CA1105596A - Crossover connections for multiplexed electrooptic displays - Google Patents
Crossover connections for multiplexed electrooptic displaysInfo
- Publication number
- CA1105596A CA1105596A CA318,148A CA318148A CA1105596A CA 1105596 A CA1105596 A CA 1105596A CA 318148 A CA318148 A CA 318148A CA 1105596 A CA1105596 A CA 1105596A
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- Prior art keywords
- leads
- substrate
- electrode
- electro
- optic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1345—Conductors connecting electrodes to cell terminals
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1343—Electrodes
- G02F1/134309—Electrodes characterised by their geometrical arrangement
- G02F1/134327—Segmented, e.g. alpha numeric display
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- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Mathematical Physics (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Geometry (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
- Liquid Crystal (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A liquid crystal display cell has connections between front and back electrode leads on the front and back substrates made at the edge of the display by a metallization process applied to the ends of the leads. This permits multiple crossover connections to multiplexing electrodes on the back substrate to be made via multiple contact terminals on the front substrate
A liquid crystal display cell has connections between front and back electrode leads on the front and back substrates made at the edge of the display by a metallization process applied to the ends of the leads. This permits multiple crossover connections to multiplexing electrodes on the back substrate to be made via multiple contact terminals on the front substrate
Description
11(~5596 "CROSSOYER CONN[CTIONS FOR t`lUL1IPLEXED ELECTRO-OPTIC DISPLAYS"
BACr~GROUI~D OF TllE INVENTION
This invention relates to electro-optic display cells suitable for multiplexing, and r,lore particularly to multiple crossover connections between S the front and back electrodes on the display substrates. The invention is particularly described with reference to a liquid crystal display cell, but is not limited thereto.
Electro-optic display cells are known of the liquid crystal type (dynamic scattering, twisted nematic or pleochroic dye) colloidal light - 10 valve, electrochromic type (organic and inorganic), and electrophoretic.
These are all "passive" display systems and all have the cornmon feature of - employin~ a cell made up of two parallel substrates spaced a few mils apart - -- and sealed around the edges to form a chamber containing active electro-optic ~dterial. The f~ont substrate is always transparent and carries transparent - 15 electrodes in the form of segmented characters or numerals. The back substrate , -. - !
may or may not be transparent and also carries electrodes. The display is activated by applying a voltage between selected segments of the front and back electrodes on the respective substrates. Multiplexed displays require ; multiple connections via external contact terminals on the display.
!
¦I Previous constructions and methods for making displays have employed - , front and back substrate members with electrodes formed by etching, sputtering throunh a mask, photoresist or similar processes to form the individua1 segments and lead lines on the front and back substrate surfaces.
.'' i , 1, 1 i~'5~6 It is convenicnt, however, from a findl assembly standp~int to make external connections to the display on only one of the substrates. This is con~lonly done by extending the electrode lead lines to contact terminals which are exposed on an overhanying edge of the display outside of the seal. In non-multiplexed displays, or in diode-controlled switching displays such as shown in U.S. Patent 4,042,920 issued August 16, 1977 to Harsch et al, there n~y be only one back electrode or electrode on the back substrate which is co~lon to all the segments on the front substrate. However in the case of true multiplexed displays, numerous back electrodes are employed for each multi-segnlent character which are connected by lead lines to selected segments arranged to interact with selected segments on the front substrate, so that ~only one segment is common to two tenninals. In this case, multiple crossover connections are needed between the front and back electrodes in order to connect the hack electrode lcads to a plurality of contact tenminals on the front substrate. - - - ~
., .
i Conventional techniques of the prior art for making crossover connections ljhave employed application of a sr,lall quantity of a conducting paste on the - ~ Ifront sr back plate which bridges the space between the substrates. The conductive paste application involves additional processing steps, increases ,the problem in maintaining uniform spacing between substrates~ and may be disptaced or dislodged to break contact between front and back electrodes.
Acco dingly, one object of the present invention is to provide an improved crossover connection arrangement for Multiplexed electro-optic !~displays.
,, Another object of the invention is to provide an improved construction lfor interconnecting electrodes on front and back substrates of a liquid - crystal display.
!
I!
