JPH05503166A - Imaging device with intermediate transfer member - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Imaging device with intermediate transfer member Branch of development The present invention relates to image transfer technology and apparatus for use in electrophotography.

Background of the invention Various conventional publications describe the formation of single or multiple powder toner and liquid toner images. transfer from the photoreceptor to the intermediate transfer member and subsequently to the final substrate. We deal with photographs.

U.S. Patent No. 3,838.919 to Takahashi, color toner images are sequentially formed into images. are formed on recording members, and are individually transferred to intermediate transfer members to form one recording member at a time. A powder toner device is described as being transferred.

U.S. Pat. No. 4,144,808 to Isawa et al. Describes a method for printing onto a metal plate that is heated prior to transfer using an intermediate transfer member. ing.

U.S. Patent No. 4,518,976 to Kurumi et al. a single color powder toner device that is developed on and electrostatically transferred to an intermediate transfer member; is listed. Downstream of this transfer, the intermediate transfer member and the image thereon are preheated. The film is heated before being transferred to the base layer.

U.S. Patent No. 4,515,460, issued to Knechter, each has a separate - such that the image is subsequently developed on the photoreceptor and electrostatically transferred to the intermediate transfer member. describes a powder toner device made in the United States. All individual images are transferred to an intermediate transfer member. After being imaged, these images are electrostatically transferred to the final substrate. statue or There is no mention of heating the base layer.

U.S. Patent No. 4,585,319 to Kaihon et al. Heated intermediate transfer member and heated to a temperature slightly higher than the temperature of the intermediate transfer member describes a powder developer type monochromatic device that uses a heated transfer fixing roller. Ru.

U.S. Pat. No. 4,690.539 to Radulski et al. A multicolor liquid toner that is developed on a light receiving device and transferred to a belt-type intermediate transfer member. It describes the inner device. removed from the toner image on a liquid carrier or belt It looks like this. Intermediate transfer member or back transfer The problem is not explained.

U.S. Patent No. 4,708,460 to Langton transferred from the device to an intermediate transfer member, heated on the transfer member, and then transferred to the final substrate. describes a monochromatic liquid toner device such as the one shown in the image.

No. 3,847,478, issued to Young, developed image is transferred to an intermediate transfer member and developed on a second image or photoreceptor, so that both images are transferred to an intermediate transfer member. A sheet of paper is passed between an intermediate transfer member and a light receiving device, and then transferred to opposite sides of the sheet. Describes a duplex printing device such as the one pictured.

Summary of the invention The present invention contemplates providing an improved image transfer device.

One object of the present invention is to transfer an image from an image bearing surface to an intermediate transfer member, which is subsequently transferred to a final transfer member. Improved transfer to the base layer.

An object of the present invention is to provide a method and apparatus.

A further object of the invention is to intermediate multiple superimposed images without reverse transfer. An object of the present invention is to provide a method and apparatus for sequentially transferring to a transfer layer.

The latent image thus formed on the latent image supporting surface according to the preferred embodiment of the present invention provides an imaging device for printing an image on a substrate, which device A developing device that develops a latent image using a liquid developer to form a developed liquid toner image. and, a first intermediate transfer member; The image developed in the first transfer zone is transferred from a latent image bearing surface force 1 to a first intermediate transfer member. a first transfer device for transferring; a second intermediate transfer member; transferring the developed image in the second transfer zone from the first image intermediate transfer member to the second intermediate transfer member; a second transfer device for transferring onto a photographic member; a second transfer device for transferring the developed image from the second intermediate transfer member to the base layer; Contains.

In a preferred embodiment of the invention, the imaging device transfers the developed liquid toner image to a first heating to a first temperature above room temperature in a transfer zone; and a heating device for heating to a second temperature higher than the first temperature.

Further, in a preferred embodiment of the invention, the imaging device transfers the first intermediate transfer member to the first intermediate transfer member. heating the second intermediate transfer member to a second temperature higher than the first temperature; and an intermediate transfer member heating device for heating the intermediate transfer member.

In still other preferred embodiments of the invention, the liquid toner image is removed from the image bearing surface. the transfer is enhanced at a temperature higher than the first given temperature; a second temperature at which the transfer of the liquid toner image to the final substrate is higher than the first given temperature; improved at temperatures above a given temperature, Undesired image transfer from the intermediate transfer member to the image bearing surface or the first applied temperature a third given temperature that is greater than or less than said second given temperature; increased at temperatures above; the first temperature is higher than the first given temperature and the third given temperature is higher than the first given temperature; temperature, wherein said second temperature is higher than said second given temperature. It will be destroyed.

In a preferred embodiment of the invention, the imaging device also transfers the first intermediate transfer member to the first intermediate transfer member. a first voltage device for maintaining the voltage at a voltage of . at least a portion of the latent image bearing surface or a second voltage, the first voltage is different from the second voltage. It's done differently. The apparatus holds the second intermediate transfer member at a third voltage. It is desirable to include a second voltage device to

In a preferred embodiment of the invention, the development device transfers the developed liquid toner image to an intermediate After being transferred to the transfer member, the latent image is developed into a second developed liquid toner image by a developer device. and the first transfer device is operable to form a first image onto the image bearing surface. transferring the second liquid toner image to the first intermediate transfer member without substantial reverse transfer of the second liquid toner image; and is operable to form a composite image. A second transfer device transfers this composite image to a second transfer device. is operable to transfer to an intermediate transfer member.

In a preferred embodiment of the invention, a development device develops different latent images on an image bearing surface. the first transfer device is operable to form different liquid toner images thereon; This different liquid toner image is then transferred to a second intermediate transfer member. The image is operable to transfer the image to the first intermediate transfer member. This third transfer device connects the device for supplying the base layer to the second transfer zone and the first and second transfer members to each other; the developed liquid toner image is transferred to one side of the substrate. , including a device for allowing a different liquid toner image to be transferred to the other side of the substrate. Yes.

Furthermore, in a preferred embodiment of the present invention, the latent image formed on the latent image supporting surface An imaging device for printing an image from is provided, this imaging device is A developing device that develops a latent image with a liquid developer to form a developed liquid toner image. Place and A developed image is received from the latent image bearing surface in a first transfer zone, followed by a second transfer zone. a heated intermediate transfer member that transfers to the final substrate in a transfer zone; Cooling a portion of the intermediate transfer member and then applying an image to the cooled portion of the intermediate transfer member. a cooling device for transferring the imaged portion; Contains.

In a preferred embodiment of the invention, the transfer of the liquid toner image from the image bearing surface occurs in the first The liquid toner image on the final substrate is enhanced at a temperature above a given temperature of at a second given temperature higher than said first given temperature. the transfer of undesirable images from the intermediate transfer member to the image bearing surface is a third given temperature that is higher than the given temperature or lower than said second given temperature; temperature at which the intermediate transfer member is heated in the second transfer zone. heated to a temperature equal to or higher than the second temperature, and the cooling device moves the intermediate transfer member to the first temperature. is operable to cool to a temperature above the third temperature and below the third temperature.

In a preferred embodiment of the present invention, a developing device is configured to transfer the developed liquid toner image to After being transferred to the intermediate transfer member, the latent image is developed to form a second developed liquid toner image. the intermediate transfer member and the cooling device; transfer this second liquid toner image without substantial reverse transfer of said first liquid toner image to an image bearing member. to transfer the developed liquid toner image to an intermediate transfer member to form a composite image. Operable.

Furthermore, in a preferred embodiment of the present invention, the latent image formed on the latent image supporting surface provides an imaging device for printing an image on a substrate, which imaging device uses a liquid developer. a developing device that develops the latent image with an agent to form a developed liquid toner image; an intermediate transfer member heated to a first temperature and an image developed in the first transfer zone; a first transfer device that transfers the latent image from the image support surface to the intermediate transfer member; heating the base layer to a temperature higher than the first temperature for transferring from the intermediate transfer member to the base layer; a second transfer device including a heating device for heating to a second temperature.

In a preferred embodiment of the invention, a heating device is provided on the image during the second transfer. It includes a heated support roller operable to apply heat and pressure.

In a preferred embodiment of the invention, the development device transfers the developed liquid toner image to an intermediate After transfer to the transfer member, the latent image is developed to form a second developed liquid toner image. the first transfer device is operable to form the first transfer device on the development device; a second developed liquid toner image without substantial reverse transfer of the developed liquid toner image to the image bearing member. and is operable to transfer the liquid toner image to an intermediate transfer member to form a composite image. Ru.

Brief description of the drawing The present invention may be better understood and appreciated by the following detailed description taken in conjunction with the drawings. However, among these drawings, FIG. 1 is constructed according to a preferred embodiment of the present invention. , is a simplified cross-sectional view of an operable electrostatographic apparatus; FIG. A simplified cross-section of an electrostatographic apparatus constructed and operable in accordance with a preferred embodiment. is a diagram, FIG. 3 shows an operable electrostatic capacitor constructed in accordance with yet another preferred embodiment of the invention. 1 is a simplified cross-sectional view of a photographic device, FIG. 4 shows an operable electrostatic 1 is a simplified cross-sectional view of a photographic device, FIG. 5 shows an operable electrostatic capacitor constructed in accordance with yet another preferred embodiment of the present invention. 1 is a simplified cross-sectional view of a photographic device, FIG. 6 shows an operable electrostatic capacitor constructed in accordance with yet another preferred embodiment of the invention. 1 is a simplified cross-sectional view of a photographic device, Figure 7 shows the temperature along a low heat capacity intermediate transfer member arranged as shown in Figure 6. FIG. 2 is a diagrammatic diagram of change.

Detailed description of the preferred embodiment There is now shown an electrostatographic imaging apparatus constructed and operative in accordance with a preferred embodiment of the present invention. Please refer to Figure 1. This and other embodiments of the invention are negatively charged pertains to a liquid developer device having charged toner particles and a positively charged photoreceptor. It is explained as follows. Such devices are designed to protect areas that are not toned or are ivrite-white mod e) operates. The present invention combines toner charging, a charged battery of a light receiving device, and such as a "write-blank" system. It is also useful for other recording devices.

