JP2008028043A - Light emitting diode driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control a whole current amount, to simplify control of the amount of currents conducted to a light emitting diode, and to eliminate troublesome current amount adjustment. <P>SOLUTION: A plurality of unit driving circuits are formed by connecting in series first current mirror circuits 13, 14 and 15 to the respective light emitting didoes of light emitting diode modules 11 and 12 obtained by forming the red light emitting diode, the green light emitting diode and the blue light emitting diode by making an anode side a common electrode. The respective unit driving circuits are connected in parallel at every light emitting diode module, parallel circuits are connected between the light emitting diode modules in series, and a plurality of series driving circuits are formed. Second current mirror circuits are connected to the series driving circuits. The respective first current mirror circuits of the applied series driving circuit are controlled. Same current is made to flow to the unit driving circuits of the applied series driving circuit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light emitting diode driving device that controls lighting of a light emitting diode.

Conventionally, for example, a plurality of blue (B), red (R), and green (G) light emitting diodes are connected in series, and a control FET (field effect transistor) is connected in series to each series circuit. A device is known that is connected in parallel, and each FET is driven by a color tone control circuit to realize light emission of mixed colors including white by light emission of three colors (see, for example, Patent Document 1).
JP 2005-129877 A

  By the way, recently, light emitting diodes in which R, G, and B light emitting diodes are incorporated as one module are commercially available, and white light can be easily obtained by flowing the same amount of current through each light emitting diode. The light emission color can be easily changed by changing the amount of current flowing through the diode.

  Many of such light emitting diode modules have a single electrode with the anode side or the cathode side of the light emitting diode as a common electrode in order to simplify wiring. Considering that a plurality of light emitting diode modules having a common electrode on the anode side or the cathode side are connected in series and used for lighting or the like in order to suppress the total current amount, the driving described in Patent Document 1 described above is used. The method could not be controlled at all.

  The present invention can be driven by connecting a plurality of light emitting diode modules formed with the anode side or cathode side as a common electrode in series, thereby reducing the total amount of current and energizing the light emitting diode. Provided is a light emitting diode driving device that can easily control the amount of current to be performed and does not require troublesome current amount adjustment.

  In one embodiment of the present invention, a plurality of light emitting diode circuits each formed by using a single light emitting diode or a series circuit of a plurality of light emitting diodes as a common electrode on the anode side or the cathode side, and A plurality of unit driving circuits are formed by connecting a first current mirror circuit in series to each light emitting diode circuit of the light emitting diode module, and the unit driving circuits are connected in parallel to each other for each light emitting diode module. A plurality of series drive circuits formed by connecting the circuits in series between the light emitting diode modules, and connected to each of the series drive circuits, and controlling each first current mirror circuit of the corresponding series drive circuit. Light emitting diode having a second current mirror circuit for supplying the same current to each unit drive circuit of the series drive circuit In the Eau drive.

  According to the present invention, a plurality of light emitting diode modules formed with the anode side or the cathode side as a common electrode can be connected in series and driven, whereby the total amount of current can be suppressed, and the light emitting diode can be suppressed. Thus, it is possible to provide a light emitting diode driving device that can easily control the amount of current supplied to the light source and does not require troublesome adjustment of the amount of current.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
In FIG. 1, reference numeral 11 denotes a first light emitting diode module in which each one of a red light emitting diode 11R, a green light emitting diode 11G, and a blue light emitting diode 11B is a light emitting diode circuit, and its anode side is connected to a common electrode 11e. Is a second light emitting diode module in which each one of the red light emitting diode 12R, the green light emitting diode 12G, and the blue light emitting diode 12B is a light emitting diode circuit, and its anode side is connected to the common electrode 12e. The common electrode 11e of the first light emitting diode module 11 is connected to the + Vcc power supply terminal.

  Here, the light emitting diode module is described as a light emitting diode circuit of a red light emitting diode, a green light emitting diode, and a blue light emitting diode. However, the number of light emitting diodes is not limited to this. As a light emitting diode circuit of a diode, a green light emitting diode, and a blue light emitting diode, a plurality of light emitting diodes of the same number may be connected in series.

