Lighting device and lighting fixture

Abstract

To provide a lighting device and a lighting fixture capable of suppressing a loss at a high dimming degree while suppressing a light source from being turned off at a low dimming degree even when a resistance element for mounting and detection is provided in parallel with the light source.SOLUTION: A lighting device includes: a connection part connected to a light source module including a light source and a mounting detection resistor connected in parallel with the light source; a power conversion part configured to convert an input power into a power corresponding to the light source module and supply the power to the light source module; and a control part configured to control an operation of the power conversion part in accordance with a dimming signal. The power conversion part includes: a current detection resistor configured to detect a current flowing through the light source module; and a voltage detection part configured to detect an output voltage of the power conversion part. In the lighting device, the control part corrects a reference value corresponding to a dimming degree represented by the dimming signal based on an estimated value of the current flowing through the mounting detection resistor, and controls the operation of the power conversion part so that a magnitude of the current flowing through the light source module becomes a magnitude corresponding to the corrected reference value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a lighting device and a lighting fixture. [Background technology]

[0002] There are lighting devices that are used by connecting them to light source modules that have light sources such as LEDs. There are also lighting fixtures that include a light source module and a lighting device. The lighting device converts AC power supplied from a commercial power source or the like into power compatible with the light source module, and supplies the converted power to the light source module to light up the light source of the light source module.

[0003] The lighting device changes the brightness of the light emitted from the light source module by changing the amount of power supplied to the light source module in response to a dimming signal input from an external device. The lighting device has a current detection resistor element connected in series to the light source. The lighting device lights the light source at a brightness corresponding to the dimming signal by changing the amount of power supplied to the light source module so that the amount of current detected by the current detection resistor element matches a reference value set in response to the dimming signal.

[0004] In such lighting fixtures, a resistive element is provided in parallel with the light source of the light source module, and the lighting device detects whether the light source module is attached or not based on a change in voltage that occurs depending on whether the light source module is attached or not.

[0005] If a resistor element for attachment detection is provided in parallel with the light source, a large proportion of the current flows through the resistor element for attachment detection when a low dimming level is set, which may cause the light source to turn off. Therefore, it has been proposed to prevent the light source from turning off by supplying a current to the light source module that takes into account the current flowing through the resistor element for attachment detection when a low dimming level is set.

[0006] However, in order to supply a current to the light source module that takes into account the current flowing through the resistance element for attachment detection and to appropriately turn on the light source at a brightness corresponding to the dimming signal, it is necessary to increase the magnitude of the current detected by the resistance element for current detection as much as possible in order to finely adjust the magnitude of the current supplied to the light source module. To achieve this, the resistance value of the resistance element for current detection must be increased. However, increasing the resistance value of the resistance element for current detection increases the loss in the resistance element for current detection when a high dimming level is set, resulting in a decrease in circuit efficiency.

[0007] For this reason, in lighting devices and lighting fixtures, even when a resistor for detecting attachment is provided in parallel with the light source, it is desirable to be able to prevent the light source from being turned off at low dimming levels while also suppressing losses at high dimming levels. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2021-157970 Summary of the Invention [Problem to be solved by the invention]

[0009] An embodiment of the present invention provides a lighting device and a lighting fixture that can suppress the extinguishing of a light source at low dimming levels while also suppressing losses at high dimming levels, even when a resistance element for detecting attachment is provided in parallel with the light source. [Means for solving the problem]

[0010] According to an embodiment, a light source module includes a connection unit connected to a light source and a light source module having a mounting detection resistor connected in parallel to the light source, a power conversion unit that converts input power into power corresponding to the light source module and supplies the converted power to the light source module connected to the connection unit, and a control unit that receives an input of a dimming signal and controls the operation of the power conversion unit in accordance with the dimming signal to light the light source module at a brightness corresponding to the dimming level represented by the dimming signal, and the power conversion unit is connected in series to the light source module and includes a current detection resistor that detects a current flowing through the light source module, and a and a voltage detection unit that detects the output voltage of the power conversion unit, wherein the control unit has information on the resistance value of the attachment detection resistor, estimates the current flowing through the attachment detection resistor based on the output voltage of the power conversion unit detected by the voltage detection unit and the resistance value of the attachment detection resistor, sets a reference value corresponding to the dimming level represented by the input dimming signal, corrects the reference value corresponding to the dimming level based on the estimated value of the current flowing through the attachment detection resistor, and controls the operation of the power conversion unit so that the magnitude of the current flowing through the light source module corresponds to the corrected reference value. [Effects of the Invention]

[0011] Provided are a lighting device and a lighting fixture that can suppress the extinguishing of a light source at a low dimming level while suppressing loss at a high dimming level, even when a resistance element for detecting attachment is provided in parallel with the light source. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a block diagram schematically illustrating a lighting fixture according to an embodiment. [Figure 2] FIG. 10 is a block diagram schematically illustrating a modified example of the lighting fixture according to the embodiment. [Figure 3] FIG. 10 is a block diagram schematically illustrating a modified example of the lighting fixture according to the embodiment. [Figure 4] FIG. 10 is a block diagram schematically illustrating a modified example of the lighting fixture according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Each embodiment will be described below with reference to the drawings. 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 different depending on the drawing. In the present specification and the drawings, elements similar to those described above with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0014] FIG. 1 is a block diagram schematically illustrating 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 is connected to the light source module 100. The light source module 100 is, for example, detachably connected to the lighting device 10. The lighting device 10 is also connected to a power source PS. The lighting device 10 is, for example, detachably connected to the power source PS. The lighting device 10 supplies a predetermined power to the light source module 100 based on the power supplied from the power source PS, thereby lighting the light source module 100.

