Background Art Lamp apparatuses having a function of air purification, <BR> i. e. , air-purifying lighting devices as generally known are lighting devices such as three-wavelength lamps integrated with an anion generator including a high negative voltage generator. Anions are generated due to ionization by the electrons emitted from the high negative voltage generator, thereby purifying indoor air.

For example, "air-cleaning lighting equipment"as disclosed in International Patent Publication No. WO 96/001970 and"air-purifying lighting equipment with an anion control sensor"as disclosed in International Patent Publication No. WO 02/083315 are such conventional air- purifying lighting devices.

The anion generators included in the two disclosed

lighting devices are basically identical with only one difference in that the anion generator disclosed in WO 02/083315 further includes a sensor for controlling the amount of anions according to the intensity of illumination of the lighting device.

As shown in FIG. 1, those anion generators commonly include a long cathode electron gun 3 having a radial cross- section which is engaged into a housing 1 of the lighting device by means of extensions 5b and which includes a plurality of discharge electrodes 3a for emitting electrons, a cylindrical anode ion collecting panel 5 surrounding the electron gun 3 and having a plurality of through holes 6a at the outer circumferential surface thereof, a cover 7 having a plurality of through holes 7a and disposed at the upper surface of the ion collecting panel 5 and an insulating member 5a interposed between the cover 7 and the ion collecting panel 5.

When a high negative voltage is supplied to the discharge electrodes 3a of the cathode electron gun 3 and a positive voltage is supplied to the cylindrical ion collecting panel 5, electrons are emitted from the discharge electrodes 3a. While traveling toward the ion collecting panel, the electrons collide with air and thereby generate anions. The generated anions and the air flow out and in through the through holes 6 formed at the outer

circumferential surface of the ion collecting panel 5.

There are, however, drawbacks associated with a conventional lighting device having such an anion generator.

Heat generated from a lamp in the lighting device adversely affects the stable operation of a high voltage generating circuit that generates a high voltage supplied to the anion generator or the lamp. Accordingly, the discharge of anions and/or the inflow of air through the through holes 6 and 7a cannot be smooth and the anion generator cannot generate a constant amount of anions. In addition, the anions generated by the electron gun are attached together with various surrounding contaminants to the ion collecting panel 5 that functions as an anode. The contamination of the anode greatly reduces the amount of anions generated, thereby lowering air purification efficiency of the anion generator.

Disclosure of the Invention The present invention has been made to solve the above- mentioned problems occurring in the prior art, and an object of the present invention is to provide an air-purifying lighting device which blocks heat generated from a lamp, prevents a thermal shock to a high voltage generating circuit included in an anion generator and provides an open space, instead of separate inlet and outlet, to facilitate the discharge of anions generated from the anion generator and

the inflow of air mediating the anion generation, thereby maximizing anion generation efficiency and preventing reduction of. the amount of anions generated due to the attachment of contaminants.

In order to accomplish the above object of the present invention, there is provided an air-purifying lighting device having a lamp unit and an anion generator on a housing with a socket electrode, comprising a power supply unit disposed within the housing to distribute power supplied through the socket electrode to the lamp unit and the anion generator, wherein said anion generator includes a long cathode electron gun coated with an insulator and having one end fixed to the housing to be electrically connected to the power supply unit and a conductive anode ring member surrounding part of the cathode electron gun, keeping apart from the outer circumferential surface of the surrounded part of the cathode electron gun.

Preferably, the lighting device further comprises a thermal insulator provided between the lamp unit and the power supply unit.

Preferably, a carbon fiber is additionally provided at the free end of the cathode. electron gun.

Preferably, the lighting device further comprises a cylindrical radiator provided between the lamp unit and the anion generator to surround lower part of the cathode

electron gun.

Preferably, the cylindrical radiator is made of silver to release silver ions due to the heat generated from the lamp unit. Also, the cylindrical radiator has a plurality of holes at the outer circumferential surface thereof to discharge out the released silver ions.

