DE2032611A1 - Method and apparatus for developing an electrostatic latent image - Google Patents

Description

Patent attorneys Dipl.-Ing. R ¥ eickmann, 2032611

Dipl.-Ing. H.Weickmann, Dipl.-Phys. Dr. K. Fingke D1PL.-ING. R A.WEICKMANN, Dipl.-Chem. B. Huber

8 MUNICH 86, DEN

PO Box 860 820

MÖHLSTRASSE 22, CALL NUMBER 48 3921/22

XEROX CORPORATION, Rochester, U.Yo 14603, VoSt.A "

Method and apparatus for developing a latent

electrostatic image

The invention relates to a method and an apparatus for developing an electrostatic latent image with a developer.

The generation and development of images on the surface of photoconductive materials by an electrostatic process is already known. The basic process is described in US Pat. No. 2,297,691 and consists in applying a uniform electrostatic charge to a photo-conductive insulating material layer that this layer is irradiated with a light-shadow image to dissipate the charge in the exposed area parts and that the electrostatic latent image produced in this way is developed by the deposition of a finely divided electroscopic material, which is also referred to as "toner". The doner is normally attracted to those areas of the substrate which contain a charge, so that a toner image corresponding to the latent electrostatic image is formed. This can then be transferred to another image carrier, for example a sheet of paper. There can then duroh heat exposure are permanently fixed · Save duroh gleiohmäßige charging and B · radiation dtr fotoleitfähig ^

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Layer with a light-shadow image can be the latent Electrostatic image can also be generated directly by charging in an image-wise distribution · The toner image can on the photoconductive sole can be fixed in case the image transfer should not take place »Other suitable fixing methods, for example solvent or coating treatment, can also be carried out instead of heat setting

Similarly, there are various methods of applying the electroscopic particles to the electrostatic one known latent image. These include, for example, the cascading development according to the US patent 2,618,552, the powder cloud development according to US Pat. No. 2,221,776 and the magnetic brush development according to FIG U.S. Patent 2,874,063.

The development of an electrostatic latent image can AUOH with a liquid rather than be done with a dry Entwioklerstoff _e In the conventional liquid development, which is also referred to as elektrophoretisohe development, brings to a non-conductive carrier liquid, in which a finely divided solid which is dispersed charged with and the uncharged areas of the image surface in touch. Under the influence of the electric field of the image-wise distributed charge pattern, the suspended particles migrate into the charged areas of the image surface and are thus separated from the non-conductive carrier liquid. This electrophoretic migration of charged parts causes these particles to be deposited on the image surface in an image-wise distribution

Another method sur developing electrostatic latent images iat the in the US PatenteohrifV 3084043 bt »sohriebene liquid process which AUOH as polar liquid

009883/1940.

development is called. In this process, an electrostatic latent image is developed or made visible, in that a liquid developer is applied to the image area, which is on a Beschiokungselement This is with a regular pattern of bumps and provided indentations on its surface. The wells of the loading element contain one Layer of a relatively conductive liquid developer * fes, the distance from the electrostatographic image surface is held. The development itself takes place by moving the coating that has been provided with the liquid developer. " kungselementes to the picture surface in a development position. The liquid developer is then only used by the charged image area parts from the recessed areas of the charging element tightened. It can be pigmented or colored. That described in US Pat. No. 3,084,045 Development process differs from electrophoretic development »in which there is a contact between the developer liquid and the charged and uncharged Areas of an electrostatic latent image is generated in the case of polar liquid development, a contact between the polar liquid and the areas not to be developed, preventing the electrostatic latent image. There is a reduced contact between a liquid developer and the parts of the surface that do not belong to the image favorable, as there is thus a formation of background drawings is prevented. Another different property of the polar liquid process compared to the electrophoretic one Development consists in the fact that the liquid phase of a polar developer contributes to the development has a picture plane. In the case of electrophoretic development, the liquid phase only functions as a carrier medium for the developer particles.

• Another well-known liquid process is that in. The US

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Wetting development described in patent specification 3,285,741 “In this process, an aqueous developer is brought into contact evenly with the entire image area, whereby only the charged areas of the image area are wetted due to the type of wetting and the electrical properties of the developer. The developer material is to be relatively conductive and a resistivity of about '10 to about ₀ 10 Ohm cm habeno His wetting properties should be such that the measured on the image surface upon application of the wetting angle is not in the loaded! Surface portions is less than 90 ° and in the charged surface parts is greater than 90 °

With the polar liquid development, the electrophoresis Development and the wetting development can produce images of satisfactory quality, but occur it also has disadvantages that require an improvement in the process. In certain types of processes, a charging element is used provided with developer liquid by simply bringing it into contact with the developer liquid so that it adheres to its surface in an uneven distribution. This requires special treatment or machining the surface of the charging element to remove excess developer fluid, so that an even distribution of the developer fluid is produced. This process, also known as "wiping", removes excess developer fluid while maintaining a sufficient supply on the Beschiokungselement, the for even loading of the electrostatic latent image is required have an even layer of developer liquid in its wells to ensure a good To achieve development of the entire picture surface. Furthermore,

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len the elevations of the coating element free of developer fluid be to avoid background buildup in the To minimize the development of the latent electrostatic image. To meet these requirements you need to be precise working methods and devices for metering the Developer liquid on the absorption element and Precise methods and devices for wiping the loading element be applied·

Appropriate scraping methods for electrophoretical development the polar liquid development and the wetting " development work with a doctor blade or a squeegee roller arrangement on the surface of the Beschiokungselementes, so that when it is moved, the developer fluid is scraped off or wiped off and that formed with it PiIm is smoothed · With this dosing and stripping is an exact setting of the distance, the touch pressure and the angle between the scraper blade and the loading element is difficult to maintain over a longer period of time, since a progressive wear of the Abstreiohblätter and / or the Besohiokungselementes occurs.