  The first current mirror circuit 13 is connected in series to the cathode terminal of the red light emitting diode 11R of the first light emitting diode module 11 to form a unit drive circuit, and another first first current mirror circuit 11G is connected to the cathode terminal of the green light emitting diode 11G. The unit drive circuit is formed by connecting the current mirror circuit 14 in series, and the unit drive circuit is formed by connecting another first current mirror circuit 15 in series to the cathode terminal of the blue light emitting diode 11B.

  The first current mirror circuit 13 includes a pair of PNP transistors 16 and 17 and resistors 18 and 19 connected in series to the emitters of the transistors 16 and 17, respectively. The red light emitting diode 11R is connected to the cathode terminal of the red light emitting diode 11R through the resistors 18 and 19. The bases of the transistors 16 and 17 are connected to each other, and the transistor 16 short-circuits the base and collector.

  The first current mirror circuit 14 includes a pair of PNP transistors 20 and 21 and resistors 22 and 23 connected in series to the emitters of the transistors 20 and 21, respectively. It is connected to the cathode terminal of the green light emitting diode 11G via the resistors 22 and 23. The bases of the transistors 20 and 21 are connected to each other, and the transistor 20 is short-circuited between the base and the collector.

  The first current mirror circuit 15 includes a pair of PNP transistors 24 and 25 and resistors 26 and 27 connected in series to the emitters of the transistors 24 and 25. The emitters of the transistors 24 and 25 are respectively connected to the emitters of the transistors 24 and 25. It is connected to the cathode terminal of the blue light emitting diode 11B through the resistors 26 and 27. The bases of the transistors 24 and 25 are connected to each other, and the transistor 24 short-circuits the base and the collector.

  The collectors of the transistors 17, 21 and 25 are connected to each other, whereby unit drive circuits for driving the respective light emitting diodes 11R, 11G and 11B of the first light emitting diode module 11 are connected in parallel to each other. become.

  The common electrode 11e to which the light emitting diodes 11R, 11G, and 11B of the first light emitting diode module 11 are connected is connected to the + Vcc terminal, and the connection terminal between the collectors of the transistors 17, 21, and 25 is the second terminal. The light emitting diode modules 12 are connected to a common electrode to which the light emitting diodes 12R, 12G, and 12B are connected.

  Another first current mirror circuit 28 is connected in series to the cathode terminal of the red light emitting diode 12R of the second light emitting diode module 12 to form a unit drive circuit, and another cathode is connected to the cathode terminal of the green light emitting diode 12G. One current mirror circuit 29 is connected in series to form a unit drive circuit, and another first current mirror circuit 30 is connected in series to the cathode terminal of the blue light emitting diode 12B to form a unit drive circuit. .

  The first current mirror circuit 28 includes a pair of NPN transistors 31, 32 and resistors 33, 34 connected in series to the emitters of the transistors 31, 32. The collector of the transistor 32 is connected to the red light emitting diode 12R. Connected to the cathode terminal. The bases of the transistors 31 and 32 are connected to each other, and the transistor 31 short-circuits the base and the collector.

  The first current mirror circuit 29 includes a pair of NPN transistors 35 and 36 and resistors 37 and 38 connected in series to the emitters of the transistors 35 and 36. The collector of the transistor 36 is connected to the green light emitting diode 12G. Connected to the cathode terminal. The bases of the transistors 35 and 36 are connected to each other, and the transistor 35 short-circuits the base and the collector.

  The first current mirror circuit 30 includes a pair of NPN transistors 39, 40 and resistors 41, 42 connected in series to the emitters of the transistors 39, 40. The collector of the transistor 40 is connected to the blue light emitting diode 12B. Connected to the cathode terminal. The bases of the transistors 39 and 40 are connected to each other, and the transistor 39 short-circuits the base and collector.

  The emitters of the transistors 31 and 32 are respectively connected via resistors 33 and 34, the emitters of the transistors 35 and 36 are respectively connected via resistors 37 and 38, and the emitters of the transistors 39 and 40 are respectively connected to a resistor 41. , 42 are connected to each other and grounded. As a result, the unit drive circuits that drive the light emitting diodes 12R, 12G, and 12B of the second light emitting diode module 12 are connected in parallel to each other.

