JP2007042533A - Lighting apparatus and lighting head to be used for the apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid flowing of an electric current in a discrimination circuit when a light is on, in case a lighting head is provided with the discrimination circuit in parallel with a lighting circuit. <P>SOLUTION: A lighting device is provided with lighting heads (H1, H2), with which a lighting circuit (LC) fitted with a plurality of light emitting diodes (3...) and a discrimination circuit (SC) fitted with a discrimination resistance (4) are connected in parallel, is connected to a power source unit (G) and a lighting becomes on. The discrimination circuit (SC) is provided with a switching element (D) which is kept in a non-conductive state when a direct current power source voltage supplied from the power source unit (G) reaches at least an operative voltage of LED's (3...), and the power source unit (G) is provided with a discrimination resistance measuring circuit (KC) which detects a resistance value of the discrimination resistance (4) in a state that the power source unit is kept at non-operative voltage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illumination device for lighting an illumination head including an illumination circuit to which a light emitting diode is connected, in a replaceable manner with a power supply device, and the illumination head.

  When using an illumination head with a large number of light emitting diodes (light emitting diodes) connected to a power supply unit, supply an appropriate current that allows the rated current to flow to each light emitting diode from the power supply unit to the illumination head. The power supply power is set to light up.

Recently, even when an illumination head capable of individually lighting individual light emitting diodes is connected to the power supply device, there is a power supply device that can control the supply current according to the number of lighting so that the rated current can be supplied to each light emitting diode. It has been proposed (see Patent Document 1).
Japanese Patent Laid-Open No. 2000-6466

  However, this type of power supply adjusts the current according to the number of light-emitting diodes when a specific lighting head is connected. When used as a power supply for lighting heads with different specifications, The current cannot be adjusted accordingly.

Therefore, recently, as shown in FIG. 6, different types of illumination heads 52A and 52B can be attached to and detached from the power supply device 51 via a connector 53, and the illumination heads 52A and 52B are provided with a light emitting diode 54 such as a light emitting diode. In parallel with the mounted illumination circuit 55, an identification circuit 57 having an identification resistor 56 having a higher resistance value than that of the light emitting diode 54 is formed, and by applying an identification voltage less than the lighting lower limit voltage of the light emitting diode 54, the identification resistor 56 is applied. The resistance value of the illumination head 52 is measured, the type of the illumination head 52 is determined based on the resistance value, and the current corresponding to the illumination heads 52A and 52B is supplied from the power supply circuit 58 of the power supply device 51 at the operating voltage. A device has been proposed.
According to this, since the types of the lighting heads 52 </ b> A and 52 </ b> B connected to the power supply device 51 can be discriminated, it is possible to light with appropriate brightness according to the specification of each lighting head 52.
JP2004-158840

  However, even though the resistance value of the identification resistor 56 is larger than that of the light emitting diode 54, it is not infinite. Therefore, when the operating voltage of the light emitting diode 54 is applied to the illumination circuit 55, a part of the current is identified. Since the current flows through the circuit 57, not only the supply current must be set in consideration of that amount, but also a wasteful current flows through the identification resistor 56 at the time of lighting, which is not preferable from the viewpoint of energy saving. .

  Therefore, the present invention has a technical problem to prevent a current from flowing through the identification circuit when the lighting head is provided with the identification circuit in parallel with the illumination circuit.

  In order to solve this problem, the present invention connects an illumination head in which an illumination circuit having one or more light emitting diodes and an identification circuit having an identification resistor are connected in parallel to a power supply device. A lighting device to be lit, wherein a switching element that is maintained in a non-operating state when a DC power supply voltage supplied from the power supply device is at least an operating voltage of a light emitting diode is interposed in the identification circuit, and the power supply The apparatus includes an identification resistance measurement circuit that detects a resistance value of the identification resistance in a state where the power supply voltage is maintained at a non-operating voltage.

According to the present invention, since the switching element that is cut off when the DC power supply voltage is at least the operating voltage of the light emitting diode is interposed in the identification circuit, for example, when a capacitor is used as the switching element, the capacitor Since direct current is not passed, when a direct current power supply voltage is applied, it is maintained in a non-passing state.
Here, if the power supply voltage is changed from a certain voltage value (3 V) in the non-operating voltage to another voltage value (0 V), the capacitor is charged and then discharged. It is possible to determine the resistance value interposed between the illumination head and the illumination head.
Next, if an appropriate current corresponding to the specification of the identified illumination head is supplied as a direct current, the capacitor does not pass a direct current, so no current flows through the identification circuit, and there is no wasteful power consumption during lighting.

