JP2006222780A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader for reading the image plane of a reading object such as a document set on a platen glass by moving a carriage in the direction of vertical scanning under a state where a reading light source mounted on the carriage is lighted while moving the carriage in the direction of vertical scanning below the platen glass in the housing in which the reading reference position is corrected with high precision by such an arrangement as power consumption is saved without lighting the reading light source. <P>SOLUTION: The image reader 1 comprises a power saving light source 7 arranged above the edge part of a platen glass 8 on the home sensor side and outputting test light being received by a CCD sensor 4, and a controller 5 as a control means for correcting a preset red reference position based on the moving distance of a carriage 21 between a moment in time when the carriage 21 is no longer detected by a home sensor 6 after carriages 21/22 are moved from a home position and a moment in time when the test light from the power saving light source 7 is received by the CCD sensor 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control technique for correcting a reading reference position of an image reading apparatus included in a copying machine, a facsimile machine, or the like.

An image reading apparatus provided in a copying machine, a facsimile machine, or the like irradiates a reading target (such as a document) set on a platen glass with reading light while scanning a carriage having a reading light source in the sub-scanning direction. The reflected light is received by a CCD sensor and an image to be read is read.
The reading reference position of this image reading apparatus is determined based on the step number of the stepping motor from when the carriage at the home position is no longer detected by the home sensor by the step control of the stepping motor that drives the carriage, or the CCD It is determined by a predetermined pixel position of the sensor.

  However, in this method, the reading reference position varies from machine to machine. Therefore, in the image reading apparatus disclosed in Patent Document 1, the platen cover is closed without placing the reading object on the platen glass, and the reading is performed. The scanning reference position is corrected by scanning the carriage with the light source turned on and performing pre-scanning with the CCD sensor.

Specifically, in the image reading apparatus disclosed in Patent Document 1, when the carriage is scanned with the reading light source turned on, the end point of the platen glass is detected by the CCD sensor, and the end point and the image area output signal are detected. Are calculated to correct the reading start position of the CCD sensor and the output time of the image area signal.
JP-A-8-18748

  It is an object of the present invention to provide an image reading apparatus that has a configuration that is completely different from Patent Document 1 and that saves power consumption without turning on a reading light source, and that performs high-precision correction of a reading reference position. To do.

The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.
First, as described in claim 1, a platen glass attached to the upper surface of the casing, a carriage that reciprocates in the sub-scanning direction below the platen glass in the casing, and the platen glass mounted on the carriage. A reading light source that irradiates reading light to a reading target set on the glass; a CCD sensor that receives the reading light reflected by the reading target; and a home position at one end of the carriage in the sub-scanning direction in the housing And a home sensor for detecting whether or not the platen glass is positioned in the vicinity of the edge of the platen glass on the home sensor side and outputting test light that can be received by the CCD sensor. With the power light source and the power saving light source turned on and the reading light source turned off, the carriage is moved from the home position, and the key is moved. A reading reference position that is set in advance based on the distance that the carriage has moved between when the ridge is no longer detected by the home sensor and when the test light from the power-saving light source is received by the CCD sensor. And a control means for correcting the above.

  According to a second aspect of the present invention, the check relating to the correction of the reading reference position by the control unit is performed when the power of the image reading apparatus is turned on.

  According to a third aspect of the present invention, the check relating to the correction of the reading reference position by the control unit is performed when the image reading apparatus shifts to the energy saving mode.

  Further, according to a fourth aspect of the present invention, the check related to the correction of the reading reference position by the control unit is performed at a predetermined date and time set in advance.

Since the present invention is configured as described above, the following effects can be obtained.
First, in the first aspect of the invention, the reading light source is turned off without turning on the reading light source such as a fluorescent lamp lamp, and the reading reference position is corrected with the power saving light source such as the LED lamp turned on. Thus, the power consumption can be saved and energy saving can be achieved. Further, according to the present invention, the carriage moves from the home position to the distance that the carriage moves between the time when the carriage is no longer detected by the home sensor and the time when the test light from the power-saving light source is received by the CCD sensor. Based on this, addition / subtraction is performed to correct the reading reference position set in advance in the program, and the reading reference position can be corrected with high accuracy by a simple calculation, thereby improving the reliability.

