JP2568073Y2 - Variable resistor - Google Patents

Description

[Detailed description of the invention]

[0001]

In the present invention, the resistance is changed by sliding a slider on a resistor, and the resistance is largely changed at the end of the movable range of the slider. It relates to a variable resistor.

[0002]

2. Description of the Related Art Recently, as a variable resistor used in a vehicle-mounted sensor or the like, when a slider sliding on a resistor is slightly moved at an end of a movable range (for example, near a stroke end). What is required is a circuit designed so that the resistance value greatly changes.

FIG. 5 is an explanatory view showing a circuit pattern shape of a conventional variable resistor which meets such a demand. On an insulating substrate 1, electrodes 2 and 3 and a portion connected to the electrode 2 and in the vicinity of the electrode 3 are shown. A strip resistor 4 extending, a high resistor 5 overlapping the small region including the gap G between the strip resistor 4 and the electrode 3 and connecting the electrode 3 and the strip resistor 4, and a substantially parallel to the strip resistor 4; And a band-shaped current collector 6 extending to the electrode 2 is printed, and a terminal 7 (a so-called one terminal) is attached to the electrode 2.
A terminal 8 (so-called three terminals) is mounted on the belt-shaped current collector 6, and a terminal 9 (so-called two terminals) is mounted on the belt-shaped current collector 6. Here, the electrodes 2 and 3 and the belt-shaped current collector 6 are printed with silver, the belt-shaped resistor 4 and the high-resistance body 5 are printed with carbon, but the high-resistance body 5 is printed with the belt-shaped resistor 4. It is formed of carbon having a larger specific resistance than that of carbon. Note that, in order to prevent sulfuration and oxidation of the band-shaped current collector 6, carbon having a very small specific resistance may be formed on the band-shaped current collector 6 as an overcoat layer.

The variable resistor provided with such a circuit pattern is provided on the band-shaped resistor 4 and the band-shaped current collector 6 with a predetermined voltage applied between the terminals 7 and 8, that is, between the electrodes 2 and 3. By sliding the slider 10 along the longitudinal direction, the resistance value between the slider 10 and the terminal 8 is changed,
This change in resistance is output as a change in voltage between the terminals 8 and 9. That is, the slider 10 is movable in the left-right direction in FIG.
When the slider 10 is located at the left end of the movable range S in the figure, the output voltage between the terminals 8 and 9 becomes maximum.
The output voltage between 9 is minimal.

FIG. 6 is a graph showing the operating characteristics of such a variable resistor. The output voltage ratio indicating the magnitude of the output voltage between the terminals 8 and 9 with respect to the input voltage between the terminals 7 and 8 is a variable. Y, the stroke amount of the slider 10 is a variable x, the slider 1
The stroke amount when 0 reaches the gap G is m,
Assuming that the stroke amount when the slider 10 reaches the stroke end is s, m ≦ x ≦ than when 0 ≦ x ≦ m.
In the case of s, the manner of change of the output voltage ratio Y becomes sharper. That is, when the slider 10 has not reached the gap G, the value of Y changes according to the change in the resistance value of the belt-shaped resistor 4. Since the value of Y changes according to the change in the resistance value of the high-resistance element 5 on G, this variable resistor greatly changes the output voltage ratio Y when the slider 10 is moved by a small stroke near the stroke end. be able to.

[0006]

By the way, in the above-mentioned conventional example, defining the relative position between the electrodes 2 and 3 and the strip-shaped resistor 4 which are separately formed by printing with high precision is inevitable because printing displacement is inevitable. Although it is difficult, this printing deviation is caused by the electrode 3
The distance of the gap G between the resistor and the strip-shaped resistor 4 varies, so that the variation in the total resistance of the resistance pattern and the stroke point at which the rate of change of the resistance value is changed (the value of m)
Has a large variation, so that stable operation characteristics cannot be expected.

Further, in this conventional example, since two types of resistance patterns, that is, the band-shaped resistor 4 and the high resistor 5, must be separately formed by printing, there is a problem that the production is complicated.

The present invention has been made in view of the above-mentioned problems in the prior art, and has as its object the resistance value can be largely changed at the end of the movable range of the slider, and stable operation characteristics are expected. It is to provide a variable resistor that can be used.

