# US 5,999,767 A · Image forming apparatus for forming a plurality of page images formed on one side of sheet on both sides of sheet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,999,767 A - Document ID: US5999767A - Status: Granted - Kind: A - Application number: 08/979,367 - Filed: 1997-11-26 - Granted: 1999-12-07 - Earliest claimed: 1995-03-28 - Assignees: Canon Kabushiki Kaisha - Inventors: Eiichi Ando - Web page: https://patentgrep.com/patent/US5999767A ## CPC - G03G 15/6544: {Details about the binding means or procedure} - G03G 15/50: {Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control (sequencing control G03G21/14)} - H04N 1/3873: {defined only by a limited number of coordinate points or parameters, e.g. corners, centre; for trimming} - G03G 2215/00582: Plural adjacent images on one side - G03G 2215/00586: duplex mode - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image forming apparatus including an image forming unit for forming images of two pages on one side of a sheet and forming images of other two pages on the other side of the sheet, a storage unit for storing an image to be formed by the image forming unit, and a control unit for controlling to store images in the storage unit in a first mode of fastening or to fasten the longer side of the sheet so as to locate an image of a (4N-1)-th page at the back side of an image of a (4N-3)-th page and locate an image of a 4N-th page at the back side of an image of a (4N-2)-th page, and in a second mode of fastening or to fasten the shorter side of the sheet so as to locate an image of a 4N-th page at the back side of an image of a (4N-3)-th page and locate an image of a (4N-1)-th page at the back side of an image of a (4N-2)-th page, wherein the image forming unit forms the images in the storage unit located by the control unit, on the sheet. ## Claims ### Claim 1 An image forming apparatus comprising: image forming means for forming images of four pages on the front side of a sheet, images of(8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in a first mode of fastening or to fasten the longer side of the sheet and in the case of a portrait image or in a second mode of fastening or to fasten the shorter side of the sheet and in the case of a landscape image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of(8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in said first mode and in the case of a landscape image or in said second mode and in the case of a portrait image, so as to locate images of(8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 2 (depends on 1) An image forming apparatus according to claim 1, further comprising: reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 3 (depends on 1) An image forming apparatus according to claim 1, further comprising: fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 4 (depends on 3) An image forming apparatus according to claim 3, wherein said fastening means is a stapler. ### Claim 5 (depends on 1) An image forming apparatus according to claim 1, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 6 (depends on 1) An image forming apparatus according to claim 1, wherein the image is an image written horizontally. ### Claim 7 An image forming apparatus comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in a first mode of fastening or to fasten the longer side of the sheet and in the case of a portrait image or in a second mode of fastening or to fasten the shorter side of the sheet and in the case of a landscape image, so as to locate images of(8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of(8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in said first mode and in the case of a landscape image or in said second mode and in the case of a portrait image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 8 (depends on 7) An image forming apparatus according to claim 7, further comprising: reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 9 (depends on 7) An image forming apparatus according to claim 7, further comprising: fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 10 (depends on 9) An image forming apparatus according to claim 9, wherein said fastening means is a stapler. ### Claim 11 (depends on 7) An image forming apparatus according to claim 7, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 12 (depends on 7) An image forming apparatus according to claim 7, wherein the image is an image written horizontally. ### Claim 13 An image forming apparatus for forming a portrait image, comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in a first mode of fastening or to fasten the longer side of the sheet, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in a second mode of fastening or to faster the shorter side of the sheet, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 14 (depends on 13) An image forming apparatus according to claim 13, further comprising reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 15 (depends on 13) An image forming apparatus according to claim 13, further comprising fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 16 (depends on 15) An image forming apparatus according to claim 15, wherein said fastening means is a stapler. ### Claim 17 (depends on 13) An image forming apparatus according to claim 13, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 18 (depends on 13) An image forming apparatus according to claim 13, wherein the image is an image written horizontally. ### Claim 19 An image forming apparatus for forming a portrait image, comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in a first mode of fastening or to fasten the longer side of the sheet, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in a second mode of fastening or to fasten the shorter side of the sheet, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of(8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 20 (depends on 19) An image forming apparatus according to claim 19, further comprising reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 21 (depends on 19) An image forming apparatus according to claim 19, further comprising fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 22 (depends on 21) An image forming apparatus according to claim 21, wherein said fastening means is a stapler. ### Claim 23 (depends on 19) An image forming apparatus according to claim 19, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 24 (depends on 19) An image forming apparatus according to claim 19, wherein the image is an image written horizontally. ### Claim 25 An