KR100476661B1 - Automatic test system for LCD inverter - Google Patents

Abstract

The present invention relates to an automatic LCD inverter inspection system, comprising a relay / switch circuit for sequentially selecting the LCD lamp by mounting one or more inverters and one or more LCD lamps, and receiving power from the power supply relay power and circuit It supplies power, applies the voltage of the selected LCD lamp cold end to the oscilloscope, applies the inverter input terminal voltage and transformer voltage to the voltage meter as the LCD lamp is selected, and classifies the relay driving signal sent from the relay controller. Jig circuit unit for controlling the; And a panel connected to the relay control device, the panel controlling the transmission of the relay drive signal for selecting the LCD lamp, and including a computer control unit for transmitting the relay drive signal from the relay control device to the jig circuit unit when the panel is operated. LCD inverter automatic inspection system.

According to the present invention, the operation inspection of the LCD inverter is performed for each lamp connected to the inverter, the inverter Vcc power information, inverter on / off power information, inverter dimming power information, LCD lamp selection information, inverter input terminal voltage information, transformer voltage Information, shutdown operation information, transformer resistance information and current / voltage information on the LCD lamp stage can be easily measured, and a program that provides an easy-to-operate interface can quickly check the operation of the LCD inverter.

Description

 Automatic test system for LCD inverter

The present invention relates to an automatic LCD inverter inspection system, and more particularly, connected to a power supply, an oscilloscope, a voltage measuring instrument and a relay control device, and is composed of a jig circuit unit and a computer control unit, and includes inverter Vcc power information and inverter on / off power information. Inverter automatic inspection that measures inspection information related to LCD inverter such as inverter dimming power information, LCD lamp selection information, inverter input stage voltage information, transformer voltage information, shutdown operation information, transformer resistance information and current / voltage information of LCD lamp stage. It's about the system.

Recently, due to the rapid market increase of TFT LCD (Thin Film Transistor-Liquid Crystal Display), the requirement of the inverter to turn on and control the lamp of the TFT LCD is increasing rapidly.

Unlike plasma display panels (PDPs) and field emission displays (FEDs), LCDs are non-light-emitting (light-receiving elements) and cannot be used where there is no light. In order to compensate for these disadvantages, a backlight for uniformly irradiating the display surface of the LCD is used. As a backlight, a Cold Cathode Flourescent Lamp (CCFL) backlight is most commonly used (a light source Cold cathode fluorescent lamps are preferred because they consume less power, provide bright white light, and diffuse light into the display surface to spread light evenly.) An inverter is used to adjust.

1 is a circuit diagram schematically showing a general basic circuit of an inverter for controlling a lamp of an LCD.

According to FIG. 1, the control circuit controls on / off of the switch S1 by using current sensing (feeding back a current through the lamp) and a dimming signal, and the voltage Vd controlled by this changes the current in the cathode tube so that the brightness of the lamp is changed. Adjust

After the cathode tube is turned on, in order to maintain the lighting state and to adjust the brightness, AC voltage must be applied to the hot end of the lamp (the side where the current flows into the lamp). The lower circuit which uses autogenous oscillation is comprised. To turn on the lamp, a high pressure for initial discharge must be applied, to excite the gas in the lamp. Electromagnetic waves are emitted by the excited gas and electrons emitted from the electrodes, and the emitted electromagnetic waves emit fluorescent materials.

C1 and C2 are stabilizing capacitors for turning on lamp 1 and lamp 2, respectively, and electrical energy is transferred to the secondary side of the transformer by the lower circuit, and the voltage of the transformer is increased until the lamp is turned on. The current passing through the lamp passes through the entire sensing resistor Rs, and the control circuit controls the input terminal current of the inverter so that the voltage applied to the sensing resistor Rs is kept constant. That is, when the current of the sensing resistor Rs is higher or lower than the reference value, the control circuit adjusts the reference voltage and the sensing voltage to be the same to keep the current flowing through the lamp constant.

In addition, the function of the inverter is called “shut down operation”, in which the high voltage is continuously generated in the inverter when the lamp is unlit (i.e., no voltage is applied to the sensing resistor) due to the failure of the lamp. It means the function of the protection circuit to stop the operation of the entire circuit so as not to.

2 is a diagram schematically illustrating a method of inspecting an existing LCD inverter 200.

