JP2000284665A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image forming device capable of detecting whether the state of a fixed image is good or bad and further detecting the dispersion of the state of the fixed image on one recording body. SOLUTION: When fixing test images TX and TY are formed on the recording body S periodically or according to selection by an operator, an image color information detection part 43 detects the intensity IbRX, IbGx, IbRX and IbRY, IbGY, IbRY of the straight advance transmitted light of the images TX and TY color-separated by RGB filters 39X and 39Y. A supervisory control part obtains the welded state of toner on the fixing test image by referring to table data based on the intensity information, judges the image state and further detects the dispersion of the image state. By utilizing that the non- uniformity and the non-conformity of the fixing condition of a fixing device and the image forming condition of a developing device, etc., are estimated based on the judged result and the calculated dispersion, the supervisory control part changes the control value of a driving control part, etc., so as to reflect it on the fixing condition and the image forming condition, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile. More specifically, the present invention relates to an image forming apparatus capable of detecting an image state after fixing without visually recognizing the image state.

[0002]

2. Description of the Related Art For example, in an image forming apparatus such as an electrophotographic copying machine, a permanent image is obtained by fixing a toner image transferred to a recording medium. Here, as a fixing method, there are methods such as heat fixing, pressure fixing, and solvent fixing. Among them, a heat roller type fixing device using heat fixing is widely and generally used. As this fixing device, for example, a fixing device including a heating roller and a pressure roller is known. The heating roller is a metal roller having good heat conduction and small heat capacity. The heating roller has a heater lamp inside, and the surface temperature is detected by a thermistor or the like, and the temperature is controlled so as to be within a predetermined fixing temperature range. On the other hand, the pressing roller has a core material whose surface is coated with elastic silicon rubber or the like. The heating roller and the pressure roller are rotatably supported in a state where they are pressed against each other. When the recording material on which the toner image is transferred passes between the heating roller and the pressure roller, the toner melts. At the same time, the toner image is pressed against the recording medium to fix the toner image, thereby obtaining a permanent image. In the fixing device provided in the color image forming apparatus, the surface of the heating roller is also covered with silicone rubber.

Here, when thick paper or an OHP sheet having a large heat capacity is used as a recording medium, if fixing is performed under the same conditions as plain paper, the toner does not sufficiently melt, which may result in poor fixing. There is. For this reason, a good image state is ensured by supplying a larger amount of heat than supplying plain paper by raising the fixing temperature or lowering the fixing speed.

[0004]

However, in the conventional apparatus, it was not possible to detect the quality of the image of the fixed image fixed on the recording medium. Therefore, for example, in a conventional image forming apparatus, when a recording medium different from the supposed basis weight or type is used, or when an abnormality in the temperature control of the heating roller occurs, a defective melting of the toner, etc. Therefore, there is a possibility that a good image state cannot be obtained. In addition, if there are variations in fixing conditions and image forming conditions, such as variations in the temperature of the heating roller in the axial direction (temperature distribution) and variations in the distance between the rollers in the axial direction,
When the image state of the fixed image partially fluctuates and a good image state and a poor image state are formed in the fixed image formed on one recording medium, and a uniform image state cannot be obtained. There was also. However, the image quality in these cases could not be confirmed until the fixed image was visually recognized.

Further, when a large number of copies are made at one time, it is troublesome to check the image condition of the whole or a part for each sheet. Is common. Further, when an OHP sheet was used as a recording medium, the quality of the whole or a part of the image was not known until an actual translucent image was visually recognized by a projector. For this reason, when the image after copying is visually recognized, if the image state is defective, a lot of time must be spent to make a copy again, or an unsatisfactory OHP sheet must be used. Had occurred.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an image capable of detecting the quality of an image state of a fixed image and detecting a variation in the image state of the fixed image on one recording medium. It is an object to provide a forming apparatus.

[0007]

According to the image forming apparatus of the present invention which has been made to solve the above problems, there is provided an image forming means for forming an image on a recording medium, and an image forming means for forming an image on the recording medium. A fixing unit for fixing the image formed on the recording medium, the light emitting element irradiating light to the fixed image fixed on the recording medium by the fixing unit; and An image color information detecting unit including a light receiving element for detecting color information of light transmitted or reflected through the fixed image, a spectral filter provided between the light emitting element and the light receiving element, and the image color information detecting unit And an image color information detecting means for processing the color information detected in the step (a), wherein the image color information detecting means transmits the fixed image at at least two or more different positions in the recording medium. Others can detect the color information of the light reflected, respectively.

In this image forming apparatus, first, an image forming means forms an image (toner image) on a recording medium. Next, the fixing unit fixes the image created by the image creating unit on the recording medium. Then, the image color information detecting means detects the color information of the fixed image fixed on the recording medium. The detection of the color information is performed as follows. First, a light emitting element irradiates a fixed image on a recording medium with light. Then, light transmitted or reflected by the fixed image is received by the light receiving element. At this time, since a spectral filter is provided between the light emitting element and the light receiving element, light received by the light receiving element is transmitted light or reflected light passing through the spectral filter. That is, the image color information detecting means obtains the color information by detecting the intensity information of the transmitted light or the reflected light of the fixed image color-separated through the spectral filter. Here, examples of the spectral filter include an RGB filter having three color filters of red (R), green (G), and blue (B).

After that, the image color information processing means processes the color information of the fixed image detected by the image color information detecting means. Therefore, by using the processing result, for example, by reflecting (feeding back) the processing result on the fixing condition, the image forming condition, and the like so as to improve the image state, a good fixed image is automatically generated. Can be controlled. Further, the image state of the fixed image can be evaluated, and a warning or a serviceman call can be displayed to the operator.

In particular, since the image color information detecting means obtains the color information of the fixed image at at least two or more different positions on the recording medium, it calculates the difference between the color information at each measurement point and By evaluating the variation of the image state in the sheet recording body, for example, the variation of the image state in the transport direction or the direction intersecting (for example, orthogonally) to the transport direction,
The processing result can also be reflected in the fixing conditions and the like so as to suppress variations in the conveyance direction such as the fixing conditions such as the temperature distribution in the axial direction of the heating roller and the direction perpendicular thereto.
Further, even when it is determined that the image state is defective for a part of the recording medium, a warning or a serviceman call can be displayed to the operator.

Further, by calculating the average value or removing the abnormal value, the accuracy of the quality evaluation of the fixed image can be improved. When the color information of the fixed image is detected at only one place and the noise is superimposed on the detection result due to any cause, the quality of the fixed image cannot be accurately evaluated. This is because such a situation can be avoided by detecting the color information.

The reason why the color information of the fixed image is detected and processed in this way is that the color information can be used as one of the indexes for evaluating the image state of the fixed image. For example, for some reason, cyan (C), magenta (M), yellow (Y)
If any of the toners is insufficiently fused,
The brightness becomes low, and the image becomes a dull image state in which the predetermined saturation is not reproduced. On the other hand, when all of the cyan (C), magenta (M), and yellow (Y) toners are sufficiently melted, a clear color image state is obtained in which the brightness is sufficiently high and a predetermined saturation is secured. .

To explain with reference to the drawings, when fixing is performed well, toners CT (cyan), MT (magenta), and YT (yellow) on the recording material S as shown in FIG. ) Is sufficiently melted, and each color toner C
Since the layer surfaces of T, MT, and YT are all smooth, the intensity of the linearly transmitted light for each color increases. On the other hand, if reflected light is used, the intensity of specularly reflected light (directly reflected light) increases. For this reason, a good image is obtained in which the brightness is sufficiently ensured, and thus the predetermined saturation is obtained.

