JP7634358B2 - Image reader - Google Patents

Description

The present invention relates to an image reading device for reading images of documents, such as sheets of paper or booklets.

For example, the image reading devices of this type are described in Patent Documents 1 and 2. The image reading devices described in these patent documents include an image reading device main body on which a document is placed and an image of the document is read, and a cover body that is provided on the image reading device main body and that holds the document.

In the image reading device of Patent Document 1, the cover is supported on the scanner body via a hinge so that it can swing freely. A document pressing member for pressing down the document is fixed to the cover. In Patent Document 2, an automatic document feeder (ADF) is attached to the cover, and an impact mitigation member is provided to prevent a loud impact sound from being generated when the cover collides with the lower housing when closed.

JP 2004-282561 A JP 2016-208186 A

In Patent Document 1, when resistance to the rotation occurs due to deterioration of the hinge over time or wear of the rotating shaft, and the cover body tends to float away from the position where it presses the document, the document pressing member is fixed to the cover body, so the document cannot be pressed evenly.

In addition, in Patent Document 2, when the lid approaches the position where it holds down the document, a load is applied to the rotation by the shock absorbing member, causing the lid to float away from the position where it holds down the document. As in Patent Document 1, the document pressing member is fixed to the lid, so it may not be possible to press the document evenly. If the document cannot be pressed evenly, the image quality of the image obtained by scanning will deteriorate.

The present invention provides an image reading device that can adequately press the document even if the document holder is not completely closed and is raised above the pressing position.

In view of the above, the image reading device according to the present invention comprises:
a housing having an original placement table on an upper surface thereof, on which an original is placed;
an image reading means for reading an original placed on the original placement table;
a document pressing unit that can be opened and closed between a pressing position for pressing the document placed on the document placement table and an opening position for opening the document placement table;
a hinge that rotatably connects the document holder to the housing,
the document pressing section has a document pressing section main body and a document contact section that contacts the document,
the document contact portion is movable in conjunction with the document pressing portion main body and is capable of protruding from the document pressing portion main body toward the document placing table,
the document contact portion is provided with a locking portion that engages with a locked portion provided on the document pressing portion main body ,
The locked portion is disposed at a position facing the hinge of the document pressing portion main body, and the locking portion is disposed at a position facing the hinge of the document contact portion .

According to the present invention, even if the document pressing portion is lifted from the position where the document is pressed, the document can be pressed appropriately.

1 is a schematic diagram of an image reading apparatus according to an embodiment of the present invention; 1 is a top view of an image reading apparatus according to an embodiment of the present invention; FIG. 4 is another top view of the image reading apparatus according to the embodiment of the present invention. FIG. 2 is a block diagram of a control unit of the image reading apparatus. FIG. 4 is another side view of the image reading apparatus according to the embodiment of the present invention. FIG. 4 is another rear view of the image reading apparatus according to the embodiment of the present invention. 4A and 4B are another top view and a schematic cross-sectional view of the image reading apparatus according to the embodiment of the present invention. 1 is a schematic diagram of an image reading apparatus according to an embodiment of the present invention; 1 is a schematic diagram of an image reading apparatus according to an embodiment of the present invention; FIG. 2 is a cross-sectional view of a hinge 30 according to an embodiment of the present invention. FIG. 4 is a cross-sectional view of another aspect of the hinge 30 according to an embodiment of the present invention. 4A and 4B are another schematic cross-sectional view and a detailed view of a main part of the image reading device according to the embodiment of the present invention; 4A and 4B are another schematic cross-sectional view and a detailed view of a main part of the image reading device according to the embodiment of the present invention; 1 is a schematic cross-sectional view of an image reading apparatus according to an embodiment of the present invention.

A preferred embodiment of the present invention will be described in detail below with reference to the drawings.

Figure 1 is a perspective view of one embodiment of a flatbed scanner as an example of an image reading device of the present invention.

As shown in FIG. 1, the flatbed scanner 1 of this embodiment is a device in which an original D is placed on a glass original placement table 11 provided on the upper part of the lower housing 60, the original D is covered with an original pressing unit 20, and a carriage (including an image reading sensor 41 such as a CCD [Charge Coupled Device] or a CIS (Contact Image Sensor), which is an example of an image reading means) 40 (see FIG. 3) provided in the lower housing 60 of the flatbed scanner 1 is scanned in the direction of the arrow y to read an image of the original D.

In this embodiment, the document holder 20, which can be opened and closed relative to the lower housing 60 of the flatbed scanner 1, is attached to the end of the lower housing 60 so as to be rotatable about an axis parallel to the longitudinal direction of the lower housing 60 on the xy plane.

