Sheet feeding apparatus having means for determining the leading edge of a sheet

Claim 2

A sheet guiding apparatus, comprising: a guiding path for guiding a sheet; detection means for detecting the presence/absence of the sheet in said guiding path; a power-supply switch for turning on and off a power supply; and control means which determines that the sheet is a rolled sheet if said detection means detects the sheet when said power-supply switch has been turned on, and determines that a leading edge of the sheet has passed if said detection means has detected no sheet when said power-supply switch has been turned on and then said detection means detects the sheet.

Claim 3

An apparatus according to claim 1, further comprising feeding means for feeding the sheet along said guiding path.

Claim 4

An apparatus according to claim 2, wherein said detection means detects presence/absence of the sheet at an upstream side of said feeding means.

Claim 5

An apparatus according to claim 2, wherein said power-supply switch turns on and off a power, supply which serves as an operational source for said feeding means.

Claim 6

An apparatus according to claim 2, further comprising image forming means for forming an image on the sheet fed by said feeding means.

Claim 7

An image forming apparatus, comprising: image forming means for forming an image on a sheet; feeding means for feeding the sheet while pressing the sheet against said image forming means; detection means for detecting whether the sheet is present at a predetermined position at an upstream side of said feeding means; a power-supply switch for turning on and off a power supply; and control means which determines that the sheet is a rolled sheet if said detection means detects the sheet when said power-supply switch has been turned on, and determines that a leading edge of the sheet has passed if said detection means has detected no sheet when said power-supply switch has been turned on and then said detection means detects the sheet, and for controlling said feeding means based on a result of that determination.

Claim 8

An image forming apparatus, comprising: image forming means for forming an image on a sheet; feeding means for feeding the sheet while pressing the sheet against said image forming means; detection means for detecting whether the sheet is present at a predetermined position at an upstream side of said feeding means; a power-supply switch for turning on and off a power supply; and control means which determines that the sheet is a rolled sheet if said detection means detects the sheet when said power-supply switch has been turned on, and determines that a leading edge of the sheet has passed if said detection means has detected no sheet when said power-supply switch has been turned on and then said detection means detects the sheet, and for controlling said feeding means based on a result of that determination.

Claim 9

An image forming apparatus, comprising: image forming means for forming an image on a sheet; feeding means for feeding the sheet while pressing the sheet against said image forming means; detection means for detecting whether the sheet is present at a predetermined position at an upstream side of said feeding means; a power-supply switch for turning on and off a power supply; and control means for determining whether the sheet comprises a rolled sheet or a cut sheet, according as said detection means detects or does not detect the sheet, respectively, when said power-supply switch has been turned on, and for controlling said feeding means based on a result of that determination, wherein said control means controls said feeding means so as to feed the sheet in accordance with whether the sheet comprises a rolled sheet or a cut sheet, after the completion of the image formation.

Claim 10

An image forming apparatus, comprising: image forming means for forming an image on a sheet; feeding means for feeding the sheet while pressing the sheet against said image forming means; detection means for detecting whether the sheet is present at a predetermined position at an upstream side of said feeding means; a power-supply switch for turning on and off a power supply; and control means for determining whether the sheet comprises a rolled sheet or a cut sheet, according as said detection means detects or does not detect the sheet, respectively, when said power-supply switch has been turned on, and for controlling said feeding means based on a result of that determination, wherein said control means controls said feeding means so as to feed the sheet in accordance with whether the sheet comprises a rolled sheet or a cut sheet, after the completion of the image formation.

Claim 11

An apparatus according to claim 7, wherein said control means controls said feeding means to feed the sheet after completion of the image formation by an amount which depends on whether the sheet is a rolled sheet or a cut sheet.

Claim 12

An apparatus according to claim 8, wherein, when the sheet is a cut sheet, said control means controls said feeding means so as to feed the sheet until a trailing edge of the cut sheet passes through said feeding means after completion of the image formation.

Claim 13

An apparatus according to claim 9, wherein, when the sheet is a cut sheet, said control means controls said feeding means so as to feed the sheet until a trailing edge of the cut sheet passes through said feeding means after completion of the image formation based on detection of the trailing edge of the cut sheet by said detection means.

Claim 14

An apparatus according to claim 8, wherein, when the sheet is a rolled sheet, said control means controls said feeding means so as to feed the sheet until a portion of the rolled sheet in which an image is formed is discharged outside a main body of the apparatus after completion of the image formation.

Claim 15

A sheet feeding apparatus, comprising: holding means for holding a rolled sheet; feeding means for feeding the rolled sheet while drawing the sheet from said holding means; a rotating member disposed between said holding means and said feeding means for guiding the sheet in contact therewith only in a vicinity of which includes a central portion in a width direction; and a detachable cover for holding said holding means and said rotating member.

Claim 16

A sheet feeding apparatus, comprising: holding means for holding a rolled sheet; feeding means for feeding the rolled sheet while drawing the sheet from said holding means; a rotating member disposed between said holding means and said feeding means for guiding the sheet in contact therewith only in a vicinity of which includes a central portion in a width direction; and a detachable cover for holding said holding means and said rotating member.

