CN103491668B

CN103491668B - Light source control device

Info

Publication number: CN103491668B
Application number: CN201310216840.7A
Authority: CN
Inventors: 村松隆雄; 武田仁志; 伊藤昌康; 村上健太郎
Original assignee: Koito Manufacturing Co Ltd
Current assignee: Koito Manufacturing Co Ltd
Priority date: 2012-06-11
Filing date: 2013-06-03
Publication date: 2017-04-26
Anticipated expiration: 2033-06-03
Also published as: EP2675247A1; CN104902630B; CN103491668A; JP2014017463A; JP6030922B2; EP2675247B1; EP2800457A2; EP2800457A3; EP2800457B1; CN104902630A

Abstract

The present invention provides a light source control device which can cope appropriately even though the wirings around a light source or the bypass switches are in poor conduction. The semi-conductor light source control device comprises a driving circuit for generating a driving current; a second bypass switch (110-2) in parallel connection with a second LED (2-2); and a third bypass switch (110-3) in parallel connection with a third LED (2-3). When the second bypass switch (110-2) is cut off and the third bypass switch (110-3)is turned on, the polarity of a current flowing through a second bypass connecting wiring (280-2) is reverse with the polarity of the current flowing through the second bypass connecting wiring when the second bypass switch (110-2) is turned on and the third bypass switch (110-3) is cut off. The semi-conductor light source control device is configured to force the second and third bypass switches to be turned on when the second bypass connecting wiring is in poor conduction.

Description

Light source control device

Technical field

The present invention relates to a kind of light source control device being controlled to light source.

Background technology

In recent years, in the lamps apparatus for vehicle such as headlamp, replace the existing Halogen lamp LED with filament and service life more The long and lower LED of power consumption（Light Emitting Diode）Deng semiconductor light source.The luminous degree of LED be brightness with The size of current for flowing through LED is related, therefore, in the case where LED is used as into light source, need for the electric current to flowing through LED The lamp circuit being adjusted.

The applicant proposes a kind of technology in patent document 1, and it is in order that the luminous intensity distribution of headlamp is variable, carry out enough Fine distribution controls, as light source LED matrix is adopted, and makes the independent lighting/light-offs of each LED.In the lighting that patent document 1 is recorded In circuit, with each LED by-pass switch is provided with parallel, turned on/off by the by-pass switch and realize the independent lighting of LED/ Turn off the light.

Patent document 1：Japanese Unexamined Patent Publication 2011-192865 publications

In the case of using the bypass mode described in patent document 1, the distribution of LED peripheries is more complicated.If matched somebody with somebody Line is complicated, then there is a problem of that the possibility for coming in contact the poor flows such as bad or broken string increases.

The content of the invention

The present invention in view of above-mentioned condition and propose, even if its object is to provide a kind of light source or by-pass switch is all There is the light source control device that poor flow also can deal adequately with the distribution for enclosing.

A mode of the invention is related to light source control device.The light source control device has：Drive circuit, its generation is flow through The driving current of the multiple semiconductor light sources being connected in series；1st by-pass switch, its with multiple semiconductor light sources in a part simultaneously Connection connection；And the 2nd by-pass switch, it is connected in series with the 1st by-pass switch, and with multiple semiconductor light sources in it is another A part is connected in parallel.For by the connecting node between the 1st by-pass switch and the 2nd by-pass switch and multiple semiconductor light sources A part and multiple semiconductor light sources in another part between connecting node connection connection wiring, the 1st bypass open The polarity of the electric current of connection wiring is flow through when shut-off is opened and the 2nd by-pass switch is connected, is connected with the 1st by-pass switch and the 2nd bypass The opposite polarity of the electric current of connection wiring is flow through when switching off.Consist of, the situation of poor flow occurs in connection wiring Under, forcibly connect both the 1st by-pass switch and the 2nd by-pass switch.

According to which, can connection wiring occur poor flow in the case of, forcibly make the 1st by-pass switch and Both 2nd by-pass switches are connected.

The another way of the present invention is also a kind of light source control device.The device has：String is flow through in drive circuit, its generation The driving current of multiple semiconductor light sources of connection connection；By-pass switch, its with multiple semiconductor light sources at least a portion simultaneously Connection connection；Main control circuit, it makes by-pass switch periodically turn on/off in usual lighting；And abnormality detection auxiliary Circuit, the both end voltage of its by-pass switch when by-pass switch disconnects is less than the 1st voltage or higher than the higher than the 1st voltage the 2nd In the case of voltage, the amount for making the electric charge of capacitor holding is changed with the 1st time constant to the 1st direction, cannot make capacitor The amount of the electric charge of holding with the 1st time constant to the 1st towards the electric charge for keeping in the case of change, capacitor amount with than the 2nd time constant of 1 time constant length to the 1st towards the contrary 2nd towards change.Main control circuit is based on the two of capacitor Terminal voltage determines whether exception, in the case where being judged to there occurs exception, forcibly connects by-pass switch.

According to which, it is possible to use difference between the 1st time constant and the 2nd time constant, determine whether to there occurs different Often.

Additionally, any combination of above-mentioned inscape or by the present invention inscape or be described in device, method, Phase double replacement between system etc., is effective as the mode of the present invention.

The effect of invention

Even if in accordance with the invention it is possible to provide light source or the distribution around by-pass switch there is poor flow also can be appropriate The light source control device of reply.

Description of the drawings

Fig. 1 is the electricity of the structure for representing Semiconductor-light-control control device and connected part involved by embodiment Lu Tu.

Fig. 2 is the circuit diagram of the structure of the delayed amplitude set circuit for representing Fig. 1.

Fig. 3 is the curve map for representing the relation between the absolute value of driving voltage and offset voltage.

Fig. 4 is the circuit diagram of the structure of the down converter drive circuit for representing Fig. 1.

Fig. 5 is the circuit diagram of the structure of the 2nd bypass circuit and the 3rd bypass circuit for representing Fig. 1.

Fig. 6's（a）Extremely（c）It is the curve map of the time change for representing driving current.

Fig. 7 is the sequential of the change of the 2nd by-pass switch drive signal when representing PWM dim lights and the 2nd anomaly detection signal Figure.

Fig. 8 is the circuit diagram of the structure for representing the semiconductor light source lamp circuit involved by comparative example.

Fig. 9's（a）Extremely（c）It is the structure for representing the Semiconductor-light-control control device involved by the variation of the 1st, the 2nd and the 3rd Circuit diagram.

Figure 10 is the structure for representing Semiconductor-light-control control device and connected part involved by the 4th variation Circuit diagram.

Figure 11 is the electricity of the structure of the 2nd bypass circuit for representing the Semiconductor-light-control control device involved by the 5th variation Lu Tu.

Figure 12 be represent 2LED break in the case of the 2nd lighting light-off control signal change sequential chart.

The explanation of label

6 Vehicular accumulator cells, 8 power switches, 100 Semiconductor-light-control control devices, 102 flyback adjusters, 104 frequency reducings conversion Device, 106 control circuits, 108 current sense resistors, 128 output capacitors, 142 fly-wheel diodes, 144 inductors.

Specific embodiment

Below, to each shown in the drawings identical or equivalent inscape, part, signal, identical label is marked and appropriate Omit repeat specification in ground.In addition, in the drawings, the part for illustrating unessential part will be omitted and is indicated. In addition, for the label of the marks such as voltage, electric current or resistance, being occasionally used for representing each magnitude of voltage, current value as desired Or resistance value.

In this manual, so-called " state that components A is connected with part B ", except components A and part B it is physically direct Outside the situation of connection, also including components A and part B via will not produce other parts for affecting on electrical connection state and Situation about connecing in succession.In the same manner, so-called " part C is arranged on the state between components A and part B ", except components A and part C, Or outside part B and part C situation about being directly connected to, also include via other that affect will not be produced on electrical connection state Part and situation about being indirectly connected with.

Semiconductor-light-control control device involved by embodiment is generated and flows through the multiple semiconductor light sources being connected in series i.e. The driving current of LED.By-pass switch is set in parallel with each LED.If by-pass switch is connected（Disconnect）, then corresponding LED into To turn off the light（Lighting）State.The connecting node between connecting node and corresponding 2 by-pass switches between 2 adjacent LED it Between be provided with bypass connection wiring.Semiconductor-light-control control device is configured to, and broken string occurs in bypass connection wiring or connects When touching bad, pressure connects 2 by-pass switches that the bypass connection wiring is connected.Thus, there is above-mentioned conducting not In the case of good, can make the LED of correlation becomes light-off state.

Fig. 1 is the structure for representing Semiconductor-light-control control device 100 and connected part involved by embodiment Circuit diagram.Semiconductor-light-control control device 100 is multiple to what is be connected in series（It is N number of）Vehicle-mounted LED2-1 to 2-N supplies are driven Streaming current Iout, makes these LED point lamps.N is the natural number more than or equal to 2.Semiconductor-light-control control device 100 and N number of LED2-1 to 2-N is equipped in the lamps apparatus for vehicle such as headlight.Semiconductor-light-control control device 100 and Vehicular accumulator cell 6, electricity Source switch 8 connects.

Vehicular accumulator cell 6 produces 12V（Or 24V）Direct-flow storage battery voltage（Supply voltage）Vbat.Power switch 8 is to set The relay switch for being controlled to the overall on/off of N number of LED2-1 to 2-N is set to, is gone here and there with Vehicular accumulator cell 6 Connection ground is arranged.If power switch 8 is connected, from the positive terminal of Vehicular accumulator cell 6, using battery tension Vbat as input Voltage and supply to Semiconductor-light-control control device 100.The negative terminal of Vehicular accumulator cell 6 is connected with fixed voltage terminal, i.e. It is grounded.

Each LED2-1 to 2-N is connected side by side and inversely with electrostatic protection Zener diode 252-1 to 252-N.That is, The negative pole of the 1st electrostatic protection Zener diode 252-1 is connected with the positive pole of 1LED2-1, the 1st electrostatic protection Zener diode The positive pole of 252-1 is connected with the negative pole of 1LED2-1.For the 2nd electrostatic protection Zener diode 252-2 to N electrostatic is protected Shield Zener diode 252-N, is similarly attached.The corresponding LED of electrostatic protection Zener diode protection will not be because quiet Electricity and causing trouble.

Semiconductor-light-control control device 100 is flyback adjuster 102, down converter 104, control with switching regulaor Circuit 106, current sense resistor 108, N number of bypass circuit 270-1 to 270-N and bypass drive circuit 112.Control circuit 106 pairs of flyback adjusters 102 and down converter 104 are controlled, and drive comprising flyback drive circuit 134, down converter Circuit 136 and delayed amplitude set circuit 138.Bypass drive circuit 112 is realized by microcomputer.

Flyback adjuster 102 is voltage regulator, and the battery tension Vbat of input is transformed to into target voltage Vt and defeated Go out.The lead-out terminal of the high-side of flyback adjuster 102 is ground side, therefore, target voltage Vt is applied to flyback regulation The voltage of the lead-out terminal of the low level side of device 102, with negative polarity.Flyback adjuster 102 includes input capacitor the 114, the 1st Switch element 116, input transformer 124, output diode 126, output capacitor 128, voltage detecting diode 130 and voltage Sensing capacitor 132.

Input capacitor 114 is arranged in parallel with Vehicular accumulator cell 6, and battery tension Vbat is smoothed.More specifically Ground says that input capacitor 114 is arranged near input transformer 124, realizes being carried out for the switch motion of flyback adjuster 102 The function of voltage smoothing.

The switch element 116 of first winding 118 and the 1st of input transformer 124 is connected in series, and the series circuit is relative to car Carry battery 6 to be connected in parallel with input capacitor 114.For example the 1st switch element 116 is by N channel MOSFET（Metal Oxide Semiconductor Field Effect Transistor）Constitute.One end of the Secondary Winding 120 of input transformer 124 with One end connection of output capacitor 128, the other end of Secondary Winding 120 is connected with the positive pole of output diode 126.Output capacitance The other end of device 128 is connected with the negative pole of output diode 126.One end of output capacitor 128 is low with flyback adjuster 102 The lead-out terminal connection of level side, applies target voltage Vt.The other end of output capacitor 128 and the height of flyback adjuster 102 The lead-out terminal connection of level side.

Control terminal to the 1st switch element 116（Grid）It is applied through the square waveform of the generation of flyback drive circuit 134 Leading portion control signal S1 of shape.1st switch element 116 is effective in leading portion control signal S1（assert）When connect when being high level It is logical, disconnect when when cancelling being low level.