  The series circuit of the red light emitting diode 11R of the first light emitting diode module 11, the first current mirror circuit 13, the red light emitting diode 12R of the second light emitting diode module 12 and the first current mirror circuit 28 is one series drive. A green light emitting diode 11G of the first light emitting diode module 11, a first current mirror circuit 14, a green light emitting diode 12G of the second light emitting diode module 12, and a first current mirror circuit 29 are formed. Forming one series driving circuit, the blue light emitting diode 11B of the first light emitting diode module 11, the first current mirror circuit 15, the blue light emitting diode 12B of the second light emitting diode module 12 and the first current mirror. The series circuit of the circuit 30 is also one series. To form a dynamic circuit.

  The transistor 16 constituting the first current mirror circuit 13 has its collector connected to the collector of an NPN transistor 44 constituting the second current mirror circuit 43, and the transistor constituting the first current mirror circuit 14. 20 has its collector connected to the collector of an NPN transistor 46 constituting the second current mirror circuit 45, and the transistor 24 constituting the first current mirror circuit 15 has its collector connected to the second current mirror circuit. 47 is connected to the collector of an NPN transistor 48 that constitutes 47.

  The transistor 44 has a base connected to the base of the transistor 31 and an emitter grounded through a resistor 49 in series. The transistor 46 has a base connected to the base of the transistor 35, and an emitter grounded through a resistor 50 in series. The transistor 48 has a base connected to the base of the transistor 39 and an emitter grounded through a resistor 51 in series.

  Then, the control signal SR of the red light emitting diode is input from the terminal T1 to the base of the transistor 31 through the resistor 52, and the control signal SG of the green light emitting diode is input from the terminal T2 to the base of the transistor 35 through the resistor 53. The blue light emitting diode control signal SB is input to the base of the transistor 39 from the terminal T3 via the resistor 54.

  In such a configuration, when the control signal SR of the red light emitting diode is input to the base of the transistor 31 from the terminal T1, the transistors 31 and 32 of the first current mirror circuit 28 operate and the second current mirror circuit 43 Transistor 44 operates. When the control signal SG of the green light emitting diode is input to the base of the transistor 35, the transistors 35 and 36 of the first current mirror circuit 29 are operated and the transistor 46 of the second current mirror circuit 45 is operated. When the blue light emitting diode control signal SB is input to the base of the transistor 39, the transistors 39 and 40 of the first current mirror circuit 30 operate and the transistor 48 of the second current mirror circuit 47 operates.

  In one series drive circuit, the resistance values of the resistors 18, 33, 49 are the same, the resistance values of the resistors 19, 34 are the same, and the resistance values of the resistors 19, 34 are the same as those of the resistors 18, 33, 49. It is smaller than the resistance value by a predetermined ratio. Similarly, in another series drive circuit, the resistance values of the resistors 22, 37, 50 are the same, the resistance values of the resistors 23, 38 are the same, and the resistance values of the resistors 23, 38 are the resistors 22, 37, 50. The resistance value is smaller at a predetermined ratio. Similarly, in another series drive circuit, the resistance values of the resistors 26, 41, 51 are the same, the resistance values of the resistors 27, 42 are the same, and the resistance values of the resistors 27, 42 are the resistors 26, 41, 51. The resistance value is smaller at a predetermined ratio.

  Accordingly, when the control signal SR for the red light emitting diode is input, a predetermined current flows through the collector of the transistor 31 and the same current flows through the series circuit of the resistor 18, the transistors 16, 44 and the resistor 49. A current that is a predetermined multiple of the current flowing through the collector of the transistor 16 flows through the transistor 17 through the red light emitting diode 11R and the resistor 19, and the transistor 32 through the red light emitting diode 12R and the resistor 34 flows into the collector of the transistor 44. A current that is a predetermined multiple of the flowing current flows. The transistor 32 is controlled so that the same amount of current as the red light emitting diode 11R always flows through the red light emitting diode 12R.

