JP2002139883A - Image forming device, image forming method and method for discriminating additional information image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method, an image forming device and a method for discriminating additional information image by which an additional information image can be surely formed without impairing the original quality of an image nor costing so much, and outputted additional information such as the image forming device and an output date is surely detected from the formed image without lowering commercial value as the image forming device. SOLUTION: In this image forming device having plural processing parts for performing electrification, image exposure and development on an image forming body and forming a color image by using thick toner and thin toner of the same color, an additional information toner image is formed by at least one processing part for thin toner, and then transferred and fixed on transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an image forming method for forming an image using toner by electrophotography, and more particularly to forming an additional information image using a light toner, a white toner or a transparent toner. The present invention relates to an image forming apparatus, an image forming method, and a method for determining an additional information image.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic method, an image forming body is uniformly charged by a charging means and then exposed to an image to form a latent image. The latent image portion is developed by the subsequent developing means to form a toner image. In a digital image forming apparatus, image exposure is performed by, for example, dots that have been subjected to pulse width modulation, and reversal development is performed in which toner adheres to dot portions. The amount of toner adhering to the dot portion is determined by the area and potential state of the dot portion on the image forming body, the developing bias for the dot portion, the state of the charge of the toner, and the like.

A high-density image portion recorded on an image forming body by an image exposure means has a large number of dots per area,
The size of the dots is also large. On the other hand, the low-density image portion has a small number of dots per area and a small size of one dot. Thus, after development, the amount of toner adhered to the high density image portion on the image forming body is large, and the amount of toner adhered to the low density image portion is small. The difference in the density of the recorded image is expressed by the amount of toner adhering to the area of the image formed on the image forming body by development. At this time, in order to increase the density gradation and improve the image quality, it has been proposed to use dark toner (high density dark color toner) and light toner (low density light color toner) of the same color.

However, if a high-quality image can be easily obtained in this way, a high-quality image that faithfully reproduces a manuscript can be easily obtained by anyone. It is also possible. In recent years, it has been demanded in recent years, particularly for a color copying machine, a color printer, and the like, to reliably clarify the source of a formed image, that is, which image forming apparatus, when, and who output.

For this purpose, additional information for discrimination must be output together with the original image. But,
A method in which the additional information impairs the quality of the original image or a method that is extremely costly reduces the commercial value of the image forming apparatus, and thus is difficult to adopt. For this reason, to date no truly safe method has not been found.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to form an additional information image reliably without impairing the quality of an original image, at a low cost, and without reducing the commercial value of an image forming apparatus. Another object of the present invention is to provide an image forming method and an image forming apparatus capable of reliably detecting additional information such as an image forming apparatus and an output date and time output from a formed image, and a method of determining an additional information image used therein. .

[0007]

The object of the present invention is achieved by adopting the following constitution.

[1] In an image forming apparatus having a plurality of process units for performing charging, image exposure, and development on an image forming body and forming a color image using dark and light toners of the same color,
An image forming apparatus, wherein an additional information toner image is formed by at least one light toner process unit, and then transferred to a transfer material and fixed.

[2] In an image forming apparatus having a plurality of process units for performing charging, image exposure and development on an image forming body, at least one of the processing units has a developing device for transparent toner, and Forming an additional information toner image with a transparent toner, and then transferring and fixing the image to a transfer material.

[3] In an image forming apparatus having a plurality of processing units for performing charging, image exposure and development on an image forming body, at least one of the processing units has a developing device having a white toner, and Forming an additional information toner image with a white toner on a sheet, and then transferring and fixing the image to a transfer material.

[4] An image forming method for forming a color image using a dark toner and a light toner of the same color, which has a plurality of process units for performing charging, image exposure and development on the image forming body,
An image forming method, wherein an additional information toner image is formed by at least one light toner process unit, and then transferred to a transfer material and fixed.

[5] The image forming method according to [4], wherein the additional information toner image is formed using yellow light toner.

[6] A method of discriminating an additional information image, wherein an image is formed by the image forming method according to [4] and discriminating means using a band-pass filter is used.

[7] In an image forming method for forming an image on an image forming body by a plurality of process units performing charging, image exposure and development, at least one of the process units has a developing device for transparent toner, An image forming method, wherein an additional information toner image is formed on a body with a transparent toner, and then transferred to a transfer material and fixed.

[8] An image forming method for forming an image on an image forming body by a plurality of process units for performing charging, image exposure and development, wherein at least one of the process units includes a developing device having a white toner, An image forming method, wherein an additional information toner image is formed on a body with white toner, and then transferred to a transfer material and fixed.

[0016]

[9] The image forming method according to [7] or [8], wherein the additional information toner image contains a phosphor.

[10] A method for determining an additional information image, wherein an image is formed by the image forming method according to [7], and a transparent toner information determining means is used.

[11] A method for determining an additional information image, wherein an image is formed by the image forming method according to [8], and a means for determining white toner information is used.

