Wireless communication device

Abstract

To prevent voltage from being supplied from the main board side to the wireless communication board side when the user disconnects the wireless communication board connector from the main board connector, with no ground connected to the ground terminal on the wireless communication board.SOLUTION: When a control unit (854) detects that no current flows from a pull-up resistor (857) to ground (GND) through the detection terminals (851), first terminal (811), second terminal (812), and ground terminal (852), it stops supplying voltage to the output terminal (853).SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a wireless communication device.

Background Art

[0002] Patent Document 1 describes an image forming apparatus provided with a main body side substrate to which a circuit board for wireless communication can be attached.

[0003] In the image forming apparatus of Patent Document 1, connectors are provided on each of the main body side substrate and the circuit board for wireless communication. The user can attach the circuit board for wireless communication to the main body side substrate by inserting the connector of the circuit board for wireless communication into the connector of the main body side substrate. Further, the user can remove the electrical component from the main body side substrate by pulling out the connector of the circuit board for wireless communication from the connector of the main body side substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When attaching a wireless communication substrate to a main substrate as in Patent Document 1, power supply terminals and ground terminals are provided on the respective connectors. When the connectors are connected to each other, the power supply terminals and the ground terminals of each other are electrically connected to each other.

[0006] By the way, the attachment and detachment between the connector of the main board and the connector of the wireless communication board are performed by the user's hand. For this reason, when the user removes the connector of the component from the connector of the board, depending on the way of removal, the ground terminals may separate from each other earlier than the power terminals while the power terminals are still electrically connected. In this case, the ground is not connected to the ground terminal of the wireless communication board, and there is a risk that a voltage may be supplied to the wireless communication board from the board side while the potential of the ground terminal of the wireless communication board remains electrically floating.

[0007] One aspect of the present invention aims to prevent a voltage from being supplied from the main board side to the wireless communication board side in a state where the ground is not connected to the ground terminal of the wireless communication board when the user removes the connector of the wireless communication board from the connector of the main board.

Means for Solving the Problem

[0008] In order to solve the above problems, a wireless communication device according to one aspect of the present invention includes a main board and a wireless communication board, and is a wireless communication device in which the main board and the wireless communication board are detachable. The main board includes a first connector having a detection terminal, a ground terminal, and an output terminal, a current unit that flows a current toward the detection terminal, a ground unit wired to the ground terminal, a power supply unit that supplies a voltage toward the output terminal, and a control unit. The wireless communication board includes a second connector having a first terminal connectable to the detection terminal, a second terminal connectable to the ground terminal, and an input terminal connectable to the output terminal. The first terminal and the second terminal are electrically connected. When the control unit detects that the current flowing from the current unit to the ground unit stops flowing through the detection terminal, the first terminal, the second terminal, and the ground terminal, the control unit stops the voltage supply to the output terminal by the power supply unit.

[0009] According to the above configuration, when the first connector and the second connector are connected, the current flowing from the current section toward the detection terminal flows from the detection terminal to the ground section via the first terminal connected to the detection terminal, the second terminal connected to the first terminal via wiring, and the ground terminal connected to the second terminal.

[0010] Also, according to the above configuration, when the second connector connected to the first connector is removed from the first connector, if the first terminal connected to the detection terminal is separated from the detection terminal and / or the second terminal connected to the ground terminal is separated from the ground terminal, the current stops flowing in the order of the current section, the detection terminal, the first terminal, the second terminal, the ground terminal, and the ground section.

[0011] Therefore, according to the above configuration, the control unit can prevent a voltage from being supplied from the output terminal of the main board to the input terminal of the wireless communication board in a state where the second terminal of the wireless communication board is not connected to the ground section when the user removes the second connector of the wireless communication board from the first connector of the main board, by detecting that the current flowing from the current section toward the detection terminal has stopped flowing.

[0012] A wireless communication device according to one aspect of the present invention includes a main board, a sub-board, and a wireless communication board, and is a wireless communication device in which the main board and the wireless communication board are detachable via the sub-board. The main board includes a first connector having a detection terminal, a ground terminal, and an output terminal, a current unit that flows a current toward the detection terminal, a ground unit wired to the ground terminal, a power supply unit that supplies a voltage toward the output terminal, and a control unit. The wireless communication board includes a second connector, and the sub-board includes a first sub-connector having a first sub-terminal connectable to the detection terminal, a second sub-terminal connectable to the ground terminal, and a third sub-terminal connectable to the output terminal, and a second sub-connector connected to the second connector of the wireless communication board. The first sub-terminal and the second sub-terminal are electrically connected. When the control unit detects that the current flowing from the current unit to the ground unit stops from a state where the current flowing from the current unit to the ground unit is detected via the detection terminal, the first sub-terminal, the second sub-terminal, and the ground terminal, the control unit stops the voltage supply to the output terminal by the power supply unit.

