TW508979B - Inverter for LCD backlight - Google Patents

Abstract

Disclosed is an inverter for LCD backlight. The inverter for LCD backlight according to the invention includes a first switching element connected to an input terminal of a DC/AC converter operating a lamp by using an inputted power for determining supply of the inputted power, a dimming control section for comparing a first dimming signal with a second dimming signal inputted from outside in accordance with a dimming mode selection signal, and outputting first, to third control signals to perform a PWM dimming, an analog dimming or a complex dimming control, an error amplifier for receiving a feedback signal F/B of a feedback part connected to the lamp by means of an inverting terminal, an a first control signal outputted from the dimming control section by means of a non-inverting terminal to output a compared signal in accordance with a state of the signals inputted to each terminal, a first comparator for receiving a pyramidal wave for controlling the PWM dimming having a predetermined cycle or a third control signal outputted from the dimming control section by means of the non-inverting terminal, and a second control signal outputted from the dimming control section by means of the inverting terminal, comparing the two signals, and outputting a signal in accordance with a compared value, a second switching element connected between an output terminal of the error amplifier and a ground terminal for performing on/off operation in accordance with a voltage level of a signal outputted from the first comparator, and converting a potential of the output terminal of the error amplifier to a ground potential, and a second comparator for receiving the output signal of the error amplifier by means of the non-inverting terminal and an oscillating signal of a predetermined cycle by means of the inverting terminal, and comparing the two signals to control on/off operations of the first switching element in accordance with the compared result. The inverter for LCD backlight according to the invention can operate in an analog dimming control, a PWM dimming control or a complex dimming control. When shifted to the dimming mode in the complex dimming control, the inverter for LCD backlight according to the invention is capable of enhancing responsive characteristics.

Description

508979 Case No. 90Π1770 Amendment— 丨 Fifth, the description of the invention (1) The present invention relates to the control signal of LCD backlight, which can be analogized to the dimming red according to the operation set by the producer, and the 1M modulation during the dimming control operation. Light or composite dimming is used to control the response characteristics. In general, the converter is protected and has a unique circuit. This is called a power conversion device. In addition to the group of people = the power is converted into AC power using vibrators or using discharge tubes Erfu flow vibration, and generators and AC generators or tubes or thyristors. g. In addition, recently, many use of crystals have been commonly used for mobile, factory power supply, 'emergency power supply in case of power failure, LCD power supply, fluorescent lamp current of car A. The backlight of the display device or other display device uses the current backlight converter to control the dimming and PWM dimming, which is largely divided into analogies according to the operator's previous method. 卞 The method has one of different lightning failures and PWM dimming. , Can use ei temple, but use analog dimming and therefore, recently there is no problem in sending two gamma ... than dimming or PWM dimming complex, human 1 " two ways, and according to demand to implement the light-like circuit ^ V /. first. This composite dimming method has the power of each dimming: 疋 i Lein has the difficulty of analog dimming and pwm dimming. You Dou Pishu said that due to the large volume, the design and maintenance problems were reduced. When light was converted to pwm dimming, a response was repeated. I :: The system is designed to solve the above problems, except for the circuit ... Control signals come from analogy