~i ~, DRAWI~GS
11C~5596 The invent on, both a~ tc crg~nizat;~n and method of practice, together with further objects and advantages thereof, will best be understood by reference to the following description, taken in ccnnection with the accompanying drawings, in which:
Figs. 1 and 2 are front and back plan views respectively of an electro-optic cell, Fig. 3 is an enlarged co~posite schematic diagram showing superimposed bottom and top electrode patte~ns for a portion of an electro-optic display cell, and Figs. 4, 5, and 6 are enlarged cross-section elevation drawings taken through a portion of the end of a display along lines IV-IY, V-Y and Vl-VI respectively of Fig. 3.
SUMMARY OF THE INVENTION
i 1~ Briefly stated, the invention is practised by providing in a multiplexing electro-optic display cell havingfirst and second spaced substrates, a sealing spacer member disposed around the periphery enclosing an electro-optic material and sealing between substrates, the improvement comprising:
a plurality of contact terminals disposed outside the spacer member on the first substrate, a plurality of electrode leads disposed on the second substrate connected to electrode areas and each having a terminating end portion extending to the edge of the second
BACr~GROUI~D OF TllE INVENTION
This invention relates to electro-optic display cells suitable for multiplexing, and r,lore particularly to multiple crossover connections between S the front and back electrodes on the display substrates. The invention is particularly described with reference to a liquid crystal display cell, but is not limited thereto.
Electro-optic display cells are known of the liquid crystal type (dynamic scattering, twisted nematic or pleochroic dye) colloidal light - 10 valve, electrochromic type (organic and inorganic), and electrophoretic.
These are all "passive" display systems and all have the cornmon feature of - employin~ a cell made up of two parallel substrates spaced a few mils apart - -- and sealed around the edges to form a chamber containing active electro-optic ~dterial. The f~ont substrate is always transparent and carries transparent - 15 electrodes in the form of segmented characters or numerals. The back substrate , -. - !
may or may not be transparent and also carries electrodes. The display is activated by applying a voltage between selected segments of the front and back electrodes on the respective substrates. Multiplexed displays require ; multiple connections via external contact terminals on the display.
!
¦I Previous constructions and methods for making displays have employed - , front and back substrate members with electrodes formed by etching, sputtering throunh a mask, photoresist or similar processes to form the individua1 segments and lead lines on the front and back substrate surfaces.
.'' i , 1, 1 i~'5~6 It is convenicnt, however, from a findl assembly standp~int to make external connections to the display on only one of the substrates. This is con~lonly done by extending the electrode lead lines to contact terminals which are exposed on an overhanying edge of the display outside of the seal. In non-multiplexed displays, or in diode-controlled switching displays such as shown in U.S. Patent 4,042,920 issued August 16, 1977 to Harsch et al, there n~y be only one back electrode or electrode on the back substrate which is co~lon to all the segments on the front substrate. However in the case of true multiplexed displays, numerous back electrodes are employed for each multi-segnlent character which are connected by lead lines to selected segments arranged to interact with selected segments on the front substrate, so that ~only one segment is common to two tenninals. In this case, multiple crossover connections are needed between the front and back electrodes in order to connect the hack electrode lcads to a plurality of contact tenminals on the front substrate. - - - ~
., .
i Conventional techniques of the prior art for making crossover connections ljhave employed application of a sr,lall quantity of a conducting paste on the - ~ Ifront sr back plate which bridges the space between the substrates. The conductive paste application involves additional processing steps, increases ,the problem in maintaining uniform spacing between substrates~ and may be disptaced or dislodged to break contact between front and back electrodes.
Acco dingly, one object of the present invention is to provide an improved crossover connection arrangement for Multiplexed electro-optic !~displays.
,, Another object of the invention is to provide an improved construction lfor interconnecting electrodes on front and back substrates of a liquid - crystal display.
!
I!
~i ~, DRAWI~GS
11C~5596 The invent on, both a~ tc crg~nizat;~n and method of practice, together with further objects and advantages thereof, will best be understood by reference to the following description, taken in ccnnection with the accompanying drawings, in which:
Figs. 1 and 2 are front and back plan views respectively of an electro-optic cell, Fig. 3 is an enlarged co~posite schematic diagram showing superimposed bottom and top electrode patte~ns for a portion of an electro-optic display cell, and Figs. 4, 5, and 6 are enlarged cross-section elevation drawings taken through a portion of the end of a display along lines IV-IY, V-Y and Vl-VI respectively of Fig. 3.