[0015] The light source module 100 includes a light source 102, an attachment detection resistor 104, and a receptacle 106. The light source module 100 includes, for example, a plurality of light sources 102. In this example, the light sources 102 are connected in series. The light sources 102 may be connected in parallel, or a combination of series and parallel connections. The number of light sources 102 may be any number. For example, the number of light sources 102 may be one.

[0016] 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 other electroluminescence type light emitting element. The light source 102 may be, for example, a light bulb.

[0017] The attachment detection resistor 104 is connected in parallel to the light source 102. For example, the attachment detection resistor 104 is connected in parallel to each of the multiple light sources 102. The attachment detection resistor 104 is used to detect the connection of the light source module 100 in the lighting device 10. The resistance value of the attachment detection resistor 104 may be any value that allows the lighting device 10 to appropriately detect the connection of the light source module 100.

[0018] The receptacle 106 is used for connection to the lighting device 10. The light source module 100 is detachably connected to the lighting device 10 via the receptacle 106. The light source module 100 is mechanically and electrically connected to the lighting device 10 via the receptacle 106.

[0019] The light source module 100 is, for example, an LED lamp. However, the light source module 100 is not limited to this and may be any light source module that includes at least a light source 102 and an attachment detection resistor 104 connected in parallel to the light source 102.

[0020] The lighting device 10 includes a connection unit 12, a power conversion unit 14, and a control unit 16. The connection unit 12 is connected to a receptacle 106 of the light source module 100. The light source module 100 is detachably connected to the lighting device 10 by connecting the receptacle 106 to the connection unit 12 of the lighting device 10.

[0021] The lighting device 10 is commonly used for a plurality of models of light source modules 100 that emit light that is different in at least one of brightness and color (color temperature). This makes it possible to suppress increases in the manufacturing costs of the lighting fixture 2 compared to, for example, manufacturing lighting devices that are specifically designed to be compatible with each of a plurality of models of light source modules 100.

[0022] The connection portion 12 has, for example, a first terminal 12a and a second terminal 12b. The first terminal 12a is connected to one end of the light source 102 and one end of the attachment detection resistor 104. The second terminal 12b is connected to the other end of the light source 102 and the other end of the attachment detection resistor 104. In this example, the attachment detection resistor 104 is connected in parallel with the light source 102 within the light source module 100.

[0023] The receptacle 106 has a terminal 106a that is connected to the first terminal 12a and a terminal 106b that is connected to the second terminal 12b. In this way, the connecting portion 12 and the receptacle 106 are, for example, a two-terminal connector.

[0024] The power conversion unit 14 converts the input power into power compatible with the light source module 100, and supplies the converted power to the light source module 100 connected to the connection unit 12. The power conversion unit 14 is connected to the power source PS, and receives input power from the power source PS.

[0025] The power conversion unit 14 has, for example, a pair of input terminals 14a and 14b and a pair of output terminals 14c and 14d. The power conversion unit 14 is connected to a power source PS via the pair of input terminals 14a and 14b, and receives input power from the pair of input terminals 14a and 14b. The power conversion unit 14 then outputs the converted power from the pair of output terminals 14c and 14d.

[0026] The power supply PS supplies, for example, AC power as input power to the power conversion unit 14. The power supply PS is, for example, a commercial power supply. The power supply PS may also be, for example, a private power generator. The power conversion unit 14 converts the AC power supplied from the power supply PS into DC power compatible with the light source module 100 and supplies the converted DC power to the light source module 100. In this way, the power conversion unit 14 lights up the light source module 100. The power conversion unit 14 outputs DC power to a pair of output terminals 14c and 14d. For example, the potential of the output terminal 14d is lower than the potential of the output terminal 14c. The output terminal 14c is a high-potential output terminal, and the output terminal 14d is a low-potential output terminal.

[0027] The input power supplied to the lighting device 10 is not limited to AC power, but may be DC power, etc. The power conversion unit 14 may convert the DC power into another DC power having a different current value or voltage value and supply it to the light source module 100.

[0028] The control unit 16 receives a dimming signal. The dimming signal is input to the control unit 16 via a wired or wireless connection, for example, from a remote control or a switch on the wall. The dimming signal may also be input to the control unit 16 from another control device, for example. In other words, the control unit 16 receives the dimming signal from an external device such as a switch or another control device. The dimming signal may also be input to the control unit 16 from an operation unit provided in the lighting fixture 2 (lighting device 10). The method of inputting the dimming signal to the control unit 16 is not limited to the above, and any method may be used as long as the dimming signal can be appropriately input to the control unit 16. The dimming signal representing the dimming level is, for example, a PWM signal with a duty ratio corresponding to the dimming level. The dimming signal may also be, for example, an AC voltage whose conduction angle is controlled by a dimmer or the like. The dimming signal may be any signal that can appropriately represent the dimming level.

[0029] The control unit 16 controls the operation of the power conversion unit 14 in response to the dimming signal, thereby lighting the light source module 100 at a brightness corresponding to the dimming level indicated by the dimming signal.

[0030] The power conversion unit 14 has, for example, a rectifier circuit 20, a high-frequency removal capacitor 22, a power factor correction circuit 24, a smoothing capacitor 26, and a converter 28. The rectifier circuit 20, the high-frequency removal capacitor 22, the power factor correction circuit 24, and the smoothing capacitor 26 may be omitted, for example, when DC power is supplied to the lighting device 10 from a power source PS. Each of these components is provided in the power conversion unit 14 as needed and may be omitted.