In addition, when a reset IC is used as a switching element that is in a non-passing state when the power supply voltage is the operating voltage of the light emitting diode and is in a conducting state when the power source voltage is the non-operating voltage, first, the non-operating voltage is applied to the lighting circuit Since no current flows and the reset IC becomes conductive and current flows only through the identification circuit, the resistance value of the identification resistor can be measured, and the illumination head can be identified.
Next, by applying an operating voltage and supplying an appropriate current according to the specifications of the identified illumination head, the identification circuit becomes non-conductive, and current flows only through the illumination circuit, which is useless when lighting. There is no power consumption.

Furthermore, when a diode that is conducted with a reverse potential to the light emitting diode is interposed in the identification circuit as a switching element, first, by applying a negative non-operation voltage, no current flows in the illumination circuit, and only the identification circuit Since the current flows through the conduction, the resistance value of the identification resistor can be measured, and the illumination head can be identified.
Then, by supplying a positive appropriate current according to the specification of the identified lighting head as a lighting voltage, current does not flow in the identification circuit but only in the lighting circuit, so there is no wasteful power consumption during lighting. .

  In this example, when the lighting head is turned on, the DC power supply voltage to the lighting circuit is at least an operation of the light emitting diode in order to prevent the current from flowing through the identification circuit provided in parallel with the lighting circuit. A switching element that is cut off when the voltage becomes a voltage is provided in the identification circuit, and an identification resistance measurement circuit that detects the resistance value of the identification resistor in a state where the DC power supply voltage is maintained at a non-operating voltage is provided.

  FIG. 1 is a circuit diagram showing an example of a lighting device according to the present invention, FIG. 2 is a table showing the relationship between the resistance value of the identification resistor and the detection voltage, FIG. 3 is a circuit diagram showing another embodiment, and FIG. A table showing the relationship between the resistance value of the identification resistor and the detection voltage, and FIG. 5 is a circuit diagram showing another embodiment.

Lighting device 1 shown in FIG. 1 is to be turned by connecting the plug P for any lighting head H ₁ and H ₂ in the connector C of the power supply G.
In the illumination heads H ₁ and H ₂ , one or more light-emitting diodes 3... And an identification resistor 4 are interposed in the illumination circuit LC extending from one terminal 2 a to the other terminal 2 b of the plug P. An identification circuit SC is formed in parallel with the illumination circuit LC.
The identification circuit SC is provided with a switching element D that becomes inactive when the direct-current power supply voltage supplied from the power supply device G is at least the operating voltage of the light-emitting diodes 3.

As the switching element D, a capacitor 5 is used in this example.
Since the capacitor 5 does not pass a direct current, it is in a non-passing state when a direct-current power supply voltage is applied. Further, because of the nature of the capacitor 5, the charging / discharging operation is repeated by changing the power supply voltage. Therefore, if the power supply voltage is changed within the non-operating voltage of the light emitting diode 3, no current flows through the illumination circuit LC. It becomes possible to discharge through the identification circuit SC.

Note that the connection form of the light emitting diodes 3... Is different for each of the lighting heads H ₁ and H _{2. In} the lighting head H _{1 of} this example, five light emitting diodes 3. lighting circuit LC 15 connected in series head H 5 or in ₂ by light emitting diodes 3 ... are connected in three rows parallel are formed.

Here, when the operating voltage Vf per one of the light emitting diodes 3 is about 1.8 V, when five light emitting diodes 3 are connected in series, the operating voltage VL = lights up all the light emitting diodes 3. When the power supply voltage supplied from the power supply device G is 9 V or higher, the illumination circuit LC is turned on and the light emitting diodes 3 are turned on.
In this case, when the rated current of one light emitting diode 3 is 20 mA, the proper lighting current of the lighting head H ₁ is about 20 mA, the proper lighting current of the lighting head H ₂ is about 60 mA, and the lighting heads H _{1 to} H ₂ Different currents need to be supplied depending on the type.
When the power supply voltage from the power supply device G to the lighting heads H _{1 to} H ₂ is lowered to a non-operation voltage (for example, 8 V), the light emitting diodes 3 are turned off and the respective lighting circuits LC are turned off.

On the other hand, the power supply G, together with the power supply circuit EC is connected to the feeding terminal 6a of the connector C for connecting the lighting head H ₁ to H _2, the ground terminal 6b, identification resistance measurement for measuring the resistance of the identification resistor 4 The circuit KC is connected to a current control circuit DC that performs current control during lighting.

