JP3535587B2 - Image forming device - Google Patents

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 such as an electrophotographic machine for forming an image on various kinds of image recording media (hereinafter referred to as "recording media") such as thick paper and thin paper. .

[0002]

2. Description of the Related Art In recent years, for the purpose of increasing the quantity and speed of color image formation, a recording light emitting source corresponding to each recording color,
An image forming apparatus has been developed which has an image forming section centered on the drive section, the photosensitive drum, and a developing device. Then, in general, a latent image is developed on the photosensitive drum by a four-color developing device of magenta (M), cyan (C), yellow (Y), and black (Bk), and the image is recorded on the recording medium. Form a color image by overlapping,
A color image is formed by transferring (recording) onto a recording medium.

By adopting such an image forming structure, it becomes possible to convey the recording medium in a substantially linear manner even when the recording medium is conveyed from the manual paper feeding section. It has become possible to convey a recording medium having a thickness that is hard to bend.

[0004]

In recent years, there is a need for utilization of various recording media such as thick paper other than ordinary paper as a recording medium for recording an image, and as described above, it is desired. This can be realized by an image forming apparatus having various configurations.

However, particularly in image formation such as electrophotography, various conditions for forming an optimum image differ depending on the type of recording medium, and therefore it is difficult to form an image on a wide variety of recording media. It is difficult because of the problem.

For example, when images are formed on various recording media having different factors (attribute information) such as thickness and material, in the process of transferring the image formed on the image forming medium to the recording medium, the recording is performed. The factor of the type of medium has a great influence on the image quality. for that reason,
In order to optimize the image quality, it is necessary to change the transfer current depending on the type of recording medium. In addition, in order to optimize the image quality depending on the type of recording medium, not only the transfer factor but also factors such as γ correction of image data and various potential control at the time of image formation can be optimized depending on the type of recording medium. Will be needed.

In the process of fixing the image formed on the recording medium with the powdery developer on the recording medium, in the heating type fixing generally used,
Since the amount of heat required for fixing is different for a recording medium having different factors such as thickness and material, it is necessary to switch the fixing temperature and the fixing passing speed depending on the type of the recording medium.

Furthermore, a method of controlling various elements by detecting the thickness of the recording medium is one important method. However, not only the thickness of the recording medium but also the surface of the recording medium is a factor that determines various elements. Since there are factors such as differences in roughness and whiteness, only the thickness of the recording medium does not necessarily correspond to a factor that determines various factors, and there is a problem that strict control may cause a problem.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image forming apparatus capable of forming a suitable image according to the type of image recording medium.

[0010]

The image forming apparatus according to claim 1, wherein SUMMARY OF THE INVENTION forms image information on the image forming medium, an image forming apparatus for transferring an image that is formed on the image recording medium, the image to be used Input means for inputting the type of recording medium
When a detection means for detecting attribute information of said image recording medium, based on the detected attribute information by the detecting means, the type of the image recording medium to be subjected to the image forming said
Is the type of image recording medium input by the input means?
And control means for changing the control information for performing image formation according to the determined type of the image recording medium.

[0011]

An image forming apparatus according to a third aspect of the invention is characterized in that the attribute information is thickness information.

According to another aspect of the image forming apparatus, the control information for forming the image is at least a transfer current value.
It is characterized by including any one of the fixing heat quantity and the γ correction for the image data.

An image forming apparatus according to a fifth aspect of the present invention is characterized in that the input means performs input by inputting bar code information specific to the type of image recording medium.

[0015]

According to the image forming apparatus of claim 1, the input device
When the stage inputs the type of the image recording medium to be used, and the detecting means detects the attribute information of the image recording medium, the control means, based on the attribute information detected by the detecting means ,
The type of image recording medium is recorded by the input means.
Discriminate among the types of recording media, and change the control information for image formation according to the discriminated image recording medium type.
To do . Generally, Oite <br/> the case where one of the image forming apparatus is used, an image recording medium which is mainly used are those generally of the same species, usually the supply service of the image forming apparatus consistent As such, the type of decision is often made. Under such circumstances, it is possible to appropriately change various factors of image formation based on the determination result of the type of the image recording medium.

[0016]

[0017] According to the image forming apparatus according to claim 2, wherein the control means determines the type of image recording medium on the basis of the thickness information of the image recording medium, an image is formed according to the type of the image recording medium Change the control information for . Thereby, the image quality can be optimized according to the thickness of the image recording medium.

