GB1580544A - Magnetic recording apparatus and method - Google Patents

Description

(54) IMPROVEMENTS RELATING TO MAGNETIC RECORDING APPARATUS AND METHOD (71) We, AM INTERNATIONAL INC., a corporation organised and existing under the laws of the State of Delaware, United States of America of 1900 Avenue of the Stars, Los Angeles, California 90067, United States of America do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a magnetic recording apparatus and method.

In some printing applications it is necessary to print alpha-numeric characters or other images of fine detail. A matrix printer which can print a column of about 32 closely spaced dots and about the same number of rows for each character, can create substantially any style of character. However, where the characters are to be of typical print size such as 2.5 mm high, the 32 print or recording elements must be spaced about 0.08 mm apart. It is difficult to manufacture such small elements and mount them at such a small spacing, and it is also difficult to do this at relatively low cost.

In one aspect, the invention provides magnetic recording apparatus wherein a magnetize able medium extends along a predetermined path, and a magnetic recording head is positioned along said path, the head comprising: a recording element which includes an elongate electrical conductor portion with a center of conduction spaced from said path by more than a first distance except along a recording location of limited length where said center of conduction is spaced from said path by a second distance which is closer than said first distance to said path; and means for passing a current through said conductor portion; said current passing means being constructed to pass a current of an amplitude that will change the magnetization of said magnetizeable medium when said current is at said second distance from said path of said medium, but not when said current is at said first distance from said path of medium.

In another aspect, the invention provides a recording apparatus comprising: a magnetizeable tape; means for moving said tape along a predetermined path; and a recording head assembly positioned along said path, for forming magnetic images on said tape; said recording head assembly including a plurality of recording elements having electrically conductive portions in the form of narrow strips that extend parallel to one another in a direction substantially parallel to the length of the tape path portion thereat and that lie close to said tape path, each strip forming a current path extending largely along its length with the center of the current path lying more than a predetermined distance from said tape path except at a predetermined short length portion of said strip where the center of said current path lies closer than said predetermined distance from said tape path; and means for applying current pulses selectively to said narrow strips with each current pulse having an amplitude large enough to magnetize a nearby portion of said tape as said current moves through the corresponding short length portion of a strip, but small enough so the current does not magnetize said tape as the current moves through the rest of the narrow strip.

The invention includes also a method for forming a magnetic image on a magnetizeable medium, comprising: selectively passing currents along a plurality of substantially parallel paths spaced from said magnetizeable medium by more than a predetermined distance from said medium except along path portions of limited length which are closer to said medium than said predetermined distance, where each of said currents is of a magnitude which causes magnetization of the medium only when moving along one of said corresponding path portions but not when moving along the rest of the path which is more than said predetermined distance from said medium.

In accordance with one embodiment of the present invention, a magnetic recording head is provided which can be utilized in a printing machine of relatively simple construction which can print images of fine detail. The recording head includes a group of recording elements which are closely spaced along a line perpendicular to the path of a magnetic recording tape, so that current through the elements produces magnetic fields that records magnetic spots on the tape. Each recording element includes an electrical conductor with a center of conduction spaced more than a predetermined distance from the magnetic tape path except at a small recording location where the center of conduction lies close enough to the magnetic tape path so that a current of predetermined magnitize through the recording element records a spot on the magnetic tape.

The conductor of each recording element can be formed by a thin layer of nickel which extends close to the magnetic tape path and a thick layer of copper lying on a face of the nickel opposite the tape path, with the copper layer having a gap at the recording location. When a current pulse is passed through the recording element, the center of conduction lies near the middle of the copper layer, so that the resulting words magnitize it.

However, at the gap in the copper layer, the current must pass through the nickel layer which lies close enough to the magnetic tape so that the resulting magnetic field is strong enough at the tape to magnetize it. A series of pulses applied to the recording elements as the magnetic tape moves thereby, creates a magnetic image on the tape. Toner is applied to the magnetic image on the tape, and the toner is transferred to paper or other print medium to produce a visible image.