[0031] The rectifier circuit 20 rectifies AC power input from the power supply PS and converts it into rectified power. The rectifier circuit 20 may be, for example, a diode bridge formed by combining four rectifier elements. In other words, the rectifier circuit 20 is a full-wave rectifier. The rectified power may be, for example, pulsating power.

[0032] The rectifier circuit 20 has a pair of input terminals 20a and 20b, a high-potential output terminal 20c, and a low-potential output terminal 20d. The input terminals 20a and 20b are electrically connected to a power supply PS. The rectifier circuit 20 converts AC power input via the input terminals 20a and 20b into rectified power, and outputs it from the high-potential output terminal 20c and the low-potential output terminal 20d. The potential of the low-potential output terminal 20d is set to a reference potential (e.g., ground potential). The potential of the high-potential output terminal 20c is set to a potential higher than the potential of the low-potential output terminal 20d.

[0033] The rectifier circuit 20 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 for the rectifier circuit 20. This allows, for example, good responsiveness to be obtained.

[0034] The high frequency removal capacitor 22 smoothes the rectified high frequency power, thereby converting it into pulsating power.

[0035] The power factor correction circuit 24 suppresses the generation of harmonics that are integer multiples of the power supply frequency in the input current of the rectifier circuit 20. In this way, the power factor correction circuit 24 improves the power factor of the input power.

[0036] The power factor correction circuit 24 includes, for example, a switching element 31, an inductor 32, and a diode 33. The switching element 31 has electrodes 31a to 31c. One end of the inductor 32 is electrically connected to the high potential output terminal 20c. The other end of the inductor 32 is electrically connected to the electrode 31a. The electrode 31b is electrically connected to the low potential output terminal 20d. The anode of the diode 33 is electrically connected to the electrode 31a. The cathode of the diode 33 is electrically connected to one end of the smoothing capacitor 26. The other end of the smoothing capacitor 26 is electrically connected to the low potential output terminal 20d.

[0037] That is, in this example, the power factor correction circuit 24 is a boost chopper circuit. The power factor correction circuit 24 converts, for example, an AC voltage of 100 V to 242 V (effective value) of the power supply PS into a DC voltage of 420 V. The power factor correction circuit 24 is not limited to this and may be any circuit that can improve the power factor of the input power.

[0038] The electrode 31c is electrically connected to the control unit 16. The electrode 31c is a so-called control electrode. The switching element 31 performs switching in response to a signal from the control unit 16. The power factor correction circuit 24 improves the power factor, for example, by switching the switching element 31 and making the input current closer to a fractional waveform of a sine wave.

[0039] The switching element 31 is, for example, an n-channel FET. For example, the electrode 31a is a drain, the electrode 31b is a source, and the electrode 31c is a gate. The switching element 31 may be, for example, a p-channel FET or a bipolar transistor.

[0040] The smoothing capacitor 26 smoothes the output voltage after the power factor correction, thereby converting the power factor corrected electric power into DC power. The smoothing capacitor 26 supplies the DC power to the converter 28.

[0041] Converter 28 has a first input terminal 28a, a second input terminal 28b, a first output terminal 28c, and a second output terminal 28d. First input terminal 28a is electrically connected to one end on the high potential side of smoothing capacitor 26. Second input terminal 28b is electrically connected to low potential output terminal 20d. Thus, DC power is supplied from smoothing capacitor 26 to converter 28.

[0042] The converter 28 has, for example, a switching element 35, a diode 36, an inductor 37, and an output capacitor 38. The switching element 35 has electrodes 35a to 35c. The electrode 35a is electrically connected to the first input terminal 12a. The electrode 35b is electrically connected to the cathode of the diode 36. The anode of the diode 36 is electrically connected to the low potential output terminal 20d. One end of the inductor 37 is electrically connected to the electrode 35b. The other end of the inductor 37 is electrically connected to the first output terminal 28c. The second output terminal 28d is electrically connected to the low potential output terminal 20d (second input terminal 28b).

[0043] The output capacitor 38 has a first electrode 38a and a second electrode 38b. The first electrode 38a is electrically connected to the first output terminal 28c. The second electrode 38b is electrically connected to the second output terminal 28d. The output capacitor 38 is connected in parallel between the first output terminal 28c and the second output terminal 28d. The output capacitor 38 smoothes the current flowing between the electrodes 35a, 35b of the switching element 35 by switching the switching element 35. As a result, DC power is output from the first output terminal 28c and the second output terminal 28d.

[0044] In this example, the converter 28 is a step-down chopper circuit. The converter 28 converts DC power into another DC power by stepping down the voltage of the input power. The converter 28 converts, for example, a 420V DC voltage of the power factor correction circuit 24 into a DC voltage of 50V to 300V. The converter 28 is, for example, a constant current circuit. The converter 28 supplies, for example, a substantially constant DC current to the light source module 100 (light source 102).

[0045] The first output terminal 28c is a high-potential output terminal, and the second output terminal 28d is a low-potential output terminal. The potential of the first output terminal 28c is higher than the potential of the second output terminal 28d. The potential of the first electrode 38a is set higher than the potential of the second electrode 38b. The first electrode 38a is, for example, an anode, and the second electrode 38b is, for example, a cathode. Conversely, the potential of the second output terminal 28d may be higher than the potential of the first output terminal 28c.

[0046] The switching element 35 is, for example, an n-channel FET. For example, the electrode 35a is a drain, the electrode 35b is a source, and the electrode 35c is a gate. The switching element 35 may be, for example, a p-channel FET or a bipolar transistor.