[0018] According to the image forming apparatus according to claim 3, wherein the control means, at least the transfer current value corresponding to the type of image recording medium, the image forming comprising any one of the γ correction to the fixing heat, and the image data The image formation is controlled by controlling the control information for performing.

According to the image forming apparatus of the fifth aspect, the input means inputs the barcode information specific to the type of the recording medium. This facilitates input of the type of recording medium.

[0020]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an overall configuration diagram of an electronic copying machine showing an application example of the image forming apparatus of the present invention.

The electronic copying machine 1 has a copying machine main body 1a, and an original table 2 for placing an original on the upper surface of the copying machine main body 1a and an original placed on the original table 2 A document pressure plate 3 for pressing down and a display operation section 4A as an input means for displaying various information and inputting various information, such as a touch panel and a liquid crystal display, are arranged. Further, inside the copying machine main body 1a, a reader unit 5 that performs reading of a document and various processes for the read image signal, and a color image corresponding to each color digital image signal sent from the reader unit 5 are produced. A printer unit 6 for reproducing an image is arranged.

As shown in FIG. 1, the leader section 5 has
A lamp 50 that scans in the direction of arrow V while illuminating a document placed between the document table 2 and the document pressure plate 3, and a reflected light image from the document is converted into signals of RGB colors by a filter of RGB three colors. A photoelectric converter (CCD) 51 for conversion and a mirror group 5 for forming a reflected light image from a document on the CCD 51.
2 and the lens 53, and an image processing unit 54 that performs a predetermined process on the image signal from the CCD 51.

The image processing unit 54 of the reader unit 5 is shown in FIG.
Will be described with reference to. FIG. 3 is a block diagram of the image processing unit 54. The image processing unit 54 samples and holds the image signal from the CCD 51 and then A / D converts it to RG.
An A / D conversion / S / H unit 540 for generating digital signals of three colors of B, and a shading correction unit 541 for performing shading correction and the like on each color component data from the A / D conversion / S / H unit 540. , This shading correction unit 54
An input masking unit 542 that corrects the signal input from 1 into an NTSC signal; a scaling processing unit 543 that performs scaling processing during a scaling operation; a LOG conversion unit 544 that converts RGB data into CMY data; This LOG converter 54
The companding unit 545 that compresses, stores, decompresses, and stores the image data from the memory 4 in a memory (not shown), and the image data stored in the memory of the companding unit 545 is supplied to the printer unit 6 described below. The masking / UCR unit 546 that performs the masking process by reading in synchronism with the color, the γ correction unit 547 that performs γ correction on the output signal of the masking / UCR unit 546, and the output signal of the γ correction unit 547. An edge enhancement unit 54 that performs edge enhancement processing to create CMYK output image data and sends it to the printer unit 6
8 and.

The printer section 6, as shown in FIG.
Laser elements 600 to 603 for generating laser light
And a photosensitive drum 61 that uses laser light as an image forming medium.
Synchronize each color with the polygon scanner 604 that scans up to 0, and drive the laser elements 600 to 603 independently of MCYK according to the image data from the reader unit 5 to drive the laser beams from the laser elements 600 to 603 of each color. Laser control unit 60 for scanning on the photosensitive drum 610
5 and a magenta (M) image forming unit 6 provided in the first stage
06, a cyan (C) image forming unit 607, a yellow (Y) image forming unit 608, and a black (K) image forming unit 609 that are configured similarly to the magenta (M) image forming unit 606; A transfer belt 618, which will be described later with reference to the medium P
A recording medium on which a toner image formed on a photosensitive drum 610, which will be described later, is transferred, which is conveyed by a transfer belt 618 and paper feeding units 621 and 622 that feed paper to the upper side, a paper re-feeding unit 623, and a manual paper feeding unit 624. Conveyance path 6 for conveying P before fixing
25, a fixing device 626A that heats and fixes the toner image on the recording medium P that has passed through the transport path 625 to the recording medium P, and the reverse side of the recording medium P when the image surface is reversed and discharged. And the reverse conveyance path 627 for discharging the recording medium P and the reverse conveyance path 627 for the recording medium P in order to perform the image formation of the second surface on the fixed recording medium P in the case of forming the images on both sides.
Sheet re-feeding path 6 for feeding from the sheet to the sheet re-feeding section 623
28, a registration roller 629 that stops the recording medium P once, and determines the conveyance timing of the recording medium P to the image forming unit 606, and the first-stage magenta (M) image forming unit 606.
And a thickness detection sensor 630 that is provided in the paper feed / transport path to detect the thickness of the recording medium P.

