Ultrasonic device, multi-feed detection device, transport device, and scanner

Abstract

To provide an ultrasonic device which is easily cleaned and has stable transmission / reception sensitivity of ultrasonic waves.SOLUTION: An ultrasonic device includes an ultrasonic element that performs at least one of transmission of an ultrasonic wave and reception of an ultrasonic wave, and a housing that accommodates the ultrasonic element, in which the housing includes a reflection surface that reflects the ultrasonic wave, a waveguide through which the ultrasonic wave propagates, and an opening that is provided at one end of the waveguide and through which the ultrasonic wave passes.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic device, a double feed detection device having a pair of ultrasonic devices, a conveying device equipped with the double feed detection device, and a scanner. [Background technology]

[0002] For example, Patent Document 1 discloses an ultrasonic device that uses ultrasonic devices to detect double-feeding of paper. Specifically, the ultrasonic device includes a pair of ultrasonic devices arranged on either side of the paper transport path to detect when multiple sheets of paper are fed simultaneously in a paper transport device of a scanner. One ultrasonic device transmits ultrasonic waves, and the other ultrasonic device receives the ultrasonic waves that have passed through the paper, and double-feeding of paper is detected based on the strength of the received signal.

[0003] According to this document, the ultrasonic device is placed inside a shield having an opening, and the opening through which the ultrasonic waves pass is provided with a mesh-like protective member to prevent foreign matter from entering. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-25242 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there was room for improvement in the ultrasonic device of Patent Document 1. Specifically, if the mesh was too coarse, foreign matter such as paper dust that passed through the protective member would adhere to the surface of the ultrasonic device, reducing the ultrasonic transmission and reception sensitivity. Furthermore, if the mesh was too fine, foreign matter adhering to the surface of the protective member would need to be cleaned, and during cleaning, the water in the cleaning solution would mix with the paper dust and adhere to the protective member, reducing the ultrasonic transmission and reception sensitivity. In other words, there has been a demand for an ultrasonic device that is easy to clean and has stable ultrasonic transmission and reception sensitivity. [Means for solving the problem]

[0006] An ultrasonic device according to one aspect of the present application comprises an ultrasonic element that performs at least one of transmitting and receiving ultrasonic waves, and a housing that houses the ultrasonic element, wherein the housing has a reflective surface that reflects the ultrasonic waves, a waveguide through which the ultrasonic waves propagate, and an opening provided at one end of the waveguide and through which the ultrasonic waves pass.

[0007] A double feed detection device according to one embodiment of the present application comprises a pair of the above-mentioned ultrasonic devices, one as a transmitting ultrasonic device and one as a receiving ultrasonic device, and the transmitting ultrasonic device and the receiving ultrasonic device are arranged on either side of a transport path for sheet-like media. Ultrasonic waves are transmitted from the transmitting ultrasonic device, and the ultrasonic waves that have passed through the media are received by the receiving ultrasonic device, and double feed of the media is detected based on the strength of the received signal.

[0008] A conveying device according to one aspect of the present application includes the above-described double feed detection device.

[0009] A scanner according to one aspect of the present application includes the above-described conveying device and a reading unit that reads an image printed on the medium. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a scanner according to a first embodiment, viewed from the front. [Figure 2] FIG. 2 is a side cross-sectional view showing a document transport path of the scanner. [Figure 3] FIG. 2 is a block diagram showing a control system of the scanner. [Figure 4] FIG. 2 is a side cross-sectional view showing the configuration of a double feed detection device. [Figure 5] FIG. 1 is a side cross-sectional view showing the configuration of an ultrasound device. [Figure 6] FIG. [Figure 7] FIG. 2 is a side cross-sectional view of a main part of the ultrasonic element. [Figure 8] FIG. 10 is a side cross-sectional view showing the configuration of an ultrasound device according to a second embodiment. [Figure 9] FIG. 11 is a side cross-sectional view showing the configuration of an ultrasound device according to a third embodiment. [Figure 10] FIG. [Figure 11] FIG. [Figure 12] FIG. 10 is a side cross-sectional view showing the configuration of an ultrasound device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Embodiment 1 ***Scanner Overview*** Fig. 1 is a perspective view of a scanner according to embodiment 1 as seen from the front. Fig. 2 is a side cross-sectional view showing a document transport path of the scanner. Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 is a so-called sheet-fed type scanner that reads an original P while moving it relative to a first reading unit 32 and a second reading unit 33, which will be described later. The scanner 100 is configured to be able to read both a first side S1 of the original P and an opposite second side S2.

[0012] Each figure illustrates three mutually orthogonal axes: the X-axis, the Y-axis, and the Z-axis. The direction along the X-axis is referred to as the "X-direction," the direction along the Y-axis as the "Y-direction," and the direction along the Z-axis as the "Z-direction." As shown in FIG. 1, the scanner 100 has a horizontally elongated rectangular shape when viewed from the front. In this embodiment, the width direction, which is the direction in which the long sides of the scanner 100 extend, is referred to as the X-direction, the depth direction as the Y-direction, and the height direction as the Z-direction. Furthermore, the direction in which the document P is transported is referred to as the downstream direction, and the direction opposite to the downstream direction is referred to as the upstream direction. In the following figures, dimensions and scales may be different from the actual dimensions to make the explanation easier to understand.

[0013] 2, the scanner 100 includes a main body 70 and a stand 71 that supports the main body 70. The stand 71 is placed on a placement surface 90. The placement surface 90 is a horizontal surface such as the top surface of a desk, for example. The main body 70 is composed of a first unit 41, a second unit 42, a third unit 43, etc. The second unit 42 and the third unit 43 are provided rotatable relative to the first unit 41 about a rotation axis (not shown) that is parallel to the X axis.

[0014] The second unit 42 and the third unit 43 are provided so as to be rotatable integrally about the rotation axis relative to the first unit 41. In more detail, the lock of the second unit 42 and the third unit 43 relative to the first unit 41 can be released by sliding the lock member 72 shown in Fig. 1 in the minus X direction. The lock member 72 is a sliding open / close button that switches between engaging and disengaging the two units. A portion of the document transport path can be exposed by rotating the second unit 42 and the third unit 43 relative to the first unit 41. In particular, by opening the second unit 42 relative to the first unit 41, a supply path R0, a transport path R1, and a reading path R2, which will be described later, can be exposed.