SUMMARY OF THE INVENTION
i 1~ Briefly stated, the invention is practised by providing in a multiplexing electro-optic display cell havingfirst and second spaced substrates, a sealing spacer member disposed around the periphery enclosing an electro-optic material and sealing between substrates, the improvement comprising:
a plurality of contact terminals disposed outside the spacer member on the first substrate, a plurality of electrode leads disposed on the second substrate connected to electrode areas and each having a terminating end portion extending to the edge of the second
2~ substrate, I
a plurality of crossover leads disposed on the first substrate connected to said contact terminals and each having a terminating end portion adjacent the electrode lead terminating end portion, and, metallized conductive layers applied between the respective pairs of terminating end portions to form a plurality of electrical connections therebetween.
I
ll(~SS96 There is also provided in a multiplexing electro-optic display cell having first and second parallel spaced substrates, a sealing spacer member disposed around the periphery enclosing an electro-optic material and sealing between substrates, the improvement comprising:
a plurality of first electrode leads connected to a plurality of first electrode areas on the first substrate, and a plurality of second electrode leads connected to a plurality of second electrode areas on the second substrate, said first and second areas defining between them a plurality of actuatable electro-optic segments, a plurality of cross-over leads disposed on the first substrate, a plurality of first and second contact terminals disposed outside said sealing spacer member along the same edge of the first substrate, said first leads being connected to the second contact terminals, said crossover leads and said second leads having respective terminating end portions extending to the ends of the first and second substrates respectively and disposed adjacent one another, and metallized conductive layers applied between the respective pairs of terminating end portions of the crossover leads and the second leads to form electrical connections therebetween.
There is fu,rther provided a liquid crystal display cell adapted for multiplexing the segments of a multi segment character and having first and second spaced substrates with a sealing spacer member disposed around the periphery and enclosing liquid crystal material between substrates, said first substrate having a plurality of first electrode leads connected to a plurality of first electrode areas, each of said first electrode areas covering t~Jo or more of said electro-optic segments, said second substrate having a plurality of second electrode leads connected to a plurality of second electrode areas, each of said second electrode areas - 4a -S9~;
covering two or more of said electro optic segments, each of the first and second areas only including together between them a single electro optic segment, a plurality of crossover leads disposed on the first substrate, a plurality of first and second contact terminals disposed outside said sealing spacer member along the same edge of the first substrate, said first leads being connected to the second contact terminals, said crossover leads and said second leads having respective terminating end portions extending to the ends of the first and second substrates respectively and disposed adjacent one another, and metallized conductive layers applied between the respective pairs of terminating end portions of the crossover leads and the second leads to form electrical connections therebetween.
'`~'~h' ,~ _ " .
11~5596 DESCRIPTlON OF T~E rR~FCRR[D ~I~lr,O~IIlE~JT
Referring first to Figs. 1 and 2 of the drawing, the front and back sides respectively of a liquid crystal display 1 are shown. A plurality of energizeable segments 2 making up the multi-segment characters, such as digits are arranged for actuation via multiplexing circuitry in a manner known in the art, via the contact terminals 3a, 3b, exposed on the lower side of a front substrate 4. A selected electro-optic segment is actuated by an electric potential of sufficient magnitude applied between one of the back segment $erminals 3a and one of the front segment terminals 3b. Polarizer layers enable the actuated seyment to appear dark against a light background.
Since the terminals 3a are located on the front substrate and since the actuating electrodes to which they are connected are located on the back substrate 5j electrical connections are necessary to make a crossover between substrates. The present invention is concerned with making crossover connections between terminals 3a and the electrodes on the back substrate in a multiplexing.display.
- Referring now to Fig. 3 of the drawing, the electrode patterns for front and back substrates are shown in schemati~ fashion superimposed over one another near the end of the display depicted in Figs. 1 and 2 for one multi-segment character. The actuatable segments are defined within the areas a - g. Upper glass substrate is indicated at 4. Below it is a back glass substrate ~ of the same length but of a lesser width and offset along one edge, as indicated by the heavy dashed line. (see also Figs. 1 and 2). ~, The substrates are disposed parallel to o~e another and separated by a fusible glass frit seal 6~ which is only a few mils in thickness. The frit may be offset from the edges of the substrates, as indicated at 7. The frit is also configured to provide an opening 8 for filling the display with liquid crystal material and subsequently sealing with a plug of solder 9.
