Patent Description:
In the related art, there has been three-line electrical equipment (such as sensors) which transmits and receives communication data in addition to detection information. Such electrical equipment requires at least two power source lines and one signal line in order to supply electric power and input and output signals. One of three-line communication methods is IO-Link (registered trademark). Non-Patent Literature <NUM> is a specification of IO-Link.

<CIT> discloses to superimpose a digital data signal on an industrial signal for transmission.

However, the technique in Non-Patent Literature <NUM> has a problem that the number of wirings increases. Also, according to the technique in Non-Patent Literature <NUM>, a sensor converts a sensor detection signal into communication data and transmits the communication data to the outside, for example. Therefore, there is a problem that a time required for external equipment to recognize the detection signal increases or that circuit configurations of the sensor and the external equipment are complicated, for the conversion processing.

Also, in one example of a technique for reducing the number of wirings, reducing the number of wirings using, for communication, a superimposed signal in which a signal related to an operation element is superimposed on a data signal is considered. However, in order to actually use the superimposed signal for communication, it is necessary for both the electrical equipment and the communication device to support the communication using the superimposed signal, and there is thus a concern of increasing costs in a case in which a series of systems is introduced.

An aspect of the present disclosure was made in view of the aforementioned problem, and an object thereof is to provide a signal processing device or the like capable of transmitting predetermined information as a superimposed signal, in which the predetermined information is superimposed on an operation signal of electrical equipment, to a communication device.

The present invention is defined by a signal processing device according to claim <NUM>.

In other words, a signal processing device according to an aspect of the present disclosure includes: a superimposed signal transmission unit which transmits, to an external communication device, an operation signal in accordance with a state of an operation element, or receives, from the communication device, an operation signal for controlling the operation element, and transmitting, to the communication device, a data signal indicating predetermined information as a superimposed signal in which the data signal is superimposed on the operation signal; an information storage unit which stores the predetermined information; and an information rewrite unit which rewrites, on the basis of an external instruction input, the information stored in the information storage unit, while the superimposed signal transmission unit transmits the superimposed signal to the communication device.

An information rewrite device according to an aspect of the present disclosure is an information rewrite device which provides an instruction for rewriting information stored in the information storage unit to the signal processing device according to the aforementioned aspect, the information rewrite device including: an information acquisition unit which acquires information to be rewritten; and a light projecting unit which projects the optical signal in accordance with the information to the light receiving unit included in the signal processing device.

An information rewrite device according to an aspect of the present disclosure is an information rewrite device which provides an instruction for rewriting information stored in the information storage unit to the signal processing device according to the aforementioned aspect, the information rewrite device including: an information acquisition unit which acquires information to be rewritten; and a current control unit which generates the rewriting current signal in accordance with the information.

An information rewrite device according to an aspect of the present disclosure is an information rewrite device which provides an instruction for rewriting information stored in the information storage unit to the signal processing device according to the aforementioned aspect, the information rewrite device including: an information acquisition unit which acquires information to be rewritten; and a current control unit which generates the rewriting current signal in accordance with the information, in which the operation signal is an ON/OFF signal, and the current control unit generates the rewriting current signal with a current value that is higher than a current value in an ON signal of the operation signal.

An information rewrite device according to an aspect of the present disclosure is an information rewrite device which provides an instruction for rewriting information stored in the information storage unit to the signal processing device according to the aforementioned aspect, the information rewrite device including: an information acquisition unit which acquires information to be rewritten; and a current control unit which generates the rewriting current signal in accordance with the information, in which the current control unit supplies a current to the signal processing device such that a current with a current value that is equal to or greater than the predetermined threshold value flows at a predetermined pulse width after activation of the signal processing device.

According to an aspect of the present disclosure, it is possible to provide a signal processing device and the like capable of transmitting predetermined information as a superimposed signal in which the predetermined information is superimposed on an operation signal of electrical equipment to a communication device.

Before explanation of electrical equipment and the like according to an aspect of the present disclosure, a configuration of electrical equipment and the like that support communication using a superimposed signal in which a signal related to an operation element is superimposed on a data signal will be described first using <FIG> is a block diagram illustrating an example of circuit configurations of electrical equipment that supports superimposed signals and an input unit that is a communication device. Here, an example of electrical equipment <NUM> (limit switch) and an input unit <NUM> will be described. The electrical equipment <NUM> and the input unit <NUM> are connected to each other with a pair of signal lines <NUM> and <NUM>. The signal line <NUM> is connected to a first input terminal <NUM> of the input unit <NUM> and a first terminal <NUM> of the electrical equipment <NUM>. The signal line <NUM> is connected to a second input terminal <NUM> of the input unit <NUM> and a second terminal <NUM> of the electrical equipment <NUM>. A route of the signal line <NUM> is provided with a power source <NUM>. The power source <NUM> is a DC power source that generates a predetermined voltage (<NUM> V here).

The electrical equipment <NUM> includes the first terminal <NUM>, the second terminal <NUM>, an operation element <NUM>, a potential difference generation circuit <NUM>, and a transmission circuit <NUM>. The transmission circuit <NUM> includes a step-down circuit <NUM>, a data generation circuit <NUM>, a superimposition circuit <NUM>, and a diagnosis circuit <NUM>. The operation element <NUM> is connected between the first terminal <NUM> and the second terminal <NUM>. The potential difference generation circuit <NUM> is connected in series to the operation element <NUM> in an electrification path between the first terminal <NUM> and the second terminal <NUM>. The potential of the second terminal <NUM> changes in accordance with a state of the operation element <NUM>. In other words, the second terminal <NUM> outputs an output signal (operation signal) in accordance with a state of the operation element <NUM> to the outside (signal line <NUM>).

The transmission circuit <NUM> is connected between the first terminal <NUM> and the second terminal <NUM>. The transmission circuit <NUM> operates as a power source using a voltage between the first terminal <NUM> and the second terminal <NUM>. The step-down circuit <NUM> steps down the voltage between the first terminal <NUM> and the second terminal <NUM> to a predetermined voltage and outputs the predetermined voltage to the data generation circuit <NUM>. The data generation circuit <NUM> operates using the voltage applied by the step-down circuit <NUM> and generates transmission data to be transmitted to the input unit <NUM>. The transmission data includes, for example, an identifier (ID information) unique to the electrical equipment <NUM>. The data generation circuit <NUM> outputs the transmission data to the superimposition circuit <NUM>. The superimposition circuit <NUM> superimposes the received transmission data as a data signal on the output signal. In this manner, the transmission circuit <NUM> outputs the superimposed signal in which the data signal is superimposed on the output signal from the second terminal <NUM> to the signal line <NUM>.

The diagnosis circuit <NUM> operates using the voltage applied by the step-down circuit <NUM> and generates diagnosis data representing diagnosis information of the electrical equipment <NUM>. The diagnosis circuit <NUM> includes a check circuit related to an element (for example, the operation element <NUM>) of the electrical equipment <NUM> and generates diagnosis data indicating whether or not the electrical equipment <NUM> is normal in accordance with whether or not an output from the check circuit is normal. The diagnosis circuit <NUM> outputs the diagnosis data (diagnosis information) to the data generation circuit <NUM>. The data generation circuit <NUM> may include the diagnosis data in transmission data.

The input unit <NUM> includes a first input terminal <NUM>, a second input terminal <NUM>, an input circuit <NUM>, an extraction circuit <NUM>, an error detection circuit <NUM>, and a unit control circuit <NUM>. In <FIG>, illustration of a configuration of a portion that performs transmission to a controller <NUM> is omitted. The potential of the first input terminal <NUM> is maintained constant (at GND, for example). A superimposed signal is input from the signal line <NUM> to the second input terminal <NUM>.

The input circuit <NUM> extracts an output signal from the superimposed signal and outputs the output signal to the unit control circuit <NUM>. The extraction circuit <NUM> extracts a data signal from the superimposed signal and outputs the data signal to the error detection circuit <NUM>. The error detection circuit <NUM> performs error detection on the data signal using an arbitrary data checking method such as cyclic redundancy check (CRC) or Manchester coding check. The error detection circuit <NUM> outputs the data signal and the error detection result to the unit control circuit <NUM>. Note that in a case in which an error is detected from the data signal, the error detection circuit <NUM> may not output the data signal to the unit control circuit <NUM>. The unit control circuit <NUM> outputs the output signal and the data signal to the controller <NUM>. The error detection circuit <NUM> and the unit control circuit <NUM> may be configured by one integrated circuit or a plurality of integrated circuits, for example.

<FIG> is a block diagram illustrating a configuration of a communication system including the electrical equipment <NUM> that supports superimposed signals. A communication system <NUM> includes a PC <NUM> (a personal computer, an information processing device), a controller <NUM>, an input unit <NUM>, an output unit <NUM>, and electrical equipment <NUM> to <NUM>. The PC <NUM> is connected to the controller <NUM>. The PC <NUM> receives information related to the electrical equipment <NUM> to <NUM> from the controller <NUM> and transmits a control command to the controller <NUM>. The controller <NUM> is connected to the input unit <NUM> and the output unit <NUM>. The controller <NUM> transmits signals for causing the electrical equipment <NUM> to <NUM> to operate or for controlling the electrical equipment <NUM> to <NUM> to the input unit <NUM> and the output unit <NUM> in response to the control command. The controller <NUM> transmits, to the PC <NUM>, signals from the electrical equipment <NUM> to <NUM> received via the input unit <NUM> or the output unit <NUM>.

