JP3014539B2 - Recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus using a magnetic linear encoder, and more particularly to a serial recording apparatus provided with a magnetic linear encoder along a moving direction of a carriage.

[0002]

2. Description of the Related Art A serial recording apparatus records (prints) a carriage on which a printing head as a recording means is mounted while scanning a recording medium, that is, recording paper, in a horizontal direction. When the fluctuation occurs, density unevenness of the recording result occurs. In particular, in a color printer, a shift in color registration occurs, which is a problem.

Conventionally, as one method of solving these problems, the amount of movement of a carriage equipped with a recording means with respect to the main body of the recording apparatus is detected, and the result of the detection is synchronized with the movement of the carriage by the recording means. A configuration for performing a recording operation is known. That is, the scale section of the linear encoder is fixed to the main body of the recording apparatus, and the detection section of the linear encoder is mounted on a carriage that moves relatively to the scale section of the linear encoder, while the output signal from the detection section is amplified. Then, the recording signal is taken out of the carriage and a recording signal is generated in synchronization with the amplified signal, thereby preventing print density unevenness and color registration deviation.

Conventionally, as a linear encoder used in this type of storage device, a film or a thin plate is provided with a portion for transmitting light and a portion for blocking light alternately, and this is detected by a combination of a photodiode and a photo transistor. Encoders have been the mainstream, but there is a problem in that high resolution is very expensive, and there is a problem that the recording device is very susceptible to dust such as paper dust.
At present, it is difficult to use it for an ink jet recording apparatus or the like that requires a resolution of about 0 dots / inch.

To solve the above-mentioned problems, a magnetic linear encoder described in Japanese Patent Publication No. 62-57929 is in a practical stage. The scale portion of the magnetic linear encoder has magnetic anisotropy in the perpendicular magnetization recording direction, and continuously magnetizes a fixed portion of the scale portion of the linear encoder at the same pitch, and triggers the recording head drive of the recording device. Are used for generating a carriage control timing signal and a position detection signal.

[0006]

In the prior art, however, the scale portion of the linear encoder has a rod shape having a circular cross section. In this case, a part of the outer periphery of the scale portion is magnetized along the axis. Therefore, when attaching the scale section to the main body frame of the recording apparatus, it is necessary to attach the magnetized section of the scale section in a certain direction toward the magnetic head, and the attaching operation involves considerable difficulty.

Accordingly, an object of the present invention is to provide a magnetic linear encoder which can be easily mounted on a main body frame of a recording apparatus without adjustment work regardless of the magnetized portion of the scale section. An object of the present invention is to provide a recording apparatus which has solved the disadvantages.

[0008]

In order to achieve the above-mentioned object, the present invention provides a carriage having a recording head mounted thereon and reciprocating along a platen, and a magnetic type arranged along the moving direction of the carriage. In a recording apparatus having a magnetized scale section of a linear encoder and a magnetic linear encoder mounted on a carriage and reading a magnetization pattern of the scale section, the scale section has a circular rod shape in cross section. The recording device is characterized in that the magnetized portion is formed by magnetizing the entire circumferential direction, and the rod-shaped scale portion is attached to the main body frame of the recording device without adjusting the magnetization direction. Is what you do.

The present invention also provides a carriage on which a recording head is mounted and which reciprocates along a platen, a magnetized scale portion of a magnetic linear encoder disposed along the moving direction of the carriage, and a carriage. In a recording apparatus having a magnetic head of a magnetic linear encoder mounted and reading a magnetization pattern of a scale portion, the scale portion has a circular rod-shaped cross section, and is magnetized in the entire circumferential direction. In this case, a recording device is used.

[0010]

Next, a preferred embodiment of the present invention will be described with reference to the drawings. The material, shape, magnetization direction and the like of the scale portion of the magnetic linear encoder suitable for use in the present invention will be outlined in advance. As the magnet material of the scale portion, an Fe—Cr—Co magnet is preferable. This magnet has the same magnetic properties as an alnico magnet, and is a material that overcomes the hard and brittle weaknesses of a permanent magnet. A 0.1 mm wire or plate can be easily mass-produced by rolling or drawing. This magnet material is used for sputtering, evaporation, CVD
Etc., or as an alloy made by sintering or a normal alloying method. In addition, the cross section is circular or rectangular (square)
Although it is a wire or a plate having an arbitrary shape such as the above, 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 (a fine pitch is required when dot control with higher precision than monochrome printing is required, for example, in color printing). The material, shape, magnetization direction, and the like of the scale portion of the magnetic linear encoder suitable for use in the present invention are as described above, but the present invention is not limited to these unless particularly limited to the claims. The material, shape, magnetization direction and the like of the scale part are not limited. As a magnetic detection head suitable for use in the present invention, an MR element, which is a magnetic resistance element made of an iron / nickel alloy, is preferable.
It is not limited to the element. In this specification,
Reference examples that are related technologies or peripheral technologies of the embodiments of the present invention will also be described.

FIG. 1 is a perspective view of a main part of a recording apparatus according to the present invention shown together with a recording sheet as a recording medium. In FIG. 1, a carriage 1 indicated by a dashed line carries a recording head 1h of an ink jet recording system or the like, and is guided so as to reciprocate by a guide shaft 11 having a spiral groove formed on an outer peripheral surface. That is, the carriage 1 includes the guide shaft 1
1 is engaged with the helical groove, and when the guide shaft 11 is driven to rotate by a carriage motor (not shown), the carriage locks the guide shaft. It moves along the spiral groove of the body 11. As a result, the carriage 1 is reciprocated in the direction of the arrow in the figure with respect to the recording sheet wound on the outer peripheral surface of the platen 12, and during this reciprocation, the recording sheet 13 is ejected by the inkjet from the recording head 1h. Images and characters are recorded by recording dots D at a pitch P on the top.

A magnetic linear encoder that detects the position of the carriage 1 and generates a synchronization signal is provided for the carriage 1 configured as described above. The magnetic linear encoder moves along the guide shaft 11. Scale part 5 which is arranged parallel to and fixed to the main body frame of the recording apparatus
And a magnetic head 502 mounted in the carriage so as to be able to move along the scale portion. The scale section 501 is formed of the above-described magnetic material, and has a magnetic pattern magnetized at a print pitch density corresponding to, for example, 180 dots / inch (dpi) or 360 dpi. The magnetic head 502 includes an MR element for reading a magnetic pattern.

A flexible printed circuit board 503 for extracting an output signal from an MR element in the magnetic head to the outside is connected to the magnetic head 502, and a contact portion 504 is connected to a connector (not shown). And then
It is connected to a substrate 5 (shown by a broken line) mounted on the carriage 1. The board 5 and the recording head 1h are electrically connected to the printer control circuit board 4 fixed to the main body frame 100 via the flexible cable 3.

FIG. 2 is an enlarged perspective view of a reference example of a magnetic linear encoder of a recording apparatus embodying the present invention. As shown in FIG.
1 is continuously magnetized at different pitches in two rows.
In FIG. 2, the upper row of magnetizing lines 505 is, for example, 180
In dpi, the lower row of magnetized lines 506 is
It is magnetized at 360 dpi which is twice the density of.

Next, FIG. 3 is a drawing showing a reference example of a detection circuit of a magnetic linear encoder, which detects a magnetic pattern of a scale portion of a linear encoder mounted on the carriage and fixed to a main body frame. The detection unit 101 (the magnetic head 502) that detects the relative movement position of the carriage with respect to the scale unit by performing the above-described operation includes an MR element or the like that operates based on the magnetoresistance effect.
The magnetoresistive elements 102 and 103 are provided integrally. Further, the detection unit 101 is connected to a substrate 5 (shown by a broken line) mounted on the carriage. To this substrate, amplifiers 104 and 105 for constituting a constant current circuit, an amplifier 106 for amplifying the detected signal, and a comparator 107 are connected in a known manner, and output an output signal 108. A variable resistor 201 for determining a reference voltage is connected to the comparator 107, mounted on the substrate 5, and adjusted on a carriage.

The operation of the above-described configuration will be described. The magnetic sensing elements 102 and 103 are respectively provided with a constant current circuit 104,
A constant current is supplied through the detecting unit 10.
As the magnetic head 1 (see FIG. 1) moves along the scale section 501 (see FIG. 1) of the linear encoder, the resistance of the magnetic sensing elements 102 and 103 changes, and the amount of change in the resistance Is detected as a voltage fluctuation and amplified by the amplifier 106, and the amplified signal is input to one input terminal of the comparator 107. In the comparator 107, an output signal 108 is obtained by comparing with a reference voltage which is set in advance by adjusting the variable resistor 201 and is input to the other input terminal of the comparator 107. The circuit example described above is for one magnetized row, for example, the magnetized line 505 (see FIG. 1), and is the same for the other magnetized row, for example, for the magnetized line 506 (see FIG. 1). Circuit is prepared.

FIG. 4 shows an output waveform corresponding to the above-described circuit example. In FIG. 4, (a) is 180 dpi.
1 that detects the magnetized line 505 corresponding to
07 shows the input waveform of FIG. 7, (c) shows the output signal 108 of the comparator 107, and (d) shows the drive pulse of the recording head 1h triggered by the rise of the waveform of (c). Similarly, (b) shows the input waveform of the comparator 107 that has detected the magnetized line 506 corresponding to 360 dpi, (e) shows the output signal 108 of the comparator 107, and (f) shows the rising edge of the waveform of (e). Shows a drive pulse of the recording head 1h that has triggered.

Therefore, the magnetizing line 506 can output a drive pulse for the recording head 1h at twice the density (at half the pitch) of the magnetizing line 505, so that the magnetizing line 506 or the magnetizing line 506 can be output. By selecting either one, a recording device capable of recording at two different pitches (180 dpi / 360 dpi) with one magnetic linear encoder can be obtained by simple software changes without hardware changes. As a result, it is easy to develop series having different recording densities, and a recording apparatus can be obtained with higher productivity.

In this example, the magnetization pitch of the scale portion of the magnetic linear encoder is 360 dpi and 180 dpi.
Although the description has been made with two types of pi, it is apparent that magnetization can be performed at other pitches, and three or more types may be provided. In this example, the MR element and the detection circuit for detecting the magnetization pattern of the magnetic linear encoder are 180 dpi and 3 dpi.
Although separately provided for 60 dpi, two magnetizing lines are provided on opposite sides of the scale section of the magnetic linear encoder, respectively, and when the scale section of the magnetic linear encoder is disposed with respect to the magnetic head 502, By inverting, one MR element and detection circuit for one magnetization pitch can be configured to detect either 180 dpi or 360 dpi.

FIG. 5 is a plan view showing another reference example of magnetization in the scale section of the magnetic linear encoder of the recording apparatus of the present invention. In FIG. 5, the lower high-density magnetization example generates the position and the drive timing of the recording head 1h as in the first example, and the upper low-density magnetization example shows the position of the recording head 1h. And to trigger functions other than the generation of drive timing. In this embodiment, it is preferable to use a bubble jet type ink jet recording apparatus as the recording apparatus and to use the timing of changing the drive pulse width of the recording head 1h as the trigger function.

FIG. 7 is a control system block diagram of the recording apparatus of the present invention. In FIG. 7, reference numeral 21 denotes a central processing unit (CPU) including a microprocessor element for controlling the operation of the entire inkjet recording apparatus. Data to be recorded and commands for controlling the operation of the recording device are transferred from a host device 20 such as a computer system to the CPU 21 via a recording data receiving unit 22 composed of a known interface circuit such as a parallel interface or a serial interface. You. The CPU 21 controls the recording head 1h in the carriage 1 via the head controller 23 and the head driver 24 based on the transferred data. The drive pulse width of the recording head is controlled to a predetermined value by using the timer 25.

If the recording data transmitted from the host device 20 is characters or symbols, the data is transmitted in the form of a character code. Converted to data. For this conversion, a character clutter generator ROM (CGROM) 26 is provided. A control program to be processed by the CPU 21 is stored in the control ROM 27. Further, a RAM 28 is provided for use as a buffer area of the transferred recording data or a work area of the CPU 21.

In addition, various detection switches and sensors 3
0 from the CPU 21 via the input port 29.
And output from CPU 21 is output port 3
1 and is input to the carriage motor drive circuit 32 to drive the carriage motor 33 and the like.

The recording head 1h is provided on the recording head 1h.
A thermistor 35 is provided as an example of the temperature detecting element of h, and detects the temperature of the recording head that changes every moment via the AD converter 34.

Next, the operation of the main part related to the present invention in the circuit configuration of FIG. 7 will be described. The MR element of the magnetic head of the carriage 1 is arranged along the scale of a magnetic linear encoder as shown in FIG. Then, trigger signals having different intervals between pulses as shown in FIGS. 4D and 4F are obtained from the signal obtained by the MR element of the magnetic head through the detection circuit 36 shown in FIG. (Because the ratio of the magnetization densities is higher in the upper and lower magnetization lines in FIG. 5, the trigger signal of f is actually shorter than the pulse interval shown in the drawing, compared with the trigger signal of d. Is). The trigger signal of f is input to the counter 37, and the obtained count value is stored in the recording head 1h.
Is read into the CPU 21 via the register 38 as the position information of. The trigger signal of f is transmitted to the head control unit 23.
And is used as a drive trigger signal for the recording head 1h. The trigger signal d is input to the interrupt input of the CPU 21. An interrupt is applied at the rising edge of this signal, and the head drive pulse is reset according to the temperature of the recording head 1h.

FIG. 8 is a flowchart showing a control procedure for adjusting, for example, the amount of ink ejected from the recording head by using the two trigger signals obtained in the above-described reference example. The operation of this embodiment will be described with reference to FIG. Note that the control procedure shown in the flowchart specifically detects the temperature of the recording head 1h at every certain recording distance (for example, every five character recording) in a bubble jet type ink jet recording apparatus, and based on the detected temperature. The present invention relates to control for suppressing a change in ink ejection amount due to head heat storage by changing a head drive pulse width.

In FIG. 8, after the power of the recording apparatus is turned on, initialization of the apparatus is performed in step S101. At this time, the position counter 37 is crued at the home position,
Thereafter, the position of the recording head 1h is updated at each rising edge of the detection signal of the lower magnetized line of the scale section 501 of the linear encoder to indicate the absolute position.

Next, in step S102, the head temperature is detected, and it is determined whether the head temperature is equal to or higher than a specified value T ₀ (for example, 40 ° C.) (step S103). Here, when the head temperature is T ₀
If it is less than W ₀ , the normal pulse width W ₀ is set in the timer 25 (step S 104). If it is more than T ₀ , the pulse width W ₁ shorter than W ₀ is used to prevent an increase in the ink ejection amount.
Is set in the timer 25.

When a recording start command is input in step S106, the carriage motor is accelerated from a stopped state to a constant speed at which recording is possible in step S107. When the position counter reaches a value indicating the recording position, at step 108 C
The PU 21 is enabled to interrupt, and the recording operation is started at the lower magnetization interval with the set pulse width. Thereafter, as the carriage 1 moves, the process jumps to the interrupt routine at every magnetization interval of the upper magnetization line in FIG.

In the interrupt routine, step S201
, The head temperature is detected, and when the head temperature is equal to or lower than T ₀ , it is determined that the recording density is low and there is no danger of an increase in the ink ejection amount, the normal pulse width W ₀ is set in the timer, and the normal pulse width is set. the recording operation is performed in W ₀ (step S203).
Since in the case of the head temperature T ₀ or more in step S201 there is a risk of increasing the ink ejection amount by increasing the head heat storage recording density, sets the pulse width shorter W ₁ from W ₀ to the timer 25 (step S202), the head The recording operation is performed with the driving energy lowered (step S109).
When the recording of the specified amount on one line is completed, step S11 is performed.
At 0, the interrupt of the CPU 21 is disabled, and the interrupt signal by the detection signal from the upper magnetized line is blocked. Thereafter, in step S111, the carriage motor is decelerated and stopped, paper feeding is performed as necessary, and the process returns to step S106. Thereafter, the steps from step S106 to step S111 are repeated.

According to the above-described control, by providing magnetizing lines having different magnetizing intervals in addition to the magnetizing line having the magnetizing interval for performing the recording position and the head drive trigger, for example, as described above, the head temperature can be increased. Can be controlled. Therefore, by providing different magnetization pitches in the scale portion of one magnetic linear encoder, interrupts are made at fixed time intervals by a timer or the like which was performed only for the magnetization line of only one magnetization pitch. (2) It is possible to eliminate the need to create a head temperature detection interval signal by software while constantly checking the current position by the CPU 21, which is advantageous in cost and can reduce the control load of the CPU 21. It is.

In the above embodiment, a bubble jet type ink recording apparatus has been described as an example. However, the present invention is not limited to the bubble jet type ink jet recording apparatus and other types of recording apparatus, such as an ink jet recording apparatus and a thermal recording apparatus, in which heat storage of the head becomes a problem. Can also be applied to the recording device.

In the above reference example, the detection signal of the upper magnetized line having a magnetized pitch different from the lower magnetized line for performing the recording head position detection and the head drive trigger is used as the head temperature detection timing. However, as a function other than the head temperature detection timing, it can be used for, for example, control of a carriage motor. further,
In the above reference example, the lower magnetized line is used as a position detection and a head drive trigger of the recording head, and the upper magnetized line is used as another position trigger, but the arrangement may be reversed. It is not particularly limited to the upper and lower relationship.

FIG. 6 is a reference example showing another magnetization pattern of the scale portion of the magnetic linear encoder of the recording apparatus of the present invention. The magnetization pattern in FIG. 6 is different from the magnetization pattern in FIG. 5 in that the magnetization pitch of the upper magnetization line is different in one row. In FIG. 6, by changing the magnetization direction (N, S) only in the recordable range and magnetizing the same range in the other ranges, the detection signal changes only in the recordable range. Therefore, since the interrupt signal mask control as shown in the second example is not required, the control load on the CPU 21 can be reduced, and the effective recording speed can be improved. In particular, the carriage 1 like a small recording device
This is particularly effective when the moving range of is always constant.

In the above example, the upper magnetization pitch is constant within the recordable range, but the magnetization pitch may be changed arbitrarily to generate a trigger signal at a desired position. In addition, the magnetizing lines are all magnetized to either polarity, but a region that does not require a detection signal may be unmagnetized.

Next, with reference to FIG. 9, a description will be given of a recording apparatus which does not require mounting adjustment when the scale portion of the magnetic linear encoder has a circular rod shape in cross section.
In the embodiment shown in FIG. 9, the scale portion 501 of the magnetic linear encoder has a rod shape, and a magnetized portion 507 is formed by magnetizing the entire circumference of the cylindrical body. For this reason, the rod-shaped scale 501 is connected to the main body frame 100 of the recording apparatus.
(See FIG. 1), there is no need to adjust the direction of magnetization.

Next, FIG. 10 shows another reference example of the magnetization of the rod-shaped scale portion. In FIG.
Two types 5a and 506a are provided. Magnetized part 50
5a is, for example, are magnetized at the magnetization pitch P ₁ of 360 dpi, the magnetized portion 506a, for example 203.2dpi
It is magnetized in the magnetization pitch P _2. When two types of resolutions are used as described above, it is preferable to provide two types of recording heads (not shown) in correspondence with each other.

FIG. 11 shows a reference example in which two magnetized portions are also provided on the rod-shaped scale portion.
Although the two magnetized portions 505b and 506b have the same magnetized density, the magnetized pitches are shifted. That is, in this example, the two magnetized portions are shifted from each other by a half pitch. In this case, by synthesizing the signals obtained from these two magnetized portions, a resolution of a half pitch of each pitch is obtained, that is, a double resolution is obtained.

[0039]

As described above, when the scale portion of the magnetic linear encoder has a rod shape, it is configured to be magnetized entirely in the circumferential direction of the scale portion. There is no need to adjust the mounting position when mounting on

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a recording apparatus according to the present invention.

FIG. 2 is an enlarged perspective view of a reference example of a magnetic linear encoder used in the recording apparatus of the present invention.

FIG. 3 is a circuit diagram showing a reference example of a detection circuit for processing a signal from a magnetic linear encoder of the recording apparatus of the present invention.

FIG. 4 is a waveform diagram showing an input waveform and an output waveform of the detection circuit of FIG. 3;

FIG. 5 is a plan view showing a reference example of another magnetization of the scale section of the magnetic linear encoder used in the recording apparatus of the present invention.

FIG. 6 is a plan view showing a reference example of still another magnetization of the scale section of the magnetic linear encoder used in the recording apparatus of the present invention.

FIG. 7 is a block diagram of a control system of the printing apparatus in FIG. 1;

FIG. 8 is a flowchart illustrating an example of the operation of the recording apparatus of the present invention.

FIG. 9 is a perspective view showing an embodiment of magnetization of a scale section of a magnetic linear encoder used in the recording apparatus of the present invention.

FIG. 10 is a perspective view showing a reference example of another magnetization of the scale portion of the magnetic linear encoder used in the recording apparatus of the present invention.

FIG. 11 is a perspective view showing a reference example of another magnetization of the scale section of the magnetic linear encoder used in the recording apparatus of the present invention.

[Explanation of symbols]

 Reference Signs List 1 carriage 1h recording head 501 scale part of magnetic linear encoder 502 magnetic head 107 amplifier 102, 103 magnetic resistance element 21 CPU 25 timer 505, 506 magnetizing line

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yuichi Hirai 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masafumi Wataya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Kazuyoshi Yoshida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shigeo Takenaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Toshiyuki Onishi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-63-113311 (JP, A) JP-A-58-154612 (JP, A) Kaihei 2-21512 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 19/18 G01B 7/00 G01D 5/245 101

Claims (1)

(57) [Claims] A carriage mounted with a recording head and reciprocating along a platen; a magnetized scale section of a magnetic linear encoder arranged along a moving direction of the carriage; and a scale mounted on the carriage and scaled. In a recording apparatus having a magnetic head of a magnetic linear encoder that reads a magnetization pattern of a section, the scale section has a circular rod shape in cross section, and is magnetized over the entire circumferential direction to form the magnetized section. The recording device is characterized in that the rod-shaped scale portion is attached to the main body frame of the recording device without adjusting the magnetization direction.