JP3552450B2 - Light emitting device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light emitting device using a field emission type electron emitting element.
[0002]
[Prior art]
Recently, a field emission type electron-emitting device has been adopted as an electron source of a flat panel display device or the like. In a flat panel display device, it is required to uniformly irradiate an electron beam to a light emitting surface having a relatively large area. Therefore, a large number of field emission cathodes are arrayed in an electron-emitting device used for this kind of application. (Chemical Digest of IVMC 91, Nagahama 1991, p. 50, Japan Electronics Industry Development Association, Vacuum Microelectronics Research Report I, March 1992.) Moon, p.37).
[0003]
As an example of a field emission type electron-emitting device, as shown in FIG. 3, a conductive base layer 2, an insulator layer 3, and an electron extraction layer 4 (hereinafter, referred to as a gate layer 4) are sequentially formed on a cathode substrate 1. Then, a hole reaching the base layer 2 is formed in the gate layer 4 and the insulator layer 3, and an emitter (cathode) 5 electrically connected to the base layer 2 is arranged in the hole to form a cathode plate 6. . Here, the tip of the emitter 4 is set at a position separated from the end of the hole of the gate layer 4 by a minute gap of about 1 μm or less. Further, as described above, a plurality of emitters 5 are arranged on one base layer 2 to form an array.
[0004]
On the other hand, in order to use the cathode as a flat display device, an anode layer 8 and an electron-beam-excited phosphor screen 9 (hereinafter, referred to as a phosphor screen 9) are sequentially formed on a phosphor screen substrate 7 to form a light-emitting face plate 10. The light emitting face plate 10 is opposed to the cathode plate 6 via a vacuum space.
[0005]
When a positive voltage of about several tens of volts to several hundreds of volts is applied to the base layer 2 in the flat-panel display device configured as described above, the emitter 5 electrically connected to the base layer 2 and the gate A high electric field of 10 ⁸ V / m or more is applied to the layer 4 and electrons are emitted from the tip of the emitter 5 by field electron emission. Here, when a positive voltage is applied to the anode layer 8 with respect to the base layer 2, most of the emitted electrons are accelerated toward the anode layer 8 and collide with the phosphor screen 9 to emit light. Works with the system.
[0006]
Usually, a metal film such as chromium is used for the base layer 2 and the gate layer 4 and does not have a light transmitting property. Further, glass is used for the phosphor screen substrate 7 and a transparent conductive film is used as the anode layer 8, and light generated on the phosphor screen 9 is extracted outside through the anode layer 8 and the phosphor screen substrate 7.
[0007]
Then, the base layer 2 and the gate layer 4 are patterned, and the phosphor screen 9 is also patterned so as to have a pattern in light emission, thereby having a function as a display element. A matrix is formed by patterning the base layer 2 and the gate layer 4 into stripes orthogonal to each other, and the corresponding phosphor screen 9 is similarly formed into a matrix pattern, thereby providing a function of displaying an arbitrary figure or character. A display element is a typical form.
[0008]
Such a flat display element has the following features.
1. High efficiency Since a field emission type electron-emitting device is used as an electron source, heating with a heater for electron emission is not required and power consumption is low. As a result, high efficiency can be obtained as a display element. When compared with an LED (several volts, several tens mA), this light emitting element has a high driving voltage of several tens of volts to several hundreds of volts, but the required current is as small as several tens of μA to several mA, so the power consumption is about the same as an LED. It can be less.
2. The electron-emitting device itself is very thin, a few μm, and the thickness of the cathode plate 6 is almost the same as that of the cathode substrate 1. Further, by arranging the electron-emitting devices in an array over a wide area, the emitted electrons can be applied to the fluorescent screen 9 without being deflected, so that the distance between the cathode plate 6 and the light-emitting surface plate 10 can be reduced. . As a result, the thickness as a display element can be reduced to the same thickness as the combined thickness of the cathode substrate 1 and the phosphor screen substrate 7.
[0009]
3. Since electrons are supplied by field emission because of low temperature dependency, the electron emission ability of the electron source does not depend much on the ambient temperature. Even at a low temperature of about −40 ° C., stable electron emission is possible. In the case of an LED, if the temperature exceeds about 80 ° C., the luminance is reduced to about 1/3 and the light source cannot be used. However, in the case of this light emitting element, the operation of the electron source can be performed up to several hundred degrees at high temperatures. Rather, the upper limit of the high-temperature operation is determined by the heat resistance of the substrate glass and peripheral components and the temperature quenching of the phosphor screen 9.
[0010]
4. As described in the first item of the feature that heat generation is small, since this light emitting element generates electrons by field emission, heat is hardly generated from the electron source. Only a small amount of heat is generated by the electrons that have entered the phosphor screen 9.
[0011]
[Problems to be solved by the invention]
However, in a conventional light emitting display device to which a field emission type electron emitting device is applied, a metal film such as chromium is used for the gate layer 4 and the base layer 2 and a transparent conductive film or the like is used for the anode layer 8 so that the light emitting face plate 10 can be used. A structure in which light is extracted on the side and display is performed, or a light-transmitting film such as a transparent conductive film is used for the gate layer 4 and the base layer 2 and a metal film is used for the anode layer 8 to collect light on the cathode plate 6 side However, the display is performed so that light emission can be taken out and display can be performed only on one of the light emitting face plate 10 side and the cathode plate 6 side. In addition, any one of the gate layer 4, the base layer 2, and the anode layer 8 was opaque, so that the light-emitting element and the display element did not have transparency or translucency.
[0012]
The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a light-emitting device capable of taking out light from any of a light-emitting surface plate side and a cathode plate side. .
[0013]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 comprises, as shown in FIG. 2 , a cathode plate 6 provided with a field emission type electron-emitting device and a light emitting surface plate 10 provided with an electron beam-excited phosphor screen in a vacuum space. A light emitting device A, which is arranged to face each other with a voltage applied between the electron-beam-excited phosphor screen and the electron-emitting device to emit light from the electron-beam-excited phosphor screen with electrons emitted from the electron-emitting device . A light-emitting device comprising a plurality of Bs superposed in the light-emitting direction , wherein the phosphor screen substrate 7 constituting the light-emitting surface plate 10 and the cathode substrate 1 constituting the cathode plate 6 are each made translucent, and The cathode layer 5 of the plate 6 is composed of a cathode forming portion 5a and a non-cathode forming portion 5b, the fluorescent surface 9 of the light emitting surface plate 10 is made translucent, and the fluorescent surface non-forming portion 9b is provided. For the non-formed portion 9b The cathode non-forming portion 5b at positions disposed, and the light emitting device A, adjust a plurality of sets overlapping B to the emission direction, the superimposition, the position opposed to the phosphor screen-free portion 9b of one of the light emitting device A In addition, the cathode forming section 5a of the other light emitting device B is arranged .
[0014]
The invention of claim 2, wherein, as shown in FIG. 2, a light emission device according to claim 1, their respective light emitting devices A, fluorescent screen of a fluorescent surface 9 different luminescent colors of B It is characterized by having.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 2 is a schematic diagram showing one embodiment of the present invention. In the light emitting device according to the present invention, the cathode plate 6 provided with the field emission type electron emitting element and the light emitting surface plate 10 provided with the electron beam excited fluorescent screen are opposed to each other via a vacuum space, similarly to the conventional example. A light emitting device that arranges and applies a voltage between the electron-beam-excited phosphor screen and the electron-emitting device to cause the electron-beam-excited phosphor screen to emit light with electrons emitted from the electron-emitting device. It has a characteristic configuration.
