Object detecting device
AssigneeKabushiki Kaisha Honda Denshi Giken
InventorsTadanori Akagi, Takahiro Imai, Masatosi Kubo
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Abstract
An object detecting device for detecting an object at least partly having a magnetic substance or magnetic-flux permeable material is formed of a detection coil arrangement including a primary coil for generating magnetic flux and a secondary coil disposed separately from the primary coil at a predetermined interval for receiving the magnetic flux from the primary coil; and a detection circuit for detecting an increase of the magnetic flux transmitted to the secondary coil due to presence of the object within a space between the primary and secondary coils. The detection circuit produces signal indicating the presence of the object upon detection of the presence.
Claims11
An object detecting device for detecting an object at least partly having a magnetic substance or magnetic-flux permeable material, comprising:
- detection coil means including a primary coil for generating magnetic flux and a secondary coil disposed separately from said primary coil at a predetermined interval for receiving the magnetic flux from said primary coil;
- and
- a detection circuit for detecting an increase of the magnetic flux transmitted to said secondary coil due to presence of said object within a space between said primary and secondary coils and for producing a signal representing the presence of said object, said detection circuit including a take-out coil for taking-out a voltage corresponding to the magnetic flux generated in said primary coil;
- comparison means for comparing voltages induced in said respective take-out and secondary coils;
- and adjustment means for adjusting an output voltage of said take-out coil so as to make an output of said comparison means be zero when said object is not present in a predetermined effective detection range above said object detecting device.
An object detecting device for detecting an object at least partly having a magnetic substance or magnetic-flux permeable material, comprising:
- detection coil means including a primary coil for generating magnetic flux and a secondary coil disposed separately from said primary coil at a predetermined interval for receiving the magnetic flux from said primary coil;
- and
- a detection circuit for detecting an increase of the magnetic flux transmitted to said secondary coil due to presence of said object within a space between said primary and secondary coils and for producing a signal representing the presence of said object, said detection circuit including;
- setting means for setting a voltage induced in said secondary coil when said object is not present in a predetermined effective detection range above said object detecting device, said setting means including an inversion amplifier which is saturated with an output voltage of said secondary coil when said object is not present in said predetermined effective detection range above said object detecting device and inverts a phase of said output voltage of said secondary coil to thereby produce the phase-inverted output voltage of said secondary coil;
- and a variable resistor for adjusting the output of said inversion amplifier;
- secondary-coil comparison means for comparing the output voltage level of said setting means with a voltage level induced in said secondary coil, said secondary-coil comparison means producing an output signal of a predetermined level when said object is not present in said predetermined effective detection range above said object detecting device;
- and
- storage and comparison means for storing the output voltage level of said secondary-coil comparison means when said object is not present in said predetermined effective detection range above said object detecting device and for comparing the stored output voltage level with an output voltage level of said secondary-coil comparison means so as to produce said signal when the voltage level of said secondary-coil comparison means is higher than said storage voltage level.
An object detecting device for detecting an object at least partly having a magnetic substance or magnetic-flux permeable material, comprising:
- detection coil means including a primary coil for generating magnetic flux and a secondary coil disposed separately from said primary coil at a predetermined interval for receiving the magnetic flux from said primary coil;
- and
- a detection circuit for detecting an increase of the magnetic flux transmitted to said secondary coil due to presence of said object within a space between said primary and secondary coils, said detection circuit being connected to the secondary coil and producing a signal representing the presence of said object, said detection circuit including;
- setting means connected to the secondary coil, said setting means setting an output voltage induced in said secondary coil when said object is not present in a predetermined effective detection range above said object detecting device and providing a fixed level voltage when said object is present in the predetermined effective detection range;
- and
- secondary-coil comparison means connected to the secondary coil and said setting means, said secondary-coil comparison means comparing an output voltage level of said setting means with a voltage level induced in said secondary coil and producing the signal representing the presence of said object when the object is located in the space.
Dependencies are inferred from the claim text.