Embodiments of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a simplified perspective view of a printing machine constructed in accordance with one embodiment of the present invention Figure 2 is a plan view of the printing machine of Figure 1, and also showing some of the circuitry thereof; Figure 3 is a perspective view of the recording head apparatus of the machine of Figure 1; Figure 4 is an underside view of a portion of the recording head of Figure 3, taken on the line 4-4 of Figure 3; Figure 5 is an enlarged view taken on the line 5-5 of Figure 3; Figure 6 is an enlarged view taken on the line 6-6 of Figure 4; Figure 7 is an enlarged view showing a portion of a character formed by the machine of Figure 1;; Figure 8 is a perspective view of a printing system constructed in accordance with another embodiment of the invention; Figure 9 is a simplified plan view of a recording element array of the type which can be utilized in the system of Figure 8; and Figure 10 is a more detailed view of the recording head of the system of Figure 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 and 2 illustrate a printing machine 10 which employs a recording head apparatus 12 of the present invention to form characters 14 of fine detail on a web of paper 16 or other print medium. The machine includes a magnetic recording tape 18 which is guided along a predetermined path by rollers 20, and which is driven along the path by a motor 22 than turns one of the rollers. The path of the recording tape 18 extends across the recording head apparatus 12, where magnetic images are recorded on the tape.

The tape then passes across a toner applying station 26 where toner is applied to the tape so that the magnetized regions receive a coating of toner particles. The tape then moves in front of the paper 16 to which the toner particles are to be transferred. A transfer head apparatus 28 is energized to cause the toner on the magnetic tape 18 to be transferred to the paper. The paper is advanced by rollers, and a fuser 30 (Fig. 1) fixes the toner to the paper, so that a permanent image is formed on the paper.

The particular machine 10 which is illustrated, is designed for printing of lines of characters on paper. Information which is received in a receiver 32 is delivered to a signal processor 34 which delivers signals to the recording head apparatus 12 and to the transfer head 28. When signals representing characters are received, signals are delivered over line 36 to the recording head apparatus 12 to cause the recording of magnetic images on the tape. The tape moves past the toner station 26 where the magnetized images are coated with toner, and the toner-coated tape moves in front of the paper 16. When a line of characters lies in front of the paper, a current pulse is delivered over line 42 to the transfer head 28 which lies behind the paper to create an electric field which causes the toner particles on the tape 18 to move from the tape against the paper 16. An electrically grounded strip 29 lies opposite the head 28 to establish a uniform electric field. After each line of characters is Printed on the paper, the paper is advanced so that a new line can be printed, while the previously printed line is fused by the fuser 30.

Figures 3-6 illustrate details of the recording head 12 which permits the recording of magnetic character images of fine detail on the magnetic recording tape 18. As shown in Figure 3, the recording head apparatus 12 includes a thin sheet-like recording head or device 50 which is mounted on a block-like support 52 that has a convex face 52f. The recording device 50 (Fig. 4) has a group of thirty-two recording elements 60a-60ff which each include a recording location 62a-62ff that can magnetize a small area of the magnetic recording tape. The recording locations 62 lie side-by-side and are spaced along a recording line 64 which extends transverse to the direction of movement of the magnetic recording tape 18 past the recording head.

Figures 5 and 6 illustrate additional details of the recording device 50 which records images in a layer 80 of magnetizable material of the magnetic recording tape 18, and showing the details of one of the recording elements 60dd thereof. The recording element 60dd includes a first or underlayer 70 of moderately good conductivity such as nickel, and a second or overlayer 72 of high conductivity material such as copper. The recording device 50 includes a supporting film 74 of nonmagnetic material such as polyester, which supports the nickel layer 70 of the recording element 60dd as well as each of the other recording elements. When a current is passed lengthwise along the printing element 60dd, the current flows along a path 76, most of which lies near the center of the copper layer 72.This is because copper has a conductivity about six times greater than nickel, and because the copper layer is thicker than the nickel layer. Near a plane 64p which includes the recording line 64, the recording element 60dd has a gap 78 in the copper layer 72. As a result, the current path 76 must extend through the nickel layer 70.

