JP6924227B2 - A substrate and an image forming apparatus having the substrate - Google Patents

Description

The present invention relates to a substrate and an image forming apparatus having the substrate.

As a technique for fixing a lightning rod to an operation panel unit of a conventional information device, for example, Patent Document 1 describes a lightning rod for an operation panel unit in which a wire for inducing static electricity in the vicinity of a touch panel is fixed to a touch panel case with a holding member. A fixed structure is described.

Japanese Unexamined Patent Publication No. 2014-182625

In the above-mentioned conventional technique, since the lightning rod is composed of a member different from the touch panel which is the object of lightning protection, a place for installing the lightning rod is required, which leads to an increase in the size of the entire device. In addition, since the touch panel and the lightning rod are held by separate members, the lightning rod must be installed in a narrow space, which is difficult to manufacture. Further, when the lightning protection target is, for example, a wireless communication antenna, there is a problem that arranging the lightning rod near the wireless communication antenna affects the characteristics of the antenna.

An object of the present invention is to solve the above-mentioned problems of the prior art.

A feature of the present invention is to provide a technique for suppressing an increase in the size of the entire image forming apparatus, reducing the influence on the characteristics of the antenna, and suppressing the generation of noise due to static electricity.

In order to achieve the above object, the substrate according to one aspect of the present invention has the following configuration. That is,
A substrate built into an image forming apparatus to enable wireless communication with a terminal.
The first surface side of the front Stories substrate, a ground pattern of the substrate is formed by a printed circuit, and, on a second surface side opposite to the first surface side of the substrate, receiving radio waves used in the wireless communication The area of the ground pattern formed on the first surface side corresponding to the region surrounded by the antenna pattern formed on the second surface side is such that the antenna pattern functioning as an antenna is formed by the printed wiring. It is characterized in that it is smaller than the area surrounded by the antenna pattern.

According to the present invention, since the substrate and the antenna pattern are integrated into a structure, it is compact and the influence on the antenna characteristics can be reduced , and the ground pattern is formed on the substrate surface on the side close to the terminal. It has the effect of effectively flowing static electricity from the user who brings the terminal closer to the ground.

Other features and advantages of the present invention will become apparent in the following description with reference to the accompanying drawings. In the attached drawings, the same or similar configurations are given the same reference numbers.

The accompanying drawings are included in the specification and are used to form a part thereof, show an embodiment of the present invention, and explain the principle of the present invention together with the description thereof.
FIG. 5 is a cross-sectional view illustrating a path in which static electricity is applied to a wireless communication module board for NFC incorporated in an operation unit of a printing device. The figure which shows the detail of the surface where the antenna pattern of the wireless communication board which concerns on Embodiment 1 is arranged. The figure which shows the substrate surface on the side opposite to the surface where the antenna pattern of the wireless communication substrate which concerns on Embodiment 1 is arranged. The figure which shows the substrate surface on the side opposite to the surface where the antenna pattern of the wireless communication substrate which concerns on Embodiment 2 is arranged. The figure which shows the result of having measured the communication distance of an antenna pattern in an experiment in order to determine the occupied area of the static electricity removal sheet which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the present invention according to the claims, and not all combinations of features described in the present embodiment are essential for the means for solving the present invention. ..

FIG. 1 is a cross-sectional view illustrating a path in which static electricity is applied to a wireless communication module board for NFC incorporated in an operation unit of a printing device. FIG. 1A shows a state in which the wireless communication module board 100 is mounted inside the operation unit of the printing device and is communicating with the mobile terminal shown in the upper left.

In FIG. 1A, the exterior of the operation unit has members 110 and 111, and since there is a gap between the members 110 and 111, static electricity enters through the gap as shown in the drawing, and the wireless communication module. It is applied to the antenna pattern 101 of the substrate 100.

Therefore, in the first embodiment, as shown in FIG. 1B, static electricity that has entered through the gap is applied to the lightning rod member (static electricity removing member) 102, and the static electricity is discharged to a ground (not shown). In this way, the influence on the wireless communication module board 100 and the antenna pattern 101 is eliminated.

A specific example will be described in detail below.

FIG. 2 is a diagram showing details of a substrate surface on which the antenna pattern 203 of the wireless communication substrate 200 according to the first embodiment is arranged.

The wireless communication board 200 is, for example, a wireless communication board incorporated in an operation unit of a multifunctional processing device (printing device) for performing NFC (Near Field Communication) communication. The antenna pattern 203 is an antenna pattern for communicating with an NFC device formed by printed wiring on the wireless communication board 200. LSI (Large-Scale Integration) 204 is an LSI that controls NFC communication. The connector 205 is electrically connected to a main control unit (host controller (not shown)) of the printing apparatus that controls the LSI 204. The circuit components and wiring patterns between the connector 205 and the LSI 204 are not shown here. The mounting hole 206 is a hole for fastening the wireless communication board 200 to the metal portion of the housing of the printing device and mounting the wireless communication board 200 to the printing device main body, and is a ground pattern 207 of the board 200 (FIG. 3). Is connected to.

