JP2009130304A - Lighting system and drive circuit for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system, and a drive circuit for the lighting system capable of increasing the number of light emitting diodes to be mounted, and of extracting light efficiently to an external. <P>SOLUTION: The lighting system 1 includes a light emitting diode matrix 4, a substrate 6 for mounting the light emitting diode matrix 4, a light reflector 7 provided on the substrate 6. The light reflector 7 includes a sidewall part 9 for reflecting emitted light from each light emitting diode 30. The light reflector 7 may include a through-hole 8 for housing the light emitting diode matrix 4 for each light emitting diode matrix. and a surface of the sidewall part 9 is covered with light reflecting material. The through-hole 8 may be formed of the cone-shaped sidewall part 9 which is enlarged in a light emitting direction of the light emitting diode matrix 4. The drive circuit for the lighting system can be driven by a single DC power source. With this structure, the lighting system 1 having an enhanced mounting density of the light emitting diodes 30, increased light emission luminance, and a good heat diffusion property can be provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lighting device and a driving circuit for the lighting device, and more particularly to a lighting device and a driving circuit for the lighting device using a light emitting diode or the like.

  Light emitting diodes (hereinafter also referred to as LEDs as appropriate) can emit various colors freely, and in the case of white light emitting diodes, light emission efficiency exceeding that of fluorescent lamps is being obtained.

  A light bulb type light emitting diode is a light emitting diode that uses the same socket as a conventional incandescent light bulb. Therefore, it can be used in place of an incandescent bulb, is maintenance-free due to its long life, and saves resources and energy in the long term even if the initial introduction cost is high.

  As a conventional light bulb type light emitting diode, for example, a structure in which a bullet type light emitting diode disclosed in Patent Document 1 is arranged on a printed board is known.

  Patent Document 2 discloses a light bulb type light emitting diode using a chip type LED, a so-called surface mount type LED, as a light emitting diode.

  Further, Patent Document 3 discloses a light emitting element mounting substrate in which light emitting diode chips are arranged in a matrix by one of the inventors of the present invention.

JP 2005-337000 A JP 2004-343025 A JP 2004-259785 A

However, since the conventional lighting device uses a bullet-type light emitting diode or a surface-mounted LED, there is a problem that light emitted from the side surface of the light emitting diode cannot be efficiently extracted.
Further, although there is a light emitting element mounting substrate in which light emitting diode chips are arranged in a matrix, the structure is complicated.

  In view of the above problems, the present invention provides a lighting device capable of increasing the number of mounted light emitting diodes and efficiently extracting light to the outside, and a driving circuit for a lighting device that operates with a single DC power source. It is an object.

In order to achieve the above object, an illumination device of the present invention includes a light emitting diode matrix, a substrate on which the light emitting diode matrix is placed, and a light reflector provided on the substrate, and the light reflector is provided for each light emitting diode. A side wall portion that reflects the emitted light.
In the above configuration, the light reflector is preferably formed with a through hole for accommodating the light emitting diode for each light emitting diode matrix.
The surface of the side wall is preferably coated with a light reflecting material. The through-hole is preferably a cone-shaped side wall portion that expands in the light emitting direction of the light emitting diode matrix.

  According to the above configuration, the light-emitting diode matrix and its drive circuit are arranged on the substrate, and through holes are provided around each light-emitting diode, and a light reflector is formed on the side walls of the through-holes. Therefore, it is possible to realize an illumination device that does not scatter light emitted from the LED and has good light emission efficiency.

  The above-described configuration further includes a driving circuit for the light emitting diode matrix, and the driving circuit includes a current control integrated circuit for controlling a driving current for the light emitting diode of the light emitting diode matrix, and a lighting control for controlling the current control integrated circuit. And a setting circuit that sends a setting signal to the lighting control integrated circuit, and the lighting control integrated circuit supplies a driving voltage for the current control integrated circuit. In the above configuration, the drive circuit preferably includes a DC power source.

  According to the above configuration, the DC power supply can be simplified, and the manufacturing cost can be reduced and the lighting device can be downsized.

