WO2014112064A1

WO2014112064A1 - Wireless communication system, and electronic component mounting device

Info

Publication number: WO2014112064A1
Application number: PCT/JP2013/050766
Authority: WO
Inventors: 重元廣田; 神藤　高広; 伸夫長坂; 泰章今寺
Original assignee: 富士機械製造株式会社
Priority date: 2013-01-17
Filing date: 2013-01-17
Publication date: 2014-07-24
Also published as: JP6189336B2; JPWO2014112064A1

Abstract

Provided are a wireless communication system that can better adapt to fluctuations in the signal intensity of wireless signals output from a transmission device, and an electronic component mounting device that uses the wireless communication system. The intensity of light received by a laser diode (93A, 94A) is detected by a TIA circuit (103, 203) as a received signal strength indicator (RSSI), and is transmitted from an AD conversion circuit (105, 205) to a transmission-side optical wireless device (91, 92) as optical intensity information (OI). In the transmission-side optical wireless device (91, 92), a control unit (106, 206) controls, on the basis of the optical intensity information (OI), the size of the drive current supplied to the laser diode (93A, 94A) of a laser diode drive circuit (104, 204).

Description

Wireless communication system and electronic component mounting apparatus

The present invention relates to a communication system for performing wireless communication and an electronic component mounting apparatus using the wireless communication system.

Conventionally, there is an optical wireless communication system using light such as infrared rays as one of wireless communication systems. For example, Patent Literature 1 discloses an optical wireless communication system that adjusts the intensity of light output from a transmission device based on the distance between the transmission device and the reception device. In this optical wireless communication system, the distance between the transmission device and the reception device is classified into three steps of distance, short distance, medium distance, and long distance, and light having an intensity corresponding to each distance is collectively transmitted from the transmission device. Each of the reception devices is arranged at a position that is separated from the transmission device by a distance, and receives an optical radio including light having a plurality of light intensities at each position.

JP 2012-60680 A

In the optical wireless communication system described above, the distance between each receiving device and the transmitting device is set in advance, and light having an intensity based on each distance is transmitted. However, in actual communication, the light intensity may fluctuate due to various factors, and such a fluctuation in the light intensity can sufficiently cope with the range of the light intensity setting value based on a predetermined distance. difficult. For example, in this type of optical wireless communication system, a laser diode (LD) is used as a light source of a transmission device. Even if the same standard LD is used as the light source corresponding to each distance of the transmission device, the output light of each LD may have different light intensity due to element-specific characteristics such as element degradation and temperature characteristics. is there. Therefore, a wireless communication system that can cope with fluctuations in the intensity of light output from the transmission device in actual communication is desired.

The present invention has been made in view of the above-described problems, and a wireless communication system capable of improving the followability with respect to fluctuations in the signal strength of a wireless signal output from a transmission apparatus, and an electronic component mounting apparatus using the wireless communication system The purpose is to provide.

A wireless communication system according to claim 1 of the present application made in view of the above problems, a first transmission unit that transmits a first wireless signal based on a supplied drive current, and a drive current supplied to the first transmission unit A first wireless device including a driving unit, a second transmission unit that receives a first wireless signal transmitted from the first transmission unit, and a signal strength of the first wireless signal received by the second transmission unit And a feedback means for transmitting the signal strength detected by the detection unit of the second wireless device as a second wireless signal from the second wireless device to the first wireless device. The first wireless device includes a processing unit that changes the magnitude of the drive current that the drive unit supplies to the first transmission unit based on the signal strength received by the feedback unit.

The radio communication system according to claim 2 is the radio communication system according to claim 1, wherein the feedback means transmits the second radio signal and the first transmission receives the second radio signal. Each of the first and second transmission units is a multiplexing apparatus that performs multiplexed optical wireless bidirectional communication, and optical wireless communication from the second transmission unit to the first transmission unit. The second radio signal including the signal strength is multiplexed.

According to a third aspect of the present invention, in the wireless communication system according to the second aspect, at least one of the first and second wireless devices is relative to the other while holding the optical axis of the optical wireless. The movable part to displace it is provided.

According to a fourth aspect of the present invention, in the wireless communication system according to any one of the first to third aspects, the feedback unit is configured to drive the drive unit in addition to the signal strength information. It transmits as a 2nd radio signal including the restriction | limiting information which restrict | limits the process which increases an electric current.

Further, the electronic component mounting apparatus according to claim 5 of the present application transmits data related to the mounting operation of the electronic component on the substrate by the wireless communication system according to any one of claims 1 to 4.