[0009]

In order to achieve the above-mentioned object, the present invention provides a pair of electrodes to which a predetermined voltage is applied on an insulating substrate, a band-shaped resistor connecting between the two electrodes,
The strip-shaped resistor is made of the same material as the strip-shaped resistor, is connected to one of the electrodes, and is located only near the end of the strip-shaped resistor.
An auxiliary resistor formed in parallel and a strip-shaped current collector extending substantially parallel to the strip-shaped resistor are printed and formed, and on the insulating substrate, made of a resistance material having an extremely large specific resistance than the strip-shaped resistor, A high resistance layer connected to the auxiliary resistor and extending substantially parallel to the strip resistor is formed by printing, and slidable along the longitudinal direction on the strip resistor and on the strip current collector and the high resistance layer. A part of the slider slides on the auxiliary resistor at the end of the movable range of the slider.

[0010]

According to the above means, only the change in the resistance value of the belt-shaped resistor contributes to the output voltage until the slider reaches or comes close to the auxiliary resistor. Since the resistance change of the band-shaped resistor and the auxiliary resistor can contribute to the output voltage, when the slider is moved to the end of the movable range, a resistance pattern that shifts from a series circuit to a parallel circuit is formed. Therefore, when the slider is moved by a small stroke at the end of the movable range, the output voltage can be greatly changed according to the change in the resistance value of the resistance pattern that shifts from the series circuit to the parallel circuit. Becomes In addition, the strip-shaped resistor is connected to both electrodes without a gap, and the relative position between the strip-shaped resistor and the auxiliary resistor, which can be collectively formed by printing, can be defined with high accuracy, which is caused by printing misalignment. Variations in operating characteristics can be avoided.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention .
Explanatory view showing a circuit pattern used, shown in Figure 2 Figure 1
To the equivalent circuit diagram, FIG. 3 is a characteristic diagram showing a graph of the behavior characteristics, the parts corresponding to FIG. 5 and 6 described above are denoted by the same reference numerals.

Before explaining an embodiment of the present invention, FIG.
This will be described below using examples shown in FIGS. In FIG. 1, on an insulating substrate 1, an electrode 2 extended in a substantially L-shape is shown.
, A bifurcated electrode 3 and a linearly extending band-shaped current collector 6 are formed by printing silver, and a terminal 7 (so-called one terminal) is attached to the electrode 2. Has terminal 8
(So-called three terminals) are attached, and terminals 9 (so-called two terminals) are attached to the belt-shaped current collector 6. Also, by printing carbon, a resistance layer 11 that connects the two electrodes 2 and 3 while covering the two electrodes 2 and 3 is formed, and a part of this resistance layer 11 One end is connected to the electrode 2 and the band-shaped resistor 4 extends substantially parallel to the band-shaped current collector 6, and the other end of the branched electrode 3 is connected in parallel to the illustrated right end of the band-shaped resistor 4. An auxiliary resistor 12 is provided. In this embodiment, carbon having a very small specific resistance is printed on the belt-shaped current collector 6 to form the overcoat layer 1.
The overcoat layer 13 and the electrode coating of the resistance layer 11 prevent the strip-shaped current collector 6 and the electrodes 2 and 3 from being sulfurized or oxidized.

On the other hand, in the slider 10 movable in the left-right direction in FIG. 1 within the movable range S, the first contact piece 10a slides on the strip-shaped current collector 6, and the second contact piece 10b The third contact piece 10c slides on the insulating substrate 1 and the auxiliary resistor 12 by sliding on the belt-shaped resistor 4. That is,
The third contact piece 10c of the slider 10 slides on the auxiliary resistor 12 near the stroke end, and
, Slide on the insulating substrate 1.

The circuit having such a configuration can be represented as an equivalent circuit shown in FIG. 2, and when a predetermined voltage is applied between the terminals 7 and 8, that is, between the electrodes 2 and 3, the band-shaped resistor 4 is applied. By moving the slider 10 along the longitudinal direction of the belt-shaped current collector 6, the resistance between the slider 10 and the terminal 8 is changed. It is output as a voltage change.

