MXPA98000251A - Hid integ reflector lamp - Google Patents

Abstract

The present invention relates to an integrated reflector lamp including a sealed cover enclosing a high pressure gas discharge chamber. A shell has an edge portion which receives the sealed cover and an opposite basal portion carrying a threaded base. A ballast to ignite and operate the discharge device that is enclosed in the shell between the threaded base and the sealed cover. The sealed cover includes a reflecting surface that directs the light emitted by the discharge chamber. The reflecting surface also provides effective heat management to prevent overheating of the ballast by the heat generated by the discharge device. The integrated lamp has luminous and photometric efficiency that exceed those of the corresponding halogen IR reflector lamps and halogen lamps, while having an external design that conforms to the external design of corresponding lamps.

Description

REFLECTOR LAMP HID INTEGRAL BACKGROUND OF THE INVENTION The invention relates to an integral reflector lamp comprising an energizable light source for emitting light, a reflector body having a reflective surface for directing the light emitted by the light source, and a lamp base having lamp contacts electrically connected to the light source. Such lamps are well known in the industry and include, for example, parabolic aluminized reflector (PAR) lamps. PAR lamps have a robust lamp cover with a pressed glass reflector body having an internal parabolic reflector surface and a pressed glass cover sealed to the reflecting body. Historically, light sources have been incandescent filaments. More recently, the light source has been a halogen burner, which provides higher efficiency than with an incandescent filament in the form of a conventional bar. Still a further improvement in the technical field has been the use of halogen lighters that include infrared reflective coatings in the lighter's capsule or in a liner inside or outside the lighter's capsule. The reflectors coated in another machine wasted infrared radiation sending it back to the filament. This increased the temperature of the filament and increased the useful light provided by a given power consumption. PAR lamps come in many different dimensions and have many different applications. This includes general indoor and outdoor location and important lighting, such as for buildings, statues, fountains, and sports field, as well as for localized lighting, such as for window displays of souvenirs, hotels, restaurants, and theaters. As a part of a worldwide movement towards more efficient lighting, recent US government legislation (commonly referred to as the National Energy Policy Act "EPACT") have established lamp efficiency values for various types of commonly used lamps including lamps with parabolic aluminized reflector (PAR) these minimum efficiency values became effective 'in 1995 and only products that reached this level of efficiency were allowed to be sold in the United States. Efficiency values for PAR-38 incandescent lamps have been established for various wattage ranges. For example, 51-66W lamps should achieve 11 lumens per watt (LPW), 67-85W lamps should reach 12.5 LPW, 86-115W lamps should reach 14 LPW and lamps in the 116-155 range should reach 14.5 LPW. There are few PAR 38 lamps currently on the market with a reflective coating of aluminum and an incandescent filament that respect EPACT standards and which have a commercially acceptable life of one thousand hours. These, which barely exceed the minimum standards, would require additional substantial improvements. Congruently, the market quickly changed to PAR lamps that had halogen burners or halogen IR burners. However, a disadvantage of halogen IR lamps or commercial halogen lamps is that they have a relatively short service life with acceptable efficiency. For example, a commercially available 90W lamp has an average service life of around 2,500 hours while that of a 60W halogen IR lamp is only slightly more than 3,000 hours. It would be desirable to have a significantly longer life since the changing of lamps, especially for fixing in high places, can easily exceed the cost of the lamp to be replaced. For example, the 90W PAR halogen lamp has a luminous efficiency of around 16 LPW while the 60W PAR lamp with a halogen IR lamp has a luminous efficiency of around 19 LPW. Additional improvements in efficiencies for these lamps at a fixed lifetime could be expected to be less than around 5%. Still another disadvantage is that the color temperature is limited for tungsten filament lamps to a maximum of 3, 650 ° K, the melting point of tungsten. Generally, however, the color temperature is confined to a range of about 2, 600-3, 000 ° K to achieve a lamp life at a commercially acceptable level. It may be desirable to offer lamps with a different color temperature because this allows the lamps to be used in specific applications. For example, it is generally desirable that for cold environments a warm color temperature (e.g., 3,000K) is desirable while for a warm environment a cold color temperature (e.g., 4,500K) is desired. Still other reflector lamps are known to include a blown glass cover and contain incandescent bar filament. These are generally known as "R" lamps, and have lower luminous efficiency than the PAR lamps, for example of the order of 9 to 11 LPW, and the same colorimetric limitations. BRIEF DESCRIPTION OF THE INVENTION Congruently, it is an object of the invention to provide a reflector lamp with improved efficiency. It is another object of the invention to provide a reflector lamp with improved lamp life.

