JP2009266837A - Temperature control device of light-emitting module and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature control device for preventing a rush current caused in a feedback loop constituting a temperature control system controlling a temperature of a device such as a light-emitting module becoming a control object from flowing to a temperature adjustment element side at the time of power supply and at the time of releasing circuit reset. <P>SOLUTION: The temperature control device controlling a peripheral temperature of the light-emitting module to a setting temperature is provided with a switching means arranged in the middle of the feedback loop of the temperature control system which drive-controls a temperature adjusting means adjusting the peripheral temperature of the light-emitting module and with a control means setting a switch means to an off-state by a prescribed time when the rush current flows from a power supply side to the temperature adjusting means at the time of power supply or at the time of releasing circuit reset. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a temperature control device for a light emitting module and a control method for the temperature control device.

Conventionally, in laser diode modules used for optical transmitters and optical amplifiers, the output characteristics of laser diodes are temperature dependent, so that the oscillation wavelength and light emission output of laser diodes need to be constant, such as Peltier elements. Is used to control the temperature (see, for example, Patent Document 1).
A configuration of a temperature control circuit for performing such temperature control is shown in FIG. In FIG. 6, the laser diode module 500 includes a laser diode 501, a PIN diode 502, a thermistor 503, and a Peltier element 504.

  In the laser diode module 500, the light emitting power of the laser diode 501 is detected by the PIN diode 502, and a current value (detected current value) corresponding to the detected light emitting power and a preset current value that flows through the PIN diode 502 are detected. A feedback loop for controlling a bias current flowing in the laser diode 501 by an APC (Auto Power Control) circuit 505 is formed so that an error from the (set current value) 510 is eliminated.

The laser diode 501 is mounted on a Peltier element 504 as a temperature adjusting element for controlling the temperature of the laser diode 501, and a thermistor that detects the ambient temperature of the laser diode 501 is located in the vicinity of the laser diode 501. 503 is arranged. The ambient temperature of the laser diode 501 is detected by the thermistor 503, and a voltage value (detected temperature voltage value 503A) corresponding to the detected temperature and a predetermined voltage value (temperature setting voltage value) Vset are compared with the comparator 506. As a result, feedback control is performed so that the ambient temperature of the laser diode 501 is always constant by inputting an error value between the detected temperature voltage value 503A and the temperature setting voltage value Vset to the Peltier element 504.
JP 2003-273447 A

PID control is suitable for feedback control for controlling the ambient temperature of the laser diode to be constant from the standpoint of steady-state error characteristics and response speed of temperature control of the ambient temperature of the laser diode. Generally, PID is used for temperature control. Control is used.
FIG. 7 shows a configuration example of a PID control unit included in the comparator 506 when PID control is performed in the temperature control system of the laser diode 501 in FIG.

  In the figure, the PID control unit includes an operational amplifier 600, a series circuit of a capacitor C1 and a resistor R1 connected between a non-inverting input terminal of the operational amplifier 600 and an input terminal 610, and a resistor connected in parallel to the series circuit. A feedback circuit composed of an input circuit composed of R2, a series circuit of a resistor R3 and a capacitor C2 connected between the non-inverting input terminal and the output terminal 611 of the operational amplifier 600, and a capacitor C3 connected in parallel to the series circuit. Circuit.

  An error value between the output (detected temperature voltage value) 503A of the thermistor 503 that detects the ambient temperature of the laser diode 501 and the temperature setting voltage value Vset is input to the input terminal 610. From the output terminal 611 of the operational amplifier 600, a signal obtained by PID-controlling an error value between the output (detected temperature voltage value) 503A of the thermistor 503 and the temperature setting voltage value Vset is output to the Peltier element 504.

  As described above, when feedback control is performed so that the ambient temperature of the laser diode is set to the set temperature, when PID control is used in the temperature control system, as shown in FIG. At time ti, a signal for generating an inrush current is output from the output terminal 611 until the capacitors C2 and C3 constituting the feedback circuit that performs the integration operation are charged. (FIG. 8A).

When an inrush current occurs in multiple circuit units at the same timing when the power is turned on or the circuit reset is released, there is a problem that the maximum current consumption value specified by the power supply of the main body of the laser module is exceeded. Yes.
In addition to a laser diode, an apparatus incorporating a device whose output characteristics have temperature dependence has a plurality of feedback loops forming a temperature control system. In an apparatus such as an optical transmitter having such a configuration, However, when the feedback loop of each temperature control system is turned on or when the circuit is reset, a signal that generates an inrush current in each feedback loop causes the inrush current to flow into the temperature adjustment element side at the same time. There is a problem of exceeding the maximum current consumption value.