11~5596 First el~ctrode areas on the underside of the front or first substrate are indicated by light dotted lines, while second electrode areas on the top surface of the bottom or second substrate are indicated by light full lines.
Coincidence of a first or front electrode area and a second or back electrode area defines segments a - 9. When the proper potential is applied to the respective electrode areas via the electrode leads running to terminals on the outside of the display, a segment a, b . . . g is actuated and becomes visible.
First, on the underside of the top substrate are a plurality of first electrode leads indicated by light dashed lines. A lead 16 is connected at one end to the electrode area common to segments e, f and at the other end to one of the external contact terminals 3b. Similarly, lead 17 is connected to the electrode area common to segments a, 9, d. Electrode lead 18 is connected to a front electrode area common to segments b, c.
.
' Turning now to the back substrate, there are three "second" electrode areas supplied by second electrode l~ads. A back electrode lead 10 is connected to areas common to segments a, b, and f a lead extension 11 supplying the 'same common segments (not sho~m) for subsequent digits located else~here il on the display.
,, Similarly, lead 12 is connected to back electrode areas common to segments e, 9 and lead extension 13 supplies the same segments on adjacent Idigits (not shown). Similarly, lead 14 is connected to back electrode areas ,common to segments c, d the extension lead 1~ to adjacent digits. Thus a - tirsta~dasecond electrode area overlap to define only a single segment between ,them, eg. the area connected to lead 10 and the area connected to lead 16 overlap only in segment f for multiplexing.
The terminating ends lOa, 12a, 14a of the back electrode leads 10, 12, 14 extend to the end of the display. ln the case of terminating ends lOa, 14a, they ~re located outsidc of the glass frit seal. Term;nating end 12a is located within the filling opening 8 in the frit.
The opening 8 in the glass frit seal may be closed after final assembly by a solder plug. In order to allow the solder to adhere, one known practice involves a metallization layer applied around the walls of the opening. An exar~ple of this is seen in U.S. Patent 4,037,930 issued to Matsuyama et al on July 26, 1977. - This patent shows a metallized layer for improving the reliability of the solder plug without recognizing the possible additional function of the metallized layer as contemplated by the present invention.
In accordance with another aspect of the present invention, there are also disposed on the underside of the top or first substrate a plurality of crossover leads 19, 20, 21. One end of each of the crossover electrode leads is connected to a respective external terminal 3a on one edge of the substrate. The other end of each of the crossover electrode leads 19, 20, 21 extends out to a different edge of the substrate so as to form the terminating ends l9a, 20a, 21a. The respective terminating end portions of the lOa, 12a, ;14a of the prevîously mentioned back leads are adjacent to and aligned with the respective terminating end portions of l9a, 2ûa, 21a of the crossover leads.
I~ Referring now to the cross-sections of Figs. 4, 5 and 6 of the drawing, tlle upper and lower substrates 4, ~ are shown in cross-section to be disposed parallel to one another and filled with liquid crystal material 22. Fig. 4 ~j~s a cross-section through a portion of the display encompassing lead 10 - land crossover lead lg. The teminating end portions l9a, lOa, are electrically ~, connected to one another on the outside of the glass frit seal 6 via one or n~ore conductive metal layers 23 applied in a manner to be described later.
Althouyh increased surface area for metallizing can be obtained by the offset due to a recessed seal, this is not an essential feature. ~he ~etallizing technique can serve to electrically connect the leads even through the very small cross-section at the end of the electrode.
Fig. 5 is a cross-section throuyh the display in the vicinity of opening ~ in the 91dSS frit, also showing the lead 12 and the crossover lead 20.
Extending portions 20a, l~a are electrically connected by a metalli2ed layer or layers 23 applied in a manner to be described later, which also coats the vicinity around the glass frit seal. After filling the interior of the display with liquid crystal material, a solder plug 9 is applied to seal the opening.
