US3598956A - Ion migration barrier - Google Patents

Ion migration barrier Download PDF

Info

Publication number
US3598956A
US3598956A US849109A US3598956DA US3598956A US 3598956 A US3598956 A US 3598956A US 849109 A US849109 A US 849109A US 3598956D A US3598956D A US 3598956DA US 3598956 A US3598956 A US 3598956A
Authority
US
United States
Prior art keywords
resistor elements
shield
print head
ions
circuit
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 - Lifetime
Application number
US849109A
Other languages
English (en)
Inventor
Richard C Cady Jr
John H Hoskinson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NCR Voyix Corp
National Cash Register Co
Original Assignee
NCR Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NCR Corp filed Critical NCR Corp
Priority claimed from AU22639/70A external-priority patent/AU451893B2/en
Priority claimed from FR7043285A external-priority patent/FR2094799A5/fr
Priority claimed from GB58205/70A external-priority patent/GB1263887A/en
Priority claimed from CH1893070A external-priority patent/CH513004A/de
Application granted granted Critical
Publication of US3598956A publication Critical patent/US3598956A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/315—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material
    • B41J2/32—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads
    • B41J2/335—Structure of thermal heads
    • B41J2/33505—Constructional details
    • B41J2/3353—Protective layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/315—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material
    • B41J2/32—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads
    • B41J2/335—Structure of thermal heads
    • B41J2/3355—Structure of thermal heads characterised by materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/315—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material
    • B41J2/32—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads
    • B41J2/335—Structure of thermal heads
    • B41J2/33555—Structure of thermal heads characterised by type
    • B41J2/33565—Edge type resistors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/315—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material
    • B41J2/32—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads
    • B41J2/335—Structure of thermal heads
    • B41J2/33555—Structure of thermal heads characterised by type
    • B41J2/3357—Surface type resistors

