JP2000293062A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably secure an excellent image state by restraining unevenness in the application of oil. SOLUTION: By forming fixing test images TA to TC on a recording body S, a supervisory control part 54 calculates measured glossiness from the intensity of reflected light concerning the respective images TA to TC detected by an image information detection part. Then, it calculates required glossiness from test image data and fixing temperature. The difference of the glossiness between the images TA to TC and a difference from the required glossiness are calculated, and 2nd cams 274A and 274C and a 1st cam 264 are turned by a specified angle so as to eliminate the differences. Thus, the press-contact force of an oil quantity regulating blade 243 is made nearly equal to a designed required value all over the axial direction. Therefore, fixing is performed in a state where the unevenness in the application of the oil is restrained, so that the fixed image in the excellent image state is obtained.

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 stably obtaining a fixed image in which a good image state is secured.

[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 pair of fixing rollers is configured by a heating roller and a pressure roller,
There is known a fixing roller provided with an oil application roller for applying oil (silicone oil) to the fixing roller in order to maintain the releasing property of the fixing roller. 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 a fixing device provided in a color image forming apparatus, the surface of a heating roller is also covered with silicone rubber, and an oil application roller (or an oil application felt) is always provided.

Here, if the oil application to the fixing roller is not uniform, there is a high possibility that the image state of the fixed image will be adversely affected. For this reason, an oil amount regulating blade is provided to uniformly scrape off the oil on the oil application roller, thereby uniformly supplying the oil, and thereby uniformly applying the oil to the fixing roller. In order to improve the uniformity of oil application, measures are taken to improve the processing accuracy of the oil amount regulating blade.

[0004]

However, in the conventional apparatus, in the initial stage of use, the oil amount regulating blade is uniformly pressed against the oil applying roller with the set pressing force to uniformly disperse the oil on the oil applying roller. To scrape
If the oil amount regulating blade deteriorates as the operating time increases, it becomes impossible to uniformly scrape off the oil in the axial direction of the oil application roller. For this reason, there is a problem that unevenness occurs in oil application to the fixing roller. As a result, the image state of the fixed image partially deteriorated. In addition, since the image quality of the fixed image fixed on the recording medium could not be detected, the deterioration of the image state was not recognized until the image after copying was visually recognized.

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 that 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 also occurred.

Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus capable of suppressing uneven oil application and ensuring a stable and good image state. Make it an issue.

[0007]

According to the image forming apparatus of the present invention which has been made to solve the above-mentioned problems, an image forming means for forming an unfixed image on a recording medium and a second image forming means which are pressed against each other are provided. (1) a fixing device, a second fixing member, a heater provided in at least one of the first fixing member and the second fixing member, and an oil application unit for applying oil to the first fixing member; And a contact heating fixing unit for fixing the unfixed image created in the above on the recording medium by contact heating, and wherein the fixed image fixed on the recording medium by the contact heating fixing unit is irradiated with light. A light-emitting element for irradiating, and a light-receiving element for detecting intensity information of light emitted from the light-emitting element and reflected or transmitted through the fixed image, and a light-receiving element of the recording medium orthogonal to a recording medium conveyance direction. Image information detecting means for detecting the image information of the fixed image at least at two or more positions different from each other, and calculating a change in the image information of each of the fixed images from the detection result by the image information detecting means. Oil application condition correction means for correcting the oil application conditions in the oil application means based on the above.

In this image forming apparatus, first, an image forming means forms an unfixed image (toner image) on a recording medium. Here, the unfixed image created on the recording medium by the image creating means includes not only a copy image of a document to be copied, image data input to the image forming apparatus, but also pre-stored in the image forming apparatus. A predetermined test image based on the test image data is also included. Next, the contact heating fixing unit fixes the unfixed image created by the image creating unit on the recording medium. When the fixing is completed, the image information detecting means detects the image information of the fixed image at at least two or more places in the recording medium having different positions in the direction orthogonal to the recording medium conveyance direction.

The detection of the image information is performed by irradiating the fixed image on the recording medium with light by the light emitting element and receiving the light reflected or transmitted from the fixed image by the light receiving element. here,
The image information refers to information related to the state of the image such as surface state, translucency, and coloring, and includes any information that can be used to know the image state. Specifically, the intensity (transmittance) of the transmitted light of the fixed image,
The intensity of the reflected light (reflectance) or color shift (shift in lightness, hue, saturation) and the like can be cited.

Subsequently, the oil application condition correction means calculates a change in the image information of the fixed image from the detection result of the image information detection means, and corrects the oil application condition in the oil application means based on the change. By this correction, for example, the calculation result is reflected (feedback) in the oil application condition so that the application unevenness is suppressed in the oil application to the first fixing member by the oil application unit, thereby automatically changing the image state ( (Variation) can be controlled so as to obtain a good fixed image with suppressed variation. Therefore,
It is possible to obtain a fixed image in which a good image state is stably secured. Here, the first fixing member includes not only a case where the fixing roller is used alone (the roller fixing system), but also a member composed of a plurality of rollers and a belt wound between the rollers (a belt fixing system) and the like. .

The recording medium may be any paper that can fix an image, such as plain paper, thick paper, an OHP sheet, or special paper coated with resin. Further, any light emitting element may be used as long as it emits light in the visible light region. For example, a halogen lamp, a light emitting diode, a semiconductor laser, and the like can be given. 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.

Further, in order to obtain the reflectance and the transmittance, the intensity of the incident light is necessary in addition to the intensity of the reflected light or the transmitted light.
Therefore, the intensity of the incident light may be separately detected in addition to the reflected light or the transmitted light. However, when the intensity of the incident light is known, such as when the intensity is constant, the evaluation can be performed only with the intensity of the reflected light or the transmitted light. In addition, for measuring the intensity of the incident light, a method of directly measuring the intensity using a half mirror or the like can be cited.
There is also a method of indirectly measuring from power consumption and the like.

Further, in the image forming apparatus according to the present invention, the oil applying means includes an oil applying roller for applying oil while being in contact with the first fixing member, and an oil applying roller which is in pressure contact with the oil applying roller and the first fixing means. An oil amount regulating member that regulates an amount of oil applied to the member to a constant amount, wherein the contact heating and fixing unit is a pressure contact force varying unit that can change a pressure contact force of the oil amount regulating member with respect to the oil application roller. Wherein the oil application condition correction means comprises:
The pressing force of the oil amount regulating member is corrected.

As in this image forming apparatus, the contact heating and fixing means has pressure contact force varying means for varying the pressure contact force of the oil amount regulating blade against the oil application roller, so that it is calculated from the detection result by the image information detecting means. Based on the change in the image information, the oil application condition correction means can correct the pressing force of the oil amount regulating member so as to suppress the change in the image information. Accordingly, the oil is uniformly applied on the first fixing member, so that it is possible to automatically control so as to obtain a good fixed image in which fluctuation of the image state is suppressed in one recording body. Therefore,
Even when the oil amount regulating member is deteriorated, it is possible to stably obtain a fixed image in which a good image state is secured.

