JPH08220933A - Image forming device - Google Patents

Abstract

PURPOSE: To cope with required image quality in image forming device. CONSTITUTION: This device is provided with a first image formation mechanism A composing a first image formation means which forms an image by an electrophotographic process, a second image formation mechanism B composing a second image formation means which forms an image by a heat transfer- process, a first image formation control part C for controlling the first image formation mechanism A, a second image formation control part D for controlling the second image formation mechanism B, and a control part F consisting of a common use part E, which is shared between the control parts C and D.

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,
In particular, the present invention relates to an image forming apparatus such as a copying machine or a printer having a composite function.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus using an electrophotographic process such as a copying machine or a laser printer, 256 gradations are obtained by a combination of direct modulation of laser light (modulation of pulse width and power) and dither matrix. The gradation expression method to obtain is adopted.

[0003]

However, in the above-mentioned conventional image forming apparatus, in order to express gradation by a combination of direct modulation of laser light and a dither matrix, for example, a 1 × 2 matrix is used. Sometimes the resolution is 4
Even if the output engine of 00 dpi is used, the resolution is substantially reduced to 200 dpi. In addition, since the particle size of the pigment of the toner used in the electrophotographic process is relatively large at 8 to 10 μm, graininess due to the density of the transferred image occurs, and especially when a photograph such as a facial photograph is transferred, the above-mentioned grainy feeling occurs. At the same time, the poor image reproducibility in the low-density region (flying of highlight portions) causes extremely poor image quality.

The present invention has been made in view of the above points, and an object thereof is to make it possible to meet the required image quality in an image forming apparatus.

[0005]

In order to solve the above problems, an image forming apparatus according to a first aspect of the present invention comprises a first image forming means for forming an image in an electrophotographic process and a second image forming means for forming an image in a thermal transfer process. And an image forming unit.

According to a second aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
In the above image forming apparatus, the first image forming unit and the second image forming unit share a part or all of the control unit.

According to a third aspect of the present invention, there is provided the image forming apparatus according to the first aspect.
Alternatively, in the second image forming apparatus, the specifying unit for selectively specifying which of the first image forming unit and the second image forming unit to use is provided in the operation unit of the apparatus main body.

An image forming apparatus according to a fourth aspect is the image forming apparatus according to the first aspect.
Alternatively, the image forming apparatus described in item 2 is provided with a switching unit that switches the image forming unit to be used to the first image forming unit or the second image forming unit according to an external selection signal.

[0009]

The image forming apparatus according to the present invention comprises the first image forming means for forming an image in the electrophotographic process and the second image forming means for forming an image in the thermal transfer process.
The image forming means to be used can be selected according to the required image quality.

An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect.
In the image forming apparatus, the first image forming unit and the second image forming unit share part or all of the control unit, so that the configuration is simplified.

An image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the first aspect.
Alternatively, in the second image forming apparatus, since the specifying unit for selecting and specifying which of the first image forming unit and the second image forming unit is used is provided in the operation unit of the apparatus main body, operability is improved.

An image forming apparatus according to a fourth aspect is the above-mentioned first aspect.
Alternatively, the image forming apparatus of No. 2 is provided with a switching unit for switching the image forming unit to be used according to the external selection signal to the first image forming unit or the second image forming unit, so that it can be used as an output terminal. ..

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a schematic configuration block diagram of an image forming apparatus showing an embodiment of the present invention, FIG. 2 is an external perspective view of the image forming apparatus of FIG. 1, and FIG. 3 is a block diagram of a main part of the image forming apparatus.

This image forming apparatus comprises a first image forming mechanism portion A which constitutes a first image forming means for forming an image by an electrophotographic process, and a second image forming means constituting a second image forming means for forming an image by a thermal transfer process. Second image forming mechanism section B, first image forming control section C for controlling first image forming mechanism section A, second image forming mechanism section B
A second image forming control unit D for controlling the image forming mechanism unit B and a control unit F including a shared unit E which is a shared unit of the control units C and D, and a first image forming mechanism provided in the operation unit G. Designating means H for providing the control section F with a designation signal for designating which of the section A and the second image forming mechanism section B is used, and the first image forming mechanism section A and the second image forming section in response to an external selection signal. And a switching means I for giving a selection signal for selecting the mechanical section B to the control section F.

Here, as shown in FIG. 2, this image forming apparatus forms an image in a thermal transfer process (sublimation transfer process) on a digital copying machine 1 which is a first image forming means for forming an image in an electrophotographic process, for example. It can be configured by incorporating the thermal printer unit 2 which is the second image forming means to be formed.

Inside the digital copying machine 1, various mechanical units for executing electrophotographic processes such as charging, exposure (writing), development, separation, and static elimination, a document reading unit (scanner) for reading a document image, and A control unit for controlling these mechanical units is built in, and the thermal printer unit 2 has a mechanical unit such as an ink sheet for forming an image in a thermal transfer process, a thermal head, and a control unit for controlling this mechanical unit. Etc. are built in. Here, a part of the control unit of the digital copying machine 1 and the control unit of the thermal printer unit 2 are shared, and the mechanical unit of the thermal printer unit 2 is provided so as to be pulled out from the digital copying machine 1.

In the digital copying machine 1, an operation unit 3 for inputting various kinds of instruction information, a display editor 4 for image editing, first to third trays 5 for paper feeding for storing image receiving papers. 7 to 7, a manual feed section 8 for manual sheet feeding, a vertical transport section 9, a sheet discharge tray 10, a pressure plate 11 for pressing a document, and the like, and a designation switch 12 forming the designation means H of FIG. To be Further, the thermal printer unit 2 is also provided with a paper discharge tray 13 and a pull-out handle 14.

As shown in FIG. 3, the control unit of the image forming apparatus includes an image processing unit 21 for controlling image processing necessary for image formation in the electrophotographic process and the thermal transfer process and writing control of the electrophotographic process. A print controller 22 for controlling image formation in the electrophotographic process, a thermal control unit 23 for controlling image formation in the thermal transfer process, a main control plate 24 for overall control, and the like.

The image processing section 21 receives the control information from the main control board 24, takes in the read image signal from the scanner 25 through the interface (I / F) 26, and performs predetermined image processing. Print controller 22
The write data is sent to the writing unit 27 which is controlled by the writing unit 27 for writing to the recording unit 28.

The image processing unit 21 is a scanner γ correction / dot correction unit 31 for performing γ correction and dot correction on an image signal from the scanner 25, and an automatic color selection (ACS) 32 for determining chromatic / achromatic. And an image separation unit 34 including a character / dot separation unit 32 that detects and separates characters and photo portions (dots), and a filter that performs color correction and color conversion after performing filter processing to improve reproducibility of image quality.・
Color conversion unit 35, scaling unit 3 for performing main-scanning / sub-scanning scaling processing
6, an interface 37 that controls data transmission / reception between the print controller 22 and the thermal control unit 23.

Further, a create section 38 for processing the original image such as inversion, italicized image formation, repeat, painting, hollowing, shadowing, etc., and after performing filter processing, γ correction and further gradation processing (dither processing). A filter / γ correction / gradation processing unit 39 for performing the following, a video control unit 40 for controlling writing timing, a CPU 41 for controlling the entire image processing unit 21, a ROM 42 and an area memory 43, a main control plate 24 and an image separation unit. Interface 44 that controls data transmission / reception with 34, editor 45 and filter / γ correction /
Interface 4 which controls data transmission / reception with the gradation processing unit 39
6 is provided. The CPU 4 of the image processing unit 21
Reference numeral 1 also controls the BR unit 47 that receives the image signal from the scanner 25.

The thermal control unit 23 inputs the information from the main control board 24 and sublimates the printer system controller 51 which controls the entire thermal printer unit, and the interface 38 for the image data after the scaling processing of the image processing unit 21 is completed. Received via Y, M, C
A frame memory 52 that is temporarily stored as data, a memory controller 53 that performs γ correction (gradation correction), correction of contrast, hue, saturation, and the like on Y, M, and C data stored in the frame memory 52, frame memory 52 Thermal data of the recording mechanism (mechanical section) 55 capable of printing in a three-color or four-color frame sequential method by reading data from the printer, generating resistance values, printing rate, head division drive data and gradation data. A head controller 57 for transferring to the head 56 is provided.

The operation of the image forming apparatus configured as described above will be described. As shown in FIG. 4, it is determined whether or not the thermal transfer process is selected and designated by the designation switch 13 of the operation unit 2, and the designation switch is selected. If the heat transfer process is not selected and designated by 13, the image forming process is performed by the digital copying machine 1 by a normal electrophotographic process, and if the heat transfer process is selected and designated by the designation switch 13, the thermal printer unit is selected. 2, the image is formed by a sublimation (thermal) transfer process.

Here, the image processing unit 2 of the digital copying machine 1
1 captures an image signal from the scanner 25 and performs image processing in real time, then sends data to the writing unit 27 to form an image by an electrophotographic process by the recording unit 28 and print it out. On the other hand, in the sublimation transfer process, the image signal from the scanner 21 is subjected to γ correction and dot correction, filter processing and color conversion processing, and scaling processing by the image processing unit 21, and the data is temporarily stored in the frame memory 52. Then, the memory controller 5
After the γ correction (gradation correction) and the correction of the contrast, hue, and saturation different from those of the output image by the electrophotographic process, the data is sent to the thermal head 56 of the recording mechanism 55 to form an image. Print out.

As described above, since the image forming apparatus includes the first image forming means for forming an image in the electrophotographic process and the second image forming means for forming an image in the thermal transfer process, the required image is formed. Depending on the quality, for example, when printing out a normal text document, etc., an image is formed by an electrophotographic process as a copying machine, and when high image quality such as a photo document is required, an image is formed by a thermal transfer process. It is possible to obtain an output image having a required image quality. High-quality transfer can be performed by thermal transfer recording because 7-bit or 8-bit modulation can be performed on a pixel-by-pixel basis, and resolution and gradation can be obtained at the same time.