[0013] According to the above configuration, even when the first connector of the main board and the second connector of the wireless communication board are connected via a sub-board provided with a first sub-connector connectable to the first connector of the main board and a second sub-connector connectable to the second connector of the wireless communication board, the same effects as the above aspect can be obtained.

[0014] The sub-board further includes a holder that covers the sub-board and the wireless communication board except for the first sub-connector, and the holder may be detachable from the main board by inserting the first sub-connector into the first connector and removing the first sub-connector from the first connector.

[0015] According to the above configuration, the holder covers the sub-board and the wireless communication board except for the first sub-connector. Therefore, according to the above configuration, the holder can be made detachable from the main board by inserting the first sub-connector into the first connector or removing the first sub-connector from the first connector.

[0016] When the control unit detects that the current stops flowing, it may stop the output of the signal transmitted from the main board to the wireless communication board via the signal line for transmitting and receiving signals between the main board and the wireless communication board.

[0017] According to the above configuration, it is possible to prevent a signal from being transmitted from the main board to the wireless communication board while the ground portion is not connected to the wireless communication board. That is, according to the above configuration, it is possible to further prevent a voltage from being supplied from the main board to the wireless communication board via the signal line.

[0018] The main board further has a switching element for controlling the voltage supply to the wireless communication board and the voltage supply to the pull-up resistor for pulling up the signal line. When the control unit detects that the current stops flowing, it may turn off the switching element to stop the voltage supply to the wireless communication board and the voltage supply to the pull-up resistor.

[0019] According to the above configuration, by turning off the switching element, it is possible to stop the voltage supply to the wireless communication board and the voltage supply to the pull-up resistor.

[0020] In a top view of the second connector of the wireless communication board, the shape of the second connector is a rectangular shape, and the first terminal and the second terminal may be arranged at two corner portions located at opposite corners of the rectangular shape.

[0021] According to the above configuration, since the first terminal and the second terminal are arranged at two corner portions located at opposite corners of the rectangular shape of the second connector, when the second connector of the wireless communication board is removed from the first connector of the main board, either the first terminal or the second terminal will leave later than the input terminal.

[0022] In a top view of the first sub-connector of the sub-substrate, the shape of the first sub-connector is a rectangular shape, and the first sub-terminal and the second sub-terminal may be arranged at two corner portions located at opposite corners of the rectangular shape.

[0023] According to the above configuration, since the first sub-terminal and the second sub-terminal are arranged at two corner portions located at opposite corners of the rectangular shape of the first sub-connector, when the first sub-connector of the sub-substrate is removed from the first connector of the main substrate, either the first sub-terminal or the second sub-terminal will separate later than the third sub-terminal.

[0024] A wireless communication device according to an aspect of the present invention includes a main substrate and a wireless communication substrate, and is a wireless communication device in which the main substrate and the wireless communication substrate are detachable. The main substrate includes a first connector having a detection terminal, a ground terminal, and an output terminal, a current unit that flows a current toward the detection terminal, a ground unit wired to the ground terminal, and a power supply unit that supplies a voltage toward the output terminal. The wireless communication substrate includes a second connector having a first terminal connectable to the detection terminal, a second terminal connectable to the ground terminal, and an input terminal connectable to the output terminal, and the first terminal and the second terminal are electrically connected.

[0025] According to the above configuration, when the first connector and the second connector are connected, the current flowing from the current unit toward the detection terminal flows from the detection terminal, through the first terminal connected to the detection terminal, the second terminal connected to the first terminal via wiring, and the ground terminal connected to the second terminal, and then flows into the ground unit.

[0026] Also, according to the above configuration, when the second connector connected to the first connector is removed from the first connector, if the first terminal connected to the detection terminal separates from the detection terminal and / or the second terminal connected to the ground terminal separates from the ground terminal, the current stops flowing in the order of the current unit, the detection terminal, the first terminal, the second terminal, the ground terminal, and the ground unit.

[0027] A wireless communication device according to an aspect of the present invention includes a main board, a sub-board, and a wireless communication board, and is a wireless communication device in which the main board and the wireless communication board are detachable via the sub-board. The main board includes a first connector having a detection terminal, a ground terminal, and an output terminal, a current unit that flows a current toward the detection terminal, a ground unit wired to the ground terminal, and a power supply unit that supplies a voltage toward the output terminal. The wireless communication board includes a second connector, and the sub-board includes a first sub-connector having a first sub-terminal connectable to the detection terminal, a second sub-terminal connectable to the ground terminal, and a third sub-terminal connectable to the output terminal, and a second sub-connector connected to the second connector of the wireless communication board. The first sub-terminal and the second sub-terminal are electrically connected.