Further, in the image forming apparatus according to the present invention, the pressure contact force varying means is a pressure contact force distribution variable means capable of changing an axial distribution of a pressure contact force of the oil amount regulating member with respect to the oil application roller. It is desirable.

As in this image forming apparatus, by providing a pressing force distribution varying means for also varying the axial distribution of the pressing force in the oil amount regulating member, the image information calculated from the detection result by the image information detecting means can be obtained. Based on the fluctuation, the oil application condition correction means can change the pressing force or the pressing force and the axial distribution thereof in the oil amount regulating member so as to more reliably suppress the fluctuation of the image information. As a result, the oil is more uniformly applied to the first fixing member, so that it is possible to automatically control so as to obtain a good fixed image with almost no change in image state in one recording body. Therefore, even if the oil amount regulating member is deteriorated, it is possible to obtain a fixed image in which a favorable image state is stably secured.

Further, 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. The information detecting means includes:
It is possible to detect intensity information of light transmitted or reflected by the fixing test image fixed on the recording medium.

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 image information is to be measured is known in advance. It is possible to reliably obtain image information on a fixed image. Therefore, it is possible to reliably calculate the quality of the image state and the fluctuation of the image state in one recording medium. Therefore, by reflecting the processing result of the image information on the obtained test image in the oil application condition, the image state can be calculated. Is improved, and the fluctuation of the image state is reliably suppressed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An embodiment of an image forming 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 in which the image forming apparatus according to the present invention is mounted. A predetermined fixing test image is created, and the glossiness measured for the fixing test image (hereinafter, referred to as a “fixing test image”). Also called "measured gloss")
The oil application condition is corrected based on information on the glossiness that should be originally obtained (hereinafter, also referred to as “required glossiness”).

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. 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 fixing device 40 includes a heating roller 212 (corresponding to a first fixing member of the present invention) and a pressure roller 213 (corresponding to a second fixing member of the present invention) disposed above and below, and oil application. And a unit 240.
The details will be described with reference to FIG. FIG. 2 shows a cross section of the fixing device 40. As shown in FIG. 2, the heating roller 212 is formed by coating a surface of a metal cylinder 212a made of a material such as aluminum having good heat conductivity and small heat capacity with silicon rubber 212b. A heater lamp 221 is provided inside the heating roller 212, and a general control unit 54 (see FIG. 10) described later.
And is heated based on the temperature control by the The surface temperature of the heating roller 212 is determined by a temperature sensor 22 such as a thermistor provided in contact with the surface.
2 is detected. The surface temperature signal detected here is input to the overall control unit 54 described later. On the other hand, the pressing roller 213
Similarly, the metal cylinder 2 having the heater lamp 221 inside
13a is coated with silicone rubber 213b.

Then, a drive control unit 55 described later (FIG. 10)
By driving the pressure roller 213 according to
The heating roller 212 also rotates following the pressure roller 213. Note that, instead of the pressing roller 213, the heating roller 212 may be driven by the drive control unit 55, and the pressing roller 213 may be rotated by following the heating roller 212.

The oil application unit 240 includes an oil tank 241 that stores oil, and an oil application roller 2 that applies the oil in the oil tank 241 to the heating roller 212.
42, an oil amount regulating blade 243 for equalizing the amount of oil carried by the oil applying roller 242, a supply roller 244 for supplying the oil in the oil tank 241 to the oil applying roller 242, and a pressing force of the oil amount regulating blade 243. And a pressure-contact force varying section 280 for changing the pressure. The oil amount regulating blade 243 is pressed against the oil application roller 242 with a predetermined pressing force (which can be changed as described later). Thereby, the supply roller 244
The excess oil supplied to the oil application roller 242 is scraped off by the oil amount regulating blade 243, so that a constant amount of oil is always uniformly carried on the oil application roller 242 in the axial direction. I have. As a result, a fixed amount of oil is evenly applied to the heating roller 212 in the axial direction.

Next, a pressure contact force variable section 280 for varying the pressure force of the oil amount regulating blade 243 will be described with reference to FIG.
This will be described with reference to FIG. FIG.
FIG. 4 is a perspective view showing an outline of FIG. 80, and FIG. 4 is an explanatory diagram for explaining an operation of the press-contact force varying unit 280. The pressing force variable section 280 includes the blade holding section 250 and the first variable section 2.
60, and second variable portions 270A and 270C.
43 in the axial direction of the oil application roller 242 (FIG. 3).
(The middle and left and right directions), and the second variable portions 270A or 270A located near both ends in the axial direction, respectively.
The distribution of the pressing force of the oil amount regulating blade 243 in the axial direction can be changed by 70C.

The blade holding section 250 includes a holding plate 251 for holding the oil amount regulating blade 243 and a holding plate 2
And a support plate 252 that supports the support plate 51 at both ends.
Reference numeral 52 denotes a support plate 25 that is rotatable about a support shaft 253.
2 attached.

The first variable section 260 is fixed above the fixed plate 261 via a fixed plate 261 fixed to the main body of the image forming apparatus 1 and four first springs 262 installed near four corners of the fixed plate 261. , And three first cams 264 for moving the first variable plate 263. Both ends of the first spring 262 are fixed to the fixed plate 261 and the first variable plate 263, respectively, and the first variable plate 263 is fixed to the fixed plate 264 such that the bottom surface 263b of the first variable plate 263 contacts the first cam 264. Pulling to the side. Further, the three first cams 264 are respectively connected to the rotating shafts 26.
The first cam 264 is rotated by rotating the rotating shaft 265 with a motor or the like.

Then, by rotating the first cam 264, the first variable plate 263 is moved in the direction shown by the arrow D in FIG. At this time, the first variable plate 26
With the movement of 3, the blade holding unit 250 and the second variable units 270A and 270C also move in the direction indicated by the arrow E in FIG. That is, when the first cam is rotated clockwise in FIG. 4, the first variable plate 263 (the blade holding unit 250 and the second variable units 270A and 270C) is rotated.
It moves upward in the middle arrow D (arrow E). Conversely, when the first cam is rotated counterclockwise in FIG.
(The blade holding unit 250 and the second variable units 270A, 270A, 2
70C) moves downward in the direction of arrow D (arrow E) in FIG.

The second variable sections 270A and 270C are provided near both ends of the oil application roller 242 (corresponding to areas where fixing test images TA and TC (see FIG. 7) to be described later are created), and are provided with blades. The second holding plate 251
Second variable plates 273A, 2 provided via springs 272
73C and the second cams 274A, 274 for moving the second variable plates 273A, 273C in the direction indicated by the arrow E in FIG.
74C. The two ends of the second spring 272 are respectively a blade holding plate 251 and a second variable plate 273A.
(273C) and the second variable plate 273A (273C).
The bottom surface 273Ab (273Cb) of C) is the second cam 274.
A (274C) so as to contact the second variable plate 273A.
(273C) is pulled toward the first variable plate 263, while the blade holding plate 251 is pulled upward in the direction of arrow F in FIG. The second cam 274A (274C) is attached to the rotating shaft 275, and the second cam 274A (27C) is rotated by rotating the rotating shaft 275 with a motor or the like.
4C) rotates. Then, by rotating the second cam 274A (274C), the blade holding plate 251 rotates about the support shaft 253 as shown by an arrow F in FIG. Accordingly, the pressing force of the oil amount regulating blade 243 against the oil application roller 242 changes.

The pressing force variable portion 28 configured as described above
The operation of 0 will be described with reference to FIGS.
First, a case where the pressing force of the oil amount regulating blade 243 against the oil application roller 242 is changed over the entire axial direction of the oil application roller 242 will be described with reference to FIG. As shown in FIG. 5, if the first cam 264 is rotated clockwise (in the direction of arrow I) in the figure from the state of FIG. 4, the first spring 262 is extended and the first variable plate 263 is extended.
Moves in the direction of arrow Du. Then, the first variable plate 263
Similarly, the blade holding unit 250 and the second variable units 270A and 270C attached to the second unit also move in the direction of the arrow Eu. Thus, the pressure contact force of the oil amount regulating blade 243 on the oil application roller 242 is reduced. In addition,
Contrary to the above, when the pressing force of the oil amount regulating blade 243 is increased, the first cam 264 may be rotated counterclockwise (in the direction opposite to the arrow I) in the figure.

Next, the case where the axial distribution of the pressing force of the oil amount regulating blade 243 against the oil application roller 242 is varied will be described with reference to FIG. As shown in FIG. 6, if only the second cam 274A is rotated clockwise (in the direction of arrow I) in the drawing from the state of FIG.
The variable plate 273A moves in the direction of the arrow Eu in the figure. Then, since the second spring 272 is extended, the side end 251e of the blade holding plate 251 moves in the arrow Fu direction in the figure. With this movement, the blade holding plate 251 rotates around the support shaft 253 counterclockwise in the figure.

Thus, the oil amount regulating blade 243
In the vicinity of the second variable portion 270A, the oil application roller 242 is pressed against the oil application roller 242 with a larger force than other portions. Therefore, the axial distribution of the pressing force of the oil amount regulating blade 243 changes. That is, the distribution of the pressing force of the oil amount regulating blade 243 has a distribution shape that is large on the near side in FIG. 6 (left side in FIG. 3) and decreases as it goes to the far side in FIG. 6 (right side in FIG. 3). On the other hand, the second cam 274
By rotating only A counterclockwise in the drawing or rotating only the second cam 274C clockwise in the drawing, the pressing force distribution having a shape opposite to that described above (small on the near side in the drawing, (Pressing force distribution that increases toward the back in the figure).

The image information detecting section 43 (see FIG. 1)
Is for detecting image information of a fixed image,
Specifically, the glossiness of the fixed image ((reflection light quantity / incident light quantity) × 100 = reflectance × 100) is detected. As shown in FIG. 7, for example, as shown in FIG. 7, the image information detecting unit 43 includes three substantially rectangular fixing test images TA, When TB and TC are formed on the recording medium S,
The fixing test image TA and the like are arranged at positions where the intensity of regular reflection light (direct reflection light) such as the test image TA can be measured. That is, the image information detection unit 43 determines the three light-emitting element and light-receiving element pairs (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. It is configured.

Specifically, the halogen lamp 41A and the CC
D sensor 42A, halogen lamp 41B and CCD sensor 42B, and halogen lamp 41C and CCD sensor 4
It is composed of three pairs of light emitting / receiving elements 2C. 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 medium S, behind the fixing device 40, a halogen lamp, which is a light emitting element, is positioned obliquely upper right (diagonally upper in the anti-conveying direction) in FIG. 41A is provided to receive specularly reflected light with respect to the incident light incident on the fixing test image TA from the halogen lamp 41A.
A CCD sensor 42A, which is a light receiving element, is provided on the upper left side (in the transport direction) of FIG. 1 where the incident angle α and the reflection angle β with respect to the fixing test image TA (recording medium S) are equal. In a similar positional relationship, the halogen lamp 41
B, CCD sensor 42B, and halogen lamp 41C
And a CCD sensor 42C. Note that the specularly reflected light (directly reflected light) refers to the incident angle of the incident light incident on the fixed image on the incident surface formed by the incident light and the normal of the fixed image at the incident point in the reflected light. Reflected light that is reflected and travels at the same reflection angle is referred to (in the following description, “specularly reflected light” is used in the same sense).

Also, a pair of halogen lamps 41A and 41A
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. 8, 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 desirable that the incident angle α and the reflection angle β are not less than 25 degrees. If the angle is smaller than 25 degrees, the component of the diffused light that wraps around from the periphery becomes large, so that the intensity information of the specularly reflected light cannot be measured accurately, and the arrangement of the halogen lamps 41A to 41C and the CCD sensors 42A to 42C becomes difficult. is there. Further, the incident angle α is more preferably 45 degrees or more. By arranging the halogen lamps 41A to 41C and the CCD sensors 42A to 42C in this way, the fixing test images TA to TC are less susceptible to the influence of the thickness of the fixing test images TA to TC and the lifting of the recording medium S at the time of measurement.
This is because the intensity information of the specularly reflected light can be measured more accurately.

As described above, the halogen lamps 41A-41
C and the CCD sensors 42A to 42C are arranged, so that the image information detecting unit 43 performs the fixing test images TA to TC.
Of the specularly reflected light (directly reflected light) can be detected. That is, the image information detection unit 43 is
The intensity IbA-IbC of the reflected light received by A-42C;
By detecting the incident light intensities (light emission intensities) IaA to IaC of the halogen lamps 41A to 41C, the glossiness of the regular reflection light of the fixing test images TA to TC is detected. In addition, the detection of the emission intensities IaA to IaC of the halogen lamps 41A to 41C includes a method of directly measuring the intensities using a half mirror or the like. Measurement method.

As shown in FIG. 9, the glossiness of the reflected light is detected when the fixing temperature and the toner adhesion amount are constant as shown in FIG. 9 (FIG. 9 shows the case where the fixing temperature is 150 ° C. and the toner adhesion amount is 1). shows a case where .6mg / cm ^2), because have a positive correlation oil application amount amount. Therefore, by detecting the glossiness of the fixed image, the amount of oil applied can be ascertained, so that it is possible to ascertain, for example, how much deviation from the normal (design required value) oil applied amount. Thus, the pressing force of the oil amount regulating blade 243 can be corrected so as to eliminate the deviation from the normal oil application amount by obtaining the gloss information.

