JP2019070609A - Seating sensor - Google Patents

Abstract

To provide a seating sensor with which it is possible to detect that there is occurrence of disconnection.SOLUTION: A seating sensor comprises: an upper film 11 and a lower film 12 built into a seat; a first conductor pattern 13 formed in the upper film 11 and having a plurality of series connected first electrodes 14-17 divided into a pair of electrode pieces 18, 19; a plurality of resistors 26 for disconnection detection for connecting between all of the electrode pieces 18, 19 of the plurality of first electrodes 14-17; and a second conductor pattern 30 formed in the lower film 12 and having a plurality of second electrodes 31-34 arranged so as to face the plurality of first electrodes 14-17 in the vertical direction so that all of the electrode pieces 18, 19 of the plurality of first electrodes 14-17 can be shorted.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a seating sensor.

  Conventionally, various things have been proposed as a seating sensor (for example, patent documents 1, 2 etc.). For example, the seating sensor described in Patent Document 1 includes a lower electrode sheet and an upper electrode sheet. The lower electrode sheet has a plurality of lower contacts, a disconnection detecting resistor, and a lower electrode circuit connecting the lower contacts and the disconnection detecting resistor in parallel. On the other hand, the upper electrode sheet has the same number of upper contacts as the lower contacts. The lower contacts and the upper contacts are arranged to face each other in the vertical direction to constitute a switch.

  Therefore, in a state where a load is applied in the vertical direction to the seating sensor in a state where a voltage is applied, the lower contact and the upper contact are in contact, the switch is turned on, and the load is not applied. It will be off. Thereby, it can be detected whether a person is sitting on the seat to which the seating sensor is attached.

  In addition, when no break occurs in the lower electrode circuit, only the resistance value of the break detection resistor is measured when no one is seated on the seat. On the other hand, when the lower electrode circuit is disconnected, no voltage is applied to the disconnection detection resistor regardless of the location of the disconnection, so when the person is not seated in the seat, the disconnection detection resistor is used. The resistance value is not measured. Therefore, the disconnection sensor can be easily detected without removing the seating sensor from the seat.

Unexamined-Japanese-Patent No. 11-297153 JP 2001-67980 A

  By the way, in patent document 1, even if the lower electrode circuit is broken, when a person is sitting in the seat, the lower electrode circuit is in a short circuit state by turning on any switch. It becomes impossible to detect the presence of disconnection.

  An object of the present invention is to provide a seating sensor capable of detecting that a break has occurred.

  A seating sensor for solving the above problems includes a first film and a second film built in a seat, and a plurality of series-connected first electrodes formed on the first film and divided into a pair of electrode pieces. A conductive pattern, a plurality of break detection resistors connecting between all the electrode pieces of the plurality of first electrodes, and a plurality of the plurality of first electrodes formed on the second film And a second conductive pattern having a plurality of second electrodes arranged to face the plurality of first electrodes in the up-down direction so as to be capable of shorting between the electrode pieces.

  According to this configuration, each of the plurality of first electrodes and the second electrode opposed to the plurality of the first electrodes in the vertical direction are turned on by a short circuit between the two electrode pieces, for example, when a person sits on the seat and contacts them. In this state, the switch is configured to be turned off by cutting between the two electrode pieces when it is not in contact. That is, the first conductive pattern and the second conductive pattern constitute an electric circuit composed of a plurality of switches connected in series. On the other hand, the first conductive pattern is connected to the plurality of disconnection detecting resistors between all the two electrode pieces of the plurality of first electrodes, so that a plurality of series connection of the plurality of disconnection detecting resistors are connected. Constitute an electrical circuit. Therefore, when disconnection occurs in any of the first conductive pattern and the plurality of disconnection detecting resistors, the electric circuit is opened and can not be energized. By monitoring the fact that the current can not be supplied, it is possible to detect that a disconnection has occurred. This is the same if the first electrode and the second electrode are in contact and the switch is in the on state, as long as the disconnection occurs at the other place. Thus, even if a person is seated in the seat, it can be detected that a break has occurred.

