FIELD OF THE DISCLOSED TECHNIQUE

The disclosed technique relates to light bulb designs.

BACKGROUND OF THE DISCLOSED TECHNIQUE

An incandescent lamp produces light by means of a tungsten filament enclosed in a sealed glass bulb. The filament is attached to a pair of contact wires, which connect to an electrical contact at the base of the bulb. When the light bulb is connected to a power source, an electric current is passed through the wires, heating the filament and causing it to emit light, part of which is in the visible spectrum. The enclosing bulb contains a low pressure inert gas (such as argon or nitrogen, or a mixture thereof) for slowing down the evaporation of the filament. A stem press anchored to the base of the bulb provides an air-tight seal for the contact wires. The base is generally made of metal and formed with a screw- thread, allowing the bulb to be inserted into a light socket.

While the traditional shape of a light bulb is quite familiar, light bulbs may be crafted in a wide variety of modified shapes. Additionally, the light bulb surface may be clear, or it may be "frosted". In a frosted bulb, the bulb interior is coated with ground silica, which serves to scatter the light, producing a softer and more even light and reducing glare. Some frosted bulbs utilize a white pigment coating on the interior, providing a more uniform dispersion and generating a "white light". Neodymium glass bulbs also produce a whiter and more natural appearing light, by filtering out the yellow light. Colored light bulbs, produced by adding a colored coating to the bulb exterior, are fairly common, such as for decoration or advertising lighting applications. Incandescent light bulbs are fairly inexpensive, leading to their widespread use for a variety of lighting needs, ranging from table lamps to vehicle headlights to flashlights. Although incandescent light bulbs are energy inefficient, as it produces substantial heat, while only a small portion (approximately 10%) of the generated light is in the visible spectrum, they are still among the most popular devices for indoor lighting in use today throughout the world.

Halogen lamps are a type of incandescent lamp, in which the bulb enclosing the tungsten filament also contains a halogen gas (e.g., iodine or bromine). The halogen gas causes a chemical reaction that removes the tungsten from the tube interior and deposits it back onto the filament. The filament is operated at a higher temperature than a standard incandescent lamp of similar power for enabling the chemical reaction. As a result, the halogen lamp is more efficient (i.e., more lumens per watt) and produces light of a higher color temperature (which appears whiter). Halogen lamps are also typically smaller in size than standard incandescent light bulbs, although generally more expensive. Halogen lamps may also be dimmable. A fluorescent lamp is made up of a sealed glass tube containing mercury and a gas (usually argon) at a low pressure, and a phosphor powder coated along the interior of the tube. On each end of the tube is an electrode with a tungsten filament. The electrodes are connected to a starter switch and to a ballast, forming a circuit with an AC power supply. During operation, an electric current heats the filament in each electrode, causing it to release electrons which ionize the gas atoms, thereby forming a plasma. The free electrons and ions collide with and excite the mercury atoms, causing it to emit photons, mainly in the ultraviolet (UV) spectral region. The UV photons are absorbed by the phosphor coating on the glass tube, causing the phosphor to fluoresce and emit visible light. The starter enables sufficient electron flow between the filaments and prevents flickering, while the ballast regulates the power flow through the lamp. The composition of the phosphor coating the glass tube controls the color of the emitted light. The fluorescent lamp tubes are usually straight, but may also be circular, U-shaped, or other shapes. Compact fluorescent lamps (CFLs) are smaller in volume, usually consisting of a number of small-diameter tubes joined in a bundle or coiled into a spiral. Fluorescent lamps are more energy efficient than incandescent lamps, as they produce very little heat, require less operating power for the same amount of light, and last longer. Fluorescent lamps generally produce a brighter whiter light than incandescent lamps, and are widely used for lighting large areas. US Patent No. 3,067,352 to Vodicka et al, entitled "Coated electric lamp and method of manufacture", discloses an electric lamp having a translucent light-diffusing decorative coating on the exterior of the lamp envelope, producing a soft-colored lighting effect.

US Patent No. 3,652,892 to Nameda et al, entitled "Illuminating lamp having concave segments on exterior bulb surface", discloses a light bulb having numerous concave and convex segments formed on its outer surface, where the lenticular and prismatic action of the segments causes the bulb to disperse light over a broad area while maintaining its original brilliance, providing comfortable ornamental illumination.

US Patent No. 5,363,009 to Monto, entitled "Incandescent light with parallel grooves encompassing a bulbous portion", discloses an incandescent light bulb having multiple parallel grooves extending longitudinally across its bulbous portion, producing light with a perceived greater effective brightness.

