JPH058437A - Printing array for ion projection type printer - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a printing array of an ion projection printer having an ion control electrode having a long life in a hot and humid environment. A plurality of controlling a moving direction of ions accompanied by a carrier fluid by selectively forming an electric field when the carrier fluid is ejected from an exit channel along with ions generated by a corona discharge in a conductive corona chamber. This is a printing array of an ion projection printing apparatus in which a metal of an acid-resistant and non-electrolytic corrosion transition element such as Ta, Ti, Mo, W is used for each ion control electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print array of an ion projection printer, and more particularly to a print array of an ion projection printer having a long-life ion control electrode under a high temperature and high humidity environment.

[0002]

2. Description of the Related Art A conventional print head of an ion projection printer will be described with reference to FIG. Within the printhead housing 10 is a conductive corona chamber 12, a high voltage source 16 of several thousand volts applied to a corona wire 14 extending in the conductive corona chamber 12 in a direction perpendicular to the plane of the paper, and a conductive corona chamber. The environment is such that ions are generated by the reference potential source 18 and the like connected to the outer wall of the chamber 12, and the corona discharge around the corona wire 14 generates ions of a certain polarity (preferably positive), which is generated. The generated ions are attracted to the grounded wall of the conductive corona chamber 12 to fill the conductive corona chamber 12 with charged ions.

When pressurized carrier fluid (preferably air) is delivered from tube 22 through inlet channel 20 extending in the direction of arrow into conductive corona chamber 12, the carrier fluid is in conductive corona chamber 12. A large number of ions filled with the gas are transported from the conductive corona chamber 12 to the outside of the conductive corona chamber 12 through the exit channel 24 provided in the arrow direction, the ion modulation region 26, and the like.

After the ions have exited the conductive corona chamber 12 from the exit channel 24 by the carrier fluid, they are controlled according to the print information. This is done by using a thin film transistor (TFT) 38 as an ion control electrode 28 which exists in an array on the ion modulation region 26 when a carrier fluid (ion beam) carrying ions passes over the ion modulation region 26. A low voltage source 36 of about 10 to 20 volts (DC)
And the reference potential 37 are individually turned on / off.

That is, since the ion control electrode 28 and the opposing wall 40 which is grounded form a capacitor with a gap between the outlet channels 24, when the corresponding ion control electrode 28 is connected to the low voltage source 36 by the TFT 38. A low electric potential is applied between the ion control electrode 28 and the opposing wall 40, an electric field is selectively generated in the direction perpendicular to the flow direction of the carrier fluid, and the ion beam is repelled. Then, the ion beam collides with the grounded opposing wall 40 to become a neutral air molecule from an ionic state, and is released into the atmosphere. On the contrary, when the ion control electrode 28 is connected to the reference potential source 37 by the TFT 38, the ion control electrode 2
8 and the opposing wall 40 pass through without being affected by the electric field.

Ions completely passing out of the housing 10 through the outlet channel 24 are connected to a high voltage source 32 of the order of several thousand volts (DC) with a polarity opposite to that of the corona voltage source 16 and a back electrode for acceleration. Since it is affected by the electric field due to 30, it is pulled toward the back electrode 30 for acceleration. The charge acceptor 34 moving on the accelerating back electrode 30 receives and charges the ions, and a latent image charge pattern is formed on the surface thereof. Subsequently, the latent image charge pattern can be visualized by a suitable developing device (not shown).

However, the ion control electrode 28 of the conventional print array has a TFT 38 made of a-Si: H.
Aluminum was used because it is a particularly preferable material for making good contact with the electrodes of the drain, gate and gate, but corona gas having a strong oxidizing action flowing out from the conductive corona chamber 12 is used. It is known that the ion control electrode 28 is rapidly oxidized due to the exposure of the exposed aluminum, the control function of the printing array is deteriorated, and the service life of the printing array is exhausted. This phenomenon occurs because the aluminum oxide insulating layer deposited on the ion control electrode 28 acts as an electric resistance, and as a result, the actual potential applied to the ion control electrode 28 decreases.

Therefore, it has been proposed to make the ion control electrode 28 from an alloy of aluminum and copper (Al-Cu) as an improved printing array, and Al-Cu containing 5% of copper.
When using alloys, about 500 before catastrophic failure occurs
The lifetime of the ion control electrode 28 in time was observed. It is believed that this is because copper penetrates between the individual aluminum crystal grains and acts as "mortar" to stop the movement of oxygen. (See JP-A-63-297059).

When an inert material such as a noble metal such as gold or platinum is used for the ion control electrode 28, it is not corroded by the corona outflow gas, so that it is extremely corrosion-resistant experimentally. However, it is difficult to actually use these materials because they are expensive.