-SS_i〇jJJJ7〇 Description of the invention (2 ^ '—

When light or P ψ Μ 4I1 ％% A is operated, Λ or dimming is used to control the operation, and compound dimming control operation mode is used. The response characteristics when the dimming mode is switched are different from the existing LCD backlight converters that implement unique circuits. In order to achieve the above-mentioned purpose, the LCD backlight converter of the present invention includes a first conversion element that compares the current of the DC / AC converter (10) with the input power while turning the wheel-in end of the DC / AC converter (10) by using input power; The light mode selection signal or the input of the first dimming signal and the second dimming signal is rotated out of the first job. 1 3 The control signal performs analog dimming or pwM dimming or composite dimming. The feedback signal (F / B) is input to the negative electrode, and the first control signal output from the dimming control section is input to the anode terminal \ ..., and the signal state of each terminal is rotated to output the ERR (Error error of the comparison signal). ) Amplifier; with regular PWM dimming control triangle wave, or the third control signal output by the dimming control unit is input to the positive electrode, and the second control signal output by the dimming control unit is input to the negative electrode for comparison. The first comparator of the comparison value output signal; connected between the output terminal of the ERR amplifier and the ground terminal, and outputting the voltage level signal of the signal of the first comparator, ON / OFF. Output " end ~ potential change The second conversion element of the ground potential; the above-mentioned ERR ^ amplifier output signal is input to the positive electrode, and the periodic vibration signal is input to the negative electrode. After comparison, the 0 / N / FF of the first conversion element is controlled according to the comparison value. 2 comparators.

508979

AE 901 η 77η V. Description of the invention (3) Comparison of the state of the output signal and observation of the state of the output signal, The signal detected by the output end of the comparison device is quasi-control ^ j, and the load is the i-th comparison The cathode data of the receiver turns in;

System, number generation device; control the first batch of control states according to the mode selection signal. Press: Γ weekly the mode of the signal state of the first control signal. Select: No .; U The mode selection adjustment output by the above mode selection mode is adjusted to "L" signal. The first control signal generating device is input to the above-mentioned ERR amplifier according to the data. In order to achieve the above-mentioned purpose, the data input terminal of the ninth dimming control unit of the present invention is operated by the mode selection signal === the first signal The mode selection device has a ground potential No. 2 and No. 2 generating device and a second control signal generating device. The output of the control signal and the second control signal turns linearly and changes to the output signal of the U J J amplifier. The second comparator of the above ON / OFF. The above-mentioned first turn ~ f of the cow achieves the above-mentioned purpose. The third additional time operation of the present invention is that the pwm dimming mode has a control signal on the r signal. Approve I e% 名 又 位 # 私 位 第 2 ， and the output of the first conversion element of the first conversion element _ff 2 = i according to the linearly increasing output of the Zhao device. ”, The above purpose, the third of the present invention Additional feature is

