JP2009231940A - Image reading device with power saving mode, and power control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly detect user usage prediction. <P>SOLUTION: An image reading device includes: a RAM 41 for storing a plurality of thresholds corresponding to respective sizes of a plurality of manuscripts; and a control part 45 which determines a usage threshold for detecting whether or nor the manuscript in a size specified by a user is placed on a platen, determines whether or not the intensity of exterior light is changed from a smaller value to a larger value than the usage threshold, or changed from the larger value to the smaller value than the usage threshold, and controls the supply power so as to cancel a power saving mode when the intensity of the exterior light is determined to be changed from the larger value to the smaller value than the usage threshold in the power saving mode. Even when the intensity of the exterior light increases and the state of a platen cover is changed, if it is determined that the intensity of the exterior light is not changed from the smaller value to the larger value than the usage threshold, the power saving mode is maintained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus having a power saving mode, for example, a single image scanner used as a peripheral device of a personal computer, and a printer including an image reading apparatus.

2. Description of the Related Art An image scanner that has a main body having a document table having a placement surface (for example, a glass table) for placing a document and reads an image of the document placed on the placement surface of the document table is already known. ing. This type of image scanner, for example, can be raised and lowered to hold the document table, a fluorescent lamp as a light source, and the reflected light from the original that has received the light generated from the fluorescent lamp. CCD (Charge-Coupled) to convert to signal
Device). Furthermore, some image scanners of this type have a power saving mode that reduces the power consumption of the entire device (for example, Patent Document 1). When the image scanner shifts to the power saving mode, the power supply to the light source is stopped, and when the power saving mode is canceled, the power supply to the light source is started again (for example, FIG. FIG. 1b).

  As described above, the image scanner having the power saving mode saves, for example, when a predetermined button (for example, a copy execution button if the image scanner is a copying apparatus) is pressed by the user in the power saving mode. There is something to cancel the power mode. Conventionally, however, the CCD output signal value is monitored so that the total time for reading can be further shortened, and when the output signal value increases, it is detected that the document presser is raised and the power is supplied to the light source. Is considered (for example, paragraph 40 of Patent Document 1). In addition, the conventional image scanner stops power supply to the light source when a certain time has elapsed after the reading operation is finished (paragraphs 66 to 67 of Patent Document 1).

  Further, a technology for canceling the power saving mode by detecting a user's usage sign that a typical size document is placed on the placement surface of the document table and a user's usage sign that a typical size document is removed from the document table. Is also known (for example, Patent Document 2).

JP 06-309449 A JP 2004-357007 A

  For example, according to the technique described in Patent Document 2, when a document of a size smaller than a typical document in the apparatus is placed, the external light sensor detects external light and does not decrease beyond a predetermined threshold. So do not cancel the power saving mode. That is, when a document having a size smaller than a typical document in the apparatus is placed, the user use sign cannot be detected appropriately.

  In addition, when the document cover is opened with a document of a size smaller than the typical size placed, the external light increases beyond a predetermined threshold, so that the power saving mode is canceled at this point. End up. That is, the user's usage sign that the document is removed is not appropriately reflected.

  Here, the size of the document used frequently by the user does not always match the typical size of the apparatus. That is, there are users who frequently use originals smaller than the typical size. For such a user, the above-mentioned user usage sign based on the typical size is not suitable for the user.

  Accordingly, an object of the present invention is to provide a technique capable of appropriately detecting a user usage sign in accordance with a user who uses the apparatus.

  An image reading apparatus according to an aspect of the present invention is an image reading apparatus having a power saving mode, and a main body including a document table having a placement surface for placing a document, and at least a placement surface of the document table. A document table cover that is openably and closably mounted on the document table, a light source that generates light, a power source that supplies power to the light source, and the main body through the placement surface. An external light detecting means for detecting external light incident on the inside and outputting a detection signal; and whether or not each size of the original is placed on the original table corresponding to each of the sizes of the plurality of originals. Threshold storage means for storing a plurality of threshold values relating to the intensity of the external light for determination; threshold determination means for determining a threshold corresponding to the size of the document specified by the user as a use threshold; and intensity of the external light It is determined whether or not the value smaller than the use threshold has changed to a value greater than the use threshold, and whether or not the external light intensity has changed from a value greater than the use threshold to a value smaller than the use threshold. In the state where the intensity of the external light has shifted to the power saving mode without changing for a predetermined time, the intensity of the external light is changed from a value greater than the use threshold to a value smaller than the use threshold by the determination means. The power supply control means for controlling the power supply to release the power saving mode, and even when the intensity of the external light increases and the state of the document table cover changes, When the determining means determines that the intensity of the external light has not changed from a value smaller than the use threshold value to a value larger than the use threshold value, the power saving mode is maintained.

  Here, the “power saving mode” is a mode in which the power consumption of the image reading apparatus is smaller than that in a mode other than the power saving mode (for example, normal time).

  In the first preferred embodiment, each of the plurality of threshold values is greater than the intensity of external light when a document having a size smaller than the size corresponding to the threshold is placed on the document table. This is a small value, which is a value larger than the intensity of external light when a document of a size corresponding to the threshold is placed on the document table.

In a second preferred embodiment, the power control means determines whether or not the intensity of the external light has increased and decreased from the detection signal, and in the power saving mode state, When it is determined that the intensity of the external light has increased or decreased, the power saving mode is canceled. Specifically, for example, the power control means includes the following items (a) and (b):
(A) that the intensity of the detected external light has decreased below a predetermined threshold and / or that the amount of decrease in the intensity of the detected external light has exceeded a predetermined amount;
(B) that the intensity of the detected external light has increased from a predetermined threshold and / or that the amount of increase in the intensity of the detected external light has exceeded a predetermined amount;
If any one of the items is determined, if the power saving mode is in progress, the power saving mode is canceled.

  In a third preferred embodiment, the reading is mounted in the main body and receives reflected light or transmitted light from the document on the placement surface that has received light generated from the light source and converts it into an electrical signal. Further, an external light detecting means is provided, and the external light detecting means is mounted in the main body separately from the reading light detecting means.

  In a fourth preferred embodiment, the power control means stops power supply to the light source in the power saving mode, or supplies power to the light source in a normal state (for example, in the normal power mode). ) To be smaller.

  In a fifth preferred embodiment, in the third preferred embodiment, the power supply also supplies power to the reading light detection means, and the power supply control means is configured to The power supply to the reading light detecting means is stopped, or the power supplied to the light detecting means is made smaller than that in the normal state.

  In a sixth preferred embodiment, the light source is at least one of a fluorescent lamp, a xenon lamp, and a light emitting diode.

  In a seventh preferred embodiment, an image output device for outputting read image data of the original is further provided. The read image data of the original is, for example, a reading that is mounted in the main body, receives reflected light or transmitted light from the original on the placement surface that has received light generated from the light source, and converts it into an electrical signal. It is produced | generated based on the said electrical signal output from the use light detection means.

  In an eighth preferred embodiment, in the seventh preferred embodiment, the image output device also has a power saving mode, and the image output device is also supplied with power from the power source. And when the power supply control unit determines that at least the intensity of the detected external light has decreased (for example, whether or not the intensity of the external light has increased from the detection signal and whether it has decreased). If the image output apparatus is in the power saving mode, the power saving mode is canceled. .

In a ninth preferred embodiment, in the seventh preferred embodiment, the read image output device includes the following devices (1) to (4):
(1) An image data transmitting device for transmitting the read image data to a device communicably connected to the image reading device,
(2) a facsimile transmission device for transmitting the read image data to a predetermined or user-desired destination terminal by facsimile via a public telephone network;
(3) a data storage device for storing the read image data in an external storage device detachably attached to the image reading device;
(4) a printing apparatus for printing the read image data on a predetermined print medium;
At least one of the devices.

  In a tenth preferred embodiment, the reading is mounted in the main body and receives reflected light or transmitted light from the document on the placement surface that has received light generated from the light source and converts it into an electrical signal. And an external light detection means that also serves as the reading light detection means.

  In an eleventh preferred embodiment, when the power control means determines that there is no change in the external light from the detection signal after a lapse of a predetermined time after the power saving mode is canceled, for example, power control The means shifts to the power saving mode. Specifically, for example, the power supply control means (1) when the power saving mode is canceled, and (2) when the reading operation ends in a state other than the power saving mode and when the external light changes (at least externally) When a light intensity drop is detected, a timer operation is started. Thereafter, in a state other than the power saving mode, a reading operation is not performed and a change in external light is not detected (either one is detected). If the timer is reset, the timer is restarted) to enter the power saving mode.

  In a twelfth preferred embodiment, the power supply control means is configured to operate both when the opened platen cover is closed and when the closed platen cover is opened in the power saving mode. In this case, the power saving mode is canceled. In this case, for example, when the document table cover in the open state is closed by the external light detection means, the place where the intensity of the incident external light decreases (in other words, the incident path of most of the external light is It is disposed in a place where the intensity of the incident external light increases when the document table cover in the closed state is opened. The power supply control means cancels the closed state when the detected intensity of the external light is reduced by closing the document table cover in the open state, and closes it during the power saving mode. If the detected intensity of the external light is increased by opening the original platen cover in a closed state, it is canceled during the power saving mode.

  In a thirteenth preferred embodiment, the power control means is configured to place a document when a document is placed on the placement surface in a state where nothing is placed and when a document is placed in the power saving mode. The power saving mode is canceled in both cases where the original is removed from the placement surface. In this case, for example, when the external light detecting means places a document of a predetermined size on the placement surface in a state where nothing is placed, the place where the intensity of the incident external light decreases (in other words, If the original is removed from the placement surface on which the original is placed, the intensity of the incident external light is large. Is placed in an increasing location. The power supply control means is in the middle of the power saving mode when the intensity of the detected external light is reduced by placing the document on the placement surface where nothing is placed. If there is an increase in the intensity of the detected external light due to the removal of the document and removal of the document from the previous placement surface on which the document is placed, the power saving mode is If it is inside, cancel it.

  In a fourteenth preferred embodiment, in the twelfth and thirteenth preferred embodiments, for example, the power control means detects the detection by opening the document table cover that is closed in the power saving mode. When it is determined that the intensity of the external light to be increased has increased, the power saving mode is canceled, and a predetermined event (for example, execution of a reading operation) is not detected while the document table cover is open. After the transition to the power saving mode, when it is determined that the open-side document table cover is closed or the document is placed on the placement surface of the document table, the intensity of the external light is reduced. The power saving mode is canceled again. Further, for example, when the document table cover is open and in the power saving mode, the power control unit is configured to prevent the external light from being placed on the document table by placing the document on the placement surface of the document table. When it is determined that the strength has decreased, the power saving mode is canceled, and then the predetermined event is not detected while the original is placed on the placement surface and the original table cover is open. After shifting to the power saving mode, the intensity of the external light is increased by closing the opened document table cover or removing the document placed on the placement surface from the placement surface. When it is determined that the power saving mode has been determined, the power saving mode is canceled again.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 is a perspective view of an image scanner according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is a top view of the image scanner according to the present embodiment. FIG. 4 is a cross-sectional view taken along the line BB in FIG. 3 and shows the internal structure of the read head in the image scanner.

  An image scanner 1 according to the present embodiment is a flood bed type scanner having a read head 5 of a reduction optical system, and consumes more power than that in a normal power mode that consumes power necessary for reading operation. And a power saving mode for reducing the amount. The image scanner 1 includes a scanner body 10 having a document table for placing a document to be read, a document table cover 3 pivotally attached to the document table of the scanner body 10, and a scanner. A rotating shaft 13 (not shown in FIG. 1) for pivotally mounting the main body 10 and the document table cover 3 is provided (in FIG. 1, in order to make the inside of the scanner 1 easier to understand, the scanner main body 10 The outer surface and the document table cover 3 are indicated by a two-dot chain line).

  The scanner body 10 is a solid (for example, a rectangular solid) having at least a placement surface 9 on which a document is placed and an internal space. In the internal space, a read head 5 on which a linear CCD is mounted, a CCD substrate 15 for processing an output signal from the linear CCD of the read head 5, a shaft 11 for guiding the read head 5, and a read head A head drive mechanism (not shown) for reciprocating the shaft 5 along the shaft 11 (for example, a motor, a belt that operates by driving the motor to drive the read head 5), a control circuit described later, and the like are provided. ing.

  The mounting surface 9 is a table made of a material having a high transmittance that can sufficiently transmit light, for example, glass. In order to guide where the document is placed on the placement surface 9 (that is, the positioning point) at a predetermined position on or near the placement surface 9 (for example, near the upper left corner of the placement surface 9). There is a positioning guide description (for example, an arrow for instructing to place the corner of the document at the upper left corner of the placement surface 9) 20. The location indicated by the alignment guide description 20 is, for example, the origin of the read image of the document.

  The reading head 5 is a solid (for example, a solid in a rectangular parallelepiped state) having a surface (hereinafter referred to as “reading surface”) facing the mounting surface 9 of the scanner body 10 and an internal space, and is penetrated by the shaft 11. ing. The read head 5 reciprocates in a predetermined direction along the shaft 11, and a home position (the origin of the read head 5 on the travel path) is at a predetermined location (for example, the surface of the lower surface) of the read head 5. ) (Hereinafter referred to as “HP detection rib”) 21 is provided. The HP detection rib 21 contacts a predetermined location in the scanner body 10 when the reading head 5 reaches the home position. By detecting this, it can be recognized in the image scanner 1 that the reading head 5 has reached the home position.

  The reading head 5 includes a slit 7 on the reading surface (see FIGS. 1, 3 and 4), and includes a light source 23, mirrors M1 to M4, a lens 25, and a linear CCD 27 in an internal space (see FIG. 4).

  The slit 7 on the reading surface penetrates from the outside to the inside of the reading head 5, so that light can enter the inside from the outside of the reading head 7. For example, when light is emitted from the light source 23 when the original is placed on the placement surface 9 of the scanner body 10 and the original table cover 3 is closed, the original emits light from the light source 23. The reflected light enters the inside through the slit 7.

  The light source 23 receives light from a predetermined power source and emits light. Specifically, for example, at least one of a fluorescent lamp (for example, a cold cathode fluorescent lamp or a hot cathode fluorescent lamp), a xenon lamp, and a light emitting diode can be adopted as the light source 23.

  Each of the mirrors M1 to M4 accurately guides the light that has entered through the slit 7 (for example, reflected light of the light source 23 from the document) to the lens 25, and the light (for example, optical of one line of the document). Image) is arranged at such an angle that the linear CCD 27 can receive it through the lens 25. By appropriately arranging the mirrors M1 to M4, for example, if the reflected light of the light source 23 from the document enters the inside through the slit 7, the order of the mirror M1, the mirror M2, the mirror M3, and the mirror M4 And is reflected from the mirror M4 and reaches the linear CCD 27 via the lens 25.

  FIG. 5 is a block diagram illustrating a configuration of the image scanner 1.

  The image scanner 1 includes the above-described reading head 5, CCD substrate 15, external light sensor 100, head driving mechanism 38, control circuit 37, and reading image output unit 43.

  As described above, the CCD substrate 15 is a circuit substrate that can process an output signal from the linear CCD 27 in the reading head 5. The CCD substrate 15 may be mounted on the inside or the outer surface of the reading head 5 and may move as the reading head 5 travels, or may be mounted at a stationary location away from the reading head 5. The CCD substrate 15 includes, for example, a CCD power supply 33 and an A / D conversion circuit 31. The CCD power supply 33 is turned on or off based on a control signal from a control unit 45 to be described later. By turning on, the power supplied from a power supply circuit (not shown) is supplied to the linear CCD 27. The power supply to the linear CCD 27 is stopped by turning off. The A / D conversion circuit 31 receives an analog electrical signal output from the linear CCD 27, converts the analog electrical signal into a digital electrical signal, and outputs the digital electrical signal to a control unit 45 described later.

  The external optical sensor 100 is external to the scanner main body 10 that enters the scanner main body 10 from the outside of the scanner main body 10 through the mounting surface 9 separately from the optical sensor (that is, the linear CCD 27) as an image sensor for inputting the read image of the document. This is a light sensor dedicated to detecting external light provided to detect light. The external light sensor 100 is a sensor that consumes less power than at least the linear CCD 27, and is, for example, an amorphous silicon semiconductor visible light sensor. When the external light sensor 100 receives external light, it outputs an electrical signal corresponding to the intensity of the received external light (in other words, the amount of received light) to the control unit 45 of the control circuit 37 described later. The location of the external light sensor 100 on the scanner 1 will be described later.

  The head drive mechanism 38 is, for example, a belt for running the read head 5 along the shaft 11, a head drive motor for moving the read head 5 by moving the belt, or reading the motor by driving the motor. The head drive circuit etc. which drive the head 5 are included. A predetermined component (for example, a head drive circuit) of the head drive mechanism 38 receives a control signal from the control unit 45 described later, and runs the read head 5 and controls its position based on the control signal.

  The control circuit 37 includes a light source power source 35, a timer 49, a RAM 41, and a control unit 45.

  The light source power source 35 is turned on or turned off based on a control signal from the control unit 45. When the light source power source 35 is turned on, power supplied from a power supply circuit (not shown) is supplied to the light source 23 and turned off. As a result, the power supply to the light source 23 is stopped.

  The timer 49 starts a timer operation based on a timer start command from the control unit 45, and outputs a signal indicating that to the control unit 45 when time is up.

  The RAM 41 has, for example, a work area of the control unit 45 and an image area in which data of a line-shaped read image input from the linear CCD 27 to the control unit 45 each time the reading head 23 moves. The scanner 1 is not limited to the RAM 41, and may include a non-rewritable memory (for example, ROM) and a rewritable nonvolatile memory (for example, EEPROM).

  The control unit 45 is a CPU, for example, and controls the transition from the normal power mode to the power saving mode, the transition from the power saving mode to the normal power mode, or the operation of the head driving mechanism 38. Thus, the position of the read head 5 is controlled, and the operations of the light source power supply 35, the CCD power supply 33, and the timer 49 are controlled.

  For example, in the normal power mode, the control unit 45 drives the timer 49 and starts the timer operation when a predetermined operation is finished. When the control unit 45 receives a time-up signal from the timer 49 without detecting a predetermined state change, the control unit 45 shifts from the normal power mode to the power saving mode. In this case, the control unit 35 turns off the CCD power source 33 and the light source power source 35 at the same timing or at different timings. Note that the “predetermined state change” mentioned here means, for example, that the signal value received from the external light sensor 100 has undergone a predetermined change (for example, the signal value has become larger or smaller than a predetermined threshold, or the signal value The amount of change in the image data is larger than a predetermined amount), a read execution command (command to start a read operation) is received from a host device (not shown) connected to the scanner 1, or the user's scanner 1 For example, a read execution command is received by a button operation (not shown).

  In addition, when a predetermined state change (for example, the state change described above) is detected during the power saving mode, the control unit 45 shifts from the power saving mode to the normal power mode (that is, cancels the power saving mode). ). In this case, the control unit 35 turns on the CCD power source 33 and the light source power source 35 at the same timing or at different timings.

  Further, when scanning the document, the control unit 45 turns on the light source power source 35 to supply predetermined power to the light source 23 so that light is generated from the light source 23. After that, the control unit 45 causes the head driving mechanism 38 to cause the reading head 5 to reach the home position (that is, the origin) (for example, this operation is not necessary if it is already at the home position), and generates from that position. The read head 5 is moved based on the resolution of the read image. When the reading head 5 moves, the control unit 45 receives line-shaped read image data from the linear CCD 27 via the A / D conversion circuit 31 and accumulates the line-shaped read image data in the RAM 41. Thereby, the read image data of the entire document is accumulated in the RAM 41. The control unit 45 can cause the read image output unit 43 to output the read image data stored in the RAM 41 at a predetermined timing.

The read image output unit 43 outputs read image data stored in the RAM 41. Specifically, the read image output unit 43 includes, for example, the following (1) to (5),
(1) a data transmission unit for transmitting read image data by wire or wireless to a host device communicably connected to the image scanner 1;
(2) a data transmission unit that transmits read image data by, for example, e-mail to a remote device that is communicably connected to the image scanner 1 via a communication network such as the Internet;
(3) a facsimile transmission unit for transmitting the read image data to a predetermined destination or a desired destination by facsimile via a public telephone network;
(4) A data storage unit (in this case, for example) that stores read image data in an external storage device (for example, a portable recording medium such as a memory card or an external hard disk device) detachably attached to the image scanner 1 The image scanner 1 becomes a communication master or communication host, and the external storage device becomes a communication slave or communication device).
(5) A printing unit that prints the read image data on a predetermined print medium (for example, plain paper or glossy paper) by an inkjet method or an electrophotographic method,
At least one of them.

  By the way, the internal space of the scanner body 10 includes a mounting surface corresponding space composed of a trajectory when the mounting surface 9 is lowered in the vertical direction. The mounting surface corresponding space is a rectangular parallelepiped (or a cube), the horizontal length of the space is the same as the horizontal length W of the mounting surface 9, and the vertical length is the mounting surface 9 The same length and height as the vertical length L are the same as the height H of the internal space of the scanner body 10. The intensity of the external light detected in the mounting surface corresponding space is, for example, when the external light is irradiated from vertically above the mounting surface 9 compared to the amount of light detected outside the mounting surface corresponding space. It is thought that there are many.

  As described later, the external light sensor 100 described above can be used as a sensor for detecting the opening / closing of the document table cover 3, and whether or not a document of a predetermined size is placed on the placement surface 9. It can also be used as a sensor for detecting whether or not a document has been removed from the placement surface 9. The external light sensor 100 can be disposed, for example, inside the scanner body 10. As specific modes of arrangement of the external light sensor 100, for example, the following first to fourth modes are conceivable.

  (A) First arrangement mode.

  This will be described with reference to FIGS.

  The external light sensor 100 is within a range in which external light incident on the inside of the scanner body 10 can be detected, and is placed at a distance from the pivot portion (that is, the rotation shaft 13) between the document table and the document table cover 3. It is arranged at a location far from the center of the surface 9. Specifically, in the scanner body 10, when the surface including the side having the pivoting portion is the base end surface and the surface including the side facing the pivoting portion is the leading end surface, the external light sensor 100 is: It is arranged on the side closer to the tip surface than the center 44 of the mounting surface corresponding space. Preferably, for example, the external optical sensor 100 is disposed on or in the vicinity of the surface farthest from the base end surface in the placement surface corresponding space. In this case, more preferably, the external light sensor 100 is disposed at a position 12 (for example, a shallow position in the scanner main body 10) above the traveling path of the reading head 5 so that external light is easily received. (You may arrange | position in the position (for example, deep position in the scanner main body 10) 14 lower than the traveling path).

  According to the first arrangement mode, when the document table cover 3 in the closed state is opened, the external light detection sensor 100 is provided closer to the base end surface than the center of the placement surface corresponding space. In comparison, it is possible to detect that the document table cover 3 has been opened earlier.

  (B) Second arrangement mode.

  The external light sensor 100 is a place where the intensity of the external light incident on the external light sensor 100 changes depending on whether or not the document is placed on the placement surface 9 of the document table (for example, in or near the placement surface corresponding space). Is arranged. Specifically, a positioning point for positioning the document is provided on the placement surface 9 of the document table. The external light sensor 100 positions a document of a predetermined size at the positioning point, and the document is When placed, the document is disposed at a place where the incident path of most of the external light is blocked by the document. Hereinafter, a description will be given with reference to FIG. In the following description, the top, bottom, left, and right directions on the paper surface are referred to as “up”, “down”, “left”, and “right”, and the direction running from the front to the back of the paper surface is referred to as “back”.

