JPS5938907B2 - magnetic recording head - Google Patents

Description

[Detailed description of the invention] The present invention relates to a magnetic recording device.

In printing technology using magnetic recording, there is a demand for printing alphanumeric characters and other images with fine detail.

Any type of character can be sufficiently represented by a matrix printer that represents one character with a matrix of about 32 vertical and 32 horizontal dots, but the standard size of printed characters is 2.5 in height.
Since it is about millimeters, if it is divided into 32 points, the interval between each printing or recording element must be about 0.08 mm. Making such small elements and placing them closely spaced is difficult and expensive. However, according to one embodiment of the present invention, it is possible to obtain a magnetic recording head for a printing press that can print finely in fine detail with a simple structure.

This recording head has a group of recording elements arranged at narrow intervals in a straight line perpendicular to the direction in which the magnetic recording tape passes. When a current is passed through each element, the magnetic field caused by the current creates magnetized points on the magnetic tape and records are recorded. take action. Each recording element has a conductor, and the center of the conductive portion is spaced a predetermined distance from the path of the magnetic tape. However, in the area where recording is performed, the center of the conductive part is placed sufficiently close to the magnetic tape path, so that when a predetermined amount of current is applied, a magnetized point is created on the magnetic tape through the recording element. There is. The conductor of each recording element may consist mainly of a thin nickel layer placed near the magnetic tape path and a thick copper layer placed on the side of the nickel layer opposite the magnetic tape path. A gap is created in the layer at the recording location.

When a current pulse is passed through this recording element, the magnetic tape is not magnetized where the conductive part is in the center of the copper layer, but the current pulses through the nickel layer which is close enough to the magnetic tape in the gaps between the copper layers. The magnetic field generated by this current becomes strong enough on the magnetic tape to magnetize it. By applying a series of pulses to the recording element while moving the magnetic tape, a magnetized image is created on the magnetic tape. A visible image is obtained by attaching pigment to this magnetized image and transferring the pigment to paper or other printing medium. The novel features of the invention are set out in detail in the appended claims.

Further, the present invention will be fully understood by reading the following description in conjunction with the accompanying drawings. 1 and 2 depict a printing press 10 that uses the recording head 12 of the present invention to print finely detailed characters 14 on printing paper 16 or other printing media.

The printing press 10 has a magnetic recording tape 18 with rollers 20 moving the tape 18 in a predetermined path. A motor 22 is attached to one of the rollers 20, and the tape 18 is moved by rotating the roller. The path of the tape 18 is the recording head 1.
2, where a magnetic image is recorded on the tape. The tape 18 then traverses the pigment deposition point where the pigment is deposited on the tape 18 and the tape 18
Make sure that the magnetized part of the magnet is covered with pigment. The tape 18 is then moved in front of the printing paper 16 and transfers the pigment particles to the printing paper 16. This transfer operation is caused by transfer head 28. After transfer, the printing paper 16 is advanced by rollers and a fuser 30, FIG. 1, fixes the pigment to the printing paper 16 into a permanent image. The printing machine 10 described above is designed to print character strings on paper, and the printing information is received by a receiver 32 and sent to a signal processor 34, from where it is sent to the recording head 12 and the transfer head 28. A signal is given. When a signal representing a character is received, a signal is sent on line 36 to recording head 12 to create a magnetized image on tape 18. As the tape 18 moves, it covers the magnetized image with pigment as it passes the pigment deposition point 26 and moves in front of the printing paper 16. When a line of text comes before the printing paper 16, a current pulse is sent in line 42 to the transfer head 28 on the back side of the printing paper 16, and the electric field generated by this current pulse causes the tape to The pigment particles on 18 move towards the printing paper 16. At this time, a grounded strip 29 is provided on the opposite side of the head 28 to provide a uniform electric field. When one line of character strings is printed on the printing paper 16, the paper 16 is moved so that the next line can be printed, and at the same time, the printed line is fused with the fuser 30 to fix the printed image. . FIGS. 3 to 6 depict the narrow beams of the recording head 12, which is capable of recording finely detailed magnetic character images on the magnetic recording tape 18, as described above.

As shown in FIG. 3, recording head 12 includes a thin sheet-like recording head or device 50, which includes a block-like support 52 having a convex surface 52f.
It is installed on top. As shown in FIG. 4, the recording device 50 has 32 recording elements 60a-60ff, each of which has a recording location 62a-62ff, which is capable of magnetizing a narrow area of the magnetic recording tape. I'm starting to be able to do it. The recording locations 62 are arranged at intervals along a recording line 64 in a direction intersecting the direction in which the magnetic recording tape 18 moves. 5 and 6 show details of the recording device 50 in more detail, with respect to one recording element 60dd in the recording device 50, the magnetic material layer 80 of the magnetic recording tape 18 on which an image is to be recorded. Related details are shown in FIG.