  The present invention has been made in view of such circumstances, and is generated in a feedback loop that constitutes a temperature control system that performs temperature control of a device such as a light emitting module to be controlled when power is turned on or a circuit reset is released. An object of the present invention is to provide a temperature control device, a temperature control method, and a control method for the temperature control device that prevent inrush current flowing into the temperature adjustment element side.

  In order to achieve the above object, a temperature control device of the present invention drives and controls temperature adjusting means for adjusting the ambient temperature of the light emitting module in the temperature control device that controls the ambient temperature of the light emitting module to be a set temperature. Switch means provided in the middle of the feedback loop of the temperature control system, and control means for turning off the switch means for a predetermined time when an inrush current flows from the power supply side to the temperature adjustment means when power is turned on or when circuit reset is released It is characterized by having.

In the temperature control device of the present invention having the above-described configuration, the switch means provided in the middle of the feedback loop of the temperature control system for driving and controlling the temperature adjusting means for adjusting the ambient temperature of the light emitting module is controlled to drive and control the switch means. When the power is turned on by the means or when the circuit reset is released, the switch means is turned off for a predetermined time during which an inrush current flows from the power supply side to the temperature adjusting means.
As a result, when the power is turned on or when the circuit reset is released, the signal that causes the inrush current generated in the feedback loop that constitutes the temperature control system that controls the temperature of the device such as the light emitting module to be controlled can be cut off. Inflow to the temperature adjusting element side can be prevented.

  Further, the temperature control device of the present invention is a temperature control device that controls the ambient temperature of the light emitting module to be a set temperature, a temperature adjusting means for adjusting the ambient temperature of the light emitting module, and the ambient temperature of the light emitting module. A temperature sensor to detect, a first control means for driving and controlling the temperature adjusting means in accordance with a deviation between the ambient temperature of the light emitting module detected by the temperature sensor and the set temperature, and the temperature from the temperature sensor. The switch means provided in the middle of the feedback loop of the temperature control system leading to the adjustment means, and the switch means in the OFF state for a predetermined time when the inrush current flows from the power supply side to the temperature adjustment means when the power is turned on or when the circuit reset is released And a second control means.

In the temperature control device of the present invention having the above-described configuration, the ambient temperature of the light emitting module is detected by the temperature sensor, and the deviation between the ambient temperature of the light emitting module detected by the temperature sensor and the set temperature of the ambient temperature of the light emitting module is calculated. Accordingly, the temperature control means for adjusting the ambient temperature of the light emitting module is driven and controlled by the first control means.
Then, the switch means provided in the middle of the temperature control system feedback loop from the temperature sensor to the temperature adjusting means is operated by the second control means so that the inrush current is supplied from the power source side when the power is turned on or when the circuit reset is released. It is turned off for a predetermined time flowing through the temperature adjusting means.
As a result, when the power is turned on or when the circuit reset is released, the signal that causes the inrush current generated in the feedback loop that constitutes the temperature control system that controls the temperature of the device such as the light emitting module to be controlled can be cut off. Inflow to the temperature adjusting element side can be prevented.

  The temperature control device of the present invention is a temperature control device comprising a plurality of temperature adjusting means for adjusting the temperature of a plurality of devices having temperature dependence including a light emitting module incorporated in an optical transmitter, Each of the plurality of temperature adjusting means forms a feedback loop of the temperature control system, and corresponds to the plurality of switch means provided in the middle of each feedback loop and the feedback loop of the plurality of temperature control systems. A plurality of control means for driving and controlling the corresponding switch means among the plurality of switch means, and each of the plurality of control means is activated first among the plurality of temperature adjusting means. When starting the first temperature adjusting means, the first current adjustment is performed only for a predetermined time during which the inrush current flows to the first temperature adjusting means that starts first from the power supply side. After the switch means provided in the feedback loop including the degree adjustment means is turned off and the switch means is turned on, the device whose temperature is adjusted by the first temperature adjustment means reaches the set temperature. After that, the second temperature adjusting means is included for a predetermined time during which the inrush current flows from the power source side to the second temperature adjusting means that is activated first when the second temperature adjusting means that is activated next is activated. After the switch means provided in the feedback loop is turned off and the switch means is turned on, the devices adjusted in temperature by the second temperature adjusting means reach a set temperature, and then sequentially Until the temperature adjustment means to be activated at the same time, the activation timing is not overlapped with the remaining temperature adjustment means, and the start of each temperature adjustment means. The switch means provided in each feedback loop including the temperature adjustment means for a predetermined time when an inrush current sometimes flows from the power supply side to the temperature adjustment means is turned on, and then the switch means is turned on. And