[0047] The configuration of the converter 28 is not limited to the above circuit, and the converter 28 may have any configuration that can convert DC power into another DC power.

[0048] The control unit 16 is electrically connected to the electrode 31c of the switching element 31. The electrode 31c is a so-called control electrode. The control unit 16 controls the switching of the switching element 31. That is, the control unit 16 switches the switching element 31 on and off. The control unit 16 switches the switching element 31 on and off by a voltage (control signal) input to the electrode 31c. The control unit 16 controls the improvement of the power factor of the input power by the power factor improvement circuit 24, for example, by switching the switching element 31.

[0049] The control unit 16 is electrically connected to the electrode 35c of the switching element 35. The electrode 35c is a so-called control electrode. The control unit 16 controls the switching of the switching element 35. That is, the control unit 16 switches the switching element 35 on and off. The control unit 16 switches the switching element 35 on and off by a voltage (control signal) input to the electrode 35c. The control unit 16 generates a DC voltage between the electrodes 38a, 38b of the output capacitor 38, for example, by switching the switching element 35. This causes DC power to be supplied from the converter 28 to the light source module 100.

[0050] The control unit 16 stops the supply of DC power from the converter 28 to the light source module 100, for example, by turning off the switching element 35. In addition, the control unit 16 changes the voltage value and current value of the DC power supplied to the light source module 100, for example, by changing the on / off cycle (duty ratio) of the switching element 35.

[0051] Here, the off state of the switching element 31 refers to, for example, a state in which substantially no current flows between the electrodes 31a and 31b, which are the main electrodes. In the off state, for example, a weak current may flow between the electrodes 31a and 31b, so as not to affect the operation of the power factor correction circuit 24. In other words, the on state of the switching element 31 refers to a first state in which a current flows between the electrodes 31a and 31b, and the off state refers to a second state in which the current flowing between the electrodes 31a and 31b is smaller than that in the first state. The on and off states of the switching element 35 are similar to those of the switching element 31.

[0052] The configuration of the power conversion unit 14 is not limited to the above, and may be any configuration that can convert input power into power compatible with the light source module 100 and supply the converted power to the light source module 100 connected to the connection unit 12.

[0053] The power conversion unit 14 further includes a current detection resistor 40 and a voltage detection unit 42. The current detection resistor 40 is connected in series to the light source module 100. The current detection resistor 40 is electrically connected, for example, between the second input terminal 28b and the second electrode 38b of the output capacitor 38. In other words, the current detection resistor 40 is electrically connected between the anode of the diode 36 and the second electrode 38b of the output capacitor 38. The second output terminal 28d is electrically connected to the low-potential output terminal 20d via the current detection resistor 40.

[0054] The current detection resistor 40 detects the current (load current) flowing through the light source module 100. The current detection resistor 40 is connected to the control unit 16. The current detection resistor 40 inputs the detection result of the current flowing through the light source module 100 to the control unit 16. As a result, the control unit 16 detects the current flowing through the light source module 100 based on the detection result of the current detection resistor 40.

[0055] The voltage detection unit 42 is provided between the connection unit 12 and the converter 28. The voltage detection unit 42 detects the output voltage of the power conversion unit 14 (the voltage between the first terminal 12a and the second terminal 12b). In other words, the voltage detection unit 42 detects the voltage (load voltage value) applied to the light source module 100. The voltage detection unit 42 is connected to the control unit 16. The voltage detection unit 42 inputs the detection result of the output voltage of the power conversion unit 14 to the control unit 16.

[0056] Furthermore, the voltage detection unit 42 can detect the connection of the light source module 100 based on a change in voltage caused by the presence or absence of connection of the light source module 100. In other words, the voltage detection unit 42 can detect the connection of the light source module 100 based on a change in voltage caused by the connection and disconnection of the attachment detection resistor 104 between the first terminal 12a and the second terminal 12b.

[0057] When the voltage detection unit 42 detects the connection of the light source module 100, the control unit 16 controls the operation of the power conversion unit 14 based on the dimming signal, thereby lighting up the light source module 100 at a brightness according to the dimming level represented by the dimming signal.

[0058] When the voltage detection unit 42 does not detect the connection of the light source module 100, the control unit 16 stops the supply of power from the power conversion unit 14 to the light source module 100. This makes it possible to reduce unnecessary power consumption in the lighting device 2. Furthermore, for example, it is possible to prevent a state in which a large voltage is continuously applied to the connection unit 12, thereby further improving the safety of the lighting device 2.

[0059] The control unit 16 includes a reference value setting unit 50 , a comparator 51 , a calculator 52 , and a drive unit 53 .

[0060] The control unit 16 inputs a dimming signal input from an external device, etc. to the reference value setting unit 50, and also inputs the detection result of the output voltage of the power conversion unit 14 input from the voltage detection unit 42 to the reference value setting unit 50.

[0061] The reference value setting unit 50 has information on the resistance value of the attachment detection resistor 104. The reference value setting unit 50 estimates the current flowing through the attachment detection resistor 104 based on the output voltage of the power conversion unit 14 detected by the voltage detection unit 42 and the resistance value of the attachment detection resistor 104. More specifically, the reference value setting unit 50 estimates the current flowing through the attachment detection resistor 104 by I=V / R, where V is the output voltage of the power conversion unit 14, R is the resistance value of the attachment detection resistor 104, and I is the current flowing through the attachment detection resistor 104.

