TW201410063A - Power driver for field emission light source - Google Patents

Abstract

A power driver for field emission light source is disclosed. The power driver is driving a field emission light source to provide a pulse high voltage within effective load period. Where the said field emission light source having a cathode is structured coating with nano carbon particle been electron-emitting source. The power driver comprises: an input modulation module, a controller module, an output modulation module and an anode output port, N cathode output ports. The power driver converts the civil power and outputs the pulse high voltage in diming from -4KV to -9KV with preset constant current relative to the current density 0.5 to 2.0mA/cm<SP>2</SP> of effective field emission cathode area. Therefore, a longer service life and uniform light distribution can be achieved since that the pulse interval leads rest time to avoid ceaseless electron excitation phosphor.

Description

Field emission lamp drive power

The invention relates to a field emission lamp driving power source, which is used for a field emission lamp source formed by a cathode element having a nano carbon material coating layer, for generating a DC pulse and a fixed current high voltage output for driving the field. The light source emits illumination light.

The first generation of lighting fixtures is a traditional incandescent bulb, which has been gradually completely banned due to excessive energy consumption of incandescent bulbs; the second generation of lighting fixtures are mainly fluorescent lamps, halogen energy-saving bulbs (such as CFL), mercury lamps, etc., which are electronically encapsulated in vacuum glass. The mercury or halogen vapor inside it causes X-rays to emit luminescent powder. Since such lighting fixtures contain mercury or halogen, they have a great impact on the environment and will gradually be replaced. The third-generation lighting fixtures are called solid-state lighting. LED (or OLED) is mainly used to illuminate to form a lighting fixture. However, 70-80% of the electrical energy input by LEDs and OLEDs is converted into thermal energy consumption, and only 20 to 30% of electrical energy is used for illumination, and the overall luminous efficiency is insufficient. Moreover, LEDs (or OLEDs) are manufactured using a semiconductor process, which consumes a great deal of resources and uses highly toxic chemicals, and is not truly a new generation of lighting fixtures that are required by humans. Due to the principle of field emission The development of field emission sources has received increasing attention due to the generation of light by electrical energy. Since the field emission light source encapsulates the cathode element and the anode element in a vacuum glass tube, when the cathode element imparts a negative voltage, an electric field is formed with the anode element, and an electron beam is emitted from the cathode element to excite the firefly attached to the anode element. Light powder emits light, and its luminous efficiency can reach 40 to 60 lumens per watt, especially for the simple and no semiconductor process. If it can be fully developed, it should improve human lighting.

On the power supply of the field emission light source, Taiwan Patent TW M307184 discloses the use of pulse modulation technology to control the DC power output of the field emission planar luminaire; US Patent Publication No. US20090190383, Taiwan Patent TW 200807839, etc. discloses the use of alternating current as the input power source. After rectification and transformation, a high-voltage DC output is generated, but since the DC element continuously emits electrons, the anode element phosphor powder is accelerated and aged, and its life is lower than the actual use. Taiwan Patent TW 201218868 discloses a power supply that uses an AC power source to drive a field emission display, which uses DC as an input power source, converts to AC power, and then boosts to a predetermined voltage for use in a field emission display, but Due to the waveform of the AC output, only the negative half-wave has an effect, and only a negative voltage exceeding the starting voltage of the cathode element can cause the cathode element to emit electrons, which is too inefficient. U.S. Patent Publication No. 2010009704 discloses a cathode light-emitting tube driving power source 9. As shown in Fig. 1, an alternating current power source 91 filters noise and rectifies to 320 VDC through a bridge rectifier & noise filter, and is reversed by control. The controller 93 (control-inverter) generates an AC power source, and the voltage multiplier 95 boosts the voltage to a voltage required for the cathode luminescent tube 97, and a heating power source 96 generates a heating power source. The cathode element for heating the cathode arc tube 97 is used to generate hot electrons; the driving power source 9 of the field emission lamp source also includes a phase & dimmer detector to improve the power factor (power factor) correction, PFC); an output driving power cathodoluminescent tube 9 AC pulse output type, the output voltage V _O, current a _O, when the output voltage Vc is higher than the starting voltage, the voltage Vc in order to make the above an electron emission cathode element; V _O of the output voltage waveform of the AC cycle type, the current value a _O also fluctuate, the instability of the electric field and the female The arc tube 97 emits light instability.

The driving power source of the field emission light source uses the voltage of the pulse waveform, in addition to reducing the power of the entire driving power source, the manufacturing cost can be reduced, and the cathode element can periodically emit electrons only when the pulse voltage is generated. The light powder is not subject to electron bombardment for a long time, so that there is a rest time, which can extend the life of the field emission light source. However, the stability of the electric field strength between the cathode element and the anode element will affect the lumen number of the field emission light source, and if the current of the circuit is too large or the electric field is uneven, the life of the anode element will be affected, so it should be controlled; Phenomenon at lower cathode element supply voltage, the effect of affecting the life of the anode element is less obvious, such as zinc oxide or metal cathode elements, the field turn-on voltage is lower, can be lower Electron under the supply voltage; but In the case of field emission light sources using nanocarbon as the cathode element, in order to achieve higher brightness, a higher voltage is often used, thereby reducing the life of the anode element and causing an electric field due to the use of a higher voltage. Uneven area. Therefore, how to use the voltage of the pulse waveform and improve the stability of the electric field strength will be an important issue.

In view of the above-mentioned problems of the prior art, the object of the present invention is to provide a field emission lamp driving power source to achieve a power source exceeding -5 KV, a DC pulse and a fixed current to improve the efficiency of the field emission lamp source and the life of the anode element. The purpose.