Recording element 60dd has a first or bottom layer 70 made of a medium conductivity material such as nickel and a second or top layer 72 made of a high conductivity material such as copper. The recording device 50 also has a supporting thin film 74 made of a non-magnetic material such as polyester, which supports the recording element 60dd and the nickel layer 70 of the other recording elements. When a current is applied to the recording element 60dd, the current flows along a path 76, most of which passes near the center of the copper layer 72. This is because the conductivity of copper is about six times that of nickel, and the copper layer is thicker than the nickel layer. However, near the surface 64p including the recording line 64, the recording element 6
There is a gap 78 in the copper layer 72 at 0dd so that the current path must pass through the nickel layer 70 at this location. In the part of the current path 76r where the current passes only through the nickel layer, the center of the current path is at the magnetic layer 8 of the recording tape 18.
It passes through a distance A that is relatively close to 0.

The magnitude of the current pulse applied to the recording element 60dd is made sufficiently large so that the magnetic body 80 of the recording tape 18 can be magnetized by the magnetic field generated from the current path 76r, and the distance from the magnetic layer of the tape is If the magnitude of the current is made small enough that the magnetic body 80 will not be magnetized by the magnetic field generated by the other current path portion where B is B, the recording element 6
The tape 18 is magnetized by the current flowing through 0dd.
Only a small region 82 of the magnetic layer 80 is formed. To explain the recording tape 18, there is a magnetic layer 80 made of chromium dioxide or the like, a supporting layer 84 made of a material such as Mylar, which supports the magnetic layer 80, and a support layer 84 made of a material such as polyester on top of the magnetic layer 80. The main body is a thin film 86 with low friction.
It is desirable that the particles of the magnetic layer 80 are oriented in the width direction of the tape 18, and have a hysteresis characteristic close to a rectangle. Regarding the supporting thin film 74 of the recording device 50, like most of the other conductive elements of the recording device 50, it is substantially parallel to the tape 18 in the vicinity of the recording surface 64p. Also, the center of the current path suddenly changes course and approaches the tape 18 only at the gap 78 on one side of the recording element. Now, it is desirable that the cross section of each recording element such as 60dd is trapezoidal, with the layer 70, which is closer to the recording tape path, being narrower in cross section, as shown in FIG.

This trapezoidal shape is useful for recording only at the recording location 62 in two ways. For one thing, the center of the current that flows through 76 in most parts of the recording element passes through the widest copper layer near the surface 72b, and therefore the current path is close to the magnetic layer of the magnetic tape. One example is that the distance B from the center increases. Another reason is that current flows through the recording region 70r of the nickel layer at the gap between the copper layers, but if the width of the nickel layer is narrow, the current density increases, and the strength of the magnetic field near the center of the nickel layer increases. This is in the sense that it can be made larger. Although the recording element 50 can be manufactured at a relatively low cost by well-known etching and vapor deposition methods, it is difficult to form a narrow element into a trapezoidal shape with a uniform and smooth slope.

First, the main manufacturing process is to create a multilayer thin plate containing layers of materials with two different conductivities, such as nickel and copper, and to etch this thin plate to form elongated elements and all the elements as shown in Figure 4. There is a step of leaving a connected common portion or common electrode 92 and forming a groove in the remaining portion, and a step of etching a narrow gap 78 in the layer of highly conductive material. One method is to first create a nickel-copper plywood by depositing a copper layer on top of a nickel layer. Next, the copper side of this plywood is attached to a support, and a corrosion-resistant agent is applied on the nickel side in a pattern as shown in FIG. Of course, the pattern shown in FIG. 4 may also be created on the nickel surface by exposing the anti-corrosion agent to a film made by photoreducing a pattern originally drawn in large dimensions using a well-known method. Then, the upper plywood is soaked in an etching solution that corrodes both nickel and copper, creating an element with a trapezoidal cross section as shown in Figure 6. A thin polyester plate is attached to the etched plywood. Finally, an anti-corrosive agent is applied to the area other than the gap 78 on the copper layer side, and the gap 78 is created by dipping it in an etching solution that corrodes copper but does not corrode nickel. If it is not necessary to make the cross section of the recording element trapezoidal, various techniques can be used according to methods well known in the art. The completed recording device 50 may be placed on a support 52 as shown in FIG. A layer of nickel may form on the copper surface 72b of FIG. 6 during some steps, but this has no substantial effect on the operation of the device. In order to facilitate connection to each recording element 60a-60ff, each element is provided with a tail portion 90a-90ff as shown in FIG. 4, and this tail portion widens in width and extends radially as it moves away from the recording location. .

