Image forming apparatus and air flow path therein

1. An image forming apparatus comprising:

an intake opening;

at least one image developing or optical device or component positioned in the image forming apparatus;

a fixing device that heats a recording medium and is removably installable into a first position in the image forming apparatus above the intake opening and horizontally adjacent to the at least one image developing or optical device or component;

a partition, located in a second position between the fixing device and the at least one image developing or optical device or component in a horizontal direction, and including a first side that faces the fixing device and a second side that faces the at least one image developing or optical device or component;

an entrance guide attached to the fixing device and angled upward from an upstream end including a plurality of ribs to a downstream end along a conveyance direction of the recording medium; and

a flow path that extends through a gap between the fixing device and the at least one image developing or optical device or component in both

a vertical direction crossing the conveyance direction at the entrance guide, and

the horizontal direction from the first side to the second side of the partition,

wherein an outside air is drawn from the intake opening at least by a negative pressure generated by an upward current of hot air generated from the fixing device,

wherein the recording medium is guided by the entrance guide in the conveyance direction over the entrance guide and into the fixing device,

wherein the flow path directs the outside air

vertically upward through the plurality of ribs in an area on the first side of the partition,

horizontally from an area downstream of the plurality of ribs in the flow path on the first side of the partition to an area on the second side of the partition, and

to the at least one image developing or optical device or component, and

wherein the partition

guides the outside air onto the at least one image developing or optical device or component separately from the hot air generated from the fixing device,

extends substantially vertically in the second position and divides the gap,

includes a lower end at a position where the outside air drawn from the intake opening is mixed with the hot air generated by the fixing device, and

is substantially parallel to an exterior part of the fixing device.

2. The image forming apparatus according to claim 1 , wherein the entrance guide further comprises a planar portion without ribs, provided downstream from the plurality of ribs in the conveyance direction of the recording medium.

3. The image forming apparatus according to claim 1 , wherein the entrance guide comprises holes,

wherein the outside air passes through each of the holes in the area on the first side of the partition.

4. The image forming apparatus according to claim 3 , wherein the holes are provided at portions other than portions where front corners of the recording medium pass.

5. The image forming apparatus according to claim 3 , wherein a part of each of the holes contacts a leading edge of the recording medium contacts,

wherein the part of each of the holes is curved.

6. The image forming apparatus according to claim 1 , wherein an attachment of the entrance guide to the fixing device includes a fulcrum,

wherein the entrance guide moves about the fulcrum between a guide position to guide the recording medium into the fixing device and a path formation position to form the flow path for the air drawn from the intake opening.

7. The image forming apparatus according to claim 1 , further comprising a fluorinated resin coating a surface of the entrance guide.

8. The image forming apparatus according to claim 1 , wherein the entrance guide is integrally formed with the exterior part of the fixing device.

9. The image forming apparatus according to claim 1 , wherein the entrance guide is a separate member attached to the exterior part of the fixing device.

10. The image forming apparatus according to claim 1 , wherein at least a part of the partition is formed of a heat-resistant member.

11. The image forming apparatus according to claim 1 , wherein the gap between the fixing device and the at least one image developing or optical device or component is greater than or equal to 10 mm.

12. The image forming apparatus according to claim 1 , wherein heating of the fixing device is automatically stopped to change the fixing device to a standby mode each time a predetermined period of time elapses or images are formed on a predetermined number of recording media during continuous image formation.

13. The image forming apparatus according to claim 1 , wherein the fixing device comprises:

a fixing member having a heat source therein; and

an opposing member provided opposite the fixing member to form a fixing nip between the fixing member and the opposing member.

14. The image forming apparatus according to claim 13 , wherein the fixing member is controlled to have a surface temperature of 165° C. or lower.

15. The image forming apparatus according to claim 1 , wherein the fixing device includes an opening,

wherein the recording medium is conveyed into the opening and inside the fixing device,

wherein the entrance guide covers and uncovers the opening, and

wherein the opening is automatically covered by the entrance guide upon removal of the fixing device from the image forming apparatus.

16. An image forming apparatus comprising:

an intake opening;

at least one image developing or optical device or component positioned in the image forming apparatus;

a fixing device including a recording medium opening and being removably installable in the image forming apparatus to heat a recording medium moving in a conveyance direction through the recording medium opening into an interior of the fixing device to fix an image onto the recording medium;

an entrance guide attached to the fixing device and including a recording medium guide face and an end with a plurality of ribs; and

a flow path that extends through a gap in both

a vertical direction crossing the conveyance direction at the entrance guide, and

a horizontal direction from a first side of the gap adjacent to the fixing device to a second side of the gap adjacent to the at least one image developing or optical device or component,

wherein an outside air is drawn from the inlet opening at least by a negative pressure generated by an upward current of hot air generated from the fixing device,

wherein the entrance guide

moves between a guide position to guide the recording medium in the conveyance direction over the entrance guide into the fixing device and a path formation position retracted from the guide position to form the flow path for the outside air,

opens the recording medium opening in the guide position and closes the recording medium opening in the path formation position,

moves to the path formation position to automatically close the recording medium opening as the fixing device is removed from the image forming apparatus, and

exposes the recording medium guide face to an exterior of the fixing device so that the recording medium guide face is oriented in the vertical direction and faces away from the interior of the fixing device when the entrance guide moves from the guide position to the path formation position, and

wherein the flow path directs the outside air

vertically upward across the plurality of ribs in an area on the first side of the gap,

horizontally from an area downstream of the plurality of ribs in the flow path on the first side of the gap to an area on the second side of the gap, and

to the at least one image developing or optical device or component.

17. The image forming apparatus according to claim 16 , wherein the entrance guide includes a surface coated with a fluorinated resin and integrally formed with the exterior part of the fixing device.