CA1047757A - Cascade development station having a roughened development plate for enhancing developer mixture turbulence - Google Patents
Cascade development station having a roughened development plate for enhancing developer mixture turbulenceInfo
- Publication number
- CA1047757A CA1047757A CA215,953A CA215953A CA1047757A CA 1047757 A CA1047757 A CA 1047757A CA 215953 A CA215953 A CA 215953A CA 1047757 A CA1047757 A CA 1047757A
- Authority
- CA
- Canada
- Prior art keywords
- development
- developer
- imaging member
- deflection elements
- recited
- 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
- G03G15/0801—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer for cascading
Abstract
ABSTRACT OF THE DISCLOSURE
A special inexpensive development electrode within a cascade development station is positioned closely adjacent to a xerographic drum. The plate is roughened by producing protuber-ances thereon forming a waffle-like or diamond-shaped knurled pattern for impeding free fall of the development powder and for causing the development mixture to have considerable motion radially with respect to the drum, which in turn greatly increases the number of development events, increases the quantity of toner made available within the development station for a fixed supply of development mixture to increase the copy output rate of the machine and which more effectively scavenges toner on background portions of the drum and prevents buildup of toner on the develop-ment plate.
A special inexpensive development electrode within a cascade development station is positioned closely adjacent to a xerographic drum. The plate is roughened by producing protuber-ances thereon forming a waffle-like or diamond-shaped knurled pattern for impeding free fall of the development powder and for causing the development mixture to have considerable motion radially with respect to the drum, which in turn greatly increases the number of development events, increases the quantity of toner made available within the development station for a fixed supply of development mixture to increase the copy output rate of the machine and which more effectively scavenges toner on background portions of the drum and prevents buildup of toner on the develop-ment plate.
Description
22 ~
~047757 1 This lnvention relates to the field of xerogra-phic development stations.
In spite of the fact that a tremendous amount of research has been performed in the field of the 5 development of electrostatic lmages by the application of developer thereto, it is desirable to still further increase development efficiency. In ordinary commercial cascade development stations, the development mixture first contacts an upper drum portion and is thereafter 10 accelerated by gravity so that often a large portion of the development powder does not contact lower portions of the drum due to high centrlfugal forces acting on the developer. Furthermore, background toner on the drum still exists which often produces unattractive copies, and 15 additionally, excessive buildup of toner is often produced on the development electrode. Thus, it is highly desirable ` to substantially reduce these undesirable effects to allow for a more ef~icient use of available developer mixture and to produce cleaner copy. The attainment of increased 20 development efficiency results in the production of a greater number of copies per minute for any given drum size, or conversely results in the employment of a smaller drum for a fixed rate of copy output. Additionally, because of the increased developer efficiency, the carrier 25 will tend to become more depleted of toner. This condition causes a greater charge imbalance to exist on the carrier which in turn can enhance developer scavenging of the background areas to produce copy free from background toner.
.
., . ~
~ 2 `~ ~
. . .
..
lV47757 A straightforward inexpensive means for accomp-lishing these results is greatly desired.
Thus the present invention provides a xerographic development station including an imaging member having a surface for bearing an electrostatic image to be developed, a development plate having a surface spaced from said imag-ing member surface for defining a development zone there-between and means for introducing developer into said development zone to be cascaded therethrough along paths of travel adjacent said imaging member surface for develop-ing said electrostatic image, the improvement comprising said development plate surface comprising a roughened surface for defining a large plurality of angled deflection elements thereon, said deflection elements covering at least a substantial portion of said development plate surface and being shaped to introduce a substantial component of motion :
to said developer in a direction transverse to said paths of travel thereof through said development zone for direct-ing said cascading developer toward said imaging member surface for increasing development efficiency.
More particularly, the invention provides a xerographic development station including a cylindrical ` imaging member having a surface for bearing an electrostatic image to be developed; a development plate spaced from said imaging member for defining a development zone there-between, said development zone having an input end and an output end; means for rotating said imaging member for moving said electrostatic image bearing surface through said development zone from said input end to said output 3~ end; and means for introducing developer into said develop-ment zone to be cascaded therethrough from said input end ,, ~ .~
,. ~- .
1047~57 to said output end along paths of travel generally in a tangential direction with respect to said imaging member surface for developing said electrostatic image, the improve-ment comprising: wherein said development plate is spaced from said imaging member by a distance which generally decreases from said input end of said development zone toward said output end of said development zone, and wherein said development plate includes a development plate surface, said development plate surface being roughened over at least a substantial portion thereof for defining a large plurality of angled deflection elements thereon, the decreasing spac-ing of said development zone providing a reduction in the - tangential velocity of said developer for increasing the density of the developer within said development zone, and said deflection elements providing an increase in the radial velocity of said developer with respect to said imaging member surface for directing said developer toward said imaging member surface.
. .
The foregoing goals have been accomplished by
~047757 1 This lnvention relates to the field of xerogra-phic development stations.
In spite of the fact that a tremendous amount of research has been performed in the field of the 5 development of electrostatic lmages by the application of developer thereto, it is desirable to still further increase development efficiency. In ordinary commercial cascade development stations, the development mixture first contacts an upper drum portion and is thereafter 10 accelerated by gravity so that often a large portion of the development powder does not contact lower portions of the drum due to high centrlfugal forces acting on the developer. Furthermore, background toner on the drum still exists which often produces unattractive copies, and 15 additionally, excessive buildup of toner is often produced on the development electrode. Thus, it is highly desirable ` to substantially reduce these undesirable effects to allow for a more ef~icient use of available developer mixture and to produce cleaner copy. The attainment of increased 20 development efficiency results in the production of a greater number of copies per minute for any given drum size, or conversely results in the employment of a smaller drum for a fixed rate of copy output. Additionally, because of the increased developer efficiency, the carrier 25 will tend to become more depleted of toner. This condition causes a greater charge imbalance to exist on the carrier which in turn can enhance developer scavenging of the background areas to produce copy free from background toner.
.
., . ~
~ 2 `~ ~
. . .
..
lV47757 A straightforward inexpensive means for accomp-lishing these results is greatly desired.
Thus the present invention provides a xerographic development station including an imaging member having a surface for bearing an electrostatic image to be developed, a development plate having a surface spaced from said imag-ing member surface for defining a development zone there-between and means for introducing developer into said development zone to be cascaded therethrough along paths of travel adjacent said imaging member surface for develop-ing said electrostatic image, the improvement comprising said development plate surface comprising a roughened surface for defining a large plurality of angled deflection elements thereon, said deflection elements covering at least a substantial portion of said development plate surface and being shaped to introduce a substantial component of motion :
to said developer in a direction transverse to said paths of travel thereof through said development zone for direct-ing said cascading developer toward said imaging member surface for increasing development efficiency.
More particularly, the invention provides a xerographic development station including a cylindrical ` imaging member having a surface for bearing an electrostatic image to be developed; a development plate spaced from said imaging member for defining a development zone there-between, said development zone having an input end and an output end; means for rotating said imaging member for moving said electrostatic image bearing surface through said development zone from said input end to said output 3~ end; and means for introducing developer into said develop-ment zone to be cascaded therethrough from said input end ,, ~ .~
,. ~- .
1047~57 to said output end along paths of travel generally in a tangential direction with respect to said imaging member surface for developing said electrostatic image, the improve-ment comprising: wherein said development plate is spaced from said imaging member by a distance which generally decreases from said input end of said development zone toward said output end of said development zone, and wherein said development plate includes a development plate surface, said development plate surface being roughened over at least a substantial portion thereof for defining a large plurality of angled deflection elements thereon, the decreasing spac-ing of said development zone providing a reduction in the - tangential velocity of said developer for increasing the density of the developer within said development zone, and said deflection elements providing an increase in the radial velocity of said developer with respect to said imaging member surface for directing said developer toward said imaging member surface.
. .
The foregoing goals have been accomplished by
2~ virtue of the employment, in the preferred embodiment, of a development electrode which has a surface which is . roughened to a sufficient extent to modify the paths of travel of developer between the electrostatic drum surface and the development electrode surface. By doing so, it has been found that a great many of the above-men-tioned goals are attained. Preferably, the surface is roughened by producing protuberances thereon which are diamond or waffle-shaped to increase radial developer veloclty and decrease tangential developer velocity to thereby increase development efficiency. Also, the : electrode is designed to provicle a variable spacing - .
~ 3a-.
.
104'77Si' between the electrode and the drum -- generally wider at the beginning and narrower at the end. This permits a reduction in the tangential velocity of the falling developer and hence, a greater developer density.
