JP2000284553A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of detecting normal/ defective of the image state on the fixation image without observing it. SOLUTION: Relating to a general controlling part, a fixation test image T is formed on a rereading body S periodically or by selection of an operator. As a result, the image information detecting part 43 detects the strength Ib of straight passing light of the fixation test image T. Then, the above general controlling part compares the strength Ib of the straight passing light detected by the image information detecting part 43 and the ideal strength (Ibr) of the straight passing light of the calculated fixation test image T based on test image data, from the comparison result, the general controlling part changes the controlling value to reflecting it on the fixing condition, the image forming condition or the like. In such a manner, the image formation of a copying or the like can be performed in a sate of always securing the excellent image state, without observing normal/defective of the image state of the fixed image. Therefore, the events being forced to take fruitless copying again, or to have to adopt bad looking OHP sheet can be evaded.

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 increasing the fixing temperature or decreasing the fixing speed to supply a larger amount of heat than that supplied to 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. The quality of the image condition was not understood. Therefore, for example, when a recording medium different from the conventionally supposed basis weight and type is used, or when an abnormality in the temperature control of the heating roller occurs, a good image state due to poor melting of the toner or the like is obtained. There was a possibility that it could not be obtained.

Further, when a large number of copies are made at one time, it is troublesome to check the quality of the image one by one, so it is generally performed after all copies are completed. . Further, when the OHP sheet was used as the recording medium, the quality of the image state was not known until the actual translucent image was visually recognized by the 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 problem, and has as its object to provide an image forming apparatus capable of detecting the quality of a fixed image.

[0007]

According to the image forming apparatus of the present invention which has been made to solve the above-mentioned 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. Fixing means for fixing the fixed image on the recording medium, image information detecting means for detecting image information of a fixed image fixed on the recording medium by the fixing means, and image information detected by the image information detecting means. And an image information processing means for processing.

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 test image data previously stored in the image forming apparatus. A predetermined test image is also included. Next, the fixing unit fixes the image created by the image creating unit on the recording medium. Then, the image information detecting means detects the image information of the fixed image fixed on the recording medium. Then, the image information processing means processes the image information detected by the image 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.

The recording medium may be any paper that can fix the image, such as plain paper, thick paper, OHP sheet, and special paper coated with resin. Further, the image information refers to information related to the state of the image such as surface state, fixing property, translucency, and color developing property, and includes any information as long as the image state can be known. . Specifically, the intensity of transmitted light (transmittance) of the fixed image, the intensity of reflected light (reflectance), or a color shift (a shift in brightness, hue, and saturation) can be given.

Further, according to the image forming apparatus of the present invention, there is provided an image forming means for forming an image on a recording medium, and a fixing means for fixing the image generated by the image forming means on the recording medium. In the image forming apparatus, the light emitting element for irradiating the fixed image fixed on the recording medium by the fixing unit with light, and the intensity information of the transmitted light emitted from the light emitting element and transmitted through the recording medium and the fixed image, The transmitted light intensity information detecting means includes a light receiving element for detecting, and transmitted light intensity information processing means for processing the transmitted light intensity information detected by the transmitted light intensity information detecting means.

In this image forming apparatus, first, the 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 transmitted light intensity information detecting means detects the transmitted light intensity information of the fixed image fixed on the recording medium. The intensity information of the transmitted light is detected by irradiating the fixed image on the recording body with light by the light emitting element and receiving the transmitted light transmitted through the recording body and the fixed image by the light receiving element. Irradiation of light from the light emitting element to the fixed image is performed directly or via a recording medium. The light received by the light receiving element is transmitted light that has passed through both the recording medium and the fixed image. The transmitted light intensity information thus obtained by the transmitted light intensity information detecting means is processed by the transmitted light intensity information processing means. 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, control is performed to automatically obtain a good fixed image. be able to. Further, the image state of the fixed image can be evaluated, and a warning or a serviceman call can be displayed to the operator.

The reason why the transmitted light intensity information is detected and processed as described above is that the transmitted light intensity information can be used as one of the indexes for evaluating the image state of the fixed image. For example, if the fixation of the toner is insufficient for some reason, the transmittance of the fixed image is low, and an image state in which the image looks slightly darker is obtained. On the other hand, when the toner is sufficiently fixed, since the light passes through the fixed image without being refracted, the transmittance of the fixed image is high, and the image state is bright and easy to see.
Referring to the drawings, when the fixing is performed well, the toner is sufficiently melted and the surface of the fixed image TGA on the recording medium S becomes smooth as shown in FIG. The light intensity increases. For this reason, when projected by the projector, the image looks bright and has a good image.