The voltage detecting of input transformer 124 winding 122, voltage detecting diode 130 and voltage detecting capacitor 132 Cathode voltage detection circuit is constituted, the cathode voltage detection circuit is used for the size to target voltage Vt as positive polarity voltage Detected.Voltage detecting is grounded with one end of winding 122, and the other end is connected with the positive pole of voltage detecting diode 130.Voltage The negative pole of detection diode 130 is connected with one end of voltage detecting capacitor 132.Another termination of voltage detecting capacitor 132 Ground.Apply positive voltage corresponding with the absolute value of target voltage Vt in one end of voltage detecting capacitor 132.The voltage is used as inspection Survey voltage Vd and be supplied to flyback drive circuit 134.

Flyback drive circuit 134 is based on detection voltage Vd, carries out the electricity for target voltage Vt to be remained constant Pressure feedback control.Flyback drive circuit 134 is adjusted to the frequency and dutycycle of leading portion control signal S1, so that target is electric Setting voltages of the pressure Vt close to such as -100V or so.

Down converter 104 is arranged on the back segment of flyback adjuster 102, comprising the 2nd switch element 140, fly-wheel diode 142 and inductor 144, but the capacitor smoothed not comprising output voltage.

2nd switch element 140 is for example made up of N channel MOSFET.Logical is applied to the control terminal of the 2nd switch element 140 Cross back segment control signal S2 of the square wave shape of the generation of down converter drive circuit 136.2nd switch element 140 is in back segment Connect when control signal S2 is high level, disconnect in low level.The drain electrode of the 2nd switch element 140 and output capacitor 128 High-side is the lead-out terminal connection of the high-side of flyback adjuster 102.The source electrode of the 2nd switch element 140 and afterflow two The negative pole connection of pole pipe 142.

The positive pole of fly-wheel diode 142 is connected with one end of inductor 144.The positive pole and inductor of fly-wheel diode 142 Connecting node between 144 one end, it is defeated with the low level side that the low level side of output capacitor 128 is flyback adjuster 102 Go out terminal connection.The other end of inductor 144 is connected with the negative side of N number of LED2-1 to 2-N.

Current sense resistor 108 is arranged on the path of driving current Iout.One end of current sense resistor 108 and the 2nd Connecting node connection between the source electrode of switch element 140 and the negative pole of fly-wheel diode 142.Current sense resistor 108 it is another One end is grounded, and is connected with the side of the positive electrode of N number of LED2-1 to 2-N.Produce and driving current in current sense resistor 108 The voltage drop Vm that Iout is directly proportional.

Because the side of the positive electrode of N number of LED2-1 to 2-N is grounded, so the negative side in N number of LED2-1 to 2-N is inductance The other end of device 144 applies the driving voltage Vout of negative polarity.In usual lighting, driving voltage Vout becomes size and is in Luminance（=corresponding by-pass switch disconnects）LED quantity × 1 LED the suitable negative voltage of forward drop Vf.

Down converter drive circuit 136 is based on voltage drop Vm, carries out for driving current Iout to be maintained at into regulation electricity Current Feedback Control in the range of stream.As down converter drive circuit 136, if the size of driving current Iout exceedes rule Fixed current upper limit value Ith1, then disconnect the 2nd switch element 140, if the size of driving current Iout is less than than upper current limit The also little floor level of electric current Ith2 of value Ith1, then connect the 2nd switch element 140.As down converter drive circuit 136, such as The size of fruit driving current Iout exceedes current upper limit value Ith1, then back segment control signal S2 is set to into low level, if driven The size of electric current Iout is less than floor level of electric current Ith2, then back segment control signal S2 is set to into high level.

Delayed amplitude set circuit 138 is based on driving voltage Vout, to current upper limit value Ith1 and floor level of electric current Ith2 Difference be that delayed amplitude, ao I is set.Delayed amplitude set circuit 138 is less than than target in the absolute value of driving voltage Vout In the case of the also little voltage threshold Vth of the absolute value of voltage Vt, delayed amplitude, ao I is made with the absolute value of driving voltage Vout Become big and increase, in the case where the absolute value of driving voltage Vout exceedes voltage threshold Vth, make delayed amplitude, ao I with drive The absolute value of dynamic voltage Vout becomes big and reduces.

Fig. 2 is the circuit diagram of the structure for illustrating delayed amplitude set circuit 138.Delayed amplitude set circuit 138 has the 1st Operational amplifier 146, the 1st diode 148, the 1st resistance 150, the 2nd resistance 152, the 3rd resistance 154, the 4th resistance the 156, the 5th are electric Resistance 158 and reference voltage source 160.Apply positive control power source voltage Vcc in one end of the 3rd resistance 154.3rd resistance 154 it is another One end of one end and the 2nd resistance 152, one end of the 5th resistance 158 and one end of the 4th resistance 156 are connected.4th resistance 156 it is another One end is grounded.Apply driving voltage Vout in the other end of the 5th resistance 158.The other end and the 1st operation amplifier of the 2nd resistance 152 The inversing input terminal connection of device 146.The inversing input terminal of the 1st operational amplifier 146 is via the 1st resistance 150 and the 1st two pole The positive pole connection of pipe 148.The negative pole of the 1st diode 148 is connected with the lead-out terminal of the 1st operational amplifier 146.To the 1st computing The non-inverting input terminal of amplifier 146 applies reference voltage V ref generated by reference voltage source 160.The 1st two will be applied to The voltage of the positive pole of pole pipe 148 is referred to as offset voltage Voffset.As shown in the above, offset voltage Voffset and delayed amplitude, ao I correspondences, more high then delayed amplitude, ao I of offset voltage Voffset is bigger.

For the resistance value of the periphery of the 1st operational amplifier 146, with the 3rd differential resistance for becoming reference voltage V ref 154th, the value of the 4th resistance 156 and the 5th resistance 158 is compared, and fills the 1st resistance 150 of decision magnifying power, the value of the 2nd resistance 152 Divide big, so that feedback current will not affect on the differential generation of reference voltage V ref.

Fig. 3 is the curve map of the relation between the absolute value and offset voltage Voffset for representing driving voltage Vout.Negative When the absolute value of the driving voltage Vout of polarity is less, the common connection of the 3rd resistance 154, the 4th resistance 156 and the 5th resistance 158 The voltage of node is larger relative to reference voltage V ref, therefore, the 1st operational amplifier 146 carries out electric current reduction（sink）And make Offset voltage Voffset reduces.When the voltage of common connecting node is equal with reference voltage V ref, offset voltage Voffset Reach maximum.

During in order to realize that the absolute value in driving voltage Vout becomes voltage threshold Vth, delayed amplitude, ao I is offset voltage Voffset reaches the control of maximum, and reference voltage V ref is set as to be equal to voltage threshold in the absolute value of driving voltage Vout The voltage of common connecting node during Vth.Especially, when the setting voltage of flyback adjuster 102 is -100V, by benchmark electricity Pressure Vref is set as the voltage of the common connecting node in driving voltage Vout=-Vth=-50V.

If the absolute value of driving voltage Vout increases and exceedes voltage threshold Vth, the 1st operational amplifier 146 does not enter Row effect, directly using the voltage of common connecting node as offset voltage Voffset.Delayed amplitude set circuit 138 passes through will The above-mentioned absolute value relative to driving voltage Vout is delivered to down converter and drives with offset voltage Voffset that mountain peak shape changes Dynamic circuit 136, so as to be controlled to delayed amplitude, ao I, the switching frequency for making down converter 104 falls in the scope of regulation It is interior.

Fig. 4 is the circuit diagram of the structure for illustrating down converter drive circuit 136.Down converter drive circuit 136 has Have the 2nd operational amplifier 162, comparator 164, gate drivers 166, the 1st current mirror circuit 170, the 7th resistance 172, 8 resistance 174, the 10th resistance 178, the 12nd resistance 182, the 13rd resistance 184, l npns bipolar transistor the 190, the 3rd are switched Element 202, the 4th switch element 204 and the 2nd current mirror circuit 206.

Offset voltage Voffset is applied to the non-inverting input terminal of the 2nd operational amplifier 162.2nd operational amplifier 162 lead-out terminal is connected with the base stage of 1npn types bipolar transistor 190, inversing input terminal and 1npn type bipolaritys The emitter stage connection of transistor 190.One end of 8th resistance 174 is connected with the emitter stage of 1npn types bipolar transistor 190, The other end is grounded.The colelctor electrode of 1npn types bipolar transistor 190 is via the 7th resistance 172 and the 1st current mirror circuit 170 connections.

1st current mirror circuit 170 has the 6th resistance 168, the 9th resistance 176, the 11st resistance 180,1pnp types double Polar transistor 192,2pnp types bipolar transistor 194 and 3pnp types bipolar transistor 196.These components with The mode for constituting known current mirror circuit is connected with each other.1st current mirror circuit 170 will flow through the 7th resistance 172 Electric current, using the electric current for flowing through the 10th resistance 178 and the electric current for flowing through the 3rd switch element 202 as output, makes input as input The size of electric current and being substantially equal to the magnitudes for output current.

2nd current mirror circuit 206 has the 14th resistance 186, the 15th resistance 188,2npn type bipolar transistors 198 and 3npn types bipolar transistor 200.These components to constitute known current mirror circuit in the way of it is mutual Connection.2nd current mirror circuit 206 will flow through the electric current of the 10th resistance 178 as input, will flow through the 4th switch element 204 Electric current as output, make the size of input current and being substantially equal to the magnitudes for output current.

3rd switch element 202 is for example made up of P channel MOSFET.4th switch element 204 is for example by N channel MOSFET structure Into.The source electrode of the 3rd switch element 202 is connected with the 1st current mirror circuit 170.The grid of the 3rd switch element 202 with compare The inverted output terminal connection of device 164.The drain electrode of the 3rd switch element 202 is connected with the drain electrode of the 4th switch element 204.4th opens The grid for closing element 204 is connected with the inverted output terminal of comparator 164.The source electrode of the 4th switch element 204 is anti-with the 2nd electric current Penetrate mirror circuit 206 to connect.

12nd resistance 182 and the 13rd resistance 184 are sequentially connected in series between control power source voltage Vcc and earth level. Connecting node between 12nd resistance 182 and the 13rd resistance 184, the drain electrode and the 4th switch element 204 with the 3rd switch element 202 Drain electrode between connecting node connection.Connection between the drain electrode of the 3rd switch element 202 and the drain electrode of the 4th switch element 204 Node, is connected with the non-inverting input terminal of comparator 164.To the inversing input terminal applied voltage of comparator 164, Vm drops.

The non-inverted lead-out terminal of comparator 164 is connected with gate drivers 166.Gate drivers 166 make back segment control The phase place of signal S2 is consistent with the phase place of the signal occurred at the non-inverted lead-out terminal of comparator 164.That is, if comparator The signal occurred at 164 non-inverted lead-out terminal is high level（Low level）, then gate drivers 166 make back segment control signal S2 becomes high level（Low level）.

Using offset voltage Voffset as the 2nd operational amplifier 162 and 1npn types bipolar transistor 190 being input into, Output Voffset/（The resistance value of the 8th resistance 174）Electric current.According to the output of the comparator 164 with voltage drop Vm to be input into Phase place, the electric current is poured into or pulled out to the divider node between the 12nd resistance 182 and the 13rd resistance 184.For 3rd switch element 202 of electric bridge mode and the 4th switch element 204, are high level in the grid of the 2nd switch element 140（2nd opens Close element 140 to connect）Timing, the 3rd switch element 202 connects, the partial pressure section between the 12nd resistance 182 and the 13rd resistance 184 The voltage of point rises, setting electric current higher limit Ith1.If driving current Iout rises and reaches current upper limit value Ith1, Substantially it is changed into low level with the grid of the 2nd switch element 140（2nd switch element 140 disconnects）While, the 4th switch element 204 connect.Thus, the voltage of the divider node between the 12nd resistance 182 and the 13rd resistance 184 is reduced, setting electric current lower limit Ith2。

The mean value of driving current Iout is by the branch pressure voltage setting between the 12nd resistance 182 and the 13rd resistance 184. Further, since the effect of delayed amplitude set circuit 138, if the close voltage threshold Vth of the absolute value of driving voltage Vout, Filling/sourcing current becomes big, therefore, delayed amplitude, aos I of current upper limit value Ith1- floor level of electric current Ith2=become big.Driving voltage The absolute value of Vout differs bigger with voltage threshold Vth, and delayed amplitude, ao I is less.As shown in the above, this is for making frequency reducing The switching frequency of converter 104 falls in prescribed limit.