Preferably, the power supply unit includes a rectifier circuit for rectifying the power supplied from a power source, an inverter for converting the rectified DC power into AC, a first high-voltage transformer for converting the AC power provided from the inverter into high-voltage power to be used in the lamp unit, a second high-voltage transformer for converting the power rectified by the rectifier circuit into high-voltage power to be used in the anion generator, and a high-voltage circuit for generating a high voltage to be applied to the anion generator using the power converted by the second high-voltage transformer.

Preferably, the power supply unit further includes a variable circuit for controlling the amount of anions generated from the anion generator by controlling the magnitude of power converted by the second high-voltage transformer.

Preferably, the power supply unit further includes a switching circuit for connecting or disconnecting the power rectified by the rectifier circuit and supplied to the inverter in order to control the on-off operation of the lamp

unit.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned by practicing the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Brief Description of the Drawings The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment (s) of the invention and together with the description serve to explain the principle of the invention. In the drawings : FIG. 1 is a schematic view showing the structure of an anion generator incorporated in a conventional air-purifying light device; FIG. 2 is a schematic view showing the structure of an air-purifying lighting device according to the present invention ; and FIG. 3 is a schematic view of a power supply unit

included in an air-purifying lighting device according to a preferred embodiment of the present invention.

Best Mode for Carrying Out the Invention Reference will now be made in detail to the preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIG. 2 is a schematic view showing the structure of an air-purifying lighting device according to the present invention. FIG. 3 is a schematic view of a power supply unit included in an air-purifying lighting device according to a preferred embodiment of the present invention Referring to FIGs. 2 and 3, the lighting device having an air-purifying function according to the present invention includes a housing 10, a lamp unit 50 for illumination and an anion generator 30 for air purification.

The housing 10 has a socket electrode 10a at the bottom thereof to receive supply voltages from an external power source. Also, the housing 10 has a power supply unit assembled with the socket electrode lOa and including a rectifier circuit 13, an inverter 15, a high voltage circuit 19 and a transformer. The power supply unit converts power supplied from the external power source into controllable one

which will then be distributed and supplied to the lamp unit 50 and the anion generator 30.

The lamp unit 50 for illumination can be one or more lamps, and particularly three-wavelength lamps. The number of lamps can be determined according to the design of the lighting device.

The anion generator 30 includes a long cathode electron gun 31 coated with an insulator 33 and an anode ring member 37 surrounding part of the electron gun 31, keeping apart from the outer circumferential surface of the electron gun 31.

The cathode electron gun, 31 is electrically connected to the power supply unit provided within the housing 10. When the power supply unit applies a high-voltage negative bias to the cathode electron gun 31 and a positive bias to the anode ring member 37, electrons are emitted from the free end of the electron gun 31 into the air between both electrodes. The emitted electrons collide with the air to neutralize or anionize various hazardous components generally present as cations or positive ions in the air (for example, tobacco smoke, SOx, Nox, Co and so on), thereby purifying the air.

The anode ring member 37 is disposed to surround part of the cathode electron gun 31. The two electrodes are kept apart from each other so that the air between the electrodes acts as a conductor mediating an anion generating mechanism.

The anode ring member 37 replaces an anode ion collecting panel as used in the prior art to surround the entire cathode electron gun. The ion collecting panel has a low rate of generation of anions because its openings forming an air inlet/outlet are getting blocked up with attached contaminating cations. The anode ring member 37 can completely solve this problem in the prior art.

In the anion generator of the lighting device according to the present invention, the anode ring member 37 is merely a means forming an electric circuit of the anion generating mechanism. Since most surroundings of the cathode electron gun 31 are opened, cations in the air are mostly neutralized with the anions generated by the emission of electrons.

Accordingly, the anion generator of the present invention can solve such problems as reduction of the generation of anions that may be caused by cations attached to the anode ring member 37 and restriction to the inflow and outflow of the air that mediates the anion generating mechanism.

Preferably, a carbon fiber 35, for example, an active carbon fiber, should be provided at the free end, of the cathode electron gun 31. The carbon fiber 35 itself contains lots of anions due to freely movable six electrons in a loose bond. Also, the carbon fiber 35 having micropores can effectively adsorb hazardous cations in the air and remove unpleasant odors. Moreover, when the electrons emitted from

the electron gun 31 collide with the carbon fiber, the rate of generation of electrons will be greatly increased, thereby enhancing the air purification effect.

