CN101365037B - Image reading apparatus, image forming apparatus and image forming system - Google Patents

Abstract

The present invention provides an image reading device, an image forming device, and an image forming system using the image reading device and the image forming device. The image reading device reads an image of a document. An image reading section (105) reads an image of a document. When the document is on standby, the scanning mechanism (16) moves the image reading portion (105) relative to the document. When the image reading section is on standby, the document feeding mechanism (23, 27, 61) moves the document relative to the image reading section. When the document is moved relative to the standby image reading section, the shutter (33, 46, 129) moves to a first position where the shutter is opened to allow the image reading section to read an image of the document. When the image reading section (105) moves relative to the document on standby, the shutters (33, 46, 129) move to a second position where the shutters are closed, allowing the image reading section (105) to read An image of the document.

Description

Image reading device, image forming device, and image forming system

technical field

The present invention relates to an image reading device, an image forming device, and an image forming system using the image reading device and the image forming device.

Background technique

Conventional image forming devices, such as copiers, facsimile machines, and multifunction printers (MFPs), are equipped with image reading devices for reading document images. The image reading device includes an automatic document feeder (ADF) and a scanner. The ADF feeds multi-page documents to the scanner page by page. The scanner reads an image of each document page fed by the ADF.

The scanner includes an image reading sensor. The image reading sensor reads an image of a document fed by the ADF and an image of a document placed on a flatbed. In order to read the image of a document placed on the platform, the document must be pressed against the platform by the flatbed. For this reason, when reading an image of a document fed by the ADF, the image reading sensor must be positioned outside the image reading area on the platform.

The conventional image reading device of the aforementioned structure suffers from the problem that the image reading sensor disposed outside the image reading area increases the overall size of the image reading device.

Contents of the invention

The object of the present invention is to solve the problems of the aforementioned conventional devices.

Another object of the present invention is to provide an image reading apparatus and an image forming apparatus in which a shutter is provided so that the shutter can be opened or closed with respect to the image reading portion so that the image reading portion is positioned at the image reading portion. area so that the overall size of the image reading device can be smaller.

The image reading device reads an image of a document. The image reading section 105 reads an image of a document. When the document is on standby, the scanning mechanism 16 moves the image reading portion 105 relative to the document. The document feeding mechanisms 23 , 27 , 61 move the document relative to the image reading portion 105 when the image reading portion 105 is on standby. When the document moves relative to the image reading section 105 on standby, the shutters 33, 46, 129 move to the first position, and at the first position, the shutters 33, 46, 129 are opened, allowing the image reading section 105 to read the document. image. When the image reading section 105 moves relative to the document on standby, the shutters 33, 46, 129 move to the second position, and at the second position, the shutters 33, 46, 129 are closed, allowing the image reading section 105 to read the document. image.

Further areas of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only. Since various modifications and alterations within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Description of drawings

The present invention will be more fully understood from the detailed description given hereinafter and the accompanying drawings, which are given by way of illustration only and thus do not limit the invention, in which:

FIG. 1 is a front view of an image forming system;

2 is a left side view of the image forming system;

FIG. 3 illustrates the structure of the image forming apparatus of the first embodiment;

4A is a first cross-sectional side view illustrating a relevant portion of the image reading device in an automatic mode;

FIG. 4B is an expanded view of the relevant part of FIG. 4A;

5A is a second sectional side view illustrating another relevant part of the image reading apparatus in a manual mode;

FIG. 5B is an expanded view of relevant parts of FIG. 5A;

Figure 5C is a partial enlarged view showing the position of the shutter in manual mode;

Figure 5D is a partial enlarged view showing the position of the shutter in automatic mode;

6 is a perspective view illustrating the structure of a driver portion in an automatic mode;

Figure 7 illustrates details of the bracket;

8 is a perspective view illustrating the structure of a driver portion in a manual mode;

Figure 9 illustrates the positional relationship between the locking member and the feeder;

FIG. 10A is a perspective view illustrating the structure of a document pressure plate used in an image reading apparatus;

Figure 10B illustrates the shutter viewed from the direction indicated by the arrow M shown in Figure 5B when the shutter opens the window;

FIG. 11 is a perspective view illustrating the structure of a document pressure plate;

Figure 12 is a perspective view illustrating the shutter;

Figure 13 illustrates various positions of the carriage in the platform scanner;

FIG. 14 is a time chart illustrating the operation of the image reading device;

Figure 15 illustrates a modification of the shutter 33;

16A is a sectional view illustrating the structure of the image reading device of the second embodiment;

Fig. 16B is an expanded view of the relevant part of Fig. 16A;

17 is a perspective view illustrating the structure of a driver portion of the image reading device of the second embodiment;

Fig. 18 is a perspective view illustrating the structure of the document pressure plate;

19A is a first developed sectional view illustrating the structure of a relevant portion of the image reading apparatus in an automatic mode;

Figure 19B is a perspective view of the valve shown in Figure 19A when the valve is opened from the direction indicated by the arrow P in Figure 19A;

20 is a second developed sectional view illustrating the structure of a relevant part of the image reading apparatus in manual mode;

21A is a sectional side view illustrating a third embodiment of a relevant part of the image reading device in an automatic mode;

Figure 21B is a partial enlarged view illustrating the position of the shutter in manual mode;

Figure 21C is a partial enlarged view illustrating the position of the shutter in automatic mode;

FIG. 22 is a perspective view illustrating the structure of the document pressure plate of the image reading apparatus in the manual mode;

Figure 23 illustrates the position of the joystick;

Figure 24 illustrates various positions of the carriage in the platform scanner.

