Image Forming Apparatus

• US 20100054771A1
• Filed: 08/24/2009
• Published: 03/04/2010
• Est. Priority Date: 08/28/2008
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha (Brother Industries Limited)
• Original Assignee: Brother Kogyo Kabushiki Kaisha (Brother Industries Limited)
• Inventors: YOKOI, Katsuyuki, MIYAHARA, Kensuke, FURUKAWA, Toshio
• Granted Patent: US 8,515,298 B2
• Time in Patent Office: Days
• US Class Current: 399/44
• CPC Class Codes: G03G 15/20 for fixing, e.g. by using heat
• CPC Class Codes: G03G 15/234 by inverting and refeeding the image receiving material with an image on one face to the recording member to transfer a second image on its second face, e.g. by using a duplex tray; Details of duplex trays or inverters
• CPC Class Codes: G03G 2221/1645 for conducting air through the machine, e.g. cooling

Abstract

An electrophotographic image forming apparatus is provided. The image forming apparatus includes an image forming unit configured to form an image on a recording medium; a fixing unit configured to fix the image onto the recording medium by applying heat and pressure; a re-transport unit configured to re-transport the recording medium which has passed through the fixing unit, to the image forming unit along a re-transport path; a cooling unit provided between the fixing unit and the image forming unit along the re-transport path and configured to cool the recording medium transported by the re-transport unit; a parameter signal output unit configured to output a signal corresponding to a parameter for controlling the cooling unit; and a controller configured to control the cooling unit according to the signal output from the parameter signal output unit.

Claims

1. An electrophotographic image forming apparatus comprising:

an image forming unit configured to form an image on a recording medium;

a fixing unit configured to fix the image onto the recording medium by applying heat and pressure;

a re-transport unit configured to re-transport the recording medium which has passed through the fixing unit, to the image forming unit along a re-transport path;

a cooling unit provided between the fixing unit and the image forming unit along the re-transport path and configured to cool the recording medium transported by the re-transport unit;

a parameter signal output unit configured to output a signal corresponding to a parameter for controlling the cooling unit; and

a controller configured to control the cooling unit according to the signal output from the parameter signal output unit.

2. The image forming apparatus according to claim 1,

wherein the cooling unit comprises a fan configured to rotate by a rotation speed to generate blowing air, the amount of which varies according to the rotation speed,

wherein the parameter signal output unit comprises a temperature sensor and a humidity sensor, and outputs the signal corresponding to a temperature measured by the temperature sensor and a humidity measured by the humidity sensor, and

wherein the controller controls the rotation speed of the fan according to the signal output from the parameter signal output unit.

3. The image forming apparatus according to claim 2, further comprising a medium accommodating unit which accommodates a recording medium on which an image is to be formed by the image forming unit,

wherein the temperature sensor and the humidity sensor are provided in the proximity of the recording medium accommodated in the medium accommodating unit.

4. The image forming apparatus according to claim 2,

wherein the controller controls the fan to rotate at a first rotation speed if a combination of the temperature and the humidity corresponding to the signal output from the parameter signal output unit is within a first range,

wherein the controller controls the fan to rotate at a second rotation speed if the combination of the temperature and the humidity corresponding to the signal output from the parameter signal output unit is within a second range,

wherein the controller controls the fan to rotate at a third rotation speed if the combination of the temperature and the humidity corresponding to the signal output from the parameter signal output unit is within a third range, and

wherein the controller controls the fan not to rotate if the combination of the temperature and the humidity corresponding to the signal output from the parameter signal output unit is not within any of the first, second and third range.

5. The image forming apparatus according to claim 1,

wherein the image forming unit comprises:

a photosensitive drum capable of carrying developer on a surface thereof;

a charging unit configured to charge the surface of the photosensitive drum;

an exposure unit configured to expose the surface of the photosensitive drum to form an electrostatic latent image thereon;

a developing roller configured to supply developer to the electrostatic latent image to form a developer image;

a transfer roller configured to cause the developer image to be transferred from the surface of the photosensitive drum to the recording medium,

wherein the parameter signal output unit measures an electric resistance value of the recording medium as the parameter and outputs a signal corresponding to the measured electric resistance.

6. The image forming apparatus according to claim 5,

wherein the parameter signal output unit measures the electric resistance of the recording medium based on a voltage applied between the photosensitive drum and the transfer roller, and an electric current flowing between the photosensitive drum and the transfer roller.

7. The image forming apparatus according to claim 5,

wherein the image forming unit further comprises:

a pair of registration rollers between which the recording medium passes; and

a voltage applying unit configured to apply a voltage between the pair of registration rollers,

wherein the parameter signal output unit measures the electric resistance of the recording medium based on a voltage applied between the pair of registration rollers and an electric current flowing between the pair of registration rollers.

8. The image forming apparatus according to claim 1,

wherein the image forming unit comprises:

a photosensitive drum capable of carrying developer on a surface thereof;

a charging unit configured to charge the surface of the photosensitive drum;

an exposure unit configured to expose the surface of the photosensitive drum to form an electrostatic latent image thereon;

a developing roller configured to supply developer to the electrostatic latent image to form a developer image;

a transfer roller configured to cause the developer image to be transferred from the surface of the photosensitive drum to the recording medium,

a transfer current control unit configured to control a transfer current between the transfer roller and the photosensitive drum to be constant,

wherein the parameter signal output unit measures a voltage between the transfer roller and the photosensitive drum as the parameter and outputs a signal corresponding to the measured voltage.

9. An image forming apparatus comprising:

an image forming unit configured to form an image on a recording medium;

a fan configured to generate blowing air toward the recording medium;

a temperature sensor configured to measure a temperature;

a humidity sensor configured to measure a humidity; and

a controller which controls the fan according to the temperature measured by the temperature sensor and the humidity measured by the humidity sensor.

10. An image forming apparatus comprising:

an image forming unit configured to form an image on a recording medium;

a resistance measuring unit configured to measure an electric resistance of the recording medium; and

a controller which controls the image forming unit based on the electric resistance of the recording medium.

11. The image forming apparatus according to claim 10,

wherein the resistance measuring unit measures the electric resistance of the recording medium based on a temperature and a humidity.