  In the seating sensor, the resistance value of one of the plurality of disconnection detection resistors is the resistance value of the other one of the plurality of disconnection detection resistors and any other two or more of the plurality of disconnection detections. It is preferable to set so as to be different from all of the combined resistance values of the resistances.

  According to this configuration, when the plurality of first electrodes and the plurality of second electrodes do not contact and all switches are in the off state, the resistance value of the first conductive pattern or the like is the plurality of disconnection detection resistors The combined resistance value is obtained by adding all the resistance values of. On the other hand, when any one of the first electrode and the second electrode is in contact and the switch is turned on, the resistance value of the first conductive pattern or the like is the breakage of the first electrode (both electrode pieces). The resistance value (combined resistance value) is obtained by subtracting the resistance value of the detection resistor. The resistance value of the disconnection detection resistor to be subtracted at this time is different from all of the resistance values of the other disconnection detection resistors and the combined resistance values of any other two or more of the disconnection detection resistors. The first electrode and the second electrode in which the switch is in the on state are identified. This makes it possible to determine at which position of the seat a person is sitting.

In the seating sensor, it is preferable that resistance values of the plurality of disconnection detection resistances are set to be in a relationship of multiples of powers of 2 different in index.
According to this configuration, the resistance value of one of the break detection resistors is combined with the resistance value of the other break detection resistor and any other two or more break detection resistors by simple mathematical expression calculation. It can be set to be different from all of the resistance values.

  In the seating sensor, it is preferable that each of the plurality of disconnection detection resistors is a linear pattern straddling between the two electrode pieces, and a resistance value is set based on a line width of the pattern.

According to this configuration, the resistance value of the disconnection detection resistor can be easily adjusted by adjusting the line width of the pattern.
In the seating sensor, the first film is preferably disposed above the second film.

  According to this configuration, the first film, which is provided with the first conductive pattern and the plurality of disconnection detecting resistors and has a more complicated electrical structure, is located above the second film, that is, the surface of the seat. By arranging at a closer position, for example, it is possible to reduce the number of inspection and repair steps at the time of disconnection detection.

  The present invention has the effect of being able to detect that a break has occurred.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which shows the structure typically about 1st Embodiment of a seating sensor. About the seating sensor of the embodiment, (a) is a bottom view which shows an upper film, (b) is a top view which shows a lower film. The equivalent circuit schematic which shows the electric constitution about the seating sensor of the embodiment. FIG. 7 is a bottom view of the top film for a second embodiment of a seating sensor. The equivalent circuit schematic which shows the electric constitution about the seating sensor of the embodiment. The list figure which shows the relationship between the on / off state of a switch, and a synthetic resistance value (resistance value). The bottom view which shows an upper film about the modification of a seating sensor. The bottom view which shows a 1st electrode about the modification of a seating sensor. The bottom view which shows a 1st electrode about another modification of a seating sensor. The bottom view which shows a 1st electrode about another modification of a seating sensor.

First Embodiment
Hereinafter, a first embodiment of the seating sensor will be described. In the following, the front-rear direction and the width direction of the seat will be referred to as the “front-rear direction” and the “width direction”, respectively.

  As shown in FIG. 1, a seat 1 of a vehicle such as a car includes a seat cushion 2 and a seat back 3. The seat cushion 2 includes a cushion pad 4 and a seat cover 5 covering the cushion pad 4 from above. In the seat 1, a film-like sensor body 10 is embedded immediately below the seat cover 5. At a front end (rear end) of the sensor body 10, a connector 41 for connection to an ECU (Electronic Control Unit) 40 is connected.

  As shown in FIGS. 2A and 2B, the sensor body 10 has an upper film 11 as a first film extending along the seating surface of the seat cushion 2, and a cushion pad 4 below the upper film 11. And a lower film 12 as a second film spreading in The upper film 11 and the lower film 12 are both formed in a thin film shape with an insulating resin material (for example, polyester etc.).