In the temperature control device of the present invention having the above-described configuration, the plurality of temperature adjusting means for adjusting the temperature of the plurality of devices having temperature dependency including the light emitting module incorporated in the optical transmitter are respectively feedback loops of the temperature control system. A plurality of switch means are provided in the middle of each of these feedback loops.
A plurality of control means for driving and controlling the corresponding switch means among the plurality of switch means prevents the start timings of the temperature adjustment means of the plurality of temperature adjustment means from overlapping each other and each temperature adjustment means Control is performed so that the switch means is turned on after the switch means provided in each feedback loop is turned off for a predetermined time during which the inrush current flows from the power supply side to each temperature adjusting means at the time of startup.
As a result, when power is turned on or when circuit reset is released, a rush occurs in a plurality of feedback loops constituting a temperature control system that controls the temperature of a plurality of devices whose output characteristics such as light emitting modules to be controlled have temperature dependence It is possible to cut off a signal that causes a current, and to prevent an inrush current from flowing into the temperature adjustment element side.

  Further, the temperature control method of the present invention is a temperature control method in which the temperature control means is driven and controlled by the first control means so that the ambient temperature of the light emitting module mounted on the temperature adjustment means becomes a set temperature. Switch means provided in the middle of the feedback loop of the temperature control system from the temperature sensor for detecting the ambient temperature of the light emitting module to the temperature adjustment means is provided corresponding to the feedback loop of the temperature control system. A first step of turning off after a predetermined time when an inrush current flows from the power supply side to the temperature adjusting means when the power is turned on or when the circuit reset is released, and turning on the light after the predetermined time has passed. A second step of detecting an ambient temperature of the module by a temperature sensor; and a light emitting module detected by the temperature sensor. And a third step of driving and controlling the temperature adjusting means by the first control means so that the ambient temperature of the light emitting module is set to a set temperature in accordance with a deviation between the ambient temperature of the light source and the set temperature. It is characterized by that.

In the temperature control method of the present invention having the above-described configuration, when the temperature control unit is driven and controlled by the first control unit so that the ambient temperature of the light emitting module mounted on the temperature control unit is a set temperature, The switch means provided in the middle of the feedback loop of the temperature control system from the temperature sensor for detecting the ambient temperature of the light emitting module to the temperature adjusting means is turned on by the second control means when the power is turned on or when the circuit reset is released. The inrush current is turned off for a predetermined time that flows from the power source to the temperature adjusting means, and is turned on after the predetermined time has elapsed.
As a result, when the power is turned on or when the circuit reset is released, the signal that causes the inrush current generated in the feedback loop that constitutes the temperature control system that controls the temperature of the device such as the light emitting module to be controlled can be cut off. Inflow to the temperature adjusting element side can be prevented.

  The temperature control apparatus control method of the present invention includes a plurality of temperature adjusting means for adjusting the temperature of a plurality of devices having temperature dependency including a light emitting module incorporated in an optical transmitter, and the plurality of temperature adjustments. Each means forms a feedback loop of the temperature control system, a plurality of switch means provided in the middle of each feedback loop, and provided corresponding to the feedback loops of the plurality of temperature control systems, A control method of a temperature control device having a plurality of control means for driving and controlling the corresponding switch means among the switch means, wherein each of the plurality of control means is the first of the plurality of temperature adjustment means During the activation of the first temperature adjustment means that starts at a time, an inrush current only flows for a predetermined period of time that flows from the power source side to the first temperature adjustment means that is activated first. The first step of turning off the first switch means provided in the feedback loop including the first temperature adjusting means, and after turning on the switch means, the first temperature adjusting means After the temperature-adjusted device reaches the set temperature, a predetermined time during which the inrush current flows from the power source side to the second temperature adjusting unit when the second temperature adjusting unit is started next is started. A second step of turning off the second switch means provided in the feedback loop including the second temperature adjustment means, and after turning on the switch means, the second temperature adjustment After the device temperature-adjusted by the means reaches the set temperature, the start-up time is sequentially applied to the remaining temperature-adjusting means until the temperature-adjusting means that is activated lastly. The switch means provided in each feedback loop including the temperature adjustment means for a predetermined time during which the rush current flows from the power supply side to the temperature adjustment means when the temperature adjustment means is started is turned off. And a third step of turning on the switch means.