In this way, the terminal to which the conductive wire is attached can be made wider and the connection becomes easier. A terminal on the opposite side of the recording device 50 from the tail portion 90 serves as a common electrode 92 and is connected to all recording elements. Near the recording location, the recording element is shaped like an elongated string and runs parallel to the magnetic tape path along with other recording elements. The recording device 50 installed on a support 52 is connected to a signal processor 34 by a number of conductive wires represented by lines 36 as shown in FIG.
Use by connecting to. FIG. 7 shows the state of the magnetic image recorded on the magnetic recording tape 18, and the image indicated by 100 is the upper part of the letter "C".

However, when actually printing, it is necessary to create a mirror image.
This image 100 is formed by a collection of magnetized regions 102,
The magnetized area 102 is divided into vertical stages corresponding to the spacing between recording locations between the recording elements, and horizontal stages representing the space created by moving the tape 18 between repeated currents flowing through the recording elements. It is divided by. By sprinkling pigment onto the tape 18 recorded in this way and transferring it to paper, a continuous image can be created on the paper. In one example of a printing press according to the invention, the recording elements are spaced 0.08 mm apart along the recording line 64, each element having a width of approximately 0.04 mm, and the thickness of the nickel layer 70 of each element being 0.005 mm. The thickness of the copper layer is 0.03 mm, and the length of the gap 78 is 0.02 mm.

The thicker the copper layer, the better; however, if the copper layer becomes thicker, the etching process becomes difficult even if etching is performed from both sides of the nickel-copper plywood when the spacing between recording elements is narrow as described above. Next, the current pulse applied to each recording element is a 10 ampere 1 microsecond pulse, and 2 pulses are applied every 8 elements.
At microsecond intervals, pulses can be supplied to all elements in four times. Current pulses with a rise time of 1 microsecond are easily obtained with the device of the invention.
Of course, if the cross-sectional area is as small as this element, a current of 10 amperes cannot continue to flow.
Such a large current can be passed for only 1 microsecond without destroying the device. Thus, one row of dots is recorded on the magnetic recording tape 18 every 60 microseconds, and each row of dots is almost in a straight line.
Further, the tape 18 is moved at a speed of 1.25 meters per second so that dots are formed on the magnetic tape every 0.08 mm. In FIG. 8, a recording head 112 with a wide recording width is used and a magnetic recording tape 114 with an equally wide recording width is used.
1 shows a printing machine 110 that is configured to create a magnetized dot array that spans the width of a sheet of paper.

Here, the tape 114 records a character image at the head 112 and then moves to a transfer point 116 to transfer the tape image onto a magnetic drum 118. The image on the drum is then pigmented at a pigment deposition point 120 and transferred to printing paper or print media 122. In this printing machine 110, approximately 20
If the tape is centimeter wide, the recording head 112 will have about 2,000 recording elements, making wiring to each element extremely difficult.

For example, if the terminals of each element are 2 mm wide and spread out every 4 mm, 2,000 devices will require a length of 8 meters. Therefore, although there are actually a few more elements, the terminals of each element are generally arranged as shown in FIG. 9 to minimize the space required for connection. The array 130 in FIG.
2, each element has a string-like portion 134 and a recording location 136, and all recording locations are connected to the recording line 16.
They are lined up along 8.

In addition, each element is divided into six groups 161-166,
Each group has four recording elements 132, for a total of 24 elements. The first element group 161 has four elements 132a-132d, which are connected to the recording line 1.
One side of 68 is connected to a common connection part 1601, and the other side has a terminal part 172 for each element separately. Similarly, the second and third element groups 162 and 163 are also connected to the recording line 1.
It is connected to common connection parts 1621 and 1631 on the lower side of 68, and has separate terminal parts 172 on the upper side. The remaining three element groups 164-166 are symmetrical to the upper three groups, and are connected to common connection parts 1641, 1651, and 1661 above the recording line 168, respectively, and have separate terminal parts 172 below. . The current for operating the recording element 132 is supplied to two terminals 182 and 184.
The power source 180 is obtained from a power source 180 having a power source. In other words, one end 182 of the power supply is connected to the common connection portion 16 of each of the six recording element groups through six switches 161s to 166s.
11-1661, and the other end 184 of the power supply is connected to cross conductors 191c-198c through four switches. Each of these crossing conductive wires connects three 172 terminals, and for example, a line 191c connects three recording elements 132a, 1321, and 132d lined up in the same column. Therefore, when the two switches 161s and 191 are closed simultaneously, current will flow through element 132a to record a point on the magnetic tape at the recording location 136 of this element. Each recording element 132a-1
In order to sequentially apply current to 32x, first close the group switch, for example 161s, and then close the switches 191 to 194 one after another moment by moment.
Next, the switch 161s should be opened, the switch 164s should be closed, and the switches 191-194 should be closed moment by moment in order. By the way, the string-like portion 1 of each recording element 132
A diode 200 is inserted where 34 and the cross conducting wire 191c are connected to limit the direction of current flowing through the element to one direction. This can eliminate unnecessary current. For example, when switches 191 and 161s are closed to operate element 132a, current flows unexpectedly upward through element 132b, through cross conductor 192c, downward through element 132J, and then upward through element 1321. However, this can be prevented by inserting a diode. If the element 132 is made using printed circuit technology, the spacing between the recording locations 136 can be reduced to several tens of microns, but if it is made that small, it becomes difficult to connect cross-conducting wires like 191c, and the width also increases. is too narrow, and if a chip-shaped diode is used, there will be no place to mount the diode 200.

