JP2008020782A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which, when using special toner such as transparent toner and white toner, can form a special toner image at an appropriate position without changing the arrangement of an image forming part as an engine using the special toner including an image forming part using other color toners. <P>SOLUTION: The image forming apparatus is provided with: a first toner image forming means to form a toner image with color toner prepared for normal image formation; a second toner image forming means as a means to form a toner image with the special toner, that is replaceable with a means to form a toner image with other special toner; a discriminating means to discriminate the kind of the toner to be used by the second toner image forming means; and a changing means to change the image formation order in the second toner image forming means related to the first toner image forming means in accordance with the result of the discrimination made by the discriminating means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine or a printer that employs an electrophotographic method, and more particularly to an image that forms an image using a special toner such as a white toner or a transparent toner in addition to a black toner or a color toner. The present invention relates to a forming apparatus.

JP-A-11-249375 JP 2000-267517 A JP 2002-072613 A JP 2002-082508 A JP 2002-099127 A

  In recent years, in image forming apparatuses such as copying machines and printers that employ this type of electrophotographic method, a white toner layer is applied to the surface of a recording sheet for the purpose of increasing the added value in addition to improving the quality of color images. It can be used as a base to make the paper base uniform, or a clear (transparent) toner can be laminated on the surface of the image as an overcoat layer to improve glossiness, or a magnetic toner can be used to read the code. There have been proposed methods of use such as improving the decorativeness using a toner of a specific color such as a metal color or forming a stereoscopic image using a foamed toner.

  As described above, in the image forming apparatus using the special toner such as the white toner and the transparent toner, the special toner such as the white toner and the transparent toner has different optimum layer positional relationship with respect to the color toner depending on the type. . For example, a base layer made of white toner needs to be formed on the lowermost layer with respect to color toner in order to improve the surface properties of paper, and an overcoat layer made of transparent toner forms a glossy layer. Therefore, it is necessary to form the uppermost layer with respect to the color toner, and the foamed toner needs to be formed on the uppermost layer in consideration of transferability to paper.

  Therefore, in the image forming apparatus using the special toner such as the white toner and the transparent toner, regarding the formation of the toner image made of the special toner such as the white toner and the transparent toner, Japanese Patent Application Laid-Open Nos. 2002-072613 and 2002-2002. As disclosed in Japanese Patent No. 082508, Japanese Patent Laid-Open No. 2002-099127, and the like, various techniques have already been proposed.

  The image forming apparatus according to the above-mentioned Japanese Patent Application Laid-Open No. 2002-072613 is an image forming apparatus in which a color toner image transferred onto a transfer material and a transparent toner layer are fixed. The glossiness is different, and a transparent toner layer is provided on the color toner image.

  Further, an image forming apparatus according to the above-mentioned Japanese Patent Application Laid-Open No. 2002-082508 includes a developing unit that forms a color toner image on an image carrier based on image information, a transfer unit that transfers the color toner image to a transfer material, and In an image forming apparatus including a fixing unit that heat-fixes a color toner image transferred to the transfer material to form an image, a transparent toner image is superimposed on the color toner image corresponding to the color toner image. The image forming apparatus further includes a transparent toner image forming unit and a transparent toner image formation control unit that variably controls the degree of superimposition of the transparent toner image with the color toner image.

  Further, the image forming apparatus according to the above Japanese Patent Application Laid-Open No. 2002-099127 or the like is an image forming apparatus that forms an image by transferring a toner image formed on an image carrier to a transfer material. A white toner image is formed in between, image data for forming a normal toner image is used as the image data for the white toner image, and a process for attaching a substantially constant amount of white toner to the toner image forming portion is performed. It is configured as follows.

  Japanese Laid-Open Patent Publication No. 2000-267517 discloses a technique for selecting a printing apparatus that performs an image stabilization operation according to an image forming environment and formed toner information in order to reduce setup time and toner consumption. As has already been proposed.

  The image stabilization operation execution method according to Japanese Patent Application Laid-Open No. 2000-267517 can form a toner image based on an original image on a recording sheet and form a predetermined toner image on a predetermined surface of a predetermined member. A method for performing an image stabilization operation performed to stabilize a toner image based on an original image formed on a recording sheet in an image forming apparatus including a plurality of printing apparatuses, the image forming environment and (Or) detecting information on the formed toner image, and selecting a printing device for performing an image stabilization operation from the plurality of printing devices based on the detection result, and causing the selected printing device to perform image stabilization. It is configured to perform the digitizing operation.

  Further, as a technique for controlling the density of the white toner and the transparent toner, for example, a technique disclosed in Japanese Patent Laid-Open No. 11-249375 has been proposed.

  A color image forming apparatus according to Japanese Patent Application Laid-Open No. 11-249375 uses a latent image forming unit that forms a latent image on an image carrier, and uses at least cyan, magenta, and yellow colored toner and transparent toner for the latent image. A color image forming apparatus comprising: a developing unit that performs color development; a transfer unit that transfers a formed development image onto a transfer material; and a fixing unit that fixes the transferred image onto the transfer material. A light amount measuring unit that measures the amount of reflected light when irradiated with light, and a development amount control unit that controls the amount of development of the transparent toner based on the amount of reflected light when irradiated to the transfer material. It is a thing.

  In the color image forming apparatus according to the above-mentioned Japanese Patent Application Laid-Open No. 11-249375, for example, the development amount control means controls the development amount of the transparent toner based on the amount of reflected light when the transfer material is irradiated with light. By changing the potential, the amount of exposure light, etc., the change in developability due to environmental changes or toner density changes is corrected.

  However, the conventional technique has the following problems. That is, in the case of the image forming apparatus proposed in the above-mentioned JP-A-2002-072613, JP-A-2002-082508, JP-A-2002-099127, etc., all of the embodiments have a tandem configuration. However, the arrangement of the engine differs depending on whether it is white toner or transparent toner.

  For example, in the image forming apparatus according to Japanese Patent Application Laid-Open No. 2002-072613, as shown in FIG. 1, the transparent toner engine is arranged at the first stage with respect to the intermediate transfer member as shown in FIG. The transparent toner engine is arranged at the last stage in a system in which the toner is directly transferred to the transfer material.

  Further, in the image forming apparatus according to Japanese Patent Application Laid-Open No. 2002-082508, a transparent toner engine is arranged at the final stage by a method of transferring directly to a transfer material.

  On the other hand, in the image forming apparatus according to Japanese Patent Laid-Open No. 2002-099127, as shown in FIG. 1, the white toner engine is at the final stage with respect to the intermediate transfer member, as shown in FIG. In addition, a white toner engine is arranged in the first stage by a method of transferring directly to a transfer material.

  By the way, special toners such as transparent toner and white toner are used for special purposes, and are different from other yellow (Y), magenta (M), cyan (C), and black (K) toners. It is desirable that the engine using the special toner such as the transparent toner and the white toner is configured to be replaceable according to the needs of the user.

  However, the engine using the special toner such as the transparent toner and the white toner needs to be arranged in the first stage or the last stage depending on the type of the special toner and the configuration of the image forming apparatus. Therefore, the arrangement of all five engines must be changed, including special toner engines and yellow (Y), magenta (M), cyan (C), and black (K) engines. Therefore, there is a problem that the user's replacement work becomes very complicated.

  Further, in the case of the image stabilization operation execution method according to the above Japanese Patent Laid-Open No. 2000-267517, if the image stabilization operation is frequently performed, the normal image forming operation cannot be executed during that time, so that the productivity is increased. Has a problem in that the toner consumption decreases and toner consumption increases.

  Further, in the case of the image stabilization operation execution method according to the above Japanese Patent Laid-Open No. 2000-267517, the full-color image is obtained by superimposing yellow (Y), magenta (M), cyan (C), and black (K) toners. Since it is formed by combining, when selecting a printing device that performs an image stabilization operation from among a plurality of printing devices and configuring the selected printing device to perform an image stabilization operation, There is a problem in that a color for which the image quality stabilization operation is not executed occurs and color misregistration occurs.