[0028] According to the above configuration, even when the first connector of the main board and the second connector of the wireless communication board are connected via a sub-board provided with a first sub-connector connectable to the first connector of the main board and a second sub-connector connectable to the second connector of the wireless communication board, the same effects as the above aspect can be obtained.

Effects of the Invention

[0029] According to an aspect of the present invention, when a user removes the connector of the wireless communication board from the connector of the main board, it is possible to prevent a voltage from being supplied from the main board side to the wireless communication board side in a state where the ground is not connected to the ground terminal of the wireless communication board.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0031] [Embodiment 1] Before explaining the characteristic configuration of the present invention below, for understanding of the present invention, first, the configuration of the image forming apparatus 1 according to Embodiment 1 of the present invention will be described.

[0032] [Configuration of Image Forming Apparatus 1] FIG. 1 is a perspective view showing the image forming apparatus 1 according to Embodiment 1 of the present invention. FIG. 2 is a right side view showing the image forming apparatus 1. The image forming apparatus 1 is an example of the wireless communication apparatus according to the present invention.

[0033] In the following description, the lower right side in FIG. 1 is defined as the front side of the image forming apparatus 1, the upper left side in FIG. 1 is defined as the rear side of the image forming apparatus 1, the upper right side in FIG. 1 is defined as the left side of the image forming apparatus 1, and the lower left side in FIG. 1 is defined as the right side of the image forming apparatus 1. Also, the upper side and the lower side in FIG. 1 are defined as the upper side and the lower side of the image forming apparatus 1, respectively.

[0034] The image forming apparatus 1 includes an apparatus main body 2. The apparatus main body 2 is a housing that houses a paper feeding unit, an image forming unit, a discharging unit, a re-conveying unit, a motor, etc. not shown in the figures. As shown in FIGS. 1 and 2, the apparatus main body 2 is composed of a front cover 20, a rear cover 21, a right side cover 22, a left side cover 23, an upper cover 24, and an upper end cover 25.

[0035] The image forming apparatus 1 includes a main board 85, a holder 82, and an opening / closing cover 83. The main board 85 is a control board that is disposed on the back side of the right side cover 22 and controls each part of the image forming apparatus 1. The holder 82 holds a wireless communication board 81 and a sub-board 86. The image forming apparatus 1 is configured such that the user can detach the holder 82 from the main board 85 with the opening / closing cover 83 open.

[0036] The wireless communication board 81 is a board that communicates with an external terminal such as a smartphone by radio waves and realizes wireless communication via a wireless LAN. In this embodiment, the wireless communication board 81 is exemplified as a board for a wireless LAN, but it may be a board that realizes wireless communication according to other communication standards. For example, it may be a board for NFC (Near Field Communication) or a board for Bluetooth (registered trademark).

[0037] FIG. 3 is a perspective view showing the attachment status of the holder 82, the wireless communication board 81, and the sub-board 86 to the main board 85. FIG. 4 is a perspective view showing the status in which the holder 82 holds the wireless communication board 81 and the sub-board 86 as shown in FIG. 3.

[0038] (Wireless communication board 81) As shown in FIG. 3, the wireless communication board 81 includes a second connector 81a and an antenna 81b for performing wireless communication. The second connector 81a is a connector that connects to a second sub-connector 86b provided on the sub-board 86 and is configured to be detachable from the sub-board 86. The antenna 81b is an antenna element for transmitting radio waves from the wireless communication board 81 and receiving radio waves.

[0039] Also, as shown in FIG. 4, the wireless communication board 81 further includes a wireless communication module 81c. The wireless communication module 81c has a role of transmitting the signal received by the antenna 81b to the main board 85 or instructing the antenna 81b to transmit radio waves based on an instruction from the main board 85.

[0040] (Main board 85) The main board 85 includes a first connector 85a and an opening 85b. The first connector 85a is a connector that connects to a first sub-connector 86a provided on the sub-board 86. The first connector 85a is configured such that the sub-board 86 held by the holder 82 can be detachably attached. The first connector 85a has a concave connector shape. The opening 85b is a hole used to position the holder 82 with respect to the main board 85. The aperture diameter of the opening 85b is slightly larger than the outer shape of the protruding portion 82f of the holder 82 and is dimensioned such that the protruding portion 82f can be inserted therethrough.

[0041] (Sub-board 86) As shown in FIG. 3, the sub-board 86 is a board interposed between the main board 85 and the wireless communication board 81. The sub-board 86 is a board for converting the pin shape of the male terminal of the second connector 81a of the wireless communication board 81 into a convex first sub-connector 86a so as to fit into the concave shape of the first connector 85a of the main board 85.

[0042] (Holder 82) As shown in FIGS. 3 and 4, the holder 82 covers the sub-board 86 and the wireless communication board 81 except for the first sub-connector 86a of the sub-board 86. With the wireless communication board 81 and the sub-board 86 held by the holder 82, the wireless communication board 81 and the sub-board 86 are attached to the main board 85. The first sub-connector 86a of the sub-board 86 is connected to the first connector 85a of the main board 85.

[0043] When the holder 82 is attached to the main board 85, the protruding portion 82f of the holder 82 is inserted into the opening 85b, and the first connector 85a of the main board 85 and the first sub-connector 86a of the sub-board 86 are connected.

[0044] The holder 82 is composed of a first unit 82a and a second unit 82b. The first unit 82a and the second unit 82b are fitted to each other and integrated.

[0045] (Detachable structure of the main board 85, sub-board 86, and wireless communication board 81) FIG. 5 is a cross-sectional view showing the detachable structure between the connectors of the main board 85, sub-board 86, and wireless communication board 81. The left view of FIG. 5 shows a state where the connectors of each board are removed. The right view of FIG. 5 shows a state where the connectors of each board are attached.

[0046] As shown in FIG. 5, a first connector 85a is installed on the board surface 85c of the main board 85. A first sub-connector 86a is installed on the first board surface 86i of the sub-board 86, and a second sub-connector 86b is installed on the second board surface 86j which is the back surface of the first board surface 86i.

[0047] The first sub-connector 86a is connected to the first connector 85a of the main board 85 so that the first board surface 86i of the sub-board 86 and the board surface 85c of the main board 85 are parallel. The second sub-connector 86b is connected to the second connector 81a of the wireless communication board 81 so that the second board surface 86j of the sub-board 86 and the board surface 81d of the wireless communication board 81 are parallel.

[0048] The main board 85 is electrically connected to the wireless communication module 81c via the first connector 85a, the first sub-connector 86a, the second sub-connector 86b, and the second connector 81a. As will be described later, the main board 85 can supply a power voltage to the wireless communication board 81 via the first connector 85a, the first sub-connector 86a, the second sub-connector 86b, and the second connector 81a, and can perform signal transmission and reception with the wireless communication module 81c, command transmission, and the like.

[0049] As shown in FIGS. 1 and 2, the image forming apparatus 1 includes an opening / closing cover 83 that closes an opening 22b formed in a side surface 22a of the right side cover 22. When the opening / closing cover 83 is open, the user can remove the holder 82 from the main board 85 in the image forming apparatus 1. As described above, the shape of the first sub-connector 86a of the sub-board 86 is not a pin shape but a convex shape. Further, the first connector 85a of the main board 85 is a concave shape. Therefore, since it is easy to fit the first sub-connector 86a of the sub-board 86 into the first connector 85a of the main board 85, the user can easily attach and detach the holder 82 to and from the main board 85.

[0050] When the power of the image forming apparatus 1 is on, there is a possibility that the opening / closing cover 83 is opened by the user and the holder 82 is removed from the main board 85. If the user removes the holder 82 from the main board 85 while the power of the image forming apparatus 1 is on, depending on the direction in which the holder 82 is removed from the main board 85, the first sub-connector 86a of the sub-board 86 in the holder 82 may come out while being inclined with respect to the first connector 85a of the main board 85.

[0051] In this case, between the first sub-connector 86a and the first connector 85a, there may be a situation where while the respective power supply terminals remain electrically connected, the respective ground terminals separate from each other earlier than the power supply terminals. When the ground is not connected between the wireless communication module 81c and the main board 85, and a power supply voltage is supplied from the main board 85 to the wireless communication board 81 via the first sub-connector 86a, the first connector 85a, etc., a high power supply voltage is supplied to the wireless communication board 81, that is, the wireless communication module 81c, and there is a risk that the wireless communication module 81c may be damaged.

[0052] Therefore, when the ground is not connected to the ground terminal of the wireless communication board 81, the configuration of the image forming apparatus 1 that can stop the voltage supply from the main board 85 to the wireless communication board 81 will be described in detail.

[0053] (Configuration example of wireless communication board 81, sub-board 86, and main board 85) FIG. 6 is a diagram showing a configuration example of the image forming apparatus 1. The first connector 85a of the main board 85 is provided with a detection terminal 851, a ground terminal 852, and an output terminal 853. The first sub-connector 86a of the sub-board 86 is provided with a first sub-terminal 861, a second sub-terminal 862, and a third sub-terminal 863. A plurality of terminals for transmitting and receiving signals from SDIO (Serial Data Input Output) signal lines and CMD (Command) signal lines are respectively provided on the first connector 85a and the first sub-connector 86a.

[0054] When the holder 82 is attached to the main board 85 and the first connector 85a of the main board 85 and the first sub-connector 86a of the sub-board 86 are connected, the detection terminal 851 and the first sub-terminal 861 are connected, the ground terminal 852 and the second sub-terminal 862 are connected, and the output terminal 853 and the third sub-terminal 863 are connected.

[0055] In addition, the second connector 81a of the wireless communication board 81 is provided with a second terminal 812 and an input terminal 813. Further, the second sub-connector 86b of the sub-board 86 is provided with a fourth sub-terminal 864 and a fifth sub-terminal 865.

[0056] The second connector 81a of the wireless communication board 81 and the second sub-connector 86b of the sub-board 86 are connected. The second terminal 812 and the fourth sub-terminal 864 are connected, and the input terminal 813 and the fifth sub-terminal 865 are connected. A plurality of terminals for transmitting and receiving signals from the SDIO signal line and the CMD signal line are respectively provided on the second connector 81a and the second sub-connector 86b.

[0057] The main board 85 includes a control unit 854, a transistor 855, four pull-up resistors 856, a pull-up resistor 857, and a resistor 858. Further, the control unit 854 includes a power control unit 854a and a detection unit 854b. The transistor 855 is an example of a switching element.

[0058] The sub-board 86 is a multi-layer printed circuit board, and a metal layer is formed on the intermediate layer. The first sub-terminal 861 and the second sub-terminal 862 are respectively connected toward the metal layer of the sub-board 86. The first sub-terminal 861 and the second sub-terminal 862 are electrically connected via the metal layer of the sub-board 86.

[0059] The second sub-terminal 862 and the fourth sub-terminal 864 are electrically connected via a through-hole 86g connecting the first board surface 86i (see FIG. 8) and the second board surface 86j (see FIG. 8) of the sub-board 86.

[0060] When the first connector 85a and the first sub-connector 86a are not connected, a high level (hereinafter referred to as H level) is input to the detection unit 854b by the pull-up resistor 857. Also, when the first connector 85a and the first sub-connector 86a are connected, since current flows to the ground (GND) through the detection terminal 851, the first sub-terminal 861, the second sub-terminal 862, and the ground terminal 852, a low level (hereinafter referred to as L level) is input to the detection unit 854b.

[0061] When a high level is input to the detection unit 854b, since the detection terminal 851 and the first sub-terminal 861, or the ground terminal 852 and the second sub-terminal 862 are not connected, the detection unit 854b instructs the power control unit 854a to stop supplying the power voltage. Also, when a low level is input to the detection unit 854b, since the detection terminal 851 and the first sub-terminal 861 are connected and the ground terminal 852 and the second sub-terminal 862 are connected, the detection unit 854b instructs the power control unit 854a to supply the power voltage.

[0062] The control unit 854 has an SDIO signal line and a CMD signal line for controlling the CPU (Central Processing Unit) 814 provided on the wireless communication board 81, and each signal line is pulled up by a pull-up resistor 856. Note that the CPU 814 is included in the wireless communication module 81c.

[0063] The ground of the CPU 814 is connected to the ground (GND) of the main board 85 via the second terminal 812 of the wireless communication board 81, the fourth sub-terminal 864 of the sub-board 86, the through-hole 86g connecting the first board surface 86i and the second board surface 86j, the second sub-terminal 862, and the ground terminal 852 of the main board 85. Also, the wireless communication module 81c including the CPU 814 will be supplied with the power voltage from the main board 85 via the output terminal 853, the third sub-terminal 863, the fifth sub-terminal 865, and the input terminal 813.

[0064] In the control unit 854, an output circuit (not shown) that outputs signals to the SDIO signal line and the CMD signal line is constituted by an open-drain circuit or an open-collector circuit, and outputs either an L level or a high impedance. When the output circuit becomes high impedance, the signal becomes an H level by the pull-up resistor 856.

[0065] When the power control unit 854a detects that the detection terminal 851 and the first sub-terminal 861, or the ground terminal 852 and the second sub-terminal 862 are not connected by the detection unit 854b, it turns off the transistor 855 to stop the supply of the power voltage (+3.3V) to the wireless communication board 81. At this time, the supply of the power voltage to the pull-up resistor 856 is also stopped. As a result, when the supply of the power voltage to the wireless communication board 81 is stopped, no voltage is supplied to the signal line, and latch-up or the like does not occur. Note that the power voltage is supplied from the 3.3V power supply of the main board 85.

[0066] Also, when the power control unit 854a detects that the detection terminal 851 and the first sub-terminal 861 are connected and the ground terminal 852 and the second sub-terminal 862 are connected by the detection unit 854b, it turns on the transistor 855 to supply the power voltage to the wireless communication board 81. At this time, the supply of the power voltage to the pull-up resistor 856 is also performed.

[0067] <Specific example when the holder 82 is removed from the main board 85> For example, when the holder 82 is removed from the main board 85, that is, when the first sub-connector 86a is pulled out from the first connector 85a, before the output terminal 853 and the third sub-terminal 863 are separated, if the detection terminal 851 and the first sub-terminal 861, or the ground terminal 852 and the second sub-terminal 862 are separated, no current flows from the pull-up resistor 857 to the ground, and the detection unit 854b detects an H level.

[0068] When the power control unit 854a detects that the detection terminal 851 and the first sub-terminal 861, or the ground terminal 852 and the second sub-terminal 862 are not connected by the detection unit 854b, it turns off the transistor 855 to stop the supply of the power voltage to the wireless communication board 81. At this time, the supply of the power voltage to the pull-up resistor 856 is also stopped.

[0069] FIG. 7 is a flowchart for explaining the processing procedure of the image forming apparatus 1. First, the control unit 854 determines whether or not the first sub-connector 86a connected to the first connector 85a has been removed based on whether an H level or an L level is input to the detection unit 854b (S1).

[0070] If the first sub-connector 86a has not been removed from the first connector 85a (S1, No), the control unit 854 repeats the process of step S1.

[0071] If the first sub-connector 86a has been removed from the first connector 85a (S1, Yes), the control unit 854 uses the power control unit 854a to turn off the transistor 855 to stop the supply of the power voltage to the wireless communication board 81 and the pull-up resistor 856 (S2), and ends the process.

[0072] As described above, when the user removes the first sub-connector 86a of the sub-board 86 from the first connector 85a of the main board 85 via the holder 82, it is possible to prevent the power voltage from being supplied from the output terminal 853 of the main board 85 to the input terminal 813 of the wireless communication board 81 without the ground being connected to the first sub-terminal 861 or the second sub-terminal 862 of the sub-board 86.

[0073] (Arrangement example of the first sub-terminal 861 and the second sub-terminal 862) FIG. 8 is a plan view showing the first substrate surface 86i and the second substrate surface 86j of the sub-substrate 86. The first substrate surface 86i is the surface facing the substrate surface 85c of the main substrate 85 shown in FIG. 5. The second substrate surface 86j is the surface facing the substrate surface 81d of the wireless communication substrate 81 shown in FIG. 5. The left figure of FIG. 8 shows the first substrate surface 86i. The right figure of FIG. 8 shows the second substrate surface 86j.

[0074] When looking at the sub-substrate 86 from the first substrate surface 86i shown in the left figure of FIG. 8, a wiring pattern 86e is arranged in the hatched portion 86m of the sub-substrate 86. The first sub-connector 86a is electrically connected to the wiring pattern 86e.

[0075] On the other hand, when looking at the sub-substrate 86 from the second substrate surface 86j shown in the right figure of FIG. 8, a wiring pattern 86f is arranged in the hatched portion 86n of the sub-substrate 86. The second sub-connector 86b is electrically connected to the wiring pattern 86f.

[0076] A through hole 86g penetrating the sub-substrate 86 is provided in the sub-substrate 86. The wiring pattern 86e shown in the left figure of FIG. 8 and the wiring pattern 86f shown in the right figure of FIG. 8 are electrically connected via the through hole 86g. By electrically connecting the wiring pattern 86e and the wiring pattern 86f, the first sub-connector 86a and the second sub-connector 86b are electrically connected.

[0077] As shown in the left figure of FIG. 8, in a top view of the first sub-connector 86a of the sub-substrate 86, the first sub-terminal 861 and the second sub-terminal 862 are arranged at two corner portions located at the diagonals of the rectangular shape.

[0078] In this way, since the first sub-terminal 861 and the second sub-terminal 862 are arranged at two corner portions located at the diagonals of the rectangular shape of the first sub-connector 86a, when the first sub-connector 86a of the sub-substrate 86 is pulled out obliquely from the first connector 85a of the main substrate 85, either the first sub-terminal 861 or the second sub-terminal 862 will leave later than the third sub-terminal 863.

[0079] [Embodiment 2] Hereinafter, Embodiment 2 of the present invention will be described in detail. As described above, in this embodiment, a configuration in which the wireless communication board 81 held by the holder 82 is detachable from the main board 85, that is, a configuration in the case where there is no sub-board 86 will be described.

[0080] (Detachable Structure of Main Board 85 and Wireless Communication Board 81) FIG. 9 is a cross-sectional view showing the detachable structure between the connectors of the main board 85 and the wireless communication board 81. The left diagram of FIG. 9 shows a state where the connectors of each board are removed. The right diagram of FIG. 9 shows a state where the connectors of each board are attached.

[0081] As shown in FIG. 9, a first connector 859 is installed on the board surface 85c of the main board 85. A second connector 815 is installed on the board surface 81d of the wireless communication board 81. Note that the first connector 859 has the same configuration as the first connector 85a in FIG. 5. Also, the second connector 815 has the same configuration as the first sub-connector 86a in FIG. 5.

[0082] The second connector 815 is connected to the first connector 859 of the main board 85 so that the board surface 81d of the wireless communication board 81 and the board surface 85c of the main board 85 are parallel. Note that "parallel" includes not only the case of being completely parallel but also a state close to parallel, for example, a state deviated by several degrees from a parallel plane.

[0083] FIG. 10 is a diagram showing a configuration example of the image forming apparatus 1A. In the image forming apparatus 1A shown in FIG. 10, as shown in FIG. 9, the wireless communication board 81 and the main board 85 are directly connected without passing through the sub-board 86. A detection terminal 851, a ground terminal 852, and an output terminal 853 are provided on the first connector 859 of the main board 85. Also, a first terminal 811, a second terminal 812, and an input terminal 813 are provided on the second connector 815 of the wireless communication board 81.

[0084] When the first connector 859 of the main board 85 is connected to the second connector 815 of the wireless communication board 81, the detection terminal 851 and the first terminal 811 are connected, the ground terminal 852 and the second terminal 812 are connected, and the output terminal 853 and the input terminal 813 are connected.

[0085] Similar to the first embodiment, the main board 85 includes a control unit 854, a transistor 855, four pull-up resistors 856, a pull-up resistor 857, and a resistor 858. The control unit 854 includes a power control unit 854a and a detection unit 854b.

[0086] On the wireless communication board 81, the first terminal 811 and the second terminal 812 are electrically connected by wiring arranged on the wireless communication board 81. The wireless communication board 81 is a multi-layer printed circuit board, and a metal layer is formed in the intermediate layer. The first terminal 811 and the second terminal 812 are respectively connected toward the metal layer of the wireless communication board 81. The first terminal 811 and the second terminal 812 are electrically connected via the metal layer of the wireless communication board 81.

[0087] Via the second terminal 812 of the wireless communication board 81 and the ground terminal 852 of the main board 85, the ground of the CPU 814 is connected to the ground (GND) of the main board 85. Also, the wireless communication module 81c including the CPU 814 will be supplied with the power supply voltage from the main board 85 via the output terminal 853 and the input terminal 813.

[0088] When the first connector 859 and the second connector 815 are not connected, a high level is input to the detection unit 854b by the pull-up resistor 857. Also, when the first connector 859 and the second connector 815 are connected, since current flows to the ground (GND) through the detection terminal 851, the first terminal 811, the second terminal 812, and the ground terminal 852, a low level is input to the detection unit 854b. The pull-up resistor 857 is an example of a current part. The ground (GND) is an example of a ground part.

[0089] When an H level is input to the detection unit 854b, since the detection terminal 851 and the first terminal 811, or the ground terminal 852 and the second terminal 812 are not connected, the detection unit 854b instructs the power control unit 854a to stop the supply of the power voltage. Also, when an L level is input to the detection unit 854b, since the detection terminal 851 and the first terminal 811 are connected and the ground terminal 852 and the second terminal 812 are connected, the detection unit 854b instructs the power control unit 854a to supply the power voltage.

[0090] The control unit 854 has an SDIO signal line and a CMD signal line for controlling the CPU 814 provided on the wireless communication board 81, and each signal line is pulled up by a pull-up resistor 856. Note that the CPU 814 is included in the wireless communication module 81c.

[0091] In the control unit 854, an output circuit (not shown) that outputs signals to the SDIO signal line and the CMD signal line is constituted by an open-drain circuit or an open-collector circuit, and outputs either an L level or a high impedance. When the output circuit becomes high impedance, the signal becomes an H level by the pull-up resistor 856.

[0092] When the power control unit 854a detects that the detection terminal 851 and the first terminal 811, or the ground terminal 852 and the second terminal 812 are not connected by the detection unit 854b, it turns off the transistor 855 to stop the supply of the power voltage (+3.3V) to the wireless communication board 81. At this time, the supply of the power voltage to the pull-up resistor 856 is also stopped. Thereby, when the voltage supply to the wireless communication board 81 is stopped, no voltage is supplied to the signal line, and latch-up or the like does not occur. Note that the power voltage is supplied from a power supply unit (not shown).

[0093] Further, when the detection unit 854b detects that the detection terminal 851 and the first terminal 811 are connected and the ground terminal 852 and the second terminal 812 are connected, the power control unit 854a turns on the transistor 855 to supply the power voltage to the wireless communication board 81. At this time, the power voltage is also supplied to the pull-up resistor 856.

[0094] When the first connector 859 and the second connector 815 are connected, the power voltage is supplied to the wireless communication board 81. For example, when the second connector 815 connected to the first connector 859 is removed, if the detection terminal 851 and the first terminal 811, or the ground terminal 852 and the second terminal 812, are separated before the output terminal 853 and the input terminal 813 are separated, no current flows from the pull-up resistor 857 to the ground, and the detection unit 854b detects the H level.

