JP6182931B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus represented by a facsimile.

  Conventionally, an image reading means having a photoelectric element such as an image sensor is read on the forward path moving from the home position to the opposite side of the scanning direction, and after the image reading is completed, the moving direction is reversed and the home direction is reversed. An image reading apparatus that returns the position to the position is known (for example, Patent Document 1).

  In the image reading apparatus, in order to correct the reading result and obtain appropriate image information, a reference plate (for example, a white plate) is provided outside the image reading region, and the reference plate is read by the image reading means. Based on the reading result, processing such as gain correction of the photoelectric element is performed. The image reading apparatus described in Patent Document 1 is configured such that such a reference plate is disposed on both sides in the scanning direction of the image reading means so that the light reflection characteristics of the reference plate can be appropriately obtained.

JP 2002-135540 A

  By the way, the image reading means is usually driven by a motor, and the amount of movement thereof may be grasped by the amount of rotation of the motor. This is because the rotary encoder for grasping the rotation amount of the motor requires less installation space than the linear encoder for directly grasping the position of the image reading means, and is easy to install.

  However, when the drive system (consisting of gears, belts, etc.) that drives the image reading means deteriorates over time, the correspondence between the rotation amount of the motor and the movement amount of the image reading means changes, thereby shifting to the image reading position. May occur.

  Specifically, for example, when a position reference mark is provided at the home position of the image reading unit and the position of the image reading unit is grasped based on the position of the position reference mark, an image at a position close to the position reference mark is compared. The image at a position far from the position reference mark, that is, the image where the movement amount of the image reading means increases, has a correspondence between the rotation amount of the motor and the movement amount of the image reading means as described above. By changing, there is a possibility that it cannot be read accurately.

  Accordingly, the present invention has been made in view of such circumstances, and an object thereof is to provide an image reading apparatus capable of accurately reading an image over a long period of time.

  In order to solve the above problems, an image reading apparatus according to a first aspect of the present invention includes a document table that forms a document placement area on which a document is placed, and a document placed on the document placement area. Reading means while moving in the scanning direction, and provided on both sides in the moving direction of the reading means with respect to the document placement area, and is readable by the reading means that constitutes a position reference in the moving direction of the reading means And a position reference unit.

  According to this aspect, the image reading apparatus is provided on both sides of the moving direction since the position reference portions that can be read by the reading unit and that constitute the position reference in the moving direction of the reading unit are provided on both sides of the moving direction. By reading the position reference portion, it is possible to grasp the relationship between the driving amount of the reading means and the distance between the position reference portions, and as a result, even when the drive mechanism of the reading means is deteriorated. The image can be read accurately.

  An image reading apparatus according to a second aspect of the present invention is the image reading apparatus according to the first aspect, wherein the reflection reference that is readable by the reading means forms a reference of the amount of reflected light on both sides of the moving direction with respect to the document placement area. It comprises a part.

  According to this aspect, since the reflection reference portion that makes a reference of the amount of reflected light and that can be read by the reading unit is provided on both sides of the moving direction with respect to the document placement region, the reading unit is started when the reading operation is started. By selecting and reading the reflection reference portion close to, the overall reading operation time can be shortened.

  An image reading apparatus according to a third aspect of the present invention is the image reading apparatus according to the second aspect, wherein the image reference device is a position reference portion on one side of the position reference portions provided on both sides in the movement direction with respect to the document placement region. A first standby position that forms a standby position of the reading unit is set on the side away from the document placement area with respect to one position reference portion, and the positions provided on both sides in the movement direction with respect to the document placement area A second standby position that constitutes a standby position of the reading means is set on the side away from the document placement area with respect to a second position reference portion that is a position reference portion on the other side of the reference portions. And

  According to this aspect, since the image reading apparatus has the standby positions on both sides of the document placement area, the reciprocating operation of the reading unit is unnecessary, power consumption can be reduced, and unnecessary operation sound can be generated. Occurrence can also be prevented.

  In the image reading apparatus according to the fourth aspect of the present invention, the first standby position is set to a position overlapping with the first reflection reference part which is one of the reflection reference parts, and the second standby position. The position is set at a position overlapping with the second reflection reference part which is the reflection reference part on the other side of the reflection reference part.

  According to this aspect, in the image reading apparatus, the first standby position is set to a position that overlaps the first reflection reference portion, and the second standby position is set to a position that overlaps the second reflection reference portion. The outer dimension in the width direction can be reduced, and the space of the image reading apparatus can be saved.

  An image reading apparatus according to a fifth aspect of the present invention is the image reading apparatus according to the fourth aspect, wherein the reading means reads the first reflection reference portion when starting the document reading operation from the first standby position, When the document reading operation is started from the second standby position, the second reflection reference portion is read.

  According to this aspect, the reading unit reads the first reflection reference portion when starting the document reading operation from the first standby position, and when starting the document reading operation from the second standby position. Since the second reflection reference portion is read, the movement distance of the reading means is short when reading the reflection reference portion, and the overall reading operation time can be shortened.