  In addition, a resist control pattern for controlling the image forming position of each color is not formed for toners of all colors of yellow (Y), magenta (M), cyan (C), and black (K). It is difficult to control and it is difficult to divide the implementation conditions.

On the other hand, special toners such as transparent toner, white toner, magnetic toner, specific color toner, and foam toner are yellow (Y), magenta (M), cyan (C), and black (K) toners. Differently, it has the following characteristics.
1) Since it is not indispensable for forming a full color image by mixing with other color toners, it is not necessary to consider the balance with other color toners.
2) Since the use of special toner is limited, it is not always necessary to maintain the optimum state, and it is sufficient that the image quality stabilization operation is performed immediately before use.
3) Depending on the type of special toner, a solid image is often formed uniformly, and adjustment of gradation characteristics is not necessary.
4) Depending on the image forming apparatus, the arrangement of engines using special toners may differ from those of yellow (Y), magenta (M), cyan (C), and black (K) engines.

  Therefore, special toners such as transparent toner, white toner, magnetic toner, specific color toner, and foamed toner have a problem that it is necessary to execute a dedicated image quality stabilization operation.

  The special toners such as the transparent toner and the white toner have a feature that an optimum layer positional relationship with respect to the color toner differs depending on the type. For example, white toner is for improving the surface properties of paper, so it is formed on the bottom layer, and transparent toner is for improving gloss, so it is formed on the top layer. In consideration of transferability, it is formed on the uppermost layer.

  Further, in the case of the color image forming apparatus according to the above-mentioned JP-A-11-249375, in order to control the development amount of the transparent toner, the transparent toner patch is applied at a predetermined timing in the same manner as other color toners. It is necessary to measure the density of the patch formed and made of the transparent toner by the light amount measuring means.

  However, high-value-added toners such as the above-described transparent toner and white toner have a small production amount, and therefore, compared with yellow (Y), magenta (M), cyan (C), and black (K) toners. It is expensive and valuable, and it is valuable to control the development amount of special toner such as transparent toner according to the result of detecting the density of the patch after forming the patch like normal process control. Since the special toner is consumed unnecessarily, there is a problem that means for controlling the toner development amount cannot be frequently executed.

  As a result, the development amount of the special toner such as the transparent toner or the white toner deviates from the target density, and the special toner such as the transparent toner or the white toner is unnecessarily consumed, or the gloss imparting effect or the background by the special toner is reduced. There is a problem that the effect of improving the whiteness of the film cannot be obtained sufficiently.

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and the object of the present invention is to use the special toner when a special toner such as a transparent toner or a white toner is used. Provided is an image forming apparatus capable of forming a special toner image at an appropriate position without changing the arrangement of the image forming section, which is an engine, including an image forming section using other color toners. There is.

  Another object of the present invention is to provide an image forming apparatus capable of appropriately controlling the density of the special toner without lowering the productivity or unnecessarily consuming the special toner. It is to provide.

  Furthermore, another object of the present invention is to provide an image forming apparatus capable of appropriately controlling the density of the special toner without unnecessarily consuming special toner such as transparent toner and white toner. There is to do.

That is, the invention described in claim 1 includes a first toner image forming unit that forms a toner image composed of toner of a color used for normal image formation;
Means for forming a toner image made of special toner, second toner image forming means exchangeable with means for forming a toner image made of other special toner;
Discrimination means for discriminating the type of toner used in the second toner image forming means;
An image forming apparatus comprising: a changing unit that changes an image forming order of the second toner image forming unit with respect to the first toner image forming unit according to a determination result of the determining unit. .

According to a second aspect of the present invention, there is provided an intermediate transfer member onto which a plurality of toner images formed by the first toner image forming unit and the second toner image forming unit are transferred,
The image forming apparatus according to claim 1, further comprising a transfer unit configured to transfer a plurality of toner images transferred onto the intermediate transfer member onto a transfer material.

Furthermore, the invention described in claim 3 conveys the transfer material on which a plurality of toner images formed by the first toner image forming unit and the second toner image forming unit are transferred. A transfer material conveying means;
Transfer means for transferring a plurality of toner images formed by the first toner image forming means and the second toner image forming means onto a transfer material conveyed by the transfer material conveying means; The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

  According to a fourth aspect of the present invention, when the discrimination unit determines that the toner used in the second toner image forming unit is a transparent toner, the toner made of the transparent toner is used. 4. The image forming apparatus according to claim 2, wherein the image forming order is changed so that the image is formed on the uppermost layer on the transfer material.

  Furthermore, in the invention described in claim 5, when the discrimination unit determines that the type of toner used in the second toner image forming unit is a white toner, the toner made of the white toner is used. 4. The image forming apparatus according to claim 2, wherein the image forming order is changed so that the image is formed on the lowermost layer on the transfer material.

  According to a sixth aspect of the present invention, when the determination unit determines that the type of toner used in the second toner image forming unit is a low-resistance type toner, 4. The image forming apparatus according to claim 2, wherein the image forming order is changed so that a toner image made of a toner having a low resistance value is transferred last.

Furthermore, the invention described in claim 7 includes a first toner image forming means for forming a toner image composed of toner of a color used for normal image formation;
Means for forming a toner image made of special toner, second toner image forming means exchangeable with means for forming a toner image made of other special toner;
First and second image quality stabilizing toner images are formed by the first toner image forming unit and the second toner image forming unit, and the first and second image quality stabilizing toner images are formed. A means for detecting and stabilizing the image quality of the first toner image forming means and the second toner image forming means, the image quality stabilizing operation of the first toner image forming means; An image forming apparatus comprising: an image quality stabilizing unit that operates differently from the image quality stabilizing operation of the toner image forming unit.

  In the invention described in claim 8, the image quality stabilizing means includes an image quality stabilizing operation of the first toner image forming means and an image quality stabilizing operation of the second toner image forming means. The image forming apparatus according to claim 7, wherein the time for performing the stabilization operation is different.

  Furthermore, the invention described in claim 9 is characterized in that the image quality stabilizing means includes an image quality stabilizing operation of the first toner image forming means and an image quality stabilizing operation of the second toner image forming means. The image forming apparatus according to claim 7, wherein sizes of toner images formed for the stabilizing operation are different.

  According to a tenth aspect of the present invention, in the image quality stabilizing means, the toner image used in the image quality stabilizing operation of the second toner image forming means is smaller. The image forming apparatus described.

  Further, in the invention described in claim 11, the image quality stabilizing unit includes an image quality stabilizing operation of the first toner image forming unit and an image quality stabilizing operation of the second toner image forming unit. The image forming apparatus according to claim 7, wherein the number of toner images formed for the stabilization operation is different.

  The invention described in claim 12 is characterized in that the image quality stabilizing means uses fewer toner images in the image quality stabilizing operation of the second toner image forming means. 11 is an image forming apparatus.

  Further, in the invention described in claim 13, the image quality stabilizing unit performs the image quality stabilizing operation of the second toner image forming unit immediately before or during the image forming operation by the second toner image forming unit. The image forming apparatus according to claim 7, wherein the image forming apparatus is executed at least at any one time immediately after.

According to a fourteenth aspect of the present invention, there is provided an intermediate transfer member for transferring the first and second toner images formed by the first toner image forming unit and the second toner image forming unit,
Secondary transfer means for transferring the first and second toner images transferred onto the intermediate transfer member to a transfer material;
Separating means for separating the secondary transfer means from the intermediate transfer member;
During the image quality stabilizing operation of the first toner image forming unit, the secondary transfer unit is separated from the intermediate transfer member by the separating unit, and during the image quality stabilizing operation of the second toner image forming unit, The image forming apparatus according to claim 7, wherein the secondary transfer unit is not separated from the intermediate transfer member by the separation unit.

Furthermore, the invention described in claim 15 is a first toner image forming means for forming a toner image made of toner of a color used for normal image formation;
Means for forming a toner image made of special toner, second toner image forming means exchangeable with means for forming a toner image made of other special toner;
Control so that the image area of the toner image made of the special toner formed by the second toner image forming means is larger than the image area of the toner image made of the normal toner formed by the first toner image forming means. An image forming apparatus including a control unit for controlling the image forming apparatus.

