JP2000284552A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of detecting normal or defective of the image state on the fixed image, and moreover the dispersion of the image state on the fixed image on a sheet of recording material. SOLUTION: Relating to a general controlling part, fixation test images TA to TC is formed on recording material periodically or by selection of an operator. The reflection light strength information detecting part 43 is, let detecting the strength of these reflection light. Then, the general controlling part detects normal or defective of the image state on these fixation test images by respectively comparing strength of these normal reflection light and the ideal strength thereof, and detecting the dispersion of the image state from the dispersion of the strength. Then, by using that from the comparison result of the ideal strength and the calculated dispersion, unevenness or inappropriateness of the image fixing condition or the fixing device 40, the developing device, or the like is estimated, the general controlling part changes the controlling value of the drive controlling part to reflect it on fixing conditions, the image forming conditions or the like.

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 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 increasing the fixing temperature or decreasing the transport speed of the recording medium to supply a larger amount of heat than that supplied to the plain paper.

[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 quality of the image in these cases could not be confirmed until the fixed image was visually recognized.

Further, when a large number of copies are made at once, it is troublesome to confirm the image quality of the whole or a part of each image one by one. General. 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 light emitting element for irradiating the fixed image fixed on the recording medium by the fixing means with light, and the fixing device for irradiating light from the light emitting element. A reflected light intensity information detecting means including a light receiving element for detecting the intensity information of the reflected light reflected by the image; and a reflected light intensity information processing means for processing the reflected light intensity information detected by the reflected light intensity information detecting means. Wherein the reflected light intensity information detecting means is capable of detecting intensity information of reflected light reflected by the fixed image at at least two or more different positions in the recording medium. That.

In this image forming apparatus, first, an image forming means forms an image (toner image) on a recording medium. Here, the image created by the image creating means on the recording medium includes a copy image of a document to be copied, image data input to the image forming apparatus, and a test stored in the image forming apparatus in advance. A predetermined test image based on image data is included. Next, the fixing unit fixes the image created by the image creating unit on the recording medium. Then, the reflected light intensity information detecting means detects the intensity information of the reflected light of the fixed image fixed on the recording medium. The intensity information detection of the reflected light is performed by irradiating the fixed image on the recording medium with light by the light emitting element and receiving the reflected light from the fixed image by the light receiving element.

Then, the reflected light intensity information processing means processes the reflected light intensity information detected by the reflected light intensity information detecting means. Therefore, by using this processing result, for example, by reflecting (feeding back) the processing result on fixing conditions, image forming conditions, and the like so that the image state is improved,
Control can be performed so that a good fixed image is automatically obtained. Further, the evaluation of the fixed image can be performed, and a warning or a serviceman call can be displayed to the operator. In particular, since the reflected light intensity information detecting means obtains the reflected light intensity information of the fixed image at at least two or more different positions in the recording medium, it calculates the reflected light intensity difference at each measurement point. By evaluating the variation of the image state in one 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 be reflected in the fixing condition and the like so as to suppress the variation in the conveying direction such as the temperature distribution in the axial direction of the heating roller and the direction perpendicular to the fixing condition. Also,
Even when it is determined that a part of the recording medium is inferior in image state fixability, a warning or a serviceman call or the like 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 intensity information of the reflected light is detected at only one location, if noise is superimposed on the detection result due to any cause, the quality of the fixed image cannot be accurately evaluated. The reason is that such a situation can be avoided by detecting the intensity information of the reflected light by using the method.

In the present invention, the reason for detecting and processing the intensity information of the reflected light is that the intensity information of the reflected light can be used as one of the indexes for evaluating the image state of the fixed image.
For example, if the fixing of the toner is insufficient for some reason, the reflectance of the fixed image is low, and the image looks frosted and is hard to see. On the other hand, when the toner is sufficiently fixed, the fixed image appropriately reflects the ambient light, and the image has a moderately glossy and easy-to-view image state. However, when the toner is extremely fixed (over-fixed), the reflectance becomes extremely high, and the surface becomes glaring like a photograph printed on photographic paper, and conversely, the image state becomes difficult to see. This will be described with reference to the drawings. When fixing is performed well, for example, when the toner is sufficiently melted and then pressed with a roller, the surface of the fixed image TGA fixed on the recording material S is smooth as shown in FIG. Therefore, the intensity of specularly reflected light (directly reflected light) increases. Conversely, when the fixing is poor, the toner does not melt sufficiently and the shape of the toner particles remains, so that the surface of the fixed image TGB on the recording medium S does not become smooth as shown in FIG. Because of the irregularities, the incident light is scattered, the intensity of the specularly reflected light decreases, and the intensity of the diffusely reflected light increases. Therefore, by detecting the intensity information of the specular reflection light or the diffuse reflection light, it is possible to determine the quality of the image state of the fixed image. In addition, the regular reflection light (direct reflection light)
Of the reflected light, the reflected light that travels by being reflected at the same angle of incidence as the incident angle of the incident light that has entered the fixed image in the incident surface formed by the incident light and the normal of the fixed image at the incident point (In the following description, “specular reflection light” is used in the same meaning). In addition, the diffusely reflected light refers to reflected light, of the reflected light, which is incident on the fixed image, is scattered by irregularities of the fixed image, and travels in a direction other than the direction of regular reflection (also in the following description). And “diffuse reflected light” in the same sense).

