Capactive load driving circuit, capacitive load driving method, and apparatus using the same

A capacitive load drive circuit for charging and discharging a capacitive load, comprising:

• a plurality of energy accumulating elements to which a plurality of different initial potentials are respectively applied;
• a reference potential terminal to which either a reference power supply potential from a power source or a ground potential is applied as a reference potential;
• and
• switching means for selectively connecting (A) the energy accumulating elements and the reference potential terminal with (B) the capacitive load,
• one of the plurality of energy accumulating elements being a first energy accumulating element having a first initial potential which is not 0, one of the plurality of energy accumulating elements being a second energy accumulating element having a second initial potential whose polarity is the same as a polarity of the first initial potential and whose absolute value is larger than an absolute value of the first initial potential,
• the reference potential being either (a) the ground potential, (a) a potential which has the same polarity as the first initial potential supplied from the power source and which has a smaller absolute value than the first initial potential, or (c) a potential whose polarity is reverse to the polarity of the first initial potential supplied form the power source,
• the switching means carrying out (i) a first charging step of selectively connecting the capacitive load with the reference potential terminal and then selectively connecting the capacitive load with the first energy accumulating element so as to change, toward the first initial potential, a terminal voltage of the capacitive load, (ii) a second charging step of selectively connecting the capacitive load with the second energy accumulating element so as to increase an absolute value of the terminal voltage of the capacitive load, and (iii) a discharging step of selectively connecting the capacitive load with the first energy accumulating element so as to decrease the absolute value of the terminal voltage of the capacitive load and so as to regenerate electrostatic energy to be accumulated in the first energy accumulating element, the thus regenerated electrostatic energy being approximately equal to electrostatic energy as accumulated in the first energy accumulating element before the step (i), the steps (i) through (iii) being carried out in this order.

A capacitive load drive circuit for charging and discharging a capacitive load, comprising:

• a power supply terminal to which a power supply potential from a power source is applied;
• a plurality of energy accumulating elements to which a plurality of different initial potentials are respectively applied;
• and
• switching means for selectively connecting (A) the energy accumulating elements and the power supply terminal with (B) the capacitive load,
• one of the plurality of energy accumulating elements being a first energy accumulating element having a first initial potential whose polarity is the same as a polarity of the power supply potential and whose absolute value is smaller than an absolute value of the power supply potential, one of the plurality of energy accumulating elements being a third energy accumulating element having either (a) a potential whose polarity is the same as the polarity of the first initial potential and whose absolute value is smaller than the absolute value of the first initial potential, (b) a ground potential, or (c) a third initial potential whose polarity is reverse to the polarity of the first initial potential,
• the switching means carrying out (i) a first charging step of selectively connecting the capacitive load with the third energy accumulating element and then selectively connecting the capacitive load with the first energy accumulating element so as to change, toward the first initial potential, a terminal voltage of the capacitive load, (ii) a second charging step of selectively connecting the capacitive load with the power supply terminal so as to increase an absolute value of the terminal voltage of the capacitive load, and (iii) a discharging step of selectively connecting the capacitive load with the first energy accumulating element so as to decrease the absolute value of the terminal voltage of the capacitive load and so as to regenerate electrostatic energy to be accumulated in the first energy accumulating element, the thus regenerated electrostatic energy being approximately equal to electrostatic energy as accumulated in the first energy accumulating element before the step (i), the steps (i) through (iii) being carried out in this order.

A capacitive load drive circuit for charging and discharging a capacitive load, comprising:

• a plurality of energy accumulating elements to which a plurality of different initial potentials are respectively applied;
• and
• switching means for selectively connecting the plurality of energy accumulating elements with the capacitive load,
• one of the plurality of energy accumulating elements being a first energy accumulating element having a first initial potential which is not 0, one of the plurality of energy accumulating elements being a second energy accumulating element whose absolute value is larger than an absolute value of the first initial potential, one of the plurality of energy accumulating elements being a third energy accumulating element having either a potential whose polarity is the same as a polarity of the first initial potential and whose absolute value is smaller than the absolute value of the first initial potential, a ground potential, or a third initial potential whose polarity is reverse to the polarity of the first initial potential,
• the switching means carrying out (i) a first charging step of selectively connecting the capacitive load with the third energy accumulating element and then selectively connecting the capacitive load with the first energy accumulating element so as to change, toward the first initial potential, a terminal voltage of the capacitive load, (ii) a second charging step of selectively connecting the capacitive load with the second energy accumulating element so as to increase an absolute value of the terminal voltage of the capacitive load, and (iii) a discharging step of selectively connecting the capacitive load with the first energy accumulating element so as to decrease the absolute value of the terminal voltage of the capacitive load and so as to regenerate electrostatic energy to be accumulated in the first energy accumulating element, the thus regenerated electrostatic energy being approximately equal to electrostatic energy as accumulated in the first energy accumulating element before the step (i), the steps (i) through (iii) being carried out in this order.

A capacitive load drive circuit for charging and discharging a capacitive load, comprising:

• a power supply terminal to which a power supply potential from a power source is applied;
• a reference potential terminal to which either a reference power supply potential that is different from the power supply potential or a ground potential is applied as a reference potential;
• a plurality of first energy accumulating elements to which initial potentials are respectively applied, the initial potentials being different from one another and being between the reference potential and the power supply potential;
• and
• switching means for selectively connecting (A) the reference potential terminal, the plurality of energy accumulating elements, and the power supply terminal with (B) the capacitive load,
• the switching means carrying out the steps of (1) connecting the capacitive load with the reference potential terminal and then sequentially connecting the capacitive load with the first energy accumulating elements in an order of the initial potentials from the initial potential closest to the reference potential, so as to change, toward the power supply potential, a terminal voltage of the capacitive load, (2) selectively connecting the capacitive load with the power supply terminal so as to increase an absolute value of the terminal voltage of the capacitive load, and (3) selectively connecting the capacitive load with the first energy accumulating elements in an order of the initial potentials from the initial potential closest to the power supply potential, so as to decrease the absolute value of the terminal voltage of the capacitive load and so as to so as to regenerate electrostatic energy to be accumulated in the first energy accumulating elements, the thus regenerated electrostatic energy being approximately equal to electrostatic energy as accumulated in the first energy accumulating elements before the step (1), the steps (1) through (3) being carried out in this order.

An apparatus which includes a capacitive load, and a capacitive load drive circuit for charging and discharging the capacitive load, wherein:

• the capacitive load drive circuit includes:
• a power supply terminal to which a power supply potential is applied from a power source;
• a reference potential terminal to which either a reference power supply potential supplied from the power source which is different from the power supply potential, or a ground potential is applied as a reference potential;
• an energy accumulating element to which an initial potential between the reference potential and the power supply potential is applied;
• and
• switching means for selectively connecting (A) the reference potential terminal, the energy accumulating element, and the power supply terminal with (B) the capacitive load,
• the switching means carrying out (i) a first charging step of connecting the capacitive load with the reference potential terminal and then connecting the capacitive load with the energy accumulating element, (ii) a second charging step of selectively connecting the capacitive load with the power supply terminal, and (iii) a discharging step of connecting the capacitive load with the energy accumulating element, the steps (i) through (iii) being carried out in this order,
• the following relationship being satisfied:
• Cd/Cs≦0.164{Ts/(R·Cd)}0.2198, if Ts/(R·Cd)<2.5;
• and
• Cd/Cs≦0.2, if Ts/(R·Cd)≧2.5,
• where Cs is a capacitive component of the energy accumulating element, Cd is a capacitance of the capacitive load, Ts is a time during which the energy accumulating element is kept connected to the capacitive load, and R is a resistance value of charge and discharge paths of the energy accumulating element with respect to the capacitive load, the charge and discharge paths including switching means.