The main object of the present invention is to provide a field emission lamp driving power source, which is applied to a field emission lamp source composed of a cathode element coated with a nano carbon material, as shown in FIG. 2, which is a field emission lamp driving power source 3 and Schematic diagram of the power supply of the field emission lamp source 1; the input power source 39 of the field emission lamp driving power source 3 is an external power source, usually taking the AC power of the mains as an input or DC as an input, and converting the input AC power into DC power via the bridge rectifier 332, and then The transformer circuit 352 is boosted to a predetermined voltage and supplied to the field emission lamp source 1 from the anode output terminal 31 and the cathode output terminal 32. The anode element 4 and the cathode element 5 of the field emission lamp source 1 are packaged in the glass casing 2 at a spaced interval, and an electric field is formed by applying a voltage to the anode element 4 and the cathode element 5 after evacuation; the field emission lamp source 1 has an anode. The power input terminal P and a cathode power input terminal N are respectively connected to the anode output terminal 31 and the cathode output terminal 32 of the field emission lamp driving power source 3. The cathode element 5 of the field emission light source 1 The cathode wire 56 is connected to the cathode filament 51. The cathode wire 56 is connected to the cathode power input terminal N and the cathode filament 51, and the cathode output terminal 32 can be introduced into the cathode filament 51. The cathode filament 51 is made of metal or non-metal material and is covered with A layer of nanocarbon material 53 uses nano carbon material 53 as an electron emission source. When the field emission lamp driving power source 3 supplies a turn-on voltage exceeding the cathode element 5, the nano-carbon material 53 of the cathode filament 51 emits electrons, impinging on the phosphor powder of the anode element 4 to emit light. .

The field emission light source of the invention has an anode input end and a cathode input end, the cathode input end is connected to the cathode output end of the field emission lamp driving power source, and the anode input end is connected to the anode output end of the field emission lamp driving power source; the field emission lamp The driving power source comprises: an input modulation module, a control module and an output modulation module, and outputs a high voltage pulse voltage at the cathode output end, the voltage of the high voltage pulse voltage is V _O , and the cathode output end is connected to the anode output end. current of predetermined fixed current a _O, where V _O = -5 ~ -9KV system by a user or other control means, which is adjustable V _O (diming); nano-carbon material for the cathode element, the current a _O is preferably fixed to a predetermined current, the current output range of the emission current density of the cathode active field area is 0.5 ~ 2.0mA / current ² cm.

The input modulation module comprises an input isolation circuit, a bridge rectifier and a voltage regulator. The input isolation circuit can accept a commercial AC input such as 90~264VAC, 50~60HZ, and isolate the mains and the field emission lamp driving power. The circuit forms a primary side power isolation, such as isolation mainly composed of a diode (eg, Zener diode Zener) The bridge rectifier is connected to the input isolation circuit for converting the commercial power into direct current (voltage is Vi), and for different bridge rectifiers, for example, full-wave rectification or half-wave rectification, for example, conversion to Vi=350 VDC, However, it is not limited to this; the voltage regulator is connected to the bridge rectifier, and if the voltage regulator is connected to the automatic light controller, the external signal generated by the automatic light controller can be accepted to modulate and output different direct current The voltage Vi is output to the control module; if the voltage regulator is a manual voltage regulator (such as a knob), the voltage of the different DC power can be modulated and outputted to the control module by manual adjustment; For example, the voltage regulator is adjusted to Vi=250VDC~450VDC, which can be adjusted to the output voltage of -5KV~-9KV with respect to the positive output compared with the 20 times magnification of the transformer circuit; in order to further make the voltage Vi not change with load or current The voltage Vi output from the voltage regulator is output to the control module to modulate the output waveform and control its stability.

The control module comprises a pulse width modulation circuit, a control circuit and an output rectification filter circuit, wherein the switching power supply can be used to convert the DC power into a pulse power supply; wherein the pulse width modulation circuit (PWM circuit) The DC power Vi (such as 200~450VDC) connected to the input modulation module is converted into a voltage signal whose pulse width is adjustable; the control circuit is used to control the pulse width to be converted into Setting a pulse voltage of the frequency; the output rectification filter circuit is configured to filter the pulse voltage to form a low voltage pulse voltage Vk. The load time Tk of the low-voltage pulse voltage Vk is 0.1~1.0T (for a better load time, 0.12~0.86T, but not limited thereto), where T is Pulse period.

The output modulation module includes a transformer circuit and a current regulation circuit, and the voltage conversion circuit is configured to adjust the low voltage pulse voltage Vk to a predetermined voltage V _O of the high voltage pulse voltage, and the current regulation circuit has a control function. After the transformer circuit is modulated, the output power adjustment control is performed at a predetermined voltage V _O , so that the current intensity of the loop is maintained at a preset fixed current A _O , and the current output range is an effective field emission cathode area current density of 0.5. The current of ~2.0mA/cm ² does not change with the load fluctuation (that is, when the field emission light source is emitting light, it does not change with the field emission light source resistance, and the peak value is constant voltage and constant current); the output modulation module is The negative voltage sends the high voltage pulse voltage to the cathode output terminal, and the high voltage pulse voltage V _O and the current A _{O have} a payload time Te=1/5T~2/3T (1/5T≦Te≦2/3T); T is the pulse period of the high voltage pulse voltage; for a practical circuit design, the pulse period T of the high voltage pulse voltage can be matched with the pulse period Tk of the low voltage pulse voltage Vk, but not limited thereto; the payload time Te Transmitting light source for the field The voltage V _O of the output high voltage pulse voltage exceeds the start voltage Vc of the field emission light source.