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, a laser control unit 59 (FIG. 1)
0), the image data read by the image reading unit 2 is input. Then, the laser light is modulated and emitted from the laser light source, and this laser light is
Scans in the main scanning direction, and is 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 these toner images have 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. 10, the control circuit of the copying machine 1 is mainly configured by a general control unit 54. The overall control unit 54
The microcomputer also corresponds to the oil application condition correcting means of the present invention, and 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, which will be described later, is also stored in this R.
It is stored in the OM. In addition, the RAM temporarily stores numerical values and the like that appear during execution of the arithmetic processing,
Various buffers are provided for reading data as needed.

An input / output port of the overall control unit 54 includes an IR control unit 51 for controlling the operation of the image reading unit 2 and a fixing unit 4.
A drive control unit 55 for controlling the driving / stopping of the zero and the speed control of the pressure roller 213; a conveyance control unit 56 for controlling the supply of the recording medium; a scanner control unit 57 for controlling the laser beam scanning by the polygon mirror 21; A high-voltage control unit 58 for controlling high voltages such as charging of the photosensitive drum 30, application of a developing bias and a transfer bias, a laser control unit 59 for controlling laser light modulation, an image information detecting unit 43, and a fixing device 4
0 fixing temperature (exactly the surface temperature of the heating roller 212)
Temperature sensor 222 which detects
1 etc. are connected. In addition, the general control unit 54 includes:
A signal is input from the operation panel 53 via the controller 52.

The copier 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
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. At this time, the temperature sensor 222 detects the surface temperature (fixing temperature) of the heating roller 212 of the fixing device 40 and outputs the detection result to the overall control unit 5.
Send to 4.

Here, the operation of the copying machine 1 when generating the fixing test images TA to TC in order to detect the glossiness of the fixed image will be described with reference to the flowchart shown in FIG. The subroutine shown in this flowchart is executed 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. First, test image data previously stored in the ROM in the overall control unit 54 is input to the laser control unit 59 shown in FIG. 10, and predetermined fixing test images TA to TC are created by the above-described procedure (FIG. 10). S1). Here, it is preferable that the fixing test image TA or the like be a single color patch, and furthermore, any one of yellow (Y), cyan (C), magenta (M), and black (K) using one type of toner. It is preferred that Further, the patches may be gradation.

It is preferable that the fixing test image T be 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 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. With this, compared to creating only one fixing test image,
The reflected light intensity (reflectance) 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 of (three or more) fixing test images having the same image density may be created in the recording medium transport direction, and an average value of the reflected light intensity (reflectance) for each fixing test image may be obtained.

Further, the surface temperature of the heating roller 212 when the recording medium S passes through the fixing device 40, that is, the fixing temperature is detected by the temperature sensor 222 (S2). Subsequently, the overall control unit 54 calls the test image data stored in the ROM and reads it (S3), and calculates the required gloss level based on the read test image data and the fixing temperature. (S4). Next, the image information detection unit 43
Intensity Ib of regular reflection light of fixing test images TA, TB, TC
A, IbB, IbC and halogen lamps 41A, 4
Upon detecting the light emission intensities IaA, IaB, IaC of 1B, 41C, the central control unit 54 calculates the measured glossiness of each of the fixing test images TA to TC using them (S5).

Subsequently, the overall control unit 54 calculates the rank of the gloss difference between the fixing test images TA and TB (S6).
The rank of the gloss difference is classified into seven levels (A to G) as shown in Table 1.
(Fixed rank), and the case where the measured glossiness of the fixing test image TA is larger than the measured glossiness of the fixing test image TB is defined as the standard (D rank). The ranks are classified into three stages for each case when the size is small.

[0051]

[Table 1]

Then, the second cam 274A is rotated by a predetermined angle according to the rank of the gloss difference so as to eliminate the gloss difference (S7). That is, the second cam 274A is rotated by a predetermined angle so that the pressure contact force of the oil amount regulating blade 243 in the region where the fixing test image TB is created and the region where the fixing test image TA is created are substantially equal. Thus, the amount of oil on the oil application roller 242 in the region where the fixing test image TB is created and the region where the fixing test image TA is created are substantially equal.

The overall control unit 54 calculates the gloss difference between the fixing test images TC and TB as a rank as shown in Table 1 (S8). Then, according to the gloss difference rank, the second cam 274C is rotated by a predetermined angle so as to eliminate the difference (S9). That is, the second cam 274C is rotated by a predetermined angle so that the pressure contact force of the oil amount regulating blade 243 in the region where the fixing test image TB is created and the region where the fixing test image TC is created are substantially equal. Accordingly, the amount of oil on the oil application roller 242 in the region where the fixing test image TB is created and the region where the fixing test image TC is created are substantially equal. By the processing up to this point, a substantially constant amount of oil is uniformly carried on the oil application roller 242 in the axial direction.

Further, the overall control unit 54 calculates the difference between the fixing test image TB and the required glossiness as a rank as shown in Table 2 (S10). Then, according to the rank of the gloss difference, the first cam 264 is rotated by a predetermined angle so as to eliminate the difference (S11). That is, the first cam 264 is rotated by a predetermined angle so that the pressing force of the oil amount regulating blade 243 becomes substantially equal to the design required value.

[0055]

[Table 2]

As a result, since the pressing force of the oil amount regulating blade 243 is substantially equal in the entire axial direction by the processing up to S9, the pressing force is substantially equal to the design required value in the entire axial direction. Accordingly, a predetermined amount of oil is uniformly carried on the oil application roller 242 in the axial direction, so that uneven oil application is suppressed, and a good image state can be stably secured.

As described above in detail, according to the copying machine 1 of the first embodiment, the predetermined fixing test images TA to TC are created on the recording medium S periodically or by an operator's selection. Is done. Then, the overall control unit 54
The required glossiness is calculated based on the test image data and the fixing temperature detected by the temperature sensor 222. Further, based on the reflected light intensity and the like obtained by the image information detection unit 43, the measured glossiness of each of the fixing test images TA to TC is calculated. Then, the overall control unit 54 first compares the measured glossiness of the fixing test images TA and TC with the measured glossiness of the fixing test image TB to calculate the ranks of the gloss difference, and according to the ranks, calculates the second rank. The cams 274A and 274C are each rotated by a predetermined angle. As a result, the axial distribution of the pressing force of the oil amount regulating blade 243 changes, and the difference in gloss between the fixing test image TB and the fixing test images TA and TC, that is, the difference in the amount of applied oil, is almost eliminated. Therefore, the oil is uniformly and uniformly carried on the oil application roller 242 in the axial direction.