Claim 17

An apparatus according to claim 12, wherein said rotating member has a radius greater at a central portion of said rotating member than at two end portions thereof.

Claim 18

An image forming apparatus comprising: feeding means for feeding a sheet; image forming means for forming an image on the sheet being fed by said feeding means; detection means for detecting whether the sheet is present at a predetermined position at an upstream side of said feeding means; a power-supply switch for turning on and off a power supply; and control means for controlling said feeding means in forming the image on the sheet by said image forming means so that, if said detection means detects the sheet when said power-supply switch has been turned on, said feeding means feeds the sheet forward for formation of the image on the sheet, and if said detection means detected no sheet when said power-supply switch was turned on and then said detection means detects the sheet, said feeding means feeds the sheet until a leading portion of the sheet reaches said image forming means, and then feeds the sheet forward to form the image on the sheet.

Claim 19

An image forming apparatus comprising: feeding means for feeding a sheet; image forming means for forming an image on the sheet being fed by said feeding means; detection means for detecting whether the sheet is present at a predetermined position at an upstream side of said feeding means; a power-supply switch for turning on and off a power supply; and control means for controlling said feeding means in forming the image on the sheet by said image forming means so that, if said detection means detects the sheet when said power-supply switch has been turned on, said feeding means feeds the sheet forward for formation of the image on the sheet, and if said detection means detected no sheet when said power-supply switch was turned on and then said detection means detects the sheet, said feeding means feeds the sheet until a leading portion of the sheet reaches said image forming means, and then feeds the sheet forward to form the image on the sheet.

Claim 20

An apparatus according to claim 14, wherein said control means controls said feeding means so as to feed the sheet until a part on which the image is formed, is fed out of a main body of the apparatus, if said detection means detects the sheet when the power supply switch is turned on.

Claim 21

An apparatus according to claim 14, wherein said control means controls said feeding means so as to feed the sheet until a trailing end of the sheet passes out of said feeding means after completion of image forming if said detection means detected no sheet when said power-supply switch was turned on and then the detection means detects the sheet.

Claim 22

An image forming apparatus comprising: feeding means for feeding a sheet; image forming means for forming an image on the sheet being fed by said feeding means; detection means for detecting whether the sheet is present at a predetermined position at an upstream side of said feeding means; a power-supply switch for turning on and off a power supply; and control means for controlling said feeding means so that after completion of image forming, if said detecting means detected the sheet when said power-supply switch was turned on, said feeding means feeds the sheet until a part on which the image has been formed is fed out of a main body of the apparatus, and if said detection means detected no sheet when said power-supply switch was turned on and then said detection means detects the sheet, said feeding means feeds the sheet until a trailing end of the sheet passes out of said feeding means.

Claim 23

An image forming apparatus comprising: feeding means for feeding a sheet; image forming means for forming an image on the sheet being fed by said feeding means; detection means for detecting whether the sheet is present at a predetermined position at an upstream side of said feeding means; a power-supply switch for turning on and off a power supply; and control means for controlling said feeding means so that after completion of image forming, if said detecting means detected the sheet when said power-supply switch was turned on, said feeding means feeds the sheet until a part on which the image has been formed is fed out of a main body of the apparatus, and if said detection means detected no sheet when said power-supply switch was turned on and then said detection means detects the sheet, said feeding means feeds the sheet until a trailing end of the sheet passes out of said feeding means.

Claim 24

A recording apparatus comprising: recording means for recording an image on a sheet based on received image data; a reflection type photosensor provided at a sheet feeding path; memory means for storing the received image data; a reflecting surface provided at a position facing said reflection type photosensor across the sheet feeding path; wherein a reflectivity of said reflecting surface is made to be such that a relationship among an output current I W of said reflection type photosensor for a white portion of a sheet, an output current I B of said reflection type photosensor for an end mark of the sheet, and an output current I R of said reflection type photosensor for said reflecting surface is I B 21 I R <I W , and control means for controlling said recording means so that said recording means records an image on a sheet based on received image data when output current produced by said reflection type photosensor is I W , and when output current produced by said reflection type photosensor changes from I W to I B during a recording operation, recording is continued until the end of a current page, and then received image data is directly stored in said memory means, and when output current produced by said reflection type photosensor is I R , received image data is directly stored in said memory means.

Claim 25

A recording apparatus comprising: recording means for recording an image on a sheet based on received image data; a reflection type photosensor provided at a sheet feeding path; memory means for storing the received image data; a reflecting surface provided at a position facing said reflection type photosensor across the sheet feeding path; wherein a reflectivity of said reflecting surface is made to be such that a relationship among an output current I W of said reflection type photosensor for a white portion of a sheet, an output current I B of said reflection type photosensor for an end mark of the sheet, and an output current I R of said reflection type photosensor for said reflecting surface is I B 21 I R <I W , and control means for controlling said recording means so that said recording means records an image on a sheet based on received image data when output current produced by said reflection type photosensor is I W , and when output current produced by said reflection type photosensor changes from I W to I B during a recording operation, recording is continued until the end of a current page, and then received image data is directly stored in said memory means, and when output current produced by said reflection type photosensor is I R , received image data is directly stored in said memory means.