Detailed ways

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

first embodiment

{The overall structure}

FIG. 1 is a front view of an image forming system 100 . FIG. 2 is a left side view of the image forming system 100 .

FIG. 3 illustrates the configuration of the image forming system of the first embodiment.

Referring to FIG. 3 , an image forming system 100 includes an image forming device 1 and an image reading device 13 provided on the image forming device 1 . The image forming system takes the form of, for example, a multifunction printer (MFP) such as a copier or a facsimile. The image forming system 100 may take any other device form as long as the image forming system 100 includes an image reading device 13 for reading an image of a document (for example, printed paper) and a device for printing the image on a printing medium such as paper. The image forming apparatus 1 is sufficient.

The image forming apparatus 1 may be a monochrome printer or a color printer. The image forming apparatus 1 may also be of an inkjet type, a thermal printing type, or any other type. The image forming apparatus 1 includes four imaging drum units that respectively form yellow (Y), magenta (M), cyan (C), and black (B) images. This embodiment will describe a tandem color electrophotographic printer that uses electrophotographic processing to form images.

The image forming unit 8 includes four imaging drum units that form toner images of respective colors and transfer the toner images onto a printing medium. The fixing portion 9 fixes the toner image that has been transferred onto the printing medium. The paper cassette 2 accommodates therein a stack of printing media, and feeds the printing media to the image forming unit 8 page by page.

The paper cassette 2 includes a feed roller 3 that feeds the printing medium sheet by sheet into the medium transport path. The feed roller 3 includes a one-way clutch (not shown). When the clutch rotates in one direction, the driving force is transmitted through the clutch. When the clutch is rotated in the other direction, the clutch rotates in an idle manner so that no driving force is transmitted through the clutch.

Sensors 4 and 6 are provided along a medium conveyance path in which a print medium is conveyed from paper cassette 2 to image forming unit 8 . Before the printing medium fed from the paper cassette 2 is fed into the image forming unit 8 , the transport roller 5 corrects the skew of the printing medium. The transport roller 7 advances the printing medium fed by the transport roller 5 into the image forming unit 8 .

The image forming unit 8 includes a plurality of imaging drum units, each of which performs charging, exposure, development, and transfer processing of an image of a corresponding color. When the printing medium passes through the imaging drum unit, the toner images of the respective colors are transferred onto the printing medium stacked in alignment with each other. The printing medium bearing the toner images passes through a fixing point defined between the heating roller and the pressing roller of the fixing portion 9 where the toner images of the respective colors are fused into a full-color image.

Discharge rollers 10 and 11 are provided along a medium conveying path in which the printing medium discharged from the fixing portion 9 is conveyed. The discharge roller 11 discharges the printing medium onto a discharge tray 12 .

Image reading device 13 is provided on image forming device 1 , and includes document feed tray 17 , document feed section 14 , discharge tray 19 , and flatbed scanner 15 . Document feeding section 14 is hingedly coupled to flatbed scanner 15 so that document feeding section 14 can pivot relative to flatbed scanner 15 . When the document feeding portion 14 pivots away from the flatbed scanner 15, it allows a user to place a document on the flatbed 20 of the flatbed scanner 15 to manually feed the document. When the document feed portion 14 is pivoted toward the platform scanner 15, the user is not allowed to place a document on the platform 20 but is allowed to place the document on the document feed tray 17 to automatically feed the document pages. The document feed tray 17 supports document sheets thereon, and includes guides 18 extending in a direction substantially parallel to the traveling direction of the document and provided oppositely, between which the document sheets are placed. The guide 18 guides the document pages placed on the document feeding tray 17 to the image reading device 13 . The document feeding section 14 feeds the document sheet to the image reading position 62 (FIG. 4B) where the image of the document is optically read by the image reading section 105 through the hole 16a. The document page is discharged onto the discharge tray 19 every time the image of the document page has been read.

{Structure of image reading device}

The structure of the image reading device 13 will be described below.

FIG. 4A is a first sectional side view illustrating a relevant portion of the image reading device 13 in the first mode or automatic mode. FIG. 4B is an expanded view of relevant parts of FIG. 4A . FIG. 5A is a second sectional side view illustrating another relevant portion of the image reading device 13 in the second mode or manual mode. FIG. 5B is an expanded view of relevant parts of FIG. 5A . FIG. 5C is a partially enlarged view showing the position of the shutter 33 in the manual mode. FIG. 5D is a partially enlarged view showing the position of the shutter 33 in the automatic mode. FIG. 6 is a perspective view illustrating the structure of a driver portion in an automatic mode.

The document feeding section 14 is generally called an ADF, and feeds a document of one or more pages to the image reading position 62 page by page in an automatic mode.

The platform scanner 15 is used in manual mode to read images of documents placed on the platform 20 . Platform scanner 15 includes document support plate or platform 20 , document platen 21 , and scanning mechanism or carriage 16 . The stage 20 is a plate-shaped member made of a light-transmitting material (for example, glass), on which an image reading area A ( FIG. 13 ) is defined. In the manual mode, the user places a document page in the image reading area A. As shown in FIG. The document pressing plate 21 has a lower surface to which a reflective white sheet 21a is attached. The reflective white sheet 21a extends to cover the part of the image reading area A except the "window" 101. In the automatic mode, the image reading device 105 reads the image of the document through the window 101. The reflective white sheet 21a may be larger than the image reading area A. Referring to FIG. The document pressing plate 21 presses the document placed in the image reading area on the platform 20 so that the reflective white sheet 21a comes into close contact with the document. The automatic mode and manual mode will be described in more detail later. The carriage 16 is located under the lower surface of the platform 20 and reciprocates along the guide rail 16a in manual mode.

