JP2547078B2 - Carriage braking method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carriage braking method in a recording apparatus of a type in which a carriage is reciprocally moved to perform recording, and particularly noise generated during carriage braking can be reduced. And the carriage braking method.

[Prior Art] Conventionally, so-called serial type printers that carry out recording by reciprocally moving a carriage have been put into practical use and widely spread. Serial printers are classified into impact type and non-impact type. Conventional impact type printers have relatively stable performance, relatively high recording speed, and low running cost. For this reason, it has spread more quickly than the non-impact type and has a high market share. However, in principle, impact type printers inevitably increase noise, and non-impact printers capable of recording with low noise have attracted attention due to the recent demand for quieter offices. . In printers aiming for such low noise, noise that is not a problem with the conventional impact type becomes noticeable, and among them, noise particularly when the carriage reciprocates cannot be ignored. is there. The serial type printer performs recording by reciprocating the carriage, and it is necessary to perform the reversing operation at the position where the carriage exceeds the recording range. Since the recording operation cannot be performed during this inversion operation,
In order to shorten the recording time, that is, to increase the recording speed, it is necessary to shorten the reversal time.Therefore, when a DC motor is used as the drive source, when the carriage exceeds the recording range, the motor immediately By reversing the energization in the reverse direction, the carriage is turned over in a minimum time.

[Problems to be Solved by the Invention] However, when sudden braking is performed in this way,
A large impact is applied to the motor shaft, the pulley shaft, etc., and the noise generated at the time of reversal becomes large. As a method of preventing the generation of such a large noise, the carriage is braked by using a so-called short brake that short-circuits the energizing terminals of the motor by using a switching element such as a transistor.
Although this method can reduce the noise, this method does not have sufficient braking force. Therefore, the time until the motor stops becomes longer and the recording time can be shortened, that is, the recording speed can be increased. Can not.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a carriage braking method capable of shortening the reversing time while keeping the noise at the time of reversing the carriage small. I am trying.

[Means for Solving the Problems] The present invention has been made to achieve the above-described object, and includes a recording head whose drive is controlled based on a recording signal, a carriage on which the recording head is mounted, and a recording target. Recording comprising a platen for supporting a medium, a recording medium feeding mechanism for moving the recording medium, and a carriage control mechanism for reciprocating the carriage in a direction orthogonal to the moving direction of the recording medium. In a carriage braking method for an apparatus, the carriage control mechanism detects a DC motor, a transmission unit that transmits power of the DC motor, a linear encoder that detects a position of the carriage, and a rotation angle of the DC motor. With a rotary encoder, when the carriage moves into the braking range, the DC motor is energized in the reverse direction for braking and after a predetermined time has passed, The pulse rate (LEP) of the linear encoder and the pulse rate (REP) of the rotary encoder are measured, and the measurement result is compared with the preset pulse rate (Pref). If LEP <Pref, the DC motor is selected. Reverse current is applied to end the reversal operation. If LEP ≥ Pref, further compare LEP and REP. If LEP = REP, perform reverse current to the DC motor. If LEP> REP, reverse to DC motor. The carriage is braked by turning off the energization in the direction and performing a short brake operation.
It is characterized by stopping and reversing.

[Operation] When the carriage is braked in such a configuration, first, when a reverse current is applied to the motor, the motor starts braking, and the inertia of the carriage and the transmission means and the motor shaft or the motor shaft are press-fitted. When the inertia of the carriage increases due to the amount of sliding friction with the pulley, a slip occurs between the transmission means and the motor shaft or the pulley press-fitted into the motor shaft. At this time, a difference occurs between the output of the linear encoder indicating the position of the carriage and the output pulse rate of the rotary encoder indicating the rotation angle of the motor. When this output is detected and the reverse current to the motor is stopped and short brake or free run is performed, the slip between the transmission means and the motor shaft is reduced. Then, when slippage disappears, the reverse current is passed again. This operation is repeated, and if the motor rotation speed falls below a certain value, the carriage will stop by continuing to supply a reverse current to the motor.
Start moving in the opposite direction. With the above operation, the carriage has no noise when reversing due to abrupt braking, and the time required for reversing can be shortened.

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings. First
FIG. 1 is a perspective view showing a main mechanism of a recording apparatus as an embodiment of the present invention.

The frame of the recording device includes a base frame 1, a left side plate 2, and a right side plate 3.

The carriage mechanism includes a recording head 50, a carriage 20 on which the recording head 50 is mounted, a main shaft 30, and a carriage.
20 DC motor 31, drive belt 32, recording head
FPC 33, drive pulley 34, for supplying a recording signal to 50,
It is composed of components such as the driven pulley 35 and the like. Recording head
The reference numeral 50 is attached to the carriage 20 and can move between the left side plate 2 and the right side plate 3 as the carriage 20 moves. The carriage 20 slides on the main shaft 30 via an integrally configured bearing having high slidability. The power source at this time is the DC motor 31, and the DC motor
31 is a drive pulley 34 attached to the shaft by press fitting
The power is transmitted to the carriage 20 through the flat belt 32 that engages with the drive pulley 34. Driven pulley
35 is provided at a position facing the drive pulley 34 and applies proper tension to the drive belt 32 by the belt tension urging means 36. The rotary encoder 101 detects the rotational position of the DC motor 31, while the position of the carriage is the linear encoder 1 held by the slit plate 102 and the carriage 20.
Detected by 03. In the present embodiment, the case where the flat belt is used as the power transmission member has been described, but a transmission system such as a wire that can transmit power to the pulley by friction may be used instead of the flat belt. There is no hindrance.