  An image reading apparatus according to a sixth aspect of the present invention is the image reading apparatus according to any one of the first to fifth aspects, wherein a distance between the position reference portions provided on both sides in the moving direction with respect to the document placement area is set. The distance acquisition mode, which is acquired by reading the position reference portion while moving the reading means in a predetermined direction, is executed at a predetermined timing.

  According to this aspect, the distance between the position reference portions provided on both sides of the moving direction with respect to the document placement area is obtained by reading the position reference portion while moving the reading means in a predetermined direction. Since the distance acquisition mode is executed at a predetermined timing, it is possible to always read the image accurately by grasping the relationship between the driving amount of the reading means and the distance between the position reference portions at the predetermined timing. It becomes.

  An image reading apparatus according to a seventh aspect of the present invention is the image reading apparatus according to any one of the first to sixth aspects, wherein one of the position reference portions provided on both sides in the moving direction with respect to the document placement area. From the point of time when the position reference part is detected while moving the reading means in the first direction that is the moving direction of the reading means, the motor that is the driving source of the reading means is rotated by the rotation amount B1 to move the reading means. Further, the position reference portion on the one side is detected again while moving the reading means in the second direction opposite to the first direction by moving the reading means in a predetermined distance in the first direction and then moving the reading device in the reverse direction. The difference between the rotation amount B2 of the motor at the time of detection and the rotation amount B1 is set as a correction value B, and the preview operation is performed while moving the reading unit in the first direction. And wherein the addition of the correction value B to the driving amount of the motor when performing the document reading operation while moving in the second direction the reading means at a lower speed than during the preview read operation.

  According to this aspect, in the case where the movement direction of the reading unit differs between the preview operation and the document reading operation after obtaining the correction value B by detecting the position reference unit by switching the moving direction of the reading unit. The correction value B is added to the motor drive amount. Therefore, when a gear is used as the driving mechanism of the reading means, backlash between the gears is canceled, and an error due to a difference in reading direction can be canceled, so that an image can be read accurately.

  An image reading apparatus according to an eighth aspect of the present invention is the image reading apparatus according to any one of the third to seventh aspects, wherein the reading unit receives the first standby when an operation stop command is received during the document reading operation. Returning to the closest standby position among the position and the second standby position.

  According to this aspect, when the reading unit receives an operation stop command while executing the document reading operation, the reading unit returns to the standby position that is closer to either the first standby position or the second standby position. It is possible to reduce power consumption by avoiding unnecessary operation of the means.

1 is a perspective view of an image reading apparatus according to the present invention. 1 is a schematic diagram of a configuration of an image reading apparatus according to the present invention. FIG. 3 is a perspective view showing a state in which the medium cover is opened in the image reading apparatus according to the present invention. FIG. 3 is a plan view showing a document table in the image reading apparatus according to the present invention. FIG. 3 is a schematic diagram showing a positional relationship of reading means with respect to a document placement area in the image reading apparatus according to the present invention. 6 is a flowchart of a distance acquisition mode when the power is turned on and the power saving mode is restored in the image reading apparatus according to the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the same structure in each Example, the same code | symbol is attached | subjected and it demonstrates only in the first Example, The description of the structure is abbreviate | omitted in a subsequent Example.

  FIG. 1 is a perspective view of an image reading apparatus according to the present invention, FIG. 2 is a schematic diagram of a configuration of the image reading apparatus according to the present invention, and FIG. 3 is a diagram illustrating a case where a medium cover is opened in the image reading apparatus according to the present invention. FIG. 4 is a plan view showing a document table in the image reading apparatus according to the present invention.

  FIG. 5 is a schematic diagram showing the positional relationship of the reading means with respect to the document placement area in the image reading apparatus according to the present invention. FIG. 6 shows the distance when the image reading apparatus according to the present invention is turned on and when the power saving mode is restored. It is a flowchart of acquisition mode.

  In the XYZ coordinate system shown in each figure, the X direction indicates the depth direction of the recording apparatus, the Y direction indicates the width direction of the recording apparatus, and the Z direction indicates the height direction of the recording apparatus. In each figure, the −X direction is the front side of the apparatus, and the + X direction side is the back side of the apparatus.

  With reference to FIGS. 1 to 3, components of an ink jet printer 10 (hereinafter referred to as “printer 10”) as an example of a recording apparatus will be described. The printer 10 includes an apparatus main body 12 and an image reading device 14. The apparatus main body 12 includes a housing 16 constituting an external appearance, a lid 18 that can be opened and closed with respect to the housing 16 on the front surface of the housing, and an operation unit 20 provided on the front surface of the housing 16. Although not shown, when the lid 18 is opened, the medium accommodating portion 22 provided in the housing 16 can be accessed.