[0016]
In this embodiment, a transparent material typified by glass is used for each of the phosphor screen substrate 7 constituting the light emitting face plate 10 and the cathode substrate 1 constituting the cathode plate 6, and the cathode layer 5 is formed of a cathode made of a reflective emitter. It comprises a forming part 5a and a non-cathode forming part 5b. As the phosphor screen 9, a phosphor powder is applied to form an opaque yet translucent film, or a transparent uniform phosphor layer is formed by an evaporation method or the like. The fluorescent screen 9 includes a fluorescent screen forming section 9a and a non-fluorescent screen forming section 9b. The cathode forming section 5a is disposed at a position facing the fluorescent screen forming section 9a, and a position facing the fluorescent screen non-forming section 9b. The non-cathode forming portion 5b is disposed at the bottom of the screen. Note that the phosphor screen 9 in the present invention may be formed on the cathode plate 6 side.
[0017]
With this configuration, light emission occurs where the cathode forming portion 5a is disposed, and external light can be transmitted without emitting light in the non-cathode forming portion 5b. Therefore, according to the present invention, irrespective of light emission or non-light emission of the light emitting device itself, external light can be transmitted by a light emitter disposed outside the light emitting device.
[0018]
In addition, by placing a display object using reflected light of the light emitting device outside the light emitting device, or by attaching a display film on which the display object is drawn to the light emitting device, the light emitting device and the display object can be viewed simultaneously. Can be.
[0019]
The present invention is characterized in that it has formed overlapping two pairs of the light - emitting device, the superposition is, in a position facing the phosphor screen-free portion 9b of one of the light emitting device A, the other light emitting It is configured such that the cathode forming section 5a of the apparatus B is arranged. Further, phosphors of different emission colors are applied to the phosphor screens 9 of the respective light emitting devices A and B.
[0020]
The light-emitting device configured as described above can prevent mixing of emission colors due to the spread of the electron beam, and can provide a multi-color light-emitting device by using different emission colors for the phosphors of the light-emitting devices A and B. . In particular, a light emitting device capable of realizing full color can be obtained by stacking three sets of the above light emitting devices and setting the emission color of each phosphor screen 9 to blue, green, and red.
[0021]
【The invention's effect】
According to the first aspect of the invention, regardless of whether the light emitting device itself emits light or not, it is possible to transmit external light from a light emitter disposed outside the light emitting device. Further, it is possible to provide a light emitting device of multicolor no mixed emission color due to expansion of the electron beam.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing one embodiment of the present invention.
FIG. 2 is a schematic view showing a different embodiment of the present invention.
FIG. 3 is a schematic diagram showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cathode substrate 2 Base layer 3 Insulator layer 4 Gate layer 5 Cathode layer 5a Cathode formation part 5b Cathode non-formation part 6 Cathode plate 7 Phosphor screen substrate 8 Anode layer 9 Electron beam excited fluorescent screen (fluorescent screen)
9a phosphor screen forming section 9b phosphor screen non-forming section 10 light emitting face plate

Claims (2)

A cathode plate having a field emission type electron-emitting device and a light-emitting surface plate having an electron beam-excited phosphor screen are arranged to face each other via a vacuum space, and a voltage is applied between the electron beam-excited phosphor screen and the electron-emitting device. A light emitting device that emits an electron beam-excited phosphor screen with electrons emitted from the electron-emitting device by applying a plurality of light- emitting devices , the light- emitting device comprising a plurality of light- emitting devices that are stacked in the light-emitting direction. The surface substrate and the cathode substrate constituting the cathode plate are each made of a light-transmitting material, and the cathode layer of the cathode plate is formed of a cathode forming portion and a cathode non-forming portion, and the fluorescent surface of the light emitting surface plate is made of a light-transmitting material. In addition, a fluorescent screen non-forming portion is provided, the cathode non-forming portion is arranged at a position facing the fluorescent screen non-forming portion , and a plurality of light emitting devices are superposed in the light emitting direction. of In a position facing the phosphor screen-free portion of the optical device, the light emitting apparatus characterized by being configured as a cathode forming portion of the other light emitting device is disposed. The light-emitting device according to claim 1, wherein the fluorescent surface of their respective light emitting device was used as the fluorescent surface of different emission colors.

Images