On the other hand, if the fixing is not good,
As shown in FIG. 6, since the surface of the fixed image TGB on the recording medium S is not smooth but uneven without the toner being sufficiently melted, the incident light is refracted and transmitted, so that the intensity of the refracted transmitted light is reduced. The intensity increases and the intensity of the straight transmitted light decreases. For this reason, when projected by the projector, the image looks a little dark and poor. Therefore, by detecting the intensity information of the straight transmitted light or the refracted transmitted light, the quality of the fixed image can be determined. Note that the straight transmitted light refers to the transmitted light in which the incident light that has entered the fixed image travels straight without being bent by refraction or the like (in the following description, “straight transmitted light” is used in the same meaning). The term “refracted transmitted light” refers to transmitted light whose incident light that has entered a fixed image has its path deflected due to refraction or the like (in the following description, “refracted transmitted light” is used in the same sense).

In order to obtain the transmittance, the intensity of incident light is required in addition to the intensity of transmitted light. Therefore, in addition to the transmitted light,
The intensity of the incident light may be separately detected. 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, in the measurement of the intensity of the incident light, a method of directly measuring the intensity using a half mirror or the like, and a method of indirectly measuring the applied voltage, the current consumption, the power consumption, and the like of the light emitting element can also be used. .

Further, if the transmitted light is used to evaluate the image state of the fixed image, it is sufficient to obtain the intensity of the transmitted light or to calculate the transmittance after obtaining the intensity of the incident light. This is advantageous in that it is simple and easy to process, and is not easily affected by deformation such as waving or curling of the recording medium. In particular, when transmitted light is used when an OHP sheet is used as a recording medium, it is very preferable because the image state of a fixed image can be evaluated in the same state as when an OHP sheet is actually used.

The light emitting element may be any element that 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. 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, a CCD, a photodiode, and the like can be given.

In the image forming apparatus according to the present invention, it is preferable that the light receiving element is disposed coaxially with an optical axis of the light emitting element.

Since the light receiving element is arranged coaxially with the optical axis of the light emitting element as described above, the intensity information of the straight transmitted light can be obtained. By processing this, the processing result is fixed as described above. It can be reflected in conditions and the like. Alternatively, it is possible to know the quality of the image state and notify the operator. Further, the transmittance of the linearly transmitted light or the intensity information of the linearly transmitted light may range, for example, from 0% to 100% for the transmittance, and from zero to almost the same value as the intensity of the incident light for the intensity information. For,
It is advantageous over a case where refracted transmitted light is detected, in that the measurement range is wide and it is strong against noise. In addition, as compared with the case where only the intensity information of the straight transmitted light is used, the incident light intensity (emission intensity) information of the light emitting element is also obtained, and when the straight transmittance (the ratio of both) is calculated and used, It is more desirable because it becomes strong against disturbance such as fluctuation of the light emission intensity of the light emitting element.

Further, in the image forming apparatus according to the present invention, the light receiving element is arranged at a position deviated from the optical axis of the light emitting element so as to see an intersection between the optical axis and the recording medium. You may.

By arranging the light receiving element non-coaxially with the optical axis of the light emitting element so as to look at the intersection between the recording medium and the optical axis, the intensity information of the refracted transmitted light can be obtained. This is because, as described above, it is possible to easily determine whether the image state of the fixed image is good or not, or the processing result can reflect the fixing condition and the like. Also,
The transmittance of the refracted transmitted light, or the intensity information of the refracted transmitted light, is smaller in the value of the transmissivity and the intensity information obtained in comparison with the straight transmitted light, and its range, that is, the measurement range is narrow, but it is larger depending on the quality of the image state. Since the value changes, it is more advantageous than the case of using the straight transmitted light in that the quality of the image state can be easily determined. In addition, as compared with the case where only the intensity information of the refraction and transmission light is used, the incident light intensity information of the light emitting element is also obtained and the refraction transmittance is calculated and used. ) Is more preferable because it also becomes strong against disturbances such as fluctuations in (1).

Further, in the image forming apparatus according to the present invention, the transmitted light intensity information detecting means has two or more light receiving elements, one of which is arranged coaxially with the optical axis of the light emitting element. Others may be arranged at positions deviated from the optical axis while allowing for the intersection of the optical axis of the light emitting element and the recording medium.

By arranging the light receiving elements in this manner, it is possible to obtain the intensity information of both the straight transmitted light and the refracted transmitted light. It is possible to reduce the influence of disturbance and noise.