The automatic mode is an operation mode of the image reading device 13 in which the document feeding section 14 feeds a document of one or more pages into the image reading area A where the document is read. The fetching section 105 reads the image of the document. In the automatic mode, the carriage 16 remains at the image reading position 62 shown in FIGS. 4A and 4B , and the image reading section 105 reads an image of a document.

The manual mode is another operation mode of the image reading device 13 , in which a user manually places a document page on the platform 20 so that the image of the document is read by the image reading section 105 . In the manual mode, the carriage 16 moves along the guide rail 16a at a constant speed relative to the platform 20 in the direction indicated by the arrow C in FIG.

Referring to FIGS. 4A and 6 , a hopper 28 flattens the leading edge of a document page supported on the document feed tray 17 . The feeder 28 is arranged to pivot about an axis 28a ( FIG. 6 ) between the position of FIG. 4A and the position of FIG. 5A , and is urged upwards by a spring 29 . Feed rollers 22 feed document pages to image reading device 13 page by page. Separation pad 31 is urged against feed roller 22 by spring 30 and cooperates with feed roller 22 to separate the uppermost page from the document stack. The transport roller 23 transports the document pages to the image reading point 62 page by page. Every time an image of one page has been read by the image reading portion 105, the discharge rollers 25 discharge the document page. Spring 26 urges a document pressing member or platen 27 so that platen 27 softly presses the document against transparent guide 61 while allowing the document pages to pass through image reading position 62 . The document is advanced face down through the image reading position 62 with the image side of the document sliding on the transparent guide 61 . The paper presser 27 extends in a direction substantially perpendicular to the traveling direction of the document. The feed roller 22, the transport roller 23, and the discharge roller 25 rotate around drive shafts 35, 36, and 37, respectively. The conveying roller 23, the discharge roller 25, the paper platen 27, and the colorless transparent guide 61 constitute a document feeding mechanism.

The transparent guide 61 is in the form of a light-transmitting acrylic plate, thus performing the function of a "window" 101 through which the image reading section 105 reads the image of the document in the automatic mode. The transparent guide 61 also performs the function of a guide that guides the document when it passes the image reading position 62 relative to the image reading portion 105 in the automatic mode. The document feeding section 14 includes a plate-shaped shutter 33 provided to open and close the window 101 . In the automatic mode, the shutter 33 moves to the first position or the open position to open the window 101, thereby allowing the image reading part 105 to read the image of the document through the window 101; and in the manual mode, moves to the second position or the closed position to close window 101, thereby not allowing the image reading section 105 to read the image of the document through the window 101. The shutter 33 is formed of a rigid material, and includes a rack 33a formed thereon. The rack 33a meshes with the pinion 32 to constitute a rack-pinion mechanism. When the pinion 32 rotates around the drive shaft 39, the shutter 33 moves in the horizontal direction shown in FIGS. 4A-4B and 5A-5B.

The carriage 16 is substantially box-shaped, and carries the image reading portion 105 mounted thereon. The bracket 16 is mounted on the guide rail 16a, and can move horizontally on the guide rail 16a.

FIG. 7 illustrates details of the bracket 16 . The image reading section 105 mounted on the carriage 16 moves together with the carriage 16 in the feeding direction (direction C in FIG. 5A ) while scanning the image of the document in a lateral direction approximately perpendicular to the feeding direction.

Referring to Figure 7, a light source or cold cathode tube 100 sends light to a document. The electrodes of the cold cathode tube 100 should be electrodes with long life and low power consumption, such as molybdenum electrodes, but they can be any type of electrodes. The light reflected by the document is incident on the mirror 101a and then on the mirror 101b. The image reading system 105 includes a sensor element 103 such as a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS); and optical elements such as a lens 102 and light guides such as mirrors 101a and 101b. The lens 102 condenses the light reflected by the mirror 101 b on the image sensor 103 . The image sensor 103 takes the form of a Charge Coupled Device (CCD) and converts received light into a digital signal.

In the automatic mode, the shutter 33 moves to open the window 101 (FIGS. 4A, 4B and 5D). The carriage 16 is held at the image reading position 62 so that the image reading portion 105 reads the document through the window 101 . The image reading section 105 reads only the portion of the document image that directly faces the reading sensor 105 through the window 101 . When the document moves through the window 101 , the image reading section 105 reads the image of the document through the window 101 . It should be noted that the image reading position 62 is within the image reading area A (FIG. 13) defined on the platform 20, in which the reading sensor 105 moves to read the image of the document in the manual mode. . The document is conveyed in a narrow path defined between the transparent guide 61 and the paper platen 27 . The spring 26 urges the document presser 27 downward so that the document presser 27 presses the document against the transparent guide 61 while allowing the document to pass through the narrow path.

An opaque guide may be used in place of the transparent guide 61, in which case the window 101 may be a pure opening (eg, a slit) formed in the opaque guide. The opening should extend in a lengthwise direction substantially perpendicular to the direction of travel of the pages of the document and have a length greater than the width of the document. The opening should have a width wide enough that the image reading section 105 can read the image of the document through the hole 16a when the document is moved relative to the image reading section 105 .

In the manual mode, the shutter 33 is moved horizontally to the left, and the window 101 is completely closed at the image reading position 62, as shown in FIGS. 5A, 5B and 5C.

{driver section}

The driver section of the image reading device 13 will be described below.

FIG. 6 is a perspective view illustrating the structure of a driver portion in an automatic mode.

FIG. 8 is a perspective view illustrating the structure of a driver portion in a manual mode.