The input unit <NUM> is receiving equipment (communication device), is connected to a plurality of pieces of electrical equipment such that communication can be performed therebetween, and can receive superimposed signals from the electrical equipment. In the illustrated example, the electrical equipment <NUM> and <NUM> is connected to the input unit <NUM>. In other words, the input unit <NUM> can receive superimposed signals from the electrical equipment <NUM> and <NUM>. In the configuration example, the input unit <NUM> cyclically receives the data signals included in the superimposed signals from the electrical equipment <NUM> and <NUM>. Note that the data signals may not be cyclically received. The connection between the input unit and the electrical equipment <NUM> and <NUM> is established by a pair of signal lines, for example. Also, the input unit <NUM> can extract data signals from the received superimposed signals, determine communication states between the electrical equipment that is transmission sources of the superimposed signals and the input unit <NUM> itself, and output the result to the controller <NUM>. The input unit <NUM> can configure the communication system <NUM> as illustrated in <FIG> along with a plurality of pieces of equipment including the electrical equipment <NUM> and <NUM> and the controller <NUM>.

When a communication error is detected in communication between the input unit <NUM> and the electrical equipment <NUM> and <NUM> in regard to the communication state between the input unit <NUM> and the electrical equipment <NUM> and <NUM>, the input unit <NUM> can determine whether or not the communication error has occurred in a transition period of values of the operation signals in the electrical equipment <NUM> and <NUM>. Note that communication errors detected in a period other than the transition period include, for example, a communication error due to repetition of instantaneous disconnection when a switch contact point is in an unstable state, a communication error due to disturbance noise, disconnection of a wiring, and the like.

The electrical equipment <NUM> and <NUM> operates using power supplied from the input unit <NUM> and transmits signals in accordance with states of operation elements included in the electrical equipment <NUM> and <NUM> to the input unit <NUM>. Here, the electrical equipment <NUM> is a limit switch including a switch as the operation element. The electrical equipment <NUM> is a sensor including a sensing element as the operation element. When the electrical equipment <NUM> is a limit switch, and when the electrical equipment <NUM> is a sensor, the operation element <NUM> can output an ON/OFF signal as an output signal (operational signal). Although the case in which the electrical equipment <NUM> is a limit switch will be described below, the same can apply to the case in which the electrical equipment <NUM> is a sensor.

The output unit <NUM> (receiving equipment) is connected to electrical equipment <NUM> to <NUM>. Each piece of the electrical equipment <NUM> to <NUM> is connected to the output unit <NUM> with a pair of signal lines. The output unit <NUM> causes the electrical equipment <NUM> to <NUM> to operate and controls the electrical equipment <NUM> to <NUM> on the basis of instructions from the PC <NUM> and the controller <NUM>. Also, the output unit <NUM> transmits data signals received from the electrical equipment <NUM> to <NUM> to the controller <NUM>. The output unit <NUM> receives superimposed signals from the electrical equipment <NUM> to <NUM> and extracts data signals from the received superimposed signals. Further, the output unit <NUM> can determine a communication state between the output unit <NUM> and the electrical equipment. Then, the output unit <NUM> can output the determination result to the controller <NUM>.

The electrical equipment <NUM> to <NUM> operates using power supplied from the output unit <NUM> and is controlled by a control signal received from the output unit <NUM>. Here, the electrical equipment <NUM> is a relay device including a coil as an operation element. The electrical equipment <NUM> is an electromagnetic valve including a coil as an operation element. The electrical equipment <NUM> is an electric actuator including a coil as an operation element.

In regard to operations of the electrical equipment and the communication device in communication using superimposed signals, an example of operations of the electrical equipment <NUM> and the input unit <NUM> will be described using <FIG>. Note that <FIG> can be similarly described for a combination of the electrical equipment <NUM> and the input unit <NUM> and for a combination of any of the electrical equipment <NUM> to <NUM> and the output unit <NUM> as well. <FIG> is a diagram schematically illustrating an example of a signal waveform. (a) in <FIG> illustrates a case in which the cycle of the output signal (operation signal) is longer than the cycle of the data signal, and (b) illustrates a case in which the cycle of the output signal is shorter than the cycle of the data signal. A signal obtained by superimposing the output signal and the data signal is the superimposed signal. The waveform of the superimposed signal is a waveform obtained by superimposing the waveform of the output signal and the waveform of the data signal. The amplitude of the output signal is greater than the amplitude of the data signal. Therefore, it is possible to ascertain the original value of the output signal and the original value of the data signal form the superimposed signal. Here, the output signal is H in a case in which the switch of the electrical equipment <NUM> is ON, and the output signal is L in a case in which the switch of the electrical equipment <NUM> is OFF.

The value of the superimposed signal can be split into L1, L2, H1, and H2 from the lowest value. If the superimposed signal is within a range L, the output signal is L. The range L includes L1 and L2. If the superimposed signal is within a range H that is higher than the range L, then the output signal is H. The range H includes H1 and H2. In a case in which the superimposed signal is L1 or H1, the data signal is L. In a case in which the superimposed signal is L2 or H2, the data signal is H.

If the input unit <NUM> receives the superimposed signal from the electrical equipment <NUM>, then the input unit <NUM> determines which of H and L the output signal from the superimposed signal is (which of ON and OFF the switch of the electrical equipment <NUM> is). Then, the input unit <NUM> can extract a data signal from the superimposed signal and output information in accordance with the data signal to the outside.

In this manner, the input unit <NUM> can determine which of ON and OFF the switch of the electrical equipment <NUM> is on the basis of the superimposed signal and further execute processing in accordance with the data signal.

Also, the input unit <NUM> can output an identifier and position information of the electrical equipment <NUM> along with information indicating disconnection of a wiring and the like to the outside. The PC <NUM> can provide, to a user, a notification regarding a communication state between the input unit <NUM> and the electrical equipment <NUM> in three categories, namely normal, alert, and a failure, for example, in accordance with information received from the input unit <NUM> via the controller <NUM>. The user can determine whether or not maintenance is to be performed on the electrical equipment <NUM> through acquisition of the information related to the communication state between the input unit <NUM> and the electrical equipment <NUM> using the PC <NUM>.

Since a data signal is superimposed on an output signal and is then transmitted in communication using a superimposed signal, in a case in which the electrical equipment <NUM> that does not support superimposed signals is connected to the input unit <NUM> that supports superimposed signals, for example, the electrical equipment does not transmit the data signal to the input unit <NUM>. In this case, since the input unit <NUM> cannot extract the data signal from the superimposed signal, the input unit <NUM> can execute only processing equivalent to that of the input unit <NUM> that does not support superimposed signals. Thus, the signal processing device according to an aspect of the present disclosure uses predetermined information related to the electrical equipment <NUM> stored in advance as the data signal, generates a superimposed signal in which the data signal is superimposed on the operation signal of the electrical equipment <NUM>, and transmits the superimposed signal to the input unit <NUM>.

The block diagram illustrates configurations of signal processing device <NUM> and an information rewrite device <NUM> according to an aspect of the present disclosure. Note that it is assumed that the input unit <NUM> supports communication using superimposed signals in the following description. Also, although the electrical equipment <NUM> and the input unit <NUM> that support communication using superimposed signals will be described below, the same can apply to the electrical equipment <NUM>, <NUM>, and <NUM> and the output unit <NUM> that support communication using superimposed signals as well using a similar technical idea.

The signal processing device <NUM> can receive and store predetermined information related to the electrical equipment <NUM> from the information rewrite device <NUM>. The signal processing device <NUM> can use the predetermined information as a data signal, generate a superimposed signal in which the data signal is superimposed on an operation signal of the electrical equipment <NUM>, and transmit the superimposed signal to the input unit <NUM>. The signal processing device <NUM> can have any configuration as long as the signal processing device <NUM> can be disposed between the electrical equipment <NUM> and the input unit <NUM> and may include an outer shape like a communication cable, for example. The signal processing device <NUM> includes an electrical equipment-side terminal <NUM>, a communication device-side terminal <NUM>, a light receiving unit <NUM>, an information storage unit <NUM>, and a transmission control circuit <NUM>. The transmission control circuit <NUM> includes a monitoring unit <NUM>, an information rewrite unit <NUM>, and a superimposed signal transmission unit <NUM>.

The electrical equipment-side terminal <NUM> is a terminal used by the signal processing device <NUM> to transmit or receive an output signal to or from the external electrical equipment <NUM>. The electrical equipment-side terminal <NUM> and the electrical equipment <NUM> are connected to each other with a communication cable or the like. The communication device-side terminal <NUM> is a terminal used by the signal processing device <NUM> to transmit or receive an output signal to or from the input unit <NUM>. The communication device-side terminal <NUM> is also a terminal used by the signal processing device <NUM> to transmit a superimposed signal to the information rewrite device <NUM>. Although in the illustrated example, two devices, namely the input unit <NUM> and the information rewrite device <NUM> are connected to the one communication device-side terminal <NUM>, it is possible to selectively establish connection to either the input unit <NUM> or the information rewrite device <NUM>.