The wireless communication system according to claim 1, wherein the first transmission unit transmits the first wireless signal from the first transmission unit of the first wireless device to the second transmission unit of the second wireless device. The signal strength of the first radio signal received in step S1 is detected by the detector, and the signal strength is transmitted as a second radio signal from the second radio device to the first radio device by the feedback means. In the first wireless device, the magnitude of the drive current supplied from the drive unit to the first transmission unit is changed based on the signal strength received by the feedback unit.

In such a configuration, the signal strength of the first radio signal is quickly feedback-processed from the second radio device on the reception side to the first radio device on the transmission side using the radio signal (second radio signal). The transmission output of the first transmission unit is changed. Therefore, it is possible to improve the followability with respect to the fluctuation of the signal strength of the first radio signal caused by various factors in actual communication.

In the radio communication system according to claim 2, the feedback means includes a second transmission unit that transmits the second radio signal and a first transmission unit that receives the second radio signal, and each transmission unit is multiplexed. The apparatus is a device that performs multiplexed optical wireless bidirectional communication, while the second wireless signal including the signal strength is multiplexed in the optical wireless communication from the second transmission unit to the first transmission unit. Sent. With such a configuration, in a wireless communication system in which two-way communication is performed, signal intensity (light intensity) feedback processing can be performed in the two-way communication, and there is no need to separately provide a line for sending signal strength to the transmission side. Therefore, it is possible to simplify the configuration of the wireless communication system while improving the followability to the fluctuation of the signal strength of the first wireless signal.

The wireless communication system according to claim 3 further includes a movable unit that displaces at least one of the first and second wireless devices relative to the other while holding the optical axis of the optical wireless. Here, in the configuration in which at least one of the first and second radio apparatuses is movable, the distance between the radio apparatuses varies as the positions of the first and second radio apparatuses are relatively displaced. For this reason, the signal strength of the first radio signal received by the second transmission unit varies according to the distance between the two radio devices. Thus, in a communication system in which the signal strength varies depending on the distance between the two wireless devices due to the provision of the movable unit, if the signal strength is feedback processed and the transmission output of the first transmission unit is changed, The effect obtained by improving the followability with respect to fluctuations in strength is great.

Further, in the wireless communication system according to claim 4, the information of the second wireless signal transmitted by the feedback unit is transmitted by including the restriction information for restricting the processing for increasing the drive current of the drive unit. Unnecessary power consumption can be reduced.

Further, in the electronic component mounting apparatus according to claim 5, in the electronic component mounting apparatus that transmits data related to the mounting operation of the electronic component on the board by the wireless communication system, actual communication, for example, between the movable portion and the fixed portion. Thus, the electronic component mounting apparatus can be improved in the followability to the fluctuation of the signal strength of the radio signal generated by the communication.

It is a perspective view of the electronic component mounting apparatus to which the radio | wireless communications system of this embodiment is applied. It is a schematic plan view of the state which removed the upper cover of the electronic component mounting apparatus shown in FIG. It is a block diagram of an electronic component mounting apparatus. It is a block diagram of an optical wireless apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, an electronic component mounting apparatus (hereinafter sometimes abbreviated as “mounting apparatus”) will be described as an example of an apparatus to which the communication system of the present application is applied.

(Configuration of mounting device 10)
As shown in FIG. 1, the mounting device 10 includes a device main body 11, a pair of display devices 13 provided integrally with the device main body 11, and

supply devices

15 and 16 provided detachably with respect to the device main body 11. Is provided. The mounting device 10 according to the present embodiment is based on the control of the control device 80 shown in FIG. 3, and electronic components (not shown) with respect to the circuit board 17 transported by the transport device 21 housed in the device main body 11. It is an apparatus which implements mounting work. In this embodiment, as shown in FIG. 1, the direction in which the circuit board 17 is transported by the transport device 21 (the left-right direction in FIG. 2) is the X-axis direction, and is horizontal to the transport direction of the circuit board 17. A direction perpendicular to the direction is referred to as a Y-axis direction and will be described.

The device body 11 includes display devices 13 at both ends in the Y-axis direction on one end side in the X-axis direction. Each display device 13 is a touch panel display device, and displays information related to the mounting operation of the electronic component. Further, the apparatus main body 11 includes

supply devices

15 and 16 that are mounted so as to be sandwiched from both sides in the Y-axis direction. The supply device 15 is a feeder-type supply device, and includes a plurality of tape feeders 15A that are housed in a state where various electronic components are taped and wound on a reel. The supply device 16 is a tray-type supply device, and has a plurality of component trays 16A (see FIG. 2) on which a plurality of electronic components are placed.