The additional information in the present invention is a tracking mark when the information is copied to prevent forgery and the like.
Refers to an identification mark recorded with a normal image, a copy date, a document number, an image forming apparatus number such as a copying machine or a printer, and the like.

[0020]

First, an embodiment of the present invention will be described.

Any of the image forming apparatuses of the present invention decomposes image density information into image data for light toner and image data for dark toner, and uses image exposure based on image data for light toner and light toner. Forming a light toner image by image development, forming a dark toner image by image exposure based on the dark toner and development using the dark toner, superimposing the light toner image on the image, and forming a transparent toner image. Image data,
A description will be given of an image forming apparatus that forms each image at a designated location based on white toner image data. Of course, the present invention is not limited to this mode of the apparatus, but is a preferred configuration example of an image forming apparatus.

1. Example of Image Forming Apparatus Used in the Present Invention As shown in the cross-sectional view of FIG. 1, this embodiment forms an image by superimposing a light toner image and a dark toner image by repeating charging, image exposure, and development on an image forming body. An image forming apparatus for forming, in particular, an image forming apparatus for forming an image by superimposing light and dark toner images of Y, M, C, and K colors in a tandem system, and having a small shape. I have.

The image forming apparatus shown in FIG. 1 is a tandem type color image forming apparatus using an intermediate transfer member, and a yellow (Y) and a magenta (M) are formed on the peripheral portion of a transfer belt 14a as an intermediate transfer member. , Cyan (C) and black (K) are provided.
In each process unit 100, Y, M, C, and K toner images using light and dark toners are formed, the toner images are transferred in a superimposed manner on the transfer belt 14a, and the transferred color toner images are transferred. It is configured to be collectively transferred onto recording paper as a material, fixed, and discharged outside the apparatus.

Since the four process units 100 have a common structure, only one of them will be described. The photoconductor drum 10 serving as an image forming body includes a photoconductor made of a light-transmitting conductive layer and an organic photoconductive layer (OPC) on the outer periphery of a cylindrical base formed of a transparent member such as glass or transparent acrylic resin. A layer is formed.

The photosensitive drum 10 is rotated in a counterclockwise direction indicated by an arrow with the light-transmitting conductive layer grounded by the power of a driving source (not shown) or by the transfer belt 14a.

Reference numerals 11A and 11B both denote scorotron chargers as charging means, which are attached to the photosensitive drum 10 in a direction perpendicular to the moving direction of the photosensitive drum 10 so as to face the photosensitive drum 10 and have the same polarity as the toner. A uniform potential is applied to the photosensitive drum 10 by the discharge.

The exposure optical systems 12 (L) and 12 (H)
Each is a linear exposure element (not shown) in which a plurality of LEDs (light emitting diodes) as light emitting elements for image exposure are arranged in an array in parallel with the axis of the photosensitive drum 10 and a selfoc as an equal-magnification imaging element. A lens (not shown) is configured as an exposure unit attached to a holder. Exposure optical systems 12 (L) and 12 (H) are attached to a cylindrical holding member and housed inside the base of the photosensitive drum 10. In addition, as the exposure element, a linear element in which a plurality of light emitting elements such as FL (phosphor emission), EL (electroluminescence), and PL (plasma discharge) are arranged in an array is used. Reference numeral 12 (L) denotes an image exposure unit that performs image exposure using image data for light toner, and 12 (H) denotes an image exposure unit that performs image exposure using image data for dark toner.

An exposure optical system 12 (L), which is an image exposure means for light toner, is provided with a scorotron charger 11A and a developing device 13 having light toner built therein.
Between (L) and the developing unit 13 (L), the photosensitive drum 10 is disposed inside the photosensitive drum 10 in a state provided on the upstream side in the rotation direction of the photosensitive drum 10. The exposure position of the exposure optical system 12 (H), which is an image exposure means for dark toner, on the photosensitive drum 10 is on the downstream side of the developing device 13 (H), and incorporates a scorotron charger 11 B and dark toner. Developing device 13
(H), the photosensitive drum 1 is provided on the upstream side in the rotation direction of the photosensitive drum 10 with respect to the developing device 13 (H).
0.

The developing device 13 (L) is a developing device which contains a one-component light toner or a two-component developer of a light toner and a magnetic carrier and performs reversal development by contact or non-contact. The developing device 13 (H) incorporates a one-component dark toner or a two-component developer of a dark toner and a magnetic carrier, which enables superposition development without destroying the toner image, and performs soft development or more preferably non-development. This is a developing device that performs reversal development by contact development.

In forming an image, the image data of each color of Y, M, C, and K is divided into image data for light toner and image data for dark toner, which will be described in detail later. Image exposure is performed by the optical system 12 (L), and development with light toner is performed by the developing device 13 (L). The image data for the dark toner is subjected to image exposure by an exposure optical system 12 (H), and a developing device 13 (H).
As a result, development with dark toner is performed, and a toner image with dark toner is formed on the photosensitive drum 10 on the toner image with light toner. This toner image is transferred onto a transfer belt 14a described later at a transfer position. The transfer residual toner remaining on the drum after the transfer is cleaned by a cleaning device 19 that electrostatically collects the toner.