On the other hand, if the fixing is not good, FIG.
As shown in FIGS. 0 to 22, one of the toners CT, MT, and YT attached to the recording medium S does not melt, and the surface of the insufficiently melted toner layer is not smooth but uneven. Since the incident light is refracted and transmitted by the insufficiently melted toner layer, the intensity of the refracted transmitted light increases and the intensity of the straight transmitted light decreases. More specifically, in FIG. 20, the incident light is refracted by the toner CT, and in FIG.
Incident light is refracted in FIG. 22, and in FIG.
The incident light is refracted at T and CT. On the other hand, if the reflected light is used, the incident light is diffused, the intensity of the specularly reflected light decreases, and the intensity of the diffusely reflected light for each color increases. For this reason, the image becomes a dull image with low brightness and in which the predetermined saturation is not reproduced.

Therefore, by detecting the color information of the linearly transmitted light, the refracted transmitted light, the specularly reflected light, or the diffusely reflected light, it is possible to determine whether the image state of the fixed image including the fused state of each color toner layer is good. You can do it. The straight transmitted light refers to a transmitted light in which incident light incident on a fixed image travels straight without being bent by refraction or the like (in the following description, “straight transmitted light” has the same meaning).
), The refracted transmitted light refers to transmitted light whose path has been bent due to refraction or the like of incident light incident on a fixed image (in the following description, "refracted transmitted light" is used in the same sense). In addition, the specularly reflected light (directly reflected light) refers to the incident angle of the incident light incident on the fixed image on the incident surface formed by the incident light and the normal line of the fixed image at the incident point in the reflected light. Reflected light that is reflected and travels at the same angle of reflection is referred to as “specular reflected light” in the same sense in the following description.
), The diffusely reflected light refers to the reflected light of the reflected light, which is incident on the fixed image, is diffused by unevenness of the fixed image and travels in a direction other than the direction of regular reflection (the following description). In the same manner, "diffuse reflected light" is used in the same sense).

The use of transmitted light for evaluating the image state of a fixed image is advantageous in that it is less susceptible to deformation such as waving or curling of the recording medium, and is particularly advantageous when an OHP sheet is used as the recording medium. It is very preferable to use the transmitted light since the image state of the fixed image can be evaluated in the same state as when the OHP sheet is actually used. On the other hand, the use of reflected light for evaluating the image state of a fixed image is advantageous in that it is less affected by the type of recording medium.

In addition to the plain paper, any recording medium may be used as long as it can fix an image, such as a thick paper, an OHP sheet, or a special paper coated with a resin. Further, any light-emitting element may be used as long as it emits light in the visible light region. For example, a halogen lamp, a light emitting diode, a semiconductor laser, and the like can be given. On the other hand, the light receiving element only needs to have a sensitivity range that responds to light emitted from the light emitting element.
For example, a CCD, a photodiode, and the like can be given. In addition, in order to obtain the transmittance and the reflectance, the intensity of incident light is necessary in addition to the intensity of transmitted light. Therefore, the intensity of the incident light may be separately detected in addition to the transmitted light. However, when the intensity of the incident light is known, such as when the intensity is constant, the evaluation can be performed only with the intensity of the transmitted light. In addition, for measuring the intensity of the incident light, a method of directly measuring the intensity using a half mirror or the like can be cited.
There is also a method of indirectly measuring from power consumption and the like.

Further, in the image forming apparatus according to the present invention, the image color information detecting means includes two or more sets of the light emitting element, the light receiving element, and the spectral filter in a direction intersecting with a conveying direction of the recording medium. It is desirable to have a set.

By providing two or more sets of the light emitting element, the light receiving element, and the spectral filter in the direction intersecting the transport direction of the recording medium, the direction of the recording medium intersecting the transport direction is provided. , Color information of a fixed image can be detected at two or more different positions. Thus, for example, it is possible to detect whether there is a change in the fixing condition or the image forming condition in the direction orthogonal to the transport direction among the fixing units, such as the temperature distribution in the axial direction of the heating roller. Therefore, if the color information of the fixed image in the direction intersecting with the conveyance direction of the recording medium varies, the fixing conditions (temperature, pressure, oil application amount, etc.) and the like in the direction orthogonal to the conveyance direction among the fixing means and the like. Since it can be estimated that there is some variation in image forming conditions (such as charge voltage),
An abnormality such as a fixing condition can be detected. Therefore, as described above, it is possible to suppress the variation by reflecting the processing result on the fixing condition or the like, or to know the quality of the image state and notify the operator of the quality.

Further, in the image forming apparatus according to the present invention, the image color information detecting means includes at least one of the light emitting element and the light receiving element movable in a direction intersecting a conveying direction of the recording medium. It can also be.

As described above, at least one of the light-emitting element and the light-receiving element can be moved in a direction intersecting the conveying direction of the recording medium, so that one light-emitting element or light-receiving element, or one set of light-emitting elements can be used. The color information of the fixed image at two or more different positions on the recording medium can be detected in the direction intersecting the conveyance direction of the recording medium only by using the set of light receiving elements. That is, the same effect as when two or more sets of light emitting elements and light receiving elements are provided in a direction intersecting the transport direction can be obtained. Therefore, even in this case, it is possible to detect whether or not there is a change in the fixing condition or the image forming condition in the direction orthogonal to the transport direction among the fixing units and the like. Further, it is possible to detect an abnormality of the fixing unit or the like. As a result, it is possible to suppress the variation by reflecting the processing result on the fixing condition or the like, or to notify the operator of the quality of the image state.

In the case where only the light-emitting element is movable, a plurality of light-receiving elements may be arranged corresponding to the positions where color information is detected. In this case, a plurality of light emitting elements may be arranged corresponding to the positions where color information is detected.

According to the image forming apparatus of the present invention, the image creating means has a test image data memory for storing test image data for creating a predetermined test image on the recording medium. The image color information detecting means detects color information of light transmitted or reflected by the fixing test image fixed on the recording medium, and the image color information processing means processes the color information of the fixing test image. .

By using the fixing test image obtained from the previously stored test image data, the position of the fixed image whose color information is to be measured is known in advance. Color information on a fixed image can be reliably obtained. Therefore, it is possible to reliably determine the quality of the image state and the variation in the image state of one recording medium, and reflect the processing result of the obtained color information on the test image in the fixing condition, the image forming condition, and the like. As a result, the image state can be improved, and variations in the image state can be suppressed. Further, by performing a process of comparing the obtained color information with ideal color information expected from the test image data (that is, the originally expected color information), it is possible to easily and accurately determine the quality of the image state and its variation,
Alternatively, it can be reflected on fixing conditions and the like.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An embodiment of an image reading apparatus according to the present invention will be described in detail with reference to the drawings. First, the first embodiment will be described. A first embodiment is an electrophotographic copying machine equipped with an image forming apparatus according to the present invention,
In addition to copying a document image, a predetermined test image is created to grasp the image state of the fixing test image.

As shown in FIG. 1, the copying machine 1 includes an image reader section IR and a page printer section PRT. Then, based on the image data transferred from the image reader section IR, the page printer section PRT prints the image of the document by an electrophotographic process.

The image reader section IR includes an original glass 10
An image reading unit 2 that detects reflected light from an image of a document set thereon, photoelectrically converts the reflected light, and reads image data corresponding to the image of the document, and an image that performs data processing according to various image forming modes. And a processing unit 3. Note that the image reading section 2 includes a data memory section 9 for temporarily storing the read image data. A document cover 11 for holding a document is mounted above the image reader IR.

