JPH10125481A - Cold cathode tube lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold cathode tube lighting device capable of aiming at reduction of assembling man-hour and cost down following it by eliminating any complicated assembling process. SOLUTION: A printed wiring board 2 is provided on the opposite side to a luminescent surface (light radiation part) 3 of a cold cathode 1, said printed wiring substrate 2 is electrically connected and also fixed to the electrode terminals 7, 8 of the cold cathode 1 by means of wiring pattern 2-4 formed thereon, and this wiring pattern 2-4 is faced to the external wall of the cold cathode 1 and formed in parallel to the discharge current route of the cold cathode 1 and the wiring pattern 2-4 is construct as a proximity conductor for lighting accessory electrically connected to either one of the electrodes 7, 8 of the cold cathode 1. Accordingly, the wiring pattern 2-4 of the printed wiring board 2 can be assigned to have such functions as electric current supply to the cold cathode 1 and a proximity conductor, and a complicated assembling process for the cold cathode lighting device is eliminated so as to aim at reduction of the assembly man-hours and cost down following the reduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold-cathode tube lighting device used as a light source for an image forming apparatus or the like.

[0002]

2. Description of the Related Art FIG. 4 shows a configuration of a conventional cold cathode tube 101 used in an image forming apparatus or the like.

FIG. 4 is a sectional view of a conventional cold-cathode tube lighting device. A cold-cathode tube 101 includes an electrode 107 made of nickel or the like provided at both ends of a light-emitting region in a glass wall or a glass tube 104. 108, electrode leads 105 and 106 drawn out from both electrodes 107 and 108 while being sealed outside the glass wall or glass tube 104, and electrodes 107 and 1
08 is connected to a power supply (not shown) for lighting the cold-cathode tube 101 via the electrode leads 105 and 106, a proximity conductor 110 and a reflector 111 provided on the opposite side of the light emitting surface 103. It is composed of The glass wall or glass tube 104 is filled with an inert gas (not shown) such as argon or xenon.
12 are applied.

Here, the principle of lighting the cold cathode tube 101 will be described.

When a high voltage of about 1 kV is applied between the electrodes 107 and 108 of the cold cathode tube 101, residual electrons existing in the glass wall or the glass tube 104 move, and the electrons excite the inert gas, The excited gas is supplied to the electrode 10
By colliding with 7, 108, a large amount of secondary electrons are emitted and discharge is started. Ultraviolet rays emitted when the secondary electrons collide with the inert gas to excite the inert gas impinge on the phosphor 112, so that the phosphor 112 emits light.

Therefore, at the start of discharge, both electrodes 107,
It is necessary to apply a high voltage between the electrodes 108 and the adjacent conductors 11 extending from one electrode 107 (or 108).
When 0 is present, discharge is likely to start, and both electrodes 107,
The voltage applied between the electrodes 108 can also be kept low.
Note that a metal foil having high conductivity such as an aluminum foil or a copper foil is used for the proximity conductor 110.

Further, in order to obtain the light quantity on the light emitting surface 103 as efficiently as possible, it is necessary to provide a reflector 111 on the side opposite to the light emitting surface 103. By providing the reflector 111, light traveling toward the side opposite to the light emitting surface 103 is reflected by the reflector 111, and the light emitting surface 10
It is possible to increase the amount of light on the three sides. As the material of the reflector 111, a material such as PET having high heat resistance, which is printed or coated with a white paint having high reflection efficiency, is used. The reflector 111 is laminated with the proximity conductor 110 with an adhesive 113 or the like. Is attached to the glass wall or glass tube 104 on the opposite side.

The proximity conductor 110 is connected to one of the electrodes 1.
07 (or 108) is electrically connected by caulking or the like, and at the same time, a lead wire 109 for supplying a current to the cold cathode tube 101 is also connected by caulking or the like.