As described above, a high voltage is required to drive the lamp 230, but the amount of current flows up to 10 mA or less. This current value is the amount of current remaining and leakage while the current flows from the hot end 210 of the lamp 230 to the cold end (side from which the current flows out of the lamp) 220, so the brightness of the lamp 230 is actually increased. It is a numeric value. Therefore, the amount of current in the lamp 230 should be measured at the cold end 220 of the lamp 230 so as not to affect the operation of the inverter 200. In addition, due to the high frequency (30 ~ 80KHz) of the power source used in the lamp 230, when the lamp line 220 is disconnected and a measurement instrument is directly connected, the range of the measured value does not reach the confidence value.

Due to the above-described problems, as shown in FIG. 2, a conventional high frequency current probe 300 can be measured without breaking the lamp connection line 220, but the high frequency current probe 300 measures the current. Since the line is designed to penetrate the probe 300, the measured value can be obtained by detecting the magnetic change generated when the current flows in the cold end connection line 220 of the lamp 230 and changing the voltage value. That is, a plurality of probes 300 may be provided to pin the cold end 220 of the lamp 230, and may be connected to the measuring instrument 400 to confirm the measured value.

However, such a probe 300 is quite expensive, and thus it is difficult to provide as many lamps 230 as the number of lamps 230 of the inverter 200 to be inspected. Repeatedly biting the connecting line 220 of 230 is easily broken.

3A and 3B illustrate a conventional process of confirming a shutdown operation of the LCD inverter 200.

In the case where the lamp 230 is normally connected and operated as shown in FIG. 3A, the inverter 200 provides a voltage, but when one of the lamps 230 malfunctions as shown in FIG. 3B, the protection circuit 204 of the inverter is operated. .

As described above, in order to confirm the shutdown operation of the inverter 200, it is cumbersome and inefficient to disconnect the plurality of lamp connectors 232 manually from the connector 202 of the inverter 200 and confirm the function of the protection circuit 204. It can only be work.

Therefore, as inverters are mass-produced in a variety of multifunctional systems, and production processes are automated, there is a need to automate inspection methods of existing LCD inverters that rely on manual labor.

The present invention is devised to meet the requirements as described above, and is connected to an oscilloscope, a voltage measuring instrument and a relay control device, consisting of a jig circuit unit and a computer control unit inverter Vcc power information, inverter on / off power information, inverter dimming By measuring the information of the LCD inverter such as power supply information, LCD lamp selection information, inverter input terminal voltage information, transformer voltage information, shutdown operation information, transformer resistance information, and current / voltage information of the LCD lamp stage, The aim is to provide an inverter automatic inspection system that can efficiently and efficiently inspect inverters produced by various models in a short time.

In order to achieve the above object, the automatic LCD inverter inspection system according to the present invention is equipped with one or more inverters and one or more LCD lamps constitute a relay / switch circuit for sequentially selecting the LCD lamps one by one, the power supply from the power supply It supplies relay power and circuit power, applies the voltage of the selected LCD lamp cold end to the oscilloscope, applies the inverter input voltage and transformer voltage to the voltage meter as the LCD lamp is selected, and relays sent from the relay controller. A jig circuit unit for classifying a driving signal to control a relay; And a relay control signal connected to the relay control device and having a manager panel, the relay driving signal for selecting the LCD lamp, the relay driving signal for flowing the sensing stage current of the inverter connected to the predetermined LCD lamp to ground, the inverter Vcc power supply, and the inverter. To measure the resistance of the on / off power source, the inverter dimming power source, the relay drive signal to flow the current of the power supply to ground to turn on or off, or the resistance on the transformer which is provided in the inverter to perform a voltage transformer function And a computer control unit configured to transmit a relay driving signal to a jig circuit unit for flowing a current of the current to ground.

Hereinafter, the LCD inverter automatic inspection system according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram schematically illustrating a form in which the automatic LCD inverter inspection system 510 according to the present invention is connected to an external device.

According to FIG. 4, the LCD inverter automatic inspection system (hereinafter referred to as “inverter inspection system according to the present invention”) 510 according to the present invention includes a jig circuit unit 512 and a computer control unit 514. The jig circuit unit 512 and the computer control unit 514 are connected to the voltage meter 520, the power supply 530, the oscilloscope 540, and the relay control unit 550, respectively, and the jig circuit unit 512 is connected to one or more of the jig circuit unit 512. And an inverter 560 and an LCD lamp (hereinafter referred to as "lamp") 570. In addition, the computer controller 514 includes a lamp selector 514a, a power controller 514c, a data processor 514d, and a display 514b.

