JP2000284551A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that the quality of an image state on the fixing image can be detected without observing the image state. SOLUTION: Relating to a general controlling part 54, the fixation test image T is formed on a recording body S, by the periodical selection or the selection of an operator. As a result, the image color information detecting part 43 detects strength IbR, IbG and IbR of straight advance transmission light of the fixation test image T being color disassembled by a RGB filter 39. Then, the general controlling part 54, judges a fusion state of toner in the fixation test image by referring to table data, changing the controlling value of such as the drive controlling part based on the judgment result thereof, to reflect it on the fixing condition, the image forming condition, or the like. In such a manner, a futile recopy, or a situation being impelled to adopt a poor locking OHP sheet is avoided.

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. Furthermore, when a large number of copies are made at once, 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.

[0006]

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. A fixing unit for fixing the image formed on the recording medium, the light emitting element irradiating light to the fixed image fixed on the recording medium by the fixing unit; and An image color information detecting unit including a light receiving element for detecting color information of light transmitted or reflected through the fixed image, a spectral filter provided between the light emitting element and the light receiving element, and the image color information detecting unit Image color information processing means for processing the color information of the light detected in step (1).

In this image forming apparatus, first, the 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 color information detecting means detects the color information of the fixed image fixed on the recording medium.

The detection of the color information is performed as follows. First, a light emitting element irradiates a fixed image on a recording medium with light. Then, light transmitted or reflected by the fixed image is received by the light receiving element. At this time, since a spectral filter is provided between the light emitting element and the light receiving element, light received by the light receiving element is transmitted light or reflected light passing through the spectral filter. That is, the image color information detecting means obtains color information by detecting intensity information of transmitted light or reflected light of the fixed image passed through the spectral filter. Here, examples of the spectral filter include three color filters of red (R), green (G), and blue (B).

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

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

On the other hand, if the fixing is not good, FIG.
As shown in FIGS. 1 to 23, any one of the toners CT, MT, and YT attached to the recording medium S does not melt, so that the surface of the insufficiently melted toner layer is not smooth but uneven. Since the incident light is refracted and transmitted by the insufficiently melted toner layer, the intensity of the refracted transmitted light increases and the intensity of the straight transmitted light decreases. More specifically, in FIG. 21, the incident light is refracted by the toner CT, and in FIG.
Incident light is refracted, and in FIG.
The incident light is refracted at T and CT. On the other hand, if the reflected light is used, the incident light is diffused, the intensity of the specularly reflected light decreases, and the intensity of the diffusely reflected light for each color increases. For this reason, the image becomes a dull image with low brightness and in which the predetermined saturation is not reproduced.

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

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

As the recording medium, in addition to plain paper, any recording medium that can fix an image, such as a thick paper, an OHP sheet, a special paper coated with a resin or the like, may be 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. On the other hand, the light receiving element only needs to have a sensitivity range that responds to light emitted from the light emitting element. For example, a CCD, a photodiode, and the like can be given.

In the image forming apparatus according to the present invention, the image color information detecting means detects color information for each of the fixed images on the plurality of recording media fixed in succession, and executes the image color information processing. The means may also process the variation regarding the color information of each fixed image.

By detecting the color information of the fixed images on the plurality of recording media successively fixed as described above and processing the change of the color information of the fixed image, the change of the fixed image can be known. Therefore, it is possible to detect whether or not the heat supply in the fixing unit is properly performed when a recording medium that requires a large amount of heat for fixing such as a thick paper or an OHP sheet is used. it can.
If the amount of heat is not supplied properly, even if the original recording medium can be fixed well, the amount of heat is gradually removed from the fixing unit and the fixing is not sufficiently performed. This is because it fluctuates gradually. 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, The information detecting means detects color information of light transmitted or reflected on the fixing test image fixed on the recording medium, and the image color information processing means,
It is desirable to process the color information of the fixing test image.

Since the position of the fixed image to be detected is known in advance by using the fixed test image obtained from the previously stored test image data, the color information of the fixed image can be reliably obtained. Can be. Therefore, the quality of the image can be reliably determined, and the processing result of the color 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 color information with ideal color 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

[0020]

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 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; a halogen lamp 41; a CCD sensor 42;
An image color information detection unit 43 including a GB filter 39;
And a paper discharge tray 46 for accommodating the recording medium that has been copied and discharged outside the apparatus.

Here, the image color information detecting section 43 is for grasping information for detecting the image state of the fixed image, and specifically, for detecting the color information of the fixed image, that is, the color developing property. It is. As shown in FIG. 2, for example, as shown in FIG. 2, the image color information detecting unit 43 outputs a substantially rectangular fixing test image T at the upper left corner when the conveyance direction indicated by the arrow in the recording material S is directed upward. When formed above, it is arranged at a position where the color development state of the fixing test image T can be measured.

That is, a halogen lamp 41, which is a light emitting element, is provided on the lower side of the recording medium S discharged from the fixing unit 40 in the drawing, behind the fixing unit 40 in the recording medium S. An RGB filter 39 for color-separating light radiated from the halogen lamp 41 and transmitted through the fixing test image T, and an RGB filter 39 on the upper side in the figure so as to sandwich the conveyance path of the recording medium S coaxially with the optical axis 41L. A CCD sensor 42 for receiving light is provided. As described above, the image color information detection unit 43 is configured in a state where the halogen lamp 41, the CCD sensor 42, and the RGB filter 39 form a set.