It is still another objective to provide a reflector lamp with greater flexibility with respect to photometric parameters such as color temperature and color produced. It is a further object of the invention to provide such types of lamps that can be operated in the same fixings as incandescent lamps and halogen PAR lamps and incandescent "R" lamps. According to the invention, the aforementioned objects are achieved in a lamp according to the type of writing in the first paragraph of the present description and as it is defined in claim 1. The modality described above provides a reflector lamp that is a significant energy saving substitute of the known PAR lamps having an incandescent filament, including halogen lamps and halogen IR lamps, as well as the known "R" lamps the lamp according to this embodiment comprises the same fixing the corresponding lamp, screwed in the same sockets, and operated on the same line voltage. So, your accommodation is simple. Furthermore, in addition to the substantially improved luminous efficiency, the gas discharge device can be designed, through the selection of filling constituents such as with different metal halides, to have colorimetric parameters such as temperature of color, over a wide range than is possible with PAR lamps and known R lamps. Then, there is more flexibility for lamps designed for a particular environment. In accordance with a significantly commercial implementation, the lamp has an exit substantially within the ANSI outputs for a PAR '38 lamp which is widely used in illuminated public spaces. According to still another embodiment, during the normal operation of the lamp, the discharge device is free of acoustic resonance in alternative lamps existing under a lamp of lower resonant frequency and the ballast circuit energizes the discharge lamp in order to have an existing alternative lamp having a fundamental frequency and harmonics that are integral multiples of the fundamental frequency. The fundamental frequency and the lowest resonant frequency of the lamp (in a current base) are greater than around 19 kHz, and the harmonics mentioned above have magnitudes that are insufficient to induce acoustic resonance. The operation of high frequency AC current of a hidden lamp is desirable because it makes it possible for the inductive elements of the ballast to be greatly reduced in dimension, also offering some increase in the relative efficiency of the system with respect to the 60 Hz operation. due to the smaller ballast losses. However, such operation has been prevented in the systems of the state of the art because of the presence of acoustic resonance at or near the fundamental frequency of the ballast. The frequencies at which acoustic resonance occurs depend on several factors, including the size of the discharge chamber (ie, length, diameter, shape of the end of the chamber, the presence or absence of an intubation), density of filling gas, the operating temperature and the orientation of the lamp. As it is used in the present "acoustic resonance" means that the level of resonance that causes disturbances of the discharge arc visible to the human eye. With state-of-the-art systems known from the article "An Autotracking System for Stable Hf Operation of HID Lamps'P F. Bernitz, Symp. Light Sources, Karlsruhe 1986, the discharge device has acoustic resonance that occurs at frequencies of low and medium range (for example, 100 to 500 Hz and 5,000 to 7,000 Hz) as well as at high frequencies such as around 19 kHz.The discharge chamber, being of quartz, is only limited in narrow operating windows attached to the low and high extremes by frequencies in which the acoustic resonance occurs depending on the control of the dimensions, as the discharge chambers were made of quartz glass, dimensional control is difficult at high manufacturing speeds. Consequently, even by discharge devices of the same type and wattage, the system designer was confronted with narrow operating windows which could be different not only for lamps of different manufacturers, but also of lamp to lamp of the same manufacturer. The systems of the state of the art are typically related to complex sensors and operation flaws so as not to reach acoustic resonance in their operation. However, the circuits for this system are expensive, complex and bulky and therefore are not desirable for integrated lamps. According to the embodiment mentioned above, however, the inventors have established that the discharge arc device can be selected to have its lowest acoustic resonance frequency (on a current basis) at a frequency substantially higher than the audible frequency. of about 19 kHz, in a mode at around 30 kHz, this to allow safe operation in the upper window of about 19 kHz and the lowest resonant frequency. This allows a relatively simple, compact, low cost ballast circuit without complicated operation schemes and sensors. It is convenient to note that the acoustic resonance is technically induced by the energy of the lamp, that is, the product of the current of the lamp and the voltage of the same. In this way, acoustic resonances can be defined in terms of energy frequencies, which are usually twice the frequencies of the current. However, the frequency of the current of the corresponding lamp at which the acoustic resonance occurs for a given discharge device operated on a given ballast is easily identifiable. Congruently, the acoustic resonance frequency will be established here in terms of lamp current frequency and lamp energy frequencies, and where only one is given, the other can be quickly determined from the 1: 2 ratio given above. The invention is also based on the recognition that acoustic resonance can be induced not only by the fundamentally controlled frequency but also by the harmonics of the output current (or power) of the typical electronic ballast. Even if the fundamental frequency is below the lowest resonance frequency of the lamp, acoustic resonance can still be induced by harmonics with sufficient amplitude above the lowest resonant frequency of the lamp. Consequently, for free resonance operation, the ballast should have a driving signal in which any harmonics above the lowest resonant frequency of the lamp are sufficiently small in amplitude so as not to induce acoustic resonance. In still another embodiment, the ballast keeps the fundamental frequency substantially constant during the operation of the lamp in its stable state. This also reduces the costs and dimensions of the ballast for the lamp by eliminating several of the control components of the systems belonging to the state of the art associated with loading and sweeping of the frequency and maintenance of the constant energy. Favorably, the discharge chamber comprises a ceramic wall. The term "ceramic wall" is here understood to mean a wall of a refractory material such as monocrystalline metal oxide (e.g., sapphire), polycrystalline metal oxide (e.g., densely polycrystalline sintered aluminum oxide).; wastage of aluminum from itrium, or itrium oxide), and polycrystalline non-oxidized material (for example aluminum nitride). Such materials allow high wall temperatures above 1,400 to 1,600K and are satisfactorily resistant to chemical attack by halides, halogens and sodium. This has the advantage that the smaller dimensions for the discharge chamber can decrease the amount of ceramic material to be used. Otherwise the use of ceramic material allows many smaller tolerances than those of