In FIG. The arrow 201 indicates the direction in which static electricity is applied to the wireless communication board 200. This corresponds to the intrusion direction of static electricity shown in FIG. That is, it corresponds to the direction in which static electricity is applied to the antenna pattern from the gap between the members 110 and 111 in FIG. When static electricity is applied to the wireless communication substrate 200 in this way, the performance of the antenna for wireless communication may deteriorate. Therefore, it is an object of the present embodiment to minimize the influence of static electricity.

FIG. 3 is a diagram showing a substrate surface on the side opposite to the surface on which the antenna pattern of the wireless communication substrate 200 according to the first embodiment is arranged. The wireless communication board 200 is housed as a wireless communication board on which a circuit for wireless communication and an antenna pattern are mounted in an electronic device such as a printing device or a mobile terminal.

Here, the static electricity removing sheet 208 made of aluminum, which is a conductive member, is closely attached to the board 200 on the board surface on the opposite side of the antenna pattern 203, and the static electricity removing sheet 208 is attached to the housing metal using the mounting holes 206 of the board 200. And fasten with screws. As a result, the static electricity applied to the static electricity removing sheet 208 is sent to the ground of the electronic device through the mounting hole 206. Since the static electricity removing sheet 208 is made of a conductive member, if it is attached to the same surface of the substrate 200 as the antenna pattern 203, the performance as an antenna deteriorates. Therefore, in the first embodiment, the static electricity removing sheet 208 is attached to the surface opposite to the surface on which the antenna pattern 203 of the substrate 200 having a thickness of about 1.6 mm is arranged to prevent deterioration of the antenna performance. There is. Further, by making the end of the static electricity removing sheet 208 substantially coincide with the end of the antenna pattern 203 in the vicinity of the portion of the substrate to which static electricity is applied, the static electricity removing sheet 208 is placed in the middle of the path in which static electricity enters the antenna pattern 203. It has a structure to be arranged.

Here, the area of the static electricity removing sheet 208 is set to be approximately one-third of the area occupied by the antenna pattern 208 based on the examination results shown in FIG.

In FIG. 2, the antenna pattern 203 occupies an area of 15 mm × 50 mm, and the static electricity removing sheet 208 has a width of 5 mm, which is approximately one-third of the area occupied by the antenna on the opposite surface of the antenna pattern 203. It is pasted.

The static electricity removing sheet 208 may not be in the form of a sheet, but may be formed on the substrate by printed wiring.

FIG. 5 is a diagram showing a result of measuring the communication distance of the antenna pattern 203 by an experiment in order to determine the occupied area of the static electricity removing sheet according to the embodiment.

When the static electricity removing sheet is not provided, when the width of the static electricity removing sheet is 5 mm, and when the width of the static electricity removing sheet is 7 mm, the communication distance with each other device is shown. Here, the measured value has an error of ± about 2 mm. In addition, the other device used a mobile terminal with a built-in NFC reader / writer. In the measurement method here, the diagonal center of the antenna pattern 203 and the center of the antenna of the mobile terminal are substantially aligned, the horizontal direction in FIG. 2 is the X direction, the vertical direction is the Y direction, and the direction perpendicular to the substrate 200 is the Z direction. It is supposed to be.

From the results shown in FIG. 5, no significant deterioration is observed in the performance of the antenna when there is no static electricity removing sheet and when the width of the static electricity removing sheet is 5 mm. However, when the width of the static electricity removing sheet is 7 mm, the communication distance is shortened by 6 to 20 mm in each of the Z direction, the Y direction, and the X direction, and it can be seen that the performance of the antenna is deteriorated.

Based on this result, the width of the static electricity removing sheet 208 on the opposite surface of the antenna pattern 203 is set to 5 mm, which is less than one-third of the width of 15 mm of the antenna pattern 203, so that the performance of the antenna is not affected. I understand. That is, by reducing the size of the static electricity removing sheet 208 directly behind the antenna pattern 203 to one-third or less of the effective area of the antenna pattern 203, the influence on the antenna performance is reduced.

As described above, according to the first embodiment, the static electricity removing sheet is arranged on the substrate surface opposite to the substrate surface on which the antenna pattern is arranged, and the size of the static electricity removing sheet affects the antenna performance of the antenna pattern. The size should not be given. As a result, the influence of static electricity applied to the wireless communication board can be reduced.