  The upper film 11 includes a pair of front and rear transversely extending portions 11a and 11b extending in the width direction, a connecting portion 11c connecting longitudinally central portions of the transversely extending portions 11a and 11b in the longitudinal direction, and a transversely extending portion An extension 11d is integrally connected to the longitudinal center portion of 11b and extends rearward.

  On the lower surface of the upper film 11, for example, a first conductive pattern 13 made of a conductive ink such as silver paste or carbon paste is formed by printing. The first conductive pattern 13 has a plurality of (four) substantially circular first electrodes 14, 15, 16, 17 disposed at both ends of the laterally extended portions 11 a and 11 b. Each of the first electrodes 14 to 17 is divided into a pair of substantially semicircular electrode pieces 18 and 19 in the width direction. That is, the two electrode pieces 18 and 19 are insulated by the gap C formed to extend in the front-rear direction between them.

  Further, the first conductive pattern 13 extends from the rear along the extension 11 d and is connected to the electrode piece 18 of the first electrode 14, and the electrode piece 19 of the first electrode 14 and the first electrode 15. A lead 22 connecting between the electrode pieces 19, a lead 23 connecting between the electrode piece 18 of the first electrode 15 and the electrode piece 18 of the first electrode 16, an electrode piece 19 of the first electrode 16 and the first electrode A lead 24 connecting between the 17 electrode pieces 19 and a lead 25 connected to the electrode piece 18 of the first electrode 17 and extending rearward along the extension 11 d are provided. The first conductive pattern 13 is connected to the ECU 40 at the ends (connectors 41) of the leads 21 and 25.

  In addition, on the lower surface of the upper film 11, a plurality of (four) break detection resistors 26 made of a conductive ink such as carbon paste are printed. Each of the break detection resistors 26 is a linear print pattern extending in the width direction and straddling between the two electrode pieces 18 and 19 of each of the plurality of first electrodes 14 to 17, and between the two electrode pieces 18 and 19. Connect The plurality of disconnection detection resistors 26 are set to have the same line width so that their resistance values become equal.

On the other hand, the lower film 12 also has a pair of laterally extending portions 12a and 12b, a connecting portion 12c, and an extending portion 12d integrally with the upper film 11.
On the upper surface of the lower film 12, for example, a second conductive pattern 30 made of a conductive ink such as silver paste or carbon paste is formed by printing. The second conductive pattern 30 has a plurality of (four) substantially circular second electrodes 31, 32, 33, 34 disposed at both ends of the laterally extending portions 12a, 12b. That is, the second conductive pattern 30 is formed by the plurality of second electrodes 31 to 34 scattered on the lower film 12 and is not connected to the ECU 40.

  The upper film 11 and the lower film 12 are vertically stacked through spacers (not shown) made of an insulating resin material. At this time, the first electrodes 14 to 17 and the second electrodes 31 to 34 are disposed to face each other in the vertical direction through the openings formed in the spacer. Each of the plurality of first electrodes 14 to 17 and the second electrodes 31 to 34 facing the same in the vertical direction are turned on by a short circuit between the two electrode pieces 18 and 19 when a person sits on the seat 1 and contacts them, for example. In this state, switches (so-called membrane switches) SW1, SW2, SW3, and SW4 are configured to be turned off by cutting between the two electrode pieces 18 and 19 when they are not in contact with each other.

Next, the electrical configuration of the sensor body 10 will be described.
As shown in FIG. 3, the sensor body 10 forms an electric circuit including a plurality of series-connected disconnection detection resistors 26 by the first conductive pattern 13 and the plurality of disconnection detection resistors 26 formed on the upper film 11. Do. Further, the sensor body 10 includes a plurality of first electrodes 14 to 17 (both electrode pieces 18 and 19) formed on the upper film 11 and a plurality of second electrodes 31 to 34 formed on the lower film 12. An electric circuit composed of switches SW1 to SW4 connected in series is configured. The switches SW1 to SW4 are connected in parallel to the corresponding break detection resistor 26.

