KR100381547B1 - Glare shielding device of welding helmet and control method thereof - Google Patents

Abstract

The present invention relates to an anti-glare device of a welding helmet, and in particular, the anti-glare device includes a microprocessor for controlling the start time and the drive time of the liquid crystal panel. The microprocessor generates a start control signal of the liquid crystal drive unit, a drive control signal of the liquid crystal drive unit, and a power off control signal in response to simultaneous detection of the welding light and the high frequency signal generated during welding. The liquid crystal starter is kept in the floating state in the standby mode and starts the liquid crystal panel at high speed with the difference voltage between the high voltage and the starting voltage when the welding light is detected. The liquid crystal driver keeps the floating state in the standby mode and drives the liquid crystal panel in response to the drive control signal.

Therefore, in the present invention, it is maintained in the floating state in the standby mode to minimize the power consumption, start the liquid crystal panel at high speed in response to the detection of the welding light to quickly protect the glare of the welding operator from the welding light at the initial startup, microprocessor It can be used in various welding methods by reliably maintaining the operation mode by detecting the high frequency signal generated at the time of welding.

Description

Anti-glare device for welding helmet and its control method {GLARE SHIELDING DEVICE OF WELDING HELMET AND CONTROL METHOD THEREOF}

The present invention relates to an anti-glare device for a welding helmet and a control method thereof, and in particular, an anti-glare device that can automatically adjust the light transmittance to protect the eyes of the welding operator from light generated during the welding or cutting of the metal and its It relates to a control method.

An anti-glare device is a device for protecting an operator's eyes from light generated by a welding and cutting torch. This anti-glare device is to block the light of less than 780nm (IR) and less than 365nm (UV) and to control the transmission of visible light so that the welding position can be visually confirmed without glare.

U.S. Patent No. 5,315,099 (corresponding to German Patent No. 2,606,416) includes an anti-glare plate, an electronic circuit connected to the anti-glare plate for applying an electrical operating voltage to the anti-glare plate, and a light sensing and corresponding light beam. An anti-glare device having an optical sensor for applying a signal to an electronic circuit is disclosed.

In addition, US Pat. No. 5,444,232 (corresponding to European Patent No. 630,627) discloses an antiglare plate, an optical signal detector for generating a dimming signal, an evaluation circuit for controlling the antiglare plate, and a time for brightening the antiglare plate. There is disclosed an anti-glare device having a control circuit for controlling the control and detecting the intensity of light detected by the optical sensor. The control circuit is connected to a timing generating circuit for detecting a delay of the dimming signal generated by the detector, and has means for interconnecting data corresponding to logic and / or time.

The device disclosed in U.S. Patent No. 5,444,232 detects light intensity or amount of light and welding duration, and optimally adjusts the time to brighten by computing these parameters logically and / or temporally with each other by a suitable control circuit. do.

However, this method has a simple circuit configuration, but there is a delay time from the input of the welding light to the operation of the anti-glare device, and it is necessary to operate a control circuit including a microcomputer to continuously detect the change in the input light. There is a problem that the current consumption of the power supply is large.

In addition, the product to which the auto-off function is applied in order to prevent the continuous current consumption has to operate the on-switch during reuse, and there is a problem in that the sensitivity of the input light is adjusted according to the welding conditions.

In addition, when the welding signal is detected using only the optical signal as in the above-described prior art, there is a problem that the anti-glare device may malfunction because the detected signal is different depending on the type of the welding machine and the welding machine.

Thus, an anti-glare device using a non-optical detection means using a transformer has been developed. However, when the device is applied with noise from the surroundings, continuous light blocking occurs on the anti-glare plate due to unintended malfunction by the noise magnetic field. There is a problem that the welding light can not be identified, and thus the welding operation state cannot be confirmed.

An object of the present invention is to drive the liquid crystal panel quickly by the hardware control by the light detection in order to solve the problems of the prior art described above to block the welding light, and in the case of continuous welding operation micro The present invention provides an anti-glare device for welding helmets and a method of controlling the same, which minimizes power consumption by operating the liquid crystal panel by software control by a processor and enables welding work while checking the working position without glare. have.

1 is a perspective view of a welding helmet equipped with an anti-glare device according to an embodiment of the present invention.