The computer control unit 514 of the inverter inspection system 510 according to the present invention is a program for realizing the functions of the lamp selection unit 514a, the power control unit 514b, the data processing unit 514c, and the display unit 514d. It can be implemented in the form, in which case an existing programming language such as C language can be used.

The jig circuit unit 512 and the computer control unit 514 of the inverter inspection system 510 according to the present invention is preferably connected to each external device through a General Purpose User Interface Bus (GPIB) cable.

In general, a digital volt meter (DVM) may be used as the voltage meter 520, and the voltage meter 520 may measure an input / output voltage of the circuit (ie, an external voltage).

The power supply unit 530 provides a relay / circuit power source of the jig circuit unit 512, a dimming power source of the inverter 560, an inverter Vcc power source, an inverter on / off power source, and measures a small current.

The oscilloscope 540 is a device for displaying a signal waveform using a CRT. The oscilloscope 540 can measure the output current value and frequency of the inverter and is sequentially connected to the sensing resistance of the inverter (connected to the lamp) by a relay. (See Figure 8).

The relay control device 550 is generally called a "control box" or "relay box" and transmits a relay drive signal for each terminal number so as to control a plurality of relays (relays).

The jig circuit unit 512 is equipped with one or more inverters 560 and one or more lamps 570 to configure a relay / switch circuit for sequentially selecting the lamps 570 one by one, the relay / switch circuit is an oscilloscope 540, It is provided on the connection line of the power supply 530, voltage measuring instrument 520, relay control device 550, respectively.

5 shows an example in which the jig circuit unit 512 according to the present invention mounts the inverter 560 and the lamp 570.

According to FIG. 5, the jig circuit unit 512 mounts the inverter 560 to the clip 51 of the board (in this case, one inverter 560 is mounted), and each connector 561 of the inverter 560. ) Is connected to the lamp connector 571 via the connector 52 on the board (a plurality of lamps 570 are connected to the inverter 560).

The jig circuit part 512 is installed on the back of the board, and the connector 52 on the board is connected to the jig circuit part 512. Since the arrangement of the connector pins is different according to the model of the inverter, the connector 52 on the board is connected to the jig circuit part ( In connection with the 512, it is preferable to have various interface cards 53 corresponding to each inverter model to connect the jig circuit unit 512 and the connector.

The jig circuit unit 512 includes a switch 54, and functions the respective components of the computer control unit 514 by sending a jig circuit start signal to the computer control unit 514 when the switch 54 is turned on by the inspector. A function for resetting an external device connected to the inverter test system 510 according to the present invention may be further added.

6 is a circuit diagram schematically showing the internal configuration of the LCD automatic inspection system 510 according to the present invention and the form connected to each external device.

The jig circuit unit 512 receives power from the power supply 530 to supply the relay power and the circuit power, and applies the current / voltage of the lamp stage selected by the relay controller 550 to the oscilloscope 540. In addition, the jig circuit unit 512 controls the relay by applying the inverter input terminal voltage and the transformer voltage to the voltage meter 520 as the lamp 570 is selected, and classifying the relay driving signal transmitted from the relay controller 550. do.

Accordingly, the oscilloscope 540 may measure current / voltage values of individual lamp stages connected to one inverter 560.

Since the relay controller 550 transmits a relay driving signal for each terminal number 101 to 114, the jig circuit unit 512 includes a control unit circuit 58 so that the relay on the circuit can be operated in accordance with each relay driving signal. For example, the relay driving signal 102, the relay driving signal 103, and the relay driving signal 104 may each be configured to control the relay connected to the Vcc power supply of the inverter, the on / off power supply of the inverter, and the dimming power supply line. 58).

7 is a table showing the function of the relay drive signal for each terminal number of the relay control device 550 connected to the automatic LCD inverter inspection system 510 according to the present invention.

The number given to the relay shown in FIG. 6 means the terminal number of the table shown in FIG.

As the jig circuit unit 512 applies the inverter input terminal voltage and the transformer voltage to the voltage meter 520 as described above, the voltage meter 520 can measure each voltage value and the data processor 514d of the computer controller 514. ) May perform a transformer test of the inverter (transformer) by comparing the voltage values (for example, if the transformer is burned by a high voltage spark, an abnormal voltage ratio is calculated so that the data processor 514d may check for abnormality. , The display unit 114b displays a message indicating whether or not the transformer function is abnormal).

