JP7422984B2 - Lighting devices and lighting equipment - Google Patents

Description

Embodiments of the present invention relate to a lighting device and a lighting fixture.

2. Description of the Related Art A lighting fixture is known that includes a light source module having a light source such as an LED, and a lighting device that supplies power to the light source module to light the light source. In such lighting equipment, a common lighting device is used to light a plurality of types of light source modules having different color temperatures, brightness, and the like. Thereby, the lighting device can be used in common for a plurality of types of light source modules, and the types of light source modules can be easily exchanged.

To identify the type of light source module, for example, a resistor is installed in the light source module in series with the light source, the resistance value of this resistor is changed for each type, and the resistance value of the resistor of the connected light source module is determined by the lighting device. This is done by detecting.

When a resistor is provided in series with the light source in a light source module, the resistance value of the resistor needs to be as low as several ohms in order to suppress power consumption during lighting. Therefore, if unintended wiring resistance, contact resistance, etc. occur between the light source module and the lighting device, there is a possibility that the resistance value of the resistor of the light source module cannot be appropriately detected. That is, there is a possibility that the brightness will not match the light source module.

Furthermore, in lighting devices, a substantially constant current is caused to flow through the light source by detecting a current flowing through a resistor connected in series with the light source and performing feedback control. At this time, if an unintended resistance component such as wiring resistance or contact resistance occurs between the light source module and the lighting device, the current value cannot be detected properly, and the brightness of the light source module may be different from the unintended brightness. There is a possibility that it will become. Furthermore, there is also a concern that when the state of the resistance component changes unintentionally during lighting, the change in the state of the resistance component may appear as a change in the brightness of the light source module.

Therefore, in lighting devices and lighting fixtures, even when an unintended resistance component occurs between the light source module and the lighting device, the light source module can be lit at an appropriate brightness depending on the type of light source module. Additionally, it is desirable to be able to suppress changes in brightness during lighting of the light source module due to unintended resistance components.

JP2016-66433A

Embodiments of the present invention make it possible to light up the light source module at an appropriate brightness depending on the type of light source module even when an unintended resistance component occurs between the light source module and the lighting device. Provided are a lighting device and a lighting fixture that can suppress changes in brightness during lighting of a light source module caused by a resistance component that does not occur.

According to the embodiment, a connection portion for removably connecting a light source module including a light source and a resistor connected in series with the light source; and a power source capable of outputting DC power corresponding to the light source module. a supply unit, a control unit that controls output of the DC power by the power supply unit, and a detection circuit that detects connection of the light source module to the connection unit, and the connection unit is configured to A plurality of different light source modules can be selectively connected, and the detection circuit is electrically connected to the resistor via the connection part when the light source module is connected to the connection part, A detection voltage for detecting connection of the light source module is applied to the resistor, and when the light source module is connected to the connection part, the control unit connects the resistor with electricity through the connection part. Detection of connection of the light source module to the connection portion based on the voltage value of the connection terminal when the detection circuit applies the detection voltage to the resistor; By detecting the resistance value of the resistor, a first resistance value of the resistor is detected, a first reference voltage is set based on the detected first resistance value, and the light source module is connected. After detecting, by operating the power supply unit and detecting the resistance value of the resistor of the light source module based on the DC power supplied from the power supply unit to the light source and the resistor. , detecting a second resistance value of the resistor, and setting a second reference voltage for feedback controlling the operation of the power supply unit based on the detected second resistance value of the resistor. , detecting the current flowing through the power supply section, and controlling the power supply section so that the current flowing through the light source is constant based on the detected value of the current flowing through the power supply section and the second reference voltage. Feedback control of the operation is performed, and the control unit operates the power supply unit so as to supply a preset fixed current value to the light source of the light source module, thereby causing the power supply unit to operate the power supply unit to supply the light source and the light source of the light source module. The second resistance value of the resistor of the light source module is detected based on the DC power supplied to the resistor, and the control section receives a signal representing the dimming degree and controls the power supply section. DC power output from the light source module to the light source module is varied according to the type of the light source module and according to the dimming degree, and the first resistance value of the resistor is detected by applying the detection voltage. If the current value based on the first reference voltage and the dimming level set based on is less than the fixed current value, the second resistance value of the resistor is determined by the DC power of the power supply unit. A lighting device that does not perform detection is provided.

Even when an unintended resistance component occurs between the light source module and the lighting device, the light source module can be lit with an appropriate brightness depending on the type of light source module, and the light source caused by the unintended resistance component can be A lighting device and a lighting fixture are provided that can suppress changes in brightness during lighting of a module.

FIG. 1 is a block diagram schematically showing a lighting device and a lighting fixture according to an embodiment. FIG. 2 is a circuit diagram schematically representing an example of a detection circuit. It is an explanatory view showing typically an example of operation of a control part. It is an explanatory view showing typically an example of operation of a control part. FIG. 2 is a graph diagram schematically representing an example of a current flowing through a light source and a winding current of a power supply unit. FIGS. 6A and 6B are graphs schematically representing an example of the operation of the control unit. It is a graph schematically representing an example of the operation of the control unit.

Each embodiment will be described below with reference to the drawings.
Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be shown differently depending on the drawing.
In the present specification and each figure, the same elements as those described above with respect to the existing figures are denoted by the same reference numerals, and detailed explanations are omitted as appropriate.

FIG. 1 is a block diagram schematically showing a lighting device and a lighting fixture according to an embodiment.
As shown in FIG. 1, the lighting fixture 2 includes a lighting device 10 and a light source module 100. The lighting device 10 includes a control section 12, a connection section 14, a power supply section 16, and a detection circuit 18.

The lighting device 10 is electrically connected to a power source PS, for example. For example, AC power is supplied to the lighting device 10 from a power source PS. The power supply PS is, for example, a commercial power supply. The AC voltage of the AC power supplied from the power supply PS is, for example, 100V to 242V (effective value). The power source PS may be, for example, a private generator. Note that the power supplied to the lighting device 10 is not limited to alternating current power, and may be direct current power or the like. In the following, a case where AC power is supplied to the lighting device 10 will be described as an example.

The lighting device 10 is electrically connected to the light source module 100. The lighting device 10 converts AC power supplied from the power source PS into DC power corresponding to the light source module 100 and supplies the DC power to the light source module 100. Thereby, the lighting device 10 lights up the light source module 100.

The connecting portion 14 is used for electrical connection with the light source module 100. The connecting portion 14 is detachably connected to the light source module 100. Any one of a plurality of types of light source modules 100 having different color temperatures, brightness, etc. is selectively connected to the connecting portion 14 . The connecting portion 14 allows any of a plurality of types of light source modules 100 to be detachably connected.

The light source module 100 includes, for example, a light source 102 and a connected portion 104. The light source module 100 includes, for example, a plurality of light sources 102. In this example, each light source 102 is connected in series. Each light source 102 may be connected in parallel, or may be connected in series and in parallel, for example. The number of light sources 102 may be arbitrary. The number of light sources 102 may be one, for example.

For example, a light emitting diode (LED) is used as the light source 102. The light source 102 may be, for example, an organic light emitting diode (OLED), an inorganic electroluminescence light emitting element, an organic electroluminescence light emitting element, or another electroluminescent light emitting element. good. The light source 102 may be, for example, a light bulb. In the following description, the light source 102 is assumed to be an LED.

Furthermore, the light source module 100 further includes a resistor 106. Resistor 106 is connected in series with light source 102. For example, the resistor 106 is connected in series to each of the plurality of light sources 102. One end of the resistor 106 is electrically connected to the low potential side terminal (cathode) of the light source 102. The resistance value of the resistor 106 differs depending on the type of light source module 100. The resistance value of the resistor 106 is set, for example, to about 0Ω to several Ω. However, the resistance value of the resistor 106 is not limited to this, and may be any value.

The connected portion 104 is electrically connected to the connecting portion 14 of the lighting device 10 . The connected portion 104 is detachably connected to the connecting portion 14 . Further, the connected portion 104 is, for example, mechanically attached to the connecting portion 14 and held by the connecting portion 14 in a state of being connected to the connecting portion 14 .

The connected portion 104 includes a first connected terminal 104a, a second connected terminal 104b, and a third connected terminal 104c. The first connected terminal 104a is electrically connected to the high potential side terminal (anode) of the light source 102. The second connected terminal 104b is electrically connected to the connection point between the light source 102 and the resistor 106. The third connected terminal 104c is electrically connected to the other end of the resistor 106 (the terminal opposite to the one end connected to the light source 102).