Fig. 6 depicts a cross-section through the terminals 3a and the terminals 3b, both sets of terminals being disposed on the underside of the top substrate 4 as previously described.
The metallization technique to provide the conductive layer or layers - 23 is preferably applied by sputtering or evaporating a layer of titanium, followed by a layer of platinum or palladium, followed by a layer o, gold.
Other suitable metallizing techn;ques or applications of other types of t5 conductive layers may also be employed. Soldering can be applied to inlprove the reliability of the electrical connection, and of course at the location depicted in Fig. 5, a solder plug is necessary to seal the opening.
.~ . I
While the invention has been particularly described for a liquid crystal display, it is applicable to any type of electro-optic display which employs two substrates with electrodes thereon and spaced from one another for actuatingmultiplexed segments common to front and back electrodes. Although the invention has been described with particular reference to three common -' back electrodes with three corresponding crossover electrodes, it is applicable to any number of multiplexing arrangements for numerals, alphabetical characters or other display indicia.
; i ~l~S5g~
h'hile there has been described herein what is considered to be the preferred enlbodiment of the invention other modifications will occur to those skilled in the art and it is desired to include in the appended claims all such modifications as fall within the true spirit and scope of the invention.
,. . !
"
,. ' .
., i.
., - i
a plurality of crossover leads disposed on the first substrate connected to said contact terminals and each having a terminating end portion adjacent the electrode lead terminating end portion, and, metallized conductive layers applied between the respective pairs of terminating end portions to form a plurality of electrical connections therebetween.
I
ll(~SS96 There is also provided in a multiplexing electro-optic display cell having first and second parallel spaced substrates, a sealing spacer member disposed around the periphery enclosing an electro-optic material and sealing between substrates, the improvement comprising:
a plurality of first electrode leads connected to a plurality of first electrode areas on the first substrate, and a plurality of second electrode leads connected to a plurality of second electrode areas on the second substrate, said first and second areas defining between them a plurality of actuatable electro-optic segments, a plurality of cross-over leads disposed on the first substrate, a plurality of first and second contact terminals disposed outside said sealing spacer member along the same edge of the first substrate, said first leads being connected to the second contact terminals, said crossover leads and said second leads having respective terminating end portions extending to the ends of the first and second substrates respectively and disposed adjacent one another, and metallized conductive layers applied between the respective pairs of terminating end portions of the crossover leads and the second leads to form electrical connections therebetween.
There is fu,rther provided a liquid crystal display cell adapted for multiplexing the segments of a multi segment character and having first and second spaced substrates with a sealing spacer member disposed around the periphery and enclosing liquid crystal material between substrates, said first substrate having a plurality of first electrode leads connected to a plurality of first electrode areas, each of said first electrode areas covering t~Jo or more of said electro-optic segments, said second substrate having a plurality of second electrode leads connected to a plurality of second electrode areas, each of said second electrode areas - 4a -S9~;
covering two or more of said electro optic segments, each of the first and second areas only including together between them a single electro optic segment, a plurality of crossover leads disposed on the first substrate, a plurality of first and second contact terminals disposed outside said sealing spacer member along the same edge of the first substrate, said first leads being connected to the second contact terminals, said crossover leads and said second leads having respective terminating end portions extending to the ends of the first and second substrates respectively and disposed adjacent one another, and metallized conductive layers applied between the respective pairs of terminating end portions of the crossover leads and the second leads to form electrical connections therebetween.
'`~'~h' ,~ _ " .
11~5596 DESCRIPTlON OF T~E rR~FCRR[D ~I~lr,O~IIlE~JT
Referring first to Figs. 1 and 2 of the drawing, the front and back sides respectively of a liquid crystal display 1 are shown. A plurality of energizeable segments 2 making up the multi-segment characters, such as digits are arranged for actuation via multiplexing circuitry in a manner known in the art, via the contact terminals 3a, 3b, exposed on the lower side of a front substrate 4. A selected electro-optic segment is actuated by an electric potential of sufficient magnitude applied between one of the back segment $erminals 3a and one of the front segment terminals 3b. Polarizer layers enable the actuated seyment to appear dark against a light background.
Since the terminals 3a are located on the front substrate and since the actuating electrodes to which they are connected are located on the back substrate 5j electrical connections are necessary to make a crossover between substrates. The present invention is concerned with making crossover connections between terminals 3a and the electrodes on the back substrate in a multiplexing.display.