The lamp selector 514a is connected to the relay controller 550 and includes a panel to control the transmission of the relay drive signal for selecting the lamp 570, and when the panel is operated, the relay is controlled from the relay controller 550. The driving signals (corresponding to terminal numbers 101, 105, 106, 110, 111, and 114) of the 55 are transmitted to the jig circuit unit 512. In addition, the lamp selector 514a includes a panel connected to the relay controller 550 to receive a relay driving signal for flowing a sensing resistance terminal current of the inverter 560 to which the predetermined LCD lamp 570 is connected to ground. . This is to check the shutdown function of the inverter protection circuit.

8 is a circuit diagram showing a form in which the relay 59 is connected to the sensing resistor stage in order to inspect the shutdown operation of the automatic LCD inverter inspection system 510 according to the present invention.

When the relay driving signal is sequentially transmitted, the relay 59 causes the sensing terminal current connected to the corresponding lamp 570 to flow to the ground, and the protection circuit 562 of the inverter recognizes this as an inoperation of each lamp 570. Stop the function of the entire circuit. However, if the current of the inverter transformer (or the cold terminal of the lamp 570) is measured at the oscilloscope 540 at this time, the protection circuit 562 of the inverter is malfunctioning, and the data processor 514d receives the current measurement value. A shutdown operation test of the inverter 560 corresponding to each lamp 570 may be performed.

Thus, even when performing a shutdown test, only one current measurement probe is sufficient, and there is no need to manually connect / short the connector of the lamp 570 manually.

In addition, the lamp selector 514a is connected to the relay controller 550 to measure the current on the transformer stage to measure resistance on the transformer (as described above, provided in the inverter 560 to perform a voltage transformer function). It is provided with a panel for receiving a relay drive signal (corresponding to terminal numbers 108 and 109) flowing to the ground, and when the panel is manipulated so that the relay drive signal from the relay controller 550 to the jig circuit unit 512.

The power control unit 514c includes a panel that receives a drive signal (corresponding to terminal numbers 102, 103, and 104) of the relay 56 that causes the current of the power supply 530 to flow to ground to turn on / off the power. When the selection command is transmitted through the relay control device 550, the corresponding relay driving signal is transmitted to the jig circuit unit 512, respectively. The power controller 514c may control the inverter Vcc power, the inverter on / off power, the inverter dimming power, and the like.

The data processor 514d may be configured to measure the numerical data measured by the voltage meter 520, the power supply 530, the oscilloscope 540, and the relay controller 550, the control information, or the electrical numerical data provided to the jig circuit unit 512. Collecting and comparing these data with each other or with reference data inputted in advance, inverter Vcc power information, inverter on / off power information, inverter dimming power information, LCD lamp selection information, inverter input stage voltage information, transformer voltage information, shutdown Inspection information including operation information, transformer resistance information, and current / voltage information of the LCD lamp stage is generated.

The display unit 514b displays and displays the information generated by the data processing unit 514d so that the inspector can check the inspection result through the monitor screen.

Hereinafter, an embodiment in which the inverter test system 510 according to the present invention is used will be described in brief.

First, the inspector mounts the inverter 560 to the clip 51 of the board on which the jig circuit unit 512 is configured, and connects a plurality of lamp connectors, board connectors and inverter connectors. At this time, the jig circuit unit 512 is connected through the board connector and the interface card.

The inspector then loads the computer controller (preferably implemented as a program executable on a computer) 514 and activates the start switch on the board.

First, the inverter test system 510 according to the present invention measures the resistance value of the transformer, checks the current in the standby state, and then applies the on / off voltage of the inverter to measure the lamp input current.

Next, the inverter test system 510 according to the present invention examines the shutdown operation of the protection circuit 562 and applies a dimming voltage of the inverter 560 to measure the dimming current.

The measured data is displayed on the monitor by the computer control unit 514, and the test result (for example, "Good" or "Not Good" message can be displayed for each test step) is determined.

Finally, the inverter inspection system 510 according to the present invention repeatedly measures the above-described process for each lamp 570 to check the overall function of the inverter, and the computer controller 514 stores the measured data and the result of the forceps. .

The present invention has been described above with reference to the preferred embodiments, which are merely examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains do not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not possible that are not illustrated above. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

According to the present invention, the operation inspection of the LCD inverter is performed for each lamp connected to the inverter, the inverter Vcc power information, inverter on / off power information, inverter dimming power information, LCD lamp selection information, inverter input terminal voltage information, transformer voltage Information, shutdown operation information, transformer resistance information and current / voltage information of LCD lamp stage can be easily measured.

