Image forming apparatus and high voltage power thereof

1. An image forming apparatus comprising:

an AC high voltage power supply;

a DC high voltage power supply; and

a high voltage power supply apparatus, which outputs an output voltage at an output end by superposing an output of said AC high voltage power supply and an output of said DC high voltage power supply, said high voltage power supply apparatus including a positive peak detector detecting a positive peak of the voltage at an output end, and a negative peak detector detecting a negative peak of the voltage at an output end,

wherein an output voltage of at least one of said AC high voltage power supply and said DC high voltage power supply is controlled on the basis of the detection result of at least one of the positive peak detector and the negative peak detector, and

wherein an output voltage of said AC high voltage power supply is controlled on the basis of the detection result of said positive peak detector, and an output voltage of said DC high voltage power supply is controlled on the basis of the detection result of said negative peak detector.

2. An image forming apparatus comprising:

an AC high voltage power supply;

a DC high voltage power supply; and

a high voltage power supply apparatus, which outputs an output voltage at an output end by superposing an output of said AC high voltage power supply and an output of said DC high voltage power supply, said high voltage power supply apparatus including a positive peak detector detecting a positive peak of the voltage at an output end, and a negative peak detector detecting a negative peak voltage of the voltage at an output end,

wherein an output voltage of at least one of said AC high voltage power supply and said DC high voltage power supply is controlled on the basis of the detection result of at least one of the positive peak detector and the negative peak detector, and

wherein said positive peak detector and said negative peak detector respectively include a DC load, said DC high voltage power supply outputs a voltage of a negative polarity, and the DC load of said positive peak detector has a resistance value of not less than the DC load of said negative peak detector.

3. An image forming apparatus comprising:

an AC high voltage power supply;

a DC high voltage power supply; and

a high voltage power supply apparatus, which outputs an output voltage at an output end by superposing an output of said AC high voltage power supply and an output of said DC high voltage power supply, said high voltage power supply apparatus including a positive peak detector detecting a positive peak of the voltage at an output end, and a negative peak detector detecting a negative peak voltage of the voltage at an output end,

wherein an output voltage of at least one of said AC high voltage power supply and said DC high voltage power supply is controlled on the basis of the detection result of at least one of the positive peak detector and the negative peak detector, and

wherein, with respect to the detection results of said positive peak detector and said negative peak detector, response speeds of control performed by said AC high voltage power supply and said DC high voltage power supply are different by at least two times from each other.

4. An image forming apparatus comprising:

an AC high voltage power supply;

a DC high voltage power supply; and

a high voltage power supply apparatus, which outputs an output voltage at an output end by superposing an output of said AC high voltage power supply and an output of said DC high voltage power supply, said high voltage power supply apparatus including a positive peak detector detecting a positive peak of the voltage at an output end, and a negative peak detector detecting a negative peak voltage of the voltage at an output end; and

a positive peak control signal input part and a negative peak control signal input part, wherein the positive peak voltage and the negative peak voltage of the output voltage at an output end is variably controlled in accordance with a positive peak control signal and a negative peak control signal, which are inputted from the positive peak a control signal input part and the negative peak control signal input part,

wherein an output voltage of at least one of said AC high voltage power supply and said DC high voltage power supply is controlled on the basis of the detection result of at least one of the positive peak detector and the negative peak detector, and

wherein, in case a positive peak value and negative peak value of said output voltage are changed, a change timing of said positive peak control signal and a change timing of said negative peak control signal are different.

5. An image forming apparatus comprising:

an AC high voltage power supply;

a DC high voltage power supply; and

a high voltage power supply apparatus, which outputs an output voltage at an output end by superposing an output of said AC high voltage power supply and an output of said DC high voltage power supply, said high voltage power supply apparatus including a positive peak detector detecting a positive peak of the voltage at an output end, and a negative peak detector detecting a negative peak voltage of the voltage at an output end,

wherein an output voltage of at least one of said AC high voltage power supply and said DC high voltage power supply is controlled on the basis of the detection result of at least one of the positive peak detector and the negative peak detector, and

wherein an output duty of said AC high voltage power supply is variable.

