(19) Japanese Patent Office (JP)
`(12) Kokai Unexamined Patent Application Bulletin (A)
`(11) Laid Open Patent Application No.
`
`5-66166
`(43) Publication Date
`
`March 19, 1993
`Number of Claims
`
`2
`
`Number of Pages
`
`7
`
`Examination Request
`
`not yet made
`
`
`(51)
`
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`Int. Cl.5
`G01L 5/00
`
`Identification Code
`101 Z
`
`
`Internal File No.
`8505-2F
`
`FI
`
`
`Tech. Indic.
`
`
`000010098
`Alps Electric Co., Ltd.
`1-7 Yukigayaotsukacho, Ota-ku,
`Tokyo-to
`TOKUYAMA, Hiroshi
`Alps Electric Co., Ltd.
`1-7 Yukigayaotsukacho, Ota-ku,
`Tokyo-to
`ITO, Isao
`Alps Electric Co., Ltd.
`1-7 Yukigayaotsukacho, Ota-ku,
`Tokyo-to
`Patent Attorney: NOZAKI, Teruo
`
`
`(21) Application No.:
`
`3-254527
`
`
`
`(71)
`
`Applicant:
`
`(22) Application Date:
`
`September 6, 1991
`
`(72)
`
`Inventor:
`
`(72)
`
`Inventor:
`
`(74)
`
`
`
`Agent:
`
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`
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`
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`
`(54) [Title of the Invention] Seat Detection Device
`
`(57) [Abstract]
`[Object] To be able to discern whether a load acting on a
`sitting part of a seat is a person sitting, or due to something
`other than a person.
`[Constitution] Strip-shaped conductors 12 and 13 are
`arranged in a sitting part 1a of a seat 1 so as to form load
`detection units S1 to S9 in a matrix, produced by the facing
`portions of the same. When a load acts on this, current
`values from the respective load detection units S1 to S9,
`which correspond to the magnitude of the load, are
`detected. Whether the load is due to a person, or results
`from something other than a person is discerned on the
`basis of which of the load detection units S1 to S9 have
`detected a load, and the magnitudes of the detection
`current values.
`
`
`
`
`
`(cid:44)(cid:51)(cid:53)(cid:21)(cid:19)(cid:20)(cid:25)(cid:16)(cid:19)(cid:20)(cid:22)(cid:27)(cid:21) (cid:16) (cid:40)(cid:91)(cid:17) (cid:20)(cid:19)(cid:20)(cid:26)
`(cid:55)(cid:82)(cid:92)(cid:82)(cid:87)(cid:68) (cid:48)(cid:82)(cid:87)(cid:82)(cid:85) (cid:38)(cid:82)(cid:85)(cid:83)(cid:17)(cid:15) (cid:51)(cid:72)(cid:87)(cid:76)(cid:87)(cid:76)(cid:82)(cid:81)(cid:72)(cid:85)
`Translation by Patent Translations Inc. 206-357-8508 mail@PatentTranslations.com
`
`1
`
`

`
`[CLAIMS]
`[Claim 1] A seat detection device characterized by
`comprising: a plurality of load detection units installed in a
`sitting part of a seat; and a discernment unit that discerns
`whether or not a person has sat in the seat, on the basis of
`the detection output at each of the plurality of load detection
`units.
`[Claim 2] The seat detection device recited in claim 1,
`comprising: two flexible sheets which are laid, in an overlaid
`manner, on the sitting part of the seat; a plurality of flexible
`conductors, provided on
`the
`facing surfaces of
`the
`respective flexible sheets; and a spacer that maintains a
`gap between the facing portions of the facing conductors,
`wherein a plurality of load detection units are formed by the
`portions of the conductors that face each other in a matrix.
`[Detailed Description of the Invention]
`[0001]
`[Field of Industrial Application] The present invention
`relates to a seat detection device that detects whether or not
`a person has sat in a seat such as, for example, an
`automobile seat; and in particular relates to a seat detection
`device capable of discerning whether or not a load acting on
`a seat unit is a person, based on the detection output of a
`plurality of detection units.
`[0002]
`[Prior Art] Detection of whether or not a person has sat in
`a seat can be used for various control operations. For
`example, it is possible to control the balance of car stereo
`speakers and the blowing direction of an air conditioner by
`way of detecting where people are sitting in the seats of an
`automobile.
`[0003]
`[Problems to Be Solved by the Invention] However, there
`are problems insomuch as it is not easily possible to discern
`whether a person has sat down, or whether something other
`than a person, such as for example luggage, has been
`placed, simply by disposing pressure sensors or the like in
`the sitting part of a seat.
`[0004] The present invention solves the conventional
`problems described above, and an object thereof is to
`provide a seat detection device capable of discerning
`whether a load is due to a person or something other than
`a person, based on the distribution and the like of the load
`that acts on the sitting part of the seat.
`[0005]
`[Means for Solving the Problems] The seat detection
`device according to the present invention is characterized
`by comprising: a plurality of load detection units installed in
`a sitting part of a seat; and a discernment unit that discerns
`whether or not a person has sat in the seat, on the basis of
`the detection output at each of the plurality of load detection
`units.
`[0006] Furthermore,
`the means described above
`comprises: two flexible sheets which are laid, in an overlaid
`manner, on the sitting part of the seat; a plurality of flexible
`conductors, provided on
`the
`facing surfaces of
`the
`respective flexible sheets; and a spacer that maintains a
`gap between the facing portions of the facing conductors,
`wherein a plurality of load detection units are formed by the
`portions of the conductors that face each other in a matrix.
`[0007]
`[Operation] In the means described above, when a load
`has been detected by the load detection units installed in
`the sitting part of the seat, whether the load is due to a
`person, or due to something other than a person, is detected
`
`JP-05-066166-A (2)
`by way of the combination of the positions of the detection
`units that detected the load and the like.
`[0008] Furthermore, in terms of the structure of the plurality
`of load detection units, by using two flexible sheets and
`conductors formed in a matrix between these flexible sheets,
`load detection units can be made with which there is no
`unnatural feeling when the person sits.
`[0009]
`[Embodiments] Hereafter,
`is
`invention
`the present
`described with reference to the drawings. FIG. 1 is a
`perspective view showing an automobile seat; FIG. 2 is a
`plan view showing the arrangement of load sensor units
`installed in the sitting part of this automobile seat; FIG. 3 is
`an exploded perspective view of a flexible sheet and
`conductors comprised by a load detection unit; FIG. 4 is a
`partial enlargement thereof; and FIG. 5 is an enlarged
`sectional view of the load detection unit. A detection unit A
`of a detection device, which is a feature of the present
`invention, is installed in a sitting part 1a of the automobile
`seat 1 shown in FIG. 1. This detection part A is installed
`within the seat, on the inside of a surface sheet of the seat.
`Furthermore, a load detection device B is provided in a
`backrest 1b of the seat 1. This load detection device B is
`installed within the backrest, on the inside of a surface sheet.
`Further, a load detection device C, which detects the load of
`a person's feet, is installed on the floor of the automobile.
`[0010] As shown in FIG. 3, the detection unit A of the
`detection device according to the present invention is
`constituted by overlaying two overlaid flexible sheets 10 and
`11 of an insulating material such as rubber. A plurality of
`strip-shaped conductors 12 are provided on the top face of
`the lower flexible sheet 10, and a plurality of strip-shaped
`conductors 13 are also provided on the bottom face of the
`upper flexible sheet 11; and with both flexible sheets 10 and
`11 overlaid, as shown in FIG. 2, load detection units are
`formed with a matrix configuration, as indicated by S1 to S9,
`resulting from the overlaid portions of the conductors 12 and
`13.
`[0011] To describe the structure of the detection unit A in
`more detail, as shown in FIG. 4, a plurality of grooves 10a
`are formed in the top face of the flexible sheet 10 and the
`conductors 12 are adhesively fastened, embedded within
`these grooves 10a. This conductor is made from a
`conductive rubber wherein, for example, fine carbon
`particles have been mixed into silicone rubber. A spacer
`pattern 14 is formed from a nonconductive material such as
`silicone ink on the surface of this lower conductor 12. This
`spacer pattern 14 comprises edge patterns 14a that cover
`both edges of the surface of the conductor 12, and a grid
`pattern 14b that is formed in a fine grid shape between these
`edge patterns 14a.
`[0012] Furthermore, as shown in FIG. 3, a plurality of
`grooves 11a are also formed on the bottom face of the upper
`flexible sheet 11, and the conductors 13 are adhesively
`fastened, embedded in these grooves 11a. This conductor
`13 is also made from the same conductive rubber as the
`conductor 12. Then, as shown in FIG. 4, a spacer pattern
`
`
`
`Translation by Patent Translations Inc. 206-357-8508 mail@PatentTranslations.com
`
`2
`
`

`
`JP-05-066166-A (3)
`flexible sheets 10 and 11 may also be fastened by these
`fastening buttons 2. If the attachment holes 10b and 11b are
`fastened by these fastening buttons 2, by way of somewhat
`separating these fastening parts from the facing portions of
`the conductors 12 and 13, which is to say the matrix
`configured load detection units S1 to S9, the fastening force
`resulting from the fastening buttons 2 can be absorbed by
`the flexibilities of the flexible sheets 10, 11 and the
`conductors 12, 13. Thus, there will be almost no influence
`on the detection operations with the facing portions of the
`conductors 12 and 13, because pressure will not act on the
`load detection units S1 to S9 as a result of the fastening
`force of these fastening buttons 2.
`[0016] FIG. 6 shows an example of the configuration of a
`circuit that is connected to the load detection unit A. The
`conductors 12 and 13 are connected to input parts 12a and
`13a, respectively, of a matrix switch 21. The matrix switch
`21 is switched under the control of a multiplexer 24, and
`under this control, the input parts 12a of the conductors 12,
`and the input parts 13a of the conductors 13 are switched
`to, in sequence, and the load detection units S1 to S9
`assume a detection state in sequence. A power source 25
`is provided on the output parts from the matrix switch 21,
`and for each of the load detection units S1 to S9 that are
`switched to in sequence by the matrix switch 21, it is
`detected whether or not an electric current is flowing
`between the conductors 12 and 13, and the value of the
`current is detected. This detection output is converted to a
`digital signal by an A/D converter 22, and processing is done
`by a microprocessor 23.
`[0017] With the microprocessor 23, by way of an ON-OFF
`judgment as to whether a current is flowing in each load
`detection unit S1 to S9, and by way of the detected value of
`the current at each load detection unit S1 to S9, it is
`discerned whether the load that acts on the seat unit 1a of
`the seat 1 is due to a person, or is due to something other
`than a person.
`[0018] FIG. 7 shows an example of this discernment
`operation. First, in step (a), it is determined whether all nine
`load detections units S1 to S9 that are shown in FIG. 2 are
`OFF (in a state in which no current flows between the
`conductors 12 and 13); if they are all OFF, it is determined
`that no load is acting upon the sitting part 1a, and if they are
`not all OFF, which to say, if any of the load detection units
`S1 to S9 is ON, it is determined that a load is acting on the
`sitting part 1a, and [control] moves to the next step (b) and
`thereafter.
`[0019] In step (b), it is determined whether four or more of
`the nine load detection units S1 to S9 are ON. If, among the
`load detection units S1 to S9, fewer than three places are
`ON, it is determined that this is a load due to something
`other than a person.