  The external light sensor 100 is disposed at a predetermined position (or in the vicinity thereof) behind a place on the placement surface 9 where a predetermined portion of the document is superimposed. Specifically, for example, when the document is placed such that the upper left corner of the document overlaps the upper left corner of the placement surface 9, the external light sensor 100 is set to a predetermined depth at the back of the upper left corner of the placement surface 9. The location (or its vicinity) LC is provided. For example, when the document is placed such that the center of the upper edge of the document overlaps the center of the upper edge of the placement surface 9, the external light sensor 100 is located at the back of the center of the upper edge of the placement surface 9. It is provided at a predetermined position (or its vicinity) C. Further, for example, when the document is placed such that the upper right corner of the document overlaps the upper right corner of the placement surface 9, the external light sensor 100 is positioned at a predetermined position (or the back of the upper right corner of the placement surface 9 (or (Neighborhood) RC is provided.

  In the second arrangement mode, the external light sensor 100 is preferably arranged as close to the mounting surface 9 as possible. For example, as in the first arrangement mode, the reading head You may arrange | position in the deep place below 5 driving paths.

  According to the second arrangement mode, it is detected whether or not a document is placed on the placement surface 9, whether or not the document is removed, and that the intensity of external light has changed due to the document table cover 3 being closed. can do. Thus, as a user use sign other than opening the document table cover 3 (that is, a sign that the image scanner 1 can be used by the user), the document is placed, the document is removed (or replaced), or the document table cover 3 Can be detected.

  (C) Third arrangement mode.

  The external optical sensor 100 is mounted on the outer surface or inside of the reading head 5. Specifically, for example, as illustrated in FIG. 9, the external optical sensor 100 is disposed on the outer surface of the reading head 5 and on the surface facing the mounting surface 9 (that is, the upper surface that easily receives external light). Is done. More specifically, for example, the external optical sensor 100 is a place on the upper surface of the reading head 5 and passes through the mounting surface corresponding space when the reading head 5 travels in the mounting surface corresponding space. It is arranged at a location far from the center of the space corresponding to the placement surface.

  In the third arrangement mode, the control unit 45 (see FIG. 5) controls the head driving mechanism 38 when the document reading process is not being performed (for example, during the power saving mode), and FIG. As shown in FIG. 3, the reading head 5 is on standby at a predetermined location (for example, home position) such that the position of the external light sensor 100 can detect external light (for example, a position in the mounting surface corresponding space). Let In this case, when starting the reading operation, if the standby position of the reading head 5 is not the home position, the control unit 45 starts the reading operation after moving the reading head 5 to the home position.

  In the third arrangement mode, when the control unit 45 shifts from the normal power mode to the power saving mode, the reading head 5 is placed by the external optical sensor 100 and the document is placed on the placement surface 9 of the document table. It may be moved to a place where the intensity of the external light incident on the external light sensor 100 changes depending on whether or not it has been changed, and may be kept waiting at that place during the power saving mode. Specifically, when the control unit 45 shifts from the normal power mode to the power saving mode, the reading head 5, the external light sensor 100, a document of a predetermined size is positioned at a positioning point, and the document is placed. Then, the document may be moved to a place where most of the incident path of the external light is blocked by the document, and may be kept in the place during the power saving mode.

  (D) Fourth arrangement mode.

  The external light sensor 100 is mounted on the CCD substrate 15. Specifically, for example, as illustrated in FIG. 10, the external optical sensor 100 is disposed on a CCD substrate 15 mounted on the outer surface (or inside) of the read head 5. More specifically, for example, the external optical sensor 100 passes through the mounting surface corresponding space when the reading head 5 travels in the mounting surface corresponding space, and is located on the tip side from the center of the mounting surface corresponding space. Located in a distant place.

  In the fourth arrangement mode, the control unit 45 (see FIG. 5) controls the head driving mechanism 38 when the document reading process is not being performed (for example, during execution of the power saving mode), and FIG. As shown in FIG. 4, the reading head 5 is placed at a predetermined position (for example, a home position) such that the position of the external light sensor 100 is a position where the external light can be detected (for example, a predetermined position directly below the mounting surface 9). Wait. In this case, when starting the reading operation, if the standby position of the reading head 5 is not the home position, the control unit 45 starts the reading operation after moving the reading head 5 to the home position.

  Even in the fourth arrangement mode, when the control unit 45 shifts from the normal power mode to the power saving mode, the reading head 5 and the external light sensor 100 are placed on the placement surface 9 of the document table. It may be moved to a place where the intensity of the external light incident on the external light sensor 100 changes depending on whether or not it is placed, and may stand by at that place during the power saving mode. Specifically, when the control unit 45 shifts from the normal power mode to the power saving mode, the reading head 5, the external light sensor 100, a document of a predetermined size is positioned at a positioning point, and the document is placed. Then, the document may be moved to a place where most of the incident path of the external light is blocked by the document, and may be kept in the place during the power saving mode.

  The above is a specific example of the arrangement mode of the external light sensor 100.

  As described above, the image scanner 1 according to the present embodiment shifts from the normal power mode to the power saving mode based on the signal value output from the external light sensor 100 and the change thereof, and changes the power saving mode. Or cancel it.

  FIG. 11 shows an example of the relationship between the signal value output from the external light sensor 100 and its change, and the power mode in the scanner 1. Hereinafter, an example of a flow when shifting to the power saving mode or canceling the power saving mode will be described with reference to FIG. In the following description, it is assumed that the document placed on the placement surface 9 of the scanner body 10 is a document having a transmittance capable of transmitting at least a small amount of light.

  When the document table cover 3 of the image scanner 1 is closed, external light cannot pass through the placement surface 9 of the scanner body 10 of the scanner 1 and enter the scanner 1. The external light sensor 100 arranged in the substantially no external light is detected. Therefore, the signal value output from the external light sensor 100 is the smallest value E4.

  Further, when a predetermined time elapses without detecting the predetermined state change as described above from the time when the predetermined operation is completed in the scanner 1, the scanner 1 shifts from the normal power mode to the power saving mode. During the power saving mode, the light source power supply 35 and the CCD power supply 33 are in an off state, and power is not supplied to the light source 23 and the linear CCD 27.

  In this state, it is assumed that the document table cover 3 is opened at time T1, for example.

  In that case, if no document is placed on the placement surface 9 of the scanner body 10, a large amount of external light enters the scanner body 10, and the external light sensor 100 receives the external light. Then, as shown in FIG. 11, the external light sensor 100 outputs a signal having a high value E1 corresponding to the large amount of external light and inputs the signal to the control unit 45.

  If the value of the signal input from the external light sensor 100 exceeds the predetermined threshold EX (that is, if the value of the signal input from the external light sensor 100 exceeds the predetermined threshold EX), the control unit 45 ), The power saving mode is canceled, and the warm-up process for the reading operation is started (specifically, for example, the control unit 45 turns on the light source power source 35 and the CCD power source 33 to turn on the light source 23 and the linear power source). The power supply to the CCD 27 is started). At the same time, the control unit 45 starts a timer 49.

  Now, after the document table cover 3 is opened at time T1, when the document table cover 10 is kept open without being placed on the document table, the external light sensor 100 outputs a high signal value E1. The signal I have is kept output. From time T1, a predetermined time elapses without performing a predetermined operation (for example, placing a document, closing the document table cover 3, or moving the reading head 5), and time T1 ′ is reached. When the time is up (that is, when the time is up), the control unit 45 shifts from the normal power mode to the power saving mode. Specifically, for example, the control unit 45 turns off the light source power source 35 and the CCD power source 33 so that power is not supplied to the light source 23 and the linear CCD 27.

  After that, when a document of a typical size (for example, A4 size) is placed on the placement surface 9 at time T2, the external light received by the external light sensor 100 is blocked by the document with the most incident path of external light being blocked. The amount of light is greatly reduced. For this reason, the value of the signal output from the external light sensor 100 is changed from a high E1 to a considerably low value E3 (that is, the external light sensor 100 is, for example, an incident path of most of the external light by a document of a predetermined size, for example. (This will be described later.)

