Apparatus for detecting seated condition for toilet seat

• US 5,625,294 A
• Filed: 11/18/1994
• Issued: 04/29/1997
• Est. Priority Date: 11/19/1993
• Status: Expired due to Fees

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.), INAX Corporation (LIXIL Group Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.), INAX Corporation (LIXIL Group Corp.)
• Inventors: Yamaguchi, Yuji, Kawai, Shinji, Nonomura, Mitsugu, Takamata, Akira, Tanaka, Seiji
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): Solis, Jose M.
• Application Number:
  US08/343,984
• Time in Patent Office: 893 Days
• Field of Search: 340/562, 4/305, 4/668, 4/250, 4/DIG. 3, 4/215, 324/661, 324/686, 324/675
• US Class Current: 324/668
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/94026 Automatic threshold calibration; e.g. threshold automatically adapts to ambient conditions or follows variation of input

Abstract

An apparatus for detecting seated condition for toilet seat which detects whether the change in input voltage of determining circuit, over predetermined time, in response to electrostatic capacity is existed or not. When the change is existed, the present apparatus computes and renews the set value 1 for detecting un-seated condition and the set value 2 for detecting seated condition based on the changed input potential.

Accordingly, the present apparatus is the apparatus for detecting whether a human is seated or un-seated on a toilet seat using electrostatic capacity and the present invention can reduce the error in detection caused by the change in electrostatic capacity owing to a person, temperature and humidity.

Claims

1. An apparatus for detecting seated condition for toilet seat comprising:

a toilet seat which is rotatively displaced in the state in which an opening edge of a toilet seat is covered and in the state in which said toilet seat is apart from said opening edge;

a conductor provided in the inside of said toilet seat;

a means for detecting electrostatic capacity, in the form of electric information, which exists between said conductor in said toilet seat in the state in which the opening edge of said toilet seat is covered and the ground or between said conductor and another conductor which is provided in the inside of said toilet seat; and

a determining means which determines whether a human body is seated on said toilet seat or a human body is not seated on said toilet seat based on said electric information of said means for detecting electrostatic capacity, which compares a first set value for determining in response to the level of electric information which will be detected in the un-seated condition and a second set value for determining in response to the level of electric information which will be detected in the seated condition with electric information which is repeatedly outputted from said means for detecting electrostatic capacity, and which determines whether the seated condition exists in which a human is seated on said toilet seat or the un-seated condition exists in which a human is not seated on said toilet seat based on said compared result;

wherein said determining means, when the present result of determining shows "un-seated condition", computes and renews said first set value for determining in response to electric information which is detected in seated condition and said second set value for determining in response to electric information which is detected in un-seated condition every time when the gradual change in electric information outputted from said means for detecting electrostatic capacity is detected.

4. An apparatus for detecting seated condition for toilet seat according to claim 1 wherein said determining means, when the present result of determining shows "seated condition", repeats to compare the electric information detected from said means for detecting electrostatic capacity and said first set value for determining until it determines "un-seated condition".

5. An apparatus for detecting seated condition for toilet seat according to claim 1, wherein said determining means, when the present result of determining shows "un-seated condition", repeats to compare the electric information detected from said means for detecting electrostatic capacity and said third set value for determining until it determines "seated condition".

6. An apparatus for detecting seated condition for toilet seat according to claim 1, wherein said means for detecting electrostatic capacity comprises:

an oscillating circuit which generates high-frequency signal;

a transformer whose primary coil is connected with the output end of said oscillating circuit and whose secondary coil is connected with said conductor; and

a detection and smoothing circuit which is connected with said primary coil of said bonding transformer and which conducts the enveloping detection and smoothing of high-frequency signal whose amplitude changes, from said oscillating circuit, based on the change in resonance characteristic caused by said secondary coil and electrostatic capacity between said conductor which is connected with said primary coil of said bonding transformer and which is provided in the inside of said toilet seat and the ground, or between said conductor and another conductor which is provided in the inside of said toilet seat.

2. An apparatus for detecting seated condition for toilet seat comprising:

a toilet seat which is rotatively displaced in the state in which an opening edge of a toilet seat is covered and in the state in which said toilet seat is apart from said opening edge;

a conductor provided in the inside of said toilet seat;

a means for detecting electrostatic capacity, in the form of electric information, which exists between said conductor in said toilet seat in the state in which the opening edge of said toilet seat is covered and the ground or between said conductor and another conductor which is provided in the inside of said toilet seat; and

a determining means which determines whether a human body is seated on said toilet seat or a human body is not seated on said toilet seat based on said electric information of said means for detecting electrostatic capacity, which compares a third set value in response to electric information which will be detected immediately after a human is seated on said toilet seat with electric information which is outputted from said means for detecting electrostatic capacity and determines whether a human is seated on said toilet seat or not based on said compared result, which compares a first set value for determining in response to the level of electric information which will be detected in un-seated condition and a second set value for determining in response to the level of electric information which will be detected in the seated condition with electric information which is repeatedly outputted from said means for detecting electrostatic capacity, and which determines whether the seated condition exists in which a human is seated on said toilet seat or the un-seated condition exists in which a human is not seated on said toilet seat based on said compared result;

wherein said determining means, when the present result of determining shows "un-seated condition", computes and renews said first set value for determining in response to electric information which is detected in seated condition and said second set value for determining in response to electric information which is detected in un-seated condition every time when the gradual change in electric information outputted from said means for detecting electrostatic capacity is detected.

3. An apparatus for detecting seated condition for toilet seat according to claim 2, wherein said determining means, when the present result of determining shows "un-seated condition", repeats to compare the electric information detected from said means for detecting electrostatic capacity and said third set value for determining until it determines "seated condition".

7. An apparatus for detecting seated condition for toilet seat according to claim 2, wherein said means for detecting electrostatic capacity comprises:

an oscillating circuit which generates high-frequency signal;

a transformer whose primary coil is connected with the output end of said oscillating circuit and whose secondary coil is connected with said conductor; and

a detection and smoothing circuit which is connected with said primary coil of said bonding transformer and which conducts the enveloping detection and smoothing of high-frequency signal whose amplitude changes, from said oscillating circuit, based on the change in resonance characteristic caused by said secondary coil and electrostatic capacity between said conductor which is connected with said primary coil of said bonding transformer and which is provided in the inside of said toilet seat and the ground, or between said conductor and another conductor which is provided in the inside of said toilet seat.

8. An apparatus for detecting seated condition for toilet seat according to claim 2 wherein said determining means, when the present result of determining shows "seated condition", repeats to compare the electric information detected from said means for detecting electrostatic capacity and said first set value for determining until it determines "un-seated condition".