The image forming unit 606 of the printer unit 6 is
As shown in FIG. 1, a photosensitive drum 610 that forms a latent image by exposure to laser light, a developing device 611 that develops toner on the photosensitive drum 610, and a developing bias that is arranged in the developing device 611 and applies a developing bias. , A sleeve 612 for developing toner, and a developer concentration sensor 6 for detecting the developer concentration by the amount of light reflected from the developer on the sleeve 612.
13 and 1 to charge the photosensitive drum 610 to a desired potential 1
The secondary charger 614, the cleaner 615 that cleans the surface of the photosensitive drum 610 after transfer, and the surface of the photosensitive drum 610 that has been cleaned by the cleaner 615 are discharged to remove the primary charger 6
14, an auxiliary charger 616 for obtaining good charge, a pre-exposure lamp 617 for erasing the residual charge on the photosensitive drum 610, and discharge from inside the transfer belt 618 to form a toner image on the photosensitive drum 610. A transfer charger 619 for transferring the image onto a recording medium (transfer member) P, and a development density sensor 620 for detecting the amount of reflected light from the development formed on the photosensitive drum 610 are provided.

The thickness detection sensor 630 of the printer unit 6
It will be described with reference to FIG. FIG. 2 shows a thickness detection sensor 63
It is a block diagram which shows an example of 0. This thickness detection sensor 63
Reference numeral 0 includes a light emitting diode 631 that emits light toward the recording medium P, and a light receiving position sensor 632 that receives the light reflected by the reflecting surface 633 on the surface of the recording medium P. The light receiving position sensor 632 outputs an analog signal 632a corresponding to the incident position when the incident position on the light receiving position sensor 632 changes. The resolution of such a sensor 632 is about 10 microns, and it is possible to detect the difference in the thickness of the recording medium to the extent that it is necessary to change each parameter of the electrophotographic process.

FIG. 4 is a diagram showing an example of a setting mode screen displayed on the display / operation unit 4 according to the first embodiment of the present invention.
On the setting mode screen of the display operation unit 4, a PG key 40 indicated by "PG1" to "PG9" and a setting end key 41 to be pressed at the end of setting are displayed to register various recording media P to be used. It can be done. The type of the recording medium P is pre-assigned to each PG key 40, and the control information relating to the image formation of the recording medium P is stored in the ROM 11A described later in association with the type of each recording medium P. These PG keys 40 generally cover the types of paper used in the market. When the service person presses the PG key 40 corresponding to the type of the recording medium P to be used among the PG keys 40 displayed on the setting mode screen, the selected PG key 40 is highlighted and the recording medium P is selected. The fact that is selected is displayed to the service personnel. The figure shows a case where the PG key 40 indicated by "PG2" and "PG8" is selected and highlighted, and the information of the selected recording medium P is set by pressing the setting end key 41. After the mode is completed, the data D regarding the thickness stored in the ROM 11A described later is used as the threshold for the thickness determination in the RAM.
I am trying to remember it in 12. This registration operation is generally performed as one of the service modes performed by a service person when installing the copying machine 1A.

FIG. 5 is a block diagram showing the control system of the first embodiment.

The electronic copying machine 1A of the first embodiment is a central processing unit (CP) which controls the sequence of the copying machine 1A.
U) R that stores a sequence program including 10A and thickness information and various control information for image formation
A CPU 1 having a control means including an OM11A
A recording medium P backed up by a battery to the address bus and data bus of 0 A and set by the display operation unit 4.
RAM 12 that stores a value such as a threshold value of the thickness of the recording medium P based on the type information of A, an A / D converter 13 that converts an analog value into a digital value, and a transfer high voltage and the like according to a command from the CPU 10A. ON / OF of load
CPU 10 and I / O port 14 for giving F control signal
D / generates an analog control value for analog control of each load including transfer high voltage according to a command from A.
The A converter 15 and the display operation unit 4 are connected to each other. The A / D converter 13 also includes a recording medium P.
The thickness detection sensor 630 for detecting the thickness of the I / O port 14 and the D / A converter 15 is connected to
The transfer high voltage generating circuit 16 is connected. The transfer high voltage generating circuit 16 outputs the transfer high voltage proportional to the analog control value from the D / A converter 15 from the I / O port 14.
It is generated based on the N signal. In this way, by providing the thickness detection sensor 630 on the paper feed / conveyance path, the thickness of the recording medium P fed for the image formation is detected before the image formation. You can Then, the analog signal detected as the thickness of the recording medium P is converted into a digital value by the A / D converter 13.