[0015] The third unit 43 is rotatable about a rotation axis (not shown) parallel to the X-axis relative to the first unit 41 and the second unit 42. By rotating the third unit 43 relative to the second unit 42, a discharge path R3 downstream from a reading path R2 (described later) can be exposed. The third unit 43 is engaged with the second unit 42 by a snap-fit ​​structure not shown, and when the user applies an external force to the third unit 43, the engagement of the third unit 43 with the second unit 42 is released, and the third unit 43 can be opened.

[0016] The main body 70 is provided rotatably around a rotation axis 60 relative to the stand 71, and the main body 70 can take two positions by this rotation. The posture of the main body unit 70 shown in Figures 1 and 2 is one of two postures, which is a normal reading posture. The main body unit 70 can take the other posture, a booklet reading posture (not shown), by rotating from this normal reading posture so that the reading path R2 approaches horizontal. As shown in Figure 1, an operation unit 73 is provided on the front surface of the main body unit 70. The operation unit 73 is provided with a plurality of operation buttons 73a to 73c. ​​Functions such as a power button and a reading button are assigned to the operation buttons 73a to 73c, and they accept operations by the user.

[0017] ***Document transport path*** Next, the document transport path in the scanner 100 will be described with reference to Fig. 2. In Fig. 2, the thick dashed line indicates the transport path along which the document P is transported. The transport paths are provided in the following order from the upstream side: supply path R0, transport path R1, reading path R2, and discharge path R3, and transport the original P from the original support section 75 to the front surface 42b of the second unit 42. The front surface 42b is a paper discharge tray. Note that the original P includes not only sheet-shaped originals, but also card-shaped originals and booklet-shaped originals.

[0018] The supply path R0 is the most upstream conveyance path before the first roller pair 20. The conveyance path R1 is the conveyance path between the first roller pair 20 and the second roller pair 21. The reading path R2 is the conveyance path between the second roller pair 21 and the third roller pair 22. The first unit 41 constitutes the lower side of the supply path R0, the conveying path R1, and the reading path R2. The second unit 42 constitutes the upper side of the supply path R0, the conveying path R1, and the reading path R2. The discharge path R3 is formed between the second unit 42 and the third unit 43.

[0019] 2, the reading path R2 is connected to the discharge path R3 by the flap 35. In the booklet reading position (not shown), the flap 35 assumes the position indicated by the two-dot chain line, the reading path R2 is not connected to the discharge path R3, and the document P is discharged from the reading path R2 diagonally downward (in the negative Y direction) in front of the main body 70. The normal reading position is suitable for reading a sheet-like document P, that is, a document P that has low rigidity and is easily bent. The booklet reading position is suitable for reading a document P that has high rigidity and is not easily bent, such as a plastic card or booklet.

[0020] As shown in Fig. 2, before reading, the document P is supported in an inclined position by support portion 74b and document support portion 75. Support portion 74b is the portion of upper cover 74 in Fig. 1 that has been rotated and erected. Upper cover 74 is provided rotatable about a rotation axis (not shown), and opens and closes the feed port for document P by rotating. As shown in Figure 1, when the top cover 74 is closed and in a stored state, the document support units 75 are stored within the top cover 74. When the top cover 74 is open, as shown by the dotted lines, the two document support units 75 rotate and stand upright at the top of the main body unit 70, making it possible to support a document P. The scanner 100 employs a so-called center feed system, so that the center position of the document P in the X direction, i.e., the width direction, is consistent regardless of the size of the document P. The top cover 74 and the document support units 75 are components of the first unit 41.

[0021] 2, when multiple sheets of original P are set on the original support section 75, the uppermost original P is sent downstream by the roller 20a of the first roller pair 20. The first roller pair 20 is composed of the roller 20a, which is a drive roller, and the roller 20b, which is a driven roller. The roller 20a is provided in the second unit 42. The roller 20a is a drive roller that receives power from a transport motor 47 (FIG. 3) and rotates. Roller 20b is provided in first unit 41. Roller 20b is provided opposite roller 20a across supply path R0. A torque limiter (not shown) is attached to roller 20b, and is configured to prevent double feeding of documents P. 2, the conveying direction of the document P on the conveying path R1 is defined as the conveying direction Pf. Note that the present invention is not limited to a configuration in which the document P is fed from the top, and the lower roller 20b may be a drive roller and the roller 20a may be a driven roller, or the document P may be fed from the bottom.

[0022] A multi-feed detection device 58 is provided on the transport path R1. The multi-feed detection device 58 is composed of an ultrasonic device 50a and an ultrasonic device 50b, which are arranged opposite each other across the transport path R1. The multi-feed detection device 58 detects multi-feeding of documents P passing through the transport path R1. In a preferred embodiment, the ultrasonic device 50a transmits ultrasonic waves and the ultrasonic device 50b receives them. In other words, the multi-feed detection device 58 includes a pair of ultrasonic devices, 50a for transmission and 50b for reception, with the ultrasonic device 50a and 50b being arranged across the transport path R1, which is the transport path for sheet-like media P. The ultrasonic device 50a transmits ultrasonic waves, and the ultrasonic device 50b receives the ultrasonic waves that have passed through the media P. The multi-feed detection device 58 detects multi-feeding of the media P based on the strength of the received signal. Details of the ultrasonic devices 50a and 50b will be described later. Further, a configuration including a conveying path including at least the supply path R0 and the conveying path R1, and the double feed detection device 58 is referred to as a conveying device 95. In other words, the conveying device 95 includes the double feed detection device 58.

[0023] A second roller pair 21 is provided downstream of the first roller pair 20 . The second roller pair 21 is composed of roller 21a provided in first unit 41 and roller 21b provided in second unit 42. Roller 21b is provided so as to be able to move forward and backward relative to roller 21a, and is pressed toward roller 21a by a pressing member (not shown), such as a coil spring. This causes roller 21b to move forward and backward relative to roller 21a depending on the thickness of the document P being transported. Both roller 21a and roller 21b receive power from transport motor 47 (FIG. 3) and rotate. When second unit 42 is closed relative to first unit 41, roller 21a and roller 21b come into contact with each other. When second unit 42 is opened relative to first unit 41, roller 21b moves away from roller 21a.

[0024] A first reading unit 32 and a second reading unit 33 are disposed facing each other downstream of the second roller pair 21. The first reading unit 32 is provided in a first unit 41, and the second reading unit 33 is provided in a second unit . The first reading unit 32 reads a first side S1 of the document P, and the second reading unit 33 reads a second side S2 opposite to the first side S1 of the document P. The second reading unit 33 is provided so as to be movable toward and away from the first reading unit 32, and is pressed toward the first reading unit 32 by a pressing spring 34, which is an example of a pressing member. This causes the second reading unit 33 to move toward and away from the first reading unit 32 depending on the thickness of the document P being transported. In this embodiment, the first reading unit 32 and the second reading unit 33 are configured with contact image sensor modules (CISMs). In other words, the scanner 100 includes a transport device 95 and the first reading unit 32 and the second reading unit 33 as reading units that read images printed on the medium P.

[0025] A third roller pair 22 is provided downstream of the first reading unit 32 and the second reading unit 33. The third roller pair 22 is composed of a roller 22a provided in the first unit 41 and a roller 22b provided in the second unit 42. Roller 22b is provided so as to be movable toward and away from roller 22a, and is pressed toward roller 22a by a pressing member (not shown), such as a coil spring. Both roller 22a and roller 22b rotate by receiving power from a conveyance motor 47 (FIG. 3). When the second unit 42 is closed relative to the first unit 41, roller 22a and roller 22b come into contact. When the second unit 42 is opened relative to the first unit 41, roller 22b moves away from roller 22a. When the second unit 42 is opened, the first reading unit 32 and the second reading unit 33 are exposed, allowing cleaning. At this time, the ultrasonic devices 50a and 50b are also exposed, allowing cleaning of both. If the dirt is light, it is preferable to remove the foreign matter with an air blower, and if the dirt is stubborn, cleaning with a cleaning liquid is performed.

[0026] A flap 35 is provided downstream of the third roller pair 22. The flap 35 switches between the two document transport paths by rotating. In this embodiment, the flap 35 is configured to rotate in conjunction with the change in position of the main body 70. To rotate the flap 35 in conjunction with the change in position of the main body 70, a linking mechanism (not shown), for example, a cam mechanism, is used to mechanically rotate the flap in conjunction with the position of the main body 70. However, the configuration is not limited to this, and the flap 35 may also be configured to rotate by a solenoid (not shown).

[0027] The discharge path R3 is also called a U-turn path because the document P conveyed in the negative Z direction is made to make a U-turn along the flap 35 and discharged in the positive Z direction. Discharge path R3 is provided with a fourth roller pair 23 and a fifth roller pair 24. The fourth roller pair 23 is composed of a roller 23a provided in the third unit 43 and a roller 23b provided in the second unit 42. Roller 23b is provided so as to be able to move toward and away from roller 23a, and is pressed toward roller 23a by a pressing member (not shown), for example a coil spring. As a result, roller 23b moves forward and backward relative to roller 23a depending on the thickness of the transported document P. Roller 23a is a drive roller that is driven by transport motor 47 (FIG. 3). Roller 23b is a driven roller.

[0028] The fifth roller pair 24 is composed of a roller 24a provided in the third unit 43 and a roller 24b provided in the second unit 42. The roller 24b is provided so as to be movable toward and away from the roller 24a, and is pressed toward the roller 24a by a pressing member (not shown), such as a coil spring. As a result, roller 24b moves forward and backward relative to roller 24a depending on the thickness of the transported document P. Roller 24a is a drive roller that is driven by transport motor 47 (FIG. 3). Roller 24b is a driven roller.

[0029] When the third unit 43 is closed relative to the second unit 42, the rollers 23a and 23b come into contact with each other. Similarly, the rollers 24a and 24b come into contact with each other. When the third unit 43 is opened relative to the second unit 42, the rollers 23a and 23b are separated from each other. Similarly, the rollers 24a and 24b are separated from each other. The document P that has passed through the discharge path R3 is discharged in the positive Z direction by the fifth roller pair 24, and is supported in an inclined position by the front surface 42b of the second unit 42.

[0030] ***Control block configuration*** FIG. 3 is a block diagram showing the control system of the scanner. Next, the control system of the scanner 100 will be described with reference to FIG. The control unit 80 includes a calculation unit 81 including one or more processors, and a storage unit 85 including a non-volatile memory or a volatile memory. The first reading unit 32, the second reading unit 33, the transport motor 47, and the double feed detection device 58 are connected to the control unit 80, and the control unit 80 controls these units in an integrated manner. Conveyance motor 47 is the drive source for roller 20a, rollers 21a and 21b, rollers 22a and 22b, roller 23a, and roller 24a. In reality, a separate drive motor is provided for each roller, but in Figure 3, they are shown as a single functional block.

[0031] The control unit 80 is connected to an interface unit 86 and can receive various data and signals input from an external device 87 such as a personal computer, and can output the read data read by the scanner 100 to the external device 87. The storage unit 85 stores various data and programs for controlling the scanner 100. The calculation unit 81 reads and executes various programs stored in the storage unit 85, thereby functioning as a transport control unit 82, a reading control unit 83, a multiple feed determination unit 84, and the like.

[0032] The transport control unit 82 controls the transport motor 47 to rotate the above-mentioned rollers, thereby feeding, transporting, and discharging the document P. The reading control unit 83 controls the first reading unit 32 and the second reading unit 33 while the document P is being transported, and makes them read the image of the document P.

[0033] The multifeed determination unit 84 is a state detection unit that detects the state of the document P and determines whether the document P has been multifed based on a reception signal input from the transmission / reception circuit 55 of the multifeed detection device 58. In a preferred embodiment, the transmission / reception circuit 55 is configured to be switchable between an ultrasonic transmission circuit and a reception circuit. In the ultrasonic device 50a, the transmission / reception circuit 55 functions as a transmission circuit that transmits ultrasonic waves and causes the ultrasonic element 10 to emit ultrasonic waves at a frequency corresponding to the drive signal. In the ultrasonic device 50b, the transmission / reception circuit 55 functions as a reception circuit that receives ultrasonic waves and detects the signal level of the ultrasonic waves incident on the ultrasonic element 10. Note that a configuration including dedicated transmission circuits and reception circuits may also be used. The multifeed determination unit 84 determines that the document P has been multifed if the voltage value of the reception signal from the ultrasonic device 50b is smaller than a predetermined threshold. Note that if the multifeed determination unit 84 determines that the document P has been multifed, the transport control unit 82 stops transport of the document P.

[0034] ***Configuration of the double feed detection device*** Fig. 4 is a side cross-sectional view showing the configuration of a double feed detection device. Fig. 4 illustrates a side cross-sectional view of the main parts of ultrasonic device 50a and ultrasonic device 50b, which are arranged opposite each other across transport path R1. In Fig. 4, the coordinate axes are the X axis, the transport direction Pf of document P, and the perpendicular direction Pe that is perpendicular to the transport direction pf, as three mutually orthogonal axes.

[0035] As shown in FIG. 4, ultrasonic waves emitted from the ultrasonic element 10 of the ultrasonic device 50a are reflected by the reflecting surface 13 of the housing 11, pass through the waveguide 14, and are emitted from the opening 12. Then, they enter the ultrasonic device 50b via the transport path R1. In a preferred embodiment, the ultrasonic device 50b has the same configuration as the ultrasonic device 50a. The ultrasonic waves passing through the transport path R1 enter the opening 12 of the ultrasonic device 50b, pass through the waveguide 14, and are reflected by the reflecting surface 13 to enter the receiving ultrasonic element 10. At this time, the emitted ultrasonic beam is transmitted around the central axis 65. Specifically, the ultrasonic waves are emitted from the ultrasonic element 10 around the central axis 65a, are reflected by the reflecting surface 13, travel around the central axis 65b, are reflected by the receiving reflecting surface 13, travel around the central axis 65c, and enter the receiving ultrasonic element 10. The central axes 65a to 65c are collectively referred to as the central axis 65.

[0036] Here, the central axis 65b as the first axis is inclined at an angle θ with respect to the transport path R1. In a preferred example, the angle θ is approximately 70°. However, this is not limited thereto, and the angle θ may be any angle between 60° and 80°. By inclining the central axis 65b of the ultrasonic beam with respect to the transport path R1 in this manner, multiple reflections of ultrasonic waves between the document P and the transmitting ultrasonic element 10 can be suppressed. More specifically, when the central axis 65 coincides with the direction perpendicular to the document P, i.e., when the angle θ is 90°, there is a risk that the ultrasonic waves emitted from the ultrasonic element 10 will be multiple-reflected between the document P and the ultrasonic element 10. In other words, the central axis 65b as the first axis is inclined with respect to the perpendicular to the document P, which is the object to be irradiated with ultrasonic waves.

[0037] ***Ultrasound Device Configuration*** FIG. 5 is a side cross-sectional view showing the configuration of an ultrasonic device, and is an enlarged view of the ultrasonic device 50a in FIG. 4. FIG. 6 is a perspective view of the main board. FIG. 7 is a side cross-sectional view of the main part of the ultrasonic element. Here, the configurations of the ultrasonic devices 50a and 50b will be explained using the ultrasonic device 50a as a representative. As mentioned above, the ultrasonic device 50b has the same configuration as the ultrasonic device 50a, and only the placement orientation is different.

[0038] As shown in FIG. 5, the ultrasonic device 50a is composed of a housing 11, a main board 9, an ultrasonic element 10, and the like. The housing 11 is a case that houses the ultrasonic element 10. As shown in Fig. 5, the housing 11 is composed of a base 11a, which is a plate-shaped portion substantially parallel to the transport path R1, a first wall 11b extending from the base 11a along the central axis 65a, a second wall 11c extending from the base 11a along the central axis 65b, and a third wall 11d facing the second wall 11c. The first wall 11b and the second wall 11c are provided so as to open in a V-shape from the base 11a. The inner surface of the base 11a is a flat reflecting surface 13. A perpendicular line to the reflecting surface 13 is set as a center line 61.

[0039] An opening 12 is formed at the end of the second wall 11c and the third wall 11d. The opening 12 has a rectangular shape when viewed from the transport path R1 side. The inner surfaces of the second wall 11c and the third wall 11d form a waveguide 14. A central axis 65b passes through the center of the waveguide 14. In other words, the waveguide 14 extends along the central axis 65b, which serves as a first axis. The housing 11 can be made of metal or resin. When the housing 11 is made of metal, a shielding effect is obtained that protects the ultrasonic element 10 from the effects of static electricity and electromagnetic waves. When the housing 11 is made of resin, the housing 11 can be efficiently formed by injection molding. For example, in the housing 11 of this embodiment, molding efficiency is good when it is made of two resin parts: a plate-like part including the base 11a from which the reflecting surface 13 extends, and a part including the first wall 11b, the second wall 11c, and the third wall 11d.

[0040] A main board 9 is attached between the end of the first wall 11b and the end of the third wall 11d. An ultrasonic element 10 is mounted on the main board 9. The surface of the ultrasonic element 10 is called a transmitting / receiving surface 10a. 6, the main board 9 is a rectangular board. On both short sides of the main board 9, there are provided notched holes 9a for screw fastening. An ultrasonic element 10, a transmitting / receiving circuit 55, a cover member 76, etc. are mounted on the surface of the main board 9. The ultrasonic element 10 is a component that is rectangular in plan view.

[0041] 7, the ultrasonic element 10 has a configuration in which an element substrate 3 is layered on a base substrate 8. The base substrate 8 is a mounting substrate, and has a plurality of terminals (not shown) on its underside. The element substrate 3 is composed of a semiconductor substrate 1, a diaphragm 2, etc. In a preferred example, the semiconductor substrate 1 is a silicon substrate. However, it is not limited to a silicon substrate, and any semiconductor substrate will do. The semiconductor substrate 1 has a plurality of openings 1a, which are through-holes, arranged in a grid pattern. Walls that separate the plurality of openings 1a are called partition walls 1b.

[0042] In a preferred example, the diaphragm 2 is made of a laminate in which a plurality of SiO2 films are stacked. However, this is not limiting, and the diaphragm 2 may also be made of a laminate in which a plurality of SiO2 films and ZrO2 films are alternately stacked. The diaphragm 2 is provided on the surface of the semiconductor substrate 1 facing the base substrate 8, covering the plurality of openings 1a. A vibrating section 7 is formed in the diaphragm 2 in a portion overlapping the opening 1a. The vibrating section 7 is formed by laminating a first electrode 4, a piezoelectric element 5, and a second electrode 6 in this order on the diaphragm 2. The first electrode 4 is a solid electrode and is provided so as to cover all of the openings 1a and the partition walls 1b. The piezoelectric element 5 is selectively provided in a portion overlapping the opening 1a. In a preferred example, the piezoelectric element 5 is made of zinc zirconate titanate (PZT), but is not limited to this. The second electrode 6 is provided, for example, in a stripe pattern along the extension direction of the short side of the main substrate 9. A space is provided between the vibrating section 7 and the base substrate 8 so as not to inhibit the vibration of the vibrating section 7.

[0043] As shown in Fig. 7, one ultrasonic transducer Tr is configured by the vibration unit 7 provided in the opening 1a. Then, as shown in Fig. 6, a plurality of ultrasonic transducers Tr are provided in a matrix on the transmitting / receiving surface 10a of the ultrasonic element 10. The ultrasonic transducer Tr is electrically connected to the transmitting / receiving circuit 55. A metal cover member 76 is provided on the surface of the main board 9, covering the ultrasonic elements 10 and the transmission / reception circuit 55. The cover member 76 has an opening 76a that exposes the transmission / reception surface 10a of the ultrasonic elements 10. A power supply potential such as GND is supplied to the cover member 76, and the cover member 76 protects the ultrasonic elements 10 and the transmission / reception circuit 55 from static electricity and electromagnetic waves. Note that the cover member 76 is not essential, and may not be provided if the housing 11 is made of metal and has shielding properties. A connector 77 is mounted on the back surface of the main board 9. A cable (not shown) is connected to the connector 77, and the connector 77 is electrically connected to the control unit 80 (FIG. 3).

[0044] 5 shows a cross section in the short side direction of the main board 9. The main board 9 is fixed to the housing 11 with screws through two notched holes 9a (FIG. 6) provided at the front and rear in the depth direction (X direction). 5, the reflecting surface 13 is provided on a central axis 65a that is a perpendicular line to the transmitting / receiving surface 10a of the ultrasonic element 10. The central axis 65a is inclined with respect to a center line 61 that is a perpendicular line to the reflecting surface 13. The central axis 65b, which serves as a first axis, is inclined with respect to the center line 61 that is a perpendicular line to the reflecting surface 13 in a direction different from that of the central axis 65a.

[0045] In other words, the ultrasonic element 10 has an ultrasonic transmission / reception surface 10a, and the reflecting surface 13 is provided on a central axis 65a that is perpendicular to the transmitting / receiving surface 10a. The central axis 65a, which is perpendicular to the transmitting / receiving surface 10a, is inclined with respect to a center line 61, which is perpendicular to the reflecting surface 13. The central axis 65b, which serves as a first axis, is inclined in a different direction from the central axis 65a, which is perpendicular to the transmitting / receiving surface 10a, with respect to the center line 61, which is perpendicular to the reflecting surface 13. The ultrasonic device 50a also includes an ultrasonic element 10 that performs at least one of transmitting and receiving ultrasonic waves, and a housing 11 that houses the ultrasonic element 10. The housing 11 has a reflecting surface 13 that reflects ultrasonic waves, a waveguide 14 through which the ultrasonic waves propagate, and an opening 12 that is provided at one end of the waveguide 14 and through which the ultrasonic waves pass.

[0046] As described above, the ultrasonic device 50, the double feed detection device 58, the transport device 95, and the scanner 100 of this embodiment can provide the following effects. The ultrasonic device 50 comprises an ultrasonic element 10 that performs at least one of transmitting and receiving ultrasonic waves, and a housing 11 that houses the ultrasonic element 10. The housing 11 has a reflecting surface 13 that reflects ultrasonic waves, a waveguide 14 through which the ultrasonic waves propagate, and an opening 12 provided at one end of the waveguide 14 and through which the ultrasonic waves pass.

[0047] For example, when the ultrasonic device 50 is a transmitting ultrasonic device 50a, even if foreign matter enters through the opening 12, the foreign matter remains on the reflecting surface 13, and adhesion of foreign matter to the transmitting / receiving surface 10a of the ultrasonic element 10 can be suppressed. Therefore, the receiving sensitivity of the ultrasonic waves can be ensured. Furthermore, foreign matter on the reflecting surface 13 can be cleaned by blowing air. The same applies to the ultrasonic device 50b. Therefore, it is possible to provide an ultrasonic device 50 that is easy to clean and has stable ultrasonic transmission and reception sensitivity.

[0048] The ultrasonic element 10 has an ultrasonic wave transmitting and receiving surface 10a, and the reflecting surface 13 is provided on a central axis 65a that is perpendicular to the transmitting and receiving surface 10a. According to this, ultrasonic waves emitted from the ultrasonic element 10 on the transmitting side travel along the central axis 65a, are reflected by the reflecting surface 13, and travel along the central axis 65b. On the receiving side, ultrasonic waves incident along the central axis 65b are also reflected by the reflecting surface 13, travel along the central axis 65c, and are incident on the ultrasonic element 10 on the receiving side. Therefore, stable transmission and reception sensitivity can be obtained by appropriate reflection of ultrasonic waves.

[0049] Furthermore, the central axis 65a, which is a line perpendicular to the transmitting / receiving surface 10a, is inclined with respect to the central line 61, which is a line perpendicular to the reflecting surface 13. This allows the ultrasonic waves to be reflected appropriately.

[0050] Furthermore, the waveguide 14 extends along a central axis 65b as a first axis, and the central axis 65b is inclined in a direction different from the central axis 65a, which is the perpendicular to the transmitting / receiving surface 10a, with respect to the center line 61, which is the perpendicular to the reflecting surface 13. Therefore, stable transmitting and receiving sensitivity can be obtained by appropriate reflection of ultrasonic waves.

[0051] Furthermore, the central axis 65b as the first axis is inclined with respect to a perpendicular line to the document P as an object to be irradiated with ultrasonic waves. This makes it possible to suppress multiple reflections of ultrasonic waves between the document P and the ultrasonic element 10 for transmission.

[0052] The double feed detection device 58 comprises a pair of ultrasonic devices 50a for transmitting and 50b for receiving, with the ultrasonic device 50a and the ultrasonic device 50b arranged on either side of the transport path R1, which is the transport path for the sheet-like medium P. Ultrasonic waves are transmitted from the ultrasonic device 50a, and the ultrasonic waves that have passed through the medium P are received by the ultrasonic device 50b, and double feed of the medium P is detected based on the strength of the received signal. According to this, the double feed detector 58 includes an ultrasonic transmitting device 50a and an ultrasonic receiving device 50b that are easy to clean and have stable ultrasonic transmission and reception sensitivity. Therefore, it is possible to provide a double feed detector 58 that is easy to clean and has stable ultrasonic transmission and reception sensitivity.

[0053] The conveying device 95 is equipped with a double feed detection device 58 . This makes it possible to provide a transport device 95 equipped with a double feed detector 58 that is easy to clean and has stable ultrasonic transmission and reception sensitivity.

[0054] The scanner 100 includes a conveying device 95, and a first reading unit 32 and a second reading unit 33 as reading units that read an image printed on a medium P. This makes it possible to provide a scanner 100 equipped with a double feed detector 58 that is easy to clean and has stable ultrasonic transmission and reception sensitivity.

[0055] Embodiment 2 ***Different aspects of ultrasound equipment - 1*** FIG. 8 is a side cross-sectional view showing the configuration of an ultrasound device according to the second embodiment, and corresponds to FIG. The ultrasonic device 50 of the above embodiment may be provided with a discharge hole 15 for discharging foreign matter that has entered the housing 11. Hereinafter, the same parts as those in the above embodiment will be given the same reference numerals, and duplicated explanations will be omitted.

[0056] As shown in FIG. 8, an ultrasonic device 51 of this embodiment has a discharge hole 15 for discharging foreign matter that has entered the housing 11. Except for this, the ultrasonic device 51 has the same configuration as the ultrasonic device 50 described above. The discharge hole 15 is a through-hole that penetrates the first wall 11b, and is provided in a portion of the first wall 11b facing the reflecting surface 13. In a preferred example, the discharge hole 15 is provided horizontally in the X direction along the reflecting surface 13. In other words, the housing 11 has the discharge hole 15 at a position different from the opening 12. Note that although the receiving ultrasonic device 51b is not shown in FIG. 8, it has the same configuration as the ultrasonic device 51a.

[0057] Foreign matter that enters through opening 12 is likely to adhere to waveguide 14 and reflecting surface 13. According to ultrasonic device 51 of this embodiment, foreign matter that has adhered to waveguide 14 and reflecting surface 13 can be discharged from discharge hole 15, as indicated by the white arrow, by blowing air toward opening 12 using an air duster (not shown). Note that discharge hole 15 is not limited to being provided in the above-mentioned position, and may be provided in any position where foreign matter on waveguide 14 and reflecting surface 13 can be discharged by the airflow from opening 12.

[0058] As described above, according to the ultrasonic device 51 of this embodiment, in addition to the effects of the above embodiment, the following effects can be obtained. The housing 11 of the ultrasonic device 51 has a discharge hole 15 at a position different from the opening 12 . According to this, by blowing air toward the opening 12, foreign matter adhering to the waveguide 14 and the reflecting surface 13 can be easily discharged through the discharge hole 15. Therefore, it is possible to provide an ultrasonic device 51 that is easy to clean and has stable ultrasonic transmission and reception sensitivity.

[0059] Embodiment 3 ***Different aspects of ultrasound equipment - 2*** Fig. 9 is a side cross-sectional view showing the configuration of an ultrasound device according to embodiment 3, and corresponds to Fig. 8. Fig. 10 is a perspective view of a protective member. Fig. 11 is an enlarged view of the protective member. In the ultrasonic device 51 of the above embodiment, the opening 12 may be provided with a mesh-like protective member 17. Hereinafter, the same parts as those in the above embodiment will be given the same reference numerals, and duplicated explanations will be omitted.

[0060] 9, an ultrasonic device 52 of this embodiment is provided with a mesh-like protective member 17 at the opening 12. Other than this, the configuration is the same as that of the ultrasonic device 50 described above. As shown in Fig. 10, the protective member 17 is attached to the support frame 16. The support frame 16 is a rectangular resin frame and has a rectangular opening 16b. The opening 16b is set to a size slightly larger than the opening 12 of the ultrasonic device 52. The protective member 17 is attached to the opening 16b of the support frame 16. In other words, the mesh-like protective member 17 is provided at the opening 12 of the ultrasonic device 52. Cutout holes 16a for screw fastening are provided on both short sides of the support frame 16. In Fig. 9, the support frame 16 is fixed to the housing 11 with screws through two cutout holes 16a (Fig. 10) provided at the front and rear in the depth direction (X direction).

[0061] As shown in Fig. 11, the protective member 17 is a filter configured in a mesh shape by intersecting wires 17a. While Fig. 11 shows an example in which the wires 17a intersect at right angles, the present invention is not limited to this and any configuration in which the wires 17a intersect may be used. In a preferred example, polyester is used for the wires 17a. However, the material is not limited to polyester, and metal materials such as copper, iron, brass, and SUS, alloy materials, and synthetic resins such as nylon and polyester may also be used. The ultrasonic device 52 is equipped with an exhaust hole 15, so small foreign matter can be easily cleaned with an air blow. Therefore, the protective member 17 is required to have the function of preventing the intrusion of large foreign matter, such as eraser shavings adhering to the medium P. For this reason, the protective member 17 is designed to have a coarse mesh size so that it will not become clogged or adhere with paper dust even when washed with a cleaning solution.