  In the second aspect of the invention, since the reading reference position does not shift so frequently, every time a document is set on the platen glass and reading processing is performed, a check related to correction of the reading reference position is performed. The check for the correction of the reading reference position is made by performing the check for the correction of the reading reference position when the image reading apparatus is turned on, such as when going to work in the morning. The frequency can be kept low, further saving power consumption and energy saving.

  In the invention described in claim 3, since the reading reference position does not shift so frequently, every time a document is set on the platen glass and reading processing is performed, a check related to correction of the reading reference position is performed. Instead of performing a series of reading processes by some users, and when the image reading apparatus shifts to the energy saving mode, a check related to correction of the reading reference position is performed. Thus, the frequency of the correction of the check can be suppressed to be low, so that the power consumption can be further saved and the energy can be saved. Further, if a check related to the correction of the reading reference position is performed before the reading process, the user is kept waiting until the reading process is started. In the present invention, the image reading apparatus is in the energy saving mode without waiting for the user. When the process shifts to step S2, a check related to the correction of the reading reference position can be performed to improve workability.

  Further, in the invention described in claim 4, since the reading reference position does not shift so frequently, a check related to correction of the reading reference position is performed every time a document is set on the platen glass and reading processing is performed. For example, the check frequency related to the correction of the reading reference position is configured such that the check related to the correction of the reading reference position is performed at a predetermined date and time such as 9:00 am every Monday. Is kept low, power consumption can be further saved, and energy saving can be achieved.

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of an image reading apparatus 1 included in a copying machine, a facsimile machine, and the like. FIG. 2 is a side sectional view of the image reading apparatus 1. The image reading apparatus 1 includes a casing 10 that constitutes an apparatus main body frame, and a casing 10. Mounted on the full-rate carriage 21, and a scanning device 2 including a platen glass 8 attached to the upper surface of the plate, a full-rate carriage 21 that reciprocates in the sub-scanning direction below the platen glass 8 in the housing 10 and a half-rate carriage 22. The reading light source 20 such as a fluorescent lamp that irradiates the reading target 30 such as a document set on the platen glass 8 with a linear line of reading light in the main scanning direction of the platen glass 8, and the platen glass 8. A CCD (charge coupled device: charge co) that receives the reading light reflected by the reading object 30 via the mirrors 26, 27, and 28 and the lens 3. (upled device) sensor 4, home sensor 6 that is a detecting means for detecting whether or not full-rate carriage 21 is located at the home position at one end in the sub-scanning direction within housing 10, and one side end of housing 10. A platen cover (not shown) that is pivotably attached to the platen glass 8 so as to be openable and closable. A reading object 30 such as a document set on the platen glass 8 with the platen cover closed. Is configured to read the image.

  The scanning device 2 disposed inside the housing 10 includes a full rate carriage 21 on which a reading light source 20 and a first mirror 26 are mounted, and a half rate carriage 22 on which a second mirror 27 and a third mirror 28 are mounted. The driving device for driving the two carriages 21 and 22 includes a stepping motor 9 (see FIG. 3) that is a driving source, and a stepping motor 9 disposed at one end portion in the sub-scanning direction inside the housing 10. A toothed large diameter pulley and a small diameter pulley attached to the drive shaft, a driven shaft disposed at the other end in the sub-scanning direction inside the housing 10, and the driven shaft. Toothed large-diameter pulley and small-diameter pulley, a large-diameter pulley of the drive shaft, a toothed outer belt wound around the large-diameter pulley of the driven shaft, a small-diameter pulley of the drive shaft, and the Small diameter of driven shaft Comprising an inner belt with teeth around Li and wound, the full rate carriage 21 is attached to the outer belt, and the half rate carriage 22 is attached to the internal belt. Then, the diameter of the large-diameter pulley and the small-diameter pulley of the drive shaft is formed at a ratio of 2: 1, and the diameter of the large-diameter pulley and the small-diameter pulley of the driven shaft is formed at a ratio of 2: 1. The half-rate carriage 22 is configured to be driven at half the speed.