In the image forming apparatus according to the present invention, the transmitted light intensity information detecting means detects the transmitted light intensity information for each of the fixed images on the plurality of recording media fixed in succession. The transmitted light intensity information processing means may also process a variation relating to the transmitted light intensity information of each fixed image.

The transmitted light intensity information is detected for each of the fixed images on the plurality of recording materials which are fixed in succession in this way, and the variation of the transmitted light intensity information of the fixed image is also processed. Since it is possible to know the fluctuation, it is detected whether or not the heat supply is properly performed in the fixing unit when a recording medium that requires a large amount of heat for fixing such as an OHP sheet is used. can do. If the heat supply is not performed properly,
This is because even if the original recording medium can be fixed well, the amount of heat is gradually removed from the fixing unit and fixing is not sufficiently performed, so that the intensity information of the transmitted light of the fixed image also gradually changes. Therefore, by detecting this variation and using the result of the detection to appropriately change the fixing conditions and the like, it is possible to obtain a good fixed image according to the characteristics such as the heat capacity of the recording medium used even when forming images continuously. Can be controlled so that

In the image forming apparatus according to 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, and The intensity information detecting means includes:
It is preferable that intensity information of transmitted light transmitted through the fixing test image fixed on the recording medium is detected, and the transmitted light intensity information processing means processes the transmitted light intensity information of the fixing test image.

By using the fixing test image obtained from the test image data stored in advance as described above, the position of the fixed image to be detected is known in advance, so that the intensity information of the transmitted light of the fixed image can be surely obtained. Can be obtained. Therefore, the quality of the image state can be reliably determined, and the processing result of the transmitted light intensity information on the obtained test image can be reflected on the fixing condition, the image forming condition, and the like. 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 the quality of the image state, or to determine the fixing condition or the like. Can be reflected in

[0027]

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 a fixed 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; an image information detecting unit 43 including a halogen lamp 41 and a CCD sensor 42; And a paper discharge tray 46 for accommodating the recording medium discharged outside the apparatus.

Here, the image information detecting section 43 is for grasping information for detecting the image state of the fixed image, and specifically, for detecting the intensity information of the transmitted light of the fixed image. . This image information detection unit 43 is, for example,
As shown in FIG. 5, when a substantially rectangular fixing test image T is formed on the recording medium S at the upper left corner when the conveyance direction indicated by the arrow in the recording medium S is directed upward, this fixing test image It is arranged at a position where the intensity of the transmitted light of T can be measured. That is, a halogen lamp 41 which is a light emitting element is provided on the lower side in the figure of the recording medium S discharged from the fixing device 40 behind the fixing device 40 in the recording material S, and the optical axis 41L of the halogen lamp 41 is provided. A CCD sensor 42, which is a light receiving element, is provided on the upper side in FIG. As described above, the image information detecting unit 43 communicates with the halogen lamp 41 and the CC.
The D sensor 42 is configured in a paired state.

The arrangement of the halogen lamp 41 and the CCD sensor 42 may be upside down. Further, not only is the optical axis 41L of the halogen lamp 41 and the recording medium S orthogonal to each other as shown in FIG. 2, but also the optical axis 41L of the halogen lamp 41 and the recording medium S form a predetermined angle as shown in FIG. The halogen lamp 41 and the CCD sensor 42 may be arranged as described above.

However, when the halogen lamp 41 and the CCD sensor 42 are arranged as shown in FIG.
It is desirable that the angle between L and the recording medium is 45 degrees or more. If the angle is smaller than 45 degrees, the component of the reflected light becomes large, and the intensity information of the straight transmitted light cannot be measured accurately. Further, the angle is more preferably 90 degrees (the state of FIG. 2). Thus, the halogen lamp 41
If the CCD sensor 42 is arranged, the influence of the thickness of the fixing test image T and the lifting of the recording medium S during measurement can be made less likely, and the intensity information of the straight transmitted light can be measured more accurately.

By arranging the halogen lamp 41 and the CCD sensor 42 in this manner, the image information detecting section 4
Reference numeral 3 can detect the intensity information of the straight transmitted light of the fixing test image T. That is, the image information detection unit 43
By detecting the intensity Ib of the transmitted light received by the sensor 42, the intensity information of the straight transmitted light of the fixing test image T is detected. The intensity information of the straight transmitted light is detected because it 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, the image information detecting section 43 may also detect the light emission intensity Ia of the halogen lamp 41 and detect the ratio between them (that is, transmittance = Ib / Ia). Thereby, it is possible to eliminate the influence on the intensity Ib of the transmitted light due to the fluctuation of the emission intensity Ia of the halogen lamp 41 and the like. In the present embodiment, the light emission intensity of the halogen lamp 41 is kept constant, and the transmitted light intensity information is used as it is without obtaining the transmittance.