Process unit 1 for four colors of Y, M, C and K
The transfer belt 14a in which 00 is opposed in parallel has a volume resistivity of 10 ¹⁰ to 10 ¹⁵ Ω · cm and a surface resistivity of 10 ¹⁰ to 10 ¹⁵ Ω.
・ Cm ² endless belt, for example, modified polyimide,
Thermosetting polyimide, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride, dispersed conductive material in engineering plastics such as nylon alloy, outside the semi-conductive film substrate of 0.1 to 1.0 mm thickness, preferably Thickness 5 as a toner filming prevention layer
This is a seamless belt having a two-layer structure and having a fluorine coating of about 50 μm. In addition, as the base of the transfer belt 14a, a semiconductive rubber belt having a thickness of 0.5 to 2.0 mm in which a conductive material is dispersed in silicon rubber or urethane rubber can be used. Transfer belt 14a
Is stretched in contact with a driving roller 14d, a driven roller 14e, a tension roller 14k, and a backup roller 14j. At the time of image formation, the driving roller 14d is rotated by a driving motor (not shown) to rotate the driving roller 14d. At the transfer position, the transfer belt 14a is pressed against the photosensitive drum 10 by the primary transfer device 14c, and the transfer belt 14a is rotated in the direction indicated by the arrow in the drawing.

A primary transfer unit 14c, which is a transfer roller for each color, is provided to face the photosensitive drum 10 for each color with the transfer belt 14a interposed therebetween, and the transfer belt 14a and the photosensitive body for each color are provided. A transfer area (no reference numeral) for each color is formed between the transfer area and the drum 10. Primary transfer unit 14 for each color
By applying a DC voltage having a polarity opposite to that of the toner (positive polarity in this embodiment) to c, and forming a transfer electric field in the transfer area, the toner image on the photosensitive drum 10 for each color is transferred onto the transfer belt 14a. Transfer to

The static eliminator 14m, which is a static elimination means for each color,
Preferably, the primary transfer unit 1 is constituted by a corona discharger.
The transfer belt 14a charged by 4c is neutralized.

The process unit 1 of black (K) is started by starting a photoconductor drive motor (not shown) by starting image recording.
00 is rotated in the direction indicated by the arrow in the figure, and at the same time, the application of the potential to the K photoconductor drum 10 is started by the charging action of the K scorotron charger 11A.

After a potential is applied to the K photosensitive drum 10, an electrical signal corresponding to the first color signal, that is, the image data for the K light toner, is applied by the K light toner exposure optical system 12 (L). Is started, and an electrostatic latent image for light toner corresponding to the K image of the original image is formed on the surface of the K photosensitive drum 10.

The latent image for light toner is subjected to reversal development in a contact state by a developing device 13 (L) for light toner of K, and a toner image of light toner of K is formed in accordance with the rotation of the photosensitive drum 10 of K. It is formed. Then the scorotron charger 11
B and the exposure optical system 12 for the dark toner of K
(H), an electrostatic latent image for dark toner corresponding to the image of K is formed, and the developing device 13 (H) for dark toner forms the K latent image.
Is formed on the previously formed toner image of the light K toner.

The K toner image formed of the light and dark toners formed on the K photoreceptor drum 10 as the image forming body by the above-described image forming process is the first toner image in the K transfer area (no sign). The image is transferred onto the transfer belt 14a by a K primary transfer device 14c as a transfer unit.

Next, the transfer belt 14a is synchronized with the C toner image, and the cyan (C) process unit 10
0, the light color of C formed on the photosensitive drum 10 of C,
Toner image composed of dark toner is C transfer area (no sign)
, The primary transfer device 14c of C as the first transfer means
As a result, a toner image composed of light and dark toners C is superposed on the toner image composed of light and dark toners K.

By the same process, the image is synchronized with the superposed toner images of K and C, and is formed on the photosensitive drum 10 of M by the process unit 100 of magenta (M). M corresponding to the image data of
In the M transfer area (no symbol), the M primary transfer unit 14c, which is the first transfer means, transfers the M toner images of the K and C toner images from above the K and C toner images. A toner image composed of light and dark toners is formed by being superimposed, synchronized with the superimposed toner images of K, C, and M.
The toner image formed of the light and dark toners of Y corresponding to the image data of Y based on the fourth color signal is formed on the photosensitive drum 10 of the first color in the Y transfer area (no sign). By the Y primary transfer device 14c, a toner image composed of light and dark toners of Y is superimposed on the K, C and M toner images, and the transfer belt 14a
A superimposed color toner image of K, C, M and Y is formed thereon.

In the present image forming apparatus, a process unit 100 is further added (this process unit is referred to as 100 WT). After an electric potential is applied to the photosensitive drum 10 to this process unit, image writing is started by an electrical signal corresponding to all image data by the exposure optical system 12 (W) for white toner of W, On the surface of the drum 10, an electrostatic latent image for white toner corresponding to all images of the original image is formed.

