JPS5818856A - Disk-type low pressure electric-discharge lamp - Google Patents

Abstract

PURPOSE:To obtain a disk-type low pressure electric-discharge lamp, the entire luminous surface of which emits homogeneous light, by providing a magnetic- field generator which produces a magnetic field perpendicularly crossing the plate surface of the lamp tube, and making a discharge path developing between an anode and a cathode to rotate along the plate surface due to the effect of the above magnetic field. CONSTITUTION:A lighting circuit is illustrated in the figure. When the lamp is subjected to direct-current lighting by means of a direct-current power source 9 and a ballast 10 which is provided between the lamp and the power source 9, discharge is initiated between an anode 5 and a cathode 4. At this point, discharge doesn't develop over the entire plane of the lamp tube because of the nature of discharge, and develops between the cathode 4 and a part of the anode 5. Discharge arises in the area of a discharge path (A) as indicated by the slant lines, and shifts to the area (B) then to the area (C) since a magnetic field is applied in the same direction. Since electrons existing in the discharge area inside the tube continuously receive the force of the magnetic field as explained above, the discharge path continues to rotate clockwise. As a result, the discharge path appears to be spreading over the entire plate surface, and the luminance of the entire plate surface of the lamp tube can be made homogeneous.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-pressure discharge lamp having a disc-shaped outer shape, and its purpose is to make the brightness uniform over the entire light-emitting surface.

FIG. 1c&) is a plan view showing an embodiment of a disc-shaped low-pressure discharge lamp according to the present invention, and FIG. Inside the lamp tube 1 are a pair of electrodes, namely a cathode 4 consisting of a filament whose surface is coated with an electron radioactive substance and supported by two encapsulation wires 2.3 approximately at the center of the lamp tube 1; It has an endless strip-shaped anode 5 with a busy peripheral edge, and @3 for positive &5.
The enclosed wire 6 is connected. In addition, a phosphor 7 that determines the nature of the light emitted to the outside is thinly and uniformly coated on the inner surface of the lamp tube 1, and a predetermined lid is placed inside the tube.
Inert scum such as eeAr and Kr and mercury are sealed. A magnetic field generating device 8 is provided on the outside flat surface of the lamp tube 1 so that the generated magnetic field intersects (most preferably intersects) the direction of the electric field of the lamp.

Next, the operation of the discharge lamp having such a configuration will be explained with reference to FIGS. 2 and 3. Figure 2 is a lighting circuit diagram, with DC power supply 9
When the DC current is turned on via the ballast W, a discharge starts between the anode 5 and the cathode 4. In this case, due to the characteristics of discharge, the discharge does not occur over the entire plane of the lamp tube 1, but occurs between a portion of the anode 5 and the cathode 4. That is, a discharge occurs in the region of the discharge path A as shown by diagonal lines in FIG. On the other hand, a magnetic field is applied to the lamp tube 1 in a direction that crosses the 1' field direction of the discharge (tJI, in Figure 3, a magnetic field is applied that penetrates from the front to the back of the paper). ) Therefore, the electrons in the discharge path move in a direction perpendicular to both the direction of movement of the electrons and the direction of application of the magnetic field (clockwise direction as shown by the arrow in Section 31).
(N), the discharge path changes from the Alk region to the B
Move to area. In the above formula, the charge of -eld electron, V
represent the electron velocity and the BFi applied magnetic flux density, respectively. Furthermore, since a magnetic field is applied in the same direction in region B, the discharge path next moves to region C. In this way, the discharge area in the tube #! Since the electrons continue to receive the force from the magnetic field, the discharge path continues to rotate clockwise, and visually the discharge path appears to spread over the entire plane, and the lamp tube 1
It is possible to make the brightness uniform over the entire flat plate surface. Furthermore, if the direction of the magnetic field is reversed, the direction of rotation of the discharge path will be reversed, but there will be no difference at all. In addition, the magnetic field generator VIT
By applying a reflective film such as titanium oxide to the inner surface of the lamp tube 1 on the side where the lamp 8 is installed, and applying a phosphor to the inner surface of the lamp tube 1, the luminous flux can be greatly improved. Further, the magnetic field generator 8 may be attached to the outer surface of one side of the lamp tube 10, or may be attached to the odor side of the lamp separate from the lamp.

As described above, the low-pressure discharge lamp of the present invention is a low-pressure discharge lamp having a cathode approximately at the center of the disc-shaped lamp tube; and a band-shaped anode extending approximately over the entire length of the periphery within 1-t'L, Ef%'. The lamp tube is equipped with a magnetic field generating device in which the generated magnetic field is orthogonal to the flat plate surface of the lamp tube, so the discharge path generated between the anode and the polar pole rotates along the flat plate surface due to the action of the magnetic field, and the entire light emitting surface is It was possible to easily provide a disc-shaped low-pressure discharge lamp that emits light uniformly.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of a disc-shaped low-pressure open air lamp according to the present invention, FIG. 1(b) is a cross-sectional view of the same, and FIG. Figures 3 and 3 are drawings for explaining the discharge state.Patent: Matsushita Electric Works Co., Ltd. Representative Patent Attorney Toshimaru Takemoto (and 2 others) 1z (0) (b) 23, υ

Claims (1)

[Claims] (1) A cathode is located approximately at the center of the disc-shaped lamp tube,
A low-pressure discharge lamp having a band-shaped anode along substantially the entire length of the periphery of the tube, the disk-shaped low-pressure discharge lamp comprising a magnetic field generating device whose generated magnetic field is orthogonal to the flat surface of the lamp tube.