CA2120699C - Electrode structure for an electrophoretic display apparatus - Google Patents
Electrode structure for an electrophoretic display apparatusInfo
- Publication number
- CA2120699C CA2120699C CA002120699A CA2120699A CA2120699C CA 2120699 C CA2120699 C CA 2120699C CA 002120699 A CA002120699 A CA 002120699A CA 2120699 A CA2120699 A CA 2120699A CA 2120699 C CA2120699 C CA 2120699C
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- Canada
- Prior art keywords
- line
- lines
- character
- anode
- conductors
- 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 - Fee Related
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Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3433—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices
- G09G3/344—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices based on particles moving in a fluid or in a gas, e.g. electrophoretic devices
- G09G3/3446—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices based on particles moving in a fluid or in a gas, e.g. electrophoretic devices with more than two electrodes controlling the modulating element
-
- 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
- G02F1/165—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 translational movement of particles in a fluid under the influence of an applied field
- G02F1/166—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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect
- G02F1/167—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 translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2310/00—Command of the display device
- G09G2310/06—Details of flat display driving waveforms
- G09G2310/061—Details of flat display driving waveforms for resetting or blanking
Abstract
Anode electrode structure (12) for a display such as an electrophoretic display panel. An anode electrode structure (12) which is fabricated in accordance with the present invention includes a multipli city of anode line segments (2), (7), (13) and (18 wherein each anode line segment comprises at least a first and a second conducto r. An embodiment of the inventive anode electrode structure (12) enables a selective erase operation of a line (8) in a display wi thout partial erasure of adjacent lines (3), (14). (19).
Description
21206~9 Electrode Structure For An Electrophoretic DisplaY Apparatus DescriPtion Technical Field The present invention relates to a segmented type anode electrode for an electrophoretic display and, in particular, to an anode electrode for use in fabricating a flat panel display such as an electrophoretic display panel.
Background Art Electrophoretic displays are known which incorporate a plurality of parallel cathode lines and a plurality of transverse grid lines insulated from the cathode lines. The cathodes and grids are referred to as rows and columns and the terms can be interchanged.
The grid cathode structure forms an X-Y matrix enabling one to address the display at each X-Y intersection to enable pigment particles to migrate to the anode electrode. Such electrophoretic displays have been the subject matter of other prior art patents and essentially the assignee herein, namely CopyTele, Inc.
of Huntington Station, New York, has developed many such displays as well as operating techniques for such displays.
As is well known to those of ordinary skill in the art, a display is formed in an electrophoretic display panel as a result of movement of electrically charged particles that are suspended in a fluid which is disposed within a panel structure, which panel structure supports the row and column electrodes and the anode electrode structure. The movement of the electrically charged particles is caused by applying potentials to predetermined intersections of the row and column electrodes and to the anode electrode structure to provide predetermined electric fields. As described in U.S.
Patent No. 4,655,897, entitled "Electrophoretic Display Panels and Associated Methods", issued on April 7, 1987 and in U.S. Patent No. 4,850,819, entitled "Electrophoretic Display Panel Apparatus and Methods Therefor", issued on July 25, 1989, a typical 8.5" x 11" electrophoretic display panel having a resolution of 200 lines per inch comprises approximately 2200 cathode or row electrodes, approximately 1700 grid or column electrodes, and an overlying anode electrode structure.
There is an anode electrode structure which comprises conductor strips instead of a solid thin layer of ITO. This anode structure is described in a copending application entitled DUAL ANODE FLAT PANEL ELECTROPHORETIC
DISPLAY, filed on May 1, 1989, Serial No. 345,825 to Frank J. DiSanto and Denis A. Krusos and assigned to CopyTele, Inc., the assignee herein, which is now U.S. Patent 5,053,763, issued on October 1, 1991. In an electrophoretic display panel which is used to display characters, characters are formed utilizing a predetermined number of such anode conductor strips in a group, the predetermined number of anode conductor strips being referred to as a character line and each of the predetermined number of anode conductor strips in the character line being referred to as an anode line segment. For example, in a typical such electrophoretic display panel, a character line is comprised of 26 anode line segments, each of which is approximately .125" wide and each of which is spaced approximately .001"
from adjacent segments.
