JPH05298627A - Recording device - Google Patents

Abstract

PURPOSE:To obtain the recording device of high print quality by forming grooves at both ends of the scale of a magnetic linear encoder and fitting those grooves into holes for positioning of the side plates of a recording device main body. CONSTITUTION:The grooves 520 are formed integrally by forging machining at both the end parts of the scale part 501, and a fine-pitch magnetized pattern is magnetized at its magnetized part 511 on the bases of the reference surface 520A of the grooves 520 formed at both the end parts of the scale. The scale part 501 of this magnetic linear encoder is positioned at the recording device main body by having the reference surfaces 520A of the grooves engaged with the positioning holes formed in the side plates 101A and 101B of the recording device main body. The scale part 501 is positioned lengthwise by making the inside surface 520B of one groove 520 about on the outside surface of the side plate 101A and positioning and fixing the inside surface 520B of the groove 520 provided at the other end part with a leaf spring 102 fitted to the side plate 101B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device using a magnetic linear encoder.

[0002]

2. Description of the Related Art Conventionally, a linear encoder is generally used for detecting the position of a carriage of a recording apparatus, detecting the amount of movement, and the like. As a linear encoder system, generally, two systems of an optical system and a magnetic system are known.

However, since the optical linear encoder optically reads the slit formed on the band-shaped scale, if dust or dust adheres to the slit,
There is a problem that a reading error occurs, and the pitch of the slits cannot be made fine (minimum pitch: about 140 μm) due to processing restrictions when forming the slits on the band-shaped scale, so the detection accuracy is high. There was a problem of having an eye field.

On the other hand, in the magnetic type linear encoder, since the magnetized portion magnetized in the magnetic material is magnetically read, it is resistant to dust and dust, and the magnetized pitch of the magnetized portion can be made fine ( Minimum pitch: about 40 μm)
It has the features that the detection accuracy can be improved and the response speed is fast.

Further, a magnetic material that can be rolled, drawn, cut, etc. has been developed, which has become cheap in terms of cost, and has been attracting attention in recent years.

9 and 10 are a perspective view and a sectional view, respectively, showing a schematic structure of a magnetic linear encoder used in a conventional recording apparatus. 9 and 10, reference numeral 101 indicates a scale portion made of a magnetic material,
The scale portion 101 is provided with a magnetized portion 102 magnetized at a fine pitch. A head 103 is provided at a position facing the magnetized portion 102. When the head 103 moves in the direction of arrow A or B in the figure, the ferromagnetic magnetoresistive effect element 104 provided on the head 103 is provided.
The magnetized pattern of the magnetized portion 102 is read by (hereinafter referred to as an MR element), and position detection, movement amount detection, and the like are performed based on the read magnetized pattern.

However, in order to read the magnetization pattern of the magnetized portion 102 with the MR element 104, the magnetization pattern and M
It is necessary to keep the air gap G with the R element 104 to be about 10 mm, the mechanism for guaranteeing this air gap G becomes complicated, and further adjustment is required, so the magnetic linear encoder becomes expensive. There was a problem.

In order to solve this problem, it has been proposed that a magnetic material is processed into a wire shape and the head is incorporated into a housing having a bearing to keep a constant air gap. 11 and 12 are a perspective view and a sectional view, respectively, showing this solution. 11 and 12, reference numeral 2
Reference numeral 02 denotes a scale portion formed in a wire shape and having a circular cross section and made of a magnetic material. The scale portion 202 is provided with a magnetized portion 202 magnetized at a fine pitch.
A head 203 is provided at a position facing the magnetized portion 202. When the head 203 linearly moves in directions C and D shown by arrows in the figure, the MR element 204 provided on the head 203 causes the magnetized portion to move. Position detection, movement amount detection, etc. are performed by a pattern reading detection circuit (not shown).

The air gap G for reading the magnetized pattern with the MR head 204 has bearings 205 and 205 fitted to the wire-shaped scale portion 201 and the head 20.
The housing 206 for supporting 3 always maintains about 10 μm without any adjustment or the like, and since the mechanism is simple, it is possible to provide a magnetic linear encoder at a low cost, and since there is no need for maintenance, various It is being used in devices.

Further, since the wire-shaped scale portion is formed by drawing, the cost of the scale portion is low.

On the other hand, the recording apparatus is required to have high printing accuracy due to the widespread use of personal computers and word processors, and the recording apparatus is strongly required to be reduced in price due to the reduction in price of the personal computer. ..

Under such circumstances, the magnetic linear encoder has been used for position detection and movement amount detection of a carriage having a recording head.

When the wire-shaped scale portion is fixed to the recording apparatus, it is difficult to position and fix the scale portion in the recording apparatus when the sectional shape is circular. Therefore, fixing members are attached to both ends of the scale portion. It is fixed, and the member is positioned and fixed with respect to the recording apparatus.

[0014]

However, in the conventional example, since the scale fixing member is added, the number of parts is increased, and the step of positioning and fixing the fixing member at both ends of the scale portion is performed. Since it is necessary, the manufacturing process becomes complicated, which causes the cost of the magnetic linear encoder to increase.

Further, the surface due to the mutual angle difference between the MR element of the magnetic linear encoder and the magnetized portion of the scale portion is deteriorated by the addition of the fixing member and the step of adhering and fixing. It was

Further, since it is necessary to fix the fixing members to both ends of the scale portion, the magnetic head is attached to the scale portion, so that the workability is poor when handling the magnetic linear encoder. It was.

When the magnetic linear encoder as described above is used in a recording apparatus, the cost of the magnetic linear encoder increases and the cost of the entire recording apparatus increases, and the accuracy of the rotational direction of the magnetic linear encoder decreases. Due to the addition of the adjustment process at the time of attachment to the device, there were major problems of increased cost and reduced reliability.

Further, in the conventional example, since the wire-shaped scale portion is fitted with the bearing attached to the housing supporting the head, the air gap between the magnetizing pattern and the MR element is kept constant. However, since the scale portion has a circular cross-sectional shape, the head rotates with respect to the scale portion. Further, since the magnetized portion is magnetized in a part of the wire shape, the magnetized portion is linear because the outer peripheral portion is an arc, and the magnetized portion is required to obtain a desired linear encoder output. The mutual angular difference between the magnetization pattern and the MR element must be suppressed to about ± 5 °.

This will be described with reference to FIG. 13 for explaining the mutual angular difference between the magnetization pattern and the MR element and FIG. 14 which is a graph showing the change in the output of the linear encoder due to the angular difference. In, the MR element 303 is provided so as to face the magnetized pattern of the magnetized portion 302 provided on the scale portion 301. Since the cross-sectional shape of the scale portion 301 is circular as shown, the MR element 303 freely rotates with respect to the scale portion 301. Further, since the outer circumference of the scale portion 301 is arcuate, the magnetized portion 302 is linearly magnetized in a part of the scale portion 301, and therefore when the MR element rotates in the + θ and −θ directions in the figure, As shown in the graph of FIG. 14, the output of the MR element 303 changes. To obtain the desired output from the MR element
4 output of Va or more is required, and the magnetizing unit 302 and MR
When the mutual angle difference between the elements 303 is ± 5 ° or more, the output of the MR element 303 becomes Va or less, and it becomes impossible to obtain a desired output.

Therefore, when the magnetic linear encoder is used in a recording apparatus, it is indispensable to suppress the mutual angular difference between the MR element and the magnetized portion within ± 5 °, and it is necessary to improve and adjust the precision of parts. However, there is a big problem that the cost of the entire recording apparatus increases.

Therefore, an object of the present invention is to provide a recording apparatus using a magnetic linear encoder which can be positioned with high accuracy with respect to the recording apparatus and can be easily attached to the recording apparatus.

Another object of the present invention is to provide a recording apparatus using a magnetic linear encoder that eliminates the mutual angular difference between the MR element and the magnetized portion and does not require an adjustment process or highly accurate parts. It is in.

[0023]

In order to achieve the above object, the present invention provides a recording apparatus using a magnetic linear encoder comprising a magnetized scale portion and a magnetic head movable along the scale portion. In the above, a groove is formed at both ends of the scale of the magnetic linear encoder, and the groove of the scale portion is fitted and positioned in the positioning hole of the side plate of the recording apparatus main body, and the scale portion is attached to the side plate of the recording apparatus main body. The recording apparatus is characterized in that it is biased in the axial direction with respect to.