  According to a sixteenth aspect of the present invention, the density of the toner image formed by the second toner image forming unit is set to the image of the toner image made of normal toner formed by the first toner image forming unit. 16. The image forming apparatus according to claim 15, wherein detection is performed using an image area of special toner other than the area.

  Further, in the invention described in claim 17, the mode of forming a toner image by the second toner image forming means is a full image mode in which a toner image is uniformly formed on the entire surface of the transfer material, A partial image mode for forming a toner image only on a part thereof is selectable. When the full image mode is selected, a toner image made of normal toner formed by the first toner image forming unit is selected. 16. The image forming apparatus according to claim 15, wherein the density of the toner image formed by the second toner image forming unit is detected using an image area of special toner other than the image area.

  The invention described in claim 18 detects the density of the toner image formed by the second toner image forming means at at least one end of the transfer material in the main scanning direction or the sub-scanning direction. The image forming apparatus according to claim 17.

  According to the present invention, when a special toner such as a transparent toner or a white toner is used, an image forming unit that is an engine using the special toner is arranged including an image forming unit using another color toner. It is possible to provide an image forming apparatus capable of forming a special toner image at an appropriate position without replacing the toner.

  In addition, according to the present invention, it is possible to provide an image forming apparatus capable of appropriately controlling the density of the special toner without reducing productivity and unnecessarily consuming the special toner. .

  Furthermore, according to the present invention, it is possible to provide an image forming apparatus capable of appropriately controlling the density of the special toner without unnecessarily consuming special toner such as transparent toner or white toner.

  Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1
FIG. 2 shows a tandem full-color printer as an image forming apparatus according to Embodiment 1 of the present invention. Note that this tandem full-color printer includes an image reading device and functions as a full-color copying machine. Of course, the full-color printer does not have to include an image reading device.

  In FIG. 2, reference numeral 1 denotes a main body of a tandem full-color printer. An image reading device (IIT: 1T) that reads an image of an original 2 is provided at one upper end (left end in the illustrated example) of the full-color printer main body 1. Image Input Terminal) 4 is provided. The image reading device 4 illuminates a document 2 placed on a platen glass 5 with a platen cover 3 by a light source 6, and reflects a reflected light image from the document 2 with a full-rate mirror 7, half-rate mirrors 8 and 9, and a combined image. Scanning exposure is performed on an image reading element 11 composed of a CCD or the like through a reduction optical system composed of an image lens 10, and the image of the original 2 is read at a predetermined dot density (for example, 400 dpi or 600 dpi). It is like that.

  The image of the document read by the image reading device 4 is transferred to the image processing device 12 (Image Processing System) as image data of three colors of red (R), green (G), and blue (B) (each 8 bits), for example. The image processing apparatus 12 performs predetermined image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame deletion, color / moving editing, etc. on the image data of the document 2. Is done.

  The image data subjected to the predetermined image processing by the image processing device 12 as described above is an image of four colors of yellow (Y), magenta (M), cyan (C), and black (K) (each 8 bits). As described below, yellow (Y), magenta (M), cyan (C), and black (K) image forming units 13Y, 13M, 13C, and 13K ROSs 14Y, 14M, 14C, These ROSs 14Y, 14M, 14C, and 14K are subjected to image exposure using a laser beam LB in accordance with the image data of each color. As will be described later, the image processing device 12 is configured to process image data corresponding to the special toner. The image data corresponding to the special toner is stored in a user interface (not shown), a personal computer, or the like. It comes to be input from.

  By the way, inside the tandem-type full-color printer main body 1, yellow (Y), magenta (M), and cyan (C) as a first toner image forming unit group including a plurality of first toner image forming units. , Black (K) image forming units 13Y, 13M, 13C, and 13K are arranged in series at regular intervals in the horizontal direction.

  The tandem full-color printer main body 1 has the special toner (T) image formation using a special toner as a second toner image forming unit in addition to the first toner image forming unit group. The special toner (T) image forming unit 13T is arranged in tandem upstream of the first toner image forming unit group.

  These five image forming units 13T, 13Y, 13M, 13C, and 13K are basically configured in the same manner except for the type of toner to be used, and are roughly divided into predetermined rotations along the direction of arrow A. A photosensitive drum 15 that rotates at a speed, a primary charging scorotron 16 that uniformly charges the surface of the photosensitive drum 15, and an image corresponding to each color is exposed on the surface of the photosensitive drum 15 to electrostatically The image forming apparatus includes a ROS 14 that forms a latent image, a developing device 17 that develops the electrostatic latent image formed on the photosensitive drum 15 with toner of a corresponding color, and a cleaning device 18.

  As shown in FIG. 2, the ROS 14 modulates the semiconductor laser 19 according to the image data, and emits a laser beam LB from the semiconductor laser 19 according to the image data. The laser beam LB emitted from the semiconductor laser 19 is deflected and scanned by the rotary polygon mirror 22 via the reflecting mirrors 20 and 21, and the focal length is adjusted according to the scanning angle by an unshown f-θ lens. Then, scanning exposure is performed on a photosensitive drum 15 as an image carrier through a plurality of reflecting mirrors 23 and 24.

  From the image processing apparatus 12, the ROS 14T of the image forming units 13T, 13Y, 13M, 13C, and 13K for the special toner (T), yellow (Y), magenta (M), cyan (C), and black (K) colors. , 14Y, 14M, 14C, and 14K, image data of each color is sequentially output, and laser beams LB emitted according to the image data from these ROSs 14T, 14Y, 14M, 14C, and 14K are respectively transferred to the respective photosensitive drums 15T, The surfaces of 15Y, 15M, 15C, and 15K are scanned and exposed to form electrostatic latent images. The electrostatic latent images formed on the photosensitive drums 15T, 15Y, 15M, 15C, and 15K are respectively developed by the developing devices 17T, 17Y, 17M, 17C, and 17K with special toner (T), yellow (Y), It is developed as a toner image of each color of magenta (M), cyan (C), and black (K).

  Special toner (T), yellow (Y), magenta (M), magenta (M), sequentially formed on the photosensitive drums 15T, 15Y, 15M, 15C, and 15K of the image forming units 13T, 13Y, 13M, 13C, and 13K. As shown in FIG. 2, the cyan (C) and black (K) toner images are transferred to intermediate transfer belts as intermediate transfer members disposed below the image forming units 13T, 13Y, 13M, 13C, and 13K. 25, the toner images are transferred in a multiple manner in a state of being superposed by the primary transfer rolls 26T, 26Y, 26M, 26C, and 26K.

  In this embodiment, yellow (Y), magenta (M), cyan (C), and black (K) image forming units 13Y, 13M, 13C, and 13K groups are intermediate transfer belts 25 serving as image carriers. A plurality of the intermediate transfer belts 25 are arranged from a second position to a predetermined position which is a final position. The image forming portion 13T of the special toner (T) is disposed on the outer periphery of the intermediate transfer belt 25 at another predetermined position that is the most upstream position of the intermediate transfer belt 25.

  The intermediate transfer belt 25 is wound around the drive roll 27, the tension roll 28, the steering roll 29, the backup roll 30 and the idle roll 32 with a constant tension, and has a constant speed (not shown). A drive roll 27 that is rotationally driven by an excellent dedicated drive motor is driven to circulate at a predetermined speed equal to the photosensitive drums 15T, 15Y, 15M, 15C, and 15K along the arrow B direction. As the intermediate transfer belt 25, for example, a flexible synthetic resin film such as polyimide is formed in an endless belt shape.

  The special toner (T), yellow (Y), magenta (M), cyan (C), and black (K) toner images transferred in multiple onto the intermediate transfer belt 25 are transferred to the backup roll 30 as an intermediate transfer. The transfer sheet 33 is secondarily transferred onto a transfer sheet 33 as a transfer material by a pressing force and electrostatic force by a secondary transfer roll 39 that is in pressure contact with the belt 25, and the toner image of each color is transferred onto the transfer sheet 33. It is conveyed to the fixing device 47 by the continuous conveying belts 45 and 46. The transfer paper 33 on which the toner images of the respective colors are transferred is subjected to a fixing process by heat and pressure by a fixing device 47, and in the case of single-sided printing, on a discharge tray 59 provided outside the printer main body 1 as it is. To be discharged.