FIG. 9 illustrates the positional relationship between the lock member 38 and the feeder 28 .

Referring to FIGS. 6 and 8 , the drive shafts 35 , 36 ( FIG. 4A ), 37 ( FIG. 4A ), and 39 are mounted on the base frame 43 of the image reading device 13 . The gears for driving the shutter 33 include a first gear 32a and a second gear 32b, and the first gear 32a and the second gear 32b are disposed on opposite sides of the document path. Gears 32 a and 32 b are mounted on a drive shaft 39 . The shaft 28 a of the feeder 28 is also mounted to the base frame 43 .

The image reading device 13 includes a drive motor 34 that drives drive shafts 35-37 and 39, a locking member 38 coupled to the drive shaft 35, a sensor 42 that detects a document on the feeder 28, a sensor 42 mounted to the drive shaft 39 The torque limiter 40 on the upper body, the rib 43a ( FIG. 9 ) formed on the base frame 43 and abutting against the locking member 38 , and the gears 44 and 54 - 60 .

When a user places one or more pages of a document on the feeder 28, the document depresses the sensor 42 so that the sensor 42 detects the document. A gear 54 coupled to the drive shaft 35 drives the feed roller 22 and locking member 38 in rotation (FIG. 9). A gear 56 coupled to the drive shaft 36 drives the transfer roller 23 (FIG. 5A) in rotation. The gear 60 is coupled to the drive shaft 37 and drives the discharge roller 25 in rotation.

The gears 55 - 59 are of double gear type and transmit the driving force of the drive motor 34 to the gears 54 , 56 and 60 . Gear 58 meshes with gears 57 and 59 . The gear 57 meshes with the gear 56 . Gear 59 meshes with gears 44 , 55 and 60 .

In the automatic mode in which the document feeding part 14 feeds the document to the image reading position 62, the driving motor 34 rotates in the direction shown by the hollow arrow F in FIG. move. Drive motor 34 drives gear 54 which in turn causes locking member 38 to rotate in the direction indicated by arrow L (FIG. 9). Thus, the locking member 38 unlocks the feeder 28, allowing the feeder 28 to rotate about the axis 28a in the direction indicated by the hollow arrow G (Fig. 6). The feeder 28 moves upward in the direction indicated by arrow K (FIG. 9).

In the manual mode in which the user manually places the document on the table 20, the drive motor 34 rotates in the direction indicated by the hollow arrow H in FIG. 8, so that the shutter 33 moves in the B direction. Since the locking member 38 locks the feeder 28, the feeder 28 rotates about the shaft 28c in the direction indicated by the hollow arrow I.

FIG. 10A is a perspective view illustrating the structure of the document pressure plate 21 used in the image reading device 13 .

FIG. 10B illustrates the shutter 33 viewed from the direction indicated by arrow M of FIG. 5B when the shutter 33 opens the window 101 .

FIG. 11 is a perspective view illustrating the structure of the document pressure plate 21 .

FIG. 12 is a perspective view illustrating the shutter 33 .

Referring to FIGS. 10A , 10B and 11 , the image reading device 13 includes a cover 41 that seals the platform 20 , and a document feeding mechanism composed of a transport roller 23 , an ejection roller 25 , a paper platen 27 and a transparent guide 61 . The cover 41 includes elongated holes 41a and 41b formed at opposing positions therein. The shutter 33 includes posts 33 a and 33 b ( FIG. 12 ) that are loosely fitted into elongated holes 41 a and 41 b , respectively, so that the shutter 33 can slide relative to the cover 41 . The shutter 33 may take the form of a white plastic plate or plate-like member to which a reflective white sheet is attached.

Referring back to FIGS. 6 and 8, when a torque greater than a predetermined value is applied to the torque limiter 40, the torque limiter 40 allows the gear 44 to rotate in an idle manner, thereby not transmitting the driving force from the gear 44 to the first and Second gears 32a and 32b. The predetermined value of the torque should be, for example, 300 g·cm, which is larger than a value sufficient to open and close the shutter 33 .

In the automatic mode, the shutter 33 is opened to open the window 101 as shown in FIGS. 10B and 11 . In the manual mode, the shutter 33 is closed, as shown in FIG. 10A , to close the window 101 .

FIG. 13 illustrates various positions of carriage 16 in platform scanner 15 . When the image reading operation is not started, the carriage 16 is in the position H, which is the initial position. In the automatic mode, when the user presses the start button to scan or copy a document, the carriage 16 is moved from the initial position H to a position E where the image reading section 105 reads the document passing the reading position 62 image of the document. In the manual mode, the image reading section 105 starts reading an image of a document at position B and stops reading at position C. Carriage 16 slows down and stops at position G after passing position C. As shown in FIG. The distance D between position C and position G is longer than the distance F between position B and position E.

{How the image forming system works}

{Operation Principle of Image Forming Device}

The operating principle of the image forming system 100 of the foregoing structure will be described below. First, the operating principle of the image forming apparatus 1 will be described.

A feed roller 3 feeds a printing medium (for example, paper) from a paper cassette 2 page by page. The printing medium is conveyed to the image forming unit 8 by conveying rollers 5 and 7, and the image forming unit 8 in turn transfers the toner images of the respective colors onto the printing medium. The printing medium with the toner image is then fed to the fixing section 9 . The print media passes through a fusing point where the toner image is fused with heat and pressure into a full-color image. Then, the printing medium is discharged to a discharge tray 12 by discharge rollers 10 and 11 . This completes the work of the image forming apparatus 1 .

{How the image reading device works}

{auto mode}

The working principle of the image reading device 13 will now be described. First, the working principle of the image reading device 13 in the automatic mode will be described.