The light receiving unit <NUM> can receive an optical signal from the outside. Specifically, the light receiving unit <NUM> can receive predetermined information related to the electrical equipment <NUM> as the optical signal from the information rewrite device <NUM>. The light receiving unit <NUM> may be a photo transistor that generates a current when receiving light, for example, and the optical signal received by the light receiving unit <NUM> is transmitted to the information rewrite unit <NUM>. Note that the signal processing device <NUM> may be provided with a window portion that transmits light in order for the light receiving unit <NUM> to be able to efficiently receive the optical signal.

The information storage unit <NUM> can store the predetermined information related to the electrical equipment <NUM>. The predetermined information is written in the information storage unit <NUM> by the information rewrite unit <NUM>, and the predetermined information is read by the superimposed signal transmission unit <NUM>.

The transmission control circuit <NUM> includes a partial configuration of the transmission circuit <NUM> in <FIG>. In other words, the transmission control circuit <NUM> further includes a data generation circuit <NUM>, a superimposition circuit <NUM>, a diagnosis circuit <NUM>, and the like, which are not illustrated in <FIG>. The data generation circuit <NUM>, the diagnosis circuit <NUM>, and the information rewrite unit <NUM> can be realized by a micro processing unit (MPU), for example, using information stored in the memory and executing commands of a program that is software for realizing each function.

The monitoring unit <NUM> can monitor reception of the optical signal performed by the light receiving unit <NUM>. The monitoring unit <NUM> may perform monitoring only during a preset monitoring time or may continue the monitoring until the light receiving unit <NUM> receives the optical signal. The monitoring unit <NUM> can transmit a monitoring result to the superimposed signal transmission unit <NUM>.

The information rewrite unit <NUM> can rewrite information stored in the information storage unit <NUM> on the basis of an instruction input from the outside. In other words, the information rewrite unit <NUM> can acquire the predetermined information from the optical signal received by the light receiving unit <NUM> and cause the information storage unit <NUM> to store the predetermined information. The information rewrite unit <NUM> overwrites the predetermined information in the information storage unit <NUM> in accordance with the type of the information.

The superimposed signal transmission unit <NUM> can generate a superimposed signal in which transmission data (data signal) generated by the data generation circuit <NUM> is superimposed on the operation signal output from the operation element <NUM> of the electrical equipment <NUM> by the superimposition circuit <NUM> and transmit the superimposed signal to the input unit <NUM>. Specifically, the superimposed signal transmission unit <NUM> can generate the superimposed signal by superimposing the data signal generated from the predetermined information stored in the information storage unit <NUM> on the operation signal received from the electrical equipment <NUM> through the electrical equipment-side terminal <NUM>. The superimposed signal transmission unit <NUM> can transmit the generated superimposed signal to the input unit <NUM> via the communication device-side terminal <NUM>.

The information rewrite device <NUM> can be communicably connected to the signal processing device <NUM> and an input terminal <NUM>, which will be described later. The information rewrite device <NUM> can acquire the predetermined information related to the electrical equipment <NUM> from the input terminal <NUM>. The information rewrite device <NUM> can project light in regard to the acquired predetermined information as an optical signal to the signal processing device <NUM>. The information rewrite device <NUM> can receive the superimposed signal from the signal processing device <NUM> through the communication device-side terminal <NUM> and verify whether or not the predetermined information indicated by the data signal included in the superimposed signal conforms to details projected as an optical signal by the device itself. Note that the information rewrite device <NUM> may output the verification result to a display unit, which is not illustrated, or external equipment including the input terminal <NUM>. The information rewrite device <NUM> includes a light projecting unit <NUM> and a rewrite circuit <NUM>, and the rewrite circuit <NUM> includes an information acquisition unit <NUM> and an information verification unit <NUM>.

The light projecting unit <NUM> can project the predetermined information input from the information acquisition unit <NUM> as an optical signal. The light projecting unit <NUM> may be a light emitting diode (LED), for example, and may project the optical signal toward the light receiving unit <NUM> of the signal processing device <NUM> with an optical cable or the like. The optical signal may represent the predetermined information by causing a projection pattern to change, for example. Specifically, the light projecting unit <NUM> may provide a notification of the predetermined information using a light color change, a blinking pattern, and light intensity. The light projecting unit <NUM> can further project optical signals indicating a start of rewriting and an end of rewriting before and after the projection of the optical signal in accordance with the information to be rewritten.

The rewrite circuit <NUM> can execute various functions to rewrite the predetermined information related to the electrical equipment <NUM> stored in the information storage unit <NUM> of the signal processing device <NUM>. The rewrite circuit <NUM> can receive the superimposed signal from the signal processing device <NUM> through the communication device-side terminal <NUM> and verify the superimposed signal.

The information acquisition unit <NUM> can acquire information to be rewritten from the input terminal <NUM>. The information acquisition unit <NUM> inputs the acquired information to the light projecting unit <NUM>.

The information verification unit <NUM> can extract the data signal from the superimposed signal received from the signal processing device <NUM> and verify whether or not the predetermined information related to the electrical equipment <NUM> indicated by the data signal conforms to details projected as the optical signal by the light projecting unit <NUM>. Specifically, the information verification unit <NUM> executes two kinds of verification, namely verification regarding whether or not the information storage unit <NUM> has been rewritten in the signal processing device <NUM> and verification regarding whether or not the predetermined information after the rewriting conforms to the detail of the projection.

The input terminal <NUM> is communicably connected to the information rewrite device <NUM> and can input the predetermined information related to the electrical equipment <NUM>, which the information storage unit <NUM> of the signal processing device <NUM> is caused to store, to the information rewrite device <NUM>. The input terminal <NUM> may be, for example, a smartphone, and a user of the input terminal <NUM> may input the predetermined information through a touch operation or the like. At this time, the information rewrite device <NUM> may be an adaptor that is provided with a dedicated light source operating as the light projecting unit <NUM> and that can be connected to the smartphone. Further, the input terminal <NUM> may be configured integrally with the information rewrite device <NUM>. In a case in which the input terminal <NUM> is a smartphone, the smartphone may use a display or an illumination LED as the light projecting unit <NUM>.

Also, the predetermined information related to the electrical equipment <NUM> may be input to the input terminal <NUM> by a method other than the manual method. In a case in which ID information or the like of the electrical equipment <NUM> is provided at a part of a casing of the electrical equipment <NUM> as a two-dimensional code, for example, the input terminal <NUM> may read and acquire the two-dimensional code using a camera or the like.

<FIG> is a circuit diagram illustrating configurations of the signal processing device <NUM> and the information rewrite device <NUM> according to an aspect of the present disclosure. Note that in the illustrated example, illustration of a part of circuit that has been described using <FIG> is omitted.

In the signal processing device <NUM>, each of the electrical equipment-side terminal <NUM> and the communication device-side terminal <NUM> includes two paths. A current supplied from the power source <NUM> is input to a + terminal side of the communication device-side terminal <NUM>, and the current is input to the transmission control circuit <NUM> through a diode D1. In other words, the signal processing device <NUM> drives the transmission control circuit <NUM> and the like using the current supplied from the power source <NUM>.

The light receiving unit <NUM> illustrated as "PhotoTR" in the drawing receives an optical signal along the path represented by the broken line from the light projecting unit <NUM> illustrated as "LED" in the information rewrite device <NUM> and inputs an electric signal obtained by converting the optical signal to the transmission control circuit <NUM>.

The transmission control circuit <NUM> transmits and receives a current and a signal using the electrical equipment-side terminal <NUM> and the communication device-side terminal <NUM>. Specifically, the transmission control circuit <NUM> receives an output signal in accordance with a state of the operation element <NUM> of the electrical equipment <NUM> from the electrical equipment <NUM>, which is not illustrated, through the electrical equipment-side terminal <NUM> and superimposes the predetermined information stored in the information storage unit <NUM> on the output signal to generate a superimposed signal. Further, the transmission control circuit <NUM> transmits the generated superimposed signal to the rewrite circuit <NUM> of the information rewrite device <NUM> through the communication device-side terminal <NUM>.

The transmission control circuit <NUM> can rewrite the predetermined information stored in the information storage unit <NUM> with details input from the light projecting unit <NUM> by forming the light receiving unit <NUM> and the light projecting unit <NUM> with the circuit configurations as described above. Then, the superimposed signal in which the rewritten details are superimposed on the output signal can be transmitted to the rewrite circuit <NUM>. In this manner, the information rewrite device <NUM> can verify whether or not the predetermined information included in the superimposed signal received by the rewrite circuit <NUM> conforms to details projected from the light projecting unit <NUM>.

<FIG> is a diagram illustrating a specific example of rewriting and verification of information using the signal processing device <NUM> and the information rewrite device <NUM> according to an aspect of the present disclosure. Note that in the following description, it is assumed that information to be rewritten using the input terminal <NUM> has been input in advance to the information rewrite device <NUM>.

In the illustrated example, "DC" represents a DC current supplied from the power source <NUM>, and "DC-ON" represents a timing at which the power source <NUM> is activated. "(LED-ON)" and "(LED-OFF)" represent whether or not the light projecting unit <NUM> is projecting light. "Activate rewriting", "rewritten data", and "end rewriting" correspond to "a projection pattern corresponding to a rewriting start instruction indicating a start of rewriting", "a projection pattern in accordance with rewritten data that is details to be rewritten", and "a projection pattern corresponding to a rewriting end instruction indicating an end of rewriting", respectively. Also, "Verification mode: receiving operation" is an operation mode to receive a superimposed signal transmitted from the signal processing device <NUM>, and "verification" is an operation mode to verify predetermined information indicated by a data signal included in the received superimposed signal.

"LED monitoring, "rewrite mode", and "ordinary operation mode: transmission operation" respectively indicate operation modes in the signal processing device <NUM>. "LED monitoring" indicates that the monitoring unit <NUM> is monitoring reception of an optical signal performed by the light receiving unit <NUM> in the signal processing device <NUM>, and "rewrite mode" indicates that the information rewrite unit <NUM> is in a state in which details in the information storage unit <NUM> can be rewritten in the signal processing device <NUM>. "Ordinary operation mode: transmission operation" indicates a state where the signal processing device <NUM> generates a superimposed signal, in which a data signal indicating predetermined information is superimposed on an output signal acquired from the electrical equipment <NUM> and transmits the superimposed signal to the information rewrite device <NUM>. In other words, operation modes in which when an optical signal has been detected by the monitoring unit <NUM>, the superimposed signal transmission unit <NUM> does not transmit the superimposed signal and the information rewrite unit <NUM> rewrites information stored in the information storage unit <NUM> on the basis of the optical signal are "LED monitoring" and "rewrite mode". Also, an operation mode in which after the rewriting processing performed by the information rewrite unit <NUM> has been completed, the superimposed signal transmission unit <NUM> transmits the superimposed signal is "ordinary operation mode: transmission operation".

First, if the power source <NUM> is activated, then the transmission control circuit <NUM> of the signal processing device <NUM> releases a reset state, and after performing initial processing, the monitoring unit <NUM> starts to monitor reception performed by the light receiving unit <NUM> in "LED monitoring".

On the other hand, the information rewrite device <NUM> changes the state from "(LED-OFF)" to "(LED-ON)" asynchronously with the state of the signal processing device <NUM>. The information rewrite device <NUM> then projects an optical signal in order from "activate rewriting", "rewritten data", and "end rewriting" using the light projecting unit <NUM>. After a series of projecting processes are completed, the information rewrite device <NUM> shifts the operation mode to "ordinary operation mode: transmission operation" and starts reception of the superimposed signal.

If the reception of the optical signal projected during an operation in "LED monitoring" is detected, then the signal processing device <NUM> shifts the operation mode to "rewrite mode". The signal processing device <NUM> receives information with which an optical signal of a projection pattern in accordance with "rewritten data" received after an optical signal of a projection pattern in accordance with "activate rewriting" is received during an operation in "rewrite mode" is rewritten, and performs rewriting of the information storage unit <NUM> using the information rewrite unit <NUM>. Thereafter, if an optical signal of a projection pattern in accordance with "end rewriting" is received, "rewrite mode" is ended, and the operation mode is shifted to "ordinary operation mode: transmission operation". The signal processing device <NUM> generates a data signal using predetermined information after rewriting stored in the information storage unit <NUM> and transmits a superimposed signal including the data signal to the information rewrite device <NUM> using the superimposed signal transmission unit <NUM> in "ordinary operation mode: transmission operation".

If the information rewrite device <NUM> receives the superimposed signal from the signal processing device <NUM> during an operation in "ordinary operation mode: transmission operation", then the information rewrite device <NUM> shifts the operation mode to "verification" and then performs verification of the predetermined information indicated by the data signal included in the superimposed signal using the information verification unit <NUM>.

In this manner, the predetermined information related to the electrical equipment <NUM> stored in the signal processing device <NUM> is rewritten using the information rewrite device <NUM>. Therefore, the user can rewrite the predetermined information even after production or shipping of the signal processing device <NUM>. The signal processing device <NUM> can thus transmit, to the input unit <NUM>, the superimposed signal in which the predetermined information after rewriting is superimposed on the output signal received from the electrical equipment <NUM>. Therefore, even in a case in which the electrical equipment <NUM> does not support transmission of superimposed signals, for example, it is possible to realize transmission of superimposed signals through utilization of the signal processing device <NUM>.

Note that although the signal processing device <NUM> shifts the operation mode to "rewrite mode" on the basis of the optical signal including a rewriting activation instruction in the description of <FIG>, the trigger of the shifting to "rewrite mode" is not limited thereto. The signal processing device <NUM> may be triggered by reception of some light at the light receiving unit <NUM> after activation of the device, for example, to shift to "rewrite mode" or may shift to "rewrite mode" on the basis of an input from external equipment.

Although the signal processing device <NUM> is illustrated as a device that is different from the electrical equipment <NUM> in the description of <FIG>, the signal processing device <NUM> may be configured integrally with the electrical equipment <NUM>. For example, the configuration of the signal processing device <NUM> may be incorporated in the electrical equipment <NUM>.

Each diagram in <FIG> is a flow diagram illustrating a flow of processing executed by the signal processing device <NUM> and the information rewrite device <NUM> according to an aspect of the present disclosure. (a) of <FIG> illustrates a flow diagram of the signal processing device <NUM>, and (b) of <FIG> illustrates a flow diagram of the information rewrite device <NUM>. Note that in the following description, it is assumed that the signal processing device <NUM> and the information rewrite device <NUM> are connected to the power source <NUM> similarly to <FIG> and information to be rewritten has been input in advance in the information rewrite device <NUM> using the input terminal <NUM>.

First, the flow diagram of the signal processing device <NUM> will be described using (a) of <FIG>. First, the signal processing device <NUM> and the power source <NUM> are activated (S1). After S1, the signal processing device <NUM> releases a reset state if current supply is started (S2). Then, after the reset state is released, the signal processing device <NUM> executes initialization processing, and after the initialization processing is completed, the monitoring unit <NUM> starts to monitor reception performed by the light receiving unit <NUM> (S3).

After S3, the monitoring unit <NUM> determines whether or not the light receiving unit <NUM> has detected an optical signal projected from the light projecting unit <NUM> (S4). If the optical signal is projected from the light projecting unit <NUM> through processing in S12, which will be described later, then the light receiving unit <NUM> receives the optical signal. In a case in which it is determined that the monitoring unit <NUM> has detected the projected optical signal (YES in S4), the monitoring unit <NUM> further determines whether or not the light receiving unit <NUM> has received a rewriting activation instruction as an optical signal (S5). On the other hand, in a case in which it is determined that no optical signal has been detected in S4 (NO in S4), the monitoring unit <NUM> determines whether or not a preset monitoring time has elapsed (S6).

In a case in which it is determined that the rewriting activation instruction projected from the light projecting unit <NUM> through processing in S14, which will be described later, has been received in S5 (YES in S5), the processing proceeds to S7. In S7, the information rewrite unit <NUM> rewrites the predetermined information related to the electrical equipment <NUM> stored in the information storage unit <NUM> on the basis of an optical signal projected from the light projecting unit <NUM> through processing in S15, which will be described later (S7). On the other hand, in a case in which it is determined that no rewriting activation instruction has not been received, the processing proceeds to S8.

In a case in which it is determined that the monitoring time has not elapsed in S6 (NO in S6), the processing proceeds to S4, and the processing in S4 to S6 is executed again. On the other hand, in a case in which it is determined that the monitoring time has elapsed (YES in S6), the processing proceeds to S11. In a case in which it is determined that the monitoring time has not elapsed in S8 (NO in S8) similarly to S6, the processing proceeds to S4, and the processing in S4 to S8 is executed again. On the other hand, in a case in which it is determined that the monitoring time has elapsed (YES in S8), the processing proceeds to S11.

In S9, the monitoring unit <NUM> determines whether or not an optical signal indicating a rewriting end instruction projected from the light projecting unit <NUM> through processing in S16, which will be described later, has been received (S9). In a case in which it is determined that the optical signal has not been received (NO in S9), the monitoring unit <NUM> determines whether or not a preset monitoring time has elapsed (S10). In a case in which it is determined that the monitoring time has not elapsed (NO in S10), the processing proceeds to S9, and the processing in S9 is executed again. On the other hand, in a case in which it is determined that the monitoring time has elapsed (YES in S10), the signal processing device <NUM> ends reception of a rewriting instruction related to the predetermined information, and the processing proceeds to S11.