508979 Case No. 90111770 V. Description of the invention (4) When the above-mentioned dimming control section operates the composite dimming control by the mode selection signal, the third control signal is provided by the mode selection device with a high level potential, and the control signal is provided by the second control signal The generating device outputs the linear number "i-th control signal generating device, ... the control signal linearly rises and changes in the binary state," and if the first control signal is in the grounded state, it operates in the PWM dimming control mode and changes linearly. Zone time, operating in analog dimming control mode. The above-mentioned objects and advantages of the present invention are made clearer based on examples described later with reference to the schematic diagrams familiar with this technical field. Below, specific examples of correct implementation of the present invention will be specifically described with reference to the drawings. Fig. 1 is a circuit showing the structure of the LCD backlight converter of the present invention. Fig. 1 is provided with a DC / ac converter (10) that performs voltage transformation; connected to a rotating power source (Vi η) and the DC / AC converter ( 1 〇), according to the input control signal operation ON / OFF, the rotating power (Vin) is input to the reverse switch (Q 1) of the D (: / ac converter (1 0). At this time, the above reverse The _ / 〇 control of the switch (Q1) is implemented by the dimming control. The reference number on the first figure 丨 0 0 dimming mode control section implements PWM dimming control and analog dimming control and composite dimming according to the present invention. Light, let ’s consider the ERR amplifier with the symbol OP1. Use the negative input to connect the feedback signal (F / B) of the feedback part of the desk lamp. Use the positive input and output at the output terminal of the dimming control unit ^ (10Q). Signal (A) and compare the output. The reference symbol ci shows the capacitor connected between the output terminal of the above err amplifier (0P1) and the negative electrode. The reference symbol OP3 shows that the output signal of the ERR amplifier (OP1) is input through the anode terminal and the negative electrode Enter the oscillator to send a vibration letter ^ yjoy / y ^ yjoy / y Correct the month: And the heart S ί 2 S Ϊ Result control · Amplifier (〇P1) The above-mentioned reverse opening and connection =; shows 'connected to the output terminal of the upper-level amplifier (0P1) 0P2 is a transistor that functions as a HΛ conversion element. Reference symbol (1 00)' s flute 9 Recognition-the angular wave is input to the positive electrode, and the above-mentioned dimming control unit puts the wheel-out signal for the terminal Λ1A) input to the cathode terminal for comparison, because the crystal (q2) is batched; the above-mentioned transistor (Q2) is based on The terminal of the pole is used to operate the electric comparator. The output signal of the ON / OFF of the output signal of the RR amplifier (0P1)] _ #The following is a description of the second embodiment of the electric motorcycle of the present invention having the above-mentioned structure with reference to FIG. 2 and FIG. The dimming control from the output (A) Qiu nnn takes over the output of the ERR amplifier. Therefore, as described above, in the analog dimming field or the pw dimming field, the first output terminal ⑴ and the second output terminal of the first and second output terminals Λ and 出 are out of FIG. 2 or 4 A, b for reference). Figure 2 illustrates the analog dimming operation with reference to Figure 2. The molding pressure flowing in the above-mentioned dimming control unit (丨 〇〇) is selected at the ground potential, and the dimming control unit (10.) detects; after the power is turned on, the first dimming signal (DS1) or the second dimming, The dimming pull mode is: (j) and the second output terminal input V line number, as shown in Figure 2 reference symbol a. "Wang Aihua" "Therefore, load three of the positive data input terminal of the first comparator (0P2). Page 12 508979 King No. 9011177η V. Description of the invention (6) The angular wave is for PWM rotation, so the triangular wave (Figure 2 The reference symbol c) is left at the ground potential 'on Q2 and the output of the ERR amplifier (OP1) is controlled by the signal output from the first output terminal (A) of the above-mentioned light control section (100). This' is control The output signal of the second comparison d of 0N / 0FF of the above-mentioned reverse switch (Q1) is adjusted by the signal of the negative pole of the second comparator (0P3) (= 2 reference symbol 0sc). ^ &Amp; 疋ί = The pulse signal becomes the Pei output signal, and analog dimming control is implemented, as shown in Fig. 2. The pWM dimming operation will be described with reference to Fig. 3. Press type number ί Mode selection of the above-mentioned dimming control section (100). At the terminal (MS) = two-two quasi-potentials' dimming control unit 00) Detection is a PWM dimming mode such as the output change of the output terminal (A) and the second output terminal, as shown in the figure 3 reference symbols a and b The voltage is the signal output at the port, which helps to maintain a high level. The signal from the two output terminals (B) helps The rotation is changed. ': At this time, the positive data input terminal of the angular negative open-cell comparator (〇P2), the above ER: ii waveform has a pulse shape. The positive electrode of the comparator (〇P3) is Actually load the signal of 0N / 0FF operation of the 2nd (Q2). Touch the bluff, 疋 follow the transistor