Further, according to the present invention, in a recording apparatus using a magnetic linear encoder comprising a magnetized scale portion and a magnetic head movable along the scale portion, the magnetic head extends along the scale portion via a bearing. The recording apparatus is slidably attached to the scale unit and is provided with rotation preventing means for preventing the magnetic head from rotating with respect to the scale unit.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described with reference to the drawings. The material, shape, magnetization direction, etc. of the scale portion of the magnetic linear encoder suitable for use in the present invention will be outlined in advance. Fe-Cr-Co magnets are preferable as the magnet material of the scale portion. This magnet has magnetic properties equivalent to those of an alnico magnet, and is a material that overcomes the hard and brittle weakness of a permanent magnet, and a 0.1 mm wire or plate can be easily mass-produced by rolling or drawing. This magnet material is used for sputtering, vapor deposition, and CVD.
It is formed as a thin film formed by a film forming method such as the above, or is formed as an alloy product formed by sintering or a normal alloying method. As for the shape, the cross section is circular or rectangular (square).
Although it is a wire or plate having an arbitrary shape such as, it can be easily obtained at low cost by using the above-mentioned magnet material. Also,
The magnetization direction is preferably perpendicular magnetization in order to make the pitch fine (fine pitch is necessary when more precise dot control is required than in monochrome printing such as in color printing). The material, shape, magnetizing direction, etc. of the scale portion of the magnetic linear encoder suitable for use in the present invention are as described above, but the present invention, unless otherwise limited to the claims, It is not limited to the material, shape, magnetizing direction, etc. of the scale part. Further, as a magnetic detection head suitable for use in the present invention, an MR element, which is a magnetoresistive element made of an iron-nickel alloy, is preferable.
It is not limited to the element.

Referring to FIG. 1 showing a recording apparatus using a magnetic linear encoder of the present invention, a carriage 1 shown by a one-dot chain line is equipped with a recording head 1h of a wire dot type, a thermal transfer type, an ink jet type or the like. .. The carriage 1 is also guided by a lead screw 11 having a spiral groove formed on the outer peripheral surface thereof, and the engagement portion thereof is driven along the spiral groove by the rotation of the lead screw 11, so that the carriage 1 is mounted on the outer peripheral surface of the platen 12. The dots D are recorded on the recording medium 13 at the pitch P while reciprocating in the direction of the arrow in the drawing with respect to the recording medium 13 sent while being wound, and an image, a character or the like is drawn.

The carriage 1 constructed as described above includes
A magnetic linear encoder for detecting the position of the carriage and the amount of movement of the carriage is provided. This magnetic linear encoder uses, for example, 18
Scale part 501 magnetized with a magnetized pattern at a pitch density corresponding to 0 dot / inch (dpi) or 360 dpi
Is a frame 100 of the recording apparatus main body (schematically shown)
On the other hand, the magnetic head main body 502 including an MR element is fixed inside the carriage to detect the position of the carriage 1.

Further, a flexible substrate 503 is connected to the magnetic head body 502 for extracting the output from the MR element in the magnetic head to the outside, and this substrate 503 is connected.
Is connected to a connecting portion 504 via a connector (not shown) and is connected to a substrate 5 (shown by a broken line in the drawing) mounted on the carriage 1.

The substrate 5 and the recording head 1h are electrically connected to the recording device control circuit substrate 4 fixed on the frame 100 of the main body through the flexible cable 3.

(First Embodiment) FIG. 2 is a perspective view of a magnetic linear encoder of the present invention for achieving the above-mentioned first object of the present invention, and FIG. 3 is a scale portion of the magnetic linear encoder. FIG. 3 is a cross-sectional view showing a state in which is attached to the recording apparatus main body.