The white toner latent image is subjected to reversal development in a non-contact state by a white toner developing unit 13 (W), and the photosensitive drum 10 of the process unit 100WT is processed.
The toner image is formed by the white toner in accordance with the rotation of.

In one embodiment of the present invention, a white toner image is superimposed on the K, C, M, and Y toner images by the WT primary transfer device 14c as the first transfer means. Formed on the transfer belt 14a.
A superposed color toner image of Y and white is formed.

In another embodiment, subsequently, charging by the scorotron charger 11B and an electrostatic latent image for the transparent toner corresponding to the entire image by the exposure optical system 12 (T) for the transparent toner are formed. After the toner image of the transparent toner is formed on the previously formed toner image of the white toner by non-contact development by the developing unit 13 (T), the process proceeds to the transfer step.

The photosensitive drum 10 of the process unit 100WT which is an image forming body by the image forming process described above.
The toner image formed of white or further transparent toner formed on the WT transfer area (no sign)
Is transferred onto the transfer belt 14a by the WT primary transfer device 14c, which is a transfer unit of the WT.

The transfer residual toner remaining on the peripheral surface of the photosensitive drum 10 for each color after the transfer is cleaned by a cleaning device 19 which is a cleaning means of the image forming body for each color.

Transfer from a paper feed cassette 15 as a transfer material storage means via a timing roller 16 as a transfer material feeding means in synchronism with the formation of the superimposed color toner and the white or further transparent toner image on the transfer belt 14a. The material (recording paper) P is a secondary transfer unit 14g as a second transfer unit
Is transferred to the transfer area (no sign), and a superimposed color toner image on the transfer belt 14a is transferred to the recording paper P by a secondary transfer unit 14g to which a DC voltage having a polarity opposite to that of the toner is applied.
It is transcribed all at once.

The recording paper P to which the color toner image and the white or further transparent toner image have been transferred is neutralized by a neutralizing electrode 16b which is a separating means composed of a saw-toothed electrode plate, conveyed to a fixing device 17, and fixed to a fixing roller 17a. The toner image on the recording paper P is fixed by applying heat and pressure between the recording paper P and the pressure roller 17b, and then discharged to a tray outside the apparatus.

The transfer residual toner remaining on the peripheral surface of the transfer belt 14a after the transfer is cleaned by a cleaning device 19a which is a transfer belt cleaning means provided opposite to the driven roller 14e across the transfer belt 14a. .

In the present embodiment, Y, M,
Although the development using light and dark toners is performed for the four colors C, K, and C, the development is performed using only the dark toner for Y, M, and C, and the development using only the light and dark toners is performed only for K. Good.

In this embodiment, the image density data for each of the colors Y, M, C, and K is divided into image density data for light toner and image density data for dark toner. Is an exposure optical system 12 (L) for light toner
As a result, the image density data for the dark toner is subjected to image exposure on the photosensitive drum 10 by the exposure optical system 12 (H) for the dark toner.

FIG. 2 is a block diagram of the image processing system according to the present embodiment. An original image is read by an image reading means using a solid-state imaging device such as a CCD (F1). The amplified analog image signal output from the CCD is converted to an 8- to 10-bit digital signal by A / D conversion.
After the conversion, shading correction and subsequent image processing (1) such as color space conversion, logarithmic conversion, black generation, and color correction are performed. The image data may be read from the stored memory and subjected to the same processing.

The image data obtained in the image processing (1) is
By checking the density distribution of the data and the density difference between adjacent dots, it is possible to determine whether the original image is a halftone image such as a photograph or a picture or a character image such as a character or a line drawing. (F3).

The image data obtained in the image processing (1) is
The image data for light toner (F5C) and the image data for dark toner (F5D) are determined based on the result of determining whether the image is a halftone image or a character image, or on the designated output form (F3). Is created.

The decomposed light and dark toner image data are subjected to γ correction for each toner (F6A, F6B),
MTF correction (F7A, F7B) and PWM modulation are performed (F
8A, F8B). In the PWM modulation, it is preferable to form large dots so as to improve dot reproduction in a highlight portion (low-density portion) and increase the recording unit. For example, the image data for light toner is subjected to two-pixel PWM in order to enhance the gradation, and the recording unit is increased. On the other hand, with respect to the image data for dark toner, since the emphasis is placed on the resolving power, this is performed with one pixel PWM. Note that intensity modulation may be used instead of PWM modulation.

The light-toner image data after the PWM modulation is subjected to image exposure on the photosensitive drum 10 by the exposure optical system 12 (L) (F9C), and the dark-toner image data after the PWM modulation is exposed to light. Image exposure on the photosensitive drum 10 is performed by the system 12 (H) (F9D).

It is preferable that these correction values be changed successively in accordance with the image discrimination. That is, in the half tone, the form in which the γ correction is performed is used, the MTF correction is weakened, and the PWM recording unit is increased. On the other hand, for character images, it is preferable to make changes such as setting the γ correction higher, increasing the MTF correction, and reducing the PWM recording unit.

