JP4443657B2 - Film sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a film sensor that detects pressure acting on a film, and more particularly to a film sensor that improves pressure detection performance.
[0002]
[Related background]
The film sensor is used as a pressure sensor for detecting pressure. For example, a flat film wire 11 shown in FIG. 4 is a plastic film 12 made of a flexible electrically insulating circuit board such as polyethylene terephthalate (PET). , 13, the insulating layer 14 is joined using an adhesive. At this time, the plastic films 12 and 13 are formed on one surface with conductive layers 12a and 13a printed with, for example, a conductive paint, and the conductive layers 12a and 13a are arranged to face each other. On the other hand, the insulating layer 14 is provided with an opening 14a at a predetermined location, and the conductive layers 12a and 13a are opposed to each other through a space (gap) corresponding to the thickness of the insulating layer 14 at this portion, thereby The detection part 15 which detects the pressure which acts on the film electric wire 11 from is comprised.
[0003]
Accordingly, when pressure is applied to the opening portion 14a from either one of the surfaces of the film electric wire 11, one or both of the plastic films 12 and 13 are elastically deformed, and the conductive layer 12a and the conductive layer 13a are opened. By utilizing electrical conduction at the portion 14a, pressure detection by a detection circuit (not shown) is enabled.
When such a film sensor is curved, the plastic films 12 and 13 are distorted due to the difference between the inner diameter and the outer diameter of the bending, and the conductive layer 12a and the conductive layer 13a are brought into contact with each other at the detection unit 15 due to the distortion. In the film sensor, the predetermined detection unit 15 detects this electrically by detecting it electrically.
[0004]
[Problems to be solved by the invention]
However, in the above-described film sensor, when a long time elapses in a state where bending is applied, the conductive layers 12a and 13a are separated from each other in the detection unit and the electrical contact is released. The cause is that the plastic films 12 and 13 are bonded with an adhesive via the insulating layer 14, and one or both of the films 12 and 13 slip relative to each other over time, causing the film sensor to bend. This is because the distortion caused by this is eliminated.
[0005]
Therefore, at the beginning of bending the film sensor, even if it can be detected that the bending has been applied, there is a possibility that the bending cannot be detected after a long time in that state.
Therefore, in order to prevent such slippage of the adhesive that causes a change in bending detection, for example, the entire film sensor is bonded using an epoxy thermosetting adhesive, or an insulating layer. Although the method of heat-seal | fusing the whole of both the films which intervened can be considered, manufacturing cost became expensive and the economical malfunction generate | occur | produced.
[0006]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a film sensor that can accurately detect bending even when the film sensor is bent for a long time.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has a structure in which an insulating layer is bonded using an adhesive between the respective films, and each of the above-described components disposed opposite to each other with a first gap provided at a predetermined location. A film sensor having a detection unit constituted by a conductive layer on a film and detecting a pressure acting on the film by contact between the conductive layers, wherein the relative of the film caused by the adhesive in each detection unit to prevent slippage, the film sensor, characterized in that each of the vicinity is provided a fixing means for fixing between the films of the detection portion is provided.
[0008]
That is, by joining the films partially in the vicinity of the detection unit, relative bending of the film is prevented and the bending is accurately detected. Further, in the fixing means, a second gap is provided in order to prevent relative slip of the film in each of the detection units, and by fixing the films facing each other across the second gap, It is preferable to prevent relative slip of the film.
[0009]
In the fixing means, it is preferable to prevent relative slip of the film by caulking a fixing jig between the films in order to prevent relative slip of the film in each of the detection units.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a film sensor according to the present invention will be described with reference to the drawings of FIGS. In the following drawings, the same components as those in FIG. 4 are denoted by the same reference numerals for convenience of explanation.
FIG. 1 is a cross-sectional view showing the structure of a first embodiment of a film sensor according to the present invention. In the figure, the detection unit 15 includes an opening 14a that constitutes the first gap of the present invention provided at a predetermined location of the insulating layer 14, and a conductive layer on each film that is disposed to face the opening 14a. It is composed of
[0011]
