JPH01267591A - Multicolor image forming device - Google Patents

Abstract

PURPOSE:To form a multicolor image which uses a character font with simple constitution by referring to a font storage part with input image code data, and referring to fonts regarding image information, color by color, in surface order according to input color information. CONSTITUTION:The fonts are stored and characters, etc., are recorded by an electrophotographic method capable of high-density recording according to image data generated by using the fonts. When an input image is a color character image, pieces of image information which are decomposed by the colors are converted into image data in surface order by referring to font data by color components. Toner images are formed on an image formation body by the color components according to the image data and put one over another in order to form a multicolor toner image. Thus, not only black characters, but also chromatic characters of yellow, magenta, cyan, etc., are printed with high quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multicolor image forming apparatus using electrophotography, and particularly to a multicolor image forming apparatus using character fonts.

[Background of the Invention] Image forming apparatuses are known in which character information is transferred in the form of code data, which is converted into image data consisting of pixels of one to several bits to produce a visible image.

The data referred to in this conversion is called a font, and a dedicated data conversion means is used to convert this into image data.

[Problems to be Solved by the Invention] Incidentally, the conventional image forming apparatus described above creates image data using a character font, and forms a black and white toner image based on this. , there was nothing that could record color characters.

On the other hand, various image forming apparatuses for forming color images are known, but the apparatus described in JP-A-58-184381 in particular has a simple configuration and is capable of high speed, which is a feature of electrophotography. It is an excellent product that takes advantage of its characteristics and high image quality. The special effects of this device is to form toner images of one color on the photoreceptor (image forming body) in a superimposed manner.

Color reproduction in this device is performed by forming a plurality of types of toner on the photoreceptor at the same position in an overlapping manner, or by forming them adjacent to each other. However, when forming color characters with this device, it was not clear how to form the image data of the characters.

Therefore, the present invention takes these points into consideration and proposes a multicolor image forming apparatus that can perform color recording using fonts.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the present invention, at least the characters, the size of the characters,
an image input means that outputs the coordinate information of characters on the screen as image code data; a font storage section that stores font data and outputs the font data according to an input address signal; It has a font data conversion section that has a function of converting data into image data consisting of pixel information, and an image buffer memory that temporarily stores the image data output from the font data conversion section, and the obtained image data 1 based on
This apparatus is characterized in that a toner image is formed on an image forming member in a plane-sequential manner for each color component, thereby forming a multicolor toner image.

[Function] The multicolor image forming device according to the present invention has a built-in font,
Based on image data formed using this, characters and the like are recorded by electrophotography, which allows high-density recording.

When the input image is a color character image, the color-separated image information is converted to image data one color component at a time by referring to the font data.

In this way, toner images are formed on the image forming body one color component at a time based on the obtained image data, and are sequentially superimposed to form a multicolor toner image.

As a result, it is possible to print not only black characters but also chromatic characters such as yellow, magenta, and cyan with high quality.

[Example] Next, an example of the multicolor image forming apparatus according to the present invention will be described in the first example.
This will be explained in detail with reference to the figures below.

FIG. 1 shows a block diagram of the basic configuration of the present invention.

The present invention has a font storage section 1 in which fonts such as characters and symbols are stored.

The input means 2 to the font data converter 10 is for inputting image information as a code, and this image code data includes at least data representing the type of character, the size of the character, and position information (coordinate information) of the character. It consists of

Of the input image code data, character information is decoded by a font data conversion section 10, and an address signal is sent to a font storage section 1 having font data.

In the font storage section 1, font data corresponding to the input address signal is referred to and outputted to the font data conversion section 10.

In the font data conversion section 10, conversion is performed using information representing the size of characters in the image code data as a parameter to form character image data on a two-dimensional plane.

　　.

Next, this character image data is stored in the corresponding area of the image buffer memory 5 according to the position information of the input image code data.

When one screen worth of image data regarding certain specific color information is formed, this image data is output in accordance with a request signal from the electrophotographic recording section 6.

In the electrophotographic recording section 6, an electrostatic latent image is formed based on the sent image data, and a toner of a color corresponding to the image is attached and developed.

Each process from image data creation to development is executed for each color, and after a multicolor toner image is formed, a fixing process is performed to record (copy) a target color original.

FIG. 2 shows an example of the configuration of the font data converter 10 described above.

The character information constituting the image code data is decoded by the decoder 11 and sent to the address (8) of the font storage unit 1.
issue is created.

Based on the created address signal, the character font corresponding to the character is referred to, and this is the image data forming unit 12.
sent to.

The image data forming section 12 forms character image data corresponding to the size of the input character from the sent font data and information on the size of the input character, and sends this to the line buffer 13.

Image code data indicating the size of the characters is also roughly supplied to the address signal forming section 14. Address signal forming section 1
Image code data roughly representing the positional information of characters is supplied to 4, and an address signal representing the recording position (coordinates) is formed by these data.

This address signal and the image data in the line buffer 13 are output in correspondence, and the image data is stored in the area specified by the address signal.

FIG. 3 shows an example of the electrophotographic recording section 6. As shown in FIG.