The power supply section 16 is electrically connected to the connection section 14 . The power supply section 16 outputs DC power corresponding to the light source module 100. For example, the power supply unit 16 outputs a plurality of DC powers corresponding to a plurality of types of light source modules 100. In other words, the power supply unit 16 changes at least one of the voltage value and current value of the DC power depending on the type of light source module 100.

The detection circuit 18 detects the connection of the light source module 100 to the connection section 14 . The detection circuit 18 is electrically connected to the resistor 106 via the connection part 14 when the light source module 100 is connected to the connection part 14, and supplies the detection voltage Vdet to the resistance for detecting the connection of the light source module 100. 106.

The detection circuit 18 has, for example, a detection state and a rest state. The detection state is a state in which the detection voltage Vdet is applied to the resistor 106 and connection of the light source module 100 can be detected. The rest state is a state in which the application of the detection voltage Vdet to the resistor 106 is stopped and the detection of the connection of the light source module 100 is stopped.

The control section 12 has a connection terminal 12a that is electrically connected to the resistor 106 via the connection section 14 and the detection circuit 18 when the light source module 100 is connected to the connection section 14. The voltage value of the connection terminal 12a changes depending on whether or not the light source module 100 (resistor 106) is connected to the connection portion 14. The control unit 12 detects the connection of the light source module 100 to the connection unit 14 based on the voltage value of the connection terminal 12a when the detection circuit 18 applies the detection voltage Vdet to the resistor 106.

Further, the voltage value of the connection terminal 12a also changes depending on the type of light source module 100 connected to the connection portion 14 (the resistance value of the resistor 106). Therefore, the control unit 12 uses the voltage value of the connection terminal 12a when the detection circuit 18 applies the detection voltage Vdet to the resistor 106 or when the power supply unit 16 outputs DC power to the light source module 100. , detects the resistance value of the resistor 106 of the light source module 100, identifies the type of light source module 100 connected to the connection part 14, and causes the power supply part 16 to output DC power corresponding to the detected resistance value. Thereby, the light source module 100 can be lit with an appropriate color temperature and brightness corresponding to the product type.

The detection circuit 18 is electrically connected to the control section 12. The detection circuit 18 switches between a detection state and a dormant state based on the control of the control unit 12. The control unit 12 controls the switching of the detection circuit 18 between the detection state and the rest state, and sets the detection circuit 18 to the detection state, thereby detecting the attachment of the light source module 100 based on the voltage value and detecting the light source module 100 as described above. The resistance value of the resistor 106 is detected. Furthermore, when the power supply section 16 is operated, the control section 12 puts the detection circuit 18 into a dormant state.

The lighting device 10 further includes, for example, a filter circuit 30, a rectifier circuit 32, an inrush prevention circuit 34, a power factor correction circuit 36, a smoothing capacitor 38, a control power supply circuit 40, a step-down circuit 42, and drive circuits 44, 46. . Each of these parts is provided in the lighting device 10 as necessary and can be omitted.

Filter circuit 30 is electrically connected to power supply PS. For example, the filter circuit 30 suppresses noise contained in the AC power supplied from the power supply PS.

Rectifier circuit 32 is electrically connected to filter circuit 30 . The rectifier circuit 32 rectifies the AC voltage input through the filter circuit 30 and converts it into a rectified voltage. For the rectifier circuit 32, for example, a diode bridge combining four rectifier elements is used. That is, the rectifier circuit 32 is a full-wave rectifier. The rectified voltage is, for example, a pulsating voltage.

The rectifier circuit 32 has a pair of input terminals 32a and 32b, a high potential output terminal 32c, and a low potential output terminal 32d. Input terminals 32a and 32b are electrically connected to filter circuit 30. The rectifier circuit 32 converts the AC voltage input through the input terminals 32a and 32b into a rectified voltage, and outputs the rectified voltage from the high potential output terminal 32c and the low potential output terminal 32d. The potential of the low potential output terminal 32d is set to a reference potential (eg, ground potential). The potential of the high potential output terminal 32c is set to a higher potential than the potential of the low potential output terminal 32d.

The rectifier circuit 32 may be a half-wave rectifier or the like. The rectified voltage may be a full-wave rectified pulsating current or a half-wave rectified pulsating current. For example, a Schottky barrier diode is used in the rectifier circuit 32. Thereby, for example, good responsiveness can be obtained.

The rush prevention circuit 34 is electrically connected to the high potential output terminal 32c. The inrush prevention circuit 34 suppresses inrush current that occurs when the power is turned on.

The power factor correction circuit 36 is connected between the output of the inrush prevention circuit 34 and the low potential output terminal 32d. The power factor correction circuit 36 suppresses the generation of harmonics that are integral multiples of the power supply frequency in the rectified voltage. Thereby, the power factor improvement circuit 36 improves the power factor of the rectified voltage.

The power factor correction circuit 36 includes, for example, a switching element 51, an inductor 52, and a diode 53. The switching element 51 has electrodes 51a to 51c. One end of the inductor 52 is electrically connected to the output (high potential output terminal 32c) of the inrush prevention circuit 34. The other end of the inductor 52 is electrically connected to the electrode 51a. The electrode 51b is electrically connected to the low potential output terminal 32d. The anode of the diode 53 is electrically connected to the electrode 51a. A cathode of the diode 53 is electrically connected to one end of the smoothing capacitor 38. The other end of the smoothing capacitor 38 is electrically connected to the low potential output terminal 32d.

That is, in this example, the power factor correction circuit 36 is a boost chopper circuit. The power factor correction circuit 36 converts, for example, an AC voltage of the power supply PS of 100V to 242V (effective value) into a DC voltage of 420V. The power factor improvement circuit 36 is not limited to this, and may be any circuit that can improve the power factor of the rectified voltage.

The electrode 51c is electrically connected to the drive circuit 44. The electrode 51c is a so-called control electrode. The switching element 51 switches according to a signal from the drive circuit 44. The power factor improvement circuit 36 improves the power factor by, for example, switching the switching element 51 to bring the input current closer to a half-waveform of a sine wave.

The switching element 51 is, for example, an n-channel FET. For example, the electrode 51a is a drain, the electrode 51b is a source, and the electrode 51c is a gate. The switching element 51 may be, for example, a p-channel type FET or a bipolar transistor.

The smoothing capacitor 38 converts the pulsating voltage into a DC voltage by smoothing the pulsating voltage after power factor improvement.

The control power supply circuit 40 is electrically connected to one end of the smoothing capacitor 38 on the high potential side, for example. As a result, the DC voltage smoothed by the smoothing capacitor 38 is input to the control power supply circuit 40 . The control power supply circuit 40 converts the DC voltage smoothed by the smoothing capacitor 38 into a drive voltage for the drive circuits 44 and 46, and supplies the drive circuit 44 and 46 with the drive voltage. The drive circuits 44 and 46 are driven in response to power supplied from the control power supply circuit 40.

The voltage step-down circuit 42 is electrically connected to the control power supply circuit 40 . For example, the step-down circuit 42 steps down the drive voltage for the drive circuits 44 and 46 generated by the control power supply circuit 40 to the drive voltage for the control section 12, and supplies the step-down drive voltage to the control section 12. . The control unit 12 is driven in response to power supplied from the voltage step-down circuit 42 .

The power supply section 16 has a first input terminal 16a, a second input terminal 16b, a first output terminal 16c, and a second output terminal 16d. The first input terminal 16a is electrically connected to one end of the smoothing capacitor 38 on the high potential side. The second input terminal 16b is electrically connected to the low potential output terminal 32d. As a result, the power supply unit 16 is supplied with DC voltage.

The power supply unit 16 converts DC input power into a plurality of DC powers corresponding to a plurality of types of light source modules 100. Then, the power supply section 16 supplies the converted DC power to the light source module 100 from the first output terminal 16c and the second output terminal 16d.

The input power input to the power supply section 16 may be pulsating power or alternating current power. For example, when the input power is AC, the power supply unit 16 may include a rectifier that rectifies the input power, a smoothing capacitor that smoothes the rectified power, and the like.

Power supply unit 16 includes, for example, a switching element 55, a diode 56, an inductor 57, and an output capacitor 58. Switching element 55 has electrodes 55a to 55c. The electrode 55a is electrically connected to the first input terminal 16a. The electrode 55b is electrically connected to the cathode of the diode 56. The anode of the diode 56 is electrically connected to the low potential output terminal 32d. One end of the inductor 57 is electrically connected to the electrode 55b. The other end of the inductor 57 is electrically connected to the first output terminal 16c. The second output terminal 16d is electrically connected to the low potential output terminal 32d (second input terminal 16b).

Output capacitor 58 has a first electrode 58a and a second electrode 58b. The first electrode 58a is electrically connected to the first output terminal 16c. The second electrode 58b is electrically connected to the second output terminal 16d. The output capacitor 58 is connected in parallel between the first output terminal 16c and the second output terminal 16d. The output capacitor 58 smoothes the current flowing between the electrodes 55a and 55b of the switching element 55 by switching the switching element 55. As a result, DC power is output from the first output terminal 16c and the second output terminal 16d.

In this example, the power supply section 16 is a step-down chopper circuit. The power supply unit 16 generates a plurality of DC powers by stepping down the voltage of input power. The power supply section 16 converts the 420V DC voltage of the power factor correction circuit 36 into a 50V to 300V DC voltage. The power supply section 16 is, for example, a constant current circuit. For example, the power supply unit 16 outputs a substantially constant current C1 to the light source module 100.

The first output terminal 16c is a high potential side output terminal, and the second output terminal 16d is a low potential side output terminal. The potential of the first output terminal 16c is higher than the potential of the second output terminal 16d. The potential of the first electrode 58a is set higher than the potential of the second electrode 58b. The first electrode 58a is, for example, an anode, and the second electrode 58b is, for example, a cathode. On the contrary, the potential of the second output terminal 16d may be higher than the potential of the first output terminal 16c.

The switching element 55 is, for example, an n-channel FET. For example, electrode 55a is a drain, electrode 55b is a source, and electrode 55c is a gate. The switching element 55 may be, for example, a p-channel type FET or a bipolar transistor.

The power supply section 16 is not limited to the above circuit, and may be any circuit capable of outputting a plurality of DC powers corresponding to a plurality of types of light source modules 100.

The drive circuit 44 is electrically connected to the control section 12 and the electrode 51c of the switching element 51. The electrode 51c is a so-called control electrode. The drive circuit 44 controls switching of the switching element 51 based on the control of the control unit 12. That is, the drive circuit 44 switches the switching element 51 on and off. The drive circuit 44 switches the switching element 51 on and off according to the voltage (control signal) input to the electrode 51c. The drive circuit 44 improves the power factor of the rectified voltage in the power factor improvement circuit 36 by switching the switching element 51, for example.

The drive circuit 46 is electrically connected to the control section 12 and the electrode 55c of the switching element 55. The electrode 55c is a so-called control electrode. The drive circuit 46 controls switching of the switching element 55 based on the control of the control unit 12. That is, the drive circuit 46 switches the switching element 55 on and off. The drive circuit 46 switches the switching element 55 on and off according to the voltage (control signal) input to the electrode 55c. The drive circuit 46 generates a DC voltage between each electrode 58a, 58b of the output capacitor 58 by, for example, switching the switching element 55. Thereby, DC power is supplied from the power supply section 16 to the light source module 100.

The drive circuit 46 stops the supply of DC power from the power supply section 16 to the light source module 100, for example, by turning off the switching element 55. Further, the drive circuit 46 changes the voltage value and current value of the DC power according to the type of light source module 100, for example, by changing the on/off cycle (duty ratio) of the switching element 55.

Here, the off-state of the switching element 51 is, for example, a state in which substantially no current flows between the electrodes 51a and 51b, which are the main electrodes. In the OFF state, for example, a weak current that does not affect the operation of the power factor correction circuit 36 may flow between the electrodes 51a and 51b. In other words, the on state of the switching element 51 is a first state in which a current flows between the electrodes 51a and 51b, and the off state is a first state in which a current flows between the electrodes 51a and 51b. The second state is smaller than . The on state and off state of the switching element 55 are also the same as the on state and off state of the switching element 51.

The connection portion 14 of the lighting device 10 includes, for example, a first connection terminal 14a, a second connection terminal 14b, and a third connection terminal 14c. The first connection terminal 14a is electrically connected to the first output terminal 16c. The second connection terminal 14b is electrically connected to the connection terminal 12a and the detection circuit 18. The third connection terminal 14c is electrically connected to the second output terminal 16d.

Further, the first connecting terminal 14a is electrically connected to the first connected terminal 104a in a state where the connecting portion 14 is connected to the connected portion 104. Similarly, in a state where the connecting portion 14 is connected to the connected portion 104, the second connecting terminal 14b is electrically connected to the second connected terminal 104b, and the third connecting terminal 14c is connected to the third connected terminal It is electrically connected to 104c.

Thereby, the light source 102 and the resistor 106 connected in series are electrically connected to the first output terminal 16c and the second output terminal 16d of the power supply section 16 via the connecting section 14 and the connected section 104. . More specifically, the high potential side terminal of the light source 102 is electrically connected to the first output terminal 16c via the first connection terminal 14a and the first connected terminal 104a, and the other end of the resistor 106 is connected to the first output terminal 16c via the first connection terminal 14a and the first connected terminal 104a. It is electrically connected to the second output terminal 16d via the third connection terminal 14c and the third connected terminal 104c. As a result, a DC current flows through the light source 102 and the resistor 106 in accordance with the output of DC power by the power supply unit 16, and the light source 102 lights up.

The connection terminal 12 a of the control section 12 is electrically connected to the resistor 106 via the second connection terminal 14 b of the connection section 14 and the detection circuit 18 . Thereby, the voltage value of the connection terminal 12a changes depending on whether the resistor 106 is connected or not and the resistance value of the resistor 106.

The lighting device 10 further includes a resistor 60. The resistor 60 is electrically connected between the second output terminal 16d and the third connection terminal 14c. The resistor 60 is electrically connected between the second electrode 58b of the output capacitor 58 and the third connection terminal 14c.

Power supply section 16 further includes a detection resistor 62. The detection resistor 62 is electrically connected between the second input terminal 16b and the second electrode 58b of the output capacitor 58. In other words, the detection resistor 62 is electrically connected between the anode of the diode 56 and the second electrode 58b of the output capacitor 58. The second output terminal 16d is electrically connected to the low potential output terminal 32d via the detection resistor 62.

The control unit 12 is electrically connected to the resistor 60 and the detection resistor 62. The control unit 12 is electrically connected, for example, between the resistor 60 and the third connection terminal 14c. As a result, the detection voltage of the resistor 60 is input to the control unit 12 . The control unit 12 detects the current C1 flowing through the light source 102 and the resistor 106 based on the detected voltage of the resistor 60. The control unit 12 is electrically connected, for example, between the detection resistor 62 and the second electrode 58b. As a result, the detection voltage of the detection resistor 62 is input to the control section 12 . The control unit 12 detects the current flowing through the power supply unit 16 based on the voltage detected by the detection resistor 62. More specifically, the control unit 12 detects the winding current C2 flowing through the switching element 55 and the inductor 57 based on the detection voltage of the detection resistor 62. More specifically, the winding current C2 is a current flowing between each electrode 55a and 55b of the switching element 55. In other words, the detection resistor 62 is a resistor for detecting the unsmoothed current flowing through the switching element 55.

The control section 12 includes a reference voltage setting section 20, an operational amplifier 22, and a comparator 24. The reference voltage setting section 20 is electrically connected to the connection terminal 12a. Thereby, the voltage value of the connection terminal 12a is input to the reference voltage setting section 20. Based on the voltage value of the connection terminal 12a when the detection circuit 18 applies the detection voltage Vdet to the resistor 106 or when the power supply section 16 outputs DC power to the light source module 100, the reference voltage setting section 20 Set the reference voltage Vref. In other words, the reference voltage setting section 20 changes the reference voltage Vref according to the type of light source module 100 connected to the connection section 14 (the resistance value of the resistor 106). Thereby, the power supply unit 16 can output DC power corresponding to the type of light source module 100, and the light source module 100 can be lit with an appropriate color temperature and brightness corresponding to the type. The reference voltage setting section 20 inputs the set reference voltage Vref to the operational amplifier 22. The reference voltage Vref is input to the operational amplifier 22, and the detected value of the current C1 detected by the resistor 60 is input to the operational amplifier 22. The operational amplifier 22 inputs to the comparator 24 an error amplification output ERA corresponding to the difference between the reference voltage Vref and the detected value of the current C1.

The comparator 24 compares the detection value of the winding current C2 detected by the detection resistor 62 and the error amplification output ERA of the operational amplifier 22. The control unit 12 generates a control signal for controlling switching of the switching element 55 based on the comparison result of the comparator 24, and inputs the control signal to the drive circuit 46. The control unit 12 feedback-controls the operation of the power supply unit 16 based on the detected value of the current C1 detected by the resistor 60 and the detected value of the winding current C2 detected by the detection resistor 62. Thereby, the current C1 flowing through the light source 102 can be made substantially constant.

Further, the lighting device 10 further includes a dimming circuit 65. A dimming signal is input to the dimming circuit 65 from, for example, an external wall switch. The dimming signal may be, for example, an AC voltage whose conduction angle is controlled by a dimmer or the like. The dimming circuit 65 is electrically connected to the control section 12 . For example, the dimming circuit 65 generates a signal representing the degree of dimming based on the dimming signal, and inputs the signal to the control unit 12. The signal representing the degree of dimming is, for example, a PWM signal with a duty ratio corresponding to the degree of dimming.

For example, the control unit 12 inputs a signal input from the dimming circuit 65 to the reference voltage setting unit 20. The reference voltage setting section 20 is based on the voltage value of the connection terminal 12a when the detection circuit 18 applies the detection voltage Vdet to the resistor 106 or when the power supply section 16 outputs DC power to the light source module 100, for example. When setting the reference voltage Vref, the reference voltage Vref corresponding to a dimming level of 100% is set. Then, the reference voltage setting section 20 changes the reference voltage Vref based on the signal input from the dimming circuit 65.

The reference voltage setting unit 20 sets the reference voltage Vref corresponding to the degree of dimming, for example, by multiplying the reference voltage Vref of the degree of dimming of 100% by a coefficient corresponding to the degree of dimming. For example, when a dimming level of 70% is set in the dimming signal, the reference voltage setting unit 20 multiplies the reference voltage Vref of the 100% dimming level by 0.7 to achieve 70% dimming level. A reference voltage Vref corresponding to the luminous intensity is set.

The reference voltage setting unit 20 sets the voltage value to 100 based on the voltage value of the connection terminal 12a when the detection circuit 18 applies the detection voltage Vdet to the resistor 106 or when the power supply unit 16 outputs DC power to the light source module 100. After setting the reference voltage Vref corresponding to a dimming level of %, for example, the reference voltage Vref corresponding to a dimming level of 100% is stored and held. The reference voltage setting unit 20 sets the reference voltage corresponding to a dimming level of 100% until the detection circuit 18 detects the connection of the light source module 100 again in response to, for example, turning on the power again or reconnecting the light source module 100. The voltage Vref is memorized and held.

The control unit 12 inputs a control signal based on the comparison result of the comparator 24 to the drive circuit 46. The drive circuit 46 controls switching of the switching element 55 based on a control signal input from the control unit 12, for example. Thereby, the light source module 100 is dimmed at a dimming degree according to the dimming signal. The brightness of the light source module 100 is controlled according to the dimming signal. In this way, the control unit 12 and the drive circuit 46 change the DC power output to the light source module 100 according to the type of the light source module 100, and also change it according to the dimming signal input from the outside.

FIG. 2 is a circuit diagram schematically representing an example of a detection circuit.
As shown in FIG. 2, the detection circuit 18 includes switching elements 71 and 72 and resistors 73 and 74. The switching elements 71 and 72 have, for example, a pair of main electrodes and a control electrode. For example, bipolar transistors, FETs, etc. are used for the switching elements 71 and 72.

One main electrode of the switching element 71 is electrically connected to the voltage step-down circuit 42 . As a result, the driving voltage generated by the step-down circuit 42 is applied to the switching element 71. The voltage applied to the switching element 71 is not limited to the drive voltage generated by the step-down circuit 42, and may be, for example, the drive voltage generated by the control power supply circuit 40. The voltage applied to the switching element 71 may be any voltage that enables detection of attachment of the light source module 100 and identification of the type of the light source module 100.

The other main electrode of switching element 71 is electrically connected to one end of resistor 73. A control electrode of the switching element 71 is electrically connected to the control section 12 . The other end of the resistor 73 is electrically connected to the second connection terminal 14b of the connection portion 14 and one end of the resistor 74. The other end of the resistor 74 is electrically connected to the connection terminal 12a of the control section 12.

One main electrode of the switching element 72 is electrically connected to the second connection terminal 14b of the connection part 14. The other main electrode of the switching element 72 is electrically connected to the third connection terminal 14c of the connection part 14 and the resistor 60. A control electrode of the switching element 72 is electrically connected to the control section 12 .

The control unit 12 controls switching of the switching elements 71 and 72. When switching element 71 is turned on and switching element 72 is turned off, the voltage of step-down circuit 42 is applied to resistor 73 as detection voltage Vdet.

When the light source module 100 is not attached to the connection part 14, when the detection voltage Vdet is applied to the resistor 73, the voltage value corresponding to the voltage drop across the resistor 73 and the resistor 74 is applied to the connection terminal 12a. is input.

When the light source module 100 is attached to the connecting portion 14, the resistor 73 is electrically connected to the resistor 106 and the resistor 60 of the light source module 100 via the connecting portion 14 and the connected portion 104. . Resistor 106 and resistor 60 are connected in series with resistor 73. Therefore, when the light source module 100 is attached to the connection part 14, when the detection voltage Vdet is applied to the resistor 73, the detection voltage Vdet applied to the resistor 73 is The voltage value divided by the voltage value is input to the connection terminal 12a.

Therefore, the voltage value of the connection terminal 12a changes depending on whether the light source module 100 is connected or not, and also changes depending on the resistance value of the resistor 106. The reference voltage setting section 20 of the control section 12 detects whether or not the light source module 100 is connected and the resistance value of the resistor 106 of the light source module 100 based on the change in the voltage value of the connection terminal 12a.

In this way, in the detection circuit 18, by turning on the switching element 71 and turning off the switching element 72, it is possible to detect attachment of the light source module 100 and detect the resistance value of the resistor 106 of the light source module 100. The detection state is as follows. Then, in the detection circuit 18, by turning off the switching elements 71 and 72, the detection circuit 18 enters a hibernation state in which detection of attachment of the light source module 100 and detection of the resistance value of the resistor 106 of the light source module 100 are suspended.

In the rest state, the detection voltage Vdet is not applied to the resistors 60, 73, and 106. As described above, the resistance value of the resistor 106 is set to about 0Ω to several Ω. Therefore, the resistance values of the resistor 60 and the resistor 73 are similarly set to about several ohms. Therefore, a relatively large current flows through the resistors 60, 73, and 106. In particular, when the resistance value of resistor 106 is 0Ω, a relatively large current flows through resistor 73. Therefore, if the detection voltage Vdet is constantly applied to the resistor 73, there is a possibility that the resistor 73 generates heat and causes an unnecessary increase in power consumption. By providing switching elements 71, 72, etc. to enable a rest state, such increases in heat generation and power consumption can be suppressed.

The control unit 12 detects whether or not the light source module 100 is connected and the resistance value of the resistor 106 of the light source module 100, causes the reference voltage setting unit 20 to set the reference voltage Vref, and sets the type and dimming of the light source module 100. When outputting DC power according to the signal to the light source module 100, the switching element 71 is turned off and the switching element 72 is turned on.

As a result, for example, the connection state between the connection part 14 and the connected part 104 is released with the light source module 100 turned on, and the connection state between the third connection terminal 14c and the third connection terminal 104c is first released. When this happens, a relatively large current flowing through the light source 102 flows into the connection terminal 12a of the control unit 12 via the second connection terminal 14b and the second connected terminal 104b, causing the control unit 12 to malfunction. It is possible to prevent it from being put away. By keeping the switching element 72 in the on state, the current flowing from the second connection terminal 14b and the second connected terminal 104b can flow to the resistor 60 side. Thereby, even when the connection state between the connection section 14 and the connected section 104 is released while the light source module 100 is turned on, failure of the control section 12 can be suppressed. Therefore, the safety of the lighting device 10 can be further improved.