Further, the overall control section 54 calculates the rank of the gloss difference by comparing the measured gloss level of the fixing test image TB with the required gloss level, and according to the rank, the first cam 264.
Are rotated by a predetermined angle. As a result, the pressing force of the oil amount regulating blade 243 becomes substantially equal to the required design value, so that a predetermined amount of oil is uniformly carried on the oil application roller 242 in the axial direction. Therefore, even if the oil amount regulating blade 243 has deteriorated,
Since the fixing is performed in a state where the oil is uniformly applied to the heating roller 212, a fixed image in which a good image state is stably secured can be obtained. Therefore, it is possible to avoid re-use of unnecessary copies and the need to use OHP sheets having poor appearance.

(Second Embodiment) Next, a second embodiment will be described. The copying machine according to the second embodiment has almost the same configuration as the copying machine 1 according to the first embodiment, but instead of detecting the glossiness of the fixing test image, the transmittance ((the amount of transmitted light) / Incident light amount) × 100), and the measured transmittance (hereinafter, “measured transmittance”)
This is different from the first embodiment in that the oil application conditions are corrected based on information on the transmittance that should be originally obtained (hereinafter, also referred to as “required transmittance”). Accordingly, the configuration of the image information detecting unit is also different from that of the first embodiment. Therefore, the image information detection unit will be described with reference to FIGS. 12 and 13, and thereafter, control for correcting the oil application condition will be described.
This will be described with reference to the flowchart shown in FIG. In addition,
Descriptions of the same components as those in the first embodiment, copy operations, and the like are omitted, and the same components are denoted by the same reference numerals.

First, the configuration of the image information detecting section according to the present embodiment will be described. The image information detection unit 143 includes:
For detecting the intensity information of the transmitted light of the fixed image, for example, as shown in FIG. 12, three substantially rectangular rectangles arranged near the upper side of the recording material S when the conveyance direction indicated by the arrow is directed upward. When the fixation test images TA, TB, and TC having a shape are formed on the recording medium S, the transmitted light that enters the fixation test image TA or the like and travels straight without being bent by refraction or the like (hereinafter, referred to as “light”). It is arranged at a position where the intensity of “straight transmitted light” can be measured. That is, the image information detection unit 143 is a set of three light-emitting elements and light-receiving elements (light-emitting / light-receiving element pairs) arranged in a direction intersecting with the transport direction of the recording medium S (a direction orthogonal to the present embodiment). It is composed of Specifically, the halogen lamps 141A and 141C
CD sensor 142A, halogen lamp 141B and CCD
Sensor 142B and halogen lamps 141C and CC
The D sensor 142C is composed of three light-emitting / light-receiving element pairs.

Then, the halogen lamp 141A and the CCD
The sensor 142A is arranged at a position where the intensity of the transmitted light of the fixing test image TA can be measured. That is,
A halogen lamp 141A, which is a light-emitting element, is provided on the lower side in the drawing of the recording medium S discharged from the fixing apparatus 40 in the conveyance path of the recording medium S behind the fixing device 40, and the optical axis of the halogen lamp 141A is provided. The light receiving element CC is located on the upper side in FIG.
A D sensor 142A is provided. In a similar positional relationship, the halogen lamp 141B and the CCD sensor 142
B, halogen lamp 141C and CCD sensor 14
2C is also arranged.

The halogen lamp 141A and the CCD sensor 142A, and the lamp 141B and the sensor 142,
B, the lamp 141C and the sensor 142C may be arranged at opposite positions. In addition to the case where the optical axis of the halogen lamp 141A and the recording medium S are orthogonal to each other as shown in FIG. 12, the halogen lamp 141A as shown in FIG.
The halogen lamp 141A and the CCD sensor 142A may be arranged so that the optical axis of the light source and the recording medium S form a predetermined angle. The halogen lamp 141B and the CCD sensor 14
2B, halogen lamp 141C and CCD sensor 1
The same applies to the case of 42C.

However, as shown in FIG. 13, the halogen lamps 141A to 141C and the CCD sensors 142A to 142
When C is arranged, the angle between the optical axis and the recording medium is 4
It is desirable that it is 5 degrees or more (less than 90 degrees). 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. More preferably, the angle is 90 degrees (the state shown in FIG. 12). Thus, the halogen lamps 141A to 141A
When 1C and the CCD sensors 142A to 142C are arranged,
This is because the fixing test images TA to TC are less susceptible to the influence of the thickness of the recording medium S and the rise of the recording medium S during measurement, and the intensity information of the straight transmitted light can be measured more accurately.

As described above, the halogen lamps 141A to 141A
By arranging the 41C and the CCD sensors 142A to 142C, it is possible to detect the transmittance of the straight test transmitted light of the fixing test images TA to TC. That is, the image information detecting unit 143 determines the intensity IdA-IdC of the transmitted light received by the CCD sensors 142A-142C and the intensity of the halogen lamp 14
Incident light intensity (emission intensity) IaA to Ia of 1A to 141C
C, the fixing test images TA to TC
Can be detected. If the emission intensity of the halogen lamps 141A to 141C is fixed, the intensity information of the transmitted light can be used as it is without calculating the transmittance.

As shown in FIG. 14, the transmittance of the linearly transmitted light is detected when the fixing temperature and the toner adhesion amount are constant as shown in FIG.
° C, the amount of toner adhered is 1.6 mg / cm ² ), which has a positive correlation with the amount of oil applied. For this reason, if the transmittance of the fixed image is detected, the amount of applied oil can be ascertained, so that it is possible to ascertain, for example, how much deviation from the regular (design required) amount of oil is applied. Thus, the pressing force of the oil amount regulating blade 243 can be corrected so as to eliminate the deviation from the normal oil application amount by obtaining the information of the transmittance.

Next, control for correcting the pressing force of the oil amount regulating blade 243 will be described with reference to the flowchart shown in FIG. The subroutine shown in this flowchart is executed 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. First, test image data previously stored in the ROM in the overall control unit 54 is input to the laser control unit 59 shown in FIG. 10, and predetermined fixing test images TA to TC are created by the above-described procedure (FIG. 10). S
21). Further, the surface temperature of the heating roller 212 when the recording medium S passes through the fixing device 40, that is, the fixing temperature is detected by the temperature sensor 222 (S22).

Subsequently, the general control unit 54 calls the test image data stored in the ROM and reads it (S23), and based on the read test image data and the fixing temperature, the required transmittance. Is calculated (S2
4). Next, the image information detection unit 143 outputs the intensity IdA, Id of the straight transmitted light of the fixing test images TA, TB, TC.
B, IdC, and halogen lamps 141A, 141
Upon detecting the light emission intensities IaA, IaB, IaC of B, 141C, the central control unit 54 calculates the measured transmittance of each of the fixing test images TA to TC using these (S25).