On the other hand, the page printer section PRT has an optical scanning section 4, an image processing section 5, and a transport section 6.
The optical scanning section 4 includes a polygon mirror 21 and a reflection mirror 22 for scanning and irradiating the photosensitive drum 30 with laser light. The image processing unit 5 includes a photosensitive drum 30, a charging charger 31, and developing units 32Y and 3
2C, 32M, 32K, a transfer drum 34 having a transfer charger 33, and a cleaning device 35. The transport unit 6 includes a paper cassette 44 for stacking and storing the recording medium.
And various transport rollers for transporting the recording medium supplied from the paper cassette 44 or the manual feed tray 45; a fixing device 40; a halogen lamp 41; a CCD sensor 42;
An image information detection unit 43 including a GB filter 39 and a paper discharge tray 46 for storing a recording medium that has been copied and discharged outside the apparatus are provided.

Here, the image color information detecting section 43 detects the color information of the fixed image. As shown in FIG. 2, for example, as shown in FIG. 2, the image color information detection unit 43 includes two substantially rectangular fixing test images TX arranged near the upper side when the transport direction indicated by the arrow in the recording medium S is directed upward. , TY is the recording medium S
When it is formed above, it is arranged at a position where the color information of the straight transmitted light of the fixing test images TX and TY can be measured. That is, the image color information detection unit 43 is configured by two sets of a light emitting element, a light receiving element, and an RGB filter arranged in a direction intersecting with the conveying direction of the recording medium S (in the present embodiment, orthogonal direction). ing. Specifically, the halogen lamp 41X, the CCD sensor 42X, and the RGB filter 3
9X, halogen lamp 41Y, CCD sensor 42Y and R
It is composed of a light-emitting / light-receiving element pair including two sets of spectral filters of a GB filter 39Y.

The halogen lamp 41X and the CCD sensor 42X are arranged at positions where color information of transmitted light of the fixing test image TX can be measured. That is, a halogen lamp 41X, which is a light emitting element, is provided on the lower side in the drawing of the recording medium S discharged from the fixing device 40 in the conveyance path of the recording medium S behind the fixing device 40. A halogen lamp 4 is provided on the upper side in the figure so as to sandwich the conveyance path of the recording medium S coaxially with the optical axis 41XL.
An RGB filter 39X for color-separating light emitted from 1X and transmitted through the fixing test image TX, and a CCD sensor 42X for receiving transmitted light after the color separation are provided. With the same positional relationship, the halogen lamp 41Y and the CCD
The sensor 42Y and the RGB filter 39Y are also arranged.

Here, the RGB filters 39X (39Y)
Is a disk-shaped rotating plate 38 in which three color filters of a red filter 39R, a green filter 39G, and a blue filter 39B are fitted at equal intervals (equal angles). Then, in accordance with the timing at which the fixing test image TX (TY) passes through the detection area of the image color information detection unit 43, the overall control unit 54 (see FIG.
By driving the rotation motor 37 connected to the
The fixing test image TX (T
The transmitted light of Y) is received by the CCD sensor 42X (42Y).

Note that the halogen lamps 41X and C
The CD sensor 42X, the lamp 41Y, and the sensor 42Y may be arranged at opposite positions. In addition to the case where the optical axis 41XL of the halogen lamp 41X and the recording medium S are orthogonal to each other as shown in FIG. 2, the optical axis 41XL of the halogen lamp 41X and the recording medium S form a predetermined angle as shown in FIG. The halogen lamp 41X and the CCD sensor 42X may be arranged as described above. Also, the arrangement of the RGB filters 39X is such that the light from the halogen lamp 41X is used for fixing test
Halogen lamp 41X so as to separate light before irradiating
And the recording medium S may be provided. The halogen lamp 41Y, the CCD sensor 42Y, and the filter 39Y
The same applies to the arrangement position in the case of.

However, when the halogen lamp 41X (41Y) and the CCD sensor 42X (41Y) are arranged as shown in FIG. 3, the angle between the optical axis 41XL (41YL) and the recording medium is 45 degrees or more. It is desirable. If the angle is smaller than 45 degrees, the component of the reflected light increases, and it becomes impossible to accurately measure the intensity information of the straight transmitted light after color separation. Further, the angle is more preferably 90 degrees (the state of FIG. 2). Thus, the halogen lamp 41X
(41Y) and the CCD sensor 42X (42Y) are less likely to be affected by the thickness of the fixing test image TX (TY) and the rise of the recording medium S during measurement, and the intensity information of the straight transmitted light after color separation. Is more accurately measured.

As described above, the halogen lamps 41X and 41Y
And the CCD sensors 42X and 42Y, the image color information detecting section 43 makes the fixing test images TX and TY
, The color information of the straight transmitted light can be detected. That is, the image color information detection unit 43 includes the CCD sensors 42X and 4
Intensities IbRX and Ib of transmitted light after color separation received by 2Y
By detecting GX, IbBX and IbRY, IbGY, IbBY, the color information of the straight transmitted light of the fixing test images TX and TY is detected. The reason why the color information of the straight transmitted light is detected is that the straight transmitted light has a positive correlation with the quality of the image state as described above, and has a wide measurement range and is strong against noise.

Further, in the image color information detecting section 43,
Incident light intensity (emission intensity) IaRX, IaGX, IaBX (IaRY, IaG) of the halogen lamp 41X (41Y)
Y, IaBY) may also be detected. By calculating the ratio of the two (IbRX / IaRX, etc.) and using this, it is possible to eliminate the influence on the intensity of the transmitted light due to fluctuations in the emission intensity of the halogen lamps 41X and 41Y. In the present embodiment, the halogen lamp 4
The emission intensity of 1X and 41Y was kept constant, and the intensity information of the transmitted light after color separation was used as it was without obtaining the ratio between the two.

Next, a brief description will be given of the operation of the copying machine 1 configured as described above when copying is performed. In the copying machine 1, the following processing is performed in the order of yellow (Y), cyan (C), magenta (M), and black (K) reproduction colors. First, the processing of yellow (Y) will be described. The image reading unit 2 detects yellow (Y) of the original image
Read the image data corresponding to. In addition, the surface of the photosensitive drum 30 rotating in the direction of the arrow in FIG. 1 is uniformly charged by the charging charger 31. Then, the image data read by the image reading unit 2 is input to a laser control unit 59 (see FIG. 4) described later. Then, the laser light is modulated and emitted from the laser light source, and this laser light is scanned in the main scanning direction by the polygon mirror 21, further reflected by the reflection mirror 22, and enters the photosensitive drum 30. As a result, an electrostatic latent image corresponding to the reproduced color of yellow (Y) is formed on the photosensitive drum 30. This electrostatic latent image is developed by the developing device 32Y to become a toner image. This toner image is transferred onto a recording medium S supplied from a paper cassette 44 or a manual feed tray 45 by a transfer charger 33 arranged to face the photosensitive drum 30.

Next, cyan (C), magenta (M),
The processing for black (K) is performed similarly. By these processes, the four color toner images are transferred onto the recording medium S in a superimposed manner. Thereafter, the recording material S to which the toner image has been transferred is heated and pressed in the fixing device 40. As a result, the toner is melted, and the toner image is fixed on the recording medium S to form a full-color image. After the image is fixed, the recording medium is discharged out of the apparatus and stored in the paper discharge tray 46. This completes the copying for one sheet.