  The power supply circuit EC supplies a DC drive power supply 7 for supplying a power supply voltage VL when the light emitting diodes 3 are turned on, and an identification voltage VM (for example, 2. 5V), a DC identification power supply 8 and a ground power supply 9 for dropping the power supply voltage to the ground potential, and a changeover switch 11 for switching the power supplies 7 to 9 according to a control signal output from the control device 10 is provided. Made up.

  The identification resistance measuring circuit KC is provided with an operational amplifier 13 having a feedback resistor 12, a non-inverting input terminal 13a is connected to the ground, an inverting input terminal 13b is connected to the ground terminal 6b of the connector C, and an output terminal 13c is connected. A resistance value is calculated by the determination circuit 14 based on the output signal of the operational amplifier 13 and connected to the determination circuit 14, and the calculation result is outputted to the control device 10. It outputs to the current setter 15 of the current control circuit DC.

The current control circuit DC controls the current flowing through the illumination circuits LC of the illumination heads H ₁ and H ₂ in accordance with the current setting signal, and the ground terminal 6b of the connector C is a current via an FET (field effect transistor) 16. Connected to the detection resistor 17 (1Ω), the operational amplifier 18 is connected to the gate of the FET 16, the current setting device 15 is connected to the non-inverting input terminal 18a of the operational amplifier 18, and the source of the FET 16 is connected to the inverting input terminal 18b. The detection signal obtained by the voltage drop of the current detection resistor 17 is input to the inverting input terminal 18 b of the operational amplifier 18.

The above is one configuration example of the present invention, and the operation thereof will be described next.
When arbitrary lighting heads H _{1 to} H ₂ are connected to the power supply device G, a current value to be supplied is set.
First, a control signal for turning on the identification power supply 8 is output from the control device 10 to the changeover switch 11 to supply, for example, the identification voltage VM = 2.5V.
At this time, since the identification voltage VM is set to the non-operating voltage of the light emitting diodes 3..., No current flows through the illumination circuit LC.
Further, the potential of the inverting input terminal 13b of the operational amplifier 13 is equal to the potential of the non-inverting input terminal 13a due to the virtual short-circuit operation, and is 0V in this example.
Therefore, the capacitor 5 interposed in the identification circuit SC is charged with the potential of the identification voltage VM, and the output of the operational amplifier 13 at this time is maintained at 0.

When the control device 10 outputs a control signal for conducting the ground power supply 9 to the changeover switch 11 when the charging of the capacitor 5 is completed, the power supply voltage becomes 0, so that the electric energy stored in the capacitor 5 is stored. Is discharged through the discrimination resistance measurement circuit KC, and the detection voltage V ₁₃ (absolute value of the peak value) output from the operational amplifier 13 is
V ₁₃ = VM × R ₁₂ / R ₄ (1)
R ₄ : resistance value of the identification resistor 4
R ₁₂ : represented by the resistance value of the feedback resistor 12, and becomes 0 V due to the time constant T for a while.
Time constant T is T = C ₅・ R ₄ ……………………………… (2)
C ₅ : Capacity of the capacitor 5

Here, the resistance value _{R 12} of the feedback resistor 12 and 2.2 k, when the identification voltage VM = 2.5V, the resistance value _{R 4} of the identification resistor _{4 R 4 (kΩ) = 2.2} / 2. 5 / V ₁₃ (3)
Since it is, the resistance value _{R 4} is set as shown in FIG. 2, it can be changed by 0.1V detection voltage _{V 13} to 0.1～1.0V.
Therefore, by setting the current based on the detected voltage V _13, it is possible to set 10 different current.

In this example, according to the appropriate currents 20 mA and 60 mA of the illumination circuits LC of the respective illumination heads H _{1 to} H ₂ , the identification circuit SC is connected to the identification resistor 4 having a resistance value R ₄ = 8.8 kΩ and 2.9 kΩ. Once you have instrumentation, determination circuit 14 in the detection voltage V ₁₃ is = 0.1 V, 0.3V is measured, is output to the current setting unit 15 of the current control circuit DC through the detection signal the control unit 10 .

In the current setting unit 15, a current of 20 (60) mV corresponding to the set current 20 (60) mA according to the detection voltage V ₁₃ = 0.1 (0.3) V based on the input detection signal. A setting signal is output to the non-inverting input terminal 18 a of the operational amplifier 18.

In this state, when a control signal for turning on the drive power supply 7 is output from the control device 10 to the changeover switch 11 and a DC power supply voltage of the operating voltage VL = 9 V is supplied, the capacitor 5 is interposed in the identification circuit SC. Therefore, no current flows, and a current flows through the illumination circuit LC.
Therefore, when the operating voltage of the light-emitting diodes 3 is applied to the illumination circuit LC, a part of the current does not flow to the identification circuit SC, and there is no trouble in setting the supply current in consideration of the amount. There is no waste of energy by passing a useless current.