The CPU 10A has a thickness detecting sensor 63.
Based on the thickness detection result detected by 0, the type of the recording medium P used for image formation is determined, and the determined recording medium P is determined.
Of the recording medium P and the type of the recording medium P input by the display operation unit 4 are determined, and if they are the same, control information for forming an image according to the type of the recording medium P is determined.
And controls the, if they do not match, and an image is formed prohibition processing such as warning or an image formation stop. This CPU1
In the image forming control performed by 0A, optimum control is performed by sending control data determined by the detected thickness value of the recording medium P and the type of the input recording medium P to the D / A converter 15. Value to D / A converter 15
And a load ON signal is generated by the I / O port 14, and the transfer high voltage generator 16 is controlled in accordance with the timing of image formation to apply a transfer high voltage in an amount according to the thickness of the recording medium P. Is supposed to do. Here, the determination can be performed by calculation by the CPU 10A, numerical value conversion by a lookup table, or the like.

The ROM 11A stores the sequence program as described above, and, for example,
Thickness range D _{2L to} D _2U corresponding to “PG2”, “PG8”
The thickness information Dn of the recording medium P is stored in association with each PG _n , as in the thickness range D _{8L to} D _8U corresponding to.

Next, the operation of the first embodiment will be described with reference to FIGS. 6 and 7.
It will be described in accordance with the flowchart of. FIG. 6 shows a recording medium P
7 is a flowchart showing a setting process, and FIG. 7 is a flowchart showing a sequence for controlling the transfer high voltage according to the type of the recording medium P.

First, the setting process of the recording medium P will be described with reference to the flowchart of FIG. This setting process is
It is performed based on a registration operation by a service person when the copier 1A is installed.

When the service person selects the setting mode,
The CPU 10A executes the selected setting mode. C
The PU 10A displays a setting mode screen as shown in FIG. 2 on the display operation unit 4 along with the execution of this setting mode (S
1). The display color of each PG key 40 is determined by the value of the flag FPG _n indicating the “PG” state.
The CPU 10A continues to confirm the input of the setting end key 41 (S2), and also the PG corresponding to the type of each recording medium P.
The input of the key 40 is confirmed (S3). The service staff is P
When the G key 40 is pressed and input, the CPU 10A changes the flag FPG _n corresponding to the input PG key 40 to a state different from the current state (S4). And
The CPU 10A changes the display of the PG key 40 based on the state of the flag FPG _n (S5). This series of input operations is repeated. When the service person finishes the setting and presses the setting end key 41 to input (S2), the CPU 10A
By inputting the setting end key 41, it is judged whether the flag FPG _n of each “PG” is 1 by exiting the setting mode (S6, 7, 8, 10), and the flag “PG” is 1
_n ”, the corresponding data D _n regarding thickness is RO
Read from M11A and store in RAM12 (S
9). As shown in FIG. 2, in the step S3,
When PG keys 40 indicated by "PG2" and "PG8" is pressed, the RAM 12, the thickness range D _2L to D _2U corresponding to "PG2", thickness range corresponding to "PG8" D
_{8L to D8U} are stored. In this way, the setting process of the recording medium P to be used is completed.

Next, the control of the transfer high voltage according to the type of the recording medium P will be described with reference to the flowchart of FIG.