  Similarly, when the green light emitting diode control signal SG is input from the terminal T2, a predetermined current flows through the collector of the transistor 35, and the same current flows through the series circuit of the resistor 22, the transistors 20, 46, and the resistor 50. A current that is a predetermined multiple of the current flowing through the collector of the transistor 20 flows through the transistor 21 via the green light emitting diode 11G and the resistor 23, and the transistor 36 flows through the green light emitting diode 12G and the resistor 38 to the collector of the transistor 46. A current that is a predetermined multiple of the flowing current flows. The transistor 36 is controlled so that the same amount of current as the green light emitting diode 11G always flows through the green light emitting diode 12G.

  Similarly, when the blue light emitting diode control signal SB is input from the terminal T3, a predetermined current flows through the collector of the transistor 39, and the same current flows through the series circuit of the resistor 26, the transistors 24, 48, and the resistor 51. Then, a current that is a predetermined multiple of the current flowing through the collector of the transistor 24 flows through the transistor 25 via the blue light emitting diode 11B and the resistor 27, and the collector of the transistor 48 flows through the transistor 40 through the blue light emitting diode 12B and the resistor 42. A current that is a predetermined multiple of the flowing current flows. The transistor 40 is controlled so that the same amount of current as the blue light emitting diode 11B always flows through the blue light emitting diode 12B.

  In this way, the amount of current flowing through the red light emitting diodes 11R and 12R of the light emitting diode modules 11 and 12 is controlled by the control signal SR, and the green light emitting diodes 11G and 12G of the light emitting diode modules 11 and 12 are controlled by the control signal SG. The amount of current flowing is controlled, and the amount of current flowing through the blue light emitting diodes 11B and 12B of the light emitting diode modules 11 and 12 is controlled by the control signal SB. If the amount of current flowing through the red light emitting diodes 11R and 12R, the amount of current flowing through the green light emitting diodes 11G and 12G, and the amount of current flowing through the blue light emitting diodes 11B and 12B are equal, the light emitting color of each of the light emitting diode modules 11 and 12 is white. Become. In addition, varying the amount of current flowing through each of the light sources allows light emission with various colors.

  Since the red light emitting diodes 11R and 12R, the green light emitting diodes 11G and 12G, and the blue light emitting diodes 11B and 12B of the light emitting diode modules 11 and 12 are respectively connected in series via the first current mirror circuit, a plurality of light emitting elements are emitted. Compared with a diode module connected in parallel, the total amount of current can be suppressed. Moreover, troublesome adjustments such as matching the amounts of current between circuits such as when connected in parallel are unnecessary. In addition, the control of the amount of current flowing through each color light emitting diode can be easily controlled by one control signal SR, SG, SB, respectively.

(Second Embodiment)
In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment mentioned above, and detailed description is abbreviate | omitted.
As shown in FIG. 2, four light emitting diode modules are connected in series, and the third and second light emitting diode modules 11 and 12 in the first embodiment described above are connected between the third and second light emitting diode modules. 4 light emitting diode modules 61 and 62 are connected in series.

  That is, in the third light emitting diode module 61, each one of the red light emitting diode 61R, the green light emitting diode 61G, and the blue light emitting diode 61B is a light emitting diode circuit, and its anode side is connected to the common electrode 61e. In the fourth light emitting diode module 62, each of the red light emitting diode 62R, the green light emitting diode 62G, and the blue light emitting diode 62B is a light emitting diode circuit, and its anode side is connected to the common electrode 62e.

  The first current mirror circuit 63 is connected in series to the cathode terminal of the red light emitting diode 61R of the third light emitting diode module 61 to form a unit driving circuit, and another first first current mirror circuit 61G is connected to the cathode terminal of the green light emitting diode 61G. The unit drive circuit is formed by connecting the current mirror circuit 64 in series to form a unit drive circuit by connecting another first current mirror circuit 65 in series to the cathode terminal of the blue light emitting diode 61B.

  The first current mirror circuit 63 includes a pair of PNP transistors 66 and 67 and resistors 68 and 69 connected in series to the emitters of the transistors 66 and 67. The emitters of the transistors 66 and 67 are respectively connected to the emitters of the transistors 66 and 67. The red light emitting diode 61R is connected to the cathode terminal of the red light emitting diode 61R through the resistors 68 and 69. The bases of the transistors 66 and 67 are connected to each other, and the transistor 66 short-circuits the base and the collector.

