JPS5946742A - Optical writing device - Google Patents

Abstract

PURPOSE:To prevent the deterioration of luminous brightness following the temperature rise of a phosphor and fully perform the functions of an optical printer and such by providing a heat sink that cools the phosphor. CONSTITUTION:An electrode array 21 in which small electrodes 20 are arranged in an array form is provided in the direction (A) that is vertical intersected with the move direction (B) of a sensitive body drum and one end of each of the electrodes 20 is coated with a phosphor 22 and then the section other than that is coated with the phosphor 22 of each of the electrodes 20 is imbedded in an insulator in an area (a). An electrode section 20a coated with the phosphor 22 forms an anode section and a thermion flows into this anode from a cathode filament and then a dot-type luminous pattern is formed by irradiating the phosphor 22 with the thermion. One end side of metal coats 23 that are good heat conductors is connected at the rear of this anode 20a and forms a heat sink that cools the phosphor 22. These metal coats 23 are imbedded in the insulator in an area (b).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical pledge device that uses a fluorescent dot to emit light.

Optical printers are known as one of the fields in which people can record their memories on a recording medium. This optical printer requires a light source of some kind, and various kinds of light sources have been used in the past. The most common method is one that uses a laser, and Kone uses a method in which the laser beam is turned on and off using an optical modulator, and at the same time the blade 1 is deflected using a rotating mirror and the photosensitive surface is placed on the foot. It becomes.

In addition, a method using 0FT (optical fiber thread) is also easy, and the method uses OFT arranged in a length corresponding to the printing width to raster-wise run the light-emitting surface. It is a method. Furthermore, LED (light emitting diode) 7
The optical printer using A1' is also available in Japan, and uses a dense array of LEDs as the original light source. In addition, liquid crystal light shutter arrays are currently being developed, in which liquid crystals are increasingly arranged in an array to turn off and on the interference from the light source.

Among the above technologies, the laser method F-&'J: has the drawback that the optical system occupies the entire device and the space required for the optical system is large, making the device itself bulky, and the rotating mirror etc. The OFT method requires a commercial transportation mechanism, which has drawbacks such as lack of reliability and the equipment itself is expensive.Also, with the OFT method, the equipment becomes larger like the laser method, or the equipment becomes more expensive. There are disadvantages such as high cost.Furthermore, the LED method requires advanced technology to prevent LED chimps, which has the disadvantage of increasing equipment cost.Finally, the liquid crystal light shutter method However, it has the disadvantage that it requires a light source such as a fluorescent light source and a polarizing plate, making the configuration complicated.

Therefore, an optical writing device (chair) has been proposed that uses a phosphor to emit light in a dot shape and eliminates the drawbacks mentioned above. A phosphor is coated on each of the electrode arrays arranged in an array inside the device, and this phosphor forms a dot-shaped light emitting pattern, which is used for recording the mounds on a recording medium. Therefore, the use of a device with a built-in light amount, such as a light source, has the advantage of simplifying the configuration and making the device itself inexpensive and compact.

However, in the case of a phosphor-emitting device that is used for recording images, the luminous power ('N degrees) of the phosphor is limited. Regarding heating, it is important to avoid raising the temperature of the anode (electrode) on which the phosphor is coated. Thermionic electrons from the cathode filament flow through the anode, and the fang 1 is irradiated onto the phosphor to emit light.

Therefore, along with this Jl, the phosphor surface is heated Jl, which reduces the luminous efficiency of the phosphor. In order to prevent this, it is better to cool the anode part in some way.

Normally, when recording an image at high speed and in a flat box using such a light-emitting device using a light emitting device, when recording at minute dots (for example, 10 dots)/mm, the image recording speed is 100 μm.
The light emitting power of the dots (pitch dots) must be large. In the case of a self-recording device used in actual situations, the light emitting power of ordinary and dots is 50 to 200 mw / (:1n
About 2 is required. In this way, the luminous power of several tens (convex) is required compared to the fluorescent display tube which is centrally used in the display.

To this end, it is essential to efficiently direct electrons to the anode and to cool the anode to prevent the temperature of the phosphor from rising.

Honkyuaki has developed an optical writing device called C3 that solves the above-mentioned problems.
The purpose is to provide

The present invention will be explained below with reference to illustrated embodiments.

Now, as shown in Figure 1, a fluorescent display tube that has conventionally been generally used for displays, etc. has a Makabe container 1 with at least one field of vision being transparent, and a fluorescent display tube installed inside this container. It also includes a cathode filament (usually a directly heated filament) 4, a grid 5, and an anode coated with a phosphor 6 (see Figure 2) 7. In this example, the Makabe container 1 consists of a face glass 2 and a transparent plate glass 3, both of which are transparent. Further, the anode 7 is provided on the insulating layer 8 and is connected to wiring within the insulating layer 8 as appropriate.

The anodes (light-emitting portions) 7 of the fluorescent display 1 having a sensing structure are arrayed as minute dots (for example, a pitch of 100 μm in the case of 10 dots/m7IL) and arranged in 5 rows. This array direction is a direction perpendicular to the drawing in the figure, and the length in this array direction is equal to the width to be printed. For example, if printing is to be done in a width of 210 mm on A4 size paper, the quality of the light emitting part of the fluorescent display tube is 21 (JT nm, the number of dots per square) is 2100 (0 dot).

Such a light emitting device] 0, as shown in Figure 13,
An optical splitter f- which uses a phosphor array is an attempt to combine the roof mirror lens array with an image forming element for printing using an electronic photocopy tool. νIJchi, Ne' 31
At 81, the flood light drum 12 rotates in the direction of arrow B.
・Charging is not performed by the reciter 13, and then,
The light-emitting butter 7 by the light-emitting device 10 is connected to the element J1.
The formation J≦ and the force 1 formed on the drum 12 through the kneading are visualized by the current image J4, and this visible image is visualized by the transfer 'Cθ Den-515. The animal is given to the transfer sheet S].

This invention applies to such printers once a month! -) This relates to the structure of a light-emitting device, that is, a light-emitting device.

Now, among the phosphors conventionally used in fluorescent display tubes, ZnO:Zn is known as a typical one. Such a phosphor is a low-speed electron beam-excited phosphor, and has appropriate conductivity so as not to cause a surface charge amplifier due to so-called -order oxidation. Also,
Because the electron source enters only near the surface, the emission center near the surface becomes more efficient.

The phosphor is usually applied by electrodeposition onto the anode electrode. Generally speaking, as the voltage of the anode increases, the luminous power increases by 1 in proportion to the voltage of the anode.

Furthermore, even if the positive current richness is increased using a structure such as a Daishi lens, the light emission will still become thicker.However, if the first method f' increases the emission power, ,
The temperature of the phosphor begins to rise. As the temperature of the phosphor rises, the power of the light emitted decreases, and at a certain point this light emission power reaches its limit.

In conventional fluorescent display tubes, Zn is used as a phosphor between the light emitting legs.
When O:Zn is used, there is no problem as a display at about 600 to 800 fL, and no consideration is given to the temperature rise of the phosphor as described above.

However, in the case of optical insulating devices, a power density of about 50 to L50 mw/cm is required as described above (i:+J).
20,000 L or more), it is necessary to cool the phosphor τ by some method.

The present invention is based on the above-mentioned points.

Figure 4 shows a sister example of this. In the direction A perpendicular to the moving direction B of the photoreceptor drum 12, a single minute electrode 20 is arranged in an electrode array 21 arranged in a γ array.
There are 11 locations. At one end of each turtle 20, there is a 5 figure VC bow J-'b+t1<fluorescent body 22 crab=cloth sane ℃, valley' of the evil ball 20, imaginary element body 22 or nitrogen cloth J. The other parts are to be buried within the body in the area marked a in Figure 4. The electrode portion 20a (see Figure 5) on which the phosphor 22 is placed is a field pole (anode).
Thermionic electrons flow from the cathode filament 4 (see figure j'1) to this anode, and the phosphor 22 is irradiated with it, thereby forming a dot-shaped light emitting pattern.