- Referring now to Fig. 3 of the drawing, the electrode patterns for front and back substrates are shown in schemati~ fashion superimposed over one another near the end of the display depicted in Figs. 1 and 2 for one multi-segment character. The actuatable segments are defined within the areas a - g. Upper glass substrate is indicated at 4. Below it is a back glass substrate ~ of the same length but of a lesser width and offset along one edge, as indicated by the heavy dashed line. (see also Figs. 1 and 2). ~, The substrates are disposed parallel to o~e another and separated by a fusible glass frit seal 6~ which is only a few mils in thickness. The frit may be offset from the edges of the substrates, as indicated at 7. The frit is also configured to provide an opening 8 for filling the display with liquid crystal material and subsequently sealing with a plug of solder 9.
11~5596 First el~ctrode areas on the underside of the front or first substrate are indicated by light dotted lines, while second electrode areas on the top surface of the bottom or second substrate are indicated by light full lines.
Coincidence of a first or front electrode area and a second or back electrode area defines segments a - 9. When the proper potential is applied to the respective electrode areas via the electrode leads running to terminals on the outside of the display, a segment a, b . . . g is actuated and becomes visible.
First, on the underside of the top substrate are a plurality of first electrode leads indicated by light dashed lines. A lead 16 is connected at one end to the electrode area common to segments e, f and at the other end to one of the external contact terminals 3b. Similarly, lead 17 is connected to the electrode area common to segments a, 9, d. Electrode lead 18 is connected to a front electrode area common to segments b, c.
.
' Turning now to the back substrate, there are three "second" electrode areas supplied by second electrode l~ads. A back electrode lead 10 is connected to areas common to segments a, b, and f a lead extension 11 supplying the 'same common segments (not sho~m) for subsequent digits located else~here il on the display.
,, Similarly, lead 12 is connected to back electrode areas common to segments e, 9 and lead extension 13 supplies the same segments on adjacent Idigits (not shown). Similarly, lead 14 is connected to back electrode areas ,common to segments c, d the extension lead 1~ to adjacent digits. Thus a - tirsta~dasecond electrode area overlap to define only a single segment between ,them, eg. the area connected to lead 10 and the area connected to lead 16 overlap only in segment f for multiplexing.
The terminating ends lOa, 12a, 14a of the back electrode leads 10, 12, 14 extend to the end of the display. ln the case of terminating ends lOa, 14a, they ~re located outsidc of the glass frit seal. Term;nating end 12a is located within the filling opening 8 in the frit.
The opening 8 in the glass frit seal may be closed after final assembly by a solder plug. In order to allow the solder to adhere, one known practice involves a metallization layer applied around the walls of the opening. An exar~ple of this is seen in U.S. Patent 4,037,930 issued to Matsuyama et al on July 26, 1977. - This patent shows a metallized layer for improving the reliability of the solder plug without recognizing the possible additional function of the metallized layer as contemplated by the present invention.
In accordance with another aspect of the present invention, there are also disposed on the underside of the top or first substrate a plurality of crossover leads 19, 20, 21. One end of each of the crossover electrode leads is connected to a respective external terminal 3a on one edge of the substrate. The other end of each of the crossover electrode leads 19, 20, 21 extends out to a different edge of the substrate so as to form the terminating ends l9a, 20a, 21a. The respective terminating end portions of the lOa, 12a, ;14a of the prevîously mentioned back leads are adjacent to and aligned with the respective terminating end portions of l9a, 2ûa, 21a of the crossover leads.
I~ Referring now to the cross-sections of Figs. 4, 5 and 6 of the drawing, tlle upper and lower substrates 4, ~ are shown in cross-section to be disposed parallel to one another and filled with liquid crystal material 22. Fig. 4 ~j~s a cross-section through a portion of the display encompassing lead 10 - land crossover lead lg. The teminating end portions l9a, lOa, are electrically ~, connected to one another on the outside of the glass frit seal 6 via one or n~ore conductive metal layers 23 applied in a manner to be described later.
Althouyh increased surface area for metallizing can be obtained by the offset due to a recessed seal, this is not an essential feature. ~he ~etallizing technique can serve to electrically connect the leads even through the very small cross-section at the end of the electrode.
