JPH06222345A - Channel structural body for plasma address - Google Patents

Abstract

PURPOSE:To provide the channel structural body for plasma address having a structure which can be more easily produced. CONSTITUTION:This channel structural body for plasma address has a transparent substrate 56, plural fiber-shaped supporting members 88 which are fixed approximately parallel on the main plane of this transparent substrate and a transparent cover sheet member 90 which covers the top of these plural fiber- shaped supporting members. lonizing gases are sealed within the structural body. Then, the structure is simple and the production process is simplified and, therefore, a remarkable contribution is made to a reduction of costs and an improvement in reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma addressing channel structure for selectively ionizing (plasmaizing) an ionizable gas therein to address a data element.

[0002]

2. Description of the Related Art Plasma address devices have various applications, for example, megasample analog memory devices,
It is used in video cameras, liquid crystal flat display panels, etc. Such an apparatus is disclosed in U.S. Pat. No. 4,896,149 to Buzak et al.
No. 217396). In the example of this patent, the ionizable gas is enclosed in a plurality of parallel channels that traverse the display screen, and the gas in each channel is selectively ionized (plasmaized), and display elements along that channel are placed. Address. A reference electrode, or anode, and a data strobe electrode, or cathode, are provided along the entire length of each channel as a structure for ionizing the gas.

When the gas in the channel is ionized,
A data signal is provided on a plurality of data lines that intersect the channel vertically to address the display elements. The liquid crystal material supported by the channel array is driven according to the data signal to display an image.

FIG. 4 is an exploded perspective view of a portion of a conventional plasma addressed structure. A plurality of parallel channels 12 are formed in the glass substrate 10, each channel has a substantially trapezoidal cross section, and an ionizable gas is enclosed in each channel. Adjacent channels 12 are separated by a support structure 18 composed of two sidewalls 14 and an upper wall 16. These plurality of support structures 18 support the liquid crystal material and other components. Row electrodes for strobes, ie cathodes 20 and ground reference electrodes, ie anodes 22.
Are arranged on the bottom surface 4 of each channel 12. The cathode 20 and the anode 22 are relatively thin and thin metal layers. Each cathode 20 receives a row strobe signal from the corresponding output amplifier of a data strobe circuit (not shown) and the gas enclosed in its channel 12 is selectively ionized.

[0005]

The problem of the apparatus of FIG. 4 is that the glass substrate 10 is used, and therefore the manufacturing process for forming the above channel structure is complicated.
According to conventional techniques for forming a channel structure or other components that enclose an ionizable gas as described above, the channel 1
2, the production of the cathode 20 or the anode 22 includes photolithography techniques, the channel 12, the cathode 20
Alternatively, the anode 22 may be roughly formed by sputtering, vapor deposition, CVD, or the like, and a screen printing technique is used for final forming the anode 22. It is desirable that the channel structure suitable for the plasma address structure is formed by a manufacturing method simpler than the conventional one.

It is an object of the present invention to provide a plasma addressing channel structure having a structure that is easier to manufacture.

[0007]

The plasma addressing channel structure of the present invention has a structure that is easy to manufacture.
This channel structure includes a transparent substrate 56 and a plurality of fiber-shaped support members 8 fixed to the main surface of the transparent substrate substantially in parallel.
8 and a transparent cover sheet member 90 covering the plurality of fiber-like support members, and the ionizable gas is sealed inside.

[0008]

DETAILED DESCRIPTION OF THE INVENTION As used herein, the terms "horizontal" and "vertical" are used as illustrated in FIG. That is,
The "column" direction is the vertical direction (48a) and the "row" direction is the horizontal direction (48b). Further, the term "inner" is used to refer to a so-called inner component or a portion of a component, such as below a component if the upper end face of the component means the "inner" face of the component. It means that the number of other components on the upper side is larger than the number of other components on the side. in this case,
It goes without saying that the "outer" face is the lower end face of the component.

FIG. 2 shows a flat display panel system 4
It is a schematic diagram which shows the structure of 0. The display panel 42 has a display surface 44. A plurality of identical data storage elements or display elements 46 are arranged in a rectangle, and are arranged at a predetermined distance in the vertical direction 48a and the horizontal direction 48b.