  The sensor body 10 is supplied with power by the ECU 40 via the connector 41. The ECU 40 monitors the current flowing to the sensor body 10 through the connector 41 to detect the state of the seat 1 and the like. Specifically, when all the switches SW1 to SW4 are in the OFF state, a current having a minimum value flows in the sensor body 10 in accordance with the combined resistance value of all the disconnection detection resistors 26. The ECU 40 detects that a person is not sitting on the seat 1, for example, based on the current value at this time. Alternatively, when all the switches SW1 to SW4 are in the on state, a current having a maximum value flows in the sensor body 10. The ECU 40 detects, for example, that a person is sitting in a normal posture (or weight) on the seat 1 based on the current value at this time. Alternatively, if some of the switches SW1 to SW4 are in the off state, a current flows in the sensor body 10 according to the combined resistance value (or resistance value) of the disconnection detection resistors 26 in the number of the switches SW1 to SW4. . The ECU 40 detects, for example, that a person is sitting in a biased posture (or weight) based on the current value at this time. Alternatively, when disconnection occurs anywhere in the first conductive pattern 13 and the plurality of disconnection detection resistors 26, no current flows in the sensor body 10. The ECU 40 detects the occurrence of the disconnection based on the current value (zero) at this time.

  And ECU40 outputs the control signal according to those detection results to an appropriate apparatus. Specifically, when detecting that a person is sitting on the seat 1, for example, the ECU 40 outputs a control signal for driving a notification member (a warning lamp or the like) that urges the user to wear a seat belt. Alternatively, the ECU 40 outputs a control signal for permitting the operation of the air bag or the like.

  The ECU 40 selectively selects a control signal for driving an informing member that promotes the wearing of the seat belt or a control signal for permitting the operation of the air bag or the like according to the number of switches SW1 to SW4 in the on state. It may be output to That is, the ECU 40 controls the control signal for driving the notification member that promotes the wearing of the seat belt and the control for permitting the operation of the air bag etc. only when the number of switches SW1 to SW4 in the on state is plural, for example. A signal may be output.

Next, together with the operation of the present embodiment, its effects will be described.
(1) In the present embodiment, the first conductive pattern 13 and the second conductive pattern 30 constitute an electric circuit composed of a plurality of serially connected switches SW1 to SW4. On the other hand, the first conductive pattern 13 is connected to the plurality of disconnection detection resistances 26 between all the two electrode pieces 18 and 19 of the plurality of first electrodes 14 to 17, thereby detecting disconnections of a plurality of series connections. An electric circuit composed of the resistor 26 is configured. Therefore, when a break occurs in any of the first conductive pattern 13 and the plurality of break detection resistors 26, the electric circuit is opened and can not be energized. By monitoring the fact that the current can not be supplied, it is possible to detect that a disconnection has occurred. Even if the first electrodes 14 to 17 and the second electrodes 31 to 34 are in contact and the switches SW1 to SW4 are in the on state, this is the same as long as the disconnection occurs in other places. Thus, even if a person is sitting on the seat 1, it can be detected that a break has occurred.

  (2) In the present embodiment, the upper film 11 is disposed above the lower film 12. Therefore, the first conductive pattern 13 and the plurality of break detecting resistors 26 are provided, and the upper film 11 having a more complicated electrical structure is disposed above the lower film 12, that is, closer to the surface of the seat 1. This can reduce, for example, the number of inspection and repair steps at the time of disconnection detection. Specifically, if the sheet skin 5 of the seat cushion 2 is peeled off, the upper film 11 having a more complicated electrical structure and a higher possibility of disconnection may be exposed immediately for smooth inspection and repair. It can be done.

  (3) In the present embodiment, the resistance 26 for disconnection detection is a linear print pattern (linear pattern) straddling between the two electrode pieces 18 and 19, so that the line width of the print pattern is adjusted. The disconnection detection resistor 26 can be easily set to a desired resistance value.

  (4) In the present embodiment, by adopting the second conductive pattern 30 composed of the plurality of second electrodes 31 to 34 scattered on the lower film 12, it is possible to substantially prevent the occurrence of disconnection of itself.