[0062] As described above, according to the ultrasonic device 52 of this embodiment, in addition to the effects of the above embodiment, the following effects can be obtained. A mesh-like protective member 17 is provided at the opening 12 of the ultrasonic device 52 . This prevents large foreign matter from entering the housing 11, and by blowing air toward the opening 12, foreign matter adhering to the waveguide 14 and the reflecting surface 13 can be easily discharged through the discharge hole 15. Furthermore, even if the protective member 17 is washed with a cleaning solution, clogging and adhesion of paper powder can be prevented. Therefore, it is possible to provide an ultrasonic device 52 that is easy to clean and has stable ultrasonic transmission and reception sensitivity.

[0063] Embodiment 4 ***Different aspects of ultrasound equipment - 3*** FIG. 12 is a side cross-sectional view showing the configuration of an ultrasonic device according to the fourth embodiment, and corresponds to FIG. In the above embodiment, the ultrasonic device 51 has one reflecting surface 13, but it may have multiple reflecting surfaces. Hereinafter, the same parts as those in the above embodiment will be assigned the same reference numerals, and duplicated explanations will be omitted.

[0064] The ultrasonic device 53 of this embodiment includes two reflecting surfaces inside the housing 18: a first reflecting surface 19a and a second reflecting surface 19b. 12, the housing 18 of the ultrasonic device 53 has a rectangular shape in a side view. A bottom 18a is provided along one long side of the housing 18. A discharge hole 15b is provided in the bottom 18a. The center line of the discharge hole 15b is defined as a center line 62. A first wall 18b is provided along one short side of the housing 18. One end of the main board 9 is fixed on top of the first wall 18b. The back surface of the main board 9 is the other long side of the housing 18. A second wall 18c is provided along the other short side of the housing 18. An opening 12 is formed between the other end of the main substrate 9 and the second wall 18c.

[0065] Inside the housing 18, an inclined first reflecting surface 19a is provided between the first wall 18b and the bottom 18a. An inclined second reflecting surface 19b is provided between the second wall 18c and the bottom 18a. The first reflecting surface 19a is provided on a central axis 66a that is a perpendicular line to the transmitting / receiving surface 10a of the ultrasonic element 10. A central line 63 that is a perpendicular line to the first reflecting surface 19a is inclined with respect to the central axis 66a. A central line 64 that is a perpendicular line to the second reflecting surface 19b intersects with the center line 63 of the first reflecting surface 19a. Discharge hole 15b is provided between first reflecting surface 19a and second reflecting surface 19b. First reflecting surface 19a and second reflecting surface 19b are provided in line symmetry with respect to center line 62 of discharge hole 15b.

[0066] With this configuration, as shown in FIG. 12, ultrasonic waves emitted from the ultrasonic element 10 of the ultrasonic device 53a are reflected by the first reflecting surface 19a, then further reflected by the second reflecting surface 19b, and emitted from the opening 12. Specifically, the ultrasonic waves are emitted from the ultrasonic element 10 around the central axis 66a, reflected by the first reflecting surface 19a, travel around the central axis 66b, reflected by the second reflecting surface 19b, travel around the central axis 66c, and emitted from the opening 12. In the housing 18, the portion along the inner wall of the second wall 18c becomes the waveguide 14b. In the receiving ultrasonic device 53b, the ultrasonic waves enter the ultrasonic element 10 via the reverse route described above. In addition, the housing 18 can be formed of the same material as the housing 11.

[0067] In other words, the housing 18 has a first reflecting surface 19a and a second reflecting surface 19b as reflecting surfaces, the first reflecting surface 19a is provided on a central axis 66a which is a perpendicular line to the transmitting / receiving surface 10a of the ultrasonic element 10, a center line 63 which is a perpendicular line to the first reflecting surface 19a is inclined with respect to the central axis 66a, and a center line 64 which is a perpendicular line to the second reflecting surface 19b intersects with the center line 63 of the first reflecting surface 19a. In addition, a discharge hole 15b is provided between the first reflecting surface 19a and the second reflecting surface 19b in the housing 18, and the first reflecting surface 19a and the second reflecting surface 19b are provided in line symmetry with the center line 62 of the discharge hole 15b as the center of symmetry.

[0068] Foreign matter that has entered through opening 12 is likely to adhere to waveguide 14b, first reflecting surface 19a, and second reflecting surface 19b. According to the ultrasonic device 53 of this embodiment, by blowing air toward the opening 12 using an air duster (not shown), foreign matter adhering to the waveguide 14b, the first reflecting surface 19a, and the second reflecting surface 19b can be discharged through the discharge hole 15b, as shown by the white arrows. Furthermore, according to the ultrasonic device 53, the housing 18 can be configured to have a low height. More specifically, as shown in Fig. 12, by providing two reflecting surfaces, the main board 9 can be arranged along the long side of the housing 18, thereby realizing a compactly configured housing 18. As a result, the height t2 of the housing 18 can be made smaller than the height t1 of the housing 11 in Fig. 8, resulting in a more compact configuration.

[0069] As described above, according to the ultrasonic device 53 of this embodiment, in addition to the effects of the above embodiment, the following effects can be obtained. The housing 18 of the ultrasonic device 53 has a first reflecting surface 19a and a second reflecting surface 19b as reflecting surfaces, the first reflecting surface 19a is provided on a central axis 66a which is a perpendicular line to the transmitting / receiving surface 10a of the ultrasonic element 10, the central line 63 which is a perpendicular line to the first reflecting surface 19a is inclined with respect to the central axis 66a, and the central line 64 which is a perpendicular line to the second reflecting surface 19b intersects with the central line 63 of the first reflecting surface 19a.

[0070] According to this, by providing two reflecting surfaces, it is possible to arrange the main board 9 along the long side of the housing 18, thereby providing a compact ultrasonic device 53. Furthermore, since the transmitting / receiving surface 10a of the ultrasonic element 10 does not face the opening 12, adhesion of foreign matter to the transmitting / receiving surface 10a can be suppressed. Therefore, it is possible to provide an ultrasonic device 53 that is easy to clean and has stable ultrasonic transmission and reception sensitivity.