In this image forming apparatus, a transparent toner image and a white toner are formed in the same manner as in the color image forming process for modifying the base of the transfer material, and are formed on the same transfer material as the color toner image. For example, in a region designated based on region designation data, an arbitrary reforming level is realized. Depending on the purpose, a designated area and whether to form only a transparent toner image, only a white toner image, or both of them are designated.

For example, after specifying the area, both the white toner and the transparent toner are applied to the base improvement section. To adjust the glossiness of an image, only the transparent toner is applied. Further, when the transfer material surface is colored and whitening is desired, only the white toner is adhered. When there are a plurality of these purposes, different conditions are designated on the same screen in different areas.

As described above, it is preferable that the image data W for a white toner image and the image data T for a transparent toner image can be independently set in condition, and the amount of adhesion can be determined thereby.

In the most frequent cases, the formation of a white toner layer and the mixing of the white toner layer with the normal color image toner to reduce the effect of coloring and surface properties of the transfer paper on the color image reduce the saturation. This is the formation of a transparent toner layer for suppressing the reduction. In this case, the white toner layer area and the transparent toner layer area coincide with each other and overlap with the area of the normal color image. Therefore, it is preferable to obtain the area from the normal color image data as follows.

In the image data W for the white toner image, the adhesion amounts T _K + T _Y + T _M + T _{C of} the respective color toners are obtained from the black component image signals K and the Y, M, and C image signals, and T _K + T _Y + T _M + T. _{When C} > 0, the adhesion amount T _W of the white toner is given by T _W = Z ₁ −α ₁ (T _K + T _Y + T _M + T _C ), and the image data of the white toner is formed in accordance therewith (Z ₁ is A predetermined constant, α _1, is a constant of 0.3 to 1.0).

The amount of adhesion can be determined in the same manner for the transparent toner. The threshold values for the adhesion conditions of the white toner and the transparent toner and the adhesion amounts of the toners of the respective colors are set to 0 or more in the above equation. However, the threshold values should be controlled according to the type of the image and the gloss and color of the base transfer paper. Is preferred.
For simplicity, the amount of the adhered white toner or transparent toner may be a fixed amount (α ₁ = 0).

It is preferable that the amount of the white toner or the transparent toner adhered is controlled so as to be changed according to the base transfer paper.

2. FIG. 3 is a block diagram showing the overall configuration of the image forming apparatus according to the present invention. The image forming apparatus is a copying machine having a copy protection function, and includes a copying machine main body 101,
It has an additional information management unit 102, a card reader 103, and a numeric keypad (operation unit) 104. Here, the card reader 103 is used for reading information and performing copy management for each department in the organization.
Reference numeral 104 is used to identify a department by inputting a password.

FIG. 4 shows a detailed configuration of the copying machine main body 101. As shown in FIG. 4, the copier main body has an information reading unit 201, which can read a document by the information reading unit 201 and store the read image data in the image information storage unit 203.

Further, the information addition determining circuit 202 plays a role of creating additional information data based on the section number obtained from the additional information management unit 102 and writing the same in the image information storage unit 203 when information is added. Further, the information addition determining circuit 202 is configured to add the additional information
02 is compared with the department number of the additional information added to the original read from the image information storage unit 203, the result is displayed on the display unit 204, and the result is copied according to the result. Continue or interrupt processing. The image forming apparatus 205 copies and outputs image data of the image information storage unit 203.

The operation of adding additional information during normal copying in a copying machine with a copy protection function having such a configuration will be described with reference to FIG.

As shown in the flowchart of FIG. 5, when the copy start key is pressed, the additional information management unit 102
In step S301, an IC card inserted into the card reader 103 is detected. Here, the information of the section is recorded on the IC card.

If the IC card is not detected in S301 and it is determined that the IC card is not inserted into the card reader 103, then the password is correctly input by the ten keys (operation unit) 104. It is determined whether or not there is (S302). Numeric keys (operation unit) 104
If it is determined that the personal identification number has not been correctly input, the processing is interrupted.

When an IC card is detected, or when a password is correctly input by the ten-key (operation unit) 104, the copying machine main unit 101 displays the department number recorded on the IC card or the ten-key (operation unit). ) 10
The section number corresponding to the password number 4 is added from the additional information management unit 102 as additional information.

FIG. 6 shows an example of additional information to which the department number is added. Here, reference numeral 401 denotes the copying machine main body 101
Indicates a predetermined machine number. Also, 4
02 is a section number recorded on the IC card. The new identification number 403 is obtained by combining the machine number 401 and the department number / date and time 402 into one.

As described above, the section number corresponds to the copy machine main body 101.
The new identification number is added to the machine number of the vehicle. Then, additional information is created based on the identification number (S305), and this is written as image data in the image information storage unit (S306), and a copy output is performed based on the information in the image information storage unit 203 (S307). .

In order to perform the output, the data is put in F3 as the additional information image data of FIG. 2 and added to the normal image data.