Second Embodiment
Hereinafter, a second embodiment of the seating sensor will be described. The second embodiment has a configuration in which the resistance for disconnection detection of the first embodiment is changed. Therefore, the same configuration is denoted by the same reference numeral, and the description thereof is partially omitted.

  As shown in FIG. 4, on the lower surface of the upper film 11 of the sensor body 50 according to the sensor body 10, a plurality of (four) disconnection detection resistors 51, 52, 53, made of conductive ink such as carbon paste, for example 54 are print-formed. Each of the break detection resistors 51 to 54 is a linear print pattern extending in the width direction and straddling between the two electrode pieces 18 and 19 of each of the plurality of first electrodes 14 to 17. Connect between

Next, the electrical configuration of the sensor body 50 will be described.
As shown in FIG. 5, the sensor body 10 is composed of a plurality of series connected disconnection detection resistors 51 to 54 by the first conductive pattern 13 formed on the upper film 11 and the plurality of disconnection detection resistors 51 to 54. Construct an electrical circuit. Further, the sensor body 50 includes a plurality of first electrodes 14 to 17 (both electrode pieces 18 and 19) formed on the upper film 11 and a plurality of second electrodes 31 to 34 formed on the lower film 12. An electric circuit composed of switches SW1 to SW4 connected in series is configured.

  Here, in all of the plurality of disconnection detection resistors 51 to 54, the resistance value of one disconnection detection resistor 51 to 54 is the resistance value of the other disconnection detection resistors 51 to 54 and any other two or more Are set to be different from all of the combined resistance values of the disconnection detection resistors 51 to 54.

  Specifically, the resistance values R1, R2, R3, and R4 of the plurality of disconnection detection resistors 51 to 54 are set to satisfy the relationship of multiples of powers of two different in the exponents. That is, the resistance values R1 to R4 are set to satisfy the relationship of the following expression.

Ri = 2 ^ (i-1) × R1, where i = 1 to 4
The setting of such resistance values R1 to R4 is performed based on the setting of the line width of the linear printing pattern of the disconnection detection resistors 51 to 54. That is, the plurality of disconnection detection resistors 51 to 54 are made of the same material (that is, a material having the same resistivity), and their thickness dimensions are set to be equal to one another. The line widths W1, W2, W3, and W4 of the plurality of disconnection detection resistors 51 to 54 are set to satisfy the relationship of the following formula.

Wi = 2 ^ (1-i) × W1, where i = 1 to 4
FIG. 6 is a list showing the relationship between the on / off states of the switches SW1 to SW4 and the combined resistance value (resistance value) of the sensor body 10. As shown in FIG. As shown in the figure, it is confirmed that setting of the resistance values R1 to R4 as described above results in an exclusive combined resistance value (resistance value) according to the on / off state of the switches SW1 to SW4. In other words, by monitoring the combined resistance value (resistance value) of the sensor body 50, that is, the current flowing through the sensor body 50, it is possible to detect the on / off states of all the switches SW1 to SW4.

  The ECU 40 controls, for example, a control signal for driving a notification member prompting the user to wear the seat belt and a control for permitting operation of an air bag or the like only when the number of switches SW1 to SW4 in the on state is plural. A signal may be output. Alternatively, according to the positions of the switches SW1 to SW4 in the on state, the ECU 40 outputs a control signal for driving a notification member that promotes the wearing of the seat belt or a control signal for permitting the operation of the air bag or the like. May be