Each display element 46 in this array is the intersection of a vertical column electrode 50 and a channel 52 arranged in a horizontal row, both column electrodes and row channels being formed thin and thin. There is. Each row along each channel 52 of display element 46 represents one horizontal line of display data in this embodiment. 3 is a cutaway perspective view of a portion of the apparatus of FIG.

In FIG. 1, FIG. 2 and FIG. 3, the column electrode 50
The width of the channel 52 determines the size of the display element 46. The column electrode 50 includes the first non-conductive transparent substrate 5
4, the channel 52 is cut and formed in the main surface of the second non-conductive transparent substrate 56. It is easy for those skilled in the art that only one transparent substrate is sufficient for a reflective display device, for example, a direct-viewing type or projection type display device of an encapsulating liquid crystal cell instead of a twisted nematic liquid crystal cell. You can understand.

A layer 58 of electro-optic material such as nematic liquid crystal is encapsulated between substrates 54 and 56. Board 56
An ionizable gas is enclosed in the channel 52 formed in the channel. The thin film dielectric layer 80 is formed of an insulator such as glass, mica, or plastic, and functions as an insulating layer between the ionizable gas in the channel 52 and the liquid crystal layer 58. Without this dielectric layer 80, the liquid crystal material would flow into the channel 52 and contaminate the ionizable gas or the liquid crystal material or both. This dielectric layer 80
Is a solid or encapsulating electro-optical material, and may be removed when a material that has high temperature resistance and does not cause turbidity with the ionizable gas is used.

The column electrodes 50 each receive a data drive signal of an analog voltage on the parallel output conductors 60 from different output amplifiers 62 of the data driver 64. Channels 52 each receive pulsed data strobe signals from parallel output conductors 66 of different output amplifiers 68 of data strobe generator 70. The display system 40 is provided with a scan controller 72 to control the operation of the data driver 64 and the data strobe generator 70 in order to synchronize the images over substantially the entire display area 44. As a result, during each row scan, the display elements 46 in all columns of that row are addressed.

The display panel 42 includes a pair of substantially parallel electrode assemblies 74, which are separated by an electro-optic material layer 58 and a dielectric layer 80. On the inner surface 82 of the substrate 54 of the electrode assembly 74, the substantially parallel transparent column electrodes 50 of indium tin oxide are formed in a striped pattern. Adjacent column electrodes 50 have a distance of 8 from each other.
4, the distance 84 is the horizontal distance between adjacent display elements 46 in a row.

As shown in FIGS. 3 and 1, channel 52 includes elongated fiber 88 and substrate 56 of electrode assembly 76.
It may be formed by bonding on the inner surface of. The channel 52 is also provided with a reference electrode 92 and a row electrode 94. As a result, the channel 52 will be formed by the fiber 88, the inner surface 86 of the substrate and the dielectric layer 80. The substrate 56 is preferably transparent. More preferably, the substrate 56 has a coefficient of thermal expansion of 71E-7 / ° C to 75.
E-7 / ° C. (“E-7” means 10 −7 power)
The one formed of glass in the range is preferable. One example of a glass material suitable for the present invention is the commercially available Scott (Scho
tt) D-263 glass. The size of the substrate 56 is arbitrary, but may be, for example, 15.24 cm × 15.24 cm (6 inches × 6 inches).

The fiber 88 may also be of suitable size and shape,
A cylindrical fiber suitable for mass production may be used. An example of the diameter of these fibers is from about 76 μm (3 mil) to about 152 μm.
μm (6 mil). The length of the fiber is 4
It can be almost the same as the length of 4.

The fiber 88 of this embodiment can be made of glass or a similar material, with glass being preferred.
The coefficient of thermal expansion of the glass of the fiber is then
The coefficient of thermal expansion of the substrate 56 forming 2 is the same as or approximates. In order to achieve the object of the present specification, the difference in thermal expansion coefficient between the two is within about 2 to 3 CTE (coefficient of thermal expansion unit).