Along the current path region 76r where the current passes only through the nickel layer, the center of current flow is located a relatively small distance A from a layer of magnetizable material 80 on the recording tape 18. The magnitude of the current pulse passing through the recording element 60dd, is chosen so that the resulting magnetic field at the current path portion 76r is strong enough to magnetize the material 80 of the recording tape. However, the current magnitude is small enough that the magnetic field will not magnetize the material 80 at the distance B between adjacent portions of the current path and the tape layer. As a result, only a small region 82 of the magnetizable material 80 of the tape will become magnetized by the current pulse which is passed longitudinally through the recording element 60dd.It may be noted that the recording tape 18 includes a supporting base 84 of a material such as Mylar (Registered Trade Mark) which supports the layer 80 of magnetizable material such as chromium dioxide, and that a thin low friction film 86 of material such as polyester is provided over the magnetizable layer 80. The particles of the layer 80 are preferably oriented transverse to the length of the tape, and have a highly square hysteresis loop characteristic. It also may be noted that the supporting film 74 of the recording head as well as most of the conductive recording element extends almost parallel to the tape 18 at regions near the recording plane 64p, and it is only the gap 78 on one side of the recording element that causes the center of the current path 76 to suddenly veer close to the tape.

As shown in Figure 6, each recording element such as 60dd is preferably tapered in cross-section with the side nearest the path of the recording tape, at the layer 70, being of narrowest width. This tapering helps to assure recording only at the recording locations, in two ways. The tapering results in the center of current at 76 along most of the recording element, lying nearer the widest portion or base 72b of the copper layer, which results in the distance B from the center of conduction to the recording material of the magnetic tape being greater. Additionally, when the current passes through the recording portion 70r of the nickel layer along the gap 78 in the copper, the current flows along a nickel layer of small width. This results in higher current intensity, and therefore greater magnetic intensity immediately opposite the center of the nickel layer.

The recording device 50 can be constructed at relatively low cost, by well known etching or deposition processes, although the tapering may not be as smooth or uniform for elements of small width. The process can involve forming a multilayer sheet that includes two materials of different conductivity such as nickel and copper, etching grooves across part of the sheet to leave the elongated elements that are connected together at one end to form a common area or base 92 (Figure 4) and etching narrow gaps 78 in the layer of higher conductivity. In one method, a layer of copper is deposited over a layer of nickel to form a nickel-copper sandwich. The copper face of the sandwich is then attached to a support and a resist is applied over the nickel layer in the pattern shown in Figure 4.

Of course, such a pattern can be initially drawn to a large scale and photo-reduced, and then used to expose resist to sensitize it, all in a well known manner. The sandwich is then dipped in an etchant that etches both the nickel and copper to produce elements tapered in cross-section, of the type shown in Figure 6. The resulting etched sandwich is then attached to the polyester sheets 74.

Resist is then utilized over the copper layer except where the gaps 78 are to be formed, and the device is then immersed in an etch ant that etches copper but not nickel. Of course, a variety of methods can be employed, especially where tapering of the recording elements along their thickness is not required, all in accordance with methods well known in the art. The recording device 50 then can be mounted on the support 52 in a manner shown in Figure 3. One process results in there being an additional nickel layer lying over the copper base 72b (Fig. 6) but which has substantially no effect on the subsequent operation of the device.

In order to facilitate connections to the different recording elements 60a-60ff, each of the elements is formed with a tail 90a-90ff (Fig. 4), with the tails being tapered in width and extending in a radiating pattern from the region of the recording location. This provides relatively wide lead ends which facilitate electrical connections thereto. The end of the recording device 50 opposite the leads 90 forms a common base or lead 92 that is coupled to all of the recording elements.