FIG. 14 is a timing chart illustrating the operation of the image reading device 13 .

When the user places a document on the document feeding tray 17, the document slides on the document feeding tray 17 toward the sensor 42 and presses down the sensor 42, so that the sensor 42 detects the document (time t0). Subsequently, the user presses, for example, a start button (not shown) to order reading of an image of a document (time ts). Then, the drive motor 34 rotates in the direction indicated by the hollow arrow F in FIG. 6 . When a document is not placed on the document feeding tray 17 (ie, when the sensor 42 does not detect the document), it is determined that there is no document on the feeder 28 even if a command to read the document is given by the user. Thus, the drive motor 34 does not rotate.

When the drive motor 34 rotates in the F direction ( FIG. 6 ), the gears 44 , 54 - 59 and 60 rotate in the directions indicated by the arrows in FIG. 6 . The lock member 38 coupled to the drive shaft 35 rotates in the same direction as the gear 54 and then abuts against a rib 43 a ( FIG. 9 ) formed on the base frame 43 to stop. This disengages the locking member 38 from the feeder 28 , thereby unlocking the feeder 28 .

Since the first gear 32a and the second gear 32b mounted on the drive shaft 39 rotate simultaneously with the lock member 38, the shutter 33 slides in the N direction of FIG. 6 . When the posts 33a and 33b of the shutter 33 abut the lengthwise ends of the elongated holes 41a and 41b formed in the cover 41, respectively, a large load is applied to the drive shaft 39 so that the shutter 33 cannot move any further. As a result, the torque limiter 40 allows the gear 44 to rotate in an idle manner, so that the driving force is no longer transmitted from the gear 44 to the first gear 32a and the second gear 32b. Thus, the first and second gears 32a and 32b stop rotating. This causes the shutter 33 to stop sliding, and the shutter 33 opens the window 101 (time t1). Thus, the window 101 is exposed, as shown in FIG. 11 .

When the feeder 28 is unlocked, the force of the spring 29 pivots the feeder 28 about the axis 28a in the direction indicated by the hollow arrow G ( FIG. 6 ), thereby allowing the document to come into close contact with the feed roller 22 . Feed rollers 22 feed documents from document feed tray 17 to transport rollers 23 page by page. Subsequently, the transport roller 23 feeds the document to the image reading position 62 above the aperture 16b of the image reading portion 105 on standby, as shown in FIG. 4A. Then, the image reading section 105 starts reading of the document image (time t2). The paper presser 27 presses the document against the window 101 of the transparent guide 61 while allowing the document to pass through the image reading position 62 .

After the image of the document has been read, the transport roller 25 discharges the document onto the discharge tray 19 . In this way, the document is fed from the document feeding tray 17 to the image reading position 62, so that the image reading portion 105 reads the image of the document (time t2 to time t4).

When all the document pages have been fed from the document feeding tray 17, the sensor 42 returns to the position shown in FIG. 8 (the sensor 42 protrudes upward), and the detection output of the sensor 42 becomes "OFF" (time t3).

When the last page of the document has passed the image reading position, the reading of the document image is completed (time t4). Thereafter, the drive motor 34 rotates for a predetermined time, and then stops when the last page of the document has been ejected (time t5).

Then, the drive motor 34 stops rotating for a predetermined time, and then the drive motor 34 temporarily rotates in the opposite direction shown by the hollow arrow H ( FIG. 8 ) under the control of the program (timing t6 ). This causes gears 44, 54-59 and 60 to rotate in the direction indicated by the arrows in FIG. Then, the locking member 38 coupled to the drive shaft 35 rotates in the same direction as the gear 54, pushing the feeder 28 downward so that the feeder 28 pivots about the shaft 28a in the direction indicated by the hollow arrow I. This locks the feeder 28.

As the lock member 38 rotates, the first gear 32a and the second gear 32b fixed to the drive shaft 39 rotate simultaneously. As shown in FIG. 8, the shutter 33 slides in the B direction (FIG. 8) to close the window 101 of the transparent guide 61, as shown in FIG. 10A. Then, the drive motor 34 stops rotating (timing t7).

{manual mode}

The working principle of the image reading device 13 in the manual mode will be described below.

In manual mode, the document is placed on the platform 20 and thus is not detected by the sensor 42 . The shutter 33 remains in a position where the shutter 33 closes the window 101, as shown in Figures 5A, 8 and 10A.

When the user depresses, for example, a start button (not shown) to command reading of an image of a document, the carriage 16 moves at a constant speed in a direction indicated by an arrow C in FIG. 5A . The image reading section 105 moves together with the carriage 16 while reading an image of a document placed on the platform 20 .

The image data read by the image reading device 13 is sent to the image forming device 1, and the image forming device 1 starts image formation.

As described above, in the automatic mode, the image reading section 105 remains at the image reading position 62 and reads an image of a document. In the manual mode, the image reading sensor 105 moves across the image reading area A defined on the platform 20 . The image reading position 62 is within the image reading area A on the platform 20 . As a result, the overall size of the image reading device 13 can be small.

Furthermore, the shutter 33 opens and closes in an interlocking relationship with the drive motor 34 . This simple mechanism provides uniform reflection of light from the image side of the document, ensuring that the image reading section 105 accurately reads the image of the document.

{Modification of the first embodiment}

FIG. 15 illustrates a modification of the shutter 33 . The shutter 33 may be replaced by another shutter 433 shown in FIG. 15 . The shutter 433 corresponds to a structure in which the shutter 33 and the document presser 21 are made as a single piece. The shutter 433 moves in interlocking relationship with the drive motor 34 .