Note that the configuration of the detection circuit 18 is not limited to the above. For example, the switching element 72 may be omitted if there is a low possibility that the connection state between the connecting part 14 and the connected part 104 will be released while the light source module 100 is turned on. The configuration of the detection circuit 18 may be any configuration capable of switching between a detection state and a rest state.

The control unit 12 puts the detection circuit 18 into a detection state with the operation of the power supply unit 16 stopped, and after detecting the presence or absence of connection of the light source module 100 and the resistance value of the resistor 106 of the light source module 100. , by operating the power supply unit 16 with the detection circuit 18 in a dormant state, the resistance value of the resistor 106 of the light source module 100 is determined based on the DC power supplied from the power supply unit 16 to the light source 102 and the resistor 106. Try detection again.

An unintended resistance component R may occur on the signal line SL between the resistor 106 and the connection terminal 12a of the control unit 12. The resistance component R is, for example, wiring resistance or contact resistance. More specifically, the resistance component R is, for example, a contact resistance between the second connection terminal 14b and the second connected terminal 104b.

When the detection circuit 18 is in the detection state and the resistance value of the resistor 106 of the light source module 100 is detected based on the drive voltage of the step-down circuit 42, a current flows along the path of the arrow A1 shown in FIG. . If the resistance component R exists in this case, the resistance component R will be in series with the resistor 73 and in series with the resistor 106. For this reason, the resistance value of the resistor 106 appears large, and there is a possibility that the resistance value of the resistor 106 will be detected incorrectly.

On the other hand, when the power supply section 16 is operated and the resistance value of the resistor 106 of the light source module 100 is detected based on the DC power of the power supply section 16, the path of the arrow A2 shown in FIG. Current flows. If the resistance component R exists in this case, the resistance component R will be in series with the resistor 74 and in parallel with the resistor 106. Therefore, the influence of the resistance component R can be suppressed compared to the case where the current flows along the path indicated by the arrow A1. In this way, after detecting the resistance value of the resistor 106 of the light source module 100 with the detection circuit 18 in the detection state, the resistance value of the resistor 106 of the light source module 100 is detected based on the DC power of the power supply section 16. By performing the detection again, erroneous detection of the resistance value of the resistor 106 of the light source module 100 can be suppressed. Thereby, the light source module 100 can be lit with appropriate brightness depending on the type of the light source module 100.

In the following, the resistance value of the resistor 106 detected by the detection circuit 18 in the detection state will be referred to as a first resistance value, and the resistance value of the resistor 106 detected by operating the power supply unit 16 will be referred to as a second resistance value. . The control unit 12 detects the connection of the light source module 100 to the connection unit 14 and changes the resistance value of the resistor 106 based on the voltage value of the connection terminal 12a when the detection circuit 18 applies the detection voltage Vdet to the resistor 106. By performing the detection, the first resistance value of the resistor 106 is detected, and after detecting the connection of the light source module 100, the power supply unit 16 is operated and power is supplied from the power supply unit 16 to the light source 102 and the resistor 106. The second resistance value of the resistor 106 is detected by detecting the resistance value of the resistor 106 of the light source module 100 based on the DC power generated.

FIG. 3 is an explanatory diagram schematically showing an example of the operation of the control section.
In FIG. 3, the horizontal axis is the voltage value of the connection terminal 12a of the control section 12, and the vertical axis is the reference voltage Vref set by the reference voltage setting section 20. In other words, the horizontal axis is the resistance value of the resistor 106 of the light source module 100. The reference voltage setting unit 20 has a functional expression FU representing the relationship between the voltage value of the connection terminal 12a (resistance value of the resistor 106) and the reference voltage Vref as shown in FIG. In the power supply section 16 of the step-down chopper circuit, duty control is often performed based on the on-width and off-width of the switching element 55, and the output current value converges at the maximum value or minimum value of the on-width. Therefore, the functional expression FU is a third-order polynomial or a fourth-order polynomial. However, the functional expression FU is not limited to this, and may be a linear expression, a quadratic polynomial, or the like.

As described above, in the detection circuit 18, when the light source module 100 is not attached, the resistors 73 and 74 are connected to the connection terminal 12a, and the voltages of the resistors 73 and 74 are input to the connection terminal 12a. When the light source module 100 is installed, the resistors 60 and 106 are connected in series with the resistor 73, and the voltage obtained by dividing the voltage of the resistor 73 by the resistors 60 and 106 is applied to the connecting terminals. 12a. In this case, the voltage value of the connection terminal 12a becomes the highest when the light source module 100 is not attached. Then, when the light source module 100 is attached, the voltage value of the connection terminal 12a decreases according to the resistance value (dividing voltage ratio) of the resistor 106.

The reference voltage setting unit 20 determines that the light source module 100 is not attached, for example, when the voltage value of the connection terminal 12a is higher than the upper limit value. In this case, the control unit 12 does not output DC power from the power supply unit 16.

Further, the reference voltage setting unit 20 determines that a light source module 100 that is not compatible with the lighting device 10 is attached, for example, when the voltage value of the connection terminal 12a is lower than the lower limit value. In this case, the control section 12 does not output DC power from the power supply section 16, as in the case where the control section 12 is not attached.

Then, when the voltage value of the connection terminal 12a is in the range between the lower limit value and the upper limit value, the reference voltage setting unit 20 determines the reference voltage Vref based on the functional formula FU, and sets it in the operational amplifier 22. Note that, contrary to the above, the detection circuit 18 may be configured so that the voltage value of the connection terminal 12a is the lowest when the light source module 100 is not attached.

In addition, the functional formula FU may be affected by variations in the resistance values of various parts such as the detection circuit 18, variations in the offset voltage of the operational amplifier 22 and the comparator 24, or variations in the drive voltage of the control power supply circuit 40 and the step-down circuit 42. Variations occur among individual lighting devices 10.

Therefore, as shown in FIG. 3, the reference voltage setting unit 20 has an adjustment value for adjusting individual variations in the lighting device 10 of the functional formula FU. The adjustment value is input to the reference voltage setting unit 20 by being individually adjusted, for example, in the manufacturing process stage before shipping.

The reference voltage setting unit 20 calculates the adjusted voltage value by multiplying the voltage value of the connection terminal 12a by the adjustment value, and refers to the function formula FU based on the adjusted voltage value. Accordingly, the reference voltage Vref is determined. Thereby, variations among individual lighting devices 10 can be suppressed, and the light source module 100 can be more appropriately lit with brightness according to the product type.

It is desirable to set a plurality of adjustment values in accordance with a plurality of output current values. However, since performing the adjustment process multiple times deteriorates the workability and productivity of the manufacturing process, realistically, the adjustment process is often performed only once. On the other hand, if the adjustment process is performed with one output current, there is a possibility that the desired adjustment value will not be achieved with another output current. For example, there is a possibility that the variation in output current after adjustment exceeds the range of allowable variation.

For example, since there are detection variations due to the minimum resolution (1 bit) of the control unit 12, the variation width of the output current increases when the slope of the functional formula FU is large. Therefore, if the adjustment value obtained when adjusting the output current at the maximum value is applied to the output current minimum value, the output current variation will increase because it is not the desired adjustment value. For example, if the 1-bit variation in the maximum current value is ±3% and the 1-bit variation in the minimum current value is ±1%, a difference of ±4% will occur due to output current adjustment. If the tolerance is ±3%, the adjusted value must be ±2% instead of ±3%, so even if a limit is set on the adjusted value and the variation range is ±3%, it will be ±2%. Use as adjustment value.

In this way, the reference voltage setting section 20 sets the maximum value and minimum value for the adjustment value. The reference voltage setting unit 20 sets the maximum value and minimum value of the adjustment value, for example, so as to limit a change in the voltage value of the connection terminal 12a by more than a predetermined amount. The reference voltage setting unit 20 sets the maximum value and minimum value of the adjustment value, for example, so as to limit a change of ±2% or more in the voltage value of the connection terminal 12a. Thereby, even when the adjustment process is performed using the output current at one point, it is possible to suppress the variation in the output current after the adjustment from exceeding the allowable range of variation. In other words, even when adjusting the voltage value of the connection terminal 12a with one adjustment value, the variation in the output current after adjustment exceeds the range of allowable variation in the entire output current range. It is possible to prevent this from happening.