conventional pressed quartz glass technology. The lowest possible tolerance, on a lamp-to-lamp basis, greater uniformity with respect to the acoustic resonance characteristics as well as the colorimetric properties. According to another embodiment, the discharge device includes a central cylindrical zone with end walls. The end walls are spaced apart by an axial distance "L" and the central zone having an internal diameter "ID", and the ratio L: ID is about 1 to 1. The lamps having a ceramic discharge chamber with such a central area they are known, for example, in U.S. Patent No. 5,424,609 (Gevens et al). However, in the disclosed lamp, the central zone is longer and narrower than 1: 1, having a ratio L: ID equal to or greater than 4: 3. The inventors have found that proportions of about 1 to 1 yield a favorable result with respect to the lowest resonant frequency of the lamp. In this proportion, the first acoustic resonance for the longitudinal direction (controlled by the L dimension) substantially coincides with the first acoustic resonance for the radial and asymmetric directions (controlled by the ID dimension). Generally, as the ratio varies from 1: 1, the longer dimension will lower the frequency at which the acoustic resonance occurs for the respective radial / asimutal or longitudinal modes, the lower resonant frequency of the lamp being determined thereby. Consistent with a very favorable embodiment, the system includes a plurality of discharge chambers each having a lower resonant frequency (on a current basis) above about 19 kHz and energized by the ballast to a competent emission light. . The present inventors do not take into account any practical discharge devices in quartz glass which have their lowest resonance frequency in a current base above about 19 kHz. Even more so with a ceramic discharge chamber having a L: ID ratio of about 1: 1 discussed above, the maximum wattage ratio for such discharge devices has a lower resonance frequency above 19 kHz (on a current basis) the inventors expect it to be around 35W. This mode is significant to provide relatively high light output that can be operated above about 19 kHz without acoustic resonance. Favorably, the multiple discharge devices are enclosed in a common outer lamp cover. The discharge devices can be electrically connected in series. Connecting the discharge devices in series ensures that each device has the same lamp current. In still another embodiment, the reflector lamp includes a plurality (such as a pair) of de-load chambers electrically connected in parallel. In this arrangement, one of the discharge devices can ignite and burn while the other does not. However, at the end of the life of one of the discharge devices, the other discharge device can then turn on and burn, effectively increasing the service life by the whole number of the present discharge device. This also has the advantage of offering instantaneous restriction for a hot lamp, since when one discharge device is distinguished, the other cooler discharge device that has not burned will turn on. Preferably the discharge chamber is provided with a starting aid, which with one end extends around and extends encloses the plug structure of the discharge chamber and with a second end is connected to an opposite terminal. Congruently to yet another embodiment, the light source is a high pressure gas discharge device, and the lamp further comprises (i) a compressed glass lamp cover sealed in a gas tight manner and enclosing the High pressure gas discharge, the pressed glass lamp cover including the reflecting body having the reflecting surface. (ii) a shell having a first end portion carrying the base of the lamp and a second end portion receiving the lamp cover, and (iii) a ballast for energizing the discharge device to emit light, the ballast being mounted in the shell between the pressed glass lamp cover and the first end portion, the ballast including a pair of input terminals each electrically connected to a respective contact at the base of the lamp and a pair of output terminals each electrically connected to the discharge device the cover of the lamp being received in the second portion of the end of the shell with the reflecting surface positioned to reflect the light and heat generated by the discharge device away from the ballast. It has been found that the pressed glass reflector body directs the heat generated by the discharge device away from the components of the ballast, even under the base conditions. This is due to the reflective surface as well as the thickness of the pressed glass. In comparison, a thin-walled blown glass lamp cover without a reflecting surface, such as the lamp disclosed in US Patent 4,490,649, requires the use of an internal glass partition, having an IR reflective film, positioned on the cover to achieve desirable ballast temperatures. This provides a rather complicated construction as well as the drawback that the supply wires connected to the discharge device must pass through the screen. Congruently with another embodiment, the integrated lamp includes a circuit board having a first side and a second side carrying the components of the ballast circuit, the circuit board being mounted on the shell with the first side facing the reflector body and with the second face facing the base of the lamp, the circuit board defining a first compartment in the shell between the body of the reflector and the circuit board and a second compartment between the circuit board and the base of the lamp, and the circuit board being substantially free of perforations and being secured to the shell to delay air communication between the first compartment and the second compartment in the shell. This construction has the advantage that the circuit board acts as a barrier to the flow of air, preventing circulation against the hot, rear surface of the reflector body with respect to the transfer of heat via convection in the shell to the components of the circuit. This also provides a simple construction with respect to that shown in U.S. Patent 4,490,649, 1 which employs an axially mounted circuit board and an additional body of insulating material in the shell between the circuit board and the lamp cover. In yet another embodiment, the ballast operates the discharge device with a lamp current having a constant polarity, that is, in DC. This has the advantage of not inducing acoustic resonance, by means of this relieving the restrictions imposed on the shape of the arc tube etc. Necessary for high frequency AC operation, while still allowing a compact circuit which can allow a compact integrated reflector lamp. These and other aspects, features and advantages of the invention will become apparent with reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an integrated HID reflector lamp having a unitary structure including a sealed reflecting unit, a ballast and a shell enclosing the ballast and fixing the reflecto-ra lamp unit; Figure 2 shows the discharge chamber of the lamp of figure 1 in detail; Fig. 3 is a block diagram of a high frequency ballast for operating the lamp of Fig. 1; Figure 4 (a) and 4 (b) are graphs illustrating the superior stability in correlation with the temperature color (CCT) and the color provided (CRI) of a metal halide lamp with a ceramic arc tube against a quartz arc tube; Figure 5 illustrates the schematic of an integrated PAR lamp HID according to the invention superimposed on the scheme of a PAR lamp of ANSI