  In this image reading apparatus 1, a full-rate carriage 21 that moves at a constant speed in the sub-scanning direction and a half-rate carriage 22 that moves at half the speed of the full-rate carriage 21 are reciprocally moved in conjunction with each other on the platen glass 8. Reading light is emitted from the reading light source 20 of the full-rate carriage 21 toward the image surface of the reading target 30 such as a set original. Then, the reading light reflected on the image surface of the reading object 30 passes through the first mirror 26 of the full-rate carriage 21, the second mirror 27 and the third mirror 28 of the half-rate carriage 22, and the secondary light inside the housing 10. The reading light reflected toward the other side in the scanning direction and reflected by the third mirror 28 is imaged on the CCD sensor 4 via the lens 3 to generate a digital signal obtained by converting optical information into an electrical signal. It is configured as follows.

  An upper frame 11 is attached along the boundary between the frame on the upper surface of the housing 10 and the platen glass 8 at one end portion in the sub-scanning direction on the upper surface of the housing 10 (end portion on the home sensor 6 side). The other end in the sub-scanning direction (the end on the side opposite to the home sensor 6) protrudes in the vicinity of the edge of the platen glass 8 (above the edge). A power-saving light source 7 such as an LED lamp that outputs test light that can be received by the CCD sensor 4 through the mirrors 26, 27, and 28 is attached to a protruding portion 11 a of the upper frame 11 that protrudes above the edge of the platen glass 8. It has been.

  More specifically, a recess is formed on the lower surface of the protrusion 11a of the upper frame 11, and the power saving light source 7 is embedded in the recess, so that the test light from the power saving light source 7 does not diffuse in all directions. It is configured to irradiate only in one direction (directly below). The power-saving light source 7 is disposed at the home position of the full-rate carriage 21, and when the focal point of the first mirror 26 of the full-rate carriage 21 is located directly below the power-saving light source 7, the power-saving light source 7 The test light is configured to be received at a predetermined region (image forming point) of the CCD sensor 4 via the mirrors 26, 27, and 28.

  The power-saving light source 7 is disposed in the longitudinal direction (main scanning direction) of the upper frame 11. In this embodiment, the power-saving light source 7 is disposed at one end portion of the upper frame 11 in the longitudinal direction. The power-saving light source 7 may be arranged at the longitudinal center of the upper frame 11 or the like, and the arrangement position of the upper frame 11 in the longitudinal direction is particularly limited. is not.

  As shown in FIG. 3, the CCD sensor 4, the home sensor 6, the power saving light source 7, the stepping motor 9, the reading light source 20, and the like are communicatively connected to a controller 5 that is a control unit of the image reading apparatus 1. The reading reference position for starting reading by the CCD sensor 4 is the reading area of the platen glass 8 from the time when the carriages 21 and 22 waiting at the home position start driving and the full rate carriage 21 is not detected by the home sensor 6. Is set in advance in the control program of the controller 5 on the basis of the time until the time of entering or the number of rotation steps of the stepping motor 9, and this reading reference position is checked (pre-scan) as follows, If there is a deviation between the reading reference position on the program and the reading reference position actually measured by the check, correction is performed.

  The controller 5 moves the carriages 21 and 22 from the home position while the power-saving light source 7 is turned on and the reading light source 20 is turned off, and when the full-rate carriage 21 is not detected by the home sensor 6 (first time) Time point) and the time point (second time point) when the focus of the first mirror 26 of the full rate carriage 21 is located directly below the power saving light source 7 and the test light from the power saving light source 7 is received by the CCD sensor 4. The reading reference position set in the program is corrected based on the distance moved by the full-rate carriage 21 between them.

  When the first time point is earlier than the second time point, the distance that the full-rate carriage 21 has moved between the first time point and the second time point is the time during this time or the stepping motor rotated during this time A calculation is performed based on the number of rotation steps of 9, and a correction is made by adding the distance traveled by the full-rate carriage 21 to the reading reference position set in the program to set a new reading reference position.

  On the other hand, when the first time point is later than the second time point, the distance of the full-rate carriage 21 moved between the first time point and the second time point is the distance of the stepping motor 9 rotated during this time. Calculation is made based on the number of rotation steps, correction is performed to subtract the distance moved by the full-rate carriage 21 from the reading reference position set on the program, and a new reading reference position is set.