The document holder 20 is a member that covers the document placement table 11 and the document D placed on the document placement table 11.

In the flatbed scanner 1 according to this embodiment, the lower housing 60, the document pressing section 20, the hinge 30 (see FIG. 8), the upper cover 12 (see FIG. 3), the carriage 40 (see FIG. 7), the carriage lock member 65 (see FIG. 5), and the shafts 42a and 42b (see FIG. 7) are made of metal, and the ground path for static electricity can be shortened, so that it is possible to prevent static electricity from discharging to the board or the like along the path and causing destruction. In addition, metal parts that are not connected to the ground can be a source of noise, but since there are metal parts connected to the ground around it, it is possible to connect to the ground with the minimum number of parts required. In this embodiment, iron is used as the metal, but this is not limited to this, and stainless steel, aluminum, copper, etc. can also be used.

Figure 2 is a top view of the flatbed scanner 1 according to this embodiment. The flatbed scanner 1 has an operation unit 50 provided adjacent to the document holder 20 at the end opposite the hinge 30 during rotation of the document holder 20 (the radial tip end during rotation).

The operation unit 50 is composed of a scan start button 51, a scan stop button 52, and a power button 53. When the scan start button 51 is pressed, the carriage 40 moves in the sub-scanning direction (y direction) while the image reading sensor 41 scans in the main scanning direction, thereby starting image reading of the document D on the document placement table 11. Note that, for the start of scanning, the application side operating on the information processing device connected to the flatbed scanner 1 may transmit a scan setting and a scan start instruction at the same time, or these may be combined. In other words, when the application of the information processing device detects that the scan start button 51 has been pressed on the flatbed scanner 1, the information processing device may transmit the scan setting and the scan start instruction again to the flatbed scanner 1, and scanning may be performed. Furthermore, the information processing device connected to the flatbed scanner 1 may be located in a remote location via a network, and the connection method is not limited to wired, but may be wireless.

Figure 3 is a top view of the flatbed scanner 1 according to this embodiment. Figure 3(a) shows the flatbed scanner 1 with the top cover 12 and document tray 11 attached, and Figure 3(b) shows the flatbed scanner 1 with the top cover 12 and document tray 11 removed.

As shown in FIG. 3(b), a control board 63 is disposed on the bottom surface of the flatbed scanner 1.

The control board 63 is connected to the image reading sensor 41 by a connection cable (connection means) 64. The connection cable 64 is composed of a flexible flat cable (FFC) or the like. A scan start signal based on pressing the scan start button 51 is sent to the control unit (control means) 68 (see FIG. 4) mounted on the control board 63. FIG. 4 shows a control block diagram of the flatbed scanner 1. When a scan start signal is sent from an external information processing device to the control unit 68 via a communication unit, the control unit 68 sends a control signal to the image reading sensor 41 via the connection cable 64, which is an example of an interface unit, based on the set scan setting, and simultaneously sends a control signal to the drive means 69 of the carriage 40, thereby executing the image reading operation of the original D. The control signal to the drive means 69 may be sent via the connection cable 64, but in this embodiment, since the drive means 69 is provided separately from the carriage 40, a separate cable is used. The control unit 68 performs general drive control of the image reading sensor 41 and the carriage 40 in addition to starting the scan, and is composed of a CPU and an ASIC, for example.

One end of the connection cable 64 is connected to the image reading sensor 41, and the other end is connected to a connector (not shown) provided on the control board 63.

Figure 5 is a side view of the flatbed scanner 1 according to this embodiment. A carriage lock member 65 is provided on the lower housing 60 to restrict movement of the carriage 40 in the scanning direction (y direction). This carriage lock member 65 is provided slidably on the lower housing 60, and the movement of the carriage 40 is restricted by sliding the carriage lock member 65 to a fixed position. Restricting the movement of the carriage 40 prevents the carriage 40 from moving inside the lower housing 60 when, for example, the flatbed scanner 1 is moved, which would cause unnecessary load to be applied. Sliding the carriage lock member 65 to the release position releases the restriction on the movement of the carriage 40.

Figure 6 is a rear view of the flatbed scanner 1 according to this embodiment. A power cable that supplies power to the power supply board is connected to the power supply board via a power cable connector 71, and power is supplied to the device. In addition, a communication cable for connecting an information processing device that transmits the scanned image of the document D acquired by the flatbed scanner 1 and receives the scanning settings is connected to the control board 63 via a communication cable connector 72. A USB cable or the like is used as the communication cable. In this embodiment, the control board 63 and the power supply board are configured as a common board.

