Canon Kabushiki Kaisha

Jun Hirabayashi

Harumi Ishiyama

Yasunori Chigono

Norio Takahashi

Yukio Nagase

Hideki Kubo

Sumito Tanaka

Megumi Ito

Izuru Horiuchi

Yoichi Takikawa

Seiji Mashimo

Seiichi Shinohara

Takayuki Jinno

Tadashi Furuya

Nobuyuki Ito

Takahiro Hosokawa

Takamasa Seto

Megumi Uchino

An image forming apparatus includes a rotatable photosensitive member, a charging member, an exposure unit, a developing member, a transfer member, and a pre-exposure unit. The pre-exposure unit exposes a surface of the photosensitive member after the toner image is transferred to the recording material and before being charged by the charging member. The pre-exposure unit includes a substrate disposed adjacent to one end of the photosensitive member with respect to a longitudinal direction of the photosensitive member, and in which a first light emitting element and a second light emitting element having directional characteristics narrower than that of the first light emitting element are mounted.

Image forming apparatus including pre-exposure unit having light emitting elements of different directional characteristics

A power supply apparatus includes a transformer including primary and secondary coils, a heatsink that radiates heat, and a substrate supporting the heatsink and including primary and secondary circuits. The transformer outputs a voltage to the secondary coil according to a voltage input to the primary coil. The heatsink includes a protruding portion protruding from a position where the heatsink is in contact with the substrate in a direction protruding from a surface of the substrate. The heatsink further includes an extending portion extending from part of the protruding portion to an area of the secondary circuit of the transformer, in a state spaced apart from the substrate. The extending portion enters the area of the secondary circuit when viewed in a direction perpendicular to the surface of the substrate. A distance between the extending portion and the surface of the substrate is longer than at least 1 millimeter (mm).

Power supply apparatus and image forming apparatus

A power supply apparatus includes a transformer, an electrolytic capacitor provided in primary circuitry of the transformer, a board, and a heat sink having a protruding portion and a cover portion. The electrolytic capacitor includes an explosion-proof valve that opens to cause an electrolytic solution to be jetted from the electrolytic capacitor. The electrolytic capacitor is placed on the board so that a surface of the electrolytic capacitor opposite to a surface on which the explosion-proof valve is provided faces the board. The cover portion has a hole formed in the cover portion and, when the cover portion is viewed in a direction vertical to the surface of the electrolytic capacitor on which the explosion-proof valve is provided, at least the explosion-proof valve and the hole formed in the cover portion do not overlap each other and the cover portion encompasses the explosion-proof valve.

The switching circuit includes a first capacitor to which a pulse signal output from a control unit is input, a rectification circuit including at least a first diode and a second diode, the rectification circuit rectifying a voltage input from the first capacitor, and generating a first voltage, and a first switching element including a first terminal, a second terminal and a third terminal, the first voltage generated by the rectification circuit being applied between the first terminal and the second terminal.

Switching circuit, power supply apparatus, and image forming apparatus

The electronic apparatus includes a first circuit board on which a circuit mounted, a second circuit board arranged close to the circuit on the first circuit board, and a conductive terminal, which is in contact with a ground pattern on the first circuit board, and is arranged at a location between the circuit and the second circuit board so as to extend over the circuit.

Circuit board, electronic apparatus, and image forming apparatus

The power supply apparatus includes a switching element configured to drive a transformer, a primary side and a secondary side of the transformer being insulated from each other, a control unit configured to output a pulse signal for driving the switching element, and a comparing unit configured to compare a target voltage of an output voltage that is output from the secondary side of the transformer and the output voltage, and to control the output voltage to be the target voltage, wherein the comparing unit cuts off an input of the pulse signal to the switching element in a case where the output voltage is larger than the target voltage, and wherein the control unit determines a frequency or an on-duty ratio of the pulse signal according to the target voltage.

The power supply apparatus includes an inductor; a switching element, which is connected in series to the inductor, and is configured to be driven in accordance with an input pulse signal; and a booster circuit, which is connected to both ends of the inductor, and includes a plurality of rectification units each including a diode and a capacitor, wherein the power supply apparatus is configured to repeat an operation of successively driving the switching element in accordance with the input pulse signal in a cycle that is longer than a cycle in which the switching element is successively driven.

The power supply apparatus includes an inductor; a switching element connected to another end of the inductor, the switching element configured to drive the inductor by being turned on or turned off in accordance with an input pulse signal; a boost converter circuit connected to both ends of the inductor and including a plurality of rectification units, the boost converter circuit configured to amplify a voltage generated in the inductor, each of the plurality of rectification units including a diode and a capacitor; and a voltage boosting element configured to supply a voltage obtained by boosting an input voltage to the inductor.

The circuit board has a surface mount LED with a lens on the circuit board. A conductive portion and remaining space in the periphery of the LED are covered with solid copper foil so that reflectance of light and a heat dissipation effect are enhanced. In addition, layer structures between the circuit board and an assembled component are the same between contact portions with the assembled component so that tilt in mounting the board is suppressed. As a result, the circuit board having mounted thereon the surface mount LED having high directivity can be accurately mounted on the assembled component, tilt of an optical axis can be suppressed, the reflectance of light from the LED can be increased, and the heat dissipation effect can be enhanced.

Circuit board and image forming apparatus

An incidence angle of laser light with respect to a photosensitive member in a main-scanning direction is different depending on an exposure position. Hence, the spot shape of the laser light on the photosensitive member is different in the main-scanning direction. A filter coefficient is changed in the main-scanning direction, and image data is corrected with the filter coefficient.

Image forming apparatus

The power supply apparatus includes a transformer, a switch connected to a primary side of the transformer, a first line connected to a secondary side of the transformer to output a voltage of a first polarity, a second line connected to the secondary side of the transformer to output a second polarity voltage whose polarity is opposite to the first polarity, a first diode connected to the first line in a direction, a first capacitor connected to the first line, a second diode connected to the second line in another direction opposite to the direction of the first diode, a second capacitor connected to the second line, a resistor connected to the first line on an output side of the first diode, and a controller controlling a frequency of the switch to control an output from the second line constant.

Image forming apparatus correcting unevenness of potential distribution due to change of exposure spot shape of light beam on photosensitive member

The power supply apparatus includes a transformer having a primary side and a secondary side insulated from each other, a switch element for switching current flowing in the primary side of the transformer, a control part configured to control an operation of the switch element, and two feedback parts configured to detect an output voltage from the transformer so as to output, to the control part, a detection signal in accordance with the output voltage for feedback to the primary side of the transformer.

The power supply apparatus includes a switch element for turning ON and OFF supply of electric power to a primary winding of a transformer; a determining unit connected to an auxiliary winding of the transformer, for determining an ON-time of the switch element; and a switching unit for switching the ON-time determined by the determining unit.

Growing community of inventors

Numazu, Japan

Jun Hirabayashi