In S11, the signal processing device <NUM> starts to transmit the superimposed signal using the superimposed signal transmission unit <NUM> (S11). Note that the predetermined information indicated by the data signal included in the superimposed signal transmitted in S11 is details before rewriting in a case in which the processing has proceeded from S6 to S11 and is details after rewriting in S7 in a case in which the processing has proceeded from S9 or S10 to S11.

The signal processing device <NUM> according to an aspect of the present disclosure can transmit the superimposed signal in which the predetermined information is superimposed on the operation signal to the communication device through the aforementioned processing. Also, it is possible to rewrite the predetermined information included in the details transmitted as the superimposed signal on the basis of the optical signal. Therefore, the user can rewrite the predetermined information even after production and shipping of the signal processing device <NUM>. Further, it is possible to realize transmission of the superimposed signal using the signal processing device <NUM> even in a case in which the external electrical equipment <NUM> does not support the transmission of superimposed signals.

Next, the flow diagram of the information rewrite device <NUM> will be described using (b) of <FIG>. First, the information rewrite device <NUM> and the power source <NUM> are activated (S12). Note that if the power source <NUM> has already been activated through the aforementioned processing in S1, it is not necessary to activate the power source <NUM> in S12. Thereafter, the information rewrite device <NUM> starts projection using the light projecting unit <NUM> (S13).

After S13, the information rewrite device <NUM> projects a rewriting activation instruction as an optical signal using the light projecting unit <NUM> (S14). Thereafter, the information rewrite device <NUM> uses information that has been input from the input terminal <NUM> and has already been acquired by the information acquisition unit <NUM> as an optical signal and projects the optical signal using the light projecting unit <NUM> (S15). If the light projecting unit <NUM> ends the projection of the predetermined information as the optical signal, then the information rewrite device <NUM> projects an optical signal indicating a rewriting end instruction using the light projecting unit <NUM> (S16) and ends a series of projecting processes (S17).

After S17, the rewrite circuit <NUM> of the information rewrite device <NUM> determines whether or not the superimposed signal transmitted by the signal processing device <NUM> through the aforementioned processing in S11 has been received (S18). In a case in which it is determined that the superimposed signal has been received (YES in S18), the information verification unit <NUM> verifies whether or not the predetermined information indicated by the data signal extracted from the superimposed signal conforms to the details projected as the optical signal by the light projecting unit <NUM> in S14 (S19). The information rewrite device <NUM> outputs the result of the verification in S19 to a display unit or external equipment, which is not illustrated (S20).

The information rewrite device <NUM> according to an aspect of the present disclosure can rewrite the information stored in the information storage unit <NUM> of the signal processing device <NUM> with the optical signal through the aforementioned processing. Then, the information rewrite device <NUM> can verify whether or not the information has been correctly rewritten from the superimposed signal received from the signal processing device <NUM>.

In the aforementioned configuration example, the signal processing device <NUM> is configured to start the transmission of the superimposed signal after rewriting the information stored in the information storage unit <NUM>. However, the signal processing device <NUM> is configured to rewrite the information during the transmission of the superimposed signal.

The signal processing device <NUM> and the information rewrite device <NUM> according to an aspect of the present disclosure will be described using <FIG>. Note that the information rewrite device <NUM> is the same as the information rewrite device <NUM> according to the aforementioned configuration example.

Although a basic configuration of the signal processing device <NUM> is the same as that in the aforementioned configuration example, a part of the configuration is different. In the modification example, the superimposed signal transmission unit <NUM> is different in that a superimposed signal is transmitted even when the monitoring unit <NUM> is monitoring reception performed by the light receiving unit <NUM> and the transmission of the superimposed signal is stopped at a timing at which the light receiving unit <NUM> detects the optical signal.

<FIG> is a diagram illustrating a specific example of rewriting and verification of information using the signal processing device <NUM> during transmission of a superimposed signal and the information rewrite device <NUM>. Note that in the following description, it is assumed that the information to be rewritten has been input to the information rewrite device <NUM> in advance using the input terminal <NUM>, and description of the items with the same names as those in <FIG> will be omitted. Also, operations of the information rewrite device <NUM> are the same as those in <FIG>, and description thereof will thus be omitted.

First, if the power source <NUM> is activated, then the transmission control circuit <NUM> of the signal processing device <NUM> releases a reset state, performs initial processing, and then operates in "LED monitoring (ordinary operation mode)". Here, "LED monitoring (ordinary operation mode)" is an operation mode in which both the monitoring of the reception of the light receiving unit <NUM> performed by the monitoring unit <NUM> and the transmission of the superimposed signal performed by the superimposed signal transmission unit <NUM> are performed.

If reception of the optical signal is detected during the operation in "LED monitoring (ordinary operation mode)", then the signal processing device <NUM> stops the transmission of the superimposed signal and then shifts the operation mode to "rewrite mode". The signal processing device <NUM> rewrites information on the basis of the optical signal received from the light projecting unit <NUM> of the information rewrite device <NUM> as described above using <FIG>, then ends "rewrite mode", and shifts the operation mode to "ordinary operation mode: transmission operation". Operations of the signal processing device <NUM> in "ordinary operation mode: transmission operation" are the same as the details described above using <FIG>. In this manner, the signal processing device <NUM> can rewrite the information using the information rewrite device <NUM> even after the transmission of the superimposed signal is started.

<FIG> is a flow diagram illustrating an example of a flow of processing executed by the signal processing device <NUM> according to an aspect of the present disclosure. Note that description of the same processing as those in (a) of <FIG> will be omitted in the following description. Also, the flow diagram of the information rewrite device <NUM> are completely the same as that in (b) of <FIG>.

The signal processing device <NUM> executes the processing in S1 and S2 and then starts transmission of the superimposed signal performed by the superimposed signal transmission unit <NUM> and monitoring of the light receiving unit <NUM> performed by the monitoring unit <NUM> (S21). After S21, the signal processing device <NUM> executes the processing in S4 to S6 similarly to the aforementioned operation example. Here, since the superimposed signal transmission unit <NUM> has already started the transmission of the superimposed signal in S21, the point at which the series of processes end is different from that in (a) of <FIG> in a case in which the monitoring unit <NUM> determines that the preset monitoring time has elapsed S6 (YES in S6).

In a case in which it is determined that the rewriting activation instruction has been received in S5 (YES in S5), the superimposed signal transmission unit <NUM> stops the transmission of the superimposed signal (S22). The processing then proceeds to S7. On the other hand, in a case in which it is determined that the rewriting activation instruction has not been received (NO in S5), the processing proceeds to S8, and whether or not a monitoring time for the rewriting activation instruction has elapsed is determined (S8). Here, a point that the series of the processes end in a case in which the monitoring unit <NUM> determines that a preset monitoring time has elapsed in S8 (YES in S8) since the superimposed signal transmission unit <NUM> has already started the transmission of the superimposed signal in S21 is different from that in (a) of <FIG>.

After S7, the signal processing device <NUM> executes the processing in S9 and S10 similarly to the aforementioned operation example. Then, in a case in which it is determined that the rewriting end instruction has been received in S9 (YES in S9), or in a case in which it is determined that the monitoring time has elapsed in S10 (YES in S10), the superimposed signal transmission unit <NUM> restarts the transmission of the superimposed signal (S23). Thereafter, the signal processing device <NUM> ends the series of processes.

The signal processing device <NUM> can rewrite the information on the basis of the optical signal even after the transmission of the superimposed signal is started and transmit the superimposed signal generated using information after the rewriting through the aforementioned processing.

In the aforementioned configuration example and the modification example <NUM>, the information rewrite device <NUM> is configured to input information to be rewritten to the signal processing device <NUM> through projection using the light projecting unit <NUM>. However, the information rewrite device <NUM> may be configured to able to transmit the information to be rewritten to the signal processing device <NUM> through a path used to transmit and receive superimposed signals, for example.

<FIG> is a block diagram illustrating configurations of the signal processing device <NUM> and the information rewrite device <NUM> according to an aspect of the present disclosure.

Although a basic configuration of the signal processing device <NUM> is the same as that in the aforementioned configuration example, a part of the configuration is different. The signal processing device <NUM> includes a current detection unit <NUM> instead of the light receiving unit <NUM> and the monitoring unit <NUM>.

The current detection unit <NUM> is connected to the input unit <NUM> or the information rewrite device <NUM> and can detect a current value of a current signal supplied from a signal line used to transmit and received superimposed signals. Specifically, the current detection unit <NUM> can detect a current value of a current signal input to a communication device-side terminal <NUM> and can transmit the detection result to the transmission control circuit <NUM>.

The transmission control circuit <NUM> can rewrite information using the information rewrite unit <NUM> on the basis of the detection result of the current value obtained by the current detection unit <NUM>. Specifically, in a case in which a variation pattern of the current value of the current signal received by the current detection unit <NUM> from the input unit <NUM> or the information rewrite device <NUM> indicates an information rewriting instruction, the transmission control circuit <NUM> executes rewriting of the information based on the current signal. In the following description, the current signal indicated by the information to be rewritten by variations in current value will be referred to as a rewriting current signal. The information rewrite unit <NUM> is different from that in the aforementioned configuration example in that the information stored in the information storage unit <NUM> is rewritten on the basis of the rewriting current signal.