SUMMARY OF THE DISCLOSED TECHNIQUE

In accordance with one aspect of the disclosed technique, there is thus provided a lamp, made up of a filament enclosed in a bulb for producing light electrically, where the bulb includes frosted regions and non-frosted regions defining an ornamental light emission pattern. The bulb may be the bulb of a standard incandescent lamp, the bulb like housing of a halogen lamp, or the bulb enclosing the sealed tube of a fluorescent lamp. The light emission pattern may include horizontal stripes, vertical stripes, diagonal stripes, curved stripes, geometric shapes, imagery, and the like. The light emission pattern may be viewable on the surface of the bulb, or on a nearby surface illuminated by the incandescent lamp. The frosted regions may be formed by etching the interior or exterior surface of the bulb, such as via sandblasting or acid etching. The sandblasting process may utilize silica powder or aluminum powder. The acid etching process may utilize a glass etching cream. The etching may alternatively be performed by mechanical etching means or by using a laser. The frosted regions may also be formed during the initial formation of the bulb.

In accordance with another aspect of the disclosed technique, there is thus provided a method for providing an ornamental light emission pattern. The method includes the procedure of forming frosted regions on the non-frosted surface of a lamp, made up of a filament enclosed in a bulb for producing light electrically. The bulb may be the bulb of a standard incandescent lamp, the bulb like housing of a halogen lamp, or the bulb enclosing the sealed tube of a fluorescent lamp. The method may further include the procedures of positioning a pattern template around the exterior of the bulb, where the pattern template defines a desired pattern, and sandblasting the surface of the bulb through the pattern template. The sandblasting procedure may utilize silica powder or aluminum powder. Alternatively to the sandblasting procedure, the method may include the alternate procedure of acid etching the surface of the bulb through the pattern template. The acid etching procedure may utilize a glass etching cream. The frosted regions may alternatively be etched onto the surface of the bulb by mechanical etching means or by using a laser. The frosted regions may also be formed during the initial formation of the bulb.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed technique will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:

Figure 1A is a side view illustration of a light bulb having a light emission pattern of alternating vertical stripes etched onto its surface, constructed and operative in accordance with an embodiment of the disclosed technique;

Figure 1 B is a top view illustration of the light bulb of Figure 1A;

Figure 1C is a bottom view illustration of the light bulb of Figure

1A;

Figure 2A is a side view illustration of a light bulb having a light emission pattern of planetary and celestial imagery etched onto its surface, constructed and operative in accordance with another embodiment of the disclosed technique;

Figure 2B is a top view illustration of the light bulb of Figure 2A;

Figure 2C is a bottom view illustration of the light bulb of Figure

2A;

Figure 3A is a side view illustration of a halogen lamp having a light emission pattern of alternating vertical stripes etched onto its surface, constructed and operative in accordance with a further embodiment of the disclosed technique; Figure 3B is a top view illustration of the halogen lamp of Figure

3A;

Figure 3C is a bottom view illustration of the halogen lamp of Figure 3A.

Figure 4A is a side view illustration of a fluorescent lamp having a light emission pattern of alternating vertical stripes etched onto its surface, constructed and operative in accordance with yet another embodiment of the disclosed technique;

Figure 4B is a top view illustration of the fluorescent lamp of Figure 4A; and

Figure 4C is a bottom view illustration of the fluorescent lamp of Figure 4A;

DETAILED DESCRIPTION OF THE EMBODIMENTS

The disclosed technique overcomes the disadvantages of the prior art by providing a novel light bulb design. The light bulb includes a pattern formed on the outer surface of the bulb, producing a visually pleasing lighting particularly beneficial for decorative or ornamental purposes. The pattern also has the effect of reducing glare or brilliance of the emitted light, and further enables the focusing of higher intensity light in limited regions, thereby resulting in the emitted light being particularly pleasant. The ornamental pattern may be for example alternating vertical stripes, alternating horizontal stripes, alternating diagonal stripes, alternating curved stripes, alternating geometric shapes (e.g., squares, circles, triangles, and the like), images (e.g., celestial themed elements such as stars and planets, musical themed elements such as musical notes and keys, and the like), and a combination of any of the above. The ornamental pattern may be viewable on the surface of the light bulb itself. The ornamental pattern may also be viewable on a nearby surface which is illuminated by the light bulb (e.g., a wall, ceiling, floor, and the like).

Reference is now made to Figures 1A, 1 B and 1C, which are respective side view, top view and bottom view illustrations of a light bulb, generally referenced 110, having a light emission pattern of alternating vertical stripes etched onto its surface, constructed and operative in accordance with an embodiment of the disclosed technique. The alternating vertical stripes result in a pattern of alternating bands of light when light bulb 110 is turned on, reducing glare and resulting in a visually pleasing light.

Reference is now made to Figures 2A, 2B and 2C, which are respective side view, top view and bottom view illustrations of a light bulb, generally referenced 120, having a light emission pattern of planetary and celestial imagery etched onto its surface, constructed and operative in accordance with another embodiment of the disclosed technique. The imagery on light bulb 120 produces decorative shapes and images which are illuminated when light bulb 120 is turned on. The decorative images may be visible both on the bulb itself and on any nearby surface illuminated by the bulb. Light bulb 120 may be suitable, for example, for the bedroom of a child or infant.