FIG. 7 shows a typical example of the additional information used in this embodiment. As a method of forming additional information,
As shown in FIG. 7, a document 501 is formed by adding a barcode or the like to a copy output area.

The above is an example of printing with yellow light toner. When the transparent toner and the white toner are used, the output is performed in the same manner and the additional information can be formed.

3. Image Forming Apparatus to which the Present Invention is Applicable Next, FIG. 8 shows a cross-sectional configuration diagram of an image forming apparatus according to another embodiment having the same effects as those shown in FIG.

Using light toner and dark toner, Y, M, C,
Although the process units 100 for forming K toner images are arranged in parallel as in FIG. 1, in the present embodiment, the toner images are superimposed on a transfer material without an intermediate transfer member. I have to. Only the differences from FIG. 1 will be described. In the image formation, the recording paper P discharged from the paper supply cassette 15 passes through the timing roller 16 in synchronization with the toner image formation on the process unit 100, and is conveyed to the transport belt 14. Transported to

As the white toner image or the transparent toner image formed by the process unit 100WT is first transferred onto the recording paper P, the process unit 100WT shifts to the right end in FIG. Also, the order of forming the white toner and the transparent toner image is reversed.

The transported recording paper P is charged to the same polarity as the toner by the paper charger 14m, and the rotating transport belt 1 is rotated.
4 and is transported in close contact with the process unit 10.
The toner images formed on 0WT, 100M, 100C, and 100K are transferred in a superimposed manner to form a color toner image.

The recording paper P carrying the color toner image is neutralized by the separation electrode 14n, separated from the transport belt 14 and transported to the fixing device 17, and after the color toner image on the recording paper P is fixed, the recording paper P is fixed. Discharge to an external tray.

In the embodiment shown in FIG.
For M and C, development using only the dark toner may be performed, and only K may be developed using the light and dark toner. Alternatively, Y may be developed using only the dark toner, and K, C and M may be developed using the light toner.
It is also possible to adopt a configuration in which development with dark toner is performed, and the excellent effects of the present invention can be achieved. Further, the present invention can also be applied to a monochrome image forming apparatus of K single color.

As the method of adding the additional information, the same method as described above can be used. In this embodiment, a light toner image and a dark toner image are formed on two image forming bodies by charging, image exposure, and development, respectively, as shown in the sectional configuration views of FIGS. Image forming apparatus, in which Y, M, C, and K colors are superposed by a tandem method, and a color light toner image is formed by superimposing a color dark toner image. The image forming apparatus has a small size and is suitable for forming an image consisting only of, for example, dark toner.

FIG. 9 shows an image forming apparatus in which a light toner image and a dark toner image are superimposed on an intermediate transfer member and then transferred onto recording paper. This is an image forming apparatus in which a formed color image composed of a light toner and a color image composed of a dark toner are superimposed on a recording sheet. Members having the same functions as those already described with reference to FIGS. 1 and 8 are denoted by the same reference numerals.

The color image forming apparatus shown in FIG. 9 includes a process unit 100L for forming a color image using light toner on the peripheral portion of the transfer belt 14a and a process unit 100L for forming a color image using dark toner. ,
A process unit 100H for forming a color image using dark toner is arranged in parallel. Since the process units 100L and 100H have a common structure,
The process unit 100L will be described. Y, M, C, and K are arranged from the upstream side in the rotation direction along the photosensitive drum 10.
Scorotron charger 1 as charging means for four colors
1. Four sets of an exposure optical system 12 (L) and a developing unit 13 (L) are provided. The photosensitive drum 10 whose peripheral surface has been cleaned by the cleaning device 19 is uniformly charged by the scorotron charger 11Y, and is further exposed to light toner by the exposure optical system 12 (L) Y based on Y image data for light toner. A latent electrostatic image of Y is formed, and a developing device 13 (L) Y containing a light toner forms a Y toner image with the light toner.

An M toner image of light toner is superimposed on the Y toner image of light toner by a scorotron charger 11M, an exposure optical system 12 (L) M, and a developing device 13 (L) M. Further, a scorotron charger 11C, an exposure optical system 12
(L) C, a C toner image of light toner is superposed by the developing unit 13 (L) C, and a scorotron charger 11K, an exposure optical system 12 (L) K, and a developing unit 13 are formed thereon.
(L) The K toner image of light toner is superimposed and formed by K.

Similarly, for the process unit 100H, Y, M, C,
A scorotron charger 11 for K4 color, an exposure optical system 12 (H) for exposing an image based on image data for dark toner, and a developing device 13 (H) containing dark toner, all of Y, M, C using dark toner. , K4 color toner images are superposed.

The color toner image formed of the light toner formed on the process unit 100L is transferred onto the transfer belt 14a by the primary transfer unit 14c, and is transferred to the transfer belt 14a.
The color toner image of the dark toner formed on the process unit 100H is transferred onto the color toner image of the light toner transferred thereon so as to overlap.