The insulating layer 14 in the vicinity of the detection unit 15 is provided with an opening 14b constituting the second gap of the present invention, and the films 12 and 13 facing each other across the opening 14b are bonded and fixed. Thus, the fixing means of the present invention is configured. In other words, in this embodiment, openings 14b are provided at several locations in the insulating layer 14 in the vicinity of the detection unit 15, and the films 12 and 13 are heat-sealed by means of, for example, ultrasonic welding. This prevents the films 12 and 13 from slipping.
[0012]
In addition, it is necessary to set the shape of the conductive layers 12a and 13a in advance so that the conductive layers 12a and 13a are not formed at the locations to be heat-sealed.
As described above, in this embodiment, openings are provided in several places of the insulating layer in the vicinity of the detection portion, and the portions that are opposed to each other with the opening therebetween and in which the conductive layer is not formed are partially fixed. Thus, the relative slip of the film due to the adhesive can be prevented, and the bending can be accurately detected even when the film sensor is bent for a long time.
[0013]
Next, the second and third embodiments shown in FIGS. 2 and 3 will be described. 2 and 3, the fixing means of the present invention is configured by caulking fixing jigs 16 and 17 between the films 12 and 13 in the vicinity of the detection unit 15.
That is, in the second embodiment shown in FIG. 2, slipping of the films 12 and 13 is prevented by caulking the eyelets 16 between several films 12 and 13 in the vicinity of the detection unit 15. Further, in the third embodiment shown in FIG. 3, in the vicinity of the periphery of the detection unit 15, the wire 17 is caulked between several films 12 and 13 to prevent the films 12 and 13 from slipping.
[0014]
In these examples, the shapes of the conductive layers 12a and 13a are set in advance so that the conductive layers 12a and 13a are not formed on the films 12 and 13 where the eyelets 16 and the wires 17 are crimped. It is necessary to keep.
As described above, in the second and third embodiments, the film is formed by the adhesive by partially fixing the film between the films in which the conductive layer is not formed with several fixing jigs in the vicinity of the detection unit. The relative slip of the film is prevented, and the bending can be accurately detected even if the film sensor is bent for a long time.
[0015]
Accordingly, in the present invention, as shown in the above embodiment, fixing means for preventing the plastic film from slipping are provided at several places near the periphery of the detection unit, and when the film sensor as described above is bent, It is possible to prevent a change with time in the bending detection.
The present invention is not limited to these examples, and various modifications can be made without departing from the scope of the present invention. For example, the fixing jig of the present invention is not limited to the eyelet or wire of the embodiment, and can be realized by various fixing jigs.
[0016]
【The invention's effect】
As described above, in the present invention, it has a detection part constituted by a conductive layer on each film arranged opposite to each other with a first gap provided at a predetermined location, and the contact between the conductive layers causes the A film sensor for detecting the pressure acting on the film, comprising a fixing means for fixing the gap between the films in the vicinity of the detection unit, so that even if the film sensor is bent, it is accurate even if a long time elapses. Bending can be detected.
[0017]
3. The fixing means according to claim 2, wherein a second gap is provided in the vicinity of the detection unit, and the films facing each other with the second gap are fixed to prevent relative slip of the film. Even when the film sensor is bent for a long time, the bending can be accurately detected.
Further, in claim 3, in the fixing means, a fixing jig is caulked between the films in the vicinity of the detection unit to prevent relative slip of the film and the film sensor is bent. Even if a long time elapses, bending can be detected accurately.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the structure of a first embodiment of a film sensor according to the present invention.
FIG. 2 is also a cross-sectional view showing the structure of a second embodiment.
FIG. 3 is a cross-sectional view showing the structure of a third embodiment.
FIG. 4 is a cross-sectional view showing the structure of a conventional film electric wire.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Film electric wire 12 Plastic film 12a, 13a Conductive layer 14 Insulating layer 14a Opening part 15 Detection part 16 Eyelet 17 Wire

Claims (3)

A detecting unit having a structure in which an insulating layer is bonded using an adhesive between each film, and is configured by a conductive layer on each film disposed to face each other with a first gap provided at a predetermined position. A film sensor for detecting pressure acting on the film by contact between the conductive layers,
In order to prevent relative slip of the film due to the adhesive in each of the detection units, a film sensor provided with a fixing means for fixing between the films in the vicinity of each of the detection units. In the fixing means, a second gap is provided in order to prevent relative slip of the film in each of the detection sections, and the films facing each other across the second gap are fixed. The film sensor according to claim 1. 2. The film sensor according to claim 1, wherein the fixing means caulks a fixing jig between the films in order to prevent relative slip of the film in each of the detection units.

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