The scale portion 501 has grooves 520 at both ends.
520 is integrally formed by forging, and the magnetized portion 511 has a magnetized pattern magnetized at a fine pitch. The magnetization pattern magnetized in the magnetized portion 511 is magnetized with reference to the reference surface 520A of the groove 520 formed at both ends of the scale. The scale portion 501 of this magnetic linear encoder performs positioning with respect to the recording apparatus body by fitting the reference surface 520A of the groove 520 into the positioning holes provided in the side plates 101A and 101B of the recording apparatus body. .. To position the scale portion 501 in the longitudinal direction, the inner surface 520B of one groove 520 is butted against the outer surface of the side plate 101A, and the inner surface 520B of the groove 520 provided at the other end is attached to the side plate 101B. The leaf spring 102 is positioned and fixed by urging it in the direction of arrow F in FIG. The biasing force in the direction of arrow F also has a function of removing the bending of the scale portion 501 due to its own weight.

Magnetic head body 50 composed of MR elements and the like
2 is fixed to the housing 513. Bearings 514 and 514 are fixed to both ends of the housing 513, and by fitting with the scale portion 501, an air gap G between the MR element and the magnetized portion 511 is fixed (10 μm).
To maintain.

(Second Embodiment) FIG. 4 is a perspective view of a magnetic linear encoder of a second example for achieving the above-mentioned other object of the present invention, and FIG. 5 is a perspective view of the second example. FIG. 3 is a cross-sectional view of a state in which the scale unit of the magnetic linear encoder is attached to the recording apparatus main body.

The scale portion 501 has bearings 514 and 514 for supporting the magnetic head 502 including the MR element 502 and the like.
Has a non-circular cross section that prevents
01 and the engaging portions of the bearings 514 and 514 described later are configured in complementary shapes. The scale portion and the bearing can have any shape as long as the engaging portion has a non-circular cross section, but in view of the manufacturing process of the linear encoder, it is preferable that the scale portion and the bearing have a finite axis of symmetry. As an example, as shown in FIG. 4, the scale portion 501 has a straight line portion in the facing portion, and the other facing portion has an arc shape, and the magnetizing pattern is formed on the magnetizing portion 511 in the straight portion at a fine pitch. Is magnetized.

The aforementioned magnetic head 502 is the housing 51.
3, the bearings 514, 514 are fixed at both ends of the housing 513, and by fitting with the scale portion 501, an air gap G10 (about μm) between the MR element 515 and the magnetized portion 511 is fixed. It keeps constant. Further, the bearings 514, 514 are formed with a linear portion corresponding to the linear portion of the scale portion 501, that is, a complementary shape, and the magnetic head 502 is formed by this linear portion.
Is prevented from rotating with respect to the magnetized portion 511 of the scale portion 501, and it is guaranteed that the mutual angular difference between the MR element 515 and the magnetized portion 511 is maintained within ± 5 °.

As described above, the scale element 501 has a cross-sectional shape having a finite axis of symmetry, and the opposing portion has a linear portion.
Rotation with respect to the magnetized portion 511 is prevented, and a mutual angular difference can be guaranteed within ± 5 ° with a simple configuration without adjustment. Further, since the width of the magnetized portion can be increased by magnetizing the linear portion of the cross-sectional shape of the scale portion, the output of the MR element 515 can be stabilized. Furthermore, since the cross section of the scale part has a straight line part, the magnetized part can be easily identified visually, and can be easily attached when incorporating it into the recording device. Since it can be used for positioning when fixing the recording medium, the process at the time of assembling the device can be simplified and the cost of the recording device can be reduced.

Further, since the scale portion can be manufactured by drawing, the adoption of this second sectional shape can greatly contribute to the stabilization of the manufacturing line.

In the second embodiment, the case where the magnetized portion is provided on one side of the cross section of the scale portion has been described. However, when the magnetized portions are provided on both of the facing straight line portions, the MR element and the magnetized portion are magnetized. Since the parts need not be aligned, the assembly process can be further simplified.

The same effect can be obtained by providing the magnetized portion in a portion other than the straight line portion of the cross section of the scale portion.

Further, the inner circumference of the bearing is circular, and the same effect can be obtained by providing the housing with a portion for preventing rotation corresponding to the linear portion of the cross section of the scale portion. In this case, the shape of the bearing is simplified, so that the cost is further reduced.

Even if the cross-sectional shape of the scale portion is formed in a semicircular shape as shown in FIG. 6, the same effect can be obtained, and the straight line portions do not have to face each other.

Even if the cross-sectional shape of the scale portion is formed into an elliptical shape as shown in FIG. 7, the same effect can be obtained for preventing the angular difference between the MR element and the magnetized portion. In this case, the magnetic linear encoder is used. Durability is improved.