To obtain the reflectance, the intensity of the incident light is required in addition to the intensity of the reflected light. Therefore, the intensity of the incident light may be separately detected in addition to the reflected light. But,
If 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 reflected light. In addition, in the measurement of the intensity of the incident light, there is a method of directly measuring the intensity using a half mirror or the like, and a method of indirectly measuring the applied voltage, current consumption, power consumption, and the like of the light emitting element. .

Further, when reflected light is used, the transmittance of a fixed image cannot be obtained with a recording medium that is opaque or hard to transmit light when transmitted light is used. This is advantageous in that it is hardly affected by the paper type such as the thickness, and the reflectance can be reliably obtained from the fixed image fixed on any type of recording medium, and the image state of the fixed image can be reliably evaluated. Further, in the case where a color shift (brightness, saturation, color tone shift) of the fixed image is used as the image state evaluation of the fixed image, a filter corresponding to each color such as RGB is used to adjust the reflected light or transmitted light for each color. Processing such as measuring the intensity is troublesome, but when using reflected light, it is enough to obtain the intensity or calculate the reflectivity after obtaining the intensity of the incident light. This is advantageous in that the structure is simple and the processing is easy.

The recording medium may be any paper that can fix an image, such as plain paper, thick paper, OHP sheet, or special paper coated with resin. The light-emitting element may be any element that emits light having a wavelength and intensity that can appropriately evaluate a fixed image. For example, a lamp such as a halogen lamp, a light emitting diode, a semiconductor laser, or the like can be given.
Further, the light receiving element may be any element having a sensitivity range that responds to light emitted from the light emitting element. For example, CCD,
Examples include a photodiode.

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

As described above, by providing two or more sets of light emitting elements and light receiving elements in the direction intersecting with the transport direction of the recording body, two different types of the recording medium in the direction intersecting with the transport direction are provided. Intensity information of the reflected light of the fixed image can be detected at more than three positions. This allows
For example, temperature distribution in the axial direction of the heating roller,
It is possible to detect whether there is a change in a fixing condition or an image forming condition in a direction orthogonal to the transport direction among the fixing units and the like. Therefore, if the intensity information of the reflected light 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, And the like, and image forming conditions (charge voltage and the like) can be estimated to have some variation, so that it is possible to detect an abnormality of the fixing unit and the like. Therefore, as described above, it is possible to suppress the variation by reflecting the processing result on the fixing condition and the like, and to notify the operator of the quality of the image state by grasping the quality.

Further, in the image forming apparatus according to the present invention, the reflected light intensity information detecting means may include at least one of the light emitting element and the light receiving element movable in a direction intersecting the conveyance direction of the recording medium. It can also be included.

As described above, by allowing at least one of the light emitting element and the light receiving element to move in a direction intersecting the transport direction of the recording medium, one light emitting element or light receiving element, or one set of light emitting elements The intensity information of the reflected light of the fixed image at two or more different positions on the recording medium can be detected in the direction intersecting the conveying 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 and 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. When only the light emitting element is movable, a plurality of light receiving elements may be arranged corresponding to the positions where the reflected light intensity information is detected, and conversely, when only the light receiving element is movable. In this case, a plurality of light emitting elements may be arranged corresponding to the positions where the reflected light intensity information is detected.

Further, 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 reflected light intensity information detecting means detects intensity information of reflected light reflected on a fixing test image fixed on the recording medium, and the reflected light intensity information processing means detects an intensity of reflected light of the fixing test image. Process information.

By using the fixing test image obtained from the test image data stored in advance as described above, the position of the fixed image whose reflected light intensity is to be measured is known in advance. Thus, it is possible to reliably obtain reflected light intensity information on the fixed image. Therefore,
It is possible to reliably determine whether the image state is good or not and the variation in the image state on one recording medium, and reflect the processing result of the reflected light intensity information on the obtained test image in the fixing condition and the image forming condition. 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 intensity information with ideal intensity information expected from the test image data (that is, originally obtained), it is possible to easily and accurately determine whether the image state is good or not, and whether the image state is uneven, or This can be reflected on fixing conditions and the like.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Hereinafter, 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. The first embodiment is an electrophotographic copying machine equipped with the image forming apparatus according to the present invention, which can copy an image of a document, and also prepares a predetermined test image to create an image state of a fixing test image. It is to grasp.

As shown in FIG. 1, the copying machine 1 comprises 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. The image reading section 2 includes a 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, a developing device 32Y,
32C, 32M, and 32K, a transfer drum 34 having a transfer charger 33, and a cleaning device 35.
The transport unit 6 includes a paper cassette 4 for stacking and storing recording media.
4, various conveyance rollers for conveying the recording medium supplied from the paper cassette 44 or the manual feed tray 45, a fixing device 40, a reflected light intensity information detection unit 43 including a halogen lamp 41 and a CCD sensor 42, And a paper discharge tray 46 for accommodating the recording medium that has been copied and discharged outside the apparatus.