Page 13 508979 V. Description of Invention (7) II. That is, 'the first comparator (P2) is operated according to the output signal of the first comparator (Op2). Therefore, the signal applied to the anode data input terminal of the second comparator (0p3) is the "ERR1 OUT1" signal shown in Fig. 3. . Therefore, in order to control the second comparison ij (^ 〇P3) output signal of 0N / 0FF of the above-mentioned reverse switch (Q1), it is the L number of the negative terminal of the second comparator (〇p3) according to the load (reference symbol in FIG. 3) osc :) is adjusted with the signal (reference symbol ERR1 〇ϋτ in Figure 3) input to the positive data input terminal of the second comparator (Qpg). However, as shown in Figure 3, "OUT DRIVER" outputs pulses as a shovel and implements PWM dimming control. ° " Finally ', the composite dimming control will be described with reference to FIGS. 4 and 5. According to the range of the voltage flowing from the i-th output terminal (A) of the dimming control unit (100), the F / B terminal receives and determines the output of the ERR amplifier. Therefore, the dimming control unit (100) controls the operation in the analog dimming field or the pfM dimming field according to the input conditions of the first dimming signal or the second dimming signal. 〇) The signal waveforms output from the first output terminal (A) and (B) (a, b on Figure 2 or Figure 4). Also, input the positive data from the first comparator (0P2). The three-shaped wave at the input / end is generated by the PWM rotation, which helps to operate in the pffM dimming field. According to the change of the first dimming signal or the second dimming signal, the operation is on the second analog 8V on the first output. The "(a, b)" output from the terminal (A) and the second output terminal 线性 changes linearly to control the output of the above-mentioned ERR amplifier (〇ρι). M Operate at ρψΜ according to the first or second $ 周 光 # operation In the field of light, lose 508979, which is _MM 90111770_ May 5, Invention Description (8) ____ ~ The signal (b) from the enemy output (β) is a linear operation. B 1 of the output (A) The signal (a) is operated at a predetermined characteristic: the output of the first device (0P1). Therefore, the first ratio ^ 2 controls two, and 疋 changes according to the operation of a spherical wave It is operated by the ON / _ operation of the first switch Mih. ^ Open_〇 At this time 'Figure 4 shows the time when the PWM operation field and class are changed to a dimming signal. Figure 5 Betting money: According to the material, according to the…… resistance ratio, the electric output fixed at the second output terminal ⑷ (R2) This operation is PWM dimming. The potential of σ ~, from 1 to 5 The conversion element of the reference symbol _ is based on the signal from the output terminal (A) of the above-mentioned one, and supports dimming. As an analogy, the result is actually based on the linear dimming signal. The analog dimming requires a point and the dimming control section of the fan-shaped dimming control section of the square mouth (100) first output end U) turns out. &Quot;, b (a) 'So the operation is analogous at this time, the 5th The figure shows the simplest structure of the implementation of the book 'not the actual two] = pull-type control function circuit structure, the structure is divided into the comparison of the structure of the implementation of the implementation of the number and output its comparison signal, 5 weeks of photochemical Signal status of the signal (^ 1) and the reference signal (DS2) or itself; the comparator of the second dimming signal state at the output of the ^ wheel; The state of the detection output signal sent to the above bibby tiger is the output terminal of the 2nd output terminal (B). The output terminal of the At Atrium device shall prevail. Control the input and output of your first circuit structure part; control $ 15 page 508979

The mode selection signal (MS) is output at the third round output (c), ^ case number 901Π770 V. Description of the invention (9) At the same time, the mode σ ~ state of the output signal state of the first output (A) is adjusted, and The mode selection adjustment signal and the release section output to the mode selection section, and operate the analog dimming and PWM dimming signals separately to generate a second circuit configuration section that is divided. The structure of the output terminal U) of the 1st wheel is not marked with the symbol in Figure 5. According to the function A, since this structure can be realized by a microcomputer, its details are detailed. The connection relationship is omitted from the description. The structure is as explained above. The LCD backlight converter of the present invention does not use b ^ I / OFF 1C power supply, but the output of 0 / 0FF ERR amplifier. = Two-light and analog dimming and reduce power supply fluctuations. Stable circuit: Reliability with IC. I hope to the east, as I have described, although the present invention has illustrated the drawings and described specific examples, it can be variously reorganized and changed in the field of the claimed invention.