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 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
The high-voltage control unit 58 that controls high voltage such as charging of the photosensitive drum 30, the application of a developing bias, and the application of a transfer bias, the laser control unit 59 that performs laser beam modulation control, and the image information detection unit 43 are connected. Have been. In addition, the general control unit 5
Signals from an operation panel 53 are input to the controller 4 via a 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 image T is created in order to grasp the image state of the fixed image, the test image data stored in advance in the ROM in the general control unit 54 uses the laser control data shown in FIG. Input to the unit 59,
According to the above procedure, a predetermined fixing test image T is created. The generation of the fixing test image T 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.

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 an arbitrary color using a plurality of toners. When a plurality of toners are used, the melting state of the toner in various images can be detected. 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. 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 transmitted light intensity (transmittance) of each fixing test image is detected, and a straight line representing the relationship between the image density and the transmitted light intensity (transmittance) is obtained from the result by the least square method, A true value of transmitted light intensity (transmittance) for each fixing test image can be obtained. With this, compared to creating only one fixing test image,
The transmitted light intensity (transmittance) of the fixing test image can be detected with higher accuracy. Therefore, the image state of the fixing test image can be grasped more accurately. Alternatively, a plurality (three or more) of fixing test images having the same image density may be created in the recording medium transport direction, and the average value of the transmitted light intensity (transmittance) of each fixing test image may be obtained.

When the fixing test image T is created,
The image information detecting unit 43 measures the intensity Ib of the straight transmitted light of the fixing test image T created on the recording medium S, and transmits this data to the overall control unit 54. After that, the general control unit 5
4 shows the intensity Ib of the straight transmitted light and the fixing test image T
Is compared with the ideal intensity Ibr of the straight transmitted light obtained in advance from the image data. In the present embodiment, the light emission intensity of the halogen lamp 41 is kept constant, and the transmitted light intensity information is used as it is without obtaining the transmittance. Further, utilizing the fact that the comparison result corresponds to the quality of the image state of the fixing test image T, the overall control unit 54 determines whether or not the image state is good or not. 40 heating rollers 40
By changing the control values of the drive control unit 55, the conveyance control unit 56, the high-pressure control unit 58, and the like, the obtained comparison result, such as changing the control temperature of a, is reflected on the fixing condition and the image forming condition. Thereby, a fixed image in a good image state can be formed. 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.

As described above in detail, according to the copying machine 1 of the first embodiment, a predetermined fixing test image T is created on the recording medium S periodically or by an operator's selection. Then, the image information detection unit 43 measures the intensity Ib of the straight transmitted light of the fixing test image T. Then, the overall control unit 54 calculates the ideal intensity Ib of the straight transmitted light of the fixing test image T calculated based on the test image data and the intensity Ib of the straight transmitted light measured by the image information detecting unit 43.
and br. By reflecting the comparison result in the fixing conditions and the like, a fixed image in a good image state can be 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, one patch-like fixing test image (hereinafter, also simply referred to as a “patch”) T is formed on the recording medium S. A pattern created by arranging a plurality of patches TP in a direction (horizontal direction in the figure) orthogonal to the transport direction of the recording medium S (upward in the figure) as shown in FIG. 5, and a plurality of patches as shown in FIG. A pattern in which TPs are formed by arranging them in the transport direction of the recording medium S (vertical direction in the figure), a pattern in which patches TP are formed at four corners of the recording medium S as shown in FIG. There is a pattern in which a plurality of patches TP are arranged and created thereon.

Here, in the case where the image information detecting section 43 composed of one set of the halogen lamp 41 and the CCD sensor 42 is used as exemplified in the first embodiment,
With the pattern shown in FIG. 6, the intensity information of the transmitted light can be detected for a plurality of patches TP. On the other hand, when a pattern as shown in FIGS. 5, 7, and 8 is created as a fixing test image, an image information detection unit including a plurality of sets of halogen lamps and a CCD sensor in a direction intersecting the transport direction is used. There is a need to. In any case,
When the transmitted light intensity information of the plurality of fixing test images (patches) TP is detected, the transmitted light intensity information can be accurately measured by calculating an average value or the like.

Further, as described 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. 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.

