JPH0693148B2 - Multicolor recorder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor recording apparatus such as an electrophotographic recording apparatus or an electrostatic recording apparatus capable of recording a recorded image in multiple colors, and more particularly to a latent image recording apparatus. The present invention relates to an improvement of a multicolor recording apparatus that can obtain a multicolor recording image by rotating the image carrier once.

[Prior Art] As a conventional multicolor recording apparatus of this type, for example, Japanese Patent Laid-Open No. 58-16
Some are listed in the 3961 bulletin. This is for recording an image of, for example, three colors, and as shown in FIG. 7, it has a photosensitive drum 1 as a latent image carrier that rotates in a predetermined direction, and a part of the periphery of the photosensitive drum 1 is provided. Is provided with a pre-charger 2 which charges the surface of the photosensitive drum 1 to a predetermined potential in advance, while a semiconductor laser element 3 (specifically 3a, 3b, 3c) is provided, and developing devices 4 (specifically, 4a, 4b, 4c) corresponding to different color components (for example, cyan, yellow, and magenta) are provided behind each semiconductor laser element 3, respectively. In addition,
A transfer device 6 for transferring each toner image formed on the photosensitive drum 1 onto a transfer paper 5 as a transfer medium is disposed behind the final-stage developing device 4c. In addition, in FIG.
Reference numeral 7 is a cleaner that removes residual charges and residual toner on the surface of the photosensitive drum 1 after the transfer process.

In such a multicolor recording apparatus, the first semiconductor laser element 3a forms a latent image corresponding to the first color on the photosensitive drum 1 which is charged in advance to a predetermined potential, and the first developing device 4a forms the latent image. After toner-developing the first latent image, a second semiconductor laser element 3b forms a latent image corresponding to a second color on the photosensitive drum 1, and a second developing device 4b forms the second latent image. The image is toner-developed, and then the final stage semiconductor laser element 3c forms a latent image corresponding to the third color on the photosensitive drum 1, and the final stage developing device 4c forms the toner image on the third latent image. After development, each toner image is transferred to the transfer paper 5 through the transfer device 6, and the transfer image is fixed on the transfer paper 5 through a fixing process not shown. Therefore, in such a multicolor recording apparatus, a plurality of, in this example, three color images are simultaneously transferred onto the transfer paper 5 while the photosensitive drum 1 makes one rotation.

[Problems to be Solved by the Invention] However, in such a conventional multicolor recording apparatus, the toner layer developed by the developing device 4 is held on the photosensitive drum 1 with a certain degree of adhesion. However, the holding force is not sufficient, and when developing the latent image with the developing device 4b or 4c in the subsequent stage by toner, the developing device 4a in the preceding stage is used.
Alternatively, there is a possibility that a part of the toner layer developed with toner in 4b may peel off. Therefore, the toner image is disturbed or the separated toner is mixed in the developing device 4b or 4c in the subsequent stage, and the toners of respective colors are mixed with each other in the developing device in the subsequent stage, and the toner is obtained by the developing device in the subsequent stage. The color tone of the toner image may be impaired, and the image quality of the transferred image may be deteriorated accordingly.

In order to deal with such a situation, in the prior art, as shown in FIGS. 8 and 9, the photosensitive drum 1 of each developing device 4 is clearly assigned to the latent image developing portion for each color.
A slit plate 9 provided with a large number of slits 9a at predetermined intervals is provided in each opening 8 facing the slit plate 9
The slits 9a are provided so that their positions do not overlap with each other. According to this type, only the portion corresponding to each slit 9a position of each slit plate 9 is regulated as a latent image developing portion, so that a part of the toner layer previously developed is mixed in the developing device in the subsequent stage. That situation is effectively avoided. However, in this type, since the resolution of the toner image, and by extension, the transfer image, is restricted by the pitch p between the slits 9a, it becomes difficult to obtain a high-resolution transfer image. .

The present invention has been made by paying attention to the above problems, and the first aspect of the present invention is to prevent the deterioration of the life of the latent image carrier while minimizing the mixing of toner in the developing means and the latent image carrier. The present invention provides a multicolor recording apparatus capable of effectively suppressing the disturbance of the toner image of No. 1 and capable of obtaining a high-resolution transferred image at high speed. Multi-color recording that effectively suppresses toner mixing in the developing device and disturbance of the toner image on the latent image carrier while effectively suppressing deterioration of image quality, and also enables high-speed transfer images to be obtained at high speed. A third aspect of the present invention further provides a device for effectively mixing an ion latent image forming means to use a normal non-translucent toner and to mix color toner images by superimposing color toner images. Can get There is provided a multicolor printing apparatus.