Along the recording location, the recording elements are in the form of narrow strips that extend parallel to one another and parallel to the path of the magnetic tape. After the recording device is mounted on the support 52, the leads are coupled to multiple leads of the line 36 (Figure 2) that is connected to the signal processor 34.

Figure 7 illustrates the form of the magnetic image which can be recorded on the magnetic recording tape 18, the image 100 representing the upper portion of a stylized form of the letter "C" (in practice a mirror image is formed of the desired character to be printed). The image is formed by a series of magnetized areas 102 which are located in columns corresponding to the spacings of the recording locations on the recording elements, and in rows separated from one another that represent the distance which the tape 18 has moved between repeated current pulses through the recording elements.

When the magnetic image is dusted with toner and the toner is transferred to paper, a continuous image can be formed on the paper.

In one printing machine of the invention, the recording elements are 0.08 mm apart along the recording line 64, with each element being approximately 0.04 mm in width, and with each element having a nickel layer 70 of 0.005 mm thickness, a copper layer 72 of .02 mm thickness, and a gap 78 of 0.02 mm length. It may be noted that a thicker copper layer may be desirable, but it is difficult to etch a much thicker layer, even if both sides of the nickel-copper sandwich are etched, where such close spacing of the recording elements is utilized. A current pulse of 10 ampere and 1 microsecond duration is passed through each recording element, and the four groups of pulses for the four groups of eight elements each, are separated from one another by two microseconds. Current pulses with rise times of one microsecond are easily obtained in passage through the elements.Of course, the small cross-section of the elements would prevent them from carrying a continuous current of the order of magnitude of ten amperes, but they can conduct such a current for a microsecond without damage.

Each new column of spots is recorded on the magnetic recording tape 18 at sixty microsecond intervals. All of the spots of a column lie almost along a line. The tape 18 is moved at a speed of 1.25 meters per second, so that adjacent columns of spots are spaced about at 0.08 mm intervals on the magnetic recording tape.

Figure 8 illustrates a printing system 110 which utilizes a wide recording head 112 to form lines of magnetic spots that extend across the width of a broad magnetic tape record 114. Following the head 112, the tape moves past a transfer station 116 where the tape images are transferred to a magnetic drum. The images on the drum are toned by a toner 120 and transferred to a paper web print medium 122.

The recording head 112 may have to have about two-thousand recording elements spaced across a tape width of about 20 centimeters. This could make connections to the elements very difficult. For example, if two thousand elements had ends tapered to a two millimeter width and spaced four millimeters apart, the ends of the 2000 elements would occupy a region of a width of eight meters. To minimize the required space, the elements are arranged in an array of the general type illustrated in Figure 9, although with more recording elements in the array than are shown in Figure 9.

The small array 130 of Figure 9 contains twenty-four recording elements 132, each element having a strip-shaped portion 134 with a recording location 136 therealong, and with all recording locations arranged along a recording line 168. The elements are arranged in six groups 161-166, each group having four recorder elements 132, to provide the total of twenty-four elements. The first group of elements 161 includes four elements 132a-132d having a common interconnect region 160i on one side of the recording line 168, and with each element having a separate terminal portion 172 on the other side of the recording line. The second and third groups of elements 162,163 are similarly arranged, with common interconnect regions 162i, 163i below the recording line 168 and with separate terminals 172 above the line. The last three groups 164-166 of elements are symmetric to the first three groups, in that they have common interconnect regions 164i, 165i, 166i above the recording line 168 and terminals 172 below the line.

Current for operating the recorder elements 132 is provided by an electricity source 180 with two terminals or ends 182, 184. One end 182 of the source can be connected by any of six switches 161s-166s to corresponding interconnect regions 161i166i of the six groups of recorder elements.

