JPS615973A - Plane scanning type printer - Google Patents

Abstract

PURPOSE:To prevent detection accuracy from being lowered due to an ink mist adhered to a head or the like, by a construction wherein movement of a belt fixed to a head carriage is detected through the number of pulses generated by a rotary encoder. CONSTITUTION:The head carriage 15 is fixed to the belt 13, and the belt 13 is driven by rotating a motor 11, thereby reciprocating the carriage. The movement of the belt is detected through the number of pulses generated by the rotary encoder 16. The encoder 16 is of the hermitically sealed type, so that the detection accuracy is not lowered even in the presence of an ink mist, and minute movements can be detected by enhancing the resolving power.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a plane scanning printer that records ten images by moving a recording head back and forth within a plane.

Structure of conventional example and its issues An example of a conventional flat scanning printer is shown in FIG.

In the figure, 1i''lt motor, 2 is the motor's googly, 3 is the belt, 4 is the pulley, and 6 is the helad carriage. 6 is the linear scale, with scales or holes 7 made at equal intervals. When the carriage 6 moves, the photo sensor 8
The scale or hole 7 is detected optically and outputted as a pulse signal. The linear scale 6, hole 7, and photo sensor 8 form a linear encoder.

When a linear encoder is used in a plane scanning printer in this way, the linear scale 6 becomes dirty with ink mist etc. emitted from the head, resulting in a decrease in accuracy. Also scale graduation 7
Due to physical limitations on the density, high-density, that is, fine position detection, has been impossible. Therefore, there was a drawback that accurate printing control could not be performed.

OBJECTS OF THE INVENTION It is an object of the present invention to overcome the above-mentioned drawbacks, and to provide a flat scanning printer having a head moving mechanism that is capable of high-definition head position detection without much deterioration in accuracy.

Structure of the Invention The present invention provides a plane scanning printer that moves a head carriage in accordance with the movement of a belt stretched between a motor and a pulley, and is provided with a rotary encoder that rotates in accordance with the rotation of the motor or pulley or the movement of a belt. It is. Since the position of the head carriage, that is, the recording head, is accurately detected by the pulse output of the rotary encoder, the recording position can be accurately controlled.

Description of examples Embodiments of the present invention will be described below with reference to the drawings.

Figure 2 shows an embodiment of the present invention, with 11 motors, 12 a motor gully, 13 a belt with high sliding friction such as a timing belt, 14 a pulley, 15 a head carriage with a recording head mounted thereon, and 16 a closed-loop belt. 17 is a coupler, and 18 and 19 are position sensors placed at both ends of the horizontal movement of the flat carriage. The state in which the head carriage 16 is at the left end position adjacent to the upper sensor 18 is in a standby state. Therefore, the position sensor 18°1
If the output of 9 is used as the counter reset signal and the pulse output signal of the rotary encoder 16 is used as the counter input signal, the distance between the position sensors 18, 19 and the carriage 15 is proportional to the direction of the counter output, so the moving position of the carriage is detected. be done.

Since this rotary encoder 16 is a closed-loop type,
Detection accuracy does not decrease even for ink mist from the head, and for fine movement detection, it is easy to select a rotary encoder with high resolution or use a rotary encoder with a gear for multiplying the rotation speed. can be realized.

FIG. 3 shows another embodiment of the invention. The difference from FIG. 2 is that the rotary encoder 26 is directly connected to the shaft of the pulley 14 by a coupler 27, and that a central sensor 3o is provided exactly between the end position sensors 18 and 19. . Other parts are the same as those in FIG. 2, are given the same reference numerals, and explanations are omitted. The operation of the rotary encoder 26 is the same as that of the rotary encoder 16 shown in FIG. 2, so a description thereof will be omitted.

Further, the central sensor 3o is provided to more accurately grasp the moving position of the head carriage 15, and by correcting the counter output with the sensor output, more accurate position detection can be performed.

FIG. 4 shows still another embodiment of the present invention, and shows a front view when the head carriage is moving. In the figure, the same parts as those in FIG. The difference from FIG. 2 is that the rotary encoder 16 is not directly connected to the shaft of the motor 11, but instead connects the belt 13 to the pulley 37 and roller 38.
Carriage 15
The movement of the belt 13, that is, the movement of the belt 13, is captured by the pulley 37 and converted into rotational movement, and the movement of the belt 13 is detected by the rotary encoder 1.
6 is the point at which the pulse output is output. With this method, when detecting movement at a more minute position, it can be easily realized by reducing the diameter of the bore of the rotary encoder 16.

Effects of the Invention As described above, the present invention is characterized in that a carriage is fixed to a belt, the belt is driven by the rotational movement of a motor to cause a head carriage to reciprocate, and the movement of this belt is detected by the number of pulses of a rotary encoder. With a flat scanning printer.

In addition, by using a rotary encoder with a high 1-resolution or by reducing the pulley diameter of the 50-tally 1 encoder, it is possible to prevent deterioration of detection accuracy due to ink mist, etc. on the encoder, which is impossible with a linear encoder. It is possible to detect minute movements.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a head carriage moving mechanism in a conventional flat scanning printer, and FIGS. 2 and 3 are plan views showing an embodiment of the head carriage moving mechanism in a flat scanning printer according to the present invention. FIG. 4 is a front view showing another embodiment of the head carriage in the flat scanning printer according to the present invention. 11...Motor, 12 -Motor ``-1'', 13
・・Timing belt, 14・・Pulley, 15・
Head carriage, 16.26 Rotor IJ-encoder, 17.27 Coupler, 1B, 19°3o
Position sensor, 37-7'-1c 38. Roller.

Claims (2)

[Claims] (1) A belt stretched between a motor and a pulley, a head carriage that moves according to the movement of the belt, a position sensor placed at the end of the movement range of the head carriage, and rotation of the motor or pulley. or a rotary encoder that rotates according to the movement of the belt. (2) The plane scanning printer according to claim 1, wherein a counter that counts the pulse output of the rotary encoder is reset by the output of the position sensor.