Here, a control system of the copying machine 1 for controlling such a copying operation and the like will be described. As shown in the block diagram of FIG.
4 as the center. The general control unit 54 also corresponds to an image color information processing unit, and mainly includes a known CPU.
It is a microcomputer configured by combining a ROM, a RAM, and the like. Various programs and reference data necessary for executing the control of the copying machine 1 are prepared and stored in the ROM incorporated in the general control unit 54 in advance. Note that test image data for creating a test image to be described later is also stored in the ROM. Also,
The RAM is provided with various buffers for temporarily storing numerical values and the like that appear during execution of the arithmetic processing, and for reading out the data as needed.

An input / output port of the general control unit 54 includes an IR control unit 51 for controlling the operation of the image reading unit 2 and a fixing unit 4.
0, a drive control unit 55 for driving and stopping, a conveyance control unit 56 for controlling the supply of the recording medium, and the polygon mirror 21.
A scanner control unit 57 for controlling laser beam scanning by
A high-voltage control unit 58 for controlling high voltages such as charging of the photosensitive drum 30, application of a developing bias and a transfer bias, a laser control unit 59 for performing modulation control of laser light, an image color information detection unit 43, and RGB. Rotating plate 38 such as filter 39X
And a rotation motor 37 for rotating the motor. Further, a signal from the operation panel 53 is input to the overall control unit 54 via the controller 52.

The copying machine 1 is totally controlled by the general control unit 54 and operates as follows. First, control information such as the size and type of the recording medium is input from the operation panel 53 to the controller 52. Next, when the copy button on the operation panel 53 is pressed, a copy request signal is transmitted, and this signal is received by the controller 52. Then, a print command is output from the controller 52 to the overall control unit 54. In response to this command, the general control unit 54 instructs the IR control unit 51 to start reading an image of a document, and also instructs the transport control unit 56 to start supplying a recording medium. Scan preparation is instructed. Also, a command is output to the high-voltage control unit 58 and the photosensitive drum 30
, The developing bias and the transfer bias are set, and preparation for image formation is made. When the image reading of the document by the image reading unit 2 is completed, the laser control unit 59
The read image data is input.

Next, the overall control unit 54 controls the controller 5
2 to output a vertical synchronization request signal and wait for reception of a vertical synchronization signal. Then, when the controller 52 outputs the vertical synchronization signal, the laser light is modulated and emitted based on the image data input to the laser control unit 59. As a result, an electrostatic latent image is formed on the photosensitive drum 30 and the developing device 32Y
(32C, 32M, 32K) to form a toner image. This toner image is transferred to a recording medium, and is
The image is fixed by 0 to form a fixed image.

Here, when the fixing test images TX and TY are created in order to grasp the image state of the fixed image, the laser control section 59 shown in FIG. The stored test image data is input, and a predetermined test image is created by the above procedure. The creation of the fixing test image TX or the like is performed after a predetermined number of copies have been made, after a predetermined operating time has elapsed, or when the operator has selected a test mode from the operation panel 53. .

The fixing test image T includes cyan (C),
Magenta (M), yellow (Y) toner CT, MT,
YT can be used in any ratio to make a patch of any color, which makes it possible to detect the melting state of the toner in various images. In the following, for example, a case will be considered in which a test image is created using 0.5 mg / cm ^{2 of} each of the toners CT and MT of cyan (C) and magenta (M). Here, the molten state of the toner is schematically illustrated for the purpose of a principle explanation, and an ideal state is considered for light absorption and transmission.

First, a state in which the toners CT and MT are completely melted will be described with reference to FIG. In this state, the toner MT absorbs a green component (hereinafter, simply referred to as “G”) of the incident light, and a blue component (hereinafter, simply referred to as “B”) and a red component (hereinafter, simply referred to as “R”). 70%). Further, the toner CT
Absorbs the component and transmits 70% of the B component. Therefore, 49% of the B component is finally transmitted.

Next, a state where the toner CT is completely melted and the toner MT is not melted will be described with reference to FIG. In this state, the toner MT absorbs the G component of the incident light, and transmits 10% each of the B component and the R component.
Further, the toner CT absorbs the R component and reduces the B component by 70%.
To Penetrate. Therefore, the B component is finally transmitted by 7%.

Further, a state where the toners CT and MT are not melted will be described with reference to FIG. In this state, the toner MT absorbs the G component of the incident light, and transmits 10% each of the B component and the R component. Further, toner C
T absorbs the R component and transmits 10% of the B component. Therefore, the B component is finally transmitted by 1%.

From the above description, it can be seen that, for example, the relationship shown in FIG. 8 exists between the fused state and the color information of the fixing test image T. The toner melting degree shown in FIG. 8 indicates how much the toner is melted with respect to the thickness of all the toners, and 0% indicates a state where neither the toner MT nor the CT shown in FIG. 5 is melted. , 50% show a state where only the toner CT shown in FIG. 6 is melted, and 100% show a state where both the toners MT and CT shown in FIG. 7 are melted. Also, when a patch of an arbitrary color is created by using cyan (C), magenta (M), and yellow (Y) toners at an arbitrary ratio, a graph similar to that of FIG. 8 can be obtained. Therefore, by storing such a graph as table data in the general control unit 54 in advance, the color information of the fixing test image T is detected as described below, and the melting state of each color toner is determined based on the table data. Can be grasped.

When the fixing test images TX and TY are created, the image color information detecting section 43 outputs the intensity IbRX and IbGX of the straight-forward transmitted light after color separation of the fixing test images TX and TY created on the recording medium S. , IbBX and IbR
Y, IbGY, and IbBY are measured, and these data are transmitted to the overall control unit 54. Thereafter, the general control unit 54
Is based on the above-described table data.
The melting state of T, MT, YT is determined. Then, since the determination results correspond to the quality of the image states of the fixing test images TX and TY, a fixed image having a good image state can be formed by reflecting the determination results in the fixing conditions and the like.

Further, each of the fixing test images TX and TY
Of the color information in the direction orthogonal to the transport direction of the recording medium S is determined from the difference between the color information. Further, the recording medium S is determined based on the difference between the image states of the fixing test images TX and TY.
Of the image state in a direction perpendicular to the transport direction of the image is evaluated. The variation of the color information corresponds to the variation of the image state in a direction orthogonal to the transport direction of the recording medium S. For example, if any one of the two fixing test images TX and TY has different color information, it indicates that there is a variation in the image state in a direction orthogonal to the conveyance direction of the recording material S. In such a case, the fixing device 40
Temperature distribution in the axial direction of the heating roller 40a is not uniform,
It can be estimated that non-uniformity occurs in a direction perpendicular to the transport direction in any of the fixing conditions, the image forming conditions, and the like, such as a portion having a low temperature.

On the other hand, when the color information of each of the two fixing test images TX and TY is different from the ideal, it can be estimated that the entire fixing conditions, image forming conditions, and the like are not suitable. Accordingly, the overall control unit 54 does not judge whether or not the image state of a part or all of the recording medium S is good or not.
By changing control values of the drive control unit 55, the conveyance control unit 56, the high-pressure control unit 58, and the like, for example, by changing the control temperature of part or all of a, the obtained comparison result and the variation are fixed to the fixing conditions and the image formation. Reflect on the conditions. This allows
A fixed image in a good image state can be formed on the entire recording medium S.

Further, the general control unit 54 calculates the average values IbRm, IbGm, and IbBm of the intensities of the linearly transmitted light after color separation, and refers to the above-mentioned table data.
It is also possible to evaluate the quality of the whole image state of the recording medium S.