Here, the reflected light intensity information detecting section 43 detects the intensity information of the reflected light of the fixed image. The reflected light intensity information detecting unit 43, for example, as shown in FIG.
Three substantially rectangular fixing test images T arranged in the vicinity of the upper side of the recording material S when the transport direction indicated by the arrow is directed upward.
When A, TB, and TC are formed on the recording medium S, they are arranged at positions where the intensity of regular reflection light of the fixing test image TA and the like can be measured. That is, the reflected light intensity information detection unit 43 is configured to set three light-emitting elements and light-receiving elements (light-emitting / light-receiving element pairs) arranged in a direction intersecting (in the present embodiment, orthogonal to) the conveyance direction of the recording medium S. ). Specifically, the halogen lamp 41A and the CCD sensor 42A, the halogen lamp 41B and the CCD sensor 42B,
And the halogen lamp 41C and the CCD sensor 42C.
It is composed of a set of light emitting and light receiving element pairs. The halogen lamp 41A and the CCD sensor 42A are arranged at positions where the intensity of the reflected light of the fixing test image TA can be measured. That is, in the conveyance path of the recording material S, behind the fixing device 40, a halogen lamp, which is a light emitting element, is positioned obliquely upper right (diagonally upper direction in the anti-conveying direction) with respect to the recording material S discharged from the fixing device 40 in FIG. 41A in which the incident angle α and the reflection angle β with respect to the fixing test image TA (recording medium S) are equal so that specular reflection light with respect to the incident light entering the fixing test image TA from the halogen lamp 41A can be received. A CCD sensor 42A, which is a light receiving element, is provided diagonally on the upper left side (diagonally above in the transport direction). With the same positional relationship, the halogen lamp 41B and the CCD
A sensor 42B, a halogen lamp 41C and a CCD sensor 42C are also arranged.

Note that the halogen lamps 41A and C
The CD sensor 42A, the lamp 41B and the sensor 42B, and the lamp 41C and the sensor 42C may be arranged at opposite positions. Further, as shown in FIG. 3, the halogen lamp 41A is so set that the directions of the incident light and the reflected light are orthogonal to the transport direction (leftward behind the fixing device 40 in FIG. 1).
Any arrangement may be used as long as light can be applied to the fixing test image TA and the like and its regular reflected light can be received, such as the arrangement of the CCD sensor 42A and the like.

However, it is preferable that the incident angle α (reflection angle β) be 15 degrees or more. If the incident angle α is less than 15, it becomes difficult to arrange the light emitting element and the light receiving element. In addition, the amount of light entering from the surroundings increases, and the measurement error increases. Further, the incident angle α is preferably set to 45 degrees or more. This is because the influence of the thickness of the fixed image (fixing test image T) or the rise of the recording medium S during measurement can be reduced.

As described above, the halogen lamps 41A to 41C
And the CCD sensors 42A to 42C are arranged, so that the reflected light intensity information detection unit 43
It is possible to detect the intensity information of the regular reflection light of the TC. That is, the reflected light intensity information detecting unit 43 is provided with the CCD sensor 42A.
By detecting the intensities IbA to IbC of the reflected light received by .about.42C, the intensity information of the specularly reflected light of the fixing test images TA to TC is detected. The reason for detecting the intensity information of the specularly reflected light is that the specularly reflected 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 reflected light intensity information detecting section 43, the halogen lamps 41A to 41A
The incident light intensity (light emission intensity) IaA to IaC of 1C may also be detected. The ratio of the two (ie, reflectivity =
By calculating and using IbA / IaA), it is possible to eliminate the influence on the reflected light intensities IbA to IbC due to fluctuations in the emission intensities IaA to IaC of the halogen lamps 41A to 41C. In the present embodiment, the light emission intensity of the halogen lamps 41A to 41C is kept constant, and the intensity information of the reflected light is used without calculating the reflectance.

Next, a brief description will be given of an operation when copying is performed in the copying machine 1 configured as described above. 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 the laser light is scanned in the main scanning direction by the polygon mirror 21 and further reflected by the reflection mirror 22 to be exposed to the photosensitive drum 30.
Incident on. 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 to a paper cassette 4 by a transfer charger 33 arranged opposite to the photosensitive drum 30.
4 or onto the recording medium S supplied from the manual feed tray 45. 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 S 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 is a microcomputer configured by combining a known CPU, 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. Further, the RAM is provided with various buffers for temporarily storing numerical values and the like appearing 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 that controls high voltages such as charging of the photosensitive drum 30, application of a developing bias and a transfer bias, a laser control unit 59 that performs modulation control of laser light, a reflected light intensity information detection unit 43, and the like. Is connected. The general control unit 54 also has an operation panel 5 via the controller 52.
3 is input.

The copying machine 1 is 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 TA, TB, and TC are created in order to grasp the image state of the fixed image, the ROM in the general control unit 54 is sent to the laser control unit 59 shown in FIG. The test image data stored in advance is input, and a predetermined fixing test image is created by the above procedure. This fixing test image T
The creation of A 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 selects a test from the operation panel 53.