  Further, in the housing 16, a medium storage unit 22, a feeding unit 24, a transport unit 26, a recording unit 28, a discharge unit 30, an image reading device 14, a control unit 34, and the medium storage unit A conveyance path for conveying a recording medium from 22 to the discharge unit 30 via the recording unit 28 is provided. Although not shown, the operation unit 20 is configured to be rotatable forward of the apparatus with respect to the housing 16.

  When the operation unit 20 is rotated to the front side of the apparatus with respect to the housing 16, the discharge unit in the housing can be accessed, and the recording medium on which recording is performed in the recording unit (not shown) 12 can be discharged. The operation unit 20 includes a power button, a print setting button, a display panel, and the like for operating the printer 10.

  Referring to FIG. 2, the control unit 34 responds to an input command from the operation unit 20, the medium storage unit 22, the feeding unit 24, the transport unit 26, the recording unit 28, the discharge unit 30, and the image reading device. 14 controls operations necessary for recording and image reading of the printer 10 such as medium feeding, conveyance, discharge, recording operation, and document reading operation. Instead of an input command from the operation unit 20, an operation required for recording and image reading of the printer 10 such as a document reading operation may be controlled by an instruction from the outside (PC or the like).

■■■ Example ■■■■
Referring to FIG. 3, the image reading apparatus 14 includes a medium placing table 36 as a “document table” and a medium cover 38. The medium cover 38 is rotatably connected to an end portion on the + X direction side of the medium mounting table 36 via a rotation shaft 40. Therefore, in this embodiment, the medium cover 38 rotates with respect to the medium mounting table 36 with the end on the −X direction side as a free end, and opens and closes the upper portion of the medium mounting table 36.

  A medium placement surface 42 that forms a “document placement area” is provided above the medium placement table 36. The medium placement surface 42 is formed of a transparent glass plate. In the present embodiment, a medium reading origin S for reading a medium as a “document” placed on the medium placing surface 42 by a reading means 44 described later at an end portion on the −Y direction side of the medium placing surface 42. Is set. Note that the periphery of the medium placement surface 42 is one step higher than the medium placement surface 42, so that the medium corner portion can be abutted against the medium reading origin S for positioning.

  In the medium cover 38, when the medium cover is in a closed state with respect to the medium mounting table 36, a medium pressing member 46 is provided on the side facing the medium mounting surface 42. For this reason, the medium placed on the medium placing surface 42 is pressed against the surface of the medium opposite to the side facing the medium placing surface 42 by the medium pressing member 46 provided on the medium cover 38.

  Thus, the medium is uniformly pressed against the medium placement surface 42 so that the medium does not float from the medium placement surface 42. The size of the medium pressing member 46 is set to be approximately the same as the size of the medium loading surface 42 so that the entire area of the opposite surface of the medium loaded on the medium loading surface 42 can be pressed. Has been.

  Referring to FIG. 4, the medium mounting table 36 further includes reading means 44, a first position reference unit 48, a second position reference unit 50, a first reflection reference unit 52, and a second reflection reference. Part 54. The first reflection reference unit 52 and the second reflection reference unit 54 are used for correcting a reading result and obtaining a reference for obtaining appropriate image information. The image reading unit reads the reflection reference unit, Based on the reading result, processing such as gain correction of the photoelectric element is performed.

  The reading means 44 irradiates the medium placed on the medium placement surface 42 located on the + Z direction side in the apparatus height direction, that is, the Z-axis direction, receives light reflected from the medium, and receives information on the medium. The optical unit is configured to extend in the X-axis direction, and corresponds to the length of the medium placement surface 42 in the X-axis direction. The reading unit 44 receives power from the drive motor 60 (FIG. 2) while being guided by a guide rail 58 extending in the Y-axis direction, and moves in the Y-axis direction to read a document.

  A rotary scale (not shown) is provided on the rotating shaft of the driving motor 60 or a rotating body (gear, pulley, etc.) that transmits the driving force from the driving motor 60 to the reading means 44. An optical detection unit (not shown) for reading the scale is provided. The rotary scale and the optical detection unit constitute a rotary encoder 59 (FIG. 2), and the rotary encoder 59 transmits the rotation amount as a signal to the control unit 34. The control unit 34 calculates the driving amount of the reading unit 44, that is, the driving amount in the Y-axis direction, based on the signal from the rotary encoder 59. The control unit 34 controls the position of the reading unit 44 in the Y-axis direction based on the calculated drive amount.

  Further, the reading unit 44 is disposed below the medium placement surface 42 in the apparatus height direction, that is, the Z-axis direction. Further, the entire area of the medium placement surface 42 is disposed so as to be included in the movement area of the reading unit 44 in the Y-axis direction. Therefore, by moving the reading means 44 along the guide rail 58 extending in the Y-axis direction, the reading surface of the medium placed on the medium placing surface 42 is read via the transparent glass plate. Can be read.