Accordingly, the above processing eliminates the need for the operator to visually recognize the image after the copy is completed. Further, even when an OHP sheet is used as a recording medium, it is not necessary to confirm a translucent image by a projector.
In the present embodiment, the halogen lamps 41X, 41
With the emission intensity of Y constant, the intensity information of the transmitted light was used as it was.

As described above in detail, according to the copying machine 1 of the first embodiment, predetermined fixing test images TX and TY are created on the recording medium S periodically or by an operator's selection. You. Then, the image color information detection unit 4
3 is the intensity IbRX, IbGX, IbBX and Ib of the straight transmitted light after color separation of the fixing test images TX and TY
RY, IbGY and IbBY are measured. Then, the overall control unit 54 determines the intensities IbRX, IbGX, and IbBX of the linearly transmitted light after color separation measured by the image color information detection unit 43.
, And IbRY, IbGY, and IbBY, the respective toners CT, MT, and MT in the fixing test images TX and TY.
The melting state of YT is determined. In addition, the fixing test image TX
The variation is calculated by comparing the pieces of color information of TY and TY. By reflecting this determination result and the calculated variation in the fixing conditions and the like, a fixed image having a good image state and no image state variation within one recording medium is formed. Therefore, it is possible to avoid unnecessary copying of the copy and use of an OHP sheet having a poor appearance.

In the first embodiment, two patch-like fixing test images (hereinafter, also simply referred to as "patches") TX and TY are provided near the upper side of the recording material S when the transport direction is upward. Are formed side by side in the left-right direction. However, as shown in FIG. 9, the fixing test image forming pattern is the same as in the present embodiment in the transport direction of the recording medium S (upward in the figure).
In addition to a pattern in which a plurality of (five in this figure) patches TP are created in a direction (horizontal direction in the figure) orthogonal to
As shown in FIG. 10, a pattern in which a plurality of patches TP are created by arranging them in the conveying direction of the recording medium S (vertical direction in the figure).
As shown in FIG. 1, a pattern in which patches TP are formed at four corners of the recording medium S, and a pattern in which a plurality of patches TP are arranged on a diagonal line of the recording medium S as shown in FIG.

Among them, in the pattern shown in FIG. 9, it is possible to evaluate the variation in the image state in the transport direction due to, for example, the variation in the temperature of the heating roller 40a in the axial direction. On the other hand, in the pattern as shown in FIG. 10, it is possible to evaluate the variation in the image state in the transport direction due to the variation in the temperature in the circumferential direction of the heating roller 40a. In this case, the image state and variation of each patch (fixing test image) can be evaluated using a set of a halogen lamp, a CCD sensor, and an RGB filter. Furthermore, in the patterns as shown in FIGS. 11 and 12, it is possible to evaluate at once the variations in both the transport direction and the direction orthogonal thereto.

Further, as in the above embodiment, the recording medium S
In addition to creating only the fixing test image, the fixing test image TP may be superimposed on the actual copy image GA as shown by the broken line in each figure by the selection of the operator. This is because there is no need to waste recording paper for the test.
When the fixing test image TP is superimposed on the copy image GA, an image forming the fixing test image TP on the periphery of the recording medium as shown in FIGS. 9 to 11 may be selected. FIG.
This is because, in the pattern shown in FIG. 5, the copy image GA and the fixing test image TP overlap.

(Second Embodiment) Next, a second embodiment will be described. The copying machine according to the second embodiment has substantially the same configuration as the copying machine 1 according to the first embodiment, and has two pairs of light-emitting / light-receiving elements provided with a spectral filter in an image color information detecting unit. However, the arrangement is different. More specifically, as shown in FIG. 13, the CCD sensors 62X and 62Y in the image color information detection unit 63 look at the intersections PX and PY between the optical axes 41XL and 41YL of the halogen lamps 41X and 41Y and the recording medium S, respectively. And the optical axes 41XL, 4 of the halogen lamps 41X, 41Y.
The difference is that they are arranged at positions deviating from 1YL.

Thus, the image color information detecting section 63 determines the intensity I of the refracted transmitted light after color separation of the fixing test images TX and TY.
cRX, IcGX, IcBX and IcRY, IcGY, I
cBY can be detected. Another difference is that the quality of the image is judged based on the judgment result of the melting state of the toner and the calculated variation and displayed on the operation panel 53 (see FIG. 4). Note that the copy operation and the test image creation operation are the same as those in the first embodiment, and therefore description thereof is omitted, and the same components are denoted by the same reference numerals.

The reason why the image color information detecting section 63 detects the color information of the refraction and transmission light of the fixing test images TX and TY is to easily perform the quality judgment including the variation in the image state of the fixed image. Because it can be. In other words, the refracted transmitted light has a narrower measurement range than the straight transmitted light, but has a negative correlation with the quality of the image state.
This is because the value greatly changes depending on the quality of the image state, so that the quality of the image state can be easily determined.

The incident light intensity (emission intensity) IaRX, IaGX, IaBX of the halogen lamp 41X (41Y)
(IaRY, IaGY, IaBY) may also be detected. By calculating the ratio of the two (such as IcRX / IaRX) and using this, the halogen lamps 41X, 41Y
This is because it is possible to eliminate the influence on the intensity of the transmitted light due to the fluctuation of the emission intensity of the light. In the present embodiment, the emission intensity of the halogen lamps 41X and 41Y is kept constant, and the intensity information of the transmitted light after color separation is used as it is without obtaining the ratio between the two.

When the fixing test images TX and TY are created, the image color information detecting section 63 outputs the intensity IcRX and IcGX of the refracted transmitted light after color separation of the fixing test images TX and TY created on the recording medium S. , IcBX and IcRY, IcG
Y and IcBY are measured. Then, these data are transmitted to the overall control unit 54. After that, the overall control unit 54
The melting state of each color toner CT, MT, YT is determined based on table data stored in the ROM in advance. Then, based on the determination result, the fixing test image T
The quality of the image state of X, TY is determined.

Further, based on the difference between the color information of the fixing test images TX and TY, the variation of the image state in the direction orthogonal to the transport direction of the recording medium S is evaluated. The variation of the color information corresponds to the variation of the image state in a direction orthogonal to the transport direction of the recording medium S. For example, if any one of the two fixing test images TX and TY has different color information, it indicates that there is a variation in the image state in a direction orthogonal to the conveyance direction of the recording material S. In such a case, the temperature distribution in the axial direction of the heating roller 40a of the fixing device 40 is not uniform, and there is a portion having a low temperature in some portions. It can be estimated that non-uniformity occurs in the orthogonal direction.

On the other hand, if the color information of any of the two fixing test images TX and TY is different from the ideal, it can be estimated that the entire fixing conditions, image forming conditions, and the like are not suitable.
Therefore, the overall control unit 54 does not determine whether the image state of part or all of the recording medium S is good or not, and determines whether the image state is good or not.
By changing control values of the drive control unit 55, the transport control unit 56, the high-pressure control unit 58, and the like, for example, by changing the control temperature of part or all of Oa, the obtained comparison result and the variation can be used for fixing conditions and image formation. Reflect on the conditions. Thereby, a fixed image in a good image state can be formed on the entire recording medium S.

Further, the general control unit 54 calculates the average values IbRm, IbGm, and IbBm of the intensity of the linearly transmitted light after color separation, and refers to the table data stored in advance in the ROM to thereby obtain the recording medium. It is also possible to evaluate the quality of the entire image state of S. Therefore, the operator does not need to visually recognize the image after the copy is completed. Further, even when an OHP sheet is used as a recording medium, it is not necessary to confirm a translucent image by a projector.
In the present embodiment, the halogen lamps 41X, 41
With the emission intensity of Y constant, the intensity information of the transmitted light was used as it was.

The result of the quality evaluation including the variation of the image state is displayed on the operation panel 53, for example. When the image state is poor, a warning sound is issued, and when the image state is extremely bad, Is displayed on the operation panel 53, indicating that the subsequent copying is stopped and that a service person needs to be contacted. Thereby, the operator can easily know the variation and the quality of the image state of the image after the copy is completed. Therefore, the operator does not need to visually recognize the image after the copy is completed. When an OHP sheet is used as a recording medium, it is possible to know the quality of an image without confirming a translucent image by a projector.

As described in detail above, according to the copying machine of the second embodiment, predetermined fixing test images TX and TY are created on the recording medium S periodically or by an operator's selection. . Then, the image color information detection unit 63
Are the intensities IcRX, IcGX, IcBX and IcRY, Ic of the refracted transmitted light after color separation of the fixing test images TX and TY.
GY and IcBY are measured. And the overall control unit 54
From the intensity information measured by the image color information detection unit 63, each color toner CT, MT,
The fused state of the YT is obtained, and the quality of the image state is determined. Then, the image state of each fixing test image TX and the like is determined based on the determination result, and the variation of the image state is also evaluated. These evaluation results are notified to the operator via the operation panel 53 and the like. Therefore, it is possible to avoid unnecessary copying of the copy and use of an OHP sheet having a poor appearance.

(Third Embodiment) Next, a third embodiment will be described. The configuration of the copying machine according to the third embodiment is almost the same as that of the copying machine 1 according to the first embodiment, but as shown in FIG. The difference is that it can be moved in a direction intersecting the transport direction, specifically, in a direction orthogonal to the transport direction. Another difference is that the RGB filter 39 is arranged between the halogen lamp 41 and the recording medium S. That is, as shown in FIG. 15, the screw shaft 84 is provided in a direction orthogonal to the transport direction. A drive motor 85 is provided at the end, and an output shaft of the drive motor 85 and the screw shaft 84 are connected. Further, a CCD sensor 82 is attached to the screw shaft 84. And
By driving the drive motor 85, the screw shaft 84 rotates, and the rotation causes the CCD sensor 82 to move.

On the other hand, the number of halogen lamps and RGB filters corresponding to the number of measurement points in the direction orthogonal to the transport direction, that is, three patch-like fixing test images (TA to TC) as shown in FIG. in case of,
Correspondingly, three (41A, 41B, 41C) are provided. Although the CCD sensor 82 is moved in the present embodiment, the halogen lamp 41 and the RGB filter 39 may be moved to provide three CCD sensors 42, or one set of the halogen lamp 41 and the CC
These may be moved while the relative positional relationship between the D sensor 42 and the RGB filter 39 is fixed. The fixing test images TA to TC are the same as those in the first to third embodiments.
Unlike the fixing test images TX and TY used in No. 3, the test images are similar to the patterns shown in FIG.

By making the CCD sensor 82 constituting the image color information detecting section 83 movable as described above, the CC
The color information of the transmitted light of the fixed image can be detected at a plurality of locations on one recording medium S without providing a plurality of D sensors 82. As a result, the average value can be calculated from the intensity information of the transmitted light after color separation at the plurality of locations, and the determination of the melting state of the toner can be performed more accurately. Judgment is possible. In other words, the quality can be determined more accurately than the measurement at one place. Since the copy operation and the test image creation operation are the same as those in the first embodiment, the description thereof is omitted, and those having the same configuration are denoted by the same reference numerals.

When the fixing test images TA to TC are created, the CCD sensor 82 detects the intensity IbRA of the nine linearly transmitted lights after color separation of the fixing test images TA, TB, and TC created on the recording medium S. , IbGA, IbBA and Ib
RB, IbGB, IbBB and IbRC, IbGC, I
bBC is sequentially moved and measured, and each data is transmitted to the overall control unit 54. Then, the overall control unit 54 obtains the fusion state of each color toner CT, MT, YT in the fixing test images TA to TC from the nine transmitted light intensity information measured by the image color information detection unit 83, and determines the quality of the image state. . Then, the quality of the fixing test images TA, TB, TC is determined based on the determination result. Further, based on the difference between the color information of each of the fixing test images TA, TB, and TC, the variation of the image state in the direction orthogonal to the conveyance direction of the recording medium S is evaluated. In particular, in the present embodiment, by evaluating the variation in the color information of the fixing test images TA to TC, it is possible to evaluate the variation in the image state in both the transport direction of the recording medium S and the direction orthogonal to the transport direction. .

On the other hand, if the color information of any one of the two fixing test images TA to TC is different from the ideal, it can be estimated that the entire fixing conditions, image forming conditions, and the like are inappropriate.
Therefore, the overall control unit 54 does not determine whether the image state of part or all of the recording medium S is good or not, and determines whether the image state is good or not.
By changing control values of the drive control unit 55, the transport control unit 56, the high-pressure control unit 58, and the like, for example, by changing the control temperature of part or all of Oa, the obtained comparison result and the variation can be used for fixing conditions and image formation. Reflect on the conditions. Thereby, a fixed image in a good image state can be formed on the entire recording medium S.

Further, the general control unit 54 calculates an average value I for each color filter of nine intensities detected by the image color information detection unit.
By calculating bRm, IbGm, and IbBm and referring to table data stored in the ROM in advance, it is also possible to evaluate whether the image state of the entire recording medium S is good. Therefore, the operator does not need to visually recognize the image after the copy is completed. OHP is used as a recording medium.
When using a sheet, there is no need to check a translucent image by the projector. In the present embodiment, the light emission intensity of the halogen lamp 41A and the like is set to be constant.
The transmitted light intensity information was used as it was.

Accordingly, the operator does not need to visually recognize the image after the copy is completed. In addition, O as a recording medium
Even when using an HP sheet, it is not necessary to check a translucent image by the projector. Furthermore, in order to remove the influence of disturbance, the light emission intensity IaRA, IaGA, IaBA, etc. of the halogen lamp 41A and the like are also detected, the ratios with the transmitted light intensity are calculated, and the average of these is used to calculate the image state. May be determined.

As described in detail above, according to the copying machine of the third embodiment, a plurality of fixing test images T
A to TC are created on the recording medium S. On the other hand, the intensity IbRA, IbGA, IbBA of the nine straight transmission light after color separation of the fixing test images TA to TC, and IbRB, Ib
GB and IbBB and IbRC, IbGC and IbBC are sequentially measured while the CCD sensor 82 moves. Then, based on the nine intensities measured by the image color information detection unit 83, the overall control unit 54 sets the fixing test images TA, TB,
The melting state of each color toner CT, MT, YT at TC is determined, and the variation of color information is obtained. Then, by reflecting these results in the fixing conditions and the like, it is possible to form a fixed image in a good image state and without variation over the entire recording medium S. Therefore, it is possible to avoid unnecessary copying of the copy and use of an OHP sheet having a poor appearance.

(Fourth Embodiment) Next, a fourth embodiment will be described. The copying machine according to the fourth embodiment has substantially the same configuration as the copying machine 1 according to the first embodiment, but transmits a fixed image obtained by copying a normal original without creating a test image. The difference is that color information of light is detected and processed. Another difference is that the RGB filter 39 is arranged between the halogen lamp 41 and the recording medium S. The image color information processing program is executed after a predetermined number of copies have been made, after a predetermined operating time has elapsed, or when the operator has selected. Hereinafter, the processing of the color information including the variation will be described with reference to FIG. The copy operation and the test image creation operation
The description is omitted because it is the same as the first embodiment,
The components having the same configuration are denoted by the same reference numerals.

When the image color information processing program is executed, first, the image reading section 2 obtains image data corresponding to the image of the original. Next, the image color information detection unit 93 sets the fixed image G
RX1, RX2, R in which the color information of the transmitted light of
In X3,... And RY1, RY2, RY3,..., It is checked in which area the fixed image G (image data) exists. For example, in the case shown in FIG. 13, it is found that the fixed image G exists in the regions RX2 and RY2. Then, the IR control unit 51 issues a command to the image color information detection unit 93 via the overall control unit 54 to detect the color information of the transmitted light in the regions RX2 and RY2. Next, a copy image (fixed image) of the document is created based on the image data read on the recording medium S by the above-described electrophotographic process.

When the recording medium S is discharged from the fixing device 40 and the areas RX2 and RY2 reach the detection area of the image color information detecting section 93, the image color information detecting section 9 is detected.
Reference numeral 3 denotes the intensity Ig of the linearly transmitted light after the color separation of the fixed image G by the RGB filter 39X by the CCD sensor 92X.
The intensity IgRY, IgGY, and IgBY of the straight transmitted light after the RX, IgGX, and IgBX are color-separated by the RGB filter 39Y by the CCD sensor 92Y are measured, respectively. Then, when these data are transmitted to the overall control unit 54, the melting state of each color toner CT, MT, YT is determined based on the table data stored in the ROM in advance. Further, the overall control unit 54 compares the color information in the two regions RX2 and RY2 to calculate the variation.

From these comparison results and variations, the fixing device 40
The control unit 54 controls the drive control unit 55, the transport control unit 56, the high-pressure control unit 58, and the like by using the fact that the non-uniformity or inconsistency of the image forming conditions of the developing unit 32Y and the like is estimated. By changing the value, the comparison result with the ideal color information and the calculated variation are reflected in the fixing condition and the image forming condition. Thereby, a fixed image in a good image state can be formed on the entire recording medium S. In addition, since the above-mentioned comparison result can be obtained with high accuracy without being affected by disturbance, it is possible to change the fixing conditions and the like with higher accuracy, so that a better fixed image can be obtained. Therefore, the operator does not need to visually recognize the image after the copy is completed. Further, when an OHP sheet is used as a recording medium, it is not necessary to confirm a translucent image by a projector.

As described above in detail, according to the copying machine of the fourth embodiment, when the processing program for the image color information is executed at a predetermined time or by the operator's selection, the image of the original to be copied is copied. Whether or not image data exists in an area that can be measured by the image color information detection unit 93 from the data, and if so, the position (for example, the areas RX2 and RY)
2), the image color information detection unit 93 measures the intensity IgRX, IgGX, IgBX and IgRY, IgGY, IgBY of the straight transmitted light after color separation of the fixed image G at the detection position (region RX2, RY2). I do. Then, the overall control unit 54 determines the region RX2 of the fixing test image G from the intensity information of the straight transmitted light measured by the image color information detection unit 93.
And the melting state of each color toner CT, MT, YT in RY2. Then, by comparing the toner fusion states of the two, the variation between the regions RX2 and RY2 is obtained, and this is reflected in the fixing conditions and the like, so that the variation in the image state in a good image state and within one recording medium is obtained. No fixed image is created. Therefore, it is possible to avoid unnecessary copying of the copy and use of an OHP sheet having a poor appearance. Further, there is an advantage that the recording medium is not wasted because no test image is created.

(Fifth Embodiment) Finally, a fifth embodiment will be described. The configuration of the copying machine according to the fifth embodiment is substantially the same as that of the copying machine 1 according to the first embodiment, but the configuration of the image color information detecting unit is different. More specifically, as shown in FIG. 17, the halogen lamp 101 is positioned diagonally on the upper right of the recording medium S (diagonally on the conveyance direction).
X is provided. Further, an RGB filter 109X for color-separating specularly reflected light with respect to incident light incident on the fixing test image TX from the halogen lamp 101X is provided.
As a result, color-separated specularly reflected light can be received,
Oblique upper left side in the figure where the incident angle α and the reflection angle β with respect to the fixing test image TX (recording medium S) are equal (upward in the transport direction)
Is provided with a CCD sensor 102X. Further, the similar positional relationship is different in that a halogen lamp 101Y, a CCD sensor 102Y, and an RGB filter 109Y are provided for the fixing test image TY.

As a result, the image color information detecting section 103 can detect the color information of the regular reflection light of the fixing test images TX and TY. Another difference is that the quality of the image is determined based on the determination result of the melting state of the toner and displayed on the operation panel 53. Note that the copy operation and the test image creation operation are the same as those in the first embodiment, and therefore description thereof is omitted, and the same components are denoted by the same reference numerals.

As described above, in the image color information detecting section 103, the color information of the fixing test images TX and TY is detected by the reflected light because the color information can be detected irrespective of the paper type and the thickness and the like can be detected. Is not easily affected by the paper type.

When the fixing test images TX and TY are created, the image color information detection unit 103 outputs the intensity IdRX and IdGX of the specularly reflected light after color separation of the fixing test images TX and TY created on the recording medium S. , IdBX and IdR
Y, IdGY, and IdBY are measured, and these data are transmitted to the overall control unit 54. Thereafter, the general control unit 54
Determines the melting state of the toner with reference to the table data stored in the ROM in advance, and determines the quality of the fixing test images TX and TY based on the determination result.

Further, the variation of the image state in the direction orthogonal to the transport direction of the recording medium S is evaluated based on the difference between the color information of each of the fixing test images TX and TY. The variation of the color information corresponds to the variation of the image state in a direction orthogonal to the transport direction of the recording medium S. For example, 2
If any one of the fixing test images TX and TY has different color information, it indicates that there is a variation in the image state in a direction orthogonal to the conveyance direction of the recording medium S. In such a case, the heating roller 40 of the fixing device 40
It is presumed that non-uniformity occurs in the direction orthogonal to the transport direction under any of the fixing conditions and image forming conditions, such as the temperature distribution in the axial direction of a is not uniform and there are some low temperature parts. it can.

On the other hand, if the color information of any of the two fixing test images TX and TY is different from the ideal, it can be estimated that the entire fixing conditions, image forming conditions, and the like are not suitable.
Therefore, the overall control unit 54 does not determine whether the image state of part or all of the recording medium S is good or not, and determines whether the image state is good or not.
By changing control values of the drive control unit 55, the transport control unit 56, the high-pressure control unit 58, and the like, for example, by changing the control temperature of part or all of Oa, the obtained comparison result and the variation can be used for fixing conditions and image formation. Reflect on the conditions. Thereby, a fixed image in a good image state can be formed on the entire recording medium S.

Further, the general control unit 54 calculates the average values IdRm, IdGm, IdBm of the intensities of the specularly reflected light after the color separation, and refers to the table data stored in the ROM in advance to record the data. It is also possible to evaluate the quality of the image state of the entire body S. Therefore, the operator does not need to visually recognize the image after the copy is completed. Further, even when an OHP sheet is used as a recording medium, it is not necessary to confirm a translucent image by a projector.
In the present embodiment, the halogen lamps 41X, 41
With the emission intensity of Y constant, the intensity information of the transmitted light was used as it was.

As described in detail above, according to the copying machine of the fifth embodiment, predetermined fixing test images TX and TY are created on the recording medium S periodically or by an operator's selection. . Then, the image color information detection unit 10
3 is the intensity IdRX, IdGX, IdBX and IdR of the specular light after color separation of the fixing test images TX and TY.
Y, IdGY and IdBY are measured. Then, the overall control unit 54 determines, based on the intensity information measured by the image color information detection unit 103, each of the color toners C in the fixing test images TX and TY.
The melting state of T, MT, YT is determined. Further, the variation is calculated by comparing the color information of the fixing test images TX and TY. By reflecting these determination results and the calculated variation in the fixing conditions and the like, a fixed image having a good image state and no image state variation within one recording medium is formed. Therefore, it is possible to avoid unnecessary copying of the copy and use of an OHP sheet having a poor appearance.

The fifth embodiment uses specularly reflected light instead of straight transmitted light to detect color information of the fixing test images TX and TY in the first embodiment. Yes, but not limited to. For example, the second
As a form corresponding to that shown in the embodiment of FIG.
As shown in FIG. 8, the CCD sensors 112X and 112Y are located at positions where the diffused reflected light of the fixing test image T with respect to the incident light from the halogen lamps 101X and 101Y can be received.
May be arranged to use diffuse reflection light.
The positions of the RGB filters 109X and 109Y may be either positions where the incident light can be color-separated or positions where the reflected light can be color-separated. Also, instead of using transmitted light in the third and fourth embodiments, reflected light can be used.

In the third and fourth embodiments,
The image information detectors 83 and 93 detect the straight transmitted light after the color separation of the fixed image, but instead of the straight transmitted light, detect the refracted transmitted light as exemplified in the second embodiment. It goes without saying that this may be done. Further, in the above embodiment, an example in which the present invention is applied to a copying machine has been described. However, the present invention can be applied to any printer having a fixing device such as a printer such as a page printer or a facsimile.

[0090]

As described above, according to the image forming apparatus of the present invention, the image color information detecting means detects the color information of the light transmitted or reflected from the fixed image at two or more different positions. Next, since the image color information processing means processes the color information detected by the image color information detection means, it is possible to determine the fused state of the toner corresponding to the variation of the image state of the fixed image and the image state of one recording medium. Variations in the results and the measured color information are obtained.

Then, by reflecting the judgment result and the variation in the fixing condition, the image forming condition, and the like, a fixed image having a good image state and no image state variation in one recording medium is automatically obtained. It is also possible to control so that In addition, by notifying the operator of the quality of the image based on the processing result using a display panel, a warning sound, or the like, the operator can grasp the quality of the fixed image including the variation in the image state without visually recognizing the quality. can do. For this reason, it is possible to avoid unnecessary copying of the copy and use of an OHP sheet having a poor appearance.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a copying machine according to a first embodiment.

FIG. 2 is a perspective view illustrating a configuration of an image color information detection unit in the copying machine of FIG. 1;

FIG. 3 is a perspective view illustrating another configuration of the image color information detection unit.

FIG. 4 is a block diagram showing a part of a control circuit of the copying machine shown in FIG. 1;

FIG. 5 is an explanatory diagram illustrating a relationship between a molten state of toner and color information.

FIG. 6 is an explanatory diagram illustrating the relationship between the melting state of toner and color information.

FIG. 7 is an explanatory diagram illustrating the relationship between the melting state of toner and color information.

FIG. 8 is a graph showing the relationship between the melting state of toner and color information (transmittance after color separation), and is a graph of table data.

FIG. 9 is an explanatory diagram illustrating a creation pattern of a test image.

FIG. 10 is an explanatory diagram illustrating a test image creation pattern.

FIG. 11 is an explanatory diagram illustrating a test image creation pattern.

FIG. 12 is an explanatory diagram illustrating a test image creation pattern.

FIG. 13 is a perspective view illustrating a configuration of an image color information detection unit in a copying machine according to a second embodiment.

FIG. 14 is a perspective view illustrating a configuration of an image color information detection unit in a copying machine according to a third embodiment.

15 is a perspective view showing a moving mechanism of the CCD sensor shown in FIG.

FIG. 16 is an explanatory diagram for describing a method of detecting color information of transmitted light in an image color information detection unit in a copying machine according to a fourth embodiment.

FIG. 17 is a perspective view illustrating a configuration of an image color information detection unit in a copying machine according to a fifth embodiment.

18 is a schematic configuration diagram illustrating a configuration of an image color information detection unit in the copying machine of FIG.

FIG. 19 is an explanatory diagram for explaining a state of transmitted light when fixing is performed satisfactorily.

FIG. 20 is an explanatory diagram for explaining a state of transmitted light when fixing is not properly performed.

FIG. 21 is an explanatory diagram for explaining a state of transmitted light in a case where fixing is not properly performed.

FIG. 22 is an explanatory diagram for explaining a state of transmitted light in a case where fixing is not properly performed.

[Explanation of symbols]

 5 Image Processing Unit 30 Photosensitive Drum 32Y, 32C, 32M, 32K Developing Device 33 Transfer Charger 34 Transfer Drum 40 Fixing Device 41X, 41Y Halogen Lamp 42X, 42Y CCD Sensor 43 Image Color Information Detecting Unit 54 Overall Control Unit S Recording Body TX , TY fixing test image

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/00 H04N 1/00 A (72) Inventor Tsuneshi Takahashi 2-3 Azuchicho, Chuo-ku, Osaka-shi, Osaka No. 13 Osaka International Building Minolta Co., Ltd. F-term (reference) 2G020 AA08 DA13 DA22 DA31 DA34 DA43 2H027 DA09 DE02 DE10 EB04 EB06 EC03 EC07 EE08 HA07 2H030 AD04 AD16 BB36 5C062 AA02 AA05 AB22 AB53 AC55 AC58 AE03 BA04 9A03 BB03 GZ05 HH23 HH31 JJ35 KK16 KK42 LL05 LL08

Claims (4)

[Claims] 1. An image forming apparatus comprising: an image forming unit that forms an image on a recording medium; and a fixing unit that fixes the image generated by the image forming unit on the recording medium. A light-emitting element for irradiating light to a fixed image fixed on a recording medium, a light-receiving element for detecting color information of light emitted from the light-emitting element and transmitted or reflected through the fixed image, the light-emitting element and the light-receiving element And an image color information detecting unit that processes the color information detected by the image color information detecting unit. The image color information detecting unit includes: An image forming apparatus capable of detecting color information of light transmitted or reflected through the fixed image at at least two or more different positions in the recording medium. 2. The image forming apparatus according to claim 1, wherein the image color information detecting unit is configured to disperse the two or more pairs of the light emitting element and the light receiving element in a direction intersecting with a conveying direction of the recording medium. An image forming apparatus comprising a combination with a filter. 3. The image forming apparatus according to claim 1, wherein the image color information detecting unit is at least one of the light emitting element and the light receiving element movable in a direction intersecting a conveying direction of the recording medium. An image forming apparatus comprising: 4. The image forming apparatus according to claim 1, wherein the image creating unit stores test image data for creating a predetermined test image on the recording medium. Wherein the image color information detecting means detects color information of light transmitted or reflected by the fixed test image fixed on the recording medium, and the image color information processing means comprises: An image forming apparatus for processing color information of a fixing test image.