  The control method of the temperature control apparatus of the present invention having the above-described configuration includes a plurality of temperature adjusting means for adjusting the temperature of a plurality of devices having temperature dependency including a light emitting module incorporated in an optical transmitter, The temperature adjusting means each forms a feedback loop of the temperature control system, a plurality of switch means provided in the middle of each feedback loop, and provided corresponding to the feedback loop of the plurality of temperature control systems, It is intended to control a temperature control device having a plurality of control means for driving and controlling the corresponding switch means among the plurality of switch means.

  In the control method of the temperature control device of the present invention, by executing each of the above steps, a switch unit corresponding to the feedback loop of the plurality of temperature control systems is provided. Each of the plurality of control means for driving control prevents the start timings of the plurality of temperature adjustment means from overlapping each other, and a predetermined time during which the inrush current flows from the power supply side to each temperature adjustment means at the start of each temperature adjustment means Thus, the switch means provided in each feedback loop is controlled to be turned on after the switch means is turned off.

  As a result, when power is turned on or when circuit reset is released, a rush occurs in a plurality of feedback loops constituting a temperature control system that controls the temperature of a plurality of devices whose output characteristics such as light emitting modules to be controlled have temperature dependence It is possible to cut off a signal that generates a current, and to prevent an inrush current from flowing into each temperature adjustment element side.

  As described above, according to the temperature control device of the present invention, the switch means provided in the middle of the feedback loop of the temperature control system that drives and controls the temperature adjustment means that adjusts the ambient temperature of the light emitting module, When the power is turned on by the control means for controlling the drive or when the circuit reset is released, the switch means is turned off for a predetermined time when the inrush current flows from the power supply side to the temperature adjusting means. At the time of release, the signal that causes the inrush current generated in the feedback loop constituting the temperature control system that controls the temperature of the device such as the light emitting module to be controlled can be cut off, and the inrush current can flow into the temperature adjustment element side. Can be prevented.

  Further, according to the temperature control method of the present invention, when the temperature control unit is driven and controlled by the first control unit so that the ambient temperature of the light emitting module mounted on the temperature control unit is set to the set temperature, The switch means provided in the middle of the feedback loop of the temperature control system from the temperature sensor for detecting the ambient temperature of the light emitting module to the temperature adjusting means is turned on by the second control means when the power is turned on or when the circuit reset is released. Since the inrush current is turned off for a predetermined time flowing from the power supply side to the temperature adjusting means and turned on after the predetermined time has elapsed, the light emitting module to be controlled is turned on when the power is turned on or the circuit reset is released. The signal that causes the inrush current generated in the feedback loop that constitutes the temperature control system that controls the temperature of the device can be cut off, and the From flowing into the current temperature adjusting device side it can be prevented.

Embodiments of the present invention will be described below with reference to the drawings.
“First Embodiment”
The structure of the temperature control apparatus of the light emitting module which concerns on 1st Embodiment of this invention is shown in FIG. In the figure, the temperature control device 1 of the light emitting module according to the first embodiment of the present invention includes a laser diode 11 constituting the light emitting module 10, a Peltier element 12 as a temperature adjusting element for cooling the laser diode 11, and a temperature sensor. A thermistor 14, an error amplifier 16, a PID control unit 18, a driver 20, and an analog switch 22 as a switch means provided in the middle of the feedback loop of the temperature control system from the thermistor 14 to the Peltier element 12. is doing.

Furthermore, the temperature control device 1 of the light emitting module according to the embodiment of the present invention includes a Schmitt trigger circuit 24, a timing circuit composed of a series circuit of a resistor R1 and a capacitor C1 connected between the power source VCC and the ground, R2 and a reset switch 26 are provided.
The laser diode 11 is mounted on the Peltier element, and the thermistor 14 is mounted in the vicinity of the laser diode 11.

The thermistor 14 detects the ambient temperature of the laser diode 11.
The detection output of the thermistor 14 is input to one input terminal of the error amplifier 16, and the temperature setting voltage value Vset corresponding to the setting value of the ambient temperature of the laser diode 11 is input to the other input terminal of the error amplifier 16. It has become so.
The PID control unit 18 is connected to the input end of the driver 20 via the analog switch 22, and the output end of the driver 20 is connected to the input end of the Peltier element 12. The PID control unit 18 corresponds to the first control means of the present invention.