For different nano carbon materials, the cathode filament coated on different materials, different cathode filament shapes, and the distance between the cathode element and the anode element, etc., so that the nano carbon material of each region on the cathode filament can be A uniform electron beam is emitted, and a current density test on the cathode filament can be performed in advance to determine a preset value of the current A _O .

Another object of the present invention is to provide a field emission lamp driving power source, the field emission lamp driving power source includes: an input modulation module, a control module, and an output modulation module; the control module includes a pulse width modulation circuit a control circuit, an output rectification filter circuit, and further comprising a feedback circuit for detecting a pulse voltage Vk outputted by the output rectification filter circuit and feeding back to the control circuit for adjusting a stable low voltage pulse The voltage Vk provides a higher precision low voltage pulse voltage Vk. Furthermore, the transformer circuit of the output modulation module can adopt a first-stage transformer or a second-level transformer; if a two-stage transformer is used, the transformer circuit is composed of a first-stage transformer circuit and a second-stage transformer circuit. The first stage transformer circuit is configured to boost the low voltage pulse voltage Vk and boost the second stage voltage transformer circuit to V _O . Further, in order to avoid the current backlash of the field emission light source, an output isolation circuit is arranged before the cathode output end, and an output isolation circuit is also arranged before the anode output end to regulate the voltage of the high voltage pulse voltage of the cathode output end. V _O and current A _O .

Another main object of the present invention is to provide a field emission lamp driving power source for a cathode element having a field emission composed of a plurality of cathode filaments (N, N greater than 1) coated with a nano carbon material. The light source, the N cathode filaments of the cathode element of the field emission light source are made of metal or non-metal material, coated with a layer of nano carbon material, and each of the N cathode filaments is made of the same material and coated with the same nano carbon material ( The same range of nano carbon materials are used, and the nano carbon material is used as an electron emission source. For different embodiments, the N cathode filaments may be of different materials or coated with different ranges of nano carbon materials, but in a preferred manner, the N cathode filaments may be assigned to each other. The same current for better field emission uniformity.

The field emission light source has an anode input end and N cathode input ends, N cathode input ends are connected to N cathode output ends of the field emission lamp driving power source, and the anode input end is connected to the anode output end of the field emission lamp driving power source; The field emission lamp driving power source comprises: an input modulation module, a control module and an output modulation module, and the input modulation module is the same as the control module.

The output modulation module includes a transformer circuit, a current regulation circuit and a current divider, and the voltage transformation circuit is configured to adjust the low voltage pulse voltage Vk outputted by the input modulation module and the control module to a predetermined high voltage V _O . The current regulating circuit has a control function, and the power adjustment control is performed after the transformer circuit is modulated and converted at a predetermined voltage V _O , so that the current intensity of the loop is maintained at a preset fixed current A _O ; the shunt system will The voltage V _O and the current A _{O of the} high voltage pulse voltage are shunted to the N cathode outputs, so that the voltage of the high voltage pulse voltage outputted by each cathode output is V _O and the current is A _O . For an unrestricted circuit architecture, the shunt The phase can be used for shunting, that is, the high voltage pulse voltage is outputted at each cathode output end at different timings; wherein the high voltage pulse voltage has a payload time of Te satisfying 1/5T≦Te≦2/3T, where T is the high voltage pulse During the pulse period of the voltage, the current from the N cathode output terminals to the anode output terminal is a preset fixed current A _O .

Since the shunt adjusts the pulse phase of the high voltage pulse voltage of the N cathode outputs to different, the N cathode inputs The high voltage pulse voltages at different phases can cause the N cathode filaments to alternately emit an electron beam to excite the anode element to generate light, which allows the anode element to have a rest time to enhance the life of the anode element.

Another main object of the present invention is to provide a field emission lamp driving power supply, the output modulation module further comprising N+1 output isolation circuits, wherein the N+1 output isolation circuits are connected to the shunt and the anode output Between the end and each of the cathode outputs to form a secondary side isolation; the shunt splits the high voltage pulse voltage at a first timing into an output isolation circuit of the first cathode output at a first timing; The two timings divide the high voltage pulse voltage into the output isolation circuit of the second cathode output by the second pulse phase, and the like; the output isolation circuit can stabilize the output voltage and current, avoid current backlash, and stabilize the field emission. The safety and illumination of the light source is stable.

In view of the above, a field emission lamp driving power source according to the present invention may have one or more of the following advantages:

(1) The voltage V _O outputted from the cathode output end of the field emission lamp driving power source of the present invention is a high voltage pulse voltage, and only the electric energy output is generated within the pulse time, which can be reduced compared to the field emission lamp driving power source of the DC output. The power of the entire drive power supply can reduce the cost of production.

(2) The voltage V _O outputted from the cathode output terminal of the field emission lamp driving power source of the present invention is an adjustable high-voltage pulse voltage, and the electron can be emitted to the anode element only when the effective load time Te is higher than the starting voltage of the cathode element. The fluorescent powder emits light, and the fluorescent powder of the anode element is not subjected to electron bombardment for a long time, so that there is a rest time, which can prolong the life of the field emission light source.

(3) The field emission lamp driving power source of the present invention is a preset fixed current output, which can provide a fixed current density to the cathode element, so that the electric field strength between the cathode element and the anode element tends to be stable, and the cathode element and the anode element are reduced. The influence of the difference in position caused by the difference in position can increase the uniformity of the field emission electric field and further increase the lumen number of the field emission light source.