  Here, if a current detection resistor 21 of 1Ω is provided in the current control circuit DC, when the current flowing through the illumination circuit SC is higher than the appropriate current of 20 mA, a detection signal of 20 mV + α is output and the current setting is performed. The control signal is output to the FET 16 so that the detection signal is reduced to 20 mV, that is, the lighting current flowing through the illumination circuit LC is 20 mA, and is maintained at an appropriate current. Is done.

  Similarly, when the current is lower than 20 mA, a detection signal of 20 mV-α is output from the 1Ω current detection resistor 21 and compared with the current setting signal 20 mV output from the current setting unit 13, and the detection signal is 20 mV. The control signal is output to the FET 16 so that the current flowing through the illumination circuit LC becomes 20 mA, and constant current control is performed.

In the case of connecting the lighting head H _2, since the current setting signal 60mV from the current setter 13 is output, similarly, the control signal to FET16 as lighting current flowing through the lighting circuit 6 is 60mA is Is output and constant current control is performed.
Further, by detecting the time constant T by the discrimination circuit 14, R ₄ is obtained by the equations (1) and (3), and the capacitance C ₅ of the capacitor ₅ is obtained by the equation (2). And the capacitance of the capacitor 5 can be combined, and there is an effect that the number of identifiable types can be remarkably increased.

FIG. 3 shows another embodiment of the present invention. In addition, the part which overlaps with FIG. 1 attaches | subjects the same code | symbol, and abbreviate | omits description.
Lighting apparatus 21 of this example was using the reset IC22 as a switching element D interposed identification circuit SC of the lighting head _{H 1} and _{H 2.}
In other words, the power supply terminal 22a and the ground terminal 22c of the reset IC 22 are connected to the terminals 2a and 2b of the plug P, and the identification resistor 4 is connected between the power supply terminal 22a and the reset terminal 22b to form the identification circuit SC.

  The reset IC 22 is electrically connected between the reset terminal 22b and the ground terminal 2c when a voltage of 0.6 to 3V is applied to the power supply terminal 22a, and between less than 0.6V and more than 3V, between the reset terminal 22b and the ground terminal 2c. Is designed to be non-conductive.

The power supply circuit EC of the power supply apparatus G includes a drive power supply 7 and an identification power supply 8, and a changeover switch 11 that switches between the power supplies 7 to 8 according to a control signal output from the control apparatus 10 is interposed.
In the identification resistance measurement circuit KC, for example, the detection resistor 23 of 2.2 kΩ is connected to the ground, and the current flowing through the identification resistors 4 of the lighting heads H _{1 to} H ₂ is caused to flow through the detection resistor 23, thereby causing a voltage drop at the detection resistor 23. And the detected voltage drop amount is used as a current identification signal, and an appropriate current to be passed through the illumination circuit LC is set according to the current identification signal.

For example, when the identification voltage VM of 2.5 V is supplied from the identification power supply 8 and the identification resistor 4 of the illumination heads H _{1 to} H ₂ is selected as shown in FIG. 4, the detection resistor 23 of 2.2 kΩ is used. The resulting voltage drop Vc can be changed by 0.1V from 0.1 to 1.0V.
Therefore, if the output of the voltage drop amount as a detected voltage V ₂₃ in the determination circuit 14, it becomes possible to identify 10 kinds of appropriate current.

In this example, the lighting heads H _{1 to} H ₂ are connected to the power supply device G, and first, a control signal for turning on the identification power supply 8 is output from the control device 10 to the changeover switch 11, for example, the identification voltage VM = 2. Supply 5V.
At this time, since the identification voltage VM is set to the non-operating voltage of the light emitting diodes 3..., No current flows through the illumination circuit LC.
Further, since the identification voltage VM is electrically connected between the reset terminal 22b of the reset IC 22 and the ground terminal 2c, it flows from the identification resistor 4 of the identification circuit SC to the ground via the detection resistor 23 of the identification resistance measuring circuit KC.

Here, in accordance with the appropriate currents 20 mA and 60 mA of the illumination circuits LC of the respective illumination heads H _{1 to} H ₂ , the identification circuit 4 is provided with an identification resistor 4 having resistance values R ₄ = 52.8 kΩ and 16.1 kΩ. If so, the determination circuit 14 measures the detected voltage V ₂₃ = 0.1 V and 0.3 V, and outputs the detection signal to the current setting unit 15 of the current control circuit DC via the control device 10.