As is well known to those of ordinary skill W093t07608 212 0 6 9 9 PCT/US91/07161 in the art, an entire electrophoretic display panel which is fabricated in accordance with the prior art described above can be erased by applying a negative voltage to all of the anode line segments in the anode electrode structure. In addition, to provide a "hold"
mode of operation or a "write" mode of operation, which modes of operation are described in the U.S. patents identified above, a positive voltage is applied to all the anode line segments in the anode electrode structure. Further in addition, a "selective" erase operation of a multiplicity of character lines, each of which comprises a multiplicity of anode line segments, is achieved by applying a negative voltage to the anode line segments which comprise each of the selected character lines. However, when the above-described "selective" erase operation in such an electrophoretic display panel is utilized to erase a single character line by applying a negative voltage to the anode line segments for the selected character line, a part of adjacent character lines on either side of the selected character line are also erased. Although such partial erasure also occurs when a multiplicity of character lines are erased, partial erasure is particularly unacceptable when few character lines are erased because it produces a display which is illegible and hard to read.
In general, notwithstanding that movement of particles in the electrophoretic display panel is almost perpendicular to the anode and cathode surfaces, some inherent spreading occurs. We have discovered that this inherent spreading causes the above-described erasure of parts of character lines which are adjacent to a character line which is to be erased. Further, we have discovered that such partial erasure of adjacent character lines can be eliminated if the spacing between adjacent anode line segments is increased.
However, such a solution is unsatisfactory because the amount of spacing which is required to eliminate the partial erasure is so large that the line structure of the display becomes noticeable to a viewer. The increased spacing also affects resolution as one could not achieve 200 lines per inch without proper line spacing.
As a result of the above, there is a need in the art for an anode electrode structure for a display and, in particular, for an electrophoretic display panel which provides selective erasure of lines without partial erasure of adjacent lines.
Disclosure of the Invention Embodiments of the present invention advantageously solve the above-identified need in the art by providing an anode electrode structure for a display and, in particular, for an electrophoretic display panel which provides selective erasure of a line without partial erasure of adjacent lines.
An embodiment of the present invention is an anode electrode structure which is comprised of a multiplicity of anode line segments wherein each anode line segment comprises at least a first and a second conductor. In a preferred embodiment of the present invention, the first conductor is larger than the second conductor and the inventive anode electrode structure is applied to an electrophoretic display.
One provides a full panel erase operation in an electrophoretic display panel fabricated using an embodiment of the present invention by applying a negative voltage to all anode line segments in the display panel, i.e., to the first and second conductor of each anode line segment. Further, with such a
Background Art Electrophoretic displays are known which incorporate a plurality of parallel cathode lines and a plurality of transverse grid lines insulated from the cathode lines. The cathodes and grids are referred to as rows and columns and the terms can be interchanged.
The grid cathode structure forms an X-Y matrix enabling one to address the display at each X-Y intersection to enable pigment particles to migrate to the anode electrode. Such electrophoretic displays have been the subject matter of other prior art patents and essentially the assignee herein, namely CopyTele, Inc.
of Huntington Station, New York, has developed many such displays as well as operating techniques for such displays.
As is well known to those of ordinary skill in the art, a display is formed in an electrophoretic display panel as a result of movement of electrically charged particles that are suspended in a fluid which is disposed within a panel structure, which panel structure supports the row and column electrodes and the anode electrode structure. The movement of the electrically charged particles is caused by applying potentials to predetermined intersections of the row and column electrodes and to the anode electrode structure to provide predetermined electric fields. As described in U.S.
Patent No. 4,655,897, entitled "Electrophoretic Display Panels and Associated Methods", issued on April 7, 1987 and in U.S. Patent No. 4,850,819, entitled "Electrophoretic Display Panel Apparatus and Methods Therefor", issued on July 25, 1989, a typical 8.5" x 11" electrophoretic display panel having a resolution of 200 lines per inch comprises approximately 2200 cathode or row electrodes, approximately 1700 grid or column electrodes, and an overlying anode electrode structure.
There is an anode electrode structure which comprises conductor strips instead of a solid thin layer of ITO. This anode structure is described in a copending application entitled DUAL ANODE FLAT PANEL ELECTROPHORETIC
DISPLAY, filed on May 1, 1989, Serial No. 345,825 to Frank J. DiSanto and Denis A. Krusos and assigned to CopyTele, Inc., the assignee herein, which is now U.S. Patent 5,053,763, issued on October 1, 1991. In an electrophoretic display panel which is used to display characters, characters are formed utilizing a predetermined number of such anode conductor strips in a group, the predetermined number of anode conductor strips being referred to as a character line and each of the predetermined number of anode conductor strips in the character line being referred to as an anode line segment. For example, in a typical such electrophoretic display panel, a character line is comprised of 26 anode line segments, each of which is approximately .125" wide and each of which is spaced approximately .001"
from adjacent segments.