[0009]

However, in the above-mentioned conventional cold cathode tube 101, the operation of attaching the near conductor 110 having a laminated structure and the reflector 111 to the glass wall or the glass tube 104 on the back side of the cold cathode tube 101 is performed. And the adjacent conductor 110 and the lead wire 109 are connected to the electrode leads 1 on both sides.
In addition to requiring a great deal of man-hours for the work of connecting to the reflectors 05 and 106, it is necessary to select a material having sufficient heat resistance against the heat generated when the cold-cathode tube is turned on as a material of the reflector 111, resulting in an increase in cost. There was a problem.

The present invention has been made in view of the above problems, and an object thereof is to provide a cold-cathode tube lighting device capable of eliminating a complicated assembling process and reducing the number of assembling steps and accompanying cost. To provide.

[0011]

According to a first aspect of the present invention, a printed wiring board is provided on a side opposite to a light emitting portion of a cold cathode tube, and the printed wiring board is formed thereon. Electrically connected and fixed to the electrode terminals of the cold-cathode tube by the provided wiring pattern, facing the outer wall of the cold-cathode tube, and forming the wiring pattern in parallel with the discharge current path of the cold-cathode tube; The wiring pattern is configured as a lighting assisting proximity conductor electrically connected to any one of the electrodes of the cold cathode tube.

According to a second aspect of the present invention, in the first aspect of the present invention, the wiring pattern on the printed wiring board includes a wiring pattern for supplying a current for discharging a cold-cathode tube; It is characterized in that it also serves as a wiring pattern as a proximity conductor for lighting assistance.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a printed pattern for reflecting light emitted from the cold cathode tube is formed on the glass wall of the cold cathode tube and the printed wiring board. And white wiring printing between the wiring patterns.

Therefore, according to the present invention, the printed wiring board provided on the opposite side of the light emitting portion of the cold cathode fluorescent lamp and the wiring pattern on the printed wiring board face the outer wall of the cold cathode fluorescent lamp. Since it is arranged parallel to the discharge current path and is configured to be electrically connected to one of the electrodes of the cold cathode tube, the pattern on the printed circuit board functions to supply current to the cold cathode tube and function as a proximity conductor And a complicated assembling process of the cold-cathode tube lighting device can be omitted to reduce the number of assembling steps and the associated cost.

According to the present invention, the printed pattern is formed on the wiring pattern of the printed wiring board by white screen printing between the glass wall of the cold-cathode tube and the wiring pattern of the printed wiring board. It is also possible to give the pattern the function of a reflector for the emitted light of the cold cathode tube.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view showing the structure of a cold cathode tube lighting device according to the present invention. In FIG.
Reference numeral 2 denotes a printed wiring board provided on the opposite side of the light emitting surface 3 of the cold cathode tube 1. The printed wiring board 2 is a single-sided copper foil type of a paper phenol base material, and the copper foil surface is located on the cold cathode tube 1 side and closely adheres to the glass wall 4 of the cold cathode tube 1. As described above, the printed wiring board 2 is provided by the electrode leads 5 and 6 provided on both sides of the cold cathode tube 1.
It is soldered and fixed to the upper pattern. In FIG. 1, reference numerals 7 and 8 denote electrodes.

The wiring pattern 2-4 provided on the printed wiring board 2 in parallel with the discharge current path of the cold-cathode tube 1 is soldered to the electrode lead 6 on one side of the cold-cathode tube 1. It plays the same role as the proximity conductor 110 of the conventional cold cathode tube 101 shown in FIG.

Reference numeral 2-7 denotes a white print pattern screen-printed on the wiring pattern 2-4. The print pattern 2-7 has a uniform area covering the entire light emitting area of the cold cathode tube 1. And performs the same function as the reflector 111 of the conventional cold cathode tube 101 shown in FIG.

The electrode leads 5, 6 and the lead wire 9 for supplying current to the cold cathode tube 1 are electrically connected to each other by soldering via the wiring pattern 2-4 of the printed wiring board 2. Since it becomes possible, work such as caulking as in the conventional example becomes unnecessary.

FIG. 2 is a plan view showing a wiring pattern of the printed wiring board 2.