For example, it will be one with indentations or another Patterned garnish roll together with a thin one Used Abstreiohblatt of the known type, the contact of the two elements with each other during operation causes a Creation of depressions or other notches in the leaf ready for a relatively short time. These effects occur especially with a continuously operating Developing device on, because the Besohiokungsfläohe constantly moves past the scraper blade. Besides this progressive wear, the blades are too exposed to other scratches and notches and cause an accumulation of dust or other particles, so dal BQhIitfllioh with the Bteohiokungefläohe an unevenly

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Wiping surface is brought into contact, which creates scratches and other irregularities on the wiping surface. Since the developer liquid has to be applied to the charging surface before wiping off, there is a distance and time interval in which the Beschiokungsflache is provided with excess developer liquid, so that when it moves there is an increased possibility of the liquid splashing untidy and detrimental development device operation ". The nip rolls are generally rotated by contact with the loading surface and cause inadequate wiping. Therefore, such development methods still need to be improved _{or the like}

The object of the invention is to be avoided in the development process of the type described above, the above-mentioned disadvantages and to this end to provide a developing method which operates simply and can be realized with a compact apparatus constructed ₀ where In particular, a better dosage of the developer substance duroh improved Abstreiohen to be possible. Both processes should be carried out equally.

A method of the type mentioned at the beginning is to solve this According to the invention, the object is designed in such a way that a loading area provided with a cough made of raised and recessed areas with the developer and in contact with movement is brought with an Abatreiohfläche, welohβ a uniform distribution of the developer toffea. in the recessed areas and a removal of the developer material · from the raised areas causes »and that the electro-

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static-latent image in contact with the loading surface is brought ο

The application of the developer to the boiling area can be done with a suitable transmission device « However, the wiping surface can also be used for this purpose which then also have the function of transporting the developer If it is fulfilled, it must then move in the same direction as the infiltration surface at the line of contact, but at a slower speed than it "; to the desired To achieve wiping effect «) If the wiping surface is only used for wiping, it can be opposite move the surface to be treated «, the desired wiping effect is that a scraping or retention of excess amounts of the developer and at the same time a uniform distribution takes place in an amount sufficient for development on the loading surface. Preferably should through the wiping action this necessary for development Amount of developer in the recessed areas of the Besohiokungsfläche, while the raised Areas are free of developer material correct development with minimal background drawings guaranteed

Simultaneously conveying, metering and scraping by the Abstreiohflache is preferably carried out, since there is less area elements and mechanical movements are required, and the maintenance work, the control equipment and the manufacturing cost is reduced si, _o nd

The filling area and the scraping area are such arranged so that they touch each other and are preferably moved along a narrow line past each other. Included they are arranged parallel to each other in order to achieve a sufficient wiping effect of the entire loading area

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aim. Here, the directions of movement of the loading surface and the scraping surface are parallel to one another on the line of contact. Both surfaces are preferably under pressure contact _{0 along their line of contact}

When moving the loading area at the same speed like the wiping surface, a certain dosage of developer material as well as a wiping is achieved, however, these effects are improved if there is a controlled differential movement between the loading surface and the wiping surface is created within the developing device o

This different movement generates a at the contact line between the loading surface and the scraping surface Interaction in which the loading surface is moved in contact with the moving scraper surface in such a way that that the scraping action occurs in a direction opposite to the direction of movement of the loading surface. the The wiping action should be such that the wiping surface cleans the raised areas of the loading surface and at the same time causes an even distribution of the developer material in the recessed areas of the surface. In addition, there is a removal of excess developer material as well as its return to the development material supply on, for which purpose it can be sucked out of the gap formed at the contact line between the two surfaces. At the same time, impurities such as dust, abrasion or other particles that affect the developed image are released could be kept out of the development zone

The speed difference can be realized by the cleaning surface and the skimming surface are moved in the same direction on their line of contact, whereby a sliding contact or wiping contact occurs. Even

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both surfaces can be moved in opposite directions. In general, such a speed under * - elected that the skimming surface on the Aufohickungsflache slides and a scraping effect of at least 2.5 cm / sec produced Mr a better scraping should the Relative speed between the loading surface and the skimming surface, preferably at least 13 to 25 cm / seo be. If the social difference is too small, so the scraping effect is insufficient, and excess Developer is brought into the gap between the two surfaces · This results in an image development strong background drawings. Is the difference in speed too great, the friction between the two surfaces becomes too strong and there is increased wear on both surfaces Areas as well as a higher power requirement for their drive. If the wiping surface is arranged in a stationary manner, then they do so in a single area of excessive wear and thus exposed to deformation

If the loading area and the scraping area move in one and the same direction at their line of contact, the peripheral speed of the scraping area oa should be <> 90 to about 10 $ of the speed of the loading area. In order to achieve a good scraping effect with minimal wear, the scraping surface should be at high speed of the above-mentioned surface. 250 to oa. 640 om / eec at a rate in the upper part of this Berelohes, that is having about 80 to 90? £ the speed of Besohiokungsfläohe moved becoming At lower speeds the Beaohickungsflache oa ₀ 5 to oa x 50 om / seo to the Gesohwindigkeit the Abatreiohfläohe in the lower Part of the range, i.e. oa · 10 to oa · 20 ^ the speed of the beeohiokungsflache be. In any case, there must be a difference in speed of at least approx.

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If the scraper surface is opposite in one direction that of the loading surface is moved, then there is also a scraping action with a speed difference of at least approx. 2.5 cm / sec, preferably from approx. 13 to 25 cm / sec. This procedure is particular at relatively low speed of the loading surface advantageous, since the minimal scraping effect is independent of the speed of the loading surface can only be achieved by moving the scraping surface slowly in the opposite direction »

The invention is illustrated below with reference to the figures Embodiments described. Bs show:

1 shows a schematic representation of an embodiment of the method according to the invention,

Fig. 2 to 6 further arrangements for carrying out the invention Procedure ..

In the arrangement shown in FIG. 1, there is a liquid developer 12 arranged in a storage container 11. A transfer roller 13 is rotatable on its longitudinal axis 14. stored and is with its lower part by the developer " material 12 dm container 11 passed through. When they turn the roller 13 takes the developer material with its surface and transfers it to the Besohiokungsfläohe, which is in the illustrated embodiment is an engraving roller 15, which is based on their axis 16 rotatably mounted and with a patterned surface of raised areas 21 and recessed areas 22 is provided »The roll 13 and the Besehiokungeflähe 15 are placed in contact with each other, so that at their Boundary surface formed a Sohioht 17 from Eatwioklerflüesigkeit becomes »The Yereehene BesohiokuagBroll® brings the developer fluid to the la · Tente image of an electrorfcatographic display area

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18 approach, which is shown as a plate or sheet and with a counter-roller 20 rotatably mounted on an axle 19 is brought to the development point. The peripheral speeds the transfer roller 13 and the loading roller 15 are regulated independently of one another in the usual way, so that a predetermined difference in the circumferential speeds arises that a transfer of the developer material from the transfer roller to the feed roller in dosed quantities as well as a simultaneous wiping enabled. The depressions contain the for Development of an electrostatic latent image on the recording surface sufficient amount of developer, while the bumps are free of developer when the The coating roller is brought into contact with the electrostatic latent image at the development point. The sublime Areas touch the image surface, while the wells contain the developer fluid and not with the Come into contact with the screen.

In the arrangement shown in FIG. 2, the transfer roller 25 is in a storage container 26 for liquid developer 27 rotated and touches the Besohickungsflache 28, the is shown as an endless belt and has a patterned surface 29 at the point of contact between the two surfaces a layer of developer fluid 30 is formed. As endless belt formed Beschiokungsflache is on guide rollers 31 moved, the belonging to the drive mechanism for the belt 28 The Besohik provided with developer material « Kungsband comes with a photoconductive recording surface 32 brought into contact, which is shown as a rotatable drum is · In doing so, an electrostatic latent image present on it is developed. Xn in this embodiment becomes the transfer roller 25 at a slower peripheral speed turned as I moved the Besohiokungeband, to achieve the required scraping effect "

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In the embodiment shown in Fig. 3, the transmission is Terms and conditions for the developer material are shown in volume 34 « which is performed on Hollen 35, so that it is the developer fluid 36 in the container 37 receives and on the trained as a rotatably mounted roller 38 Besohiokungsfläche transmits. This is provided with a patterned surface 39 A layer of developer liquid 40 is formed at the line of contact between the two surfaces. The roller 38 provided with developer transfers the k developer fluid on the photoconductor 41, which is called (Prommel is formed and carries an electrostatic latent image. After the development, the image can be removed from the photoconductor 41 can be transferred onto a sheet of paper 42 by bringing it into contact with the counter roller 43 with the developed image is brought «, the transfer belt is moved more slowly as the reference roller, so that the desired dosing and wiping action for the developer liquid on the Besohiokungsrolle is achieved.

In Figures 4 and 6 further embodiments are shown, in which the dosing and wiping effect for the developer material is achieved with a wiping surface, ) which is not at the same time the transfer area. In Figo4 the transfer roller 46 is rotatable in the storage container 47 stored for the developer material 48. When turning over * It carries undosed amounts of developer onto the roller 49, which has a patterned surface 50 is provided. The rotatably mounted Abetreiohrolle 51 is in Contact with the Besohiokungsfläohe 50 arranged so that when turning, a dosage and a stripping on the Be-BOhiokungsfläohe is generated and the developer remains in the recessed areas, while the raised areas freed from it. The developer substance that has accumulated on the roll can be removed with a squeegee which is held with a clamping device 45

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The desiccant roll provided with a developing agent is then in developing contact with the recording medium 52 on which an electrostatic latent image is present The desiccant fluid retained by the scraper roller can collect at the gap formed and be returned to the storage container in a known manner. "It can, for example, be wiped off with a sheet and fall back into the storage area due to its gravity.

In the arrangement shown in FIG. 6, the honeycomb roller 63 is in contact with its patterned surface 62 with the devolatilizing agent 60 in the storage container 61 When it is rotated in the container 61, the developer in excess amounts and arrives at further rotation the rotatably mounted scraper roller 64, with which the Bntwioklerstoff in the recessed areas of the Besohiokungsfläohe accumulated, is removed in the raised areas · The With the dosed amount of developer material, the surface to be treated is then brought into development contact with an electrostatic latent image present on the recording medium 65 and the stripping roller is such that the stripping roller is rotated at a lower peripheral speed than the brushing roller in order to achieve the desired wiping effect to achieve · ■

In the arrangement shown in Figure 5, there is a transfer and stripping roller 53 between the transfer roller 54 and 54 The roller 55 is arranged, which is provided with a patterned surface 56 · The one in the storage container 58 There is an indefinite amount of developer agent 57 available brought to the transfer roller 54, which makes it rotate

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transfers to the transfer and scraper roller 53 in undosed or half-dosed quantities · This roller works on the roller 55 in such a way that the developer * fabric accumulated in the depressions of their surface pattern, is practically removed on its elevations · The amount of developing agent dosed in this way The focus roller is brought into developing contact with a dielectric recording surface 59 which carries an electrostatic latent image "The transfer and fc scraper roller 53 must be rotated slower than the desiccant roller «

In dtn Tig * 5t 6 and 7 »11 · surfaces are ice surfaces rotatable cylindrical rollers shown, but such surfaces can also be designed as a band or sheet, wl · this is shown in the other figures · for example can transfer roles, independent «delivery roles and recovery rollers replaced by one ei Closes tape each become »Any common configuration of an electrostatographic Recording surface can be seen · A transfer station for transferring a developed image on a copy sheet can also be present

The wiping surface can always have a suitable configuration · For example, all can be designed as a rotatable roller or as an endless belt, which is held by a counter surface at the contact line with the touching surface · TJm to enable effective wiping of the raised areas of the soft surface? a removal element with a smooth surface should preferably be used.

Any suitable material can be provided as Atisitrelohflä®! * © it must be relatively resistant to -ilterimg »wear and tear and before »! see influence« in latwieklaretoff «· to be a suitable material for a

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be resilient and has a Shore hardness (scale A) of about ₀ to 20 cao 90 durometer units have. " Preferably the hardness oa. 40 to oa. Materials of this hardness with a hardness of 60 durometer units enable the best balance between wear properties and wiping effect · In general, materials with too low a hardness value experience too much friction and wear and produce too strong a wiping effect »while materials with too high a hardness value have insufficient contact and insufficient contact Have a scraping effect "In order to maintain a constant level of scraping efficiency even after non-operating periods, the scraping surface should preferably have little or no compression deformation." Typical suitable materials are silicone rubber, nitrile rubber, fluorosilicone rubber, Buna N rubber, neoprene, polyurethanes, leather and Corfam polymer. If a roller scraper surface is used, the following materials are suitable, which show the desired balance between wear and scraping effect: Elastomers such as Fluorosilicone (¥ 2249), Fluorosilicone Silastic LS63U, Silastic LS2311, all manufactured by Dow Corningο The following polyurethanes are also very suitable * Disogrin 6345 and Disogrin 7560, both products of Disogrin Industries, also Nuclear, manufactured by SoBingham. The nitrile copolymer Koralith from WR Grace Company is another suitable material. The fluorosilicone rubber Silastic LS63Ü from Dow Corning achieves an optimal balance between wear and tear.

The cylindrical squeegee roller can be of any suitable size and shape Have configuration. It should be stored exactly centrally on its longitudinal axis in order to have a uniform effect on the To ensure occupancy area. A roll of approx. 23 om Length and a diameter of 2.5 cm shows satisfactory results · Di · Roll can be in the form of a cylindri Have a wave and with an »over-eye or a shell from one.

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of the elastomers mentioned. A suitable roller is made of a steel core of 19 mm diameter with an elastomeric shell of approx _o 3 »2 mm thickness, so that there is a role cm with an outside diameter of approximately" 2.5.

Is the. The wiping surface is designed as an independent element, which is only intended to exert a wiping effect without transferring the developer material to the loading surface, so an independent transfer surface is normally also used. This can have any suitable configuration and can also be designed as a rotatably mounted roller or as an endless belt. It consists of a suitable material that is resistant to aging and ohemisic influences. It preferably consists of the substances already mentioned for the wiping surface «

The feed surface may be any suitable size and configuration and have to be designed as a roller, for example, in the type shown in Figure 1 ₀ It can also be an endless belt according to Figo 2 having a patterned surface. Further, metal sponge, porous ceramic materials and deep grained lithographic plates may be provided from aluminum as BeSchickungsvorrioh- "tung ₉ main characteristics are the patterned surface, preferably raised in a uniform or regular configuration and recessed Bereiohe, and the ability to a Entwioklerstoff in the recessed areas of the In order to keep background deposits to a minimum, the raised areas of the pattern are preferably fluffy, but they can also be punctiform or curved The finer the pattern on the absorbent surface, the greater the resolution of the developed image

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the image quality is maintained.

A cylindrical roller can serve as the loading device, the surface pattern of which is designed as a triple spiral, pyramid-shaped, single spiral or with square depressions. A spiral pattern, i.e. a single spiral or a triple spiral, is preferably provided, since its continuous depressions enable better movement of the developer material in relation to individual depressions, so that the stripping effect is more easily achieved Lines per cm, gate closures from 70 to 100 lines per approx and optimally 80 lines per approx. The depth of the pattern is between 0.008 and 0.2 ma, preferably approx. O ₉ l mm and optimally around. approx. 0.05 mm. With these values there is a balance between a sufficient amount of developer and an optimal image resolution. The angle of the depressions is important for the development of halftone images, especially with regard to minimal moiré effects. Therefore, an angle of the above is preferably used. 30 ° to approx. 60 ° in relation to the longitudinal axis, with an angle of approx. 45 allowing satisfactory development for all types of images

for making full size copies is one Skirting roll of oa * 23 om length and oa · 2.5 cm durometer available in the stores. Since the occupation role is more expensive is than the wiping surface, it preferably exists made of a harder material that is more resistant to wear and tear than the contact area of the scraper. device and that the constant pressure on the line of contact with the scraper withstands. Furthermore it should have little or no twisting deformation. One important thing The property for optimal development consists in ia§ dl · Beeohlokungifläoh «and the wiping surface · evenly

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are designed so that an even distribution of the developer material and an even wiping effect is achieved.Suitable materials for the feed roller are steel, brass, aluminum, elastomers and plastics such as neoprene, polyurethane, nylon or luciteo The roller can consist of a solid body or a core with a cover of a different material. Be corrosive liquid developer materials used, to the surface of the Be * - to be provided schickungsrolle with a thin protective coating to prevent corrosion and wear au comparable wrestlers' "

If a belt-shaped loading device is used, its material should also be flexible. Any metal that meets these requirements and is suitable for electrically forming a seamless belt can be used. A material with these properties is liokel. Furthermore, a patterned polyester film is suitable for a belt-shaped loading element. The use of a ribbed plate is also possible, preferably when the stripping surface and the image surface act in two different directions.

"Any suitable elektrostatografisohe image area can Torgese" hen be · Essentially this is any area that an electrostatic charge holding pot Typical such up "are drawing flat u" _ae not fotoleitfähiga dielektrisohe substances Xerodruokplatten and photoconductive insulating · The elektrostatografisohe recording surface, each have a suitable configuration, for example it can be designed as a drum tape or plate according to the arrangements shown in the Iigsir @ n shown s®in _o fyp ± a © 3Si © suitable substances are selenium, Selealegisraagta and BIaiesiittelssmsaiiiieastisssMagta with SlnkexteS j öadmiuasulfii, Gais ± TO £ iialfQS © l © ffiid s © · »! ® di © • organic total ladder including ^ thalooyaaln-Blndealt * · teleoliiohteii and Pölyviayloartoaaelo ^ © gaugaweiee waräsa,

Selenium or selenium alloy coated drums, with a Paper coated with zinc oxide binder layer or with paper coated with a phthalocyanine binder used

Any suitable liquid developer can be used. Such developers are polar and non-polar liquids. In order to achieve the right balance between charge storage capacity with high specific resistance and charge dissipation with low resistance, the developing agent should preferably have a specific resistance of approx. 1CT to approx. 10 * ohm cm and consist of a substance used for polar liquid development, electrophoretic development or wetting development * A pigment substance can be suspended or dispersed in the carrier liquid, or the carrier liquid contains a dissolved dye. Pigmented developing agents generally produce better tint density and more permanent images. The developing agent used should have a relatively long service life and be compatible with the materials with which it comes into contact during the developing process. Gravel means that chemical deterioration of an individual element of the developing device by the developing liquid should be avoided or kept to a minimum by selecting a substance suitable for this purpose. Preferably, the developer should wet the depressions of the loading area in order to enable uniform loading. Suitable liquid developers are, for example, dyes based on water, oil or alcohol, for example with carrier liquids such as mineral oil, oleic acid, polypropylene glycol, 2,5-hexanediol, glycerol, Sorbitol, vegetable oils such as castor oil, peanut oil, sunflower oil, seed oil, and olive oil. Other carrier liquids are aliphatic hydrocarbons such as petroleum solvents, gasoline, kerosene, petroleum naphtha, aromatic hydrocarbons such as benzene,

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Toluene and xylene, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol and butanol, ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone and esters such as
Ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate,
Butyl stearate and butyl oleate. These liquids can
can be used with or without dyes. A typical non-dye application is a process of secondary development with a powdered or layered coloring agent. In general, however, a colored liquid developer is preferably used. Typical coloring agents are carbon black, charcoal, iron oxide, ultramarine blue, zinc oxide, titanium dioxide, methylene blue, methyl violet tannate and benzidine yellow. The liquid developer can also
contain a dispersing agent, for example alkylated polyvinylpyrrolidone, which aids the dispersion of the pigment in the carrier liquid and promotes the absorption of the developer into the paper onto which the developed image is transferred. Furthermore, synthetic resins such as nitrocellulose and the rosin esters can be added to the transferred image to impart resistance to smearing

P The storage container for the developer, the guide rollers and drive mechanisms can be made of any material that is compatible with the liquid developer used in each case «. The storage container is said to be a limited one Have the capacity to avoid excessive consumption due to splashing and good mobility of the developing device, which accommodates the container to enable. Preferably, the container is designed such that he takes up the surface of the transfer device over its entire length, so that this device the developer can be transferred evenly to the boiling area. A suitable storage container is, for example, trough-like educated. It is preferably in the form of an in

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closed cartridge "·

If a photoconductive recording medium is used, so becomes a photoconductive layer of insulating material uniform electrostatic charge is applied, then the layer is exposed to a real-shadow image, so that an electrostatic latent image is created on the surface of the layer «, the loading device that was previously used with provided a metered amount of developer liquid and according to of the invention is then applied to the electrostatic latent image brought up for development

The Abstreichfläohe and the Beschiokungsflache are with or operated without a special deaerating feed system and as a whole constitute a developing device, in the amount of developer fluid dosed into the loading area that develop the electrostatic latent image, when the loading area is in the development position is brought to the scene. The dosing and stripping of the loading area is carried out by a controlled system different movement between the loading area and the scraper surface so that the circumference of the scraper surface when moving in the same direction as the ingestion area moves at a slower speed than the ingestion area. If the skimmer is in a the opposite direction to the surface is, this movement must be fast enough to achieve the desired wiping effect. The controlled different speed of the circumferential surfaces in the area of their line of contact is the decisive value, not the relative angular velocities.

Move the painting area and the drinking area in the same direction, the skimming surface must be

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be moved over the loading area at a lower speed, namely sufficiently fast to provide the loading area with developing agent, but sufficiently slowly to achieve a wiping effect. With the mutual movement between the Abatreichflaehe and the Aufohickungsflache and the appropriate speed difference, a layer of developer liquid is formed between the two surfaces, and the loading surface is compensated by the slower scraping surface "Process is also referred to as" sliding roller scraping ". If a single roller is used to scrape off and apply the developer material, this process can be referred to as ^{" 1} feed scraping ".

Development speeds of up to approx. 640 cm / seo can be achieved with this method. «The Beschiokungsfläche moves with a speed of ₀ 640 cm / sec, while the circumference of the skimmed surface in contact with the Aufohickungsflache and in the same direction with a speed of approx. 570 cm / sec is moved. At development speeds of approx. 2.5 to approx. 50 cm / sec, at which the loading surface is moved at approx. 2.5 to 50 cm / sec, the scraping surface moves in the same Direction with speeds of up to approx. 30 cm / sec, but at least 2.5 cm / sec slower than the occupancy area. With development and loading surface speeds of the above 13 to 38 om / sec is a good Abstreiohflache that moves in the same direction with a speed of the above. 2.5 to oa. 10 om / seo moves. If the scraping surface is moved in the opposite direction to the coating surface, its speed should produce a scraping effect of the same size as previously described. For example, the stripping surface becomes at a loading surface speed

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moves from approx. 2.5 to approx. 50 cm / seo at a speed of up to oa _o 20 om / sec. In. in any case, however, the minimum required wiping effect should be retained «

The wiping surface and the filling surface should be in contact with one another in order to effect the desired dosage of the developer and the wiping o To achieve this, the surfaces should preferably be in pressure contact with one another. The pressure can be varied depending on the hardness of the respective surface, but in general it is between approx. 180 and oa _o 2150 g / cm. Units used, the pressure between the surfaces at their line of contact is 180 to 540 g / omega. However, if a harder material such as polyurethane is used with a hardness of above _e 80 to 90 units, an increase in the pressure to about ₀ 1800 to 2150 g / cm is required · The pressure is to ensure a uniform contact of the contact line along both surfaces generated. The lowest possible pressure should be used, since there is the possibility of permanent deformation when the pressure increases. This can result in an uneven transfer of the developer substance and an uneven wiping off «. In order to avoid deformation due to possible compression deformation when the development device is not in use, the skimming surface is preferably removed from the skimming surface with a simple cam mechanism , whereby a better wiping effect is achieved up to a certain point. A change in the speed while maintaining the constant pressure can also change the pressure on the loading area

009883/1940

of transferred developer material · At, higher Speeds and constant pressure, less developer material in the recessed areas of the occupation area entered.

The viscosity of the developer fluid used depends in part on the development speed. At high speeds, a low viscosity is preferably used, while at lower speeds, substances with a higher viscosity can be used _o For high-speed operation with development speeds of more than approx The pressure between the transfer surface and the loading area should be increased by approx. 640 cm / sec. If, for example, a loading roller made of steel with a triple spiral pattern is used, the pressure when using a transfer roller with 30 durometer units is 2700 to 4500 g / cm. With increasing hardness, a higher pressure is required. At operating speeds above 250 cm / sec, heat is generated in the developer liquid, and a device must be provided to dissipate it, for example allowing a cooling liquid to circulate through the contacting elements.

A particular advantage of this development process can be observed when a cylindrical roller with re relatively low hardness, for example one with a screw thread provided cylindrical role is used · With such roles is only a very small and easy to determine Development area required * They are particularly useful for developing line drawings or small picture elements suitable

The mechanism of development in the above processes corresponds to that described in US Pat. No. 3,084,043.

009883/1940

benen, whereby the liquid developer selectively through an electrical pain removed from the soling element is «» It is described elsewhere that also with the liquid developer materials with insulating properties the development mechanism essentially corresponds to that of the polar liquid development, if a patterned Besohiokungselement is used »

According to the invention, the connection between the storage container for the developer material and the combination of transfer and stripping surface can be realized in such a way that the stripping surface is supplied with at least a sufficient amount of developer material for image development Developing agent on the wiping surface by dipping it into the developing agent inside the container or by spraying or dripping the developing agent from the container onto the wiping surface the developing agent is present in a relatively uncontrolled manner on the surface and the » In the picture belonging to the flap parts, the deposited developer substance is enlarged. The transfer and stripping surface is therefore brought into contact old of the Beeohiokungefläohe in order to achieve a transfer of the Entiokleratoffes.This contact can take place in a simple way along a line where the surface and the Abstreiohfläohe meet Contact with the boiling area is exercised with sufficient bruise "so the spreader roller at the contact point can be flattened so that there is a contact area with the bntwiok"

000883/1940

1 mass transfer trains. Under a line contact the linear contact and the contact within a narrow area should be understood «, Bei This type of developer transfer becomes the developer the Beschiokungsflache fed in such a way that it is in their recessed areas is present, but their raised areas are devoid of developer · The so with developer provided loading surface, then becomes the development contact brought up to the electrostatic latent image, this touch is similar to development required for the known dry process

A similar supply of developer material is carried out if an independent wiping surface is used, as shown, for example, in FIG immerse the Beeohiokungeflache in the development material supply, while an independent wiping surface provides the necessary wiping effect on the developer on the surface exercises. The arrangement according to Pig. 4 is also used an · independent Abetreiohflache used, the Äatwiokleretoff does not have to be applied to the sesohiokunger surface in precisely measured amounts · As can be seen from Fig. 5 the developer can also transfer material over several gunga rolls are carried out

Since the various functions required in the method according to the invention can be carried out one after the other with continuous steps and each step of the process is completed, a continuously working developing device can be implemented and an ongoing image development is only required when switching on Working in this way development »« · device an ausraiolisiai® start-up time Torsuaeh®ii ₉ nm on the BeBuhiokuiigt) surface in front of the actual picture, depending on the situation, a reliable Meng® development release itnfliflBg ^ n ssu can ·

00988311940. -

2032111

To control the timing of this process, a control device can be provided which determines the initiation and termination of the development process

The following examples serve to further explain the method according to the invention with regard to the use and comparison of different materials and method steps They are in no way to be understood as restrictive. »Example II is used for comparison purposes · Unless otherwise stated, all proportions relate to Amounts of fabric and percentages based on weights

Example I.

A combined transfer and scraper roller from oa. 23 cm in length consists of a steel core with a diameter of approx. 19 mm with a 3 | 2 mm thick sleeve made of the fluorosilicon rubber LS63U from Dow Corning Corp. with a Shore hardness (scale A) of 60 durometer units. = This role is in a developer rotatably mounted, which follows is composed:

Light mineral oil .30 parts

Ganex V216 15 parts

Microlith CT black 18 parts VM 550 methyl violet

Tannat

Rinsed pigment 3 parts Paraflint RG wax 0.5 parts

Ganex V216 is an alkylated polyvinylpyrrolidine from GAP Corporation. Miorolith CT black is a pre-dispersed; Synthetic resin carbon black pigment, which is made from the above 4OfS carbon black and 60? £ resin esters exists and is manufactured by CIBA. VM 550 methyl violet tannate is a pigment produced by Magruder Color Go ·. Paraflint RG wax is a coal water «

009883/1940

fabric wax manufactured by Moore and Munger Corporation »

This combined transmission and doctor roller is brought sberührung under a pressure of Ca ₀ 540 g / om with a feed roll of steel of 23 cm length and 2.5 cm in diameter in motion. The feed roller is provided with a triple spiral pattern of 70 lines per cm, which run at an angle of 45 ° to the longitudinal axis of the roller. The two rollers are arranged similarly to the apparatus shown in Pigd, with the feed roller in contact with a photoconductive zinc oxide binder layer held by an idle roller. The developing device is activated and the zinc oxide paper provided with an electrostatic latent image is transported , 5 cm / seco the existing on the Zinkoxidpapier imagewise distributed developer material is transferred to Xerox Peinpapier 4024 "a good quality printing with relatively low background and a resolution of about ₀ 8 line pairs per millimeter is the Ergebnisο

Example II

The procedure of Example I is repeated with the difference that the peripheral speed of the combined transmission and Abstreiohrolle coincides with that of the Beschikkungsrolle and about ₀ 15 cm / sec beträgto on the copy paper gives no readable image, since the wells of the feed roller by the action of the scraper roller no longer contains any developer material. 23 to 25 om / seo

009883/19 AO _ ^ß AD original

show similar results.

Example III

Example I is repeated with the difference that the developer fluid transferred to the coating roller with a cylindrical transfer roller with a smooth surface will. The transfer roller is made of neoprene and is in light contact with the Beschiokungsrolle. she is rotated with a peripheral speed of oa «> 15om / seo The combined transfer and scraper roller off Example I is brought into contact with the feed roller at a point under a contact pressure of approx. 540 g / cm. which is about «90 ° counterclockwise compared to the Line of contact with the transfer roller is offset. This results in an arrangement of the type shown in Pig. 4. The feed roller is rotated at a circumferential speed of approx. 15 cm / sec, the scraper roller is reversed turned to the electrical roller. The peripheral speed of the stripping roller is oa. 10 om / seo. The development is carried out in the same way as in Example I, the images obtained are of the same quality

Example IV

The procedure from Example I is repeated with the difference, that the Aufohickungsrolle with a peripheral speed of approx. 50 om / seo and the combined transmission and doctor roller with a peripheral speed of the above. 25 om / seo is turned. The Beaohiokungsrolle and the combined Transfer and stripping rollers are under a contact pressure of oa · 720 g / am · The developer fluid is composed as follows ι

Polypropylene glycol 40 parts

Staybelite Beter 8 -2TtIIe

Miorolitk OT eohwara 15- Ttilt

Ruooflex TÖ-8 8 TtUt

OQ9083 / 19AO

2032911

The polypropylene glycol is Baker PPG 2025, manufactured by used by the <Τ · Τ · Baker Chemical Company, it has an average Molecular weight of 2025. Stabelite Ester 8 is a esterified resin manufactured by the Hercules Powder Company. Rucoflex TG-8 is a triethylene glycol dicaprylate, manufactured by Hooker Chemical Company. Processing is carried out as described in Example I. the Pictures have a quality corresponding to the pictures from example I.

Example Y

A transfer roller, a feed roller and a scraper roller are arranged as shown in FIG the feed roller and the scraper roller at their line of contact move in one and the same direction · The transfer roller consists of a 19 mm thick steel core that is connected to a 3 »2 mm thick neoprene sleeve with 80 durometer units (Shore hardness A) is coated. The feed roller is a chrome plated steel roller with a diameter of 2.5 cm, with a triple spiral pattern of oa « 80 lines per cm is provided · The doctor roller consists of a steel core of oa · 19 mm diameter and a 3.2 mm thick coralith coating with 80 durometer units, a product of the company W «R · G-raoe & Co. The lower part of the The transfer roller is immersed in a developer container containing a developer with the following composition contains!

Butyl stearate 15 parts

ßanex V216 5 parts

Miorolite CT

black 8 parts

A polyvinyl carbazole binder plate is used as the recording surface «A switchable 8 gearbox is poor«

009883/1940

light speeds of rotation of the feed roller and the doctor roller in a ratio of 1.07: 1 to 6.67: 1. · 'The surface of the feed roller is moved with a peripheral speed of ca _o 250 cm / sec, a developing speed to achieve the same magnitude, the transfer roller is moved to a contact pressure of about _o 1800 g / cm on the feed roller "the doctor roller is rotated at a contact pressure of about ₀ 3600 g / cm on the feed roller, the rotational speed of the doctor roller is about ₀ 230 cm / seco the development is carried out in the manner described in Example I. The result is good quality images with relatively little background information

' Example YI

A transfer roller and a loading roller are used in arranged as shown in Pig.1. The feed roller ist.die described in example T, the transfer role exists from a 19 mm thick steel core with a 3 »2 mm thick Nuclear elastomer layer of 30 durometer units Hardness o The developer material is that described in Example V, The feed roller is rotated at 4800 rpm, resulting in a development speed of approx.640 cm / sec * The transfer roller is resiliently pressed against the loading roller with a pressure of approx. 3600 g / cm rotated by frictional contact with the feed roller « Your turning speed is, however, controlled by a band brake reduced, which acts on the axis of rotation of the transfer roller, so that its peripheral speed is about 585 cm / sec amounts to. The development takes place on a polyvinyl carbazole binder plate in the manner described in example Y " The results are good quality images «

Example VII

The procedure from Example I is repeated with the

00 98 83/1940

decided that the scorching roller has been replaced by a steel rod 3 "2 mm in diameter, with a thread of 80 lines per om and a depth of 0.08 mm". This rod and the combined transfer and scraper roller have a length of approx. 9 cm. A thin scraper is for. provided the transmission and doctor roller, it causes a rough assessment of the amount of the developer material quantity on the reel to about 1.6 mm _o at the outlet from the Entwicklerstoffbad. The development and the transfer are carried out in the manner described in Example I <> The result is an image of good quality with little background image.

The foregoing description of the invention and various embodiments relates generally to the continuous one Operation in which every operational step is systematically classified in the overall process and the uninterrupted one Working method guaranteed »It should be pointed out that every single step is also not individual in one systematic and discontinuous procedures can be carried out. For example, the loading area can in this case fully provided with developer and wiped off after which it is removed from the developer transfer point and the stripping point and used for development is specially brought to the picture

The substances and embodiments described above of the invention are only to be understood as examples. In addition to these, there are other developer substances and types of processes which can be used or carried out instead of those mentioned in the exemplary embodiments. For example the developing device can also work with a dry electroscopic developer powder *

Further embodiments are known to the person skilled in the art

009883/19 ^ 0

the above description possible, they are total covered by the basic principles of the invention

0098 83 / 19A0

Claims (1)

Claims ! Method of developing a latent electrostatic Image with a developer, characterized in that that a Besohiokungsfläohe (15) with a pattern of raised (21) and recessed areas (22) is provided with the developer (12) and brought into motion contact with a scraping surface (13), which ensures a uniform distribution of the developer material (12) in the recessed areas (22) and removal of the developer substance (12) from the raised Area (21) causes and that the electrostatic latent image with the loading surface (15) in contact is brought 2 «The method according to claim 1, characterized in that the developer (12) in an undosed amount a rotating transfer roller (13) with a smooth surface is applied, which is in transfer contact is rotated on the loading surface (15), and that the relative peripheral speed of the transfer roller (13) and the loading surface (15) is set in such a way that the transfer roller (13) acts as a wiping surface acts, whereby the developer (12) on the charging surface (15) in a metered amount and leveled off State is transferred 3. The method according to claim 2, characterized in that the surfacing surface (15) has a greater circumferential speed as the transfer roller (13) is rotated. 4. The method according to claim 1, characterized in that the Entioklerstoff is transferred to the Besohiokungsfläohe (49) in an undosed amount that the Beschikkungsfläohe (49) in line contact with a smooth one 009883/1940 ■ - 35 - ■ '■. Wiping surface (51) is brought and that both surfaces (49, 51 ") with a different peripheral speed be moved, which has a Abstreiohffekt the wiping surface (51) on the loading surface (49) of generated at least 2.5 cm / sec « 5ο method according to claim 4, characterized in that the developer material (48) is transferred to the loading surface (49) with a transfer roller (46) 6. The method according to any one of claims 1 to 5, characterized in that that a polar or a non-polar liquid is used as the developer. 7 * Method according to claim 6, characterized in that. a liquid in which a pigment is uniformly dispersed is used. Process according to Claim 6, characterized in that a liquid is used in which a dye dissolved isto 9. Method according to one of Claims 1 to 8, characterized in that the developed image is transferred to a copy medium (42) is transmitted » 10. Method according to one of Claims 1 to 9, characterized in that that the Besohickungsflache (49) with a Speed between 2.5 and 640 cm / sec is moved and that the speed difference between the loading surface (49) and the stripping surface (51) is at least 13 cm / sec. 11. The method according to claim 10, characterized in that the speed of the Aufohickungsflache (49) 2.5 to 009883/19 AO 50 cm / sec and the peripheral speed of the Abstreiehfläohe (51) *, 5 to 30 om / sec, 12 · The method according to claim 11, characterized in that the speed of the suction surface (49) 13 to 38 cm / sec and the peripheral speed of the scraper area (51) is 2.5 to 10 cm / sec 13o method according to any one of claims 1 to 12, characterized characterized in that the loading surface> (49) and the scraping surface (51) under pressure contact of up to stand at approx. 2700 g / cm, 14, the method according to any one of claims 1 to 13, characterized in that that a wiping surface (51) is used, which is made of a smooth elastomeric material with a Shore Α hardness of approx. 20 to approx. 90 and is arranged on the surface of a rotatable hollow, 15, the method according to any one of claims 1 to 14, characterized in that that a Aufohickungsfläche (49) is used, which is arranged on a rotatable roller and with a triple spiral pattern from oa «30 to approx. 120 lines per cm and a depth of about 0.008 to about 0.15 mm is provided at a line angle of 30 to 60 ° to the longitudinal axis of the roller 16 »Device for carrying out the method according to a of claims 1 to 15, characterized in that one with a regular pattern of raised (21) and a swelling surface (49) provided with recessed areas (22) and a transfer device (46) for developer material (48) and a smooth skimmer surface (51) is assigned in line contact that a drive 009883 / 19AO / 2092β Device for moving the lifting surface (49) and the scraping surface (51) at different speeds is provided and that the Besohickungsfläehe (49) to the with a latent electrostatic Image provided recording medium (52) "is movable o 17β device according to claim 16, characterized by that to transfer the developer (12) to the Besohickungsfläche (15) a transfer roller (13) is provided, which is opposite to the Besohiokungsfläohe (15) is rotated at a lower speed, so that the transfer roller (13) also acts as a scraper surface acts β 18. Device according to claim 16 or 17, characterized in that that the relative speed between the Abstreiohflache (13) and the loading surface (15) at least 2.5 cm / seo, 19 · Device according to one of claims 16 to 18, characterized characterized in that the wiping surface (51) is a rotatably mounted cylindrical roller with a smooth surface is. 20 · Device according to one of claims 16 to 19, daduroh characterized that- the Besohickungsfläohe (49) a rotatably mounted cylindrical roller with a uniform surface pattern is β 21. The device according to claim 20, characterized by that the surface pattern is designed three-way-spiral and from the above. 30 to oa. 120 lines per om with a depth of oa · 0.008 to oa. 0.15 mm, which is at an angle of about 30 to oa. 60 ° to the longitudinal axis 00988 3/19 4 0 the roller (49) run, and that the Abatreiohflache (51) a smooth cylindrical roller with an elastomer The surface is the material of which has a Shore A hardness of the above. 20 to approx. 90 has 22. The device according to claim 16, characterized in that that the transfer device (46) is a rotatably mounted cylindrical roller with a smooth surface is. 23 · Device naoh one of claims 16 to 19, characterized in that the loading area as endless belt (28, 29) is formed. 24. Device naoh one of claims 16 to 23, thereby characterized in that a device (42, 43) for transferring the developed image onto copy paper (42) is provided· Device according to Claim 17, characterized in that the transfer roller (46) operates at a peripheral speed can be rotated from approx. 2.5 to approx. 30 cm / SEO, that the Besohiokungsrolle (49) with a peripheral speed of about 2.5 to oa. 50 cm / sec can be rotated, and that both rollers (46, 49) exert a contact pressure of approx. 180 to approx. 540 g / cm on each other 26. Device according to one of Claims 16 to 25, characterized in that the boiling area is a with a surface pattern provided cylindrical rod and that the stripping roller is opposite to the Rod has a much larger diameter 27 · Device according to one of claims 16 to 19 »characterized in that the regular pattern is spirally trained iet. 0 0 8 8 8 3/1940 " ^BAD original