In order to achieve the above object, a driving circuit for a lighting device according to the present invention controls a driving current of a light emitting diode by controlling a lighting control integrated circuit that operates at a first voltage and a control signal from the lighting control integrated circuit. An integrated circuit for current control that operates at a voltage of 2 and a setting circuit that sends a setting signal to the integrated circuit for lighting control, and the integrated circuit for lighting control supplies a second voltage to the integrated circuit for current control. Supply.
In the above configuration, preferably, the first voltage is a voltage applied to the light-emitting diode matrix, and the second voltage is a voltage lower than the first voltage.

According to the above configuration, it is possible to provide a driving circuit for an illuminating device such as a light emitting diode matrix that operates with a single DC power supply, and reduction and downsizing of the illuminating device can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the mounting density of a light emitting diode can be raised, light emission brightness can be made high, and the illuminating device with favorable heat dissipation can be provided.

Embodiments of the present invention will be described below with reference to the drawings.
Initially, the illuminating device concerning the 1st Embodiment of this invention is demonstrated.
FIG. 1 is a diagram schematically illustrating the configuration of the illumination device according to the first embodiment, in which (A) is an upper plan view, and (B) is a cross-sectional view taken along line XX in (A). FIG. 2 is a bottom view schematically showing the configuration of the illumination device 1 according to the first embodiment.
As shown in FIGS. 1 and 2, the lighting device 1 includes an envelope 2 and a lighting unit 3 accommodated in the envelope 2. A window portion 2 </ b> A is provided on the light emitting surface of the envelope 2. The illuminating unit 3 has a substrate 6 on which the light emitting diode matrix 4 and a driving circuit (not shown) of the light emitting diode matrix 4 are mounted, and light emitted from the light emitting diodes 30 arranged in a matrix on the substrate 6 upward. The light reflector 7 is taken out. The light-emitting diode matrix 4 is configured by connecting a plurality of light-emitting diodes 30 in series to form a set, and arranging the sets in parallel. The window 2A is made of a material that transmits light, and for example, glass or plastic can be used. The light reflector 7 has a through hole ◯ that accommodates each light emitting diode 30 and a side wall portion 9 of the through hole 8 that surrounds the periphery of the light emitting diode 30 except for the upper surface thereof. It is placed on top.
The light reflector 7 can be entirely composed of a light reflecting member, for example, a metal having a high light reflectance, but in this embodiment, a light reflecting film is provided on the side wall 9 of a substrate such as a printed circuit board. The light reflector 7 is formed by vapor deposition or plating. The light reflector 7 is formed by forming the through holes 8 along the positions where the light emitting diodes 30 are arranged on the substrate, and forming the light reflecting film 9A on the side wall portion 9 by the above method or the like.

  Therefore, as shown in FIG. 1B, the illumination unit 3 of the present embodiment described above includes the first substrate 6 on which the light-emitting diode matrix 4 is mounted and the light-emitting diode matrix 4 of the substrate 5 of the illumination unit 3. Each light-emitting diode 30 is enclosed by a second substrate 7 that functions as a reflector. The light-emitting diode matrix 4 means a configuration in which the plurality of light-emitting diodes 30 having the above-described configuration are arranged on the first substrate 6 in a planar shape.

  As shown in FIG. 2, a driving circuit 10 for driving the light emitting diode matrix 4 is mounted on the back surface of the first substrate 6 on which the light emitting diode matrix 4 is mounted.

Next, the mounting structure of the light emitting diode matrix 4 will be described.
3 is an enlarged schematic view of the illuminating unit 3 of FIG. 2, (A) is a plan view, and (B) is a partial cross-sectional view taken along line XX of (A).
As shown in FIG. 3, the light reflector 7 has a side wall portion 9 that reflects light emitted from each light emitting diode 30. In the light reflector 7, a through-hole 8 that accommodates the light-emitting diode matrix 4 is formed for each light-emitting diode matrix 4. A substrate can be used for the light reflector 7.

The light emitting diodes 30 </ b> A to 30 </ b> D placed on the first substrate 6 have a structure inserted into a through hole 8 (also referred to as a through hole) having a circular shape or the like provided on the second substrate 7. Yes. In the illustrated case, the through hole 8 of the second substrate 7 is circular, but may be a quadrilateral, polygonal, star shape or the like. The side wall 9 of the through hole 8 provided in the second substrate 7 is covered with a light reflecting material having a mirror surface structure such as metal or glass. The side wall portion 9 of the through hole 8 is covered with a light reflecting film 9A made of a light reflecting material, and for example, solder plating is applied. These through-holes 8 have a function of a mirror that reflects light from each light emitting diode 30 of the light emitting diode matrix 4 placed on the first substrate 6 to the upper side of the substrate. Accordingly, the reflectance can be increased by making the height of the side wall portion 9 of the second substrate 7 higher than the height of the light emitting diode 30.
Here, the light-emitting diode shown in FIG. 3 is a surface-mount type, but a bullet-type light-emitting diode may be used.