  The first current mirror circuit 64 includes a pair of PNP transistors 70 and 71 and resistors 72 and 73 connected in series to the emitters of the transistors 70 and 71. The emitters of the transistors 70 and 71 are connected to the first current mirror circuit 64, respectively. The resistor 72, 73 is connected to the cathode terminal of the green light emitting diode 61G. The bases of the transistors 70 and 71 are connected to each other, and the transistor 70 short-circuits the base and collector.

  The first current mirror circuit 65 includes a pair of PNP transistors 74 and 75 and resistors 76 and 77 connected in series to the emitters of the transistors 74 and 75. The emitters of the transistors 74 and 75 are connected to the first current mirror circuit 65, respectively. It is connected to the cathode terminal of the blue light emitting diode 61B through the resistors 76 and 77. The bases of the transistors 74 and 75 are connected to each other, and the transistor 74 short-circuits the base and the collector.

  The collectors of the transistors 67, 71, and 75 are connected to each other, whereby unit drive circuits that drive the light emitting diodes 61R, 61G, and 61B of the third light emitting diode module 61 are connected in parallel to each other. become.

  A unit driving circuit is formed by connecting a first current mirror circuit 78 in series to the cathode terminal of the red light emitting diode 62R of the fourth light emitting diode module 62, and another first first current mirror circuit is connected to the cathode terminal of the green light emitting diode 62G. A unit drive circuit is formed by connecting current mirror circuits 79 in series, and a unit drive circuit is formed by connecting another first current mirror circuit 80 in series to the cathode terminal of the blue light emitting diode 62B.

  The first current mirror circuit 78 includes a pair of PNP transistors 81 and 82 and resistors 83 and 84 connected in series to the emitters of the transistors 81 and 82. The emitters of the transistors 81 and 82 are respectively connected to the emitters of the transistors 81 and 82. The resistor 83, 84 is connected to the cathode terminal of the red light emitting diode 62R. The bases of the transistors 81 and 82 are connected to each other, and the transistor 81 short-circuits the base and the collector.

  The first current mirror circuit 79 includes a pair of PNP transistors 85 and 86 and resistors 87 and 88 connected in series to the emitters of the transistors 85 and 86. The emitters of the transistors 85 and 86 are respectively connected to the emitters of the transistors 85 and 86. It is connected to the cathode terminal of the green light emitting diode 62G via the resistors 87 and 88. The bases of the transistors 85 and 86 are connected to each other, and the transistor 85 short-circuits the base and the collector.

  The first current mirror circuit 80 includes a pair of PNP transistors 89 and 90 and resistors 91 and 92 connected in series to the emitters of the transistors 89 and 90. The emitters of the transistors 89 and 90 are respectively connected to the first current mirror circuit 80. It is connected to the cathode terminal of the blue light emitting diode 62B through the resistors 91 and 92. The bases of the transistors 89 and 90 are connected to each other, and the transistor 89 has a shorted base and collector.

  The collectors of the transistors 82, 86, and 90 are connected to each other, whereby unit drive circuits that drive the light emitting diodes 62R, 62G, and 62B of the fourth light emitting diode module 62 are connected in parallel to each other. become.

  A common electrode 61e connected to each of the light emitting diodes 61R, 61G, 61B of the third light emitting diode module 61 is connected to each of the first current mirror circuits 13, 14 connected to the first light emitting diode module 11. , 15 are connected to the collector connection point p1 of the transistors 17, 21, 25.

  A common electrode 62e connected to each light emitting diode 62R, 62G, 62B of the fourth light emitting diode module 62 is connected to each first current mirror circuit 63, 64 connected to the third light emitting diode module 61. , 65 transistors 67, 71, 75 are connected to collector connection points p2.

  The common electrode 12e connected to each light emitting diode 12R, 12G, 12B of the second light emitting diode module 12 is connected to each first current mirror circuit 78, 79 connected to the fourth light emitting diode module 62. , 80 transistors 82, 86, 90 are connected to collector connection point p3.