Next, in the present invention, a process unit 100WT is added to this image forming apparatus as in FIG. The function and role of this process unit are the same as in FIG. After the photosensitive drum 10 is applied with a potential,
The scorotron charger 11 (W) for white W toner and the exposure optical system 12 (W) start image writing by electric signals corresponding to all image data, and the photosensitive drum 1
An electrostatic latent image for white toner corresponding to all the images of the original image is formed on the surface of the zero.

The white toner latent image is subjected to reversal development in a non-contact state by a white toner developing unit 13 (W), and the photosensitive drum 10 of the process unit 100WT is processed.
The toner image is formed by the white toner in accordance with the rotation of.

In the present invention, this is transferred to the above K, by the WT primary transfer device 14c, which is the first transfer means.
A white toner image is formed by superimposing on the C, M, and Y toner images, and a superimposed color toner image of K, C, M, Y, and white is formed on the transfer belt 14a.

However, in another embodiment of the present invention, charging by the scorotron charger 11 (T) and static electricity for the transparent toner corresponding to the entire image by the exposure optical system 12 (T) for the transparent toner are subsequently performed. After the electrostatic latent image is formed and the toner image of the transparent toner is formed on the previously formed white toner image by the transparent toner developing unit 13 (T), the process proceeds to the above-described transfer step. .

The photosensitive drum 10 of the process unit 100WT which is an image forming body by the above image forming process.
The toner image formed of white or further transparent toner formed on the WT transfer area (no sign)
Is transferred onto the transfer belt 14a by the WT primary transfer device 14c, which is a transfer unit of the WT.

The color toner image superimposed and transferred on the transfer belt 14a is collectively transferred by a secondary transfer unit 14g onto a recording sheet P fed through a timing roller 16, and is discharged by a discharging electrode 16b. Thereafter, the toner is fixed by the fixing device 17 and is discharged to the outside of the device.

FIG. 10 shows another embodiment in which a toner image is directly transferred to a recording sheet P without using an intermediate transfer member, so that a white toner or a transparent toner image is first transferred to the recording sheet P. . Therefore, as in FIG. 8, the process unit 100WT is located at the right end of the drawing.

In other respects, the process unit 100H for forming a color toner image using dark toner and the process unit 100L for forming a color toner image using light toner are arranged in parallel to the conveyor belt 14 in the same manner as in FIG. . In forming an image, the process unit 10
The recording paper P discharged from the paper feed cassette is transported to the transport belt 14 via the timing roller 16 in synchronization with the formation of the toner image by the dark toner on 0H. Paper charger 1
4m, the recording paper P is conveyed in close contact with the conveyance belt 14, and a color toner image formed of the dark toner formed on the process unit 100H is transferred onto the recording paper P by the primary transfer device 1.
4c, and a color toner image of the light toner formed on the process unit 100L is synchronously transferred thereon in a superimposed manner. The recording paper P carrying the color toner image of the light and dark toners is neutralized by the separation electrode 14n, separated from the conveyor belt 14, conveyed to the fixing device 17, and discharged out of the device after being fixed.

In the image forming apparatus shown in FIGS. 9 and 10, the additional information similar to that described with reference to FIG. Needless to say, it can be output in addition to.

4. Toner used in the present invention Regardless of the purpose of the present invention, the white toner can be produced in the same manner as the Y, M, and C toners.
As the colorant, a white pigment such as TiO ₂ , ZnO, or MgO is used. The transparent toner may be one that is usually used as a binder resin (also referred to as a binder resin) of the toner, and may be produced without adding a colorant.

Needless to say, the same light yellow (Y) toner as that used for normal images can be used.

The amount of the light-color Y toner image, white toner image, and transparent toner image on which additional information is recorded is not particularly limited.
In terms of the amount of toner resin, the toner layer is preferably 0.3 to 2.0 for both white and transparent toners, and 0.5 to 1.
More preferably, the number of layers is zero.

5. Additional Information Discriminating Means and Recognition Method The additional information discriminating means (method) slightly differs depending on whether the toner in which the additional information is written is a yellow light toner, a transparent toner, or a white toner. A representative example for each toner image is shown below.

5-1 Yellow Light Toner Image A typical method is to use a color CC for normal image reading.
From the image information read and color-separated in D, only dots of a specific density formed by yellow light toner recorded on the image background portion are detected (for example, a band-pass filter corresponding thereto may be used). ). Additional information is detected from the recognition of the dot pattern. This is a widely applicable method for color reading units and color copiers,
Of course, a separate detector may be used.

FIG. 11 shows a specific detection / judgment method. 5-2 Transparent Toner Image For detecting the difference in the glossiness of the base portion, additional information recorded in the image background portion is detected based on recognition of the dot pattern. Since the glossy part has a large angle dependence of the reflected light,
For example, reflected light at 90 ° and 135 ° of light incident at 45 ° is measured, and a portion having a large ratio is taken out to read a dot pattern. In this case, it is preferable that the fluorescent substance be present under the toner image or in the toner image because the difference is emphasized.