Next, the recording medium feeding mechanism part
60, a platen 70, a recording medium presser 71, an LF motor 80, an LF power transmission system 81, and other components. Platen 70
Has a cylindrical pipe shape made of aluminum, etc.
The support is provided by two rings 73a at both ends provided on the base frame 1 and rings 73b at both ends pressing the platen 70 toward the base frame via urging means such as a spring. Is realized by being held. The power transmission mechanism is configured to transmit the power of the LF motor 80 including a stepping motor or the like to the LF drive pulley (not shown) through the deceleration mechanism of the LF power transmission system 81 after increasing the torque and subdividing the feeding steps. Has become. After that, power is transmitted to a plurality of LF belts (with teeth) 74 that engage with the LF drive pulleys, and the LF belts 74 are driven while being housed in the grooves provided on the outer periphery of the platen 70. As a result, the recording medium 60 is fed by a predetermined amount. The recording medium press 71 is formed of, for example, a thin steel plate such as stainless steel, and is held between the right side plate 3 and the LF side plate 4 by a holding member 72, and the recording medium 60a is pressed by a platen 70 by urging means (not shown). The recording medium 60a plays a role of suppressing floating near the recording position of the recording medium 60a. Reference numeral 100 denotes a recovery mechanism for the recording head 50 which is provided outside the printing area.
Printhead 5 by operating 0 as needed.
Nozzle surface cleaning of 0, ink supply, non-ejection recovery,
Nozzle drying is prevented.

In order to obtain a desired character or image with this recording device, a recording signal is transmitted to the recording head 50 via the FPC 33, and at the same time, the DC motor 31 is driven to reciprocate the carriage 20. At this time, by feeding the recording medium 60a at a predetermined pitch in synchronization with the reciprocation of the carriage, characters, images, and the like are formed as a set of dots on the recording medium.

FIG. 2 is a block diagram showing the configuration of the carriage drive circuit section. CPU200 is DC for motor driver 201
The rotary encoder 101 and the linear encoder 1 are provided while giving signals such as the rotation direction of the motor 31 and brake / rotation.
The output of 03 (pulse train in this example) is read. FIG. 4 shows the outputs a and b of the CPU 200 and the operation functions of the motor driver 201 corresponding thereto. FIG. 3 shows the carriage braking method of the present invention in the configuration of FIG. First, when the carriage 20 moves into the braking range
Apply reverse current to the DC motor 31 and apply braking. afterwards,
Linear encoder after a predetermined time, for example 500μsec
Measure the pulse rate of 103 (hereinafter abbreviated as LEP) with CPU200. Next, the pulse rate (hereinafter abbreviated as REP) of the rotary encoder 101 is similarly measured, and these two are compared. If the result is LEP <Pref (Pref is a preset pulse rate), it is determined that the traveling speed of the carriage has become sufficiently small, and the DC motor 31 is further energized in the reverse direction to end the reversing operation. Let LEP =
When> Pref, LEP and REP are compared. If LEP = REP, the carriage 20 and DC motor 31 are rotating in synchronism, so the DC motor 31 is energized in the reverse direction, and when LEP> REP, the DC motor. Turn off the reverse current to 31 and perform short brake operation. After that, by repeating this procedure, the carriage 20
Brake, stop and reverse.

[Effects of the Invention] As described above, according to the present invention, when the braking action due to the reverse energization of the DC motor becomes too strong, the brake is shortened to reduce the braking action. And reduce the noise in the vehicle without overloading the transmission means.
Further, the reversing time can be greatly shortened and the recording time can be shortened as compared with the case where only the short brake is used at the time of reversing the carriage.

[Brief description of drawings]

FIG. 1 is a perspective view of a main mechanism portion of a recording apparatus as an embodiment of the present invention, FIG. 2 is a block diagram of a carriage drive circuit of the recording apparatus according to the present invention, and FIG. FIG. 4 is a flow chart showing a related carriage braking method, and FIG. 4 is an explanatory diagram showing an operation function of the DC motor driver in the block diagram shown in FIG. 50 …… Recording head 20 …… Carriage 31 …… DC motor 101 …… Rotary encoder 102 …… Slit plate 103 …… Linear encoder

Claims (1)

(57) [Claims] 1. A recording head which is drive-controlled based on a recording signal, a carriage which mounts the recording head, a platen which supports a recording medium, and a recording medium feeding mechanism for moving the recording medium. A carriage control mechanism for reciprocating the carriage in a direction orthogonal to the direction of movement of the recording medium, the carriage control mechanism comprising a DC motor and a power of the DC motor. A linear encoder that detects the position of the carriage, and a rotary encoder that detects the rotation angle of the DC motor. When the carriage moves within the braking range, the DC motor is energized in the reverse direction. After applying the brake for a predetermined time, the pulse rate (LEP) of the linear encoder and the pulse of the rotary encoder The rate (REP) is measured, and the measurement result is compared with the preset pulse rate (Pref). If LEP <Pref, the DC motor is energized in the reverse direction to end the reversing operation, and LEP ≧ Pref If there is, LEP and REP are further compared. If LEP = REP, the DC motor is energized in the reverse direction. If LPE> REP, the DC motor is de-energized in the reverse direction and the carriage is braked by performing a short brake operation. A carriage braking method characterized by stopping and reversing.