FIG. 4 is an enlarged cross-sectional view showing a modified example of the through hole 8.
As shown in FIG. 4, in order to further increase the brightness, the shape of the through hole 8 into which the light emitting diodes 30 </ b> A to 30 </ b> B are inserted is expanded in the light emitting direction of the light emitting diode matrix 4. It is more effective if the light reflection film 9 is coated on the side wall portion 9 to increase the reflection efficiency.

FIG. 5 is an enlarged schematic view of the first substrate 6 used in the illumination unit 3 of FIG. 1, (A) is a plan view, and (B) is a sectional view taken along line XX of (A). Show.
As shown in FIG. 5A, two sets of light emitting diodes 30A to 30F in which three light emitting diodes 30 are connected in series are placed on the first substrate 6, and each of the light emitting diodes 30A to 30F has a circuit pattern. Soldered on top. A copper foil is formed on the back surface of the first substrate 6.

6 is an enlarged schematic view of the second substrate 7 used in the illumination unit 3 of FIG. 1, in which (A) is a plan view and (B) is a cross-sectional view taken along line X1-X1 of (A). Is shown.
As shown in FIG. 6, the second substrate 7 corresponds to the place where each light emitting diode 30 </ b> A to 30 </ b> F placed on the first substrate 6 is placed, and is larger than each light emitting diode 30 </ b> A to 30 </ b> F. A through-hole 8 with dimensions is provided.

  The second substrate 7 is bonded to the first substrate 6 with a resist or an adhesive. The 2nd board | substrate 7 is a board | substrate which can arrange | position a pattern only on the upper surface.

  For the first substrate 6 and the second substrate 7, so-called printed boards can be used. The printed board is a flat plate-like board made of an insulating material, and a foil made of a conductive material is attached to both or one side thereof. As the insulating material for the printed circuit board, paper phenol, glass / epoxy, Teflon (registered trademark), ceramics, or the like can be used. It may be a flexible so-called flexible substrate that can be bent using a plastic film as a base material. The second substrate 7 may be made of another material as long as it can reflect light from the side surface of the light emitting diode matrix 4 described above.

  Here, as a material for forming the circuit patterns of the first substrate 6 and the second substrate 7, a conductive material is used. Among these conductive materials, it is preferable to use a substance capable of reflecting light. The conductive material is more preferably a highly reflective material. For example, a material such as solder or gold can be used as the highly reflective conductive material. In particular, the entire wall surface of the through-hole 8 provided in the second substrate 7 is formed of the highly reflective conductive material as described above, so that light from the side surface of the light emitting element is effectively reflected on the surface of the conductive material. Can be made. For this reason, since this reflected light is superimposed on the irradiation light to the front surface of a light emitting element, the illuminating device 1 can be made high-intensity.

  Circuit patterns formed on the first substrate 6 and the second substrate 7 can be formed of copper foil or the like. The thickness of the copper thin film may be about 15 μm to 50 μm. The circuit pattern can be formed by a process such as photolithography and etching. After the circuit pattern is formed, the surface of the copper foil to be a pattern may be plated with gold.

7A to 7C are process diagrams schematically illustrating a method for manufacturing a substrate on which the light-emitting diode matrix 4 used in the illumination device 1 according to the first embodiment is mounted.
First, as shown in FIG. 7A, a first substrate 6 is prepared, a circuit pattern 6A of the light emitting diode matrix 4 is provided on the upper surface on which the light emitting diode matrix 4 is placed, and a driving circuit is provided on the surface. A circuit pattern 6B is formed.
Next, as shown in FIG. 7B, each light emitting diode 30 of the light emitting diode matrix 4 is soldered to the wiring pattern 6A formed on the upper surface side of the first substrate 6.
Finally, as shown in FIG. 7C, each light-emitting diode 30 placed on the first substrate 6 is inserted into the through hole 8 of the second substrate 7, and the first substrate 6 and the second substrate The substrate 7 is bonded using an adhesive or the like to manufacture the substrate 5.

