position of the carriage; a line sensor for reading an image of the document in the main scanning direction from light reflected from the mirror; and control means for controlling movement of the carriage. In the reading device, the control unit performs the homing operation when performing the pre-scan mode when performing the homing process in the pre-scan mode when the sensor detects the carriage. An image reading apparatus characterized in that there is no image reading apparatus.
[0009]
The second means is equipped with a light source for illuminating the document and a mirror for guiding reflected light from the document illuminated by the light source, and a carriage movable in the sub-scanning direction with respect to the document, and a home position of the carriage. An image reading apparatus comprising: detecting means for detecting; a line sensor for reading an image of the document in a main scanning direction from reflected light from the mirror; and control means for controlling movement of the carriage. Are displaced by a fixed amount along the moving direction of the carriage.
[0010]
The third means is that each of the detection means is arranged such that when the carriage is located at the home position, one of the detection means is turned on and the other detection means is turned off, and the control means is provided with one of the detection means When the means is turned on and the other detecting means is turned off, it is determined that the carriage is at the home position, and the homing operation at power-on is omitted.
[0011]
A fourth means is the second or third means, wherein the detecting means is provided at both ends in a direction perpendicular to the moving direction of the carriage or at a side surface facing the both ends of the apparatus housing. Features.
[0012]
The fifth means includes the image reading device according to the first to fourth means, and an image forming means for forming a visible image on a recording medium based on image data read by the image reading device. Features.
[0013]
According to the first means, in the case where the apparatus is activated in advance by a pre-scan start command, if a certain condition is satisfied, it is considered that accurate positioning is not necessary, and the homing operation is omitted to start the scan. And a quick rise can be obtained.
[0014]
According to the second means, since the detecting means is displaced with respect to the carriage moving direction, the position can be detected more accurately than in the case of a single detecting means. The home position can be determined by the limited carriage movement.
[0015]
According to the third means, it is possible to accurately determine whether or not the carriage is at the home position when the power is turned on, and when the carriage is at the normal position, homing is omitted, thereby shortening the starting time without starting conditions. Can be.
[0016]
According to the fourth means, since the detecting means is provided at both ends in the direction orthogonal to the moving direction of the carriage or at the side surface opposite to the both ends of the apparatus casing, the position can be detected with high accuracy.
[0017]
According to the fifth means, since the image reading device operates at a quick start after the power is turned on, the operation can be performed efficiently.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 is a main part configuration diagram showing an image reading apparatus according to a first embodiment of the present invention, FIG. 2 is a diagram showing a part of an upper part of an image forming apparatus equipped with the image reading apparatus, and FIG. FIG. 4 is a diagram for explaining the relationship between home position sensors, and FIG. 4 is a flowchart showing an outline of the operation of scan control.
[0020]
The image reading device 50 has a contact glass 6 and a reference white plate (not shown) disposed on the upper part thereof. The contact glass 6 is for setting a document thereon when reading the document. As shown in FIG. 2, the original is pressed from above by a pressure plate 1a which is a pressing plate for the original so as not to float from the contact glass 6. Of course, a known document feeder (ADF) may be provided. The reference white plate is a substantially white member of uniform density provided in the main scanning direction for obtaining correction data at the time of shading correction.
[0021]
Inside the image reading device 50, a light source 504 such as a xenon lamp that irradiates the reading surface at a certain angle with respect to the surface of the reference white plate or the contact glass 6, and three light sources that reflect light reflected by the reference white plate or the document First, second and third mirrors 51, 55, and 56, a lens block 53 that forms an image of reflected light from the third mirror 56, and a line sensor that converts the reflected light of the lens 6 into an analog image signal. And a reading substrate 507 provided with various circuits for converting an image signal from the CCD 54 into a digital signal. The light source 504 and the first mirror 51 are mounted on a first carriage 501, and the second and third mirrors 55 and 56 are mounted on a second carriage 502. The first and second carriages 501 and 502 read the image of the document while moving along the contact glass 6 at a speed of 2: 1 by the drive motor 503, respectively.
[0022]
A plurality of document size detection sensors 514 for detecting the size of the document are provided at the bottom of the image reading device 50, a pressure plate open detection sensor 515 for detecting the opening and closing of the pressure plate 1a, and a home position of the first carriage 501 at the top. Is provided. In addition, although not shown, a peripheral circuit of the drive motor 503 is provided, and reading control is performed at each detection timing.
