CA2043665C - Copying machine - Google Patents
Copying machineInfo
- Publication number
- CA2043665C CA2043665C CA002043665A CA2043665A CA2043665C CA 2043665 C CA2043665 C CA 2043665C CA 002043665 A CA002043665 A CA 002043665A CA 2043665 A CA2043665 A CA 2043665A CA 2043665 C CA2043665 C CA 2043665C
- Authority
- CA
- Canada
- Prior art keywords
- sheet
- copying
- sheets
- roller
- separating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H3/00—Separating articles from piles
- B65H3/46—Supplementary devices or measures to assist separation or prevent double feed
- B65H3/52—Friction retainers acting on under or rear side of article being separated
- B65H3/5207—Non-driven retainers, e.g. movable retainers being moved by the motion of the article
- B65H3/5215—Non-driven retainers, e.g. movable retainers being moved by the motion of the article the retainers positioned under articles separated from the top of the pile
- B65H3/5223—Retainers of the pad-type, e.g. friction pads
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H7/00—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles
- B65H7/02—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
- G03G15/32—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which the charge pattern is formed dotwise, e.g. by a thermal head
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/65—Apparatus which relate to the handling of copy material
- G03G15/6502—Supplying of sheet copy material; Cassettes therefor
- G03G15/6511—Feeding devices for picking up or separation of copy sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2511/00—Dimensions; Position; Numbers; Identification; Occurrences
- B65H2511/20—Location in space
- B65H2511/21—Angle
- B65H2511/212—Rotary position
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2511/00—Dimensions; Position; Numbers; Identification; Occurrences
- B65H2511/50—Occurence
- B65H2511/51—Presence
- B65H2511/514—Particular portion of element
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2513/00—Dynamic entities; Timing aspects
- B65H2513/50—Timing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2513/00—Dynamic entities; Timing aspects
- B65H2513/50—Timing
- B65H2513/51—Sequence of process
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2553/00—Sensing or detecting means
- B65H2553/60—Details of intermediate means between the sensing means and the element to be sensed
- B65H2553/61—Mechanical means, e.g. contact arms
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2701/00—Handled material; Storage means
- B65H2701/10—Handled articles or webs
- B65H2701/13—Parts concerned of the handled material
- B65H2701/131—Edges
- B65H2701/1311—Edges leading edge
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G2215/00—Apparatus for electrophotographic processes
- G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
- G03G2215/00367—The feeding path segment where particular handling of the copy medium occurs, segments being adjacent and non-overlapping. Each segment is identified by the most downstream point in the segment, so that for instance the segment labelled "Fixing device" is referring to the path between the "Transfer device" and the "Fixing device"
- G03G2215/004—Separation device
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G2215/00—Apparatus for electrophotographic processes
- G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
- G03G2215/00367—The feeding path segment where particular handling of the copy medium occurs, segments being adjacent and non-overlapping. Each segment is identified by the most downstream point in the segment, so that for instance the segment labelled "Fixing device" is referring to the path between the "Transfer device" and the "Fixing device"
- G03G2215/00405—Registration device
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G2215/00—Apparatus for electrophotographic processes
- G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
- G03G2215/00535—Stable handling of copy medium
- G03G2215/00556—Control of copy medium feeding
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Sheets, Magazines, And Separation Thereof (AREA)
- Paper Feeding For Electrophotography (AREA)
- Controlling Sheets Or Webs (AREA)
Abstract
A copying machine wherein sheets stacked in a sheet cassette are conveyed one by one to a sheet copying portion to take copies. Between a sheet supply portion and the copying portion there is disposed a sheet separating mechanism for separating plural sheets when taken out at a time from the sheet supply portion. Further, between the said sheet separating mechanism and the sheet copying portion there is disposed a sheet position detecting measure.
Plural sheets delivered from the sheet supply portion are separated one by one by the sheet separating mechanism, then after taking synchronism with the copying portion through the sheet position detecting measure, each sheet is conveyed, so copying can be done accurately.
Plural sheets delivered from the sheet supply portion are separated one by one by the sheet separating mechanism, then after taking synchronism with the copying portion through the sheet position detecting measure, each sheet is conveyed, so copying can be done accurately.
Description
-7 ~
COPYING MACHINE
The present invention relates to a copying machine wherein sheets stacked in a sheet cassette are conveyed one by one to a sheet copying portion and copies therein.