FIG. 4 is an explanatory diagram schematically showing an example of the operation of the control section.
In FIG. 4, the horizontal axis is time, and the vertical axis is the voltage value of the connection terminal 12a.
As shown in FIG. 4, in a state where the light source module 100 is not mounted or a state where an incompatible light source module 100 is mounted, the control unit 12 detects the mounting of the light source module 100 and controls the resistor of the light source module 100. The resistance of 106 is detected periodically.

In other words, a state in which the light source module 100 is not installed or a state in which an incompatible light source module 100 is installed is a state in which DC power is not output from the power supply section 16. In addition, periodically detecting the attachment of the light source module 100 and detecting the resistance of the resistor 106 of the light source module 100 means periodically switching the detection state of the detection circuit 18 and the rest state. be.

For example, the control unit 12 detects the attachment of the light source module 100 and identifies the type of the light source module 100 at a cycle of 500 msec (eg, 200 msec or more and 800 msec or less). In other words, the control unit 12 switches the detection circuit 18 to the detection state at a cycle of 500 msec. Thereby, the time required from attachment of the light source module 100 to lighting of the light source module 100 can be shortened.

When the time when the detection circuit 18 is in the detection state is the operating time, the time when the detection circuit 18 is in the inactive state is the inactive time, and the total time of the operating time and the inactive time is the detection time, the control unit 12: For example, out of the detection time of 500 msec, 50 msec is set as the operating time. In this way, the control unit 12, for example, sets the operating time to 10% or less of the detection time, and sets the rest as the down time. Thereby, heat generation in the resistor 73 and unnecessary increase in power consumption can be appropriately suppressed.

FIG. 5 is a graph diagram schematically showing an example of the current flowing through the light source and the winding current of the power supply section.
As shown in FIG. 5, the winding current C2 flowing through the switching element 55 and the inductor 57 of the power supply section 16 changes periodically. Winding current C2 is a current before being smoothed by output capacitor 58. For example, the winding current C2 increases during the period in which the switching element 55 is on, and decreases in the period in which the switching element 55 is off. The waveform of the winding current C2 is, for example, triangular. The winding current C2 is a so-called pulse current. The switching period T of the switching element 55 is, for example, about 20 μs.

On the other hand, the current C1 flowing through the light source 102 is a smoothed current of the output capacitor 58, and is a substantially constant current as described above. The change in the current value of the current C1 is smaller than the change in the current value of the winding current C2.

The control unit 12 uses a comparator 24 to compare whether the winding current C2 is greater than or equal to the error amplification output ERA of the operational amplifier 22. As described above, the reference voltage setting unit 20 changes the reference voltage Vref set to the operational amplifier 22 based on the signal input from the dimming circuit 65. The reference voltage setting unit 20 sets the reference voltage Vref to the highest level when the dimming level is 100%, and decreases the reference voltage Vref as the dimming level decreases. The operational amplifier 22 increases or decreases the error amplification output ERA in accordance with the increase or decrease in the reference voltage Vref, and also increases or decreases the error amplification output ERA in accordance with the difference between the reference voltage Vref and the detected value of the current C1. For example, the operational amplifier 22 increases the error amplification output ERA when the detected value of the current C1 is lower than a desired current value, and increases the error amplified output ERA when the detected value of the current C1 is higher than the desired current value. decrease. Thereby, the error amplification output ERA can be changed according to the type and dimming level of the light source module 100, and the error amplification output ERA can be changed according to a change in the current C1.

After turning on the switching element 55, the control unit 12 turns off the switching element 55 in response to the fact that the winding current C2 becomes equal to or higher than the error amplification output ERA. Thereby, the operation of the power supply unit 16 can be feedback-controlled so that a substantially constant current C1 flows through the light source 102, and the light source module 100 can be lit with a brightness according to the dimming level.

In this way, the control unit 12 controls the switching of the switching element 55 based on the current value of the current C1 flowing through the light source 102 and the current value of the winding current C2 flowing through the switching element 55, thereby controlling the light source 102. The operation of the power supply unit 16 is feedback-controlled so that a substantially constant current C1 flows, and the light source module 100 is lit at a brightness according to the dimming level.

The control unit 12 detects the resistance value of the resistor 106 of the light source module 100 only when the reference voltage setting unit 20 sets the reference voltage Vref according to the type of the light source module 100. For feedback control of the power supply section 16, the current value of the current C1 flowing through the light source 102 detected by the resistor 60 and the current value of the winding current C2 flowing through the switching element 55 detected by the detection resistor 62 are used.

For example, it is also possible to detect the current value of the current C1 flowing through the light source 102 based on the voltage value of the resistor 106 and perform feedback control of the power supply section 16. However, in this case, when an unintended resistance component R occurs on the signal line SL between the resistor 106 and the connection terminal 12a of the control unit 12, the current value of the current C1 cannot be appropriately detected. Therefore, the brightness of the light source module 100 may become unintended. Furthermore, there is also a concern that when the state of the resistance component R changes during lighting, the change in the state of the resistance component R may appear as a change in the brightness of the light source module 100. In other words, there is a concern that the brightness of the light source module 100 may flicker due to a change in the state of the resistance component R.

Therefore, as described above, the resistance value of the resistor 106 of the light source module 100 is detected only when the reference voltage Vref is set by the reference voltage setting section 20, and the resistance value of the resistor 106 of the light source module 100 is detected for feedback control of the power supply section 16. The current value of the current C1 flowing through the light source 102 detected by the detection resistor 62 and the current value of the winding current C2 flowing through the switching element 55 detected by the detection resistor 62 are used. In this case, the path for detecting the current value of the current C1 and the path for detecting the current value of the winding current C2 are not easily affected by the resistance component R. As a result, even when an unintended resistance component R occurs, the brightness of the light source module 100 may become unintended, or a change in the state of the resistance component R may be caused by a change in the brightness of the light source module 100. It is possible to prevent this from happening.

Note that, for example, by inputting the reference voltage Vref to the comparator 24 instead of the error amplification output ERA and comparing the reference voltage Vref and the current value of the winding current C2 with the comparator 24, the current value can be calculated without using the current C1. , feedback control may be performed using only the winding current C2. In this case, similarly to the above, when an unintended resistance component R occurs, the brightness of the light source module 100 may become unintended, or the change in the state of the resistance component R may cause the light source module It is possible to prevent the brightness from appearing as a change of 100 degrees.

In this way, the control unit 12 detects the current flowing through the power supply unit 16, and controls the current flowing through the light source 102 to be constant based on the detected value of the current flowing through the power supply unit 16 and the reference voltage Vref. The operation of the power supply unit 16 is feedback-controlled. The detected value of the current flowing through the power supply section 16 may be the detected value of the current C1 detected by the resistor 60, or the detected value of the winding current C2 detected by the detection resistor 62. The control unit 12 detects at least one of the current C1 and the winding current C2 as a current flowing through the power supply unit 16.

FIGS. 6A and 6B are graphs schematically representing an example of the operation of the control unit.
In FIGS. 6A and 6B, the horizontal axis is time, and the vertical axis is the current IF flowing through each light source 102. In FIG.
FIGS. 6A and 6B schematically represent an example of an operation performed by the control unit 12 regarding detection of the resistance value of the resistor 106 of the light source module 100.

When the light source module 100 is not installed, the control unit 12 first adjusts the drive voltage of the step-down circuit 42 by periodically bringing the detection circuit 18 into the detection state while stopping the operation of the power supply unit 16. Based on this, the first resistance value of the resistor 106 is detected by detecting the connection of the light source module 100 and the resistance value of the resistor 106 of the light source module 100 (the timing shown in FIG. 6(a) T11 to T12, and timing T21 to T22 in FIG. 6(b)).

When the control unit 12 detects attachment of the compatible light source module 100 based on the voltage value of the connection terminal 12a, the control unit 12 sets a standard corresponding to a dimming level of 100% based on the voltage value of the connection terminal 12a and the function formula FU. A voltage Vref (first reference voltage) is determined. As mentioned above, the control unit 12 (reference voltage setting unit 20) calculates the adjusted voltage value by multiplying the voltage value of the connection terminal 12a by the adjustment value, and Based on the voltage value of , the reference voltage Vref is determined by referring to the functional formula FU. When setting the reference voltage Vref corresponding to a dimming level of 100%, the control unit 12 sets the current flowing through each light source 102 as a target current value DAC1 (first target current value).