The disclosed technique is applicable to any type of lamp which is an integral unit, i.e., for etching a pattern on the outer surface of the lamp or light bulb itself, and not on a separate component attached to the bulb. For example, the disclosed technique may be implemented on the bulb of a standard incandescent lamp, the bulb-like housing of a halogen lamp, or the bulb enclosing the sealed tube of a fluorescent lamp. Reference is now made to Figures 3A, 3B and 3C, which are respective side view, top view and bottom view illustrations of a halogen lamp, generally referenced 130, having a light emission pattern of alternating vertical stripes etched onto its surface, constructed and operative in accordance with a further embodiment of the disclosed technique. A halogen lamp generally has its tungsten filament inside a small transparent envelope (i.e., an "interior bulb"), which is itself enclosed by a larger glass bulb-like housing (i.e., an "exterior bulb"). Accordingly, the light emission pattern is etched onto the exterior bulb of the halogen lamp. The alternating vertical stripes on halogen lamp 130 produces a visually pleasing light with reduced glare, and also enables focusing the brighter (whiter) light produced by a halogen lamp on separate strips or bands within the overall field of illumination. Standard halogen lamps project light with a field of illumination of 10°, 38° or 60°, and the patterns on the bulb surface allow limiting the high intensity light within this range.

Reference is now made to Figures 4A, 4B and 4C, which are respective side view, top view and bottom view illustrations of a fluorescent lamp, generally referenced 140, having a light emission pattern of alternating vertical stripes etched onto its surface, constructed and operative in accordance with yet another embodiment of the disclosed technique. Fluorescent lamp 140 includes a sealed glass tube (not shown) which is contained in a housing (resembling the bulb of a standard incandescent lamp) enclosing the sealed fluorescent tube. The alternating vertical stripes, etched onto the surface of the lamp's housing, result in a pattern of alternating bands of light when fluorescent lamp 140 is turned on, reducing glare and resulting in a visually pleasing light resembling the pattern of light bulb 110 (Figures A, 1 B and 1C). The disclosed technique is generally applicable to any type of light bulb size or shape, and any type of bulb material (e.g., glass, plastic, and the like). It is noted that the bulb of a conventional incandescent lamp is generally made of glass, although other materials may be employed for enclosing fluorescent lamps and halogen lamps. The disclosed technique may be applied to colored light bulbs, frosted light bulbs, light bulbs of varying brightness or luminous output, light bulbs of varying power consumption levels, and the like.

In accordance with the disclosed technique, a method for providing an ornamental light emission pattern includes forming frosted regions and non-frosted regions on the surface of an incandescent lamp made up of a filament enclosed in a glass bulb for producing light. In general, the patterned light bulbs are prepared by placing the light bulbs on a conveyor belt, with the bulb portion facing upwards (i.e., the base is at the bottom). A pattern template is then positioned over the light bulb, and lightly adhered to the bulb if necessary. The pattern template is generally a type of hard covering with gaps shaped in the form of the desired pattern (e.g., gaps of alternating vertical stripes to provide the pattern of light bulb 110, or gaps of planetary and celestial imagery to provide the pattern of light bulb 120). Once the pattern template is properly positioned, a silica powder (i.e., ground quartz) is forcibly propelled onto the light bulb surface using a pneumatic injection apparatus in a sandblasting process. The injection apparatus includes a chamber containing the silica powder, which is propelled outwards via air pressure by means of an air pump assembly. The propelled silica powder is embedded into the surface of the glass bulb, causing extremely slight micro-fissures in the glass, which serves to create the light emission pattern on the bulb surface. The silica powder that does not reach the bulb during the propulsion (i.e., scattering in the surrounding area) may be collected and reused for subsequent sandblasting. It is noted that the silica powder should be extremely fine, so as not to damage the glass bulb. Furthermore, the silica powder must be dry, as wet powder will be too sticky for suitable injection. After the sandblasting of the light bulb is complete, the bulb is transported along the conveyor belt, and the aforementioned process continues with the next light bulb (i.e., positioning the required pattern template, sandblasting, and so forth).

As an alternative to silica powder, aluminum powder may be utilized for the sandblasting process. Aluminum powder is more delicate than silica powder, and is thus preferable for injection of plastic tubes (e.g., in fluorescent lamps) or other tube materials that are softer than glass, although it may also be used for sandblasting of glass bulbs, typically resulting in a lighter and more subtle pattern.

Rather than a sandblasting process, the pattern may be formed onto the light bulb via acid etching. A suitable glass etching cream, typically containing fluoric acid, may be smeared onto the bulb surface through the pattern template, etching the glass surface in the pattern formation. However, since fluoric acid is extremely corrosive and toxic, tremendous care must be taken with its use.

The light bulb may also be fashioned with the pattern during the formation of the bulb itself. In the initial glassblowing process, the molten glass may be inflated into the desired shape with the blow tube using a pattern template, resulting in the formation of a patterned bulb.

The pattern may alternatively be etched onto the light bulb mechanically, using an appropriate glass etching tool (e.g., a quartz or diamond cutter). Further alternatively, the etching may be performed optically, by means of a laser.

It will be appreciated by persons skilled in the art that the disclosed technique is not limited to what has been particularly shown and described hereinabove.