It is preferable that the fixing test image T is a patch other than black (K), and yellow (Y), cyan (C), and magenta (M) using one type of toner.
Or a patch of any color using a plurality of toners. When a plurality of toners are used, it is possible to detect the melting state of the toner in various images. Further, since the amount of toner adhered to the fixing test image T can be increased, the result can be used to widen the amount of toner adhered and other correction ranges. In addition, measurement accuracy can be improved. Further, a plurality (three or more) of fixing test images having different image densities by a predetermined value may be created in the recording medium transport direction. In this way, the reflected light intensity (reflectance) of each fixing test image is detected, and a straight line representing the relationship between the image density and the reflected light intensity (reflectance) is obtained from the result by the least square method.
The true value of the reflected light intensity (reflectance) for each fixing test image can be obtained. As a result, the transmitted light intensity (transmittance) of the fixing test image can be detected with higher accuracy than when only one fixing test image is created. Therefore, the image state of the fixing test image can be grasped more accurately. Also, a plurality (three or more) of fixing test images having the same image density are created in the recording medium transport direction, and the reflected light intensity (reflectance) of each fixing test image is determined.
May be obtained.

When the fixing test image TA and the like are created, the reflected light intensity information detecting unit 43 detects the regular reflection light intensity IbA of the fixing test images TA to TC created on the recording medium S.
The IbC is measured and these data are transmitted to the overall control unit 54. Thereafter, the overall control unit 54 sets the ideal intensity IbA of the regular reflection light, which is obtained in advance from the intensity IbA to IbC of the regular reflection light and image data such as the fixing test image TA.
r to IbCr are compared. The result of comparison with the ideal strength corresponds to the quality of the fixing test images TA to TC, respectively.

Further, each fixing test image TA, TB, T
From the difference between the reflected light intensities IbA to IbC of C, the variation of the reflected light intensity in the direction orthogonal to the conveyance direction of the recording medium S is obtained. Also, the variation in the reflected light intensity is due to the recording medium S
Of the image state in a direction orthogonal to the transport direction of the image. For example, three fixing test images TA, T
When only one of B and TC has low reflected light intensity,
This indicates that there is a variation in the image state in a direction orthogonal to the transport direction of the recording medium 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, any of the reflected light intensities IbA to Ib of the three fixing test images TA and the like.
If the value of C is also low, it can be estimated that the overall fixing conditions, image forming conditions, and the like are inappropriate. Therefore, the overall control unit 54
Is used to determine whether the image state of a part or all of the recording paper S is good or not, and to change the control temperature of the entire heating roller 40a or a part of the heating roller 40a of the fixing device 40, for example. By changing control values of the drive control unit 55, the transport control unit 56, the high-voltage control unit 58, and the like, the obtained comparison result and the calculated variation are reflected on the fixing condition and the image forming condition. Thereby, a fixed image in a good image state can be formed on the entirety of one recording sheet S.

Further, the general control unit 54 calculates an average value Ibm of the intensities IbA to IbC of the specularly reflected light, and determines the fixing test image T obtained from the average value Ibm and the test image data.
By comparing with the ideal intensity Ibr of the regular reflection light of A to TC, the quality of the image state of the entire recording medium S can be evaluated. In the present embodiment, the halogen lamp 41A is used.
The emission intensity of ~ 41C was kept constant, and the intensity information of the reflected light was used as it was without obtaining the reflectance.

Therefore, the operator does not have 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.

As described above in detail, according to the copying machine 1 of the first embodiment, predetermined fixing test images TA to TC are created on the recording medium S periodically or by an operator's selection. You. Then, the reflected light intensity information detecting unit 43 measures the intensity IbA to IbC of the regular reflected light of the fixing test images TA to TC. And the overall control unit 54
The intensities IbA to IbC of the specular reflected light measured by the reflected light intensity information detecting unit 43 are compared with the ideal intensities IbAr to IbCr. In addition, intensity variations are calculated by comparing the intensities IbA to IbC. By reflecting the comparison 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 in 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, three patch-like fixing test images (hereinafter, also simply referred to as patches) TA, T near the upper side of the recording material S when the transport direction is upward.
B and TC are formed side by side in the left and right direction. The fixing test image forming pattern is, as shown in FIG. 5, a direction orthogonal to the transport direction of the recording medium S (upward in the figure), as in this embodiment. (5 in this figure)
7, a pattern in which a plurality of patches TP are arranged in the transport direction of the recording medium S (up and down direction in the figure) as shown in FIG. 6, and a pattern in which the recording medium S is formed as shown in FIG. Pattern to create a patch TP in the four corners of
As shown in FIG. 8, a plurality of patches T
A pattern formed by arranging P is exemplified. Among them, in the pattern as shown in FIG. 5, for example, it is possible to evaluate the variation in the image state in the direction orthogonal to the transport direction due to 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. 6, it is possible to evaluate variations in the image state in the transport direction due to variations in the temperature of the heating roller 40a in the circumferential direction. In this case, one set of halogen lamp and CC
Using the D sensor, the image state and the variation of each patch (fixing test image) can be evaluated. Further, FIG.
8 and the pattern shown in FIG. 8, it is possible to evaluate at once a variation in both the transport direction and the direction orthogonal thereto.