By the way, in the arrangement using staggered terminals 172 as shown in FIG. 9, the terminal portion can be made wider without increasing the size of the entire array.
This terminal 172 is used as a terminal on the opposite side of the recording element from the common connection portion such as 1611, and the terminals of the groups such as 161 are arranged at different positions. For example, one end of the element 132d of the group 161 is connected to the terminal 172 immediately above the common connection portion 1641 of the other group.
The terminal of the element 132c of the same group 161 is located immediately above the upper side of the terminal of the element 132d. Similarly, the terminals of the other elements are also staggered, but the terminal of element 132a is located on the outer side, closer to the edge of the group. The terminals of the next adjacent group of 164 are similarly arranged, and the terminals of the first element 132
The terminal of e is arranged immediately below the common connection part 1611 of other groups, and the terminals of other elements 132f, 1132g and 132h are arranged in a staggered manner, and the terminal gradually connects to the recording line 1.
It will be located far away from 68. By arranging the terminals in this manner, a large number of terminals can be provided in a small space, and the entire terminal section can be manufactured primarily by printed circuit technology. Of course, the recording location does not necessarily have to be located on the line 68, but it is advantageous if it is on the line since no delay circuit is required. 9th
When 2048 elements are arranged in 64 groups of 32 elements each in the same arrangement as shown in the figure, the interval between the recording locations of each element is 0.1 mm, and the terminal size is a square of 1.25 mm on each side. , the size of the entire array falls within a range of 20 cm and 5 cm in length and width.

FIG. 10 shows a portion of an array 270 of the above type, which consists of eight units 272, each unit containing eight element groups, e.g. 281-288. Each group has 32 elements and their terminals 252 are staggered. This array is curved gently, and the recording locations are lined up along 290 lines. However, in FIG. 10, the protective sheet 250 is cut out so that the arrangement can be clearly seen. Although a special embodiment of the present invention has been described above, modifications and variations can be easily made by those skilled in the art.

Therefore, the scope of the claims of the present invention should be considered to include such modifications.

[Brief explanation of drawings]

FIG. 1 is a simplified external view of a printing press constructed in accordance with one embodiment of the present invention. FIG. 2 is a plan view of the printing press shown in FIG. 1, also partially showing the circuitry. FIG. 3 is an external view of the recording head of the printing machine of FIG. 1. 4 is a view of the inside of the recording head of FIG. 3 taken along a plane perpendicular to the arrow 4 in FIG. 3. FIG. FIG. 5 is an enlarged view of a cross section perpendicular to the arrow 5 in FIG. FIG. 6 is an enlarged view of a cross section perpendicular to the arrow 6 in FIG. 4. FIG. 7 is an enlarged view of a portion of the characters produced by the printing machine of FIG. 1.
FIG. 8 is an external view of a printing press manufactured according to another embodiment of the present invention. FIG. 9 is a simplified plan view of a recording element array that can be used in the apparatus of FIG. 10th
The figure shows a slightly more detailed view of the recording head of the apparatus of FIG. 12... Recording head, 18...
... Magnetic tape, 16... Printing paper, 28.
...Transfer head, 36...Device for passing current, 60a to 60ff...Recording element, 62,8
2,136... Recording location, 70,72...
...Electric conductor portion, 74...Support thin film, 76.
... Center of current path, 80 ... Magnetized medium,
118...Magnetic drum, 132b...
Third element, 132d...First element, 132
e~132g...Conductor part, 133c...
...Second element, 1611-1661... Common connection part, 161s-166s, 191, 194...
...Switch, 168...Record line,...
...terminal, 180...power supply device.