Figure 1a is a rear view of a welding helmet equipped with an anti-glare device according to an embodiment of the present invention.

2 is a circuit diagram of a preferred embodiment of the anti-glare device of the present invention.

3 is a flow chart for explaining the operation of the control unit of FIG.

* Explanation of symbols for the main parts of the drawings

10: welding helmet 12: anti-glare plate

13 liquid crystal panel 14 solar cell

15 optical sensor 16 antenna

17: temperature sensor 18: adjustment knob

19: reset switch 20: solar cell circuit

30: charging circuit 40: oscillating circuit

50: high voltage amplifier 60: regulator

70: starting voltage generating unit 80: driving circuit power supply control unit

90: light detector 100: high frequency detector

110: temperature detector 112: delay time setting unit

114: reset circuit 118: time adjustment unit

120: liquid crystal driver 130: liquid crystal driver

140: control unit

In order to achieve the above object, the apparatus of the present invention provides a liquid crystal panel, a solar cell circuit converting light into electrical energy and outputting the first and second output voltages, and charging the first output voltage to provide an operating voltage. A charging circuit, an oscillation circuit for generating an oscillation signal in response to the second output voltage, a high voltage amplifier for generating a high voltage by charge pumping the operating voltage in response to the oscillation signal, and regulating the high voltage A regulator for generating a liquid crystal drive voltage, a start voltage generator for generating a liquid crystal start voltage in response to the oscillation signal, and a transition from a standby state to an operating state in response to a light detection signal to provide a ground voltage and a power-off control signal A driving circuit power control unit which switches from an operating state to a standby state and maintains a floating state in response to the second output voltage; A light detector for detecting welding light using a power source and outputting a light detection signal using the operating voltage as a power source, a high frequency generated during welding using the light detection signal as a power source, and a liquid crystal drive control signal A high frequency detector for outputting a high frequency detection signal using a power supply; and in a standby state by the driving circuit power control unit, the high frequency detection unit maintains a floating state, and responds to the photodetection signal to the liquid crystal panel at a difference voltage between the high voltage and the liquid crystal startup voltage. Is started at a high speed initially and maintains a start-up operation for a predetermined time in response to a start control signal; and in a standby state, the liquid crystal starter is kept in a floating state by the drive circuit power supply control part, and in response to a drive control signal, Responsive to the liquid crystal panel by the difference between the liquid crystal driving voltage and the ground voltage in response to A liquid crystal drive unit for driving a light source and an operation in response to the light detection signal, and then start the control signal during the startup time initially in response to the high frequency detection signal, and after the startup time has elapsed. And a control unit generating a control signal and stopping the generation of the driving control signal, generating the power off control signal and performing a standby mode when there is no light detection signal and a high frequency detection signal.

According to the method of the present invention, in a standby mode, photovoltaic conversion of ambient external light is performed by a solar cell to generate first and second output voltages, and the first output voltage is charged to generate a predetermined level of operating voltages. 2, charge pumping the operating voltage in response to the output voltage to generate a high voltage and a starting voltage, respectively, maintaining the liquid crystal starting portion and the liquid crystal driving portion in a floating state, detecting the welding light, and detecting the welding light. And releasing the liquid crystal driving unit and the liquid crystal driving unit from the floating state to switch to an operation mode, starting the liquid crystal panel with the difference voltage between the high voltage and the starting voltage through the liquid crystal starting unit, and detecting a high frequency signal generated during welding. And when the high frequency signal is detected, controlling the end of the startup time of the liquid crystal driving unit and driving the liquid crystal panel alternately through the liquid crystal driving unit. Parts of liquid crystal driving in the floating state and the liquid crystal in the absence of activation wave signal and detect light, and is characterized in that it comprises the step of performing a standby mode.

Hereinafter, an anti-glare device and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view of a welding helmet equipped with an anti-glare device according to an embodiment of the present invention, Figure 1a shows a rear view of the welding helmet. The welding helmet 10 is provided with an anti-glare plate 12 on the front portion. The welding helmet 10 is made of a light material such as nonflammable plastic. The anti-glare plate 12 is provided with a liquid crystal panel 13, a solar cell 14, an optical sensor 15, an antenna 16, a temperature sensor 17, and the like, and a circuit board on the rear surface of the solar cell 14. This is installed. An adjustment knob 18 for adjusting the liquid crystal driving voltage level is installed on the side of the welding helmet 10, and a reset switch 19 and a time delay adjusting knob 118 are installed on the rear surface of the plate 12. do. On the surface of the liquid crystal panel 13 is attached an optical filter that blocks other rays except visible light.

