KR101003910B1 - Lamp driving device - Google Patents

Abstract

The present invention relates to a lamp driving device for detecting an abnormal state of the lamp by miniaturizing the circuit.

Lamp driving apparatus according to the present invention, the power supply for converting the input voltage supplied from the outside into a voltage of AC; A transformer for converting an AC voltage from the power supply into a driving voltage of a lamp; A lamp unit operated by a driving voltage from the transformer unit; And determining an abnormal state of the lamp unit by receiving the voltage of the lamp unit, and outputting a control signal for uniformly maintaining the brightness of the lamp unit when the lamp unit is judged to be in a normal state. It includes; lamp control unit for outputting a control signal for stopping the operation of the power supply.

Lamp, Drive Circuit, Feedback Voltage, Open Lamp (OLP), Layer Short

Description

Lamp drive unit {LAMP DRIVING DEVICE}

The present invention relates to a lamp driving device, and more particularly, is connected to any one or more lamps among a plurality of lamps, and outputs a control signal for controlling the operation of the lamp driving device by receiving a voltage of a connected lamp and a predetermined reference voltage. It relates to a lamp driving device.

In general, an LCD panel (Liquid Crystal Display Panel) does not have self-luminous, and therefore, an auxiliary light source for assisting the backlight is required. In this case, as an auxiliary light source of the LCD panel, a cold cathode fluorescent lamp (CCFL) or an external electrode fluorescent lamp (External Electrode Fluorescent Lamp) is mainly used.

Cold Cathode Fluorescent Lamp operates with low current and uses the advantages of low power consumption, low heat generation, high brightness and long life, and is the screen indicator of the backlight and copier of computer monitor such as liquid crystal display (TFT-LCD). It is used in various display devices, such as these.

A high AC voltage is required to light up the cold cathode fluorescent lamp, and a power supply device is required to provide the high AC voltage.

A power supply device for driving a cold cathode fluorescent lamp mainly drives one or more lamps, including a transformer, and studies are being actively conducted to detect and protect occurrence of abnormal conditions in a plurality of lamps.

According to the present invention, when a plurality of lamp voltages and reference voltages are simultaneously applied, a layer short is generated in a transformer of a lamp driving apparatus or an open state is generated in any one or more lamps. It is an object of the present invention to provide a lamp driving apparatus capable of miniaturizing a circuit by detecting only one control unit.

Lamp driving apparatus according to the first embodiment of the present invention, the power supply for converting the input voltage supplied from the outside into the voltage of AC; A transformer for converting an AC voltage from the power supply into a driving voltage of a lamp; A lamp unit operated by a driving voltage from the transformer unit; And determining an abnormal state of the lamp unit by receiving the voltage of the lamp unit, and outputting a control signal for uniformly maintaining the brightness of the lamp unit when the lamp unit is judged to be in a normal state, and when the lamp unit is determined to be an abnormal state. And a lamp controller which outputs a control signal for stopping the operation of the power supply unit.

In this case, when it is determined that the lamp unit is in a normal state, the lamp control unit transfers the voltage of the lamp unit as a control signal to the power supply unit.

In particular, the abnormal state of the lamp unit determined by the lamp control unit may be a layer short of the transformer unit or an open lamp of the lamp unit.

In addition, the lamp unit may be composed of a plurality of lamps.

The lamp control unit may include a plurality of abnormality detection units connected to odd or even ones of the plurality of lamps and outputting the control signal by receiving a voltage of the connected lamp and a predetermined reference voltage. .

Each of the abnormality detector may include: a voltage selector configured to receive a voltage of the connected lamp and a preset reference voltage; A first distribution resistor connected between the reference voltage and the voltage selector; A second distribution resistor connected between the voltage selector and ground; And a smoothing capacitor connected in parallel with the second distribution resistor.

The voltage selector may include: a first diode having an anode connected to the connected lamp and a cathode connected to a contact of the ground resistance and the smoothing capacitor; And a second diode having an anode connected to the first distribution resistor and a cathode connected to the cathode of the first diode.