As the electrophotographic recording section 6, a color copying machine using a drum-shaped image forming body can be used.

In FIG. 3, reference numeral 20 denotes an image forming body, and the surface thereof has a photoconductive photoreceptor surface layer of ○PC, Se, or the like. This is rotated in the direction of the arrow.

A charger 21 uniformly charges the surface of the image forming body 20. In the image forming body 20, a writing unit D performs image exposure of a color image for each color.

Developing units 22 to 25 use toners of different colors such as yellow, magenta, cyan, and black as developers. 26 and 27 are used to make it easier to transfer the color image formed by superimposing a plurality of color toner images on the image forming body 20 onto the recording paper (transfer material) P, or to make it easier to separate the recording paper P. , a pre-transfer charger and a pre-transfer exposure lamp, respectively, which are provided as necessary.

28 is a transfer device for transferring a color image, 29 is a recording paper P
30.31 Fixing device that fixes the toner image transferred to
are a static elimination lamp and a static elimination corona discharger, respectively.
Use either one or a combination of both.

32 is a separation electrode, and 33 is a cleaning device that comes into contact with the surface of the image forming body 20 after the color image has been transferred to remove residual toner on the surface, which is the surface (site) where the first development was performed. By the time the cleaning blade 34 and the fur brush 3 have separated from the surface of the image forming body 20,
5.

Here, the charger 21 may be a scorotron corona as shown in the figure, which can provide stable charging with little influence of previous charging, since it charges the surface of the image forming body 20 which is already charged. It is preferred that the discharger be square.

Next, an example of the process of forming a multicolor image using this electrophotographic recording section 6 will be explained based on FIG. 4.

Here, since the image forming body 20 has a photoconductive layer on a conductive substrate, the latent image forming means uses a charging M21 that uniformly charges the surface of the image forming body 20 and a light beam such as a laser to form a latent image on the image forming body 20.
It is configured in combination with an image exposure device that performs image exposure by irradiating the upper surface.

FIG. 4 shows changes in the surface potential of the image forming body 20, where T1 is the first developed toner image, T2
indicates a toner image developed for the second time. Note that for convenience of explanation, the polarity of the latent image is assumed to be positive.

1. The image forming body 20 is uniformly charged by the charger 21 and has a surface potential of E.

2. Image exposure of the first color is performed by the image exposure device, and the potential of the exposed portion decreases in accordance with the amount of irradiated light.

In this way, an electrostatic latent image is formed.

3. The electrostatic latent image is developed by one of the developing units 22 to 25 to which a positive bias approximately equal to the surface potential E of the unexposed area is applied.

As a result, the positively charged toner (T1) is deposited on a relatively low potential area (exposed area), and a first color toner image T1 is formed.

4. The image forming body 20 is charged by the charger 21 with the toner image attached thereto.
The surface potential of the image forming member 20 becomes E regardless of the presence or absence of toner.

5. The image exposure device performs image exposure for the second color, and the exposed area P
The potential of H decreases depending on the amount of irradiated light. In this way, an electrostatic latent image is formed.

When the area to which the toner has adhered during the first color development is exposed again, the potential becomes approximately equal to the potential after development.

Develop with toner of a different color from the first color toner in the same manner as in 6.3. As a result, two-color toner images TI and T2 are obtained on the image forming body 20.

Thereafter, the same process is repeated a necessary number of times to obtain a multicolor toner image on the image forming body 20. Thereafter, a fixing and separating process is performed, and the color original is recorded on the recording paper P.

In addition, when using the recording unit (multicolor printer) 6 explained in FIGS. 3 and 4, it is possible to take advantage of the advantages of electrophotography, that is, high speed and high resolution, and also to have a simple configuration and small size. It has the advantage of being easy to convert.

FIG. 5 and subsequent figures show other examples of the present invention.

FIG. 5 shows an example of a configuration in which two or more images are combined in the image buffer memory 5.

Therefore, a second input means 3 is provided.

Image data in a format stored in the image buffer memory 5 is transferred from the second input means 3, and is combined with the image data input by the first input means 2 in the image buffer memory 5. The second input means 3 is, for example, a scanner that scans a document with a solid-state element or the like. You can input any image such as a photograph or figure.

According to this example, a composite image of characters, symbols, photographs, graphic surfaces, etc. can be formed.

FIG. 6 is a block diagram showing an example of an image forming apparatus in which the method of converting image code to image data can be changed by an external control signal. A predetermined suppression signal is generated by the control unit 7.

As a control signal for conversion, it is possible to specify the size and color of a character by using keys manually.

FIG. 7 is an application example of FIG. 6, in which a color control signal is used as the control signal, and is input to the input means 2, the font data converter 10, and the electrophotographic recording section 6.

In the electrophotographic recording section 6, image formation is performed one color at a time sequentially, and the control section 7 instructs input of an image matching the color and conversion into image data.

The font data converter 10 converts the font data according to the color to be created.
For example, processing is performed to increase the width of characters in the order of yellow, magenta, cyan, and black.

The reason why the thickness of the characters is changed depending on the color to be recorded is as follows.