In addition, according to the present invention, the operation of the LCD inverter can be quickly performed by using a program that provides an easy-to-operate interface, and the measurement results are displayed on the monitor so that the measurement results can be recognized at a glance, and in proportion to the high productivity. Quality inspection can be carried out efficiently, saving human and material resources for product management.

1 is a circuit diagram schematically showing a general basic circuit of an inverter for controlling a lamp of an LCD.

2 is a diagram schematically illustrating a method of inspecting an existing LCD inverter.

3A and 3B illustrate a conventional process of confirming a shutdown operation of the LCD inverter.

4 is a block diagram schematically showing a form in which the automatic LCD inverter inspection system according to the present invention is connected to an external device.

5 illustrates an example in which the jig circuit unit according to the present invention mounts an inverter and a lamp.

6 is a circuit diagram schematically showing the internal configuration of the LCD inverter automatic inspection system according to the present invention and the form connected to each external device.

7 is a table showing the function of the relay drive signal for each terminal number of the relay control device connected to the automatic LCD inverter inspection system according to the present invention.

FIG. 8 is a circuit diagram illustrating a form in which a relay is connected to a sensing resistance stage in order to inspect a shutdown operation of the automatic LCD inverter inspection system according to the present invention.

<Explanation of symbols for main parts of drawing>

510: LCD inverter automatic inspection system 512: jig circuit unit

514: computer control unit 514a: lamp selection unit

514b: display unit 514c: power supply control unit

514d: data processor 520: voltage measuring instrument

530: power supply 540: oscilloscope

550: relay controller 560: LCD inverter

570: LCD lamp

Claims (7)

In the device connected to the power supply, oscilloscope, voltage meter and relay control device to inspect the LCD inverter, A relay / switch circuit configured to sequentially select one or more LCD lamps by mounting one or more inverters and one or more LCD lamps, supplying relay power and circuit power by receiving power from a power supply, and selecting the selected LCD lamp cold end A jig circuit unit configured to control the relay by applying a voltage of an oscilloscope, applying an inverter input terminal voltage and a transformer voltage to a voltage meter as the LCD lamp is selected, and classifying a relay driving signal transmitted from a relay controller; And And a panel connected to the relay control device and configured to control transmission of a relay driving signal for selecting an LCD lamp, and when the panel is operated, a computer control unit for transmitting the relay driving signal from the relay control device to the jig circuit unit. LCD inverter automatic inspection system comprising a. According to claim 1, wherein the jig circuit portion LCD switch automatic inspection system comprising a switch to send a jig circuit start signal to the computer control unit. According to claim 1, wherein the jig circuit portion In the mounting of the inverter and the LCD lamp LCD inverter automatic inspection system, characterized in that attached to the connector provided with an interface card corresponding to the type of the inverter and the LCD lamp. The method of claim 1, wherein the computer control unit A panel connected to the relay control device and configured to control a transmission by receiving a relay driving signal for flowing a sensing stage current of an inverter connected to a predetermined LCD lamp to ground; and when the panel is operated, a corresponding relay from the relay control device And a driving signal to be transmitted to the jig circuit unit so that the jig circuit unit can measure a shutdown operation of the inverter. The method of claim 1, wherein the computer control unit It is connected to the relay control device, and controls the transmission by receiving a relay drive signal for flowing the current of the power supply to the ground to turn on / off any one or more of the inverter Vcc power, inverter on / off power, inverter dimming power And a panel to control the relay drive signal from the relay controller to the jig circuit unit when the panel is operated. The method of claim 1, wherein the computer control unit And a panel connected to the relay control device and configured to control a transmission by selecting a relay driving signal for flowing a current of a transformer to ground to measure a resistance on a transformer provided in the inverter to perform a voltage transformer function. And when the panel is manipulated, the relay drive signal is transmitted from the relay controller to the jig circuit unit. The method of claim 4, wherein the computer control unit Connected to the power supply, oscilloscope and voltage meter, inverter Vcc power information, inverter on / off power information, inverter dimming power information, LCD lamp selection information, inverter input terminal voltage information, transformer voltage information, shutdown operation information, transformer resistance information And LCD / inverter automatic inspection system, characterized in that by providing one or more information from the current / voltage information of the LCD lamp stage received from the power supply, oscilloscope, voltage meter or relay controller.