[0062] The reference value setting unit 50 also sets a reference value for the current supplied to the light source module 100 based on the input dimming signal and an estimated value of the current flowing through the attachment detection resistor 104. In setting the reference value, the reference value setting unit 50 first sets a reference value corresponding to the dimming level indicated by the input dimming signal. The reference value setting unit 50 has a reference value corresponding to 100% dimming level, for example. The reference value setting unit 50 sets the reference value corresponding to the dimming level by multiplying the reference value for 100% dimming level by a coefficient corresponding to the dimming level. For example, if the dimming signal sets 70% dimming level, the reference value setting unit 50 multiplies the reference value for 100% dimming level by 0.7 to set the reference value corresponding to 70% dimming level. As a result, the light emitted from the light source 102 is dimmed at a dimming level according to the dimming signal. The brightness of the light emitted from the light source 102 is controlled according to the dimming signal. In this way, the control unit 16 changes the load current value of the DC power supplied from the power conversion unit 14 to the light source module 100 in accordance with the dimming signal input from the outside.

[0063] After setting a reference value corresponding to the dimming level, the reference value setting unit 50 corrects the reference value corresponding to the dimming level based on an estimated value of the current flowing through the attachment detection resistor 104. The reference value setting unit 50 determines a correction value for the reference value according to the estimated value of the current flowing through the attachment detection resistor 104.

[0064] The reference value setting unit 50 has table data 60 that represents the correspondence between, for example, an estimated value of the current flowing through the attachment detection resistor 104 and a correction value of the reference value corresponding to the dimming level. The reference value setting unit 50 determines a correction value corresponding to the estimated value of the current flowing through the attachment detection resistor 104 by referring to the table data 60 based on the input estimated value of the current flowing through the attachment detection resistor 104. However, the method for determining the correction value is not limited to the above. The reference value setting unit 50 may have, for example, a relational expression that represents the correspondence between the estimated value and the correction value, and determine the correction value based on the relational expression. The method for determining the correction value may be any method that can appropriately determine the correction value.

[0065] When the lighting device 10 is used in common with a plurality of models of light source modules 100, the magnitude of the output voltage of the power conversion unit 14 required to supply a predetermined amount of current to the light source 102 differs depending on the light source module 100 (light source 102). As described above, the magnitude of the current flowing through the attachment detection resistor 104 varies depending on the magnitude of the output voltage of the power conversion unit 14. Therefore, by determining a correction value according to an estimated value of the current flowing through the attachment detection resistor 104, it is possible to determine an appropriate correction value according to the characteristics of the light source module 100 (light source 102). In other words, it is possible to appropriately correct the reference value of the current supplied to the light source module 100 according to the characteristics of the light source module 100 (light source 102).

[0066] The proportion of the current flowing through the attachment detection resistor 104 increases as the output voltage of the power conversion unit 14 increases. In other words, it is considered that the larger the estimated value of the current flowing through the attachment detection resistor 104, the larger the proportion of the current flowing through the attachment detection resistor 104, and the magnitude of the current supplied to the light source 102 is smaller than the desired value.

[0067] Therefore, the reference value setting unit 50 (table data 60) determines the correction value so that the reference value increases as the estimated value of the current flowing through the attachment detection resistor 104 increases. As a result, even when the lighting device 10 is commonly used with multiple models of light source modules 100, it is possible to supply to the light source module 100 a current of a magnitude that takes into account the current flowing through the attachment detection resistor 104 according to the characteristics of the light source module 100. For example, it is possible to prevent a large proportion of the current flowing to the attachment detection resistor 104 side from causing the brightness of the light emitted from the light source 102 to be lower than desired. For example, it is possible to prevent a large proportion of the current flowing to the attachment detection resistor 104 side from causing the light source 102 to be unintentionally turned off when a low dimming level, such as 1%, is set.

[0068] The reference value setting unit 50 corrects the reference value by multiplying the reference value corresponding to the dimming level by the determined correction value. The reference value setting unit 50 sets the corrected reference value as the final reference value and inputs the corrected reference value to the comparator 51.

[0069] The control unit 16 inputs the detection value of the current flowing through the light source module 100, which is detected by the current detection resistor 40, to the comparator 51. The comparator 51 calculates the difference between the input corrected reference value and the detection value of the current flowing through the light source module 100, and inputs the calculated difference to the calculator 52.

[0070] Based on the input difference, the calculator 52 generates a control signal for controlling the switching of the switching element 35 so as to supply a current of a magnitude corresponding to the corrected reference value to the light source module 100, and inputs the generated control signal to the driver 53.

[0071] The driver 53 generates a drive signal according to the control signal and inputs the generated drive signal to the electrode 35c of the switching element 35. The driver 53 also generates a drive signal for switching the switching element 31, for example, and inputs the generated drive signal to the electrode 31c of the switching element 31, thereby operating the power factor correction circuit 24.

[0072] In this way, the control unit 16 feedback-controls the operation of the power conversion unit 14 based on the detection value of the current detected by the current detection resistor 40. In this way, the control unit 16 controls the operation of the power conversion unit 14 so that the magnitude of the current flowing through the light source module 100 is substantially constant according to the corrected reference value.

[0073] The configuration of the control unit 16 is not limited to the above, and may be any configuration that can control the operation of the power conversion unit 14 so that the magnitude of the current flowing through the light source module 100 corresponds to the corrected reference value. For example, a drive unit that drives the switching element 31 (power factor correction circuit 24) may be provided separately from the drive unit 53 that drives the switching element 35 (converter 28). The control unit 16 may further include, for example, a drive unit that drives the switching element 31 (power factor correction circuit 24).