Fig. 1 is returned, Semiconductor-light-control control device 100 is configured to, N number of LED2-1 to 2-N individually can be carried out a little Lamp/light-off control.Bypass drive circuit 112 generates N number of for what is be controlled to the lighting/light-off of each LED2-1 to 2-N Lighting light-off control signal Sc1～ScN.The level list of each lighting light-off control signal Sc1 to ScN of bypass drive circuit 112 pairs Solely it is controlled, to obtain desired brightness and light distribution patterns.Specifically, bypassing drive circuit 112 makes 1LED2- In the case of 1 lighting, the 1st lighting light-off control signal Sc1 is set to into low level, in the case where making 1LED2-1 turn off the light, 1st lighting light-off control signal Sc1 is set to into high level.2nd lighting light-off control signal Sc2 to N lightings is turned off the light and is controlled Signal ScN processed is similarly arranged.Bypass drive circuit 112 is by each lighting light-off control signal Sc1 to ScN to corresponding bypass Circuit 270-1 to 270-N is exported.

1st bypass circuit 270-1 is in parallel to N LED2-N with 1LED2-1 respectively to N bypass circuits 270-N Connection.1st bypass circuit 270-1 to N bypass circuits 270-N is successively in the high-side output end of down converter 104 It is connected in series between son and low level side lead-out terminal.

1st bypass circuit 270-1 makes the two of 1LED2-1 when the 1st lighting light-off control signal Sc1 is high level Turn between end, i.e. be attached with the impedance lower than 1LED2-1.Thus, 1LED2-1 turns off the light.Below, make above-mentioned The state of the bypass circuit that LED turns off the light referred to as bypasses on-state.1st bypass circuit 270-1 turns off the light in the 1st lighting and controls letter When number Sc1 is low level, make to be attached with the impedance higher than 1LED2-1 between the two ends of 1LED2-1.Thus, 1LED2-1 lightings.Below, the state of the above-mentioned bypass circuit for making LED point lamp is become into bypass off-state.

1st bypass circuit 270-1 generate for the exception of 1LED2-1 and its distribution of periphery is detected 1 anomaly detection signal Sdet1, and supply to bypass drive circuit 112.In the feelings that the 1st anomaly detection signal Sdet1 is high level Under condition, the 1st bypass circuit 270-1 in bypass off-state when, be applied to the voltage of the 1st bypass circuit 270-1 with it is short Road detection voltage compare it is relatively low, or with higher than short-circuit detecting voltage burn out detection voltage compared with it is higher.Short-circuit detecting voltage It is set as that forward drop Vf than 1 LED is low.Burn out detection voltage is set as that forward drop Vf than LED is high, and compares 2 Forward drop sum 2Vf of individual LED is low.

2nd bypass circuit 270-2 to N bypass circuits 270-N similarly, is each based on the 2nd lighting light-off control Signal Sc2 to N lighting light-off control signals ScN, control the lighting/light-off state of 2LED2-2 to N LED2-N.Separately Outward, the 2nd bypass circuit 270-2 generates respectively the 2nd anomaly detection signal Sdet2 to N exceptions to N bypass circuits 270-N Detection signal SdetN, supplies to bypass drive circuit 112.

In the case that bypass drive circuit 112 makes the luminance-reduction of 1LED2-1 in usual lighting, put out the 1st lighting Lamp control signal Sc1 is with dim light frequency f1 from hundreds of Hz to several kHz periodically i.e. with square wave change in shape.By this The impulse modulation of the 1st lighting light-off control signal Sc1, so that 1LED2-1 is with dim light frequency f1 point off, reduces human eye sense The lightness being subject to.The dutycycle of the 1st lighting light-off control signal Sc1 is set as that desired luminous degree can be obtained. In the case of this, due in 1LED2-1 lightings, carrying out to flowing through the large change of driving current size of 1LED2-1 Suppress, so make colour cast be inhibited.For each 2LED2-2 to N LED2-N, bypass drive circuit 112 is also same Sample ground has PWM（Pulse Width Modulation）Dim light function.

Bypass drive circuit 112 is based on the 1st anomaly detection signal Sdet1, judges the distribution of 1LED2-1 and its periphery Whether exception there occurs.If the 1st anomaly detection signal Sdet1 becomes high level, bypass drive circuit 112 is judged to occur Exception, pressure makes the 1st lighting light-off control signal Sc1 become high level.For example, the 1st should be made according to PWM dim lights function Lighting light-off control signal Sc1 is low level period, and bypass drive circuit 112 will the 1st lighting light-off control signal Sc1 guarantor Hold as high level.In addition, bypass drive circuit 112 is if it is not determined that to there occurs exception, then should make the 1st lighting light-off control Signal Sc1 processed is low level period, also makes the 1st lighting light-off control signal Sc1 become high level.Bypass drive circuit 112 For 2LED2-2 to N LED2-N also has identical abnormal detection function.

1st bypass connection wiring 280-1 is by between the 1st bypass circuit 270-1 and the 2nd bypass circuit 270-2 1 bypass side connecting node NB1 and the the 1st load-side connecting node NL1 between 1LED2-1 and 2LED2-2 are connected Connect.In the feelings that the 1st bypass circuit 270-1 is in bypass off-state and the 2nd bypass circuit 270-2 is in bypass on-state Under condition, the polarity for flowing through driving current Iout of the 1st bypass connection wiring 280-1 is the direction from the lateral bypass side of load. In the situation that the 1st bypass circuit 270-1 is in bypass on-state and the 2nd bypass circuit 270-2 is in bypass off-state Under, the polarity for flowing through driving current Iout of the 1st bypass connection wiring 280-1 is the direction from bypass side loading side.By This, flows through the polarity of driving current Iout of the 1st bypass connection wiring 280-1, in the case of the latter in the case of the former Flow through the opposite polarity of driving current Iout of the 1st bypass connection wiring 280-1.

2nd bypass connection wiring 280-2 to（N-1）Connection wiring 280- is used in bypass（N-1）Also it is identical.

Bypass bypass circuit 270-1 to the N bypass circuit 270-N of drive circuit 112 and the 1st are configured to, and use in bypass It is in the case that connection wiring there occurs poor flow, 2 both bypass circuits being connected with the bypass connection wiring are strong System is set to bypass on-state.

Fig. 5 is the circuit diagram of the structure for representing the 2nd bypass circuit 270-2 and the 3rd bypass circuit 270-3.2nd bypass electricity Road 270-2 includes the 2nd switch level shifting circuit 254-2, the 2nd bypass/pressure limiting circuit 250-2, the 2nd burn out detection electricity Road 272-2, the 2nd short-circuit detecting circuit 274-2, the 2nd detection signal level shifting circuit 276-2 and the 2nd integrating circuit 278-2.

2nd switch receives the 2nd lighting light-off control signal with level shifting circuit 254-2 from bypass drive circuit 112 Sc2, is transformed it into and be set on the basis of the cathode voltage of 2LED2-2 low level 2nd by-pass switch drive signal Sd2.The phase place of the 2nd by-pass switch drive signal Sd2 is consistent with the phase place of the 2nd lighting light-off control signal Sc2, and the 2nd bypass is opened Closing the low level of drive signal Sd2 becomes the cathode voltage of 2LED2-2.So, the 2nd switch uses level shifting circuit 254- 2 pairs of the 2nd lighting light-off control signals Sc2 carry out level conversion, and to corresponding 2nd bypass/pressure limiting circuit 250-2 supplies.

2nd bypass/pressure limiting circuit 250-2 includes the 2nd by-pass switch 110-2 being connected in parallel with 2LED2-2.2nd Bypass/pressure limiting circuit 250-2 is high level in the 2nd by-pass switch drive signal Sd2（Low level）In the case of, by making 2nd by-pass switch 110-2 is connected（Disconnect）And make 2LED2-2 turn off the light（Lighting）.Additionally, 2 bypasses/pressure limiting circuit 250-2 is configured to, and when the 2nd by-pass switch drive signal Sd2 is low level, using the 2nd by-pass switch 110-2, limits the 2nd The upper limit of the both end voltage of by-pass switch 110-2.

2nd bypass/pressure limiting circuit 250-2 includes pressure limiting Zener diode 256, counterflow-preventing diode 258, the 16th resistance 260 and the 2nd by-pass switch 110-2.2nd by-pass switch 110-2 is for example made up of N channel MOSFET.

The negative pole of pressure limiting Zener diode 256 is connected with the drain electrode of the 2nd by-pass switch 110-2.Their connecting node with 1st bypass is connected with connection wiring 280-1.The positive pole of pressure limiting Zener diode 256 connects with the positive pole of counterflow-preventing diode 258 Connect.The grid of the 2nd by-pass switch 110-2 has the 2nd by-pass switch drive signal Sd2 via the input of the 16th resistance 260.2nd bypass The source electrode of switch 110-2 is connected with the 2nd bypass connection wiring 280-2.

By the 2nd by-pass switch drive signal Sd2 for turning on/off the 2nd by-pass switch 110-2, the 2nd bypass The gate electrode side of switch 110-2 is connected with the series circuit of pressure limiting Zener diode 256 and counterflow-preventing diode 258.That is, it is anti-reverse The negative pole of stream diode 258 is connected between the 16th resistance 260 and the grid of the 2nd by-pass switch 110-2.

Zener voltage=6V, the Vf=0.5V of counterflow-preventing diode 258 in pressure limiting Zener diode 256, the 2nd by-pass switch During threshold voltage of the grid=the 2.5V of 110-2, if the both end voltage of the 2nd by-pass switch 110-2 is voltage between drain-source 9V is reached, then the 2nd by-pass switch 110-2 begins to turn on, therefore, the higher limit of the both end voltage of the 2nd by-pass switch 110-2 is Burn out detection voltage is 9V.

The Zener voltage of pressure limiting Zener diode 256 is set as, makes the Vf of burn out detection voltage and 2LED2-2 most Big value compare it is higher and relatively low compared with the Zener voltage specified by the 2nd electrostatic protection Zener diode 252-2, and with the The Vf sums of the Vf and 3LED2-3 of 2LED2-2 are compared relatively low.For example, there are the feelings of substantially the same characteristic in each LED Under condition, during maximum=6V, the Zener voltage=20V of the 2nd electrostatic protection Zener diode 252-2 in the Vf of LED, pressure limiting is neat The Zener voltage of diode 256 received is set as the scope of 3V to 9V.

Counterflow-preventing diode 258 is used to avoid hindering based on the 2nd by-pass switch of the 2nd by-pass switch drive signal Sd2 The on/off of 110-2.For example, turn off the light or as broken string described later or contact in the 2LED2-2 for making to be connected in parallel Bad measure and when forcing to connect the 2nd by-pass switch 110-2, if bypassed without counterflow-preventing diode the 258, the 2nd The grid voltage of switch 110-2, can be via the 2nd bypass in an ON state from the beginning of the forward direction of pressure limiting Zener diode 256 Switch 110-2 and reduce.Counterflow-preventing diode 258 prevents above-mentioned condition.

2nd break detection circuit 272-2 disconnects in the 2nd by-pass switch 110-2（That is nonconducting state）When, judge to pass through Whether there is poor flow on the path of driving current Iout of 2LED2-2.2nd short-circuit detecting circuit 274-2 is by the 2nd When way switch 110-2 disconnects, judge whether 2LED2-2 or wiring closet are short-circuited exception.In the 2nd break detection circuit In the case of detecting exception in 272-2 or the 2nd short-circuit detecting circuit 274-2, via the 2nd detection signal level conversion electricity Road 276-2 and make the integrating condenser 282 of the 2nd integrating circuit 278-2 with the charging of the 1st time constant.The charging is in the 2nd bypass Switching drive signal Sd2 is low level and detects in the 2nd break detection circuit 272-2 or the 2nd short-circuit detecting circuit 274-2 Continue during going out exception.During in addition, integrating condenser 282 is with 2nd time constant longer than the 1st time constant Discharged.