Fig. 5 is a cross-section throuyh the display in the vicinity of opening ~ in the 91dSS frit, also showing the lead 12 and the crossover lead 20.
Extending portions 20a, l~a are electrically connected by a metalli2ed layer or layers 23 applied in a manner to be described later, which also coats the vicinity around the glass frit seal. After filling the interior of the display with liquid crystal material, a solder plug 9 is applied to seal the opening.
Fig. 6 depicts a cross-section through the terminals 3a and the terminals 3b, both sets of terminals being disposed on the underside of the top substrate 4 as previously described.
The metallization technique to provide the conductive layer or layers - 23 is preferably applied by sputtering or evaporating a layer of titanium, followed by a layer of platinum or palladium, followed by a layer o, gold.
Other suitable metallizing techn;ques or applications of other types of t5 conductive layers may also be employed. Soldering can be applied to inlprove the reliability of the electrical connection, and of course at the location depicted in Fig. 5, a solder plug is necessary to seal the opening.
.~ . I
While the invention has been particularly described for a liquid crystal display, it is applicable to any type of electro-optic display which employs two substrates with electrodes thereon and spaced from one another for actuatingmultiplexed segments common to front and back electrodes. Although the invention has been described with particular reference to three common -' back electrodes with three corresponding crossover electrodes, it is applicable to any number of multiplexing arrangements for numerals, alphabetical characters or other display indicia.
; i ~l~S5g~
h'hile there has been described herein what is considered to be the preferred enlbodiment of the invention other modifications will occur to those skilled in the art and it is desired to include in the appended claims all such modifications as fall within the true spirit and scope of the invention.
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"
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., i.
., - i
Claims (6)
1. In a multiplexing electro-optic display cell having first and second spaced substrates, a sealing spacer member disposed around the periphery enclosing an electro-optic material and sealing between substrates, the improvement comprising:
a plurality of contact terminals disposed outside the spacer member on the first substrate, a plurality of electrode leads disposed on the second substrate connected to electrode areas and each having a terminating portion extending to the edge of the second substrate, a plurality of crossover leads disposed on the first substrate connected to said contact terminals and each having a terminating end portion adjacent the electrode lead terminating end portion, and, metallized conductive layers applied between the respective pairs of terminating end portions to form a plurality of electrical connections therebetween.
a plurality of contact terminals disposed outside the spacer member on the first substrate, a plurality of electrode leads disposed on the second substrate connected to electrode areas and each having a terminating portion extending to the edge of the second substrate, a plurality of crossover leads disposed on the first substrate connected to said contact terminals and each having a terminating end portion adjacent the electrode lead terminating end portion, and, metallized conductive layers applied between the respective pairs of terminating end portions to form a plurality of electrical connections therebetween.
2. In a multiplexing electro-optic display cell having first and second parallel spaced substrates, a sealing spacer member disposed around the periphery enclosing an electro-optic material and sealing between said substrates, the improvement comprising:
a plurality of first electrode leads connected to a plurality of first electrode areas on the first substrate, and a plurality of second electrode leads connected to a plurality of second electrode areas on the second substrate, said first and second areas defining between them a plurality of actuatable electro-optic segments, a plurality of cross-over leads disposed on the first substrate, a plurality of first and second contact terminals disposed outside said sealing spacer member along the same edge of the first substrate, said first leads being connected to the second contact terminals, said crossover leads and said second leads having respective terminating end portions extending to the ends of the first and second substrates respectively and disposed adjacent one another, and metallized conductive layers applied between the respective pairs of terminating end portions of the crossover leads and the second leads to form electrical connections therebetween.
a plurality of first electrode leads connected to a plurality of first electrode areas on the first substrate, and a plurality of second electrode leads connected to a plurality of second electrode areas on the second substrate, said first and second areas defining between them a plurality of actuatable electro-optic segments, a plurality of cross-over leads disposed on the first substrate, a plurality of first and second contact terminals disposed outside said sealing spacer member along the same edge of the first substrate, said first leads being connected to the second contact terminals, said crossover leads and said second leads having respective terminating end portions extending to the ends of the first and second substrates respectively and disposed adjacent one another, and metallized conductive layers applied between the respective pairs of terminating end portions of the crossover leads and the second leads to form electrical connections therebetween.
