1. A method for controlling opening and closing of a door for a drawer-type cooking device including: a door capable of opening and closing an opening of a cooking device body; a motor for driving the door in an openingclosing direction; and a rotation sensor disposed in relation to an output shaft of the motor and generating a detection signal based on rotation of the motor, the method comprising,
at the rotation sensor, generating two rotation pulses having different phases according to a rotation direction of the motor, and
determining the rotation direction of the motor based on the two rotation pulses.
2. The method for controlling opening and closing of a door for a drawer-type cooking device according to claim 1, further comprising driving the motor in the rotation direction according to the determined rotation direction of the motor and performing an assisting operation by the motor.
3. The method for controlling opening and closing of a door for a drawer-type cooking device according to claim 1, further comprising accumulating the rotation pulses and obtaining an absolute position of the door in the openingclosing direction.
4. The method for controlling opening and closing of a door for a drawer-type cooking device according to claim 3, further comprising performing speed control of the door based on the absolute position.
5. A drawer-type cooking device comprising: a door capable of opening and closing an opening of a cooking device body; a motor for driving the door in an openingclosing direction; a rotation sensor disposed in relation to an output shaft of the motor and generating a detection signal based on rotation of the motor; and a control unit for controlling drive of the motor including a rotation direction by receiving an input of the detection signal of the rotation sensor, wherein
the rotation sensor is a sensor for generating two rotation pulses having different phases according to a rotation direction of the motor, and
the control unit determines the rotation direction of the motor based on the two rotation pulses from the rotation sensor.
6. The drawer-type cooking device according to claim 5, wherein the control device drives the motor in the rotation direction according to the determined rotation direction of the motor and performs an assisting operation by the motor.
7. The drawer-type cooking device according to claim 5, wherein the rotation pulses are accumulated to obtain an absolute position of the door in the openingclosing direction.
8. The drawer-type cooking device according to claim 7, wherein speed control of the door is performed based on the absolute position.
9. A drawer-type cooking device comprising: a door capable of opening and closing an opening of a cooking device body; a motor for driving the door in an openingclosing direction; a rotation sensor disposed in relation to an output shaft of the motor and generating a detection signal based on rotation of the motor; and a control unit for controlling drive of the motor including a rotation direction by receiving an input of the detection signal of the rotation sensor, wherein
when a malfunction occurs in the motor for driving the door by breakdown or short circuit in the motor wiring, the malfunction is immediately detected.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An optical pickup configured to accept a multi-layer optical disc, comprising:
a laser source for emitting an optical beam,
an objective lens for focusing the light beam onto the multi-layer optical disc,
a polarizing grating located at a position through which a reflected light beam from the multi-layer optical disc passes, for branching the reflected beam into at least two light beams comprising a 0-order light beam and a +1-order light beam having a direction of polarization which is orthogonal to that of the 0-order light beam,
an optical detector for receiving the two light beams,
a first light receiving zone which is provided in the optical detector, and onto which the 0-order light is irradiated, and,
a second light receiving zone which is provided in the optical detector and onto which the +1-order light beam is irradiated,
wherein the first light receiving zone has four zones, and the second light receiving zone has two zones, and a servo signal generation circuit configured to generate a push-pull signal by taking a difference between a sum signal of signals from two zones of the four zones and a sum signal of signals from the other two zones of the four zones, to generate an offset signal having substantially no push-pull signal components by taking a difference between a signal from one of the two zones of the second light receiving zone and a signal from another zone of the two zones of the second light receiving zone, to obtain a focus error signal by using signals from the first light receiving zone, and to obtain a tracking error signal by taking a difference between the push-pull signal and the offset signal.
2. An optical pickup configured to accept a multi-layer optical disc, comprising:
a laser source for emitting an optical beam,
an objective lens for focusing the light beam onto a multi-layer optical disc,
a polarizing grating located at a position through which a reflected light beam from the multi-layer optical disc passes, for branching the reflected light beam into at least three light beams comprising a 0-order light beam, a +1-order light beam having a direction polarization orthogonal to that of the 0-order light beam, and a \u22121-order light beam having a direction of polarization orthogonal to that of the 0-order light beam,
an optical detector for receiving the three light beams,
a first light receiving zone which is located in the optical detector and onto which the 0-order light beam is irradiated,
a second light receiving zone which is located in the optical detector, and onto which the +1-order light beam is irradiated,
a third light receiving zone which is located in the optical detector and onto which the \u22121-order light beam is irradiated,
wherein the first light receiving zone has four zones, and the second light receiving zone has two zones, and a servo signal generation circuit configured to generate a push-pull signal by taking a difference between a sum signal of signals from two zones of the four zones and a sum signal of signals from the other two zones of the four zones, to generate an offset signal having substantially no push-pull signal components by taking a difference between a signal from one of the two zones of the second light receiving zone and a signal from another zone of the two zones of the second light receiving, zone to obtain a focus error signal by using signals from the first light receiving zone, and to obtain a tracking error signal by taking a difference between the push-pull signal and the offset signal.