508979 Case No. 90111770 Amendment Brief Description of Drawings Figure 1 is a circuit diagram of the LCD backlight converter of the present invention. Fig. 2 is an example of a time stamp of an analog dimming operation in the dimming operation of the present invention. Fig. 3 is an example of a time stamp of the PWM dimming operation in the dimming operation of the present invention. Figure 4 is an example of a composite dimming time stamp of the present invention. Fig. 5 is a detailed example of the dimming mode control section shown in Fig. 1. [Illustration of drawing symbols] 10 ------- DC / AC converter 100 ------ Dimming control section

Page 17

Claims (1)

1 & 1. An LCD backlight converter 'which includes the use of input power to turn, the DC / AC converter's wheel-in terminal, and the input first turn element; to select the signal according to the dimming method, and compare the input from the outside The dimming control unit for the first dimming chirp and the second dimming chirp, and outputting the first to third control signals to perform similar dimming or PWM dimming or composite dimming; Sinbis > will be connected to the lamp The feedback signal (F / B) is input to the negative electrode, and the above-mentioned: the work control signal output by the light control unit is input to the positive electrode, and an ERR amplifier that compares signals is rotated in accordance with the # status of the input terminal; PWM with a period of time 5 week light control triangle wave, or the third control signal input by the dimming control unit is input to the positive electrode, and the dimming control unit is input: the second control signal is input to the negative electrode and compared according to the comparison value. First comparator; f is above, between the output terminal of the E⑽ amplifier and the ground terminal, the output is at the first ratio mentioned above. The voltage level operation of the comparator signal is 〇N / 〇FF, and the potential of the output terminal of the err amplifier is replaced by the second conversion element of the ground potential. The ERR amplifier wheel-out signal is input to the positive electrode, and the fixed vibration signal is input. After the comparison with the negative electrode, the second comparator of the 0N / 0FF of the nine-switching element is controlled according to the comparison value, and the second comparator of the LCD backlight is 1st to 2nd. The LCD backlight according to the scope of application patent No. 1IM changes the above-mentioned dimming control. The unit includes a comparison of the first dimming signal and a reference signal, and the comparison of the second dimming signal, the state of the second dimming signal connected to the output terminal, = the output of the output, and the comparison or track of the state of the output signal. Page 508979 Correction 6. The scope of the patent application is based on the state of the _ 浐 flute 9 μ & signal detected by the output terminal of the above comparison device, and is input to the above-mentioned first comparison; 2nd control signal generating device of 2 control center 2 control; Negative data input terminal—mode selection device b that controls the signal state of the first control signal according to the mode selection signal b; μ, Ϊ = modulo output by the mode selection mode ^ selection adjustment signal point No. 1 J tuning The light and P0 dimming signals are used to generate a “1” number, and the first control signal generating device that is loaded on the positive pole of the above ERR amplifier is a characteristic LCD backlight converter II. The LCD backlight changes to cry, and it is described as analogy by operation of the mode selection signal. The third control k has a ground potential by the mode selection device, and outputs through the first control signal generation device and the second control signal generation device. The first control signal and the second control signal output a linearly rising signal, and the output signal of the aforementioned ERR amplifier controls the second comparator responsible for the aforementioned first amplifier as Of light ah ^ _ ^ Laid the LCD backlight inverter. ^ 4 · According to the LCD backlight converter described in item 2 of the scope of the patent application, the above-mentioned dimming control section includes a mode selection device having a high level potential when the mode control signal is operated in the pWM dimming mode. The first χ control signal has a high level potential by the first control signal generating device, and the second control signal is output by the 2 control signal generating device with a linear rising and falling signal, and according to the control operation of the first comparator 〇N / 〇FF The second conversion device controls a second comparator that is in charge of 〇N / 〇FF of the first conversion element. Page 19 Ping —— ~ ^ 0ΜΠ770_ VI. Patent application scope LCD backlight converter with characteristics. 5 · If you apply for the second item in the patent scope, "η" is required. The above-mentioned dimming control unit includes a tf converter, and the 3rd bracketing mode & number selection operation composite dimming control mode. 2 第 3 控制 ## The mode selection device has a high level to discriminate.] F Device output linearly rises and changes ;: the shape of a bear line! · Health: 1 The device generates the first control signal at the ground potential The state rises linearly, and even l ^} When the first control signal above is at the ground potential state, PWM dimming is used to control the output, i. The dimming control mode selects the LCD backlight converter with the characteristic of & Λ operation. Page 20