  The red light emitting diode 11R and the first current mirror circuit 13 of the first light emitting diode module 11, the red light emitting diode 61R and the first current mirror circuit 63 of the third light emitting diode module 61, and the fourth light emitting diode module 62. The red light emitting diode 62R and the first current mirror circuit 78, and the red light emitting diode 12R and the first current mirror circuit 28 of the second light emitting diode module 12 form a series driving circuit.

  Further, the green light emitting diode 11G and the first current mirror circuit 14 of the first light emitting diode module 11, the green light emitting diode 61G and the first current mirror circuit 64 of the third light emitting diode module 61, and the fourth light emitting diode. The series circuit of the green light emitting diode 62G and the first current mirror circuit 79 of the module 62 and the green light emitting diode 12G and the first current mirror circuit 29 of the second light emitting diode module 12 form one series drive circuit. .

  Further, the blue light emitting diode 11B and the first current mirror circuit 15 of the first light emitting diode module 11, the blue light emitting diode 61B and the first current mirror circuit 65 of the third light emitting diode module 61, and the fourth light emitting diode. The series circuit of the blue light emitting diode 62B and the first current mirror circuit 80 of the module 62 and the blue light emitting diode 12B and the first current mirror circuit 30 of the second light emitting diode module 12 form one series driving circuit. .

  Two NPN transistors 94 and 95 that form a second current mirror circuit 93 together with the NPN transistor 44 are provided. The NPN transistor 94 has a collector connected to the collector of the transistor 16 constituting the first current mirror circuit 13, and a base connected to the cathode terminal of the red light emitting diode 61R of the third light emitting diode module 61. The emitter is connected to the bases of the transistors 66 and 67 constituting the first current mirror circuit 63 via a resistor 96 in series.

  The NPN transistor 95 has a collector connected to the collector of the transistor 66 constituting the first current mirror circuit 63, and a base connected to the cathode terminal of the red light emitting diode 62R of the fourth light emitting diode module 62. The emitter is connected to the bases of the transistors 81 and 82 constituting the first current mirror circuit 78 through a resistor 97 in series. The collector of the transistor 81 is connected to the collector of the NPN transistor 44.

  Two NPN transistors 99 and 100 that constitute the second current mirror circuit 98 together with the NPN transistor 46 are provided. The NPN transistor 99 has a collector connected to the collector of the transistor 20 constituting the first current mirror circuit 14, and a base connected to the cathode terminal of the green light emitting diode 61G of the third light emitting diode module 61. The emitter is connected to the bases of the transistors 70 and 71 constituting the first current mirror circuit 64 via a resistor 101 in series.

  The NPN transistor 100 has a collector connected to the collector of the transistor 70 constituting the first current mirror circuit 64, and a base connected to the cathode terminal of the green light emitting diode 62G of the fourth light emitting diode module 62. The emitter is connected to the bases of the transistors 85 and 86 constituting the first current mirror circuit 79 through a resistor 102 in series. The collector of the transistor 85 is connected to the collector of the NPN transistor 46.

  Two NPN transistors 104 and 105 that constitute the second current mirror circuit 103 together with the NPN transistor 48 are provided. The NPN transistor 104 has a collector connected to the collector of the transistor 24 constituting the first current mirror circuit 15, and a base connected to the cathode terminal of the blue light emitting diode 61B of the third light emitting diode module 61. The emitter is connected to the bases of the transistors 74 and 75 constituting the first current mirror circuit 65 through a resistor 106 in series.

  The NPN transistor 105 has a collector connected to the collector of the transistor 74 constituting the first current mirror circuit 65, and a base connected to the cathode terminal of the blue light emitting diode 62B of the fourth light emitting diode module 62. The emitter is connected to the bases of the transistors 89 and 90 constituting the first current mirror circuit 80 via a resistor 107 in series. The collector of the transistor 89 is connected to the collector of the NPN transistor 48.