As described above, according to this embodiment, the following effects can be obtained in addition to the effects of the first embodiment.
(1) In the present embodiment, when the plurality of first electrodes 14 to 17 and the plurality of second electrodes 31 to 34 are noncontact and all the switches SW1 to SW4 are in the off state, the resistance of the first conductive pattern 13 or the like The value is a combined resistance value obtained by adding all the resistance values R1 to R4 of the plurality of disconnection detection resistors 51 to 54. On the other hand, when any of the first electrodes 14 to 17 and the second electrodes 31 to 34 are in contact and the switches SW1 to SW4 are turned on, the resistance value of the first conductive pattern 13 etc. The resistance value (combined resistance value) is obtained by subtracting the resistance values R1 to R4 of the break detection resistances 51 to 54 provided on the two electrode pieces 18 and 19). The resistance values R1 to R4 of the disconnection detection resistors 51 to 54 which are subtracted at this time are the resistance values R1 to R4 of the other disconnection detection resistors 51 to 54 and any two or more disconnection detection resistors 51 The first electrodes 14 to 17 and the second electrodes 31 to 34 in which the switches SW1 to SW4 are in the ON state are specified by being different from all of the combined resistance values of to 54. This makes it possible to determine at which position of the seat 1 a person is sitting.

  (2) In the present embodiment, the resistance values R1 to R4 of the plurality of disconnection detection resistors 51 to 54 are set to be in the relationship of multiples of powers of 2 different in index. Therefore, the resistance values R1 to R4 of one of the disconnection detection resistors 51 to 54, the resistance values R1 to R4 of the other disconnection detection resistors 51 to 54, and any other two or more disconnections by simple mathematical expression calculation It can be set to be different from all the combined resistance values of the detection resistors 51 to 54.

  (3) In the present embodiment, each of the plurality of disconnection detecting resistors 51 to 54 is a linear pattern (printed pattern) straddling between the two electrode pieces 18 and 19, and based on the line width of the pattern The resistance values R1 to R4 are set. Therefore, by adjusting the line width of the pattern, the resistance values R1 to R4 of the disconnection detection resistors 51 to 54 can be easily adjusted. This can reduce the number of manufacturing steps and costs.

The above embodiment may be modified as follows.
As shown in FIG. 7, it is also conceivable to omit any one of the disconnection detection resistors 51 to 54 of the sensor body 50. For example, it is also conceivable to cut the gap between the two electrode pieces 18 and 19 of the first electrode 17 by omitting the disconnection detection resistor 54. In other words, instead of the disconnection detecting resistor 54 of the resistance value R4, a resistor of infinite resistance may be adopted. In this case, if no current flows in the sensor body 10, it is detected that at least the switch (SW4) formed by the first electrode 17 is in the OFF state. On the other hand, when the switch (SW4) formed by the first electrode 17 is in the on state, the resistance value of the first conductive pattern 13 or the like changes in accordance with the on / off state of the other switches SW1 to SW3. For example, when any one of the first electrodes 14 to 16 and the second electrodes 31 to 33 is in contact and the switches SW1 to SW3 are turned on, the first electrodes 14 to 16 (both electrode pieces 18 and 19) are provided. The resistance value (combined resistance value) is obtained by subtracting the resistance values R1 to R3 of the disconnection detection resistors 51 to 53. The resistance values R1 to R3 of the disconnection detection resistors 51 to 53 subtracted at this time are the resistance values R1 to R3 of the other disconnection detection resistors 51 to 53 and any two or more disconnection detection resistors 51 The first electrodes 14 to 16 and the second electrodes 31 to 33 in which the switches SW1 to SW3 are in the ON state are specified by being different from all of the combined resistance values of to 53. This makes it possible to determine at which position of the seat 1 a person is sitting.

  As shown in FIG. 8, in the first embodiment, the first electrode 60 divided into the pair of substantially semicircular electrode pieces 61 and 62 in the front-rear direction may be adopted. Then, a linear disconnection detection resistor 63 is used to connect the two electrode pieces 61 and 62 so as to fill the entire gap C1 formed so as to extend in the width direction between the two electrode pieces 61 and 62. May be Note that the resistance may be a disconnection detection resistor of a linear print pattern that extends in the front-rear direction and spans between the two electrode pieces 61 and 62.