The prior art will be discussed in detail hereinbelow with respect to the drawings.
The present invention has been accomplished for solving the problems of the prior art and it is an object thereof to provide a copying machine capable of separating and delivering only the sheet to be fed and copying sheets accurately one by one even in the event of feed of plural sheets at a time.
It is another object of the present invention to provide a copying machine capable of separating and delivering only the sheet to be fed and copying sheets accurately one by one even in the event of feed of plural sheets at a time, by a simple and inexpensive means without using a complicated and expensive apparatus.
It is a further object of the present invention to provide a copying machine which is far superior to the conventional copying machines in point of sheet separating accuracy and performance in feeding paper and can be'realized at a relatively low cost.
In the copying machine of the present invention, in order to achieve the above-mentioned objects, a sheet separating mechanism for separating plural sheets when taken out from a sheet supply portion is provided between the sheet supply portion and a copying portion, and a sheet position detecting means is provided between the sheet separating mechanism and the sheet copying portion.
Thus, in the copying machine of the present invention, in the event of feed of plural sheets at a time in the sheet supply portion, the sheets are separated one by one in the sheet separating mechanism and the position of each sheet thus separated is detected to take synchronism with the sheet copying stage.
In accordance with one aspect of the present invention there is provided a copying machine comprising: a sheet separating mechanism including a roller adapted to rotate to feed a sheet in a forward direction, a separating piece having a predetermined frictional force and adapted to hold the sheet between said separating piece and said roller, a pressing piece for pressing said separating piece toward said roller; a sheet guide means comprising a low friction member, 3 ~
disposed on an upstream side in a sheet conveyance direction from a sheet supply portion to a sheet copying portion with respect to a contact portion of said roller on the surface of said separating piece; and a sheet position detecting means disposed between said sheet separating mechanism and said sheet copying portion, said sheet supply portion taking out stacked sheets, said sheet copying portion copying to such sheets, wherein said sheet separating mechanism separates only a sheet which is in close contact with said roller from other sheets when a plurality of sheets are taken out between said sheet supply portion and said sheet copying portion from said sheet supply portion.
The above and further objects and novel features of the present invention will more fully appear from the following detailed description when read in connection with the accompanying drawings, in which:
Fig. 1 is a schematic sectional view of a body of a conventional copying machine;
Fig. 2 is a schematic sectional view of a copying machine according to an embodiment of the present nvent lon;
- 2a -2 ~ 4 Fig. 3 is a partial enlarged view of a separating mechanism disposed in the copying machine body shown in Fig. 2; and Fig. 4 is a schematic sectional view of a body of a copying machine according to another embodiment of the present invention.
Fig. 1 is a sectional view showing a conventional paper feeder disclosed, for example, in Japanese Patent Publication No. 52378/88~ In the same figure, the reference numeral 1 denotes a photosensitive drum for copying; the numeral 2 denotes a sheet; numeral 3 denotes a sheet cassette; numeral 4 denotes an inner plate on which are stacked sheets 2 in the sheet cassette 3;
numeral 5 denotes a spring for pushing the inner plate 4 upwards; numeral 6 denotes a sheet separating pawl for separating the sheets 2; numeral 7 denotes a pickup roller for conveying the sheets 2; numerals 8a and 8b denote register rollers; numerals 9a and 9b denote fixed guide plates for guiding each sheet 2 to the register rollers 8a and 8b; numeral 10 denotes a movable guide plate for guiding each sheet 2 to the register rollers 8a and 8b; numerals lla and llb denote guide plates for guiding each sheet 2 to the photosensitive drum 1;
numeral 12 denotes a corona discharger; numeral 13 :
denotes a separating belt provided at an end portion of the photosensitive drum l; numeral 14 denotes a separating roller; numeral 15 denotes a separating roller which is in pressure contact with the separating roller 14; numeral 16 denotes a fixing device; and numeral 17 denotes a conveyor belt for conveying each sheet 2 to the fixing device 16.
The operation will now be described. The sheets 2 which are each conveyed in synchronism with an image on the photosensitive drum 1 are stacked on the inner plate 4 in the sheet cassette 3. The inner plate 4 is pushed upwards by the spring 5 and the height of the stacked sheets 2 is kept constant by the sheet separating pawl 6.
In this position the sheets 2 are delivered one by one from the sheet cassette 3 and conveyed by a predetermined length with rotation of the pickup roller 7 having a sectional shape corresponding to a partially cut-out circumference. Each sheet 2 thus delivered is guided by the fixed guide plates 9a, 9b and the movable guide plate 10 and reaches the register rollers 8a, 8b, then is further guided by the guide plates lla, llb and reaches the photosensitive drum 1.
At an end portion of the photosensitive drum 1 there is provided the separating belt 13, and one end of the sheet 2, in a separated state from the photosensitive h drum 1, is supplied with potential by the discharge from the corona discharger 12. A toner image on the drum 1 is here transferred onto the sheet 2. After completion of the transfer, the ~ront end of the sheet 2 is separated from the drum 1 by the separating belt 13 and is held between the separating roller 14 and the separating roller 15 which is in pressure contact with the roller 14. In this way the front end of the sheet 2 is completely separated from the photosensitive drum 1.
Subsequently, the sheet is conveyed to the fixing device 16 by the conveyor belt 17.
The conventional copying machine is constructed as above, so in the event of feed of plural sheets at a time, the plural sheets are conveyed in a stacked state.
Consequently, the conveyance of sheet and the copying operation may not be synchronized with each other, or there may arise deterioration of the image ~uality due to paper jam or defective transfer.
Preferred embodiments of the present invention will be described in detail hereinunder with reference to the accompanying drawings. The portions indicated by the same reference numerals as those referred to above in connection with Fig. l represent the same portions, so explanation will be omitted with respect to some of them.
.._ 20~3665 In Fig. 2, the reference numeral 18 denotes a roller provided between a pickup roller 7 and register rollers 8a, 8b and adapted to rotate in the direction of arrow A; numeral 19 denotes a separating piece made of rubber for example, numeral 20 denotes a pressing piece made of a spring material for example to press the separating piece 19 to the roller 18; numeral 21 denotes a separating mechanism constituted by the roller 18, separating piece 19 and pressing piece 20;
numerals 22a and 22b denote guide plates for guiding sheets 2 to the separating mechanism 21; numerals 23 denotes guide plate for guiding each sheet 2 to the register rollers 8a and 8b; and numeral 24 denotes a sensor for detecting a front end position of each sheet 2.
Referring to Fig. 3, which is a partial enlarged view of the separating mechanism shown in Fig. 2, the same members as in Fig. 2 are indicated by the same reference numerals. In Fig. 3, numeral 25 denotes a top sheet to be fed; numeral 26 represent the second and following sheets fed plurally; arrow B represents an urging force created by the pressing piece 20; Nl represents a frictional force created between the roller 18 and the sheet 25; N2 represents a frictional force created between the sheets 25 and 26; N3 represents a frictional force created between the sheets 26 and the separating piece 19.
Next, operation of the paper feeder constructed as above will now be described. The sheets 2 are stacked in a sheet cassette, and with rotation of the pickup roller 7, the sheets are delivered one by one from the sheet cassette 3 and conveyed a predetermined length. Each sheet 2 thus delivered is guided by the guide plates 22a and 22b and reaches the separating mechanism 21. In the event of feed of plural sheets at a time, the top sheet 25 is conveyed by the roller 18 which is rotating in the direction of arrow A, under the frictional force N1, rotatively together with the roller 18, while the conveyance of the second and following sheets 26 is prevented by the frictional force N3 which is larger than the frictional force N2, but smaller than N1, whereby the sheets which have been fed plurally are separated one by one and then conveyed. The sheet 25 thus delivered is detected its front end position by the sensor 24 to take synchronism with an image on the photosensitive drum 1. The sheet 2 which has passed the sensor 24 is guided by the guide plate 23 and the movable guide plate 10 and reaches the register rollers 8a and 8b, then is further guided by guide plates lla and llb and reaches the photosensitive drum 1. The operations which follow are the same as in the prior art.
In the above embodiment, at a certain mounting angle of the separating piece 19, the sheet 2 when entering the separating mechanism 21 buckles due to the frictional force of the separating piece and causes 20436~
paper jam, so it is difficult to adjust the mounting angle of the separating piece 19. For solving this problem, in the embodiment illustrated in Fig. 4, the separating piece 19 is covered with a sheet 27 of a low friction material up to a position near the separating portion. Consequently, even without adjusting the mounting angle of the separating piece 19, or even when the sheet 2 is of weak stiffness, the sheet does not buckle when entering the separating mechanism 21, the assembling work efficiency is high, and there can be attained the same effects as in the previous embodiment.