[0074] As described above, in the lighting fixture 2 and lighting device 10 according to this embodiment, the control unit 16 corrects the reference value corresponding to the dimming level based on an estimated value of the current flowing through the attachment detection resistor 104. As a result, the lighting fixture 2 and lighting device 10 according to this embodiment can supply a current to the light source module 100 that takes into account the current flowing through the attachment detection resistor 104. For example, even when the lighting device 10 is used in common with multiple models of light source modules 100, it is possible to prevent models from being unintentionally turned off when a low dimming level, such as 1%, is set.

[0075] Furthermore, in the lighting fixture 2 and lighting device 10 according to this embodiment, the resistance value of the current detection resistor 40 is increased, and the magnitude of the detected current is prevented from increasing, while preventing the light source module 100 from being unintentionally turned off when a low dimming level is set. In the lighting fixture 2 and lighting device 10 according to this embodiment, the resistance value of the current detection resistor 40 can be set lower than when the reference value is not corrected. Therefore, it is possible to prevent a deterioration in circuit efficiency due to an increase in loss in the current detection resistor 40 when a high dimming level is set.

[0076] In this way, in the lighting fixture 2 and lighting device 10 of this embodiment, even when the attachment detection resistor 104 is provided in parallel with the light source 102, it is possible to suppress the extinguishing of the light source 102 at low dimming levels while also suppressing losses at high dimming levels.

[0077] FIG. 2 is a block diagram schematically illustrating a modified example of the lighting fixture according to the embodiment. 2, in lighting fixture 2a and lighting device 10a, reference value setting unit 50a of control unit 16a corrects the reference value corresponding to the dimming level based on an estimated value of the current flowing through attachment detection resistor 104 and the characteristics of light source 102. Note that components that are substantially the same in function and configuration as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0078] The reference value setting unit 50a has table data 60a representing the correspondence between, for example, an estimated value of the current flowing through the attachment detection resistor 104, characteristic information representing the characteristics of the light source 102, and a correction value of the reference value corresponding to the dimming level. For example, if the light source 102 is a light-emitting element such as an LED, the characteristic information represents the forward voltage VF of the light source 102. For example, if multiple light sources 102 are connected in series, the forward voltage VF is the sum of the forward voltages VF of the multiple light sources 102. In other words, the forward voltage VF is the voltage at which current begins to flow through the multiple light sources 102.

[0079] The reference value setting unit 50a measures the forward voltage VF of the light source 102, for example, based on the current detection value detected by the current detection resistor 40 and the output voltage of the power conversion unit 14 detected by the voltage detection unit 42.

[0080] The reference value setting unit 50a determines a correction value according to the estimated value of the current flowing through the attachment detection resistor 104 and the characteristics (forward voltage VF) of the light source 102 by referring to the table data 60a based on the input estimated value of the current flowing through the attachment detection resistor 104 and the measured forward voltage VF. However, as mentioned above, the method for determining the correction value is not limited to the above. The method for determining the correction value may be any method that can appropriately determine the correction value.

[0081] It is believed that the larger the forward voltage VF, the smaller the current that flows through the light source 102 when a predetermined voltage is applied. In other words, it is believed that the proportion of the current that flows through the attachment detection resistor 104 increases as the forward voltage VF increases.

[0082] Therefore, the reference value setting unit 50a (table data 60a) determines a correction value such that the reference value increases as the estimated value of the current flowing through the attachment detection resistor 104 increases, and also determines a correction value such that the reference value increases as the forward voltage VF increases. This allows the light source module 100 to more appropriately supply a current of a magnitude that takes into account the characteristics of the light source 102 and the current flowing through the attachment detection resistor 104. For example, when a low dimming level, such as 1%, is set, the proportion of current flowing through the attachment detection resistor 104 increases, and unintentional extinguishing of the light source 102 can be more appropriately prevented. For example, the resistance value of the current detection resistor 40 can be set lower, and loss in the current detection resistor 40 can be more appropriately reduced even when a high dimming level is set.

[0083] The characteristics of the light source 102 are not limited to the forward voltage VF. The characteristics of the light source 102 may include, for example, the characteristics of the current-voltage curve of the light source 102. The reference value setting unit 50a may identify the type of light source 102 based on, for example, the forward voltage VF, and correct the reference value (determine the correction value) based on the current-voltage curve corresponding to the identified type. The characteristics of the light source 102 are not limited to the above and may be any characteristic necessary for correcting the reference value.

[0084] FIG. 3 is a block diagram schematically illustrating a modified example of the lighting fixture according to the embodiment. As shown in FIG. 3, in lighting fixture 2b and lighting device 10b, reference value setting unit 50b of control unit 16b corrects the reference value corresponding to the dimming level based on the estimated value of the current flowing through attachment detection resistor 104 and the dimming level indicated by the dimming signal.

[0085] The reference value setting unit 50b has, for example, table data 60b that indicates the correspondence between the estimated value of the current flowing through the attachment detection resistor 104, the dimming level, and the correction value of the reference value corresponding to the dimming level.

[0086] The reference value setting unit 50b determines a correction value corresponding to the estimated value of the current flowing through the attachment detection resistor 104 and the dimming level indicated by the input dimming signal by referring to the table data 60b. However, as mentioned above, the method for determining the correction value is not limited to the above. The method for determining the correction value may be any method that can appropriately determine the correction value.

[0087] The greater the dimming level, the higher the voltage supplied to the light source module 100, and the greater the proportion of current flowing through the attachment detection resistor 104. In other words, the proportion of current flowing through the attachment detection resistor 104 increases as the dimming level increases.