  If the first time point and the second time point are the same, the reading reference position set in the program is not corrected.

  As described above, the reading light source 20 is turned off without turning on the reading light source 20 such as a fluorescent lamp lamp, and the check related to the correction of the reading reference position is performed with the power saving light source 7 such as an LED lamp turned on. Thus, power consumption can be saved, energy saving can be achieved, and this correction can be performed with high accuracy with a simple calculation, improving reliability.

  Since the reading reference position does not deviate so frequently, a check relating to correction of the reading reference position is not performed every time the reading object 30 such as a document is set on the platen glass 8 and reading processing is performed. When the power of the image reading apparatus 1 is turned on, such as when going to work in the morning, a check related to the correction of the reading reference position may be performed. Since the frequency of checks can be kept low, power consumption can be further saved and energy saving can be achieved.

  Alternatively, after a series of reading processes by some users, the image reading apparatus 1 may be configured to perform a check related to the correction of the reading reference position when the image reading apparatus 1 shifts to the energy saving mode. Thus, the frequency of checks related to the correction of the reading reference position is kept low, so that power consumption can be further saved and energy saving can be achieved. If the check related to the correction of the reading reference position is performed before the reading process, the user is kept waiting until the reading process is started. In this configuration, the image reading apparatus 1 is set in the energy saving mode without waiting for the user. It is configured to perform a check related to the correction of the reading reference position when the shift is made, and workability can be improved.

  Alternatively, a check related to correction of the reading reference position may be performed at a predetermined date and time set in advance, for example, a check related to correction of the reading reference position may be performed every Monday at 9:00 am As a result, the frequency of checks related to the correction of the reading reference position is kept low, power consumption can be further saved, and energy saving can be achieved.

  Although three examples of the check timing related to the correction of the reading reference position have been described above, two or more of these three examples may be used together, or the reading reference position is corrected at a time completely different from these three examples. The check related to the correction may be performed, and the timing of the check related to the correction of the reading reference position is not particularly limited.

FIG. 2 is a plan view showing a schematic configuration of the image reading apparatus 1. FIG. 3 is a side sectional view showing a schematic configuration of the image reading apparatus 1. FIG. 6A is a diagram when the carriages 21 and 22 are at the home position. FIG. 6B is a diagram when the carriages 21 and 22 are moving in the sub-scanning direction. 2 is a block diagram showing a control configuration of the image reading apparatus 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reader 2 Scan apparatus 3 Lens 4 CCD sensor 5 Controller 6 Home sensor 7 Power-saving light source 8 Platen glass 9 Stepping motor 10 Case 11 Upper frame 11a Protrusion part 20 Reading light source 21 Full-rate carriage 22 Half-rate carriage 26 First mirror 27 Second mirror 28 Third mirror 30 Reading target

Claims (4)

A platen glass attached to the upper surface of the housing;
A carriage that reciprocates in the sub-scanning direction below the platen glass in the housing;
A reading light source that is mounted on the carriage and irradiates reading light to a reading target set on the platen glass;
A CCD sensor that receives the reading light reflected by the reading object;
A home sensor for detecting whether or not the carriage is located at a home position at one end in the sub-scanning direction in the housing;
In an image reading apparatus comprising:
A power-saving light source that is arranged near the edge of the platen glass on the home sensor side and outputs test light that can be received by the CCD sensor;
The carriage is moved from the home position with the power-saving light source turned on and the reading light source turned off, and the test light from the power-saving light source is detected when the carriage is no longer detected by the home sensor. Control means for correcting a preset reading reference position based on the distance traveled by the carriage between the time point when the light is received by the CCD sensor;
An image reading apparatus comprising:   The image reading apparatus according to claim 1, wherein the check related to the correction of the reading reference position by the control unit is performed when the power of the image reading apparatus is turned on.   The image reading apparatus according to claim 1, wherein the check related to the correction of the reading reference position by the control unit is performed when the image reading apparatus shifts to an energy saving mode.   The image reading apparatus according to any one of claims 1 to 3, wherein the check related to the correction of the reading reference position by the control unit is performed at a predetermined date and time set in advance.

Images