The apparatus of the present invention is illustrated using a liquid developer apparatus.

In accordance with a preferred embodiment of the present invention, the solution of Example 1 of U.S. Pat. No. 4,794.651 Any suitable developer can also be used in carrying out the present invention. . Particularly useful are toners that solvate the developer carrier liquid at elevated temperatures above room temperature. - A liquid developer containing particles.

As in conventional electrostatographic equipment, the apparatus of FIG. It includes a drum 0 arranged for rotation about an axis 12 in the direction. this The drum 10 is formed with a cylindrical photodetector surface 16 .

The corona discharge device 18 uniformly charges the photodetector surface 16 positively. Surface I6 is moved into image-receiving relationship with respect to the exposure unit including lens 2o.

This lens 20 is a light receiving device that receives a desired image that can be generated by a laser. Focusing on surface 16 and selectively discharging this photoreceiver surface to receive the electrostatic latent image. It is generated on the device surface 16.

Subsequent rotation of drum 10 develops the charged photoreceptor surface 16 carrying the electrostatic latent image. in operative association with unit 22 and applying liquid developer to the electrostatic latent. Develop the image. In order to perform multicolor copying or printing, the developing unit 22 is For example, the developer may include a number of developers for each color, and these developers may be No. 4,690,539, incorporated by reference. to selectively engage the photoreceptor or change between liquid toner or multiple colors. in a single development station or any other suitable development equipment such as It can also happen. Generally, this processing is carried out at relatively low temperatures, i.e. with suitable equipment. This is done at an ambient temperature of

In accordance with a preferred embodiment of the invention, following the application of toner the receiver surface 16 is normally A positively charged rotating roller 26, preferably in the direction indicated by arrow 28 Pass through rotating rollers. This roller 26 acts as a metering roller, This reduces the thickness of the liquid on the receiver surface 16. Normally from the light receiving device surface 16 The spatial separation of this roller 26 is approximately 50 microns.

The voltage of the roller 26 is the voltage of the area of the latent image and the area of the background on the surface of the photoreceptor. It is preferable to do it in the middle of the pressure.

Usually this voltage is +200V for roller 26, +50V for background area, and latent image area. This is done up to approximately +100OV.

The liquid passing through the a-lar 26 is relatively free of pigment particles except in the area of the latent image. Must.

Under rigidizing roller 30 or roller 26 It is desirable that it be installed on the flow side. This stiffening roller is shown in the present invention for reference, for example. No. 3,959°574 and U.S. Pat. No. 3.8, incorporated herein by reference. Slightly conductive elastic materials such as those described in either or both of 63,603. Preferably, it is formed from an elastic polymeric material, such as a polymeric material. roller 3 0 is preferably elastically pressed against the conductive photoreceiver surface 16.

In a preferred embodiment of the invention, an electrically biased constriction roller It is used as a roller 30. The roller 30 is at least several hundred V and negatively charged to a potential of the same sign as the charge of the pigment toner particles up to 2000V. repulses pigment particles charged to the same potential and causes these particles to become more densely packed. approaches the image area of the photoreceptor surface 16, thus compressing and stiffening the image. It is done so that it will be done.

An intermediate transfer member 40 is provided downstream of the stiffening roller 30. The photographing member is rotated in a direction opposite to the direction of rotation of the light receiving device surface 16 as shown by the arrow 41. direction, so that the relative motion between each surface becomes zero at the approach position. It has become. Intermediate transfer member 40 receives the toner image from receiver surface 16 and transfers the toner image to receiver surface 16. It is operable to transfer the toner image to a receiving substrate 42, such as paper. Inside this A heating device 46 for heating the intermediate transfer member 40 is disposed inside the intermediate transfer member 40. Can be done.

Various types of intermediate transfer members are known, such as those described in US [HI Patent No. 4,684,2 No. 38, PCT Publication No. WO90104216 and U.S. Patent No. 4,974,0 No. 27, all of which are incorporated herein by reference. There is.

Following the transfer of the toner image to intermediate transfer member 40, receiver surface 16 is moved to a cleaning station. 49. This station is made of polyethylene or neorene foam Any passageway including a cleaning roller 50, which can be made of a suitable elastic material such as It can also be used as a regular cleaning station. This cleaning roller 50 is all or A clear lubricating cleaner preferably containing a liquid developer side from which almost all toner particles are removed. Can be moistened by cleaning liquid.

This cleaning roller 50 moves so that its surface faces the surface 16 at its clamping portion, and receives light. as it provides an abrasive action to remove residual particles and carrier liquid from the device surface 16. be.

The scraper 56 removes residual toner that could not be removed by the cleaning station 49. The goal is to complete the process.

The lamp 58 detects any residual charge exhibiting the above-mentioned image characteristics. Removal from device surface 16 completes the operating cycle.

The transfer of the image to intermediate transfer member 40 is effected at an intermediate voltage opposite to that of the charged particles. By charging the transfer member and thereby causing transfer by electrophoresis. It is desirable to assist. According to the present inventors, for at least a desirable developer, raises the temperature of the developed toner image to a temperature above the development temperature and room temperature. This helps this first transfer, even if the first transfer is by electrophoresis. It has been found that it works like this.

The subsequent final transfer of the image from intermediate transfer member 40 to substrate 42 is accomplished by heat and pressure. It is desirable to receive assistance.

According to the present invention, a temperature higher than that used for the first transfer or this subsequent final transfer is It is desirable to use it for photographs.

In the prior art, the liquid toner image was first transferred to an intermediate transfer member. . The toner image is surface heated during the first and second transfers to aid in the final transfer. It was done.

In the present invention, a desirable first transfer step, i.e., intermediate transfer of a liquid toner image, is performed. heating the image either before or during the first transfer to the member; Contains. The desired final transfer step, i.e., the transfer of the liquid toner image to the final substrate. further heating the copy prior to the second transfer and/or the colleague of the second transfer. I'm reading.

This additional heating may occur, for example, on the intermediate transfer member between the first and final transfer periods. 40 and/or by heating from outside the image. This can be done by heating the image on the inter-transfer member 40.

The image solvates the liquid to form a single phase without evaporating a substantial amount of the liquid carrier. Preferably, it is heated to a temperature such that it forms. Differently or additionally This further heating is due to conductive heating from the final substrate of the final transfer. It can be done by

These preferred first and second transfer steps are suitable for both monochrome and multicolor images. This improves the quality of the build-up on the final substrate.

For multi-color devices, separate colors can be matched to each other and then matched to be superimposed as a whole. These colors are sequentially transferred to the intermediate transfer member 40, and then both of these colors are transferred to paper or the like. It is useful to transfer it to another base layer 42. In this case, for this form, When the image being transferred returns to the first transfer point, it has already been transferred to the intermediate transfer member at a low temperature. There is a tendency for the heated image to be transferred in whole or in part to the receiver surface 16. It has been discovered.

Embodiments of the invention described herein provide improved first and final transfers and provide multicolor For the device, it solves the problem of reverse transcription.

Generally speaking, some embodiments of the present invention provide a first, relatively low temperature temperature, and the intermediate transfer member 40 is at a second, slightly higher temperature. transfer, and the final base layer 42 or a third, even higher temperature, good intermediate transfer section. characterized by being adapted to provide good transfer from the material 40 to the base layer 42; That is to say.

Alternatively, or additionally, some embodiments provide that the toner image is located on the receiver surface 16. The toner is transferred from the toner to the intermediate transfer member 40 and then to the final base layer 42. The temperature is higher during transfer to the intermediate transfer member than when the image is on the photoreceptor surface. It is characterized by a higher temperature when it is transferred to the final base layer than during the previous transfer. You get it.

Alternatively, or additionally, some embodiments provide that the multicolor toner image is sequentially transferred to a light receiving device. transferred as a group from surface 16 to intermediate transfer member 40 and then to final substrate 42. In cases where the composite multicolor toner image is The multicolor toner image is characterized by an even higher temperature when it is transferred to the final base layer. It is possible to do so.

In one embodiment of the invention, the image is moved from a first, relatively cold receiver surface to a second, relatively cool, receiver surface. The first intermediate transfer member may be transferred to a first intermediate transfer member at an intermediate temperature. Then the statue is transferred to the second intermediate transfer member. Is the final transfer the second intermediate transfer member? A third, higher temperature step is then applied to the final base layer. during the first transcription The temperature of the image is higher than the temperature of the part of the photoreceptor surface that is not in contact with the intermediate transfer member. is desirable.

Now, returning to FIG. 1, the intermediate transfer member 40 moves from the light receiving device surface 16 to the intermediate transfer member 40. heated to a temperature sufficient to enhance electrophoretic transfer of toner particles to It is. The image is heated in the surface of the transfer onto the intermediate transfer member 40, and this heating occurs when the image is transferred to intermediate transfer member 40. This process continues until the temperature of the co-worker on the transfer member 40 reaches the temperature of the intermediate transfer member 40. Ru. The rotation of the intermediate transfer member 40 transfers the heated intermediate transfer member 40 to a heated support. In the image transfer relationship with the final base layer 42 that is pressed against the intermediate transfer member by the holding roller 43. It moves it. The heated support roller 43 applies the paper, i.e. the final base layer. Heating this causes the image in contact with the paper to be heated by conductive heat from the base layer. Complete or nearly complete final transfer of the image to the substrate is achieved by heat and pressure. heat to a sufficient degree to ensure that the

The present invention provides transfer from the photoreceptor surface to the intermediate transfer member and from the intermediate transfer member to the final base layer. Although described in terms of a monochromatic format that provides improved transfer, the present invention can be applied to a variety of Different colors are sequentially formed on the photoreceptor surface 16 and aligned one by one with each other. transferred to the image transfer member 40 and then transferred in one rotation to the final base layer 42 of the entire image. It is particularly useful in multicolor devices, such as those in which multicolor images are produced.

The final base layer 42 is applied to the intermediate transfer portion only when all colors have been transferred to the intermediate transfer member 4o. material 40 to form a final multicolor image on a final substrate 42. It performs transcription.

As mentioned above, the first transfer of sequential images from receiver surface 16 to image transfer member 40 In the meantime, the previously transferred image is allowed to return to the area where the first transfer took place. Already Reverse transfer of the image transferred to the light receiving device surface 16 is desirable for the final printed image. No processing part occurs.

Generally, if the intermediate transfer member is heated to a useful temperature to make a good final transfer In some cases, the image tends to be transferred back onto the receiver surface.

The arrangement of FIG. selection of the correct temperature and the correct temperature for the final base layer 42 and image in the second transfer. In cases where there is a risk that the image on the transfer member may return to the photoreceptor surface due to temperature selection, In this case, the temperature of the image is kept low enough so that it is not so sticky that it sticks to the receiver surface. This substantially eliminates the problem of reverse transfer to the light receiving device surface 16.

FIG. 2 shows a second embodiment of the invention, in which a heated support Roller 43 is replaced by an unheated support roller 44 and final base layer 42 is heated. All other parts and operations, except for being preheated by heat lamp 45, The parts of the apparatus and their operation are generally similar to those shown in the figure. Figures 1 and 2 A combination of embodiments is also useful, whereby paper, the final base layer 42 is preheated by a lamp 45 and heated by a heating roller 43. It is.

A third embodiment of the device of the invention is shown in FIG.

In this case, the intermediate transfer member 40 is either sufficient to improve the transfer or is already in the transfer state. to substantially reversely transfer the previously imaged image from the intermediate transfer member 40 to the light receiving device surface 16. It is heated to a first, moderate temperature that is not too high. The image is internally heated to a temperature high enough to ensure good transfer to the final substrate 42 by the device 48. The image is transferred to a second intermediate transfer member 47 which is heated.

In a preferred embodiment of the present invention, the intermediate transfer member 40i;! The first voltage (receiving This intermediate transfer from the light receiving device surface 16 is held at a voltage different from that of the light receiving device surface 1G). The second intermediate transfer member 4 is adapted to improve the transfer of the image to the member 4o. 7 is charged to a second voltage different from the first voltage and transferred from the intermediate transfer member 40. Transfer of the image to the second intermediate transfer member 47 is improved.

Transfer to the second intermediate transfer member 47 is performed for each image sequentially, and are collected on the first intermediate transfer member 40, and then the entire multicolor image is is transferred to the second intermediate transfer member 47 for final transfer to the final base layer 42. It is desirable that this be done in the same way.

An embodiment of the duplex apparatus of the present invention that prints on both sides of the substrate at the same time is shown in FIG. It is shown. of separate colors forming a multicolor image printed on the first side of the substrate 42. The images are first transferred sequentially to the intermediate transfer member 40 and then as a group to the second intermediate transfer member 40. It is desirable that the image be transferred to the photographic member 47. The second intermediate transfer member 47 is an intermediate transfer member Preferably, the temperature is higher than 40°C. printed on the opposite side of the base layer At that time, these images are transferred from the locked state to be transferred with the second intermediate transfer member 47. The images are sequentially transferred to the intermediate transfer member 40 which is detached and held.

Next, both the intermediate transfer member 40 and the second intermediate transfer member 47 are pressed together. While the final base layer 42 is between the intermediate transfer member 40 and the second intermediate transfer member 47 of these images on both sides of the paper, i.e. the base layer, by means of heating and pressing action. It performs transcription. The second intermediate transfer member 47 or the base layer 42 and the image are heated to an appropriate temperature. to ensure good transfer of the image on intermediate transfer member 40 to substrate 42. It is understood that what is done and what is desirable. Alternatively or additionally, paper, That is, the base layer can be heated prior to transfer as explained in connection with FIG. Wear.

In some preferred embodiments of the present invention, intermediate transfer member 40 includes receiver surface 16. heating the image to a first temperature during a first transfer from to intermediate transfer member 40, A second, higher temperature prior to the second and final transfer from member 40 to final base layer 42. It works to heat up the temperature.

These exemplary embodiments include the apparatus shown in FIG. This device is transfer station 60 or intermediate transfer member 40 returns to contact receiver surface 16 except that it is adapted to be operatively associated with this intermediate transfer member 40 immediately before. The device is generally the same as that of FIG. The intermediate transfer member 40 is located at the cooling station 6 Intermediate transfer before and during contact with the image on the surface of the light receiving device after being cooled at 0 The temperature of the member 40 is locally reduced. This localized cooling is At the point of final transfer of the toner image from the intermediate transfer member 40 to the final base layer 42, the photoreceptor surface 16 to the intermediate transfer member 40 at a higher temperature than for the first transfer from the transfer member 40 to the intermediate transfer member 40. It makes it possible to

The cooling station 60 may include, for example, a photoreceptor surface or a cooled roller in contact therewith. The cooling air flow may include a device for providing a flow of cooling air to the roller. either one or the other temperature of both cooling devices or intermediate transfer member 40 above room temperature, but below the final transfer temperature. It is cooled to a low temperature.

In multicolor equipment, a roller cooling system or, if used, this roller should be The rollers of the cooling station 6o are coated with a sticky coating from the intermediate transfer member 40. This is done in such a way as to avoid transferring the image to.

Another exemplary embodiment of this type is shown in FIG. This is the same as that in FIG. 8 of WO90104216 referred to above. This fruit In the embodiment, the intermediate transfer member 140 has a small heat capacity, and the first transfer is completed. It is heated only after that.

As shown in FIG. 7, which is the same as FIG. 9 of the above-referenced application, the first transcription The temperature at is above room temperature to improve the first transfer and to improve the second transfer. The temperature at has been done. For multicolor devices, the temperature and heat capacity are determined by rotating either the first transfer or the reverse transfer. It is chosen to be carried out at a temperature low enough to avoid

In the embodiments described above, intermediate transfer members 40 and 47 are Explain that each has a heating device inside to heat it to the required temperature. It was done. Other methods of heating intermediate transfer members known in the art also incorporate the present invention. It can be used for implementation.

example A color liquid developer was prepared as follows.

Preparing black liquid developer 10 parts by weight of Elvax 5720 (Eng., I., D.) ) and 5 parts by weight of Isopar L ([5opar L) or jacket] Mixed for 1 hour at low speed in a double planetary mixer connected to an oil heating unit with The heating unit was set at 130°C.

25 parts by weight of Mogul L Carbon Black (Kapot) (Mogul L carbon bulk) and 5 parts by weight of Isopar El The mixture was then mixed in a double planetary mixer and the resulting mixture was further mixed for 1 hour. Mixed at high speed. 20 parts by weight of Isopar Elkako preheated to 110°C was added to the mixture, and the mixing was continued at high speed for 1 hour. Then the heating unit The cutter was shut off and mixing continued until the temperature of the mixture dropped to 40"C. .

The resulting mixture is 4. 76mm (3/16in) carbon steel material (carbon Varnish-1 crusher H (S-1 attri tor device) and diluted 16% with Isoparel. , milled without cooling until the temperature rose to about 60°C. Then at about 30°C A cooling action was started to lower the temperature and milling continued for a total of 24 hours.

The mixture is removed from this equipment and is purified by Isopar L to 15% solids by weight. diluted to solids concentration. The obtained The particles of this concentration had an average diameter of 2.5 microns.

charge director or final liquid as known in the art. Added to body developer. In a preferred embodiment of the present invention, the following is incorporated herein by reference: Charge of Example 1 of PCT Publication W○ 90/+4617, in which the description is incorporated It was added to the director or the final liquid developer.

Preparing color developer 10 parts by weight of Elv Asox 5720 (Ei DuPont) and 5 parts by weight Isopal is connected to an oil heating unit set at 130°C at low temperature. The mixture was mixed for 1 hour in a double mixer with a double jacket.

Preheated Isopar® is then added to reduce the solids concentration to preferably 35%. The mixture was reduced and mixing continued at high speed for 1 hour. The heating unit is then shut off and mixed. The mixture continued until the temperature of the mixture decreased to 40°C.

The mixture was then coated with 4.76 mm (3/+6 in) carbon steel Varnish-1. It was transferred to a grinder and the pigment was added to the material in the grinder. A mixture of materials Due to viscosity, it is diluted with Isopar L to approximately 12-16% solids concentration ratio. , milled without cooling until the temperature rose to about 60°C. Then set the temperature to approx. Cooling was started to reduce to 30°C and milling continued for a total of 24 hours.

The mixture was removed from the apparatus and washed with Isopar.

Diluted to a solids concentration of 5% by weight. The particles in the resulting toner dilution were 25 microns. It had an average diameter of

A charge director known in the art is added to obtain the final liquid developer. Ta. In a preferred embodiment of the present invention, the above-mentioned PCT publication WO90/1. The charge director of Example 1 of 4617 was added to obtain the final liquid developer. .

Suitable colored pigments known in the art of making liquid developers, such as U.S. Pat. No. 4,794. , No. 561, the pigments listed in the table could be used. Other suitable pigments are East Yellow DI 350 (Sico Yellow DI350) (BASF), Lithol Rubin D4576 (BASF), Lyonol Blue F G 7351 (LyonolBlue FG 7351) (TOYO) and Lionor Yellow 7G1310 (TOYO), these are available in amounts and combinations related to the required color and intensity. done to. Aluminum stearate can optionally be added in small amounts.

For pigments bleached by steel, use other grinding media such as zirconia. can be done.

These developers have a receiver containing a relatively large concentration of toner particles within a liquid carrier. may be used to form individual color liquid toner images on optical device surface 16. can.

Preferably, the light receiving device surface 16 is formed of selenium. The intermediate transfer member 40 Coated with a 1mm thick layer of highly flexible polyurethane with 20-25 Shore A hardness Preferably formed by a cylindrical aluminum core. This layer is KYN[OA[RTACK] is much harder than urethane. ) Offset Blanket and What is Desirable Offset Blanket? It is covered. Cover this layer with a thin conductive layer of conductive acrylic, and this Covered by a layer of polyurethane Oll[IIm with a hardness of 20]. this Layer is Sailuo) Model (Sy 1-0ff type) 291 or 294 silicone release coating The outer surface is covered with a thin layer of

A liquid developer prepared by the method described above was used in the apparatus of FIG. desirable Preferably, the temperature of the intermediate transfer layer should be less than about 50°C. Approximately 50°C For temperatures higher than , the already transferred colors are transferred back to the receiver surface 16. There is a tendency. Heating the intermediate transfer member 40 increases the Improve image transfer. The temperature of the intermediate transfer member 40 is slightly lower than the temperature at which reverse transfer begins to occur. It is desirable to be heated to a high temperature.

Improvement in the first transfer when the intermediate transfer member is heated reduces the amount of pigmented toner particles in the image. It is believed that this is the result of partial solvation of the carrier liquid by the carrier liquid.

One feature of the liquid developer that is desirable in practicing the present invention is the pigment contained therein. is to solvate the carrier liquid at elevated temperature to give the toner particles . carrier into toner particles during first transfer to heated intermediate transfer member 40 – There is a partial solvation of the liquid, which causes the particles to partially coalesce during the first transfer. It is believed that it can form a film. Fused toner is not fused. It is believed that they transfer better than toner particles.

Furthermore, upon solvation of the toner material or some carrier liquid, the toner particles It is separated from the unsolvated carrier liquid. This separated liquid A film is formed between the color image and the photoreceptor surface, and this believed to reduce adhesion of the toner image and aid in complete transfer of the image to the intermediate transfer member. It is being

Heating the image before and/or during the final transfer is performed on the intermediate transfer member. is understood to ensure complete or nearly complete transfer of the image from to the final substrate. There must be. This heating of the image occurs only through conduction from the paper, that is, the base layer. Therefore, when carried out, the paper, i.e. the base layer, should be at a temperature of at least about 70°C. It has been experimentally discovered that this is necessary. Like 80 or 90°C Temperatures substantially lower than these are considered intermediate, although higher temperatures can also be used. The image is not sufficiently transferred to ensure complete transfer from transfer member 40 to paper, ie, substrate 42. It does not make it sticky.

The exact temperature used for a particular form and combination of toner particles and carrier It is related to the material properties of the liquid and the quality of the release agent layer on the intermediate transfer member. Reverse transcription is an image or by the relative tackiness of the image to aid the release agent layer. to be influenced. If the release characteristics of the surface of the intermediate transfer member are weak, the temperature of the intermediate transfer member may be It is also possible to increase the degree. However, this also impairs transfer to the final substrate. Make it weak.

In a particularly representative working example, the following temperatures were used: Used for transferring monochromatic images In a first example, the intermediate transfer member was heated to a surface temperature of 100"C; The paper, ie, the base layer, was not heated. The result of the calculation is 52 during the image or the first transfer. This shows that the temperature ranged from 63°C to 63°C. Between the first and second transcription During the period of time the biopsy temperature is increased to the temperature of the intermediate transfer member of 100°C and the image is transferred to the paper, i.e. During the second and final transfer to the base layer, it was cooled to a temperature of 73 to 78°C.

In a second representative example of operation for sequentially transferring multicolor images to an intermediate transfer member, In this case, the intermediate transfer member is heated to 50°C and the support roller 43 is heated to 120°C. It was heated.

The temperature of the image in the first transfer is approximately 43°C and in the second transfer from 75 to 7 The temperature was up to 8°C.

The temperatures shown in Figure 7 are also representative of values suitable for single image transfer. be. For transfer of multiple images to intermediate transfer member 140, the first transfer temperature is reversed. It must be low enough to ensure that no damage occurs.

Some features and subcombinations of the invention are beneficial, while other features and subcombinations are beneficial. It is understood that it can be used without any. Various detailed information It is noted that changes may be made within the scope of the claims without departing from the spirit of the invention. . It is therefore understood that the invention is not limited to the specific details shown and described above. must be understood.

international search report PWm Pc'T7ISkn+61m l1w+ 1211 ・PMHII Tsuru ↑International search report NL　9000182 Continued from page 1 ■Int, C1,' Identification symbol Office serial number Inventor Labon, Amiran I Srael country 59576 special table 15-503166 (13) Bat Yam, Palfour Street 143 Holon, Sprinzak St. Lee) 20

Claims (17)

[Claims] 1. An imaging device that prints an image onto a substrate from a latent image formed on a latent image support surface. There, Developing the latent image with a liquid developer to form a developed liquid toner image. a device; a first intermediate transfer member; transferring the developed image from the latent image bearing surface to the first intermediate transfer zone in a first transfer zone; a first transfer device that transfers onto a photographic member; a second intermediate transfer member; transferring the developed image from the first intermediate transfer member to the first intermediate transfer member in a second transfer zone; a second transfer device for transferring to the second intermediate transfer member; a third transfer of the developed image from the second intermediate transfer member to the base layer; a device; an imaging device containing. 2. the developed liquid toner image in the first transfer zone at a temperature above room temperature; a first temperature and a second temperature higher than the first temperature in the second transfer zone; a heating device for heating to a temperature of An imaging device according to claim 1, comprising: 3. heating the first intermediate transfer member to a first temperature, and heating the second intermediate transfer member to a first temperature; an intermediate transfer member heating device that heats the material to a second temperature higher than the first temperature; An imaging device as claimed in claim 1 comprising: 4. Transfer of the liquid toner image from the image bearing surface is at a first given temperature or higher. transfer of the liquid toner image to the final substrate is enhanced at the first applied temperature. improved at a temperature equal to or higher than a second given temperature higher than undesired image transfer from said intermediate transfer member to said image bearing surface or said first application; increase at a temperature higher than a given temperature but lower than said second given temperature. added, In this case, the first temperature is equal to or higher than the first given temperature, and the third given temperature is higher than the first given temperature. the second temperature is equal to or less than the given temperature, and the second temperature is equal to or more than the second given temperature. is being done, An apparatus according to claim 2 or 3. 5. a first voltage device that holds the first intermediate transfer member at a first voltage; An imaging device according to any of the preceding claims. 6. at least a portion of the latent image bearing surface is brought to a second voltage; is different from the second voltage. Imaging device. 7. a second voltage device that maintains the second intermediate transfer member at a third voltage; An imaging device according to claim 5 or 6. 8. The developing device transfers the developed liquid toner image from the developing device to the intermediate transfer. Forming a second developed liquid toner image on this development device after transfer to the photographic member. the first transfer device is operable to develop a latent image to transfer the latent image; , transferring the second liquid to the image bearing surface without substantial reverse transfer of the first image to the image bearing surface. operable to transfer a toner image to the first intermediate transfer member; An apparatus as claimed in any of the preceding claims. 9. the second transfer device transferring the composite image to the second intermediate transfer member; 9. A device as claimed in claim 8, wherein the device is operable to: 10. The developer device develops different latent images on the image bearing surface to produce different liquid toners. - operable to form an image; transfer of the formed liquid toner image from the first intermediate transfer member to the second image transfer section; Subsequent to the transfer to the material, the first transfer device transfers the different liquid toner image to the first Any of the preceding claims is operable to be transferred to an intermediate transfer member of equipment described in any of the above. 11. The third transfer device, an apparatus for supplying a base layer to the second transfer zone and the first and second transfer members; the developed liquid toner image on the base layer. one side of the substrate, and the different liquid toner image is transferred to the other side of the substrate. An apparatus according to claim 10, wherein the apparatus is made of: 12. In an imaging device that prints an image from a latent image formed on a latent image supporting surface, Developing the latent image with a liquid developer to form a developed liquid toner image. a device; receiving a developed image from the latent image bearing surface in a first transfer zone; a heated intermediate transfer member that transfers to the final substrate in a transfer zone of 2; Cooling a portion of the intermediate transfer member, and then transferring a portion of the imaged image to the intermediate transfer member. a cooling device for transferring onto the cooled portion of the intermediate transfer member; an imaging device containing. 13. Transfer of a liquid toner image from said image bearing surface is performed at a temperature above a first given temperature. transfer of the liquid toner image to the final substrate is enhanced at the first given temperature. at a second given temperature higher than Undesired image transfer from the intermediate transfer member to the image bearing surface is caused by the first imparting a third given temperature higher than the given temperature but lower than said second given temperature; increased at a temperature higher than the In this case, the intermediate transfer member is heated to a temperature equal to or higher than the second temperature in the second transfer zone. and the cooling device cools the intermediate transfer member in the first transfer zone. operable to cool to a temperature above the first temperature and below the third temperature; being done, Apparatus according to claim 12. 14. The development device transfers the developed liquid toner image to the intermediate transfer member. operative to form a second developed liquid toner image on the developer device after imaging; possible, The intermediate transfer member and the cooling device are configured to support the image support of the first liquid toner image. transferring the second developed liquid toner image to the surface without substantial reverse transfer to the surface; operable to transfer to an intermediate transfer member to form a composite image; Apparatus according to claim 12 or 13. 15. In an imaging device that prints an image onto a substrate from a latent image formed on a latent image supporting surface. hand, Developing the latent image with a liquid developer to form a developed liquid toner image. a device; an intermediate transfer member heated to a first temperature; a first transfer device that transfers the image from the latent image support surface to the intermediate transfer member; a second transfer device for transferring the developed image from the intermediate transfer member to the base layer; , including; the second transfer device, an apparatus for heating the base layer to a second temperature higher than the first temperature; an imaging device containing. 16. the heating device applies heat and pressure to the image during the second transfer; Claim 15 including a heated support roller operable to equipment. 17. The development device transfers the developed liquid toner image to the intermediate transfer member. developing the latent image after imaging to form a second developed liquid toner image on the imaging device; is operable to The first transfer device substantially transfers the developed liquid toner image to the image support member. transfer the second developed liquid toner image to the intermediate transfer station without causing reverse transfer; Claim 15 or 16, wherein the method is operable to transfer the image to a material. Equipment described in Section.