Further, as in the above-described embodiment, in addition to forming only the fixing test image on the recording medium S, the fixing test image TP is superimposed on the actual copy image GA as shown by a broken line in each figure by the operator's selection. You may make it. This is because the recording paper S for the test need not be wasted.
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. This is because in the pattern as shown in FIG. 8, the copy image GA and the fixing test image TP overlap.

(Embodiment 2) 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 the reflected light intensity information detecting unit also has three light-emitting / light-receiving element pairs. , The arrangement is different. More specifically, as shown in FIG.
Sensors 62A-62C are halogen lamps 41A-41
The intersections PA, PB, and PC between the optical axes 41AL, 41BL, and 41CLa of the C and the recording medium S are respectively expected, and more specifically, at the positions deviated from the optical axes of the specularly reflected light, more specifically, the intersections PA and PB. , PC, respectively, on the normal of the paper surface of the recording medium S, ie, the optical axis 6 of the CCD sensors 62A to 62C.
The difference is that 2AL to 62CL and each normal are aligned. As a result, the reflected light intensity information detecting unit 63 determines the intensity I of the diffuse reflected light of the fixing test images TA to TC.
cA to IcC can be detected. Another difference is that the quality of the image state is determined based on the comparison result and the calculated variation and displayed on the operation panel. 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 reflected light intensity information detecting section 63, the intensity I of the diffuse reflected light of the fixing test images TA to TC is obtained.
The reason for detecting cA to IcC is that it is possible to easily determine the quality of the fixed image including the variation in the image state. That is, although the diffuse reflection light has a narrower measurement range than the regular reflection light, it has a negative correlation with the quality of the image state, and its value greatly changes depending on the quality of the image state. It is because it can be done.
Further, the luminous intensity IaA of the halogen lamps 41A to 41C.
To IaC, and the ratio between them (reflectance, for example, IbA /
IaA) may be calculated, and this may be used to determine the quality of the image state. In this case, the halogen lamp 4
This is because it is possible to eliminate the influence of the fluctuations of the emission intensities IaA to IaC of 1A to 41C on the intensities IcA to IcC of the diffuse reflection light.

When the fixing test image TA and the like are created, the reflected light intensity information detecting section 63 outputs the intensity IcA of the diffuse reflected light of the fixing test images TA to TC created on the recording medium S.
Measure ~ IcC. Then, these data are transmitted to the overall control unit 54. Thereafter, the overall control unit 54 compares the intensities IcA to IcC of the diffuse reflection light with the ideal intensities IcAr to IcCr of the diffuse reflection light obtained in advance from image data such as the fixing test image TA. Based on the results, the image quality of the fixing test images TA to TC is determined. Further, each fixing test image TA,
Based on the difference between the intensities IcA to IcC of TB and TC, the variation of the image state in the direction orthogonal to the transport direction of the recording medium S is evaluated. This makes it possible to estimate variations in a direction orthogonal to the transport direction such as fixing conditions and image forming conditions, or inconsistencies in overall fixing conditions and image forming conditions. Further, the overall control unit 54 calculates an average value Icm of the intensity IcA to IcC of the diffuse reflection light, and compares the average value Icm with the ideal intensity Icr of the diffuse reflection light of the fixing test images TA to TC obtained from the test image data. Recording medium S
The quality of the entire image state can also be evaluated.

The evaluation result of the quality including the variation of the image state is displayed on, for example, the operation panel 53. If the image state is poor, a warning sound is emitted. 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 TA to TC are created on the recording medium S periodically or by an operator's selection. . Then, the reflected light intensity information detecting unit 63 measures the intensity IcA to IcC of the diffuse reflected light of the fixing test images TA to TC. And the overall control unit 54
From the intensities IcA to IcC of the diffuse reflected light measured by the reflected light intensity information detecting unit 63, the image state of each fixing test image TA and the like is determined, and the variation of the image state is 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.

(Embodiment 3) Next, a third embodiment will be described. The configuration of the copying machine according to the third embodiment is substantially the same as that of the copying machine 1 according to the first embodiment, but the configuration of the reflected light intensity information detecting unit is different. More specifically, as shown in FIG.
Corresponding to one of the halogen lamps 41A to 41C,
Two CCD sensors 42A-42C and 62A-
62C, and has three sets of one light emitting element and two light receiving elements. The CCD sensors 42A to 42C receive specularly reflected light of incident light from the halogen lamps 41A to 41C, respectively.
The optical axes 41AL, 41BL, and 41CL of A to 41C and the intersections PA, PB, and PC of the recording medium S are respectively seen, and are arranged on the normal line of the recording medium S passing through the intersections PA, PB, and PC. . As a result, the reflected light intensity information detecting unit 73 can detect the regular reflected light intensity IbA to IbC and the diffuse reflected light intensity IcA to IcC of the fixing test images TA to TC. It is also different in that the result of judging the image state is displayed on the operation panel.

In the reflected light intensity information detecting section 73, the specular reflected light IbA for each of the fixing test images TA to TC.
ＩIbC and the intensities IcA to IcC of the diffuse reflection light are calculated, and the intensity ratio of the regular reflection light to the diffuse reflection light is calculated and used.
This is because the influence of disturbances such as fluctuations of A to IaC can be removed. 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.