3. An optical pickup as set forth in claim 2, further including a diffraction element located at a position through which a reflected beam from the multi-layer disc passes, wherein a half-wave plate having a phase difference which is integer times as large as an about \xbd of an oscillation wavelength of the semiconductor laser, is located at a position just before the diffraction element so as to turn the direction of polarization of the light beam by a predetermined angle in order to cause the light beam incident upon the diffraction element to have polarized components.
4. An optical pickup as set forth in claim 2, wherein the second or third light receiving zone detects a signal obtained from a substantially center part of the light beam which does not include a push-pull signal component of the +1-order light beam or the \u22121-order light beam, or parts in the vicinity of the outsides of the light beam, as viewed in the direction of tracks of an optical disc, which do not contain a push-pull component.
5. An optical pickup as set forth in claim 2, further including a diffraction element located at a position through which a reflected beam from the multi-layer disc passes, wherein the diffraction element diffracts the +1-order light beam or the \u22121-order light beam having the specific direction of polarization in a substantially center part of the light beam which does not include a push-pull signal component, parts in the vicinity of the outsides of the light beam, as viewed in the direction of tracks of an optical disc, which does not include a push-pull signal component, and the +1-order light beam or the \u22121-order light beam is detected by the second or third light receiving zone.
6. An optical pickup as set forth in claim 2, further including a diffraction element located at a position through which a reflected beam from the multi-layer disc passes, wherein the diffraction element is a polarizing grating having such a configuration that a part of the light beam which is diffracted by the diffraction element and which are not detected by the second or third light receiving zone is diffracted as a component having a specific direction of polarization, the direction of polarization thereof or a diffracted angle thereof is detected by the second or third light receiving zone.
7. An optical disc unit comprising:
an optical pick-up capable of accepting a multi-layer optical disc,
said optical pick-up comprising:
a laser source for emitting an optical beam,
an objective lens for focusing the light beam onto the multi-layer disc,
a polarizing branching element located at a position through which a reflected light beam from the multi-layer optical disc passes, for branching the reflected beam into at least two light beams, comprising a 0-order light beam and a +1-order light beam having a direction of polarization which is orthogonal to that of the 0-order light beam,
an optical detector for receiving the two light beams,
a first light receiving zone which is provided in the optical detector, and onto which the 0-order light is irradiated, and,
a second light receiving zone which is provided in the optical detector and onto which the +1-order light beam is irradiated,
wherein the first light receiving zone has four zones, and the second light receiving zone has two zones, and a servo signal generation circuit configured to generate a push-pull signal by taking a difference between a sum signal of signals from two zones of the four zones and a sum signal of signals from the other two zones of the four zones, to generate an offset signal having substantially no push-pull signal components by taking a difference between a signal from one of the two zones of the second light receiving zone and a signal from another zone of the two zones of the second light receiving zone, to obtain a focus error signal by using signals from the first light receiving zone, and to obtain a tracking error signal by taking a difference between the push-pull signal and the offset signal.
8. An optical disc unit comprising:
an optical pick-up configured to accept a multi-layer optical disc,
said optical pick-up comprising:
a laser source for emitting an optical beam,
an objective lens for focusing the light beam onto the multi-layer optical disc,
a diffraction element located at a position through which a reflected light beam from the multi-layer optical disc passes, for branching the reflected beam into at least two light beams comprising a 0-order light beam and a +1-order light beam having a direction of polarization which is orthogonal to that of the 0-order light beam,
a first light receiving zone which is provided in the optical detector, and onto which the 0-order light is irradiated, and,
a second light receiving zone which is provided in the optical detector and onto which the +1-order light beam is irradiated,
and a servo signal creating circuit for creating a focus error signal and a tracking error signal,
wherein the servo signal creating circuit is configured to obtain a push-pull signal from the first light receiving zone and an offset signal having substantially no push-pull signal component from the second light receiving zone, to create the tracking error signal by taking a difference between the push-pull signal and the offset signal, and to create the focus error signal from the first light receiving zone.