Figure 7 is a top view of an image reading device according to one embodiment of the present invention. A cross section taken along line A-A in Figure 7(a) is shown in Figure 7(b). A shaft 42a extending from one end to the other end of the lower housing 60 is inserted into an engagement hole member 43 provided in the lower part of the carriage 40, and the movement of the carriage 40 is achieved by controlling a belt that engages with an engagement portion provided on the carriage 40, which is an example of a drive means 69, using a control board 63. Note that in this embodiment, a belt and a motor that drives the belt are used as the drive means 69, but the drive means 69 is not limited to this and may be a motor and a lead screw, and various modifications are possible.

The engagement hole member 43 is formed in a cylindrical shape having a predetermined length in the y direction with respect to the shaft 42a. In this embodiment, the shaft 42b extending from one end side to the other end side of the lower housing 60 is inserted at a position opposite the shaft 42a with respect to the center in the x direction, thereby supporting the movement of the carriage 40, and a belt for driving the carriage 40 is provided at a position outside of the shaft 42b (outside in the x direction). The belt is provided on the shaft 42a side, which prevents the carriage 40 from tilting and moving when the driving force of the belt is transmitted to the engagement hole member 43. That is, the carriage 40 is stably supported by supporting one end side with the shaft 42a at a predetermined distance from the side wall of the lower housing 60 and supporting the other end side with the shaft 42b at a predetermined distance from the side wall of the lower housing 60 with respect to the center of the carriage 40 in the x direction, and the belt provided on the shaft 42a side prevents the carriage 40 from tilting during movement when the carriage 40 is driven.

<Document holder configuration>
Fig. 8 is a schematic diagram of an image reading device according to an embodiment of the present invention. As shown in Fig. 8, the document holder 20 is rotatably attached to the lower housing 60 via a hinge 30. A pair of hinges 30 are attached to the rear end of the document holder 20 and are spaced apart in the y direction. Both hinges 30 have the same configuration.

Figure 9 is an enlarged view of the hinge 30. Figure 9(a) shows the state in which the fixed part 31 is attached to the hinge 30, and Figure 9(b) shows the state in which the fixed part 31 is removed from the hinge 30. The hinge 30 extends in the z direction and has the fixed part 31 that is inserted and fixed to the lower housing 60, and the rotating part 33 that is movably connected to the fixed part 31 via the hinge shaft 32.

The document holder 20 also has a rotary damper 34 to reduce the impact caused by a collision with the document placement table 11 when the document holder 20 moves in the closing direction. The rotating part 33 has racks 35a, 35b through which the hinge shaft 32 passes, and meshes with pinions 36a, 36b arranged on both sides of the rotary damper shaft 37 that passes through the rotary damper 34, and a force is applied to reduce the impact when the document holder 20 moves in the closing direction.

In addition, one of the racks 35a and 35b is fixed to the rotating part 33, while the other is fixed by a stepped screw or the like so that it can rotate a small amount around the axis of the hinge shaft 32. With this configuration, even if there is a phase difference between the gears on both sides of the rotary damper 34 due to tolerances or installation errors, one side can rotate a small amount, so the rotational movement of the document pressing part 20 becomes smooth and the load can be applied evenly to the rotary damper shaft 37.

The configuration for transmitting the drive from the rotating unit 33 to the rotary damper 34 may be a pair of rack 35a and pinion 36a, but in this embodiment, racks 35a, 35b and pinions 36a, 36b are arranged on both sides of the rotary damper 34. By arranging them on both sides of the rotary damper 34, the load applied to the rotary damper shaft 37 when the document pressing unit 20 rotates can be made equal on the left and right.

With a pair of drives, the document holder 20 tilts to one side when it rotates, and a large load is placed on the connecting part on one side (for example, the rack 35a and pinion 36a). By arranging them on both sides, wear on the racks 35a, 35b and the pinions 36a, 36b, and wear on the rotary damper shaft 37 can be reduced.

Which of the racks 35a and 35b is fixed to the rotating part 33 for each of the left and right hinges 30 and which one is allowed to rotate only a small amount can be changed as needed, but aligning them on the outside or inside of the housing 60 in the y direction makes it easier to balance the load on each part and reduces the wear mentioned above. For example, when aligned on the outside, one hinge will have 35a fixed and the other will have 35b fixed. However, in order to make the hinges 30 a common part for the left and right sides, the part to which the racks 35a and 35b are fixed may be the same.

In this embodiment, the rack 35a or 35b is configured to be able to rotate a small amount around the axis of the hinge shaft 32, but the same effect can be obtained by configuring either the pinion 36a or the pinion 36b to be able to rotate a small amount around the axis of the rotary damper shaft 37.

In this embodiment, the torque load applied to the rotary damper 34 is configured to act only in the direction in which the document holder 20 closes, but the torque load may also be applied in the direction in which the document holder 20 opens.

Figure 10 shows a cross-sectional view of the hinge 30 in a plane (xz plane) perpendicular to the rotary damper shaft 37. In Figure 10, (a) corresponds to the open position of the document holder 20, (b) corresponds to the 45° closed position, and (c) corresponds to the pressing position (90° closed position). As shown in Figure 10, in this embodiment, the teeth of the racks 35a and 35b mesh with the pinions 36a and 36b at all positions during the opening and closing operation of the document holder 20.

At this time, when the document holder 20 is located between (a) and (b), the torque load applied to the rotary damper 34 by the weight of the document holder 20 is below the limit value of the rotary damper 34, so the document holder 20 is stopped at this position.

On the other hand, when the document holder 20 is located between (b) and (c), the torque load applied to the rotary damper 34 by the weight of the document holder 20 exceeds the limit value of the rotary damper 34, so the document holder 20 moves toward the pressing position (c) while being decelerated by the rotary damper 34. In this way, by appropriately setting the limit value, it is possible to adjust the angle at which the document holder 20 can be stopped.

Also, FIG. 11 shows another embodiment of the pinions 36a and 36b. In FIG. 11, (a) corresponds to the open position of the document pressing unit 20, (b) corresponds to the 45° closed position, and (c) corresponds to the pressing position (90° closed position). In this embodiment, the gears of the racks 35a and 35b and the pinions 36a and 36b are configured to mesh only near the pressing position and near the open position of the document pressing unit 20. With this configuration, the rotary damper 34 can be operated only near the open position and near the pressing position of the document pressing unit 20, and the document pressing unit 20 can be opened and closed smoothly in the state between them. However, this is not limited to this, and the document pressing unit 20 may be configured so that the racks 35a and 35b and the pinions 36a and 36b mesh only at desired positions between the open position and the pressing position.

In addition, in this embodiment, the gear teeth of the rack 35 and the pinion 36 are configured with multiple teeth, but the drive may be transmitted to the rotary damper 34 with a single tooth or an equivalent configuration. In other words, the rotary damper 34 may be operated by providing a protrusion on the rack 35 and another protrusion on the pinion 36 against which the protrusion can abut.

With the above-described configuration, this embodiment can mitigate the impact caused by a collision between the document placement table 11 and the document pressing unit 20 with a simpler configuration than the conventional slider that is slidable in a direction perpendicular to the axial direction of the hinge shaft, a cam portion that abuts against the slider, and a force that biases the slider toward the cam portion.

<Configuration of Document Contact Section>
Fig. 12(a) is a cross-sectional view taken along line B-B in Fig. 8, and Fig. 12(b) shows an enlarged view of the frame portion of Fig. 12(a). The document pressing unit 20 is composed of a document pressing unit main body 21 and a document abutment unit 22. In Fig. 12(a), the document pressing unit main body 21 and the document abutment unit 22 can rotate about a hinge shaft 32 between a pressing position where the document is pressed and an open position where the document placement table 11 is opened, and the document abutment unit 22 can rotate relatively to the document pressing unit main body 21. The document pressing unit main body 21 has an opening having an engagement unit 21a, and the document abutment unit 22 has an engaged unit 22a. The locking portion 21a is movable within the opening in which the locked portion 22a is provided, and by engaging (contacting) with the locked portion 22a provided at the end of the opening, the document contact portion 22 is rotatable a predetermined amount relative to the document pressing portion main body 21 and is prevented from coming off the document pressing portion main body 21. Figure 12(c) shows a state in which the document contact portion 22 protrudes toward the negative side in the z direction relative to the document pressing portion main body 21.

The rotation axis of the document contact part 22 does not have to be the hinge axis 32, but may be a separate axis dedicated to the document contact part 22, or a common axis with other components, and the document contact part 22 may rotate around that axis. In either case, the document contact part 22 also moves (rotates) in conjunction with the movement of the document pressing part main body 21 between the pressing position and the release position.

To prevent impact noise when the document contact portion 22 comes into contact with the document pressing portion main body 21, it is preferable to provide a cushioning material 25 such as sponge or rubber on either the document contact portion 22 or the document pressing portion main body 21, or both. As an example, it may be provided on either one of the contact points between the locking portion 21a and the locked portion 22a, as long as it is provided so as to be sandwiched between the two when the document contact portion 22 comes into contact with the document pressing portion main body 21.

<If the document holder is not lifted from the pressing position>
13A is a cross-sectional view of the entire flatbed scanner 1, and FIG. 13B is an enlarged view of the frame of FIG. 13A. The state in which the document D is pressed evenly by the document pressing unit 20 is shown. In order to press the document D placed on the document placing table 11, an elastic member 23 and a background plate sheet 24 are provided on the lower surface of the document contacting unit 22. The elastic member 23 may be a rubber or sponge member. The background plate sheet 24 is formed in a rectangular shape substantially the same as the document placing table 11. The color of the background plate sheet 24 may be selected from white, black, and the like as required. When the document pressing unit 20 moves to the pressing position shown in FIG. 11, the background plate sheet 24 can press the document D evenly. At this time, the document contacting unit 22 is in a storage position stored in the document pressing unit main body 21.

Even if the document D is a thick document or a booklet that is open, the document contact portion 22 can be rotated to the opposite side from the document placement table 11 and positioned in a retracted storage position within the document pressing portion main body 21, so that the document D can be pressed evenly.

<If the document holder is not pressed down>
Fig. 14(a) shows an enlarged cross-sectional view corresponding to Fig. 13(b) in a state in which the document pressing unit 20 is floating from the pressing position, and Fig. 14(b) is an explanation showing the operation of the document contact unit 22 at that time. When the document pressing unit 20 is not completely closed and floats from the pressing position as shown in Fig. 14(a), the document contact unit 22 can rotate about the hinge shaft 32 with respect to the document pressing unit main body 21 to a protruding position protruding toward the document placing table 11 side. As shown in Fig. 14(b), the document contact unit 22 protrudes toward the document placing table 11 side with respect to the document pressing unit main body 21, so that the document D can be uniformly pressed.

In addition, to assist the protrusion of the document contact portion 22, it is advisable to provide a biasing member such as a spring or elastic material in the document pressing portion 20.

Furthermore, in each of the above-described embodiments, a flatbed scanner has been described as an example of an image reading device, but the present invention is of course not limited to this, and the present invention may be applied to devices equipped with an image reading device (image reading means), such as various processing devices such as copiers and multifunction devices.

D Document 1 Scanner body 11 Document placement platform 12 Upper cover 20 Document pressing section 21 Document pressing section body 21a Locked section 22 Document abutment section 22a Locking section 23 Elastic member 24 Background plate sheet 25 Cushioning material 30 Hinge 31 Fixed section 32 Hinge shaft 33 Rotating section 34 Rotary damper 35a, 35b Rack 36a, 36b Pinion 37 Rotary damper shaft 40 Carriage 41 Image reading sensor 42a, 42b Shaft 43 Engagement hole member 50 Operation section 51 Scan start button 52 Scan stop button 53 Power button 60 Lower housing 63 Control board 64 Connection cable 65 Carriage lock member 68 Control section 69 Driving means 71 Power cable connector 72 Communication cable connector

Claims (5)

a housing having an original placement table on an upper surface thereof, on which an original is placed;
an image reading means for reading an original placed on the original placement table;
a document pressing unit that can be opened and closed between a pressing position for pressing the document placed on the document placement table and an opening position for opening the document placement table;
a hinge that rotatably connects the document holder to the housing,
the document pressing section has a document pressing section main body and a document contact section that contacts the document,
the document contact portion is movable in conjunction with the document pressing portion main body and is capable of protruding from the document pressing portion main body toward the document placing table,
the document contact portion is provided with a locking portion that engages with a locked portion provided on the document pressing portion main body ,
an original pressing portion disposed on a main body of the original pressing portion so as to face the hinge; and an original contact portion disposed on the main body of the original pressing portion so as to face the hinge . The image reading device according to claim 1, characterized in that the movement of the document contact part within the document pressing part body is restricted by the engagement of the locking part with the locked part. The image reading device according to claim 1 or 2, characterized in that the document contact part moves in conjunction with the document pressing part main body, with the hinge being the rotation center of the document pressing part main body as the rotation center. The image reading device according to any one of claims 1 to 3, characterized in that the document pressing unit body is provided with a biasing member that biases the document contact unit toward the document placement table. The image reading device according to any one of claims 1 to 4, characterized in that it has a buffer member that is sandwiched between the document contacting portion and the document pressing portion main body when the locking portion of the document contacting portion comes into contact with the locked portion of the document pressing portion main body.

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