As is well known to those of ordinary skill W093t07608 212 0 6 9 9 PCT/US91/07161 in the art, an entire electrophoretic display panel which is fabricated in accordance with the prior art described above can be erased by applying a negative voltage to all of the anode line segments in the anode electrode structure. In addition, to provide a "hold"
mode of operation or a "write" mode of operation, which modes of operation are described in the U.S. patents identified above, a positive voltage is applied to all the anode line segments in the anode electrode structure. Further in addition, a "selective" erase operation of a multiplicity of character lines, each of which comprises a multiplicity of anode line segments, is achieved by applying a negative voltage to the anode line segments which comprise each of the selected character lines. However, when the above-described "selective" erase operation in such an electrophoretic display panel is utilized to erase a single character line by applying a negative voltage to the anode line segments for the selected character line, a part of adjacent character lines on either side of the selected character line are also erased. Although such partial erasure also occurs when a multiplicity of character lines are erased, partial erasure is particularly unacceptable when few character lines are erased because it produces a display which is illegible and hard to read.
In general, notwithstanding that movement of particles in the electrophoretic display panel is almost perpendicular to the anode and cathode surfaces, some inherent spreading occurs. We have discovered that this inherent spreading causes the above-described erasure of parts of character lines which are adjacent to a character line which is to be erased. Further, we have discovered that such partial erasure of adjacent character lines can be eliminated if the spacing between adjacent anode line segments is increased.
However, such a solution is unsatisfactory because the amount of spacing which is required to eliminate the partial erasure is so large that the line structure of the display becomes noticeable to a viewer. The increased spacing also affects resolution as one could not achieve 200 lines per inch without proper line spacing.
As a result of the above, there is a need in the art for an anode electrode structure for a display and, in particular, for an electrophoretic display panel which provides selective erasure of lines without partial erasure of adjacent lines.
Disclosure of the Invention Embodiments of the present invention advantageously solve the above-identified need in the art by providing an anode electrode structure for a display and, in particular, for an electrophoretic display panel which provides selective erasure of a line without partial erasure of adjacent lines.
An embodiment of the present invention is an anode electrode structure which is comprised of a multiplicity of anode line segments wherein each anode line segment comprises at least a first and a second conductor. In a preferred embodiment of the present invention, the first conductor is larger than the second conductor and the inventive anode electrode structure is applied to an electrophoretic display.
One provides a full panel erase operation in an electrophoretic display panel fabricated using an embodiment of the present invention by applying a negative voltage to all anode line segments in the display panel, i.e., to the first and second conductor of each anode line segment. Further, with such a
2 1 2U699 display panel, one provides a "hold" operation or a "write"
operation by applying a positive voltage to all anode line segments in the display panel, i.e., to the first and second conductor of each anode line segment. Lastly, with such a display panel, one provides a selective erase operation by applying a negative voltage to a selected group of anode line segments, i.e., to the first and second conductor of each of the selected group of anode line segments, and by applying a positive voltage to all the other anode line segments in the display panel, i.e., to the first and second conductor of each of the other anode line segments.
Advantageously, in accordance with the present invention, the addition of a conductor between anode line segments of an anode electrode structure which is fabricated in accordance with the prior art eliminates partial erasure of lines which are adjacent to a line which is being erased.
Further, as will be set forth in detail below, the additional conductor can be made sufficiently small that it is not visible to a viewer.
According to a still further broad aspect of the present invention, there is provided an electrophoretic display having a fluid-tight envelope having a portion thereof which is at least partially transparent. An electrophoretic fluid is contained within the en~elope. The fluid has pigment particles suspended therein. A cathode and grid electrode structure are provided and have a plurality of cathode and grid conductors passing through the envelope and the fluid.
The improvement in this combination comprises an anode electric having a plurality of elongated parallel anode conductors passing through the envelope and the fluid and arranged in a multiplicity of groups of at least two conductors. One of the at least two conductors of each group of conductors is larger than another of each group of conductors.