  If the value E3 of the signal input from the external light sensor 100 is smaller than the predetermined threshold EX (that is, if the value of the signal input from the external light sensor 100 falls below the predetermined threshold), the control unit 45 The power saving mode is canceled and warm-up processing for reading operation is started. At the same time, the control unit 45 starts a timer 49.

  After that (that is, at time T3), when the document table cover 3 is closed, external light is not substantially incident on the placement surface 9 and the scanner body 10 and is output from the external light sensor 100. The value of the signal changes from a very low value E3 to the lowest E4 mentioned above. At that time, for example, the control unit 45 resets and restarts the timer 49 (not necessarily resetting and restarting).

  Now, after restarting the timer 49 at time T3, when a predetermined time elapses and time T3 ′ is reached without performing a predetermined operation (that is, when the time is up), the control unit 45 resumes from the normal power mode. Transition to power saving mode.

  It is assumed that the document table cover 3 is opened at time T4 during the power saving mode. However, since the document of typical size remains placed on the placement surface 9 of the scanner body 10, the amount of external light received by the external light sensor 100 is not so large, and is therefore output from the external light sensor 100. The signal value is a low value E3 that does not exceed the predetermined threshold value EX. In this case, the control unit 45 does not cancel the power saving mode (for example, the power saving mode may be canceled at this time and the normal power mode may be shifted).

  Thereafter, when the document of the typical size is removed from the placement surface 9 at time T5, a lot of external light enters the scanner body 10, and the external light sensor 100 receives the lot of external light. Therefore, the output signal value of the external light sensor 100 changes from a low value E3 to a high value E1, that is, exceeds a predetermined threshold value EX. In that case, the control unit 45 cancels the power saving mode and starts warm-up processing for the reading operation. At the same time, the control unit 45 starts a timer 49.

  Now, after the document is removed from the placement surface 9 at time T5, when the document table cover 10 remains open without being placed, the external light sensor 100 receives a high signal value. A signal having E1 continues to be output. When a predetermined time elapses from time T1 and the time T5 'is reached (that is, when the time is up), the control unit 45 shifts from the normal power mode to the power saving mode.

  Thereafter, it is assumed that an original (for example, B5 size) smaller than the typical size is placed on the placement surface 9 at time T6. In this case, the amount of external light incident on the scanner body 10 is reduced, although not as much as when a typical-size document is placed. Therefore, the value of the output signal of the external light sensor 100 changes from a high value E1 to a slightly high value E2.

  If the value of the signal input from the external light sensor 100 is smaller than the predetermined threshold value EX (that is, if the value of the signal input from the external light sensor 100 falls below the predetermined threshold value), the control unit 45 saves. The power mode is canceled, but the signal value E2 input at this time T6 is not smaller than the detection threshold value EX, so the power saving mode is not canceled (at this point, the timer may be reset and restarted. You do n’t have to).

  Thereafter, when the document table cover 3 is closed at time T7, the external light is not substantially incident on the placement surface 9 and the scanner body 10 at all. Therefore, the output signal value of the external light sensor 100 changes from a slightly high value E2 to the lowest value E4, that is, falls below a predetermined threshold value EX. In that case, the control unit 45 cancels the power saving mode and starts warm-up processing for the reading operation. At the same time, the control unit 45 starts a timer 49.

  According to the above description, the control unit 45 operates as described below.

  FIG. 12 shows an operation flow of the control unit 45 when shifting to the power saving mode, and FIG. 13 shows an operation flow of the control unit 45 when releasing the power saving mode.

  As shown in FIG. 12, if the control unit 45 is in a predetermined operation (for example, reading an image of a document) in the normal power mode, the control unit 45 continues to execute the process (Y in step S1 and N in step S5). .

  When the predetermined operation ends (Y in S1 and Y in S5), the control unit 45 starts the timer 49 (S6).

  If the time is up without performing a predetermined operation after S6 (N in S1 and Y in S6), the control unit 45 shifts from the normal power mode to the power saving mode. Specifically, the control unit 45 turns off the CCD power source 33 and the light source power source 35 to stop the power supply to the linear CCD 27 and the light source 23. Further, when the external optical sensor 100 is on the reading head 5 (or on the circuit board 15 mounted on the reading head 5), the control unit 45 moves the reading head 5 to the placement surface when shifting to the power saving mode. 9 is moved to a predetermined place where the external light sensor 100 is located at a place where the intensity of the external light incident on the external light sensor 100 changes depending on whether an original is placed on the cover 9 or whether the cover 3 is closed or opened. Stop (S4). The controller 45 keeps the read head 5 at a predetermined position during the power saving mode.

  During the power saving mode, as shown in FIG. 13, when the signal value input from the external light sensor 100 to the control unit 45 exceeds or falls below a predetermined detection threshold EX (Y in S11), the control unit 45 Cancels the power saving mode (Y in S12 and S13). Specifically, the control unit 45 turns on the CCD power source 33 and the light source power source 35 so that power is supplied to the linear CCD 27 and the light source 23. If the standby position of the read head 5 is not the home position, the control unit 45 moves the read head 5 to the home position and stops it (S14).

  With the processing flow as described above, the transition from the normal power mode to the power saving mode and the cancellation of the power saving mode are performed.

  According to the above-described processing flow, for example, the control unit 45, when in the power saving mode, opens the closed document table cover (specifically, the signal value input from the external light sensor 100 is When it is detected that the signal value has increased above a predetermined threshold and / or the amount of increase in the signal value exceeds a predetermined value), the power saving mode is canceled. Then, when a predetermined time elapses without performing a predetermined operation such as placing a document of a typical size from when the document table cover 3 is opened, the control unit 45 (when the time is up), the document table cover 3. Even when is open, the normal power mode shifts to the power saving mode. In the power saving mode, when the opened document table cover 3 is closed or when a document is placed on the placement surface 9, the power saving mode is canceled again.

  Further, according to the above-described processing flow, the control unit 45 places a document of a typical size on the placement surface 9 of the document table when the document table cover 3 is open and in the power saving mode. If it does, cancel the power saving mode. Thereafter, when a predetermined time elapses without performing a predetermined operation such as closing the cover 3 (that is, when the time is up), the control unit 45 places the document on the placement surface 9 and opens the document table cover 3. Even in this state, the normal power mode is shifted to the power saving mode. In the power saving mode, the control unit 45 removes from the placement surface 9 a document of a typical size placed on the placement surface 9 when the opened document table cover 3 is closed. (Specifically, when it is detected that the signal value from the external light sensor 100 has decreased below a predetermined threshold value EX and / or that the amount of decrease in the signal value has exceeded a predetermined amount) ), Cancel power saving mode.

  According to this flow, a typical-size document is placed on the placement surface 9, a typical-size document is removed from the placement surface 9, and the document table cover 3 is closed. A user use sign other than opening the document table cover 3 can be detected, and the power save mode is canceled when one of the user use signs is detected during the power save mode. . Thereby, the total reading time of the image scanner can be further shortened.

  By the way, the above-mentioned “place where most of the incident path of external light is blocked by a document of a predetermined size” is, for example, as follows.

  That is, as shown in FIG. 14A, when a document of a predetermined size is not placed on the placement surface 9, external light can pass anywhere on the placement surface 9. The light incident path substantially includes the mounting surface corresponding space itself (or further in the vicinity thereof) (note that the incident angle θ of external light with respect to the mounting surface 9 is 90 as shown in the figure. For example, when 0 degree <θ <90 degrees, the incident path of the external light includes the mounting surface corresponding space and the vicinity thereof.