specifications; Figure 6 (a) illustrates a mounting construction for two serial discharge devices; Figure 6 (b) illustrates a mounting construction for two series discharge devices; and DESCRIPTION OF THE PREFERRED MODALITY Figure 1 shows a HID 200 integrated reflector lamp having a sealed reflecting unit 250 received in a shell 250 enclosing a ballast 300. The reflecting unit has a glass cover 227 of gas-sealed sealed lamp in a tight manner and enclosing a high pressure discharge chamber 3. The lamp cover 227 includes a pressed glass reflector body with a base portion 229 and a parabolic surface 230 which extends toward an edge 231 of the reflecting body. (Figure 1) A cover in the form of pressed glass lens 233 is hermetically sealed to the reflecting body at the edge 231. The parabolic surface 230 has an optical axis 234 with a focus 235 on the optical axis and has a reflective coating 237 on it. , such as aluminum, forming a reflecting surface. Other suitable materials for the reflective coating include silver and multilayer dichroic coatings. The base portion of the reflector body includes bushes 239 through which the conductive supports 240, 241 extend in a gas-tight fashion. The conductive supports are connected to respective feed legs 40, 50 of the discharge chamber 3. The discharge chamber 3 being arranged transverse to the optical axis 234. The conductive supports also support a light transmitting sleeve 243 around the chamber 3. The cover 227 has a gas filling which in the absence of an appropriately sized sleeve can withstand convective currents during the operation of the lamp. The light transmitting sleeve 243 provides thermal regulation by means of a control over the convective cooling of the discharge chamber 3. The shell 250 is molded from a resin material which resists the operating temperatures reached by the unit sealed reflector and ballast. Suitable materials include PBT, Polycarbonate, polyetheramide, polysulfin and polyphenylsulfin. The shell has an edge portion 251 which retains the outer surface of the edge 231 of the sealed reflecting unit and provides a shoulder by which the lamp 200 can be secured in a standard PAR fixation. A circumferential shoulder provides a seat for a corresponding flange 245 of the reflector body. The sealed reflective unit is secured by the edge 251 with a clasp axially adjusted against the shoulder 253. Opposed to the edge portion, the shell has a basal portion which receives a threaded base 275. The welded base has solderless connections. with the input power 310, 311 of the ballast 300. The shell includes an additional shoulder 255 which supports a circuit board 320 of the ballast. The shoulder 255 includes tabs (not shown) that extend through respective holes in the circuit board. The tabs have end portions that are pressed against the circuit board, by plastic welding for example, to fix the circuit board against the shoulder. The sleeve 243 and / or the lenses 225 can be constructed to block the ultraviolet light emitted by the discharge chamber 3. The UV blocking function can be obtained through the use of UV blocking glass, such as glass with an addition of cerium and titanium, or a UV filter such as a dichroic coating. Such glass blockers and UV filters are known in the state of the art. The filter can also be applied to the wall of the discharge device 3. Additionally, the color of the light emitted by the discharge device can be altered by color correction materials for the ceramic discharge chamber 3, the sleeve 243 or the lens 225 or with color correction filters, such as dichroic filters, in those components. The discharge chamber 3 is shown in greater detail in Figure 2 (which is not on a true scale). The discharge chamber is made of ceramic, that is, it has ceramic walls. The discharge chamber has a central zone formed from a circular cylindrical wall 31 with an internal diameter "ID" close to both portions of wall ends 32a, 32b, each wall end portion 32a, 32b forming an end face 33a, 33b of the discharge space 11. The wall end portions each have an opening in which the ceramic enclosed contact pin 34, 35 is adhered to the wall end portion 32a, 32b in a manner adjusted to gas leak test by means of sintered joints Ceramic enclosed contact pins 34, 35 define opposite end areas of the discharge chamber and each enclosing a feed intern 40, 41 very closely over a length 1; 50, 51 of an associated electrode 4, 5 provided with tips 4b, 5b. The feed passer is connected to the enclosed contact pins 34, 35 in a gas passage proof manner by means of glazed ceramic seals 10 on its side facing the opposite side of the discharge space. The electrode tips 4b, 5b are located at a mutual distance "EA". The feed passages each comprise a portion 41, 51 being highly resistant to the halide made of, for example, Mo A1; 03 cer et, and a portion 40, 50 which is adhered to an enclosed contact pin 34, 35 in a leak-tight manner by means of glazed ceramic gasket 10. The glazed ceramic gasket extends over some distance, for example 4 mm. The portions 40, 50 are made of a metal having a coefficient of expansion that harmonizes very well with that of the enclosed contact pins. For example, Nb is a very suitable material. The feed passages described make this possible to operate the lamp in any desired combustion position. Each electrode 4, 5 comprises a rod electrode 4a, 5a which is provided with a winding 4c, 5c near the electrode tips 4b, 5b. The electrode tips lie adjacent to the end faces 33a, 33b of the end wall portions. A further description of the discharge device and its enclosed contact plug structure is available in US Pat. No. 5,442,609. A starter aid 260 is secured to the discharge device 3 and consists of a length of wire having one end 261 connected to the feed passer 40. Its other end 262 is a loop extending around the pin structure of the feed. Opposite locked contact. In the area of the loop, enclosed contact pin structure has a separation between the portion 51 and the inner wall of the in-closed contact pin 35 in which the start and damping gas is present. When an ignition pulse is applied through the feed passages 40, 50, the feed edges of the start pulse cause the starting and damping gas in the loop area 262 to be io-nice. This ionization provides free electrons as well as UV light that generates additional electrons that reduces the electrical potential required to start. Protection Against Acoustic Resonance An important feature of the integrated HID re-flector lamp according to the present invention is the selection of the discharge chamber to have its lowest acoustic resonance frequency (on a lamp current basis) at a frequency substantially higher than the audible frequency of around 19 kHz. This provides a fairly large frequency window in which the ballast can operate above the audible range without the danger of inducing annoying arc flickering or arc shifting which could lead to its shutdown or even a failure of the discharge device 3. In one preferred practical mode, the lamp according to Figure 1 was constructed as a rear retrofit lamp to replace PAR 38 lamps used in, for example, high hood fasteners to illuminate commercial establishments, such as public areas of shopping malls. The discharge device has a proportional energy of 20 W. The discharge chamber is made of polycrystalline aluminum oxide, has an internal diameter ID of 3.mm and an interspaced between the tips of the electrodes "EA" of 2.0 mm . The enclosed contact pins 