(Second Embodiment) Next, a second embodiment will be described. The configuration of the copying machine according to the second embodiment is substantially the same as that of the copying machine 1 according to the first embodiment, but the configuration of the image information detecting unit and the transmitted light intensity information are compared with the ideal intensity. Subsequent processing is different. Specifically, as shown in FIG. 9, the CCD sensor 62 in the image information detecting unit 63 is connected to the optical axis 41L of the halogen lamp 41.
The difference is that the intersection point P of the halogen lamp 41 is arranged at a position deviated from the optical axis 41L while allowing for the intersection point P between the recording medium S and the recording medium S. Thus, the image information detecting unit 63 can detect the intensity Ic of the refracted transmitted light of the fixing test image T. Another difference is that the quality of the image is judged based on the comparison result 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 image information detecting section 63,
The reason why the intensity Ic of the refracted transmitted light of the fixing test image T is detected is that the quality of the image state of the fixed image can be easily determined. That is, although the refracted transmitted light has a narrower measurement range than the straight transmitted light, it has a negative correlation with the quality of the image state of the toner, and its value greatly changes depending on the quality of the image state. Can be easily performed. Alternatively, the light emission intensity Ia of the halogen lamp 41 may be detected to calculate the ratio (Ib / Ia) between the two, and the quality of the image state may be determined using the calculated ratio. In this case, the emission intensity I of the halogen lamp 41
This is because it is possible to eliminate the influence on the intensity Ic of the refracted transmitted light due to the fluctuation of a.

When the fixing test image T is created,
The image information detecting section 63 measures the intensity Ic of the refracted transmitted light of the fixing test image T created on the recording medium S, and transmits this data to the overall control section 54. After that, the general control unit 5
Reference numeral 4 denotes a comparison between the intensity Ic of the refracted transmitted light and the ideal intensity Icr of the refracted transmitted light obtained in advance from the image data of the fixing test image T, and based on the comparison result, the image state of the fixed test image T. Is determined. The result of this determination is displayed on the operation panel 53. If the image state is defective, a warning sound is issued. If the fixing failure is severe, the subsequent copying is stopped and the service person is contacted. Is displayed on the operation panel 53. As a result, the operator can easily know whether the image state of the image after the copy has been completed is good or not. 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 second embodiment, when a predetermined fixing test image T is created on the recording medium S, the image information detecting section 63 The intensity Ic of the refracted transmitted light of the post-test image T is measured.
Then, the overall control unit 54 compares the intensity Ic of the refraction and transmission light measured by the image information detection unit 63 with the ideal intensity Icr of the refraction and transmission light of the fixing test image T calculated based on the test image data. Then, the quality of the image state of the fixing test image T on the recording medium S is determined. The result of this determination is notified to the operator via the operation panel 53 and the like. This avoids wasteful recopying and the need to use OHP sheets with poor appearance.

(Third Embodiment) 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 image information detecting unit is different. Specifically, as shown in FIG. 10, the difference is that the image information detection unit 73 is provided with two CCD sensors 42 and 62. The CCD sensor 42 is the optical axis 41 of the halogen lamp 41
The CCD sensor 62 is arranged coaxially with L, and is located at a position deviated from the optical axis 41L of the halogen lamp 41 while seeing the intersection P between the optical axis 41L of the halogen lamp 41 and the recording medium S. . Thus, the image information detecting section 73 can detect the intensity Ib of the straight-forward transmitted light and the intensity Ic of the refracted transmitted light of the fixing test image T.
Another difference is that an image state determination result is displayed on the operation panel.

The image information detecting section 73 detects the intensity Ic of the straight transmitted light Ib and the refracted transmitted light of the fixing test image T, calculates the intensity ratio between the straight transmitted light and the refracted transmitted light, and uses the intensity ratio for quality judgment. This is because the influence of disturbance such as a change in the light emission intensity Ia of the halogen lamp 41 can be removed, so that the quality of the image state can be more reliably determined. The copy operation and the test image creation operation are the first
Since the configuration is the same as that of the first embodiment, the description thereof is omitted, and components having the same configuration are denoted by the same reference numerals.

When the fixing test image T is created,
The image information detection unit 73 measures the intensity Ib of the straight transmission light and the intensity Ic of the refraction transmission light of the fixing test image T created on the recording medium S, and transmits these data to the general control unit 54.
Send to Thereafter, the overall control unit 54 determines the ratio between the intensity Ib of the straight transmitted light and the intensity Ic of the refracted transmitted light, the ideal intensity Ibr of the straight transmitted light of the fixing test image T previously obtained from the image data, and the refracted transmitted light. The ratio with the ideal intensity Icr is compared. Then, based on the comparison result, the overall control unit 54 determines whether the image state of the fixing test image T is good. By comparing the two types of intensity information using the ratios, it is possible to determine the quality of the image state with high accuracy and without being affected by disturbance. Thereafter, the result of this determination is displayed on the operation panel 53. As a result, the operator can easily know whether the image state of the image after the copy has been completed is good or not.