`[0020] In step (c), it is determined whether or not S1, S5,
`
`
`
`15 made of a nonconductive material such as silicone ink is
`formed on both edges of the facing surface on the bottom
`face of this conductor 13 (in FIG. 4, the facing surfaces are
`shown facing upward). The conductor 13 is exposed
`between the spacer patterns 15 at the two edges.
`[0013] As shown in FIG. 3, with the flexible sheet 10 and the
`flexible sheet 11 overlaid, the two conductors 12 and 13 face
`each other in a matrix. As shown in the sectional view in FIG.
`5, the structure of the facing portions of these conductors,
`which is to say the load detection units S1 to S9, results in
`a situation in which the two conductors 12 and 13 face each
`other across the grid pattern 14b of the spacer pattern 14.
`Now, in FIG. 5, when pressure is applied from above to the
`conductor 13, via the upper flexible sheet 11, as indicated
`by the arrow, in the load detection units indicated by S1 to
`S9, the bottom face of the conductor 13 and the top face of
`the conductor 12 make contact with each other across a gap
`(i) in the grid pattern 14b. The contact area over which the
`conductors 12 and 13 make contact in this gap (i) in the grid
`pattern 14b at this time is affected by the magnitude of the
`pressure that acts on them; when the pressure is large, the
`area where the conductors 12 and 13 make contact in the
`load detection units S1 to S9 increases. Conversely, if the
`pressure is small, the contact area decreases. Accordingly,
`if a prescribed voltage is applied to the conductors 12 and
`13, an electric current that corresponds to the magnitude of
`the contact area between the conductors 12 and 13 will flow
`between the two conductors 12 and 13. That is, when no
`load is applied, then in the load detection units S1 to S9 no
`electric current will flow between the conductors 12 and 13,
`and when a load is applied, the current that flows between
`the conductors 12 and 13 will vary according to the
`magnitude of that load.
`[0014] Further, an edge pattern 14a is formed on both edges
`of the top face of the conductors 12, and a spacer pattern
`15 is formed on both edges of the bottom face of the
`conductors 13; and providing this edge pattern 14 and this
`spacer pattern 15 makes it possible to accurately detect any
`increase or decrease in the current value caused by
`changes in the pressure. That is to say, in a state in which
`the strip-shaped conductors 12 and 13 face each other
`across the grid pattern 14b, if pressure is applied to both,
`then sagging occurs in the edges of conductors 12 and 13
`due to the pressure, and the conductors 12 and 13
`preferentially make contact via these edges. Because the
`contact area between these edges is relatively large, if there
`is no nonconductive pattern in these edges, a relatively
`large current will flow between the edges. Due to the
`presence of a current flowing between these edges, the
`value of the current caused by changes in the area over
`which the conductors 12 and 13 make contact across the
`gap (i) in the grid pattern 14b can no longer be accurately
`captured. Thus, by providing a nonconductive pattern at the
`edges of the conductors 12 and 13, the value of the current
`corresponding to the change in pressure can be accurately
`detected.
`[0015] As shown in FIG. 3, attachment holes 10b and 11b
`are formed in the flexible sheets 10 and 11 so as to be
`located in the same places relative to each other, and the
`flexible sheets 10 and 11 are attached by way of these
`attachment holes 10b and 11b at the inside of the surface
`sheet on the sitting part 1a of the seat 1. As shown in FIG.
`1, fastening buttons 2 are attached on the sitting part 1a of
`the automobile seat 1, and depressions may be formed in
`these areas. The attachment holes 10b and 11b in the
`
`Translation by Patent Translations Inc. 206-357-8508 mail@PatentTranslations.com
`
`3
`
`

`
`JP-05-066166-A (4)
`S9 in the detection unit A is enlarged.
`[0027] For example, if joint use is made of the detection unit
`A and a load detection device B, after determining the load
`that has acted on the detection unit A by way of the steps
`shown in FIG. 7, a further determination is made as to
`whether or not a load is acting on the load detection device
`B. Then, when it has been determined that a person is sitting
`on the sitting part 1a, by way of the steps shown in FIG. 7,
`if the load detection device B detects a load even once, it
`may be determined that this is a person sitting.
`[0028] Furthermore, if joint use is made of the detection unit
`A and the load detection device C, at a fixed time after a
`person has placed their foot on the load detection device C
`and that load has been detected, detection with the
`detection unit A in the sitting part 1a begins, and when it has
`been determined that this is a person by way of the steps in
`FIG. 7, this may be discerned to be a person sitting. Further,
`if the load detection device B provided in the back rest 1b is
`used, if the backrest 1b is reclined, the load detected by the
`load detection device B will increase and the detection
`current value will increase, and therefore whether or not the
`backrest of the seat has been reclined can be determined
`by way of this increase.
`[0029] Note that, in the above working example, as shown
`in FIG. 2, in the detection unit A, load detection units are
`formed in 9 places indicated by S1 to S9, but the number of
`these load detection units is not limited to nine, and may be
`more than this. Furthermore, the plurality of load detection
`units need not be configured in a matrix, but may be
`configured as independent pressure sensors. Further, the
`detection device described above
`is not
`limited
`to
`automobile seats, but rather can be installed in the seats of
`a theater or waiting room, as well as in seats in a home, and
`used for detecting people.
`[0030]
`[Effects of the Invention] With the present invention as
`[described] above, it is possible to accurately discern
`whether an acting load is due to a person, or due to
`something other than a person, by way of a plurality of load
`detection units arranged in the sitting part of a seat.
`[Brief Description of the Drawings]
`[FIG. 1] perspective view showing an automobile seat
`equipped with a detection device according to the present
`invention;
`[FIG. 2] plan view showing a plurality of load detection units
`installed in a sitting part;
`[FIG. 3] exploded perspective view showing the structure of
`key portions of the detection device;
`[FIG. 4] enlarged perspective view showing the structure of
`conductors comprised by the load detection unit;
`[FIG. 5] enlarged sectional view of the load detection unit;
`[FIG. 6] block diagram showing an electric circuit in the
`detection device;
`[FIG. 7] flowchart showing the sensing operations with the
`detection device;
`[Explanation of the Symbols]
`
`and S8 of the load detection units are all OFF. If a person
`has sat down on the sitting part 1a, then the row in the
`middle, S1, S5, and S8, will never be all OFF. Accordingly,
`if S1, S5, and S8 are all OFF, it is determined that this is a
`load due to something other than a person. Similarly in step
`(d), if the load detection units S4, S5, and S6 of the
`horizontal row in the middle are all OFF, it is determined that
`this is a load other than a person.
`[0021] Next, in step (e), it is determined whether or not, for
`each of the load detection units S1 to S9 in the nine places,
`the sum total of the values of the currents flowing between
`the conductors 12 and 13 is less than or equal to a
`prescribed value. If the sum total of the currents flowing in
`all the load detection units S1 to S9 is greater than or equal
`to a prescribed value (for example, 2 mA), it is determined
`that the load acting on the sitting part 1a is due to something
`other than a person.
`[0022] In step (f), it is determined whether the value of the
`current detected in any of the load detection units S1 to S9
`is greater than or equal to 40% of the sum total of the current
`values detected in all of the load detection units S1 to S9. If
`the value of the current detected in any load detection unit
`is greater than or equal to 40% of the sum total of the current
`values detected, it is determined that this is a load due to
`something other than a person.
`[0023] Further, in step (g), it is determined whether the sum
`of the detected current values of the load detection units S4
`and S6 is greater than or equal to 50% of the sum total of
`the current values detected in all of the load detection units
`S1 to S9. In the case of a person, the sum of the current
`values detected in load detection units S4 and S9 on the two
`edges will never be 50% or more of the sum total of the
`current values detected. Thus, if the sum of the currents
`detected due to S4 and S9 is greater than or equal to 50%,
`it is determined that it is a load other than a person.