(4) The cathode output end of the field emission lamp driving power source of the present invention can be a multi-track output, and can be provided for each cathode filament when applied to a field emission light source of a plurality of cathode filaments or a field emission light source of a planar illumination. The same voltage and current (or different voltages and currents can be designed) such that each cathode filament can emit the same (or different) electron density relative to the anode element, causing the anode element to produce the same brightness relative to each cathode filament.

The principle of illuminating the field emission is to generate a tunneling effect by the cathode element of the electric field. When the electric field applies a sufficient voltage to the cathode filament and the anode element of the cathode element, the vacuum energy level near the surface of the cathode element is lowered. The electrons are emitted, and when the electrons collide with the phosphor powder of the anode element, they emit light. The principle of field emission is: When no electric field E is present (E=0), the surface electrons of the cathode filament must have sufficient energy. If it is larger than qφ, there is a chance to overcome the potential energy barrier and the electrons escape from the surface, where q is the electron charge and φ is the potential difference. (The difference between the vacuum energy level and the Fermi level). However, when we add an electric field (E>0), the potential energy distribution in the vacuum region will change, so that the barrier of the electrons will become smaller, and the electrons will have a greater chance to directly penetrate the potential barrier. The field emits the outside of the cathode element; the larger the applied electric field, the smaller the barrier energy barrier, and the greater the probability of electrons penetrating and escaping.

The principle of field emission can be expressed by the Fowler-Nordheim equation: This formula can be further simplified to approximate the Fowler-Nordheim equation: Where N(ε, T) is the supply function of electrons (ie, the concentration of electrons), t(ε) is the tunneling probability, ε _h is the highest energy state of a tunneling electron, and ε _l is the lowest of a tunneling electron. Energy state, J is the emission current density (unit: mA/cm ² ) of the electron emission point on the surface of the cathode filament, E is the electric field of the vertical surface (unit is V/μm), A and B are correction coefficients, , v ( y )=0.95- y ² , α is the emission area (unit is cm ² ), β is the electric field enhancement factor (unit is cm ^-1 ), It is the working function (in eV) of the surface material of the cathode filament.

It can be seen from the above formula that the field emission current is related to the working function, electric field and field enhancement factor of the surface material of the cathode filament; if the working function of the surface material of the cathode filament is lower, the electrons are more easily emitted from the cathode. Similarly, as the electric field is larger, the electrons are more easily emitted from the surface of the cathode element.

According to the Fowler-Nordheim equation, reducing the working function of the cathode filament can reduce the initial voltage of the field emission electric field and increase the field emission current. Since the band gap of the carbon nano-material is quite high, about It is 5.45 ev (different from various nano carbon materials), so it has a negative electron affinity of about -1 ev, and its field emission starting voltage is very low (at a current density of 10 μA/cm ² field emission) The initial voltage is 3~10V/μm) and can withstand a relatively high current density. Compared with other materials, nano carbon material is more suitable as the material of cathode filament.

As a result of long-term research by the inventors of the present invention, it has been found that when the electric field voltage exceeds the field emission starting voltage, if the current density is low (or too high), the distance between the cathode element and the anode element may not be a fixed distance, or an electric field. The effect of the effect, the electric field strength of each region may be different, which will cause the electron beam energy of some regions to be higher, resulting in higher brightness of the partial region, unevenness, and even the phosphor powder in the partial region. Continue to be stimulated to reduce life expectancy. The power supply of the field emission lamp can only control the amplitude of the voltage (fixed voltage mode) Or controlling the power output of the power supply (fixed power mode); as a result of long-term research by the inventors of the present invention, the electrical characteristics of the electric field of the field emission lamp source are not completely the same as those of the conventional lamp, and are resistance characteristics. The combination with the characteristics of the capacitor is like the charging characteristics of the battery. Therefore, if the known power supply circuit architecture is used, the floating current will cause the field emission electron beam to be uneven, which will affect the lumen number and lifetime of the field emission light source.

In order to make the present invention more precise and detailed, the preferred embodiments are illustrated in the accompanying drawings. Referring to FIG. 3, it is a block diagram of a first embodiment of the field emission lamp driving power supply 3 of the present invention. In this embodiment, the field emission lamp driving power source 3 has a cathode output terminal 32 and an anode output terminal 31. The internal circuit includes the following modules: an input modulation module 33, a control module 34, and an output modulation module 35. After the external power source 39 is input, the field emission lamp driving power source 3 outputs a high voltage pulse voltage to the cathode output terminal 31 with respect to the anode output terminal 31. The voltage of the high voltage pulse voltage is V _O , and the cathode output terminal 32 is output to the anode. The current at terminal 31 is a fixed current A _O . For the field emission lamp source 1 applied to the field emission lamp driving power source 3 of the present invention, the cathode filament 51 of the cathode element 5 of the field emission lamp source 1 is covered with a layer of nano carbon material, and the nano carbon material is used as an electron emission source. For different nano carbon material combinations, the cathode element 5 has different starting voltages Vc, and the starting voltage Vc of the nano carbon material is generally -3.5 KV or more. When the field emission lamp driving power source 3 supplies the starting voltage Vc exceeding the cathode element 5, the nano carbon material of the cathode filament 51 emits electrons, which impinge on the phosphor powder of the anode element 4 to emit light.