Along the length of each channel 52 is a pair of electrodes 92 and 94 on the substrate inner surface 86 or fiber 88.
Are placed on the surface of. Adjacent channels 52 are separated from each other by a distance 96, the diameter of cylindrical fiber 88. This separation distance 96 also determines the vertical dimension of the channel 52. Column electrode 50 and channel 52
The area of intersection with and determines the size of the display element 46,
This state is shown by a dotted line portion 46 in FIG.

Since the row electrode 94 functions as a cathode in the display system and is exposed to a harsh environment, it is required to have resistance to charged particles. The cathode (row electrode) 94 suitable for the present invention must also have sufficient strength and conductivity. It is also necessary that the coefficient of thermal expansion be the same or within about 2 CTE when bonded to the substrate. Therefore, as a material that satisfies these conditions, nickel.
Materials having substantially the same coefficient of thermal expansion can be used such as wires, copper coated with thorium tungsten, iron wires, and conductive alloys. Suitable commercially available materials for the cathode row electrode 94 are available, for example, from Material Research Corp. of New York.

The reference electrode 92, which serves as the anode in this display system, is formed by bonding a suitable wire to the surface of the fiber 88 or the substrate inner surface 86, as shown in FIG. The reference electrode 92 is less exposed to the harsh environment during operation than the row electrode 94, which functions as a cathode. The reference electrode 92, which is an anode suitable for the present invention, is
It is necessary to have a property and strength capable of maintaining a current for obtaining a uniform plasma discharge over the entire length of the channel 52, and have substantially the same coefficient of thermal expansion (within about 2 CTE) when bonded to a substrate. Therefore, the reference electrode 92 can be formed of copper, aluminum, or another suitable alloy having the substantially same thermal expansion coefficient. Suitable anode reference electrode 92 materials are commercially available and are available, for example, from Material Research, Inc., supra.

The reference electrode 92 of the channel 52 is connected to a common reference potential which can be fixed to the ground potential, as shown in FIG. The row electrodes 94 of the channel 52 are respectively connected to different output amplifiers 68 of the data strobe generator 70. The reference electrode 92 and the row electrode 94 are preferably connected to the reference potential source and the data strobe generating output terminal 66 on the back side of the display panel 42, respectively.

The reference electrode 92 does not encounter a more harsh environment than the row electrode 94 in the operating condition. Therefore, the reference electrode 92 may be deposited and formed on the inner substrate surface 86 with a conductive material. The deposition technique is suitable for mass production of the channel structure of the device of the present invention. Reference electrode 9
2 may be deposited and molded on the substrate 56 or fiber 88 before, during, or after molding the channel 92. The use of screen deposition techniques to shape the reference electrode 92 is one of the preferred manufacturing methods for practicing the present invention.

The reference electrode 92 has a width 98 that forms a relatively large area of the conductive surface in the channel 52 to accommodate gas ionization. The conductive surface region having the width 98 of the reference electrode 92 overcomes the disappearance of the ionized gas due to the non-conductive structure of the channel 52 and the dielectric layer 80, so that the ionized state of the gas can be maintained.

Reference electrode 92 and row electrode 94 having a width 98
Is a conductive surface region that occupies most of the bottom portion of the channel 52. This relatively large conductive surface area maintains the ionized (plasma) state of a small amount of gas. Therefore, the depth of each channel 52 may be formed shallow by using, for example, a fiber having a small diameter, which simplifies the manufacturing process and increases the effective viewing angle of the display panel 42.
Can be realized.

A suitable transparent conductive material for forming the reference electrode 92 is, for example, indium tin oxide or metal or a mixture of nickel and indium tin oxide to maintain conductivity over the entire length of the channel. It may be done. However, the conductivity of such materials is relatively low. Therefore, it is made of indium tin oxide and has a wide width 9
Although not shown, the reference electrode 92 having 8 may be formed by depositing a thin metal strip having high conductivity on indium tin oxide.

Alternatively, thick film screening techniques may be employed to deposit wide strips of nickel or similar material on the substrate surface 86. The fiber 88 is arranged substantially in the center in the width direction of the molded strip,
As the substrate softens during the sintering cycle, it sinters in place. This configuration has the effect of reducing the number of processing steps required, and one molding step forms the electrode on either side of the fiber 88 and fixes the fiber 88 on the nickel electrode. . By alternating the anode and cathode functions of the electrodes, all of the channels 52 have both anode and cathode functions, and the total number of electrodes and connections can be halved from the previous embodiment. But in this case,
The driving method of the channel 52 becomes more complicated.