Definitions

  • An ion migration barrier for a circuit configuration (like a thermal print head) including a plurality of resistor elements which are selectively energized to produce localized areas of heat.
  • a circuit configuration like a thermal print head
  • the ion migration barrier isolates the resistor elements from the source of ions when it is positioned therebetween to thereby prolong resistor element life.
  • the source of ions appears to be the thermally sensitive paper which is used with the print head.
  • This invention relates to an ion migration barrier for use in circuit configurations having planar resistors whose operating lives are shortened due to ions migrating towards one of the terminal ends thereof.
  • a typical application for this invention resides in the thermal print head art.
  • One such print head is shown in copending U.S. Pat. application, Ser. No. 672,131, filed Oct. 2, I967, by Richard C. Cady and Robert M. Whitely, which application is assigned to the assignee of the present invention.
  • Another thermal print head is shown in U.S. Pat. No. 3,l6l,457, which issued Dec. 15, 1964, on the application of Hans Schroeder et al.
  • a thermal print head of the type in which this invention may be used contains a plurality of resistor elements arranged on a substrate in the form of a printing matrix.
  • the print head also includes circuit connection means for selectively energizing selected ones of said resistor elements to form desired characters to be printed. Those resistor elements which are selectively energized become heated, and, when the print head is brought into contact with a thermally sensitive paper, the desired characters are formed thereon.
  • a print head of the type described in the previous paragraph fails after printing about 5,000,000 lines when the print head is subjected to actual printing life tests.
  • the heating values of the resistors used in the print head also change approximately +25 percent after 5,000,000 lines of printing. It appears as though sodium ions from the thermally sensitive paper migrate towards the negative ends of the resistors to shorten the lives thereof.
  • the life of the print head is considerably increased.
  • Print heads employing applicants ion barrier operated without failure beyond the printing of 15,000,000 lines in actual life tests. During these tests, the heating values of the resistors used in the print heads varied less than 2 percent during the printing of over l5,000,000 lines, compared to the 25 percent variation experienced after the printing of 5,000,000 lines in print heads without applicants barrier.
  • This invention relates to an ion migration barrier for use in circuit configurations having a plurality of resistor elements therein, which configurations are used in environments containing ions which tend to migrate towards the resistor elements and cause the failure thereof.
  • the barrier is an electrically conduction shield which is positioned between the resistor elements and the source of ions to isolate the resistor elements from the source of ions and thereby prolong the operating life of the resistor elements.
  • FIGv I is a general view in perspective, and partly in cross section, of a circuit configuration having planar resistors and an ion migration barrier of this invention.
  • FIG. 2 is a cross-sectional view, in elevation, of the circuit configuration shown in FIG. I and is taken along line 2-2 thereof.
  • FIG. 3 is a schematic plan view of the circuit configuration shown in FIG. 1, showing details of the connecting means for the planar resistors.
  • FIG. 4 is a cross-sectional view, in elevation, of the circuit configuration shown in FIG. I and is taken along line 4-4 thereof.
  • FIG. 1 is a general view, in perspective, showing a portion of a circuit configuration having planar resistor elements which are arranged in groups 12 to form a matrix for a thermal print head.
  • the top surface 14 of the configuration 10 comes into contact with a conventional, thermally responsive printing paper ll (FIG. 2) when printing is to be effected, and selected groups I2 of the resistor elements are energized to produce discrete areas of heat to form the desired characters on the printing paper 11.
  • Twenty-five groups 12 of resistor elements are arranged in a five-by-five matrix, as shown in FIG. 3, for the printing of a character.
  • the general construction of the circuit configuration 10, made by conventional printed circuit techniques, is shown in FIGS. 1 to 4 inclusive.
  • the configuration 10 includes a base 16 (like glass), on which a layer 18 of tantalum oxide is deposited.
  • a lamination composed of a first layer of tantalum, a layer of gold, and a second layer of tantalum is then deposited over the layer 18, and the lamination is masked and etched to produce individual planar resistor elements 20, 22, and 24 (made from the first layer of tantalum) for each group 12, and support elements 26, 28, 30, 32, and 34 (also made from the first layer of tantalum
  • the support elements 26, 28, 30, 32, and 34 support conductor layers 26a, 28a, 30a, 32a, and 34a (made from the layer of gold), respectively, which are used in a connection pattern which is used to connect the resistor elements to a source of electrical potential (not shown).
  • the connection pattern for interconnecting the various resistor elements in the circuit configuration 10 is best shown in FIGS. 1 and 3.
  • the gold layer 26a has a leg portion 36, which contacts one end of the resistor element 24 to make an electrical connection thereto.
  • the remaining end of the resistor element 24 has a gold conductor strip 38 connected thereto to connect it with one end of the resistor element 22.
  • a conductor strip 40 similar to the strip 38, is used to electrically connect the remaining end of the resistor element 22 with one end of the resistor element 20.
  • the remaining end of the resistor element 20 is electrically connected to a gold layer 42 sup ported on an extension 44, of reduced width, of the resistor element 20.
  • the resistor elements 20, 22, and 24 of each group 12 are in spaced, parallel relationship with one another and are series connected.
  • the gold layer 260 may be connected to the negative terminal of a source of potential, and the gold layer 42 may be connected to its positive terminal through a conventional switching arrangement (not shown).
  • the switching arrangement controls the selective energization of the particular groups 12 to effect the particular heating pattern desired to produce a specific character on the thermally responsive paper with which the configuration 10 may be used.
  • the particular connection pattern used (that is, whether it is a common positive or a common negative) is of course de pendent upon the external circuitry with which the configuration It) is used.
  • connection pattern described for one group 12 of resistor elements is generally the same for all groups 12 shown in FIG. 3.
  • the groups 12 are slightly offset in the horizontal direction (as viewed in FIG. 3) to facilitate producing the connection pattern.
  • Each of the gold layers like 260, 28a, 30a, 32a, and 34a has a thin layer 46 of tantalum deposited thereover, as shown in FIG. 2, and similarly the gold connector strips like 38 and 40 (FIG. I) also have a thin layer 48 deposited thereover to enable a protective layer of glass 50 to adhere thereto; these thin layers of tantalum come from the second layer of tantalum which is part of the lamination deposited on the layer 18.
  • the layer of glass 50 also protects the various resistor elements 20, 22, and 24 of the groups 12.
  • the ion migration barrier of this invention is positioned in a circuit configuration between the source of ions and the resistor elements to be protected.
  • the source of ions which migrate to the resistor elements, to curtail their useful lives is the thermally sensitive paper with which the configuration I0 (which is a thermal print head in the illustrated embodiment) is used.
  • the surface 14 of the configuration 10 contacts the thermally sensitive paper ll (FIG. 2), therefore, an ion migration barrier 52 is positioned between the surface 14 and the resistor elements of the groups 12.
  • the barrier 52 is electrically conducting.
  • the ion barrier 52 may be made of several different conductors and semiconductors by a variety of conventional techniques.
  • the barrier 52 was made of chromium which was vapor deposited on the layer of glass 50.
  • the barrier 52 has a thickness of about 500 to 2,000 Angstrom units. Any material selected for a barrier 52 should adhere well to the layer of glass 50, which should also be made thick enough to withstand the voltage between the barrier 52 and the underlying printed layers like 260, 38, and 40 and the resistor elements of the groups [2.
  • the barrier 52 may be electrically biased positively or negatively with respect to the resistor elements 20, 22, and 24 of the groups 12 and their connection pattern. Leaving the barrier 52 electrically isolated also appears to have merit.
  • the ion barrier 52 shown in FIGS. 1, 2, and 4 is actually one continuous layer extending across the entire configuration 10. In some cases, it may be desirable to have a separate shield (not shown) covering each group 12 of resistor elements. This separate shield is similar to the barrier 52 except that it is biased or pulsed with the same current which is used to energize the resistor elements of the particular group 12 of resistor elements with which the separate shield is associated.
  • the positive sodium ions which apparently come from the thermally sensitive paper, as previously mentioned, seem to distribute themselves evenly over the top surface 54 (FIG. 2) of the barrier 52 instead of being attracted to the negative ends of the resistor elements 20, 22, and 24, where they would cause early failure of these elements. Without the barrier 52, the positive ions would penetrate the layer of glass 50 and move along the resistor elements of the groups 12 under the influence of electrical fields along the lengths of these elements, between them, and between the interconnection leads and the resistor elements and finally settle at the negative ends of the resistor elements to cause their early failure.
  • An optional layer of glass 56 protects the barrier 52 from abrasion and damage.
  • the drawings depicting an embodiment of this invention are not drawn to scale,
  • the printed resistor elements are approximately 600 Angstrom units thick, and the gold layers, like 260. 28a, etc.. are approximately 2,000 Angstrom units thick.
  • an electrically conductive shield positioned between said resistor elements and said source of ions to isolate said ions from said resistor elements.
  • circuit as claimed in claim 2 further comprising a layer of dielectric material positioned between said resistor elements and said shield.
  • a thermal print head having an external surface for contacting a record medium in printing engagement therewith comprising:
  • circuit connection means for selectively energizing selected ones of said resistor elements to form characters using said matrix
  • said print head being adapted for use in an environment in eluding a source of ions which ions migrate through said external surface towards said resistor elements to cause the deterioration thereof;
  • an electrically conductive shield positioned between said external surface and said resistor elements to minimize deterioration of said resistor elements and prolong their useful lives.
  • thermal print head having an external surface for contacting a record medium in printing engagement therewith and having a plurality of resistor elements arranged on a substrate in the form ofa printing matrix;
  • circuit connection means for selectively energizing selected ones of said resistor elements to form characters using said matrix
  • thermally sensitive record medium contacting said external surface in printing engagement with said print head
  • an electrically conducting shield positioned between said resistor elements and said external surface to minimize deterioration of said resistor elements and prolong their useful lives.