The other end 184 of the source can be connected by any one of 4 switches 191-194 to cross conductors 191c-198c. Each cross conductor such as 191c, is coupled to three terminals 172 of three recorder elements 132a, 132i, 132q that are arranged in a row. Thus, when the two switches 16tis and 191 are both closed at the same instant, a current can flow through the element 132a so that its recording location 136 can record a spot on the magnetic tape. One way of passing a current through each of the recording elements 132a-132x would be to first close one of the group switches such as 161s and leave it closed, while each of the column switches 191-194 are closed momentarily in sequence. Next, switch 161s would be opened, switch 164i closed, and the switches 191-194 again closed momentarily in sequence.It may be noted that each of the recorder elements 132 is provided with a diode 200 to interconnect the cross conductor such as 191c to the strip portion 134 of an element, to allow current flow only in one direction through the element. This is to prevent unwanted current flows. For example, at a time that switches 191 and 161s are closed, to energize element 132a, it would otherwise be possible for current to flow unintentionally down element 132i, up element 132j, across part of cross conductor 1 92c and down element 132b.

The elements 132 can be formed by printed circuit methods so that their recording locations 136 are spaced a small distance apart such as only a few mils. However, such small width would make connection of an element to a cross conductor such as 191c difficult, and also such a small width is too small to provide a region for mounting even a small diode 200 if a separate chip-like diode is to be utilized. The layout illustrated in Figure 9 with staggered terminals 172, enables enlarged terminal areas to be provided without unduly enlarging the size of the entire array. The terminals 172 are formed at the ends of the recorder elements opposite the interconnect regions such as 161i, and all of the terminals of a group such as 161 are arranged in a staggered fashion.

The element 132d at one end of the group 161, has a terminal 172 located immediately above the interconnect region 164i of another group. The terminal of a next element 132c of the group 161 is located immediately above and slightly to one side of the terminal of element 132d. This continues until the terminal of element 132a is located furthest out and closest to one side of the group. The terminals of a next adjacent group 164 are correspondingly located, with the terminal of a first element 13 2e located immediately under the interconnect region 161i of another group, and the terminals of the other elements 132f, 132g, 132h are arranged in a staggered fashion with the terminals progressively further from one end of the group being located progressively further away from the recording line 168.This arrangement of the terminals allows a large number of terminals to be located in a small space and with all of the terminal regions formed primarily by a printed circuit method. Of course, the recording locations do not have to be located along a line 68, although it is often advantageous to do so to avoid the need for delay circuitry.

In an array similar to that of Figure 9, but with 2048 different elements arranged in 164 groups of 132 elements each, with the elements spaced 0.1 millimeter apart at their recording locations, and with terminals that are 1.25 millimeters wide and 1.25 millimeters long, the entire array can be contained on an area of only about 20 centimeters by 5 centimeters. Figure 10 illustrates a portion of an array 270 of this type, which is constructed with eight modules 272, each module containing eight groups 281-288 of elements with each group containing thirty-two elements with their terminals 252 arranged in a staggered fashion. The array has been bent in a gentle curve so that the recording locations are arranged along a line 290, and a covering sheet 250 is shown cut-away to aid in illustrating the array.

Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art and consequently it is intended that the claims be interpreted to cover such modifications and equivalents.