Then, the overall control unit 54 calculates the rank of the transmittance difference between the fixing test images TA and TB (S2).
6). The rank of the gloss difference is divided into seven stages (A to G ranks) as shown in Table 3, and the fixing test images TA and T
The case where there is no difference in the measured transmittance of B is defined as a standard (D rank), and the rank is classified into three stages when the measured transmittance of the fixing test image TA is larger than and smaller than the measured transmittance of the fixing test image TB. Have been.

[0069]

[Table 3]

Then, according to the rank of the transmittance difference, the second cam 274A is rotated by a predetermined angle so as to eliminate the transmittance difference (S27). That is, the second cam 274A is rotated by a predetermined angle so that the pressure contact force of the oil amount regulating blade 243 in the region where the fixing test image TB is created and the region where the fixing test image TA is created are substantially equal. Thus, the amount of oil on the oil application roller 242 in the region where the fixing test image TB is created and the region where the fixing test image TA is created are substantially equal.

Further, the overall control unit 54 calculates the transmittance difference between the fixing test images TC and TB as a rank as shown in Table 3 (S28). Then, according to the rank of the transmittance difference, the second cam 274C is rotated by a predetermined angle so as to eliminate the difference (S29). That is, the second cam 274C is rotated by a predetermined angle so that the pressure contact force of the oil amount regulating blade 243 in the region where the fixing test image TB is created and the region where the fixing test image TC is created are substantially equal. Thereby, the fixing test image T
The amount of oil on the oil application roller 242 in the area where B is created and the area where the fixing test image TC is created are substantially equal. The oil application roller 24
A substantially constant amount of oil is uniformly carried on the surface 2 in the axial direction.

Further, the overall control unit 54 calculates a difference between the fixing test image TB and the required transmittance as a rank as shown in Table 4 (S30). Then, according to the rank of the transmittance difference, the first cam 264 is rotated by a predetermined angle so as to eliminate the difference (S11). That is, the first cam 264 is rotated by a predetermined angle so that the pressing force of the oil amount regulating blade 243 becomes substantially equal to the design required value.

[0073]

[Table 4]

As a result, since the pressing force of the oil amount regulating blade 243 is substantially equal in the entire axial direction by the processing up to S29, the pressing force is substantially equal to the design required value in the entire axial direction. Accordingly, a predetermined amount of oil is uniformly carried on the oil application roller 242 in the axial direction, so that uneven oil application is suppressed, and a good image state can be stably secured.

As described above in detail, according to the copying machine according to the second embodiment, a predetermined fixing test image T on the recording medium S is periodically or selected by the operator.
A to TC are created. Then, the overall control unit 54 calculates the required transmittance based on the test image data and the fixing temperature detected by the temperature sensor 222. Further, based on the reflected light intensity and the like obtained by the image information detection unit 143, the actually measured transmittance of each of the fixing test images TA to TC is calculated. Then, the overall control unit 54 first compares the measured transmittances of the fixing test images TA and TC with the measured transmittances of the fixing test image TB to calculate the ranks of the transmittance differences, respectively. The cams 274A and 274C are each rotated by a predetermined angle. As a result, the axial distribution of the pressing force of the oil amount regulating blade 243 changes, and the transmittance difference between the fixing test image TB and the fixing test images TA and TC, that is, the difference in the amount of applied oil is almost eliminated. Therefore, the oil is uniformly and uniformly carried on the oil application roller 242 in the axial direction.

Further, the overall control unit 54 calculates the rank of the transmittance difference by comparing the actually measured transmittance of the fixing test image TB with the required transmittance, and according to the rank, the first cam 264.
Are rotated by a predetermined angle. As a result, the pressing force of the oil amount regulating blade 243 becomes substantially equal to the required design value, so that a predetermined amount of oil is uniformly carried on the oil application roller 242 in the axial direction. Therefore, even if the oil amount regulating blade 243 has deteriorated,
Since the fixing is performed in a state where the oil is uniformly applied to the heating roller 212, a fixed image in which a good image state is stably secured can be obtained. Therefore, it is possible to avoid re-use of unnecessary copies and the need to use OHP sheets having poor appearance.

(Third Embodiment) Finally, a third embodiment will be described. The copying machine according to the third embodiment has substantially the same configuration as the copying machine 1 according to the first embodiment, except that a glossy image of a fixed image obtained by copying a normal original without forming a test image is formed. The difference is that the oil application condition is corrected by detecting the degree. The oil application condition correction program is executed after a predetermined number of copies have been made, after a predetermined operation time has elapsed, or when the operator has selected. Another difference is that the emission intensity of the halogen lamp is fixed. FIG. 16 shows a process of correcting the oil application condition in the copying machine according to the present embodiment.
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 oil condition correction program is executed, first, the image reading section 2 (see FIG. 1) obtains image data corresponding to the image of the document. Next, the area RA in which the image information detection unit 93 can detect the intensity information of the reflected light of the fixed image G
1, RA2, RA3, ... and RB1, RB2, RB3, ...
In RC1, RC2, RC3,..., It is checked in which area the fixed image G (image data) exists. For example, in the case shown in FIG. 16, the areas RA2, RB1,
It is found that a fixed image exists in RC2. Then, from the IR control unit 51 (see FIG. 10) to the image information detection unit 93 via the general control unit 54, the areas RA2 and RA2 are output.
In RB1 and RC2, a command to detect the intensity information of the reflected light is issued. Next, a copy image (fixed image) G of the document is formed on the recording medium S based on the read image data by the above-described electrophotographic process.

Then, the overall control unit 54 controls the temperature sensor 2
The surface temperature (fixing temperature) of the heating roller 212 detected at 22 and the respective image data of the areas RA2, RB1, and RC2 stored in the data memory unit 9 provided in the image reading unit 2 are read. Next, areas RA2 and R
The required gloss levels LAr, LBr, and LCr are calculated from the image data B1 and RC2 and the fixing temperature, respectively. Then
The image information detecting unit 93 ejects the recording medium S from the fixing device 40, and first, when the area RB1 reaches the detection area of the image information detecting unit 93, the image information detecting unit 93
The intensity IgB of the reflected light of the fixed image G by the D sensor 92B
Then, at the timing when the areas RA2 and RC2 reach the detection area, the intensity IgA of the reflected light is detected by the CCD sensor 92A.
And the intensity IgC of the reflected light is measured by the CCD sensor 92C. Then, the overall control unit 54 calculates the respective measured gloss levels LA, LB, and LC in the areas RA2, RB1, and RC2 of the fixed image G from the measurement results. Then, a difference LAD (= LA−L) between the measured glossiness and the required glossiness in each of the areas RA2, RB1, and RC2.
Ar (including the sign), LBD, and LCD are calculated.