The invention, from another broad aspect also encompasses the method of selectively erasing an electrophoretic display. The method comprises the steps of - 5a - 2 1 20699 positioning a conductive control line beneath an anode character line in a display. A voltage of a given polarity is applied to the control line when an erase voltage of the opposite polarity is applied to the character line The given voltage is also applied to all other character lines not being erased.
Brief Description of the Drawinqs A complete understanding of the present invention may be gained by considering the following detailed description in conjunction with the accompanying drawing, in which:
FIG. 1 shows, in pictorial form, a portion of a preferred embodiment of an anode electrode structure which is fabricated in accordance with the present invention for use in providing an electrophoretic display panel.
Best Mode for CarrYinq Out The Invention FIG. 1 shows a preferred embodiment of anode PCT/l~S 91 /07161 6 ~3 Rec'd P~JT/P~Q 0 l SEP 1993 electrode structure 12 for use in fabricating an electrophoretic display panel. Electrophoretic display panels are well known in the art and detailed descriptions regardi,ng their fabrication and operation can be found in the U.S. Patents identified above in the Background of the Invention plus many others.
Thus, for purposes of clarity, the following detailed description will only show details of the anode electrode structure of the present invention. Further, for purposes of illustration, the electrophoretic display panel which is fabricated using an embodiment of the inventive anode electrode structure is adapted to display characters. Lastly, in accordance with the present invention, a line of displayed characters is formed utilizing a predetermined number of anode line segments wherein each anode line segment comprises a first and a second conductor.
FIG. 1 shows a portion of anode electrode structure 12 which is fabricated in accordance with the present invention and which forms at least a portion of a line of displayed text in the display. Typically, each anode line is fabricated from a thin layer of IT0 deposited on a glass sheet. The IT0 layers are practically transparent and fabricated on the glass sheet by conventional processing techniques as described in the above-noted patents. The IT0 lines are deposited on a glass sheet 60. In a typical electrophoretic display panel which is fabricated in accordance with the present invention, a line of displayed text is comprised of 26 anode line segments.
As shown in FIG. 1, anode electrode structure 12 is comprised of a multiplicity of anode line segments, however, only segments 2, 7, 13, and 18 are shown for the sake of clarity. In accordance with the illustrative embodiment of the present invention, each SUBSTITIJTE SHEEl~
212~699 ..
PCT/US 91 /o7 l 61 Rec'd P~r/PTO ~ 1 SEP 1993 of anode line segments 2, 7, 13, and 18 is comprised of two, spaced apart conductors. In particular, anode line segment 2 is comprised of larger conductor strip
operation by applying a positive voltage to all anode line segments in the display panel, i.e., to the first and second conductor of each anode line segment. Lastly, with such a display panel, one provides a selective erase operation by applying a negative voltage to a selected group of anode line segments, i.e., to the first and second conductor of each of the selected group of anode line segments, and by applying a positive voltage to all the other anode line segments in the display panel, i.e., to the first and second conductor of each of the other anode line segments.
Advantageously, in accordance with the present invention, the addition of a conductor between anode line segments of an anode electrode structure which is fabricated in accordance with the prior art eliminates partial erasure of lines which are adjacent to a line which is being erased.
Further, as will be set forth in detail below, the additional conductor can be made sufficiently small that it is not visible to a viewer.
According to a still further broad aspect of the present invention, there is provided an electrophoretic display having a fluid-tight envelope having a portion thereof which is at least partially transparent. An electrophoretic fluid is contained within the en~elope. The fluid has pigment particles suspended therein. A cathode and grid electrode structure are provided and have a plurality of cathode and grid conductors passing through the envelope and the fluid.
The improvement in this combination comprises an anode electric having a plurality of elongated parallel anode conductors passing through the envelope and the fluid and arranged in a multiplicity of groups of at least two conductors. One of the at least two conductors of each group of conductors is larger than another of each group of conductors.
The invention, from another broad aspect also encompasses the method of selectively erasing an electrophoretic display. The method comprises the steps of - 5a - 2 1 20699 positioning a conductive control line beneath an anode character line in a display. A voltage of a given polarity is applied to the control line when an erase voltage of the opposite polarity is applied to the character line The given voltage is also applied to all other character lines not being erased.
Brief Description of the Drawinqs A complete understanding of the present invention may be gained by considering the following detailed description in conjunction with the accompanying drawing, in which:
FIG. 1 shows, in pictorial form, a portion of a preferred embodiment of an anode electrode structure which is fabricated in accordance with the present invention for use in providing an electrophoretic display panel.
