Light-emitting device, light-emitting array unit, print head, image forming apparatus and light-emission control method
View Patent ↗A light-emitting device includes: plural light-emitting array units that each include plural light-emitting elements, and for which lighting up and not lighting up are controlled by using a combination of a selection signal for selecting a control target for lighting up or not lighting up and a light-up signal for supplying power for lighting up to each light-emitting element forming the plural light-emitting elements; a selection signal generating unit that sends plural selection signals including the selection signal to the plural light-emitting array units; and a light-up signal generating unit that sends plural light-up signals including the light-up signal to the plural light-emitting array units.
1. Alight-emitting device comprising:
a plurality of light-emitting array units that each include a plurality of light-emitting elements, and for which lighting up and not lighting up are controlled by using a combination of a selection signal for selecting a control target for lighting up or not lighting up and a light-up signal for supplying power for lighting up to each light-emitting element forming the plurality of light-emitting elements;
a selection signal generating unit that sends a plurality of selection signals including the selection signal to the plurality of light-emitting array units;
a light-up signal generating unit that sends a plurality of light-up signals including the light-up signal to the plurality of light-emitting array units;
a plurality of transfer elements that are respectively provided for the plurality of light-emitting elements; and
a plurality of AND circuits each provided between one of the plurality of light-emitting elements and one of the plurality of transfer elements that are provided corresponding to the one of the light-emitting elements, each of the AND circuits receiving input of the selection signal and a signal from the one of the plurality of transfer elements and outputting a signal to the one of the plurality of light-emitting elements.
2. The light-emitting device according to claim 1 , wherein the plurality of selection signals are sent respectively on a one-to-one basis for a plurality of classes formed by dividing the plurality of light-emitting array units.
3. The light-emitting device according to claim 2 , wherein each of the plurality of selection signals is sent in a temporal sequence to the light-emitting array units included in a corresponding one of the plurality of classes.
4. The light-emitting device according to claim 3 , wherein the plurality of light-up signals are provided respectively on a one-to-one basis for a plurality of groups formed by dividing the plurality of light-emitting array units.
5. The light-emitting device according to claim 2 , wherein the plurality of light-up signals are provided respectively on a one-to-one basis for a plurality of groups formed by dividing the plurality of light-emitting array units.
6. The light-emitting device according to claim 1 , wherein the plurality of light-up signals are provided respectively on a one-to-one basis for a plurality of groups formed by dividing the plurality of light-emitting array units.
7. The light-emitting device according to claim 1 , further wherein plurality of transfer elements send a transfer signal for sequentially setting the plurality of light-emitting elements included in each of the plurality of light-emitting array units, as a control target for lighting up or not lighting up.
8. A light-emitting array unit comprising:
a plurality of light-emitting elements;
a plurality of transfer elements that are respectively provided for the plurality of light-emitting elements, and that sequentially set a light-emitting element forming the plurality of light-emitting elements, as a control target for lighting up or not lighting up;
a control terminal through which a selection signal is received to control whether or not to light up the light-emitting element set as the control target;
a light-up signal terminal through which a light-up signal is received to supply power for lighting up to the light-emitting element set as the control target;
a plurality of AND circuits each provided between one of the plurality of light-emitting elements and one of the plurality of trannsfer elements that is provided corresponding the one of the light-emitting elements, each of the AND circuits receiving input of the selection signal sent to the control terminal and a signal from the one of the plurality of transfer elements and outputting a signal to the one of the plurality of light-emitting elements.
9. The light-emitting array unit according to claim 8 , wherein
the plurality of transfer elements in the light-emitting array unit are a plurality of transfer thyristors each having a first gate terminal, a first anode terminal and a first cathode terminal, and
the plurality of light-emitting elements are a plurality of light-emitting thyristors each having a second gate terminal, a second anode terminal and a second cathode terminal,
the light-emitting array unit further comprising a plurality of first electrical parts that each connect two of the first gate terminals of the plurality of transfer thyristors to one another.