[0023]
Whether the first carriage 501 is at the home position is detected by turning on the sensor 506 when the filler 509 provided on the first carriage 501 enters the home position sensor 506 and turning off when the filler 509 is removed from the sensor 506. I'm using
[0024]
Conventionally, when the power of the image reading device 50 is turned on, the first carriage 501 performs a homing operation, and then, after performing adjustment such as black level and white level adjustment of the reading substrate 507, the image reading device 50 performs the reading operation. Control was performed to make it possible.
[0025]
Here, the homing operation is such that when the home position sensor 506 is on when the power is turned on, the first carriage 501 is temporarily moved in a direction away from the home position sensor 506, and then turned on again after the home position sensor 506 is turned off. The timing of returning and turning on is determined to improve the position accuracy, and the home position is set. Also, when the home position sensor 506 is off when the power is turned on, the first carriage 501 is moved in a direction to turn on, and the home position is similarly determined.
[0026]
In recent years, as the energy saving technology advances, a method of shutting off the power of the image reading apparatus to suppress unnecessary power consumption when the reading operation is not performed has been generalized. In this case, when the user wants to use the scanner, the scanning operation cannot be performed unless the user has to wait for the initial operation such as the homing process and the adjustment of the reading substrate 507 every time. In the past, if the power was left on, such an initial operation was unnecessary and scanning could be performed immediately, so that the energy saving effect was increased, but the stress was also increased.
[0027]
Therefore, in the first embodiment, the homing operation is omitted if a certain condition is satisfied only in the case where the pre-scan is requested and the automatic return from the energy saving mode (power off) is performed. This shortens the return time.
[0028]
In a general scanner, a network scanner or the like can be considered as a case of returning from the energy saving mode by using a limited condition of pre-scan as a trigger. In other words, this is a case where a command to perform pre-scanning is sent from the network to the image reading apparatus, and then a document is set. Pre-scanning is often used to test whether various settings are correct in advance, so if the user does not like the scanned data, the data should be discarded. Normal. Therefore, even if there is a slight registration deviation, it is sufficient that the image of the document can be confirmed, and it is considered that there is little possibility that registration accuracy becomes a problem.
[0029]
Therefore, in the first embodiment, as shown in the flowchart of FIG. 4, when a scan command is received, it is first checked whether or not the command is a pre-scan command (step 101). If the command is not a pre-scan command, homing is performed (step 102), and then the lamp of the light source 4 is turned on.
[0030]
On the other hand, if the state of the home position sensor 506 is ON when the command is the pre-scan command, it can be said that the first carriage 501 is present at least near the home position, and the homing is omitted to return. Is also less likely to cause problems. Therefore, homing is omitted and the process proceeds to step 103. Conversely, if the home position sensor 506 is off, the first carriage 501 is considered to be far away from the home position. Since homing is indispensable since it is possible to hit the edge of the device and break it, the process proceeds to step 102 and after performing homing, proceeds to step 103.
[0031]
After the lamp is turned on, adjustment such as adjustment of the black level and white level of the reading substrate 507 is performed (step 104), and then the image reading device 50 is ready for reading (step 105), and the scanner operation is started. (Step 106).
[0032]
By performing these controls, it is possible to reduce the return time. In addition, there is an advantage in that it can be easily dealt with by changing the software with respect to the conventional machine, and since the hardware does not need to be changed, the change can be reflected even if the machine is not a newly developed machine.
[0033]
In the first embodiment described above, the number of home position sensors is one. However, in the second embodiment described below, two home position sensors are used. This second embodiment will be described with reference to FIGS. FIG. 5 is a view for explaining the positional relationship between the carriage and the home position sensor according to the second embodiment, and FIG. 6 is a flowchart showing an outline of the operation of scan control in the second embodiment.
[0034]
That is, as shown in FIG. 5, the first and second home position sensors 521 and 522 are arranged at both ends in a direction orthogonal to the moving direction of the first carriage 501 with a slight shift with respect to the moving direction. . Thereby, the detection accuracy is improved, and the moving distance of the first carriage 501 during homing is shortened, so that the return time is also shortened.
[0035]
As described above, in the first embodiment, the position is determined by turning the first carriage 501 off and on with respect to the home position sensor 506. However, the first home position sensor 521 is provided at both ends of the first carriage 501. By disposing the second home position sensor 522 and slightly shifting the mounting position in a direction orthogonal to the moving direction, the first home position sensor 521 can be turned on and the second home position sensor 522 can be turned off. it can. As the shift amount of the home position sensor is reduced, the state where the home position sensors are off and on becomes a pinpoint, and the position accuracy is improved. Therefore, according to the second embodiment, a more accurate home position can be obtained than in the first embodiment.
[0036]
In the homing process, the first carriage 501 is moved to turn the home position sensor 506 off and on in the first embodiment. However, in the second embodiment, it is sufficient to detect only a small pinpoint state. Therefore, it is not necessary to turn the home position sensor off and on to search for the position. As a result, although homing for returning from the energy saving mode is performed, the moving time of the first carriage 501 can be reduced, so that the returning time can be reduced. Further, the present invention is applicable not only to the return under limited conditions as in the first embodiment, but to any return state.
[0037]
In the second embodiment, as shown in the flowchart of FIG. 6, when a scan command is received at the time of returning from the power saving shut-down mode, the state of the home position sensor is detected and the first home position is detected. It is checked whether the sensor 521 is on (step 201), and then it is checked whether the second home position sensor 522 is on (step 202). When the first home position sensor 521 is off and the second home position sensor 522 is off, homing is performed (step 203). On the other hand, when the first home position sensor 521 is on and the second home position sensor 522 is also on, and after performing the homing process in step 203, the lamp of the light source 504 is turned on, and the black level of the reading substrate 507 is detected. Adjustments such as white level adjustment are performed (Step 204), and then the image reading device 50 is ready for reading (Step 205), and the scanner operation is started (Step 206).
[0038]
In the conventional machine, when shifting to the energy saving mode, the scanner motor cannot be excited while the power is off even if the carriage is normally located at the home position, and the carriage moves due to external vibration or impact. He had been homing when he returned, as he might have been lost. On the other hand, in the second embodiment, when returning from the energy saving mode with the power cutoff, the states of the first and second home position sensors 521 and 522 are detected, and the first home position sensor 521 is turned on. If the second home position sensor 522 is in the off state (pinpoint), it is determined that the first carriage 501 is at the home position, and the homing operation can be omitted to quickly reach the readable state. By arranging a plurality of home position sensors in this manner, the position detection accuracy can be improved, so that it is easy to determine whether homing needs to be performed simply by checking the state of the home position sensor. In the case where there is no homing, the return time can be reduced by not performing homing.
[0039]
Hereinafter, an image forming apparatus using the image reading apparatuses according to the first and second embodiments will be described.
[0040]
7 is a diagram illustrating a schematic configuration of an image forming apparatus including the image reading device illustrated in FIG. 1, and FIG. 8 is a block diagram illustrating a schematic configuration of a control circuit of the image forming device illustrated in FIG.
[0041]
Hereinafter, the image forming apparatus according to the present embodiment will be described.
When a start key on the operation unit 30 is pressed, a document bundle placed on a document table 2 in an automatic document feeder (hereinafter ADF) 1 is fed from the bottom document. The sheet is fed to a predetermined position on the contact glass 6 by the feed roller 3 and the feed belt 4. After the reading unit 50 reads the image data of the document on the contact glass 6, the document that has been read is discharged by the feed belt 4 and the discharge roller 5. Further, when the document set detection sensor 7 detects that the next document is present on the document table 2, the document is fed onto the contact glass 6 in the same manner as the previous document. The feed roller 3, the feed belt 4, and the discharge roller 5 are driven by a transport motor 26.
[0042]
The transfer sheets stacked on the first tray 8, the second tray 9, and the third tray 10 are fed by the first sheet feeding device 11, the second sheet feeding device 12, and the third sheet feeding device 13, respectively, and are vertically conveyed. The sheet is transported by the unit 14 to a position where it contacts the photoconductor 15. The image data read by the reading unit 50 is written on the photoconductor 15 by the laser from the writing unit 57, and passes through the developing unit 27 to form a toner image. Then, the toner image on the photoconductor 15 is transferred while the transfer paper is conveyed by the conveyance belt 16 at the same speed as the rotation of the photoconductor 15. Thereafter, the image is fixed by the fixing unit 17, and the image is discharged to the finisher 60 of the post-processing device by the sheet discharging unit 18.