A system from the thermistor 14 to the Peltier element 12 through the error amplifier 16, the PID control unit 18, and the driver 20 forms a feedback loop of the temperature control system, and an analog switch 22 is interposed in the middle.
The analog switch 22 is driven and controlled by the output of the Schmitt trigger circuit 24. The Schmitt trigger circuit 24 corresponds to the control means or the second control means of the present invention.

The operation of the temperature control device for a light emitting module according to the embodiment of the present invention having the above configuration will be described with reference to the operation waveform diagram of FIG. FIG. 2A shows a current waveform flowing into the Peltier element 12 from the power supply side via the driver 20.
In the above configuration, when the reset switch 26 is operated when the temperature control device is turned on or at t1 when the circuit reset is released (FIG. 2B), a timing circuit composed of a series circuit of the resistor R1 and the capacitor C1 is provided. If not, the operation signal is input to the Schmitt trigger circuit 24, and the analog switch 22 is turned on in FIG. 2C by the output signal of the Schmitt trigger circuit 24. Inrush current that rises sharply as shown in FIG.

  However, in this embodiment, when the reset switch 26 is turned on, the operation signal of the reset switch 26 is delayed until the time t2 by the timing circuit including the resistor R1 and the capacitor C1, and is input to the Schmitt trigger circuit 24. As a result, the analog switch 22 is turned on at time t2, that is, the period during which the analog switch 22 is turned on is delayed only during the period when the inrush current flows from the power supply side. ), A drive current for adjusting the ambient temperature of the laser diode 11 is supplied after time t2 without inrush current flowing. At time t3, the ambient temperature of the laser diode 11 reaches the set temperature and becomes a steady state.

  According to the temperature control apparatus of the first embodiment of the present invention, the switch means provided in the middle of the feedback loop of the temperature control system that drives and controls the temperature adjustment means for adjusting the ambient temperature of the light emitting module is provided as the switch means. When the power is turned on by the control means for controlling the drive or when the circuit reset is released, the switch means is turned off for a predetermined time when the inrush current flows from the power supply side to the temperature adjusting means. It is possible to prevent an inrush current generated in a feedback loop that constitutes a temperature control system that controls the temperature of a device such as a light emitting module to be controlled from flowing into the temperature adjusting element side when released.

“Second Embodiment”
Next, FIG. 3 shows a configuration of a temperature control device according to the second embodiment of the present invention. In the figure, the temperature control apparatus according to the second embodiment of the present invention includes a plurality of temperature adjusting means for adjusting the temperature of a plurality of devices having temperature dependency including a light emitting module incorporated in an optical transmitter. It is a temperature control device.
In FIG. 3, a device having temperature dependency of a laser diode 300 and an etalon 302 is incorporated in the optical transmitter 30. The temperature control apparatus according to the second embodiment of the present invention performs temperature control of these devices.

The main parts of the optical transmitter 30 are a laser diode 300 that is a light source, an etalon 302 that selects a wavelength from the output light of the laser diode 300, and an optical modulation that modulates light emitted from the laser diode 300 by a given data signal. A MOD 303 and an APC (Automatic Power Control) circuit 305 that controls the optical output of the laser diode 300 to be constant.
A temperature control device according to this embodiment is added to this. The photodiode (PD1) 310 has a function of detecting and monitoring the output light of the laser diode 300 when the APC circuit 305 controls the light output of the laser diode 300.

The temperature control apparatus according to this embodiment includes a Peltier element (TEC1) 306 and a Peltier element (TEC2) 307 as temperature adjustment elements in order to adjust the temperature of the laser diode 300 and the etalon 302 whose output characteristics are temperature dependent. It has.
A laser diode 300 is mounted on the Peltier element (TEC1) 306, and a thermistor 308 that detects the ambient temperature of the laser diode 300 is disposed in the vicinity of the laser diode 300. The laser diode 300 and the thermistor 308 constitute a laser diode module.
The Peltier element (TEC1) 306 mainly has a function of adjusting the ambient temperature of the laser diode 300.

  An etalon 302 is mounted above the Peltier element (TEC2) 307, and a thermistor 309 for detecting the ambient temperature of the etalon 302 is disposed in the vicinity of the etalon 302.

  A part of the light emitted from the laser diode 300 is directly incident on the photodiode PD310 and monitored. A part of the light emitted from the laser diode 300 passes through the etalon 302 and is detected and monitored by the photodiode (PD2) 311.