FIG. 8 schematically shows the structure of the illumination device 20 according to the second embodiment, where (A) is a front view and (B) is a partial cross-sectional view.
As shown in FIG. 8A, the illuminating device 20 is a so-called bulb-type illuminating device, in which the illuminating unit 20 is disposed in a base 21 and is made of glass or the like, and has a substantially spherical shape with an end opened. 22 is connected to the upper part of the base 21. Electrodes 23 and 24 are formed on the base 21. The base 21 has the same structure as that for a so-called incandescent lamp that is lit by a commercial power source. A DC power supply 14 is connected to the electrodes 23 and 24.

  FIG. 8B shows a cross-sectional view of the illumination unit 3 disposed in the base 21. The illumination unit 20 has the same configuration as the illumination unit 1 shown in FIG.

FIG. 9 is a block diagram showing a configuration of a drive circuit of the light emitting diode 30 used in the lighting devices 1 and 20 of the first and second embodiments.
The drive circuit 10 of the light emitting diode 30 includes a current control integrated circuit 11 that controls the drive current of the light emitting diode matrix 4, a lighting control integrated circuit 12 that controls the current control integrated circuit 11, and a lighting control integrated circuit 12. Is configured by a setting circuit 13 for sending a setting signal to the power source and a DC power source 14.
The DC power source 14 is supplied to the lighting control integrated circuit 12 and will be referred to as a first voltage. The DC power supply 14 is a circuit that converts a commercial AC power supply 15 such as 100 V into a DC having a predetermined voltage. The DC power supply 14 includes a ripple removal filter including a capacitor that rectifies an alternating current obtained by stepping down the commercial AC power supply 15 using a transformer and shapes the rectified pulsating voltage into a DC power supply. The DC power supply 14 may be configured from a so-called switching power supply. The voltage of the DC power supply 14 is, for example, 12V, 24V, 36V, 48V or the like. In the following description, it is assumed that the voltage is 12V.

  Here, the DC power supply 14 may be built in the lighting device 1 or provided outside the lighting device 1. As shown in FIG. 8, when the DC power supply 14 is built in the lighting device 20, the lighting device 20 can be used by replacing it with an incandescent bulb.

  The lighting control integrated circuit 12 has a function of generating a driving signal for the current control integrated circuit 11 and supplying driving power for the current control integrated circuit 11. Thereby, the current control integrated circuit 11 is supplied with a second voltage lower than the first voltage supplied to the lighting control integrated circuit 12, for example, 5V. In the following description, it is assumed that the current control integrated circuit 11 operates at 5V.

The drive voltage of the light emitting diode 30 and the lighting control integrated circuit 12 connected in series is supplied from the DC power supply 14 (first voltage). Generally, the operating voltage (second voltage) of the current control integrated circuit 11 is used. The voltage is higher than 5V, for example, 12V. Therefore, the DC power supply 14 can be simplified by supplying the operating voltage from the lighting control integrated circuit 12 to the current control integrated circuit 11.
Thereby, according to the illuminating devices 1 and 20 of this invention, the DC power supply 14 should just output only a single voltage. For this reason, the configuration of the DC power source 14 is simplified, and the manufacturing cost can be reduced and the lighting devices 1 and 20 can be downsized.

  The driving circuit 10 of the light emitting diode 30 described above can be used not only as the lighting devices 1 and 20 but also as a driving circuit for other lighting devices.

  The light-emitting diode matrix 4 includes a plurality of light-emitting diodes 30 that are connected in series to form a set, and the set is a plurality of sets. When the light emitting diode 30 is GaN-based, the forward voltage is about 3.5V. When the DC voltage is 12V, three light emitting diodes 30 can be connected in series to form a set. The number of sets can be appropriately set according to the brightness of the lighting devices 1 and 20. The number of sets can also be designed according to the number of driving of the current control integrated circuit 11. Therefore, as the number of groups, for example, a value of 8, 16, 32, etc. can be selected.

  The lighting control integrated circuit 12 is a lighting control circuit for continuously (CW) lighting or pulse lighting the light emitting diode matrix 4. The lighting control integrated circuit 12 may be a circuit in which a plurality of sets of light emitting diodes 30 are pulsed with a phase shifted.