After setting the target current value DAC1, the control unit 12 determines whether the current value of DAC1×SLV, which is obtained by multiplying the target current value DAC1 by the dimming level SLV based on the dimming signal, is greater than or equal to a preset fixed current value DACth. Determine.

When the control unit 12 determines that the current value of DAC1×SLV is equal to or greater than the fixed current value DACth, the control unit 12 corresponds to the fixed current value DACth so as to supply the fixed current value DACth to each light source 102 of the light source module 100. The reference voltage Vref thus obtained is set in the operational amplifier 22, and the power supply section 16 is operated (timings T13 to T14 in FIG. 6(a)).

After supplying the fixed current value DACth to each light source 102, the control unit 12 determines the resistance value of the resistor 106 of the light source module 100 based on the DC power supplied from the power supply unit 16 to the light source 102 and the resistor 106. By performing the detection, the second resistance value of the resistor 106 is detected (timings T14 to T15 in FIG. 6(a)). In this way, when detecting the second resistance value of the resistor 106 of the light source module 100 using the DC power of the power supply section 16, the control section 12 applies the preset fixed current value DACth to each light source 102. and the resistor 106. Thereby, the second resistance value of resistor 106 can be appropriately detected.

The control unit 12 generates a reference voltage Vref (second reference voltage) corresponding to a dimming level of 100% based on the voltage value of the connection terminal 12a and the functional formula FU when the fixed current value DACth is supplied to each light source 102. Determine. When setting this reference voltage Vref, the control unit 12 sets the current flowing through each light source 102 as a target current value DAC2 (second target current value).

Note that when detecting the first resistance value of the resistor 106 based on the drive voltage of the step-down circuit 42, the current supplied to each light source 102 is set to be the same as the fixed current value DACth. It is preferable. Thereby, the first resistance value of the resistor 106 is detected based on the drive voltage of the step-down circuit 42, and the second resistance value of the resistor 106 is detected based on the DC power of the power supply unit 16. The function expression FU can be commonly used in and. However, when detecting the first resistance value of the resistor 106 based on the drive voltage of the step-down circuit 42, the current supplied to each light source 102 may be different from the fixed current value DACth. In this case, two corresponding functional expressions FU may be provided in the reference voltage setting section 20 in advance.

After setting the target current value DAC2, the control unit 12 sets a reference voltage Vref corresponding to DAC2×SLV in the operational amplifier 22 so that the current value of DAC2×SLV is supplied to each light source 102 of the light source module 100, By operating the power supply unit 16, the light source module 100 is turned on at a brightness according to the type of the light source module 100 and the dimming degree SLV of the dimming signal (timing T16 in FIG. 6(a)).

On the other hand, when the control unit 12 determines that the current value of DAC1×SLV is less than the fixed current value DACth, the controller 12 controls the DAC1×SLV so that the current value of DAC1×SLV is supplied to each light source 102 of the light source module 100. By setting the reference voltage Vref corresponding to SLV in the operational amplifier 22 and operating the power supply unit 16, the light source module 100 is lit with a brightness according to the current value of DAC1×SLV (timing shown in FIG. 6(b) T23-T24).

After lighting the light source module 100 with a brightness according to the current value of DAC1×SLV, if the dimming degree SLV changes and the current value of DAC1×SLV becomes equal to or higher than the fixed current value DACth, the control unit 12 Similarly to the above, the fixed current value DACth is supplied to each light source 102, and the resistance value of the resistor 106 of the light source module 100 is determined based on the DC power supplied from the power supply section 16 to the light source 102 and the resistor 106. The detection is performed again (timings T25 to T26 in FIG. 6(b)).

Then, the control unit 12 operates the power supply unit 16 to supply the current value of DAC2×SLV to each light source 102 of the light source module 100, thereby adjusting the type of light source module 100 and the dimming level SLV of the dimming signal. The light source module 100 is turned on at the corresponding brightness (timing T27 in FIG. 6(b)).

In this way, when the control unit 12 determines that the current value of DAC1×SLV is less than the fixed current value DACth, the second resistance value of the resistor 106 of the light source module 100 is determined by the DC power of the power supply unit 16. Detection is not performed. Thereby, after the light source module 100 lights up brightly based on the reference voltage Vref corresponding to the fixed current value DACth, it can be suppressed from turning dark based on the reference voltage Vref corresponding to DAC2×SLV. In other words, it is possible to prevent the light source module 100 from becoming poorly visible when it is turned on.

FIG. 7 is a graph schematically representing an example of the operation of the control section.
In FIG. 7, the horizontal axis is the degree of dimming, and the vertical axis is the current IF flowing through each light source 102.
The characteristics CT1 and CT2 in FIG. 7 are obtained when an unintended resistance component R occurs on the signal line SL between the resistor 106 and the connection terminal 12a of the control unit 12 in the light source module 100 of a predetermined type. Schematically represents an example of the characteristics of.

Characteristics CT3 and CT4 in FIG. 7 indicate that in a light source module 100 of a different type from characteristics CT1 and CT2, an unintended resistance component R is present on the signal line SL between the resistor 106 and the connection terminal 12a of the control unit 12. This diagram schematically represents an example of the characteristics when this occurs. The light source module 100 with the characteristic CT3 and the characteristic CT4 is a light source module 100 with lower brightness than the light source module 100 with the characteristic CT1 and the characteristic CT2. Therefore, in the light source module 100 with the characteristic CT3 and the characteristic CT4, the current IF required for the dimming degree is lower than in the light source module 100 with the characteristic CT1 and the characteristic CT2.

The characteristic CT1 and the characteristic CT3 are examples of the current IF when the dimming degree is adjusted from 100% to 0%. The characteristic CT2 and the characteristic CT4 are examples of the current IF when the dimming degree is adjusted from 0% to 100%. When the dimming level is set to a low value, there is a high possibility that the current value of DAC1×SLV will be less than the fixed current value DACth, as in the example shown in FIG. 6(b). In characteristic CT2, the current value of DAC1×SLV is greater than or equal to the fixed current value DACth at a dimming level of approximately 35%. In characteristic CT4, the current value of DAC1×SLV is greater than or equal to the fixed current value DACth at approximately 90% dimming level.

In this way, when a low dimming level is set at the start of lighting, unintended resistance components R may occur, such as in the area where the dimming level is less than 35% of the characteristic CT2 and the area where the dimming level is less than 90% of the characteristic CT4. Due to this influence, the current value may be lower than the one depending on the type of light source module 100, and the brightness may become darker than the original brightness. The influence of the unintended resistance component R affects a wider range of dimming degree as the type of light source module 100 has lower brightness. Furthermore, the influence of the unintended resistance component R may appear as a larger difference in current value as the type of light source module 100 has higher brightness, making it appear darker.

On the other hand, if a high dimming level is set at the start of lighting, the unintended resistance component R It is possible to suppress the influence of By supplying a current value according to the type of light source module 100, it is possible to light the light source module 100 with appropriate brightness. Furthermore, as shown in characteristics CT1 and CT3, after the resistance value of the resistor 106 is detected using the DC power of the power supply section 16, even if a low dimming level is set after that, the DAC2×SLV By setting the reference voltage Vref corresponding to , in the operational amplifier 22, the influence of the unintended resistance component R can be suppressed.

The characteristic CT5 in FIG. 7 schematically represents an example of the characteristic of the light source module 100 of the lowest brightness among the plurality of types of light source modules 100 that may be connected to the lighting device 10. .

As shown in FIG. 7, the control unit 12 sets the design value of the current value of each light source 102 for lighting the light source module 100 of the lowest brightness type at 100% dimming level as a fixed current value DACth. do.

Furthermore, when setting the reference voltage Vref based on the voltage value of the connection terminal 12a and the functional formula FU, the current flowing through each light source 102 may become lower than the desired current value due to the influence of the unintended resistance component R. There is a possibility that it will happen.

Therefore, the control unit 12 sets the minimum value of the current flowing through each light source 102 so that the current flowing through each light source 102 does not become less than the minimum value. The control unit 12 sets the minimum value of the current flowing through each light source 102 for each dimming level. For example, the control unit 12 sets the characteristic CT5 of the light source module 100 of the type with the lowest brightness as the minimum value of the current for each dimming level, and the current flowing through each light source 102 is set to the current value of the characteristic CT5 for each dimming level. Avoid the following.