[0095] When the power control unit 854a detects that the detection terminal 851 and the first terminal 811, or the ground terminal 852 and the second terminal 812, are not connected by the detection unit 854b, the power control unit 854a turns off the transistor 855 to stop the supply of the power voltage to the wireless communication board 81. At this time, the supply of the power voltage to the pull-up resistor 856 is also stopped.

[0096] As described above, when the user removes the second connector 815 of the wireless communication board 81 from the first connector 859 of the main board 85, it is possible to prevent the voltage from being supplied from the output terminal 853 of the main board 85 to the input terminal 813 of the wireless communication board 81 without the ground being connected to the first terminal 811 or the second terminal 812 of the wireless communication board 81.

[0097] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims. The configurations obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention.

Description of Reference Numerals

[0098] 1, 1A Image forming apparatus 81 Wireless communication substrate 81a, 815 Second connector 81b Antenna 81c Wireless communication module 81d Substrate surface 82 Holder 85 Main substrate 85a, 859 First connector 86 Substrate 86a First sub-connector 86b Second sub-connector 814 CPU 854 Control unit 854a Power control unit 854b Detection unit 855 Transistor 856, 857 Pull-up resistor

Claims

1. A wireless communication device comprising a main board, a sub-board, and a wireless communication board, wherein the main board and the wireless communication board are detachable via the sub-board, the main board includes a first connector having a detection terminal, a ground terminal, and an output terminal, a current unit that flows a current toward the detection terminal, a ground unit wired to the ground terminal, a power supply unit that supplies a voltage toward the output terminal, and a control unit, the wireless communication board includes a second connector, the sub-board includes a first sub-connector having a first sub-terminal connectable to the detection terminal, a second sub-terminal connectable to the ground terminal, and a third sub-terminal connectable to the output terminal, and a second sub-connector connected to the second connector of the wireless communication board, the first sub-terminal and the second sub-terminal are electrically connected, when the control unit detects that the current flowing from the current unit to the ground unit stops from a state where it detects the current flowing through the detection terminal, the first sub-terminal, the second sub-terminal, and the ground terminal, the control unit stops the voltage supply to the output terminal by the power supply unit. The wireless communication device is characterized by this.

2. The wireless communication device according to claim 1, further comprising a holder that covers the sub-board and the wireless communication board except for the first sub-connector, wherein the holder is detachable from the main board by inserting and removing the first sub-connector to and from the first connector.

3. The wireless communication device according to claim 2, wherein when the control unit detects that the current stops flowing, the control unit stops the output of a signal transmitted from the main board to the wireless communication board via a signal line for transmitting and receiving signals between the main board and the wireless communication board.

4. The main board further has a switching element that controls the voltage supply to the wireless communication board and the voltage supply to a pull-up resistor for pulling up the signal line, The wireless communication device according to claim 3, wherein when the control unit detects that the current stops flowing, the control unit turns off the switching element to stop the voltage supply to the wireless communication board and the voltage supply to the pull-up resistor.

5. A wireless communication device comprising a main board and a wireless communication board, wherein the main board and the wireless communication board are detachable, The main board includes a first connector having a detection terminal, a ground terminal, and an output terminal, a current section that flows a current toward the detection terminal, a ground section wired to the ground terminal, a power supply section that supplies a voltage toward the output terminal, and a control section. The wireless communication board includes a second connector having a first terminal connectable to the detection terminal, a second terminal connectable to the ground terminal, and an input terminal connectable to the output terminal. The first terminal and the second terminal are electrically connected. When the control section detects that the current flowing from the current section to the ground section stops from a state where it detects the current flowing through the detection terminal, the first terminal, the second terminal, and the ground terminal, the control section stops the voltage supply to the output terminal by the power supply section. In a top view of the second connector of the wireless communication board, the shape of the second connector is a rectangular shape. A wireless communication device, wherein the first terminal and the second terminal are arranged at two corner portions located at opposite corners of the rectangular shape.

6. In a top view of the first sub-connector of the sub-board, the shape of the first sub-connector is a rectangular shape. The wireless communication device according to claim 1, wherein the first sub-terminal and the second sub-terminal are arranged at two corner portions located at opposite corners of the rectangular shape.

7. A wireless communication device including a main board, a sub-board, and a wireless communication board, wherein the main board and the wireless communication board are detachable via the sub-board, the main board includes a first connector having a detection terminal, a ground terminal, and an output terminal, a current section that flows a current toward the detection terminal, a ground section wired to the ground terminal, and a power supply section that supplies a voltage toward the output terminal. The wireless communication board includes a second connector. The sub-board includes a first sub-connector having a first sub-terminal connectable to the detection terminal, a second sub-terminal connectable to the ground terminal, and a third sub-terminal connectable to the output terminal, and a second sub-connector connected to the second connector of the wireless communication board. A wireless communication device, wherein the first sub-terminal and the second sub-terminal are electrically connected.

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