  However, as shown in FIG. 14B, for example, a predetermined portion (for example, a corner) of the document is superimposed on the document positioning point (for example, a corner of the mounting surface 9) of the mounting surface 9, and the predetermined surface is placed on the mounting surface 9. When a document of a size is placed, the range on the placement surface 9 through which external light can pass becomes narrower by the size of the document. For this reason, most of the incident path of the external light is blocked by the placed document of a predetermined size, and the light receiving intensity of the external light is the same as that before placing the document in the placement surface corresponding space (or in the vicinity thereof). The region BR is divided into a region BR that does not change substantially and a region BL in which the external light is blocked and the received light intensity of the external light is weaker than the region BR. The location in the latter area BL (in other words, the area including the outer frame of the document of a predetermined size in the placement surface corresponding area or the vicinity thereof) is “the incidence of most of the external light by the document of the predetermined size”. This is the place where the route is blocked.

  The range of the region BL varies depending on the value of the incident angle θ of the external light. However, the external light sensor 100 can detect a document of a predetermined size regardless of the incident angle θ. It is arranged at a place where the light receiving intensity of external light can be reduced.

  Meanwhile, in the above-described embodiment, the following several modifications can be considered.

  (A) First modification.

  The power saving mode includes a sub power saving mode and a main power saving mode. When shifting from the normal power mode to the power saving mode, the normal power mode changes to the sub power saving mode and the sub power saving mode. When shifting from the mode to the main power saving mode, and when shifting from the power saving mode to the normal power mode, release from the main power saving mode to the sub power saving mode, and then from the sub power saving mode to the normal power mode. To do. Specifically, when the control unit 45 shifts from the normal power mode to the sub power saving mode, the control unit 45 stops the power supply to the reading light detection unit (linear CCD 27 in the above embodiment) or reads the reading light. The power supplied to the detection means is made smaller than that in the normal power mode. Then, after a certain period of time has elapsed since then, the control unit 45 shifts to the main power saving mode, that is, stops the power supply to the light source 23 or reduces the supply power to the light source 23 from that in the normal power mode. Also make it smaller. In addition, when the control unit 45 shifts from the power saving mode to the normal power mode, the control unit 45 first starts supplying power to the light source 23 or supplies power to the light source 23 from the main power saving mode. After that, the power supply to the reading light detection means is started, or the supply power to the reading light detection means is made larger than that in the sub power saving mode. In this way, by stopping or starting the power supply with a time difference, it is possible to shorten the total time required for reading or to further reduce the power consumption.

  (B) Second modification.

  The predetermined detection threshold EX may be a fixed value or a variable value. In the latter case, for example, the control unit 45 varies in the following manner.

  That is, another optical sensor capable of detecting light irradiated on the outer surface of the scanner 1 is disposed on the outer surface of the image scanner 1 (hereinafter, the optical sensor is referred to as “ambient light sensor” The light detected by the light sensor is called “ambient light”). The ambient light sensor inputs a signal having a value corresponding to the intensity of the received ambient light to the control unit 45.

  In addition, a threshold table in which a plurality of detection thresholds corresponding to a plurality of ambient light intensities are recorded in a memory (for example, EEPROM) in the image scanner 1 is prepared.

  The control unit 45 acquires a detection threshold value EX corresponding to the value of the signal input from the ambient light sensor at an arbitrary time point (for example, when the power is turned on or when the reading operation is started) from the threshold value table, The acquired detection threshold is set as the current detection threshold.

  Note that the method of changing the detection threshold is not limited to the method of referring to the table, and various methods can be adopted. For example, the control unit 45 may detect a signal value (in other words, a signal value input from the external optical sensor 100 after a predetermined time (for example, this time or when the main body is turned on for the first time or when a reading operation is started for the first time or for the first time)). Then, the detected intensity of the external light is stored as a history in a memory (for example, RAM or EEPROM), and based on the signal value stored therein (for example, based on the minimum value and the maximum value of the signal value). The detection threshold value may be varied.

  (C) Third modification.

  When the read image output unit 43 is also supplied with power from a predetermined power supply circuit and the read image output unit 43 also has a power saving mode and a normal power mode, the control unit 45 Based on the signal value from the optical sensor 100, the power mode of the read image output unit 43 is set to the normal power mode or the power saving mode. Specifically, for example, when the reading image output unit 43 is in the normal power mode, the control unit 45 stops supplying power to at least one of the reading light detection unit and the light source, or supplies power supplied thereto. In order to make it smaller, the reading image output unit 43 is set in a power saving mode in parallel with it (specifically, power supply to the reading image output unit 43 is stopped or power supplied thereto is reduced). To do). In addition, when the reading image output unit 43 is in the power saving mode, the control unit 45 determines whether to start power supply to at least one of the reading light detection unit and the light source, or to increase the power supplied thereto. At the same time, the power saving mode of the read image output unit 43 is canceled in parallel (specifically, power supply to the read image output unit 43 is started or the power supplied thereto is increased). .

(D) Fourth Modification A fourth modification will be described with reference to FIG.

  As shown in FIG. 15, the image scanner 1 is provided with a cover opening / closing sensor 200 that detects opening / closing of the document table cover 3.

  The cover open / close sensor 200 is mounted on a portion where the document table and the document table cover 3 are mounted (for example, a hinge or a rotating shaft 13 pivotally attached to the document table cover 3) or in the vicinity thereof (the document table and the document table). It may be mounted in a place far from the center of the mounting surface 9 at a distance from the mounting portion with the base cover 3). The cover opening / closing sensor 200 outputs a detection signal (for example, a high level signal) having a first value and inputs it to the control unit 45 (see FIG. 5) when the document table cover 3 is opened. When the document table cover 3 is closed, a detection signal having a second value (for example, a high level signal) is output and input to the control unit 45. As a result, the control unit 45 can receive the detection signal output from the cover open / close detection means and detect whether the document table cover is opened or closed based on the value of the detection signal.

  The cover open / close sensor 200 is, for example, a photocoupler that includes a light emitting element that emits light and a light receiving element that receives light from the light emitting element and inputs a signal corresponding to the intensity of the light to the control unit 45. In this case, although not shown, the document table cover 3 has a projection that blocks light from the light emitting element to the light receiving element when the cover 3 is closed (that is, when the cover 3 covers the placement surface 9). Is provided. With this configuration, when the document table cover 3 is opened, the light receiving element of the photocoupler receives light of a predetermined intensity from the light emitting element and inputs a detection signal corresponding to the intensity to the control unit 45. It is possible to detect that the document table cover 3 is opened. When the document table cover 3 is closed, the intensity of light received by the light receiving element from the light emitting element is weaker than the predetermined intensity (for example, becomes zero), and the value of the detection signal changes accordingly. Therefore, the control unit 45 can detect that the document table cover 3 is closed.

In this way, the control unit 45 determines whether or not the document table cover 3 is closed and opened based on the detection signal of the cover open / close sensor, and the document table cover 3 is closed and opened. If any one of these is detected, if it is in the power saving mode, it is canceled. In addition, the control unit 45 detects a predetermined event (for example, the end of the reading operation) such as the document table cover 3 being closed after the document table cover 3 is detected and the power saving mode is canceled after being detected. If the fixed time elapses, the mode shifts to the power saving mode. If the document table cover 3 is detected to be closed in the power saving mode, the power saving mode is canceled again. Specifically, for example, the control unit 45 has the following (1) to (3):
(1) When the power saving mode is canceled
(2) When the reading operation is finished in a state other than the power saving mode,
(3) When it is detected that the document table cover 3 is closed and opened in a state other than the power saving mode,
When at least one of the timer starts, the reading operation is not performed and the opening / closing of the document table cover 3 is not detected, and a fixed time has elapsed (when any one of them is detected) Reset the timer and restart) to enter power saving mode.

  The above is the description of the fourth embodiment. According to this embodiment, when it is detected that the document table cover 3 is closed in the power saving mode with the document table cover 3 opened, the power saving mode is canceled. That is, since a sign that the user is about to start the image reading operation is quickly detected and preparation for reading is started, the time required for reading the image can be shortened as a whole.

In the fourth embodiment, the cover opening / closing sensor 200 is not limited to a photocoupler, and other devices such as the following device (1) or (2),
(1) a button that is pressed when the platen cover is closed and returns to the original state when the platen cover is opened;
(2) an external light sensor that detects external light incident on the surface of the document table or in the main body from outside the main body and outputs a detection signal;
It may be.