`[0024] Then, if all the conditions of the above steps (a)
`through (g) are satisfied, it is determined that the load on the
`sitting part 1a is due to a person having sat down. Note that,
`once it has been determined, according to steps (a) through
`(g), that a person has sat down, until the values of the
`currents detected with all of the load detection units S1 to
`S9 have all reached zero, the state in which a person has
`been detected is held, even if one of the conditions in steps
`(b) through (g) is lacking. In this way it is possible to maintain
`a state in which a person has been detected even if, after a
`person first sits down in the sitting part 1a, the body is
`moved greatly.
`[0025] Further, the seat shown FIG. 1 is provided with, not
`only the detection unit A described above, but also the load
`detection device B in the backrest 1b and the load detection
`device C, which serves to detect the pressure of feet on the
`floor. Even more reliable detection of people is possible by
`jointly using the load detection device having the detection
`unit A and the circuit shown in FIG. 6, and either one of, or
`both of, the load detection devices B and C.
`[0026] The load detection devices B and C comprise, for
`example,
`two overlaid
`flexible sheets, conductors
`respectively provided on the facing surfaces thereof, and
`nonconductive spacers
`interposed between
`the
`two
`conductors; this is configured so that when no load is acting,
`no current flows between the two conductors; and when a
`load has acted, the value of the current between the
`conductors can increase and decrease in accordance with
`the magnitude of that load. That is to say, this is structured
`in a manner in which one of the load detection units S1 to
`
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`
`4
`
`

`
`1
`1a
`1b
`A
`
`
`
`
`seat
`sitting part
`backrest
`detection unit
`
`flexible sheet
`10, 11
`conductor
`12, 13
`spacer pattern
`14
`S1 to S9 load detection unit
`
`[FIG. 1]
`
`
`
`[FIG. 2]
`
`JP-05-066166-A (2)
`
`[FIG. 3]
`
`[FIG. 4]
`
`
`
`
`
`
`
`
`
`Translation by Patent Translations Inc. 206-357-8508 mail@PatentTranslations.com
`
`5
`
`

`
`[FIG. 5]
`
`JP-05-066166-A (3)
`[FIG. 6]
`
`
`
`
`
`
`
`Translation by Patent Translations Inc. 206-357-8508 mail@PatentTranslations.com
`
`6
`
`

`
`[FIG. 7]
`
`JP-05-066166-A (4)
`
`
`
`
`
`Translation by Patent Translations Inc. 206-357-8508 mail@PatentTranslations.com
`
`7
`
`

`
`Patent Traneiatierta tam.
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`Seattie. WA 98101, USA htipzilwww.PateniTrar;sialiol1s.com
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`
`Certification of Translation
`
`Translators Declaration: July 7, 2016
`
`I, Martin Cross, hereby declare;
`
`That I possess advanced knowledge of the Japanese and English languages. My
`qualifications are as follows:
`
`0
`
`-
`
`over 25 years as a Japanese-English translator focusing primarily on patents,
`and technical and scientific documents;
`co—author of the Japanese Patent Translators Handbook, published by
`American Translators Association;
`0 United States district court recognition as an expert in Japanese technical
`translation for patent litigation; and
`0 work experience inciuding design and testing of electronic circuits for
`Research and Development Laboratories Waterloo Ltd.
`
`The attached translation is, to the best of my knowledge and belief, a true and accurate
`translation from Japanese to English of Japanese Unexamined Patent Application
`Number JP-05-066166-A. i understand that willful false statements and the like are
`punishable by fine or imprisonment, or both (18 U.S.C. 1001), and may jeopardize the
`validity of the application or any patent issuing thereon. I declare under penalty of perjury
`that all statements made herein of my own knowledge are true, and all statements made
`on information and belief are believed to be true.
`
`Martin Cross
`
`8