Particularly, when an abnormal state occurs in the lamp, the voltage selector is configured to turn off the first diode, turn on the second diode, and when the lamp is in a normal state, the first and second diodes are turned off. It is on.

In addition, the lamp control unit provided in the lamp driving apparatus according to the second embodiment of the present invention is connected to each of the plurality of lamps, and receives the voltage and the predetermined reference voltage of the connected lamp to output the control signal It may include a plurality of abnormality detection unit.

When the lamp driving apparatus according to the present invention is applied with a plurality of lamp voltages and reference voltages simultaneously, and a layer short is generated in the transformer of the lamp driving apparatus or an open state is generated in any one or more lamps, And by detecting the abnormal state through only one lamp control unit composed of a second diode, there is an effect that can be miniaturized.

Details of the configuration and effects of the lamp driving apparatus according to the present invention will be clearly understood by the following detailed description with reference to the drawings showing preferred embodiments of the present invention.

First Example

Hereinafter, a lamp driving apparatus according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a lamp driving apparatus according to a first embodiment of the present invention, Figure 2 is a circuit diagram showing a lamp driving apparatus according to a first embodiment of the present invention, Figure 3 is an operation of the lamp control unit of the present invention A circuit diagram showing a state.

First, the lamp driving apparatus according to the first embodiment of the present invention, as shown in Figure 1, may be composed of the power supply unit 10, the transformer unit 20, the lamp unit 30 and the lamp control unit 40. have.

The power supply unit 10 is connected to the transformer unit 20 and receives an input voltage Vin supplied from the outside and converts the voltage into an alternating voltage Vc having a predetermined magnitude.

At this time, the power supply unit 10 is controlled by the control signal P0 transmitted from the lamp control unit 40, thereby stopping the operation or maintaining the lamp unit 30 at the same brightness (AC voltage) Increase or decrease the size of Vc) and output it.

The transformer unit 20 is connected to the power supply unit 10 and the lamp unit 30, and a driving voltage for driving the lamp unit 30 by using the AC voltage Vc output from the power supply unit 20. Convert to (V01 to V0n).

In this case, the transformer 20 may be formed of one or more transformers, and outputs a plurality of driving voltages V01 to V0n according to the number of lamps provided in the lamp unit 30.

The lamp unit 30 includes first to n-th lamps 30a to 30n, is connected to the transformer unit 20 and the lamp control unit 40, and a driving voltage output from the transformer unit 20. It operates by receiving (V01 ~ V0n).

In addition, the lamp control unit 40 is connected to the lamp unit 30 and the power supply unit 10, the first to n-th lamp (30a ~ 30n) of the lamp unit 30 when the lamp driving device is in a normal state ) Is transmitted to the power supply unit 10 as a control signal P0, and when an abnormal state occurs in the transformer unit 20 or the lamp unit 30, the operation of the power supply unit 10 is stopped. The control signal P0 is transmitted to the power supply unit.

In particular, the control signal P0 is transmitted to the power supply unit 10 using the voltage of the lamp unit 30 as a feedback signal when the lamp driving device is in a normal state, and low level when the abnormal state occurs. ) Is delivered to the power supply 10.

Hereinafter, the lamp unit 30 and the lamp control unit 40 will be described in more detail with reference to FIGS. 2 and 3.

As shown in FIG. 2, the lamp unit 30 includes first to n-th lamps 30a to 30n, and each of the first to n-th lamps 30a to 30n has a ground resistance between the ground and the ground. (R11 to Rn1) are connected.

In addition, the odd-numbered lamps 30a, 30c to 30 (n-1) of the first to nth lamps 30a to 30n have contacts with the ground resistances R11 and R31 to R (n-1) 1. Connected to the lamp control unit 40, and transmits the voltage (P1, P3, P (n-1)) of each odd-numbered lamp (30a, 30c ~ 30 (n-1)) to the lamp control unit 40 do.