WHAT WE CLAIM IS: 1. A magnetic recording apparatus wherein a magnetize able medium extends along a predetermined path, and a magnetic recording head is positioned along said path, the head comprising: a recording element which includes an elongate electrical conductor portion with a center of conduction spaced from said path by more than a first distance except along a recording location of limited length where said center of conduction is spaced from said path by a second distance which is closer than said first distance to said path; and means for passing a current through said conductor portion;

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (13)

**WARNING** start of CLMS field may overlap end of DESC **. groups, in that they have common interconnect regions 164i, 165i, 166i above the recording line 168 and terminals 172 below the line. Current for operating the recorder elements 132 is provided by an electricity source 180 with two terminals or ends 182, 184. One end 182 of the source can be connected by any of six switches 161s-166s to corresponding interconnect regions 161i166i of the six groups of recorder elements. The other end 184 of the source can be connected by any one of 4 switches 191-194 to cross conductors 191c-198c. Each cross conductor such as 191c, is coupled to three terminals 172 of three recorder elements 132a, 132i, 132q that are arranged in a row. Thus, when the two switches 16tis and 191 are both closed at the same instant, a current can flow through the element 132a so that its recording location 136 can record a spot on the magnetic tape. One way of passing a current through each of the recording elements 132a-132x would be to first close one of the group switches such as 161s and leave it closed, while each of the column switches 191-194 are closed momentarily in sequence. Next, switch 161s would be opened, switch 164i closed, and the switches 191-194 again closed momentarily in sequence.It may be noted that each of the recorder elements 132 is provided with a diode 200 to interconnect the cross conductor such as 191c to the strip portion 134 of an element, to allow current flow only in one direction through the element. This is to prevent unwanted current flows. For example, at a time that switches 191 and 161s are closed, to energize element 132a, it would otherwise be possible for current to flow unintentionally down element 132i, up element 132j, across part of cross conductor 1 92c and down element 132b. The elements 132 can be formed by printed circuit methods so that their recording locations 136 are spaced a small distance apart such as only a few mils. However, such small width would make connection of an element to a cross conductor such as 191c difficult, and also such a small width is too small to provide a region for mounting even a small diode 200 if a separate chip-like diode is to be utilized. The layout illustrated in Figure 9 with staggered terminals 172, enables enlarged terminal areas to be provided without unduly enlarging the size of the entire array. The terminals 172 are formed at the ends of the recorder elements opposite the interconnect regions such as 161i, and all of the terminals of a group such as 161 are arranged in a staggered fashion. The element 132d at one end of the group 161, has a terminal 172 located immediately above the interconnect region 164i of another group. The terminal of a next element 132c of the group 161 is located immediately above and slightly to one side of the terminal of element 132d. This continues until the terminal of element 132a is located furthest out and closest to one side of the group. The terminals of a next adjacent group 164 are correspondingly located, with the terminal of a first element 13 2e located immediately under the interconnect region 161i of another group, and the terminals of the other elements 132f, 132g, 132h are arranged in a staggered fashion with the terminals progressively further from one end of the group being located progressively further away from the recording line 168.This arrangement of the terminals allows a large number of terminals to be located in a small space and with all of the terminal regions formed primarily by a printed circuit method. Of course, the recording locations do not have to be located along a line 68, although it is often advantageous to do so to avoid the need for delay circuitry. In an array similar to that of Figure 9, but with 2048 different elements arranged in 164 groups of 132 elements each, with the elements spaced 0.1 millimeter apart at their recording locations, and with terminals that are 1.25 millimeters wide and 1.25 millimeters long, the entire array can be contained on an area of only about 20 centimeters by 5 centimeters. Figure 10 illustrates a portion of an array 270 of this type, which is constructed with eight modules 272, each module containing eight groups 281-288 of elements with each group containing thirty-two elements with their terminals 252 arranged in a staggered fashion. The array has been bent in a gentle curve so that the recording locations are arranged along a line 290, and a covering sheet 250 is shown cut-away to aid in illustrating the array. Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art and consequently it is intended that the claims be interpreted to cover such modifications and equivalents. WHAT WE CLAIM IS:

1. A magnetic recording apparatus wherein a magnetize able medium extends along a predetermined path, and a magnetic recording head is positioned along said path, the head comprising: a recording element which includes an elongate electrical conductor portion with a center of conduction spaced from said path by more than a first distance except along a recording location of limited length where said center of conduction is spaced from said path by a second distance which is closer than said first distance to said path; and means for passing a current through said conductor portion;

said current passing means being constructed to pass a current of an amplitude that will change the magnetization of said magnetizeable medium when said current is at said second distance from said path of said medium, but not when said current is at said first distance from said path of medium.