  In such a configuration, when the control signal SR of the red light emitting diode is input to the base of the transistor 31 from the terminal T1, the transistors 31 and 32 of the first current mirror circuit 28 operate and the second current mirror circuit 43 Transistor 44 operates. When the control signal SG of the green light emitting diode is input to the base of the transistor 35, the transistors 35 and 36 of the first current mirror circuit 29 are operated and the transistor 46 of the second current mirror circuit 45 is operated. When the blue light emitting diode control signal SB is input to the base of the transistor 39, the transistors 39 and 40 of the first current mirror circuit 30 operate and the transistor 48 of the second current mirror circuit 47 operates.

  In one series drive circuit, the resistance values of the resistors 18, 68, 96, 83, 97, 33, and 49 are the same, the resistance values of the resistors 19, 69, 84, and 34 are the same, and the resistors 19, The resistance values of 69, 84, and 34 are smaller than the resistance values of resistors 18, 68, 96, 83, 97, 33, and 49 by a predetermined ratio. Similarly, in another series drive circuit, the resistance values of the resistors 22, 72, 101, 87, 102, 37, and 50 are the same, the resistance values of the resistors 23, 73, 88, and 38 are the same, and the resistance 23 , 73, 88, and 38 are smaller than the resistance values of the resistors 22, 72, 101, 87, 102, 37, and 50 by a predetermined ratio. Similarly, in another series drive circuit, the resistance values of the resistors 26, 76, 106, 91, 107, 41, 51 are the same, the resistance values of the resistors 27, 77, 92, 42 are the same, and the resistor 27 , 77, 92, 42 are smaller than the resistance values of the resistors 26, 76, 106, 91, 107, 41, 51 by a predetermined ratio.

  Therefore, when the control signal SR for the red light emitting diode is input, a predetermined current flows through the collector of the transistor 31, and the same current flows through the resistor 18, transistors 16, 94, resistor 96, transistor 95, resistor 97, transistor 44, resistor 49. Flows in a series circuit. A current that is a predetermined multiple of the current flowing through the collector of the transistor 16 flows through the transistor 17 through the red light emitting diode 11R and the resistor 19, and the transistor 67 through the red light emitting diode 61R and the resistor 69 passes through the collector of the transistor 66. A current that is a predetermined multiple of the flowing current flows, a current that is a predetermined multiple of the current that flows to the collector of the transistor 81 flows through the transistor 82 via the red light emitting diode 62R and the resistor 84, and a transistor that flows through the red light emitting diode 12R and the resistor 34. A current of a predetermined multiple of the current flowing through the collector of the transistor 44 flows through 32. The transistors 17, 67, 82, and 32 are controlled so that the same amount of current always flows through the red light emitting diodes 11R, 61R, 62R, and 12R.

  Similarly, when the green light emitting diode control signal SG is input from the terminal T2, a predetermined current flows through the collector of the transistor 35, and the same current flows through the resistor 22, the transistors 20, 99, the resistor 101, the transistor 100, the resistor 102, and the transistor. 46 and the resistor 50 flow in a series circuit. A current that is a predetermined multiple of the current flowing through the collector of the transistor 20 flows through the transistor 21 through the green light emitting diode 11G and the resistor 23, and the transistor 71 through the green light emitting diode 61G and the resistor 73 flows into the collector of the transistor 70. A current that is a predetermined multiple of the flowing current flows, a current that is a predetermined multiple of the current that flows to the collector of the transistor 85 flows through the green light emitting diode 62G and the resistor 88, and a transistor that flows through the green light emitting diode 12G and the resistor 38. A current of a predetermined multiple of the current flowing through the collector of the transistor 46 flows through 36. The transistors 21, 71, 86, and 36 are controlled so that the same amount of current always flows through the green light emitting diodes 11G, 61G, 62G, and 12G.

  Similarly, when the control signal SB of the blue light emitting diode is input from the terminal T3, a predetermined current flows through the collector of the transistor 39, and the same current flows through the resistor 26, the transistors 24 and 104, the resistor 106, the transistor 105, the resistor 107, and the transistor. 48 and the resistor 51 flow in a series circuit. A current that is a predetermined multiple of the current flowing through the collector of the transistor 24 flows through the transistor 25 via the blue light emitting diode 11B and the resistor 27, and the collector of the transistor 74 passes through the blue light emitting diode 61B and the resistor 77 to the collector of the transistor 74. A current that is a predetermined multiple of the flowing current flows, and a current that is a predetermined multiple of the current that flows to the collector of the transistor 89 flows through the transistor 90 through the blue light emitting diode 62B and the resistor 92, and the transistor through the blue light emitting diode 12B and the resistor 42. A current that is a predetermined multiple of the current flowing through the collector of the transistor 48 flows through 40. The transistors 25, 75, 90, and 40 are controlled so that the same amount of current always flows through the blue light emitting diodes 11B, 61B, 62B, and 12B.