The same effect can be obtained even if the cross-sectional shape of the scale portion is formed in a triangular shape as shown in FIG. 8, and the same effect can be obtained even if it is formed in a polygonal shape.

[0044]

As described above, according to the present invention,
Since it is configured as described above (grooves are integrally formed with the scale portion at both ends of the scale portion by forging), an inexpensive, simple configuration, and accurate recording device can be obtained.
Further, as a result, a recording apparatus that is inexpensive and has high printing quality and high reliability can be obtained.

Further, according to the present invention, the air gap between the MR element and the magnetized portion of the magnetic linear encoder can be maintained constant, and the angular difference between the MR element and the magnetized portion can be eliminated. Therefore, it is possible to obtain a recording device that can obtain a stable MR element output. Further, as a result, a recording apparatus that is inexpensive and has high printing quality and high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a recording apparatus of the present invention.

FIG. 2 is a perspective view of a magnetic linear encoder used in the recording apparatus of the present invention to achieve the first object of the present invention described above.

FIG. 3 is a cross-sectional view of a state in which the scale unit of the magnetic linear encoder of FIG. 2 is attached to the recording apparatus main body.

FIG. 4 is a perspective view of a magnetic linear encoder of a second example used in the recording apparatus of the present invention to achieve the other object of the present invention described above.

5 is a cross-sectional view of a state where the scale unit of the magnetic linear encoder of FIG. 4 is attached to the recording apparatus main body.

FIG. 6 is a sectional view of a magnetic linear encoder of a third example.

FIG. 7 is a sectional view of a magnetic linear encoder of a fourth example.

FIG. 8 is a sectional view of a magnetic linear encoder of a fifth example.

FIG. 9 is a perspective view of a magnetic linear encoder used in a conventional recording apparatus.

10 is a sectional view of a magnetic linear encoder used in the recording apparatus of the conventional example of FIG.

FIG. 11 is a perspective view of a magnetic linear encoder used in a recording apparatus of a conventional example.

FIG. 12 is a sectional view of a magnetic linear encoder used in the conventional recording apparatus of the conventional example of FIG. 11.

FIG. 13 is an explanatory diagram of a mutual angular difference between the MR element and the magnetized portion.

FIG. 14 is a graph showing the output of the MR element according to the mutual angular difference between the MR element and the magnetized portion.

[Explanation of Codes] 1 Carriage 11 Lead screw 501 Scale part 502 Magnetic head 520 Groove 513 Housing 514 Bearing 515 MR element

Claims (9)

[Claims] 1. A recording apparatus using a magnetic linear encoder comprising a magnetized scale portion and a magnetic head movable along the scale portion, wherein grooves are formed at both ends of the scale of the magnetic linear encoder. A recording part characterized in that the groove of the scale part is fitted and positioned in a positioning hole of the side plate of the recording device body, and the scale part is axially biased with respect to the side plate of the recording device body. apparatus. 2. The recording apparatus according to claim 1, wherein the magnetic head is mounted so as to be movable along the scale portion via a bearing. 3. The recording apparatus according to claim 1, wherein the groove is formed integrally with the scale portion by forging. 4. A recording device using a magnetic linear encoder comprising a magnetized scale portion and a magnetic head movable along the scale portion, the magnetic head being slidable along the scale portion via a bearing. A recording apparatus, which is attached to the scale unit and is provided with a rotation preventing unit that does not rotate the magnetic head with respect to the scale unit. 5. The recording apparatus according to claim 4, wherein the rotation preventing means forms a non-circular cross section of the scale portion,
A recording apparatus provided by forming a cross-sectional shape of a support hole of the bearing in a complementary shape to a cross-sectional shape of a scale portion. 6. The recording apparatus according to claim 5, wherein the scale portion has at least one linear portion in a part of its cross section. 7. The recording apparatus according to claim 6, wherein a linear portion of a cross section of the scale portion is magnetized. 8. The recording apparatus according to claim 7, wherein the cross section of the scale portion has at least one axis of symmetry. 9. The recording apparatus according to claim 8, wherein the cross section of the scale is semicircular, elliptical or triangular.