  When the cover opening / closing sensor 200 is the button (1), the button may be mounted at a predetermined location on the surface of the document table outside the area of the placement surface 9 and covered by the document table cover 3, for example. It may be good (or may be provided not on the platen but at a place on the platen cover 3 that overlaps the predetermined place). The predetermined location may be, for example, a location far from the center of the placement surface 9 in the distance from the mounting portion of the document table and the document table cover 3, or as shown in FIG. And a portion where the document table cover 3 is attached or in the vicinity thereof.

  When the cover open / close sensor 200 is the external light sensor (2), the sensor 200 may be mounted in the scanner body 10 or may be mounted on the outer surface of the scanner body 10. That is, the external light sensor is mounted in a state where the intensity of the external light received when the document table cover 3 is changed from the open state to the closed state is reduced and the document table cover 3 is changed from the closed state to the open state. Any place where the intensity of the external light received will increase. For example, the external light sensor may be mounted at or near the mounting portion between the document table and the document table cover 3, or at a distance from the mounting portion between the document table and the document table cover 3. It may be installed in a place far from the center.

(E) Fifth Modification A fifth modification will be described with reference to FIGS. 16 and 17.

  In the fifth modified example, in the above-described embodiment, the control unit 45 uses the signal value threshold corresponding to the typical size, and performs the transition between the power saving mode and the normal power mode. The transition between the power saving mode and the normal power mode is performed using a signal value threshold corresponding to a plurality of size deviations.

  In the fifth modification, the RAM 41 (threshold storage means) stores a table in which the sizes of a plurality of documents are associated with the thresholds corresponding to each. Here, the threshold value corresponding to the size of the document is a threshold value corresponding to the signal value from the external light sensor 100 for determining whether or not the document of the size is placed on the document table. Is a value smaller than the intensity of the external light when a document of a size smaller than the size is placed on the document table, and the light of the external light when the document of the size is placed. It is a value larger than the strength.

  In addition, the control unit 45 accepts a setting of a document size desired (for example, frequently used) from a user by an input device (not shown) and stores it in the RAM 41. Further, the control unit 45 acquires the size of the original set by the user stored in the RAM 41, determines a threshold corresponding to the size of the original from the RAM 41 as a use threshold, and uses the threshold to use the power saving mode. And control the transition between normal power mode. Here, the control unit 45 corresponds to threshold determination means, determination means, and power supply control means.

    FIG. 16 is a diagram illustrating an operation flow of the control unit 45 when canceling the power saving mode in the fifth modification.

  In the fifth modified example, during the power saving mode, as shown in FIG. 16, the control unit 45 acquires the setting of the size of the document stored in the RAM 41 (step S21), and the document from the RAM 41. A threshold (usage threshold) corresponding to the size of is determined (step S22).

  Next, when the signal value input from the external light sensor 100 to the control unit 45 changes from a value smaller than the use threshold value to a larger value, or when the signal value changes from a value larger than the use threshold value to a smaller value ( The control unit 45 cancels the power saving mode (Y in S24 and S25). Specifically, the control unit 45 turns on the CCD power source 33 and the light source power source 35 so that power is supplied to the linear CCD 27 and the light source 23. Next, when the standby position of the read head 5 is not the home position, the control unit 45 moves the read head 5 to the home position and stops it (S26).

  With the processing flow as described above, the transition from the normal power mode to the power saving mode and the cancellation of the power saving mode are performed.

  According to the processing flow described above, the control unit 45 sets the size (set size) set by the user on the document table placement surface 9 when the document table cover 3 is open and in the power saving mode. When a document of the above size is placed, the power saving mode is canceled. Thereafter, when a predetermined time elapses without performing a predetermined operation such as closing the cover 3 (that is, when the time is up), the control unit 45 places the document on the placement surface 9 and opens the document table cover 3. Even in this state, the normal power mode is shifted to the power saving mode. In the power saving mode, the control unit 45 removes from the placement surface 9 a document of a set size when the opened document table cover 3 is closed or placed on the placement surface 9. (Specifically, when the signal value from the external light sensor 100 decreases from a value larger than a predetermined use threshold value to a smaller value, the power saving mode is canceled.)

  According to this flow, a document of a set size is placed on the placement surface 9, a document of a set size is removed from the placement surface 9, and the document table cover 3 is closed. A user use sign other than opening the document table cover 3 can be detected, and the power save mode is canceled when one of the user use signs is detected during the power save mode. . Thereby, the total reading time of the image scanner can be further shortened. In addition, since the usage sign can be detected not only for the typical size but also for a document of a size set by the user, an appropriate user usage sign corresponding to the user of the apparatus can be detected.

  FIG. 17 shows an example of the relationship between the signal value output from the external light sensor 100 and its change, and the power mode in the scanner 1. Hereinafter, an example of a flow when shifting to the power saving mode or canceling the power saving mode will be described with reference to FIG. In the following description, it is assumed that the document placed on the placement surface 9 of the scanner body 10 is a document having a transmittance capable of transmitting at least a small amount of light. Further, in this example, the user sets a document of a size smaller than the typical size as the size of the document that is frequently used, whereby the use threshold value in the process is the threshold value EX2 corresponding to the small size. Shall.

  When the document table cover 3 of the image scanner 1 is closed, external light cannot pass through the placement surface 9 of the scanner body 10 of the scanner 1 and enter the scanner 1. The external light sensor 100 arranged in the substantially no external light is detected. Therefore, the signal value output from the external light sensor 100 is the smallest value E4.

  Further, when a predetermined time elapses without detecting the predetermined state change as described above from the time when the predetermined operation is completed in the scanner 1, the scanner 1 shifts from the normal power mode to the power saving mode. During the power saving mode, the light source power supply 35 and the CCD power supply 33 are in an off state, and power is not supplied to the light source 23 and the linear CCD 27.

  In this state, it is assumed that the document table cover 3 is opened at time T1, for example.

  In that case, if no document is placed on the placement surface 9 of the scanner body 10, a large amount of external light enters the scanner body 10, and the external light sensor 100 receives the external light. Then, as shown in FIG. 17, the external light sensor 100 outputs a signal having a high value E1 corresponding to the large amount of external light and inputs the signal to the control unit 45.

  If the value of the signal input from the external light sensor 100 exceeds the threshold value EX2 corresponding to the size set by the user (that is, the value of the signal input from the external light sensor 100 sets the threshold value EX2). If exceeded, the power saving mode is canceled, and warm-up processing for the reading operation is started (specifically, for example, the control unit 45 turns on the light source power source 35 and the CCD power source 33, and Power supply to the light source 23 and the linear CCD 27 is started). At the same time, the control unit 45 starts a timer 49.

  Now, after the document table cover 3 is opened at time T1, when the document table cover 10 is kept open without being placed on the document table, the external light sensor 100 outputs a high signal value E1. The signal I have is kept output. From time T1, a predetermined time elapses without performing a predetermined operation (for example, placing a document, closing the document table cover 3, or moving the reading head 5), and time T1 ′ is reached. When the time is up (that is, when the time is up), the control unit 45 shifts from the normal power mode to the power saving mode. Specifically, for example, the control unit 45 turns off the light source power source 35 and the CCD power source 33 so that power is not supplied to the light source 23 and the linear CCD 27.

  After that, when a document having a size (for example, L plate) smaller than a typical size (for example, A4 size) is placed on the placement surface 9 at time T2, most of the incident path of external light is blocked by the document. Thus, the amount of external light received by the external light sensor 100 is greatly reduced. Therefore, the value of the signal output from the external light sensor 100 changes from a high E1 to a low value E2 (that is, the external light sensor 100 is a place where the incident path of the external light is blocked by, for example, a small-size document. Is provided.