The user operates the display / operation unit 4 to set various modes for image formation (S11), and operates the display / operation unit 4 to input a copy start (S).
12), the CPU 10A starts the paper feeding sequence (S13). The thickness detection sensor 630 is a CPU
Under the control of 10 A, the thickness is detected when the registration roller 629 holds the recording medium P, and the detection result is input to the A / D converter 13. A / D converter 1
3 outputs the input analog thickness detection result to the CPU 10A as a digitized thickness value D (S1).
4). CPU10A determines whether within the thickness range D _2L to D _2U corresponding to the selected "PG2" (S1
5) If it is within the range, the control data C defining the analog control amount of the transfer high voltage is set to C = C ₂ (S1).
6). Further, the CPU 10A determines whether or not it is within the thickness range D _{8L to} D _8U corresponding to the selected “PG8” (S
17) If it is within that range, the control data C defining the analog control amount of the transfer high voltage is set to C = C8 (S1).
8). The thickness value D is in the thickness range D _{2L to} D _2U and D _{8L to} D
_In cases other than _8U , the control data C is set to C = C ₀ (S1
9) A warning screen is displayed on the display operation unit 4 informing that the used recording medium P is not a registered recording medium (S20), and the user is asked whether or not to execute the copy operation. It is judged by the input (S21). here,
If the copy is not executed, the sequence ends. When executing the copy, the control data C is transferred to the D / A converter 15 in the same manner as when it is determined to be "PG2" or "PG8".
, An analog control amount corresponding to the control data C is set (S22), and an image forming sequence including generation of a transfer high voltage is performed based on the analog control amount (S23).
The process ends.

Here, there are two types of registered recording media P, “PG2” and “PG8”, and the CPU
Although the sequence in which the control amount is determined by 10A by the comparison calculation is used as an example, the method for determining the number of sections and the control amount is not limited to this.

According to the first embodiment as described above, the thickness detecting section 630 for detecting the thickness of the recording medium P and the display operating section 4 for setting and inputting the type of the recording medium P are provided and used together. Thus, the type of the recording medium P can be accurately discriminated, and various factors for image formation can be appropriately changed based on the discrimination result, so that an image suitable for the recording medium P can be formed. Further, in the case of a recording medium P such as a paper other than the designated paper, which is considered to have a problem in image formation or paper conveyance, a machine abnormality occurs due to an image formation prohibition process such as a warning to the operator or an image formation stop. Can be prevented in advance.

Next, a second embodiment of the present invention will be described.

The electronic copying machine 1B of the second embodiment has a copying machine body 1a as in the case of the first embodiment, and an original table 2 and an original platen 3 are provided on the upper surface of the copying machine body 1a. A display operation unit 4 as an input unit that displays various information and can input various information, such as a touch panel and a liquid crystal display, is arranged. Also, this copying machine body 1a
As in the first embodiment, the reader unit 5 and
The printer unit 6 is arranged.

The display / operation unit 4 uses the recording medium P to be used.
When registering, the setting mode screen is displayed, and the setting end screen is displayed on the setting mode screen.

Further, in the first embodiment, the display operation unit 4 is used as a means for inputting the type of the recording medium P to be used, but the electronic copying machine 1B of the second embodiment instead uses A barcode reader unit 17 for reading a barcode attached to the recording medium P is provided.

In recent years, beginning with image quality adjustment of cameras, even in copying machines, a bar code is attached to the characterized image quality sample, and various settings expressing the characteristics of the image sample are changed by reading the bar code. It has been practiced to perform such image quality adjustment. In such a model, a bar code reader can be used as an input means. Each ordinary recording medium P is provided with a barcode used for distribution, and the type of the recording medium P can be input by reading the barcode. In the setting mode, the bar code of each recording medium P to be used is read, the type of the read recording medium P is recognized,
The data D regarding the recognized thickness of the recording medium P can be read from the ROM 11B to the RAM 12 as in the first embodiment.

FIG. 8 is a schematic block diagram of the fixing device 626.
The fixing device 626 includes a fixing roller 901 which is rotatably arranged and has a heating heater 906a such as a halogen lamp as a heating means therein, and a heating heater 906b such as a halogen lamp as a heating means.
A pressure roller 902 that rotates while being pressed against 01 to hold the recording medium P between it and the fixing roller 901; a release agent application device 903 as a release agent supply application means; and cleaning devices 904a and 904b. A temperature measuring unit 907 such as a thermistor, which is in contact with one or both surfaces of the fixing roller 901 and the pressure roller 902 and measures the temperature of the roller, and a motor 908 that rotationally drives the pressure roller 902. A heat roller fixing system that includes a recording medium P sandwiched between the rollers 901 and 902 to heat and pressurize an unfixed developer image on the recording medium (transfer medium) P to fix the image on the transfer medium. belongs to. The temperature measuring device 907 outputs a signal of the detected temperature to the CPU 10.