Next, the overall control unit 54 corrects the pressing force of the oil amount regulating blade 243 at a portion corresponding to the areas RA2 and RC2. That is, the difference (including the sign) between the gloss difference LAD and LBD is calculated as a rank as shown in Table 5, and the second cam 274A is rotated by a predetermined angle so as to eliminate the difference according to the rank. Let it. Similarly, the difference (including the sign) between the gloss difference LCD and the LBD is calculated as a rank as shown in Table 5, and the second cam 274C is rotated by a predetermined angle so as to eliminate the difference according to the rank. Move.

[0081]

[Table 5]

By such correction, in the areas RA2 and RC2, the respective required glossiness LAr, LC
In this state, a gloss level deviated from r by the required gloss level LBr of the area RB1 is obtained. That is, the area RA
2, RB1 and RC2 are in a state in which a gloss level deviated by the required gloss level LBr from the required gloss level of each area is obtained. Therefore, since the glossiness and the amount of applied oil have a correlation, the amount of oil deviated by a certain amount from the prescribed value is uniformly carried on the oil applying roller 242. That is, the oil amount regulating blade 243 is uniformly pressed against the oil application roller 242 with a pressing force deviated from the normal pressing force by a certain value over the entire axial direction.

Further, the overall control unit 54 calculates a gloss difference between the area RB2 and the required gloss as a rank as shown in Table 2. Then, according to the rank of the gloss difference,
The first cam 264 is rotated by a predetermined angle so as to eliminate the difference. That is, the first cam 2 is adjusted so that the pressing force of the oil amount regulating blade 243 becomes substantially equal to the design required value.
64 is rotated by a predetermined angle. As a result, the pressure contact force of the oil amount regulating blade 243 has already become substantially equal in the entire axial direction, so that the pressure contact force becomes substantially equal to the design required value in the entire axial direction. Accordingly, a predetermined amount of oil is uniformly carried on the oil application roller 242 in the axial direction, so that uneven oil application is suppressed, and a good image state can be stably secured. The second
As illustrated in the embodiment, by comparing the required transmittance with the actually measured transmittance, the oil amount regulating blade 24 may be used.
The pressing force of No. 3 can also be corrected.

As described above, according to the copying machine of the third embodiment, when the oil application condition correction program is executed, the image information detecting section 93 measures the image data of the original to be copied. The image information detecting section 93 checks whether or not there is image data in the area where the image can be formed, and if there is image data, the position (for example, the areas RA2, RB1, RC2). RC
Upon detecting the reflected light intensities IgA, IgB, and IgC in 2, the overall control unit 54 calculates the measured glossiness using the detected intensities IgA, IgB, and IgC. Further, regions RA2, RB2, calculated based on the image data corresponding to regions RA2, RB1, RC2 stored in data memory unit 9 and the surface temperature (fixing temperature) of heating roller 212 detected by temperature sensor 222. R
The required gloss at C2 is calculated. continue,
By comparing the actually measured glossiness with the required glossiness, a rank of various glossiness differences is calculated, and a second rank is determined according to the rank.
The cams 274A and 274C and the first cam 264 are rotated by a predetermined angle.

Thus, the oil amount regulating blade 243
Is substantially equal to the design required value in the entire axial direction. Therefore, even when the oil amount regulating blade 243 is deteriorated, a predetermined amount of oil is uniformly carried on the oil application roller 242 in the axial direction, so that uneven oil application is suppressed and a stable and good image state is secured. Thus, a fixed image can be obtained. Therefore, it is possible to avoid re-use of unnecessary copies and the need to use OHP sheets having poor appearance. In addition, there is an advantage that the recording medium is not wasted because no test image is created.

The above-described embodiment is merely an example, and does not limit the present invention in any way. Needless to say, various improvements and modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, the intensity information of the regular reflection light (gloss) or the intensity information of the straight transmitted light (transmittance) of the fixed image is detected to correct the oil application condition in the oil application unit. The oil application conditions in the oil applying means can be similarly corrected by detecting the intensity information of the diffuse reflected light or refracted transmitted light, color shift (shift in brightness, hue, saturation), and the like. Note that the diffusely reflected light refers to reflected light, of the reflected light, in which incident light 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, and the refracted transmitted light is Out of the transmitted light, the transmitted light whose path has been bent by refraction or the like of the incident light incident on the fixed image. (In the following description, “diffuse reflected light” and “refracted transmitted light” are used in the same sense. ).

That is, when correcting the oil application condition in the oil applying means based on the intensity information of the diffuse reflected light of the fixed image, the reflected light intensity of the fixed image may be detected as described below. . That is, for example, FIG.
As shown in FIG. 7, a CCD sensor may be provided at the following position with respect to the halogen lamps 41A to 41C provided on the upper right side in the figure.

(1) The CCD sensors 62A to 62C are located at positions deviated from the optical axis of the regular reflection light while allowing the intersections PA to PC between the optical axes 41AL to 41CL of the halogen lamps 41A to 41C and the recording medium S to be seen. Is provided. More specifically, on the normal to the surface of the recording medium S passing through the intersections PA to PC, that is, the normal and the optical axis 62AL of the CCD sensors 62A to 62C.
CCD sensors 62A to 62CL
62C is arranged. Thereby, the fixing test images TA ~
The intensities IcA to IcC of the diffuse reflection light for TC can be detected. (2) The CCD sensors 42A to 42C exemplified in the first embodiment and the CCD sensors 62A to 62 described above.
C is provided. Thereby, the intensities IbA to Ib of the specular reflected light
Both bC and the intensity of the diffuse reflected light IcA to IcC can be detected.

When correcting the oil application conditions in the oil application means based on the intensity information of the refracted transmitted light of the fixed image, the transmitted light intensity of the fixed image may be detected as described below. . That is, for example, as shown in FIG.
The CCD sensors may be provided at the following positions for A to 141C.

(1) The optical axis 1 is adjusted while allowing the intersections PA to PC between the optical axes 141AL to 141CL and the recording medium S to be seen.
CC at a position outside each of 41AL to 141CL
D sensors 162A to 162C are provided. Thereby, the intensity I of the refracted transmitted light for the fixing test images TA to TC is obtained.
eA to IeC can be detected. (2) The CCD sensors 142A to 142C exemplified in the second embodiment and the C
CD sensors 162A to 162C are provided. Thereby, both the intensities IdA to IdC of the straight transmitted light and the intensities IeA to IeC of the refracted transmitted light can be detected.

Further, when correcting the oil application conditions in the oil applying means based on information on the color misregistration of the fixed image, the transmitted light intensity after color separation of the fixed image is determined, for example, as described below. What is necessary is just to detect. That is, for example, as shown in FIG. 19, the halogen lamps 141A to 141C provided on the lower side in FIG.
An RGB filter 139 including a red (R) filter, a green (G) filter, and a blue (B) filter on the optical axes 141AL to 141CL of 41A to 141C and between the halogen lamps 141A to 141C and the recording medium S.
A to 139C may be provided, and the CCD sensor may be provided at the following positions.