Next, the operating characteristics of this variable resistor are shown in FIGS.
3 will be described.

In these figures, the output voltage ratio Y indicating the magnitude of the output voltage between the terminals 8 and 9 with respect to the input voltage between the terminals 7 and 8 is represented by the resistance between the terminals 8 and 9 and the resistance between the terminals 7 and 8. The resistance value between the terminals 7 and 8 is represented by the resistance value between the terminals 7 and 9 (between the terminal 7 and the slider 10) and the resistance value between the terminals 8 and 9.
9 (between the slider 10 and the terminal 8). Therefore, the stroke amount of the slider 10 is set as a variable x,
The stroke amount when the slider 10 reaches the auxiliary resistor 12 is n, the stroke amount when the slider 10 reaches the stroke end is s, and the resistance layer 11 (the strip-shaped resistor 4 and the auxiliary resistor 12) If 0 ≦ x <n, the current can not be passed through the auxiliary resistor 12 and can be regarded as a series circuit using only the resistance value change of the belt-shaped resistor 4.
The resistance value between the terminals 7 and 8 can be expressed as rs, and the resistance value between the terminals 8 and 9 can be expressed as r (s−x), and the output voltage ratio Y is as shown in the following Expression 1.

[0018]

Y = (s−x) / s (where 0 ≦ x <n) However, when n ≦ x ≦ s, a current flows not only in the band-shaped resistor 4 but also in the auxiliary resistor 12. Since a parallel circuit using the resistance value change of the resistors 4 and 12 is configured, the terminals 7 and 9 are connected.
The resistance value between the terminals 8 and 9 is rx, and the resistance value between the terminals 8 and 9 is r (s−
x) / 2, so that the resistance value between the terminals 7 and 8 is r (s + x)
/ 2, and the output voltage ratio Y is as shown in the following Expression 2.

[0019]

Y = (s−x) / (s + x) (where n ≦ x ≦ s) As a result, the output voltage ratio Y is equal to the stroke amount x of the slider 10.
As shown by the solid line in FIG. 3, the value of Y rapidly changes when the stroke amount x of the slider 10 toward the stroke end is n or slightly exceeds n. ing. That is, this variable resistor can change the output voltage ratio Y greatly by moving the slider 10 by a small stroke near the stroke end.

In addition, the variable resistor includes a band-shaped resistor 4.
However, both electrodes 2 and 2 do not pass through a gap as in the conventional example.
3, the resistance value is not affected by the variation in the gap interval of this kind, and the relative position between the strip-shaped resistor 4 and the auxiliary resistor 12 that can be collectively printed can be defined with high accuracy. Therefore, it is possible to avoid a variation in the operating characteristics due to the printing deviation, and thus to obtain a variable resistor having stable operating characteristics capable of performing a desired resistance value change.

Further, in the above variable resistor, the auxiliary resistor 12 for largely changing the resistance value near the stroke end is made of the same material as the belt-shaped resistor 4, and a high resistor is separately printed as in the conventional example. Since there is no need to perform this process, there is an advantage that the printing process of the resistance pattern is completed only once.

However, when the stroke amount x of the slider 10 is n
From the point of (s-n) / s to (s-
n) / (s + n) or (s-n) / (s + n)
Changes rapidly from (s−n) / s to the resistance value.
Position is detected because the stroke amount does not correspond one-to-one.
Cannot be reliably performed.
Since the slider comes into contact with the upper part, wear of the slider piece
However, there is a problem that the life cannot be prolonged severely.

FIG . 4 shows a variable resistor according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a circuit pattern shape, corresponding to FIG.
The parts are denoted by the same reference numerals. The variable resistor shown in FIG. 4 includes the contact pieces 10 a to 10 of the slider 10 on the insulating substrate 1.
The high-resistance layer 14 made of a resistance material having an extremely higher specific resistance than the resistance layer 11 is previously provided in the three belt-like regions where c slides.
Is printed and formed on each of the high-resistance layers 14, and the band-shaped current collector 6, the band-shaped resistor 4, and the auxiliary resistor 12 are formed by printing, which is greatly different from the examples shown in FIGS. I have. Reference numeral 15 in FIG. 4 denotes an electrode provided for checking the resistance value of the upper resistance layer 14 connected to the auxiliary resistor 12 on the upper side in the figure.
In this example, a phenolic carbon ink was printed.