FIG. 9 is a block diagram showing the control system of the second embodiment.

The electronic copying machine 1B of the second embodiment has a central processing unit (CP) which controls the sequence of the copying machine 1B.
U) R storing a sequence program including 10B and thickness information and various control information for image formation
A CPU 1 having a control means including an OM11B
A value such as a threshold value of the thickness of the recording medium P based on the type information of the recording medium P input by the barcode reader unit 17 is stored in the 0B address bus and data bus R.
AM12 and A / D that converts analog value to digital value
The converter 13, the bar code reader 17 for inputting the type of the recording medium P, and the timer circuit 1 for generating a signal of a frequency that changes based on the data from the CPU 10B.
8 and ON / O of each load by the command from CPU 10B
Heating heater 906 based on the I / O port 14 that gives the FF control signal and the ON signal from the I / O port 14
heater drive circuit 19 for supplying electric current to a and 906b
And ON / OF by the ON signal from the I / O port 14.
The motor drive unit 19 drives the motor 908 at a rotation speed according to the reference frequency signal from the timer circuit 18.
And a heater driving unit 20 that drives the heaters 906a and 906b.

The CPU 10B has rollers 901 and 902 based on the temperature information input from the temperature measuring unit 907.
The surface temperature of as is maintained in the range of the temperature range T ₁ through T ₂ necessary for fixing, and performs the control of the heater drive unit 20. In this way, the fixing temperature is controlled by the CPU.
This is possible by changing the temperature range values T ₁ and T ₂ managed by 10B. Further, the CPU 10B is adapted to control the fixing speed as follows. Usually, when a considerably large load torque is required for rotational driving like a fixing device, a DC motor is applied to the motor 908. In this DC motor, the rotation frequency can be controlled by detecting the rotation frequency of the rotor with a Hall element or the like and performing PLL control on the frequency with respect to the reference frequency. Therefore, the rotation speed can be changed by changing the reference frequency. The fixing temperature is changed by changing the value of the temperature setting range based on the input type of the recording medium P and the detection result of the thickness of the recording medium P, and the rotation reference frequency of the fixing drive motor is changed by a counter circuit or the like. By controlling with the timer circuit 18, the fixing speed can be controlled. The generation of each control value for the thickness value of the recording medium P is the same as in the first embodiment.
The calculation by the CPU 10B and the use of a look-up table can be considered. Also, when setting the fixing speed,
Besides the use of the timer circuit 18 described above, it can be realized by a circuit that selects one frequency from a plurality of reference frequencies.

Next, the setting process of the recording medium P of the second embodiment will be described with reference to the flowchart of FIG.

When the service person selects the setting mode,
The CPU 10B executes the selected setting mode. C
The PU 10B displays the setting mode screen on the display operation unit 4 along with the execution of the setting mode (S21). While the input of the setting end key is continuously confirmed (S22), the input from the barcode reader unit 17 is confirmed (S23). When there is an input from the bar code reader unit 17 by the operation of the service person, the CPU 10B determines the type of the recording medium P corresponding to the input (S24), and corresponds to the determined type of the recording medium P. The thickness D and control information to be stored are read from the ROM 11B and stored in the RAM 12 (S25), and this series of input operations is repeated. When the service person finishes the setting and presses the setting end key to input (S22), the CPU 10B ends the setting mode by inputting the setting end key.

As the thickness of the recording medium P becomes thicker, the amount of heat applied from the back side cannot participate in fixing, and as a result, it becomes necessary to give a larger amount of heat. Thus, there are two points of control of the amount of fixing heat that can be varied during image formation: the fixing temperature and the fixing speed. That is, when more heat is required, the fixing temperature may be higher and the fixing speed may be slower. Therefore, according to the second embodiment, as in the case of the transfer high voltage of the first embodiment, the fixing heat amount control is performed as a parameter of the electrophotographic process in consideration of the difference in the type of the recording medium P.
It is possible to maintain the optimum image quality.