Claims (1)

[Claims] 1. A magnetic recording head 12 located along a path of a magnetic recording device in which a magnetized medium 80 is stretched along a predetermined path, the recording head having a short length. including electrical conductor portions 70, 72 in which the center of the current path and the center 76 of the current path are separated by a distance B or more except at a location 82; It has one recording element 60dd with a second distance A smaller than the first distance, and a device 36 for passing a current through the conductor portion, and the magnitude of the current passed by the current passing device 36 is as described above. changing the magnetization of the magnetized medium 80 when the current is at a second distance A from the path of the magnetized medium 80 and changing the magnetization of the medium when the current is at a first distance B from the medium path; A magnetic recording head that is as big as it is. 2. The magnetic recording head according to claim 1, wherein the conductor portions 70, 72 include a first layer 70 located close to the magnetic medium 80 and having a first conductivity; a second layer 72 located on the opposite side of the magnetic medium 80 from the first layer and electrically connected to the first layer and having a second conductivity higher than the first conductivity; , a magnetic recording head in which the second layer of the conductive portion is missing at the recording location 82. 3. The width of the electrical conductor portions 70, 72 is narrowed in the thickness direction such that the width of the electrical conductor portions 70, 72 is the smallest on the surface closest to the path of the magnetized medium 80. The magnetic recording head described in section. 4. The magnetic recording head according to claim 2, wherein the first layer 70 is made of nickel and the second layer 72 is made of nickel.
A magnetic recording head such as is made of copper. 5. A magnetic recording head 12 located along a path of a magnetic recording device in which a magnetized medium 80 is stretched along a predetermined path, the magnetic recording head 12 having a convex and gentle shape with respect to the path of the magnetized medium 80. a supporting thin film 74 made of a non-magnetic material that has a curved shape and is closest to the magnetized medium 80 at a predetermined location; and a plurality of recording elements 60a to 60ff mounted in parallel on the supporting thin film 74. each recording element has a string of electrical conductor having a termination 76 of the current path away from the path by a first distance B or more excluding a portion along a recording location of limited length; The center 76 of the current path is a second distance A shorter than the first distance B up to the path, and the recording elements 60a to 60 are apart from the path.
ff, and the current is applied to the magnetized medium 80 at a predetermined location.
a current that changes the magnetization of the magnetized medium when the current is a second distance A distance from the path of the magnetized medium 80 and does not change the magnetization of the magnetized medium when the current is a first distance B distance from the path of the magnetized medium 80; A magnetic recording head comprising a device 36 for passing an electric current through the conductor portion, which is configured to carry a current. 6. The magnetic recording head according to claim 5, wherein the recording elements 60a to 60ff are divided into a plurality of groups, and each group has a common connection portion 161i to which one end of each element is connected. .about.166i, the other end of each element being a separate terminal 172, the groups being closely spaced across the width of the path of the magnetized medium 80, and the current carrying device comprising: A power supply device 180 for supplying current; a first plurality of switches 161s-1 for connecting the power supply device to the common connection portion;
66s, and a second plurality of switches 191-191 for connecting the power supply device to the separate terminals of the recording element.
194 magnetic recording head. 7. A magnetic recording head according to claim 5, wherein the plurality of recording elements form a first element group, and each recording element has a string-like conductor portion including the recording location 136. The recording location is an almost virtual recording line 168
are located at close intervals along the recording line, and the elements have a common connecting portion 161i where the elements connect to each other on a first side of the recording line and a string-like portion of the elements on a second side of the recording line. Each element has a separate terminal 172, which is several times wider.
Further, the terminals are arranged in a staggered manner, and the first element 132d has a first terminal extending to a predetermined side of the string-like portion of the first recording element, and A second recording element 133c having a string-like portion adjacent to the string-like portion has a second terminal extending to a predetermined side of the string-like portion of the second recording element. slightly farther from the recording line than the first terminal;
A third recording element 132b having a string-shaped portion adjacent to the string-shaped portion of the second recording element has a third terminal extending to a predetermined side of the string-shaped portion of the third recording element. In the magnetic recording head, the third terminal is slightly farther from the recording line than the second terminal. 8. The magnetic recording head according to claim 7, wherein the plurality of recording elements has a second group of elements arranged at narrow intervals, each element extending substantially along the recording line 168. the second group has a common connection portion 164i on the second side of the recording line, and the second group has a common connection portion 164i on the second side of the recording line; On the side, the elements of the second group each have separate terminals 172, and the terminals of the second group of elements are arranged staggered from each other like the terminals of the first group of elements. magnetic recording head.