JPH0358875A - Paper thickness detecting method for printer - Google Patents

Abstract

PURPOSE:To detect the thickness accurately even for paper which has uneven parts other than the original thickness such as perforation, folding lines, holes and corner cuts, etc. by performing measurement of a paper thickness at a spot of the original thickness. CONSTITUTION:One half of the thickness of the thinnest paper among papers to be applicable for the printer is previously designated as a decision value. The thickness of paper which is fitted on the printer are measured at two spots, and the absolute value of a difference of the two measurement results and the decision value are compared by a comparison/operation circuit 40. When the absolute value is equivalent or lower than the decision value, an average value of the measurement values is determined as the thickness of the paper. When the absolute value is not equivalent or lower than the decision value, the thickness of the fitted paper is further measured again at different two spots, and the absolute value of a difference of the two measurement results, which are re-measured, and the decision value are compared, and when the difference is equivalent or lower than the decision value, an average value of the re-measurement value is determined as the thickness of the paper. As the result, regardless of the setting position of paper, a paper thickness can be measured at a spot of the original thickness of the paper.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention adjusts the thickness of paper in order to set the head gap using a platen position adjustment mechanism that moves the platen toward and away from the print head. The present invention relates to a paper thickness detection method for a printer equipped with a paper thickness measuring mechanism.

[Conventional technology]

Platen. In printers that print using a wire dot printing head that moves reciprocally along with the carriage in the axial direction facing the printer, the distance from the paper surface on the platen to the tip of the print head (hereinafter referred to as the "hand gyanop") must be set appropriately. If this distance is not maintained, printing quality may deteriorate due to the distance being too far away, print head wires may break due to being too close, and cartridge spacing may malfunction due to unnecessary ink adhesion from the ink ribbon. In order to avoid these problems, it is necessary to always maintain an appropriate head gap.

Therefore, each time a paper is loaded, the operator has to operate or check that the distance from the surface of the paper to the tip of the print head is a proper value, which is very inconvenient.

Claims (1)

[Claims] 1. A platen that supports paper; a print head that prints while reciprocating in parallel along the platen; a paper feeding mechanism that feeds the paper; and a paper feed mechanism that feeds the paper from the surface of the paper on the platen. In a paper thickness detection method for a printer that has a head gap adjustment mechanism that adjusts the distance to the tip of the print head and a paper thickness measurement mechanism that measures the paper thickness of the loaded paper, the printer is used. 1/2 of the thickness of the thinnest sheet of paper is predetermined as a judgment value, the thickness of the loaded paper is measured at two points, and the absolute value of the difference between the measurement results at those two points and the judgment value are determined in advance. If the absolute value is equal to or less than the judgment value, the average value of the measured values is determined as the thickness of the paper, and if the absolute value is not equal to or less than the judgment value, the thickness of the loaded paper is determined. The thickness is remeasured at two points that are different from the two points mentioned above, and the absolute value of the difference between the two remeasured measurement results is compared with the judgment value, and if the difference is equal to or less than the judgment value. A paper thickness detection method for a printer, characterized in that the average value of remeasured values is determined as the paper thickness.