  In the control unit 45, the value E2 of the signal input from the external light sensor 100 has become smaller than the threshold value EX2 (that is, the value of the signal input from the external light sensor 100 has decreased from a value greater than the threshold value to a smaller value). Therefore, the power saving mode is canceled and the warm-up process for the reading operation is started. At the same time, the control unit 45 starts a timer 49. As described above, since the threshold value EX2 corresponding to the document size (small size) set by the user is used, when a small-size document is placed, it is possible to appropriately shift to the normal power mode. .

  After that (that is, at time T3), when the document table cover 3 is closed, external light is not substantially incident on the placement surface 9 and the scanner body 10 and is output from the external light sensor 100. The value of the signal changes from the value E2 to the lowest E4 mentioned above. At that time, for example, the control unit 45 resets and restarts the timer 49 (not necessarily resetting and restarting).

  Now, after restarting the timer 49 at time T3, when a predetermined time elapses and time T3 ′ is reached without performing a predetermined operation (that is, when the time is up), the control unit 45 resumes from the normal power mode. Transition to power saving mode.

  It is assumed that the document table cover 3 is opened at time T4 during the power saving mode. However, since a small-size document is still placed on the placement surface 9 of the scanner body 10, the value of the signal output from the external light sensor 100 is a value E2 that does not exceed the threshold value EX2. . In this case, the control unit 45 does not cancel the power saving mode (for example, the power saving mode may be canceled at this time and the normal power mode may be shifted).

  Thereafter, when the small-size document is removed from the placement surface 9 at time T5, a lot of external light enters the scanner body 10 and the external light sensor 100 receives the lot of external light. Therefore, the output signal value of the external light sensor 100 changes from the value E2 to a high value E1, that is, from a value smaller than the threshold value EX2 to a larger value. In that case, the control unit 45 cancels the power saving mode and starts warm-up processing for the reading operation. At the same time, the control unit 45 starts a timer 49.

  Now, after the document is removed from the placement surface 9 at time T5, when the document table cover 10 remains open without being placed, the external light sensor 100 receives a high signal value. A signal having E1 continues to be output. When a predetermined time elapses from time T1 and the time T5 'is reached (that is, when the time is up), the control unit 45 shifts from the normal power mode to the power saving mode.

  As described above, according to the fifth modification, the document of the set size is placed on the placement surface 9, the document of the set size is removed from the placement surface 9, and the document table cover 3 is closed. It is possible to appropriately detect a user usage sign other than opening the document table cover 3 and when one of the user usage signs is detected during the power saving mode. The power saving mode is canceled. Thereby, the total reading time of the image scanner can be further shortened. Further, since it is possible to deal with not only the typical size but also a document of a size set by the user, it is possible to appropriately detect a user use sign corresponding to the user of the apparatus.

  As mentioned above, although preferred embodiment and the modification of this invention were demonstrated, these are the illustrations for description of this invention, Comprising: It is not the meaning which limits the scope of the present invention only to this embodiment and modification. The present invention can be implemented in various other forms. For example, the control unit 45 cancels the power saving mode based on whether the output signal value from the external light sensor 100 (that is, the intensity of the external light detected by the external light sensor 100) falls below or exceeds a predetermined threshold. Whether or not to cancel the power saving mode is determined based on whether or not the increase or decrease amount of the output signal value exceeds a predetermined change amount instead of or in addition to In other words, it may be determined whether the document table cover 3 is opened or closed, or whether a document of a predetermined size is placed on the placement surface 9 or removed. Further, the method of mounting the document table cover 3 on the document table so as to be openable and closable is not limited to the method using the rotating shaft 13, and various methods such as a hinge can be adopted, for example.

1 is a perspective view of an image scanner according to an embodiment of the present invention. AA sectional drawing of FIG. FIG. 3 is a top view of the image scanner according to the present embodiment. FIG. 4 is a cross-sectional view taken along the line BB in FIG. 3 and shows an internal structure of a reading head in the image scanner. 1 is a block diagram showing a configuration of an image scanner 1. FIG. The figure for demonstrating the 1st arrangement | positioning aspect of the external light sensor. The figure for demonstrating the 1st arrangement | positioning aspect of the external light sensor. The figure for demonstrating the 2nd arrangement | positioning aspect of the external light sensor. The figure for demonstrating the 3rd arrangement | positioning aspect of the external light sensor 100. FIG. The figure for demonstrating the 4th arrangement | positioning aspect of the external light sensor 100. FIG. The figure which shows an example of the relationship between the signal value output from the external light sensor 100, its change, and the electric power mode in the scanner. The figure showing the operation | movement flow of the control part 45 in the case of transfering to power saving mode. The figure which shows the operation | movement flow of the control part 45 when canceling | emitting a power saving mode. The figure for demonstrating the place where most incident paths of external light are obstruct | occluded by the document of a predetermined size. The figure for demonstrating the 4th modification. The figure which shows the operation | movement flow of the control part 45 in the case of canceling | releases the power saving mode in a 5th modification. The figure which shows an example of the relationship between the signal value output from the external optical sensor 100 in the 5th modification, its change, and the electric power mode in the scanner 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image scanner, 3 Document stand cover, 5 Reading head, 9 Mounting surface, 10 Scanner main body, 15 CCD board | substrate, 100 External light sensor, 23 Light source, 27 Linear CCD, 41 RAM, 45 Control part.

Claims (3)

In an image reading apparatus having a power saving mode,
A main body provided with a document table having a placement surface for placing a document;
A document table cover attached to the document table so as to be openable and closable so as to cover at least a placement surface of the document table;
A light source that generates light;
A power source for supplying power to the light source;
External light detection means for detecting external light entering the main body through the placement surface and outputting a detection signal;
Threshold storage means for storing a plurality of threshold values relating to the intensity of the external light for determining whether or not each document of the size is placed on the document table, corresponding to each of a plurality of document sizes. ,
Threshold determination means for determining a threshold corresponding to the size of the document designated by the user as a use threshold;
Whether the intensity of the external light has changed from a value smaller than the use threshold to a value greater than the use threshold, and whether the intensity of the external light has changed from a value greater than the use threshold to a value less than the use threshold A determination means for determining whether or not,
In a state where the intensity of the external light has shifted to the power saving mode without changing for a predetermined time, the determination means determines that the intensity of the external light has changed from a value greater than the use threshold to a value less than the use threshold. A power control means for controlling the power to release the power saving mode,
Even when the intensity of the external light increases and the state of the platen cover changes, the intensity of the external light is changed from a value smaller than the use threshold to a value greater than the use threshold by the determination means. If it is determined that the power saving mode is not maintained,
Image reader. Each of the plurality of threshold values is a value smaller than the intensity of external light when a document having a size smaller than the size corresponding to the threshold is placed on the document table. The image reading apparatus according to claim 1, wherein the image reading apparatus has a value larger than an intensity of external light in a state where an original having a size corresponding to the threshold is placed. Mounted on the document table so as to be openable and closable so as to cover a power-saving mode, a main body having a document table having a placement surface for placing a document, and at least a placement surface of the document table. In a power control method for an image reading apparatus, comprising: an original table cover; a light source; and a power source for supplying power to the light source.
The image reading device stores a plurality of threshold values relating to the external light intensity for determining whether or not a document of each size is placed on the document table, corresponding to each of a plurality of document sizes. Threshold storage means for
A threshold value determining step for determining a threshold value corresponding to the size of the document designated by the user as a use threshold value;
Detecting external light incident on the main body through the mounting surface and outputting a detection signal;
Whether the intensity of the external light has changed from a value smaller than the use threshold to a value greater than the use threshold, and whether the intensity of the external light has changed from a value greater than the use threshold to a value less than the use threshold A step of determining whether or not,
In a state where the intensity of the external light has shifted to the power saving mode without changing for a predetermined time, the determination means determines that the intensity of the external light has changed from a value greater than the use threshold to a value less than the use threshold. Controlling the power supply to release the power saving mode;
Even when the external light intensity increases and the state of the document table cover changes, it is determined that the external light intensity has not changed from a value smaller than the use threshold value to a value larger than the use threshold value. A power control method comprising: maintaining the power saving mode.

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