Further, there is one using conductive silicon as the ion control electrode 28. In this, a thin conductive thin film (chromium) is vapor-deposited on the substrate 42 by the sputtering method, and the conductive thin film of the ion control electrode 28 is formed. Pattern into shape,
When a thin film layer of n + type silicon is vapor-deposited on the conductive thin film and then patterned, the surface of the n + type silicon is oxidized, and the peculiar thickness of the electrode has almost no influence on the electrical conductivity of the electrode ( About 10 to 20 angstroms) of silicon dioxide is formed on the surface of the thin film layer, the thin film protects the ion control electrode 28 from oxidation by the corona effluent gas, and the impurity doping in the n + type silicon causes electrical conduction of the electrode. It has been reported that a life of about 1000 hours was obtained by keeping the temperature good.

Further, an ion control electrode using silicide (CrSi) as conductive silicon is also considered, which is not affected by oxidation or etching due to corona outflow gas because the silicide is chemically inactive. The reason is that it is compatible with the manufacturing process of the print head.
(See JP-A-2-2035).

[0012]

However, in the above-mentioned conventional improved printing array, the high-temperature and high-humidity environment (28
When a print test was performed at 85 ° C, 85%
The Cu alloy print array has a life of about 100 hours due to oxidation by ions, and the print array made of CrSi, which is conductive silicon, showed no oxidation on the surface of the ion control electrode 28. Electrolytic corrosion occurs due to the adsorption of water and the life is about 100 hours. Both of them have a problem that they do not have a sufficient life under high temperature and high humidity environment.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a printing array of an ion projection type printing apparatus having an ion control electrode having a long life in a high temperature and high humidity environment. To do.

[0014]

SUMMARY OF THE INVENTION In order to solve the above conventional problems, the present invention applies an electric field to ions accompanying a carrier fluid discharged from a conductive corona chamber of a print head of an ion projection printer. A printing array of an ion projection printer having a control electrode is characterized in that a metal of a transition element that is acid-resistant and non-electrolytic is used for the control electrode.

[0015]

According to the present invention, in a printing array of an ion projection printer, a carrier fluid is discharged together with ions generated by corona discharge in a conductive corona chamber of a print head of the ion projection printer. At this time, the control electrode that controls the moving direction of the ions accompanying the carrier fluid by selectively forming an electric field uses a metal of a transition element that is acid-resistant and non-electrolytically corroded. Oxidation and electrolytic corrosion of the control electrodes that occur can be greatly suppressed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The print head of the ion projection printing apparatus according to the embodiment of the present invention has substantially the same configuration as the conventional print head shown in the schematic view of FIG.

The outline structure of the print head of the ion projection printer of this embodiment will be briefly described with reference to FIG. 2. In the conductive corona chamber 12 inside the housing 10 of the print head, the area around the corona wire 14 is described. Ions are generated by the corona discharge, and the generated ions are electrically conductive in the corona chamber 12
Once filled, the pressurized carrier fluid is pumped from the tube 22 through the inlet channel 20 into the conductive corona chamber 12 and from the outlet channel 24 into the ion modulation region 26 on the print array carrying a large number of ions. Go out of the housing 10.

When the ions are emitted from the outlet channel 24 along with the carrier fluid, the thin film transistors (TFTs) 38 individually turn on / off the ion control electrodes 28 formed in array in the ion modulation region 26. O
By performing FF, an electric field is selectively generated in a direction perpendicular to the flow direction of the carrier fluid, thereby giving information to be printed on the ions.

The ions carrying the print information emitted from the outlet channel 24 to the outside of the housing 10 jump to the acceleration back electrode 30 connected to the high voltage source 32 of the opposite polarity to the corona voltage source 18. The charge acceptor 34 moving on the accelerating back electrode 30 receives the ions, and a latent image charge pattern is formed on the surface. The latent image charge pattern is printed by an appropriate developing device. Also,
It is also possible to attach the latent image charge pattern to a conductive drum, develop the latent image charge pattern on the conductive drum, visualize it and transfer it to the image support sheet.

Next, description will be given with reference to FIG. 1, which is a plan view of the printing array of this embodiment. The printing array is on the substrate 42.
Ta (tantalum) formed on one side of the upper surface so as to be discrete at equal intervals in the direction perpendicular to the traveling direction of the ion beam.
Made ion control electrode 28, thin film transistor switch element (TFT) 38 connected to each of the divided ion control electrodes 28, and ON / OFF of each TFT 38
External IC address bus drive circuit 64 for supplying the control signal of No. 1 through the address bus line 44 and low potential or reference potential to each ion control electrode 28 selectively via the data bus line 46. And an external IC data bus driving circuit 66 for giving.

The wiring from the ion control electrode 28 is connected to the source electrode 52 of the TFT 38, and the address bus line 44 is connected to the gate electrode 50 of the TFT 38.
The data bus line 46 is connected to the drain electrode 48 of the TFT 38.