Preferably, the anion generator 30 further includes a cylindrical radiator 39 between the lamp unit and the anion generator to surround the lower part of the cathode electron gun 31.

The cylindrical radiator 39 prevents the heat generated from the lamp unit 50 from being directly transferred to the anion generator 30 to cause an adverse effect to the operation of the anion generator 30.

According to the preferred embodiment of the present invention, the cylindrical radiator 39 is made of silver to release silver ions due to an activation by the heat generated from the lamp unit 50. The cylindrical radiator 39 has a plurality of holes 39a at the outer circumferential surface thereof to discharge out the released silver ions.

Silver ions generated from the cylindrical radiator 39 using the heat generated from the lamp unit 50 have bactericidal and antibacterial/antifungal effects. Also, the silver ions can balance hormone levels in humans, block a water vein and electromagnetic waves, emit far-infrared rays and anions, and relax human body and mind.

According to the preferred embodiment of the present invention, it is possible to apply an anode voltage to the

silver radiator 39 to form an anode together with the anode copper ring member 37. The anode radiator can accelerate the generation of silver ions beneficial to the human health, because silver ions are generated by the collision of the electrons generated from the anion generator, as well as by the heat generated from the lamp unit.

The air-purifying lighting device according to the present invention provides the power supply unit within the housing 10 to distribute and supply power to the lamp unit 50 for illumination and the anion generator 50 for air purification.

The power supply unit includes a rectifier circuit 13 for rectifying the power supplied from a power source 11, an inverter 15 for converting the rectified DC power into AC, a first high-voltage transformer 17a for converting the AC power provided from the inverter into high-voltage power to be used in the lamp unit 50, a second high-voltage transformer 17b for converting the power rectified by the rectifier circuit 13 into high-voltage power to be used in the anion generator 30, and a high-voltage circuit 19 for generating a high voltage to be applied to the anion generator 30 using the power converted by the second high- voltage transformer 17b.

The power supply unit provides two separate transformers 17a and 17b for the lamp unit 50 and the anion

generator 30, respectively. When a single high-voltage transformer is used, it may generate excess heat due to overload. Also, the excess heat may adversely affect the operation of the anion generator to lower the anion generation efficiency or stop the operation of the anion generator. The two separate transformers can basically prevent the problems occurring when a single transformer is used.

The power supply unit may further include a switching circuit 14 for connecting or disconnecting the power rectified by the rectifier circuit 13 and supplied to the inverter 15. With the switching circuit 14, the power supply unit can control the operation of a variable circuit 18 that controls the amount of anions generated from the anion generator 30 by controlling the magnitude of power converted by the second high-voltage transformer 17b and the on-off operation of the lamp unit 50.

In the power supply unit, high heat may be generated during the operations of the transformers. When the heat is transferred into the components of the power supply unit within the housing, it will have a detrimental effect on the operation of the power supply unit, and particularly the high-voltage circuit vulnerable to heat.

As a solution to the above problem, a thermal insulator 20 is provided on top of the housing 10. The thermal

insulator 20 prevents the transfer of heat from the lamp unit 50 to the power supply unit, thereby stabilizing the operation of the anion generator 30.

Industrial Applicability As explained above, the air-purifying lighting device according to the present invention blocks heat generated from the lamp unit, prevents a thermal shock to the high-voltage circuit of the anion generator and provides an open space, instead of separate inlet and outlet, to facilitate the discharge of anions generated from the anion generator and the inflow of air mediating the anion generating, thereby maximizing anion generation efficiency and preventing reduction of the amount of generated anions due to the attachment of contaminants. Also, the silver radiator provided adjacent to the lamp unit to surround the lower part of the electron gun releases silver (Ag+) ions due to the heat generated from the lamp unit. In other words, the anion generator of the air-purifying lighting device generates both anions and silver ions that are cations beneficial to the human body.

The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.