(1) Halogen lamps 141A to 141C
The CCD sensor 142 is located on the upper side in the figure so as to sandwich the conveyance path of the recording medium S coaxially with the optical axes 141AL to 141CL.
A to 142C are provided. Thereby, the fixing test image T
Intensities IdRA to Id of straight transmitted light after color separation of A to TC
RC, IdGA to IdGC, IdBA to IdBC can be detected. (2) Optical axes 141AL to 141CL and recording medium S
And the optical axis 141 while allowing for the intersections PA to PC
CCD sensors 162A to 162C are provided at positions deviated from each of AL to 141CL. Thereby, the intensity IeR of the refracted transmitted light for the fixing test images TA to TC.
A to IeRC, IeGA to IeGC, IeBA to IeB
C can be detected. . In the case where the oil application condition is corrected by the oil application condition means based on the information on the color shift of the fixed image, the reflected light intensity after color separation may be detected.

Further, in the above-described embodiment, an example in which the pressing force variable portion includes the first variable portion and the second variable portion has been described. ,
Only the first variable unit may be provided. Further, the roller fixing type is exemplified as the contact heating fixing means, but the present invention is not limited thereto, and a belt fixing type may be used. Further, an example in which the present invention is applied to a copying machine has been described, but any apparatus having an image forming apparatus such as a printer such as a page printer or a facsimile can be applied.

[0094]

As described above, according to the image forming apparatus of the present invention, the image information detecting means is fixed to at least two or more positions of the recording medium which are different in the direction perpendicular to the recording medium conveyance direction. The image information of the fixed image is detected. Then, the oil application condition correction unit calculates a change in the image information of the fixed image from the detection result of the image information detection unit, and corrects the oil application condition so as to suppress the change. Thus, even when the oil amount regulating member is deteriorated, the fixing is performed in a state where the oil is uniformly applied to the first fixing member. Therefore, it is possible to obtain a fixed image in which a favorable image state is stably secured. Therefore, it is possible to avoid re-use of unnecessary copies and use of an OHP sheet having a poor appearance.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a configuration of a fixing device in the copying machine of FIG.

FIG. 3 is a perspective view showing a schematic configuration of a pressure contact force variable unit that changes a pressure contact force of the oil amount regulating blade of FIG. 2;

FIG. 4 is an explanatory diagram illustrating an operation of a pressure contact force variable unit that changes the pressure contact force of the oil amount regulating blade of FIG.

FIG. 5 is an explanatory diagram for explaining an operation of a first variable unit in the pressing force variable unit of FIG. 3;

FIG. 6 is an explanatory diagram for explaining an operation of a second variable unit in the pressing force variable unit of FIG. 3;

FIG. 7 is a perspective view illustrating a schematic configuration of an image information detection unit in the copying machine of FIG. 1;

FIG. 8 is a perspective view showing another configuration of the image information detection unit.

FIG. 9 is a diagram illustrating a relationship between an oil application amount and glossiness.

FIG. 10 is a block diagram showing a part of a control circuit of the copying machine shown in FIG. 1;

FIG. 11 is a flowchart illustrating control for correcting the pressing force of the oil amount regulating blade.

FIG. 12 is a perspective view illustrating a schematic configuration of an image information detection unit according to a second embodiment.

FIG. 13 is a perspective view showing another configuration of the image information detection unit.

FIG. 14 is a diagram illustrating a relationship between an oil application amount and transmittance.

FIG. 15 is a flowchart illustrating control for correcting a pressing force of an oil amount regulating blade according to the second embodiment.

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

FIG. 17 is a perspective view illustrating another configuration of the image information detection unit (when detecting intensity information of diffuse transmission light of a fixed image, etc.).

FIG. 18 is a perspective view showing another configuration of the image information detection unit (in the case where intensity information of refracted transmitted light of a fixed image is detected).

FIG. 19 is a side view showing another configuration of the image information detection unit (in the case of detecting color shift information of a fixed image).

[Explanation of symbols]

 5 Image Processing Unit 30 Photoconductor Drum 31 Charger 32Y, 32C, 32M, 32K Developing Device 33 Transfer Charger 34 Transfer Drum 40 Fixing Device 41A-41C Halogen Lamps 42A-42C CCD Sensor 43 Image Information Detecting Unit 54 General Control Unit (Oil) Coating condition correcting means) 212 Heating roller (first fixing member) 213 Pressure roller (second fixing member) 240 Oil applying section 242 Oil applying roller 243 Oil amount regulating blade 221 Heater lamp 222 Temperature sensor 260 First variable section 270A, 270C Second variable section S Recording medium TA to TC Fixing test image

Continued on front page F term (reference) 2H027 DE02 DE07 DE10 EA18 EA20 EC04 EC06 EC07 EC09 FD08 2H033 AA02 AA09 AA16 AA39 BA25 BA43 BA44 BA45 BA46 BB01 BB19 BB28 BB34 5C074 AA07 AA08 BB02 BB11 BB11 BB11

Claims (4)

[Claims] An image forming means for forming an unfixed image on a recording medium, a first fixing member and a second fixing member pressed against each other, and at least one of the first fixing member and the second fixing member. A contact heating fixing unit for fixing an unfixed image created by the image creating unit on the recording medium by contact heating, comprising a heater provided and oil applying means for applying oil to the first fixing member. A light emitting element for irradiating light to the fixed image fixed on the recording medium by the contact heating fixing means, and detecting intensity information of light emitted from the light emitting element and reflected or transmitted through the fixed image. An image for detecting image information of the fixed image at least at two or more positions of the recording medium different from each other in a direction orthogonal to the recording medium conveyance direction. An oil application condition correction unit that calculates a change in image information of each of the fixed images from a detection result of the image information detection unit, and corrects an oil application condition in the oil application unit based on the change. An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein the oil applying unit is configured to apply an oil in contact with the first fixing member and apply the oil, and the oil applying roller is pressed against the oil applying roller and the oil applying roller presses the oil applying roller. (1) an oil amount regulating member that regulates the amount of oil applied to the fixing member to a constant amount, wherein the contact heating and fixing unit is capable of changing a pressure contact force of the oil amount regulating member with respect to the oil application roller; An image forming apparatus comprising a variable unit, wherein the oil application condition correcting unit corrects a pressing force of the oil amount regulating member. 3. The image forming apparatus according to claim 2, wherein said pressure contact force varying means is capable of changing an axial distribution of a pressure contact force of said oil amount regulating member with respect to said oil application roller. An image forming apparatus, characterized in that: 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. An image forming apparatus, comprising: a test image data memory for detecting the intensity of light transmitted or reflected by a fixed test image fixed on the recording medium.