The current value of the rewriting current signal may be in any range of a value that can be distinguished from other current signals. If an output signal received from the electrical equipment <NUM> is an ON/OFF signal, and in a case in which a current value that is higher than a current value in an ON signal of the output signal is detected by the current detection unit <NUM>, for example, the information rewrite unit <NUM> may recognize variations in current value as the rewriting current signal.

Although the basic configuration of the information rewrite device <NUM> is the same as that in the aforementioned configuration example, a part of the configuration is different. The information rewrite device <NUM> includes a current control unit <NUM> instead of the light projecting unit <NUM>.

The current control unit <NUM> can generate the rewriting current signal in accordance with the predetermined information input from the information acquisition unit <NUM> and transmit the generated rewriting current signal to the signal processing device <NUM>. The current control unit <NUM> may generate the rewriting current signal using a current value that is higher than the current value in the ON signal of the output signal of the electrical equipment <NUM>, for example.

<FIG> is a circuit diagram illustrating configurations of the signal processing device <NUM> and the information rewrite device <NUM> according to an aspect of the present disclosure. Note that in the following description, description of items that have already been described in <FIG> will be omitted.

The signal processing device <NUM> includes a current detection unit <NUM> between the - side of the communication device-side terminal <NUM> and the transmission control circuit <NUM>. The current detection unit <NUM> is configured of a resistor or an operation amplifier, for example, and can perform, using the operation amplifier, amplification and output adjustment on a signal indicating the current value of the current signal detected using the resistor and then output the result to the transmission control circuit <NUM>.

In a case in which the current value of the current signal from the current detection unit <NUM> is a current value that is higher than the current value in the ON signal of the output signal of the electrical equipment <NUM>, for example, the transmission control circuit <NUM> determines that the current signal is the rewriting current signal. In a case in which it is determined that the transmission control circuit <NUM> determines that the current signal is the rewriting current signal, the information rewrite unit <NUM> rewrites the information stored in the information storage unit <NUM> on the basis of the rewriting current signal.

In the information rewrite device <NUM>, the current control unit <NUM> can be realized by combining a transistor and a resistor as illustrated in the drawing. In a case in which the current control unit <NUM> is configured as illustrated in the drawing, the current control unit <NUM> can generate the rewriting current signal by switching ON/OFF of the transistor in accordance with information received by the information acquisition unit <NUM> of the rewrite circuit <NUM> from the input terminal <NUM>, for example.

<FIG> is a schematic view illustrating an overview of the rewriting current signal. In the illustrated example, "supplied current" of the vertical axis represents a current value of the rewriting current signal supplied from the information rewrite device <NUM> to the signal processing device <NUM>. Also, "SW = OFF" corresponds to the range L of the superimposed signal in <FIG>, and "SW = ON" corresponds to the range H of the superimposed signal in <FIG>. "Predetermined threshold value" is a value that is sufficiently large as compared with the range H of the superimposed signal.

In the drawing, "Data = <NUM>" and "Data = <NUM>" indicate ranges of binary values converted by the current detection unit <NUM> on the basis of the current value. In other words, in a case in which the current value of the rewriting current signal is between "<NUM>" and "predetermined threshold value", the current detection unit <NUM> converts the current value into the binary value "<NUM>" and transmits the binary value to the transmission control circuit <NUM>. On the other hand, in a case in which the current value of the rewriting current signal is greater than "predetermined threshold value", the current detection unit <NUM> converts the current value into the binary value "<NUM>" and transmits the binary value to the transmission control circuit <NUM>. In this manner, the information rewrite unit <NUM> of the transmission control circuit <NUM> can rewrite the information stored in the information storage unit <NUM> using the binary value obtained by converting the current value of the rewriting current signal.

Although "predetermined threshold value" is illustrated as a value that is sufficiently large as compared with the range H of the superimposed signal in <FIG>, "predetermined threshold value" is not limited thereto. If the current detection unit <NUM> can recognize the range H and the range L of the superimposed signal, that is, which of ON and OFF the switch of the electrical equipment <NUM> is, for example, "predetermined threshold value" may be different in accordance with a state of the switch of the electrical equipment <NUM>.

Specifically, the signal processing device <NUM> does not detect a current corresponding to the range L as the superimposed signal when the signal processing device <NUM> is transmitting or receiving an output signal that is an OFF signal for a reason that the switch of the electrical equipment <NUM> is OFF or the like. At this time, the current control unit <NUM> may generate the rewriting current signal using a current value that is higher than a current value in the OFF signal of the output signal. Then, in a case in which the current detection unit <NUM> detects the current value that is higher than the current value in the OFF signal of the output signal, the information rewrite unit <NUM> may recognize variations in current value as the rewriting current signal. In other words, in a case in which the switch of the electrical equipment <NUM> is OFF, and the current detection unit <NUM> recognizes that the superimposed signal is in the range L, for example, a value that is sufficiently larger than the range L but is smaller than the range H may be set as "predetermined threshold value". In this case, when the switch of the electrical equipment <NUM> is OFF, it is possible to set the current value of the rewriting current signal to be lower than the current value when the switch is ON.

<FIG> is a diagram illustrating a specific example of rewriting and verification of information using the signal processing device <NUM> and the information rewrite device <NUM>. Note that in the following description, it is assumed that information to be rewritten has already been input to the information rewrite device <NUM> in advance using the input terminal <NUM> and description of items with the same names as those in <FIG> will be omitted.

First, if the power source <NUM> is activated, then the transmission control circuit <NUM> of the signal processing device <NUM> releases a reset state, performs initial processing, and then operates in "current detection". Here, "current detection" is an operation mode in which the current detection unit <NUM> detects a current value of a current signal.

On the other hand, the information rewrite device <NUM> performs control using the current control unit <NUM> such that the current value of the current signal to be supplied to the signal processing device <NUM> decreases immediately after the activation of the power source <NUM>. Thereafter, the information rewrite device <NUM> performs control using the current control unit <NUM> such that the current value of the current signal to be supplied to the signal processing device <NUM> is equal to or greater than a predetermined threshold value and transmits the current signal corresponding to the rewriting activation instruction to the signal processing device <NUM>. After the transmission of the current signal corresponding to the rewriting activation instruction, the information rewrite device <NUM> transmits information to be rewritten in "rewritten data" as a rewriting current signal indicated by an increase or a decrease in current value. After the transmission of the rewriting current signal in accordance with the information to be rewritten, the information rewrite device <NUM> transmits a current signal corresponding to a rewriting end instruction to the signal processing device <NUM> in "end rewriting".

If the current detection unit <NUM> detects a current value that is equal to or greater than the predetermined threshold value during an operation in "detect current", then the signal processing device <NUM> moves on to "rewrite mode". Then, the information rewrite unit <NUM> rewrites the information in the information storage unit <NUM> on the basis of the rewriting current signal received from the information rewrite device <NUM> during the operation in "rewrite mode". Thereafter, if the rewriting end instruction is received, then the information rewrite device <NUM> ends "rewrite mode", performs predetermined processing in "internal processing", and shifts the operation mode to "ordinary operation mode: transmission operation". Operations of the signal processing device <NUM> in "ordinary operation mode: transmission operation" are the same as the details described above using <FIG>. In this manner, the signal processing device <NUM> can rewrite the information on the basis of the rewriting current signal.

Each diagram in <FIG> is a flow diagram illustrating an example of a flow of processing executed by the signal processing device <NUM> and the information rewrite device <NUM> according to an aspect of the present disclosure. (a) of <FIG> illustrates a flow diagram of the signal processing device <NUM>, and (b) of <FIG> illustrates a flow diagram of the information rewrite device <NUM>. Note that description of the same processing as that in (a) and (b) of <FIG> will be omitted in the following description.

First, the flow diagram of the signal processing device <NUM> will be described using (a) of <FIG>. The signal processing device <NUM> executes the processing in S1 and S2, then starts detection of a current value of a current signal using the current detection unit <NUM>, and determines whether or not a current that is equal to or greater than a predetermined threshold value has been detected (S31). If a current value of a current signal to be supplied to the signal processing device <NUM> increases through processing in S41, which will be described later, then the current detection unit <NUM> detects the current that is equal to or greater than the predetermined threshold value (YES in S31).

After the current detection unit <NUM> detects the current that is equal to or greater than the predetermined threshold value in S31, the information rewrite device <NUM> transmits information to be rewritten as an increase or a decrease in current value through processing in S42, which will be described later. The information rewrite unit <NUM> of the transmission control circuit <NUM> rewrites the information in the information storage unit <NUM> on the basis of the detection result of the current detection unit <NUM> regarding the increase or the decrease in current value (S32). Thereafter, the current detection unit <NUM> determines whether or not a current signal corresponding to the rewriting end instruction has been received from the information rewrite device <NUM> (S33). In a case in which it is determined that the current signal has been detected, the transmission control circuit <NUM> ends the rewriting of the information and starts transmission of a superimposed signal using the superimposed signal transmission unit <NUM> (S11).