[0043]
The finisher 60 of the post-processing device can guide the transfer paper conveyed by the paper discharge roller 19 of the main body toward the normal paper discharge roller 62 and the staple processing unit. When the switching plate 61 is switched upward, the sheet is discharged to the normal paper output tray 64 via the transport roller 63, and when the switching plate 61 is switched downward, the staple table 68 is transported via the transport rollers 65 and 67. Can be transported.
[0044]
The transfer paper stacked on the staple table 68 is aligned by a paper alignment jogger 69 every time one sheet is discharged, and is stapled by the stapler 66 when a part of the copy is completed. The transfer paper group bound by the stapler 66 is stored in the stapling completion paper discharge tray 70 by its own weight.
[0045]
On the other hand, the normal paper discharge tray 64 is a paper discharge tray that can move back and forth. The paper discharge tray section 64 that can be moved back and forth has a function of moving back and forth for each document or each copy section sorted by the image memory, and sorting the copy paper that is simply discharged.
[0046]
When images are formed on both sides of the transfer paper, the transfer paper fed and imaged from each of the paper feed trays 8 to 10 is not guided to the paper output tray 64 side, and the branch claw 41 for path switching is used. By setting it on the upper side, it is once stocked in the duplex paper supply unit 111. Thereafter, the transfer paper stocked in the duplex paper supply unit 111 is re-fed from the duplex paper supply unit 111 in order to transfer the toner image formed on the photoconductor 15 again, and the branch pawl 41 for switching the path is used. Is set on the lower side, and guided to the discharge tray 64. As described above, the double-sided paper feeding unit 111 is used when forming images on both sides of the transfer paper.
[0047]
The photoconductor 15, the transport belt 16, the fixing unit 17, the paper discharging unit 18, and the developing unit 27 are driven by a main motor 25, and the respective paper feeding devices 11 to 13 drive the main motor 25 by paper feeding clutches 22 to 24, respectively. Driven by transmission. The vertical transport unit 14 is driven to transmit the drive of the main motor 25 by the intermediate clutch 21.
[0048]
FIG. 8 illustrates a control device centering on the main controller. The main controller 20 controls the entire image forming apparatus. The main controller 20 is connected with a main motor 25 and various clutches 21 to 24 necessary for paper conveyance and the like. An operation unit 30 for displaying to an operator, inputting function settings from the operator, controlling a scanner, controlling to write a document image in an image memory, controlling to form an image from an image memory, and the like. 49, a distributed control device such as an automatic document feeder (ADF) 1 is connected. The display is performed via the liquid crystal display 31, and the function setting input from the operator is performed by the key input unit 32. Each decentralized control device and the main controller 20 exchange machine status and operation commands as needed. A control program executed by each distributed control device is stored in a ROM inside each distributed control device. An IC card slot 27 is connected to the main controller 20, and control program data stored in an IC card external to the image forming apparatus is downloaded to the ROM inside the distributed control device via the IC card slot 27 and controlled. It is possible to change the program.
[0049]
The operation from image reading to image writing in the image forming apparatus will be described with reference to FIG. 7 again.
[0050]
The reading unit 50 includes a contact glass 6 on which a document is placed and an optical scanning system. The optical scanning system includes an exposure lamp 51, a first mirror 52, a lens 53, a CCD image sensor 514, and the like. I have. The exposure lamp 51 and the first mirror 52 are fixed on a first carriage (not shown), and the second mirror 55 and the third mirror 56 are fixed on a second carriage (not shown). When reading an original image, the first carriage and the second carriage are mechanically scanned at a relative speed of 2: 1 as described above so that the optical path length does not change.
[0051]
This optical scanning system is driven by a scanner drive motor (not shown). The document image is read by the CCD image sensor 54, converted into an electric signal, and processed. By moving the lens 53 and the CCD image sensor 54 in the horizontal direction in FIG. 7, the image magnification changes. That is, the positions of the lens 53 and the CCD image sensor 54 in the left-right direction are set corresponding to the designated magnification.
[0052]
The writing unit 57 includes a laser output unit 58, an imaging lens 59, and a mirror. Inside the laser output unit 58, a rotating polygon mirror (polygon mirror) that rotates at high speed at a constant speed by a laser diode as a laser light source and a motor. Is provided.
