SHEET FEEDING APPARATUS AND IMAGE FORMING APPARATUS

Abstract

A sheet feeding apparatus has: a tray on which sheets to be fed are stacked; a sheet feeding portion which separates and feeds the sheets stacked on the tray one by one; and a sensor which discriminates a type of sheet. In a state in which one sheet of the sheets stacked on the tray is protruded from the tray by the sheet feeding portion, the sensor discriminates the type of the protruded sheet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional explanatory diagram illustrating a whole image forming apparatus.

FIG. 2 is a perspective explanatory diagram of a sheet feeding apparatus.

FIG. 3 is a perspective explanatory diagram of the sheet feeding apparatus in the case where a side regulating member has been moved.

FIG. 4 is a cross sectional explanatory diagram of the sheet feeding apparatus.

FIG. 5 is a constructional explanatory diagram of a sheet detecting sensor.

FIG. 6 is a constructional explanatory diagram of the sheet detecting sensor.

FIG. 7 is a constructional explanatory diagram of the sheet detecting sensor having a dust proofing member.

FIG. 8 is a constructional explanatory diagram of the sheet detecting sensor having the dust proofing member.

Claims

1. A sheet feeding apparatus comprising: a tray on which sheets to be fed are stacked;a sheet feeding portion which separates and feeds the sheets stacked on the tray one by one; anda sensor which discriminates a type of sheet,wherein in a state in which one sheet of the sheets stacked on the tray is protruded from the tray by the sheet feeding portion, the sensor discriminates the type of the protruded sheet.

2. An apparatus according to claim 1, further comprising a regulating member which is movable in a width direction which crosses a feeding direction of the sheets stacked on the tray and regulates a position of an edge portion of each of the sheets stacked on the tray in a width direction which crosses a feeding direction of the sheet, wherein the sensor is provided on the regulating member.

3. An apparatus according to claim 2, further comprising an extending portion which is provided for the regulating member and extends to a downstream side of the sheet feeding portion, wherein the sensor is provided for the extending portion.

4. An apparatus according to claim 1, wherein the sensor is a transmissive photosensor.

5. An apparatus according to claim 1, wherein the sensor has: a light emitting portion which emits light; anda photosensing portion which receives the light that has been emitted by the light emitting portion and has transmitted the sheet fed by the sheet feeding portion,and the sensor is a sensor in which the light emitting portion and the photosensing portion are integrated.

6. An apparatus according to claim 5, further comprising: a regulating member which is movable in a width direction which crosses a feeding direction of the sheets stacked on the tray and regulates a position of an edge portion of each of the sheets stacked on the tray in a width direction which crosses a feeding direction of the sheet; anda guiding portion, formed in the regulating member, which guides the sheet fed by the sheet feeding portion to a position between the light emitting portion and the photosensing portion.

7. An apparatus according to claim 1, further comprising a dust proofing member which prevents a foreign substance from being deposited onto a sensor surface of the sensor.

8. An apparatus according to claim 1, further comprising a regulating member which is movable in a width direction which crosses a feeding direction of the sheets stacked on the tray and regulates a position of an edge portion of each of the sheets stacked on the tray in a width direction which crosses a feeding direction of the sheet, wherein the regulating member has an extending portion extends to a downstream side of the sheet feeding portion,the sensor is provided for the extending portion, andthe sensor has a light emitting portion which emits light and a photosensing portion which receives the light that has been emitted by the light emitting portion and has transmitted the sheet fed by the sheet feeding portion, and the light emitting portion and the photosensing portion are integrated.

9. An image forming apparatus comprising: the sheet feeding apparatus according to claim 1; andan image forming portion which forms an image onto the fed sheet.

10. An apparatus according to claim 8, wherein the image forming portion forms the image according to the sheet type determined based on an output of the sensor.