Landscapes

  • Electronic Switches (AREA)
US849109A 1969-08-11 1969-08-11 Ion migration barrier Expired - Lifetime US3598956A (en)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US84910969A 1969-08-11 1969-08-11
DE2055064A DE2055064C3 (de) 1969-08-11 1970-11-09 Thermodruckknopf
AU22639/70A AU451893B2 (en) 1969-08-11 1970-11-25 Thermal printhead
FR7043285A FR2094799A5 (de) 1969-08-11 1970-12-02
GB58205/70A GB1263887A (en) 1969-08-11 1970-12-08 Thermal print head
CH1893070A CH513004A (de) 1969-08-11 1970-12-22 Thermodruckkopf

Publications (1)

Publication Number Publication Date
US3598956A true US3598956A (en) 1971-08-10

Family

ID=27542599

Family Applications (1)

Application Number Title Priority Date Filing Date
US849109A Expired - Lifetime US3598956A (en) 1969-08-11 1969-08-11 Ion migration barrier

Country Status (2)

Country Link
US (1) US3598956A (de)
DE (1) DE2055064C3 (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4942240A (de) * 1972-03-06 1974-04-20
JPS49105133U (de) * 1972-12-22 1974-09-09
JPS49104647A (de) * 1973-02-05 1974-10-03
US3852563A (en) * 1974-02-01 1974-12-03 Hewlett Packard Co Thermal printing head
JPS5060237A (de) * 1973-09-27 1975-05-24
JPS5156236A (de) * 1974-11-11 1976-05-17 Sharp Kk
DE2537142A1 (de) * 1974-11-15 1976-05-26 Hewlett Packard Co Duennfilm-thermodruckkopf
US3973106A (en) * 1974-11-15 1976-08-03 Hewlett-Packard Company Thin film thermal print head

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3409902A (en) * 1966-05-27 1968-11-05 Texas Instruments Inc High speed thermal printer

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3409902A (en) * 1966-05-27 1968-11-05 Texas Instruments Inc High speed thermal printer

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4942240A (de) * 1972-03-06 1974-04-20
JPS545690B2 (de) * 1972-03-06 1979-03-20
JPS49105133U (de) * 1972-12-22 1974-09-09
JPS49104647A (de) * 1973-02-05 1974-10-03
JPS5737467B2 (de) * 1973-02-05 1982-08-10
JPS5060237A (de) * 1973-09-27 1975-05-24
JPS5419180B2 (de) * 1973-09-27 1979-07-13
US3852563A (en) * 1974-02-01 1974-12-03 Hewlett Packard Co Thermal printing head
JPS5156236A (de) * 1974-11-11 1976-05-17 Sharp Kk
DE2537142A1 (de) * 1974-11-15 1976-05-26 Hewlett Packard Co Duennfilm-thermodruckkopf
US3973106A (en) * 1974-11-15 1976-08-03 Hewlett-Packard Company Thin film thermal print head

Also Published As

Publication number Publication date
DE2055064C3 (de) 1974-03-28
DE2055064B2 (de) 1973-08-30
DE2055064A1 (de) 1972-05-31

Similar Documents

Publication Publication Date Title
US4214122A (en) Resistive planar graphical entry device
US3161457A (en) Thermal printing units
US3483356A (en) Thermal printing head
US4196411A (en) Dual resistor element
US4030408A (en) Thermal printer head
KR850007528A (ko) 용량성 스위치 및 스위치 어레이
US3598956A (en) Ion migration barrier
US3518406A (en) Thermal half-select printing matrix
US3466423A (en) Thermal half-select printing matrix
US2958009A (en) Electroluminescent device
US4204107A (en) Thick-film thermal printing head and method of manufacturing the same
US3267485A (en) Electrode printing assembly
US3470563A (en) Shielded electrostatic transducer
US3631512A (en) Slave printing apparatus
US3961155A (en) Thermal printing element arrays
US3825722A (en) Thermal printing head
EP0037664B1 (de) Zweidimensionaler Thermodruckkopf
GB1011069A (en) Improvements in or relating to electrothermic printing or recording apparatus
US3699588A (en) Recorder for recording on heat-sensitive material
EP0077546B1 (de) Thermische Aufzeichnungseinrichtung
US3733613A (en) Electrode and terminal structure for non-impact printer
US4217480A (en) Thermal print bar
US3246204A (en) Electroluminescent digital display device
US3870856A (en) Thermal printing head
US4636816A (en) Electrostatic print head