In this embodiment, the voltage of the output high-voltage pulse voltage is adjustable, and the voltage of the output high-voltage pulse voltage V _{O is} between V _O =-5~-9KV by manual knob adjustment or electronic control adjustment. The user or other control device is adjusted according to the required brightness. For the cathode element 5 of the nano carbon material, the output current A _O in the present embodiment is a set fixed current, which does not change with the change of the output voltage V _O , and the output current A _O is preset, according to the cathode filament 51. Electric field characteristic curve with coated nano carbon material (JE characteristic diagram, emission current density (Emission current density) and emission field (α), emission area (α), cathode element 5 and anode element 4 Electric field enhancement factor (β), etc., can be calculated theoretically or experimentally to obtain a better current A _O value.

In general, the nano-carbon material coated by the cathode filament 51 comprises various nano-scale carbon structures, such as hollow tubular carbon nano tubes (CNTs) and solid fibrous nano carbon fibers (carbon nano). Fiber, CNF), single or multi-layered graphite sheet of graphite thickness, spherical fullerene, graphene with only a few atomic thickness, carbon nano-horn ), caron nano-filament (wall), crystallized carbon particles or amorphous carbon particles; among them, carbon nanotubes and nano carbon fibers, can be divided into linear or a carbon nano-coil tube (coil-CNT or CNC) and a carbon nano-coil fiber (coil-CNF or CNF), depending on the composition ratio thereof, the cathode filament 51 and The electric field characteristic curve (JE characteristic diagram), the emission area (α), the electric field enhancement factor (β) of the cathode element 5 and the anode element 4 of the coated nano carbon material are also different, and can be obtained by theoretical calculation or experiment. current density, and then decides a fixed value according to area a _O of the cathode filament 51, the fixed value a _O Previously set in the output module 35 modulation.

The input modulation module 33 of the embodiment includes an input isolation circuit 331, a bridge rectifier 332, and a voltage regulator 333. The input isolation circuit 331 can accept an input of an external power source, such as an AC input of a commercial power source such as 90~264VAC, 50~60HZ. Or the input of the direct current, the input of the external power source of the embodiment is 90~264VAC, and the commercial power of 50~60HZ is input, but not limited thereto. The input isolation circuit 331 is a circuit for isolating the mains and the field emission lamp driving power source 3. For example, the isolation function mainly composed of a diode is used. In this embodiment, a Zener diode is used to form a primary side isolation. However, the bridge rectifier 332 is connected to the input isolation circuit 331 for converting the commercial power into direct current. For different bridge rectifiers, full-wave rectification or half-wave rectification can be used, in this embodiment. To improve the power efficiency, the full-wave rectification is adopted to convert the commercial power to Vi=350 VDC; the voltage regulator 333 is connected to the bridge rectifier 332, and the voltage regulator 333 can be connected to the light automatic controller of the lamp, and the voltage regulation is performed. The device 333 can receive an external signal generated by the automatic light controller to modulate and output different DC voltages Vi to the control module 34. In this embodiment, a manual knob type voltage regulator 333 can be used. The manual adjustment is used to modulate the output of different DC voltages, Vi=250VDC~450VDC, and output to the control module 34.

The control module 34 includes a pulse width modulation circuit 341, a control circuit 342, and an output rectification filter circuit 343 for converting a DC power source into a pulse power source using a switching power supply; wherein the pulse width modulation circuit 341 The (PWM circuit) converts the DC power Vi (250-450 VDC) input from the input modulation module 33 into a voltage signal that is adjustable in pulse width; the control circuit 342 can control the pulse width to The pulse voltage is converted to a set frequency, which is a pulse voltage of 50 kHz in this embodiment; the output rectification filter circuit 343 filters the pulse voltage to form a low voltage pulse voltage Vk. Referring to FIG. 4, the control waveform diagram of the present embodiment converts the input DC power Vi into a periodic low-voltage pulse voltage Vk under a cycle timing signal (Clock), and the load time Tk is 0.1~. 1.0T, different tolerances for different phosphors, can be selected from 0.12 to 0.86T, where T is the pulse period. The control module 34 can use other power electronics technologies, such as a flyback converter, a push-pull converter, a forward converter, etc., this embodiment uses a switching converter control mode; for different control modes Group 34 is controlled using different principles, which are merely equivalent conversions and are also included in the techniques of the present invention. Specifically, if the bridge rectifier 332 is full-wave rectification, the bridge rectifier 332 outputs DC power and its voltage is continuous Vi; if the bridge rectifier 332 is half-wave rectified, the bridge rectifier 332 outputs a half wave. The direct current, whose voltage is intermittent Vi, as shown in Figure 4. Specifically, the field emission lamp driving power source 3 of the present invention is a pulse output of a constant voltage and a constant current, in the process of controlling voltage and current. In the control module 34, the excess power can be adjusted in a PWM manner to improve the power correction factor PFC of the field emission lamp driving power source 3.

The output modulation module 35 includes a transformer circuit 352 and a current regulation circuit 351 for adjusting the low voltage pulse voltage Vk to a predetermined voltage V _O of the high voltage pulse voltage. The current regulating circuit 351 adjusts the current intensity of the control loop to a predetermined fixed A _O and sends the negative voltage to the cathode output terminal 32. As shown in FIG. 5, the current A _O is a predetermined fixed current. Specifically, since the loop current is only a small current of mA level, the current regulating circuit 351 has a comparison circuit that can detect the loop current, amplifies the detected current value, and adjusts the loop current through the error calculation; the adopted control method It can be like a Gilbert circuit, or a simple current-limiting circuit, not limited. For the cathode filament 51 coated with the nano carbon material, the preferred output current A _O is a predetermined fixed current, and the current output range is a current having a current field emission cathode area current density of 0.5 to 2.0 mA/cm ² . Based on the effective field emission cathode area of 2 cm ² , the current value is set to A _O =1.0 mA to 4.0 mA, and the loop current does not follow the load resistance through the adjustment control of the current regulation circuit 351 (the field emission source 1 starts the illuminating resistance) Varying and changing; the effective load time of the high voltage pulse voltage is Te=1/5T~2/3T; wherein T is the pulse period of the high voltage pulse voltage; the payload time Te is the output of the field emission lamp driving power source 3 The time when the voltage V _{O of the} high voltage pulse voltage exceeds the starting voltage Vc of the field emission lamp source 1 is the time during which the electrons emit light to cause the phosphor powder 41 to emit light.