[Means for Solving Problems] That is, the first aspect of the invention is to form a latent image carrier on which the multicolor toner image forming process is completed by one rotation, and to form a plurality of latent images on the latent image carrier. Latent image forming means, a plurality of developing means for developing each latent image corresponding to different color toners, a transfer means for collectively transferring the multicolor toner images developed by each developing means to a transfer medium, A heating unit that is provided in the vicinity of the periphery of the image carrier at a stage subsequent to the developing unit other than the final stage and heats and attaches each toner image formed by the developing unit other than the final stage to the latent image carrier surface by heating. It is characterized by having.

A second invention is that a latent image carrier whose multicolor toner image forming process is completed by one rotation, a latent image forming means for forming a plurality of latent images on the latent image carrier, and toners of different colors. A plurality of developing means for developing each latent image corresponding to, a transfer means for collectively transferring the multicolor toner images developed by each developing means onto a transfer medium, and a transfer means provided inside the latent image carrier. And a heating unit for heating the surface of the latent image carrier to the extent that each toner image formed by the developing unit is supposedly attached to the surface of the latent image carrier.

Furthermore, the third invention is different from the latent image carrier in which the multicolor toner image forming process is completed by one rotation and the ion latent image forming means for forming a plurality of ion latent images on the latent image carrier. A plurality of developing means for developing each ion latent image corresponding to the toner, a transfer means for collectively transferring the multicolor toner images developed by the developing means onto a transfer medium, and a transfer means near the periphery of the latent image carrier. And a heating unit that is provided after the developing unit other than the final stage and that heats and attaches each toner image formed by the developing unit other than the final stage to the surface of the latent image carrier. It is characterized in that the ion latent image formable regions corresponding to the respective color components formed by are made to coincide with each other, and the ion latent image is also formed on the toner image which is assumed to be heated.

In such a technical means, the latent image carrier may be appropriately changed in design as long as it can carry the latent image formed by the latent image forming means, and it may be a photosensitive drum, a photosensitive belt or the like. A body or a conductive substrate whose surface is coated with a derivative is used. Further, as the latent image forming means, various means such as a means for forming a latent image with light of a laser or the like and a means for forming a latent image with an ion stream are used. Further, as the developing means, various developing methods can be used, and the number, arrangement, toner color and the like can be appropriately selected. Further, as the transfer means, various types such as a thermal transfer method and an electrostatic transfer method may be adopted, but since the toner layer on the latent image carrier is assumed to be attached by the heating means, this toner layer A relatively large amount of energy is required to peel and transfer
A thermal transfer method is preferable.

The heating means of the first invention and the third invention can be appropriately selected as long as it has a latent image carrier portion corresponding to the rear side of the developing means excluding the developing means of the final stage as a heating area, and The heating means of the second invention can also be appropriately selected as long as it is arranged inside the latent image bearing member within a range that does not hinder the rotation operation of the latent image bearing member. Also, it is necessary to apply an appropriate heating temperature depending on the method of the developing means and the physical properties of the toner.

The heating temperature of the heating means is assumed to be in the middle between the glass transition point and the melting point of the toner, and not to be peeled off when the toner layer previously developed by the toner passes through the developing means portion in the subsequent stage. It is necessary to set it so that it can have cohesive force.

[Operation] According to the technical means as described above, since the heating means heats the surface of the latent image carrier corresponding to the developing means to an appropriate temperature, the latent image formed by the latent image forming means is formed. When the image is toner-developed by the developing means, each toner layer forming the toner image is not only held by electrostatic force but also put on the latent image carrier beyond the glass transition point.
For this reason, even if the toner image on the latent image carrier passes through the developing means portion in the subsequent stage, a part of each toner layer forming the toner image is not easily peeled off, and the toner on the latent image carrier is prevented. It is possible to effectively avoid a situation in which the toner is disturbed or toner of another color is mixed in the developing means. Further, since the toner particles from the developing means are evenly transferred to the latent image side, the toner density of the formed toner image becomes extremely dense, and accordingly, the toner image and, by extension, the transfer image should have high resolution. Will be possible.