  Further, in the medium mounting table 36, the first position reference unit 48 and the second position reference unit 50 are positioned so as to be positioned on the + Z direction side of the reading unit 44 in the Z-axis direction of FIG. In addition, a first reflection reference part 52 and a second reflection reference part 54 are provided. Further, the first position reference portion 48 and the first reflection reference portion 52 are provided on the + Y direction side of the medium placement surface 42, and the second position reference portion 50 and the second reflection reference portion 54 are − of the medium placement surface 42. It is provided on the Y direction side.

  The first position reference unit 48 and the second position reference unit 50 are further arranged adjacent to both sides of the medium placement surface 42 in the Y-axis direction, as shown in FIG. Further, the first position reference portion 48 and the second position reference portion 50 extend in the X-axis direction and are provided with a plurality of notches (see FIG. 5) in the X-axis direction. For this reason, when the reading unit 44 passes below the first position reference unit 48 and the second position reference unit 50, a difference occurs in the amount of reflected light.

  For this reason, the reading unit 44 detects the difference in the amount of reflected light between the first position reference unit 48 and the second position reference unit 50, so that the first position reference unit 48 and the second position reference unit 48 in the Y-axis direction of the medium mounting table 36. The position where the position reference unit 50 is provided can be read. Therefore, the position where the reading unit 44 reads the first position reference unit 48 in the Y-axis direction of the medium mounting table 36 is the first reference position YS1, and the position where the reading unit 44 reads the second position reference unit 50 is the first position. 2 reference position YS2.

  Therefore, the medium mounting table 36 forms a position reference in the moving direction of the reading means 44, that is, the position in the Y axis direction on both sides in the Y axis direction that is the moving direction of the reading means 44 with respect to the medium mounting surface 42. The first position reference unit 48 and the second position reference unit 50 are provided.

  For this reason, the first position reference portion 48 and the second position reference portion 50 that can be read by the reading means 44 and that constitute the position reference in the moving direction of the reading means 44, that is, the Y-axis direction, are provided on both sides of the moving direction. Therefore, by reading the first position reference unit 48 and the second position reference unit 50 provided on both sides, the driving amount of the reading means and the first position reference unit 48 and the second position reference unit 50 As a result, even when the drive mechanism of the reading means 44 is deteriorated, the image can be read accurately.

  Further, the first reflection reference portion 52 is disposed on the + Y direction side of the first position reference portion 48 on the + Y direction side of the medium placement surface 42 in the Y axis direction. In addition, the second reflection reference portion 54 is disposed on the −Y direction side of the medium placement surface 42 in the Y axis direction on the −Y direction side with respect to the second position reference portion 50.

  The first reflection reference portion 52 and the second reflection reference portion 54 extend in the X-axis direction in FIGS. 4 and 5 and are formed as white flat members. The first reflection reference part 52 and the second reflection reference part 54 are configured to be longer than the reading unit 44 in the X-axis direction. For this reason, when the reading unit 44 passes below the first reflection reference unit 52 and the second reflection reference unit 54, a predetermined amount of light is reflected toward the reading unit 44. ing.

  Therefore, the medium mounting table 36 has a first reflection reference portion that can be read by the reading unit 44 and that serves as a reference for the amount of reflected light on both sides in the Y-axis direction that is the moving direction of the reading unit 44 with respect to the medium mounting surface 42. 52 and a second reflection reference portion 54.

  For this reason, a first reflection reference portion 52 and a second reflection reference portion 54 that are readable by the reading means 44 and that form a reference of the amount of reflected light are provided on both sides of the moving direction, that is, the Y-axis direction with respect to the medium placement surface 42. Therefore, when the reading operation by the reading unit 44 is started, the entire reading operation time is shortened by selecting and reading either the first reflection reference unit 52 or the second reflection reference unit 54 close to the reading unit 44. be able to.

  Further, referring to FIG. 5, the first standby position YH1 that forms the standby position of the reading means 44 is relative to the first position reference portion 48 provided on the + Y direction side in the Y-axis direction with respect to the medium placement surface 42. It is set on the side away from the medium placement surface 42, that is, on the + Y direction side. Further, the second standby position YH2 that forms the standby position of the reading unit 44 is from the medium placement surface 42 to the second position reference portion 50 provided on the −Y direction side in the Y axis direction with respect to the medium placement surface 42. It is set on the far side, that is, on the −Y direction side. In FIG. 5, the first standby position YH1 and the second standby position YH2 are outside areas that do not overlap the first reflection reference portion 52 and the second reflection reference portion 54. The area may overlap with the portion 54.

  In the image reading apparatus, when the first standby position is set to a position that overlaps the first reflection reference portion and the second standby position is set to a position that overlaps the second reflection reference portion, the width direction (Y The outer dimension in the axial direction can be reduced, and space saving of the image reading apparatus can be achieved.

  For this reason, in the medium mounting table 36, the first standby position YH1 and the second standby position YH2 are provided on both sides of the medium mounting surface 42 in the Y-axis direction, so that the reciprocating operation of the reading unit 44 in the Y-axis direction becomes unnecessary. Power consumption can be reduced, and unnecessary operation noise can be prevented.