Normally, the liquid crystal panel 13 of the welding helmet is transparent, so that the operator can easily observe the front while wearing the helmet.

During welding, the optical sensor 15 and the antenna 16 detect the high frequency signal generated during the welding light and the welding to control the light transmittance of the liquid crystal panel 13 so that the working situation can be observed and the glare caused by the welding light Will be blocked.

The temperature sensor 17 allows the liquid crystal panel 13 to be quickly activated at an early stage even when the ambient temperature is lowered.

2 shows a circuit diagram of the anti-glare device of the present invention.

The anti-glare circuit includes a solar cell circuit 20, a charging circuit 30, an oscillation circuit 40, a high voltage generator 50, a regulator 60, a start voltage generator 70, a drive circuit power control unit ( 80, light detector 90, high frequency detector 100, temperature detector 110, delay time setting unit 112, reset circuit 114, liquid crystal starter 120, liquid crystal drive 130, control unit 140.

The solar cell circuit 20 supplies the voltage generated from the solar cell 14 to the charging circuit 30 using the diode D1 as the first output voltage, and the second output voltage VSO through the diode D2. )

The charging circuit 30 includes a rechargeable battery 32, light emitting diodes 34 and 36, and a smoothing capacitor 38. The charging circuit 30 prevents the LEDs 32 and 36 from overcharging the battery 32. That is, the light emitting diodes 34 and 36 consume electrical energy as optical energy when the forward voltage is above a predetermined voltage, thereby preventing overcharge. The operating voltage VCC having a constant level is output through the smoothing capacitor 38. The charging circuit 30 preferably includes a noise removing capacitor (not shown).

The oscillation circuit 40 is composed of a NAND gate, a resistor, and a capacitor, and the oscillation signal having a predetermined frequency is in phase with a frequency determined by the time constant of the resistor and the capacitor in the high state of the VSO applied to one input terminal of the NAND gate. Generates a reversed signal that is shifted 180 degrees.

The high voltage amplifier 50 inputs the oscillation signal and its inverted signal to charge-pump the operating voltage VCC to generate a high voltage VPP for driving the liquid crystal panel.

The regulator 60 outputs the liquid crystal driving voltage VLCD having a stable constant level by regulating the high voltage VPP. By adjusting the adjustment knob 18, the output level of the liquid crystal drive voltage can be set.

The start voltage generator 70 includes a charging capacitor 72 connected between the ground and the start voltage (VQ) output terminals, a charge pump circuit 74 and a gate 76 connected between the start voltage output terminal and the ground. . The gate 76 gates the oscillation signal of the oscillation circuit 40 in response to the temperature detection control signal TC. The charge pump circuit 74 pumps electric charges to the charging capacitor in response to the oscillation signal of the oscillation circuit 40 to generate a negative starting voltage VQ. In addition, the charge pump circuit 74 generates a higher level of starting voltage by increasing the number of charge pump unit cells of the charge pumping circuit in response to the temperature detection control signal through the gate 76. In other words, when the temperature of the liquid crystal panel drops below the set specific temperature, the response characteristic of the liquid crystal is slowed, and thus the initial startup is slowed. Therefore, in order to compensate the operating characteristics of the liquid crystal with temperature, a higher starting voltage is provided.

The driving circuit power control unit 80 includes a diode D3, resistors R1 and R2, and an NMOS transistor M1. The NMOS transistor M1 has a drain and a source connected between the ground voltage VSS and the ground, and the photodetection signal PIN through the power-off control signal PW, the diode D3, and the resistor R1 at the gate. Is connected. Therefore, the NMOS transistor M1 is turned on by the PIN signal so that VSS is grounded in the floating state and turned off by the PW signal so that the VSS is in the floating state again.

The photodetector 90 drives the optical sensor 15 by the VSO voltage to detect the welding light, and outputs the photodetection signal PIN detected by the VCC voltage. Therefore, the photodetection signal PIN is output at the VCC voltage level.