  The Peltier element (TEC1) 306 is driven and controlled by an automatic wave length control (AWC) circuit 312. The circuit from the thermistor 308 to the Peltier element (TEC1) 306 via the AWC circuit 312 is a temperature control system. A feedback loop is formed. In the middle of this feedback loop, an analog switch SW1 that is driven and controlled by the AWC circuit 312 is provided.

The AWC circuit 312 takes in the detection output of the thermistor 308 and the detection output of the photodiodes (PD1, PD2), and drives and controls the Peltier element (TEC1) 306 so as to suppress fluctuations in the wavelength of light emitted from the laser diode 300. .
Further, the AWC circuit 312 turns off the analog switch SW1 provided in the feedback loop for a predetermined time during which the inrush current flows from the power source side to the Peltier element (TEC1) 306 when the Peltier element (TEC1) 306 is activated. It has a function of controlling the analog switch SW1 to be turned on.

  The Peltier element (TEC2) 307 is driven and controlled by an ATC (Automatic Temperature Control) circuit 313. A circuit from the thermistor 309 to the Peltier element (TEC2) 307 via the ATC circuit 313 is temperature controlled. A feedback loop of the system is formed. In the middle of this feedback loop, an analog switch SW2 that is driven and controlled by the ATC circuit 313 is provided.

The ATC circuit 313 takes in the detection output of the thermistor 309 and drives and controls the Peltier element (TEC2) 307 so that the ambient temperature of the etalon 302 is constant so as to suppress the fluctuation of the wavelength of the light emitted from the laser diode 300. .
The ATC circuit 313 turns off the analog switch SW2 provided in the feedback loop for a predetermined time during which the inrush current flows from the power supply side to the Peltier element (TEC2) 307 when the Peltier element (TEC2) 307 is activated. It has a function of controlling the analog switch SW2 to be turned on.

  The control circuit 315 has a function of comprehensively controlling the AWC circuit 312 and the ATC circuit 313. The AWC circuit 312 and the ATC circuit 313 are controlled by the control circuit 315, such as a Peltier element (TEC1) 306, a Peltier element. (TEC2) Analog switches provided in the feedback loops so that the start timings of the TECs 307 do not overlap with each other and the inrush current flows from the power supply side to the Peltier elements 306 and 307 from the power source side when the temperature adjusting means are started. It has a function of controlling the analog switches SW1 and SW2 to be turned on after the switches SW1 and SW2 are turned off.

  Here, the control circuit 315 first activates the Peltier element (TEC1) 306 when starting the power supply of the temperature control circuit or canceling the circuit reset, and after the current flowing through the Peltier element (TEC1) 306 becomes a steady state, Control is performed so that the Peltier element (TEC2) 307 is activated. This is to prevent a large current from flowing from the power supply side at a time.

  The operation of the temperature control apparatus according to the second embodiment of the present invention having the above configuration will be described with reference to the flowchart shown in FIG. 4 and the operation waveform diagram shown in FIG. In the above configuration, when the power supply of the temperature control device is turned on (at this time, the reset signal is output from the control circuit 315 to the AWC circuit 312 (FIG. 5B)) (step 400), the control circuit 315 Under the control, the AWC circuit 312 determines whether or not a predetermined time has elapsed (step 401). In other words, the AWC circuit 312 determines whether or not a rush current has passed for a predetermined period of time flowing from the power supply side to the Peltier element (TEC1) 306 when the Peltier element (TEC1) 306 to be activated first is activated.

When a predetermined time elapses after the power is turned on, the AWC circuit 312 turns on the analog switch SW1 at time t11 (FIG. 5C).
Next, the AWC circuit 312 determines whether or not the pull-in of the Peltier element (TEC1) 306 is completed. That is, the AWC circuit 312 determines whether or not the ambient temperature of the laser diode 300 has reached the set temperature based on the detection output of the thermistor 308 by driving and controlling the Peltier element (TEC1) 306 (step 403). .

When the ambient temperature of the laser diode 300 reaches the set temperature, the current flowing into the Peltier element (TEC1) 306 becomes a steady state.
When the AWC circuit 312 determines that the pull-in of the Peltier element (TEC1) 306 has been completed, the AWC circuit 312 waits for a predetermined time T0 (for example, 5 seconds) (step 404).