34, 35 were sintered into the end wall portions 32a, 32b substantially matched with the faces 33a, 33b formed by the end wall portions. The electrodes have a tungsten rod 4a, 5a provided with a tungsten winding 4c, 5c at the tips 4b, 5b. The distance between each electrode tip and the adjacent end face is around 0.5 mm. In the preferred embodiment the ID was constant over the distance "1" of 3.0 mm between the end faces 33 (a), 33 (b). The discharge chamber has a filling of 2.3 mg of Hg and 3.5 mg of Nal, Dyl3 Til in a molar ratio of 90: 1.4: 8.6. The discharge chamber also contains Ar as a starting and damping gas. The interior of the sealed reflector cover 227 has a filler gas of 75% krypton, with the N2 balanced at a pressure of 400 Torr. The sleeve 243 has a wall thickness of 1 mm and a clearance of 2 mm from the wall 31 of the discharge device 3. In the disclosed embodiment, the mercury is used as a buffer to set the arc voltage to a level such that the lamp is retro-adjusted by the known incandescent reflector lamp. Other shock absorbers can also be used like zinc and xenon. It was found that the discharge chamber had a lower resonance frequency of around 30 kHz (on a lamp current basis) during the nominal lamp operation. There are two main groups of acoustic resonances, the first being in the longitudinal (axial) direction of the discharge chamber and the second being the azimuthal / radial resonance. It is desirable to have the lowest resonance frequency for each group in a more or less equal agility, since the lowest determines the upper end of the ballast operation window. The fundamental longitudinal frequency is given by fio = C / (2 * L) and the fundamental azimuthal / radial frequency is given by f, r0 = 1.84 * C / (I * ID), where "L" and "ID" they are the length and the internal diameter of the discharge space as shown in figure 2 and "C" is the speed of sound. The speed of sound, however, is dependent on the temperature gradient of the gas in the discharge space, and has been found to be different for the radial / azimuthal and longitudinal modes. Based on experimentation, the inventors found that the speed of sound is about 420 m / s for the longitudinal resonances and about 400 m / s for the radiating / azimuthal resonances for a discharge chamber with the filling described above. For the L ratio: specific ID of 3 mm X 3 mm of the discharge chamber described above, fJ0 * 70 kHz and farJ * 80 kHz (on a power frequency basis). This corresponds to 35 and 40 kHz, respectively, in a current pool and is viewed as being substantially close together and substantially the same. However, to bring them closer together, the ID dimension can be made longer in relation to the length L, which will lower the fundamental radial / azimuthal frequency towards that of the fundamental longitudinal resonance frequency. This has resulted in that for a lamp according to the invention the dimensions L and ID of the discharge chamber preferably satisfy the ratio L < ID < 1.2L. Furthermore, it can be noted that the deep insertion of the electrodes has little influence on the lowest acoustic resonance frequency, the deep insertion having an influence of the 2nd or 3rd order. Because of this relatively large frequency window between the lowest resonant frequency of the discharge chamber 3 and the audible frequency of 19 kHz, the ballast can have a constant frequency during the operation of the lamp, greatly simplified in its design and cost. As further described below, for the discharge device described above, the operating frequency for the fundamental frequency of the lamp current is selected at a nominal frequency of 24 kHz. This provides a "head room" of around 5kHz with the lowest resonant frequency of 30 kHz of the discharge device. Still an additional aspect is related to the control of the amplitude of the highest harmonic of the fundamental frequency, to avoid the acoustic resonance by such high harmonics. This aspect will be discussed further in the following description of the ballast. The Ballast Fig. 3 shows a block diagram of a high frequency lamp ballast for operating the lamp of Fig. 1. The ballasts have input terminals Ii, I connected with the input power 310, 311 to a circuit rectifier 110 that provides a DC input to a DC-AC 120 inverter. A resonant output circuit 130 is connected by conductive supports 240, 241 to the discharge chamber 3 of FIG. 1 and is coupled to the DC-AC inverter. A control circuit 140 controls the inverter 120 to turn on the lamp and to operate the lamp after it has been turned on with a substantially constant lamp current frequency above about 19 kHz and below the lowest resonant frequency of the lamp. The ballast includes a soft start circuit to generate a gradual increase in the ignition voltage. A feeder of low voltage energy (not shown) provides power to operate the. control circuit in starting circuit prior to oscillation of the inverter as well as during oscillation of the inverter. A stopping circuit 150 senses when the discharge chamber 3 is turned off, turns off the inverter stage and turns it back on to provide a start pulse to allow the rejection of the discharge chamber 3. The press pulses are provided for a nominal 50 ms, with a repetition frequency of nominal pulses of 400 ms. The inverter 120 is preferably a half-bridge inverter with MOSFET switches connected in the form of a pole pole. The output of the half bridge inverter appears through half points of the half bridge inverter in the form of a square wave signal, generally high frequency. The resonant output circuit 130 is of the LC network type and includes the primary coil of an inductor connected in series with a starting capacitor between the midpoints. The resonant circuit is tuned to the third harmonic of the operating frequency. The discharge chamber 3 is electrically connected in parallel with the start capacitor. The LC network provides a waveform and a current limiting function for providing a lamp current to the discharge chamber 3 of the high frequency square wave output present on the midpoints of the half bridge inverter. The control circuit 140 controls the frequency and pulse amplitude switching with the MOSFET switches to provide the current to the discharge chamber 3 at a substantially constant frequency after the lamp is turned on. During the start of the ballast, an initial frequency of around 28 kHz is present. This effectively detuned the LC network of the resonant output circuit 130 which has been tuned to the third harmonic (around 71 kHz) of the nominal operating frequency of about 24 kHz. A) Yes, the MOSFET switches are • turned on in a non-resonant condition, and the current through these interuptors is significantly lower than what could be found in resonance. After approximately 10 ms, the frequency inverter is switched to the design range of 24 kHz, which turns on the discharge chamber 3. The stop circuit 150 provides an ignition pulse voltage for 50 ms. The stop circuit includes a switch Ql. When the Ql switch is conductive the applied low voltage energy is removed from the control circuits. The switch Ql is finally controlled by the presence of an over voltage in a secondary winding of the inductor. This can occur during the generation of the ignition pulses if the discharge device does not turn on or if the discharge chamber shuts off during the inverter oscillation. In case of an over voltage across the winding it causes the switch Ql to be made conductive.

