JP2915179B2 - Flat fluorescent lamp device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat fluorescent lamp suitably used as a backlight of a liquid crystal display.

[0002]

2. Description of the Related Art In recent years, with the increasing density of LSIs,
All products tend to be downsized, and PCs, word processors and video cameras are no exception. In order to reduce the size of the display device, the size of the display device must be reduced, and a liquid crystal display is attracting attention as being most suitable for the reduction in size.

There are two types of liquid crystal displays, reflective and transmissive. The transmissive type is becoming mainstream in recent years because the screen is bright and the color can be easily viewed. This transmissive liquid crystal display requires a backlight, and as the backlight, a fluorescent lamp is mainly used. Liquid crystal displays have also been used for viewfinders in video cameras. In recent years, with the miniaturization of video cameras, liquid crystal displays smaller than 1 inch have been required. As a light, a straight tube type fluorescent lamp cannot cope with it, and a flat type fluorescent lamp has been required.

[0004]

As described above, the small flat fluorescent lamp is mainly described for use in a viewfinder of a video camera. However, the video camera is battery-powered and has an effect on peripheral devices. In consideration of the above, it is desired that the starting voltage be lower. However, when a flat fluorescent lamp is used by incorporating it into a video camera, since the light is used under no light conditions, the discharge does not shift to full emission unless a voltage higher than usual is applied due to the so-called dark effect. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to improve the startability by lowering the starting voltage at the start of discharge to improve the startability. An object of the present invention is to provide a flat fluorescent lamp device in which the effects of the effects are reduced and the effects on peripheral devices are reduced.

[0006]

According to the flat fluorescent lamp device of the present invention, a flat space sealed by an upper plate member, a lower plate member and a frame spacer member is formed, and a pair of elongated electrodes are formed in the flat space. A flat fluorescent lamp in which a fluorescent substance is applied to inner surfaces of the upper plate member and the lower plate member, and a point for lighting the flat fluorescent lamp ;
In a flat fluorescent lamp device having a lighting circuit,
Each electrode of the flat fluorescent lamp is connected to the high voltage of the lighting circuit.
Side and the low-voltage side, respectively.
A conductive metal member is attached to the outer surface of the lower plate member of the light lamp
And connecting the conductive metal member to a low voltage side of the lighting circuit.
And connected to the high voltage side of the lighting circuit
That negative high voltage is applied from the lighting circuit to the
Features.

[0007]

The flat fluorescent lamp device of the present invention has an upper plate member and
Flat space consisting of a lower plate member and a frame spacer member
Flat fluorescent lamp with a pair of elongated electrodes arranged inside
And a lighting circuit for lighting this flat fluorescent lamp
On the outer surface of the lower plate member of the flat fluorescent lamp.
Attach the conductive metal member and turn on the conductive metal member.
To the electrode connected to the low voltage side of the
Negative voltage from the lighting circuit to the electrode connected to the high voltage side of the road
Since the voltage is applied, the potential gradient in the vicinity of the cathode, which greatly affects the secondary electron emission at the start of the discharge, becomes large, and the process easily transitions to the overall discharge in the process from the secondary electron emission to the full discharge. Work on.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a 0.7-inch flat fluorescent lamp with an output of 0.4 W according to the present invention.
2 is a lower plate member, 3 is a frame spacer member, 4 and 5 are electrodes, 6 is a conductive metal member adhered to the lower plate member, and 7 electrically connects one electrode 4 and the conductive metal member 6. It is a connecting member.

The upper plate member 1 is a light-transmitting glass member having a thickness of 0.5 mm, and the inner surface thereof is coated with a phosphor of 8 μm. The lower plate member 2 and the frame spacer member 3 are made of, for example, Steatite (a sintered body of MgO and SiO ₂ ).
And a 30 μm-thick phosphor is coated on the inner surface of the lower plate member 2.

Both ends of a flat space surrounded by the upper plate member 1, the lower plate member 2, and the frame spacer member 3 are Fe--N
A pair of electrodes 4 and 5 made of i-alloy are arranged to face each other, and are connected to leads 41 and 51 that penetrate the frame spacer member 3 airtightly. The leads 41 and 51 are connected to a lighting circuit described later, and the lead 41 is connected to the low voltage side of the lighting circuit.
The lead 51 is connected to the high voltage side of the lighting circuit.
Lead 51 connected to the high voltage side of
High pressure is applied. The connecting member 7 is wound around the lead 41 connected to the low voltage side of the lighting circuit, and is connected to the conductive metal member 6 attached to the outer surface of the lower plate member 2. Various metals can be used as the conductive metal member 6. For example, a foil plate having a thickness of about 100 μm, such as aluminum or copper, is preferable.

Various lighting circuits can be used. As an example, a flyback pulse lighting circuit can be used as shown in FIG. That is, the timing and drive circuit 8 is synchronized with the synchronization signal.
The pulse generated from 1 is applied to the gate of the FET 82.
The FET 82 switches the current on the primary side of the step-up transformer 83 to generate a secondary high voltage, thereby lighting the flat fluorescent lamp L. At this time, the step-up transformer 83
Are connected such that the high voltage side of the secondary side has a negative high voltage. Then, the conductive metal member 6 attached to the outer surface of the lower plate member 2 of the lamp L and the step-up transformer 8
The lead 41 connected to the low voltage side of the secondary side of No. 3 is connected by the connecting member 7.

Next, an experimental example of the present invention will be described. Table 1 shows the positive voltage applied to the electrode connected to the high voltage side of the lighting circuit.
And negative high voltage.
The conductive metal on the electrode connected to the low voltage side of the lighting circuit.
It was investigated how the starting voltage affects the case where the members are connected and the case where the members are not connected . The conductive metal member used was copper having a thickness of 100 μm adhered to almost the entire outer surface of the lower plate member. The measuring method was such that the lighting circuit was set to 0.6 V and 0.4 W at room temperature. Adjust the inverter, turn off the power once to 0V,
Turn on again and gradually increase the voltage manually to measure the voltage to emit light over the entire surface

[0013]

[Table 1]

As shown in Table 1, on the high voltage side of the lighting circuit
Apply negative high voltage rather than positive high voltage to connected electrodes
This can reduce the lighting voltage by about 20%.
Conductive metal members on electrodes connected to the low voltage side of the lighting circuit
Is connected, the power consumption can be further reduced by about 18%. Eventually, the electrode connected to the high voltage side of the lighting circuit
Pressure to the electrodes connected to the low voltage side of the lighting circuit.
It has been confirmed that the starting voltage can be greatly reduced to 34% in the case of the present invention as compared with the case where the conductive metal member is not connected .

The electrode connected to the high voltage side of the lighting circuit
When a negative high voltage is applied than when a positive high voltage is applied
But the point is advantageous in lighting at the time of start-up, as shown in FIG. 3, when the discharge begins, the potential gradient in the vicinity of the cathode portion that significantly affect the secondary electron emission, a high voltage side of the lighting circuit To
Negative high voltage is applied when a positive high voltage is applied to the connected electrode.
It is considered that the case of adding is larger. On the other hand, lighting
The electrode connected to the low voltage side of the circuit and the conductive metal member
As shown in (a) to (c) of FIG. 4 , the lowering of the starting voltage due to the connection can provide a larger potential gradient when the conductive metal member is not provided than when the conductive metal member is not provided, and can be reduced on the low voltage side of the lighting circuit.
It is considered that the potential gradient can be further increased by connecting the connected electrode and the conductive metal member, and as a result, it is considered that the entire surface is easily discharged.

[0016]

As described in detail above, the present invention
The surface fluorescent lamp device consists of an upper plate member, a lower plate member and
A pair of elongated electrodes are placed in a flat space
A flat fluorescent lamp in which the poles are arranged, and the flat fluorescent lamp
A lighting circuit for lighting the lamp
A conductive metal member is attached to the outer surface of the lower plate member of the fluorescent lamp
Then, connect this conductive metal member to the low voltage side of the lighting circuit.
Connected to the high voltage side of the lighting circuit.
A negative voltage is applied from the lighting circuit to the illuminated electrode, so the starting voltage for shifting to full discharge is greatly reduced and the effect of the dark effect can be reduced, making it suitable as a backlight for video camera viewfinders A flat fluorescent lamp device can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a flat fluorescent lamp device of the present invention .
It is a perspective view of a fluorescent lamp.

FIG. 2 is an example of a flat fluorescent lamp device of the present invention.

FIG. 3 shows a positive high voltage applied to an electrode connected to the high voltage side of the lighting circuit .
FIG. 4 is an explanatory diagram of secondary electron emission when a negative voltage is applied and when a negative high voltage is applied .

FIG. 4 is an explanatory diagram showing a potential gradient caused by a conductive metal member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Upper plate member 2 ... Lower plate member 3 ... Frame spacer member 4, 5 ... Electrode 6 ... Conductive metal member 7 ... Connection member L ... Flat fluorescent lamp

Claims (1)

(57) [Claims] An enclosed flat space is formed by an upper plate member, a lower plate member, and a frame spacer member, and a pair of elongated electrodes are disposed in the flat space so as to face each other, and inner surfaces of the upper plate member and the lower plate member are provided. A flat fluorescent lamp in which a phosphor is coated on the flat fluorescent lamp ;
In a flat-type fluorescent lamp device including a lighting circuit, each electrode of the flat-type fluorescent lamp is provided with a high power supply of the lighting circuit.
Are respectively connected to the pressure side and the low voltage side, the conductive metal on the outer surface of the lower plate member of the flat fluorescent lamp
A member is affixed, and the conductive metal member is
Connected to the electrode connected to the
Negative high voltage is applied from the lighting circuit to the electrode connected to the pressure side.
A flat-type fluorescent lamp device.