[0088] Therefore, the reference value setting unit 50b (table data 60b) determines a correction value such that the reference value increases as the estimated value of the current flowing through the attachment detection resistor 104 increases, and also determines a correction value such that the reference value increases as the dimming level increases. This allows the light source module 100 to more appropriately supply a current of a magnitude that takes into account the dimming level and the current flowing through the attachment detection resistor 104. For example, when a low dimming level, such as 1%, is set, the proportion of current flowing through the attachment detection resistor 104 increases, and unintentional extinguishing of the light source 102 can be more appropriately prevented. For example, the resistance value of the current detection resistor 40 can be set lower, and loss in the current detection resistor 40 can be more appropriately reduced even when a high dimming level is set.

[0089] In addition, in combination with the above embodiment, the reference value setting unit 50b may correct the reference value corresponding to the dimming level based on the estimated value of the current flowing through the attachment detection resistor 104, the dimming level represented by the dimming signal, and the characteristics of the light source 102.

[0090] FIG. 4 is a block diagram schematically illustrating a modified example of the lighting fixture according to the embodiment. 4, in lighting fixture 2c, light source module 100c further includes resistive element 108. Resistive element 108 is connected in series with light source 102 and mounting detection resistor 104. Resistive element 108 is provided between terminal 106b and a connection point on the low potential side between light source 102 and mounting detection resistor 104.

[0091] In the light source module 100c, the receptacle 106 further includes a terminal 106c. The terminal 106c is connected between the resistor element 108 and the connection point on the low potential side between the light source 102 and the attachment detection resistor 104.

[0092] In lighting device 10c of lighting fixture 2c, connecting portion 12 further includes third terminal 12c. Third terminal 12c is connected to terminal 106c of receptacle 106 of connected light source module 100c. Thus, in this example, connecting portion 12 and receptacle 106 form a three-terminal connector.

[0093] Furthermore, in the lighting device 10c, the control unit 16c is connected to the third terminal 12c. As a result, in this example, the control unit 16c is connected to the current detection resistor 40 via the resistive element 108. In this example, the current flowing through the light source module 100c is detected by the current detection resistor 40 and the resistive element 108. The control unit 16c detects the current flowing through the light source module 100c based on the detection results of the current detection resistor 40 and the resistive element 108. In other words, the control unit 16c detects the current flowing through the light source module 100c from the voltage drop across the total resistance value of the current detection resistor 40 and the resistive element 108.

[0094] Therefore, in lighting fixture 2c, the magnitude of the current flowing through light source module 100c can be changed by changing the resistance value of resistor element 108. In lighting fixture 2c, the value of the current flowing through light source 102 can be changed by connecting light source module 100c with a different resistance value of resistor element 108 to lighting device 10c. In lighting fixture 2c, the full-light setting current can be changed by changing the resistance value of resistor element 108. The full-light setting current represents the magnitude of the current supplied to light source module 100c when dimming is set to 100%. In lighting fixture 2c, the value of the current flowing through light source 102 can be changed by changing light source module 100c, making it easier to change the brightness and color temperature of light source 102, for example. For example, the degree of freedom in the configuration of lighting fixture 2c can be increased.

[0095] The control unit 16c sets a reference value corresponding to 100% dimming, for example, in correspondence with the lowest resistance state of the resistance element 108 (for example, a state where the resistance value is 0). In this way, by increasing the resistance value of the resistance element 108, the magnitude of the current detected by the current detection resistor 40 and the resistance element 108 increases, and it becomes possible for the control unit 16c to recognize a smaller current value as 100% dimming. As a result, it becomes possible to change the full-light setting current by changing the resistance value of the resistance element 108. It is possible to reduce the full-light setting current by increasing the resistance value of the resistance element 108.

[0096] In this way, the control unit 16c can change the full-light setting current in accordance with the characteristics of the light source module 100c connected to the connection unit 12. In this example, the characteristic of the light source module 100c is the resistance value of the resistive element 108. However, the characteristic of the light source module 100c is not limited to this, and may be any characteristic that allows the full-light setting current to be appropriately changed.

[0097] In lighting device 10c, reference value setting unit 50c of control unit 16c corrects the reference value corresponding to the dimming level based on the estimated value of the current flowing through attachment detection resistor 104 and the full-light set current.

[0098] The reference value setting unit 50c has table data 60c that indicates the correspondence between, for example, an estimated value of the current flowing through the attachment detection resistor 104, a set current at full light, and a correction value of the reference value corresponding to the dimming level.

[0099] The reference value setting unit 50c determines a correction value corresponding to the estimated value of the current flowing through the attachment detection resistor 104 and the full-light setting current based on the input estimated value of the current flowing through the attachment detection resistor 104 and the full-light setting current detected by the current detection resistor 40 and the resistive element 108, by referring to the table data 60c. However, as mentioned above, the method for determining the correction value is not limited to the above. Any method that can appropriately determine the correction value may be used. Note that the control unit 16c may, for example, detect the full-light setting current based on the detection result of the current detection resistor 40, regardless of the presence or absence of the resistive element 108.

[0100] The larger the full-light setting current, the higher the voltage supplied to the light source module 100c, and the larger the proportion of the current flowing to the attachment detection resistor 104. In other words, the proportion of the current flowing to the attachment detection resistor 104 increases as the full-light setting current increases.