Although in the above embodiments the sensor 24 is provided between the separating mechanism 21 and the register rollers 8a, 8b, even the provision thereof between the register rollers 8a, 8b and the photo-sensitive drum 1 can afford the same effects as in the above embodiments.
According to the present invention, as set forth above, since the sheet separating mechanism is provided between the sheet supply portion and the sheet copying portion, only the sheet to be fed can be separated and delivered even in the event of feed of plural sheets of paper at time. Besides, since the sheet position detecting means is provided between the sheet separating mechanism and the sheet copying portion, it is possible to make copying accurately.
COPYING MACHINE
The present invention relates to a copying machine wherein sheets stacked in a sheet cassette are conveyed one by one to a sheet copying portion and copies therein.
The prior art will be discussed in detail hereinbelow with respect to the drawings.
The present invention has been accomplished for solving the problems of the prior art and it is an object thereof to provide a copying machine capable of separating and delivering only the sheet to be fed and copying sheets accurately one by one even in the event of feed of plural sheets at a time.
It is another object of the present invention to provide a copying machine capable of separating and delivering only the sheet to be fed and copying sheets accurately one by one even in the event of feed of plural sheets at a time, by a simple and inexpensive means without using a complicated and expensive apparatus.
It is a further object of the present invention to provide a copying machine which is far superior to the conventional copying machines in point of sheet separating accuracy and performance in feeding paper and can be'realized at a relatively low cost.
In the copying machine of the present invention, in order to achieve the above-mentioned objects, a sheet separating mechanism for separating plural sheets when taken out from a sheet supply portion is provided between the sheet supply portion and a copying portion, and a sheet position detecting means is provided between the sheet separating mechanism and the sheet copying portion.
Thus, in the copying machine of the present invention, in the event of feed of plural sheets at a time in the sheet supply portion, the sheets are separated one by one in the sheet separating mechanism and the position of each sheet thus separated is detected to take synchronism with the sheet copying stage.
In accordance with one aspect of the present invention there is provided a copying machine comprising: a sheet separating mechanism including a roller adapted to rotate to feed a sheet in a forward direction, a separating piece having a predetermined frictional force and adapted to hold the sheet between said separating piece and said roller, a pressing piece for pressing said separating piece toward said roller; a sheet guide means comprising a low friction member, 3 ~
disposed on an upstream side in a sheet conveyance direction from a sheet supply portion to a sheet copying portion with respect to a contact portion of said roller on the surface of said separating piece; and a sheet position detecting means disposed between said sheet separating mechanism and said sheet copying portion, said sheet supply portion taking out stacked sheets, said sheet copying portion copying to such sheets, wherein said sheet separating mechanism separates only a sheet which is in close contact with said roller from other sheets when a plurality of sheets are taken out between said sheet supply portion and said sheet copying portion from said sheet supply portion.
The above and further objects and novel features of the present invention will more fully appear from the following detailed description when read in connection with the accompanying drawings, in which:
Fig. 1 is a schematic sectional view of a body of a conventional copying machine;
Fig. 2 is a schematic sectional view of a copying machine according to an embodiment of the present nvent lon;
- 2a -2 ~ 4 Fig. 3 is a partial enlarged view of a separating mechanism disposed in the copying machine body shown in Fig. 2; and Fig. 4 is a schematic sectional view of a body of a copying machine according to another embodiment of the present invention.
Fig. 1 is a sectional view showing a conventional paper feeder disclosed, for example, in Japanese Patent Publication No. 52378/88~ In the same figure, the reference numeral 1 denotes a photosensitive drum for copying; the numeral 2 denotes a sheet; numeral 3 denotes a sheet cassette; numeral 4 denotes an inner plate on which are stacked sheets 2 in the sheet cassette 3;
numeral 5 denotes a spring for pushing the inner plate 4 upwards; numeral 6 denotes a sheet separating pawl for separating the sheets 2; numeral 7 denotes a pickup roller for conveying the sheets 2; numerals 8a and 8b denote register rollers; numerals 9a and 9b denote fixed guide plates for guiding each sheet 2 to the register rollers 8a and 8b; numeral 10 denotes a movable guide plate for guiding each sheet 2 to the register rollers 8a and 8b; numerals lla and llb denote guide plates for guiding each sheet 2 to the photosensitive drum 1;
numeral 12 denotes a corona discharger; numeral 13 :
denotes a separating belt provided at an end portion of the photosensitive drum l; numeral 14 denotes a separating roller; numeral 15 denotes a separating roller which is in pressure contact with the separating roller 14; numeral 16 denotes a fixing device; and numeral 17 denotes a conveyor belt for conveying each sheet 2 to the fixing device 16.