Further, the general control unit 54 transmits the obtained comparison result, for example, by changing the control temperature of the heating roller 40a of the fixing device 40, to the drive control unit 55 and the transport control unit 5.
6. Change the control values of the high-voltage control section 58 and the like to reflect them on the fixing conditions and the image forming conditions. Thereby, a fixed image in a good image state can be formed. Moreover, since the above-described comparison result is obtained with high accuracy without being affected by disturbance, it is possible to change the fixing conditions and the like with higher accuracy.
Further, a good fixed image can be obtained. 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, when the predetermined fixing test image T is created on the recording medium S, the image information detecting section 63 The intensity Ib of the straight transmitted light and the intensity Ic of the refracted transmitted light of the post-test image T are measured. And the overall control unit 54
The ratio between the intensity Ib of the linearly transmitted light and the intensity Ic of the refracted transmitted light measured by the image information detection unit 63 is calculated by calculating the ideal intensity Ibr of the linearly transmitted light calculated based on test image data for creating the fixing test image T. By comparing with the ratio of the ideal intensity Icr of the refracted transmitted light, the quality of the image state of the fixing test image T on the recording medium S is determined. The result of this determination is notified to the operator via the operation panel 53 and the like. In addition, by reflecting the comparison result in fixing conditions and the like, a fixed image in a good image state can be obtained.
Therefore, it is necessary to re-use useless copies,
The situation of having to use a P-sheet is avoided.

(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 as shown in FIG.
3 in that the three CCD sensors 82 can move 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 halogen lamps 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), three (41A, 41B, 41C) are provided correspondingly. Although the CCD sensor 82 is moved in the present embodiment,
Move the halogen lamp 41 and set the CCD sensor 42 to 3
Or one set of halogen lamps 4
The two may be moved while the relative positional relationship between 1 and the CCD sensor 42 is fixed.

By making the CCD sensor 82 constituting the image information detecting section 83 movable, the CCD
The intensity 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 sensors 82. As a result, the average value can be calculated from the transmitted light intensity information at the plurality of locations, and the quality of the image state can be determined using the average value. Therefore, the quality can be determined more accurately than the measurement at one place. The copy operation and the test image creation operation
The description is omitted because it is the same as the first embodiment,
Components 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 Ib of the straight transmitted light of the fixing test images TA, TB, TC created on the recording medium S.
A, IbB, and IbC are measured while moving sequentially, and each data is transmitted to the overall control unit 54. Thereafter, the overall control unit 54 directly transmits the intensity IbA to IbA of the transmitted light.
The average value Ibm of bC is calculated, and the average value Ibm is compared with the ideal average intensity Ibmr of the straight transmitted light of the fixing test images TA to TC obtained from each test image data. Using the comparison result, the overall control unit 54 changes control values of the drive control unit 55, the transport control unit 56, the high-voltage control unit 58, and the like, and reflects the control values on the fixing condition and the image forming condition. Thereby, a fixed image in a good image state can be formed. 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. Further, in order to remove the influence of disturbance, the light emission intensity Ia of the halogen lamp 41A or the like is used.
A and the like may be detected, and the ratios to the transmitted light intensities may be calculated, and the average of these may be used to determine the quality of the image state.

As described above in detail, according to the copying machine of the fourth embodiment, a plurality of fixing test images T
A to TC are created on the recording medium S. On the other hand, the intensity IbA to IbC of the linearly transmitted light of the fixing test images TA to TC
Are sequentially measured while the CCD sensor 82 moves. Then, the overall control unit 54 calculates the average value Ibm of the intensity IbA to IbC of the straight transmission light measured by the image information detection unit 83 and the ideal average intensity Ibmr of the straight transmission light of the fixing test image calculated based on the test image data. Compare. By reflecting the comparison result in the fixing conditions and the like, a fixed image in a good image state can be formed. Therefore, it is possible to avoid unnecessary copying of the copy and use of an OHP sheet having a poor appearance.

(Fifth Embodiment) 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, except that a fixed image obtained by copying a normal original without forming a fixing test image. Detecting transmitted light intensity information,
The processing is different. This transmitted light intensity 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, processing of transmitted light intensity information will be described with reference to FIG.
3 will be described. 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 transmitted light intensity information is executed, first, the image reading section 2 obtains image data corresponding to the image of the original. Next, regions R1, R2, R in which the image information detecting section 43 can detect the intensity information of the transmitted light of the fixed image.
In 3,..., It is investigated in which area the fixed image (image data) exists. For example, in the case shown in FIG. 13, it is found that the fixed image exists in the region R2. Then, the IR control unit 51 issues a command to the image information detection unit 43 via the overall control unit 54 to detect the intensity information of the transmitted light in the region R2. Next, a copy image (fixed image) of the document is formed on the recording medium S based on the image data read by the above-described electrophotographic process.