  Next, a distance acquisition mode of the reading unit 44 that is executed when the printer 10 is turned on and when the printer 10 returns from the power saving mode will be described with reference to FIGS. 5 and 6.

  In step S1, the reading unit 44 is moved in the second direction (+ Y direction) immediately after the printer 10 is turned on and immediately after returning from the power saving mode. Next, as step S2, when the reading unit 44 moves in the + Y direction and is located at the end of the moving region in the Y-axis direction on the + Y direction side, the current value of the drive motor 60 increases because it cannot move any further.

As step S <b> 3, when the control unit 34 detects an increase in the current value of the drive motor 60, the control unit 34 stops the rotation of the drive motor 60. As a result, the reading unit 44 is stopped from moving at the + Y direction side end of the moving region in the Y-axis direction.
As described above, the control unit 34 can determine that the current position of the reading unit 44, that is, the reading unit 44 is located at the + Y direction side end of the moving region in the Y-axis direction. Therefore, when the normal power-off operation is performed, or when shifting to the power saving mode, if the reading means 44 is moved to the end on the + Y direction side in advance and then the power is turned off or the power saving mode is shifted, the process proceeds to step S1. The time required can be shortened. When the reading unit 44 is positioned at the end in the first direction (-Y direction) and the power is turned off or the power saving mode is entered, the reading unit 44 is left in the same position and the power is turned on or the power saving mode. If the operation of step S101 performed when returning to the mode is performed on the −Y direction side instead of the + Y direction side, the moving distance of the reading unit 44 can be shortened, and the time required for step S1 can be shortened.

  Subsequently, as step S4, the control unit 34 reversely rotates the drive motor 60 to move the reading unit 44 in the first direction (−Y direction). In step S5, the reading unit 44 causes the first position reference unit 48 to be detected. In step S6, the position of the first position reference unit 48 detected by the reading unit 44 is set as a first reference position YS1. Further, a position that is separated from the first reference position YS1 by a predetermined distance L1 in the second direction (+ Y direction) is set as the first standby position YH1.

  In step S7, the reading unit 44 is further moved from the first reference position YS1 in the first direction (−Y direction). In step S8, the second position reference unit 50 is detected. In step S9, the detection position of the second position reference unit 50 detected by the reading unit 44 is set as a second reference position YS2.

  As step S10, the control unit 34 detects the position of the first position reference unit 48 detected by the reading unit 44, that is, the first reference position YS1, and the detected position of the second position reference unit 50, that is, the second reference position YS2. An actual measurement value of the distance between the first position reference unit 48 and the second position reference unit 50 is calculated from the drive amount of the drive motor 60 between the first position reference unit 48 and the second position reference unit 50. Then, the control unit 34 compares the calculated actual value with the theoretical value L3 of the distance between the first position reference unit 48 and the second position reference unit 50, and the difference between the actual measurement value and the theoretical value, that is, Calculate the feed error.

  Further, the distance L4 between the second reference position YS2 of the second position reference unit 50 and the medium reading origin S located on the −Y direction side of the medium placement surface 42 is measured during the assembly operation of the image reading device 14 and is controlled. Part 34 is recorded. Therefore, the position of the medium reading origin S in the Y-axis direction can be obtained by adding the distance L4 to the second reference position YS2. Thereby, the exact position of the medium reading origin S in the Y-axis direction is determined.

  Then, the control unit 34 adds the feed error and the distance L4 to the theoretical value L3 between the first position reference unit 48 and the second position reference unit 50, thereby the first position reference unit 48, that is, the first reference position YS1. To the medium reading origin S, an accurate driving amount L5 of the reading means 44 can be obtained.

  In step S11, the control unit 34 sets a position that is a predetermined distance L2 away from the second reference position YS2 in the first direction (−Y direction) as the second standby position YH2.

  Next, in step S12, the control unit 34 moves the reading unit 44 from the second reference position YS2 by the distance A1 in FIG. Here, the rotation amount of the drive motor 60 for moving the distance A1 is a rotation amount equal to or greater than the theoretical backlash amount of the gear. The theoretical backlash amount of the gear is a backlash amount of a theoretical mesh obtained from a dimension value of a gear (not shown) that constitutes a transmission mechanism (not shown) that transmits power from the drive motor 60 to the reading unit 44. is there.

  Next, in step S13 and step S14, the control unit 34 moves the reading unit 44 in the second direction (+ Y direction) to detect the second position reference unit 50 again. At this time, the rotation amount of the drive motor 60 when the reading unit 44 is moved by the distance A1 in the first direction (−Y direction) from the second reference position YS2 is defined as B1. In addition, when the reading unit 44 is moved in the + Y direction by the reverse rotation of the driving motor 60 and the second position reference unit 50 is read (the moving distance of the reading unit is A2), the rotation amount of the driving motor 60 is B2. If the backlash amount is zero, the rotation amount B1 and the rotation amount B2 are equal.