  In the case where the lighting control integrated circuit 12 is a circuit that causes a plurality of sets of light emitting diodes 30 of the light emitting diode matrix 4 to perform pulse lighting while shifting the phase, the following configuration can be adopted. As an example of the lighting control integrated circuit 12, it is possible to change the repetition period of the pulse, the number of divisions of the LED set to be lit in the same period, and the duty of the pulse. The lighting control integrated circuit 12 can be configured to include three blocks: a clock frequency dividing circuit, a pulse repetition period control circuit, and a pulse generation circuit.

  The clock divider circuit divides the clock signal input from the clock (CLK) to generate a reference clock signal (SFTCLK) and a latch (LATCH). The clock divider circuit can divide a predetermined number of clocks from an externally input clock. The frequency division number can be selected by the FRSEL signal. Here, the generated SFTCLK signal and LATCH signal are clock signals for the current control integrated circuit 11. The clock frequency divider circuit supplies a signal to the pulse repetition period control circuit and the pulse generation circuit.

  The pulse repetition cycle control circuit is a circuit that controls the pulse repetition cycle. This pulse repetition period control circuit generates signals of two periods, three periods, four periods, etc. based on the reference clock signal and LATCH signal generated by the clock dividing circuit. The pulse repetition period can be selected by the DIVSEL signal. Here, the generated DATA signal becomes a DATA signal to the current control integrated circuit 11.

  The pulse generation circuit is a circuit that generates a pulse. The pulse width can be changed within a range from 1/4 to 1/32 or the like with respect to the period of the DATA signal generated by the pulse repetition period control circuit. The pulse width can be selected by the DUTYSEL signal. Here, the generated standby (STB) signal becomes the STB signal of the current control integrated circuit 11.

  FIG. 10 is a block diagram showing an example of a method of driving the light-emitting diode matrix 4 by the current control integrated circuit 11 of FIG. In FIG. 10, in the light-emitting diode matrix 4, three light-emitting diodes 30 are connected in series to form one set, and 36 sets of light-emitting diodes 30 are controlled to be turned on by two current control integrated circuits 11A and 11B. The circuit configuration is as follows.

  According to the illuminating devices 1 and 20 of the present invention, in the illuminating unit 3, each light emitting diode 30 of the light emitting diode matrix 4 placed on the first substrate 6 is inserted into the through hole 8 of the second substrate 7. Therefore, the position of the light emitting element as in the conventional example is eliminated at the time of manufacture, and the yield and productivity can be improved.

  Since each light emitting diode 30 can reflect the light from the entire side surface of the light emitting element by the wall surface provided in the through hole 8 of the second substrate 7 and increase the emitted light, the high luminance of the lighting devices 1 and 20. Can be realized. In particular, if a highly light-reflective conductive material is provided on the wall surface of the through-hole 18 and the wall surface is formed into a cone shape, the brightness can be further increased.

  Since the first substrate 6 also has a circuit pattern on the back surface and has an increased surface area, the heat generated from the light emitting diode matrix 4 can be effectively dissipated. As a result, each light emitting diode 30 is less likely to generate heat, so that the luminance of the lighting devices 1 and 20 can be increased more effectively.

  Since the lighting control integrated circuit 12 used in the lighting devices 1 and 20 of the present invention can supply the driving power for the current control integrated circuit 11, the DC power supply 14 can be simplified, and the manufacturing cost can be reduced. And the size reduction of the illuminating devices 1 and 20 is realizable.

  The driving circuit 10 of the light emitting diode 30 used in the lighting devices 1 and 20 of the present invention is not limited to the lighting devices 1 and 20, but is a driving circuit for other lighting devices such as a so-called display such as an advertisement or an indicator lamp. Since it operates with a single DC power supply, it is possible to reduce the size of various lighting devices.

Hereinafter, the present invention will be described in more detail with reference to examples.
The lighting device 1 shown in FIG. 1 was manufactured. The light emitting diode matrix 4 was composed of 96 commercially available white light emitting diodes for surface mounting. The through hole 8 of the second substrate 7 is circular, and a side wall portion 9 substantially perpendicular to the first substrate 6 is covered with solder to form a light reflecting film 9A. The drive circuit 10 has the circuit configuration shown in FIG. 9 and FIG. 10 and includes three white light emitting diodes 30 connected in series as one set, and each 16 sets are pulse-driven by two current control integrated circuits 11A and 11B. .