FIG. 12 shows a specific detection / judgment method. 5-3 For White Toner Image A white toner density is detected by detecting a difference in whiteness of a white background portion which is an image background portion from image information read by a color CCD for normal image reading and color-separated, and having a density of white toner. Additional information is detected from the dot pattern recognition. In this case, it is preferable that the fluorescent substance be present under the toner image or in the toner image because the difference is emphasized.

FIG. 13 shows a specific detection determination method. 5-4 For Transparent Toner Image Containing Phosphor The phosphor containing the phosphor is detected by detecting the difference in whiteness of a white background portion, which is an image background, from image information read by a color CCD for normal image reading and color separation. Additional information is detected from pattern recognition of a dot having the density of the transparent toner.
In this case, since the phosphor is present under the transparent toner image or in the toner image, the difference in the whiteness of the background is emphasized, so that the additional information can be read accurately.

The detected whiteness pattern is the same as that shown in FIG.

[0106]

According to the present invention, it is possible to form an additional information image reliably without impairing the quality of the original image, at a low cost, and without reducing the commercial value of the image forming apparatus. It is possible to provide an image forming method, an image forming apparatus, and a method of discriminating an additional information image using the image forming apparatus and the image forming apparatus that can reliably detect additional information such as the output image forming apparatus and the output date and time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of an image forming apparatus for describing an embodiment of the present invention.

FIG. 2 is a block diagram of an image processing system.

FIG. 3 is a block diagram illustrating an overall configuration of an image forming apparatus according to the present invention.

FIG. 4 is a block diagram showing a configuration of a copying machine main body according to the present invention.

FIG. 5 is a flowchart of image formation.

FIG. 6 is a view for explaining an example of additional information.

FIG. 7 is a diagram showing a representative example of additional information.

FIG. 8 is a cross-sectional configuration diagram of an image forming apparatus for describing an embodiment of the present invention.

FIG. 9 is a cross-sectional configuration diagram of an image forming apparatus for describing an embodiment of the present invention.

FIG. 10 is a cross-sectional configuration diagram of an image forming apparatus for describing an embodiment of the present invention.

FIG. 11 is a diagram illustrating a determination unit and a recognition method of additional information.

FIG. 12 shows additional information discriminating means and a recognition method.

FIG. 13 shows additional information discriminating means and a recognition method.

[Description of Signs] 10 Photoconductor drum 11A, 11B Scorotron charger 12 (L), 12 (H) Exposure optical system 13 (L), 13 (H) Developing unit 14 Conveying belt 14a Transfer belt 14c Primary transfer unit 14g Secondary transfer unit 15 Paper cassette 16 Timing roller 17 Fixing device 100Y (M, C, K) Process unit 100L (H) Process unit

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Yotaro Sato 2970, Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2C061 AP04 AQ06 JJ02 JJ06 2C362 CA18 CA27 CB45 CB80 DA49 2H027 EJ02 EJ03 FA28 FD01 FD08 FD10 2H030 AA06 AB02 AD01 AD16 BB61

Claims (11)

[Claims] An image forming apparatus having a plurality of process units for performing charging, image exposure, and development on an image forming body and forming a color image using a dark toner and a light toner of the same color. An image forming apparatus, wherein an additional information toner image is formed in a process unit, and then transferred to a transfer material and fixed. 2. An image forming apparatus having a plurality of processing units for performing charging, image exposure and development on an image forming body, wherein at least one of the processing units has a developing device for transparent toner, and An image forming apparatus, wherein an additional information toner image is formed with a transparent toner, and then transferred to a transfer material and fixed. 3. An image forming apparatus having a plurality of process units for performing charging, image exposure and development on an image forming body, wherein at least one of the processing units has a developing device having a white toner, and An image forming apparatus, comprising: forming an additional information toner image with white toner; transferring the image to a transfer material; 4. An image forming method for forming a color image using a dark toner and a light toner of the same color, comprising a plurality of process units for charging, exposing and developing an image on an image forming body. An image forming method, wherein an additional information toner image is formed in a process section, and then transferred to a transfer material and fixed. 5. The image forming method according to claim 4, wherein the additional information toner image is formed with yellow light toner. 6. A method for determining an additional information image, wherein an image is formed by the image forming method according to claim 4, and a determination unit using a band-pass filter is used. 7. An image forming method for forming an image on an image forming body by a plurality of process units performing charging, image exposure, and development, wherein at least one of the process units includes a developing device for a transparent toner. An image forming method, wherein an additional information toner image is formed on a transparent toner, and then transferred to a transfer material and fixed. 8. An image forming method for forming an image on an image forming body by a plurality of processing units performing charging, image exposure, and development, wherein at least one of the processing units includes a developing device having a white toner. An image forming method, wherein an additional information toner image is formed on a white toner, and then transferred to a transfer material and fixed. 9. The image forming method according to claim 7, wherein the additional information toner image contains a phosphor. 10. A method for determining an additional information image, comprising: forming an image by the image forming method according to claim 7; and using a transparent toner information determining unit. 11. A method for determining an additional information image, comprising: forming an image by the image forming method according to claim 8; and using means for determining white toner information.