Next, under the control of the control circuit 315, the ATC circuit 313 determines whether or not it is the start timing of the Peltier element (TEC2) 307 (step 405).
In other words, the reset release signal is output from the control circuit 315 in the same manner as the AWC circuit 312 at time t12, and the ATC circuit 313 then detects the inrush current from the power source side when the Peltier element (TEC2) 307 is started up next. It is determined whether or not a predetermined time flowing through the Peltier element (TEC2) 307 has elapsed.

  The ATC circuit 313 turns off the analog switch SW2 provided in the feedback loop including the Peltier element (TEC2) 307 for a predetermined time when the inrush current flows from the power supply side to the Peltier element (TEC2) 307, and is at the start timing When the time t13 is reached, that is, when it is determined that it is the start timing of the Peltier element (TEC2) 307, the analog switch SW2 is turned on (step 406).

  Next, the ATC circuit 313 determines whether or not the pull-in of the Peltier element (TEC2) 307 is completed. That is, the ATC circuit 313 determines whether or not the ambient temperature of the etalon 302 has reached the set temperature based on the detection output of the thermistor 309 by controlling the driving of the Peltier element (TEC2) 307 (step 407).

When the ambient temperature of the etalon 302 reaches the set temperature, the current flowing into the Peltier element (TEC2) 307 becomes a steady state.
If the ATC circuit 313 determines that the pull-in of the Peltier element (TEC2) 307 has been completed, the ATC circuit 313 maintains this state under the control of the control circuit 315.

According to the temperature control circuit according to the second embodiment of the present invention, the plurality of temperature adjusting means for adjusting the temperature of the plurality of devices having temperature dependency including the light emitting module incorporated in the optical transmitter are respectively temperature controlled. A feedback loop of the system is formed, and a plurality of switch means are provided in the middle of each of these feedback loops.
And a plurality of control means for driving and controlling the corresponding switch means among the plurality of switch means so that the start timings of the temperature adjustment means of the plurality of temperature adjustment means are not overlapped, and each temperature adjustment Control is performed so that the switch means is turned on after the switch means provided in each feedback loop is turned off for a predetermined time when an inrush current flows from the power supply side to each temperature adjusting means when the means is started. Therefore, when power is turned on or when circuit reset is released, inrush currents are generated in multiple feedback loops that constitute a temperature control system that controls the temperature of multiple devices whose output characteristics, such as light emitting modules to be controlled, have temperature dependence Can be cut off, and inrush current can be prevented from flowing into the temperature adjusting element side.

The block diagram which shows the structure of the temperature control apparatus which concerns on 1st Embodiment of this invention. The wave form diagram which shows operation | movement of the temperature control apparatus which concerns on 1st Embodiment of this invention shown in FIG. The block diagram which shows the structure of the temperature control apparatus which concerns on 2nd Embodiment of this invention. The flowchart which shows operation | movement of the temperature control apparatus which concerns on 2nd Embodiment of this invention shown in FIG. The wave form diagram which shows the operation | movement of each part of the temperature control apparatus which concerns on 2nd Embodiment of this invention shown in FIG. The block diagram which shows schematic structure of the temperature control apparatus of the conventional light emitting module. The circuit diagram which shows the structure of the PID control part in the temperature control apparatus of the conventional light emitting module. The wave form diagram which shows the operation | movement of the temperature control apparatus of the conventional light emitting module shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Temperature controller 10, 300 ... Laser diode, 12 ... Peltier element, 14 ... Thermistor, 16 ... Error amplifier, 18 ... PID control part, 20 ... Driver, 22 ... Analog switch, 24 ... Schmitt trigger circuit, 30 ... Optical transmitter 302 ... Etalon 303 ... Optical modulator 306 ... Peltier element (TEC1) 307 ... Peltier element (TEC2) 308, 309 ... Thermistor 310, 311 ... Photo diode 312 ... AWC circuit 313 ... ATC circuit, 315 ... control circuit, SW1, SW2 ... analog switch

Claims (5)