Lamp Efficiency; Photometric Parameters The PAR 38 mode described above has a wattage system of 22 W, with the lamp consuming around 20 W and the ballast having losses of around 2 W. Table 1 compares the colorimetric and photometric parameters of this lamp (INV .) with that of a 90 W PAR 38 halogen cigarette lighter and 60 W PAR 38 lighter commercially available. Also shown are the photometric parameters of two co-known glass blow reflectors, or "R" lamps, a VR40 of 85 W and a VR40 of 120 W. The data for the lamps described above according to the invention were based on a group of 20 samples. The light emitted by the lamp sample was correlated with the color temperature (CCT) of 3000 K and the color index emitted (CRI) of > 85. The luminous efficiency of the lamp was 60 LPW. Compared to the known PAR 60 lamps of 60 W with a halogen IR burner, the luminous efficiency was 233% better, and 233% better and 314% better with respect to the PAR 38 halogen lamp of 90 W. , the discharge device has a life expectancy of around 10,000 hours, which is 3 to 4 times that of the 38 PAR halogen lamps of 90 W and the already known 60 W halogen IR lamps.

TABLE I Congruently, it is clear that the integrated lamp is superior to the PAR IR halogen lamps and available halogen lamps and the incandescent blown glass reflector lamps with respect to service life and luminous efficiency. Additionally, by altering the fill of the discharge device with the known metal halide technology, the lamp designer has great control over the photometric parameters as compared to a light generation lamp with an incandescent filament, in particular with respect to the Correlated color temperature. A significant advantage of the use of a metal halide discharge device with a ceramic wall, and at low wattages, is the significant colorimetric uniformity (a) relative to the combustion position and (b) of the lamp to lamp. This uniformity is believed to be due to the small physical dimension which allows a more uniform thermal properties in the filling of lamps during the operation and the precise dimensional control to which the ceramic material can be handled during the manufacturing speed can, which It provides lamp to lamp uniformity. It has been found that the dimensions of the ceramic discharge chamber can be handled better than 1% (six sigma) while the quartz arc tube technology dimensions can only be handled around 10%. Figure 4 (A) and 4 (B) are graphs of CCT and CRI, respectively, for metal halide lamps, ceramics, typical low wattage lamps and a typical quartz metal halide lamp as a function of 1 apposition of combustion, indicated as degrees from the vertical base position, (VBU). For 'CCT, the CDM lamp has only a variation of 75 K against a variation of around 600 K for the quartz lamp, over the range of 0-90 degrees from the VBU. Likewise, for CRI, the CDM lamp has a variation of only about 2.5 CRI against about 10 CRI of metal halide quartz lamps. Additionally, with respect to lamp-to-lamp color stability, a low wattage metal halide with a ceramic discharge chamber typically exhibits a standard deviation of 30 K at color temperature. For low wattage metal halide lamps with quartz arc tube, the standard deviation is much larger, 150-300 K. The much narrower sprinkling in color temperature is important because this makes the lamp integrated with the device metal halide discharge, ceramic is an acceptable replacement for PAR halogen lamps for interior lighting and retail. Indeed, when several reflector lamps with the ceramic discharge device are used, for example in a ceiling, these will appear as being substantially uniform, unlike the quartz metal halide lamps in which the observer could clearly notice the lack of uniformity between the lamps. A critical aspect of the integrated lamps according to the invention is that these improvements were achieved in an exterior design that substantially fits into that exterior design of the corresponding type lamp; in the mode shown on the PAR 38 lamp with the ANSI specification. This allows the integrated HID PAR 38 lamp to be retrofitted in all fixtures designed to physically accept a conventional PAR 38 lamp. Figure 5 shows the external design of the lamp in Figure 1 superimposed on the exterior design of the ANSI specification for a PAR 38 lamp. The dimensions (mm) are: Pl = 135; P2 = 135; P3 = 28.2; P4 = 40.4; P5 = 26.8; P6 = 48.8 and P7 = 540. Several characteristics facilitate this packaging.

The first is the use of compact, small HID light source having a small contour length. The contour length of the 20 W arc tube was 22 mm. The small contour length allows the arc tube to be positioned transversely to the optical axis within a reflector body that is nested in an outer shell having a maximum bore diameter within the ANSI specifications. In this PAR 38 embodiment, the cover 227 of the sealed reflector is a PAR 36 cover and has a diameter measured at the edge 231 of 96 mm. The external diameter is around 110 mm. The transverse mounting also allows the use of an axially shallow reflector body, leaving a sufficient space for the ballast. The use of a pressed glass reflecting body with a comparatively thick rear wall in conjunction with the reflective coating on the rear wall provides acceptable thermal insulation, preventing excessive heating of the ballast by the radiant energy caused by the discharge device. In this case, the minimum thickness of the reflector body in the basal portion was 3 mm. Additional thermal protection is provided by the outer periphery of the circuit board which is tightly sealed against the shoulder 255, which effectively retards air circulation from the hottest first compartment "A" adjacent to the reflector, to the second compartment "B" between the circuit board and the base. The temperatures measured inside the shell during the base operation were sufficiently low in order to ensure a circuit life comparable to that of the discharge chamber 3. Generally, the maximum temperature of the circuit could be less than 100 ° C In the lamp already described, the temperature measured on the reflector side of circuit board 320 was 83 ° C while the temperature of the components of the ballast was 75 ° C. The air temperature in compartment B between the circuit board and the shell on the side of the ballast was 74 ° C. The highest temperature of the components of the circuit was 81 ° C. The thermal regulation of the discharge chamber 3 with a filling gas, cover of Pressed thick-walled glass and surrounded by a sleeve helps in the photometric control, which allows a wide range of environmental conditions in which the lamp can be operated without notable changes of the photometric parameters. citruses. The small physical dimension of the de-loading chamber, together with the L: ID ratio of the order of 1: 1, was also important in reducing the size of the ballast. Since the discharge chamber has a lower acoustic resonance frequency at around 30 kHz in a current basis, there is a sufficient window in which the ballast can operate above 19 kHz and at a constant frequency during the operation of the lamp . The operation at high frequency is important because it allows to reduce the physical dimension of the inductive elements of the ballast. Operating at a fixed frequency provides simple control of the ballast inverters, thus reducing the size and cost. In Figure 1, the discharge chamber 3 is in a gas-filled envelope 227 sealed to a cover 233 surrounded by a sleeve 243 of quartz glass supported by fasteners connected to the current feeders 240, 241. A primary reason for that the cover 227 be sealed is to protect the feeders 40, 50 and 240, 241 from oxidation. Instead of a glass bonded at the edge 231, a seal less strong than the seal, such as an epoxy seal, can be used if the feeders are protected with an antioxidant coating. Additionally, with a suitable thermal control, a HID reflector lamp adjusted with the external design of a corresponding lamp can also be obtained with a reflector body of another material than glass, such as, for example, a high temperature plastic with a reflective coating, such as, for example, aluminum or silver deposited thereon, or applied, for example, as a mylar sheet. The body / surface of the reflector can form an integral part of the shell. Figure 6 (A) shows a construction of the assembly for a plurality (in this case two) of discharge chambers 3 (a), 3 (b) electrically in series within a reflector body, such as that shown in Figure 1 The components corresponding to those shown in figure 1 have the same reference numbers. The discharge chamber 3 (a) has a feeder 40 (a) fixed to the feeder 240 while the discharge chamber 3 (b) has a feeder 50 (b) connected to the other feeder 241. The serial connection is completed by the Conductive element 403 bypassing the feeders '50 (a) and 40 (b) of the discharge chambers 3 (a); 3 (b). The elements 401, 402 are non-condensers and provide additional mechanical support. The ignition aid 260 is not shown for purposes of clarity. With two discharge chambers operating concurrently, the lamp provides approximately twice the light output. Each discharge chamber has its lowest resonance frequency around 30 kW, so with the ballast providing lamp current at a nominal frequency of 24 kHz, there is no danger of inducing acoustic resonance. It should be noted that a single discharge chamber having a wattage ratio of 40 W, as with two 20 W discharge chambers, would have its lamp resonance frequency significantly lower than that for each of the two 20 W discharge, both closer to 19 kHz than below 19 kHz. Congruently, using two discharge chambers the large free-operating resonance window below about 19 kHz is retained while obtaining the benefit of more light output from a higher wattage lamp. While two discharge chambers are shown, concurrent operations of more than two discharge chambers is possible, as long as the circuit is modified to provide the correct ignition and operating voltage for the lamp. Other ignition aids, such as a well-known UV amplifier, can be alternatively incorporated into the lamp to improve the ignition characteristics. Figure 6 (B) shows a construction of the assembly for a pair of discharge chambers 3 (a), 3 (b) electrically connected in parallel. In this case, the feeders 240, 241 have respective conductive crossbars 240 (a), 241 (a) electrically connected to respective conductive bars of the feeders 40 (a), 40 (b); 50 (a), 50 (b) and mechanically supporting the discharge chambers 3 (a), 3 (b). Such a parallel arrangement effectively doubles the life of the lamp, since only one discharge chamber will ignite and generate light due to the negligible difference in impedance between the discharge chambers. At the end of the life of one discharge chamber, the other will take its place. This will also provide an instantaneous capacity restriction. If the discharge chamber in operation is turned off due to a voltage interruption, for example, its impedances due to its high temperatures could be high enough to not ignite. However, the other discharge chamber that was not previously operating will have a significantly lower temperature and will start immediately. One advantage of CD operation is the complete elimination of acoustic resonance and its simplicity. However, a disadvantage is that the discharge device operated on CD is more sensitive to changes in color with changes in the operating position and is susceptible to salt migration. HID lamps with ceramic discharge devices that are shown and described with respect to figure 1 have demonstrated acceptable colorimetric and photometric characteristics during 5000 hours of operation .. CLAIMS:

Claims (12)

1 \ £ i vi p? 1. A HID reflector lamp (200) to retro-fit a reflector lamp comprising a reflector body (225) and a threaded base (275), the reflector lamp comprising: a shell (250) having a wall enclosing an integral volume, said wall having a circumferential edge portion (251) defining a light emitting aperture of said shell and an opposite base portion (229), said shell generally narrowing with smaller and smaller diameters from said edge portion to said base portion, the threaded base (275) secured in said base portion, a high pressure discharge chamber (3) arranged in relation to said shell, a reflective surface (237) positioned in said shell for reflect the light emitted by said discharge chamber (3) outwardly, through said light emitting aperture, and a ballast (300) within said shell body to energize said discharge chamber for emi light, said ballast including input terminals connected to said threaded base and output terminals connected to said discharge chamber. said integrated HID lamp having an external design substantially equal to, and a substantially higher luminous efficiency than the corresponding reflector lamp.

2. An integrated HID reflector lamp according to claim 1, further comprising a sealed cover of compressed glass enclosing said discharge chamber (3) in a gas-proof manner and said reflecting surface comprising said reflecting surface defining a optical axis (234) said discharge device being arranged transverse to said optical axis.

3. An integrated lamp according to claim 1 or 2, wherein said shell (250) comprises a synthetic resin material.

4. An integrated HID reflector lamp according to claims 1, 2 or 3, wherein said discharge chamber (3) has a mercury filler, a metal halide and a rare gas.

5. An integrated HID reflector lamp according to any preceding claim, wherein said discharge chamber has a lower resonant lamp energy frequency, higher than about 38 kHz, said ballast operates said discharge device with a frequency fundamental of energy and with harmonics said fundamental frequency of energy being greater than air-dedor of 38 kHz and lower than the lowest resonant frequency of the energy of the lamp, and said harmonics above said lower resonance frequencies of lamp having amplitudes that are insufficient to induce acoustic re-sonance.

6. An integrated HID reflector lamp according to any preceding claim, wherein said discharge chamber (3) comprises a ceramic wall (31).

7. An integrated HID reflector lamp according to any preceding claim, wherein said discharge space has a lower longitudinal acoustic resonance frequency and a lower azimuth / radial acoustic resonance frequency, said discharge space being dimensioned in a manner that said lower longitudinal acoustic resonance frequency and said lower azimuthal / radial acoustic resonance frequency are substantially the same.

8. An integrated HID reflector lamp according to any preceding claim, wherein said ballast comprises switching means for providing a current, having a constant polarity, through the discharge chamber.

9. An integrated HID reflector lamp according to any preceding claim, wherein said discharge chamber (3) includes a central circular cylindrical area with substantially flat wall end portions (32a, 32b), said portions of wall ends. being spaced apart by an axial distance L, said central zone having an internal diameter ID substantially constant over a distance L, and the ratio L: ID is about 1: 1.

10. An integrated HID reflector lamp according to any preceding claim, wherein the sealed cover of pressed glass encloses the discharge chamber and comprises the reflecting surface positioned to reflect the light and heat generated by said discharge chamber away from the ballast.

11. An integrated lamp according to any preceding claim, wherein said ballast includes a circuit board (320) having a first side and a second side carrying the circuit components of said ballast, said circuit board (320) being mounted in said shell (250) with said first side facing said reflector body and with said second side facing said base of the lamp, said circuit board defining a first compartment (A) in said shell between said reflector body and said board of circuit and a second compartment (B) between said circuit board and said lamp base, and said circuit board being substantially unperforated and said shell (250) being secured to substantially completely retard air communication between said first compartment and said second compartment within said shell. An integrated lamp according to any preceding claim, further comprising a starting aid for said discharge device, said starting aid comprising a length of conductive material extending from said current conductor to the area of the other said current conductor and terminating adjacent to the wall of the discharge chamber of the other said current conductor, said discharge chamber wall of said other current conductor enclosing a narrow slit with the other current conductor in which said discharge which keeps the filling, is present.