  However, since the backlash amount is not zero in most cases, the difference between the rotation amount B1 and the rotation amount B2 is set as a correction value B as an error caused by switching the moving direction of the reading means 44. The correction value B includes not only an error due to the backlash amount but also an error due to a difference in reading direction.

  Next, in step S15, the control unit 34 moves the reading unit 44 to the first standby position YH1 or the second standby position YH2. Then, the control unit 34 causes the reading unit 44 to wait at the first standby position YH1 or the second standby position YH2 until an instruction from the user is received via the operation unit 20. In this embodiment, since the reading means 44 is located at the second reference position YS2 at the end of step S15, the reading means 44 is moved to the second standby position YH2 close to the second reference position YS2. To wait at the second standby position YH2. Thereby, it is possible to shift to the reading standby state in a short time.

  As described above, in the image reading apparatus 14, the first position reference unit 48 and the second position reference unit 50 are provided on both sides in the moving direction, that is, the Y-axis direction with respect to the medium placement surface 42. A distance acquisition mode in which the distance is acquired by reading the first position reference unit 48 and the second position reference unit 50 while moving the reading unit 44 in a predetermined direction (−Y direction or + Y direction) is set at a predetermined timing (printer 10 When the power is turned on and at the time of return from the power saving mode), it is always possible to grasp the relationship between the driving amount of the reading means 44 and the distance between the position reference portions at a predetermined timing. It becomes possible to read accurately.

  In the distance acquisition mode of the present embodiment, the second position reference unit 50 obtains the correction value B by switching and detecting the movement direction (+ Y direction and −Y direction) of the reading unit 44, and then performs a preview operation. The correction value B is added to the drive amount of the drive motor 60 when the moving direction (+ Y direction and -Y direction) of the reading means 44 is different between the document reading operation and the document reading operation. Therefore, when a gear is used as the drive mechanism of the reading means 44, backlash between the gears is canceled, and errors due to differences in reading directions can be canceled, so that an image can be read accurately.

  Next, a medium reading operation, that is, an image reading mode in the image reading device 14 controlled by the control unit 34 will be described with reference to FIG. In the following description, a case where the reading unit 44 is at the second standby position YH2 and a case where it is at the first standby position YH1 will be described in order.

  When the reading unit 44 is waiting at the second standby position YH2, when the user inputs an image reading instruction to the operation unit 20 (see FIGS. 1 and 2), the control unit 34 executes the medium reading mode. The control unit 34 moves the reading unit 44 from the second standby position YH2 in the second direction (+ Y direction), and reads the second reflection reference unit 54.

  Further, the reading unit 44 is added to the distance L2 + L4 from the second standby position YH2 to the medium reading origin S by adding a correction value B of an error due to a difference in backlash and reading direction in the first direction (+ Y Direction). Thereby, the reading means 44 can be accurately positioned at the medium reading origin S.

  Next, the control unit 34 moves the reading unit 44 from the medium reading origin S in the second direction (+ Y direction) at the first speed V1, and moves the reading surface of the medium placed on the medium placing surface 42. Performs scanning and document preview operations. Then, the reading unit 44 is stopped at the first standby position YH1.

  Next, the control unit 34 moves the reading unit 44 in the first direction (−Y direction) from the first standby position YH1 to read the first reflection reference unit 52. Then, the control unit 34 is equal to or slower than the first speed V1 with the end on the + Y direction side of the medium placed on the medium placement surface 42 obtained by the preview operation as the starting point of the main reading of the medium. While the reading means 44 is moved in the first direction (−Y direction) at the second speed V2, the reading surface of the medium is read by the reading means 44, and the main reading operation of the medium is performed. Thereby, the image reading device 14 can read information on the medium.

  Subsequently, when the reading unit 44 is waiting at the first standby position YH1, when the user inputs an image reading instruction to the operation unit 20, the control unit 34 executes the medium reading mode. The control unit 34 moves the reading unit 44 from the first standby position YH1 in the first direction (−Y direction), and reads the first reflection reference unit 52.

  Further, the reading unit 44 is moved in the first direction (−Y direction) from the first standby position YH1 to the second standby position YH2. At this time, the control unit 34 reads the reading surface of the medium placed on the medium placing surface 42 while moving at the first speed V1, and performs a document preview operation. Then, the reading unit 44 is stopped at the second standby position YH.

  Next, the control unit 34 moves the reading unit in the second direction (+ Y direction) from the second standby position YH2 to read the second reflection reference unit 54. Then, the control unit 34 reads the medium while moving the reading unit 44 in the second direction (+ Y direction) from the medium reading origin S at the second speed V2 that is equal to or slower than the first speed V1. The surface is read by the reading means 44, and the main reading operation of the medium is performed. Thereby, the image reading device 14 can read information on the medium. The above is the image reading mode of the medium.

  Therefore, in the image reading apparatus 14 of the present embodiment, the preview operation and the main reading operation of the medium placed on the medium placing surface 42 can be performed by only one reciprocation operation in the moving region in the Y axis direction of the reading unit 44. Therefore, the time required for image reading can be shortened.