{second embodiment}

The document feeding section 14 of the second embodiment is different from the first embodiment in that a shutter 46 is employed. The same elements as those of the first embodiment are assigned the same reference numerals, and their descriptions are omitted. Descriptions of the same working principles and advantages as those of the first embodiment are also omitted.

FIG. 16A is a cross-sectional view illustrating the structure of the image reading device 13 of the second embodiment.

Fig. 16B is an expanded view of the relevant part of Fig. 16A.

FIG. 17 is a perspective view illustrating the structure of a driver portion of the image reading device 13 .

FIG. 18 is a perspective view illustrating the structure of the document pressure plate 21 .

19A is a first developed cross-sectional view illustrating a relevant part structure of the image reading device 13 when the colorless transparent region 46a of the shutter 46 is located at the image reading position 62 ( FIG. 16B ) in the automatic mode.

Fig. 19B is a perspective view of the shutter shown in Fig. 19A viewed from the direction indicated by the arrow P in Fig. 19A, when the shutter opens the window.

20 is a second developed sectional view illustrating a relevant part structure of the image reading device 13 when the transparent region 46a of the shutter 46 is away from the image reading position 62 in the manual mode.

The shutters 46 are formed of a flexible material, and are respectively fixed at lengthwise ends thereof to drive shafts 45 and 47 rotatably mounted to the base frame 43 . The shutter 46 is wound around the drive shafts 45 and 47 . Referring to FIG. 16A , the drive shaft 45 is provided downstream of the paper presser 27 in the document traveling direction, and the drive shaft 47 is provided upstream of the paper presser 27 . The paper presser 27 and drive shafts 45 and 47 extend in a direction substantially perpendicular to the direction in which the document travels. Gears 49 and 51 are attached to lengthwise ends of drive shafts 45 and 47 .

The shutter 46 is kept tensioned, extending horizontally below the paper presser 27 to face the entire lower surface of the paper presser 27 . When the drive shafts 45 and 47 rotate, the shutter 46 travels in the direction indicated by arrow D or arrow E in FIGS. 17 , 19A and 20 , depending on the direction of rotation of the drive shafts 45 and 47 . The drive shafts 45 and 47 have the same diameter and the gears 49 and 51 have the same number of teeth so that the shutter 46 can advance smoothly relative to the paper platen 27 without applying uneven pressure on the shutter 46 .

The shutter 46 is formed of a white sheet material having sufficient flexibility and elasticity. The transparent area 46a of the shutter 46 serves as a "window" through which the image reading section 105 reads the image of the document. Depending on whether the image reading device 13 is working in an automatic mode or in a manual mode, the shutter 46 is advanced in the direction shown by arrow D or E (Figs. 17, 19A and 20), so that the transparent area 46a of the shutter 46 moves along The upper surface of the platform 20 moves horizontally.

In the automatic mode in which the document feeding section 14 feeds the document to the image reading position 62, as shown in FIG. The device 27 and the image reading section 105 are aligned with each other, as shown in FIG. 16B. It should be noted that the image reading position 62 is within the image reading area defined on the platform 20 . The image reading section 105 reads an image of a document moving past the image reading position, the image being read through the transparent guide 61, the stage 20, and the transparent area 46a. The document is conveyed through a narrow gap between the transparent guide 61 and the paper platen 27 after passing through the image reading position 62 . Spring 26 urges paper presser 27 toward transparent area 46a, which presses the document against transparent guide 61 while allowing the document to pass through the gap.

In the manual mode in which the user places a document on the platform 20 , the shutter 46 moves to a position on the right side of the image reading position 62 . In other words, the transparent area 46 a is no longer between the platform 20 and the transparent guide 61 , but behind the document platen 21 , as shown in FIG. 18 .

Referring to Figures 17, 19A, 19B and 20, rollers 48 and 53 are mounted to the base frame 43 and are rotatable about their axes of rotation in an idle manner. The rollers 48 and 53 facilitate smooth movement of the shutter 46 in the D and E directions and prevent damage and contamination of the shutter 46 .

Referring to Fig. 18, torque limiters 50 and 52 are mounted to drive shafts 45 and 47, respectively. When a torque greater than a predetermined value is applied to the drive shafts 45 and 47, torque limiters 50 and 52 allow idle running of gears 49 and 51, which are mounted to the shafts 45 and 47, respectively. The predetermined value of the torque should be greater than the torque sufficient to move the shutter 46, and is chosen to be, for example, 300 g·cm.

The rest of the structure is the same as the first embodiment and its description is omitted.

{How the image reading device works}

{auto mode}

The operating principle of the image reading device 13 of the second embodiment will be described below. First, the operating principle of the image reading device 13 in the automatic mode will be described.

Referring to FIG. 17, when a document is placed on the document feeding tray 17, the document is pressed against the sensor 42 so that the sensor 42 detects the document. Subsequently, the user commands to read the image of the document, and then the drive motor 34 is rotated in the direction indicated by the arrow J. FIG. When there is no document on the document feeding tray 17, the drive motor 34 does not rotate even if the user commands to read the image of the document.

The drive motor 34 drives the gears 49, 51, and 54-60 to rotate in directions indicated by arrows in FIG. 17, respectively. The lock member 38 coupled to the drive shaft 35 rotates in the same direction as the gear 54 until the lock member 38 abuts against the rib 43a formed on the base frame 43 to stop ( FIG. 9 ). Thus, the locking member 38 is disengaged from the feeder 28 , thereby unlocking the feeder 28 .