Other ob~ects, features and advantages of the present invention will become apparent upon perusal of the following detailed description taken in con~unction with the drawings in which:
FIGURE 1 schematically illustrates the positioning of the development electrode with respect to the drum;
FIGURE 2 discloses a planar view of the roughened ; surface of the development electrode facing the drum; and FIGURE 3 illustrates a cross section of a portion of the electrode of FIGURE 2.
.
.
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J-~r, ... ,. ~.
., '- ' - ~ , 1047`7S~
1 In FIGURE l, a conventional xerographic drum l is illustrated together with toner applicator 2 and development plate 3. Other conventional portions of a xerographic machine such as the corona charging station, 5 the exposure station and the drum cleaning station have not been shown in the interests of clarlty. The developer is emitted from developer applicator 2 and cascades downwardly through the development gap formed between the surface of development plate 3 and the drum surface.
10 The developer thereafter falls to the bottom of the machine as illustrated, and is thereafter transported by conveyor 6 to the top of the machine to be recirculated therethrough.
The remaining portions of the developer transport system form no part of the present invention and thus will not be - 15 described.
It is greatly preferred, although not required, -- that development plate 3 function as a metallic electrode which is electrically connected to a conventional bias source 7 as is well understood by those skilled in the art.
In order to obtain the above-described ob~ects and goals with regard to increased development efficiency, the inside surface of the metallic electrode 3 is treated during,the manufacturing process to produce a large plurality of tiny protuberances which function as deflec-25 tion elements to enhance turbulence in the development zone in the desired fashion. The stationary electrode has a surface morphology which functions to partially convert the tangential momentum of the carriers to radial momentum.
; 30 --4_ ' - .
.. . . . .
-1 In the machine constructed by the inventor and his colleagues, a surface morphology corresponding to a knurled surface was produced on a metallic plate which was formed as illustrated in FIGURE 1. The resulting 5 surface has a large plurality of diamond-shaped protuber-ances 8, 8' and 8" illustrated in FIGURE 2. These protu-berances are formed by producing cuts such as 9, 9' and 9" as illustrated in the FIGURE. A cross section indicated by cross sectional line 11 is illustrated in FIGURE 3 10 which shows one shape of the diamond protuberances. Arrow 12 illustrates the direction of toner fall.
In the constructed machine the "roughness" or ~ average height of the protuberances, namely the peak to - valley distance between the arrows 13 and 13' in FIGURE 3 15 was 9 mils. The spatial frequency of the diamond pattern in the direction of developer fall was 21.7 cycles per inch or, putting it another way, the spatial separation between corresponding portions in the pattern was about 7.5 to 200 mils for a carrier diameter of 15-20 mils.
20 The developer flow rate was approximately 41 grams per second for each inch of width of the development zone. A
conventional developer having carrier and toner was employed, having a carrier diameter of about 15 mils.
It is believed that the most economical method of manufac-25 turing the development electrode is to employ a knurlingroller for alterlng the surface morphology as described above. The scale of the surface roughness is carrier size dependent. It is preferred that the above-mentioned spatial separation in the direction of developer flow be :~, .. . _ .
.
1~47757 1 within the range of 0.5 to lO times, preferably about 7-8 times, the mean carrier diameter, and it is also preferred that the above-mentioned height of the protuberances be within the range of .3 to l.5 times the mean carrier 5 diameter. Numerous variations in the shape of the protu-berances are believed to fall within the scope of the present invention although the diamond pattern is preferred.
For example, a rounded diamond pattern resembling longitudi-nal rows of diamonds with ad~acent rows being arranged in ; 10 a staggered relationship also works very well. In addition, the surface may resemble the pattern of a waffle plate greatly reduced in scale or may take numerous other forms.
For example, elongated triangular ridges aligned in a direction transverse to the direction of toner fall could 15 be employed. However, the diamond knurl pattern whether rounded or as described above is preferred because the ~~~~ ~ ~ sides of the diamond-shaped elements produce carrier deflections in directions transverse to toner fall to produce further mixing of carriers in directions across 20 the width of the development zone. Other contemplated shapes are cones, pyramids, mushrooms, hemispheres, etc.
Randomly distributed patterns of the foregoing shapes may be employed. Shot blasted or similarly produced surfaces may be useful.
The term "plate" as used herein could comprise a non-metallic plate which does not function as a develop-ment electrode although it is greatly preferred that a metallic plate, functioning as a developing electrode, be employed. The average tangential velocity of the ~alling , 30 .