10. The light-emitting array unit according to claim 9 , wherein each of the plurality of AND circuits in the light-emitting array unit includes:
a second electrical part that is connected, at one end, to the first gate terminal of a corresponding one of the transfer thyristors and is connected, at an opposite end, to the second gate terminal of a corresponding one of the light-emitting thyristors; and
a third electrical part that is provided between the control terminal and the second gate terminal of the corresponding one of the light-emitting thyristors.
11. A print head comprising:
an exposure unit that exposes an image carrier to form an electrostatic latent image; and
an optical unit that focuses light emitted by the exposure unit on the image carrier,
the exposure unit including:
a plurality of light-emitting array units that each include a plurality of light-emitting elements, and for which lighting up and not lighting up are controlled by using a combination of a selection signal for selecting a control target for lighting up or not lighting up and a light-up signal for supplying power for lighting up to each light-emitting element forming the plurality of light-emitting elements;
a selection signal generating unit that sends a plurality of selection signals including the selection signal to the plurality of light-emitting array units;
a light-up signal generating unit that sends a plurality of light-up signals including the light-up signal to the plurality of light-emitting array units;
a plurality of transfer elements that are respectively provided for the plurality of light-emitting elements; and
a plurality of AND circuits each provided between one of the plurality of light-emitting elements and one of the plurality of transfer elements that are provided corresponding to the one of the light-emitting elements, each of the AND circuits receiving input of the selection signal and a signal from the one of the plurality of transfer elements and outputting a signal to the one of the plurality of light-emitting elements.
12. An image forming apparatus comprising:
a charging unit that charges an image carrier;
an exposure unit that exposes the image carrier to form an electrostatic latent image;
an optical unit that focuses light emitted by the exposure unit on the image carrier;
a developing unit that develops the electrostatic latent image formed on the image carrier; and
a transfer unit that transfers an image developed on the image carrier to a transferred body,
the exposure unit including:
a plurality of light-emitting array units that each include a plurality of light-emitting elements, and for which lighting up and not lighting up are controlled by using a combination of a selection signal for selecting a control target for lighting up or not lighting up and a light-up signal for supplying power for lighting up to each light-emitting element forming the plurality of light-emitting elements;
a selection signal generating unit that sends a plurality of selection signals including the selection signal to the plurality of light-emitting array units;
a light-up signal generating unit that sends a plurality of light-up signals including the light-up signal to the plurality of light-emitting array units;
a plurality of transfer elements that are respectively provided for the plurality of light-emitting elements; and
a plurality of AND circuits each provided between one of the plurality of light-emitting elements and one of the plurality of transfer elements that are provided corresponding to the one of the light-emitting elements, each of the AND circuits receiving input of the selection signal and a signal from the one of the plurality of transfer elements and outputting a signal to the one of the plurality of light-emitting elements.
13. A light-emission control method for a plurality of light-emitting array units that each include a plurality of light-emitting elements, a plurality of transfer elements that are respectively provided for the plurality of light-emitting elements, a plurality of AND circuits each provided between one of the plurality of light-emitting elements and one of the plurality of transfer elements that are provided corresponding to the one of the light-emitting elements, and for which lighting up and not lighting up are controlled by using a combination of a selection signal for selecting a control target for lighting up or not lighting up and a light-up signal for supplying power for lighting up to each light-emitting element forming the plurality of light-emitting elements, the light-emission control method comprising:
sending a plurality of selection signals including the selection signal, on a one-to-one basis, respectively to a plurality of classes formed by dividing the plurality of light-emitting array units; and
sending a plurality of light-up signals including the light-up signal, on a one-to-one basis, respectively to a plurality of groups formed by dividing the plurality of light-emitting array units; and
receiving an input of the selection signal and a signal from the one of the plurality of transfer elements at each of the AND circuits and outputting a signal to the one of the plurality of light-emitting elements.