2nd detection signal has the 17th resistance 284, the 18th resistance 286 and 4pnp types with level shifting circuit 276-2 Bipolar transistor 288.One end of 17th resistance 284 is connected with the emitter stage of 4pnp types bipolar transistor 288.At them Connecting node at apply control power source voltage Vcc.The other end of the 17th resistance 284 is connected with one end of the 18th resistance 286.It Connecting node be connected with the base stage of 4pnp types bipolar transistor 288.

2nd break detection circuit 272-2 has the 23rd resistance 210 and 6npn types bipolar transistor 212.6npn The colelctor electrode of type bipolar transistor 212 is connected with the other end of the 18th resistance 286.6npn types bipolar transistor 212 Base stage is via the 23rd resistance 210 and the connecting node of the positive pole of the positive pole and counterflow-preventing diode 258 of pressure limiting Zener diode 256 Connection.The emitter stage of 6npn types bipolar transistor 212 is connected with the 2nd bypass connection wiring 280-2.

2nd short-circuit detecting circuit 274-2 has the 19th resistance 290, the 20th resistance 292, the 21st resistance 294, the 22nd resistance 296th, 4npn types bipolar transistor 298 and 5npn types bipolar transistor 208.20th resistance 292 and the 22nd resistance 296 It is connected in series between the 1st bypass connection wiring 280-1 and the 2nd bypass connection wiring 280-2 successively.20th resistance The connecting node of the 292 and the 22nd resistance 296 and one end of the 21st resistance 294 and the base stage of 4npn types bipolar transistor 298 Connection.The other end of the 21st resistance 294 is connected with the negative pole of counterflow-preventing diode 258.4npn types bipolar transistor 298 Emitter stage is connected with the 2nd bypass connection wiring 280-2.The colelctor electrode and the 19th resistance of 4npn types bipolar transistor 298 290 one end connection.Apply control power source voltage Vcc in the other end of the 19th resistance 290.4npn type bipolar transistors The connecting node of 298 colelctor electrode and the 19th resistance 290 is connected with the base stage of 5npn types bipolar transistor 208.5npn The emitter stage of type bipolar transistor 208 is connected with the 2nd bypass connection wiring 280-2, colelctor electrode and the 18th resistance 286 The other end connects.

2nd integrating circuit 278-2 has integrating condenser 282, the 24th resistance 214 and the 25th resistance 216.24th resistance The earth level ground connection that 214 one end is substantially equal with the earth level with microcomputer, the other end and the 25th resistance 216 One end connection.The connecting node of the 24th resistance 214 and the 25th resistance 216 and the current collection of 4pnp types bipolar transistor 288 Pole connects.The other end of the 25th resistance 216 is connected with one end of integrating condenser 282.The other end of integrating condenser 282 with The earth level ground connection that the earth level of microcomputer is substantially equal.The voltage of one end of integrating condenser 282 is used as the 2nd Anomaly detection signal Sdet2 to bypass drive circuit 112 is supplied.

In the case of there occurs poor flow on the path of driving current Iout, in the disconnected of the 2nd by-pass switch 110-2 During opening, the both end voltage of the 2nd by-pass switch 110-2 rises and exceedes forward drop Vf.If its both end voltage exceedes disconnected Line detection voltage, then flow through electric current in pressure limiting Zener diode 256.Thus, the 6npn of the 2nd break detection circuit 272-2 Type bipolar transistor 212 is connected.

In addition, in the case where 2LED2-2 there occurs short circuit, during the disconnection of the 2nd by-pass switch 110-2, the 2nd The both end voltage of by-pass switch 110-2 is less than forward drop Vf.If its both end voltage be less than short-circuit detecting voltage, the 2nd The 4npn types bipolar transistor 298 of short-circuit detecting circuit 274-2 disconnects, and 5npn types bipolar transistor 208 is connected.

It is set as that the 20th resistance 292, the 21st resistance 294 and the respective resistance value of the 22nd resistance 296 meet following 3 articles Part.

（1）When the other end of the 21st resistance 294 is applied with high level, 4npn types bipolar transistor 298 is connected.

（2）The both end voltage for being applied with low level and the 2nd by-pass switch 110-2 in the other end of the 21st resistance 294 is big In or during equal to short-circuit detecting voltage, 4npn types bipolar transistor 298 is connected.

（3）The both end voltage for being applied with low level and the 2nd by-pass switch 110-2 in the other end of the 21st resistance 294 is little When short-circuit detecting voltage, 4npn types bipolar transistor 298 disconnects.

If one of connection of 6npn types bipolar transistor 212 or 5npn types bipolar transistor 208, The 4pnp types bipolar transistor 288 of the 2nd detection signal level shifting circuit 276-2 is connected.Control power source voltage Vcc It is the positive voltage on the basis of the earth level of microcomputer.In the 2nd break detection circuit 272-2 or the 2nd short-circuit detecting electricity In the case of detecting exception in the 274-2 of road, to the 2nd integrating circuit 278-2 supply control power source voltage Vccs.To integration electricity The charging of container 282 is carried out via the 25th resistance 216, and electric discharge is carried out via the 24th resistance 214 and the 25th resistance 216 's.By being set as making the resistance value of the 24th resistance 214 more than the resistance value of the 25th resistance 216, even if so as in average current 10% lighting（Connection=90% of the 2nd by-pass switch 110-2, disconnects=10%）It is this for abnormality detection during（That is, by the of the 2nd During the disconnection of way switch 110-2）During shorter dim light, it is also possible to which detection is abnormal.

3rd bypass circuit 270-3 is constituted identically with the 2nd bypass circuit 270-2, and comprising with the 2nd electricity consumption flat turn is switched Change the corresponding 3rd switch level shifting circuit 254-3 of circuit 254-2 corresponding with the 2nd bypass/pressure limiting circuit 250-2 3rd bypass/pressure limiting circuit 250-3,3rd break detection circuit 272-3s corresponding with the 2nd break detection circuit 272-2 and The corresponding 3rd short-circuit detecting circuit 274-3 of 2nd short-circuit detecting circuit 274-2 and the 2nd detection signal level shifting circuit Corresponding 3rd detection signals of 276-2 with level shifting circuit 276-3 and with the 2nd integrating circuit 278-2 the corresponding 3rd Integrating circuit 278-3.

Each the 1st bypass circuit 270-1, the 4th bypass circuit 270-4 to N bypass circuits 270-N are also bypassed with the 2nd Circuit 270-2 is constituted in the same manner.

Action to the Semiconductor-light-control control device 100 of said structure is illustrated.

Fig. 6（a）Extremely（c）It is the curve map of the time change for representing driving current Iout.Consideration makes first 1 LED point lamp, Then only about half of lighting, then the situation for making whole LED point lamps are made.Here, PWM dim lights are not considered.Fig. 6（a）Expression makes 1 LED point lamp, driving current Iout when making remaining N-1 LED turn off the light by the way that corresponding by-pass switch is connected when Between change.Fig. 6（b）The when anaplasia of driving current Iout when expression makes only about half of i.e. N/2 LED point lamp, makes residue turn off the light Change.Fig. 6（c）Represent the time change of driving current Iout when making whole LED point lamps.

In Fig. 6（a）Extremely（c）In, illustrate and delayed amplitude, ao I is adjusted, with no matter, lighting number, the light-off number of LED be such as What, makes the switching frequency i.e. situation of switch periods Ts constant of the 2nd switch element 140.But, for this explanation of reading For those skilled in the art of book, it is known that in the present embodiment, as long as with the change to the lighting number by LED, light-off number The mode that the change of switch periods Ts that change causes is suppressed is controlled to delayed amplitude, ao I.

With reference to Fig. 6（a）, in the case of the LED negligible amounts of lighting, in the turn-on time Ton of the 2nd switch element 140 Period, driving current Iout rises quickly, during the turn-off time Toff of the 2nd switch element 140, driving current Iout compared with Slowly decline.Delayed amplitude now is expressed as into Δ I1.The absolute value of driving voltage Vout is relatively low, by delayed amplitude set Offset voltage Voffset that circuit 138 is generated is relatively low.

With reference to Fig. 6（b）, in the case where the LED quantity of lighting is roughly the same with the LED quantity turned off the light, driving voltage Vout is changed into half of setting voltage of flyback adjuster 102 or so, when the turn-on time Ton of the 2nd switch element 140 and disconnection Between Toff it is identical.The overall variation speed of driving current Iout increases compared with the situation of the LED negligible amounts of lighting.

Delayed amplitude set circuit 138 is as shown in figure 3, generate higher offset voltage Voffset.Down converter drives Circuit 136 receives higher offset voltage Voffset, delayed amplitude, ao when making delayed amplitude, ao I2 be 1 with the lighting number of LED I1 compares increase.Thus, the incrementss of the overall variation speed of driving current Iout are cancelled, and switch periods Ts keep substantially permanent It is fixed.

With reference to Fig. 6（c）, in the LED negligible amounts turned off the light or without in the case of, in the connection of the 2nd switch element 140 Between during Ton, driving current Iout more slowly rises, during the turn-off time Toff of the 2nd switch element 140, driving current Iout declines quickly.Compare with the lighting number of the LED situation equal with light-off number, the overall variation speed of driving current Iout Reduce.The absolute value of driving voltage Vout is higher, by delayed amplitude set circuit 138 generate offset voltage Voffset compared with It is low.

Down converter drive circuit 136 receives relatively low offset voltage Voffset, makes delayed amplitude, ao I3 and LED's Delayed amplitude, ao I2 in the case that lighting number is equal with light-off number is compared and diminished.Thus, the overall variation of driving current Iout The reduction amount of speed is cancelled, and switch periods Ts keep constant.

Fig. 7 is the change of the 2nd by-pass switch drive signal Sd2 when representing PWM dim lights and the 2nd anomaly detection signal Sdet2 The sequential chart of change.The 2nd by-pass switch drive signal Sd2 herein is corresponding with the lighting of average current 20%.That is, the 2nd by-pass switch drives Dynamic signal Sd2 is the about a quarter that length Toff of low level period is the length Ton during being changed into high level.

In the case where not there is any exception, no matter how the 2nd by-pass switch drive signal Sd2 changes, and the 2nd is abnormal Near the constant i.e. 0V of the earth level for remaining microcomputer of detection signal Sdet2.It is assumed herein that opening in the 2nd bypass There is poor flow or broken string in the moment t1 in closing during drive signal Sd2 becomes high level.In moment t1, by the 2nd Way switch drive signal Sd2 is high level, i.e. the 2nd by-pass switch 110-2 is connected（That is conducting state）, so 6npn types are double Polar transistor 212 and the both of which of 5npn types bipolar transistor 208 are remained open.Thus, the 2nd anomaly detection signal The level of Sdet2 does not substantially change.

Be converted to low level moment t2 from high level in the 2nd by-pass switch drive signal Sd2, due to occur exception and Cause one of connection of 6npn types bipolar transistor 212 or 5npn types bipolar transistor 208, start to integration Capacitor 282 charges.

Become the moment t3 in low level period in the 2nd by-pass switch drive signal Sd2, integrating condenser 282 is full of Electricity.The voltage of the 2nd anomaly detection signal Sdet2 when integrating condenser 282 is fully charged, than using in bypass drive circuit 112 In it is determined that the 2nd anomaly detection signal Sdet2 level level threshold Vg it is high.

In the 2nd by-pass switch drive signal Sd2 from the moment t4 that low transition is high level, 6npn types bipolarity is brilliant Body pipe 212 and the both of which of 5npn types bipolar transistor 208 disconnect, and integrating condenser 282 starts electric discharge.

From the moment after t3 starts, the 2nd anomaly detection signal Sdet2 is higher than level threshold Vg, but due to microcomputer The responsiveness for bypassing drive circuit 112 is slower, so, temporarily persistently carry out the level of the 2nd by-pass switch drive signal Sd2 Conversion.

Next time low level moment t5 is converted to from high level in the 2nd by-pass switch drive signal Sd2, it is different what is occurred In the case of often still continuing, start recharged to integrating condenser 282.Then, integrating condenser 282 is again filled with electricity.

Further, since being set as the 2nd time constant involved by the electric discharge of integrating condenser 282 and charging involved the 1 time constant compare it is longer, so, even if becoming the moment t4 to moment t5 of high level in the 2nd by-pass switch drive signal Sd2 During, the voltage of the 2nd anomaly detection signal Sdet2 also remains higher than level threshold Vg.So, drive in the 2nd by-pass switch Dynamic signal Sd2 repeats after level conversion several times, and bypass drive circuit 112 is judged to the 2nd anomaly detection signal Sdet2 from low Level conversion is high level.