- - . ~, 1047 7~7 1 toner should be about equal to or greater than the tangen-tial velocity of the photoconductor in order to obtain hlgh density copies. In the constructed machine, the spacing between the surface of the development electrode 5 and the surface of the drum was varied somewhat as schematically illustrated in FIGURE 1. This spacing at portion 16 was about 175 mils, at portion 17 was about - 100 mils, at portion 18 was about 85 mils and at portion 19 was about 105 mils. While other spacing configurations 10 are possible, in general, the spacing should smoothly Yary from a relatively wide spacing in area 16 to a relatively narrow spacing in area 18. Area 19 is somewhat wider to prevent clogging. It is believed important that the separation not be restricted unduly at lower drum portions, 15 which restriction could create excessive pile up of developer whose tangential velocity is much lower than ~~- ~ that of the photoconductor. A plate having indentations therein of sufficient size to produce the above-mentioned effects may be employed and in such a case the term -20 protuberances is intended to cover plate areas separating such indentations.
In summary, a development plate is employed having a surface morphology which partially converts the tangential momentum of the carriers into radial momentum 25 in a highly controlled manner to produce enhanced develop-ment efficiency as discussed hereinabove.
While preferred embodiments of the invention -have been described, the teachings of this in~ention will readily suggest many other embodiments to those skilled 30 in the art.
- , . -
~ 3a-.
.
104'77Si' between the electrode and the drum -- generally wider at the beginning and narrower at the end. This permits a reduction in the tangential velocity of the falling developer and hence, a greater developer density.
Other ob~ects, features and advantages of the present invention will become apparent upon perusal of the following detailed description taken in con~unction with the drawings in which:
FIGURE 1 schematically illustrates the positioning of the development electrode with respect to the drum;
FIGURE 2 discloses a planar view of the roughened ; surface of the development electrode facing the drum; and FIGURE 3 illustrates a cross section of a portion of the electrode of FIGURE 2.
.
.
.. .
- :
- -3b-1 `~
J-~r, ... ,. ~.
., '- ' - ~ , 1047`7S~
1 In FIGURE l, a conventional xerographic drum l is illustrated together with toner applicator 2 and development plate 3. Other conventional portions of a xerographic machine such as the corona charging station, 5 the exposure station and the drum cleaning station have not been shown in the interests of clarlty. The developer is emitted from developer applicator 2 and cascades downwardly through the development gap formed between the surface of development plate 3 and the drum surface.
10 The developer thereafter falls to the bottom of the machine as illustrated, and is thereafter transported by conveyor 6 to the top of the machine to be recirculated therethrough.
The remaining portions of the developer transport system form no part of the present invention and thus will not be - 15 described.
It is greatly preferred, although not required, -- that development plate 3 function as a metallic electrode which is electrically connected to a conventional bias source 7 as is well understood by those skilled in the art.
In order to obtain the above-described ob~ects and goals with regard to increased development efficiency, the inside surface of the metallic electrode 3 is treated during,the manufacturing process to produce a large plurality of tiny protuberances which function as deflec-25 tion elements to enhance turbulence in the development zone in the desired fashion. The stationary electrode has a surface morphology which functions to partially convert the tangential momentum of the carriers to radial momentum.
; 30 --4_ ' - .
.. . . . .
-1 In the machine constructed by the inventor and his colleagues, a surface morphology corresponding to a knurled surface was produced on a metallic plate which was formed as illustrated in FIGURE 1. The resulting 5 surface has a large plurality of diamond-shaped protuber-ances 8, 8' and 8" illustrated in FIGURE 2. These protu-berances are formed by producing cuts such as 9, 9' and 9" as illustrated in the FIGURE. A cross section indicated by cross sectional line 11 is illustrated in FIGURE 3 10 which shows one shape of the diamond protuberances. Arrow 12 illustrates the direction of toner fall.
In the constructed machine the "roughness" or ~ average height of the protuberances, namely the peak to - valley distance between the arrows 13 and 13' in FIGURE 3 15 was 9 mils. The spatial frequency of the diamond pattern in the direction of developer fall was 21.7 cycles per inch or, putting it another way, the spatial separation between corresponding portions in the pattern was about 7.5 to 200 mils for a carrier diameter of 15-20 mils.
20 The developer flow rate was approximately 41 grams per second for each inch of width of the development zone. A
conventional developer having carrier and toner was employed, having a carrier diameter of about 15 mils.
It is believed that the most economical method of manufac-25 turing the development electrode is to employ a knurlingroller for alterlng the surface morphology as described above. The scale of the surface roughness is carrier size dependent. It is preferred that the above-mentioned spatial separation in the direction of developer flow be :~, .. . _ .