The operation will now be described. The sheets 2 which are each conveyed in synchronism with an image on the photosensitive drum 1 are stacked on the inner plate 4 in the sheet cassette 3. The inner plate 4 is pushed upwards by the spring 5 and the height of the stacked sheets 2 is kept constant by the sheet separating pawl 6.
In this position the sheets 2 are delivered one by one from the sheet cassette 3 and conveyed by a predetermined length with rotation of the pickup roller 7 having a sectional shape corresponding to a partially cut-out circumference. Each sheet 2 thus delivered is guided by the fixed guide plates 9a, 9b and the movable guide plate 10 and reaches the register rollers 8a, 8b, then is further guided by the guide plates lla, llb and reaches the photosensitive drum 1.
At an end portion of the photosensitive drum 1 there is provided the separating belt 13, and one end of the sheet 2, in a separated state from the photosensitive h drum 1, is supplied with potential by the discharge from the corona discharger 12. A toner image on the drum 1 is here transferred onto the sheet 2. After completion of the transfer, the ~ront end of the sheet 2 is separated from the drum 1 by the separating belt 13 and is held between the separating roller 14 and the separating roller 15 which is in pressure contact with the roller 14. In this way the front end of the sheet 2 is completely separated from the photosensitive drum 1.
Subsequently, the sheet is conveyed to the fixing device 16 by the conveyor belt 17.
The conventional copying machine is constructed as above, so in the event of feed of plural sheets at a time, the plural sheets are conveyed in a stacked state.
Consequently, the conveyance of sheet and the copying operation may not be synchronized with each other, or there may arise deterioration of the image ~uality due to paper jam or defective transfer.
Preferred embodiments of the present invention will be described in detail hereinunder with reference to the accompanying drawings. The portions indicated by the same reference numerals as those referred to above in connection with Fig. l represent the same portions, so explanation will be omitted with respect to some of them.
.._ 20~3665 In Fig. 2, the reference numeral 18 denotes a roller provided between a pickup roller 7 and register rollers 8a, 8b and adapted to rotate in the direction of arrow A; numeral 19 denotes a separating piece made of rubber for example, numeral 20 denotes a pressing piece made of a spring material for example to press the separating piece 19 to the roller 18; numeral 21 denotes a separating mechanism constituted by the roller 18, separating piece 19 and pressing piece 20;
numerals 22a and 22b denote guide plates for guiding sheets 2 to the separating mechanism 21; numerals 23 denotes guide plate for guiding each sheet 2 to the register rollers 8a and 8b; and numeral 24 denotes a sensor for detecting a front end position of each sheet 2.
Referring to Fig. 3, which is a partial enlarged view of the separating mechanism shown in Fig. 2, the same members as in Fig. 2 are indicated by the same reference numerals. In Fig. 3, numeral 25 denotes a top sheet to be fed; numeral 26 represent the second and following sheets fed plurally; arrow B represents an urging force created by the pressing piece 20; Nl represents a frictional force created between the roller 18 and the sheet 25; N2 represents a frictional force created between the sheets 25 and 26; N3 represents a frictional force created between the sheets 26 and the separating piece 19.
Next, operation of the paper feeder constructed as above will now be described. The sheets 2 are stacked in a sheet cassette, and with rotation of the pickup roller 7, the sheets are delivered one by one from the sheet cassette 3 and conveyed a predetermined length. Each sheet 2 thus delivered is guided by the guide plates 22a and 22b and reaches the separating mechanism 21. In the event of feed of plural sheets at a time, the top sheet 25 is conveyed by the roller 18 which is rotating in the direction of arrow A, under the frictional force N1, rotatively together with the roller 18, while the conveyance of the second and following sheets 26 is prevented by the frictional force N3 which is larger than the frictional force N2, but smaller than N1, whereby the sheets which have been fed plurally are separated one by one and then conveyed. The sheet 25 thus delivered is detected its front end position by the sensor 24 to take synchronism with an image on the photosensitive drum 1. The sheet 2 which has passed the sensor 24 is guided by the guide plate 23 and the movable guide plate 10 and reaches the register rollers 8a and 8b, then is further guided by guide plates lla and llb and reaches the photosensitive drum 1. The operations which follow are the same as in the prior art.
In the above embodiment, at a certain mounting angle of the separating piece 19, the sheet 2 when entering the separating mechanism 21 buckles due to the frictional force of the separating piece and causes 20436~
paper jam, so it is difficult to adjust the mounting angle of the separating piece 19. For solving this problem, in the embodiment illustrated in Fig. 4, the separating piece 19 is covered with a sheet 27 of a low friction material up to a position near the separating portion. Consequently, even without adjusting the mounting angle of the separating piece 19, or even when the sheet 2 is of weak stiffness, the sheet does not buckle when entering the separating mechanism 21, the assembling work efficiency is high, and there can be attained the same effects as in the previous embodiment.
Although in the above embodiments the sensor 24 is provided between the separating mechanism 21 and the register rollers 8a, 8b, even the provision thereof between the register rollers 8a, 8b and the photo-sensitive drum 1 can afford the same effects as in the above embodiments.
According to the present invention, as set forth above, since the sheet separating mechanism is provided between the sheet supply portion and the sheet copying portion, only the sheet to be fed can be separated and delivered even in the event of feed of plural sheets of paper at time. Besides, since the sheet position detecting means is provided between the sheet separating mechanism and the sheet copying portion, it is possible to make copying accurately.
Claims (3)
1. A copying machine comprising:
a sheet separating mechanism including a roller adapted to rotate to feed a sheet in a forward direction, a separating piece having a predetermined frictional force and adapted to hold the sheet between said separating piece and said roller, a pressing piece for pressing said separating piece toward said roller;
a sheet guide means comprising a low friction member, disposed on an upstream side in a sheet conveyance direction from a sheet supply portion to a sheet copying portion with respect to a contact portion of said roller on the surface of said separating piece;
and a sheet position detecting means disposed between said sheet separating mechanism and said sheet copying portion, said sheet supply portion taking out stacked sheets, said sheet copying portion copying to such sheets, wherein said sheet separating mechanism separates only a sheet which is in close contact with said roller from other sheets when a plurality of sheets are taken out between said sheet supply portion and said sheet copying portion from said sheet supply portion.
a sheet separating mechanism including a roller adapted to rotate to feed a sheet in a forward direction, a separating piece having a predetermined frictional force and adapted to hold the sheet between said separating piece and said roller, a pressing piece for pressing said separating piece toward said roller;
a sheet guide means comprising a low friction member, disposed on an upstream side in a sheet conveyance direction from a sheet supply portion to a sheet copying portion with respect to a contact portion of said roller on the surface of said separating piece;
and a sheet position detecting means disposed between said sheet separating mechanism and said sheet copying portion, said sheet supply portion taking out stacked sheets, said sheet copying portion copying to such sheets, wherein said sheet separating mechanism separates only a sheet which is in close contact with said roller from other sheets when a plurality of sheets are taken out between said sheet supply portion and said sheet copying portion from said sheet supply portion.
2. A copying machine according to claim 1, wherein said sheet separating mechanism is constructed so that if said predetermined frictional force between the surface of said separating piece and the sheet which is in close contact therewith among the plurality of sheets is N3, a second frictional force between said roller and the sheet which is in close contact therewith among the plurality of sheets is N1, and a third frictional force between the plurality of sheets is N2, said frictional forces satisfy the following relationship: N1>N3>N2.