In a temperature control device that controls the ambient temperature of the light emitting module to be a set temperature,
Switch means provided in the middle of the feedback loop of the temperature control system for driving and controlling the temperature adjusting means for adjusting the ambient temperature of the light emitting module;
A temperature control apparatus comprising: control means for turning off the switch means for a predetermined time when an inrush current flows from the power supply side to the temperature adjustment means when power is turned on or when circuit reset is released. In a temperature control device that controls the ambient temperature of the light emitting module to be a set temperature,
Temperature adjusting means for adjusting the ambient temperature of the light emitting module;
A temperature sensor for detecting an ambient temperature of the light emitting module;
First control means for driving and controlling the temperature adjusting means according to a deviation between the ambient temperature of the light emitting module detected by the temperature sensor and the set temperature;
Switch means provided in the middle of the feedback loop of the temperature control system from the temperature sensor to the temperature adjustment means;
Second control means for turning off the switch means for a predetermined time when an inrush current flows from the power supply side to the temperature adjustment means when power is turned on or when circuit reset is released;
A temperature control device comprising: A temperature control device comprising a plurality of temperature adjusting means for adjusting the temperature of a plurality of devices having temperature dependence including a light emitting module incorporated in an optical transmitter,
The plurality of temperature adjusting means each form a feedback loop of a temperature control system, a plurality of switch means provided in the middle of each of these feedback loops,
A plurality of control means which are provided corresponding to feedback loops of the plurality of temperature control systems, and which respectively drive and control the corresponding switch means among the plurality of switch means;
Have
In each of the plurality of control means, an inrush current flows from the power source side to the first temperature adjustment means that is first activated when the first temperature adjustment means that is activated first among the plurality of temperature adjustment means is activated. The switch means provided in the feedback loop including the first temperature adjusting means for a predetermined time is turned off, and after the switch means is turned on, the temperature is adjusted by the first temperature adjusting means. After the device reaches the set temperature,
The feedback loop including the second temperature adjusting means for a predetermined time when an inrush current flows to the second temperature adjusting means that is activated first from the power source side when the second temperature adjusting means that is activated next is activated. After the switch means provided in is turned off and the switch means is turned on, after the device temperature-adjusted by the second temperature adjustment means reaches a set temperature,
Sequentially, the start timing does not overlap with each of the remaining temperature adjustment means until the temperature adjustment means to be activated last, and an inrush current flows from the power supply side to each temperature adjustment means when each temperature adjustment means is activated. A temperature control device characterized in that the switch means is turned on after the switch means provided in each feedback loop including the temperature adjusting means is included in the flow for a predetermined time. In the temperature control method for driving and controlling the temperature adjusting means by the first control means so that the ambient temperature of the light emitting module mounted on the temperature adjusting means becomes a set temperature,
Switch means provided in the middle of the feedback loop of the temperature control system from the temperature sensor for detecting the ambient temperature of the light emitting module to the temperature adjustment means is provided corresponding to the feedback loop of the temperature control system. A first step of turning off after a predetermined time when an inrush current flows from the power source side to the temperature adjusting means when the power is turned on or when the circuit reset is released by the control means;
A second step of detecting an ambient temperature of the light emitting module by a temperature sensor;
Drive control of the temperature adjusting means by the first control means so that the ambient temperature of the light emitting module is set to a set temperature according to a deviation between the ambient temperature of the light emitting module detected by the temperature sensor and the set temperature. A third step,
A temperature control method comprising: A plurality of temperature adjusting means for adjusting the temperature of a plurality of devices having temperature dependence including a light emitting module incorporated in an optical transmitter, each of the plurality of temperature adjusting means forming a feedback loop of a temperature control system. A plurality of switch means provided in the middle of each feedback loop, and provided corresponding to the feedback loops of the plurality of temperature control systems, each driving a corresponding switch means among the plurality of switch means. A control method of a temperature control device having a plurality of control means for controlling,
In each of the plurality of control means, an inrush current flows from the power source side to the first temperature adjustment means that is first activated when the first temperature adjustment means that is activated first among the plurality of temperature adjustment means is activated. A first step of turning off the first switch means provided in the feedback loop including the first temperature adjusting means for a predetermined time;
After the switch means is turned on, the inrush current is supplied from the power source when the second temperature adjustment means that is started next after the device temperature-adjusted by the first temperature adjustment means reaches a set temperature. A second step of turning off the second switch means provided in the feedback loop including the second temperature adjusting means for a predetermined time flowing in the second temperature adjusting means that is activated first from the side; ,
After the switch means is turned on, each of the remaining temperature adjustments until the last temperature adjustment means that starts up after the device temperature-adjusted by the second temperature adjustment means reaches the set temperature. The temperature control means is provided in each feedback loop including the temperature adjustment means so that the start timing does not overlap with each other and the inrush current flows from the power supply side to each temperature adjustment means during the start of each temperature adjustment means. A third step of turning on the switch means after turning off the switch means;
A control method for a temperature control device, comprising:

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