When the lock member 38 is rotated, the drive shafts 45 and 47 are rotated in the same direction as the lock member 38, so that the shutter 46 is advanced in the direction indicated by the arrow D shown in FIGS. 17, 19A and 20 . When the transparent area 46a reaches the image reading position 62 shown in FIGS. 16B and 18, the shutter 46 has been completely wound and cannot be advanced in the same direction. Therefore, the shutter 46 cannot be advanced in the D direction, and tension is maintained between the drive shafts 45 and 47 . As the load is applied to the drive shafts 45 and 47, the torque limiters 50 and 52 cause the gears 49 and 51 to rotate in an idle manner and the valve 46 remains taut.

Once the feeder 28 is unlocked, the force of the spring 29 causes the feeder 28 to rotate about the shaft 28 a so that the document comes into close contact with the feed roller 22 . Feed rollers 22 feed documents page by page from document feed tray 17 toward transport rollers 23 . The transport roller 23 further feeds the document to the image reading position 62 (FIG. 16B). The document presser 27 presses the document against the transparent guide 61 so that the image reading section 105 reads an image of the document.

Once the reading of the document image has been completed, the drive motor 34 is temporarily rotated in the direction opposite to the J direction (FIG. 17) under the control of the control program. Accordingly, the drive shafts 45 and 47 rotate in opposite directions, so that the shutter 46 advances in the direction E shown in FIGS. 17, 19A and 20 . Thus, the transparent area 46a is away from the image reading position 62, preventing the image reading portion 105 from reading the document.

{manual mode}

The working principle of the image reading device 13 in the manual mode will be described below. In the manual mode, the user places the document on the platform 20 to read the image of the document.

When a user places a document on the platform 20, the sensor 42 does not detect the document and the shutter 46 is closed.

In response to a user's command, the carriage 16 runs at a constant speed on the guide rail 16a relative to the document. The image reading section 105 mounted on the carriage 16 moves together with the carriage 16 while reading an image of a document standing by on the platform 20 .

The rest of the structure works in the same manner as the first embodiment, and its description is omitted.

As described above, the second embodiment employs the flap shutter 46 instead of the shutter 33 of the first embodiment. The shutter 46 moves so that the transparent area 46 a moves to or out of the gap between the image reading portion 105 at the reading position 62 and the transparent guide 61 . When the shutter 46 having a small thickness is used, the image reading portion 105 can be brought closer to the document than when the shutter 33 having a large thickness is used.

third embodiment

The same elements as those of the first embodiment are assigned the same reference numerals, and their descriptions are omitted. Descriptions of the same working principles and advantages as those of the first embodiment are also omitted.

Fig. 21A is a sectional side view illustrating a relevant part of the image reading device 13 in the automatic mode. FIG. 21B is a partially enlarged view illustrating the position of the document pressure plate 129 in the manual mode. FIG. 21C is a partial enlarged view illustrating the position of the document pressure plate 129 in the automatic mode.

Referring to FIG. 21A , the flatbed scanner 15 further includes a sensor 200 that detects the position of the document presser 129 , a stopper 202 that abuts the document presser 129 , and a spring 201 that urges the document presser 129 toward the stopper 202 .

The flatbed scanner 15 includes a document support plate or flatbed 20 (for example, a glass plate) on which an image reading area A ( FIG. 24 ) is defined, a document pressing plate 129 , and a scanning mechanism or a scanning mechanism on which the image reading section 105 is mounted. Bracket 16. The document press plate 129 is rectangular and has approximately the same shape and area as the image reading area A. As shown in FIG.

A reflective white sheet 129a is attached to the document pressing plate 129 and extends across the entire image reading area A to press the document against the platform 20 in the manual mode. The reflective white sheet 129a extends to cover a portion of the image forming area A other than the reading position 62 where the image reading device reads an image of a document in the automatic mode.

The sensor 200 includes a lever 200 a that engages the document pressure plate 129 to detect the position of the document pressure plate 129 . The spring 201 always urges the document pressing plate 129 toward the stopper 202 so that the document pressing plate 129 abuts against the stopper 202 in the manual mode. In position P, the lever 200a causes the sensor 200 to output an "on" signal, indicating that the document pressure plate 129 abuts against the stopper 202 and is in standby. Thus, the controller (not shown) will not allow the image reading device 13 to operate in automatic mode. Upon receiving the "on" signal from the sensor 200, the controller sends a command to the carriage 16 to move toward point B shown in FIG. Image.

At position Q, the lever 200 a causes the sensor 200 to output a “closed” signal indicating that the document platen 129 is away from the stopper 202 . Thus, a controller (not shown) allows the image reading device 13 to operate in an automatic mode.

FIG. 22 is a perspective view illustrating the structure of the document pressure plate 129 for the image reading apparatus in the manual mode.

FIG. 23 illustrates the position of the operation lever 141 protruding from the document pressure plate 129 .

FIG. 24 shows various positions of the carriage 16 in the platform scanner 15. As shown in FIG.

As shown in FIGS. 22 and 23, the operating lever 141 extends to the outside of the cover 41 which seals the platform 20 and the document feeding mechanism through an opening 142 formed in the discharge tray 19 (FIG. 24). The discharge tray 19 includes a protrusion 145 having a sloped surface 143 defining a portion of the opening 142 and a stopper surface 144 . The operating lever 141 is movable in the opening 142 , and the spring 201 biases the document pressing plate 129 toward the stopper 202 . Pulling the lever 141 away from the detent 202 causes the lever 141 to climb up the ramped surface 143 and then drop into the opening 146 to engage the detent surface 144 . When the operating lever 141 falls into the opening 146, the document presser 129 is positioned so that the image reading device 13 is ready for operation in the automatic mode. The operating lever 141 , the opening 142 , the inclined surface 143 , the stopper surface 144 , the protrusion 145 and the opening 146 constitute a selection mechanism.