In FIG. 2, 2-1 is a wiring board, 2-3
Is a lead wire 9 (FIG. 1) for supplying a current to the cold cathode tube 1.
Land pattern for soldering 2-5
Reference numeral 2-6 denotes a land pattern for soldering the electrode leads 5 and 6 (see FIG. 1) of the cold cathode tube 1, and reference numeral 2-2 denotes an electrically connecting electrode lead 6 on one side of the cold cathode tube 1. The wiring pattern 2-4 is the wiring pattern (copper foil pattern) drawn in parallel to the glass wall 4 on the opposite side of the light emitting surface 3 of the cold cathode tube 1, and the wiring pattern 2-4 is shown in FIG. It performs the function of the proximity conductor 110 of the conventional cold cathode tube 101 shown.

Here, as shown in FIG. 3, the same wiring pattern 2-3 as shown in FIG. 2 for supplying a current and the wiring pattern 2-4 for performing the function of the adjacent conductor are used. If it is formed as ′, the area of the wiring board 2 ′ can be kept small, and it can be downsized. FIG.
, The same elements as those shown in FIG. 2 are denoted by the same reference numerals.

In FIG. 2, reference numeral 2-7 denotes a white printed pattern which is screen-printed so as to cover the wiring pattern 2-4.
Since the function of increasing the amount of light in the direction of the light emitting surface by reflecting the light emitted from the light source is achieved, it is not necessary to attach the reflector 111 to the glass wall or the glass tube 4 as in the conventional cold cathode tube 101 shown in FIG.

[0025]

As is apparent from the above description, according to the present invention, the printed circuit board provided on the opposite side of the light emitting portion of the cold cathode tube and the wiring pattern on the printed circuit board are formed by the cold cathode tube. It is arranged parallel to the discharge current path of the cold-cathode tube facing the outer wall, and is configured to be electrically connected to one of the electrodes of the cold-cathode tube. And a function as a proximity conductor can be provided, and the effect that the complicated assembling process of the cold-cathode tube lighting device can be eliminated to reduce the number of assembling steps and the associated cost can be obtained.

According to the present invention, the printed pattern is formed on the wiring pattern of the printed wiring board by white screen printing between the glass wall of the cold cathode tube and the wiring pattern of the printed wiring board. An effect is also obtained that the pattern can have a function of a reflector for emitted light of the cold cathode tube.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a cold-cathode tube lighting device according to the present invention.

FIG. 2 is a plan view showing a wiring pattern of a printed circuit board of the cold-cathode tube lighting device according to the present invention.

FIG. 3 is a plan view showing another example of a wiring pattern on a printed circuit board of the cold-cathode tube lighting device according to the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of a conventional cold-cathode tube lighting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cold-cathode tube 2 Printed wiring board 2-1 Wiring board 2-4 Wiring pattern 2-7 Printed pattern 3 Light emitting surface 4 Glass wall 5,6 Electrode lead 7,8 Electrode 9 Lead wire

Claims (3)

[Claims] 1. A printed circuit board is provided on the opposite side of a light emitting portion of a cold cathode tube, and the printed circuit board is electrically connected and fixed to electrode terminals of the cold cathode tube by a wiring pattern formed thereon. The wiring pattern faces the outer wall of the cold-cathode tube, and is formed in parallel with the discharge current path of the cold-cathode tube, and the wiring pattern is electrically connected to one of the electrodes of the cold-cathode tube. A cold-cathode tube lighting device characterized in that it is configured as a proximity conductor for lighting assistance. 2. The wiring pattern on the printed wiring board serves both as a wiring pattern for supplying a current for discharging a cold cathode tube and a wiring pattern as a proximity conductor for lighting assistance. The cold-cathode tube lighting device according to claim 1, wherein: 3. A printed pattern for reflecting light emitted from the cold-cathode tube is formed by white screen printing between a glass wall of the cold-cathode tube and a wiring pattern on the printed wiring board. The cold-cathode tube lighting device according to claim 1.