  In this way, the amount of current flowing through the red light emitting diodes 11R, 61R, 62R, and 12R of each light emitting diode module 11, 61, 62, and 12 is controlled by the control signal SR, and each light emitting diode module 11, 61 is controlled by the control signal SG. , 62, and 12 control the amount of current flowing through the green light emitting diodes 11G, 61G, 62G, and 12G. The control signal SB causes the blue light emitting diodes 11B, 61B, 62B, and 12B of the light emitting diode modules 11, 61, 62, and 12 to The amount of current flowing is controlled. If the amount of current flowing through the red light emitting diodes 11R, 61R, 62R, and 12R, the amount of current flowing through the green light emitting diodes 11G, 61G, 62G, and 12G and the amount of current flowing through the blue light emitting diodes 11B, 61B, 62B, and 12B are equal, The light emitting color of the light emitting diode modules 11, 61, 62 and 12 is white. In addition, varying the amount of current flowing through each of the light sources allows light emission with various colors.

  Also in this embodiment, the red light emitting diodes 11R, 61R, 62R, and 12R, the green light emitting diodes 11G, 61G, 62G, and 12G, and the blue light emitting diodes 11B, 61B, 62B, and 12B are similar to the above-described embodiment. Since each is connected in series via the first current mirror circuit, the total amount of current can be suppressed as compared with the case where a plurality of light emitting diode modules are connected in parallel. Moreover, troublesome adjustments such as matching the amounts of current between circuits such as when connected in parallel are unnecessary. In addition, the control of the amount of current flowing through each color light emitting diode can be easily controlled by one control signal SR, SG, SB, respectively.

  In each of the above-described embodiments, the light emitting diode module is described in which three light emitting diodes of a red light emitting diode, a green light emitting diode, and a blue light emitting diode are arranged in parallel. However, the present invention is not necessarily limited to this. Alternatively, two light emitting diodes arranged in parallel or four or more light emitting diodes arranged in parallel may be used.

  In each of the above-described embodiments, the light emitting diode module is a light emitting diode module having a common electrode on the anode side of the light emitting diode. However, the present invention is not limited to this. Modules can also be used. Further, a light emitting diode module in which the anode side of the light emitting diode is a common electrode and a light emitting diode module in which the cathode side of the light emitting diode is a common electrode can be mixed and used.

The circuit block diagram of the light-emitting-diode drive device which concerns on the 1st Embodiment of this invention. The circuit block diagram of the light emitting diode drive device which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11,12 ... Light emitting diode module, 11R, 11G, 11B, 12R, 12G, 12B ... Light emitting diode, 13, 14, 15, 28, 29, 30 ... First current mirror circuit, 43, 45, 47 ... Second Current mirror circuit, 16, 17, 20, 21, 24, 25 ... PNP transistor, 31, 32, 35, 36, 39, 40, 44, 46, 48 ... NPN transistor.

Claims (1)

A plurality of light emitting diode modules formed by using a single light emitting diode or a series circuit of a plurality of light emitting diodes as a common electrode on the anode side or the cathode side;
A plurality of unit driving circuits are formed by connecting a first current mirror circuit in series to each light emitting diode circuit of each light emitting diode module, and each unit driving circuit is connected in parallel to each other for each light emitting diode module. A plurality of series drive circuits formed by connecting the parallel circuits in series between the light emitting diode modules; and
A second current mirror circuit connected to each of the series drive circuits, controlling each first current mirror circuit of the corresponding series drive circuit and flowing the same current to each unit drive circuit of the corresponding series drive circuit;
A light-emitting diode driving device comprising:

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