JPS61118604A - Detection apparatus - Google Patents

Abstract

PURPOSE:To make it possible to continuously and automatically measure the thickness of a conveyed sheet member to be detected, by measuring electric capacity between first and second electrodes respectively engaged with the shafts of a pair of rollers for grasping the sheet member to be detected. CONSTITUTION:The sheet member 10 conveyed to the direction shown by the arrow A is grasped by rollers 12, 13 engaged with one ends of shafts 14, 15 in a freely rotatable manner and electrodes 16, 17 are opposed to the other ends of the shafts 14, 15 at an interval (d) while the electric capacity between the electrodes 16, 17 is measured by a measuring part 18. A detection part 19 calculates the thickness of the sheet member 10 from the electric capacity to issue output D. By this method, the thickness of the sheet member during conveying is easily calculated. For example, the thickness of printing paper is measured to make it possible to attain the enhancement of printing quality.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a detection device for detecting the thickness of a sheet-like member, and in particular, the present invention relates to a detection device for detecting the thickness of a sheet-like member, and in particular, the present invention relates to a detection device that detects the thickness of a sheet-like member, and in particular, a detection device that detects the thickness of a sheet-like member. , relates to a detection device formed to detect the thickness of the workpiece.

For example, the print media used in printing devices is not only the common forms these days, but also direct mail.

Cardboard paper, used for postcards, envelopes, etc., came into use.

Such a printing apparatus is constructed as shown in the block diagram of FIG.

The printing medium stored in the cassette section 1 is fed out in the direction of the arrow by the rotation of the pink roller 2 and is transferred to the printing section 3. A print head 5 is provided in the print section 3 so as to face the platen 7, and as the transferred print medium passes through the gap S, printing by the print head 5 is performed. The printed printing medium is discharged in the direction of arrow B by the rotation of the discharge roller 6.7, and is stacked on the stack section 8.

When such printing media are used with different thicknesses as mentioned above, the thickness of each should be adjusted to prevent jams from occurring during transportation and to obtain the desired print quality. Accordingly, the gap S is widened or narrowed by moving the dot 5 toward printing in the direction of the arrow C.

Therefore, in such a printing apparatus, it is desired that the thickness of the print medium be easily detected in order to achieve stable operation and a predetermined print quality.

[Conventional technology]

Conventionally, the thickness of the printing medium is generally detected in the fourth step.
This was done as shown in the perspective view of the figure.

The print medium 10 is manually measured using a micrometer 11.
This is done by measuring the thickness t of the printing medium 10 with the scale of the micrometer 11 across a predetermined point.

[Problem that the invention seeks to solve]

Since such detection is performed manually, it is difficult to measure the thickness t during the printing process described above.

Therefore, the thickness t is measured while the cassette 1 is stored in the cassette 1 part 1 or while the printing process is interrupted.

However, when measuring in the cassette section 1, the cassette may be replaced with another cassette at the time of printing, and in this case, a different printing medium than the one actually measured will be used.
Furthermore, interrupting the printing process delays the processing time, which is problematic in both cases.

[Means for solving problems]

The above-mentioned problem is caused by a roller set that holds a sheet-like workpiece, first and second electrodes that are engaged with each of the roller sets and face each other at a predetermined interval, and W is determined by the detection device according to the present invention, which includes a measuring section that measures the capacitance of the two electrodes, and a detecting section that outputs thickness data of the workpiece based on the output of the measuring section.

[Effect]

That is, the first and second electrodes are interlocked with rollers that sandwich the workpiece, and the capacitance is varied depending on the thickness of the workpiece.

Therefore, the capacitance is measured and the thickness of the covered portion 4A can be detected based on the measured capacitance value.゛Therefore, there is no need for manual measurement as in the past, and by setting an electrode that is locked to a roller that holds a predetermined part of the workpiece,
The thickness of the covered portion H can be detected at any time if necessary.

〔Example〕

The present invention will be explained in detail below with reference to FIGS. 1 and 2, an embodiment, and FIG. 5. Figures 1 and 2 are configuration diagrams, Figure 5
The figure is a graph, and the same reference numerals indicate the same objects throughout the figure.

As shown in FIG. 1, rollers 12, 1.3 are rotatably secured to one end of each shaft 14.15, and an electrode 16.17 is fixed to the other end via an insulator. 12
, 13 are formed such that electrodes 16 and 17 face each other at a predetermined distance d so as to sandwich a predetermined portion of the printing medium 10 being transported in the direction of arrow A, and the capacitance of the electrodes 16 and 17 is measured. It is composed of a measuring section 18 and a detecting section 19 that outputs data D of thickness t based on the measured value of the measuring section 18.

With this configuration, since the printing medium 10 is held between the rollers 12 and 13, the electrodes 16 and 17 form a capacitor whose distance d is increased or decreased depending on the length of the printing medium 10. The capacitance C in this case is expressed by the following formula, where Eo is the dielectric constant of air.

S is the area of the electrode 16.17.

do is the initial spacing between electrodes.

d is the electrode spacing.

t is the thickness of the print medium 10.

C=Eo・S/d=Eo−3/ (do+t) Therefore, the relationship between the capacitance ■C and the thickness t of the printing medium is the curve e shown in the graph of FIG. 5. For example, if the capacitance 1c is 01
At the time, the thickness L becomes tl, and the thickness t can be detected.

In this way, the measuring unit 18 measures the capacitance C,
Based on the measured value, the detection unit 19 can output data D regarding the thickness t.

When such a configuration is used in the printing apparatus, it can be formed as shown in FIG. 2.

The aforementioned rollers 12 and 13 are provided on the pass line of the printing medium fed out from the cassette 1 section 1 in the direction of arrow A, and the printing medium 10 is transported by the measuring section 18 and the detecting section 19.
Data D of the thickness t of the print medium 10 is obtained, and this thickness data D is sent to the drive section 20, and the drive section 20 moves the print head 5 in the direction of the arrow C so that the gap S is suitable for the thickness of the print medium 10. can be moved to

In addition, if a double feed occurs during printing processing, it can be detected by a sudden change in capacitance C, so double feed can be prevented by outputting an alarm signal upon detection of a sudden change in capacitance C. It has the advantage of being able to do

In the present invention, the thickness L of the paper of the printing medium 10 is detected, but the thickness t of the material to be detected can be detected if it is in the form of a sheet that is transported in a predetermined direction. It is possible, and the same effect can be obtained (7).

〔Effect of the invention〕

As explained above, the present invention allows a sheet-like member to be
It is formed so that the thickness t of the workpiece is detected by the capacitance of the electrodes latched to each of the sheets 17-j.

As a result, there is no need to manually detect the thickness t as in the past, and, for example, stable operation and improved printing quality can be achieved in printing devices, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment according to the present invention. FIG. 2 is a configuration diagram showing an embodiment of a printing apparatus to which the present invention is applied. FIG. 3 is a configuration diagram of a conventional printing device. FIG. 4 is a conventional perspective view. FIG. 5 shows a graph of the relationship between capacitance C and thickness t. In the figure, 10 is a printing medium, 16.17 is an electrode. 14. 15 is the axis, 18 is the measurement part. Reference numeral 19 indicates a detection section, and reference numeral 20 indicates a drive section.

Claims (1)

[Claims] A set of rollers that sandwich a sheet-like workpiece, first and second electrodes that are engaged with each of the set of rollers and face each other at a predetermined interval, and a capacitance of the first and second electrodes. A detection device comprising: a measurement section that performs measurement; and a detection section that outputs thickness data of the workpiece based on the output of the measurement section.