The transformer circuit 352 can be composed of a single-stage transformer or a bipolar transformer. If it is a bipolar transformer, the transformer circuit 352 is composed of a first-stage transformer circuit 3521 and a second-stage transformer circuit 3522, and the first-stage transformer circuit The 3521 can boost the low-voltage pulse voltage Vk first, and then be boosted to a predetermined voltage V _O by the second-stage transformer circuit 3522. For example, the first-stage transformer circuit 3521 converts Vk=200-450VDC four times to 800. ~1800VDC, and then the second-stage transformer circuit 3522 boosts to 4~9KV with five times of voltage transformation; here is only the ratio of boosting, so the voltage value is positive, when forming the loop, the cathode Output 32 is a negative voltage output relative to anode output 31.

The inventors of the present invention have long found that the cathode element 5 and the anode element 4 of the field emission lamp source 1 have a fixed area. After a fixed negative voltage V _{O is} applied, it is preferable to fix the electric field intensity of each region, but If the current A _O intensity of the loop is unstable, the brightness of the field emission lamp source 1 will be uneven, and the phosphor powder in a portion of the anode element 4 will be damaged due to long-term excitation, resulting in a decrease in lifetime. Due to the structure of the field emission lamp source 1, the distance between the cathode element 5 and the anode element 4 may vary depending on the position, and each part of the electric field caused is not the same. When the voltage drops or the current drops, the cathode element 5 At a position far from the anode element 4, the anode element 4 in the region does not illuminate due to the small electric field strength, and the light source is uneven or unstable. Therefore, in addition to avoiding the aforementioned problems, the field emission lamp driving power source 3 of the present embodiment can further increase the life of the anode element 4 by using the pulse voltage to allow the phosphor powder of the anode element 4 to rest.

For more precise control requirements and improved field emission lamp drive The power module corrector of the source 3, the control module 34 of the embodiment further includes a feedback circuit 344, and the feedback circuit 344 can detect the voltage value and the variation of the low voltage pulse voltage Vk output by the rectifier filter circuit 343. (variation), and feedback to the control circuit 342, the control circuit 342 adjusts the pulse width to adjust the pulse voltage; the output rectification filter circuit 343 then filters the pulse voltage to adjust and stabilize the low-voltage pulse voltage Vk.

Please refer to FIG. 6 , which is a schematic diagram of the power supply of the second embodiment of the field emission lamp driving power supply of the present invention. The present embodiment is applied to a field emission lamp source 1 , which is composed of a cathode element 5 and an anode. The component 4 is vacuum-packed in a glass envelope 2, and is supplied with power from the anode output terminal 31 and the N cathode output terminals 32a, 32b, ... 32n of the field emission lamp driving power source 3 to drive the field emission light source 1 to emit light. illumination. The field emission light source 1 of the present embodiment is a lamp tubular illumination device, and the cathode element 5 has N cathode filaments 51a, 51b, ..., 51n, and each cathode filament (51a, 51b, ..., 51n) The cathode substrate 54 is covered with a layer of nano carbon material 53, and the N cathode filaments 51a, 51b, ..., 51n are respectively connected to N cathodes of the N cathode wires 56a, 56b, ..., 56n. The power input terminals N ₁ , N ₂ , N ₃ , ..., N _n ; the anode element 4 comprises a conductive layer 42 and a phosphor powder 41. In this embodiment, transparent indium tin oxide (ITO) is used as the conductive layer 42. The phosphor powder 41 is placed thereon, and the conductive layer 42 is connected to an anode power input terminal P of an anode lead 46 (not shown). The field emission lamp driving power source 3 can generate N high voltage pulse voltages of V _O and currents of A _{O with} different phases, and is connected from the anode output terminal 31 to the anode wire 46 and the N cathode output terminals 32a, 32b, .. .32n is connected to the N cathode wires 56a, 56b, ..., 56n, and the output power is supplied to the field emission lamp source 1 to constitute a power supply circuit.

The field emission light source 1 has an anode power input terminal P and N cathode power input terminals N ₁ , N ₂ , N ₃ , . . . , N _n , and the base connector 23 of the field emission light source 1 as shown in FIG. (Fig. 10) is connected to the anode output terminal 31 and the cathode output terminals 32a, 32b, ... 32n of the field emission lamp driving power source 3, respectively. 3 the field emission lamp driving power of the N different phases generated high-voltage pulse voltage V _O, A _O current is negative voltage, the cathode element when it exceeds 5 each cathode filaments 51a, 51b, ..., 51n when the starting voltage, cathode The nanocarbon material 53 of the filaments 51a, 51b, ..., 51n emits electrons and impinges on the phosphor powder 41 of the anode element 4 to emit light.