When the recording medium S is ejected from the fixing device 40 and the region R2 reaches the detection region of the image information detection unit 43, the image information detection unit 43 determines the intensity Ig of the straight transmitted light of the fixed image G. The data is measured and transmitted to the overall control unit 54. Further, from the data memory unit 9 provided in the image reading unit 2, the image data of the region R2 is transmitted to the general control unit 54. Thereafter, the general control unit 54
Is the ideal intensity I of the straight transmitted light from the image data of the region R2.
gr is calculated, and this is compared with the intensity Ig of the straight transmitted light of the actual fixed image G in the region R2. Then, using the comparison result, the overall control unit 54 sets the drive control unit 55
And the control values of the conveyance control unit 56, the high-pressure control unit 58, and the like are changed and reflected in the fixing conditions and the image forming conditions. Thereby, a fixed image in a good image state can be formed. Further, the operator can easily know whether the image state of the image after the copy is completed is good or not. 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.

As described above in detail, according to the copying machine of the fifth embodiment, when the processing program for transmitted light intensity information is executed at a predetermined time or by an operator's selection, the original to be copied is copied. Whether there is image data in an area that can be measured by the image information detection unit 43 from the image data,
If there is image data, the position (for example, the region R2) is checked, and the image information detection unit 43 measures the intensity Ig of the straight transmitted light of the fixed image in the region R2. Then, the general control unit 54 calculates the straight traveling of the fixed image calculated based on the intensity Ig of the straight transmitted light measured by the image information detecting unit 43 and the image data corresponding to the region R2 stored in the data memory unit 9. By comparing the transmitted light with the ideal intensity Igr, the quality of the image state of the fixed image on the recording medium S is determined. This determination result is reported to the operator via the operation panel 53 or the like. 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.

Finally, a sixth embodiment will be described. In the first to fifth embodiments, the intensity information of the transmitted light is obtained from one recording medium, and the obtained information is processed and reflected on fixing conditions or the like, and the quality of the image on the recording medium is determined. . However, for example, when a cardboard or an OHP sheet that continuously removes a large amount of heat from the fixing unit 40 due to its large heat capacity is used continuously, even if the first sheet has a good image state, the amount of heat applied to the fixing unit 40 is small. Supply cannot keep up,
The fixing temperature gradually decreases, and the image state may deteriorate. On the other hand, in the present embodiment, as shown in FIG. 14, each of the fixing test images T on the plurality of recording materials S1, S2, S3.
, T2, T3,.
.. Are sequentially detected. The integrated control unit 54 processes the fixing test images T1, T2,... Of the recording materials S1, S2,..., And also calculates the fluctuation of the detection results among the recording materials S1, S2,.

Thus, for example, when using a recording medium that requires a large amount of heat for fixing, such as an OHP sheet,
When trying to fix such recording paper continuously,
Based on the current temperature control conditions of the fixing device 40, the fixing time interval (paper feed interval), the conveyance speed, and the like, it can be estimated whether or not the image can be continuously fixed while maintaining a good image state of a certain level or more. Alternatively, the amount of heat supplied to the fixing device 40, the fixing time interval, the fixing speed, and the like may be adjusted so that the toner image is continuously printed on the recording medium as quickly as possible while maintaining a favorable image state in the fixing device 40. Can be estimated, and the conditions can be changed.

Therefore, the intensity Ib1, Ib
By calculating the variation between b2, Ib3,..., and using the calculation result to change the fixing conditions and the like so as to be suitable for the recording paper to be used, an image state of a certain level or more even when fixing is performed continuously. Can be controlled so as to obtain a good fixed image having the following. In the present embodiment, the intensity Ib1 and the like of the straight transmitted light are measured. However, the refracted transmitted light may be detected in the same manner as in the second embodiment, or the third embodiment may be used. Like the form,
Obviously, both the straight transmitted light and the refracted transmitted light may be detected.

The above-described first to sixth 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 each case, the intensity of the transmitted light is measured using the ideal intensity from the fixing test image T and the fixing image G (region R2), and the comparison result is used as the fixing condition. The quality of the image state was determined based on the result of the reflection and the comparison result. However, without using the ideal intensity, using the actually measured transmitted light intensity or the transmittance determined therefrom,
The fixing condition and the like may be changed and controlled, or the quality of the image may be determined. However, if the ideal intensity is known, it is easy to calculate how much the actually measured intensity deviates from the ideal, and thus it is advantageous in that the amount of change in the fixing condition and the like can be easily determined.

In the fourth and fifth embodiments,
Although the image information detectors 83 and 43 detect the straight transmitted light of the fixed image, instead of detecting the straight transmitted light, the image information detectors 83 and 43 may detect the refracted transmitted light as exemplified in the second embodiment. Further, it goes without saying that both the straight transmitted light and the refracted transmitted light may be detected as exemplified in the third embodiment. 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 can be applied to any apparatus having an image forming unit and a fixing unit, such as a printer such as a page printer and a facsimile. Can be.

[0071]

As described above, according to the image forming apparatus of the present invention, the image state detecting means detects the image information of the fixed image. Next, the image information processing means processes the image information detected by the image information detecting means. Therefore, by reflecting the processing result in the fixing condition, a fixed image in a good image state can be obtained. In addition, by notifying the operator of the processing result using a display panel or a warning sound, the operator can grasp the quality of the fixed image without visually recognizing the quality. For this reason, useless copies must be retaken, and OH
This avoids having to use a P-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 a diagram showing a test image creation pattern.

FIG. 8 is 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 transmitted light in an image information detection unit in a copying machine according to a fifth embodiment.

FIG. 14 is a diagram for explaining a method of detecting transmitted light in an image information detection unit and a processing method thereof when a variation in a fixed image is also processed in the copying machine according to the sixth embodiment.

FIG. 15 is a diagram illustrating a state of transmitted light when fixing is performed favorably.

FIG. 16 is a diagram illustrating a state of transmitted light in a case where fixing has not been 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 41 Halogen Lamp 42 CCD Sensor 43 Image Information Detecting Unit 54 Overall Control Unit S Recording Material T Fixing Test Image

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Isogai 2-13-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka International Building Minolta Co., Ltd. 2C061 AQ06 AS13 KK03 KK04 KK26 KK28 KK35 2H027 DA32 DA50 DE02 DE07 DE10 EA12 EC03 EC06 EC19 EF09 HA02 HA03 HA12 ZA07 2H033 AA02 AA11 CA01 CA30 CA36 5C074 AA07 AA20 BB02 DD08 DD16 EE01 GG13 HH02

Claims (7)

[Claims] An image forming means for forming an image on a recording medium; a fixing means for fixing the image generated by the image forming means on the recording medium; and a fixing means for fixing the image on the recording medium by the fixing means. An image forming apparatus comprising: an image state detecting unit that detects an image state of a fixed image that has been fixed; and an image information processing unit that processes image information detected by the image state detecting unit. 2. An image forming apparatus comprising: image forming means for forming an image on a recording medium; and fixing means for fixing the image generated by the image generating means on the recording medium. Transmitted light intensity information including a light emitting element that irradiates light to a fixed image fixed on a recording medium, and a light receiving element that detects intensity information of transmitted light transmitted from the light emitting element and transmitted through the recorded body and the fixed image. An image forming apparatus comprising: a detection unit; and a transmitted light intensity information processing unit that processes intensity information of transmitted light detected by the transmitted light intensity information detection unit. 3. The image forming apparatus according to claim 2, wherein the light receiving element is arranged coaxially with an optical axis of the light emitting element. 4. The image forming apparatus according to claim 2, wherein the light receiving element is arranged at a position deviated from an optical axis of the light emitting element so as to see an intersection between the optical axis and the recording medium. An image forming apparatus comprising: 5. The image forming apparatus according to claim 2, wherein the transmitted light intensity information detecting means has two or more light receiving elements, one of which is coaxial with the optical axis of the light emitting element. An image forming apparatus, wherein the image forming apparatus is arranged at a position deviated from the optical axis while allowing the intersection between the optical axis of the light emitting element and the recording medium to be seen. 6. The image forming apparatus according to claim 2, wherein the transmitted light intensity information detecting unit is configured to fix each of the fixed images on the plurality of recording media that are continuously fixed. Wherein the transmitted light intensity information processing means also processes a change in the transmitted light intensity information of each of the fixed images. 7. The image forming apparatus according to claim 2, wherein the image creating unit stores test image data for creating a predetermined test image on the recording medium. The transmitted light intensity information detecting means detects intensity information of transmitted light transmitted through a fixed test image fixed on the recording medium, and the transmitted light intensity information processing means includes: An image forming apparatus for processing intensity information of transmitted light of the fixing test image.