Best Mode for CarrYinq Out The Invention FIG. 1 shows a preferred embodiment of anode PCT/l~S 91 /07161 6 ~3 Rec'd P~JT/P~Q 0 l SEP 1993 electrode structure 12 for use in fabricating an electrophoretic display panel. Electrophoretic display panels are well known in the art and detailed descriptions regardi,ng their fabrication and operation can be found in the U.S. Patents identified above in the Background of the Invention plus many others.
Thus, for purposes of clarity, the following detailed description will only show details of the anode electrode structure of the present invention. Further, for purposes of illustration, the electrophoretic display panel which is fabricated using an embodiment of the inventive anode electrode structure is adapted to display characters. Lastly, in accordance with the present invention, a line of displayed characters is formed utilizing a predetermined number of anode line segments wherein each anode line segment comprises a first and a second conductor.
FIG. 1 shows a portion of anode electrode structure 12 which is fabricated in accordance with the present invention and which forms at least a portion of a line of displayed text in the display. Typically, each anode line is fabricated from a thin layer of IT0 deposited on a glass sheet. The IT0 layers are practically transparent and fabricated on the glass sheet by conventional processing techniques as described in the above-noted patents. The IT0 lines are deposited on a glass sheet 60. In a typical electrophoretic display panel which is fabricated in accordance with the present invention, a line of displayed text is comprised of 26 anode line segments.
As shown in FIG. 1, anode electrode structure 12 is comprised of a multiplicity of anode line segments, however, only segments 2, 7, 13, and 18 are shown for the sake of clarity. In accordance with the illustrative embodiment of the present invention, each SUBSTITIJTE SHEEl~
212~699 ..
PCT/US 91 /o7 l 61 Rec'd P~r/PTO ~ 1 SEP 1993 of anode line segments 2, 7, 13, and 18 is comprised of two, spaced apart conductors. In particular, anode line segment 2 is comprised of larger conductor strip
3 and smaller conductor strip 5; anode line segment 7 is comprisPd of a larger conductor strip 8 and smaller conductor strip 10; anode line segment 13 is comprised of larger conductor strip 14 and smaller conductor strip 16; and anode line segment 18 is comprised of larger conductor strip 19 and smaller conductor strip 10 21.
In a preferred embodiment of the present - invention, larger conductor strips 3, 8, 14, and 19 are each .115" wide and smaller conductor strips 5, 10, 16, and 21 are each .013" wide. Further, the spaces between the conductors --spaces 4, 6, 9, 11, 15, 17, 20, and 22-- are each .001" wide. As a result of this, each anode line segment in the preferred embodiment is .130 " wide.
It should be appreciated that embodiments of 20 the present invention are not limited to an anode electrode structure having the dimensions given above.
For example, one may fabricate an anode electrode structure wherein larger conductor strips 3, 8, 14, and 19 are each .110" wide; smaller conductor strips 5, 10, 25 16, and 21 are each .016" wide; and the spaces between the conductors --spaces 4, 6, 9, 11, 15, 17, 20, and 22-- are each .002" wide. In such an embodiment, each anode line segment is .130" wide.
It should further be appreciated that 30 embodiments of the present invention are not limited to an anode electrode structure having uniform dimensions.
As such, an embodiment of the present invention may be fabricated so that anode line segments associated with respective lines of displayed text have dimensions 35 first given above as well as anode line segments having 212Qfi99 . - - -- P~-~SCi/07~
dimensions second given above.
As shown in FIG. 1, smaller conductor strips 5, 10, 16, and 21 are all electrically connected. Such connections would apply for all anode line segments 5 associated with a g~ven display line of said display and there would typically be no such connection between similarly situated conductor strips of different lines.
Of course, it should be appreciated that the present invention does not require such electrical connection 10 because appropriate voltages, as will be set forth in detail below, may be applied independently to these - conductor strips. However, for a panel which is utilized in a character display mode, the electrical connection shown in FIG. 1 is preferred. In the 15 preferred embodiment shown in FIG. 1, space 29 between one end of larger conductor strip 3 and conductor 30 is .0625" and conductor 30 is .0625" wide.
Table 1 helps illustrate the manner in which voltages are applied to anode electrode structure 12 20 for use in conjunction with an electrophoretic display panel to provide full panel erase, "hold", "write", and selective erase operations in accordance with the present invention. A full panel erase operation is provided by applying a negative voltage to all anode 25 line segments 2, 7, 13, and 18, i.e., by applying a negative voltage to larger conductive strips 3, 8, 14, and 19 and by applying a negative voltage to smaller conductor strips 5, 10, 16, and 21. Further, a "hold"
or a "write" operation is provided by applying a 30 positive voltage to all anode line segments 2, 7, 13, and 18, i.e., by applying a positive voltage to larger conductive strips 3, 8, 14, and 19 and by applying a positive voltage to smaller conductor strips 5, 10, 16, and 21. Lastly, a selective erase operation of a line 35 of text is achieved by applying a negative voltage to SU~STITUTE SHEET
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PCT/IJS 91 /o7 l 6~
03 Rec'd PCt/PTO O 1 SEP 1993 -all of the anode line segments associated with that character line and by applying a positive voltage to all the anode line segments associated with the other lines of text.
TABLE I
Operation Voltages for Larger Voltages for Smaller Conductor Strips Conductor Strips Full Panel -V -V
Erase 15Hold +V +V
Write +V +V
Selective-V for those +V
20 Erasure of associated with a line of erased text lines text to be +V for those associated with other text lines The respective voltages discussed above are supplied to the smaller conductor strips as 5, 10, and so on by a conventional voltage generator 50 and to the groups of larger conductor strips associated with corresponding lines of displayed text by an anode line driver circuit 51. With reference to Table I, however, it will be observed that the respective groups of larger conductor strips need not be connected together, and hence, the larger strips associated with lines of displayed text above and below a given line of text being erased can be energized independently of the those corresponding to the given line. Accordingly, where anode line segment 7 is the lowermost segment of a first line of displayed text and anode line segment SUBSTITUTE SHEET
2120 69~ ..
03 Rec'd P~Y/PTL 8 1 ~EP 1993 13 is the uppermost line segment of the adjacent line of displayed text beneath the first, one could selectively erase the line of text by applying a negative voltage to the large conductor strips as strip 8 associated therewith and a positive voltage to the smaller conductor strips as 10 associated therewith, which smaller conductor strips are connected together.
Lines of text which are not to be erased, as the adjacent one associated with large strip conductor 14 and small strip conductor 16, would be held by applying a positive voltage to all strip conductors associated therewith.
Those skilled in the art will recognize that further embodiments of the present invention may be made without departing from its teachings and that the present invention is not limited to the specific embodiments described above.
SUBSllTUlE SIIE~T
In a preferred embodiment of the present - invention, larger conductor strips 3, 8, 14, and 19 are each .115" wide and smaller conductor strips 5, 10, 16, and 21 are each .013" wide. Further, the spaces between the conductors --spaces 4, 6, 9, 11, 15, 17, 20, and 22-- are each .001" wide. As a result of this, each anode line segment in the preferred embodiment is .130 " wide.
It should be appreciated that embodiments of 20 the present invention are not limited to an anode electrode structure having the dimensions given above.
For example, one may fabricate an anode electrode structure wherein larger conductor strips 3, 8, 14, and 19 are each .110" wide; smaller conductor strips 5, 10, 25 16, and 21 are each .016" wide; and the spaces between the conductors --spaces 4, 6, 9, 11, 15, 17, 20, and 22-- are each .002" wide. In such an embodiment, each anode line segment is .130" wide.
It should further be appreciated that 30 embodiments of the present invention are not limited to an anode electrode structure having uniform dimensions.
As such, an embodiment of the present invention may be fabricated so that anode line segments associated with respective lines of displayed text have dimensions 35 first given above as well as anode line segments having 212Qfi99 . - - -- P~-~SCi/07~
dimensions second given above.
As shown in FIG. 1, smaller conductor strips 5, 10, 16, and 21 are all electrically connected. Such connections would apply for all anode line segments 5 associated with a g~ven display line of said display and there would typically be no such connection between similarly situated conductor strips of different lines.
Of course, it should be appreciated that the present invention does not require such electrical connection 10 because appropriate voltages, as will be set forth in detail below, may be applied independently to these - conductor strips. However, for a panel which is utilized in a character display mode, the electrical connection shown in FIG. 1 is preferred. In the 15 preferred embodiment shown in FIG. 1, space 29 between one end of larger conductor strip 3 and conductor 30 is .0625" and conductor 30 is .0625" wide.
Table 1 helps illustrate the manner in which voltages are applied to anode electrode structure 12 20 for use in conjunction with an electrophoretic display panel to provide full panel erase, "hold", "write", and selective erase operations in accordance with the present invention. A full panel erase operation is provided by applying a negative voltage to all anode 25 line segments 2, 7, 13, and 18, i.e., by applying a negative voltage to larger conductive strips 3, 8, 14, and 19 and by applying a negative voltage to smaller conductor strips 5, 10, 16, and 21. Further, a "hold"
or a "write" operation is provided by applying a 30 positive voltage to all anode line segments 2, 7, 13, and 18, i.e., by applying a positive voltage to larger conductive strips 3, 8, 14, and 19 and by applying a positive voltage to smaller conductor strips 5, 10, 16, and 21. Lastly, a selective erase operation of a line 35 of text is achieved by applying a negative voltage to SU~STITUTE SHEET
2l2o699 ,.
PCT/IJS 91 /o7 l 6~
03 Rec'd PCt/PTO O 1 SEP 1993 -all of the anode line segments associated with that character line and by applying a positive voltage to all the anode line segments associated with the other lines of text.
TABLE I
Operation Voltages for Larger Voltages for Smaller Conductor Strips Conductor Strips Full Panel -V -V
Erase 15Hold +V +V
Write +V +V
Selective-V for those +V
20 Erasure of associated with a line of erased text lines text to be +V for those associated with other text lines The respective voltages discussed above are supplied to the smaller conductor strips as 5, 10, and so on by a conventional voltage generator 50 and to the groups of larger conductor strips associated with corresponding lines of displayed text by an anode line driver circuit 51. With reference to Table I, however, it will be observed that the respective groups of larger conductor strips need not be connected together, and hence, the larger strips associated with lines of displayed text above and below a given line of text being erased can be energized independently of the those corresponding to the given line. Accordingly, where anode line segment 7 is the lowermost segment of a first line of displayed text and anode line segment SUBSTITUTE SHEET
2120 69~ ..
03 Rec'd P~Y/PTL 8 1 ~EP 1993 13 is the uppermost line segment of the adjacent line of displayed text beneath the first, one could selectively erase the line of text by applying a negative voltage to the large conductor strips as strip 8 associated therewith and a positive voltage to the smaller conductor strips as 10 associated therewith, which smaller conductor strips are connected together.
Lines of text which are not to be erased, as the adjacent one associated with large strip conductor 14 and small strip conductor 16, would be held by applying a positive voltage to all strip conductors associated therewith.
Those skilled in the art will recognize that further embodiments of the present invention may be made without departing from its teachings and that the present invention is not limited to the specific embodiments described above.
SUBSllTUlE SIIE~T
Claims (20)
1. In an electrophoretic display having a fluid-tight envelope having a portion thereof which is at least partially transparent, an electrophoretic fluid contained within said envelope, said fluid having pigment particles suspended therein, and a cathode and grid electrode structure having a plurality of cathode and grid conductors passing through said envelope and said fluid, the improvement in combination therewith comprising:
an anode electric having a plurality of elongated parallel anode conductors passing through said envelope and said fluid and arranged in a multiplicity of groups of at least two conductors, one of the at least two conductors of each group of conductors being larger than another of each group of conductors.
an anode electric having a plurality of elongated parallel anode conductors passing through said envelope and said fluid and arranged in a multiplicity of groups of at least two conductors, one of the at least two conductors of each group of conductors being larger than another of each group of conductors.
2. The anode electrode structure of claim 1, wherein the larger conductor of each group has a larger width than another conductor of each group.
3. The anode electrode structure of claim 2, wherein the larger width of each of the multiplicity of groups of conductors is substantially the same.
4. The anode electrode structure of claim 2, wherein the larger width of some of the multiplicity of groups of conductors are not substantially the same.
5. The anode electrode structure of claim 2, wherein the conductors having a smaller width in a predetermined number of adjacent groups are electrically connected.
6. The anode electrode of claim 1, wherein each of said groups of conductors are fabricated from ITO deposited on a glass sheet.
7. An electrophoretic display, comprising:
a fluid tight housing having a portion thereof which is at least partially transparent, an electrophoretic fluid contained within said housing, said fluid having pigment particles suspended therein, and a cathode and grid electrode structure having a plurality of cathode and grid conductors passing through said housing and said fluid, an anode electrode located within said housing and having a first plurality of parallel character lines each separated one from the other by a predetermined distance and forming a grid of anode lines each line of a given length and width; and a second plurality of conductive control lines each also positioned between an associated first and second character line and each of relatively the same length as said associated character lines but of a lesser width, with at least one of said first plurality of character lines adapted to receive a different operating potential than said second plurality of control lines during at least one operating mode of said display.
a fluid tight housing having a portion thereof which is at least partially transparent, an electrophoretic fluid contained within said housing, said fluid having pigment particles suspended therein, and a cathode and grid electrode structure having a plurality of cathode and grid conductors passing through said housing and said fluid, an anode electrode located within said housing and having a first plurality of parallel character lines each separated one from the other by a predetermined distance and forming a grid of anode lines each line of a given length and width; and a second plurality of conductive control lines each also positioned between an associated first and second character line and each of relatively the same length as said associated character lines but of a lesser width, with at least one of said first plurality of character lines adapted to receive a different operating potential than said second plurality of control lines during at least one operating mode of said display.
8. The electrophoretic display according to claim 7, wherein said first and second lines are fabricated from ITO
deposited on a glass sheet.
deposited on a glass sheet.
9. The electrophoretic display according to claim 8, wherein during an erase mode of said electrophoretic display, said character lines receive the same potential as said control lines.
10. The electrophoretic display according to claim 7, wherein during a "write" mode of said display, said character lines and said control lines receive a positive voltage.
11. The electrophoretic display according to claim 7, wherein during a hold mode said character lines receive the same plurality voltage as said control lines.
12. The electrophoretic display according to claim 7, wherein a single selected character line can be erased by applying a negative voltage to said selected line, with a positive voltage to all other character lines and with a positive voltage applied to said control lines.
13. A method of selectively erasing an electrophoretic display, comprising the steps of:
positioning a conductive control line beneath an anode character line in a display;
applying a voltage of a given polarity to said control line when an erase voltage of the opposite polarity is applied to said character line; and applying said given voltage to all other character lines not being erased.
positioning a conductive control line beneath an anode character line in a display;
applying a voltage of a given polarity to said control line when an erase voltage of the opposite polarity is applied to said character line; and applying said given voltage to all other character lines not being erased.
14. The method according to claim 13, wherein said control line and said character line are both fabricated from ITO.
15. The method according to claim 13, wherein said erase voltage is a negative voltage.
16. The method according to claim 15, wherein said opposite polarity voltage is positive.
17. The method according to claim 13, wherein said conductive control line is of a significantly smaller area than said character line.
18. The method according to claim 13, wherein said control line is of the same length as said character line.
19. The method according to claim 13, wherein said control line is a smaller width than said character line.
20. The method according to claim 13, including the steps of positioning another conductive control line above said character line; and applying said voltage of said given polarity to said another conductive line when said erase voltage is applied to said character line.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4506132A JP2825653B2 (en) | 1991-10-07 | 1991-10-07 | Electrode structure for electrophoretic display |
| PCT/US1991/007161 WO1993007608A1 (en) | 1991-10-07 | 1991-10-07 | Electrode structure for an electrophoretic display apparatus |
| DE69128649T DE69128649T2 (en) | 1991-10-07 | 1991-10-07 | ELECTRODE STRUCTURE FOR AN ELECTROPHORETIC DISPLAY DEVICE. |
| EP92905859A EP0607145B1 (en) | 1991-10-07 | 1991-10-07 | Electrode structure for an electrophoretic display apparatus |
| CA002120699A CA2120699C (en) | 1991-10-07 | 1991-10-07 | Electrode structure for an electrophoretic display apparatus |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/US1991/007161 WO1993007608A1 (en) | 1991-10-07 | 1991-10-07 | Electrode structure for an electrophoretic display apparatus |
| CA002120699A CA2120699C (en) | 1991-10-07 | 1991-10-07 | Electrode structure for an electrophoretic display apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2120699A1 CA2120699A1 (en) | 1993-04-15 |
| CA2120699C true CA2120699C (en) | 1998-05-05 |
Family
ID=4153325
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002120699A Expired - Fee Related CA2120699C (en) | 1991-10-07 | 1991-10-07 | Electrode structure for an electrophoretic display apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2120699C (en) |
-
1991
- 1991-10-07 CA CA002120699A patent/CA2120699C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2120699A1 (en) | 1993-04-15 |
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