When the fixing test image TA or the like is created, the image information detecting section 73 sets the intensity IbA-Ib of the regular reflection light of the fixing test image TA-TC created on the recording medium S.
C and the intensities IcA to IcC of the diffuse reflection light are measured, and these data are transmitted to the overall control unit 54. Thereafter, the overall control unit 54 determines the intensities IbA to IbC of the specularly reflected light.
And the ratio between the ideal intensity IbAr to IbCr of the specular reflection light and the ideal intensity IcAr to IcCr of the diffuse reflection light, which are obtained in advance from image data such as the fixing test image TA. Are determined, and based on the comparison result, the quality of the fixing test images TA to TC is determined. Further, each fixing test image TA, T
Based on the difference between the intensity ratios of B and TC, the variation of the image state in the direction orthogonal to the conveyance direction of the recording medium S is evaluated. This makes it possible to estimate variations in a direction orthogonal to the transport direction such as fixing conditions and image forming conditions, or inconsistencies in overall fixing conditions and image forming conditions. Further, the overall control unit 54 determines the intensities IbA to IbC of the specular reflected light.
Average value Ibm, and diffuse reflected light intensities IcA to Ic
By calculating the average value Icm of C and comparing the ideal average intensity Ibmr of the regular reflection light and the ideal average intensity Icmr of the diffuse reflection light of the fixing test images TA to TC obtained from the test image data, the entire recording medium S is obtained. It is also possible to evaluate the quality of the image state. As described above, by comparing using the ratio of the intensity information from the two light receiving elements, it is possible to determine the image state and the quality of the variation with high accuracy without being affected by disturbance. Furthermore, the general control unit 54, for example,
The drive control unit 55 and the transport control unit 5 may change the control temperature of part or all of the heating roller 40a of the fixing device 40.
6. The control values of the high-voltage control unit 58 and the like are changed to reflect the comparison results and variations found in the fixing conditions and image forming conditions. Thereby, a fixed image in a good image state can be formed on the entire recording medium S. Moreover, since the above comparison results can be obtained with high accuracy without being affected by disturbance,
Since it is possible to change the fixing conditions and the like with higher accuracy, it is possible to obtain a better fixed image.

The evaluation result regarding the quality including the variation of the image state is displayed on the operation panel 53.
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 above in detail, according to the copying machine of the third embodiment, the predetermined fixing test image TA
To TC are formed on the recording medium S, the reflected light intensity information detecting unit 73 outputs the intensity IbA to IbC of the regular reflection light and the intensity IcA to Ic of the diffuse reflection light of the fixing test images TA to TC.
Measure C. Then, the overall control unit 54 calculates the ratio between the intensity IbA to IbC of the specular reflection light and the intensity IcA to IcC of the diffuse reflection light, and further calculates the difference between the intensity ratios. The image state and its variation are evaluated. These evaluation results are notified to the operator via the operation panel 53 and the like. In addition, by reflecting the evaluation result on the fixing conditions, a fixed image having a good image state and having no variation in the image state within one recording medium can be formed. Therefore, it is possible to avoid unnecessary copying of the copy and use of an OHP sheet having a poor appearance.

(Embodiment 4) Next, a fourth embodiment will be described. The configuration of the copying machine according to the fourth embodiment is substantially the same as that of the copying machine 1 according to the first embodiment, but as shown in FIG.
The difference is that the CD sensor 82 is movable in a direction intersecting the transport direction, specifically, in a direction orthogonal to the transport direction. That is, as shown in FIG. 12, 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.
Then, by driving the drive motor 85,
The screw shaft 84 rotates, and the rotation causes C
The CD sensor 82 moves. On the other hand, the number of the halogen lamps corresponding to the number of measurement points in the direction orthogonal to the transport direction, that is, when three fixing test images (TD, TE, TF) as shown in FIG. Three (41A, 41B, 4)
1C) provided. In the present embodiment, the CCD
Although the sensor 82 is moved, the halogen lamp may be moved in reverse to provide three CCD sensors, or both may be moved simultaneously while the relative positional relationship between one set of halogen lamp and the CCD sensor is fixed. You may do so. The fixing test images TD to TF are different from the fixing test images TA to TC used in the first to third embodiments.
This is similar to the pattern shown in FIG. 8 arranged substantially diagonally on the recording medium S.

As described above, by making the CCD sensor 82 constituting the image information detecting section 83 movable, a single recording medium can be provided without providing a plurality of CCD sensors as shown in the first embodiment. The intensity information of the reflected light of the fixed image can be detected at a plurality of locations S. 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 image is created, C
The intensity IbD, IbE, and IbD of the regular reflection light of the fixing test images TD, TE, and TF created on the recording medium S by the CD sensor 82.
The IbF is measured while moving sequentially, and the respective data is transmitted to the overall control unit 54. Thereafter, the overall control unit 54 compares the intensities IbD to IbF of the specularly reflected light with the ideal intensities IbDr to IbFr of each fixing test image, and calculates a variation in the intensity from the difference between the intensities IbD to IbF. Further, the overall control unit 54 changes the control values of the drive control unit 55, the transport control unit 56, the high-voltage control unit 58, and the like, thereby reflecting the comparison result and the calculated variation on 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 the present embodiment, the fixing test images TD to TF
By calculating the variation in the intensity of the recording medium S, 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. Further, the overall control unit 54 sets an average value I of the regular reflection light intensities IbA to IbC.
bm is calculated, and the average value Ibm is compared with the ideal intensity Ibr of the regular reflection light of the fixing test images TD to TF obtained from the test image data to evaluate the image quality of the entire recording medium S. Can also. Therefore, the operator does not need to visually recognize the image after the copy is completed. In addition, even when an OHP sheet is used as a recording medium, it is not necessary to check a translucent image by a projector.

