DE2851446A1 - ELECTRO-OPTICAL DISPLAY UNIT AND METHOD OF MANUFACTURING THE SAME - Google Patents

Description

DR.-ING. DIPL.-ING.fjl. SC. Oli L-PH i-S. DPJ. OIPL-PHYS.

HÖGER - LEGAL RIGHT - 3R5ESSBACK - HAECKER

PATENT LAWYERS IN STUTTGART _

2S5H46

A 43 044 b Applicant: TII-IEX CORPORATION

Ir -1 71

November 20, 1978 -4- WATERBuRY, Conn. 06720

United States

Electro-optical display unit

and methods of making the same

The invention relates to an electro-optical display unit with a transparent front substrate and a rear substrate parallel thereto, both of which consist of a breakable material, each provided with an electrode pattern, and with a spacer and sealing material located between the substrates , which the substrates in Keeps a distance from one another and connects to one another in a sealing manner, as well as a method for producing the same.

Various types of electro-optical display units are known which work with liquid crystal material (material with dynamic scattering - twisted nematic or pleochroic material), as colloidal light valves, or, for example, with electrochromic material (organic or inorganic or based on the principle of electrophoresis). Are all of these passive display systems _? which have in common the feature that there is a cell of two parallel substrates which are spaced a few µm apart and which are tightly connected along their edge so that a closed chamber results which then contains the active material. The front substrate is always transparent and has electrodes applied in the form of a transparent layer, which are arranged in patterns of segments, with the aid of which letters and / or numbers can be represented. The rear, i.e. the substrate facing away from the viewer during operation,

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may or may not be transparent and also carries electrodes. Such display units are activated by creating them a voltage between selected electrodes on the front and back substrates.

In the known display units and methods for producing the same, one usually starts from blanks as the front and rear substrate, on which the electrodes are then produced by etching, vapor deposition through a mask , photo-resist and similar methods, around the individual segments and their to obtain leads "Similarly, the lying at the edge of the finished display unit spacing and sealing material, in general, to one or both individual substrates is applied, whereupon the corresponding to the material used process steps are executed to seal the cell. In a liquid crystal display unit, for example, a mixture of glass beads and a vitrifiable or fusible glass frit is used, the melting point of which is lower than that of the glass substrate, which is applied by means of a screen printing process and also serves as a spacer and sealing material. Difficulties arise due to the fact that the disc scanning and sealing material must be applied directly to the edge of a Sinzol substrate. Furthermore, when the substrates are produced individually, it is difficult to achieve a uniform quality of the display units. The same applies to the production of the electrode pattern. In addition, the production of the individual elements of the display units and their connection to a finished display unit have so far been relatively time-consuming.

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November 20th 1978 -6-

Starting from the state of the art, the invention is based on the object? to specify an improved electronic display unit and a method for providing the same *

This task is performed with an electro-optical display unit of the type described at the outset according to the invention solved that parts of the electrode pattern and the distance r.nd You tungsiaateri than up to at least one edge of the substrate material rich and there with this «at least essentially lie in one plane "

To produce a erülndungsgemässen iüizeigeeinheit / rt thereby sin proven verfährst which dursh following "- = :: - - fahrsnsächritts gekann ^ s _cnnet ^r:

a) One brings sin on a - ^ "breakable substrate flat material Ξ le lc t rodenmu s te r au r '

b} one brings the Elektrocenmustsr to the F.lachsateriai tsilv / eiss overcoat wet spacer and sealing material samples on j

c} convert the i-: ^r> S ";, al of the distance and sealing ^ i ^ tsrial pattern into sinan ze;: /: visible state;

d) raan cuts through the Öuostrat flat material lengthways at least one the Elaktrodenxnv.s-er and the spacer and sealing material sample to crossci- ~ n line;

d) nan connects the C ^ i.inz- and sealing material pattern of a separated Teilstü.c..t of the substrate flat material sealingly with a parallel zi-. ieai section aligned second, substrate.

c ^, "T« "

til, ⁰⁴⁴ "2851U6

November 20th 1978 -7-

The decisive advantage of the method according to the invention is there in that starting from large plates of the substrate flat material, In particular, starting from a large glass plate, important manufacturing steps for the individual display units can be carried out at the same time in each case, with display units with very uniform properties being obtained can and with considerable savings in material and working time. Accordingly, it results for electro-optical Display units according to the invention have the advantage that their essential properties are the same within narrow tolerances and that they are nevertheless produced comparatively cheaply can.