(Comparative example)
A comparative illumination device having the same structure as the example except for the second substrate was manufactured.

  When the light emitting diode matrix 4 is driven under the same conditions, the illuminance of the illumination device 1 of the example in which the through hole 8 for light reflection is provided in the second substrate 7 is about 20% to 30% with respect to the illuminance of the comparative example. % Increase was found. From this result, it was found that the lighting device 1 of the example had higher luminance than the lighting device of the comparative example.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these are also included in the scope of the present invention. For example, in the above-described embodiment, the arrangement of the light-emitting diode matrix 4 and the driving circuit 10 for the light-emitting diode matrix 4 can be appropriately changed according to the lighting devices 1 and 20.

It is a figure which shows typically the structure of the illuminating device which concerns on 1st Embodiment, (A) is an upper top view, (B) is sectional drawing which follows the XX line of (A). It is a bottom view which shows typically the structure of the illuminating device which concerns on 1st Embodiment. It is the schematic diagram which expanded the illumination part of FIG. 2, (A) is a top view, (B) has shown the fragmentary sectional view which follows the XX line of (A). It is an expanded sectional view showing a modification of a through hole. It is the schematic diagram which expanded the 1st board | substrate used for the illumination part of FIG. 1, (A) is a top view, (B) has shown sectional drawing in alignment with the XX line of (A). It is the schematic diagram which expanded the 2nd board | substrate used for the illumination part 3 of FIG. 1, (A) is a top view, (B) has shown sectional drawing in alignment with the X1-X1 line | wire of (A). (A)-(C) are process drawings which illustrate typically the manufacturing method of the board | substrate which mounts the light emitting diode matrix used for the illuminating device which concerns on 1st Embodiment. The structure of the illuminating device 20 which concerns on 2nd Embodiment is shown typically, (A) is a front view, (B) is a fragmentary sectional view. It is a block diagram which shows the structure of the drive circuit of the light emitting diode used for the illuminating device of 1st and 2nd embodiment. FIG. 10 is a block diagram illustrating an example of a method of driving a light emitting diode matrix by the current control integrated circuit of FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20: Illuminating device 2: Envelope 2A: Window part 3: Illuminating part 4: Light emitting diode matrix 5: Board | substrate 6: 1st board | substrate 6A, 6B: Circuit pattern 7: Light reflector (2nd board | substrate)
8: Through-hole 9: Side wall 9A: Light reflection film 10: Drive circuits 11, 11A, 11B: Integrated circuit for current control 12: Integrated circuit for lighting control 13: Setting circuit 14: DC power supply 15: Commercial AC power supply 21: Base 22: Cover 23, 24: Electrode 30, 30A-30F: Light emitting diode

Claims (8)

A light emitting diode matrix;
A substrate on which the light emitting diode matrix is placed;
A light reflector provided on the substrate,
The said light reflector is an illuminating device which has a side wall part which reflects the light emitted for every light emitting diode.   The lighting device according to claim 1, wherein a through-hole that accommodates the light-emitting diode matrix is formed for each light-emitting diode matrix in the light reflector.   The lighting device according to claim 1, wherein a surface of the side wall portion is covered with a light reflecting material.   The lighting device according to claim 2, wherein the through-hole is a cone-shaped side wall portion that is expanded in a light emitting direction of the light emitting diode matrix. Furthermore, a drive circuit for the light emitting diode matrix is provided, the drive circuit including a current control integrated circuit for controlling a drive current for the light emitting diodes of the light emitting diode matrix, and a lighting control integrated circuit for controlling the current control integrated circuit; A setting circuit for sending a setting signal to the integrated circuit for lighting control,
The lighting device according to claim 1, wherein the lighting control integrated circuit supplies a driving voltage for the current control integrated circuit.   The lighting device according to claim 5, wherein the drive circuit includes a DC power source. An integrated circuit for lighting control operating at a first voltage;
A current control integrated circuit that controls the drive current of the light emitting diode by a control signal from the lighting control integrated circuit and operates at a second voltage;
A setting circuit that sends a setting signal to the lighting control integrated circuit, and
The lighting control integrated circuit supplies a second voltage to the current control integrated circuit.   The lighting device drive circuit according to claim 7, wherein the first voltage is a voltage applied to a light emitting diode matrix, and the second voltage is a voltage lower than the first voltage.

Images