[Embodiment 2]
Next, Embodiment 2 of the present invention will be described. In the second embodiment, the ground pattern arranged on the opposite surface of the antenna pattern of the wireless communication board is formed by extending the ground pattern on the opposite surface of the antenna pattern with a width of 5 mm. As a result, the printed wiring pattern plays a role of removing static electricity. It has been confirmed that the effect of the second embodiment is the same as that of the first embodiment described above.

FIG. 4 is a diagram showing a substrate surface on the opposite side to the surface on which the antenna pattern of the wireless communication substrate according to the second embodiment is arranged.

In FIG. 4, both the static electricity removing sheet 208 and the ground pattern 207 of FIG. 3 are included in the ground pattern 401.

In the first embodiment described above, a member for attaching the static electricity removing sheet 208 to the substrate 200 and a cost for the work are incurred, which is added to the product cost. However, in the second embodiment, since the static electricity removing sheet 208 is not required, the member cost and the work cost for attaching can be reduced.

Further, the application example of the first embodiment can be dealt with by attaching an antistatic sheet 208 when the substrate 200 is incorporated into a plurality of different devices and when the substrate 200 is incorporated into an apparatus requiring antistatic measures. Further, when incorporating into a device that does not require static electricity countermeasures, a common substrate can be incorporated into a device having a different structure by not attaching the static electricity removing sheet to the substrate 200.

Further, when the direction in which static electricity is applied differs from that in the first embodiment depending on the shape of the device to be incorporated, it can be dealt with by changing the shape of the static electricity removing sheet according to the direction in which static electricity is applied.

On the other hand, the application example of the second embodiment is effective when it is incorporated in a device under the condition that the direction in which static electricity is applied is constant. In the second embodiment, since it is not necessary to attach the static electricity removing sheet to the substrate, it is possible to reduce the member cost and the attaching work cost.

As described above, in the antenna substrate according to the embodiment, a wireless communication antenna pattern is formed on the substrate, and an antistatic sheet within approximately one-third of the area of the antenna pattern is arranged on the opposite surface of the antenna pattern. This is achieved by grounding the static electricity removal sheet.

Further, according to another embodiment, as a wiring pattern that plays a role of removing static electricity by forming a ground pattern arranged on the opposite surface of the antenna pattern of the wireless communication board by extending on the opposite surface of the antenna pattern. Can be made to work.

(Other embodiments)
The present invention is not limited to the above embodiments, and various modifications and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.

200 ... Wireless communication board, 203 ... Antenna pattern, 204 ... LSI, 205 ... Connector, 206 ... Mounting hole, 207, 401 ... Ground pattern, 208 ... Static electricity removal sheet

Claims (11)

A substrate built into an image forming apparatus to enable wireless communication with a terminal.
The first surface side of the front Stories substrate, a ground pattern of the substrate is formed by a printed circuit, and, on a second surface side opposite to the first surface side of the substrate, receiving radio waves used in the wireless communication The area of the ground pattern formed on the first surface side corresponding to the region surrounded by the antenna pattern formed on the second surface side is such that the antenna pattern functioning as an antenna is formed by the printed wiring. A substrate characterized in that it is smaller than the area surrounded by the antenna pattern. The substrate according to claim 1, wherein a part of the ground pattern is formed at a position where static electricity from the outside of the image forming apparatus is applied to the part instead of the antenna pattern. The substrate according to claim 2, wherein a part of the ground pattern is formed at a position overlapping only a part of the formation position of the antenna pattern and at a position on the side in the intrusion direction of static electricity. The substrate according to any one of claims 1 to 3, wherein the substrate is a substrate incorporated inside an operation unit of the image forming apparatus. The substrate according to any one of claims 1 to 4, wherein the ground pattern is formed of a member that discharges static electricity to the ground. The substrate further has a mounting portion for connecting the substrate to the housing of the image forming apparatus.
The substrate according to claim 5, wherein the member that discharges static electricity to the ground discharges static electricity to the ground via a metal member attached to the mounting portion. The invention according to any one of claims 1 to 6, wherein the end portion of the antenna pattern on the substrate and the position of a part of the end portion of the ground pattern are arranged so as to substantially coincide with each other. substrate. The board includes an IC (Integrated Circuit) that controls the wireless communication.
The substrate according to any one of claims 1 to 7, wherein the antenna pattern is connected to the IC. The substrate according to claim 1 , wherein the area of the ground pattern is one-third or less of the area surrounded by the antenna pattern. The substrate according to any one of claims 1 to 9 , wherein the wireless communication is NFC (Near Field Communication) communication. An image forming apparatus comprising the substrate according to any one of claims 1 to 10.

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