image forming apparatus for forming a landscape image, comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in a second mode of fastening or to fasten the shorter side of the sheet, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in a first mode of fastening or to fasten the longer side of the sheet, so as to locate images of(8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 26 (depends on 25) An image forming apparatus according to claim 25, further comprising reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 27 (depends on 25) An image forming apparatus according to claim 25, further comprising fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 28 (depends on 27) An image forming apparatus according to claim 27, wherein said fastening means is a stapler. ### Claim 29 (depends on 25) An image forming apparatus according to claim 25, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 30 (depends on 25) An image forming apparatus according to claim 25, wherein the image is an image written horizontally. ### Claim 31 An image forming apparatus for forming a landscape image, comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in a second mode of fastening or to fasten the shorter side of the sheet, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in a first mode of fastening or to fasten the longer side of the sheet so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 32 (depends on 31) An image forming apparatus according to claim 31, further comprising reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 33 (depends on 31) An image forming apparatus according to claim 31, further comprising fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 34 (depends on 33) An image forming apparatus according to claim 33, wherein said fastening means is a stapler. ### Claim 35 (depends on 31) An image forming apparatus according to claim 31, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 36 (depends on 31) An image forming apparatus according to claim 31, wherein the image is an image written horizontally. ### Claim 37 An image forming apparatus for performing transportation from a long edge of a sheet as a leading edge, comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in the case of a portrait image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in the case of a landscape image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 38 (depends on 37) An image forming apparatus according to claim 37, further comprising reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 39 (depends on 37) An image forming apparatus according to claim 37, further comprising fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 40 (depends on 39) An image forming apparatus according to claim 39, wherein said fastening means is a stapler. ### Claim 41 (depends on 37) An image forming apparatus according to claim 37, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 42 (depends on 37) An image forming apparatus according to claim 37, wherein the image is an image written horizontally. ### Claim 43 An image forming apparatus for performing transportation from a long edge of a sheet as a leading edge, comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in the case of a portrait image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in the case of a landscape image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 44 (depends on 43) An image forming apparatus according to claim 43, further comprising reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 45 (depends on 43) An image forming apparatus according to claim 43, further comprising fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 46 (depends on 45) An image forming apparatus according to claim 45, wherein said fastening means is a stapler. ### Claim 47 (depends on 43) An image forming apparatus according to claim 43, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 48 (depends on 43) An image forming apparatus according to claim 43, wherein the image is an image written horizontally. ### Claim 49 An image forming apparatus for performing transportation from a short edge of a sheet as a leading edge, comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in the case of a landscape image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in the case of a portrait image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 50 (depends on 49) An image forming apparatus according to claim 49, further comprising reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 51 (depends on 49) An image forming apparatus according to claim 49, further comprising fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 52 (depends on 51) An image forming apparatus according to claim 51, wherein said fastening means is a stapler. ### Claim 53 (depends on 49) An image forming apparatus according to claim 49, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 54 (depends on 49) An image forming apparatus according to claim 49, wherein the image is an image written horizontally. ### Claim 55 An image forming apparatus for performing transportation from a short edge of a sheet as a leading edge, comprising: image forming means for forming images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and forming images of four other pages on the back side of the sheet; storage means for storing an image to be formed by said image forming means; and control means for controlling to store images in said storage means, in the case of a landscape image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in the case of a portrait image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, wherein said image forming means forms the images in said storage means located by said control means, on the sheet. ### Claim 56 (depends on 55) An image forming apparatus according to claim 55, further comprising reading means for reading an original image, wherein said control means stores the original image read by said reading means in said storage means. ### Claim 57 (depends on 55) An image forming apparatus according to claim 55, further comprising fastening means for fastening the back end of the sheet ejected out of said image forming means. ### Claim 58 (depends on 57) An image forming apparatus according to claim 57, wherein said fastening means is a stapler. ### Claim 59 (depends on 55) An image forming apparatus according to claim 55, wherein said control means controls to store images in said storage means in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 60 (depends on 55) An image forming apparatus according to claim 55, wherein the image is an image written horizontally. ### Claim 61 An image forming method comprising the steps of: storing in a storage device an image to be formed by an image forming means, in a first mode of fastening or to fasten a longer side of the sheet and in the case of a portrait image or in a second mode of fastening or to fasten a shorter side of the sheet and in the case of a landscape image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in said first mode and in the case of a landscape image or in said second mode and in the case of a portrait image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 62 (depends on 61) An image forming method according to claim 61, wherein the storing of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 63 An image forming method comprising the steps of: storing in a storage device an image to be formed by an image forming means, in a first mode of fastening or to fasten a longer side of the sheet and in the case of a portrait image or in a second mode of fastening or to fasten a shorter side of the sheet and in the case of a landscape image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in said first mode and in the case of a landscape image or in said second mode and in the case of a portrait image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 64 (depends on 63) An image forming method according to claim 63, wherein the storing of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 65 An image forming method for forming a portrait image, comprising the steps of: storing in a storage device an image to be formed by an image forming means, in a first mode of fastening or to fasten a longer side of the sheet, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in a second mode of fastening or to fasten a shorter side of the sheet, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and forming images of four other pages on the back side of the sheet. ### Claim 66 (depends on 65) An image forming method according to claim 65, wherein the storing of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 67 An image forming method for forming a portrait image, comprising the steps of: storing in a storage device an image to be formed by an image forming means, in a first mode of fastening or to fasten a longer side of the sheet, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in a second mode of fastening or to fasten a shorter side of the sheet, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 68 (depends on 67) An image forming method according to claim 67, wherein the storing of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 69 An image forming method for forming a landscape image, comprising the steps of: storing in a storage device an image to be formed by an image forming means, in a second mode of fastening or to fasten a shorter side of the sheet, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in a first mode of fastening or to fasten a longer side of the sheet, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 70 (depends on 69) An image forming method according to claim 69, wherein the storage of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 71 An image forming method for forming a landscape image, comprising the steps of: storing in a storage device an image to be formed by an image forming means, in a second mode of fastening or to fasten a shorter side of the sheet, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in a first mode of fastening or to fasten a longer side of the sheet, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 72 (depends on 71) An image forming method according to claim 71, wherein the storage of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 73 An image forming method for performing transportation from a long edge of a sheet as a leading edge, comprising the steps of: storing in a storage device an image to be formed by an image forming means, in the case of a portrait image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in the case of a landscape image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 74 (depends on 73) An image forming method according to claim 73, wherein the storage of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 75 An image forming method for performing transportation from a long edge of a sheet as a leading edge, comprising the steps of: storing in a storage device an image to be formed by an image forming means, in the case of a portrait image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in the case of a landscape image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 76 (depends on 75) An image forming method according to claim 75, wherein the storage of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 77 An image forming method for performing transportation from a short edge of a sheet as a leading edge, comprising the steps of: storing in a storage device an image to be formed by an image forming means, in the case of a landscape image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in the case of a portrait image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper right, lower left, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 78 (depends on 77) An image forming method according to claim 77, wherein the storage of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet. ### Claim 79 An image forming method for performing transportation from a short edge of a sheet as a leading edge, comprising the steps of: storing in a storage device an image to be formed by an image forming means, in the case of a landscape image, so as to locate images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages, and in the case of a portrait image, so as to locate images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages; and forming from information in the storage device images of four pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th pages being formed respectively upper left, lower left, upper right, and lower right of the sheet, and images of four other pages on the back side of the sheet. ### Claim 80 (depends on 79) An image forming method according to claim 79, wherein the storage of images in the storage device is in said first mode so as to make the direction of images to be formed on the front side of the sheet be opposite to the direction of images to be formed on the back side of the sheet, and in said second mode so as to make the direction of images to be formed on the front side of the sheet be the same as the direction of images to be formed on the back side of the sheet.