Further details and advantages of the invention are provided below explained in more detail with reference to drawings and / or are the subject of subclaims.

Show it:

Fig. 1 A plan view of a typical electro-optical display unit according to the invention for digital Display of digits;

FIG. 2 shows a vertical cross section through the display unit according to FIG. 1 along the line II-II in this figure;

3 shows a vertical cross section through the display unit according to FIG. 1 along the line III-III in this figure;

4a shows an enlarged schematic plan view of a part a flat substrate material with an electrode pattern composed of two interconnected pattern areas, for the rear substrate of two display

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units are suitable;

FIG. 4b shows a plan view of a plate of substrate material with a field of electrode system according to FIG. 4a;

Figure 5a is an enlarged schematic plan view of a-Eiektrodenmuster of two interconnected pattern areas which are suitable for the front substrate of a Änseigeeinheit.

5b shows a plan view of a large plate of the substrate material with a field of electrode patterns according to FIG. 5a;

6a shows an enlarged schematic plan view of interconnected patterns of a spacer and sealing material;

6b shows a plan view of a large plate of the substrate material with an array of spacer and sealant patterns required for the front substrates display units are suitable according to the requirements;

7 shows an enlarged plan view of the border area of two front substrates which are still connected to one another to illustrate one of the procedural steps of the inventive method;

7a shows a partial plan view of a substrate of one according to the invention Display unit during a later process step;

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Fig. 8

and 9 enlarged cross-sections along the line VIII-VIII and IX-IX in FIGS

10 is a partial plan view of a large plate of the substrate material with a field of spacer and sealing material samples, those for application to the rear substrates of a display unit according to the invention are suitable.

In detail, Fig. 1 of the drawing shows a display unit according to the invention, which in the case under consideration, as will become clear below, is designed as a liquid crystal display unit with a rotated nematic liquid crystal, without the invention being restricted thereto. The display unit 1 has a plurality of display segments or segments 2 which are transparent and thus normally do not stand out from their background unless they are excited, as is the case for the activated segments shown in dark in FIG 4 applies * As is clear from the cross-sections through the display unit 1 according to FIG. 1 shown in FIGS. 2 and 3, this display unit 1 has a transparent upper substrate 5, a lower substrate 6, which may or may not be transparent _e upper electrodes 7, lower electrodes 8, a spacer and sealing element 9 and a filling 10 made of liquid crystal material. If it is a nematic, twisted crystal material, the liquid crystal material of the display unit 1 requires the use of a front polarizer and a rear polarizer oriented perpendicular thereto (not shown), while a rear reflector (not shown) is required for a display unit operating with reflation. would be required taking these items

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November 20, 1978 -10-

however, are not the subject of the present invention. That Liquid crystal material of the filling 10 can be a nematic Liquid crystal material or a nematic liquid crystal mixture be, which or which has a positive dielectric anisotropy and in a known manner with respect to the upper or »front substrate 5 and the lower or rear substrate β is oriented so that there is a 90 ° rotation. With others However, types of display units according to the invention can instead of a filling 10 made of liquid crystal material, a completely different material can be provided, with the advantages of the invention can also be realized.