.
1~47757 1 within the range of 0.5 to lO times, preferably about 7-8 times, the mean carrier diameter, and it is also preferred that the above-mentioned height of the protuberances be within the range of .3 to l.5 times the mean carrier 5 diameter. Numerous variations in the shape of the protu-berances are believed to fall within the scope of the present invention although the diamond pattern is preferred.
For example, a rounded diamond pattern resembling longitudi-nal rows of diamonds with ad~acent rows being arranged in ; 10 a staggered relationship also works very well. In addition, the surface may resemble the pattern of a waffle plate greatly reduced in scale or may take numerous other forms.
For example, elongated triangular ridges aligned in a direction transverse to the direction of toner fall could 15 be employed. However, the diamond knurl pattern whether rounded or as described above is preferred because the ~~~~ ~ ~ sides of the diamond-shaped elements produce carrier deflections in directions transverse to toner fall to produce further mixing of carriers in directions across 20 the width of the development zone. Other contemplated shapes are cones, pyramids, mushrooms, hemispheres, etc.
Randomly distributed patterns of the foregoing shapes may be employed. Shot blasted or similarly produced surfaces may be useful.
The term "plate" as used herein could comprise a non-metallic plate which does not function as a develop-ment electrode although it is greatly preferred that a metallic plate, functioning as a developing electrode, be employed. The average tangential velocity of the ~alling , 30 .
- - . ~, 1047 7~7 1 toner should be about equal to or greater than the tangen-tial velocity of the photoconductor in order to obtain hlgh density copies. In the constructed machine, the spacing between the surface of the development electrode 5 and the surface of the drum was varied somewhat as schematically illustrated in FIGURE 1. This spacing at portion 16 was about 175 mils, at portion 17 was about - 100 mils, at portion 18 was about 85 mils and at portion 19 was about 105 mils. While other spacing configurations 10 are possible, in general, the spacing should smoothly Yary from a relatively wide spacing in area 16 to a relatively narrow spacing in area 18. Area 19 is somewhat wider to prevent clogging. It is believed important that the separation not be restricted unduly at lower drum portions, 15 which restriction could create excessive pile up of developer whose tangential velocity is much lower than ~~- ~ that of the photoconductor. A plate having indentations therein of sufficient size to produce the above-mentioned effects may be employed and in such a case the term -20 protuberances is intended to cover plate areas separating such indentations.
In summary, a development plate is employed having a surface morphology which partially converts the tangential momentum of the carriers into radial momentum 25 in a highly controlled manner to produce enhanced develop-ment efficiency as discussed hereinabove.
While preferred embodiments of the invention -have been described, the teachings of this in~ention will readily suggest many other embodiments to those skilled 30 in the art.
- , . -
Claims (11)
IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a xerographic development station including an imaging member having a surface for bearing an electrostatic image to be developed, a development plate having a surface spaced from said imaging member surface for defining a development zone therebetween and means for introducing developer into said development zone to be cascaded therethrough along paths of travel adjacent said imaging member surface for developing said electro-static image, the improvement comprising said development plate surface compris-ing a roughened surface for defining a large plurality of angled deflection elements thereon, said deflection elements covering at least a substantial portion of said development plate surface and being shaped to introduce a substantial component of motion to said developer in a direction transverse to said paths of travel thereof through said development zone for directing said cascading developer toward said imaging member surface for increasing development efficiency.
2. Apparatus as recited in claim 1 wherein said imaging member is cylindrical, said paths of travel of said developer are generally in tangential directions with respect to said imaging member surface, and wherein said deflection elements introduce a substantial component of motion to said developer in radial directions with respect to said imaging member for directing said developer toward said imaging member surface.
3. In a xerographic development station including a cylindrical imaging member having a surface for bearing an electrostatic image to be developed; a development plate spaced from said imaging member for defining a development zone therebetween, said development zone having an input end and an output end; means for rotating said imaging member for moving said electrostatic image bearing surface through said development zone from said input end to said output end; and means for introducing developer into said development zone to be cascaded therethrough from said input end to said output end along paths of travel generally in a tangential direction with respect to said imaging member surface for developing said electrostatic image, the improvement comprising: wherein said development plate is spaced from said imaging member by a distance which generally decreases from said input end of said development zone toward said output end of said development zone, and wherein said development plate includes a development plate surface, said development plate surface being roughened over at least a substantial portion thereof for defining a large plurality of angled deflection elements thereon, the decreasing spacing of said development zone providing a reduction in the tangential velocity of said developer for increasing the density of the developer within said development zone, and said deflection elements providing an increase in the radial velocity of said developer with respect to said imaging member surface for directing said developer toward said imaging member surface.
4. Apparatus as recited in claim 1, 2 or 3 wherein said developer is in the form of carrier and toner and wherein said deflection elements have a spatial separation in the direction of said paths of travel of said developer of from about 0.5 to about 10 times the mean carried diameter of said developer.
5. Apparatus as recited in claim 1, 2 or 3 wherein said developer is in the form of carrier and toner and wherein said deflection elements have a spatial separation in the direction of said paths of travel of said developer of from about 7 to about 8 times the mean carrier diameter of said developer.
6. Apparatus as recited in claim 1, 2 or 3 wherein said mean carrier diameter is about 15 mils and wherein said spatial separation is about 120 mils.
7. Apparatus as recited in claim 1, 2 or 3 wherein said developer is in the form of carrier and toner and wherein said deflection elements comprise protuberances and wherein the height of said protuberances are from about 0.3 to about 1.5 times the mean carrier diameter of said developer.
8. Apparatus as recited in claim 1, 2 or 3 wherein said developer is in the form of carrier and toner and wherein said mean carrier diameter is about 15 mils and wherein said deflection elements comprise protuberances and the height of said protuberances is about 9 mils.
9. Apparatus as recited in claim 1 wherein said deflection elements have a generally diamond-shaped configuration tapering away from said development plate surface.
10. Apparatus as recited in claim 8 wherein said generally diamond-shaped deflection elements have a generally rounded peripheral shape.
11. Apparatus as recited in claim 3 wherein said developer is in the form of carrier and toner and the spatial separation of said deflection elements in the direction perpendicular to said paths of travel is about 280 mils.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US42961674A | 1974-01-02 | 1974-01-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1047757A true CA1047757A (en) | 1979-02-06 |
Family
ID=23703999
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA215,953A Expired CA1047757A (en) | 1974-01-02 | 1974-12-13 | Cascade development station having a roughened development plate for enhancing developer mixture turbulence |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS50107934A (en) |
| AU (1) | AU499579B2 (en) |
| BE (1) | BE824060A (en) |
| CA (1) | CA1047757A (en) |
| DE (1) | DE2460524A1 (en) |
| FR (1) | FR2256449B1 (en) |
| GB (1) | GB1494219A (en) |
| IT (1) | IT1028128B (en) |
| NL (1) | NL7417040A (en) |
| SE (1) | SE407471B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3921571A (en) * | 1974-06-24 | 1975-11-25 | Itek Corp | Multiple development method and apparatus for electrophotographic copiers |
| DE3462633D1 (en) * | 1983-09-30 | 1987-04-16 | Toshiba Kk | Developing apparatus |
-
1974
- 1974-12-13 CA CA215,953A patent/CA1047757A/en not_active Expired
- 1974-12-16 AU AU76434/74A patent/AU499579B2/en not_active Expired
- 1974-12-18 GB GB5477774A patent/GB1494219A/en not_active Expired
- 1974-12-20 DE DE19742460524 patent/DE2460524A1/en not_active Withdrawn
- 1974-12-25 JP JP14822974A patent/JPS50107934A/ja active Pending
- 1974-12-30 FR FR7443294A patent/FR2256449B1/fr not_active Expired
- 1974-12-30 SE SE7416389A patent/SE407471B/en unknown
- 1974-12-31 NL NL7417040A patent/NL7417040A/en not_active Application Discontinuation
- 1974-12-31 IT IT3112374A patent/IT1028128B/en active
-
1975
- 1975-01-02 BE BE152111A patent/BE824060A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU7643474A (en) | 1976-06-17 |
| FR2256449B1 (en) | 1980-08-29 |
| AU499579B2 (en) | 1979-04-26 |
| IT1028128B (en) | 1979-01-30 |
| NL7417040A (en) | 1975-07-04 |
| DE2460524A1 (en) | 1975-07-10 |
| SE407471B (en) | 1979-03-26 |
| JPS50107934A (en) | 1975-08-25 |
| BE824060A (en) | 1975-07-02 |
| FR2256449A1 (en) | 1975-07-25 |
| GB1494219A (en) | 1977-12-07 |
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