[0071] In addition, a discharge hole 15b is provided between the first reflecting surface 19a and the second reflecting surface 19b in the housing 18, and the first reflecting surface 19a and the second reflecting surface 19b are arranged symmetrically with respect to the center line 62 of the discharge hole 15b. According to this, by blowing air toward the opening 12, foreign matter adhering to the waveguide 14b, the first reflecting surface 19a, and the second reflecting surface 19b can be easily discharged through the discharge hole 15b. Therefore, it is possible to provide an ultrasonic device 53 that is easy to clean and has stable ultrasonic transmission and reception sensitivity.

[0072] Variations In the above, the scanner 100 is given as an example of an electronic device, but the present invention is not limited to this and can be applied to electronic devices having a function of transporting media one sheet at a time. For example, in a printing device (printer) having a print head that prints images on paper transported on a transport path, a multi-feed detection device using the ultrasonic devices 50, 51, 52, and 53 described above may be applied to detect multi-feeding of paper. Even with this configuration, the same effects as those of the above embodiments can be obtained. [Explanation of symbols]

[0073] DESCRIPTION OF SYMBOLS 1...semiconductor substrate, 1a...opening, 1b...partition wall, 2...diaphragm, 3...element substrate, 4...first electrode, 5...piezoelectric element, 6...second electrode, 7...vibration portion, 8...base substrate, 9...main substrate, 9a...notched hole, 10...ultrasonic element, 10a...transmitting / receiving surface, 11...casing, 11a...base, 11b...first wall, 11c...second wall, 11d...third wall, 12...opening, 13...reflective surface, 14...waveguide, 14b...waveguide, 15...discharge hole, 15b...discharge hole, 16...support frame, 16a...notched hole, 16b...opening, 17...protective member, 17a...wire, 18...casing, 18a...bottom portion, 18b...first wall, 18c...second wall, 19a...first reflective surface, 19b...second reflective surface, 20...first roller pair, 20a...roller, 20b...roller, 21...second roller pair, 21a...roller, 21b...roller, 22...third roller pair, 22a...roller, 22b...roller, 23...fourth roller pair, 23a...roller, 23b...roller, 24...fifth roller pair, 24a...roller, 24b...roller, 32...first reading portion, 33...second reading portion, 35...flap, 41...first unit, 42...second unit, 42b...front surface , 43...Third unit, 47...Conveyor motor, 50...Ultrasonic device, 50a...Ultrasonic device, 50b...Ultrasonic device, 51...Ultrasonic device, 51a...Ultrasonic device, 51b...Ultrasonic device, 52...Ultrasonic device, 53...Ultrasonic device, 53a...Ultrasonic device, 53b...Ultrasonic device, 55...Transmitting / receiving circuit, 58...Double feed detection device, 60...Rotation shaft, 61...Center line, 62...Center line, 63...Center line, 64...Center line, 65...Center axis, 65a...Center axis, 65b...Center axis, 65c...Center axis, 66a...Center axis, 66b...Center axis, 66c...Center axis, 70...Main body, 71...S Stand, 72...locking member, 73...operation unit, 73a to 73c...operation buttons, 74...upper cover, 74b...support unit, 75...original support unit, 76...cover member, 76a...opening, 77...connector, 80...control unit, 81...calculation unit, 82...transport control unit, 83...reading control unit, 84...multifeed determination unit, 85...memory unit, 86...interface unit, 87...external equipment, 90...placing surface, 95...transport device, 100...scanner, R1...transport path, R2...reading path, R3...eject path, S1...first surface, S2...second surface, t1...height, t2...height, P...medium.

Claims

1. an ultrasonic element that performs at least one of transmitting and receiving ultrasonic waves; a housing that houses the ultrasonic element, The housing includes: a reflecting surface that reflects the ultrasonic waves; a waveguide through which the ultrasonic waves propagate; an opening provided at one end of the waveguide and through which the ultrasonic waves pass; Ultrasonic device.

2. The ultrasonic element has an ultrasonic transmission / reception surface, The reflecting surface is provided on a perpendicular line to the transmitting and receiving surface. The ultrasound device of claim 1 .

3. a normal to the transmitting / receiving surface is inclined with respect to a normal to the reflecting surface; 3. The ultrasound device of claim 2.

4. the waveguide extends along a first axis; the first axis is inclined with respect to a line perpendicular to the reflecting surface in a direction different from a line perpendicular to the transmitting / receiving surface; 4. The ultrasound device of claim 3.

5. The first axis is inclined with respect to a perpendicular line of an object to be irradiated with the ultrasonic waves.

5. The ultrasound device of claim 4.

6. The housing has a discharge hole at a position different from the opening.

4. The ultrasound device of claim 3.

7. A mesh-like protective member is provided at the opening.

7. The ultrasound device of claim 6.

8. the housing has a first reflecting surface and a second reflecting surface as the reflecting surface, the first reflecting surface is provided on a perpendicular line to a transmitting / receiving surface of the ultrasonic element, and the perpendicular line to the first reflecting surface is inclined with respect to the perpendicular line to the transmitting / receiving surface, a normal to the second reflecting surface intersects with a normal to the first reflecting surface; The ultrasound device of claim 1 .

9. a discharge hole is provided in the housing between the first reflecting surface and the second reflecting surface, The first reflecting surface and the second reflecting surface are provided symmetrically with respect to a center line of the discharge hole.

9. The ultrasound device of claim 8.

10. A pair of ultrasonic devices according to any one of claims 1 to 9 is provided as a transmitting ultrasonic device and a receiving ultrasonic device, The ultrasonic transmitting device and the ultrasonic receiving device are disposed across a conveyance path for a sheet-like medium, transmitting ultrasonic waves from the ultrasonic transmitting device, receiving the ultrasonic waves that have passed through the medium by the ultrasonic receiving device, and detecting double feeding of the medium based on the strength of the received signal; Double feed detection device.

11. A multi-feed detection device according to claim 10, Conveying device.

12. A conveying device according to claim 11; a reading unit that reads an image printed on the medium, scanner.

Images