The high frequency detection unit 100 drives the antenna 16 by a PIN voltage to detect a high frequency signal generated during welding, and outputs a high frequency detection signal detected by the liquid crystal drive control signal LD. Therefore, the high frequency detection signal RFIN is photodetected to be output during the normal operation of the liquid crystal panel after the liquid crystal panel is activated.

The temperature detector 110 detects the ambient temperature of the liquid crystal panel through a temperature sensor 17 such as a thermistor and outputs a temperature detection signal TIN.

The delay time setting unit 112 sets the liquid crystal off time t3 according to the resistance value set by the adjustment knob 118. From 80 ms to 500 ms can be set from the time point at which the optical signal is no longer detected.

The reset circuit 114 generates a reset pulse when the reset switch 19 is turned on and provides it to the controller.

The liquid crystal starter 120 includes a PMOS transistor M2, an NMOS transistor M3, a PNP transistor Q1, an NP transistor Q2, an analog switch SW1, a resistor R3 to R11, and a diode ( D4, D5). Analog switch SW1 selects VSS with the state shown off. On, select VPP.

The liquid crystal starter 120 turns on the transistor Q2 in response to the PIN signal. The analog switch SW1 is turned off by the collector output of the transistor Q2. Therefore, the analog switch SW1 selects and outputs VSS instead of VPP. The VSS signal turns on the PMOS transistor M2 to provide a VPP voltage to the upper electrode of the liquid crystal panel 13. In addition, since the VSS signal is applied to the base of the transistor Q1, the transistor Q1 is turned on. Since the collector output of the transistor Q1 goes high, the NMOS transistor M3 is turned on. Therefore, the VQ voltage is applied to the lower electrode of the liquid crystal panel 13 through the NMOS transistor M3. As a result, at startup, the high voltage of VPP-VQ is applied between the two electrodes of the liquid crystal panel, so that the liquid crystal panel 13 responds quickly at an initial stage. Therefore, at the start of welding, the liquid crystal panel blocks the welding light within a short time by applying a high starting voltage to the liquid crystal panel in response thereto, thereby preventing initial glare.

After the initial startup, the liquid crystal starter 120 maintains the startup time for a predetermined time by the startup control signal ST. When the set startup time has elapsed, the transistor Q2 is turned off because the ST signal goes low. Accordingly, the analog switch SW1 is turned on to select and output the VPP signal. Therefore, both PMOS transistor M2 and NMOS transistor M3 are turned off. Therefore, the supply of further starting voltage is cut off. Although the PIN signal is continuously applied, the transistor Q2 is not turned on because the ST signal remains low.

The liquid crystal driver 130 includes an NMOS transistor M4, an NPI transistor Q3, an analog switch SW2 and SW3, a resistor R12 to R14, an oscillation circuit 132, and a NAND gate 134. The analog switch SW2 selects the VLCD with the state shown in the off state. When on, select VSS. Analog switch SW3 selects VSS with the state shown off. When on, select VLCD.

The oscillation circuit 132 has a circuit configuration similar to that of the oscillation circuit 40, and generates an oscillation signal of a predetermined frequency by the RC time constant when the VSO signal goes high.

When the liquid crystal drive control signal LD becomes high, the oscillation signal is output through the NAND gate 134. The transistor Q3 repeats the on / off at a predetermined frequency by the oscillation signal. Therefore, since the analog switches SW2 and SW3 are repeatedly turned on and off according to this frequency, an AC voltage of VLCD-VSS whose phase is inverted at a predetermined frequency is applied between the upper electrode and the lower electrode of the liquid crystal panel 13. Will be. As a result, when the liquid crystal panel 13 is driven, the light transmittance is controlled in response to the VLCD level.

When the liquid crystal drive control signal LD goes low, the output of the oscillation signal is blocked at the NAND gate 134, so that the driving of the liquid crystal panel is terminated.

Here, since the operation is in the standby state, the VSS voltage is in the floating state, and thus the liquid crystal actuator 120 and the liquid crystal driver 130 are both maintained in the floating state, and thus power consumption does not occur.

The controller 140 is composed of a microprocessor or a microcomputer.

An operation of the present invention will be described with reference to FIG. 3.