When a user places one or more pages of a document on the feeder 28, the document depresses the sensor 42 (FIG. 21A), which in turn detects the document. In the automatic mode, upon receiving a detection signal from the sensor 42, the carriage 16 moves from the position H shown in FIG. image of the document. It should be noted that the image reading position 62 is within the image reading area A defined on the stage 20 .

In the manual mode, the user operates the operating lever 141 to disengage the operating lever 141 from the stopper surface 144 so that the spring 201 pulls the document pressure plate 129 toward the stopper 202 .

Thus, the document pressure plate 129 remains in abutting engagement with the stopper 202 . Thus, the lever 200a is at position P ( FIGS. 21A , 21B ), and the reflective white sheet 129a is located between the image reading position 62 and the image reading portion 105 . In response to the output of sensor 200 , a controller (not shown) causes carriage 16 to move from position H to position B where image reading device 13 waits for a user command to read a document on platform 20 .

When the user places a document in the image reading area A defined on the platform 20 , the controller controls the carriage 16 to move from point B across the image reading area A to point C. After reaching point C, carriage 16 advances further towards point G while decelerating. Thereafter, the controller controls the carriage 16 to return to the initial position H. As shown in FIG. This completes reading of the document page image.

Table 1 shows the relationship between the outputs of the sensors 200 and 203 and the work for reading the document image.

Table 1

Sensor 200 "close" "close" "open" "open" Sensor 203 "open" "close" "open" "close" image reading Automatic mode No image read Manual mode Manual mode

When the sensor 200 outputs an "on" signal, the image reading apparatus is ready for image reading in the manual mode. When the sensor 200 outputs an "off" signal and the sensor 203 outputs an "on" signal, the image reading apparatus is ready for image reading in the automatic mode.

In the third embodiment, the image reading position 62 in the automatic mode (ie, the position E shown in FIG. 24 ) is defined within the image reading area A in the manual mode. This makes the overall size of the scanner smaller. The position of the document platen 21 can be manually set to provide uniform light reflection with a simple mechanism.

While the invention has been described above, it will be obvious that the invention can be varied in many ways. Such variations are not to be regarded as a departure from the scope of the invention, and it is obvious to a person skilled in the art that all such variations are included within the scope of the claims.

Claims (10)

1. An image reading device, comprising: an image reading part (105), the image reading part (105) reads an image of a document; a scanning mechanism (16), which moves the image reading part (105) relative to the document when the document is on standby; a document feeding mechanism (23, 27, 61), which moves the document relative to the image reading part (105) when the image reading part (105) is on standby; A light-transmitting plate (20), on which the document stands by when the image reading part moves relative to the document, and the light-transmitting plate (20) is located in the document feeding mechanism (23, 27, 61) in the plane between the image reading part (105), and The shutter (33, 46, 129) is located in the plane between the document feeding mechanism (23, 27, 61) and the light-transmitting plate (20), when the document is relative to the standby image reading part (105 ) moves, the shutter (33, 46, 129) can move to the first position, and the shutter (33, 46, 129) opens the window (101) in the first position, allowing the image reading part (105) The image of the document is read through the window (101); when the document is on standby on the light-transmitting plate (20) and the image reading part (105) moves relative to the document on standby, the shutters (33, 46, 129 ) can be moved to a second position, in which the shutter (33, 46, 129) closes the window and does not allow the image reading part (105) to read the image of the document through the window (101), but The image reading part (105) can directly read the image of the document through the transparent plate (20). 2. The image reading device according to claim 1, characterized in that, the document feeding mechanism (23, 27, 61) comprises a driving motor (34), and Wherein the shutter (33, 46) moves towards the first position or the second position in an interlocking relationship with the drive motor (34). 3. The image reading device according to claim 2, characterized in that the shutter (33) is formed of a sheet material. 4. The image reading device according to claim 2, characterized in that the shutter (46) is formed of a flexible sheet material. 5. The image reading device according to claim 1, characterized in that, when the document is on standby in the image reading area, the scanning mechanism (16) makes the image reading part (105) move within the region relative to the document; and Wherein, when the document moves relative to the image reading section (105) on standby, the image reading section (105) is positioned within the image reading area. 6. The image reading device according to claim 5, further comprising a document support member (20), the image reading area (A) being defined on the document support member (20); and Wherein, the shutter (129, 433) extends to cover at least the image reading area (A) and presses the document against the document supporting member (20); Wherein, when the image reading device (13) operates in a mode in which the document is on standby and the image reading section (105) moves relative to the document to read the image of the document, the document is placed in the image reading Take the area (A). 7. The image reading device according to claim 6, wherein the mode is the first mode, and the image reading device further comprises a selection mechanism (141-146), and the selection mechanism (141-146 ) selects whether the image reading device operates in the first mode or in a second mode in which a document moves relative to the image reading section (105) on standby, and the The image reading part (105) reads the image of the document through the window. 8. The image reading apparatus according to claim 6, wherein the document feeding mechanism includes a drive motor and the shutter (129, 433) serves as a document pressing plate that presses the document against the document supporting member , Wherein the document pressing plate (129, 433) moves toward the first position or the second position in an interlocking relationship with the driving motor (34). 9. An image forming apparatus equipped with the image reading apparatus according to claim 1, and printing a document image on a printing medium, the document image being read by the image reading apparatus. 10. An image forming system comprising the image forming apparatus according to claim 9.

Images