In this embodiment, the field emission lamp driving power source 3 includes an anode output terminal 31 and a cathode output terminal 32. The cathode output terminal 32 is composed of N cathode output terminals 32a, 32b, ..., 32n, and the inside thereof. The circuit includes the following modules: an input modulation module 33, a control module 34, and an output modulation module 35. The input modulation module 33 and the control module 34 are as described in the first embodiment, and are not described herein again.

Referring to FIG. 7, the output modulation module 35 includes a transformer circuit 352, a current regulation circuit 351, and a current divider 353 for adjusting the low voltage pulse voltage Vk to a predetermined voltage of a high voltage pulse voltage. V _O ; current regulating circuit 351 modulates the high voltage pulse voltage V _{O of} the transformer circuit 352 to adjust the current intensity to a predetermined fixed A _O , and the shunt 353 can generate different phase signals, which are equal in one period T N phases are generated, and the voltage V _O modulated by the transformer circuit 352 and the fixed A _O output are sent to the a-th cathode output terminal 32a by a negative voltage at the a-th phase by the shunt 353; In the bth phase, the negative voltage is sent to the bth cathode output terminal 32b by the shunt 353, and the negative voltage is sent to the nth cathode output terminal 32n by the shunt 353 at the nth phase, as in the ninth phase. Figure. The high-voltage pulse voltage outputted to each of the cathode output terminals 32a, 32b, ... 32n is V _O , the current is A _O , and the effective load time of each high-voltage pulse voltage is 1/5T ≦ Te ≦ 2 / 3T.

The inventors of the present invention have long found that if the cathode filaments 51a to 51n of the cathode element 5 are made of the same material and the nano carbon material of the same group, the luminous efficiency of the field emission lamp source 1 is improved, and the cathode element 5 is improved. Each of the cathode filaments 51a to 51n should be given the same voltage and current with respect to the anode element 4. With the circuit architecture of the embodiment, N high-voltage pulse voltages of different phases can be outputted at N cathode output terminals 32a, 32b, ..., 32n to a negative voltage of V _O and a current of A _O , respectively, at different timings. Each of the cathode filaments 51a, 51b, ..., 51n emits electrons to cause the field emission lamp source 1 to emit uniform light.

Please refer to FIG. 7 , which is a block diagram of a third embodiment of the field emission lamp driving power supply of the present invention. In this embodiment, the field emission lamp driving power source 3 has N cathode output ends 32a, 32b, ... The 32n and an anode output terminal 31, the internal circuit includes the following modules: an input modulation module 33, a control module 34, and an output modulation module 35; wherein the output modulation module 35 includes a transformer circuit 352, Current regulation circuit 351, shunt 353 and N+1 output isolation circuits 354. The input modulation module 33 and the control module 34 are as described in the first embodiment and the second embodiment, and are not described herein again.

In this embodiment, N+1 output isolation circuits 354 are respectively connected between the N cathode output terminals 32a 3232 and the shunt 353 and between the anode output end and the output modulation module 35; the output modulation module The shunt 353 of 35 can generate different phase signals, and the voltage V _O modulated by the transformer circuit 352 and the fixed A _O output are sent to the output isolation circuit 354 at a negative voltage by the shunt 353 at the a-th phase. Outputted from the a-th cathode output terminal 32a to the field emission lamp source 1 to avoid current backlash of the a-th cathode output terminal 32a, and further stabilize the current A _O ; likewise, by shunting in the b-th phase The device 353 sends the negative voltage to the output isolation circuit 354, and then to the bth cathode output terminal 32b. At the nth phase, the negative voltage is sent to the output isolation circuit 354 by the shunt 353, and then sent to the nth cathode output. The terminal 32n is formed by the output isolation circuit 354 of the anode output terminal and the output isolation circuit 354 of each cathode output terminal to form a secondary side isolation to prevent current backlash, thereby improving safety and stable current A _O .