The first example of controlling the transfer high voltage in order to maintain the optimum image quality depending on the type of the recording medium P
However, the transfer high voltage is the same during one image formation, and cannot cope with the difference in the transfer characteristics depending on the thickness of the recording medium P in the light and shade of the image in one image. .
Therefore, when performing control according to the density of each pixel,
It is necessary to control digital image processing factors such as γ correction. Therefore, similarly to the heat quantity control, it is possible to change the γ correction coefficient of the image processing according to the type of the recording medium P. Further, in the present embodiment, since the linear paper feeding is possible from the manual paper feeding unit 624, various recording media P are fed, whereas the other paper feeding units are so-called normal type. The recording medium P is fed. Therefore, the application of the setting of the image forming mode based on the determination result of the type of the recording medium P designated and registered can be changed by the paper feeding unit. Therefore, a third embodiment that enables such processing will be described below.

The electronic copying machine 1C of the third embodiment has a copying machine body 1a as in the second embodiment, and the original table 2 and the original platen 3 are provided on the upper surface of the copying machine body 1a. And a display operation unit 4 as an input unit that displays various information and can input various information, such as a touch panel and a liquid crystal display. Further, inside the copying machine main body 1a, as in the second embodiment, the reader unit 5 is provided.
And the printer unit 6 are arranged.

FIG. 11 is a block diagram showing the control system of the third embodiment.

The electronic copying machine 1C of the third embodiment has a central processing unit (CP) which controls the sequence of the copying machine 1C.
U) R which stores a sequence program including 10C and thickness information and various control information for performing image formation
A CPU 1 having a control means including an OM11C
A RAM 12 for storing a value such as a threshold value of the thickness of the recording medium P based on the type information of the recording medium P set by the display operation unit 4 on the address bus and data bus of 0C,
A / D converter 1 that converts analog values into digital values
3, the gamma correction unit 547, and the bar code reader unit 17 similar to those in the second embodiment are connected to each other. Although not shown, the third embodiment has a motor drive unit 19 and a heater drive unit 20 as in the second embodiment.

The γ correction section 547 has a look-up table (LUT) for γ correction. This LUT
The contents of .gamma. Characteristics corresponding to the difference in the thickness of the recording medium P are recorded in each of the banks B0 to B3. The γ correction unit 547 selects a bank based on the bank selection signals S0 and S1 sent from the I / O port 14, and corrects the input image data according to the γ characteristic corresponding to the thickness of the recording medium P. To do.

The CPU 10C selects the bank selection signal S0 of the look-up table (LUT) for performing the γ correction in the γ correction unit 547 based on the determination result of the type of the recording medium P.
The S1 is generated by the I / O port 14 and sent to the LUT. In this way, the bank selection signals S0, S1
The image data is corrected according to the γ characteristic corresponding to the detected thickness of the recording medium P by selecting the bank by, and the image formation is performed based on the corrected image data. It is possible to form an image according to the above.

Next, a flow chart of a sequence for controlling the fixing heat quantity and the γ correction according to the recording medium P of the third embodiment will be shown.

When the user operates the display operation unit 4 to set various modes for image formation including the setting of the paper feed unit (S31), and operates the display operation unit 4 to input the copy start. (S32), the CPU 10C starts the paper feed sequence (S33). Then, the thickness detection sensor 6
30 is a registration roller 6 under the control of the CPU 10C.
When the recording medium P is sandwiched by 29, the thickness is detected,
The detection result is input to the A / D converter 13. A /
The D converter 13 outputs the input analog thickness detection result to the CPU 10C as a digitized thickness value D (S34). The CPU 10C selects the selected "PG
2 ”is within the thickness range D _{2L to} D _2U (S3
5), if it is within that range, the fixing rollers 901, 90
The control data CT defining the temperature of 2 is CT = CT2, and the control data CS defining the fixing speed is CS = CS2.
Then, the γ table selection signal is set to S0 = 0 and S1 = 1 (S36). It is determined whether or not the thickness value D is within the thickness range D _{4L to} D _4U (S37), and if it is within the range,
The control data CT defining the fixing roller temperature is CT = CT
4, and the control data CS defining the fixing speed is CS = C
S4 and γ table selection signals S0 = 1 and S1 = 0 are set (S38). If the thickness value D is other than that, check the paper feed unit flag. P indicating paper feeding from the manual paper feeding unit 624
In the case of F = 0, the fixing roller temperature control data CT which is the most appropriate data based on the detected thickness value D.
= CT0, fixing speed control data CS = CS0, and γ table selection signals S0 = 1 and S1 = 0 are determined (S3
1). Then, the fixing control temperature is changed based on the control data CT, and the timer circuit 1 is changed based on the fixing speed control data CS.
By setting 8, the frequency is sent to the motor drive unit 19, and the γ correction table selection signals S0 and S1 are sent to the γ correction table (S32). Then, an image forming sequence including heat fixing and γ correction by the fixing heat amount based on these control amounts is performed (S33), and the process is ended. If PF = 0 is not set in step S39, an error processing is performed to display that the image cannot be formed because the recording medium P is not registered and the recording medium P held by the registration roller unit is removed. (S4
0), the process ends. In addition, thickness values D _{2L to} D _2U , D _4L
To D _4U are “PG2” and “PG” of the types of the recording medium P which are read and registered by the barcode reader unit 17 in advance.
4 ”is a value indicating the thickness range.

