JP2004109639A - Image scanner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce lengthy time to be required until returning to a standby state from a power saving state. <P>SOLUTION: An image reading part 6, a power saving controlling means, a return processing means, and a movement controlling means are provided to an image scanner. The image reading part 6 mounts a lamp 12, and reads the image of an original using a scanning body 10 movably supported in a subscanning direction. The power saving controlling means shifts the state of a device itself from the power saving state to the standby state, when elapsed time after being in the standby state which can read the image of the original reaches predetermined time. When returning to the standby state from the power saving state, the return processing means for performing a predetermined return processing reads a white standard board 5 with the image reading part 6. The movement controlling means moves the scanning body 10 under the white standard board 5, before shifting to the power saving state. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading device that optically reads an image of a document.
[0002]
[Prior art]
In recent years, from the viewpoint of energy saving, an image reading apparatus having a power saving function has been provided. The power saving function is a function for saving power consumption of the image reading apparatus. In the image reading apparatus having the power saving function, when the startup operation after turning on the power of the apparatus is completed and the apparatus is in a standby state in which an image of a document can be immediately read (hereinafter, a standby state), the image reading apparatus performs a predetermined time. When a substantially unused state such as when the apparatus is not used continues, the apparatus automatically shifts to a power saving state. In the power saving state, power consumption is suppressed by stopping power supply to a predetermined portion of the image reading apparatus (power off). Further, there is known a device in which when a user operates a document pressing member to open / close or set a document after shifting to a power saving state, the sensor detects this and returns from the power saving state (Patent Document 1). ).
[0003]
[Patent Document 1]
JP 2001-53937 A (paragraphs 0041 and 0042)
[0004]
In a conventional image reading apparatus, when the apparatus is turned on, a start-up operation is performed according to a procedure shown in FIG. First, a carriage initialization process is performed to recognize the position of the carriage in the optical scanning system (step S1), and when this is completed, the carriage is moved below the white reference plate (step S2). In the initialization process of the carriage, the carriage is moved in the sub-scanning direction, and the position of the carriage is recognized based on the timing at which the detection signal of the carriage sensor switches from the off state to the on state (or from the on state to the off state) during this movement. I do. Next, after the lamp mounted on the carriage is turned on (step S3), automatic gain control for white level adjustment (white output adjustment) of the apparatus is performed using image data obtained by reading the white reference plate. (Step S4).
[0005]
Next, after the lamp is turned off (step S5), auto offset control for adjusting the black level (black output adjustment) of the apparatus is performed using the image data obtained by reading the white reference plate (step S6). Subsequently, after the lamp is turned on again (step S7), the image data for 100 pixels located at the central portion of the white reference plate is averaged using the image data for one line obtained by reading the white reference plate. The obtained white reference data is collected (step S8), and furthermore, using a plurality of lines of image data obtained by reading the white reference plate, the shading data for one line is obtained by averaging the image data by the number of read lines. (Step S9). Then, after the lamp is turned off again (step S10), the carriage is moved to a preset home position (step S11). By performing the start-up operation as described above, the device enters a standby state.
[0006]
[Problems to be solved by the invention]
In a conventional image reading apparatus performing such a start-up operation, when returning from the power saving state, this return operation is performed in the same procedure as the start-up operation when the power is turned on (at the time of power-on). Therefore, there is a problem that it takes a long time to return from the power saving state to the standby state.
[0007]
Also, some image reading devices use an instantaneous lamp when a document holding member (platen cover) that holds the document from above is set (placed) on a document table (platen glass). There is a function that automatically detects based on the image data for one line that is lit and read (hereinafter, document size detection function). This document size detection function is only available when the apparatus is in the standby state. It works effectively. Therefore, when the document size detection function is used, it is necessary to wait for a document to be set until the operation of returning from the power saving state is completed and the standby state is reached.
[0008]
SUMMARY An advantage of some aspects of the invention is to provide an image reading apparatus that can reduce a time required for returning from a power saving state.
[0009]
[Means for Solving the Problems]
An image reading apparatus according to the present invention is provided with image reading means for reading an image of a document using a scanning body mounted with a lamp and movably supported in a sub-scanning direction, and a standby state in which the image of the document can be read. Power saving control means for shifting the state of the self-device from the standby state to the power saving state when the elapsed time has elapsed from the standby state, and image reading means for returning from the power saving state to the standby state. It includes a return processing unit that reads a white reference plate and performs a predetermined return process, and a movement control unit that moves the scanning body below the white reference plate before shifting to the power saving state.