As described above, the band-shaped current collector 6 and the two resistors 4
When the high-resistance layer 14 is provided on the printing surface of No. 12, the surfaces of the strip-shaped current collector 6 and the two resistors 4 and 12 can be smoothed, and the contact piece 10 c is placed on the high-resistance layer 14. Since sliding resistance is smaller than sliding directly on the insulating substrate 1 in this embodiment, this embodiment is not limited to FIGS.
The movement of the slider 10 can be performed more smoothly than the example shown in FIG.
To that extent, wear can be prevented and the life can be prolonged.

If the high resistance layer 14 connected to the auxiliary resistor 12 and extending substantially in parallel with the strip-shaped resistor 4 is provided, the slider 10 moving toward the stroke end will not move until the slider 10 approaches the auxiliary resistor 12. Since the contact piece 10c can be regarded as sliding on the insulator recently, the resistance value between the terminals 8 and 9 changes in the same manner as in the examples shown in FIGS. When the moving element 10 comes close to the auxiliary resistor 12, the high-resistance layer 14 existing between the contact piece 10c and the auxiliary resistor 12 can no longer be regarded as an insulator. The voltage ratio Y changes as shown by a broken line in FIG. That is, when the slider 10 approaches the auxiliary resistor 12, a parallel circuit is formed by the high resistance layer 14, the auxiliary resistor 12, and the strip-shaped resistor 4.
Until 0 reaches the auxiliary resistor 12, the output voltage ratio Y changes according to the change in the resistance value of the strip-shaped resistor 4 and the high-resistance layer 14, and the calculation formula is omitted, but the value of Y is shown in FIG.
At the time when the slider 10 reaches the auxiliary resistor 12 (stroke amount x = n), Y = (s−n) / (S +
n). When the slider 10 reaches the auxiliary resistor 12, the high-resistance layer 14 does not contribute, so that the resistance value between the terminals 8 and 9 changes again in the same manner as in the previous embodiment.
Therefore, in this embodiment, even when the resistance value largely changes near the stroke end, the way of the change is smooth.

[0026]

[Effects of the Invention] As described above, according to the present invention ,
Not only can greatly change the resistance value at the end of the movable range of the slider, it can be avoided variations in operating characteristics due to misregistration, also rapidly without creating discontinuities
The resistance value can be changed during
Output voltage has a one-to-one correspondence and position detection is reliable
And the slider comes into contact with the high-resistance layer, so long life
It is possible to provide a highly variable resistor reliable that can be achieved service life.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a circuit pattern shape of a variable resistor used for describing an embodiment of the present invention .

FIG. 2 is an equivalent circuit diagram shown in FIG.

3 is a graph characteristics diagram of the operation characteristics.

4 is an explanatory diagram showing a circuit pattern of a variable resistor according to the actual施例of the present invention.

FIG. 5 is an explanatory diagram showing a circuit pattern shape of a variable resistor according to a conventional example.

FIG. 6 is a graph showing the operating characteristics of the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2, 3 electrode 4 Strip-shaped resistor 6 Strip-shaped current collector 7, 8, 9 terminal 10 Slider 10a, 10b, 10c Contact piece 12 Auxiliary resistor 14 High resistance layer

Claims (1)

(57) [Scope of request for utility model registration] A pair of electrodes to which a predetermined voltage is applied, a band-shaped resistor connecting between the two electrodes,
The strip-shaped resistor is made of the same material as the strip-shaped resistor, is connected to one of the electrodes, and is located only near the end of the strip-shaped resistor.
An auxiliary resistor formed in parallel, and a strip-shaped current collector extending substantially parallel to the strip-shaped resistor are printed and formed. On the insulating substrate, a resistance material having a specific resistance much larger than that of the strip-shaped resistor is formed. A high resistance layer connected to the auxiliary resistor and extending substantially parallel to the strip resistor is formed by printing, and is slidable along the longitudinal direction on the strip resistor, the strip current collector, and the high resistance layer. A variable resistor, wherein a part of a slider slides on the auxiliary resistor at an end of a movable range of the slider.