The controller 140 is reset 302 by the reset pulse provided from the reset circuit 114. When the reset signal is input, the controller 140 performs a self-diagnosis mode (304).

The controller 140 performs the self-diagnosis mode and then performs the standby mode (306). The controller 140 minimizes power consumption by maintaining an AD operation of converting an analog signal into a digital signal in the standby mode.

In the standby mode 306, photodetection is checked (308). If there is a light detection, the switch from the standby mode to the operation mode in response to the PIN signal (310). When the operation mode is set, the PW and ST signals are output in a high state (312). The liquid crystal driver 130 is released in the floating state by the PW signal.

The controller 140 starts counting T1 time (314), detects the TIN signal (316), and detects the RFIN signal (318) (318). The T3 time which is the off time delay time of the liquid crystal is calculated (320).

It is checked whether the T1 count value is 0 (322), and if it is zero, that is, when the set T1 time has elapsed, the ST signal is switched from the H state to the L state (324), and the T2 time which is the liquid crystal drive delay time is counted ( 326). After the T2 time has elapsed (328), the LD signal is output in the H state (330), the TC signal is output (332), and the mode is switched to the standby mode.

The liquid crystal starter 120 operates by the H state of the LD signal to activate the liquid crystal panel 13. The TIN signal is output in the H state when the ambient temperature is less than 0 ° C, for example, and in the L state when the temperature is 0 ° C or more. If it is below 0 ℃, the starting voltage is compensated.

If the light detection signal is not checked in step 308, the controller 140 is switched to the operation mode (334), and T3 time, which is the liquid crystal off delay time calculated in step 320, is counted (336). When the T3 time has elapsed (338), the LD signal which is the liquid crystal drive signal is switched from the H state to the Hi-Z state (340), and the T4 time which is the liquid crystal power supply discharge time is counted (342). When the T4 time has elapsed (344), the PW signal and the ST signal are switched to the Hi-Z state (346), and the standby mode is switched.

As such, the controller 140 may switch to the operation mode only when the AD consumes a lot of power and operate in the standby mode during the remaining operations, thereby minimizing the power consumption in the controller 140.

As described above, in the present invention, at the start of welding, the liquid crystal panel is quickly driven by hardware by photodetection to prevent initial glare, and the welding operation state is determined by software by interlocking photodetection and high frequency detection. Controlling the panel can prevent malfunctions and reduce power consumption in the microprocessor.

In addition, the initial glare blocking effect can be improved by compensating for the initial starting voltage by detecting the ambient temperature and degrading the response characteristic of the liquid crystal at a low temperature.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (7)