A plurality of ion control electrodes 28 formed on the substrate 42 are divided into m sections, and each section includes n ion control electrodes 28. The address bus line 44, which is connected to the external IC address bus drive circuit 64 and performs gate control, is a common signal line for the TFT 38 of each section, and n TFTs 38 for each section are provided. Drain electrodes 48 are connected to the corresponding n data bus lines 46.

Next, the operation of the printing array in the ion projection printer will be described. The external IC data bus drive circuit 66 applies a low potential or reference to each ion control electrode 28 in the target section i. Either of the potential
The data (voltage) is applied to the data bus line 46. Then, the target section i is selected by applying a pulse from the external IC address / bus drive circuit 64 to the gate electrode 50 of the TFT 38 in unit of section, and the ion control electrode 28 in the section i has a low potential or a reference voltage. Supply either of the electric potentials.

An electric field is generated between the ion control electrode 28 supplied with a low potential and the outlet channel 24 facing the ion control electrode 28, and the ion beam passing on the ion control electrode 28 receives the coulomb received in the electric field. Opposing wall 40 grounded by force
When it starts accelerating toward and collides with the opposing wall 40, it becomes electrically neutral air molecules and is released into the atmosphere. Therefore, the ion beam in this case does not "write" the latent image charge pattern on the charge receptor 34 moving on the accelerating back electrode 30.

On the other hand, the ion beam passing between the ion control electrode 28 supplied with the reference potential and the facing outlet channel 24 is not affected by the electric field, and the back electrode 3 for acceleration is used.
0, the latent image charge pattern on the charge acceptor 34.
“Write” the program.

Next, the method of manufacturing the ion control electrode 28 of the printing array of this embodiment will be described.
r gas 100sccm, pressure 6mTorr, discharge power -1kW,
The ion control electrode 28 is manufactured by depositing Ta on the substrate 42 by a sputtering method with a film thickness of about 3000 angstroms and patterning it in an array as individual electrodes.

A printing test was carried out using the printing array of this embodiment in an environment of high temperature and high humidity (28 ° C., humidity 85%), and a life of 500 hours or more was obtained. On the other hand, in a printing test under the same conditions using a printing array made of a conventional aluminum-copper alloy (Al-Cu), about 10
I only got a life of 0 hours.

Further, conventional conductive silicon (CrSi)
In the print test under the same condition using the print array made of, the surface of the ion control electrode 28 was not oxidized, but since water was adsorbed, the potential difference between adjacent bits caused electrolytic corrosion. The life was about 200 hours. However, Ta does not have such electrolytic corrosion, and the ion control electrode 28
As a result, a long life was obtained.

Further, in the embodiment, the material of the ion control electrode 28 of the printing array is Ta, but instead of T
The same printing test as in the present embodiment is performed even for a printing array having the respective ion control electrodes 28 made of i (titanium), Mo (molybdenum), W (tungsten) or an alloy of tantalum and molybdenum (Ta-Mo). When carried out, a long life similar to that of Ta was obtained.

A printing array of an ion projection type printer having an ion control electrode 28 made of Ta, Ti, Mo, W or Ta-Mo alloy can have a long life in a high temperature and high humidity environment. effective.

[0031]

According to the present invention, in a printing array of an ion projection printer, a carrier fluid is discharged together with ions generated by corona discharge in a conductive corona chamber of a print head of the ion projection printer. When a metal of a transition element that is acid-resistant and non-electrolytically resistant is used as a control electrode that controls the direction of movement of ions accompanying a carrier fluid by selectively forming an electric field when exposed to ions This has the effect of significantly suppressing the oxidation and electrolytic corrosion of the control electrode that may occur.

[Brief description of drawings]

FIG. 1 is a plan explanatory view of a printing array in an ion projection type printing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic view of the entire print head of the ion projection printing apparatus.

[Explanation of symbols]

10 ... Print head housing, 12 ... Conductive corona chamber, 14 ... Corona wire, 16 ... High voltage source, 18
... reference potential source, 20 ... inlet channel, 22 ... tube,
24 ... Exit channel, 26 ... Ion modulation region,
28 ... Ion control electrode, 30 ... Acceleration back electrode, 3
2 ... High voltage source, 34 ... Charge acceptor, 36 ... Low voltage source,
37 ... Reference potential source, 38 ... TFT, 40 ... Wall,
42 ... Substrate, 44 ... Address bus line, 46 ... Data bus line, 48 ... Drain electrode, 50 ... Gate
Electrode, 52 ... Source electrode, 64 ... External IC address / bus drive circuit, 66 ... External IC data / bus drive circuit

Claims (1)

Claim: What is claimed is: 1. A printing array of an ion projection printing apparatus having a control electrode for causing an electric field to act on ions accompanying a carrier fluid discharged from a conductive corona chamber of a print head of the ion projection printing apparatus. -In the above, in the printing array of the ion projection type printing apparatus, the control electrode is made of a metal of a transition element that is acid resistant and non-electrolytically resistant.