The spacing and sealing element 9 is often composed of a mixture of a sizing provided glass beads and a glass frit _r which is molten at a temperature lower than the melting temperature of the normally consisting of glass substrates 5 and β = The glass composition is determined using a Screen printing process applied, whereupon the glass frit according to the state of the art is vitrified by preheating »to enable handling. After further manufacturing steps, the substrates 5 and then heated together, so that the glass frit melts again and then vitrified, so that there is a spacing and sealing element between the substrates 5 and the sealingly connecting element Substrates at a distance from each other. The manufacturing steps, materials and processes explained above are known and do not form part of the present invention.

According to the invention is applied a plurality of Eiektrodenmustem on large serving as a substrate material glass plates, as Fig. 4a _R 4b, 5a and 5b show "Änschliessend be, v / dies ie FIGS. 5a, 6b and 10, to the glass plates

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for the upper and / or lower substrates 5,6 patterns from the Glass material applied for the spacer and sealing elements.

In detail, the rear or lower electrodes 8 form electrode arrangements of two electrode patterns connected to one another, as shown in FIG. 4a, the individual electrode arrangements, as shown in FIG. 4b, on a glass plate are arranged in horizontal and vertical rows and are preferably made using a photo-resist process will. Markings 11 determine the corners of the individual lower or rear substrates 6, which are divided by dividing the glass plate can be obtained. As shown in Figures 4a and 4b, each electrode array consists of a left electrode pattern and a right electrode pattern 13 connected to each other by a bridge 14 which is the connection line crosses between two markings 11. The well-known Photc-Resist process is preferably used to apply transparent, electrically conductive electrode coatings to the surface of a glass substrate to create. On the other hand, there is also the possibility of a prepared transparent coating to partially remove conductive material on the glass plate by etching so that the desired electrodes remain.

First, take the electrode assemblies with the patterns 12 and 13 and with the bridge 14 the position shown in FIG. 4b. The glass plate is then turned over, cut and broken, the individual rear substrates 6 being obtained by horizontal and vertical cutting lines, the through the markings 11. In this way, a large number of substantially identical back substrates become 6 obtained, in which a contact electrode, which is formed by the bridge 14, extends to an edge of the Substrate is enough.

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The upper and front electrodes are in a corresponding manner 7, as shown in FIGS. 5a and 5b, produced on a different glass plate, the markings 15, which after the Limit the division of the glass plate resulting individual front substrates 5. As Fig. 5a shows, form the front electro the segments with associated connecting cables. The front In FIG. 5 a, electrodes are arranged to form a left electrode pattern 16 and a right electrode pattern 17. Also is still a bridge electrode 18 is provided, which of a vertical Connection line between two markings 15 is cut. The bridge electrode 18 and the individual segments of the electrode patterns 16, 17 have contact areas 16a, 17a and 18a which extend to the edge of the finished substrate. The electrode patterns 16 and 17 and the bridge electrode 18 form one Electrode arrangement, with several such electrode arrangements on a common plate in the one shown in FIG. 5b are arranged in an obvious manner. The horizontal distance between the markings 11 on the one hand and the markings 15 on the other hand is the same. However, the vertical distance between the markings 15 is greater than that between the markings 11. The upper or front substrate 5 is thus wider so that the required overlap results and so that the contact areas 16a, 17a and 18a are freely accessible, as is clear from FIG. 3.

According to the invention, the material for the distance and Sealing elements in the manner shown in Fig. 6a and 6b applied to the Ciasplatte, from which the front substrates getting produced. As already mentioned, this material is preferably a mixture of a glass frit and glass beads predetermined size and is attached over the previously produced electrode patterns 16, 17 and the bridge element 18.

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A suitable glass frit is available from the company Methode Development Company, Chicago, Illinois, USA under the designation LC-200, Type A distributed. It goes without saying that the pattern of the material for the spacer and sealing elements 9 also on the glass plate for the lower substrates 6 could be attached above the electrode arrangements 12, 13, 14, as will be described further below will be explained in connection with FIG. Preferably, however, the glass frit (with the glass beads) is applied to the glass plate for the front substrates 5 applied, as in this case the control of the more complicated electrode holder of the front Electrodes can be done simultaneously with the control of the material pattern for the spacer and sealing elements. The glass frit is then vitrified by preheating to a temperature of about 250 ° C.

As Fig.6a shows, the glass material is applied to the electrodes provided glass plate applied so that there is a left pattern 19 and a right pattern 20 per substrate, wherein the patterns 18 and 20 each have a (in the drawing) substantially perpendicular extension 21 on v / iron, wherein both extensions 21 lie above a vertical line connecting two markings 15 to one another, and in fingers 21a end on opposite sides of the connecting line. In this way, an opening 22 results in the glass frit material along the dividing line for two adjacent substrates, which is designed so that after the connection between the front and rear substrates by means of the glass frit a converging channel 23 results which leads into the interior of the cavity between the substrates. The outer edges 24 of the patterns 19, 20, however, do not have a corresponding opening, but are widened so that in the widened area a cutting line can be laid to separate adjacent substrates.

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After applying the material sample for the distance and Sealing elements 9 over the electrode assemblies of the front electrodes and after the material has hardened by vitrification of the same in the manner described above, the plates shown in Figs. 5b and 6b can be cut or scored and broken to give a number of substantially identical front substrates 5. The scratching of the glass plate takes place on the back of the same along vertical and horizontal lines that are laid by markings 15. After the scoring, the glass plate along the scoring lines together with the vitrified hardened material pattern for the Spacer and sealing elements broken, resulting in clean edges for the individual substrates, and the glass material for the spacer and sealing elements exactly up to The edge of the substrate is sufficient and there lies essentially on the same plane as the breaking edge of the glass plate.

7 shows adjacent parts of two front substrates 5 during one of the manufacturing steps. You can see that £ about the designs 16 and 17 kit the connecting bridge elament 18, which constitute the front electrodes, the glass material patterns 19.20 are attached. It can also be seen that the glass plate has already broken along the horizontal lines. At the subsequent cracks and breaking of the glass plate strips the individual substrates 5 are then obtained, for which the shape shown in FIG. 7a results on one narrow side.

After the front and rear substrates have been completed in the manner described above, a front one is grounded and a back substrate placed on top of one another and aligned relative to one another, whereupon the glass material for the Spacer and sealing elements 9 is melted again and

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then solidified again and thereby a seal between the substrates forms. In this way, a cavity is obtained between the substrates, which is now through the opening 22 and the channel 23 can be filled with a liquid crystal material. Finally, the wall of the passage 22, 2 3 metallized by metal sputtering, whereupon the liquid crystal material is poured in. This is then followed by the sealing of the passage 22, 23 with a suitable material, for example a solder.

The cross section according to FIG. 8 shows a sealed one Display unit (partially) in which the spacer and sealing element 9 extends to the breaking edge of the substrates 5, 6 and is essentially in the same plane with them. Fig. 9 shows a partial cross-section through a sealed display unit according to the invention, which starting from the front substrates according to Fig. 7 and Fig. 7a was obtained. It can be seen that the bridge electrode 18 of the front substrate 5 and the bridge 14 of the rear substrate 6 extend exactly to the edge or to the breaking edge of the substrates 5, 6. One through The layer produced by metallization forms a conductive bridge between the bridge electrodes 14, 18 and facilitates attachment a Lötiuit te! seal 25.

The method according to the invention enables at least largely identical display units to be produced on a large scale Number of pieces using the photo-resist process and the Screen printing technology. The fact that the substrates have broken edges broken v / earth, on which both the glass material for the spacer and sealing elements as well as the electrode areas further facilitates the subsequent sealing of the individual display units as well as the production of the necessary electrical connections, with the cost of materials

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since there is practically no waste, it is reduced to a minimum.

While in the embodiment described above It is understood that the glass material is broken to obtain the passage 22, 23 in the area of the narrow sides of the substrates that the patterns 19, 20 of the glass material could also be placed in such a way that there are corresponding passages on the long sides of the display units.

As FIG. 10 shows, in an embodiment of the invention there is also the possibility of a pattern 30 made of glass material in this way on the To apply glass plate for the rear substrates 6 that the glass material the left electrode pattern 12 and the right Electrode grid 13 surrounds. If the glass plate according to FIG. 10 is then scored and along the lines running through the markings 11 If scratch lines are broken, then the glass material also extends again to the breaking edges of the rear substrates 6 and surrounds them (with the exception of the desired passage) along their entire perimeter, thereby creating even more savings of glass material allows grounding, namely when the rear substrates 6 are smaller than the front substrates 5.

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Claims (9)

DR, -IMG. DIPL-ING. M. SC. OI ^ L-PHYS. DR. DtPL-PHYS. ROGER - LEGAL RIGHT - GRIESSBACH - HAECKER PATENTANWÄLTE IN STUTTGART IOC 1 / / Λ zöb 144ο A 43 044 b Applicant: TIMEX CORPORATION! ^ November 1978 / f- WÄTERBÜRY, Conn. O672O, ÜSA patent claims: 1.1 Electro-optical display unit with a transparent front substrate and a rear substrate parallel to it, both of which consist of a frangible, each with a Material provided with an electrode pattern, and with a spacer and sealing material located between the substrates, which keeps the substrates at a distance from one another and connects them to one another in a sealing manner, characterized in that, that parts (14,18,21) of the electrode pattern (12,13,14; 16,17,18) and the spacer and sealing material (9,21,24) to at least one edge of the substrate material (5, 6) extends and there at least essentially in one plane with it lie. 2. Display unit according to claim 1, characterized in that the spacer and sealing material (9,21,24) is a frangible material and that the at least one edge of the substrate material (5,6) and the spacer and sealing material (9,21,24) lying in one plane through breakage edges are formed. 3. Display unit according to claim 2, characterized in that the spacer and sealing material (9,21,24) contains a glass frit and that the substrate material (5,6) is glass. 4. Method of manufacturing an electro-optical display unit according to one of claims 1 - 3, characterized by the following process steps: - ο - 909823/0 718 ORIGINAL INSPECTED November 20, 1978 -2- a) Place on a breakable substrate flat material an electrode pattern; b) the electrode pattern is placed on the flat material partially covering distance and. Sealant sample on; c) raan transfers the material of the spacer and sealing material sample in a frangible state; d) the substrate flat material is severed along at least one of the electrode pattern and the spacer and Sealant Pattern Crossing Line; e) one connects the spacer and sealing material pattern a severed section of the substrate flat material sealingly with an aligned parallel to the section second substrate. 5. The method according to claim 4, characterized in that a glass plate is used as the substrate flat material _r that a glass frit mixture is applied to the glass plate as a spacer and sealing material and that the glass frit mixture is converted into one by heating to an elevated temperature transferred glass-like state in which it is breakable. 6. The method according to claim 4, characterized in that one forms the spacing and sealing material pattern in such a way that that individual pattern areas are connected to one another via bridge areas. -3- 909823/0716 a 43 044 b 28h1446 November 20, 1978 -3- 7. The method according to claim 4, characterized in that the spacer and sealant pattern and the electrode pattern be designed in such a way that several, in particular among themselves, are located on a single piece of the substrate flat material essentially the same and each one display unit assigned, sample areas result. 8. The method according to claim 3, characterized in that the pattern areas of the spacer and sealing material pattern is designed in such a way that at an edge area of each display unit there is initially one that can be used as a filling opening Interruption of the spacer and seal material sample results. 9. The method according to claim 8, characterized in that for two adjacent pattern areas of the spacer and sealing material pattern a bridge area formed by a pair of asymmetrical fingers thereof is provided. 10. The method according to claim 3, characterized in that the Sever by tearing the substrate flechniciteriale and Caused breaking of the same along the torn lines. 11. Electro-optical display unit characterized by its production according to the method according to one of the claims 3 to 10. -A- 9 0 9 8 2 3 / π V 1 6