An apparatus which includes a capacitive load, and a capacitive load drive circuit for charging and discharging the capacitive load, wherein:

• the capacitive load drive circuit includes:
• a power supply terminal to which a power supply potential is applied from a power source;
• a reference potential terminal to which either a reference power supply potential supplied from the power source which is different from the power supply potential, or a ground potential is applied as a reference potential;
• a plurality of energy accumulating elements to which initial potentials are respectively applied, the initial potentials being different from one another and being between the reference potential and the power supply potential;
• and
• switching means for selectively connecting (A) the reference potential terminal, the plurality of energy accumulating elements, and the power supply terminal with (B) the capacitive load,
• the switching means carrying out (i) a first charging step of connecting the capacitive load with the reference potential terminal and then sequentially connecting the capacitive load with the energy accumulating elements in an order of the initial potentials from the initial potential closest to the reference potential, (ii) a second charging step of selectively connecting the capacitive load with the power supply terminal, and (iii) a discharging step of sequentially connecting the capacitive load with the energy accumulating elements in an order of the initial potentials from the initial potential closest to the power supply potential, the steps (i) through (iii) being carried out in this order,
• the following relationship being satisfied:
• Cd/Cs≦0.164{Ts/(R·Cd)}0.2198, if Ts/(R·Cd)<2.5;
• and
• Cd/Cs≦0.2, if Ts/(R·Cd)≧2.5,
• where Cs is a capacitive component of the energy accumulating elements, Cd is a capacitance of the capacitive load, Ts is a time during which the energy accumulating elements are kept connected to the capacitive load, and R is a resistance value of charge and discharge paths of the energy accumulating elements with respect to the capacitive load, the charge and discharge paths including switching means.

A method for driving a capacitive load by charging and discharging the capacitive load, comprising:

• an accumulating step of dividedly accumulating electrostatic energy in a plurality of energy accumulating elements;
• a charging step of sequentially supplying the electrostatic energy from the plurality of energy accumulating elements to the capacitive load so as to charge the capacitive load;
• and
• a collecting step of discharging the capacitive load so that the plurality of energy accumulating elements sequentially collect the electrostatic energy from the capacitive load.

A method for driving a capacitive load by charging and discharging the capacitive load, comprising:

• (i) a step of preparing a first energy accumulating element having an first initial potential which is not 0, a second energy accumulating element, and a reference potential terminal to which either (a) a ground potential, (b) a potential which has the same polarity as the first initial potential supplied from a power source and which has a smaller absolute value than the first initial potential, or (c) a potential whose polarity is reverse to the polarity of the first initial potential supplied form the power source is applied as a reference potential;
• (ii) an initial potential applying step of applying the first initial potential to the first energy accumulating element, and applying to the second energy accumulating element a second initial potential which has the same polarity as the first initial potential and which has a larger absolute value than the first initial potential;
• (iii) a first charging step of selectively connecting the capacitive load with the reference potential terminal and then selectively connecting the capacitive load with the first energy accumulating element so as to change, toward the first initial potential, a terminal voltage of the capacitive load;
• (iv) a second charging step of selectively connecting the capacitive load with the second energy accumulating element so as to increase an absolute value of the terminal voltage of the capacitive load;
• and
• (v) a discharging step of selectively connecting the capacitive load with the first energy accumulating element so as to decrease the absolute value of the terminal voltage of the capacitive load and so as to regenerate electrostatic energy to be accumulated in the first energy accumulating element, the thus regenerated electrostatic energy being approximately equal to electrostatic energy as accumulated in the first energy accumulating element before the first charging step,
• the steps (iii) through (v) being carried out in this order.

