CA1048258A - Device for developing electrostatic charge images - Google Patents
Device for developing electrostatic charge imagesInfo
- Publication number
- CA1048258A CA1048258A CA74211788A CA211788A CA1048258A CA 1048258 A CA1048258 A CA 1048258A CA 74211788 A CA74211788 A CA 74211788A CA 211788 A CA211788 A CA 211788A CA 1048258 A CA1048258 A CA 1048258A
- Authority
- CA
- Canada
- Prior art keywords
- roller
- developer
- rollers
- record carrier
- blades
- 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
Links
Classifications
-
- 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
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
- G03G15/0822—Arrangements for preparing, mixing, supplying or dispensing developer
-
- 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
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
- G03G15/082—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer for immersion
-
- 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
- G03G2215/08—Details of powder developing device not concerning the development directly
- G03G2215/0802—Arrangements for agitating or circulating developer material
- G03G2215/0816—Agitator type
- G03G2215/0819—Agitator type two or more agitators
Abstract
ABSTRACT:
A device for developing electrostatic charge images. The two mixing rollers are driven in opposite directions and are provided with worm-like arranged blades.
The pitch and the distance between the end faces of the blades determine the quantity of developer mixture transported in the direction of the rollers on the one hand and in the direction transverse thereto on the other hand. As a result, the level of the mixture can be kept constant over the entire width of the record carrier. Build-ups near the side-walls of the chamber are prevented.
A device for developing electrostatic charge images. The two mixing rollers are driven in opposite directions and are provided with worm-like arranged blades.
The pitch and the distance between the end faces of the blades determine the quantity of developer mixture transported in the direction of the rollers on the one hand and in the direction transverse thereto on the other hand. As a result, the level of the mixture can be kept constant over the entire width of the record carrier. Build-ups near the side-walls of the chamber are prevented.
Description
5~
"Device for developing electrostatic charge images".
According to the present invention there is provided a device for developing electrostatic charge images present on a record carrierJ com-prising a developer chamber, for containing a developer powder consisting of a mixture of toner and carrier material and accommodating two parallel adja-cent transport rollers which are contra-rotatable and ~hich are provided on their circumferential surfaces with respective blades for transporting the developer powder to and fro respectively in the axial direction of the rollersJ wherein each transport roller is prov;ded with a plurality of said blades spacedly arranged in the form of a helix of varying pitch.
In electrostatic reproduction methods first a latent electro-static image is formed on a record carrier~ the image being made visible in a subsequent developing process. During this developing process electroscopic particles are deposited on the charged areas of the record carrier, and are subsequently fixed in a fixing station so that a non-erasable image is obtained. -The developer powder consists of fine electroscopic particles and a carrier material, usually iron grains. The two types of material adhere ;;
because of friction-electrical charging. When this developer comes into contact with the record carrier bearing the latent image, the electroscopic particle - also referred to as toner - is transferred to the record carrier ~
due to the electrostatic attraction by the carrier material itself drops ;
bac~ into the developer chamber and is combined again with toner particles.
, . , ~ . .
Various devices are known in which toner ~' ,, ~ .
"Device for developing electrostatic charge images".
According to the present invention there is provided a device for developing electrostatic charge images present on a record carrierJ com-prising a developer chamber, for containing a developer powder consisting of a mixture of toner and carrier material and accommodating two parallel adja-cent transport rollers which are contra-rotatable and ~hich are provided on their circumferential surfaces with respective blades for transporting the developer powder to and fro respectively in the axial direction of the rollersJ wherein each transport roller is prov;ded with a plurality of said blades spacedly arranged in the form of a helix of varying pitch.
In electrostatic reproduction methods first a latent electro-static image is formed on a record carrier~ the image being made visible in a subsequent developing process. During this developing process electroscopic particles are deposited on the charged areas of the record carrier, and are subsequently fixed in a fixing station so that a non-erasable image is obtained. -The developer powder consists of fine electroscopic particles and a carrier material, usually iron grains. The two types of material adhere ;;
because of friction-electrical charging. When this developer comes into contact with the record carrier bearing the latent image, the electroscopic particle - also referred to as toner - is transferred to the record carrier ~
due to the electrostatic attraction by the carrier material itself drops ;
bac~ into the developer chamber and is combined again with toner particles.
, . , ~ . .
Various devices are known in which toner ~' ,, ~ .
- 2 - ~ ~
~ ~ ' P}~D 73~1'3 13-9-1971r partic~les cc~n bc dopo~itod in the de~cribe~ m~nner. The cII~elop~r is constantly spread over the full width o~ th~
record carrier by two transport ~ollers (turbulence). A device of this l~ d is known, ~or example, from German Paten-t Specification 1,094,590, in which tl~o rollers are arranged parallel ~ith respect to each other and with respect to the recorcl carrier, and are rotated in opposite directions~
l`he blades pro~ided on the circwrlference thereof act as sho~re~ 1~hi~h ~orm a wall o~ developer po1~der be~een the t~Yo rollers, the upper side of the said 1Yall touching the record carrier. Toner particles which are not electrostatically attracted by the latent image drop back into the de~eloper chamber by gravity and so does the carrier material. Howevsr, this does not ensure uniform development of the latent image~
because in practice the images are not uniforml~ distributed over the record carrier. Afte:r a ~ew hours o~ operation, a difference in development ~Yill occur - vie-~ed over the fu1l width o~ the record carrier - which may be so great that parts o~ tha image remain unvisible. A oo~tinuous supply 20~ of fresh toner is then required over the full chamber width.
.
This requires additional structural stepsO
These drawbacks can be avoided -to a given ext-ent- by using instead o~ sho~el rollers transport rollerq such as worm rollers. Thc deve~oper is then transported parallel to the record carrier by the roller arranged near the record carrier, and is returned by the second roller.
Howe~er, in such a device the toner must be supplied anew over the full chamber width if oonstant intensity o~ tIIe ' .
,~.. , -~ . ..... .. :, :
P~ll) 73-1 92 9- 1 971~
developmont in the transport direction of the developer i~
to be ensur~d.
In addition, the use o* -transport rollers gi~es rise to the probleltl o* building~up at the area o~ chanOe-o~er from one transport direction to the other. It was found -that developer polrder collects betwe~n the ends of the rollers and the chalnber ~all. Because the developer powder acts as a "viscous" liquid, at these locations in the devetopiIlg chamber a comparativaly high thrust is built up which sprcads in all directions. As a result, only a part is taken up by the transpo-t roller rotating in the opposite direc-tioll (as is desired), but a :~urth0r part forms a superfluous wall,part of ~rhich slides to within reach ~P
the other roller by gravity. A third part presses on the record carrier and thus causes unnecessa-~ colouring of -the :
edge o~ the record carrier~
The record carrier is Ped into the developer chamber in one;way or~another, usually via a guide s].ot~
Ho1rever, bhe width of this slot does not correspond to the ~ridth of.the record carrier, so that an opening always remains on the side. Because o* the thrustj the coloured developer pol~der is *orced out through this opening, thus causing contamination of the complete device as ~rell as oP the back of the record carrierO ~his escape of po1rder also occurs at comparatively high transpo~t speeds o~ the record carrier.
This problem could be mitigat~d by enlarging the developing chamber so that enough ciearance ~rould be maintained for the developer betlreen the ends of the rollers and the developer chamber, The buildi~g-up o* developer is then elimi~ated, .
_ Ll.
5l3 but the necessary level of the developer powder is no longer reached, so that toner is no longer applied to the edges of the record carrier. ~oreover, a substantial quantity of developer powder would be deposited in this space, and this powder would be lost for the developing process. Therefore, at the areas where the developer changes over from one direction of transport to the other, a given thrust must be maintained whichJ however, should be so ~-~
large that the level of the developer powder is maintained at these areas on the one hand, whilst on the other hand it should not force the developer powder out of the chamber The invention has for its object to provide a device for develop- `
ing in which the developer chamber is as small as possible on the one hand, whilst on the other hand the level of the mixture required or develoying and displaying the latent image remains constant over the full width of the record carrier.
To this end, the device according to the invention is character-ized in that the blades on the circumference of the transport rollers are provided in the form of a helix of varying pitch so that they form a worm having a pitch which varies in the axial transport direction. As a result, ~-developer particles can pass between the blades over ~he full length of the roller and be taken up by the counter roller. Thus, the developer is not only fed along the record carrier, but is notably also mixed in an uninter-rupted manner over the full width of the chamber, the relationship '~
. .
.: - : . . .. ~: , ... .
32~
bet~een ~he quantities transported in the axial direction of the roller and in the direction transverse thereto being determined by the pitch on the one hand, and by the distance between adjoining blades on the other hand. As a result~ a uniform developnlent of the latent image is always achievèd The arrangement of the blades w;th respect to eacll other (pitch o the worm) can be readily chosen over the length of the roller such that the level of the develc~per remains constant over the full width9 for example, the pitch may ~e smaller at one end of the roller than at the centre thereof. If, moreover, the last blades or ~he first blades of each roller are arranged parallel to the axis of the roller or in the opposite direction ~negative pitch~, no excessive thrust will be built up on the wall of the chamber, so that no developer powder can escape from the guide slot of the developer chamber even at low transport speeds o the record carrier.
The invention will be described in detail hereinafter with reference to the drawing.
Fig. 1 diagrammatically shows an electrostatic printer, and Fig. 2 shows the transport rollers according to the invention.
In the printer diagrammatically shown in Fig. 1, a record carrier 1 (in this case a paper strip) is transported to a printing station 5 via a shaft 2 provided with a slide roller which comprises an indicator ;
wheel 4 and which cooperates with a pressure roller 3. At the printing station, the latent image, for example, alphanumerical signs, is formed.
Subsequently, thP record carrier 1 reaches a developer chamber 6 and is deflected upwards by a guide plate g. After the latent images of the record carrier 1 have been in contact with toner 7, the superfluous developer ~;
particles are removed from the record carrier 1 by a sweeping magnet 24.
Subsequently, the record carrier 1 reaches a fixing station 25 in which the coloured toner particles are melted by heating so that they are fixed to the record carrier 1 in a non-erasable manner. The record carrier 1 is discharged from the printer via drive rollers 26 and 27.
5~
The toner mate~ial 7 i~ fed to the deyeloper chamber 6 by way o~ a t~ner cassette 23. The toner cassette 23 can be readily ~xchanged.
The supply of toner by means of the cassette 23 prevents contamination of the apparatus. The toner 7 is introduced into the developer chamber ~, by a toner feed roller 22, after which it is electrostatically combined with the carrier material, for example, iron powder present in the chamber. In the rest state, the developer chamber 6 is filled with this developer mixture approximately up to the broken line 61.
Arranged on the bottom of the developer chamber 6 are two parallel transport rollers 10 and 11 which can rotate in opposite directions as indicated by the arrows. A plan view of these transport rollers is given in Pig. 2. The rollers are provided on their circumference with the blades 12 which are arranged such that they constitute a worm. The developer material is thus displaced in known malmer in ~he longitudinal direction of the roller. Because openings are provided between these blades, during the entire transport developer particles will drop out of reach of the one roller and within reach of the other roller. In this manner, the developer powder is not only transported along the record carrier 1, but is also continuously mixed at the same time.
In order to prevent build-ups at the end of the rollers, the embodiment shown in Fig. 2 has at least the first blade 14 and 16 of each of the rollers 10 and 11, respectively, arranged parallel to the axis of the roller. Because for the indicated direction of rotation of the rollers the developer mixture is transported in the direction of the arrows 100, 110, the blades 14 and 16 cause a "wake" which draws the mixture supplied by the rollers 10 and 11 away from these rollers. This effect can be enhanced by arranging the last blade 28 and 29 opposite to the blade 16 and 14, respectively, in an opposite sense to the helix concerned. This arrangement ensures in any case that the mixture cannot be pressed onto the wall of the chamber. Moreover, it is alternatively possible to arrange the , ~
.~ - . .
S~
second bladcs 13 an(l 15 to he more incllned than the blades 12 constituting the helix, or -to arrange them axially like the blades 1~ and 16.
The pitch of the blades 12 and the distance a ~Fig. 1) between the end faces of the blades 12 determine the quantity transported by the rollers in the aYlal direction (arrows 100, 110) on the one hand, and that transported over the full length of the rollers in the direction transverse thereto ~arrows 112) on the other hand. The pitch of the helix can thus be adapted over the full length of each roller to provide a suitable transport rate at eacll part of the roller. In order to achieve the same object, it is alternatively feasible to arrange the blades 12 such that their position ~pitch) is variable or that the distance a from each other is variable, for example, by rotation or shifting in the longitudinal direction. The level of the developer mixture can thus be kept constant over the full width of the record carrier l. The dimension of the arrows 112 indicates the quantity of transversely transported developer mixture in this embodiment with a regularly varying pitch of th0 helix.
In contrast with Fig. 2, instead of the first blade or blades 13 to 16, the last blades of the rollers 10 and 11 can alternatively be arranged in the axial direction. In that case the build-up near the rele-vant chamber wall is not eliminated by a "wake" but rather by pressure. ~
However, the same effect is thus achieved. ~;
The rollers 10 and ll are driven in opposite directions by an electric motor 17 or other known manner by way of a drive system 18, 19J 20.
The rotation of the rollers lO and ll spins the developer mixture upwards and against the record carrier. This effect is enhanced by the permanent magnet 28 arranged behind the record carrier 1 and by the movement of the record carrier 1. A shiel~ 21 arranged over the roller 11 prevents dropping developer particles or carrier particles from being spun upwards again before having been combined again with toner particles. This shield rather directs the particles to the region between the two rollers 10 and 11.
: ~
~ ~ ' P}~D 73~1'3 13-9-1971r partic~les cc~n bc dopo~itod in the de~cribe~ m~nner. The cII~elop~r is constantly spread over the full width o~ th~
record carrier by two transport ~ollers (turbulence). A device of this l~ d is known, ~or example, from German Paten-t Specification 1,094,590, in which tl~o rollers are arranged parallel ~ith respect to each other and with respect to the recorcl carrier, and are rotated in opposite directions~
l`he blades pro~ided on the circwrlference thereof act as sho~re~ 1~hi~h ~orm a wall o~ developer po1~der be~een the t~Yo rollers, the upper side of the said 1Yall touching the record carrier. Toner particles which are not electrostatically attracted by the latent image drop back into the de~eloper chamber by gravity and so does the carrier material. Howevsr, this does not ensure uniform development of the latent image~
because in practice the images are not uniforml~ distributed over the record carrier. Afte:r a ~ew hours o~ operation, a difference in development ~Yill occur - vie-~ed over the fu1l width o~ the record carrier - which may be so great that parts o~ tha image remain unvisible. A oo~tinuous supply 20~ of fresh toner is then required over the full chamber width.
.
This requires additional structural stepsO
These drawbacks can be avoided -to a given ext-ent- by using instead o~ sho~el rollers transport rollerq such as worm rollers. Thc deve~oper is then transported parallel to the record carrier by the roller arranged near the record carrier, and is returned by the second roller.
Howe~er, in such a device the toner must be supplied anew over the full chamber width if oonstant intensity o~ tIIe ' .
,~.. , -~ . ..... .. :, :
P~ll) 73-1 92 9- 1 971~
developmont in the transport direction of the developer i~
to be ensur~d.
In addition, the use o* -transport rollers gi~es rise to the probleltl o* building~up at the area o~ chanOe-o~er from one transport direction to the other. It was found -that developer polrder collects betwe~n the ends of the rollers and the chalnber ~all. Because the developer powder acts as a "viscous" liquid, at these locations in the devetopiIlg chamber a comparativaly high thrust is built up which sprcads in all directions. As a result, only a part is taken up by the transpo-t roller rotating in the opposite direc-tioll (as is desired), but a :~urth0r part forms a superfluous wall,part of ~rhich slides to within reach ~P
the other roller by gravity. A third part presses on the record carrier and thus causes unnecessa-~ colouring of -the :
edge o~ the record carrier~
The record carrier is Ped into the developer chamber in one;way or~another, usually via a guide s].ot~
Ho1rever, bhe width of this slot does not correspond to the ~ridth of.the record carrier, so that an opening always remains on the side. Because o* the thrustj the coloured developer pol~der is *orced out through this opening, thus causing contamination of the complete device as ~rell as oP the back of the record carrierO ~his escape of po1rder also occurs at comparatively high transpo~t speeds o~ the record carrier.
This problem could be mitigat~d by enlarging the developing chamber so that enough ciearance ~rould be maintained for the developer betlreen the ends of the rollers and the developer chamber, The buildi~g-up o* developer is then elimi~ated, .
_ Ll.
5l3 but the necessary level of the developer powder is no longer reached, so that toner is no longer applied to the edges of the record carrier. ~oreover, a substantial quantity of developer powder would be deposited in this space, and this powder would be lost for the developing process. Therefore, at the areas where the developer changes over from one direction of transport to the other, a given thrust must be maintained whichJ however, should be so ~-~
large that the level of the developer powder is maintained at these areas on the one hand, whilst on the other hand it should not force the developer powder out of the chamber The invention has for its object to provide a device for develop- `
ing in which the developer chamber is as small as possible on the one hand, whilst on the other hand the level of the mixture required or develoying and displaying the latent image remains constant over the full width of the record carrier.
To this end, the device according to the invention is character-ized in that the blades on the circumference of the transport rollers are provided in the form of a helix of varying pitch so that they form a worm having a pitch which varies in the axial transport direction. As a result, ~-developer particles can pass between the blades over ~he full length of the roller and be taken up by the counter roller. Thus, the developer is not only fed along the record carrier, but is notably also mixed in an uninter-rupted manner over the full width of the chamber, the relationship '~
. .
.: - : . . .. ~: , ... .
32~
bet~een ~he quantities transported in the axial direction of the roller and in the direction transverse thereto being determined by the pitch on the one hand, and by the distance between adjoining blades on the other hand. As a result~ a uniform developnlent of the latent image is always achievèd The arrangement of the blades w;th respect to eacll other (pitch o the worm) can be readily chosen over the length of the roller such that the level of the develc~per remains constant over the full width9 for example, the pitch may ~e smaller at one end of the roller than at the centre thereof. If, moreover, the last blades or ~he first blades of each roller are arranged parallel to the axis of the roller or in the opposite direction ~negative pitch~, no excessive thrust will be built up on the wall of the chamber, so that no developer powder can escape from the guide slot of the developer chamber even at low transport speeds o the record carrier.
The invention will be described in detail hereinafter with reference to the drawing.
Fig. 1 diagrammatically shows an electrostatic printer, and Fig. 2 shows the transport rollers according to the invention.
In the printer diagrammatically shown in Fig. 1, a record carrier 1 (in this case a paper strip) is transported to a printing station 5 via a shaft 2 provided with a slide roller which comprises an indicator ;
wheel 4 and which cooperates with a pressure roller 3. At the printing station, the latent image, for example, alphanumerical signs, is formed.
Subsequently, thP record carrier 1 reaches a developer chamber 6 and is deflected upwards by a guide plate g. After the latent images of the record carrier 1 have been in contact with toner 7, the superfluous developer ~;
particles are removed from the record carrier 1 by a sweeping magnet 24.
Subsequently, the record carrier 1 reaches a fixing station 25 in which the coloured toner particles are melted by heating so that they are fixed to the record carrier 1 in a non-erasable manner. The record carrier 1 is discharged from the printer via drive rollers 26 and 27.
5~
The toner mate~ial 7 i~ fed to the deyeloper chamber 6 by way o~ a t~ner cassette 23. The toner cassette 23 can be readily ~xchanged.
The supply of toner by means of the cassette 23 prevents contamination of the apparatus. The toner 7 is introduced into the developer chamber ~, by a toner feed roller 22, after which it is electrostatically combined with the carrier material, for example, iron powder present in the chamber. In the rest state, the developer chamber 6 is filled with this developer mixture approximately up to the broken line 61.
Arranged on the bottom of the developer chamber 6 are two parallel transport rollers 10 and 11 which can rotate in opposite directions as indicated by the arrows. A plan view of these transport rollers is given in Pig. 2. The rollers are provided on their circumference with the blades 12 which are arranged such that they constitute a worm. The developer material is thus displaced in known malmer in ~he longitudinal direction of the roller. Because openings are provided between these blades, during the entire transport developer particles will drop out of reach of the one roller and within reach of the other roller. In this manner, the developer powder is not only transported along the record carrier 1, but is also continuously mixed at the same time.
In order to prevent build-ups at the end of the rollers, the embodiment shown in Fig. 2 has at least the first blade 14 and 16 of each of the rollers 10 and 11, respectively, arranged parallel to the axis of the roller. Because for the indicated direction of rotation of the rollers the developer mixture is transported in the direction of the arrows 100, 110, the blades 14 and 16 cause a "wake" which draws the mixture supplied by the rollers 10 and 11 away from these rollers. This effect can be enhanced by arranging the last blade 28 and 29 opposite to the blade 16 and 14, respectively, in an opposite sense to the helix concerned. This arrangement ensures in any case that the mixture cannot be pressed onto the wall of the chamber. Moreover, it is alternatively possible to arrange the , ~
.~ - . .
S~
second bladcs 13 an(l 15 to he more incllned than the blades 12 constituting the helix, or -to arrange them axially like the blades 1~ and 16.
The pitch of the blades 12 and the distance a ~Fig. 1) between the end faces of the blades 12 determine the quantity transported by the rollers in the aYlal direction (arrows 100, 110) on the one hand, and that transported over the full length of the rollers in the direction transverse thereto ~arrows 112) on the other hand. The pitch of the helix can thus be adapted over the full length of each roller to provide a suitable transport rate at eacll part of the roller. In order to achieve the same object, it is alternatively feasible to arrange the blades 12 such that their position ~pitch) is variable or that the distance a from each other is variable, for example, by rotation or shifting in the longitudinal direction. The level of the developer mixture can thus be kept constant over the full width of the record carrier l. The dimension of the arrows 112 indicates the quantity of transversely transported developer mixture in this embodiment with a regularly varying pitch of th0 helix.
In contrast with Fig. 2, instead of the first blade or blades 13 to 16, the last blades of the rollers 10 and 11 can alternatively be arranged in the axial direction. In that case the build-up near the rele-vant chamber wall is not eliminated by a "wake" but rather by pressure. ~
However, the same effect is thus achieved. ~;
The rollers 10 and ll are driven in opposite directions by an electric motor 17 or other known manner by way of a drive system 18, 19J 20.
The rotation of the rollers lO and ll spins the developer mixture upwards and against the record carrier. This effect is enhanced by the permanent magnet 28 arranged behind the record carrier 1 and by the movement of the record carrier 1. A shiel~ 21 arranged over the roller 11 prevents dropping developer particles or carrier particles from being spun upwards again before having been combined again with toner particles. This shield rather directs the particles to the region between the two rollers 10 and 11.
: ~
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A device for developing electrostatic charge images present on a record carrier, comprising a developer chamber, for containing a developer powder consisting of a mixture of toner and carrier material and accommo-dating two parallel adjacent transport rollers which are contra-rotatable and which are provided on their circumferential surfaces with respective blades for transporting the developer powder to and fro respectively in the axial direction of the rollers, wherein each transport roller is provided with a plurality of said blades spacedly arranged in the form of a helix of varying pitch.
2. A device as claimed in claim 1, wherein the pitch is smaller at one end of each roller than at the centre thereof.
3. A device as claimed in claim 1, wherein each roller is provided with a respective further blade at one end thereof arranged parallel to the axis of the roller.
4. A device as claimed in claim 2, wherein each roller is provided with a respective further blade at one end thereof arranged parallel to the axis of the roller.
5. A device as claimed in claim 3 or 4, wherein each roller is pro-vided with a respective further blade at the other end thereof arranged in the direction opposing the direction of the helix.
6. A device as claimed in claim 1 or 2, characterized in that a respective blade at each end of each roller is arranged parallel to the axis of the roller.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2353229A DE2353229C3 (en) | 1973-10-24 | 1973-10-24 | Circulating device for the developer of electrostatic latent charge images |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1048258A true CA1048258A (en) | 1979-02-13 |
Family
ID=5896255
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA74211788A Expired CA1048258A (en) | 1973-10-24 | 1974-10-21 | Device for developing electrostatic charge images |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS5549741B2 (en) |
| CA (1) | CA1048258A (en) |
| CH (1) | CH577191A5 (en) |
| DE (1) | DE2353229C3 (en) |
| FR (1) | FR2249371B3 (en) |
| GB (1) | GB1445024A (en) |
| IT (1) | IT1021871B (en) |
| NL (1) | NL7413742A (en) |
| SE (1) | SE390349B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5916934Y2 (en) * | 1976-01-22 | 1984-05-17 | キヤノン株式会社 | Developer stirring device |
| US4170287A (en) * | 1977-04-18 | 1979-10-09 | E. I. Du Pont De Nemours And Company | Magnetic auger |
| FR2425941A2 (en) * | 1978-05-16 | 1979-12-14 | Cii Honeywell Bull | DEVICE FOR APPLYING SOLID PARTICLES TO THE RECORDING MEDIA OF A NON-IMPACT PRINTER |
| DE3009471C2 (en) * | 1979-03-15 | 1982-04-29 | Tokyo Shibaura Denki K.K., Kawasaki, Kanagawa | Developer transport device for electrostatic copiers |
| JPS6312352Y2 (en) * | 1980-02-26 | 1988-04-08 | ||
| JPS6056058U (en) * | 1983-09-22 | 1985-04-19 | 株式会社リコー | Rotating shaft of developing device |
| JPH0435899Y2 (en) * | 1985-06-13 | 1992-08-25 | ||
| US5526099A (en) * | 1993-12-02 | 1996-06-11 | Matsushita Electric Industrial Co., Ltd. | Developing device and an image forming apparatus using the same |
| EP0656571A1 (en) * | 1993-12-02 | 1995-06-07 | Matsushita Electric Industrial Co., Ltd. | A developing device and an image forming apparatus using the same |
| EP0656570A1 (en) * | 1993-12-02 | 1995-06-07 | Matsushita Electric Industrial Co., Ltd. | Image forming apparatus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3167455A (en) * | 1963-01-31 | 1965-01-26 | Dick Co Ab | Developer for facsimile printing machine |
-
1973
- 1973-10-24 DE DE2353229A patent/DE2353229C3/en not_active Expired
-
1974
- 1974-10-21 IT IT53640/74A patent/IT1021871B/en active
- 1974-10-21 CA CA74211788A patent/CA1048258A/en not_active Expired
- 1974-10-21 GB GB4537874A patent/GB1445024A/en not_active Expired
- 1974-10-21 NL NL7413742A patent/NL7413742A/en unknown
- 1974-10-21 CH CH1406774A patent/CH577191A5/xx not_active IP Right Cessation
- 1974-10-21 SE SE7413194A patent/SE390349B/en not_active IP Right Cessation
- 1974-10-22 JP JP12189374A patent/JPS5549741B2/ja not_active Expired
- 1974-10-23 FR FR7435536A patent/FR2249371B3/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5074437A (en) | 1975-06-19 |
| DE2353229C3 (en) | 1981-10-08 |
| SE390349B (en) | 1976-12-13 |
| SE7413194L (en) | 1975-04-25 |
| CH577191A5 (en) | 1976-06-30 |
| FR2249371B3 (en) | 1977-08-05 |
| DE2353229A1 (en) | 1975-04-30 |
| DE2353229B2 (en) | 1980-10-23 |
| JPS5549741B2 (en) | 1980-12-13 |
| GB1445024A (en) | 1976-08-04 |
| FR2249371A1 (en) | 1975-05-23 |
| NL7413742A (en) | 1975-04-28 |
| IT1021871B (en) | 1978-02-20 |
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