3. The electro-optic display according to claim 2, wherein said first electrode areas and said second electrode areas overlap to define a single electro-optic segment between them.
4. The electro-optic display according to claim 2, wherein said crossover leads have opposite ends disposed outside the sealing spacer member on different edges of the first substrate.
5. A liquid crystal display cell adapted for multiplexing the segments of a multi segment character and having first and second spaced substrates with a sealing spacer member disposed around the periphery and enclosing liquid crystal material between substrates, said first substrate having a plurality of first electrode leads connected to a plurality of first electrode areas, each of said first electrode areas covering two or more of said electro-optic segments, said second substrate having a plurality of second electrode leads connected to a plurality of second electrode areas, each of said second electrode areas covering two or more of said electro optic segments, each of the first and second areas only including together between them a single electro optic segment, a plurality of crossover leads disposed on the first substrate, a plurality of first and second contact terminals disposed outside said sealing spacer member along the same edge of the first substrate, said first leads being connected to the second contact terminals, said crossover leads and said second leads having respective terminating end portions extending to the ends of the first and second substrates respectively and disposed adjacent one another, and metallized conductive layers applied between the respective pairs of terminating end portions of the crossover leads and the second leads to form electrical connections therebetween.
6. The display according to claim 5 wherein said metallized layers comprise three successively applied layers of titanium, platinum or palladium and gold.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US87345278A | 1978-01-30 | 1978-01-30 | |
| US873,452 | 1978-01-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1105596A true CA1105596A (en) | 1981-07-21 |
Family
ID=25361667
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA318,148A Expired CA1105596A (en) | 1978-01-30 | 1978-12-18 | Crossover connections for multiplexed electrooptic displays |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS54116897A (en) |
| AU (1) | AU522879B2 (en) |
| CA (1) | CA1105596A (en) |
| DE (1) | DE2903110A1 (en) |
| FR (1) | FR2415852A1 (en) |
| GB (1) | GB2013385B (en) |
| HK (1) | HK4283A (en) |
| MX (1) | MX4383E (en) |
| PT (1) | PT69080A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4386350A (en) * | 1979-06-26 | 1983-05-31 | Nippon Electric Co., Ltd. | Display apparatus |
| DE3049093A1 (en) * | 1980-12-24 | 1982-07-29 | SWF-Spezialfabrik für Autozubehör Gustav Rau GmbH, 7120 Bietigheim-Bissingen | ELECTRO-OPTICAL DISPLAY ELEMENT AND METHOD FOR THE PRODUCTION THEREOF |
| DE4113901A1 (en) * | 1991-04-27 | 1992-10-29 | Krone Ag | MODULAR DISPLAY DEVICE MADE FROM LIQUID CRYSTAL CELLS |
-
1978
- 1978-12-18 CA CA318,148A patent/CA1105596A/en not_active Expired
- 1978-12-18 GB GB7848875A patent/GB2013385B/en not_active Expired
- 1978-12-29 AU AU42980/78A patent/AU522879B2/en not_active Expired
-
1979
- 1979-01-16 JP JP382579A patent/JPS54116897A/en active Pending
- 1979-01-16 PT PT6908079A patent/PT69080A/en unknown
- 1979-01-27 DE DE19792903110 patent/DE2903110A1/en not_active Withdrawn
- 1979-01-29 MX MX10069079U patent/MX4383E/en unknown
- 1979-01-30 FR FR7902352A patent/FR2415852A1/en active Granted
-
1983
- 1983-01-27 HK HK4283A patent/HK4283A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| PT69080A (en) | 1979-02-01 |
| DE2903110A1 (en) | 1979-08-09 |
| FR2415852B3 (en) | 1981-11-13 |
| GB2013385B (en) | 1982-02-24 |
| FR2415852A1 (en) | 1979-08-24 |
| JPS54116897A (en) | 1979-09-11 |
| AU522879B2 (en) | 1982-07-01 |
| MX4383E (en) | 1982-04-20 |
| AU4298078A (en) | 1979-08-09 |
| HK4283A (en) | 1983-01-27 |
| GB2013385A (en) | 1979-08-08 |
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