3. A copying machine according to claim 1, wherein said sheet position detecting means further comprises a second guide means having a register roller, thereby detecting a front end position of the sheet which has been conveyed from said sheet separating mechanism, and wherein said second guide means stops said sheet for a time period to allow synchronism with said sheet copying portion and thereafter conveying said sheet.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2290464A JPH04164752A (en) | 1990-10-25 | 1990-10-25 | Copying machine |
| JP290464/90 | 1990-10-25 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2043665A1 CA2043665A1 (en) | 1992-04-26 |
| CA2043665C true CA2043665C (en) | 1998-12-01 |
Family
ID=17756360
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002043665A Expired - Lifetime CA2043665C (en) | 1990-10-25 | 1991-05-31 | Copying machine |
| CA002053555A Expired - Lifetime CA2053555C (en) | 1990-10-25 | 1991-10-16 | Copier with a superposed-sheet separation mechanism |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002053555A Expired - Lifetime CA2053555C (en) | 1990-10-25 | 1991-10-16 | Copier with a superposed-sheet separation mechanism |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH04164752A (en) |
| CA (2) | CA2043665C (en) |
| DE (2) | DE4121296A1 (en) |
| GB (2) | GB2249082B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0981016A (en) * | 1995-09-19 | 1997-03-28 | Fujitsu Ltd | Electrophotographic image forming device |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4025187A (en) * | 1974-09-05 | 1977-05-24 | Xerox Corporation | Buckle control system |
| US4113244A (en) * | 1975-04-15 | 1978-09-12 | Kurt Ruenzi | Apparatus for automatically feeding individual sheets from a stack through an office machine |
| DE2704045C3 (en) * | 1977-02-01 | 1979-06-28 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Device to prevent double triggers |
| JPS5667858A (en) * | 1979-11-08 | 1981-06-08 | Canon Inc | Sheet registration mechanism releasing device |
| EP0031726B1 (en) * | 1979-12-29 | 1984-12-12 | Mita Industrial Co. Ltd. | Electrostatic copying apparatus |
| DE3104631A1 (en) * | 1980-02-11 | 1981-11-26 | Exxon Research and Engineering Co., 07932 Florham Park, N.J. | FACSIMILE EQUIPMENT |
| US4306713A (en) * | 1980-04-25 | 1981-12-22 | International Business Machines Corporation | Document feeder |
| DE3206993C2 (en) * | 1981-02-27 | 1985-08-22 | Canon K.K., Tokio/Tokyo | Image forming apparatus with means for controlling the transport of recording material in the event of its faulty multiple feed |
| JPS5859137A (en) * | 1981-09-25 | 1983-04-08 | Konishiroku Photo Ind Co Ltd | Paper feeder |
| JPH0623872B2 (en) * | 1982-11-30 | 1994-03-30 | 三田工業株式会社 | Electrostatic copying machine |
| JPS61132941A (en) * | 1984-12-03 | 1986-06-20 | Ricoh Co Ltd | Copying device |
| JPS62140041U (en) * | 1986-02-28 | 1987-09-03 | ||
| US4974020A (en) * | 1986-09-30 | 1990-11-27 | Mita Industrial Co. | Removable developing units for a copying machine and display for indicating the useful life of the machine |
| US4900003A (en) * | 1987-11-09 | 1990-02-13 | Canon Kabushiki Kaisha | Sheet conveying apparatus |
| US5002266A (en) * | 1987-12-26 | 1991-03-26 | Canon Kabushiki Kaisha | Sheet feed apparatus for image forming system |
-
1990
- 1990-10-25 JP JP2290464A patent/JPH04164752A/en active Pending
-
1991
- 1991-05-31 CA CA002043665A patent/CA2043665C/en not_active Expired - Lifetime
- 1991-06-12 GB GB9112594A patent/GB2249082B/en not_active Expired - Lifetime
- 1991-06-27 DE DE4121296A patent/DE4121296A1/en not_active Ceased
- 1991-10-15 GB GB9121895A patent/GB2250715A/en not_active Withdrawn
- 1991-10-16 CA CA002053555A patent/CA2053555C/en not_active Expired - Lifetime
- 1991-10-25 DE DE4135315A patent/DE4135315A1/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| CA2053555C (en) | 1995-01-17 |
| GB2249082A (en) | 1992-04-29 |
| GB2250715A (en) | 1992-06-17 |
| GB9121895D0 (en) | 1991-11-27 |
| GB2249082B (en) | 1994-06-29 |
| CA2053555A1 (en) | 1992-04-26 |
| DE4121296A1 (en) | 1992-04-30 |
| CA2043665A1 (en) | 1992-04-26 |
| DE4135315A1 (en) | 1992-04-30 |
| GB9112594D0 (en) | 1991-07-31 |
| JPH04164752A (en) | 1992-06-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |