JPH08314206A - Image forming device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a small-sized image forming apparatus capable of simultaneously providing a text image with high definition and a stable graphic image output. [Structure] The image forming apparatus 1 includes an electrophotographic process 10.
And an ink jet process 20, a temperature detecting means 30 for detecting the temperature of the recording paper P, and a CPU. When the temperature detected by the temperature detecting means 30 is equal to or higher than a predetermined temperature, the CPU Inkjet process 20
To stop the operation. Alternatively, the electrophotographic process 10 is controlled so as to slow down the conveyance speed of the recording paper P.

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 for forming an image on a recording medium such as paper, and more specifically, an image in which a monochrome image and a color image or a text image and a graphic image are mixed. The present invention relates to an image forming apparatus suitable for forming an image.

[0002]

2. Description of the Related Art Conventionally, an electrophotographic recording apparatus, an ink jet recording apparatus and the like have been used as image forming means, and a generally used electrophotographic recording apparatus 100 capable of outputting a color image is illustrated. 3, the electrophotographic recording apparatus 100 includes a drum-shaped photosensitive member 101.
And a charging means 102 that uniformly charges the surface of the photoconductor 101 to a predetermined potential, and an electrostatic latent image is formed on the surface of the photoconductor 101 by exposing the surface of the photoconductor 101 that has been uniformly charged with laser light or the like. An exposing unit 103 for forming and a yellow developing unit 10 for forming a yellow toner image on the paper P.
4Y, a magenta developing unit 104M that forms a magenta toner image on the paper P, a cyan developing unit 104C that forms a cyan toner image on the paper P, and a black toner image on the paper P.
The black developing means 104Bk formed above and the developing means 104Y, 104M, 104C, 104Bk for the above four colors
A transfer unit 105 that transfers the toner images of the four colors visualized by the above to the paper P and a fixing unit 106 that fixes the toner image transferred onto the paper P are provided.

The operation of the electrophotographic recording apparatus 100 thus constructed will be described. When forming a color image, first, the surface of the photosensitive member 101 uniformly exposed by the charging means 102 is exposed. An electrostatic latent image is formed by exposing by means 103 according to the yellow image signal. In accordance with this electrostatic latent image, the yellow developing means 10
A yellow toner image is formed on the photoconductor 101 by 4Y, and the above operation is performed by the magenta developing unit 104.
M, cyan developing means 104C, black developing means 104
By repeating Bk, the four color images are superimposed on the photoconductor 101 to form a color toner image. Then, the color toner image is transferred to the paper P by the transfer unit 105 and fixed by the fixing unit 106, and a color image is formed on the paper P and output.

On the other hand, the ink jet print head 200 provided in the ink jet recording apparatus, as shown in FIGS. 4 and 5, has a nozzle plate 201, a piezoelectric ceramic plate 202, a cover plate 203, and
An ink chamber 204 and a nozzle plate 201.
Is provided with a nozzle 201Y that ejects yellow ink, a nozzle 201M that ejects magenta ink, a nozzle 201C that ejects cyan ink, and a nozzle 201Bk that ejects black ink. Then, the inkjet print head 200 configured as described above is controlled by the control unit (not shown).
Is controlled according to the image signal, the ink chamber 2
The volume of 04 changes, and as a result, ink is ejected from the nozzle plate 201, and a color image according to an image signal is formed on a paper (not shown).

Here, since the electrophotographic image forming apparatus as described above records with solid toner, there is an advantage that a clear image can be obtained without bleeding, but in the case of outputting a color image. Requires at least the number of developing means for developing the electrostatic latent image formed on the photoreceptor to form a color image, generally 3 to 4 colors. There was a problem that it became quite large.

Further, the ink jet type image forming apparatus is
By increasing the number of ink ejection ports by the number of colors, it is possible to output a color image with the same size as the ink head required to form a monochrome image. There is an advantage that the device can be downsized. However, when a line drawing mainly composed of characters is recorded by an ink jet type image forming apparatus, there is a problem that an image is blurred due to ink bleeding.

Therefore, in recent years, various image forming apparatuses have been proposed which combine an electrophotographic process and an ink jet process. In this image forming apparatus, a text image is formed by the electrophotographic process and a graphic image is formed by the ink jet process. It was a thing.

[0008]

However, since the ink used in the ink jet process of the image forming apparatus described above may be deteriorated or discolored at a high temperature, the step of passing through the fixing process of electrophotography may be performed. There is a problem that it adversely affects the output image and it is difficult to always obtain a stable image.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a small-sized image forming apparatus capable of simultaneously outputting a text image having high definition and a stable graphic image. To do.

[0010]

In order to achieve this object, an image forming apparatus of the present invention comprises at least a photoconductor, a charging means for uniformly charging the photoconductor to a predetermined potential, and exposing the photoconductor. Exposing means for forming an electrostatic latent image, developing means for developing the electrostatic latent image formed on the photoconductor with a charged developer, and an image formed on the photoconductor by the developer An electrophotographic image forming means including a transfer means for transferring the image to a recording medium and a fixing means for fixing the image transferred to the recording medium by the transfer means, and a downstream side of the fixing means in the recording medium conveying direction. A recording medium which is arranged and ejects ink to form an image on the recording medium, and further, which passes through the fixing unit and immediately before reaching the inkjet image forming unit. Temperature detecting means for detecting the temperature, when the temperature of the recording medium detected by the temperature detecting means is higher than a predetermined temperature, and a stop control means for controlling to stop the operation of the ink jet type image forming unit.

In another image forming apparatus of the present invention, at least a photoconductor, a charging unit that uniformly charges the photoconductor to a predetermined potential, and the photoconductor is exposed to form an electrostatic latent image. Exposure means, developing means for developing an electrostatic latent image formed on the photoconductor with a charged developer, and transfer means for transferring the image formed on the photoconductor by the developer onto a recording medium. An electrophotographic image forming means having a fixing means for fixing the image transferred to the recording medium by the transfer means, and an electrophotographic image forming means arranged downstream of the fixing means in the recording medium conveyance direction to eject ink. An inkjet image forming unit for forming an image on the recording medium; and a temperature detecting unit for detecting the temperature of the recording medium immediately after reaching the inkjet image forming unit after passing through the fixing unit. The detected temperature of the recording medium and a speed control means for controlling when higher than the predetermined temperature, so as to lower the operation speed of an electrophotographic image forming means by the temperature detection means.

Further, there may be provided process control means for controlling the electrophotographic image forming means to be used for forming a monochrome image and the ink jet type image forming means to be used for forming a color image.

Alternatively, there is provided process control means for controlling the electrophotographic image forming means to be used to form a monochrome text image and the ink jet type image forming means to be used to form a color image and a monochrome graphic image. May be.

[0014]

According to the image forming apparatus of the present invention having the above structure, a monochrome image mainly composed of a text image is formed by an electrophotographic image forming means, and a color image mainly composed of a graphic image is an ink jet type image. An image is formed by the forming means. At that time, the temperature detecting means detects the temperature of the recording medium immediately after reaching the inkjet image forming means after passing through the fixing means, and when the temperature of the recording medium detected by the temperature detecting means is higher than a predetermined temperature. Controls the stop control means to stop the operation of the inkjet image forming means.

Further, according to another image forming apparatus of the present invention, when the temperature of the recording medium detected by the temperature detecting means is higher than a predetermined temperature, the speed control means instead of stopping the operation is electronic. Control is performed to reduce the operation speed of the photographic image forming means.

Further, the process control means controls the electrophotographic image forming means to form a monochrome image and the ink jet type image forming means to form a color image.

Alternatively, the electrophotographic image forming means is used to form a monochrome text image, and the ink jet type image forming means is used to form a color image and a monochrome graphic image.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, the image forming apparatus 1
Is composed of an electrophotographic process 10, an inkjet process 20, and a temperature detecting means 30 for detecting the temperature of a recording medium such as paper. Then, the temperature detecting means 30
The temperature signal detected by is taken into the CPU 40 as the control means of the image forming apparatus 1, and by this signal,
The CPU 40 is configured to control the electrophotographic process 10 or the inkjet process 20 based on a control program stored in a ROM (not shown).

Here, the control program stored in the CPU 40 and the ROM (not shown) constitutes stop means, speed control means, and process control means.

In the electrophotographic process 10, the photoconductor 11 on the drum, the charger 12 for uniformly charging the photoconductor drum 11, and the uniformly charged drum surface are exposed by scanning laser light or the like to be statically exposed. An exposure device 13 that forms an electrostatic latent image, a developing device 14 that visualizes this electrostatic latent image with a developer charged to a predetermined polarity, and a developed image on a recording medium P such as paper.
And a fixing device 16 for fixing the transferred image by using energy such as heat.
Such an electrophotographic process can be general,
Since the effects of the present invention are not lost by the configuration and means, specific configurations of the charging device 12, the exposure device 13 and the like will not be described in detail here.

The ink jet head used in the ink jet process 20 is shown in FIGS.
The conventional inkjet head 2 shown in FIG.
One having the same configuration as 00 can be used.

As the temperature detecting means 30, for example, a so-called type K alumel-chromel thermocouple is used, which is arranged so as to lightly contact the paper P immediately after passing through the fixing device 16, and detects the temperature of the paper P. It can be performed.

Next, the operation of the image forming apparatus 1 configured as described above will be described with reference to FIGS.

When an image signal is sent to the CPU 40 of the image forming apparatus 1 from a personal computer or the like (not shown), the CPU 40 first converts the image signal into a monochrome image based on a control program stored in a ROM (not shown). It is separated into a text image signal, a color image signal and a monochrome graphic image signal. Then, first, the electrophotographic process 1 is performed according to the monochrome text image signal.
Send a drive control signal to 0. According to this signal, the photoconductor 11 of the electrophotographic process 10 starts rotating. The photoconductor 11 that has started to rotate is charged with, for example, a negative polarity by the charger 12. Photoreceptor 1 uniformly charged with negative polarity
The surface of No. 1 then moves to the vicinity of the exposure device 13.

At this time, the exposure device 13 is modulated according to the monochrome text image signal, so that the photoconductor 11
An electrostatic latent image corresponding to this image signal is formed on the surface of the sheet by exposure of the exposure device 13. This electrostatic latent image is visualized by the developing device 14 by adhering a developer charged to a predetermined polarity to the surface of the photoconductor. Then, the visualized image is transferred onto the paper P by the transfer device 15 and further fixed by the fixing device 16. In this way, a clear monochrome text image is formed, taking advantage of the advantages of electrophotography.

After that, the temperature of the paper P passing through the fixing device 16 is detected by the temperature detecting means 30, and the temperature signal is sent to the CPU 40, and based on this signal, the color image signal and the monochrome graphic image signal, The inkjet process 20 is drive-controlled.

At this time, if the temperature of the paper P is a predetermined temperature or higher, preferably 150 degrees Celsius or higher, the CPU 4
From 0, a temporary drive stop signal is sent to the inkjet process 20, and the operation of the inkjet process 20 is temporarily stopped. Further, the temperature is equal to or lower than the predetermined temperature, preferably 1 degree Celsius.
When the temperature is 50 degrees or less, or when the driving start signal or the driving restart signal is sent, the printing operation is
It is started or restarted.

Alternatively, if the temperature of the paper P is above a predetermined temperature,
If it is more than 150 degrees Celsius, CPU
A control signal for lowering the operation speed is sent from the electrophotographic process 10 to the electrophotographic process 10, whereby the conveyance speed of the paper P is decreased, and after passing the fixing device 16, the inkjet process 20 is performed.
It takes a long time to reach, and as a result, the paper P is naturally cooled below the predetermined temperature.

As described above, the temperature of the paper P controls the stop and start of the driving of the ink jet process 20 and the operation speed of the electrophotographic process 10, so that the ink used in the ink jet process 20 is deteriorated. Alternatively, there is no fear of discoloration, and a stable color image or monochrome graphic image can always be obtained.

In the present embodiment, the reason why the monochrome text image is formed by the electrophotographic process and the color image and the monochrome graphic image are formed by the inkjet process is that the monochrome image is formed by the electrophotographic process as compared with the inkjet process. This is because the image is more suitable for outputting characters because the contour line is too sharply output, but is not suitable for painting or a blurred output such as a focused photograph.