In addition, in the figure 7, for reaching integrating condenser 282 in during the 2nd by-pass switch 110-2 once disconnects It is illustrated to fully charged situation, but when during being not limited to this, or repeating to disconnect every time, integrating condenser 282 Jie Jin fully charged.

To the 1st bypass connection wiring 280-1 to（N-1）Connection wiring 280- is used in bypass（N-1）Wherein one The action of the Semiconductor-light-control control device 100 in the case of individual generation poor flow is illustrated.As an example, it is considered to The 2 bypasses situation that poor flow occurs in connection wiring 280-2, i.e., " X " shown in the label 218 in the circuit shown in Fig. 5 There is the situation of poor flow at the position of mark.

In the case where the 2nd bypass is with generation poor flow in connection wiring 280-2, the source of the 2nd by-pass switch 110-2 The level of the connecting node of the drain electrode of pole and the 3rd by-pass switch 110-3 rises.In the bypasses of the 2nd by-pass switch 110-2 and the 3rd Switch both 110-3 are when disconnecting, due to the characteristic difference etc. of the 2nd by-pass switch 110-2 and the 3rd by-pass switch 110-3, should The electricity of the drain electrode of the level or the 3rd by-pass switch 110-3 of the source electrode of the close 2nd by-pass switch 110-2 of level of connecting node It is flat.Also, for example, pass through if the level of the connecting node is substantial access to the level of the drain electrode of the 3rd by-pass switch 110-3 3rd short-circuit detecting circuit 274-3 is judged to there occurs short-circuit exception.3rd anomaly detection signal Sdet3 becomes high level, bypass Drive circuit 112 makes the 3rd lighting light-off control signal Sc3 be fixed as high level.

So, the 3rd by-pass switch 110-3 is connected, and the both end voltage of the 2nd by-pass switch 110-2 essentially becomes 2Vf. Because burn out detection voltage is less than 2Vf, so the 2nd break detection circuit 272-2 is judged to there occurs poor flow.2nd is abnormal Detection signal Sdet2 becomes high level, and bypass drive circuit 112 makes the 2nd lighting light-off control signal Sc2 be fixed as high level.

As a result, both the 2nd by-pass switch 110-2 and the 3rd by-pass switch 110-3 are forcibly turned on, 2LED2-2 And both 3LED2-3 are maintained light-off state.

Additionally, the electricity of the connecting node in the drain electrode of the source electrode and the 3rd by-pass switch 110-3 of the 2nd by-pass switch 110-2 In the case of the level of the source electrode for flushing nearly 2nd by-pass switch 110-2, the 2nd short-circuit detecting circuit 274-2 detects that short circuit is different Often, the 3rd break detection circuit 272-3 detects that broken string is abnormal, still by the 2nd by-pass switch 110-2 and the 3rd by-pass switch Both 110-3 are forcibly turned on.

The measure for being forcibly turned on 2 by-pass switches of taking were it not for, but will be used to make 2LED2-2 lightings 2nd by-pass switch drive signal Sd2 is set to low level, and will drive letter for the 3rd by-pass switch for making 3LED2-3 turn off the light In the case that number Sd3 is set to high level, although the 3rd by-pass switch 110-3 is connected, but driving current Iout and without flow through by the 3rd Way switch 110-3, but flow through 3LED2-3.I.e., it is impossible to make 3LED2-3 turn off the light.Letter is driven the 2nd by-pass switch is made Number Sd2 becomes high level, in the case of the 3rd by-pass switch drive signal Sd3 becomes low level, although the 2nd by-pass switch 110- 2 connect, but driving current Iout and without flow through the 2nd by-pass switch 110-2, but flow through 2LED2-2.I.e., it is impossible to make 2LED2-2 turns off the light.

As it appears from the above, in the case where the 2nd bypass is with generation poor flow in connection wiring 280-2, it is difficult to individually control 2LED2-2,3LED2-3 respective lighting/light-off state.

In the Semiconductor-light-control control device 100 involved by present embodiment, in the 1st bypass connection wiring 280-1 To（N-1）Connection wiring 280- is used in bypass（N-1）One of generation poor flow in the case of, make to turn on 2 by-pass switches that bad bypass connection wiring is connected are forcibly turned on.Thus, make what bypass connection wiring was connected 2 LED turn off the light.

It is as noted above, it is difficult to individually to the bypass in the case of there is poor flow in bypass connection wiring The respective lightings of the 2 LED/light-off state connected with connection wiring is controlled.For example, it is contemplated that semiconductor light source control dress Putting 100 is used for the driving beam of headlight for automobile, makes the LED of correlation turn off the light with not with Semiconductor-light-control control device 100 The situation of the function of dazzle can be caused to preceding vehicle or opposite vehicle.In the case, if the bypass to related LED connections There is poor flow with connection wiring, then related LED cannot be made to turn off the light and be likely to result in dazzle.Therefore, in the present embodiment, If there is poor flow in bypass connection wiring, by forcing to connect connected 2 by-pass switches, so as to It doesn't matter enough to make the bypass path of the bypass connection wiring of generation poor flow and driving current Iout, maintains correlation LED Light-off state.Thus, it is possible to avoid causing dazzle.

In addition, the Semiconductor-light-control control device 100 involved by present embodiment has PWM dim light functions, it passes through to make So that higher speed is turned on/off, the brightness to corresponding LED is adjusted by-pass switch.The by-pass switch connect when, The close 0V of both end voltage of by-pass switch, but can not be judged as short-circuit abnormal because this is not abnormal.Therefore, semiconductor light source Control device 100 is configured to, and short-circuit abnormality detection and broken string abnormality detection are not carried out when by-pass switch is connected, and opens in bypass Shut-off is detected when opening to it.

Thus, in the case that LED or distribution in PWM dim lights occurs exception, need to disconnect in by-pass switch and occur It is abnormal and no matter whether there is abnormal accessory conduction pathway switch be turned on both states at a high speed alternately in carry out abnormal judgement.As to LED's The main equipment that lighting/light-off and PWM dim light functions are controlled, is used mostly microcomputer.Generally, due to microcomputer Action is carried out with the long period interval of the degree of a few tens of milliseconds, so being not appropriate for only respective to multiple LED different at high speed The situation for often being detected and being judged.For example, in the case where dim light frequency f1 is several kHz, carries out the lighting of average current 10%, Length during the disconnection of by-pass switch is hundreds of Microsecond grade.It is this it is shorter in a period of judge abnormal/normal when, need to adopt With responsiveness high price microcomputer faster.

Therefore, in the Semiconductor-light-control control device 100 involved by present embodiment, by the effect of integrating circuit Generate regardless of whether carrying out PWM dim lights and be high level in exception, be low level anomaly detection signal when normal.It is miniature Computer bypasses drive circuit 112 based on the anomaly detection signal, judges normal/abnormal.Thus, opened using bypass in employing In the case of the PWM dim light functions of pass, do not adopt the microcomputer of high price also can examine to the exception of LED or distribution Survey.

In addition, the Semiconductor-light-control control device 100 according to involved by present embodiment, even if in driving current Iout In the case of the poor flows such as bad or broken string are come in contact on path, it is also possible to the rising to being applied to voltage on by-pass switch Suppressed.For example, it is contemplated that when 1LED2-1 lighting state is that the 1st by-pass switch 110-1 disconnects, 1LED2-1's Illustrate in distribution, i.e. Fig. 1 of the upstream side of the connecting node of the negative pole of positive pole and the 1st electrostatic protection Zener diode 252-1 Bad or broken string situation is come in contact at the distribution of " X " mark shown in the label 262 of circuit.

In the event of above-mentioned loose contact or broken string, then the both end voltage rising of the 1st by-pass switch, the 1st abnormality detection letter Number Sdet1 is high level from low transition.If bypass drive circuit 112 detects that the 1st anomaly detection signal Sdet1 is carried out Above-mentioned conversion, then be judged to that 1LED2-1 there occurs exception, and in circuit shown in Fig. 1, taking makes the 1st by-pass switch 110-1 Connect and the measure of other LED point lamps can be made.

But, due to as noted above, the responsiveness that microcomputer bypasses drive circuit 112 is slower, therefore, should Measure generally needs the time of a few tens of milliseconds to hundreds of millisecond.Here, in Semiconductor-light-control control device not with this enforcement In the case of pressure-limiting function involved by mode, due to there is no the capacitor that output voltage is smoothed, cause in above-mentioned contact After the just generation of bad or broken string, export and determined by the acceptable capacity of the energy and the 1st by-pass switch accumulated in inductor 144 Several kV（Absolute value）High voltage.Before the 1st by-pass switch is connected, above-mentioned high voltage is applied on the 1st by-pass switch. Thus, as the 1st by-pass switch, regardless of whether only applying a few V voltages in usual lighting, it is required to consider loose contact or disconnected Line and select the element of resistance to a few kV voltages.

On the other hand, the Semiconductor-light-control control device 100 with pressure-limiting function according to involved by present embodiment, When above-mentioned broken string or loose contact occur, although voltage rises between the Drain-Source of the 1st by-pass switch 110-1, but can pass through Rising of the by-pass switch 110-1 effects of of pressure limiting Zener diode 256 and the 1st to the voltage itself is limited.Thus, i.e., Consideration loose contact or broken string are made, as the 1st by-pass switch 110-1 low pressure element can be also selected.

Here, when broken string or loose contact occur, used as an example, the 1st by-pass switch 110-1 is with 10V × 1A =10W or so has acted on a few tens of milliseconds to hundreds of millisecond, but resistance is less because script is connected, and needs use to a certain degree larger Equipment, so the impact to equipment size or cost is less.

For example, it is contemplated that when it is that the 1st by-pass switch 110-1 disconnects that 1LED2-1 is for lighting state, 1LED2-1's Electricity is shown in distribution, the i.e. Fig. 1 in the downstream of the connecting node of the negative pole of positive pole and the 1st electrostatic protection Zener diode 252-1 The distribution of " X " mark shown in the label 264 on road comes in contact bad or broken string situation.In Semiconductor-light-control control device not In the case of the pressure-limiting function involved by present embodiment, the energy of the accumulation of inductor 144 is most neat by the 1st electrostatic protection Receive diode consumption.Thus, as the 1st electrostatic protection Zener diode, needs are selected to bear above-mentioned large energy consumption Element.Or, as the 1st electrostatic protection Zener diode, it is also possible to be considered as have and loose contact or broken string occur When issuable a few kV voltages compare the element of higher Zener voltage, but generally, if Zener voltage is so high, cannot Realize the function of the electrostatic protection of script.

On the other hand, the Semiconductor-light-control control device 100 with pressure-limiting function according to involved by present embodiment, if It is set to the higher limit and the 1st electrostatic protection Zener diode 252-1 defineds of the both end voltage of the 1st by-pass switch 110-1 Zener voltage is compared relatively low.Thus, as the 1st electrostatic protection Zener diode 252-1, the pole of less Zener two can be selected Pipe.

In the case of one of generation identical loose contact of 2LED2-2 to N LED2-N or broken string In the same manner, the upper limit of the voltage to applying on corresponding by-pass switch or electrostatic protection Zener diode is limited.Thus, make Low pressure element can be adopted for corresponding by-pass switch, in addition, can adopt as corresponding electrostatic protection Zener diode Use less Zener diode.

In addition, in the Semiconductor-light-control control device 100 involved by present embodiment, for controlling the lighting of LED/put out The by-pass switch of lamp, also serves as the switch for realizing the pressure-limiting function of the both end voltage for LED and works.That is, bypass is opened Close and work as lighting/light-off control function and pressure-limiting function simultaneously.Thus, it is possible to realize lighting/light-off control function And while pressure-limiting function, straining element quantity increases.

In the Semiconductor-light-control control device 100 involved by present embodiment, due in N number of LED2-1 to 2-N Deferent segment be not provided with smooth capacitor, so driving current Iout relative to the 2nd switch element 140 tracing ability more It is excellent.Especially, if the 2nd switch element 140 disconnects, driving current Iout diminishes, if the 2nd switch element 140 is connected, Then driving current Iout becomes big.Also, in order that driving current Iout is stabilized near desired value, replace smoothing and adopt The Delay control of driving current Iout.As a result, the response high speed in current feedback can be made.For example, can be due to side When the effect of road drive circuit 112 and by-pass switch and the lighting number of LED change, driving current Iout is set quickly to follow above-mentioned The change of load.Especially, the owe punching and lighting number of driving current Iout that can suppress the lighting number of LED when increasing is reduced When driving current Iout overshoot.

In addition, in the Semiconductor-light-control control device 100 involved by present embodiment, the flyback adjuster 102 of leading portion Negative pole output is set to, and the down converter 104 of back segment is also set to negative pole output.Thus, as by-pass switch, can adopt More excellent N channel MOSFET of characteristic.

On the basis of negative pole output, because inductor 144 is not arranged in the negative pole of fly-wheel diode 142 and output Between, and be provided between positive pole and output, accordingly, as the 2nd switch element 140 of down converter 104, can adopt More excellent N channel MOSFET of characteristic.Furthermore it is possible to stably detect driving voltage Vout.

In addition, in the case where Semiconductor-light-control control device is positive pole output, consider mostly LED ground connection situation and High side is driven the detection of electric current.Here, if load change, the level of test position also changes, accordingly, it is difficult to examine Survey accurate driving current.In addition, the structure of detection circuit is also possible to become more complicated.Therefore, in present embodiment institute Exported using negative pole in the Semiconductor-light-control control device 100 being related to, current detecting is set in the output that side of the positive electrode is ground side Resistance 108.Thus, even if load（Driving voltage Vout）Change, level of the change to the test position of driving current Iout Impact it is also less, can stably detect driving current Iout.In addition, it is also possible to simplify the structure of detection circuit.

When Delay control is carried out to driving current Iout, if the input voltage or driving voltage of down converter 104 Vout or both change, then the slope variation for rising or falling of driving current Iout, therefore, it is possible to make the 2nd to open Close the switching frequency change of element 140.Therefore, in the Semiconductor-light-control control device 100 involved by present embodiment, to press down Mode control lag amplitude, ao I of the change of switching frequency processed.Especially, by setting target switch frequency is avoided known Radio noise frequency band such that it is able to suppress harmful effect of the radio noise to Semiconductor-light-control control device 100.

In addition, in the Semiconductor-light-control control device 100 involved by present embodiment, by flyback adjuster 102 Act on and suppress due to the change of the input voltage of down converter 104 caused by the change of battery tension Vbat.Thus, energy It is enough to suppress because the change of the input voltage of down converter 104 causes the change of switching frequency.Stated differently, since without the need for root Delayed amplitude, ao I is selected according to the input voltage of down converter 104 and the combination of driving voltage Vout, and can be to be based primarily upon Driving voltage Vout selects delayed amplitude, ao I, therefore, it can further simplify the control for being adjusted delayed amplitude, ao I System.This also contributes to small-scaleization of control circuit, high speed.

In addition, in the Semiconductor-light-control control device 100 involved by present embodiment, in the defeated of flyback adjuster 102 Go out section and be provided with output capacitor 128.When by-pass switch is connected, if the 2nd switch element 140 is connected, the output electricity The electric charge accumulated in container 128 disposably flows through LED.But, due to the driving current in Semiconductor-light-control control device 100 Inductor 144 is provided with the path of Iout, the flowing therefore, it is possible to make above-mentioned electric charge is smoothed, suppresses driving current Iout Overshoot.When by-pass switch is disconnected, the owe punching of driving current Iout is also suppressed in the same manner.

It is following that consideration is designed in addition for the overshoot or owe punching of driving current Iout when suppressing by-pass switch to switch Semiconductor light source lamp circuit 300 involved by comparative example.

Fig. 8 is the circuit diagram of the structure for representing the semiconductor light source lamp circuit 300 involved by comparative example.Semiconductor light source Lamp circuit 300 does not substantially use the front fed inverter of smoothing capacity device.Semiconductor light source lamp circuit 300 has control Circuit 302, input capacitor 306, reset circuit 308, transformer 310, the 5th switch element 312, the 2nd diode the 314, the 3rd two Pole pipe 316, inductor 318 and current sense resistor 320.

If the size of driving current exceedes the current upper limit value of regulation, control circuit 302 disconnects the 5th switch element 312, if the size of driving current is less than floor level of electric current, connect the 5th switch element 312.

For semiconductor light lamp circuit 300, if the ratio of winding of transformer 310 is set to into Ns/p, the electricity of inductor 318 Sense is set to Ls ', and the delayed amplitude of driving current is set to Δ I ', and input voltage is set to Vin, and output voltage is set to Vout（<0）, the 5th The turn-on time of switch element 312 is set to Ton ', and its turn-off time is set to Toff ', and switching frequency is set to F ', and due to rectification The forward drop of diode is less and is ignored, then F ' can be obtained by following formulas.

In semiconductor light source lamp circuit 300, in ratio of winding=16.7 of transformer 310（Input=6V is transformed to defeated Go out=100V）, inductor 318 inductance=500 μ H, delayed amplitude=0.1A when, between Vin, Vout, F obtained by formula 1 ' Relation as described in Table 1.It is assumed herein that input voltage variation=6V to 20V, output（Load）Variation in voltage=- 4V To -88V（The LED of 22 Vf=4V of series connection）.

In the case, the maximum/minimum of switching frequency F ' changes about 17 times.Although can be right by increasing inductance The amplitude of variation is suppressed, but this can cause circuit to maximize.In addition, realizing being carried out according to input voltage and output voltage Computing and in the case that the large change of switching frequency F ' is suppressed into function in prescribed limit, control circuit scale becomes Greatly.

For the Semiconductor-light-control control device 100 involved by present embodiment, identical calculating is also carried out.For partly leading Body light source control device 100, if the inductance of inductor 144 is set to into Ls, switching frequency is set to F, and due to fly-wheel diode 142 forward drop is less and is ignored, then F can be obtained by following formulas.

In Semiconductor-light-control control device 100, target voltage Vt=-100V, the inductance=500 μ H of inductor 144, During delayed amplitude=0.1A, by relation between Vt, Vout, F that formula 2 is obtained as described in Table 2.

In the case, it is of about 6.5 times that the change of switching frequency F suppresses.In addition, the major parameter for causing the change is Driving voltage Vout, target voltage Vt are substantially fixed, therefore, it is possible to make that delayed amplitude, ao I is adjusted to suppress The scale of the control circuit of the change of switching frequency F is less.

The calculated value of the switching frequency F of observation table 2, then as driving voltage Vout declines from -4V to -44V, open Close frequency F to rise, as driving voltage Vout declines from -44V to -88V, switching frequency F is reduced.The rising of switching frequency F/ The border of reduction is the 1st section（Leading portion）Flyback adjuster 102 output voltage（2nd section（Back segment）Down converter 104 Input voltage）Only about half of i.e. -50V.Thus, by so that driving voltage Vout is more low delayed in Vout ＞ -50V Amplitude, ao I is bigger, and more low in Vout ＜ -50V, and less mode is controlled such that it is able to easily will switch frequency Rate F is limited in prescribed limit.

In addition, in the present embodiment, it was observed that the border of the rising/reduction of switching frequency F is flyback adjuster 102 Output voltage it is only about half of, but in the other embodiment with the configuration of other circuits, it is also contemplated that the border is output The situation of 1/3rd or a quarter of voltage etc..In short, between the maximum and minimum of a value of Vout, may deposit Apply the Vout of the maximum of switching frequency F when in delayed constant amplitude.Thus, if finding out this by experiment or simulation etc. Vout, so that the delayed amplitude, ao I mode minimum in the Vout constitutes circuit, then can more suitably suppress switching frequency The change of F.

For the Semiconductor-light-control control device 100 involved by present embodiment, the setting example of parameter is shown in Table 3 below Go out.

Table 3

Vout(V)	Voffset	Lower voltage limit	Upper voltage limit	Ith2	Ith1	Average current	Switching frequency
								-4	0.25	0.2356	0.2456	1.178	1.228	1.203	382.2kHz
-8	0.37	0.2332	0.2480	1.166	1.240	1.203	498.7kHz
								-12	0.48	0.2309	0.2503	1.154	1.252	1.203	542.3kHz
-16	0.60	0.2285	0.2527	1.143	1.264	1.203	555.8kHz
								-20	0.72	0.2262	0.2551	1.131	1.275	1.203	553.7kHz
-24	0.83	0.2238	0.2574	1.119	1.287	1.203	542.8kHz
								-28	0.95	0.2215	0.2598	1.107	1.299	1.203	526.1kHz
-32	1.07	0.2191	0.2621	1.095	1.311	1.203	505.7kHz
								-36	1.18	0.2167	0.2645	1.084	1.322	1.203	482.6kHz
-40	1.30	0.2144	0.2668	1.072	1.334	1.203	457.6kHz
								-44	1.42	0.2120	0.2692	1.060	1.346	1.203	431.0kHz
-48	1.54	0.2097	0.2716	1.048	1.358	1.203	403.4kHz
								-52	1.56	0.2093	0.2720	1.046	1.360	1.203	398.2kHz
-56	1.46	0.2113	0.2700	1.056	1.350	1.203	419.6kHz
								-60	1.36	0.2132	0.2680	1.066	1.340	1.203	438.2kHz
-64	1.26	0.2152	0.2660	1.076	1.330	1.203	453.4kHz
								-68	1.16	0.2172	0.2640	1.086	1.320	1.203	464.4kHz
-72	1.06	0.2192	0.2621	1.096	1.310	1.203	469.9kHz
								-76	0.97	0.2211	0.2601	1.106	1.300	1.203	468.4kHz
-80	0.87	0.2231	0.2581	1.116	1.291	1.203	457.3kHz
								-84	0.77	0.2251	0.2561	1.125	1.281	1.203	433.1kHz
-88	0.67	0.2271	0.2542	1.135	1.271	1.203	390.0kHz

Voffset is formed as, and the circuit constant of the delayed amplitude set circuit 138 shown in Fig. 2 is adjusted, so as to Near Vout=-50V, magnitude of voltage shown in curve map as shown in Figure 3 is uprised.Lower voltage limit/upper voltage limit is the drop shown in Fig. 4 The voltage of the divider node of the 12nd resistance 182 and the 13rd resistance 184 of frequency transducer drive circuits 136, corresponds respectively to electric current Lower limit Ith2, current upper limit value Ith1.Lower voltage limit/upper voltage limit be by set the 8th resistance 174, the 12nd resistance 182, Each resistance value and control power source voltage Vcc of the 13rd resistance 184, calculates according to offset voltage Voffset.Average current is The mean value of current upper limit value Ith1 and floor level of electric current 1th2.Switching frequency is in the identical formula of formula 2, to make △ I= Ith1 mono- Ith2, Vt=mono- 100V, gs=200 μ H and obtain.

Even if understanding that Ls is decreased to 200 μ H from 500 μ H, it is also possible to make switching frequency fall slightly larger than 550kHz to being slightly less than In the range of 400kHz.That is, the Semiconductor-light-control control device 100 according to involved by present embodiment, it is possible to use in will drive The inductance miniaturization of streaming current Iout smoothings.

In addition, by the semiconductor involved by the semiconductor light source lamp circuit 300 and present embodiment involved by comparative example Light source control device 100 is compared, and the output electricity of flyback adjuster 102 is increased in Semiconductor-light-control control device 100 2nd switch element 140 of container 128 and down converter 104, but due to can be from semiconductor light source lamp circuit 300 Fall reset circuit 308, so circuit scale is roughly the same.

This concludes the description of structure and the action of Semiconductor-light-control control device involved by embodiment.The embodiment Only illustrate, those skilled in the art it should be clear that above-mentioned each inscape or it is each process combination and can form various modifications example, and These variations fall within the scope of the present invention.

In embodiments, configure as the element of down converter 104, for respectively arranging the 2nd switch element 140 In the negative side of fly-wheel diode 142, the situation that inductor 144 is arranged on the side of the positive electrode of fly-wheel diode 142 is said It is bright, but it is not limited to this.As long as fly-wheel diode is connected in parallel with the output capacitor 128 of flyback adjuster 102.2nd As long as switch element is arranged on from one end of output capacitor 128 and returns the other end of output capacitor 128 to LED and from LED Driving current Iout path on, and be arranged between output capacitor 128 and fly-wheel diode.2nd switch unit The on/off of part can also be controlled based on driving current.As long as inductor 144 is arranged on the path of driving current Iout On, and be arranged between fly-wheel diode and LED.

Fig. 9（a）Extremely（c）Be illustrate Semiconductor-light-control control device 400 involved by the variation of the 1st, the 2nd and the 3rd, 500, The circuit diagram of 600 structure.Fig. 9（a）Represent the structure of the Semiconductor-light-control control device 400 involved by the 1st variation.2nd One end of switch element 440 is connected with the high-side output of flyback adjuster 102, and the other end is negative with fly-wheel diode 442 Pole connects.The connecting node of the negative pole of the other end and fly-wheel diode 442 of one end of inductor 444 and the 2nd switch element 440 Connection.The other end ground connection of inductor 444, and become the high-side lead-out terminal of LED.The positive pole of fly-wheel diode 442 with The low level side output connection of flyback adjuster 102, and become the low level side lead-out terminal of LED.

Fig. 9（b）Represent the structure of the Semiconductor-light-control control device 500 involved by the 2nd variation.Fly-wheel diode 542 The high-side output of negative pole and flyback adjuster 102 be connected and be grounded, the high-side of formation LED is exported.2nd switch unit One end of part 540 is connected with the low level side output of flyback adjuster 102, and the other end is connected with the positive pole of fly-wheel diode 542. One end of inductor 544 is connected with the connecting node of the positive pole of the other end and fly-wheel diode 542 of the 2nd switch element 540.Electricity The other end of sensor 544 becomes the low level side lead-out terminal of LED.

Fig. 9（c）Represent the structure of the Semiconductor-light-control control device 600 involved by the 3rd variation.2nd switch element 640 The low level side output of one end and flyback adjuster 102 be connected, the other end is connected with the positive pole of fly-wheel diode 642.2nd opens The connecting node of the positive pole of the other end and fly-wheel diode 642 of element 640 is closed, the low level side output of LED is formed.Afterflow two The negative pole of pole pipe 642 is connected with one end of inductor 644.The negative pole of fly-wheel diode 642 and the connection of one end of inductor 644 Node is connected with the high-side output of flyback adjuster 102.The other end ground connection of inductor 644, and become the high level of LED Side lead-out terminal.

Each Semiconductor-light-control control device 400,500,600 according to involved by the variation of the 1st, the 2nd and the 3rd, with enforcement Semiconductor-light-control control device 100 involved by mode in the same manner, can reduce the overshoot and owe punching of driving current Iout.

In embodiments, for realizing negative pole by being grounded the side of the positive electrode of the i.e. multiple LED of the high-side of output The situation of output is illustrated, but is not limited to this, for example can also be by the side of the positive electrode of multiple LED and battery tension Vbat Deng the terminal connection for applying DC voltage.

In embodiments, the situation for constituting circuit in the following manner is illustrated, i.e. the real time measure does not switch frequency Rate, but replace, based on the known relation between driving voltage Vout and switching frequency, determines driving voltage Vout and stagnant Relation between amplitude Δ I, so that delayed amplitude, ao I is changed based on the relation, but is not limited to this.For example, also may be used So that Semiconductor-light-control control device has the circuit that the switching frequency to the 2nd switch element 140 is measured, to delayed amplitude The switching frequency for being adjusted such that the measure falls in desired frequency range.

In embodiments, include N number of by-pass switch 110-1's to 110-N for Semiconductor-light-control control device 100 Situation is illustrated, but is not limited to this, it is also possible to be separately provided by-pass switch outside Semiconductor-light-control control device.

In embodiments, the situation for being driven the Delay control of electric current is illustrated, but is not limited to this, For example the dutycycle of the 2nd switch element 140 can also be controlled, so that carrying out appropriate filtered electricity to voltage drop Vm Crimping reference voltage closely corresponding with target current.

In embodiments, following situations are illustrated, i.e. by combination flyback adjuster 102 and down converter 104 Drive circuit is constituted, the drive circuit generates driving current Iout, go forward side by side and exercise the close target of size of driving current Iout The control of value, but this is not limited to, for example, the circuit shown in Fig. 8 can also be used as the drive circuit, or, it is also possible to Using the flyback adjuster for carrying out Current Feedback Control.

Figure 10 is the knot for representing Semiconductor-light-control control device 700 and connected part involved by the 4th variation The circuit diagram of structure.Semiconductor-light-control control device 700 has flyback adjuster 702, current sense resistor 708, N number of bypass circuit 270-1 to 270-N and bypass drive circuit 112.

In the Semiconductor-light-control control device 700 involved by this variation, in the 2nd bypass connection wiring 280-2 In the case that the position of " X " mark shown in label 718 occurs poor flow, with the semiconductor light source involved by present embodiment Control device 100 in the same manner, by the 2nd bypass circuit 270-2, the 3rd bypass circuit 270-3 and bypass drive circuit 112 Effect, is forcibly turned on both the 2nd by-pass switch and the 3rd by-pass switch.

In addition, the limits value of the maximum voltage of the output of flyback adjuster 702, it is contemplated that be connected in series N number of whole LED point lamps Situation and be set greater than or equal to Vf sums.For example, 30 are connected in series the maximum of the Vf of 1 LED is set to into 6V, and During individual LED, limits value is set greater than or equal to 180V.Here, the distribution of " X " mark shown in the label 762 in Figure 10 Bad or broken string moment is come in contact, due to not flowing through driving current Iout in LED, so flyback adjuster 702 is defeated Go out voltage to rise to 180V.Control circuit（It is not shown）If detecting driving current Iout no longer to flow, check which is matched somebody with somebody Line or LED break, and in the circuit in fig. 10, take the 1st by-pass switch 110-1 of connection and enable other LED lightings Measure.The measure generally needs the time of a few tens of milliseconds to hundreds of millisecond.

Here, there is no pressure limiting Zener diode 256 and counterflow-preventing diode 258 in Semiconductor-light-control control device In the case of, before the 1st by-pass switch is connected, the output voltage of flyback adjuster 702 reaches 180V.Now, if used The Vf's of LED（Under room temperature）Mean value is 4V, is 3V when electric current hardly flows, then the 1st by-pass switch is applied with 180V- The voltage of 3V × 30=90V.Accordingly, for any one in 30 by-pass switches, regardless of whether only applying generally several V's Voltage, it is necessary to consider broken string or loose contact and select the element of the voltage of resistance to 100V.

Below, if there is short-term or loose contact in the distribution of " X " mark shown in the label 764 of Figure 10, the 1st is quiet Electric protection Zener diode is applied in above-mentioned 90V when almost without flow through electric current, is applied in when control electric current is flow through 180V-4V × 30=60V.Here, if the Zener voltage of the 1st electrostatic protection Zener diode is set to into 20V, due to Voltages of the 90V or 60V higher than 20V, thus when control electric current is set to into 1A, during a few tens of milliseconds to hundreds of millisecond, the 1st The effect of electrostatic protection Zener diode has 20V × 1A=20W, and needs are selected to bear the element of the power.In order to avoid upper Situation is stated, as long as making the Zener voltage of the 1st electrostatic protection Zener diode more than or equal to 90V, but reality is thus difficult to The now effect of the electrostatic protection of script.

Therefore, the Semiconductor-light-control control device 700 involved by this variation is by with 1 bypass/pressure limiting circuit 250-1, even if so as to come in contact bad or broken string, it is also possible to suppress the voltage of applying on the 1st by-pass switch 110-1 The upper limit.Thus, the element of the resistance to high pressure more than or equal to 100V need not be selected as the 1st by-pass switch 110-1.In addition, passing through The restriction voltage that 1st bypass/pressure limiting circuit 250-1 is produced is set smaller than or equal to the 1st electrostatic protection Zener diode The Zener voltage of 252-1, then can select less Zener diode.

Additionally, in the Semiconductor-light-control control device 100 involved by embodiment, due to not having pressure-limiting function In the case of, need to make by-pass switch bear kV step voltages, so the pressure inhibition produced by arranging pressure-limiting function exists It is more significantly in embodiment.

In embodiments, LED and the one-to-one situation of by-pass switch are illustrated, but is not limited to this, it is also possible to profit Lighting/the light-off of multiple LED is controlled with a by-pass switch.For example, the feelings of a by-pass switch are connected in 2 LED of series connection Under condition, the maximum=12V of total Vf of LED, the Zener voltage=40V of electrostatic protection Zener diode, thus, as long as making pressure limiting neat The Zener voltage of diode received falls in the range of 9V to 21V.The Zener voltage of pressure limiting Zener diode is being set to into 20V When, the limits value of both end voltage is 23V, as long as selecting the element of the voltage of resistance to 30V accordingly, as by-pass switch.

In embodiments, the 2nd bypass connection wiring 280-2 is not only, even if in the 3rd bypass connection wiring The label 220 of 280-3（With reference to Fig. 5）In the case that the position of shown " X " mark occurs poor flow, also by the 2nd bypass The effect of circuit 270-2, the 3rd bypass circuit 270-3, the 4th bypass circuit 270-4 and bypass drive circuit 112, by the 2nd Way switch, the 3rd by-pass switch and the 4th by-pass switch are all forcibly turned on.

In embodiments, following situations are illustrated, i.e. the situation of poor flow occurs in bypass connection wiring Under, 2 by-pass switches being connected with the bypass connection wiring which due to broken string it is abnormal and be forcibly turned on, which by It is forcibly turned on being to rely on what characteristic of by-pass switch etc. was carried out in short-circuit exception, but is not limited to this.For example, it is also possible to right The bypass circuit of serial number odd number（1st bypass circuit 270-1, the 3rd bypass circuit 270-3 ...）Arrange in parallel respectively Resistance.Alternatively, it is also possible to arrange resistance in parallel respectively to the bypass circuit of serial number even number.In the case, use in bypass It is in the case of there is poor flow in connection wiring, the above-mentioned side by-pass switch for being provided with resistance is abnormal and strong according to short circuit Turn-on, the above-mentioned side by-pass switch for being not provided with resistance is forcibly turned on according to broken string exception.

In embodiments, to the burn out detection function and function of short circuit detection using bypass circuit and bypass drive circuit And the situation for tackling the poor flow of bypass connection wiring is illustrated, but it is not limited to this.For example, it is also possible in bypass With current measuring unit etc. is arranged in connection wiring for detecting the unit of the poor flow of bypass connection wiring, using the list Unit judges whether poor flow occurs in bypass connection wiring.Bypass drive circuit can also be made to be judged to that conducting occurs not In the case of good, pressure connects corresponding 2 by-pass switches.

In embodiments, following situations are illustrated, i.e. poor flow is detected when by-pass switch disconnects or short circuit is different In the case of often, make integrating condenser charge, in the case of in addition, make integrating condenser discharge, but be not limited to this. For example, it is also possible in the case of poor flow or short-circuit exception are detected when by-pass switch disconnects, make integrating condenser with the 1st Time constant is discharged, and in the case of in addition, is made integrating condenser and is charged with the 2nd time constant.

In the Semiconductor-light-control control device 100 involved by embodiment, using PWM dim light functions.In PWM dim lights When, bypass drive circuit 112 makes the voltage level of lighting light-off control signal periodically change with dim light frequency f1.Do not having In the case of any exception of generation, when lighting light-off control signal is low level, disconnect corresponding by-pass switch, in lighting When light-off control signal is high level, connect corresponding by-pass switch.Thus, the low level of lighting light-off control signal be with Corresponding by-pass switch disconnects corresponding state, and the high level of lighting light-off control signal is to connect right with corresponding by-pass switch The state answered.

In addition, bypass drive circuit 112 is microcomputer, action is carried out at larger time intervals.Especially, bypass Drive circuit 112 is directed to each LED, during the unusual determination of whole regulation in anomaly detection signal is monitored and judged be It is no to there occurs exception.Also, drive circuit 112 is bypassed in the case where being judged to that certain LED there occurs exception, make and the LED Corresponding lighting light-off control signal is fixed as high level.If illustrated with determining/not knowing abnormal concept, bypass If time detecting of the drive circuit 112 during it continue for unusual determination goes out abnormality, it is determined that enter to exercise for exception The connection locking control of by-pass switch.

Than the cycle of PWM dim light during due to usual unusual determination（=l/f1）It is long, so in half involved by embodiment In conductor light source control device 100, by importing integrating circuit, even if can be with when PWM dim lights be carried out, it is also possible to carry out mistake The less and more accurate short circuit exception/broken string abnormality detection of detection.