In this case, the first to n-th lamps 30a to 30n may be any one selected from a cold cathode fluorescent lamp CCFL or an external electrode fluorescent lamp EEFL.

Meanwhile, although the lamps connected to the lamp control unit 40 among the first to nth lamps 30a to 30n are described as odd-numbered lamps 30a and 30c to 30 (n-1), this is the first embodiment of the present invention. The lamp driving apparatus according to the embodiment will be described for clarity, and the even-numbered lamps 30b, 30d to 30n may be connected to the lamp control unit 40.

The lamp control unit 40 may include the first to the (n / 2) th detection units 40a to the odd or even numbered lamps among the first to nth lamps 30a to 30n of the lamp unit 30. 40 (n / 2)).

Each of the first to n-th abnormality detectors 40a to 40 (n / 2) is connected to an odd-numbered or even-numbered lamp and a reference voltage Vref of the lamp unit 30, and The voltage selector 41 receives the voltage of the connected lamp and the reference voltage Vref, and the first and second distribution resistors R0 and R2 and the smoothing capacitor C1.

In this case, the voltage selector 41 includes first and second diodes D1 and D2 and selects one or more voltages of the voltage of the connected lamp or the reference voltage Vref to supply the power to the power supply 10. ) Is output as a control signal (P0) for adjusting.

The first diode D1 of the voltage selector 41 has an anode connected to the connected lamp and a cathode connected to a contact of the second distribution resistor R2 and the smoothing capacitor C1.

In addition, an anode of the second diode D2 is connected to the first distribution resistor R0 and a cathode thereof is a contact of the cathode of the first diode D1, the second distribution resistor R2, and the smoothing capacitor C1. Connected with

The first distribution resistor R0 is first applied with the reference voltage Vref, and the other end thereof is connected with the anode of the second diode D2 to convert the reference voltage Vref to the second diode D2. To pass on.

The second distribution resistor R2 and the smoothing capacitor C1 are connected in parallel to each other, one end of which is connected to the cathodes of the first and second diodes D1 and D2, and the other end of the second distribution resistor R2 and the smoothing capacitor C1 are grounded. In this case, when the second diode D2 is turned on, the second distribution resistor R2 is connected in series with the first distribution resistor R0 to distribute the reference voltage Vref to the control signal P0. Output

In addition, the smoothing capacitor C1 smoothes the voltages P1 to P (n-1) of the lamp having the AC component applied through the lamp unit 30 to the DC component.

The operation of the lamp unit 30 and the lamp control unit 40 having such a configuration will be described below.

First, when an abnormal state does not occur in the first to n-th lamps 30a to 30n of the transformer unit 20 and the lamp unit 30, that is, when it operates normally, the first to nth / n 2) In the voltage selector 41 of the abnormality detection unit 40a to 40 (n / 2), both the first and second diodes D1 and D2 are turned on.

At this time, since the first and second diodes D1 and D2 are both turned on, the voltage selector 41 adjusts the voltages P1 to P (n / 2) and the reference voltage Vref of the lamp connected thereto. It transfers to the second distribution resistor R2 and the smoothing capacitor C1.

Accordingly, the control signal P0 sums the voltages P1 to P (n / 2) of the lamp applied by the first diode D1 and a threshold voltage of the second diode D2. You have one voltage.

For example, the first abnormality detector 40a receives the voltage P1 and the reference voltage Vref of the connected first lamp 30a at the same time. At this time, when the voltage P1 of the first lamp 30a has about 2.0V, the second distribution resistor R2 has a voltage of 2V, and the second diode D2 has a threshold voltage of 0.7. By having V, the control signal P0 eventually has a voltage of 2.7 V, which is the sum of the voltage applied to the second diode D2 and the voltage applied to the second distribution resistor R2.

In particular, when the control signal P0 having a voltage of 2.7V is applied, the power supply unit 10 recognizes this as a feedback signal of the lamp unit 30 and performs a normal operation, thereby providing a voltage of AC Will output Vc).

If an abnormal state occurs in the transformer unit 20 or the lamp unit 30, the first diode D1 of the voltage selector 41 connected to the lamp in which the abnormal state is generated is turned off, and The two diodes D2 are turned on.

At this time, the first distribution resistor R0 and the second distribution resistor R2 are connected in series by the second diode D2, and the control signal P0 is connected to the first and second distribution resistors R0, It has a voltage divided by R2).

On the other hand, the abnormal state, the transformer constituting the transformer 20, a plurality of lamps (layer short) or the lamp unit 30 that is connected between the windings due to poor insulation between the windings or ambient moisture ( One or more lamps 30a to 30n may be in an open lamp state in which an open state is generated.

For example, as shown in FIG. 3, when an abnormal state occurs in the transformer unit 20 or the lamp unit 30, the first diode D1 is turned off, and the voltage P1 of the first lamp 30a is turned off. ) Is not applied to the first abnormality detector 40a, and the second diode D2 is turned on so that the reference voltage Vref is supplied to the first and second distribution resistors R0 and R2.

According to the off state of the first diode D1 and the on state of the second diode D2, the first and second distribution resistors R0 and R2 are connected to each other in series to have a configuration of a distribution circuit. The reference voltage Vref is distributed and output as the control signal P0.

In this case, the control signal P0 is divided by the first and second distribution resistors R0 and R2 and calculated as shown in Equation 1 below, thereby reducing the low level voltage of 1V or less. Will have

Therefore, when the control signal P0 having a voltage of 1 V or less is applied to the power supply unit 10, the power supply unit 10 determines that an abnormal state has occurred in the transformer unit 20 or the lamp unit 30. 20) or to stop the operation of the lamp unit 30 to prevent damage.

Since the power supply unit 10 stops the operation by the control signal P0, the transformer unit 20 and the lamp unit 30 do not operate, and thus, the first to nth lamps 30a to 30n according to the abnormal state. ) Can be prevented.

Accordingly, the lamp driving apparatus according to the first embodiment of the present invention may be a layer short or a lamp of the transformer 20 only by the lamp control unit 40 including the first diode D1 and the second diode D2. The lamp open state of the unit 30 can be detected, and at the same time, the circuit can be miniaturized by outputting the control signal P0 used as the feedback signal in the normal state.

In addition, in the present invention, the first to (n / 2) th abnormality detection unit 40a to 40 (n / 2) is connected to the common node through the first distribution resistor R0, thereby causing an abnormal state in any one lamp. Even if an error occurs, it is possible to detect the abnormal condition at the same time as the occurrence of the abnormal condition.

2nd Example

Hereinafter, a lamp driving apparatus according to a second exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the description of the same parts as those of the second embodiment of the configuration of the first embodiment will be omitted, and only the configuration that is different from the second embodiment will be described in detail.

4 is a block diagram of a lamp driving apparatus according to a second embodiment of the present invention, and FIG. 5 is a circuit diagram of a lamp driving apparatus according to a second embodiment of the present invention.

First, as shown in FIGS. 4 and 5, the lamp driving apparatus according to the second embodiment of the present invention includes a power supply unit 10 for converting an input voltage Vin into an alternating voltage Vc, and the alternating current. The transformer unit 20 converts the voltage Vc into the driving voltages V01 to V0n of the lamp, and the lamp unit 30 and the voltage of the lamp unit 30 operated by the driving voltages V01 to V0n. Alternatively, the lamp controller 40 may be configured to determine an abnormal state of the transformer unit 20 and the lamp unit 30 to output a control signal P0.

In this case, the lamp control unit 40 is connected to all of the first to n-th lamps 30a to 30n of the lamp unit 30, respectively, and the voltages P1 to to each of the first to n-th lamps 30a to 30n. First to n-th abnormality detectors 40a to 40n may be provided to generate the control signal P0 by receiving Pn and the reference voltage Vref.

In particular, the lamp driving apparatus according to the second embodiment of the present invention is provided with one abnormality detecting unit 40a to 40n in each of the first to nth lamps 30a to 30n, thereby causing an abnormality in any one lamp. If a state occurs, it may be detected, and the abnormal state may be detected while controlling the brightness of the lamp unit 30 through only one lamp control unit 40.

Preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and various substitutions, modifications, and changes within the scope of the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It will be appreciated that such substitutions, changes, and the like should be considered to be within the scope of the following claims.

1 is a block diagram of a lamp driving apparatus according to a first embodiment of the present invention.

2 is a circuit diagram of a lamp driving apparatus according to the first embodiment of the present invention.

3 is a circuit diagram showing an operating state of the lamp control unit of the present invention.

4 is a block diagram of a lamp driving apparatus according to a second embodiment of the present invention.

5 is a circuit diagram of a lamp driving apparatus according to a second embodiment of the present invention.

Description of the Related Art

100: lamp driving device

10: power supply 20: transformer

30: lamp unit 40: lamp control unit

41: abnormality detection unit

Claims (11)

A power supply unit converting an input voltage supplied from the outside into a voltage of AC; A transformer for converting an AC voltage from the power supply into a driving voltage of a lamp; A lamp unit including a plurality of lamps operated by a driving voltage from the transformer unit; And Determines an abnormal state of the lamp unit by receiving the voltage of the lamp unit, and outputs a control signal for maintaining the brightness of the lamp unit uniformly when the lamp unit is judged to be in a normal state, and when the lamp unit is determined to be an abnormal state And a lamp control unit for outputting a control signal for stopping the operation of the supply unit. The lamp control unit includes a plurality of abnormality detection units connected to odd or even ones of the plurality of lamps, and outputting the control signal by receiving a voltage of the connected lamp and a predetermined reference voltage. Each abnormality detection unit, A voltage selector configured to receive a voltage of the connected lamp and a preset reference voltage; A first distribution resistor connected between the reference voltage and the voltage selector; A second distribution resistor connected between the voltage selector and ground; And A smoothing capacitor connected in parallel with said second distribution resistor; Lamp driving device comprising a. The method of claim 1, wherein the lamp control unit, And the lamp driving unit transmits the voltage of the lamp unit as a control signal to the power supply unit when it is determined that the lamp unit is in a normal state. The method of claim 1, An abnormal state of the lamp unit determined by the lamp control unit is a layer short of the transformer unit or an open lamp of the lamp unit. delete delete delete delete The method of claim 1, wherein the voltage selector, A first diode having an anode connected to the connected lamp and a cathode connected to a contact of the second distribution resistor and the smoothing capacitor; And A second diode having an anode connected to the first distribution resistor and a cathode connected to the cathode of the first diode; Lamp driving device comprising a. The method of claim 8, wherein the voltage selector, And an abnormal state occurs in the lamp, the first diode is turned off and the second diode is turned on. The method of claim 8, wherein the voltage selector, The lamp driving device of the first and second diodes are turned on when the lamp is in a steady state. A power supply unit converting an input voltage supplied from the outside into a voltage of AC; A transformer for converting an AC voltage from the power supply into a driving voltage of a lamp; A lamp unit including a plurality of lamps operated by a driving voltage from the transformer unit; And Determines an abnormal state of the lamp unit by receiving the voltage of the lamp unit, and outputs a control signal for maintaining the brightness of the lamp unit uniformly when the lamp unit is judged to be in a normal state, and when the lamp unit is determined to be an abnormal state And a lamp control unit for outputting a control signal for stopping the operation of the supply unit. The lamp control unit includes a plurality of abnormality detection units connected to the plurality of lamps, respectively, and outputting the control signal by receiving a voltage of the connected lamp and a predetermined reference voltage. Each abnormality detection unit, A voltage selector configured to receive a voltage of the connected lamp and a preset reference voltage; A first distribution resistor connected between the reference voltage and the voltage selector; A second distribution resistor connected between the voltage selector and ground; And A smoothing capacitor connected in parallel with said second distribution resistor; Lamp driving device comprising a.

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