The signal processing device <NUM> can receive the information to be rewritten via a signal line connected to the input unit <NUM> through the processing described hitherto. Therefore, there is no need to provide a special configuration to receive the information to be rewritten. Also, since the current signal with a current value that is higher than the current value in the ON signal of the output signal of the electrical equipment <NUM> is selectively used as the rewriting current signal, it is possible to clearly distinguish the output signal from the rewriting current signal.

Next, the flow diagram of the information rewrite device <NUM> will be described using (b) of <FIG>. The information rewrite device <NUM> executes the processing in S12 and then causes the current to be supplied to the signal processing device <NUM> to increase using the current control unit <NUM> (S41). Thereafter, the current control unit <NUM> generates a rewriting current signal including information that has already been acquired by the information acquisition unit <NUM> and that is to be rewritten as an increase or a decrease in current value and transmits the rewriting current signal (S42). If the transmission of the information to be rewritten is completed, then the current control unit <NUM> generates a current signal indicating a rewriting end instruction and transmits the current signal to the signal processing device <NUM> (S43). After S43, the information rewrite device <NUM> executes processing in S18 to S20 and verifies the predetermined information indicated by the data signal included in the superimposed signal transmitted from the signal processing device <NUM> in the processing in S11.

The information rewrite device <NUM> can rewrite the information stored in the information storage unit <NUM> with the rewriting current signal transmitted via the signal line included in the signal processing device <NUM> through the processing described hitherto. Also, since the current signal with a current value that is higher than the current value in the ON signal of the output signal of the electrical equipment <NUM> is selectively used as the rewriting current signal, the signal processing device <NUM> can clearly distinguish the output signal from the rewriting current signal.

In the aforementioned modification example <NUM>, the communication between the signal processing device <NUM> and the information rewrite device <NUM> is performed using a communication cable that is connected to the communication device-side terminal <NUM> and that can transmit and receive superimposed signals. Since the input unit <NUM> can be connected to the signal processing device <NUM> with the communication cable, the various functions included in the information rewrite device <NUM> in the modification example <NUM> may be incorporated in the input unit <NUM>, for example.

<FIG> is a block diagram illustrating configurations of the signal processing device <NUM> and the input unit <NUM> according to an aspect of the present disclosure. Note that since the configuration of the signal processing device <NUM> is the same as the configuration illustrated in <FIG>, description thereof will be omitted.

The input unit <NUM> further includes a series of configurations included in the information rewrite device <NUM> in the modification example <NUM> in addition to the configuration described in the configuration example. In other words, the input unit <NUM> includes the rewrite circuit <NUM> and the current control unit <NUM>, and the rewrite circuit <NUM> includes the information acquisition unit <NUM> and the information verification unit <NUM>. The information acquisition unit <NUM> is different from that in the modification example <NUM> in that the predetermined information related to the electrical equipment <NUM> is acquired from the PC <NUM> connected to the input unit <NUM> via the controller <NUM>.

Also, the input unit <NUM> includes an operation signal processing unit <NUM> and a data signal processing unit <NUM>. The operation signal processing unit <NUM> can detect an output signal (operation signal) from a superimposed signal. The operation signal processing unit <NUM> corresponds to the input circuit <NUM> in <FIG> and transmits the detected output signal to a control circuit (corresponding to the unit control circuit <NUM> in <FIG>), which is not illustrated in the drawing.

The data signal processing unit <NUM> can extract a data signal from a superimposed signal. The data signal processing unit <NUM> corresponds to the extraction circuit <NUM> in <FIG>, performs error detection on the extracted data signal as needed, and then transmits the data signal to the control circuit (corresponding to the unit control circuit <NUM> in <FIG>), which is not illustrated.

<FIG> is a circuit diagram illustrating configurations of the signal processing device <NUM> and the input unit <NUM> according to an aspect of the present disclosure. The circuit configuration of the signal processing device <NUM> is the same as that in <FIG>, and the circuit configuration of the input unit <NUM> is the same as that of the information rewrite device <NUM> in <FIG>. The rewrite circuit <NUM> of the input unit <NUM> receives predetermined information input from the PC <NUM> via the controller <NUM>.

Since processing executed by the signal processing device <NUM> and the input unit <NUM> according to an aspect of the present disclosure is the same as the details illustrated in (a) and (b) of <FIG> other than that the input unit <NUM> is used instead of the information rewrite device <NUM>, the description thereof will be omitted.

In this manner, the communication device that performs detection of an output signal and extraction of a superimposed signal can also function as the information rewrite device.

A superimposed signal includes a current value ranging in the range H and the range L as described above using <FIG>. Therefore, in a case in which the input unit <NUM> that does not support superimposed signals is connected to the signal processing device <NUM>, the input unit <NUM> receives a superimposed signal as an output signal, it is thus not possible to appropriately determine the range H and the range L, and there is a concern of erroneous detection.

As means for preventing erroneous detection, it is considered that the signal processing device <NUM> determines whether or not the input unit <NUM> supports communication using superimposed signals on the basis of a current value of a current supplied from the input unit <NUM>, for example. If it is possible to detect whether or not the input unit <NUM> supports the communication using superimposed signals, then the signal processing device <NUM> can cause the operation mode of transmitting a superimposed signal and an operation mode of transmitting only an output signal, for example, to operate in a switched manner.

However, since whether or not a signal is a rewriting current signal is determined on the basis of the current value in the modification example <NUM>, it is necessary to execute two kinds of processing, namely processing of "determining whether or not there is compatibility with communication using superimposed signal" and of "converting the current signal into information to be rewritten if the signal is a rewriting current signal" in regard to the current signal to achieve both of them.

<FIG> is a block diagram illustrating configurations of the signal processing device <NUM> and the input unit <NUM> according to an aspect of the present disclosure. Note that the configuration of the input unit <NUM> is the same as the configuration illustrated in <FIG>.

The signal processing device <NUM> further includes an operation mode switching unit <NUM> in addition to the configuration described in the modification example <NUM>. The signal processing device <NUM> can operate while switching an ordinary operation mode in which the superimposed signal transmission unit <NUM> transmits a superimposed signal and a low current consumption mode in which no superimposed signal is transmitted. The operation mode switching unit <NUM> can switch the operation mode of the signal processing device <NUM> between the ordinary operation mode and the low current consumption mode on the basis of a detection result obtained by the current detection unit <NUM>. The operation mode switching unit <NUM> can switch the operation mode of the signal processing device <NUM> from the low current consumption mode to the ordinary operation mode in a case in which a magnitude, a variation pattern, or the like of the current value detected by the current detection unit <NUM> is an instruction for switching to the ordinary operation mode, for example.

Although a basic configuration of the input unit <NUM> is the same as that in the modification example <NUM>, a part of the configuration is different. In the input unit <NUM>, the current control unit <NUM> can transmit information to be rewritten as a rewriting current signal similarly to the modification example <NUM> and transmit a current signal corresponding to a switching instruction for switching the operation mode of the signal processing device <NUM> between the ordinary operation mode and the low current consumption mode. The input unit <NUM> can provide a notification that the input unit <NUM> itself supports superimposed signals to the signal processing device <NUM> through the transmission of the current signal corresponding to the switching instruction. Therefore, it is possible to cause the signal processing device <NUM> to operate in the operation mode switched to the ordinary operation mode and to receive a superimposed signal.

Each diagram of <FIG> is a diagram illustrating a specific example of rewriting of information and switching of the operation mode using the signal processing device <NUM> and the input unit <NUM>. (a) of <FIG> illustrates rewriting of information, and (b) of <FIG> illustrates switching of the operation mode. (c) of <FIG> illustrates a specific example of a switching instruction and rewritten data.

(a) of <FIG> is basically the same as <FIG> other than that the input unit <NUM> is used instead of the information rewrite device <NUM>. Note that "verification mode: receive/compare" is an operation mode in which the input unit <NUM> receives and verifies the superimposed signal transmitted from the signal processing device <NUM>, and "low current consumption mode represents that the operation mode is the aforementioned low current consumption mode.

If the current detection unit <NUM> detects a current signal corresponding to a rewriting activation instruction during an operation in "low current consumption mode" after initial processing, then the signal processing device <NUM> shifts the operation mode to "rewrite mode". Note that since the superimposed signal is not transmitted during the operation in "rewrite mode", the "rewrite mode" is a type of low current consumption mode.

The signal processing device <NUM> rewrites the information storage unit <NUM> using the information rewrite unit <NUM> on the basis of the rewriting current signal detected during the operation in "rewrite mode", then ends "rewrite mode" on the basis of a rewriting end instruction, and shifts the operation mode to "ordinary operation mode: transmission operation". In other words, the operation mode switching unit <NUM> can switch the operation mode to "ordinary operation mode" if the rewriting end instruction is detected.

The signal processing device <NUM> generates a data signal using predetermined information after rewriting that is stored in the information storage unit <NUM> in "ordinary operation mode: transmission operation" and transmits a superimposed signal including the data signal to the information rewrite device <NUM> using the superimposed signal transmission unit <NUM>.