  In FIG. 2, reference numeral 41 denotes a bias application roll for applying a transfer bias to the backup roll 39, reference numeral 42 denotes a cleaning roll for cleaning the surface of the secondary transfer roll 39, and reference numeral 43 denotes a downstream side of the secondary transfer section. Reference numeral 44 is a guide plate for guiding the recording paper 33, reference numerals 45a and 45b are tension rolls for stretching the conveyor belt 45c, and reference numeral 48 is a heating roll for the fixing device 47. Reference numeral 49 denotes a pressure roll of the fixing device 47, and reference numeral 50 denotes an oil supply device of the fixing device 47.

  As shown in FIG. 2, the transfer sheet 33 has a predetermined size and material separated from one of the plurality of sheet trays 34 one by one by a sheet feed roller 35. The paper is once transported to the registration roll 38 via a paper transport path 37 composed of a pair of rollers 36 and stopped. The transfer paper 33 supplied from any one of the paper trays 34 is sent to the secondary transfer position of the intermediate transfer belt 25 by a registration roll 38 that is rotationally driven at a predetermined timing.

  When images are formed on both sides of the transfer paper 33 by the full-color printer, the transfer paper 33 on which the image is fixed on one side by the fixing device 47 is not discharged out of the apparatus as it is, but by a switching gate (not shown). Then, the transfer path of the transfer sheet 33 is switched downward, and the transfer sheet 33 is once transported to the reverse sheet transport path 57. Then, the transfer sheet 33 conveyed to the reversing sheet conveyance path 57 is reversed on the front and back through the double-sided sheet conveyance path 58 and the normal sheet conveyance path 37 in a state where the conveyance direction is reversed. In this state, the sheet is conveyed again to the secondary transfer position of the intermediate transfer belt 25 and an image is formed on the back surface, and then subjected to fixing processing by heat and pressure by the fixing device 47 and provided outside the printer body 1. It is discharged onto the discharge tray 59.

  In FIG. 2, reference numeral 55 denotes a cleaning device that cleans the surface of the intermediate transfer belt 25.

  By the way, in the digital color copying machine according to this embodiment, a first toner image forming means for forming a toner image made of toner of a color used for normal image formation and a toner image made of special toner are formed. A second toner image forming unit that is replaceable with a unit that forms a toner image made of other special toner, and a type of toner used in the second toner image forming unit. A determining unit and a changing unit that changes the image forming order of the second toner image forming unit with respect to the first toner image forming unit in accordance with the determination result of the determining unit.

  FIG. 1 is a block diagram showing a control circuit of a full-color printer according to this embodiment.

  In FIG. 1, reference numeral 100 denotes a control means having a function as a changing means composed of a CPU, MUC, etc. for controlling the image forming operation of a full-color printer. The control means 100 includes yellow (Y), magenta ( M), cyan (C), and black (K) image forming units 13Y, 13M, 13C, and 13K, and a toner image forming operation of special toner (T) image forming unit 13T, and intermediate transfer A driving means 101 for the intermediate transfer belt 25 as a body driving means, a fixing device 47 as a fixing means, a primary transfer roll 26 as a primary transfer means, a secondary transfer roll 39 as a secondary transfer means, and a secondary transfer. Secondary rotation comprising a solenoid or motor and a link mechanism for contacting and separating the roll 39 from the surface of the intermediate transfer belt 25 at a predetermined timing. Is configured to control the operation of the moving means 102.

  The image forming unit 13T for the special toner (T) is provided with an identifier 103 as a determining unit for determining the type of the special toner (T) used in the image forming unit 13T. Data indicating the type of the special toner (T) used in the determined image forming unit 13T is input to the control means 100. The identifier 103 is composed of, for example, a wireless crumb that performs data communication in a non-contact state, a protrusion provided in the image forming unit 13T, and the like, and a special toner ( What distinguishes the type of T) is used.

  The control circuit 100 determines each color of special toner (T), yellow (Y), magenta (M), cyan (C), and black (K) according to the type of special toner (T) determined by the identifier 103. The image forming units 13T, 13Y, 13M, 13C, and 13K are configured to change the order of toner image formation.

  In the above configuration, in the full-color printer according to the first embodiment, when a special toner such as a transparent toner or a white toner is used as described below, an image forming unit that is an engine using the special toner is installed. Therefore, it is possible to form a special toner image at an appropriate position without exchanging the arrangement including the image forming unit using other color toners.

  That is, in the full-color printer, as shown in FIG. 2, image forming sections for each color of yellow (Y), magenta (M), cyan (C), and black (K) are placed at predetermined positions inside the full-color printer main body 1. 13Y, 13M, 13C, and 13K, and an image forming unit 13T for special toner (T) at another predetermined position. Examples of the special toner used in the image forming unit 13T of the special toner (T) include a transparent toner, a white toner, a magnetic toner, a specific color toner such as a metal color, and a foamed toner.

  Therefore, as shown in FIG. 3, the control circuit 100 determines whether or not to use the fifth engine using the special toner (T), that is, the image forming unit 13T, prior to the printing operation. If it is determined by the identifier 103 provided in the section 13T (step 101) and it is determined that the image forming section 13T is not used, yellow (Y), magenta (M), Images of each color of cyan (C) and black (K) are sequentially formed (steps 104 to 107). Then, the control circuit 100 determines whether or not the normal printing or the transparent toner is used (step 108). If the normal printing or the transparent toner is not used, the control circuit 100 executes the secondary transfer (step 111). It is determined whether or not printing has been completed. If printing has not ended, the process returns to step 101. If printing has ended, the printing operation ends.

  When the control circuit 100 determines that the fifth engine using the special toner (T), that is, the image forming unit 13T is used (step 101), as shown in FIG. 3, the image forming unit 13T It is determined whether the toner to be used is a transparent toner or a white toner (step 102).

  At this time, the type of the special toner (T) used in the image forming unit 13T is determined by the identifier 103 provided in the image forming unit 13T as shown in FIG. The control unit 100 is notified of the toner type.

  Then, the control unit 100 performs special toner (T), yellow (Y), magenta (M), cyan (C), and the like according to the type of special toner used in the image forming unit 13T of the special toner (T). The order of forming toner images in the image forming units 13T, 13Y, 13M, 13C, and 13K for each color of black (K) is changed.

  When it is determined that the special toner used in the image forming unit 13T of the special toner (T) is a transparent toner, the control unit 100 first forms an image of the special toner (T) when forming an image. After forming a toner image with a transparent toner in a predetermined image area by the forming unit 13T (step 103), subsequently, images of each color of yellow (Y), magenta (M), cyan (C), and black (K) The toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) are sequentially formed by the forming portions 13Y, 13M, 13C, and 13K (steps 104 to 107). .

  Special toner (T) sequentially formed by the image forming portions 13T, 13Y, 13M, 13C, and 13K for each color of the special toner (T), yellow (Y), magenta (M), cyan (C), and black (K) ), Yellow (Y), magenta (M), cyan (C), and black (K) toner images are primarily transferred in a state where they are superimposed on the intermediate transfer belt 25 as shown in FIG. After that, secondary transfer is performed collectively from the intermediate transfer belt 25 onto the transfer paper 33 (step 111), and a fixing process is performed by the fixing device 47 to form a full-color image (step 112).

  At this time, as shown in FIG. 4, the toner image transferred onto the transfer paper 33 has the colors yellow (Y), magenta (M), cyan (C), and black (K) on the transfer paper 33. A color toner image composed of a toner image is formed, and a toner image composed of transparent toner is uniformly formed on the surface of the color toner image.

  Further, when the control unit 100 determines that the special toner used in the image forming unit 13T of the special toner (T) is a white toner (step 102), the control unit 100 generates a toner image when forming the image. The order of formation is changed. First, the white toner image is not formed by the image forming unit 13T of the special toner (T), and as shown in FIG. 4, yellow (Y), magenta (M), cyan ( C) and black (K) image forming portions 13Y, 13M, 13C, and 13K sequentially form yellow (Y), magenta (M), cyan (C), and black (K) toner images. (Steps 104 to 107).