[0010]
In this image reading apparatus, when the state of the apparatus is shifted from the standby state to the power saving state by the power saving control means, the movement control means moves the scanning body below the white reference plate prior to this. When the return processing is performed by the return processing means, the white reference plate can be read immediately without moving the scanning body.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0012]
FIG. 1 is a schematic diagram showing a configuration example of an image reading apparatus to which the present invention is applied. In the illustrated image reading apparatus 1, a platen glass 3 serving as a document table is attached to an upper portion of the apparatus main body 2, and a document abutting guide (document positioning member) 4 and a white reference plate 5 are further mounted on the platen glass 3. Installed.
[0013]
The platen glass 3 is made of a transparent and flat glass plate, and is attached so as to fit into a rectangular opening formed in the upper part of the apparatus main body 2. A document pressing member (not shown) for pressing a document set on the platen glass 3 from above is attached to the upper part of the apparatus main body 2 so as to be openable and closable. The document pressing member is opened and closed by a user. The document holding member may be integrally formed with an automatic document feeder (auto document feeder; ADF). The automatic document feeder sequentially conveys documents set on a document tray to image reading positions.
[0014]
The document abutment guide 4 is provided for positioning a document set on the platen glass 3, and is attached to the platen glass 3 together with the white reference plate 5. In this mounting state, the step between the platen glass 3 and the document abutting guide 4 is substantially 1 mm. As shown in FIG. 2, the document abutting guide 4 includes a first document abutting guide 4 </ b> A along a main scanning direction (a vertical direction in the figure; X direction) and a sub scanning direction (a horizontal direction in the figure; Y direction). Along the second document abutting guide 4B, the entirety is arranged in an L-shape. When the image reading apparatus is viewed in a plane, the main scanning direction X and the sub-scanning direction Y are orthogonal to each other.
[0015]
The first document abutting guide 4A regulates the position of the document in the sub-scanning direction Y, and the second document abutting guide 4B regulates the position of the document in the main scanning direction X. Therefore, when setting a document on the platen glass 3, one side of the document at right angles to the first butting guide 4A while the other side of the document is set to the second document butting guide 4B. The original is positioned on the platen glass 3 by abutting.
[0016]
The white reference plate 5 is a long plate, and is arranged parallel to the main scanning direction X while being covered by the first document abutting guide 4A. This white reference plate 5 has a white read reference surface having a uniform reflectance over the longitudinal direction (main scanning direction X), and is arranged in a state where the read reference surface is in surface contact with the platen glass 3. Have been. The document abutment position by the first document abutment guide 4A is the reading start position Ps of the document image in the sub-scanning direction Y. On the other hand, the white reference plate 5 is disposed at a position outside the document image reading range shifted in one direction (leftward in the drawing) from the reading start position Ps in the sub-scanning direction Y. The document image reading range refers to an effective range when the image of the document set on the platen glass 3 is read by the image reading unit 6. Generally, when the document holding member is opened and the apparatus main body 2 is viewed in a plan view, the area where the platen glass 3 is exposed excluding the portion where the document abutment guide 4 is stuck is the document image reading range.
[0017]
On the other hand, an image reading section 6 for optically reading an image of a document is provided inside the apparatus main body 2. The image reading section 6 mainly includes an optical scanning system 7, an imaging lens 8, and a CCD image sensor 9. The optical scanning system 7 has a full rate carriage 10 as a scanning body and a half rate carriage 11. A lamp 12, a reflector 13, and a first mirror 14 are mounted on the full-rate carriage 10, and a second mirror 15 and a third mirror 16 are mounted on the half-rate carriage 11.
[0018]
The lamp 12 and the reflector 13 irradiate linear light along the main scanning direction X toward an irradiation target on the platen glass 3 (an original set on the platen glass 3, a white reference plate 5, and the like). The reflected light from the irradiation object is sequentially reflected by the first mirror 14, the second mirror 15, and the third mirror 16, as indicated by arrows in the drawing. The imaging lens 8 forms an image of the light reflected by the third mirror 16 on a light receiving surface of the CCD image sensor 9 at a predetermined magnification. The CCD image sensor 9 serves as a reading sensor for reading an image on a document, and generates an analog image signal corresponding to light reflected from the document.
[0019]
The full-rate carriage 10 and the half-rate carriage 11 are movably supported in a sub-scanning direction Y along the platen glass 3 by a guide mechanism (eg, a guide rail) and a power transmission mechanism (eg, a wire, a pulley, etc.) not shown. ing. The carriages 10 and 11 are configured to move in the sub-scanning direction Y using a common carriage motor (for example, a pulse motor) as a drive source. The home position Ph of the full-rate carriage 10 in the sub-scanning direction Y is a position (for example, about 20 mm) slightly advanced (for example, about 20 mm) from one side of the document abutting guide 4 (4A) serving as the document image reading start position Ps. Is set to When moving in the sub-scanning direction Y, the half-rate carriage 11 moves by a moving amount (moving speed) that is half of that of the full-rate carriage 10, whereby the carriages 10 and 11 move to any position in the sub-scanning direction Y. Even in this state, the optical path length from the document surface on the platen glass 3 to the light receiving surface of the CCD image sensor 9 is always kept constant.
[0020]
FIG. 3 is a block diagram illustrating a configuration example of a control system of the image reading apparatus according to the embodiment of the present invention. 3, the CCD image sensor 9 is driven by a CCD driving circuit (driver) 17. Analog image data is output from the CCD image sensor 9. This analog image data is supplied to the analog processing circuit 18. The analog processing circuit 18 performs predetermined processing (auto gain control, auto offset control, white reference data collection, shading data collection, and other analog signal processing) at the time of the start-up operation (see FIG. 6) of the apparatus described above and the return operation described later. And a buffer circuit (not shown), a sample-and-hold circuit, a gain control circuit, an offset control circuit, an A / D (analog / digital) conversion circuit, and the like. The analog processing circuit 18 generates digital image data converted by the A / D conversion circuit.
[0021]
The controller 19 includes, for example, a CPU (Central Processing Unit), a ROM (Read-Only Memory), a RAM (Random Access Memory) and the like, and performs various processes according to a control program given in advance. The controller 19 is connected with a carriage motor 20 and a power management unit 21 together with the lamp 12 described above as one of the control targets. The carriage motor 20 serves as a common drive source when the carriages 10 and 11 are moved in the sub-scanning direction y as described above, and is constituted by, for example, a pulse motor. The power management unit 21 manages the power state (on / off) of each unit in the image reading apparatus 1.
[0022]
The controller 19 is connected to a carriage sensor 22, an open / close sensor 23, and an operation panel 24 as one of control information input means. The carriage sensor 22 detects the positions of the carriages 10 and 11 (especially, the full-rate carriage 10) in the sub-scanning direction Y when the carriages 10 and 11 are moved in the sub-scanning direction Y by driving the carriage motor 20. is there. The carriage sensor 22 is configured by, for example, a photo sensor (a photo interrupter or the like) in which a light emitting element and a light receiving element are combined. A detection piece (not shown) is attached to the full-rate carriage 10 (or the half-rate carriage 11) corresponding to the carriage sensor 22. The detection piece moves in the sub-scanning direction Y integrally with the full-rate carriage 10 (or the half-rate carriage 11), and is arranged so as to block the sensor optical axis of the carriage sensor 22 at a part within the movement range.
[0023]
Further, the on / off state of the detection signal of the carriage sensor 22 is such that the reading line position of the document image by the image reading unit 6 (the irradiation position of the light by the lamp 12 and the reflector 13) is at the reading start position Ps of the document image in the sub-scanning direction Y. It switches when it matches. That is, the sensor optical axis of the carriage sensor 22 is interrupted by the detection piece at the moment when the reading line position coincides with the document image reading start position Ps. Also, when the reading line position is located at a position that is advanced within the document image reading range (right side of the Ps position shown in FIGS. 1 and 2) from the document image reading start position Ps, the sensor light of the carriage sensor 22 is The detection piece of the carriage sensor 22 is kept in the off state by the detection piece always blocking the axis. Conversely, the reading line position is closer to the white reference plate 5 than the document reading start position Ps (FIGS. 1 and 2). (Left side of the position Ps shown in FIG. 3), the detection piece is always separated from the sensor optical axis of the carriage sensor 22 so that the detection signal of the carriage sensor 22 is maintained in the ON state. On the other hand, the controller 19 detects the position of the full-rate carriage 10 in the sub-scanning direction Y based on a detection signal (on / off state) from the carriage sensor 22, and controls the driving of the carriage motor 20 based on the detection result. Configuration.
[0024]
The open / close sensor 25 detects the open / close state of the above-described document pressing member (platen cover). The sensor sensor (for example, a rod-shaped actuator) of the open / close sensor 25 is disposed in a state of projecting upward from the platen glass 3 by a predetermined dimension. When the document pressing member is closed, the document pressing member is pressed by the document pressing member to detect the open / closed state. The open / closed state that can be detected by the open / close sensor 25 includes a state in which the document pressing member is widely opened (open state), a state in which the document pressing member is closing (closed state), and a state in which the document pressing member is completely closed. State (closed state).
[0025]
The operation panel 24 is a user interface (UI) for a user using the image reading apparatus 1 to perform various operations. The operation panel 24 includes a reading start button (in the case of a copying machine or the like, a copy start button) for instructing the start of reading of a document image, together with various setting / operation buttons (or switches) for setting a reading magnification and the like. Start button) is provided.
[0026]
Next, a processing operation of the image reading apparatus 1 having the above configuration will be described. When the power of the image reading apparatus 1 is turned on, the start-up operation of the apparatus is performed according to the procedure shown in FIG. 6, but the start-up operation is as described in the above-mentioned conventional technique. Here, a description will be given of a processing operation by the controller 19 after the power supply is turned on to be in a standby state by a start-up operation.
[0027]
FIG. 4 is a flowchart showing a processing operation when shifting from the standby state to the power saving state. First, when the image reading apparatus 1 enters the standby state, the elapsed time from the standby state is monitored by, for example, time measurement by a timer, and whether or not the elapsed time reaches a predetermined time is repeatedly performed. A determination is made (step S11). The predetermined time is set to define the timing for shifting the device to the power saving state.
[0028]
Thereafter, when it is determined that the elapsed time from when the apparatus enters the standby state has reached the predetermined time, the carriage motor 20 is driven to move the full-rate carriage 10 from the home position Ph to below the white reference plate 5 (step). S12). Thereafter, the power management unit 21 is activated to turn off the power supplies other than the operation panel 24 (for example, the power supplies for the CCD drive circuit 17, the analog processing circuit 18, the carriage motor drive circuit, and the like) (step S13). Thereby, the image reading apparatus 1 shifts from the standby state to the power saving state.
[0029]
FIG. 5 is a flowchart showing a processing operation when returning from the power saving state to the standby state. First, when the image reading device 1 enters the power saving state, by monitoring the presence or absence of an input from the operation panel 24, it is repeatedly determined whether or not the user has operated the operation panel 24 (step S21).
[0030]
Thereafter, when the user actually operates the operation panel 24, an input from the operation panel 24 is sensed, and a return operation (including a return process) from the power saving state is executed using the input as a trigger (step S22). By this return operation, the image reading device 1 returns from the power saving state to the standby state.
[0031]
Here, in the return operation of the step S22, the full-rate carriage 10 has been moved below the white reference plate 5 in advance of the transition to the power saving state at a stage before this. There is no need to perform the processing of steps S1 and S2 in the processing flow of the startup operation shown. Therefore, when returning from the power saving state to the standby state, the lamp 12 is immediately turned on, the white reference plate 5 is read, and processing from the automatic gain control can be started. Therefore, it is possible to shorten the time required to return from the power saving state.
[0032]
Further, in the apparatus having a document size detecting function for detecting the size of the document placed on the platen glass 3, when the shading data is collected and the lamp is turned off when returning from the power saving state, the full rate carriage 10 is moved to the white reference plate. 5, when the reading line position by the image reading unit 6 passes through the reading start position Ps and moves into the document image reading range (when the detection signal of the carriage sensor 22 is turned off). By turning on the document size detection function at the time of switching to the ON state), the document size detection function can be effectively activated at an earlier timing.
[0033]
Here, it is assumed that the power-saving state is restored when the user operates the operation panel 24. However, conditions for the return include, for example, when the document pressing member is opened and closed by the user, and when the automatic document feeder is used. Various conditions can be adopted, such as when a document is set, or when a model is compatible with a network, when a signal is received from the outside via a network.
[0034]
【The invention's effect】
As described above, according to the present invention, when returning to the standby state from the power saving state by moving the scanning body under the white reference plate before shifting to the power saving state, The white reference plate can be read immediately without moving. Therefore, it is possible to shorten the time required to return from the power saving state.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration example of an image reading apparatus to which the present invention is applied.
FIG. 2 is a partial plan view of the image reading apparatus shown in FIG.
FIG. 3 is a block diagram illustrating a configuration example of a control system of the image reading apparatus according to the embodiment of the present invention.
FIG. 4 is a flowchart showing a processing operation when shifting from a standby state to a power saving state.
FIG. 5 is a flowchart illustrating a processing operation when returning from a power saving state to a standby state.
FIG. 6 is a flowchart showing a start-up operation at power-on.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image reading device, 3 ... Platen glass, 4 ... Original abutting guide, 5 ... White reference plate, 6 ... Image reading part, 9 ... CCD image sensor, 10 ... Full rate carriage, 11 ... Half rate carriage, 12 lamps, 19 Controller, 20 Carriage motor, 21 Power supply management unit, 22 Carriage sensor, 23 Open / close sensor, 24 Operation panel

Claims (2)

Image reading means for reading an image of a document using a scanning body mounted with a lamp and movably supported in the sub-scanning direction,
Power saving control means for shifting the state of the self apparatus from the standby state to the power saving state when the elapsed time from the standby state in which the image of the document can be read reaches a predetermined time;
When returning to the standby state from the power saving state, a return processing unit that reads a white reference plate with the image reading unit and performs a predetermined return process,
An image reading apparatus comprising: a movement control unit configured to move the scanning body below the white reference plate before shifting to the power saving state. Document size detecting means for detecting the size of the document placed on the platen,
In returning from the power saving state, when the scanning body is moved from under the white reference plate to the home position, the reading line position by the image reading means passes through the reading start position of the document image and the document image is read. 2. The image reading apparatus according to claim 1, wherein the detection function of the document size detection unit is turned on when the document enters the reading range.

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