FIG. 2 is a schematic plan view showing the mounting apparatus 10 from the upper (upper side in FIG. 1) viewpoint with the upper cover 11A (see FIG. 1) of the apparatus main body 11 removed. As shown in FIG. 2, the apparatus body 11 includes the transport device 21, a mounting head 22 for mounting electronic components on the circuit board 17, and a moving device 23 for moving the mounting head 22. Prepare for the top.

The transfer device 21 is provided in a substantially central portion of the base 20 in the Y-axis direction, and moves the pair of conveyor belts 31, the substrate holding device 32 held on the conveyor belt 31, and the substrate holding device 32. And an electromagnetic motor 33. The substrate holding device 32 holds the circuit board 17. The output shaft of the electromagnetic motor 33 is drivingly connected to the conveyor belt 31. The electromagnetic motor 33 is, for example, a servo motor that can accurately control the rotation angle. In the transport device 21, the circuit board 17 moves in the X-axis direction together with the substrate holding device 32 when the conveyor belt 31 rotates based on the driving of the electromagnetic motor 33.

The mounting head 22 has a suction nozzle 41 that sucks electronic components on the lower surface facing the circuit board 17. The suction nozzle 41 communicates with the negative pressure air and the positive pressure air passage via a positive / negative pressure supply device 42 (see FIG. 3), sucks and holds the electronic component with the negative pressure, and supplies a slight positive pressure. The held electronic component is removed. The mounting head 22 includes a nozzle lifting device 43 (see FIG. 3) that lifts and lowers the suction nozzle 41 and a nozzle rotation device 44 (see FIG. 3) that rotates the suction nozzle 41 around its axis. The vertical position of the electronic component and the holding posture of the electronic component are changed based on control from the control device 80. The nozzle lifting device 43 includes, for example, an electromagnetic motor 43A as a drive source. The mounting head 22 has a position detection sensor 45 (see FIG. 3) for detecting the position of the electronic component to be held in the vertical direction. Further, a mark camera 47 for photographing the circuit board 17 is fixed to the mounting head 22 in a state of facing downward. The suction nozzle 41 is detachable from the mounting head 22 and can be changed according to the size and shape of the electronic component.

Further, the mounting head 22 is moved to an arbitrary position on the base 20 by the moving device 23. More specifically, the moving device 23 includes an X-axis direction slide mechanism 50 for moving the mounting head 22 in the X-axis direction, and a Y-axis direction slide mechanism 52 for moving the mounting head 22 in the Y-axis direction. . The X-axis direction slide mechanism 50 has an X-axis slider 54 provided on the base 20 so as to be movable in the X-axis direction, and an electromagnetic motor 56 as a drive source. The X-axis slider 54 moves to an arbitrary position in the X-axis direction based on driving of the electromagnetic motor 56.

The Y-axis direction slide mechanism 52 has a Y-axis slider 58 provided on the side surface of the X-axis slider 54 so as to be movable in the Y-axis direction, and an electromagnetic motor 60 as a drive source. The Y-axis slider 58 moves to an arbitrary position in the Y-axis direction based on driving of the electromagnetic motor 60. The mounting head 22 is attached to the Y-axis slider 58 and moves to an arbitrary position on the base 20 as the moving device 23 is driven. Thereby, the mark camera 47 can image the surface of an arbitrary position of the circuit board 17 by moving the mounting head 22. Image data photographed by the mark camera 47 is processed by the image processing device 71 (see FIG. 3) and output to the control device 80. The mounting head 22 is attached to the Y-axis slider 58 via the connector 48 and can be attached and detached with a single touch, and can be changed to a different type of work head, for example, a dispenser head.

Further, the base 20 has

supply devices

15 and 16 connected to each side surface in the Y-axis direction. Each of the

supply devices

15 and 16 can be attached to and detached from the base 20 in order to cope with a shortage of electronic components to be supplied, changes in the types of electronic components, and the like. Further, the base 20 is provided with a parts camera 73 at a substantially central portion in the X-axis direction at a portion to which the

supply devices

15 and 16 are connected. Each part camera 73 is fixed in a state of facing upward, and images the electronic components sucked and held by the suction nozzle 41 of the mounting head 22 from each of the

supply devices

15 and 16. The parts camera 73 outputs the captured image data to the image processing device 71 (see FIG. 3). The image processing device 71 outputs the processed data to the control device 80.