A method for driving a capacitive load by charging and discharging the capacitive load, comprising:

• (i) a step of preparing a power supply terminal to which a power supply potential is applied from a power source, a first energy accumulating element, and a third energy accumulating element;
• (ii) an initial potential applying step of applying to the first energy accumulating element a first initial potential which has the same polarity as the power supply potential and which has a smaller absolute value than the power supply potential, and applying to the third accumulating element either a potential which has the same polarity as the first initial potential and which has a smaller absolute value than the first initial potential, a ground potential, or a third initial potential whose potential is reverse to the polarity of the first initial potential;
• (iii) a first charging step of selectively connecting the capacitive load with the third energy accumulating element and then selectively connecting the capacitive load with the first energy accumulating element so as to change, toward the first initial potential, a terminal voltage of the capacitive load;
• (iv) a second charging step of selectively connecting the capacitive load with the power supply terminal so as to increase an absolute value of the terminal voltage of the capacitive load;
• and
• (v) a discharging step of selectively connecting the capacitive load with the first energy accumulating element so as to decrease the absolute value of the terminal voltage of the capacitive load and so as to regenerate electrostatic energy to be accumulated in the first energy accumulating element, the thus regenerated electrostatic energy being approximately equal to electrostatic energy as accumulated in the first energy accumulating element before the first charging step,
• the steps (iii) through (v) being carried out in this order.

A method for driving a capacitive load by charging and discharging the capacitive load, comprising:

• (i) a step of preparing a first energy accumulating element, a second energy accumulating element, and a third energy accumulating element;
• (ii) an initial potential applying step of applying to the first energy accumulating element a first initial potential which is not 0, applying to the second energy accumulating element a second initial potential which has a larger absolute value than the initial potential of the first energy accumulating element, and applying to the third accumulating element either a potential which has the same polarity as the first initial potential and which has a smaller absolute value than the first initial potential, a ground potential, or a third initial potential whose potential is reverse to the polarity of the first initial potential;
• (iii) a first charging step of selectively connecting the capacitive load with the third energy accumulating element and then selectively connecting the capacitive load with the first energy accumulating element so as to change, toward the first initial potential, a terminal voltage of the capacitive load;
• (iv) a second charging step of selectively connecting the capacitive load with the second energy accumulating element so as to increase an absolute value of the terminal voltage of the capacitive load;
• and
• (v) a discharging step of selectively connecting the capacitive load with the first energy accumulating element so as to decrease the absolute value of the terminal voltage of the capacitive load and so as to regenerate electrostatic energy to be accumulated in the first energy accumulating element, the thus regenerated electrostatic energy being approximately equal to electrostatic energy as accumulated in the first energy accumulating element before the first charging step,
• the steps (iii) through (v) being carried out in this order.

A method for driving a capacitive load by charging and discharging the capacitive load, comprising:

• a providing step of preparing a power supply terminal to which a power supply potential is applied from a power source, a reference potential terminal to which either a reference power supply potential supplied from a reference power source which is different from the power supply potential or a ground potential is applied as a reference potential, and a plurality of first energy accumulating elements;
• an initial potential applying step of respectively applying to the plurality of first energy accumulating elements initial potentials which are different from one another and which are between the reference potential and the power supply potential;
• and
• steps of (1) connecting the capacitive load with the reference potential terminal and then sequentially connecting the capacitive load with the first energy accumulating elements in an order of the initial potentials from the initial potential closest to the reference potential, so as to change, toward the power supply potential, a terminal voltage of the capacitive load, (2) selectively connecting the capacitive load with the power supply terminal so as to increase an absolute value of the terminal voltage of the capacitive load, and (3) selectively connecting the capacitive load with the first energy accumulating elements in an order of the initial potentials from the initial potential closest to the power supply potential, so as to decrease the absolute value of the terminal voltage of the capacitive load and so as to regenerate electrostatic energy to be accumulated in the first energy accumulating elements, the thus regenerated electrostatic energy being approximately equal to electrostatic energy as accumulated in the first energy accumulating elements before the step (1), the steps (1) through (3) being carried out in this order.