On the other hand, the input unit <NUM> respectively transmits a rewriting activation instruction, rewritten data, and a rewriting end instruction as current signals similarly to the information rewrite device <NUM> in <FIG> and then performs reception and verification of the superimposed signal in "verification mode: receive/compare". If there are no problems in the verification result, then the input unit <NUM> operates in "ordinary operation mode: receiving operation" and continues the communication using the superimposed signal.

In (b) of <FIG>, the switching instruction from the low current consumption mode to the ordinary operation mode that is transmitted as a current signal by the input unit <NUM> to the signal processing device <NUM> corresponds to supply of a large current for a specific period of time. In other words, the input unit <NUM> supplies a large current for a specific period of time as a switching instruction when the signal processing device <NUM> is operating in the low current consumption mode. The signal processing device <NUM> determines whether or not the current signal corresponds to the switching instruction in "check", and as a result of determining that the current signal corresponds to the switching instruction, the operation mode switching unit <NUM> switches the operation mode to the ordinary operation mode to start the transmission of the superimposed signal. After the input unit <NUM> supplies the large current corresponding to the switching instruction, the input unit <NUM> operates in "ordinary operation mode: receiving operation" and starts reception of the superimposed signal.

(c) of <FIG> is a specific example of the switching instruction from the low current consumption mode to the ordinary operation mode that is transmitted as a current signal by the input unit <NUM> and the rewriting current signal that is received as rewritten data when the signal processing device <NUM> is operating in "rewrite mode". As described above using (c) of <FIG>, the switching instruction is evaluated depending on a continuation time of the current value, for example. In other words, in a case in which the current detection unit <NUM> detects that the pulse width at the head of the current signal is equal to or greater than a predetermined pulse width, the signal processing device <NUM> determines that the current signal is a switching instruction.

On the other hand, the rewritten data is evaluated depending on a data sequence as a combination of variations in current value as binary values as described above using <FIG>. Specifically, in a case in which the rewriting current signal detected by the current detection unit <NUM> is a predetermined data sequence, the signal processing device <NUM> during an operation in the low current consumption mode may move on to the rewrite mode in which the information rewrite unit <NUM> rewrites the information stored in the information storage unit <NUM>. Conversely, the information rewrite device <NUM> may supply the rewriting current signal that is a predetermined data sequence to the signal processing device <NUM> during an operation in the low current consumption mode and then supply the rewriting current signal in accordance with information to be rewritten.

If the switching instruction is evaluated in this manner, it is possible to distinguish the current supply for switching the operation mode and the rewriting current signal in the signal processing device <NUM>.

<FIG> is a flow diagram illustrating an example of a flow of processing executed by the signal processing device <NUM> according to an aspect of the present disclosure. Note that description of the same processing as that in (a) of <FIG> will be omitted in the following description.

After the signal processing device <NUM> executes the processing in S1 and S2, the operation mode switching unit <NUM> sets the operation mode of the signal processing device <NUM> to the low current consumption mode (S71). After S71, the current detection unit <NUM> starts to detect that a current with a current value that is equal to or greater than a predetermined threshold value has been supplied from the input unit <NUM> (S72). If the current supplied from the input unit <NUM> increases through the processing in S41, then the current detection unit <NUM> detects that the current with the current value that is equal to or greater than the predetermined threshold value has been supplied from the input unit <NUM> (YES in S72), and the processing proceeds to S73.

In S73, the signal processing device <NUM> determines whether or not the current detection unit <NUM> has detected a switching instruction to the ordinary operation mode by checking whether or not the pulse width of the current signal is equal to or greater than the predetermined pulse width (S73). In a case in which it is determined that no switching instruction has been detected (NO in S73), the processing proceeds to S74. On the other hand, in a case in which it is determined that the switching instruction has been detected (YES in S73), the operation mode switching unit <NUM> sets the operation mode of the signal processing device <NUM> to the ordinary operation mode (S75), and the superimposed signal transmission unit <NUM> starts transmission of the superimposed signal (S78). Thereafter, the series of processes are ended.

In S74, the signal processing device <NUM> further determines whether or not the current detection unit <NUM> has received a rewriting activation instruction (S74). In a case in which it is determined that no rewriting activation instruction has been received (NO in S74), the signal processing device <NUM> determines whether or not a preset monitoring time has elapsed (S76). In a case in which it is determined that the monitoring time has not been elapsed (NO in S76), the processing proceeds to S74, and the processing in S74 and S76 is executed again. On the other hand, in a case in which it is determined that the monitoring time has elapsed (YES in S76), the signal processing device <NUM> ends reception of the rewriting instruction related to the predetermined information, and the processing proceeds to S11.

If the rewriting activation instruction is transmitted with a current pulse from the input unit <NUM> through processing in S81, which will be described later, then the current detection unit <NUM> detects the instruction, and the signal processing device <NUM> determines that the current detection unit <NUM> has received the rewriting activation instruction (YES in S74). Then, the information rewrite unit <NUM> rewrites the information in the information storage unit <NUM> on the basis of the rewriting current signal that has been transmitted from the input unit <NUM> through the processing in S42 and that indicates information to be rewritten as an increase or a decrease in current value (S77). Thereafter, the signal processing device <NUM> executes the processing in S9 to S11 and then ends the series of processes.

The signal processing device <NUM> can perform switching to the ordinary operation mode if the current that is equal to or greater than the predetermined threshold value is detected with a predetermined pulse width or greater during the operation in the low current consumption mode, through the aforementioned processing. Here, it is possible to employ a configuration in which the input unit <NUM> supplies a current that is equal to or greater than the predetermined threshold value to the signal processing device <NUM> in a case in which the input unit <NUM> connected to the signal processing device <NUM> is an input unit that supports reception of superimposed signals. In this case, the signal processing device <NUM> can operate in different operation modes in a case in which the signal processing device <NUM> is connected to an input unit communication device that supports superimposed signals and a in a case in which the signal processing device <NUM> is connected to an input unit that does not support superimposed signals. Therefore, it is possible to provide a convenient signal processing device <NUM> that operates in operation modes switched in accordance with the type of the input unit to which the signal processing device <NUM> is connected. Also, since the operation mode is switched to the ordinary operation mode if the current that is equal to or greater than the predetermined threshold value is detected with a predetermined pulse width or greater, it is possible to achieve distinction from the rewriting current signal.

<FIG> is a flow diagram illustrating an example of a flow of processing executed by the input unit <NUM> according to an aspect of the present disclosure. Note that description of the same processing as that in (b) of <FIG> will be omitted in the following description.

The input unit <NUM> transmits a current pulse corresponding to the rewriting activation instruction to the signal processing device <NUM> under control of the current control unit <NUM> after the processing in S12 and S41 (S81). Thereafter, the processing in S42 and S43 and S18 to S20 is executed, and the series of processes are ended.

The input unit <NUM> can rewrite the information stored in the information storage unit <NUM> with the rewriting current signal transmitted via the signal line included in the signal processing device <NUM> through the aforementioned processing.

The input unit <NUM> transmits a current pulse corresponding to the switching instruction to the ordinary operation mode to the signal processing device <NUM> under control of the current control unit <NUM> after the processing in S12 and S41 (S91). Thereafter, the input unit <NUM> controls the current control unit <NUM> and causes the current control unit <NUM> to reduce the current to be supplied to the signal processing device <NUM> (S92) and then starts an operation of receiving the superimposed signal transmitted from the signal processing device <NUM> (S93).

The input unit <NUM> can provide a notification that the input unit <NUM> itself is an input unit that supports superimposed signals to the signal processing device <NUM> through the aforementioned processing. Therefore, it is possible to cause the signal processing device <NUM> to operate in the ordinary operation mode to receive the superimposed signal. Also, since the signal processing device <NUM> performs switching to the ordinary operation mode if the current that is equal to or greater than the predetermined threshold value is detected with a predetermined pulse width or greater, it is possible to cause the signal processing device <NUM> to distinguish the current supply for switching the mode and the rewriting current signal.

Control blocks of the signal processing device <NUM>, the information rewrite device <NUM>, and the input unit <NUM> may be realized by logical circuits (hardware) formed into integrated circuits (IC chips and the like) or may be realized by software.

Claim 1:
A signal processing device (<NUM>) comprising:
a superimposed signal transmission unit (<NUM>) configured to transmit an operation signal in accordance with a state of an operation element (<NUM>) to a communication device (<NUM>, <NUM>) external to the signal processing device, and to transmit a superimposed signal to the communication device (<NUM>, <NUM>), wherein the superimposed signal is generated by superimposing a data signal indicating predetermined information on the operation signal transmitted to the communication device (<NUM>, <NUM>);
an information storage unit (<NUM>) configured to store the predetermined information; characterized in further comprising:
an information rewrite unit (<NUM>) configured to overwrite the predetermined information stored in the information storage unit (<NUM>) based on an external instruction input, wherein the information rewrite unit (<NUM>) is configured to overwrite the predetermined information in the information storage unit (<NUM>) while the superimposed signal transmission unit (<NUM>) transmits the superimposed signal to the communication device (<NUM>, <NUM>).