When a multicolor toner image is formed by overlapping as described above, when the second color latent image is formed and the photosensitive layer is made conductive by imagewise exposure, 1. The first color toner image absorbs and absorbs the laser light. , 2. The problem is that the charge possessed by the toner cannot be erased by light irradiation.

Factor 1 reduces the effective amount of exposure reaching the photosensitive layer,
This means that the charges on the photosensitive layer cannot be erased sufficiently, and the surface potential of the photosensitive member cannot be lowered sufficiently.

The second factor is that, unless the toner is a special type of photoconductive material, its charge will not be reduced by exposure to light. Therefore, this also causes the surface potential of the photoreceptor not to decrease.

For these reasons, the difference in surface potential between the exposed area and the unexposed area in the area where the toner image has been completely formed becomes small, making it impossible to develop with a sufficient amount of toner.

In other words, when trying to reproduce colors by layering toner,
The amount of toner adhesion for the second and subsequent colors decreases, and the amount of each toner adhesion becomes unbalanced, resulting in a narrow color reproduction area.

The above two factors depend on the development order of the toner, the spectral characteristics of the image exposure light (laser light), the spectral characteristics of the toner, the amount of charge of the toner, etc., so the color reproducibility changes depending on these values.

These tendencies become stronger in the order of yellow, magenta, cyan, and black, so by increasing the thickness of the characters in these order, it becomes possible to eliminate the above-mentioned effects.
This makes it possible to prevent deterioration in color reproducibility.

FIG. 8 shows a case where the image code data is configured to include, in addition to the above-mentioned characters, character size and position information, character color information as well. As for color information, each character has color information of one of seven colors, for example.

Therefore, in this example, it is possible to transfer color character information in degrees rather than as color-separated data.

In this case, the font data converting section 10 reads the sent color information, and converts the image code data related to the color to be next created by the electrophotographic recording section 6 into the image data in the same manner as in the case of FIG. is converted to

For example, green characters are converted to image data when the imaging process is yellow and cyan. Also in this case, since multicolor formation is performed by overlapping, it is preferable that the font data converter 10 changes the conversion method according to this color information.

For example, colors that require cyan toner during image creation include cyan,
Image data for blue, green, etc. is formed by changing parameters for each. Then, the image data is converted into image data that reduces the line width of the characters or reduces the amount of toner adhesion in the order of cyan, blue, and green.

FIG. 9 shows a character buffer 1 memory 8 for storing the image code inputted from the input means 2 as an extension of the example shown in FIG.
This is an example of a configuration provided between the input means 2 and the font data conversion section 10.

In this case, for example, characters of colors that require yellow toner (yellow, red, green) are first retrieved from the character buffer memory 8 and converted into image data, and then characters of colors that require magenta toner (magenta, red, It, etc.) are retrieved from the character buffer memory 8 and converted to image data. Characters are taken out from the character buffer and converted into image data, and the image data is subsequently transferred to the image buffer memory 5 in the same manner in sequence.

FIG. 10 shows a configuration example in which the image buffer memory 5 is provided with storage areas 5a to 5d corresponding to the image forming colors (yellow, magenta, cyan, black) of the electrophotographic recording section 6, as an extension of the example shown in FIG. be.

Thereby, no matter what color information the character code input from the input means 2 has, image data corresponding to the toner required to form that color can be formed.

9a is an input selector, and 9b is an output selector.

[Effects of the Invention] As explained above, according to the configuration of the present invention, a font storage section is provided, and the font storage section is configured to be referenced by input image code data, and the font storage section is configured to be referenced by input image code data, and the font storage section is configured to refer to the font storage section using input image code data. This is configured to refer to fonts related to image information for each color.

According to this, it is possible to form a multicolor image using character fonts with an extremely simple configuration.

Therefore, the multicolor image forming apparatus according to the present invention is extremely suitable for application to electrophotographic color copying machines and the like.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an example of a multicolor image forming apparatus according to the present invention, FIG. 2 is a system diagram showing a specific example of a font data conversion section, and FIG. 3 is a configuration diagram showing an example of an electrophotographic recording section. ,
FIG. 4 is an explanatory diagram of the image forming process, and FIGS. 5 to 10 are system diagrams similar to FIG. 1 showing other examples of the present invention. ■...Font storage unit 2.3...Input means 5...Image buffer memory 6...Electrophotographic recording unit? ... Leg control section 8 ... Character data buffer memory 10 ... Font data conversion section Patent applicant Konica Corporation Fig. 1 Fig. 2 Fig. 4 Fig. 5 Fig. 6

Claims (1)

[Claims] (1) Image input means that outputs at least characters, character sizes, and on-screen coordinate information of characters as image code data based on input image information; a font storage section that outputs font data; a font data conversion section that has a function of converting the image code data into image data consisting of pixel information based on the font data; and an image output from the font data conversion section. It has an image buffer memory for temporarily storing data, and forms a toner image on the image forming body sequentially one color component at a time based on the obtained image data, thereby forming a multicolor toner image. A multicolor image forming apparatus characterized by: