JPH0339279A - Gap quantity control mechanism of serial printer - Google Patents

Abstract

PURPOSE:To always keep gap quantity constant by providing a rotary sphere detecting the thickness of paper positioned on the upper part of a carriage, a movable stand supporting said sphere to perform up and down movement and a press spring pushing the movable stand between the movable stand and a carriage. CONSTITUTION:At first, a printing head 22 is fixed to a movable stand 1 at the optimum printing position using two fixing screws 4. Next, paper 6 is passed between a platen 5 and rotary spheres 2 to be sucked. Whereupon, the movable stand 1 moves in the direction shown by an arrow A by the thickness of the paper 6 around the contact point B of the stand 1 and a carriage 8. Since force always bringing this moving quantity to zero at this time is applied to the stand 1 by a spring 3, even when the thickness of the paper 6 and the number of papers 6 are different, definite gap quantity is held and printing is always performed with the same printing density.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is a gear type for serial printers! In particular, the present invention relates to a gap adjustment mechanism for a serial printer that can always maintain a constant gap amount even when printing paper of different thickness is sucked.

[Prior Art] Conventionally, in the gap adjustment mechanism of this type of serial printer, the position of the shaft with respect to the platen can be changed. Each time a paper of a different thickness was sucked in, the printer operated the copy control lever while checking the print density and adjusted the gap amount by changing the position of the shaft.

[Problems to be Solved by the Invention] In the conventional serial printer described above, the gap amount was adjusted by changing the position of the shaft relative to the platen using the copy control lever while checking the print density for each paper thickness. However, the gap amount must be readjusted each time depending on the thickness of the paper, and the print density must be checked each time the gap amount is adjusted, resulting in a waste of printing paper.

[Means for Solving the Problems] An object of the present invention is to solve the problems of the prior art described above, and to provide a gap for a serial printer that can always keep the gap amount constant even when printing paper of different thickness is taken in. The purpose is to provide an adjustment mechanism.

The gear amount adjustment N mechanism for a serial printer of the present invention has a rotating ball located at the top of the carriage of the serial printer for detecting paper thickness, and an upper tip that supports the rotating ball, and performs -E downward movement using the lower tip as a fulcrum. The present invention is characterized by having a movable base for moving the movable base, and a spring attached between the movable base and the carriage for pushing the movable base upward.

[Actual Example] Next, the gap amount adjustment mechanism of the serial printer of the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view of an embodiment of a gap adjustment mechanism for a serial printer according to the present invention.

FIG. 2 is a side view of the gang 1 adjustment mechanism of the serial printer shown in FIG. 1.

Referring to FIG. 1, reference numeral 41 is a stand located above the carriage 8 and movable with respect to the carriage 8. The carriage 8 is mounted for laterally reciprocating movement along a pair of shafts l=9.9.

2.2 is a pair of rotating balls attached to the tip of the movable table 1. A pair of rotating balls 2.2 are located above the carriage 8 of the serial printer, and detect the thickness of the paper 6 held by the platen 5 and drawn in.

A spring 3 is installed between the carriage 8 and the movable table 1, and serves to push the movable table t21 upward from the carriage 8. As a result, the pair of rotating balls 2.2 becomes
It can constantly come into contact with the paper 6 held by the platen 5 and drawn in.

4 is a fixing screw that fixes the print head 12 to the movable table f'jl. In the preferred embodiment shown, the print head I2 is fixed to the movable base 1 by a pair of left and right fixing screws 4.4. ing. As shown in FIG. 2, the fixing screw 4 is movably fixed along elongated holes 1a provided on four sides of the movable container.

Next, the operation of the gear m adjustment R bucket of the serial printer according to the present invention will be explained.

First, attach the gutter 12 to the movable base 1 using the two fixing screws 4.
Use the to fix the printing position to I&week.

Next, the paper 6 is sucked through between the platen 5 and the rotating ball 2. Then, the movable base 1 moves in the direction of arrow A by the thickness of the paper 6, using the contact point B between the movable base l and the carriage 8 as a fulcrum, or there is a force that constantly tries to reduce this movement amount to zero. Since the spring 3 is added to the movable base 1, even if the thickness of the paper 6 and the number of sheets are different, a constant gap amount is maintained and printing is always performed with the same printing density.

[Effects of the Invention] As explained above, the gap adjustment mechanism for a serial printer of the present invention has a rotating ball that detects the paper thickness and is located at the top of the carriage of the serial printer, and an upper tip that supports the rotating ball. It has a movable base that moves up and down using the lower end as a fulcrum, and a spring that is installed between the movable base and the carriage and pushes the movable base upward, allowing printing of different thicknesses. This has the effect of keeping the gap amount constant even when paper is sucked in.

[Brief explanation of drawings]

FIG. 1 shows the gap f of the serial printer according to the present invention.
FIG. 3 is a plan view of an embodiment of the t-adjustment mechanism. FIG. 2 is a side view of the gap adjustment mechanism of the serial printer shown in FIG. 1. 1...Movable table 2...Rotating ball 3...Spring 4...Fixing screw 5...Graten 6...Paper 7...Bail shaft 8...Carriage 9...Shaft 12...Print head

Claims (1)

[Scope of Claims] A rotating ball located above a carriage of a serial printer for detecting paper thickness; a movable table having an upper tip supporting the rotating ball and moving up and down using the lower tip as a fulcrum; A gap adjustment mechanism for a serial printer, comprising: a spring that is attached between the movable base and the carriage and acts to push the movable base upward.