Although the specific constitutions of the electrophotographic process and the ink jet process are not described in detail in the present embodiment, the effect of the present invention can be obtained regardless of the constitution of these processes. Even if the process of application is adopted without any influence, the same effect as that of the present embodiment can be obtained.

[0033]

As is apparent from the above description, according to the image forming apparatus of the present invention, the image is formed by the ink jet type image forming means after the image is formed by the electrophotographic image forming means. In addition, the operation of the electrophotographic image forming unit is stopped so that the image forming operation of the inkjet image forming unit is stopped or the cooling period of the recording medium can be secured when the temperature of the recording medium exceeds a predetermined temperature. By reducing the speed, it is possible to easily realize a small-sized image forming apparatus that can always obtain a clear text image and a stable graphic image.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an image forming apparatus of the present invention.

FIG. 2 is a control block diagram of the image forming apparatus of the present invention.

FIG. 3 is a diagram showing an outline of a conventional electrophotographic color image forming apparatus.

FIG. 4 is a diagram showing a configuration of an inkjet head used in a conventional inkjet color image forming apparatus.

5 is a cross-sectional view of the inkjet head shown in FIG.

[Explanation of symbols]

1 Image Forming Apparatus 10 Electrophotographic Process (Electrophotographic Image Forming Means) 11 Photosensitive Member 12 Charging Means 13 Exposure Means 14 Developing Means 15 Transfer Means 16 Fixing Means 20 Inkjet Process (Inkjet Image Forming Means) 30 Temperature Detecting Means 40 CPU

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B41J 3/54 G03G 15/22 103Z 29/38 H04N 1/23 Z G03G 15/01 B41J 3/00 E 15/22 103 3/04 101A 21/14 G03G 15/00 H04N 1/23 21/00 372

Claims (4)

[Claims] 1. A photoconductor, at least a charging unit for uniformly charging the photoconductor to a predetermined potential, an exposing unit for exposing the photoconductor to form an electrostatic latent image, and a photoconductor on the photoconductor. A developing unit that visualizes the formed electrostatic latent image with a charged developer, a transfer unit that transfers the image formed on the photoconductor by the developer onto a recording medium, and a transfer unit that transfers the image onto the recording medium. An electrophotographic image forming unit including a fixing unit that fixes the transferred image, and an electrophotographic image forming unit disposed downstream of the fixing unit in the recording medium conveyance direction, ejecting ink to form an image on the recording medium. In an image forming apparatus provided with an inkjet image forming means, a temperature detecting means for detecting the temperature of a recording medium immediately after reaching the inkjet image forming means after passing through the fixing means, and the temperature detecting means. Ri when the detected temperature of the recording medium is higher than the predetermined temperature, the image forming apparatus characterized by comprising a stop control means for controlling to stop the operation of the ink jet type image forming unit. 2. At least a photoconductor, a charging unit that uniformly charges the photoconductor to a predetermined potential, an exposure unit that exposes the photoconductor to form an electrostatic latent image, and a photoconductor on the photoconductor. A developing unit that visualizes the formed electrostatic latent image with a charged developer, a transfer unit that transfers the image formed on the photoconductor by the developer onto a recording medium, and a transfer unit that transfers the image onto the recording medium. An electrophotographic image forming unit including a fixing unit that fixes the transferred image, and an electrophotographic image forming unit disposed downstream of the fixing unit in the recording medium conveyance direction, ejecting ink to form an image on the recording medium. In an image forming apparatus provided with an inkjet image forming means, a temperature detecting means for detecting the temperature of a recording medium immediately after reaching the inkjet image forming means after passing through the fixing means, and the temperature detecting means. When the detected temperature of the recording medium is higher than the predetermined temperature Ri, the image forming apparatus characterized by comprising a speed control means for controlling so as to lower the operating speed of the electrophotographic image forming means. 3. A process control means for controlling the electrophotographic image forming means to be used for forming a monochrome image and the ink jet type image forming means to be used for forming a color image. The image forming apparatus according to item 1 or 2. 4. A process control means for controlling the electrophotographic image forming means to be used for forming a monochrome text image and the ink jet type image forming means to be used for forming a color image and a monochrome graphic image. The image forming apparatus according to claim 1 or 2, characterized in that.