Alternatively, the anode portion to which the fluorescent substance 22 is applied may be separated from the electrode, and the anode and the surface electrode for applying voltage to the kneader may be connected to each other.

Now, the electrode portion 20a to which the phosphor 22 is coated is referred to as an anode, and on the side of the anode 720a there is one end of the metal film 23, which is a good thermal conductor, as shown in Figure 5. The side is joined with a tongue, and the tongue serves as a heat hook for cooling the phosphor 22. Incidentally, such a heat-sick metal film 23 is definitely buried in the body in region b of FIG.

In this example, the heat sink is a metal film,
It is better to be as thick as possible for this V: 1m, and when forming it as a thin film, the film thickness is set large by a method such as plating after being regrown by vapor deposition or snow climbing. Furthermore, as this metal film, the face glass 2
(Fig. 671) It is better to pull it out to the outside in order to dissipate heat.

In this case, the metal film portion pulled out to the outside may be shaped like a fin.

It should be noted that heat-sickness does not necessarily have to be made of a metal body as in the above embodiment, and it is also possible to use a material with better thermal conductivity than glass substrate, such as alumina ceramic. .

When using such an insulator as a heat sink, there is no need to separate the heat sink into separate surfaces as shown in Figure 3.6. The Schick 24 phosphor 22 must be bonded to the positive portion to be covered.

]・Figure 7 shows an embodiment in which the heat sink is a slate plate of a Shinmen wafer. Specifically, in this example, a gold stripe for the heat sink is used on the substrate 25°C, an insulation film 26 is placed on top of this, and then a positive electrode and an anode electrode are placed on top of this. This is an example in which a kick pole 27 is provided. In addition, in the figure, the reference numeral 28 indicates a light lending body, and the reference numeral 29 indicates an abuser. The insulating layer 26 can be formed of, for example, a 5i02 sputtered film or an evaporated film, or a polymer M such as polyimide.

Further, as the substrate, a glazed ceramic with alumina or the like formed on the surface can be used, and since the conductor has better thermal conductivity than glass, the substrate itself can function as a heat sink.

In any case, heat dissipation is more effective by attaching heat dissipation fins made of aluminum or the like to the substrate or metal or ceramic for the heat sink.

According to the present invention, this technical problem is solved in a fluorescent light-emitting type optical writing device that can reduce the bulk, simplify the structure, and reduce the cost of an optical printer or the like. It is possible to prevent the reduction in luminance of light emitted by the rise in temperature of the phosphor, allowing the optical printer to perform its functions to the fullest. Note that the present invention can be applied to digital copiers in addition to optical printers.

[Brief explanation of the drawing]

``Figure A□ i is a cross-sectional view of a fluorescent display section for a display used to understand this invention, and Figure 2 is an enlarged cross-sectional view of the fluorescent display section of the above-mentioned fluorescent display tube. Figure 3 is a structural diagram of an electrophotographic device using the above-mentioned photoluminescent display, Figure 4 is a plan view of the main parts of an optical writing device according to an embodiment of the present invention, and Figure 5 is a diagram of electrodes and a heat sink. A perspective view of the configuration showing the mode of combination with Figure 6 is a plan view of the main part of the image according to the present invention, Figures 3 and 7 are
The figure is a sectional view of yet another embodiment of the invention.

Claims (1)

[Claims] 1. A Makabe container with at least one surface being transparent, a cathode filament disposed inside the container, and a single minute electrode arranged in an array in one direction within the Makabe container. an electrode array arranged in a row, a phosphor coated on each of the electrodes to form a fine light-emitting pattern in the shape of a tongue dot, and a heat sink made of a good thermal conductor for cooling the phosphor. 2. The optical device according to claim 4, item 1, in which the heat sink is a substrate of a Makabe container. 3. Substrate The optical pocket device according to claim 2 is made of glazed ceramic.