  Yellow (Y), magenta (M), cyan (C) formed by the image forming portions 13Y, 13M, 13C, and 13K for the respective colors of yellow (Y), magenta (M), cyan (C), and black (K). ) The black (K) color toner images are sequentially primary transferred onto the intermediate transfer belt 25, and at this point, the secondary transfer roll 39 is separated and brought into contact when the toner image passes (step 109). In addition, the toner image of each color of yellow (Y), magenta (M), cyan (C), and black (K) is transferred onto the intermediate transfer belt 25 without feeding the transfer paper 33. Then, the intermediate transfer belt 25 is circulated again to the special toner (T) image forming portion 13T, and finally, as shown in FIG. 4, the special toner (T) image forming portion 13T causes a predetermined image area. White toner Thereby forming a toner image (step 110). For example, the white toner image is formed on the entire image area as shown in FIG.

  Further, when the intermediate transfer belt 25 to which the toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) are transferred passes through the secondary transfer position, the secondary transfer is performed. Intermediate transfer in which the secondary transfer roll 39 is separated from the intermediate transfer belt 25 by the contact / separation unit 102 and toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) are transferred. After the belt 25 passes the secondary transfer position, the secondary transfer roller 39 is again brought into contact with the intermediate transfer belt 25 by the secondary transfer contact / separation means 102 as shown in FIG. 2 (step 109). .

  Thereafter, the yellow (Y), magenta (M), cyan (C), and black (K) image forming units 13Y, 13M, 13C, and 13K do not perform toner image formation and toner image transfer. When the intermediate transfer belt 25 moves to the secondary transfer position, a white toner image and yellow (Y), magenta (M), cyan (C), and black (K) toners are transferred from the intermediate transfer belt 25. Control is performed by the control means 100 so that the images are collectively transferred onto the transfer paper 33 as shown in FIG. 6 (step 111).

  Further, the control unit 100 replaces the special toner (T) image forming unit 13T, and the identifier 103 compares the special toner used in the special toner (T) image forming unit 13T with a normal color toner. When it is determined that the toner is a metal toner having a low resistance value such as gold or silver, the toner image composed of the toner having a low resistance value is transferred on the intermediate transfer belt 25 last. In addition, the image forming order is changed.

  The metallic toner such as gold and silver has a lower resistance value than that of a normal color toner. Therefore, when the toner is transferred onto the intermediate transfer belt 25 before other color toners (including black), the latter stage In the toner image transfer process, a so-called “retransfer” phenomenon that is retransferred onto the photosensitive drum 15 easily occurs.

  Therefore, the control means 100 is configured so that the toner image made of the low-resistance type toner is transferred last, that is, so as to be formed on the lowermost layer on the transfer paper 33 like the white toner. The image forming order is changed. Therefore, the toner image composed of the low-resistance toner is transferred to the intermediate transfer belt 25 lastly. Therefore, the toner image composed of the low-resistance toner transferred onto the intermediate transfer belt 25. However, it can be reliably prevented from being retransferred onto the subsequent photosensitive drum 15.

  As described above, in the full-color printer according to the first embodiment, when special toner such as transparent toner or white toner is used in the image forming unit 13T of the special toner (T), the type of the special toner (T) is As shown in FIG. 1, the determination unit 102 provided in the image forming unit 13T performs determination, and the control unit 100 controls the order of image formation according to the type of special toner by the determination unit 102. It is possible to form a special toner image at an appropriate position without changing the arrangement of the image forming unit using the special toner including the image forming unit using the toner of other colors.

Embodiment 2
FIG. 8 shows a second embodiment of the present invention. The same reference numerals are given to the same parts as those in the first embodiment. In the second embodiment, the first toner image is shown. A transfer material conveying means for conveying a transfer material onto which a plurality of toner images formed by the forming means and the second toner image forming means are carried; the first toner image forming means; and the second toner image forming means. Transfer means for transferring a plurality of toner images formed by the toner image forming means onto a transfer material conveyed by the transfer material conveying means.

  That is, in the second embodiment, as shown in FIG. 8, the special toner image forming unit 13T and the yellow (Y), magenta (M), cyan (C), and black (K) image forming units. 13Y, 13M, 13C, and 13K are horizontally arranged at regular intervals, and below these image forming portions 13T, 13Y, 13M, 13C, and 13K, not the intermediate transfer belt 25. A transfer material transport belt 25a is provided as transfer material transport means for transporting the transfer material in a supported state. On the surface of the transfer material conveyance belt 25a, a sheet conveyance path including a sheet feeding roller 35 and a sheet conveyance roller pair 36 is made of one of a plurality of sheet trays 34 having a predetermined size or material. It is once conveyed to the registration roll 38 via 37 and stopped. The transfer paper 33 supplied from any one of the paper trays 34 is sent to the transfer material transport belt 25a by a registration roll 38 that is rotationally driven at a predetermined timing. The transfer paper 33 sent to the transfer material transport belt 25a is transported in a state of being electrostatically attracted to the surface of the transfer material transport belt 25a by an unillustrated suction means, and each of the image forming units 13T, 13Y, 13M. , 13C, and 13K, the toner images are transferred, separated from the transfer material conveyance belt 25a, subjected to fixing processing by the fixing device 47, and discharged onto the discharge tray 59.

  When images are formed on both sides of the recording paper 33 by the full-color printer, the recording paper 33 on which the image is fixed on one side by the fixing device 47 is not discharged out of the apparatus as it is, but by a switching gate (not shown). Then, the conveyance path of the recording paper 33 is switched downward, and the recording paper 33 is once conveyed to the reverse paper conveyance path 57. Then, the recording paper 33 conveyed to the reversing paper conveyance path 57 is turned upside down via the double-sided paper conveyance path 58 and the normal paper conveyance path 37 with its conveyance direction reversed. In this state, the sheet is conveyed again to the secondary transfer position of the intermediate transfer belt 25 and an image is formed on the back surface, and then subjected to fixing processing by heat and pressure by the fixing device 47 and provided outside the printer main body 1. It is discharged onto the discharge tray 59.

  In FIG. 8, reference numeral 55 denotes a cleaning device for cleaning the surface of the transfer material transport belt 25a.

  FIG. 9 is a block diagram showing a control circuit of the full-color printer according to the second embodiment.

  In the full-color printer according to the second embodiment, the image forming unit 13T of special toner and the image forming units 13Y, 13M, and 13C for each color of yellow (Y), magenta (M), cyan (C), and black (K) are used. , 13K, the toner image is directly transferred onto the transfer paper 33, so that the secondary transfer means is not provided, and the secondary transfer means is not provided.

  By the way, in the second embodiment, as shown in FIG. 8, an image forming unit 13T of special toner and an image forming unit of each color of yellow (Y), magenta (M), cyan (C), and black (K). Since the toner images are directly transferred onto the transfer paper 33 by 13Y, 13M, 13C, and 13K, the order in which the toner images are formed is different from that in the above embodiment.

  In the full-color printer according to the second embodiment, when the control unit 100 determines that the special toner used in the image forming unit 13T of the special toner (T) is a transparent toner, when the image is formed , Yellow (Y), magenta (M), cyan (C), and black (K) image forming units 13Y, 13M, 13C, and 13K, yellow (Y), magenta (M), cyan (C), After the toner images of each color of black (K) are sequentially formed, a toner image of transparent toner is finally formed in a predetermined image area by the image forming unit 13T of the special toner (T).

  At this time, in the second embodiment, as shown in FIG. 8, the toner image is directly transferred onto the transfer paper 33 by the image forming units 13T, 13Y, 13M, 13C, and 13K. Since the fixing device 47 is disposed after the process, after the toner image of each color of yellow (Y), magenta (M), cyan (C), and black (K) is sequentially formed and the fixing process is completed, The transfer paper 33 is transported again onto the transfer material transport belt 25a without inverting the front and back of the transfer paper 33, and finally a toner image is formed by transparent toner to be transferred and fixed.

  Further, when the control unit 100 determines that the special toner used in the image forming unit 13T of the special toner (T) is a white toner, the special toner (T) is first formed when the image is formed. After forming and transferring a toner image of white toner on the entire surface by the image forming unit 13T, image forming units for each color of yellow (Y), magenta (M), cyan (C), and black (K) 13Y, 13M, 13C, and 13K are used to sequentially form and transfer yellow (Y), magenta (M), cyan (C), and black (K) toner images, and the fixing device 47 collectively performs fixing processing. To do.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

Embodiment 3
FIG. 10 shows a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals. In the third embodiment, the first toner image is shown. A transfer material conveying means for conveying a transfer material onto which a plurality of toner images formed by the forming means and the second toner image forming means are carried; the first toner image forming means; and the second toner image forming means. Transfer means for transferring a plurality of toner images formed by the toner image forming means onto a transfer material conveyed by the transfer material conveying means.

  However, the first toner image forming means and the second toner image forming means are not configured as toner image forming means each provided with a photosensitive drum as an image carrier, but as an image carrier. As the first toner image forming unit and the second toner image forming unit, the first toner image forming unit and the second toner are provided on the surface of the single photosensitive drum. The apparatus includes a plurality of developing units that develop the toner image using toner formed by the image forming unit.

  Further, the plurality of toner images sequentially formed on the single photosensitive drum are sequentially transferred onto a transfer material carried on a transfer material carrying drum as a transfer material carrying member. .

  That is, in the third embodiment, as shown in FIG. 10, only one photosensitive drum 15 as an image carrier is provided, and the surface of the photosensitive drum 15 is provided around the photosensitive drum 15. Formed sequentially on the photosensitive drum 15, the scorotron 16 for primary charging that is uniformly charged, the ROS 14 that forms an electrostatic latent image by exposing an image corresponding to each color on the surface of the photosensitive drum 15. A low one-tally developing device 17 having a plurality of developing devices for developing a plurality of electrostatic latent images with corresponding color toners and a cleaning device (not shown) are provided.

  As shown in FIG. 10, the rotary developing device 17 includes developing devices 17Y, 17M, 17C, and 17K for yellow (Y), magenta (M), cyan (C), and black (K). A developing unit 17T that develops an electrostatic latent image using toner is disposed along the circumferential direction, and the predetermined developing units 17T, 17Y, 17M, 17C, 17K, and 17T are appropriately opposed to the photosensitive drum 15. The electrostatic latent image formed on the photosensitive drum 15 is developed by the predetermined developing device.

  Of the plurality of developing devices 17T, 17Y, 17M, 17C, 17K, and 17T, the black developing device 17K is often used more often than other developing devices, and therefore contains a large amount of toner. It is formed larger than other developing devices as possible.

  The transfer paper 33 is fed from the paper tray 34 and then electrostatically carried on a transfer material carrying drum 25b as a transfer material carrying member, and the recording paper carried on the transfer material carrying drum 25b. Further, a predetermined toner image is sequentially transferred in multiple layers from the photosensitive drum 15 by the transfer charger 26. The type and size of the transfer paper 33 fed from the paper tray 34 is detected by a paper sensor 34a.

  The transfer paper 33 on which the predetermined toner images are transferred in multiple layers is separated from the transfer material carrying drum 25b, and then subjected to a fixing process by the fixing device 47 and discharged onto a discharge tray (not shown).

  FIG. 11 is a block diagram showing a control circuit of the full-color printer according to the third embodiment.

  The full-color printer according to the third embodiment includes a replaceable special toner developing unit 17T instead of the special toner image forming unit 13T, and the type of special toner used in the special toner developing unit 17T. An identifier 103 for identification is provided in the special toner developing device 17T.

  By the way, in the full-color printer according to the third embodiment, as shown in FIG. 10, when the control unit 100 determines that the special toner used in the image forming unit 13T of the special toner (T) is a transparent toner. In this example, yellow (Y), magenta (M), cyan (C), and black (K) toner images are sequentially formed on the photosensitive drum 15, and finally a special toner (T) developing unit 17T. Thus, a toner image is formed with a transparent toner in a predetermined image area.

  Further, when the control unit 100 determines that the special toner used in the image forming unit 13T of the special toner (T) is a white toner, the special toner (T) is first formed when the image is formed. The toner image is formed with white toner on the entire surface by the developing unit 17T, and then transferred to the image forming unit 13Y for each color of yellow (Y), magenta (M), cyan (C), and black (K). , 13M, 13C, and 13K, yellow (Y), magenta (M), cyan (C), and black (K) toner images are sequentially formed and transferred, and finally, fixing processing is performed by the fixing device 47. It is like that.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

Embodiment 4
FIG. 12 shows a fourth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and in the fourth embodiment, they are used for normal image formation. First toner image forming means for forming a toner image made of toner of the color to be formed, means for forming a toner image made of special toner, and means for forming a toner image made of other special toner The replaceable second toner image forming unit, the first toner image forming unit, and the second toner image forming unit form first and second toner images for stabilizing image quality, and And a means for detecting the second image quality stabilizing toner image and performing an operation of stabilizing the image quality of the first toner image forming means and the second toner image forming means, wherein the first toner image The image quality stabilizing operation of the forming means, and Operating in a quality stabilizing operation of the toner image forming means is configured with a different image quality stabilization means.

  In other words, as shown in FIG. 12, the fourth embodiment is basically configured in the same manner as the tandem full-color printer as the image forming apparatus according to the first embodiment. However, in this tandem full-color printer, the first and second toner image forming units form the first and second toner images for stabilizing the image quality, and the first and second toner images are formed. The image forming apparatus includes a control unit 100 as an image quality stabilizing unit that detects an image quality stabilizing toner image and stabilizes the image quality of the first toner image forming unit and the second toner image forming unit.

  In the image quality stabilization mode set at a predetermined timing, the control unit 100 performs image forming units 13Y, 13M, 13C for yellow (Y), magenta (M), cyan (C), and black (K). A toner image for stabilizing image quality (hereinafter referred to as “toner patch”) is formed by 13K, and the density and image position of the toner patch formed by the image forming units 13Y, 13M, 13C, and 13K of these colors are determined. Detection is performed by an image sensor disposed at the final stage of the image forming unit.

  In the first image quality stabilization mode, as shown in FIG. 16, for example, when the full-color printer is turned on, periodically after the power is turned on (for example, every 4 hours), and 100 sheets It is set to be executed every time printing is performed on recording paper. The image quality stabilization operation in this image quality stabilization mode is performed on the intermediate transfer belt 25 with toner patches 110Y of yellow (Y), magenta (M), cyan (C), and black (K) as shown in FIG. 110M, 110C, and 110K are formed, and the density and / or image position of the toner patches 110Y, 110M, 110C, and 110K of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are determined. The density of each color toner patch 110Y, 110M, 110C, 110K is detected by the image sensor 120 disposed in the final stage of the image forming unit, and / or the image position is within a predetermined range. If it is not within the predetermined range, the density and / or image position of each color toner patch is within the predetermined range. The toner density and developing bias of the developing devices 17Y, 17M, 17C, and 17K, the charging potential, the exposure amount, and the exposure timing of the photosensitive drums 15Y, 17M, 17C, and 17K are controlled so as to enter the inside. ing.

  However, in the first image quality stabilization mode, the image forming unit 13T using special toner is configured not to execute the image quality stabilization mode. In the image forming unit 13T using the special toner, the image forming unit 13T is executed only at the time of image formation by the second image quality stabilizing mode, for example, the image forming unit 13T using the special toner, which is different in timing from the first image quality stabilizing mode. It is comprised so that.

  At the time of image formation by the image forming unit 13T using the special toner, the second image quality stabilization mode is executed at least one timing immediately before, during or immediately after the start of the image forming operation. ing. In the fourth embodiment, for example, the second image quality stabilization operation is set to be executed only immediately before the start of the image forming operation by the image forming unit 13T using special toner.

  In the second image quality stabilization mode, as shown in FIG. 15, the image forming unit 13T using special toner causes the second image quality stabilization toner image 110T (hereinafter referred to as “toner patch”). The image sensor 120 detects the density and image position of the toner patch 110T formed by the image forming unit 13T. The area of the toner patch 110T is set smaller than that of the toner patches 110Y, 110M, 110C, and 110K.

  In the second image quality stabilization mode, the control means determines whether or not the density and / or image position of the toner patch 110T of special toner is within a predetermined range, and does not fall within the predetermined range. In this case, the toner density and development bias of the developing device 17T, or the charging potential and exposure amount of the photosensitive drum 15T, so that the density and / or image position of the toner patch 110T of special toner fall within a predetermined range. The exposure timing and the like are controlled.

  As described above, in the fourth embodiment, the image quality stabilization operation of the first toner image forming unit and the image quality stabilization operation of the second toner image forming unit are configured to have different implementation timings. Therefore, it is possible to prevent the special toner from being consumed unnecessarily by frequently performing the image quality stabilization operation of the special toner, and the image quality stabilization operation from taking a long time to reduce the productivity.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

Embodiment 5
FIG. 17 shows a fifth embodiment of the present invention. The same reference numerals are given to the same parts as those of the fourth embodiment, and in the fifth embodiment, the fourth embodiment is the same as the fourth embodiment. In addition to the configuration, the second image stabilization operation is configured to be executed immediately before printing at the start of a job using special toner and in a non-image area between image areas during printing. Yes.

  In the fifth embodiment, during the image quality stabilization operation of the first toner image forming unit, the separation unit separates the secondary transfer unit from the intermediate transfer member and also forms the second toner image. During the image quality stabilization operation of the unit, the separation unit is configured not to separate the secondary transfer unit from the intermediate transfer member.

  That is, as shown in FIG. 17, the full-color printer according to the fifth embodiment has yellow (Y), magenta (M), cyan (C), and black (K) image forming units 13Y, 13M, and 13C. , 13K and the image forming unit 13T using special toner are configured so as to be different from those in the first embodiment. The yellow (Y), magenta (M), cyan (C), and black (K) image forming units 13Y, 13M, 13C, and 13K are disposed on the downstream side of the image forming unit 13T using special toner. The image forming units 13Y, 13M for yellow (Y), magenta (M), cyan (C), and black (K) are arranged upstream of the image forming unit 13T using special toner. 13C and 13K are horizontally arranged at a certain distance.

  The image forming unit 13T using the special toner is not parallel to the image forming units 13Y, 13M, 13C, and 13K for yellow (Y), magenta (M), cyan (C), and black (K). The intermediate transfer belt 25 is disposed so as to be positioned between the tension roll 28 and the backup roll 30 in the conveyance path of the intermediate transfer belt 25. Further, the image forming unit 13T using the special toner is disposed in a state where the photosensitive drum 15T is stretched so as to curve the intermediate transfer belt 25.

  Further, as shown in FIG. 17, the cleaning device 55 for cleaning the surface of the intermediate transfer belt 25 is located downstream of the black (K) image forming unit 13K, and also in the image forming unit 13T using special toner. Arranged upstream.

  In the full-color printer according to the fifth embodiment, as shown in FIG. 18, the control unit 100 performs the second image quality stabilization operation for intermediate transfer corresponding to immediately before printing at the start of a job using special toner. It is configured to execute in the area of the belt 25 and the non-image area between the image area and the image area during printing.

  As described above, the first image quality stabilization mode is, for example, when the full-color printer is turned on, periodically after the power is turned on (for example, every 4 hours), and on 100 recording sheets. It is set to be executed every time it prints.

  As shown in FIG. 19, the control means 100 determines whether or not the job uses a special toner such as a specific color toner (step 201) and determines that the job uses a special toner such as a specific color toner. If it is determined, after performing the setup operation for executing the image quality adjustment mode of the special toner (step 202), the counter for counting the number of times of the image quality adjustment mode of the special toner is set to “0” (step 203).

  Then, the control unit 100 executes a print job using special toner such as toner of a specific color (step 204), adds “1” to the YMCK counter (step 205), and also sets “1” to the special toner counter. "Is added (step 206).

  Next, the control means 100 determines whether or not the YMCK counter has become a predetermined value or more (step 207). If the YMCK counter is not the predetermined value or more, whether or not the special toner counter has become the predetermined value or more. Is determined (step 208). If the special toner counter is not equal to or greater than the predetermined value, it is determined whether or not the printing operation is finished (step 211). If the printing operation is finished, the printing sequence is finished and the printing operation is finished. If not, the process returns to step 204 to execute the remaining printing operation.

  On the other hand, when the control unit 100 determines that the YMCK counter has reached a predetermined value or more, the secondary transfer roll 39 is retracted and separated from the intermediate transfer belt 25 (step 212), and then the YMCK image quality adjustment mode is performed. (Step 213). Thereafter, after the secondary transfer roll 39 is brought into contact with the intermediate transfer belt 25 (step 214), the YMCK counter is set to “0” (step 215), and it is determined whether or not the printing operation is finished (step 211). .

  When the control unit 100 determines that the special toner counter has reached a predetermined value or more, the image quality adjustment of the special toner is performed with the secondary transfer roll 39 kept in contact with the intermediate transfer belt 25 without being retracted. After executing the mode (step 209), the special toner counter is set to “0” (step 210), and it is determined whether or not the printing operation is finished (step 211).

  As described above, the second image quality stabilization operation using the special toner is performed in the image area during printing immediately before printing at the start of the job using the special toner and when the special toner counter exceeds a predetermined value. Therefore, the amount of special toner to be used other than image formation can be greatly reduced.

  Further, in the non-image area between the image area and the image area during printing, the secondary transfer roll 39 remains in contact with the surface of the intermediate transfer belt 25. In the case of white toner, even if the toner adheres to the surface of the secondary transfer roll 39 and is then transferred to the back surface of the transfer paper 33 through the secondary transfer roll 39, the transparent toner or white toner is hardly Since it is not conspicuous, there is no hindrance, and it is not necessary to separately execute the second image quality adjustment mode, so that productivity can be improved.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

Embodiment 6
FIG. 15 also shows a sixth embodiment of the present invention. The same parts as those in the first embodiment will be described with the same reference numerals. That is, in the sixth embodiment, FIG. As shown in the figure, the special toner patch 110T only needs to maintain a constant toner amount without considering gradation, and is therefore configured to reduce the number of patches 110T or to reduce the patch area. ing. In the sixth embodiment, since the operation of the cleaning device is omitted, if the area of the special toner patch 110T is small and the number is small, the secondary transfer roll 39 can improve the toner collection performance. .

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

Embodiment 7
FIG. 20 shows Embodiment 7 of the present invention. The same parts as those in Embodiment 4 will be described with the same reference numerals. In Embodiment 7, the second toner image will be described. Control means for controlling the image area of the toner image made of special toner formed by the forming means to be larger than the image area of the toner image made of normal toner formed by the first toner image forming means. It is configured.

  That is, in the seventh embodiment, as shown in FIG. 20, the image forming units 13Y, 13M, 13C, and 13K for each color of yellow (Y), magenta (M), cyan (C), and black (K) When forming a toner image of each color of yellow (Y), magenta (M), cyan (C), and black (K), the image area of each color toner image is set equal to the normal image area.

  On the other hand, in the seventh embodiment, as shown in FIG. 20, when the special toner image is formed by the image forming unit 13T using the special toner, the image area of the special toner image is displayed. Is set to be wider than the normal image area.

  Normally, in a printer, the image areas of toner images of yellow (Y), magenta (M), cyan (C), and black (K) are appropriately set by inputting numerical values. In the embodiment, the image area of the toner image of the special toner is automatically set so as to be, for example, about 5 mm wider than the normal image area.

  The image area of the toner image of the special toner may be set so that both ends in the main scanning direction and the sub-scanning direction are wider than the image area of the largest recording sheet, as shown in FIG. Thus, for example, when an image sensor is provided at the end on the downstream side in the main scanning direction, the image area of the toner image of the special toner is widened only at the end where the image sensor is provided. It may be set to.

  As described above, in the seventh embodiment, as shown in FIG. 20, by setting the image area of the toner image of the special toner to be wider than the normal image area, a toner patch made of the special toner is newly formed. The image quality adjustment operation can be executed by detecting the toner image of the special toner located in the image area set wider than the normal image area by the image sensor. In the case of white toner, since it is set to be wider than the normal image area in advance, the image quality adjustment operation can be executed without forming a special toner patch, and the special toner is wasted. Consumption can be reduced.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

FIG. 1 is a block diagram showing a control circuit of a tandem full color printer as an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing a tandem full-color printer as an image forming apparatus according to Embodiment 1 of the present invention. FIG. 3 is a flowchart showing the operation of the tandem full-color printer as the image forming apparatus according to Embodiment 1 of the present invention. FIG. 4 is a schematic cross-sectional view showing a toner image formation state. FIG. 5 is a schematic cross-sectional view showing a toner image formation state. FIG. 6 is a schematic plan view showing a toner image formation state. FIG. 7 is a schematic cross-sectional view showing a toner image formation state. FIG. 8 is a block diagram showing a tandem full-color printer as an image forming apparatus according to Embodiment 2 of the present invention. FIG. 9 is a block diagram showing a control circuit of a tandem full-color printer as an image forming apparatus according to Embodiment 2 of the present invention. FIG. 10 is a block diagram showing a tandem full-color printer as an image forming apparatus according to Embodiment 3 of the present invention. FIG. 11 is a block diagram showing a control circuit of a tandem full-color printer as an image forming apparatus according to Embodiment 3 of the present invention. FIG. 12 is a block diagram showing a tandem full-color printer as an image forming apparatus according to Embodiment 4 of the present invention. FIG. 13 is a block diagram showing a control circuit of a tandem full-color printer as an image forming apparatus according to Embodiment 4 of the present invention. FIG. 14 is a schematic diagram illustrating a toner patch. FIG. 15 is a schematic diagram illustrating a toner patch. FIG. 16 is a flowchart showing the operation of a tandem full-color printer as an image forming apparatus according to Embodiment 4 of the present invention. FIG. 17 is a block diagram showing a tandem full-color printer as an image forming apparatus according to Embodiment 5 of the present invention. FIG. 18 is a schematic diagram illustrating a toner patch. FIG. 19 is a flowchart showing the operation of a tandem full-color printer as an image forming apparatus according to Embodiment 5 of the present invention. FIG. 20 is an explanatory view showing the main part of a tandem full-color printer as an image forming apparatus according to Embodiment 7 of the present invention.

Explanation of symbols

  13Y: Y color image forming unit, 13M: M color image forming unit, 13C: C color image forming unit, 13K: K color image forming unit, 13T: Special toner image forming unit, 100: Control unit, 101: intermediate transfer member driving means, 102: secondary transfer contact / separation means, 103: identifier, 26: primary transfer means, 39: secondary transfer means, 47: fixing means.

Claims (18)

First toner image forming means for forming a toner image made of toner of a color used for normal image formation;
Means for forming a toner image made of special toner, second toner image forming means exchangeable with means for forming a toner image made of other special toner;
Discrimination means for discriminating the type of toner used in the second toner image forming means;
An image forming apparatus comprising: a changing unit that changes an image forming order of the second toner image forming unit with respect to the first toner image forming unit according to a determination result of the determining unit. An intermediate transfer member onto which a plurality of toner images formed by the first toner image forming unit and the second toner image forming unit are transferred;
The image forming apparatus according to claim 1, further comprising a transfer unit that transfers a plurality of toner images transferred onto the intermediate transfer member onto a transfer material. Transfer material conveying means for conveying a transfer material onto which a plurality of toner images formed by the first toner image forming means and the second toner image forming means are transferred; and
Transfer means for transferring a plurality of toner images formed by the first toner image forming means and the second toner image forming means onto a transfer material conveyed by the transfer material conveying means; The image forming apparatus according to claim 1, wherein: When the determining means determines that the toner used by the second toner image forming means is a transparent toner, a toner image made of the transparent toner is formed on the uppermost layer on the transfer material. The image forming apparatus according to claim 2, wherein the image forming order is changed as described above. When the determining means determines that the type of toner used in the second toner image forming means is white toner, a toner image composed of the white toner is formed on the lowermost layer on the transfer material. The image forming apparatus according to claim 2, wherein the image forming order is changed as described above. When the determination unit determines that the type of toner used in the second toner image forming unit is a low-resistance type toner, a toner image composed of the low-resistance type toner is used. The image forming apparatus according to claim 2, wherein the image forming order is changed so that the transfer is performed last. First toner image forming means for forming a toner image made of toner of a color used for normal image formation;
Means for forming a toner image made of special toner, second toner image forming means exchangeable with means for forming a toner image made of other special toner;
First and second image quality stabilizing toner images are formed by the first toner image forming unit and the second toner image forming unit, and the first and second image quality stabilizing toner images are formed. A means for detecting and stabilizing the image quality of the first toner image forming means and the second toner image forming means, the image quality stabilizing operation of the first toner image forming means; An image forming apparatus comprising: an image quality stabilizing unit that operates differently from the image quality stabilizing operation of the toner image forming unit. The image quality stabilizing means executes the stabilization operation at different times depending on the image quality stabilizing operation of the first toner image forming means and the image quality stabilizing operation of the second toner image forming means. The image forming apparatus according to claim 7. The image quality stabilizing means is a size of a toner image formed for the stabilization operation by the image quality stabilizing operation of the first toner image forming means and the image quality stabilizing operation of the second toner image forming means. 8. The image forming apparatus according to claim 7, wherein the image forming apparatuses are different from each other. The image forming apparatus according to claim 9, wherein the image quality stabilizing unit is smaller in a toner image used in the image quality stabilizing operation of the second toner image forming unit. The image quality stabilizing means includes the number of toner images formed for the stabilization operation by the image quality stabilizing operation of the first toner image forming means and the image quality stabilizing operation of the second toner image forming means. The image forming apparatus according to claim 7, wherein the two are different from each other. The image forming apparatus according to claim 11, wherein the image quality stabilizing unit has fewer toner images used in the image quality stabilizing operation of the second toner image forming unit. The image quality stabilizing unit executes the image quality stabilizing operation of the second toner image forming unit at least one time immediately before, during, or immediately after the image forming operation by the second toner image forming unit. The image forming apparatus according to claim 7. An intermediate transfer body for transferring the first and second toner images formed by the first toner image forming means and the second toner image forming means;
Secondary transfer means for transferring the first and second toner images transferred onto the intermediate transfer member to a transfer material;
Separating means for separating the secondary transfer means from the intermediate transfer member;
During the image quality stabilizing operation of the first toner image forming unit, the secondary transfer unit is separated from the intermediate transfer member by the separating unit, and during the image quality stabilizing operation of the second toner image forming unit, The image forming apparatus according to claim 7, wherein the secondary transfer unit is not separated from the intermediate transfer member by the separation unit. First toner image forming means for forming a toner image made of toner of a color used for normal image formation;
Means for forming a toner image made of special toner, second toner image forming means exchangeable with means for forming a toner image made of other special toner;
Control so that the image area of the toner image made of the special toner formed by the second toner image forming means is larger than the image area of the toner image made of the normal toner formed by the first toner image forming means. An image forming apparatus comprising control means for performing The density of the toner image formed by the second toner image forming unit is determined using an image area of special toner other than the image area of the toner image made of normal toner formed by the first toner image forming unit. The image forming apparatus according to claim 15, wherein the image forming apparatus is detected. The toner image is formed by the second toner image forming unit in the whole image mode in which the toner image is uniformly formed on the entire surface of the transfer material, and in the partial image mode in which the toner image is formed only on a part of the transfer material. When the full image mode is selected, the image area of the special toner other than the image area of the toner image made of the normal toner formed by the first toner image forming unit is used. The image forming apparatus according to claim 15, wherein the density of the toner image formed by the second toner image forming unit is detected. 18. The image according to claim 17, wherein the density of the toner image formed by the second toner image forming unit is detected at at least one end of the transfer material in the main scanning direction or the sub-scanning direction. Forming equipment.

Images