(Communication system applied to mounting device 10)
Here, as shown in FIG. 3, the mounting apparatus 10 according to the present embodiment uses optical wireless multiplexed communication for data communication between the control apparatus 80 of the mounting apparatus 10 and parts (various apparatuses) other than the control apparatus 80. Is used. Note that the configuration of the mounting apparatus 10 illustrated in FIG. 3 is an example in the case of applying a communication system, and is appropriately changed according to the type and number of apparatuses provided in the mounting apparatus 10. The communication system of the present application is a system that can be applied to an automatic machine operating in various production lines in addition to the electronic component mounting apparatus exemplified by the mounting apparatus 10.

As shown in FIG. 3, the control device 80 includes a controller 82 mainly composed of a computer having a CPU, ROM, RAM, and the like, an image board 84, a drive control board 85, and an I / O board 86. The controller 82 communicates with each device via each

board

84, 85, 86. Each

board

84, 85, 86 is connected to one end of a transmission path 95 via an optical wireless device 91, and optical wireless communication is performed on the transmission path 95. The other end of the transmission path 95 is connected to various devices (camera, motor, sensor, etc.) via the optical wireless device 92. For example, as illustrated in FIG. 2, the moving device 23 is provided with a light emitting / receiving unit 94 of the optical wireless device 92 facing the light emitting / receiving unit 93 of the optical wireless device 91 connected to the control device 80. . The light emitting / receiving unit 94 is fixed to the X-axis slider 54 of the moving device 23 so that the optical axis coincides with the light emitting / receiving unit 93 on the optical wireless device 91 side. Thereby, various information communication is enabled between the light emitting / receiving units 93 and 94 (optical wireless devices 91 and 92).

The image board 84 shown in FIG. 3 is a board that controls input / output of image data. For example, the controller 82 uses the image board 84 to hold information about the circuit board 17 detected by the image processing apparatus 71 from processing the image data of the mark camera 47 (type, shape, etc.) and hold the circuit board 17 by the board holding device 32. Receive camera information such as position error. The drive control board 85 is a board that controls input / output of operation commands for the electromagnetic motor and information fed back from the electromagnetic motor in real time. For example, the controller 82 receives servo control information such as torque information and position information (vertical position of the electronic component held by the suction nozzle 41) acquired by the electromagnetic motor 43A via the drive control board 85. The I / O board 86 is a board that controls input / output of an output signal of the position detection sensor 45, for example. Data input from these devices to the control device 80 is multiplexed by the optical wireless device 92 and transmitted through the transmission path 95 as an optical wireless signal. The optical wireless device 91 performs a process of demultiplexing the transmitted multiplexed signal and separating it into individual data. Of the separated data, the optical wireless device 91 transfers image data to the image board 84, servo control information to the drive control board 85, and I / O signals to the I / O board 86.

On the other hand, the controller 82 processes each data received by the optical wireless device 91. For example, the controller 82 outputs a control signal for the electromagnetic motor 43 A based on the processing result to the optical wireless device 91 via the drive control board 85. The optical wireless device 92 transfers the control signal transmitted from the optical wireless device 91 to the nozzle lifting / lowering device 43. Thus, the electromagnetic motor 43A operates based on the control signal. For example, the controller 82 outputs a control signal for changing the display of the display device 13 to the display device 13 via the I / O board 86 and the

optical wireless devices

91 and 92. As described above, various types of information transmitted and received between the control device 80 and each device other than the control device 80 are transmitted and received as data multiplexed on the transmission path 95, for example, time division multiplexing (TDM) frame data. . In multiplexed communication, for example, the data transfer rate is 3 GBPS, one frame is 8 nsec, and the number of bits of one frame is 24 bits.

In the mounting device 10 described above, an electronic component is mounted on the circuit board 17 held by the substrate holding device 32 by the mounting head 22. Specifically, the controller 82 drives the transport device 21 to transport the circuit board 17 to the working position, stops the electromagnetic motor 33, and holds the circuit board 17 in a fixed manner. The controller 82 drives the moving device 23 to move the mounting head 22 onto the circuit board 17 and images the circuit board 17 with the mark camera 47. At this time, the controller 82 determines an error in the type of the circuit board 17 and the holding position of the circuit board 17 received from the image processing apparatus 71. Next, the controller 82 drives the

supply devices

15 and 16 having electronic components according to the determination result for the type of board, and performs control to send the corresponding electronic components to the supply position to the mounting head 22. The controller 82 drives the moving device 23 to suck and hold the electronic component conveyed at the supply position by the suction nozzle 41 of the mounting head 22.

Next, the controller 82 moves the mounting head 22 holding the electronic component onto the parts camera 73 to image the state of the electronic component. At this time, the controller 82 acquires an error in the holding position of the electronic component based on the imaging result. The controller 82 moves the mounting head 22 to the mounting position on the circuit board 17, rotates the suction nozzle 41 based on the holding position error of the circuit board 17 and the electronic component, and then mounts the electronic component on the circuit board 17.

In the following description, a radio communication system suitable for application to the mounting apparatus 10 that mounts electronic components using the above-described multiplexed communication will be described.
The

optical wireless devices

91 and 92 of the present embodiment feed back the intensity values of the light received by the light emitting / receiving

units

93 and 94 to the transmitting side so that the transmission output values of the transmitting / receiving

units

93 and 94 on the transmitting side are Be changed. More specifically, as shown in FIG. 4, the light receiving / emitting unit 93 of the optical wireless device 91 includes a laser diode (LD) 93A as a light emitting element for transmission and a photo detector (Photo detector: PD) of the light receiving element. ) 93B. The optical wireless device 91 includes a multiplexer (hereinafter referred to as “MUX”) 101, a demultiplexer (hereinafter referred to as “DEMUX”) 102, a transimpedance amplifier (TIA) circuit 103, an LD drive circuit 104, an AD A conversion circuit 105 and a control unit 106 are provided. The optical wireless device 92 has the same configuration as the optical wireless device 91. As shown in FIG. 4, the light emitting / receiving unit 94 of the optical wireless device 92 includes a laser diode (LD) 94A as a light emitting element for transmission and a photo detector (PD) 94B as a light receiving element. Prepare. The optical wireless device 92 includes a multiplexer (hereinafter referred to as “MUX”) 201, a demultiplexer (hereinafter referred to as “DEMUX”) 202, a transimpedance amplifier (TIA) circuit 203, an LD drive circuit 204, an AD A conversion circuit 205 and a control unit 206 are provided. In the following description, the optical wireless device 91 will be mainly described, and the description of the optical wireless device 92 will be omitted as appropriate.

The PD 93B of the optical wireless device 91 receives an optical wireless signal from the LD 94A of the optical wireless device 92 through the transmission path 95. The PD 93B outputs a current converted according to the intensity of received light to the TIA circuit 103 as an electric signal. The TIA circuit 103 converts the current signal input from the PD 93 B into a voltage signal of a pulse signal and outputs it to the DEMUX 102. The DEMUX 102 detects the data signal of the bit string from the pulse signal input from the TIA circuit 103, demultiplexes it, separates it into individual data, and sends it to each

board

84, 85, 86 of the control device 80 (see FIG. 3). Output.

On the other hand, the MUX 101 of the optical wireless device 91 multiplexes data signals input from the

boards

84, 85, 86 of the control device 80 and outputs them to the LD drive circuit 104. The LD drive circuit 104 controls the drive current supplied to the LD 93A based on the input signal. The LD 93 A transmits a radio signal having a light intensity based on the drive current supplied from the LD drive circuit 104 to the PD 94 B of the optical radio apparatus 92 through the transmission path 95.

For example, in data transfer from the optical wireless device 91 to the optical wireless device 92, control information for the electromagnetic motor 43A (see FIG. 3) output from the control device 80 (drive control board 85) is multiplexed by the MUX 101 and the LD. The data is transmitted from the LD 93A to the PD 94B via the drive circuit 104. The optical wireless device 92 detects the control information by demultiplexing the signal input to the DEMUX 202 via the PD 94B and the TIA circuit 203. Control information detected by the DEMUX 202 is input to the nozzle lifting device 43 (see FIG. 3), and the electromagnetic motor 43A is controlled based on the control information.

Here, in such a communication system of the mounting device 10, the light intensity between the light emitting and receiving

units

93 and 94 varies depending on various factors. For example, even if laser diodes of the same standard are used for the LD 93A of the optical wireless device 91 and the LD 94A of the optical wireless device 92, the transmission output of each

LD

93A, 94A due to element-specific characteristics such as element degradation and temperature characteristics May have different values.

Further, as shown in FIG. 2, the mounting device 10 has a light emitting / receiving unit 93 (optical wireless device 91) fixed to the mounting device 10, while a light receiving / emitting unit 94 (optical wireless device 92) is mounted on the X axis. The moving device 23 is movable in the direction. In the mounting device 10 in which one of the light emitting / receiving

units

93 and 94 that performs such optical wireless communication is relatively displaced with respect to the other, the distance between the light emitting / receiving

units

93 and 94 as the moving device 23 moves, that is, The distance of the transmission path 95 varies. As the transmission path 95 varies, the intensity of light received by each of the light emitting / receiving units 93 and 94 (PD93B and 94B) varies. The laser beams output from the

LDs

93A and 94A are diffused in a region spread according to the distance from the light source, for example, from a light source such as a TEM00 mode of a Gaussian beam to a contrasting wavefront. For this reason, the intensity of light received by the

PDs

93B and 94B decreases in proportion to the distance of the transmission path 95 even if attenuation in the transmission path 95 (for example, in the air) does not occur.

If the light intensity fluctuates due to various factors as described above, errors in transmitted data increase, the transmission path 95 is disconnected, and the like. Therefore, the

optical wireless devices

91 and 92 according to the present embodiment feed back the intensity of light received by the

PDs

93B and 94B to the transmission side to change the transmission output of the

LDs

93A and 94A.

As shown in FIG. 4, the TIA circuit 103 of the optical wireless device 91 outputs the received signal strength (RSSI) based on the current signal input from the PD 93 B to the AD conversion circuit 105. The AD conversion circuit 105 outputs light intensity information OI based on RSSI input from the TIA circuit 103 to the MUX 101. For example, the TIA circuit 103 outputs a voltage signal corresponding to the received signal strength to the AD conversion circuit 105. The AD conversion circuit 105 includes, for example, a plurality of comparators, and a voltage value of RSSI is divided and input to each comparator. In each comparator, the divided voltage value and the reference voltage are compared, and a plurality of bit values of the comparison result are output to the MUX 101 as the light intensity information OI. That is, the light intensity information OI is set with a bit value representing the RSSI size. The optical wireless device 91 is provided with a plurality of LEDs 108 connected to the output terminals of the comparators of the AD conversion circuit 105, and the LEDs 108 are turned on according to the magnitude of the RSSI voltage value. Thereby, the user can confirm the magnitude of the RSSI of the wireless signal (light intensity) received by the optical wireless device 91 from the lighting of the LED 108.

The DEMUX 202 of the optical wireless device 92 detects the light intensity information OI from the bit string input from the TIA circuit 203 and outputs it to the control unit 206. The control unit 206 changes the magnitude of the drive current supplied from the LD drive circuit 204 to the LD 94A based on the input light intensity information OI. For example, when the light intensity information OI indicating the value where the intensity of light received by the PD 93B of the optical wireless device 91 is reduced is feedback-processed, the control unit 206 supplies a drive current for the LD 94A to the LD drive circuit 204. Execute the control to increase. Thereby, the transmission output on the transmission side can be adjusted according to the intensity of light actually received on the reception side, and an increase in transmission data errors in the transmission path 95 and a disconnection of the transmission path 95 can be prevented.

In the light intensity information OI, a bit value indicating the upper limit of the size for increasing the transmission output of the

LD

93A, 94A is set. More specifically, the control unit 206 controls the LD drive circuit 204 step by step based on the bit value of the light intensity information OI. For example, if the light intensity information OI is 8 bits, the drive current can be controlled based on 256 kinds of control information. However, for example, if the control information for increasing the drive current is set for the light intensity information OI as the intensity of light received by the PD 93B decreases, the transmission output of the LD 94A increases unnecessarily. Become. For example, when the user accidentally interrupts the transmission path 95 during work and the light intensity received by the PD 93B becomes almost zero, the transmission output of the LD 94A increases without limit, and the light intensity becomes dangerous for the worker. There is a risk of becoming bigger. Also, unnecessary power is consumed. Therefore, by adding a bit value indicating an upper limit for increasing the transmission output of the LD 94A to the light intensity information OI, the amount of increase in drive current in the control unit 206 can be limited, and the light intensity is limited and unnecessary power consumption is reduced. Can be reduced. The bit value indicating the upper limit set in the light intensity information OI can be set based on the maximum distance of the transmission path 95 (in this case, the distance that the moving device 23 has moved to the end in the X-axis direction) or the like. it can. In addition, for example, by setting the conditions for limiting the transmission output of the LD94A when the above-described LEDs 108 are all extinguished, the control of limiting the RSSI reduction and the transmission output to the user is performed by turning on the LEDs 108. Can be notified.