Here, the thickness of the medium is divided into three sections, and C
Although the sequence in which the PU determines the controlled variable is taken as an example, the method for determining the number of sections and the controlled variable is not limited to this.

[0061]

According to the present invention described in detail above, the following effects can be obtained.

According to the invention described in claim 1, the detecting means
It is used for image formation based on the detected attribute information.
The type of image recording medium
Discriminate among the types of image recording media,
Control information for image formation according to the type of recording medium
Since it is changed , it is possible to provide an image forming apparatus capable of forming a suitable image according to the type of the image recording medium.

[0063]

According to the second aspect of the invention, the image quality can be optimized according to the thickness of the image recording medium.

According to the third aspect of the present invention, it is possible to form a suitable image according to the type of the image recording medium by controlling the transfer current value, the fixing heat amount, the γ correction for the image data, and the like.

[0066]

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a present embodiment.

FIG. 2 is a configuration diagram of a thickness detection sensor of the present embodiment.

FIG. 3 is a block diagram of an image processing unit of this embodiment.

FIG. 4 is a diagram showing an example of a setting mode screen of the display operation unit of the first embodiment.

FIG. 5 is a block diagram showing a control system of the first embodiment.

FIG. 6 is a flowchart showing a recording medium setting process of the first embodiment.

FIG. 7 is a flowchart showing a sequence for controlling the transfer high voltage according to the first embodiment.

FIG. 8 is a configuration diagram of a fixing device according to a second embodiment.

FIG. 9 is a block diagram showing a control system of a second embodiment.

FIG. 10 is a flowchart showing a recording medium setting process of the second embodiment.

FIG. 11 is a block diagram showing a control system of a third embodiment.

FIG. 12 is a flowchart showing a sequence for performing fixing heat amount control and γ correction control according to the third embodiment.

[Explanation of symbols]

1A, 1B, 1C Electronic copying machine (image forming apparatus) 4A Display operation unit (input means) 10A, 10B, 10C CPU (control means) 11A, 11B, 11C ROM (control means) 12 RAM 17 Bar code reader section (input means) 547 γ correction unit 630 Thickness detection sensor (detection means) P recording medium

Continuation of the front page (56) Reference JP-A-5-16475 (JP, A) JP-A-5-341604 (JP, A) JP-A-5-43091 (JP, A) JP-A-7-210059 (JP , A) JP-A-6-113112 (JP, A) JP-A-4-138485 (JP, A) JP-A-6-167849 (JP, A) JP-A-7-43967 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 21/00 370-512 G03G 15/00 303 G03G 15/00 510 G03G 15/20 109

Claims (3)

(57) [Claims] 1. A forming image information on the image forming medium, an image forming apparatus for transferring an image that is formed on the image recording medium, input means for inputting the type of the image recording medium to be used, pre-Symbol image detecting means for detecting attribute information of the recording medium, wherein based on the detected attribute information by the detecting means, the input hand the type of image recording medium to be subjected to the image formation
Image forming, characterized in that a control means determines from the type of image recording medium inputted by the stage, changing the control information for performing image formation according to the type of the discriminated image recording medium apparatus. Wherein said attribute information includes the image forming apparatus according to claim 1 Symbol mounting, characterized in that the thickness information. 3. The control information for performing the image formation includes:
7. At least one of a transfer current value, a fixing heat amount, and γ correction for image data is included.
1 Symbol placing the image forming apparatus.