6. A high voltage power supply apparatus having an AC high voltage power supply and a DC high voltage power supply, wherein the high voltage power supply apparatus outputs a voltage at an output end of a voltage of an output voltage of the AC high voltage power supply superposed on an output voltage of the DC high voltage power supply, said high voltage power supply apparatus comprising:

a positive peak detector detecting a positive peak voltage of the voltage at the output end; and

a negative peak detector detecting a negative peak voltage of the voltage at the output end,

wherein at least one of the output voltages of the AC high voltage power supply and the DC high voltage power supply is controlled on the basis of at least one of the detection results of said positive peak detector and said negative peak detector, and

wherein the output voltage of the AC high voltage power supply is controlled on the basis of the detection result of said positive peak detector, and wherein the output voltage of the DC high voltage power supply is controlled on the basis of the detection result of said negative peak detector.

7. A high voltage power supply apparatus having an AC high voltage power supply and a DC high voltage power supply, wherein the high voltage power supply apparatus outputs a voltage at an output end of a voltage of an output voltage of the AC high voltage power supply superposed on an output voltage of the DC high voltage power supply, said high voltage power supply apparatus comprising:

a positive peak detector detecting a positive peak voltage of the voltage at the output end; and

a negative peak detector detecting a negative peak voltage of the voltage at the output end,

wherein at least one of the output voltages of the AC high voltage power supply and the DC high voltage power supply is controlled on the basis of at least one of the detection results of said positive peak detector and said negative peak detector, and

wherein said positive peak detector and said negative peak detector respectively include a DC load, wherein the DC high voltage power supply outputs a voltage of negative polarity, and wherein the DC load of said positive peak detector has a resistance value not less than the DC load of said negative peak detector.

8. A high voltage power supply apparatus having an AC high voltage power supply and a DC high voltage power supply, wherein the high voltage power supply apparatus outputs a voltage at an output end of a voltage of an output voltage of the AC high voltage power supply superposed on an output voltage of said DC high voltage power supply, said high voltage power supply apparatus comprising:

a positive peak detector detecting a positive peak voltage of the voltage at the output end; and

a negative peak detector detecting a negative peak voltage of the voltage at the output end,

wherein at least one of the output voltages of the AC high voltage power supply and the DC high voltage power supply is controlled on the basis of at least one of the detection results of said positive peak detector and said negative peak detector, and

wherein response speeds of control performed by the AC high voltage power supply and the DC high voltage power supply with respect to the detection results of said positive peak detector and said negative peak detector are difference by at least two times from each other.

9. A high voltage power supply apparatus having an AC high voltage power supply and a DC high voltage power supply, wherein the high voltage power supply apparatus outputs a voltage at an output end of a voltage of an output voltage of the AC high voltage power supply superposed on an output voltage of the DC high voltage power supply, said high voltage power supply apparatus comprising:

a positive peak detector detecting a positive peak voltage of the voltage at the output end;

a negative peak detector detecting a negative peak voltage of the voltage at the output end; and

a positive peak control signal input part and a negative peak control signal input part, wherein the positive peak voltage and the negative peak voltage of the output voltage are variably controlled in accordance with a positive peak control signal and a negative peak control signal, which are inputted from the positive peak control signal input and the negative peak control signal input,

wherein at least one of the output voltages of the AC high voltage power supply and the DC high voltage power supply is controlled on the basis of at least one of the detection results of said positive peak detector and said negative peak detector, and

wherein when a positive peak value and a negative peak value of the output voltage are changed, a change timing of one of the positive peak control signal and the negative peak control signal is made different from the time when the positive peak value and the negative peak value of the output voltage are changed.

10. A high voltage power supply apparatus having an AC high voltage power supply and a DC high voltage power supply, wherein the high voltage power supply apparatus outputs a voltage at an output end of a voltage of an output voltage of the AC high voltage power supply superposed on an output voltage of the DC high voltage power supply, said high voltage power supply apparatus comprising:

a positive peak detector detecting a positive peak voltage of the voltage at the output end; and

a negative peak detector detecting a negative peak voltage of the voltage at the output end,

wherein at least one of the output voltages of the AC high voltage power supply and the DC high voltage power supply is controlled on the basis of at least one of the detection results of said positive peak detector and said negative peak detector, and

wherein an output duty of said AC high voltage power supply is variable.