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

1‧‧‧ Field Light Source

2‧‧‧glass casing

23‧‧‧Base connector

3‧‧‧ Field emission light driver

31‧‧‧Anode output

32, 32a, 32b, 32n‧‧‧ cathode output

33‧‧‧Input modulation module

331‧‧‧Input isolation circuit

332‧‧‧Bridge rectifier

333‧‧‧Regulator

34‧‧‧Control Module

341‧‧‧ pulse width modulation circuit

342‧‧‧Control circuit

343‧‧‧Output rectification filter circuit

344‧‧‧Return circuit

35‧‧‧ Output Modulation Module

351‧‧‧current control circuit

352‧‧‧Transformer circuit

3521‧‧‧First-stage transformer circuit

3522‧‧‧Second stage transformer circuit

353‧‧‧Splitter

354‧‧‧Output isolation circuit

39‧‧‧Input power supply

4‧‧‧Anode components

41‧‧‧Fluorescent powder

42‧‧‧ Conductive layer

46‧‧‧Anode wire

5‧‧‧ pole components

51, 51a, 51b, ..., 51n‧‧‧ cathode filament

52‧‧‧Cathode filament support column

53‧‧‧Nano carbon material

54‧‧‧Cathode substrate

56, 56a, 56b, ..., 56n‧‧‧ cathode wire

9‧‧‧ Cathode LED driving power supply

91‧‧‧AC power supply

92‧‧‧Bridge rectifier filter

93‧‧‧Control reverser

94‧‧‧ phase adjustment detector

95‧‧‧Voltage multiplier

96‧‧‧heating power supply

97‧‧‧ Cathodoluminescence tube

N, N ₁ , N ₂ , N ₃ , ..., N _n ‧‧‧ cathode power input

P‧‧‧ anode power input

Vc‧‧‧ start voltage

V _O ‧‧‧High voltage pulse voltage

T‧‧‧Pulse cycle of high voltage pulse voltage

Te‧‧‧ payload time

Figure 1 is a waveform diagram of a field emission lamp driving power source and its output power source of the prior art; 2 is a schematic diagram of the power supply of the field emission lamp driving power source and the field emission lamp source; FIG. 3 is a block diagram of the first embodiment of the field emission lamp driving power source of the present invention; FIG. 4 is a field emission of the present invention. FIG. 5 is a control waveform diagram of a first embodiment of a field driving lamp driving power supply; FIG. 6 is a second and third embodiment of the present invention FIG. 7 is a block diagram of a second embodiment of a field emission lamp driving power supply according to the present invention; FIG. 8 is a block diagram of a third embodiment of the field emission lamp driving power supply of the present invention; The output waveform diagrams of the second and third embodiments of the field emission lamp driving power supply of the present invention; and FIG. 10 are schematic diagrams of the base connector of the field emission light source of the second and third embodiments of the present invention.

3‧‧‧ Field emission light driver

31‧‧‧Anode output

32‧‧‧ cathode output

33‧‧‧Input modulation module

331‧‧‧Input isolation circuit

332‧‧‧Bridge rectifier

34‧‧‧Control Module

341‧‧‧ pulse width modulation circuit

342‧‧‧Control circuit

343‧‧‧Output rectification filter circuit

344‧‧‧Return circuit

35‧‧‧ Output Modulation Module

351‧‧‧current control circuit

352‧‧‧Transformer circuit

3521‧‧‧First-stage transformer circuit

3522‧‧‧Second stage transformer circuit

39‧‧‧Input power supply

Claims (8)

A field emission lamp driving power source is applied to a field emission light source comprising a cathode element coated with a carbon material, the field emission light source having an anode input end and N cathode input ends, wherein N is greater than Equal to 1; the field emission lamp driving power source comprises: an input modulation module, a control module, an output modulation module, an anode output terminal and N cathode output terminals; the input modulation module includes an input An isolation circuit, a bridge rectifier and a voltage regulator, the input isolation circuit can accept an external power input, and isolate the external power supply and the circuit of the field emission lamp driving power; the bridge rectifier is connected to the input isolation circuit, The utility model converts the utility power into a constant current; the voltage regulator is connected to the bridge rectifier, and the voltage regulator receives one of an external signal or manually adjusts to adjust a voltage of the direct current different output and output To the control module; the control module comprises a pulse width modulation circuit, a control circuit, and an output rectification filter circuit; wherein the pulse width modulation circuit is connected to the input modulation module The input DC power is converted into a voltage signal which is adjustable in pulse width; the control circuit is configured to control a pulse width of the voltage signal to be converted into a pulse voltage of a set frequency; the output rectification filter circuit is configured to The pulse voltage is filtered to form a low voltage pulse voltage, which is output to the output modulation module; the output modulation module includes a transformer circuit and a current regulation circuit, and the voltage conversion circuit is used to adjust the low voltage pulse voltage Changing to a high voltage pulse voltage, the current regulating circuit stabilizes the high voltage pulse voltage modulated by the transformer circuit to have a voltage of V _O , and fixes the current intensity to A _O , and outputs the current to the anode output terminal and each of the N a cathode output terminal; wherein the voltage of the high voltage pulse voltage is V _O = -5~-9KV is an adjustable voltage, and the current from the cathode output end to the anode output end is a fixed current A _O . The field emission lamp driving power source of claim 1, wherein the control module further comprises a feedback circuit for detecting the low voltage pulse voltage output by the output rectifying and filtering circuit, and returning The control circuit is provided to adjust and stabilize the low voltage pulse voltage. The field emission lamp driving power source according to claim 1, wherein the transformer circuit is composed of a first-stage transformer circuit and a second-stage transformer circuit, and the first-stage transformer circuit is used. The low-voltage pulse voltage is boosted, and the second-stage transformer circuit is boosted to the voltage of the high-voltage pulse voltage. For example, in the field emission lamp driving power source of claim 1, the N cathode output ends and the anode output end further comprise an output isolation circuit for regulating the high voltage of each of the N cathode output terminals. The voltage of the pulse voltage V _O and the current A _O to avoid current backlash. As described in item a patent application field emission lamp driving power range, wherein the payload in a time Te of the high pressure pulse voltage, the output current A _O is a fixed current, a current output range of the effective field emission cathode area The current density is a current of 0.5 to 2.0 mA/cm ² ; wherein Te is the time when the high voltage pulse voltage of the field emission lamp driving power source exceeds the starting voltage of the field emission light source. The field emission lamp driving power source of claim 5, wherein the high-voltage pulse voltage has a payload time Te of 1/5T≦Te≦2/3T; wherein T is a pulse period of the high-voltage pulse voltage, Te is the time when the high voltage pulse voltage outputted by the field emission lamp driving power source exceeds the starting voltage of the field emission light source. The field emission lamp driving power source of claim 1, wherein if the N is greater than 1, the output modulation module further includes a shunt, and the shunt outputs the high voltage pulse voltage of the current regulating circuit to Different phases are shunted to each of the N cathode outputs. The field emission lamp driving power supply of claim 1, wherein the output modulation module further comprises N+1 output isolation circuits, wherein the N output isolation circuits are connected to the shunt and connected to the N Before the cathode output end, an output isolation circuit is connected to the anode output end, and the output isolation circuit of the anode output end and the output isolation circuit of each of the cathode output ends prevent current backlash.