Also, in multiplexed communication between the

MUXs

101 and 201 and the

DEMUXs

102 and 202, time division multiplexing frame data is transmitted and received. For example, the MUX 101 is provided with a speed conversion circuit (not shown) that performs conversion between the data transfer rate from each of the

boards

84, 85, 86 and the data transfer rate of the transmission path 95. The MUX 101 transmits the light intensity information OI input from the AD conversion circuit 105 by setting it as dummy data of the frame added by the speed conversion circuit. Alternatively, for example, the MUX 101 may set and transmit the light intensity information OI to a bit value for which data is not defined in a bit string of frame data. As a result, the feedback process can be executed with less influence on data transmission between the

optical wireless devices

91 and 92. The

optical wireless devices

91 and 92 may include a wireless line that feeds back the light intensity information OI separately from the transmission path 95.

Further, the

TIA circuits

103 and 203 are configured to output RSSI for each input from the

PD

93B and 94B. Thereby, the followability with respect to the fluctuation | variation of the intensity | strength of light received by PD93B and 94B can be improved. The

TIA circuits

103 and 203 may be configured to calculate and output an average RSSI value at a predetermined time interval. Thereby, the processing load concerning the feedback process in other circuits (MUX101 etc.) can be reduced, improving the followability with respect to the fluctuation | variation of the intensity | strength of light.

Further, the

control units

106 and 206 may be configured by programmable logic devices such as FPGA (Field Programmable Gate Gate Array) without being configured by a processor such as a CPU. Further, the

LD drive circuits

104 and 204 may include variable resistance circuits that change the drive currents of the

LDs

93A and 94A. In this variable resistance circuit, for example, the connection of a plurality of resistance elements connected in series is selected based on the light intensity information OI (bit value) input from the

control units

106 and 206, and the combined resistance value is changed. The driving current output is changed. The plurality of resistance elements of the variable resistance circuit are connected so that selectable resistance elements having resistance values that can be changed stepwise within the prescribed range of the LD93A and 94A drive current values of the LD93A and 94A. In such a configuration, optical wireless communication is used for the feedback processing of the light intensity information OI, and the feedback processing in the

control units

106 and 206 and the

LD drive circuits

104 and 204 is processed by hardware, thereby changing the light intensity. The followability to can be improved. As an example, when the moving device 23 moves the maximum distance (for example, 2.5 m) at both ends in the X-axis direction in a few seconds, the process from the light reception to the change of the drive current can be processed in the order of several μsec, and the followability is sufficient. Can be increased.

As mentioned above, according to this embodiment described in detail, there exist the following effects.
In the mounting apparatus 10 of the present embodiment, the intensity of light received by the

PDs

93B and 94B is detected as received signal intensity (RSSI) by the

TIA circuits

103 and 203, and transmitted from the

AD conversion circuits

105 and 205 as light intensity information OI. Are transmitted to the

optical wireless devices

92 and 91. In the

optical wireless devices

92 and 91 on the transmission side, the

control units

206 and 106 control the magnitude of the drive current supplied to the

LDs

94A and 93A of the

LD drive circuits

204 and 104 based on the light intensity information OI. As a result, the optical intensity information OI is quickly feedback-processed using optical wireless communication, and the transmission output of the

LD

94A, 93A is changed, thereby improving the followability to the fluctuation of the transmission output of the

LD

94A, 93A. An optical wireless communication system can be constructed.

In addition, this invention is not limited to said embodiment, It cannot be overemphasized that various improvement and change are possible within the range which does not deviate from the meaning of this invention.
For example, in the above embodiment, communication by optical wireless has been described as an example. However, the present application is not limited to this, and can be applied to wireless communication using various electromagnetic waves in addition to infrared rays and visible light. Even with such a configuration, attenuation of wireless radio waves or the like occurs according to the characteristics of the transmission device of wireless communication or the distance of the transmission path, so that the same effect as described above can be obtained by applying the present invention. Can do.
In the above embodiment, multiplexed wireless communication has been described as an example. However, the present application is not limited to this, and the present invention may be applied to wireless communication that does not use multiplexing.

Further, in the above embodiment, when the received signal strength (RSSI) of the

LD

93A, 94A becomes zero or a value close to zero due to the disconnection of the transmission path 95 or the like, the configuration or use of stopping the

optical wireless devices

91, 92 It is good also as a structure which issues the warning which notifies that to a person. Thereby, for example, when the optical axis of the light emitting / receiving

units

93 and 94 is shifted due to contact between the devices and the transmission path 95 is cut, the user corrects the direction of the light emitting / receiving

units

93 and 94 to change the mounting device 10. Appropriate responses such as starting up can be performed.

In the above embodiment, the

optical wireless devices

91 and 92 may have a configuration in which a logarithmic conversion circuit is provided between each of the

TIA circuits

103 and 203 and the

AD conversion circuits

105 and 205. For example, when the ratio (dynamic range) between the maximum value and the minimum value of the RSSI voltage value output from the

TIA circuits

103 and 203 is large, the light intensity information OI output from the

AD conversion circuits

105 and 205 is necessary. The bit width increases and the amount of data required to transmit the light intensity information OI may increase. Therefore, by providing a logarithmic conversion circuit between the

TIA circuits

103 and 203 and the

AD conversion circuits

105 and 205 and performing logarithmic conversion of RSSI, the bit width necessary for the light intensity information OI can be compressed and the amount of data can be reduced.

The

optical wireless devices

91 and 92 may be configured to transmit the optical intensity information OI with priority over the retransmission request when requesting retransmission of data by disconnecting the transmission path 95. As a result, when the transmission path 95 is disconnected, the data re-transmission is executed after increasing the transmission output of the

LD

93A, 94A, so that the data re-processing can be executed more reliably.

The

optical wireless devices

91 and 92 may be configured to transmit the light intensity information OI by increasing the transmission output of the

LDs

93A and 94A on the feedback side when the transmission path 95 is disconnected for a certain time. . Thereby, the light intensity information OI can be transmitted more reliably.

In the above embodiment, one of the optical wireless devices 91 and 92 (optical wireless device 92) is provided in the movable part (moving device 23). However, both

optical wireless devices

91 and 92 are fixed, or both devices are It is good also as a structure which can move.

Further, the configuration of the mounting device 10 of the above embodiment is an example, and is changed as appropriate. For example, the mounting device 10 includes the pair of

optical wireless devices

91 and 92, but may include two or more. For example, it is good also as a structure provided with two or more moving apparatuses 23 which can be attached or detached with respect to the apparatus main body 11. FIG. For example, it is good also as a structure provided with multiple conveyor belts 31 (plural lanes). Further, for example, a configuration in which a plurality of mounting devices 10 are drivingly connected in the transport direction may be employed.

The correspondence with the terms in the claims is as follows.
The mounting device 10 is an example of an electronic component mounting device, the light emitting / receiving unit 93 is an example of a first transmission unit, the LD driving circuit 104 is an example of a driving unit, and the optical wireless device 91 is an example of the first wireless device. As an example, the optical wireless signal from the LD 93A to the PD 94B is an example of the first wireless signal, the light emitting / receiving unit 94 is an example of the second transmission unit, the TIA 203 and the AD conversion circuit 205 are the optical detectors. The wireless device 92 is an example of a second wireless device, the LD 94A and the PD 93B are examples of a feedback unit, the control unit 106 is an example of a processing unit, and the

MUXs

101 and 201 and the

DEMUXs

102 and 202 are first included in the feedback unit. As an example of the multiplexing device of the transmission unit and the second transmission unit, the moving device 23 is an example of a movable unit.

10 mounting device, 91, 92 optical wireless device, 93, 94 light emitting / receiving unit, 93A, 94A LD, 93B, 94B PD, 101, 201 MUX, 102, 202 DEMUX, 103, 203 TIA circuit, 104, 204

LD drive circuit

105, 205 AD conversion circuit, 106, 206 control unit.

Claims

A first wireless device comprising: a first transmission unit that transmits a first wireless signal based on a supplied drive current; and a drive unit that supplies the drive current to the first transmission unit;
A second transmission unit that receives the first radio signal transmitted from the first transmission unit; and a detection unit that detects a signal strength of the first radio signal received by the second transmission unit. A wireless device;
Feedback means for transmitting the signal strength detected by the detection unit of the second wireless device as a second wireless signal from the second wireless device to the first wireless device;
The first radio apparatus includes a processing unit that changes a magnitude of the drive current that the drive unit supplies to the first transmission unit based on the signal strength received by the feedback unit. Communications system.
The feedback means includes the second transmission unit for transmitting the second radio signal and the first transmission unit for receiving the second radio signal, and the first and second transmission units are multiplexed. A multiplexing device for performing two-way optical wireless communication, wherein the second wireless signal including the signal strength is multiplexed in the optical wireless communication from the second transmission unit to the first transmission unit. The wireless communication system according to claim 1.
3. The wireless communication system according to claim 2, further comprising a movable unit that displaces at least one of the first and second wireless devices relative to the other while holding an optical axis of the optical wireless. .
The feedback means includes, in addition to the signal strength information, the processing unit transmits as the second radio signal including restriction information for limiting a process of increasing the driving current of the driving unit. The radio | wireless communications system in any one of Claims 1 thru | or 3.
5. An electronic component mounting apparatus for transmitting data related to mounting work of electronic components on a substrate using the wireless communication system according to claim 1.