The channel 52 is formed, for example, from glass.
This can be done by a variety of known techniques such as fiber sticking. The fibers 88 may be affixed to the substrate inner surface 86 by any suitable method. Similarly, when the reference electrode 92 and the row electrode 94 are coupled to the substrate inner surface 86 or the fiber 88 by a suitable method, the reference electrode 92, the row electrode 94 and the cover sheet 90 are separated, and the electrodes 92 and 94 are separated. To be electrically accessible from the outside.
In addition, the distance between the reference electrode 92 and the row electrode 94 is
It is desirable to maintain the entire length of the channel 52. If the fiber 88 is connected using a connection technique similar to that of the electrodes 92 and 94, the connection order of these components is not critical to the invention.

For example, a glass dielectric layer or a suitable adhesive organic mixture (eg, an adhesive such as 4032C frit from Electroscience Laboratories) is placed on a clean substrate surface 86. In order to apply this adhesive uniformly on the substrate surface 86, it is desirable that the surface is clean and unpainted. Further, it is desirable that the adhesive does not decompose by the plasma after processing, that is, ion bombardment by the ionized gas. The fiber 88 is placed on a substrate coated with this adhesive. This fiber placement is in any suitable manner, such as by using a metal plate with machined grooves to receive the fiber 88.
The fiber, adhesive and substrate assembly is sintered in an oven, heated and cooled to bond the fibers onto the substrate and form the desired structure. After cooling, remove the metal plate and other alignment devices.

Wire-shaped electrodes 92 and 94 may be bonded to substrate inner surface 86 or fiber 88 in a similar process. Wire-shaped electrodes 92 and 94 are preferably bonded prior to bonding fiber 88.

The reference electrode 92 or the row electrode 94 may be connected in a similar manner to a contact pad (not shown) for making electrical contact with the outside. In this case, electrical contact is made to either the pad on the glass or the pad on the circuit board connected to the glass. These contact pads are preferably made of a conductive material such as aluminum, gold, silver or other metal. In this embodiment, the edge seal (not shown) of the liquid crystal panel is placed directly on the electrodes 92 or 94 or on pads for external electrical access to the panel. The edge seal of the liquid crystal cell is preferably located slightly outside the peripheral seal (96 in FIG. 1). Perimeter seal 96 provides a seal between glass cover 90 and substrate 56. The edge seal and perimeter seal 96 may be molded by known techniques. An example of a liquid crystal edge seal is 3M (Minnesota Mining and Man).
1838 epoxy resin manufactured by ufacturing, and an example of a peripheral seal is Owens Illino.
is) XS1175M1. Alternatively, the reference electrode 92 or the row electrode 94 may be directly connected to the circuit board and a connector or other connecting component may be used.

FIG. 1 is a perspective view showing the structure of the channel structure. A row electrode (cathode) 94 is arranged adjacent to the right side of the supporting fiber 88, and the row electrode 94 is electrically connected to the contact pads 94 '. Is in contact with. In contrast, the reference electrode (anode) adjacent to the left side of the support fiber 88.
The contacts 92 are in electrical contact with the contact pads 92 '.
Instead of this structure, the electrodes 92 and 94 are connected to the channel 52.
Among them, the fiber 88 and the substrate surface 86 may be arranged at any position as long as they are coupled to one or both of them. It is desirable that neither the reference electrode 92 nor the row electrode 94 be arranged at a position adjacent to the cover sheet 90. Both the reference electrode 92 and the row electrode 94 have a cover sheet 90.
By avoiding contact with, the crosstalk is reduced and the problems associated with it are eliminated. In practice, the reference electrode 92 and the row electrode 94 should be located as far away from the cover sheet 90 as possible. This is because crosstalk decreases as the distance between the electrode and the cover sheet increases. Degassing and gas filling holes 98 are provided in the substrate surface 86.

The channel 52 is applied to a plasma liquid crystal display device as shown in FIG. In addition, channel 52
May be utilized as part of a channel structure that can be employed in other applications and similar devices.