  As shown in FIG. 9, in the second embodiment, the first electrode 65 divided into a pair of substantially semicircular electrode pieces 66 and 67 in the front-rear direction may be adopted. Then, a linear break detection resistor 68 is used to connect the two electrode pieces 66 and 67 so as to fill the entire gap C2 formed so as to extend in the width direction between the two electrode pieces 66 and 67. May be In this case, the resistance value of the disconnection detection resistor 63 may be adjusted by adjusting the opening width in the front-rear direction of the gap C2 and the line width of the disconnection detection resistor 63 filling the gap.

  As shown in FIG. 10, in the second embodiment, the first electrode 70 divided into the pair of substantially semicircular electrode pieces 71 and 72 in the front-rear direction may be adopted. Then, a linear stripe-like disconnection detecting resistor 73 connecting the two electrode pieces 71 and 72 is formed so as to fill the entire gap C3 formed so as to extend in the width direction between the two electrode pieces 71 and 72. It may be adopted. The disconnection detecting resistor 73 is composed of a plurality (three) of resistive elements 73a, 73b, 73c divided in the front-rear direction so as to be in close contact with each other. As materials of these resistive elements 73a to 73c, those having at least adjacent ones 73a to 73c having different resistivities are employed. In this case, adjustment of the resistance value of the disconnection detection resistor 63 may be performed by distribution adjustment of the line widths of the resistance elements 73a to 73c filling the gap C3. The number of divisions of the resistance elements of the disconnection detection resistor 73 may be two or four or more.

  In the first embodiment, a linear break connecting the two electrode pieces 18 and 19 so as to fill the entire gap C formed to extend in the front-rear direction between the two electrode pieces 18 and 19. A detection resistor may be employed.

  In the second embodiment, adjustment of the resistance values of the disconnection detection resistors 51 to 54 may be performed by adjusting their thickness dimensions. Alternatively, the resistance values of the disconnection detection resistors 51 to 54 may be adjusted by selecting their materials (resistivity).

  In the second embodiment, the resistance value of one of the disconnection detecting resistors 51 to 54 is the other resistance value and all of the combined resistance values of any two or more other disconnection detecting resistors 51 to 54. If they are set to be different from each other, the exponents may not be set to be in the relation of multiples of different powers of two. For example, the resistance values of the plurality of disconnection detection resistors 51 to 54 may be set so as to have a relationship of multiples of powers of three or more integers different in index.

In each of the embodiments, the disconnection detection resistances 26 and 51 to 54 may have a curved pattern extending across the two electrode pieces 18 and 19.
-In each said embodiment, 1st electrodes 14-17, 60, 65, 70 may be except circular (for example, polygon).

In each of the embodiments, the second electrodes 31 to 33 may be other than circular (for example, polygonal).
In each of the embodiments, the number of the first electrodes and the number of the second electrodes (switches) is arbitrary as long as it is plural. Further, as long as the first electrode and the second electrode face each other in the vertical direction, their arrangement is arbitrary.

  In each of the embodiments, the positional relationship between the upper film 11 and the lower film 12 in the vertical direction may be opposite to each other. That is, the lower film 12 may be disposed above the upper film 11.

Next, technical ideas that can be grasped from the above embodiment and another example will be additionally described below.
(A) first and second films incorporated in the seat,
A first conductive pattern formed on the first film and having a plurality of series-connected first electrodes divided into a pair of electrode pieces;
A plurality of break detection resistors connecting between all the electrode pieces except at most one of the plurality of first electrodes;
A plurality of second electrodes formed on the second film and arranged to face the plurality of first electrodes in the vertical direction so as to be able to short circuit between all the two electrode pieces of the plurality of first electrodes And a second conductive pattern having
The resistance value of one of the plurality of disconnection detection resistors is a combined resistance of the resistance value of the other one of the plurality of disconnection detection resistors and any other two or more of the plurality of the disconnection detection resistors. A seating sensor set to be different from all of the values.

  According to this configuration, each of the plurality of first electrodes and the second electrode opposed to the plurality of the first electrodes in the vertical direction are turned on by a short circuit between the two electrode pieces, for example, when a person sits on the seat and contacts them. In this state, the switch is configured to be turned off by cutting between the two electrode pieces when it is not in contact. That is, the first conductive pattern and the second conductive pattern constitute an electric circuit composed of a plurality of switches connected in series.

  On the other hand, the first conductive pattern is formed of the plurality of series-connected resistances for disconnection detection if the interval between all the two electrode pieces of the plurality of first electrodes is connected to the plurality of disconnection detection resistors. Construct an electrical circuit. In this case, when the plurality of first electrodes and the plurality of second electrodes are noncontact and all switches are in the off state, the resistance value of the first conductive pattern or the like is all of the plurality of disconnection detecting resistors. It becomes the synthetic resistance value which added resistance value. Then, when any one of the first electrode and the second electrode is in contact and the switch is turned on, the resistance value of the first conductive pattern or the like is the break that is provided to the first electrode (both electrode pieces). The resistance value (combined resistance value) is obtained by subtracting the resistance value of the detection resistor. The resistance value of the disconnection detection resistor to be subtracted at this time is different from all of the resistance values of the other disconnection detection resistors and the combined resistance values of any other two or more of the disconnection detection resistors. The first electrode and the second electrode in which the switch is in the on state are identified. This makes it possible to determine at which position of the seat a person is sitting.

  Alternatively, when the first conductive pattern is connected to the plurality of disconnection detecting resistors between all the electrode pieces except one of the plurality of first electrodes, the resistance of infinite resistance value is obtained. And an electric circuit of series connection including the plurality of the disconnection detecting resistors. In this case, when the resistance value of the first conductive pattern or the like is infinite, it is detected that the switch formed by the first electrode at least with the disconnection detection resistance not disposed is in the OFF state. When the switch formed by the first electrode in which the disconnection detection resistance is not disposed is in the on state, when any one of the first electrode and the second electrode is in contact and the switch is in the on state, The resistance value of the first conductive pattern or the like changes according to the on / off state of the other switches. For example, when any one of the first electrode and the second electrode is in contact and the switch is turned on, the resistance value of the resistance for the disconnection detection provided on the first electrode (both electrode pieces) is subtracted. It becomes the determined resistance value (combined resistance value). The resistance value of the disconnection detection resistor to be subtracted at this time is different from the resistance value of the other detection resistor and the combined resistance value of any two or more other detection resistors. The first electrode and the second electrode in which a switch is in an on state are identified. This makes it possible to determine at which position of the seat a person is sitting.

  C, C1 to C3: Clearance, SW1 to SW4: Switch, 1: Seat, 11: Upper film (first film), 12: Lower film (second film), 13: First conductive pattern, 14-17, 60 , 65, 70 ... first electrode, 18, 19, 61, 62, 66, 67, 71 ... 72 electrode piece, 26, 51-54, 63, 68, 73 ... resistance for disconnection detection, 30 ... second conductivity Pattern, 31 to 34 second electrode.

Claims (5)

A first film and a second film built in the seat;
A first conductive pattern formed on the first film and having a plurality of series-connected first electrodes divided into a pair of electrode pieces;
A plurality of break detection resistors connecting between all the electrode pieces of the plurality of first electrodes;
A plurality of second electrodes formed on the second film and arranged to face the plurality of first electrodes in the vertical direction so as to be able to short circuit between all the two electrode pieces of the plurality of first electrodes A seating sensor comprising: a second conductive pattern having: In the seating sensor according to claim 1,
The resistance value of one of the plurality of disconnection detection resistors is a combined resistance of the resistance value of the other one of the plurality of disconnection detection resistors and any other two or more of the plurality of the disconnection detection resistors. A seating sensor set to be different from all of the values. In the seating sensor according to claim 2,
A seating sensor, wherein resistance values of the plurality of disconnection detection resistors are set to be in a relationship of multiples of powers of 2 different in index. In the seating sensor according to claim 2 or 3,
Each of the plurality of disconnection detecting resistors is a linear pattern extending between the two electrode pieces, and the seating sensor has a resistance value set based on a line width of the pattern. In the seating sensor according to any one of claims 1 to 4,
The seating sensor, wherein the first film is disposed above the second film.