Control method and circuit for transfer current, and printer having the control circuit

A high-voltage power-supply unit comprising:

• a transfer output circuit which controls a transfer current applied to a transfer unit in order to print a predetermined image on a printing paper;
• and
• a pre-charger output circuit which controls a pre-charger,
• wherein said transfer output circuit including:
• a main controller module connected to a first signal line;
• an auxiliary controller module connected to a second signal line;
• an oscillator module connected to the main and auxiliary controller modules;
• and
• a transformer module connected to the main and auxiliary controller modules and the oscillator module,
• wherein the main controller module includes:
• a first current-switching circuit which receives a first signal through the first signal line;
• and
• a plurality of first current control circuits each of which is selected by the first current-switching circuit based on the first signal and outputs a first value,
• the number of first current control circuits being 2m where the number of the first signal lines is m,
• wherein said auxiliary controller module includes:
• a second current-switching circuit which receives a second signal through the second signal line;
• and
• a second current control circuit which is selected by the second current-switching circuit based on the second signal, and outputs a second value,
• wherein where the number of first and second signal lines is n, the number of the second current control circuits is s, and s=n−m, the number of first and second current control circuits is (2n-s+s), the transformer module being consequently able to generate and output 2n transfer currents using a combination of the first and second values, and
• wherein said pre-charger output circuit receives a signal indicative of a feed speed of the printing paper, and generates pre-charge voltage applied to the pre-charger, the second signal including the signal indicative of the feed speed.

A printer comprising:

• a photosensitive body;
• a transfer unit which transfers onto a printing paper a toner image that has been formed on said photosensitive body;
• and
• a transfer output circuit which controls a transfer current applied to said transfer unit,
• wherein said transfer output circuit includes:
• a main controller module connected to a first signal line;
• an auxiliary controller module connected to a second signal line;
• an oscillator module connected to the main and auxiliary controller modules;
• and
• a transformer module connected to the main and auxiliary controller modules and the oscillator module,
• wherein the main controller module includes:
• a first current-switching circuit which receives a first signal through the first signal line;
• and
• a plurality of first current control circuits each of which is selected by the first current-switching circuit based on the first signal, and outputs a first value,
• the number of first current control circuits being 2m where the number of the first signal lines is m,
• wherein said auxiliary controller module includes:
• a second current-switching circuit which receives a second signal through the second signal line;
• and
• a second current control circuit which is selected by the second current-switching circuit based on the second signal, and outputs a second value, and
• wherein where the number of first and second signal lines is n, the number of the second current control circuits is s, and s=n−m, the number of first and second current control circuits is (2n-s+s), the transformer module being able to generate and output 2n transfer currents using a combination of the first and second values.

A control method comprising the steps of:

• reading out, while referring to a set table, control value based on a control instruction including first and second parameters, the set table including the first and second parameters, the first parameter including 2m types of first elements, and the number of types of second parameter being s each of which includes two types of second elements;
• and
• identifying the first and second elements corresponding to the control value and set the first and second elements as first and second signals respectively,
• wherein the first signal is supplied to a main controller module including 2m first control circuits through m first signal lines, while the second signal is supplied to an auxiliary controller module including s second control circuits through s second signal lines.

A mechanical-part control circuit module comprising:

• a memory which stores a set table including first and second parameters, the first parameter including 2m types of first elements, and the number of types of second parameter being s each of which includes two types of second elements;
• a processor which not only reads out a control value based on a control instruction including the first and second parameters while referring to the set table stored in said memory, but also identifies the first and second elements corresponding to the control value, thereby setting the first and second elements as first and second signals respectively,
• wherein said mechanical-part control circuit module is connected to main and auxiliary controller modules,
• wherein the first signal is supplied to the main controller module including 2m first control circuits through m first signal lines, and the second signal is supplied to the auxiliary controller module including s second control circuits through s second signal lines, whereby the main and auxiliary controller modules output the control value based on the first and second signals.

A control device comprising:

• a main controller module connected to a first signal line;
• and
• an auxiliary controller module connected to a second signal line;
• wherein said main controller module includes:
• a first switching circuit which receives a first signal through the first signal line;
• and
• a plurality of first control circuits each of which is selected by the first switching circuit based on the first signal, and outputs a first value, the number of first control circuits being 2m where the number of the first signal lines is m,
• wherein said auxiliary controller module includes:
• a second switching circuit which receives a second signal through the second signal line;
• and
• a second control circuits which is selected by the second switching circuit based on the second signal, and outputs a second value, and
• wherein where the number of first and second signal lines is n, the number of the second control circuits is s, and s=n−m, the number of first and second control circuits is (2n-s+s), said control device being consequently able to generate and output 2n combinations of the first and second values.

A control device comprising:

• a main controller module connected to a first signal line;
• an auxiliary controller module connected to a second signal line;
• and
• a logic module connected to said main and auxiliary controller modules, said logic module performing a predetermined operation for outputs of said main and auxiliary controller modules,
• wherein said main controller module includes:
• a first switching circuit which receives a first signal through the first signal line;
• and
• a plurality of first control circuits each of which is selected by the first switching circuit based on the first signal, and outputs a first value, the number of first control circuits being 2m where the number of the first signal lines is m,
• wherein said auxiliary controller module includes:
• a second switching circuit which receives a second signal through the second signal line;
• and
• a second control circuit which is selected by the second switching circuit based on the second signal, and outputs a second value, and
• wherein where the number of first and second signal lines is n, the number of the second control circuits is s, and s=n−m, the number of first and second control circuits is (2n-s+s), said logic module being consequently able to generate and output 2n combinations of the first and second values.