In other words, the control unit 12 sets the minimum value to the reference voltage Vref determined from the voltage value of the connection terminal 12a and the functional formula FU. For example, the control unit 12 prevents the reference voltage Vref from becoming lower than the reference voltage Vref of the characteristic CT5 of the light source module 100 of the type with the lowest brightness. Thereby, the brightness of the light source module 100 can be prevented from becoming too dark due to the influence of the unintended resistance component R.

As described above, in the lighting fixture 2 and lighting device 10 according to the present embodiment, when the light source module 100 is connected to the connection section 14, the control section 12 connects the resistor 106 via the connection section 14. It has a connection terminal 12a that is electrically connected, and detects the connection of the light source module 100 to the connection part 14 based on the voltage value of the connection terminal 12a when the detection circuit 18 applies the detection voltage Vdet to the resistor 106. By detecting the resistance value of the resistor 106, the first resistance value of the resistor 106 is detected, a first reference voltage is set based on the detected first resistance value, and the connection of the light source module 100 is performed. After detecting, the power supply unit 16 is operated and the resistance value of the resistor 106 of the light source module 100 is detected based on the DC power supplied from the power supply unit 16 to the light source 102 and the resistor 106. , the second resistance value of the resistor 106 is detected, and based on the detected second resistance value of the resistor 106, a second reference voltage (reference voltage Vref ). As a result, erroneous detection of the resistance value of the resistor 106 of the light source module 100 due to the unintended influence of the resistance component R can be suppressed, and the light source module 100 can be lit with appropriate brightness according to the type of the light source module 100. .

Further, the control unit 12 detects the current flowing through the power supply unit 16, and controls the power supply so that the current flowing through the light source 102 is constant based on the detected value of the current flowing through the power supply unit 16 and the reference voltage Vref. The operation of the section 16 is feedback-controlled. The control unit 12 detects the resistance value of the resistor 106 once before and after the start of oscillation of the power supply unit 16, which is a step-down chopper circuit, and detects the resistance value of the resistor 106 in feedback control of the power supply unit 16. No constant feedback. As a result, even when an unintended resistance component R occurs, the brightness of the light source module 100 may become unintended, or a change in the state of the resistance component R may be caused by a change in the brightness of the light source module 100. It is possible to prevent this from happening.

Therefore, even when an unintended resistance component R occurs between the light source module 100 and the lighting device 10, the light source module 100 can be lit with an appropriate brightness depending on the type of the light source module 100, and It is possible to provide a lighting device 10 and a lighting fixture 2 that can suppress changes in brightness during lighting of the light source module 100 due to the resistance component R that does not occur.

In the lighting fixture 2 and lighting device 10 according to the present embodiment, the control unit 12 operates the power supply unit 16 to supply a preset fixed current value DACth to the light source 102 of the light source module 100. The second resistance value of the resistor 106 of the light source module 100 is detected based on the DC power supplied from the power supply unit 16 to the light source 102 and the resistor 106 . Thereby, the resistance value of resistor 106 can be appropriately detected.

In the lighting fixture 2 and the lighting device 10 according to the present embodiment, the control unit 12 receives the input of the signal representing the dimming level, and controls the DC power output from the power supply unit 16 to the light source module 100 depending on the type of the light source module 100. The current value is fixed based on the reference voltage Vref, which is set based on the first resistance value of the resistor 106 detected by applying the detection voltage Vdet, and the dimming level. If the current value is less than DACth, the second resistance value of the resistor 106 is not detected using the DC power of the power supply unit 16. Thereby, it is possible to prevent the light source module 100 from turning on brightly based on the reference voltage Vref corresponding to the fixed current value DACth and then becoming dark based on the reference voltage Vref corresponding to the dimming level.

In the lighting fixture 2 and lighting device 10 according to the present embodiment, the control unit 12 sets the minimum value of the current flowing through the light source 102. Thereby, the brightness of the light source module 100 can be prevented from becoming too dark due to the influence of the unintended resistance component R.

This embodiment includes the following aspects.
(Additional note 1)
a connection part for detachably connecting a light source module having a light source;
a power supply unit capable of outputting DC power corresponding to the light source module;
a control unit that controls output of the DC power by the power supply unit;
a detection circuit for detecting connection of the light source module to the connection portion;
Equipped with
The connection portion is capable of selectively connecting a plurality of light source modules of different types,
The light source module has a resistor connected in series with the light source, and changes the resistance value of the resistor depending on the product type,
The detection circuit is electrically connected to the resistor via the connection part when the light source module is connected to the connection part, and applies a detection voltage to the resistance for detecting the connection of the light source module. apply it to the device,
The control section has a connection terminal that is electrically connected to the resistor via the connection section when the light source module is connected to the connection section, and the detection circuit converts the detected voltage into the connection terminal. A standard for detecting connection of the light source module to the connection portion based on a voltage value of the connection terminal when applied to a resistor, and feedback controlling the voltage value of the connection terminal and the operation of the power supply unit. The reference voltage is set based on the voltage value of the connection terminal and the functional formula when connection of the light source module is detected, and the current flowing through the power supply unit is A lighting device that performs feedback control on the operation of the power supply unit so that the current flowing through the light source is constant based on the detected value of the current flowing through the power supply unit and the reference voltage.

(Additional note 2)
The lighting device according to supplementary note 1, wherein the functional expression is a third-order polynomial or a fourth-order polynomial.

Although several embodiments of the invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

2... Lighting equipment, 10... Lighting device, 12... Control section, 14... Connection section, 16... Power supply section, 18... Detection circuit, 20... Reference voltage setting section, 22... Operational amplifier, 24... Comparator, 30... Filter Circuit, 32... Rectifier circuit, 34... Rush prevention circuit, 36... Power factor correction circuit, 38... Smoothing capacitor, 40... Control power supply circuit, 42... Step-down circuit, 44... Drive circuit, 46... Drive circuit, 51... Switching Element, 52...Inductor, 53...Diode, 55...Switching element, 56...Diode, 57...Inductor, 58...Output capacitor, 60...Resistor, 62...Detection resistor, 65...Dimmer circuit, 71, 72...Switching element , 73, 74...Resistor, 100...Light source module, 102...Light source, 104...Connected part, 106...Resistor

Claims (2)

a connection part for detachably connecting a light source module having a light source and a resistor connected in series with the light source;
a power supply unit capable of outputting DC power corresponding to the light source module;
a control unit that controls output of the DC power by the power supply unit;
a detection circuit for detecting connection of the light source module to the connection portion;
Equipped with
The connection portion is capable of selectively connecting a plurality of light source modules of different types,
The detection circuit is electrically connected to the resistor via the connection part when the light source module is connected to the connection part, and applies a detection voltage to the resistance for detecting the connection of the light source module. apply it to the device,
The control section has a connection terminal that is electrically connected to the resistor via the connection section when the light source module is connected to the connection section, and the detection circuit converts the detected voltage into the connection terminal. The first resistance of the resistor is detected by detecting the connection of the light source module to the connection portion and the resistance value of the resistor based on the voltage value of the connection terminal when applied to the resistor. After detecting the resistance value and setting a first reference voltage based on the detected first resistance value and detecting the connection of the light source module, the power supply section is operated, and the light source is supplied from the power supply section. and detecting the resistance value of the resistor of the light source module based on the DC power supplied to the resistor, detecting the second resistance value of the resistor, and detecting the second resistance value of the resistor of the detected resistor. A second reference voltage for feedback controlling the operation of the power supply section is set based on the second resistance value, a current flowing through the power supply section is detected, and a current flowing through the power supply section is detected. feedback-controlling the operation of the power supply unit based on the detected value and the second reference voltage so that the current flowing through the light source is constant ;
The control unit operates the power supply unit to supply a preset fixed current value to the light source of the light source module, so that the power is supplied from the power supply unit to the light source and the resistor. Detecting the second resistance value of the resistor of the light source module based on DC power,
The control unit receives an input of a signal representing a degree of dimming, and changes the DC power output from the power supply unit to the light source module in accordance with the type of the light source module and in accordance with the degree of dimming, If the current value based on the first reference voltage set based on the first resistance value of the resistor detected by application of the detection voltage and the dimming level is less than the fixed current value, . A lighting device in which the second resistance value of the resistor is not detected using DC power from the power supply unit . a light source module having a light source;
A lighting device according to claim 1 ;
Lighting equipment with.

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