JPH04235074A - Serial printer - Google Patents

Abstract

PURPOSE:To improve the scanning characteristics of a printing head. CONSTITUTION:Information 15 for traveling a printing head 2 outputted from an encoder 14 is inputted to a controller 4. Based on a rule group 16 of a fuzzy logic reasoning incorporated in the controller 4, an approximate collation is conducted. Optimum drive information 5 at every timing is determined to be outputted to a scanning motor 6.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to scan control of a print head in a serial printer that scans the print head to form an image on a recording medium.

0002

2. Description of the Related Art Conventionally, in order to scan a print head in a serial printer, a controller inputs print head movement information, refers to a look-up table,
This is done through closed-loop control, where drive information is determined and output to the printhead's scanning motor.

0003

[Problems to be Solved by the Invention] However, when performing closed-loop control using a look-up table, fluctuations in the scanning characteristics of the print head caused by variations in the quality of component parts, variations in assembly adjustment, etc., and changes in the operating environment such as temperature and humidity must be avoided. Since the same look-up table must be used to deal with all the variations in the scanning characteristics of the print head caused by differences in the print head, it was not possible to fully bring out the scanning characteristics originally latent in the print head. In addition, such look-up tables must be prepared for each specified speed in three stages: acceleration stage, constant speed stage, and deceleration stage.
The amount of man-hours required to create the lookup table was also extremely large.

The present invention is intended to solve these problems, and its purpose is to provide a serial printer with good print head scanning characteristics and excellent cost performance.

[0005]

[Means for Solving the Problems] A serial printer according to the present invention is equipped with a controller incorporating a group of ambiguous inference rules that inputs print head movement information and outputs drive information to the printer's scanning motor. characterized by things.

[0006]

[Operation] According to the above configuration of the present invention, scanning of the print head is performed by ambiguous control in which the controller inputs print head movement information and outputs drive information to the print head scanning motor. .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained below with reference to the drawings.

FIG. 1 shows an embodiment of a serial printer 1 according to the present invention.

The print head 2 receives a driving force from a scanning motor 6 via a driving rope 3 in accordance with driving information 5 outputted from a controller 4, and slides along a guide shaft 7 and is moved by a feed roller 8. The conveyance direction 10 of the recording medium 9 according to
While scanning in the direction 11 perpendicular to the host computer (
(not shown) is converted into dots 13 to form an image on the recording medium 9. Scanning motor 6
The movement information 15 of the print head 2 is inputted from the encoder 14 coaxially attached to the controller 4, and the controller 4 uses the built-in vague inference rule group 1.
Approximate verification is performed based on 6, and the current drive information 5 is determined and output to the scanning motor 6. Group of rules for ambiguous reasoning 16
``If the positional deviation is very large in the positive direction and the velocity deviation is very large in the positive direction, the energization duty is set very low.'', ``If the positional deviation is very small in the negative direction and the speed deviation is close to zero, the energization duty is set very low.'' The antecedent part is an ambiguous set in the two-dimensional movement information space of the positional deviation and speed deviation of the print head 2, and the consequent part is an ambiguous set in the energization duty of the scanning motor 6. ``I
This is a forward inference in the form of "F (antecedent part), THEN (consequent part)", and consists of a group of parallel rules, with the main focus being that the print head 2 scans at a constant speed. The implementation of such fuzzy inference in the controller 4 from inputting the fuzzy inference rule group 16 and movement information 15 to performing approximate matching and determining the output of the drive information 5 is a fuzzy production method in the field of artificial intelligence. You can refer to how to implement rules, approximate matching, and defuzzification in a computer. Scanning of the print head of a serial printer configured in this way is performed by ambiguous control, so the drive information is finely tuned to each moment, and control that can fully bring out the scanning characteristics inherent in the print head. becomes possible. In addition, the rules for fuzzy inference are:
Since it is a parallel rule group and is a linguistic expression, the work for fixing the rule group and ambiguous set is easy and has a very good human interface, and the number of creation steps itself is greatly reduced. As a second embodiment, approximate matching of ambiguous inference may be realized using dedicated hardware. This configuration greatly improves the inference speed and is therefore effective as a method for implementing ambiguity control in high-speed serial printers. As a third embodiment, the acceleration of the print head may also be considered, and an ambiguous set on a three-dimensional movement information space may be used as an antecedent of a rule group for ambiguous inference. In this case, the drive information becomes finer and more suitable for each moment, making it possible to perform control that can further bring out the scanning characteristics originally latent in the print head.

0010

As described above, according to the above configuration of the present invention, the scanning of the print head is performed by inputting print head movement information and outputting drive information to the print head scanning motor by the controller. Since this is performed using ambiguous control, the drive information becomes finely tuned to suit each moment, and control that can fully bring out the scanning characteristics originally latent in the print head becomes possible. In addition, since the fuzzy inference rule set is a parallel rule set and is a linguistic expression, the task of fixing the rule set and fuzzy set is very easy and has an excellent human interface, and the creation process itself is very simple. will also be greatly reduced. In addition, since the scanning of the print head is performed using ambiguous control, the chronological continuity of drive information is high, and the discomfort caused to the user by the scanning sound of the print head is reduced. Since high-order electrical and mechanical shocks are no longer applied to the force transmission mechanism, this has the revolutionary side effect of extending the lifespan of serial printers.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a serial printer according to the present invention.

[Explanation of symbols]

1 Serial printer 2 Print head 3 Driving rope 4 Controller 5 Drive information 6 Scanning motor 7 Guide shaft 8 Feed roller 9 Recording medium 14 Encoder 16. Rules for ambiguous reasoning

Claims (1)

[Claims] 1. In a serial printer that scans a print head that converts electrical signals into dots to form an image on a recording medium, information on the movement of the print head is input and the information is sent to a scanning motor of the print head. A serial printer characterized by being equipped with a controller that outputs drive information and has a built-in group of rules for ambiguous inference.