The dielectric layer 80 suitable for the embodiment of the present invention is
It is transparent and is made of glass, polyamide plastic, mica and similar materials. Suitable dielectric layer 80
Has approximately the same coefficient of thermal expansion as the support fiber 88 and its error is in the range of about 2 CTE (coefficient of thermal expansion unit). The thickness range of the dielectric layer 80 is about 38 μm (1.5
mil) to about 76 μm (3 mil). The dielectric layer 80 is composed of a single sheet or an assembly of a plurality of sheets, the surface area of which is parallel to the display surface 44, the area of which is larger than that of the display surface 44, and the peripheral seal 96.
According to the size of. Further, the dielectric layer 80 is bonded to the substrate surface 86 by any suitable method.

For example, the dielectric layer 80 may be encapsulated on the substrate surface 86 using a peripheral seal 96. When the liquid crystal panel is inhaled and the internal pressure is returned to a pressure considerably lower than the atmospheric pressure (about one fifth of the atmospheric pressure), the position of the dielectric layer 80 is held by the external pressure and the upper surface of the fiber 88 is held. Contact. An example of the dielectric layer 80 is Scott Glass (Sc
hott glass company) D-263-000 glass.

Each of the channels 52 is filled with an ionizable gas or plasma. The gas preferably contains helium. An example of a suitable gas composition is pure helium. To address the display element 46, the ionization structure is used to selectively ionize (plasmaize) the gas in the channel 52. The ionization structure includes a reference electrode 92 that functions as an anode and a row electrode 94 that functions as a cathode.

The ionizable gas enclosed in each channel 52 acts as an electrical switch that switches between two switch states depending on the voltage from the data strobe generator 70. This switch connects the reference electrode 92 and the liquid crystal material layer 58. When the strobe signal is not provided, the gas in channel 52 is not ionized and the switch is off because the switch is non-conducting.
When the strobe signal is applied to the row electrode 94, the gas in the channel 52 is ionized (plasmaized) and brought into conduction, so that the switch is turned on.

More specifically, the ionizable gas contained in the channel 52 of the electrode assembly 76 is the dielectric layer 8
0, which forms a conductive path between the electrode assembly 74 and the reference electrode 92 by ionization of the gas. The plasma (ionized gas) in the channel 52 of the row electrode 94, which has received the strobe signal, is brought into a conductive state (switch-on state) and provides a ground conductive path to the portion of the liquid crystal material layer 58. This allows the liquid crystal material to sample the analog data voltage supplied from the column electrodes 50 at the same time. When the strobe signal turns off, the gas becomes non-conductive, and the switch turns off, the liquid crystal material layer 58 of the display element 46 holds the data sample voltage. This data sample voltage is the new data voltage for the plasma
Liquid crystal material layer 5 until it is supplied when the switch is on
8 display elements 46 continue to be held. The configuration described above allows all display elements 46 to be provided with a signal with a duty cycle of approximately 100%.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described herein, and various modifications and changes can be made as necessary without departing from the gist of the present invention. It will be apparent to those skilled in the art that changes can be made.

[0039]

According to the plasma addressing channel structure of the present invention, a plurality of fiber-like supporting members are fixed on a transparent substrate, the transparent cover sheet is covered thereover, and an ionizable gas is enclosed inside. Since it is configured, the manufacturing process is remarkably simplified as compared with the conventional one, and there are remarkable effects in reduction of manufacturing cost and improvement of reliability.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a plasma addressed flat display device suitable for utilizing the present invention.

3 is a cutaway perspective view showing a partial configuration of the apparatus of FIG. 2. FIG.

FIG. 4 is a perspective view showing a partial structure of a conventional channel structure.

[Explanation of symbols]

 56 transparent substrate 88 fibrous support member 90 cover / sheet member 92 reference electrode 94 row electrode 96 peripheral seal

Claims (1)

[Claims] 1. A transparent substrate, a plurality of fiber-shaped supporting members fixed to the main surface of the transparent substrate substantially in parallel, and a transparent cover sheet member covering the plurality of fiber-shaped supporting members. A channel structure for plasma addressing, wherein an ionizable gas is sealed inside.