[0053]
The laser light emitted from the laser output unit 58 is deflected by a polygon mirror that rotates at a constant speed, passes through an imaging lens 59, is turned back by the mirror, and condenses and forms an image on the surface of the photoconductor 15.
[0054]
The polarized laser light is exposed and scanned in a direction (main scanning direction) orthogonal to the direction in which the photoconductor 15 rotates, and performs recording in units of lines of an image signal output from a selector of an image processing unit described later. An image (electrostatic latent image) is formed on the photoconductor surface by repeating main scanning at a predetermined cycle corresponding to the rotation speed of the photoconductor 15 and the recording density.
[0055]
As described above, the laser beam output from the writing unit 58 is applied to the photoconductor 15 of the image forming system. Although not shown, a beam sensor that generates a main scanning synchronization signal is disposed at a position near one end of the photoconductor 15 where the laser beam is irradiated.
[0056]
Note that the image forming apparatus shown in FIG. 7 functions as an MFP copying machine.
[0057]
【The invention's effect】
As described above, according to the image reading device of the present invention, for example, when starting from a network and performing pre-scanning, the homing process conventionally performed can be omitted, and the startup time can be reduced. In addition, when the power is not used when the power is not used, which is required for energy saving, the stress at the time of use by the user can be reduced by a simple control change to the conventional machine.
[0058]
Further, according to the image forming apparatus of the present invention, since the image reading apparatus operates at a quick start after the power is turned on, the work can be performed efficiently.
[Brief description of the drawings]
FIG. 1 is a main part configuration diagram showing an image reading apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a part of an upper part of an image forming apparatus on which the image reading apparatus of FIG. 1 is mounted.
FIG. 3 is a diagram for explaining a relationship between a carriage and a home position sensor.
FIG. 4 is a flowchart illustrating an outline of an operation of scan control according to the first embodiment.
FIG. 5 is a diagram illustrating a positional relationship between a carriage and a home position sensor according to a second embodiment of the present invention.
FIG. 6 is a flowchart illustrating an outline of an operation of scan control according to the second embodiment.
FIG. 7 is a diagram illustrating a schematic configuration of an image forming apparatus including the image reading apparatuses according to the first and second embodiments.
8 is a block diagram schematically showing a control device of the image forming apparatus shown in FIG.
[Explanation of symbols]
2 contact glass 3 pressure plate 4 light source 5a, 5b, 5c first, second and third mirror 6 lens block 7 reading substrate 7a CCD
50 Image reading device 501 First carriage 502 Second carriage 506, 521, 522 Home position sensor

Claims (5)

A light source that illuminates the document and a mirror that guides reflected light from the document illuminated by the light source, and a carriage that is movable in the sub-scanning direction with respect to the document;
Detecting means for detecting a home position of the carriage;
A line sensor that reads an image of the document in the main scanning direction from light reflected from the mirror,
Control means for controlling the movement of the carriage;
In the image reading device provided with
The control unit may perform the homing process to perform the positioning of the carriage. In the case of a pre-scan mode, the homing operation is not performed when the sensor detects the carriage. Reader. A light source that illuminates the document and a mirror that guides reflected light from the document illuminated by the light source, and a carriage that is movable in the sub-scanning direction with respect to the document;
Detecting means for detecting a home position of the carriage;
A line sensor that reads an image of the document in the main scanning direction from light reflected from the mirror,
Control means for controlling the movement of the carriage;
In the image reading device provided with
The image reading apparatus according to claim 1, wherein the detection unit is arranged to be shifted by a fixed amount along a moving direction of the carriage. When the carriage is located at the home position, each of the detection means is arranged such that one detection means is turned on and the other detection means is turned off,
The control means determines that the carriage is at the home position when one of the detection means is turned on and the other of the detection means is off, and omits a homing operation at power-on. The image reading device according to claim 2, wherein 4. The image reading apparatus according to claim 2, wherein the detection unit is provided at both ends in a direction perpendicular to the moving direction of the carriage or at a side surface of the apparatus housing facing the both ends. An image reading device according to any one of claims 1 to 4,
Image forming means for forming a visible image on a recording medium based on image data read by the image reading device,
An image forming apparatus comprising:

Images