Further, as described above, the first image forming means (digital copying machine 1) for forming an image in the electrophotographic process is incorporated with the second image forming means (thermal printer unit 2) for forming an image in the thermal transfer process. By sharing a part of the control unit required for each image formation, the configuration of the control unit is simplified. In this case, the power supply system and the like can be shared. Further, the provision of the designation means for selecting the image forming means to be used in the operating portion of the first image forming means enables the combination of the copying machine and the thermal printer. In this case, the keys of the operation unit of the copying machine, such as designation of the print area, setting of the enlargement / reduction ratio, and color selection, can be shared.

Next, a case where the image forming apparatus according to the present invention is used as a terminal device (printer) will be described with reference to FIG. The image forming apparatus 61 is an electrophotographic printer 62 such as a laser printer which is a first image forming unit.
And a sublimation printer 63 which is the second image forming means are incorporated, and data required from the printer controller 65 is taken in through an interface 64 (corresponding to the interface 37 in FIG. 3) and a desired printing is performed. To do.

The printer controller 65 includes a plurality of, for example, three personal computers (PCA to PCC) 6
6 to 68 can be connected, and an external selection signal for selecting whether to use the electrophotographic printer 62 or the sublimation printer 63 of the image forming apparatus 61 is output by the personal computers 66 to 68 on the host side. In response to the external selection signal, the image forming apparatus 61 forms an image by the image forming means (electrophotographic printer 62 or sublimation printer 63) on the selected side.

As described above, when the image forming apparatus according to the present invention is used as a printer, it is necessary to perform a hardware switching operation by making it possible to select and designate the image forming means to be used by an external selection signal. The operability is improved by eliminating it.

In the above embodiment, the first image forming means for forming an image in the electrophotographic process and the second image forming means for forming an image in the thermal transfer process respectively form and output images individually. However, it is also possible to form an image on one sheet of image-receiving paper by an electrophotographic process and at the same time form an image on a thermal transfer process. For example, when printing a document containing a mixture of photographic images, the data separated into characters and photographs by the image separation unit 34 in FIG. After forming the image receiving sheet, the image receiving paper is sent to the mechanical section of the thermal transfer process to form an image of the photographic portion by the thermal transfer process, and then the sheet is discharged. In this case, since the electrophotographic process heats the toner fixing process,
It is better to first form the image by the electrophotographic process and then form the image by the thermal transfer recording process.

[0031]

As described above, according to the image forming apparatus of the first aspect, the first image forming means for forming an image in the electrophotographic process and the second image forming means for forming the image in the thermal transfer process.
Since the image forming means is provided, the image forming means to be used can be selected according to the required image quality,
It is possible to meet the demand for image quality.

According to the image forming apparatus of claim 2, in the image forming apparatus of claim 1, part or all of the control unit is shared by the first image forming means and the second image forming means, so that the structure is simple. become.

According to the image forming apparatus of claim 3, in the image forming apparatus of claim 1 or 2, there is provided a specifying means for selecting and specifying which of the first image forming means and the second image forming means is to be used. Since it is provided in the operation unit of the apparatus body, the operability of the selection and designation operation is improved.

According to the image forming apparatus of claim 4, in the image forming apparatus of claim 1 or 2, the image forming means used according to the external selection signal is the first image forming means or the second image forming means. Since the switching means for switching is provided, it can be used as an output terminal device and the operability of the selection designation operation is improved.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an image forming apparatus showing an embodiment of the present invention.

FIG. 2 is an external perspective view of the image forming apparatus in FIG.

FIG. 3 is a block diagram of a main part of the image forming apparatus.

FIG. 4 is an explanatory diagram for explaining the operation of the image forming apparatus.

FIG. 5 is an explanatory view showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Digital copying machine (1st image forming means), 2 ... Thermal printer unit, 3 ... Operation part, 12 ... Designation switch, 21 ... Image processing part, 23 ... Thermal control unit, 24 ... Main control board, 25 ... Scanner , 27 ...
Writing unit, 28 ... Recording unit, 55 ... Recording mechanism, 56 ... Thermal head.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03G 15/00 303 B41J 3/20 117A

Claims (4)

[Claims] 1. An image forming apparatus for forming an image,
An image forming apparatus comprising: a first image forming unit that forms an image in an electrophotographic process; and a second image forming unit that forms an image in a thermal transfer process. 2. The image forming apparatus according to claim 1, wherein the first image forming unit and the second image forming unit share part or all of a control unit. . 3. The image forming apparatus according to claim 1, wherein the operation unit of the apparatus main body is provided with a specifying unit for selectively specifying which of the first image forming unit and the second image forming unit is to be used. An image forming apparatus characterized by the above. 4. The image forming apparatus according to claim 1, further comprising a switching unit that switches an image forming unit to be used according to an external selection signal to the first image forming unit or the second image forming unit. An image forming apparatus characterized by.