As described above in detail, according to the copying machine of the fourth embodiment, the predetermined fixing test image TD
To TF are created on the recording medium S. Then, the intensity IbD to IbF of the specular reflection light of the fixing test images TD to TF
Are sequentially measured while the CCD sensor 82 moves. Then, the overall control unit 54 sets the regular reflection light intensity IbD to IbF measured by the reflected light intensity information detection unit 83 and the ideal intensity IbD.
The results of comparison with r to IbFr and the variation in strength were determined,
By reflecting these in fixing conditions and the like, the recording medium S
A fixed image without variation can be formed in a good image state over the whole. Therefore, re-use of unnecessary copies,
The need to use unsightly OHP sheets is avoided.

(Embodiment 5) Next, a fifth embodiment will be described. The copying machine according to the fifth embodiment has substantially the same configuration as the copying machine 1 according to the first embodiment, but does not generate a test image but reflects a fixed image obtained by copying a normal original. The difference is that light intensity information is detected and processed. The processing program for the reflected light intensity information is executed after a predetermined number of copies have been made, after a predetermined operating time has elapsed, or when the operator has selected.
In the first embodiment, three sets of halogen lamps 4 are used.
In this embodiment, two sets of halogen lamps 91A, 91B and CC are used.
The difference is that a set of D sensors 92A and 92B is used. Hereinafter, the processing of the intensity information including the variation will be described with reference to FIG.
This will be described with reference to FIG. 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.

When the processing program for the reflected light intensity information is executed, first, the image reading section 2 obtains image data corresponding to the image of the original. Then, the reflected light intensity information detecting unit 93 can detect the intensity information of the reflected light of the fixed image G in the areas RA1,
In RA2, RA3,... And RB1, RB2, RB3,..., It is investigated in which area the fixed image G (image data) exists. For example, in the case shown in FIG. 13, it is found that a fixed image exists in the areas RA2 and RB2. Then, the region R is transmitted from the IR control unit 51 to the reflected light intensity information detection unit 93 via the overall control unit 54.
A command is issued to A2 and RB2 to detect the intensity information of the reflected light. Next, a copy image (fixed image) of the document is formed based on the image data read on the recording medium S by the above-described electrophotographic process.

Then, the recording medium S is discharged from the fixing device 40, and the areas RA2 and RB2 are reflected by the reflected light intensity information detecting section 9.
At the timing when the light reaches the third detection area, the reflected light intensity information detecting unit 93 measures the intensity IgA of the regular reflection light of the fixed image G by the CCD sensor 92A and the intensity IgB of the regular reflection light by the CCD sensor 92B. Then, the reflected light intensity information detecting section 93 transmits these data to the general control section 5.
Send to 4. Further, from the data memory unit 9 provided in the image reading unit 2, the image data of the areas RA2 and RB2 is transmitted to the overall control unit 54. Thereafter, the overall control unit 54 calculates the ideal intensity IgrA of the regular reflection light from the image data of the area RA2, and compares this with the intensity IgA of the regular reflection light of the actual fixed image G in the area RA2. Similarly, the ideal intensity IgrB of the regular reflection light in the region RB2 is calculated, and this is compared with the intensity IgB of the regular reflection light. Further, the overall control unit 54 calculates a comparison variation between the intensities IgA and IgB in the two regions RA2 and RB2. The general control unit 54 uses the fact that the non-uniformity or inappropriateness of the image forming conditions of the fixing unit 40 and the developing unit 32Y is estimated from the comparison result and the variation, and the overall control unit 54 By changing control values of the unit 56, the high-voltage control unit 58, and the like, the comparison result with the ideal intensity 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. In addition, 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 fifth embodiment, when the processing program for the reflected light intensity information is executed at a predetermined time or by the operator's selection, the original to be copied is copied. Whether there is image data in an area that can be measured by the reflected light intensity information detection means 93 from the image data, and if so, the position (for example, the area RA
2, RB2), and the reflected light intensity information detection unit 93
The intensities IgA and IgB of regular reflection light of the fixed image G at the detection positions (areas RA2 and RB2) are measured. Then, the overall control unit 54 sets the regular reflection light intensities IgA and IgB measured by the reflected light intensity information detection unit 93 and the detection positions (areas RA2 and RB) stored in the data memory unit 9.
2) Ideal intensity IgrA and IgrB of regular reflection light of fixed image G calculated based on image data respectively corresponding to 2)
And the variation between the intensities IgA and IgB is determined. By reflecting these in the fixing conditions and the like, a fixed image having a good image state and having no variation in the image state within one recording body can be formed. 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.

The above-described first to fifth embodiments are merely examples, and do not limit the present invention in any way. Various improvements and modifications can be made without departing from the gist of the present invention. Of course. For example, in any of the above embodiments, in any case, the ideal intensity from the fixing test image TA or the fixing image G (regions R2A and R2B) and the like is used.
The intensity of the reflected light was compared with the actually measured intensity of the reflected light, and the result of the comparison was reflected in the fixing conditions and the like together with the variation in the intensity. However, instead of using the ideal intensity, the fixing condition and the like may be changed and controlled, or the quality of the image state may be determined using the actually measured intensity of the reflected light or the reflectance obtained from the intensity. However, if the ideal intensity is known, it is easy to calculate how much the actually measured intensity deviates from the ideal, and therefore it is advantageous in that the amount of change in the fixing condition can be easily determined. Further, in the fourth and fifth embodiments, the image information detecting unit 83,
Reference numeral 93 denotes specular reflected light of the fixed image. Instead of detecting specular reflected light, diffuse reflected light may be detected as exemplified in the second embodiment. Needless to say, both the regular reflection light and the diffuse reflection light may be detected as exemplified in the embodiment. Further, in the above-described embodiment, a roller fixing system is exemplified as the fixing unit. However, the fixing unit is not limited thereto, and a belt fixing system may be used. Further, in the above-described embodiment, an example in which the present invention is applied to a copying machine has been described. However, the present invention is applicable to any apparatus having an image creating unit and a fixing unit such as a printer such as a page printer or a facsimile. be able to.

[0061]

As described above, according to the image forming apparatus of the present invention, the reflected light intensity information detecting means detects the reflected light intensity information of the fixed image at two or more different positions. Next, the reflected light intensity information processing means processes the reflected light intensity information detected by the reflected light intensity information detecting means, so that the ideal intensity corresponding to the variation in the image state of the fixed image and the image state in one recording medium is obtained. , And variations in strength are obtained. By reflecting the comparison results and variations on fixing conditions and image forming conditions,
It is also possible to automatically control a fixed image in a good image state and without variation in the image state within one sheet of recording paper. In addition, by notifying the operator of the quality of the image based on the processing result using a display panel or an alarm sound, the operator can grasp the quality of the fixed image including the variation of the image state without visually recognizing the quality. it can. In addition, re-use of unnecessary copies and O
This avoids having to use an HP sheet.

[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 diagram illustrating a configuration of an image information detection unit in the copying machine of FIG. 1;

FIG. 3 is a diagram illustrating another configuration of the image 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 a diagram showing a creation pattern of a test image.

FIG. 6 is a diagram showing a test image creation pattern.

FIG. 7 is also a diagram showing a test image creation pattern.

FIG. 8 is also a diagram showing a test image creation pattern.

FIG. 9 is a diagram illustrating a configuration of an image information detection unit in a copying machine according to a second embodiment.

FIG. 10 is a diagram illustrating a configuration of an image information detection unit in a copying machine according to a third embodiment.

FIG. 11 is a diagram illustrating a configuration of an image information detection unit in a copying machine according to a fourth embodiment.

FIG. 12 is a view showing a moving mechanism of the CCD sensor shown in FIG. 11;

FIG. 13 is a diagram for explaining a method of detecting reflected light intensity information in an image information detection unit in a copying machine according to a fifth embodiment.

FIG. 14 is a diagram illustrating a state of reflected light when fixing is performed favorably.

FIG. 15 is a diagram illustrating a state of reflected light in a case where fixing has not been properly performed.

[Explanation of symbols]

5
Image processing unit 30
Photoreceptor drum 32Y, 32C, 32M, 32K
Developing device 33
Transfer charger 34
Transfer drum 40
Fixing units 41A, 41B, 41C
Halogen lamps 42A, 42B, 42C
CCD sensor 43, 63, 73, 83, 93
Reflected light intensity information detector 54
General control section S
Recording medium TA, TB, TC, TD, TE, TF
Fixing test image

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuro Ito 2-3-1-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka International Building Minolta Co., Ltd. (reference) 2C061 AP03 AP04 AQ06 AS02 AS13 KK13 KK18 KK22 KK24 KK28 KK31 KK35 2G051 AA32. BB26 CC26 DD01 DD08 DD16 EE01 EE11 GG02 GG12 HH02

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 reflected light intensity information detecting means including a light emitting element for irradiating light to a fixed image fixed on a recording medium and a light receiving element for detecting intensity information of reflected light emitted from the light emitting element and reflected by the fixed image; Reflected light intensity information processing means for processing intensity information of the reflected light detected by the reflected light intensity information detection means, wherein the reflected light intensity information detection means is provided at at least two or more different positions in the recording medium. An image forming apparatus capable of detecting intensity information of light reflected by the fixed image. 2. The image forming apparatus according to claim 1, wherein the reflected light intensity information detecting unit includes two or more sets of the light emitting element and the light receiving element in a direction intersecting a conveying direction of the recording medium. An image forming apparatus comprising: 3. The image forming apparatus according to claim 1, wherein the reflected light intensity information detecting means 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. The reflected light intensity information detecting means detects the intensity information of the reflected light reflected by the fixed test image fixed on the recording medium, and the reflected light intensity information processing means comprises: An image forming apparatus for processing intensity information of reflected light of the fixing test image.