A liquid crystal panel; A solar cell circuit converting light into electrical energy and outputting the light at first and second output voltages; A charging circuit configured to charge the first output voltage to provide an operating voltage; An oscillation circuit for generating an oscillation signal in response to the second output voltage; A high voltage amplifier configured to charge pump the operating voltage in response to the oscillation signal to generate a high voltage; A regulator configured to regulate the high voltage to generate a stable liquid crystal driving voltage; A starting voltage generator for generating a liquid crystal starting voltage in response to the oscillation signal; A driving circuit power control unit which switches from a standby state to an operating state in response to the light detection signal to provide a ground voltage, and switches from the operating state to the standby state in response to the power off control signal to maintain the floating state; A photodetector for detecting welding light using the second output voltage as a power source and outputting a photodetection signal using the operating voltage as a power source; A high frequency detector for detecting a high frequency generated during welding by using the light detection signal as a power source and outputting a high frequency detection signal using a liquid crystal drive control signal as a power source; In the standby state, the driving circuit is maintained in a floating state by the power supply control unit, and the liquid crystal panel is initially started at a high speed with a difference voltage between the high voltage and the liquid crystal starting voltage in response to the light detection signal, and in a predetermined time in response to the start control signal. A liquid crystal starter for maintaining a starting operation; A liquid crystal driver configured to maintain the floating state by the driving circuit power control unit in a standby state, and to alternately drive the liquid crystal panel with a difference voltage between the liquid crystal driving voltage and the ground voltage in response to the oscillation signal in response to a driving control signal; The operation is started in response to the light detection signal, and then the start control signal is initially generated during the start time in response to the high frequency detection signal, and the drive control signal is generated after the start time has elapsed. And a control unit configured to stop the generation of the drive control signal, generate the power off control signal, and perform a standby mode when there is no light detection signal and a high frequency detection signal. The method of claim 1, wherein the charging circuit A rechargeable battery for charging the first output voltage; A plurality of light emitting diodes connected in series to both ends of the rechargeable battery to prevent overcharging; And And a smoothing capacitor for outputting the operation voltage by smoothing the output voltage of the rechargeable battery. The method of claim 1, wherein the regulator An anti-glare device of a welding helmet, characterized in that it comprises an adjusting means for adjusting the level of the liquid crystal drive voltage to adjust the light transmittance of the liquid crystal. The device of claim 1, wherein the device is Further comprising a temperature detection unit for detecting the temperature of the liquid crystal panel, The starting voltage generating unit outputs the liquid crystal starting voltage by adjusting the level in response to a temperature control signal, And the controller is further configured to output the temperature control signal in response to the temperature detection of the temperature detector. In the standby mode, photovoltaic conversion of ambient light is performed by a solar cell to generate first and second output voltages, and the first output voltage is charged to generate a predetermined level of operating voltage, and the second output voltage is responsive to the second output voltage. Charge pumping the operating voltage to generate a high voltage and a starting voltage, respectively, and maintaining the liquid crystal actuator and the liquid crystal driver in a floating state; Detecting welding light; When the welding light is detected, releasing the liquid crystal actuator and the liquid crystal driver from the floating state to switch to the operation mode, and starting the liquid crystal panel with the difference voltage between the high voltage and the starting voltage through the liquid crystal actuator; Detecting a high frequency signal generated during welding; If the high frequency signal is detected, controlling the end of the startup time of the liquid crystal driver and driving the liquid crystal panel through the liquid crystal driver; And And a liquid crystal driving unit and a liquid crystal starting unit in a floating state in the absence of a high frequency signal and light detection, and performing a standby mode. The method of controlling a glare prevention device for a welding helmet according to claim 5, wherein the initial startup of the liquid crystal panel is accelerated by varying the level of the starting voltage in accordance with the ambient temperature of the liquid crystal panel during the startup. A liquid crystal panel; A solar cell circuit converting light into electrical energy and outputting the light at first and second output voltages; A charging circuit configured to charge the first output voltage to provide an operating voltage; An oscillation circuit for generating an oscillation signal in response to the second output voltage; A high voltage amplifier configured to charge pump the operating voltage in response to the oscillation signal to generate a high voltage; A delay time setting unit for setting off time of the liquid crystal panel; A reset circuit for generating a reset signal by the operation of the reset switch; A regulator configured to regulate the high voltage to generate a stable liquid crystal driving voltage; A starting voltage generator for generating a liquid crystal starting voltage in response to the oscillation signal; A driving circuit power control unit which switches from a standby state to an operating state in response to the light detection signal to provide a ground voltage, and switches from the operating state to the standby state in response to the power off control signal to maintain the floating state; A photodetector for detecting welding light using the second output voltage as a power source and outputting a photodetection signal using the operating voltage as a power source; A high frequency detector for detecting a high frequency generated during welding by using the light detection signal as a power source and outputting a high frequency detection signal using a liquid crystal drive control signal as a power source; In the standby state, the driving circuit is maintained in a floating state by the power supply control unit, and the liquid crystal panel is initially started at a high speed with a difference voltage between the high voltage and the liquid crystal starting voltage in response to the light detection signal, and in a predetermined time in response to the start control signal. A liquid crystal starter for maintaining a starting operation; A liquid crystal driver configured to maintain the floating state by the driving circuit power control unit in a standby state, and to alternately drive the liquid crystal panel with a difference voltage between the liquid crystal driving voltage and the ground voltage in response to the oscillation signal in response to a driving control signal; Initial reset in response to the reset signal to perform a self-diagnostic mode, start operation in response to the light detection signal, and then initially generate the start control signal during the start time in response to the high frequency detection signal; After the start time has elapsed, the drive control signal is generated. When there is no light detection signal and a high frequency detection signal, the drive control signal is generated after the delay time set by the delay time setting unit has elapsed. And a control unit which stops and generates the power-off control signal and performs a standby mode.