Consideration is not carrying out the LED lightings all the time of PWM dim lights（By-pass switch=disconnect all the time）There occurs that broken string is different in control Normal situation.Implement to by-pass switch corresponding with the LED connecting locking control there is broken string from some LED Period, by the effect of bypass/pressure limiting circuit corresponding with the LED, particularly pressure limiting Zener diode, by-pass switch as with Action is carried out in the switch for realizing pressure-limiting function.Thus, it is possible to maintain to the path of the electric current of other LED.But, in this situation Under, because by-pass switch carries out action substantially in the range of linearity, so the by-pass switch continuous action has " burn out detection electricity The power of pressure × driving current Iout ", the power attenuation in by-pass switch increases.Thus, as by-pass switch, need it is large-scale and The larger switch element of resistance to power, causes maximization and the cost increase of circuit.Here, if after broken string exception is detected By-pass switch is carried out at once connect locking control, then reduce power attenuation, but so cause to bypass sentencing in drive circuit 112 Determine number of times to tail off（The judgement time shortens）, especially in PWM dim light patterns, error detection broken string is abnormal（Malfunction）Possibility Property become big.

Even if additionally, in the case of broken string is there occurs when PWM dim lights are carried out, also due to lighting light-off control signal is for low During level, by-pass switch carries out action as the switch of realizing pressure-limiting function, so it is also possible to making in by-pass switch Power attenuation increase.By 1 cycle of PWM dim lights（=l/f1）In shared by-pass switch connection during（The light-off phase of=LED Between）Ratio be referred to as duty cycle.The duty cycle is less, and above-mentioned power attenuation is bigger caused by broken string institute.

In addition, when by-pass switch is connected, the power attenuation in by-pass switch is due to mainly by the connection of by-pass switch Resistance produce and it is less, particularly compared with the power attenuation in the case of the action in the range of linearity, circuit loss is very It is little.

Figure 11 is the knot of the 2nd bypass circuit 870-2 for representing the Semiconductor-light-control control device involved by the 5th variation The circuit diagram of structure.Other bypass circuits are constituted identically with the 2nd bypass circuit 870-2.

The difference between the 2nd bypass circuit 870-2 shown in the 2nd bypass circuit 270-2 and Figure 11 shown in Fig. 5 is main It is the structure of the 2nd switch level shifting circuit.2nd switch of the 2nd bypass circuit 870-2 uses level shifting circuit 854- 2, the 2nd lighting light-off control signal Sc2' is received from bypass drive circuit 812, transform it into the 2nd by-pass switch drive signal Sd2.Especially, the 2nd switch level shifting circuit 854-2 is in the 2nd lighting light-off control signal Sc2 ' for high level when, will 2nd by-pass switch drive signal Sd2 is set to low level, in the 2nd lighting light-off control signal Sc2 ' for low level when, by the 2nd Way switch drive signal Sd2 is set to high level.

Additionally, the 2nd bypass/pressure limiting circuit 850-2 of the 2nd bypass circuit 870-2 can not also have and the 16th resistance 260 suitable resistance.

2nd switch with level shifting circuit 854-2 comprising the 26th resistance 822, the 27th resistance 814, the 28th resistance 816, the 29 resistance 818 and 5pnp types bipolar transistor 820.One end of 26th resistance 822 connects with the terminal of bypass drive circuit 812 Connect.Bypass drive circuit 812 exports the 2nd lighting light-off control signal Sc2' from its terminal.The other end of the 26th resistance 822 with The base stage connection of 5pnp types bipolar transistor 820.The other end of one end of the 27th resistance 814 and the 26th resistance 822 and the The connecting node connection of the base stage of 5pnp types bipolar transistor 820.The other end and 5pnp type bipolaritys of the 27th resistance 814 The emitter stage of transistor 820 applies control power source voltage Vcc.The colelctor electrode of 5pnp types bipolar transistor 820 is electric with the 28th One end connection of resistance 816.The other end of the 28th resistance 816 is connected with one end of the 29th resistance 818.29th resistance 818 it is another End is connected with the negative pole of 2LED2-2.

The connecting node of the other end of the 28th resistance 816 and one end of the 29th resistance 818 is with the 2nd by-pass switch 110-2's Grid connects.The signal produced at the connecting node is the 2nd by-pass switch drive signal Sd2.

In the 2nd lighting light-off control signal Sc2 ' for high level when, the 2nd by-pass switch drive signal Sd2 is low level, the 2 by-pass switch 110-2 disconnect（2LED2-2 lightings）.In the 2nd lighting light-off control signal Sc2 ' for low level when, by the of the 2nd Way switch drive signal Sd2 is high level, and the 2nd by-pass switch 110-2 is connected（2LED2-2 turns off the light）.Carrying out PWM dim lights In the case of, bypass drive circuit 812 makes the 2nd lighting light-off control signal Sc2 ' it is with the high level of several millisecond periods/low electricity Put down alternate signal.

If the both end voltage of integrating condenser 282 exceedes the threshold voltage of regulation, bypass drive circuit 812 and lighting Light-off control signal Sc2 ' synchronously, make the signal applied to the control input terminal i.e. grid of the 2nd by-pass switch 110-2 Duty cycle and the cycle increase compared with common PWM dim lights.Especially, if the electricity of the 2nd anomaly detection signal Sdet2 Pressure exceedes level threshold Vg, then start during bypassing the unusual determination that drive circuit 812 makes for 2LED2-2, and makes the 2 lighting light-off control signals Sc2 ' 1 cycle in the ratio of shared low level duration increase.As an example Son, makes the 2nd lighting light-off control signal Sc2 ' cycle increase be hundreds of millisecond, duty cycle is rised more than or is equal to 90%。

Figure 12 is to represent the 2nd lighting light-off control signal Sc2, Sc2 in the case where 2LED2-2 breaks ' The sequential chart of change.Waveform shown in the epimere of Figure 12, represents the Semiconductor-light-control control device involved by the 5th variation logical The 2nd lighting light-off control signal Sc2 in the case of PWM dim lights is carried out during often lighting with several milliseconds or so of the 1st cycle PT1 '. Waveform shown in the stage casing of Figure 12, represents that the Semiconductor-light-control control device 100 involved by embodiment is entered in usual lighting The 2nd lighting light-off control signal Sc2 in the case of row lighting all the time.Waveform shown in the hypomere of Figure 12, represents embodiment Involved Semiconductor-light-control control device 100 carries out the 2nd in the case of PWM dim lights in usual lighting with the 1st cycle PT1 Lighting light-off control signal Sc2.

In the case that 2LED2-2 breaks in the 5th variation, the cycle of the 2nd lighting light-off control signal Sc2' Become the 2nd cycle PT2 of larger hundreds of microseconds compared with the 1st cycle PT1.Especially, drive circuit 812 is bypassed on one side Maintain the 2nd lighting light-off control signal Sc2 ' 1 cycle in high level duration length, while making low level Duration is elongated, so as to realize that the above-mentioned cycle becomes big.Additionally, the 2nd cycle PT2 can also be with the 2nd integrating circuit 278-2's The 2nd involved time constant of electric discharge is compared less.

In PT3 during the unusual determination of several seconds or so, if the 2nd lighting light-off control signal Sc2 ' when being set to high level The voltage of the 2nd anomaly detection signal Sdet2 be higher than level threshold Vg, then bypass drive circuit 812 and the 2nd lighting and turn off the light and control Synchronously, the duty cycle and cycle for making the signal being applied on the grid of the 2nd by-pass switch 110-2 keeps signal Sc2 ' The state of increase is constant.In the case where the voltage of the 2nd anomaly detection signal Sdet2 is less than level threshold Vg, bypass drives electricity Road 812 makes the 2nd lighting light-off control signal Sc2' recover the state with the 1st cycle PT1.Bypass drive circuit 812 is different the 2nd Often state of the voltage of detection signal Sdet2 higher than level threshold Vg is continued for till PT3 terminates during unusual determination In the case of, it is judged to there occurs exception（Determine abnormal）, make the 2nd lighting light-off control signal Sc2 ' and it is fixed as low level.

In embodiments, in the case where 2LED2-2 breaks, during unusual determination during PT3, make The state of the 2nd lighting light-off control signal Sc2 is identical with the state before abnormal generation.Also, if during unusual determination PT3 At the end of be judged to there occurs exception, then the 2nd lighting light-off control signal Sc2 is fixed as into high level.

So, the Semiconductor-light-control control device according to involved by the 5th variation, with the semiconductor involved by embodiment Light source control device 100 is compared, even if in lighting all the time or during PWM dim lights, it is also possible to the side in during reducing unusual determination Total length during the disconnection of way switch.By-pass switch carries out action with the range of linearity when occurring with broken string during due to the disconnection During correspondence, so, according to the 5th variation, the power attenuation in by-pass switch can be reduced.Thus, as by-pass switch Resistance to lower powered switch element can be adopted, it is possible to achieve the miniaturization of circuit, cost degradation.

Especially, it is being unsuitable for due to carrying out the situation of PWM dim lights in the level conversion based on anomaly detection signal just It is judged at once there occurs under abnormal situation, according to the 5th variation, by carrying out abnormality detection during whole unusual determination The monitoring of signal, can more accurately determine whether exception, and it is possible to the by-pass switch in during reducing unusual determination Power attenuation.

Claims

1. a kind of light source control device, it is characterised in that have：

The driving current of the multiple semiconductor light sources being connected in series is flow through in drive circuit, its generation；

1st by-pass switch, it is connected in parallel with the part in the plurality of semiconductor light source；And

2nd by-pass switch, it is connected in series with the 1st by-pass switch, and with the plurality of semiconductor light source in it is another Part in parallel connects,

The light source control device is configured to,

For by the connecting node and the plurality of semiconductor light source between the 1st by-pass switch and the 2nd by-pass switch In a part and the plurality of semiconductor light source in another part between connecting node connection connection wiring, described the The polarity of the electric current of the connection wiring is flow through when 1 by-pass switch disconnects and the 2nd by-pass switch is connected, by the described 1st The opposite polarity of the electric current of the connection wiring is flow through when way switch is connected and the 2nd by-pass switch disconnects,

In the case where the connection wiring occurs poor flow, forcibly open the 1st by-pass switch and the 2nd bypass Close both to connect,

With bypass drive circuit, the bypass drive circuit is generated for the 1st by-pass switch and the 2nd by-pass switch Disconnection, the lighting light-off control signal that is controlled of connection,

The light source control device has the 1st switch level shifting circuit and the 2nd switch level shifting circuit,

1st switch receives the lighting light-off control signal with level shifting circuit, is transformed to the semiconductor light source A part cathode voltage on the basis of and 1st drive signal consistent with the phase place of the lighting light-off control signal,

2nd switch receives the lighting light-off control signal with level shifting circuit, is transformed to the semiconductor light source Another part cathode voltage on the basis of and 2nd drive signal consistent with the phase place of the lighting light-off control signal,

1st drive signal and the 2nd drive signal are respectively switched on or switched off the 1st by-pass switch and the 2nd by-pass switch.

2. light source control device according to claim 1, it is characterised in that

Also there is ON-OFF control circuit, the both end voltage of its 1st by-pass switch when the 1st by-pass switch disconnects is low In the case of in the 1st voltage or higher than the 2nd voltage higher than the 1st voltage, forcibly connect the 1st by-pass switch, Also, the both end voltage of the 2nd by-pass switch when the 2nd by-pass switch disconnects is less than the 3rd voltage or higher than than institute In the case of stating the 4th high voltage of the 3rd voltage, forcibly connect the 2nd by-pass switch.

3. light source control device according to claim 2, it is characterised in that

The plurality of semiconductor light source is multiple light emitting diodes,

2nd voltage and the 4th voltage are respectively set as, with by the plurality of semiconductor light source a part regulation Forward drop is compared relatively low with the forward drop sum specified by the another part in the plurality of semiconductor light source.

4. the light source control device according to Claims 2 or 3, it is characterised in that

The ON-OFF control circuit is also included：

Main control circuit, it makes the 1st by-pass switch periodically turn on/off in usual lighting；And

Abnormality detection auxiliary circuit, the both end voltage of its 1st by-pass switch when the 1st by-pass switch disconnects is less than 1st voltage or higher than the 2nd voltage in the case of, make the amount of the electric charge that capacitor keeps with the 1st time constant to the 1st Towards change, in the feelings that the amount of the electric charge for keeping the capacitor is changed with the 1st time constant to the described 1st direction Under condition, the amount of the electric charge that the capacitor keeps is made with 2nd time constant longer than the 1st time constant to the described 1st Towards the contrary the 2nd towards change,

Both end voltage of the main control circuit based on the capacitor, determines whether forcibly to connect the 1st by-pass switch It is logical.