[0101] Therefore, the reference value setting unit 50c (table data 60c) determines a correction value such that the reference value increases as the estimated value of the current flowing through the attachment detection resistor 104 increases, and also determines a correction value such that the reference value increases as the full-light setting current increases. This allows the light source module 100c to more appropriately supply a current of a magnitude that takes into account the full-light setting current and the current flowing through the attachment detection resistor 104. For example, when a low dimming level, such as 1%, is set, a large proportion of the current flows through the attachment detection resistor 104, which can more appropriately prevent the light source 102 from unintentionally turning off. For example, the resistance values ​​of the current detection resistor 40 and the resistive element 108 can be set lower, and losses in the current detection resistor 40 and the resistive element 108 can be more appropriately reduced even when a high dimming level is set.

[0102] In addition, in combination with the above embodiment, the reference value setting unit 50c may correct the reference value corresponding to the dimming level based on the estimated value of the current flowing through the attachment detection resistor 104, the dimming level represented by the dimming signal, the characteristics of the light source 102, and the set current at full light.

[0103] The present embodiment includes the following aspects. (Appendix 1) a connection portion connected to a light source module having a light source and an attachment detection resistor connected in parallel to the light source; a power conversion unit that converts input power into power compatible with the light source module and supplies the converted power to the light source module connected to the connection unit; a control unit that receives a dimming signal and controls the operation of the power conversion unit in accordance with the dimming signal to light the light source module at a brightness corresponding to a dimming level indicated by the dimming signal; Equipped with The power conversion unit a current detection resistor connected in series to the light source module, the current detection resistor detecting a current flowing through the light source module; a voltage detection unit that detects an output voltage of the power conversion unit; and The control unit having information on the resistance value of the attachment detection resistor, and estimating a current flowing through the attachment detection resistor based on the output voltage of the power conversion unit detected by the voltage detection unit and the resistance value of the attachment detection resistor; setting a reference value corresponding to the dimming level indicated by the input dimming signal; correcting the reference value corresponding to the dimming level based on an estimated value of the current flowing through the resistor for attachment detection; The operation of the power conversion unit is controlled so that the magnitude of the current flowing through the light source module corresponds to the corrected reference value. Lighting device.

[0104] (Appendix 2) 2. The lighting device according to claim 1, wherein the control unit corrects the reference value corresponding to the dimming level based on the estimated value and characteristics of the light source.

[0105] (Appendix 3) 3. The lighting device according to claim 1, wherein the control unit corrects the reference value corresponding to the dimming level based on the estimated value and the dimming level indicated by the dimming signal.

[0106] (Appendix 4) The lighting device of any one of appendices 1 to 3, wherein the control unit is capable of changing a full-light setting current that indicates the magnitude of the current supplied to the light source module when the dimming level is set to 100% in accordance with the characteristics of the light source module connected to the connection unit, and corrects the reference value corresponding to the dimming level based on the estimated value and the full-light setting current.

[0107] (Appendix 5) a light source module having a light source and an attachment detection resistor connected in parallel with the light source; A lighting device according to any one of appendices 1 to 4; A lighting fixture equipped with

[0108] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0109] 2, 2a to 2c... Lighting fixture, 10, 10a to 10c... Lighting device, 12... Connection section, 14... Power conversion section, 16, 16a to 16c... Control section, 20... Rectifier circuit, 22... High frequency removal capacitor, 24... Power factor correction circuit, 26... Smoothing capacitor, 28... Converter, 31... Switching element, 32... Inductor, 33... Diode, 35... Switching element, 36... Diode, 37... Inductor, 38... Output capacitor, 40... Current detection resistor, 42... Voltage detection section, 50, 50a to 50c... Reference value setting section, 51... Comparator, 52... Calculator, 53... Drive section, 60, 60a to 60c... Table data, 100, 100c... Light source module, 102... Light source, 104... Mounting detection resistor, 106...Connected part, 108...Resistance element, PS...Power supply

Claims

1. a connection portion connected to a light source module having a light source and an attachment detection resistor connected in parallel to the light source; a power conversion unit that converts input power into power compatible with the light source module and supplies the converted power to the light source module connected to the connection unit; a control unit that receives a dimming signal and controls the operation of the power conversion unit in accordance with the dimming signal to light the light source module at a brightness corresponding to a dimming level indicated by the dimming signal; Equipped with The power conversion unit a current detection resistor connected in series to the light source module, the current detection resistor detecting a current flowing through the light source module; a voltage detection unit that detects an output voltage of the power conversion unit; and The control unit having information on the resistance value of the attachment detection resistor, and estimating a current flowing through the attachment detection resistor based on the output voltage of the power conversion unit detected by the voltage detection unit and the resistance value of the attachment detection resistor; setting a reference value corresponding to the dimming level indicated by the input dimming signal; correcting the reference value corresponding to the dimming level based on an estimated value of the current flowing through the resistor for attachment detection; The operation of the power conversion unit is controlled so that the magnitude of the current flowing through the light source module corresponds to the corrected reference value. Lighting device.

2. The lighting device according to claim 1 , wherein the control unit corrects the reference value corresponding to the dimming level based on the estimated value and characteristics of the light source.

3. The lighting device according to claim 1 , wherein the control unit corrects the reference value corresponding to the degree of dimming based on the estimated value and the degree of dimming indicated by the dimming signal.

4. The lighting device of claim 1, wherein the control unit is capable of changing a full-light setting current, which represents the magnitude of the current supplied to the light source module when the dimming level is set to 100%, in accordance with the characteristics of the light source module connected to the connection unit, and corrects the reference value corresponding to the dimming level based on the estimated value and the full-light setting current.

5. a light source module having a light source and an attachment detection resistor connected in parallel with the light source; A lighting device according to any one of claims 1 to 4; A lighting fixture equipped with

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