In particular, in the first aspect of the invention, the heating means is provided in the subsequent stage of the developing means excluding the developing means in the final stage, so that the surface of the latent image carrier is not unnecessarily heated.

Further, in the second aspect of the invention, since the heating means is provided inside the latent image carrier, the entire latent image carrier is uniformly heated, and the moisture on the surface of the latent image carrier is effectively removed.

Further, according to the third invention, an ion latent image is formed on the toner image which is assumed to be heated and attached on the latent image carrier, and the toner image is developed with another color toner. Are appropriately superposed.

[Embodiment] The present invention will be described in detail below based on an embodiment shown in the accompanying drawings.

Example 1 The multicolor recording apparatus shown in FIG. 1 records two-color images, and its basic configuration is a photosensitive drum 1 in which the surface of a conductive substrate is coated with a photosensitive film such as amorphous silicon. A plurality of semiconductor laser elements 3 (specifically 3a and 3b) used as latent image forming means and irradiating a laser beam having a wavelength of 780 nm, and toners of different colors arranged behind each semiconductor laser element 3 Developing device 4 (specifically, 4
a, 4b), a transfer roll 16 for transferring each toner to the transfer paper 5, and an oven fuser 20 as a heating means for heating the surface of the photosensitive drum 1. In FIG. 1, reference numeral 2 is a pre-charger made of scorotron or the like, and 7 is a cleaner for removing the residual toner and residual charge on the photosensitive drum 1.

In this embodiment, the developing device 4 adopts a two-component magnetic brush developing system, and this magnetic brush (not shown) is arranged so as to advance and retreat with respect to the photosensitive drum 1, and the photosensitive drum 1 when not developing. It is placed away from the surface,
It is arranged so as to be in contact with the surface of the photosensitive drum 1 during development. The toner used in this example has a glass transition point of 70 ° C and a melting point of 160 ° C.
The above is used, and an epoxy resin is used as the toner binder.

The oven fuser 20 is disposed between the first developing device 4a and the second semiconductor laser device 3b, and when the peripheral speed of the photosensitive drum 1 is 160 mm / sec, the second developing device 4b. It is designed to set the temperature near the surface of the photosensitive drum 1 corresponding to the above to 100 to 120 ° C.

Therefore, in the multicolor recording apparatus according to this embodiment, assuming that the surface of the photosensitive drum 1 is precharged to a predetermined potential by the precharger 2, first, the first semiconductor laser element 3a
Is irradiated onto the surface of the photosensitive drum 1, and a latent image corresponding to the first color is formed on the surface of the photosensitive drum 1. After that, when the first latent image reaches the first developing device 4a portion, the magnetic brush of the developing device 4a comes into contact with the surface of the photosensitive drum 1 and the first latent image is transferred by the first color toner. Toner is developed. Then, when the first toner image reaches the vicinity of the portion corresponding to the oven fuser 20, the toner layer that achieves the toner image starts melting beyond the glass transition point and is tentatively attached to the surface of the photosensitive drum 1. Next, when the surface of the photosensitive drum 1 is irradiated with the laser beam from the second semiconductor example laser element 3b, a latent image corresponding to the second color is formed on the surface of the photosensitive drum 1, and this latent image is The toner is developed with the second color toner by the second developing device 4b. At this time, the first toner image passes through the portion of the second developing device 4b, but since the first toner image is assumed to be attached to the surface of the photosensitive drum 1, the toner in this toner image is The situation that a part of the layer peels off and mixes into the second developing device 4b does not occur. Therefore, the toner image on the photosensitive drum 1 is not disturbed in the developing process, and the hue of the toner image by the second developing device 4b is not damaged. Further, in each developing process, the toner from each developing device 4 is evenly transferred to the latent image,
The toner density of each toner image is set in a dense state. When the toner images of the respective colors reach the transfer roller 16 portion, the toner images are thermally transferred onto the transfer paper 5 by the transfer roll 16, and the transfer images are reliably fixed on the transfer paper 5 through a fixing process not shown. Then, one image recording process is completed.

Since such an image recording process is performed during one rotation of the photosensitive drum 1, not only the recording speed can be increased as compared with the type in which the photosensitive drum 1 is rotated a plurality of times, but also the image recording process described above is performed. For the recorded images,
It has been confirmed experimentally that the resolution is high because the toner density of the toner image can be kept fine and the toner density of the toner image can be made dense, and the operation of the multicolor recording apparatus according to this embodiment is confirmed. It will be.

Example 2 In FIG. 2, the multicolor recording apparatus according to this example is different from Example 1 in that a heater 30 as a heating means is provided inside the photosensitive drum 1 while a non-polar one component is used as a developing device 4. A non-contact development type is used. More specifically, the developing device 4 includes a metal roll 42 and an elastic pressing blade 41, as shown in FIG.
An AC bias is applied between the metal roll 42 and the photosensitive drum 1 so that the toner particles T pass between the latent image and the metal roll 42.
Is appropriately reciprocated, and polystyrene is mainly used as the toner binder of the toner used in this embodiment. Then, the heater 30
Is designed to set the temperature of the surface of the photosensitive drum 1 corresponding to the second developing device 4b to 80 to 90 ° C. when the peripheral speed of the photosensitive drum 1 is 160 mm / sec.

It has been confirmed that this embodiment has the same effects as the first embodiment. In this case, since the heating temperature of the heater 30 is set to be lower than that in the first embodiment, the degree of the assumed adhesion of toner is smaller than that in the first embodiment, but the assumed adhesion is caused by the difference in the developing device 4. Since the peeling force acting on the toner is smaller than that in the first embodiment, the toner mixing phenomenon in the developing device 4 does not occur.
Further, in this embodiment, since the entire surface of the photosensitive drum 1 is heated by the heater 30, even if the surrounding environment is high in humidity, the moisture on the surface of the photosensitive drum 1 is not heated by the heater 30.
Since it is effectively removed by the heat of, the situation in which the image quality of the recorded image is damaged by moisture is more effectively avoided as compared with the first embodiment.

➝Embodiment 3 In FIG. 4, the multicolor recording apparatus according to this embodiment records three-color images, unlike the above-described embodiments, and three multicolor recording devices for forming latent images corresponding to the respective colors are used. A semiconductor laser device 3 (specifically, 3a, 3b, 3c) is provided, and three developing devices 4 for developing each latent image with different color toners.
(Specifically 4a, 4b, 4c) is provided, and further, between the first developing device 4a and the second developing device 4b and between the second developing device 4b and the final developing device 4c. An oven fuser 20 (specifically, 20a, 20b) as heating means is arranged between them. It has been confirmed that the recording apparatus of each color can also obtain a recording image of three colors with a desired hue and high resolution as in each of the above-described embodiments.

Example 4 In FIG. 5, the multicolor recording apparatus according to this example records two-color images, and unlike Example 1 described above, polyethylene is formed around the conductive substrate (for example, an aluminum drum). A dielectric drum 11 coated with a dielectric material such as terephthalate is used as a latent image carrier, and an ion flow control type write head 13 (specifically, as a latent image forming means).
13a, 13b) are used. As shown in FIG. 6, the write head 13 includes a discharge wire 52 to which a bias from a DC power source 51 is applied, and a shield 53 that surrounds the discharge wire 52 and is partially grounded. A large number of control electrodes 54 are provided on the surface of the shield 53 facing the dielectric drum 11 via an insulating layer 55, and each control electrode 54 and the shield 53 wall corresponding to these control electrodes 54, and an insulating layer 55 have an ion ejection path. By opening 56 and applying appropriate positive and negative pulse signals to the control electrode 54, the ion flow generated around the discharge wire 52 is controlled at the ion ejection path 56.

Therefore, according to the multicolor recording apparatus of this embodiment, in addition to the effects substantially similar to those of the above-described embodiments, an ion latent image can be formed by superimposing it on the toner image that has already been assumed. Therefore, it is possible to further widen the color reproducibility as compared with each embodiment.

[Effects of the Invention] As described above, according to the multicolor recording apparatus of the present invention, the toner image on the latent image carrier is assumed to be attached by the heat of the heating means. It is possible to prevent a situation in which a part of the toner image is peeled off when the toner image developed in step 1 passes through the developing means in the subsequent stage, and the toner image is disturbed or different color toners enter the developing means. It is possible to prevent the mixture, and accordingly, the hue of the recorded image can be kept good, and since the toner from the developing unit can be evenly arranged on the latent image, the toner density of the toner image can be made precise. Therefore, the resolution of the recorded image can be increased. Further, according to the multicolor recording apparatus of the present invention, since the latent image carrier need only be rotated once to obtain a multicolor recording image, there is no possibility of impairing the high speed recording speed. .

In particular, in the first aspect of the invention, the heating means is provided in the subsequent stage of the developing means except the final developing means, and the latent image carrier surface is not unnecessarily heated. There is no concern that the deterioration of the latent image will be unnecessarily hastened, and the deterioration of the life of the latent image carrier can be minimized.

Further, in the second aspect of the invention, since the heating means is provided inside the latent image carrier, it is not necessary to secure a space for disposing the heating means around the latent image carrier. Not only can it be made compact, but the latent heat of the latent image carrier can be uniformly heated by the heating action of the heating means, so that the moisture on the surface of the latent image carrier can be effectively removed even in a high humidity environment. It is possible to effectively prevent deterioration of image quality due to moisture.

Further, according to the third aspect of the invention, since an ion latent image is formed on the toner image that is assumed to be heated and can be developed with toner of another color, a normal non-translucent toner is used. , A mixed color image can be easily obtained by superimposing color toner images.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a first embodiment of a multicolor recording apparatus according to the present invention, FIG. 2 is an explanatory view showing a second embodiment of the multicolor recording apparatus according to the present invention, and FIG. FIG. 4 is an explanatory view showing the details of the developing device, FIG. 4 is an explanatory view showing a third embodiment of the multicolor recording apparatus according to the present invention, FIG. 5 is an explanatory view showing the fourth embodiment according to the present invention, and FIG. FIG. 7 is a perspective view showing details of a writing head in Embodiment 4, FIG. 7 is an explanatory view showing an example of a conventional multicolor recording apparatus, FIG. 8 is an explanatory view showing an example of a structure around a conventional developing device, and FIG. FIG. 9 is an explanatory view showing details of the slit plate in FIG. [Explanation of Codes] (1) …… Photosensitive drum (latent image carrier) (3) …… Semiconductor laser element (latent image forming means) (4) …… Developing device (developing means) (11) …… Dielectric Drum (latent image carrier) (13) …… Writing head (latent image forming means) (16) …… Transfer roll (transfer means) (20) …… Oven fuser (heating means) (30) …… Heater (heating) means)

Claims (3)

[Claims] 1. A latent image carrier for which a multicolor toner image forming process is completed by one rotation, a latent image forming means for forming a plurality of latent images on the latent image carrier, and toners of different colors. A plurality of developing means for developing each latent image, a transfer means for collectively transferring the multicolor toner images developed by each developing means onto a transfer medium, and a developing device other than the final stage in the vicinity of the latent image carrier. A multicolor recording apparatus, comprising: a heating unit that is respectively provided at a subsequent stage of the means, and heats and attaches each toner image formed by a developing unit other than the final stage to the surface of the latent image carrier by heating. 2. A latent image carrier that completes a multicolor toner image forming process in one rotation, a latent image forming unit that forms a plurality of latent images on the latent image carrier, and toners of different colors. A plurality of developing means for developing each latent image, a transfer means for collectively transferring the multicolor toner images developed by each developing means onto a transfer medium, and a latent image carrier provided inside the latent image carrier, And a heating unit that heats the surface of the latent image carrier to the extent that each toner image formed by the above method is supposedly attached to the surface of the latent image carrier. 3. A latent image carrier for which a multicolor toner image forming process is completed by one rotation, an ion latent image forming means for forming a plurality of ion latent images on the latent image carrier, and toners of different colors. A plurality of developing means for developing each corresponding ion latent image,
Transfer means for collectively transferring the multicolor toner images developed by the respective developing means onto the transfer medium, and a developing means other than the final stage in the vicinity of the periphery of the latent image carrier are respectively provided at the latter stages and other than the final stage. Heating means for heating and presumably adhering each toner image formed by the developing means to the surface of the latent image carrier, and forming an area where the ion latent image corresponding to each color component formed by the ion latent image forming means is mutually formed. The multi-color recording apparatus is characterized in that an ion latent image is formed even on a toner image which is supposed to be heated and is supposed to be heated.