2. Apparatus as claimed in Claim 1 wherein said electrical conductor portion comprises a narrow strip with a narrow recess therein at said recording location, said recess being formed in the side of said strip which is furthest from said path of said magnetizeable medium and extending only part of the way through the thickness of said strip.

3. Apparatus as claimed in Claim 2 wherein said strip comprises a first layer of electrically conductive material positioned near said path, and a second layer positioned directly against a face of said first layer opposite said path, the material of said second layer having a greater conductivity than the material of said first layer, and said recess being formed through the thickness of said second layer.

4. Apparatus as claimed in Claim 2 or Claim 3, wherein said strip is tapered in width along its thickness, with a minimum width at the face thereof which is nearest said path of said magnetizeable medium.

5. Apparatus as claimed in Claim 3, or Claim 4 as dependent on Claim 3, wherein the first layer is nickel and the second is copper.

6. A recording apparatus comprising: a magnetizeable tape; means for moving said tape along a predetermined path; and a recording head assembly positioned along said path, for forming magnetic images on said tape; said recording head assembly including a plurality of recording elements having electrically conductive portions in the form of narrow strips that extend parallel to one another in a direction substantially parallel to the length of the tape path portion thereat and that lie close to said tape path, each strip forming a current path extending largely along its length with the center of the current path lying more than a predetermined distance from said tape path except at a predetermined short length portion of said strip where the center of said current path lies closer than said predetermined distance from said tape path; and means for applying current pulses selectively to said narrow strips with each current pulse having an amplitude large enough to magnetize a nearby portion of said tape as said current moves through the corresponding short length portion of a strip, but small enough so the current does not magnetize said tape as the current moves through the rest of the narrow strip.

7. Apparatus as claimed in Claim 6 wherein said recording head assembly includes a supporting film of electrically insulative material, and each of said narrow strips includes a first layer of a first material and a second layer of a second material, said first layer positioned between said supporting film and said second layer, and said second layer having a higher conductivity than said first layer; said second layer of said strips having gaps therein, with said gaps of said strips arranged substantially along an imaginary recording line extending substantially perpendicular to the length of said strips.

8. Apparatus as claimed in Claim 7 wherein the first layer is nickel and the second is copper.

9. Apparatus as claimed in Claim 6, Claim 7 or Claim 8 wherein said recording elements are arranged in groups, with the recording locations of any two recording elements of a group being spaced far enough apart so that at least one recording location of an element of another group is located between them; and an energizing circuit coupled to said recording elements for passing current pulses selectively therethrough, said circuit passing said pulses simultaneously through some elements of a group of print elements while substantially no current passes through elements of any other group, and then passing current through some elements of another group of elements.

10. A method for forming a magnetic image on a magnetizeable medium, comprising: selectively passing currents along a plurality of substantially parallel paths spaced from said magnetizeable medium by more than a predetermined distance from said medium except along path portions of limited length which are closer to said medium than said predetermined distance, where each of said currents is of a magnitude which causes magnetization of the medium only when moving along one of said path portions but not when moving along the rest of the path which is more than said predetermined distance from said medium.

11. The method described in Claim 10, wherein: said magnetizeable medium moves relative to said current paths; and said current is passed in short pulses through alternate groups of said paths, wherein adjacent paths of the same group are spaced apart by at least twice the distance between adjacent paths, and then no current is passed through any of said routes for a time period which is many times longer than the duration of said pulses.

12. A magnetic recording apparatus substantially as hereinbefore described with reference to the accompanying drawings.

13. A method for forming a magnetic image on a magnetizeable medium, substantially as hereinbefore described with reference to the accompanying drawings.