In this state, when a control signal for turning on the drive power supply 7 is output from the control device 10 to the changeover switch 11 and a DC power supply voltage of the operating voltage VL = 9 V is supplied, the lighting that flows through the illumination circuit LC is performed as described above. Constant current control is performed so that the current becomes 20 mA and 60 mA.
At this time, since the identification circuit SC is in a non-conductive state, when the operating voltage of the light emitting diodes 3... Is applied to the illumination circuit LC, a part of the current does not flow to the identification circuit SC. Thus, there is no trouble in setting the supply current, and energy is not wasted by flowing unnecessary current.

FIG. 5 shows another embodiment of the present invention. In addition, the part which overlaps with FIG. 3 attaches | subjects the same code | symbol, and abbreviate | omits description.
The illuminating device 31 of the present example uses an identification resistor 4 using a diode 32 that is electrically connected to the light emitting diodes 3... As a switching element D interposed in the identification circuits SC of the illumination heads H ₁ and H _2. Connected in series.
The power supply circuit EC of the power supply device G includes a drive power supply 7 and an identification power supply 33 that applies a negative identification voltage lower than the reverse withstand voltage of the light emitting diode 3, and these are controlled by a control signal output from the control device 10. A change-over switch 11 for switching between the power sources 7 and 33 is interposed, and the other configuration is the same as that of the illumination device 21 of the second embodiment shown in FIG. 3, and the measuring means of the identification resistor 4 is different in voltage from positive to negative. Is the same as that of the lighting device 21, and the current control means is also the same as that of the lighting device 21.

  In the present invention, the supply current from the power supply device is automatically maintained at an appropriate current regardless of the specification of the illumination head, and the light emitting diode can always be lit at the rated value. It is suitable for use in which it is arbitrarily replaced with.

The circuit diagram which shows an example of the illuminating device concerning this invention. A table showing the relationship between the resistance value of the feedback resistor and the detection voltage. The circuit diagram which shows other embodiment. The table | surface which shows the relationship between the resistance value of identification resistance, and a detection voltage. The circuit diagram which shows other embodiment. Explanatory drawing which shows a conventional apparatus.

Explanation of symbols

1 lighting device 3 LEDs 4 identification resistor _H 1, _{H 2} lighting head
G power supply device LC illumination circuit SC identification circuit D switching element EC power supply circuit 10 control device KC identification resistance measurement circuit 14 discrimination circuit 15 current setting device DC current control circuit

Claims (8)

An illumination circuit that includes one or more light emitting diodes and an identification circuit that includes an identification resistor are lighting devices that are connected to a power supply device to illuminate the illumination heads that are connected in parallel with each other.
When the DC power supply voltage supplied from the power supply device becomes at least the operating voltage of the light emitting diode, a switching element that is maintained in a non-operating state is interposed in the identification circuit, and the power supply voltage is supplied to the power supply device as a non-operating voltage. An illumination device comprising: an identification resistance measurement circuit that detects a resistance value of the identification resistor in a state where the resistance is maintained.   The lighting device according to claim 1, wherein the switching element is a capacitor, and the capacitor is charged / discharged by changing a power supply voltage within a non-operating voltage, and the discrimination resistance is detected by the discrimination resistance measurement circuit based on the discharge voltage. .   The lighting device according to claim 1, wherein the switching element is a reset IC that is in a non-conductive state when the power supply voltage is an operating voltage of the light emitting diode and is in a conductive state when the power supply voltage is at a non-operating voltage.   2. The discrimination resistance measuring circuit configured to detect a resistance value of the discrimination resistor in a state where the switching element is formed of a diode that conducts at a reverse potential to the light emitting diode and maintains the power supply voltage at a negative voltage. Lighting equipment. An illumination circuit in which an illumination circuit having one or more light emitting diodes and an identification circuit having an identification resistor are connected in parallel to each other,
An illumination head, characterized in that a switching element that becomes inactive when a DC power supply voltage supplied from the power supply device is at least an operating voltage of a light emitting diode is interposed in the identification circuit.   The lighting head according to claim 5, wherein the switching element includes a capacitor that charges and discharges by changing a power supply voltage within a non-operating voltage.   The lighting head according to claim 5, wherein the switching element is a reset IC that is in a non-passing state when the power supply voltage is an operating voltage of the light emitting diode and is in a conducting state when the power source voltage is a non-operating voltage. The lighting head according to claim 5, wherein the switching element is a diode that conducts at a reverse potential to the light emitting diode.

Images