  The reading unit 44 reads the first reflection reference unit 52 when starting the document reading operation from the first standby position YH1, and reads the second reflection reference when starting the document reading operation from the second standby position YH2. The unit 54 is set to read.

  Therefore, the reading unit 44 reads the first reflection reference portion 52 when starting the document reading operation from the first standby position YH1, and reads the second reflection when starting the document reading operation from the second standby position YH2. Since the reference portion 54 is read, the moving distance of the reading means 44 is short when reading the reflection reference portions 52 and 54, and the overall reading operation time can be shortened.

  Further, when the reading unit 44 receives an operation stop command from the control unit 34 during the document reading operation, the reading unit 44 returns to the standby positions YH1 and YH2 that are closer to the first standby position YH1 or the second standby position YH2. Is set to For this reason, unnecessary operation of the reading means 44 can be avoided to reduce power consumption.

<<< Modification of Example >>>
(1) In this embodiment, the distance acquisition mode is set to be performed when the printer 10 is turned on and when the printer 10 is returned from the power saving mode. However, the distance acquisition mode may be set to be executed every time the medium reading mode is executed. . Thereby, since the correction value and the like are set immediately before the medium reading operation, the medium reading operation can always be executed in accordance with the current state of the printer 10. Thereby, the position shift of the reading means 44 in the reading operation of the medium placed on the medium placing surface 42 can be reduced.
(2) In this embodiment, steps S1 to S15 of the distance acquisition mode of the reading unit 44 are performed from the first standby position YH1 side to the second standby position YH2 side. However, the present invention is not limited to this. Steps S1 to S15 may be performed from the second standby position YH2 side toward the first standby position YH1 side.

  In summary, the image reading apparatus 14 according to the present exemplary embodiment is configured such that the medium placement table 36 that forms the medium placement surface 42 on which the medium is placed, and the medium placed on the medium placement surface 42 in the Y-axis direction. Reading means 44 that reads while moving to the medium mounting surface 42, and is provided on both sides of the moving direction (Y-axis direction) of the reading means 44 with respect to the medium mounting surface 42, and constitutes a position reference in the moving direction (Y-axis direction) of the reading means 44. A first position reference unit 48 and a second position reference unit 50 that can be read by the reading unit are provided.

  The image reading device 14 includes a first reflection reference portion 52 and a second reflection reference portion that are readable by the reading means 44 and that form a reference of the amount of reflected light on both sides of the moving direction (Y-axis direction) with respect to the medium placement surface 42. 54.

  In the image reading device 14, the first position reference portion is one of the first position reference portion 48 and the second position reference portion 50 provided on both sides of the medium placement surface 42 in the movement direction (Y-axis direction). A first standby position YH1 that forms a standby position of the reading unit 44 is set on the side away from the medium placement surface with respect to the position reference unit 48, and is provided on both sides of the movement direction (Y-axis direction) with respect to the medium placement surface. The standby position of the reading unit 44 is formed on the side away from the medium placement surface with respect to the second position reference unit 50 that is the reflection reference unit on the other side of the first position reference unit 48 and the second position reference unit 50. A second standby position YH2 is set.

  The first standby position YH1 is set to a position overlapping the first reflection reference part 52, which is one of the reflection reference parts 52 and 54, and the second standby position YH2 is the other of the reflection reference parts 52 and 54. It is set at a position overlapping the second reflection reference portion 54 that is the reflection reference portion on the side.

  The reading unit 44 reads the first reflection reference unit 52 when starting the document reading operation from the first standby position YH1, and reads the second reflection reference unit 54 when starting the document reading operation from the second standby position YH2. Read. Further, the control unit 34 reads the distance between the first position reference unit 48 and the second position reference unit 50 provided on both sides of the moving direction (Y-axis direction) with respect to the medium placement surface in the image reading device 14. A distance acquisition mode acquired by reading the first position reference unit 48 and the second position reference unit 50 while moving the means 44 in a predetermined direction (−Y direction or + Y direction) is executed at a predetermined timing.

  In the image reading device 14, the second position reference unit 50 on one side of the first position reference unit 48 and the second position reference unit 50 provided on both sides of the movement direction (Y-axis direction) with respect to the medium placement surface 42 is arranged. Then, from the point of detection while moving the reading means 44 in the -Y direction which is the moving direction of the reading means 44, the motor of the drive motor 60 which is the driving source of the reading means 44 is rotated by the rotation amount B1, and the reading means 44 is moved. Further, the second position reference unit 50 is detected again while moving the reading motor 44 in the + Y direction opposite to the −Y direction by moving the driving motor 60 in the −Y direction by a predetermined distance and then rotating the reading means 44 in the + Y direction opposite to the −Y direction. A difference between the rotation amount B2 of the drive motor 60 and the rotation amount B1 is defined as a correction value B. After performing the preview operation at the first speed V1 while moving the reading unit 44 in the −Y direction, the second speed is equal to or lower than the first speed V1 during the preview reading operation. The correction value B is added to the drive amount of the drive motor 60 when the document reading operation is performed while moving in the + Y direction at V2.

  When the reading unit 44 receives an operation stop command during the document reading operation, the reading unit 44 returns to the standby positions YH1 and YH2 that are closer to the first standby position YH1 or the second standby position YH2.

In this embodiment, the image reading apparatus 14 according to the present invention is applied to an ink jet printer as an example of a recording apparatus. However, the present invention can be applied to other liquid ejecting apparatuses in general.
Here, the liquid ejecting apparatus uses an ink jet recording head, and is not limited to a recording apparatus such as a printer, a copier, and a facsimile machine that discharges ink from the recording head to perform recording on a recording medium. And a device for ejecting a liquid corresponding to the application from a liquid ejecting head corresponding to the ink jet recording head to an ejected medium corresponding to the recording medium, and attaching the liquid to the ejected medium.

  In addition to the recording head, as a liquid ejecting head, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, and an electrode material (conductive paste) used for forming an electrode such as an organic EL display or a surface emitting display (FED) Examples thereof include an ejection head, a bioorganic matter ejection head used for biochip production, and a sample ejection head as a precision pipette.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

10 printer, 12 device body, 14 image reading device, 16 housing,
18 lid, 20 operation unit, 22 medium storage unit, 24 feeding unit, 26 transport unit,
28 recording unit, 30 discharge unit, 34 control unit, 36 medium mounting table, 38 medium cover,
40 rotating shaft, 42 medium mounting surface, 44 reading means, 46 medium pressing member,
48 1st position reference part, 50 2nd position reference part, 52 1st reflection reference part,
54 second reflection reference part, 58 guide rail, 59 rotary encoder,
60 Drive motor, A1 distance, A2 distance, B correction value, B1 rotation amount,
B2 rotation amount, L1 distance, L2 distance, L3 theoretical value, L4 distance, L5 drive amount,
S medium reading origin, V1 first speed, V2 second speed, YH1 standby position,
YH1 first standby position, YH2 second standby position, YS1 first reference position,
YS2 Second reference position

Claims (7)

A document table that forms a document placement area on which a document is placed;
Reading means for reading the document placed in the document placement area while moving in the scanning direction;
A position reference portion that is provided on both sides of the reading unit in the moving direction with respect to the document placement area and that serves as a position reference in the moving direction of the reading unit, and is readable by the reading unit;
A distance acquisition mode for acquiring a distance between the position reference portions provided on both sides of the moving direction with respect to the document placement area by reading the position reference portion while moving the reading unit in a predetermined direction is predetermined. At the timing of
An image reading apparatus. The image reading apparatus according to claim 1, further comprising a reflection reference portion that can be read by the reading unit and that forms a reference of the amount of reflected light on both sides in the moving direction with respect to the document placement area.
An image reading apparatus. The image reading apparatus according to claim 2, wherein the document is placed on a first position reference portion that is a position reference portion on one side of the position reference portions provided on both sides in the movement direction with respect to the document placement region. A first standby position which is a standby position of the reading means is set on the side away from the placement area;
The reading means on the side farther from the document placement area with respect to the second position reference part which is the position reference part on the other side of the position reference parts provided on both sides in the moving direction with respect to the document placement area A second standby position that is a standby position is set.
An image reading apparatus. 4. The image reading apparatus according to claim 3, wherein the first standby position is set to a position overlapping a first reflection reference portion that is one of the reflection reference portions.
The second standby position is set to a position overlapping with the second reflection reference part which is the reflection reference part on the other side of the reflection reference part.
An image reading apparatus. 5. The image reading apparatus according to claim 4, wherein the reading unit reads the first reflection reference portion when starting the document reading operation from the first standby position, and performs the document reading operation from the second standby position. Read the second reflection reference when starting
An image reading apparatus. 6. The image reading apparatus according to claim 1, wherein a position reference portion on one side of the position reference portions provided on both sides in the movement direction with respect to the document placement region is the reading unit. From the point of time when the reading means is detected while being moved in the first direction which is the moving direction of the motor, the motor which is the driving source of the reading means is rotated by the rotation amount B1, and the reading means is further moved in the first direction by a predetermined distance. Move
Next, the motor is rotated in the reverse direction to detect the position reference portion on the one side again while moving the reading means in the second direction opposite to the first direction, and the rotation amount B2 of the motor at the time of detection is detected. , The difference between the rotation amount B1 and the correction value B,
Driving amount of the motor when performing the document reading operation while moving the reading unit in the second direction at a lower speed than the preview operation after performing the preview operation while moving the reading unit in the first direction The correction value B is added to
An image reading apparatus. The image reading apparatus according to any one of the preceding claims 3, wherein the reading means, when receiving the operation stop instruction during execution of the original reading operation, the first standby position and the second standby Return to the nearest standby position,
An image reading apparatus.

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