The detection of color information in the image color information detecting section 43 using transmitted light is advantageous in that it is less affected by deformation of the recording medium, such as waving or curling. 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 RGB filter 39 is a disk-shaped rotating plate 38 in which three color filters of a red filter 39R, a green filter 39G, and a blue filter 39B are fitted at equal intervals (equal angles) in a circumferential direction. is there. The motor control unit 3 adjusts the timing at which the fixing test image T passes through the detection area of the image color information detection unit 43.
6 drives the rotary motor 37 connected to the rotary plate 38, so that the three color filters 39R, 39G, 3
9B, the transmitted light of the fixing test image T through each filter is received by the CCD sensor 42.

The arrangement of the halogen lamp 41 and the CCD sensor 42 may be reversed. 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. Further, the RGB filter 39 may be disposed between the halogen lamp 41 and the recording medium S so that the light of the halogen lamp 41 is separated before the fixing test image T is irradiated.

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 increases, and it becomes impossible to accurately measure the intensity information of the straight transmitted light after color separation. Further, the angle is more preferably 90 degrees (the state of FIG. 2). By arranging the halogen lamp 41 and the CCD sensor 42 in this manner, it is difficult to be affected by the thickness of the fixing test image T and the lifting of the recording medium S at the time of measurement, and the intensity information of the straight transmitted light after color separation can be obtained more accurately. This is because it can be measured in a short time.

By arranging the halogen lamp 41, the CCD sensor 42, and the RGB filter 39 in this manner, the image color information detecting section 43 can detect the fixing test image T
The intensity of the linearly transmitted light that has been color-separated into species can be detected. That is, the image color information detection unit 43
Intensities IbR (through the filter 39R), IbG (through the filter 39G), and IbB (through the filter 39B) of the transmitted light of the three colors received by the sensor 42
Is detected, the color information of the straight transmitted light of the fixing test image T is detected. The color information of the straight transmitted light is detected because the straight transmitted light has a positive correlation with the quality of the image state, has a wide measurement range, and is strong against noise.

In the image color information detecting section 43, the light emission intensities IaR, IaG,
IaB may also be detected. The ratio of both (Ib
R / IaR, etc.), and by using this, it is possible to eliminate the influence on the intensity IbR, etc. of the transmitted light due to the fluctuation of the emission intensity IaR, etc. of the halogen lamp 41. In the present embodiment, the halogen lamp 41
And the intensity information of the transmitted light is used as it is without obtaining the ratio between the two.

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

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

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

An input / output port of the general control unit 54 includes an IR control unit 51 for controlling the operation of the image reading unit 2 and a fixing unit 4.
0, a drive control unit 55 for driving and stopping, a conveyance control unit 56 for controlling the supply of the recording medium, and the polygon mirror 21.
A scanner control unit 57 for controlling laser beam scanning by
A high-voltage control unit 58 for controlling high voltages such as charging of the photosensitive drum 30, application of a developing bias and a transfer bias, a laser control unit 59 for performing modulation control of laser light, an image color information detection unit 43, and RGB. A motor controller 36 for controlling the rotation of a rotary motor 37 for rotating the rotary plate 38 of the filter 39 is connected. Further, a signal from the operation panel 53 is input to the overall control unit 54 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 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 is based on 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.

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

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

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

Further, a state where neither toner CT nor MT is melted will be described with reference to FIG. In this state, the toner MT absorbs the G component of the incident light, and transmits 10% each of the B component and the R component. Further, toner C
T absorbs the R component and transmits 10% of the B component. Therefore, the B component is finally transmitted by 1%.

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

When the fixing test image T is created, the motor control unit 36 rotates the rotary motor 37 at the timing when the fixing test image T reaches the detection area of the image color information detecting unit 43, The RGB filter 39 is rotated. Then, the filters 39R, 39G,
39B, the image color information detecting unit 43
The intensity IbR, IbG, IbB of the straight transmitted light after color separation of the fixing test image T created above is measured, and these data are transmitted to the overall control unit 54. Thereafter, the overall control unit 54 determines the melting state of each color toner CT, MT, YT based on the table data described above.

Next, the toners CT, MT, and YT of the respective colors are used.
The overall control unit 54 determines whether the image state is good or not based on the determination result of the melted state of the fixing unit 40 by, for example, the heating roller 40 a of the fixing device 40.
The control results of the drive control unit 55, the transport control unit 56, the high-pressure control unit 58, and the like are changed, and the determined determination results are reflected in the fixing conditions and the image forming conditions. Thus, all of the toners CT, MT, and YT of each color can be sufficiently melted, so that 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 color information detecting section 43 detects the intensity IbR, IbG, I of the straight transmitted light of the fixing test image T.
Measure bB. Based on the intensity IbR, IbG, IbB of the color-separated straight-through light measured by the image color information detection unit 43, the integrated control unit 54 determines the melting state of each color toner CT, MT, YT in the fixing test image T. Judge. By reflecting this determination 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 “patch”) T is created on the recording medium S. A pattern formed 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. 9, and a plurality of patches TP as shown in FIG. FIG. 11 shows a pattern formed by arranging TPs in the transport direction of the recording material S (vertical direction in the figure).
And a pattern in which a plurality of patches TP are formed on the diagonal line of the recording medium S as shown in FIG.

Here, in the case where the image color information detecting section 43 including one set of the halogen lamp 41, the CCD sensor 42, and the RGB filter 39 is used as exemplified in the first embodiment, With the pattern as shown in FIG. 10, color information of transmitted light can be detected for a plurality of patches TP. On the other hand, as a fixing test image,
When creating patterns as shown in FIGS. 9, 11, and 12, it is necessary to provide an image color information detection unit including a plurality of sets of halogen lamps, a CCD sensor, and an RGB filter in a direction intersecting the transport direction. is there. In any case, when the intensity information of the transmitted light after the color separation of the plurality of fixing test images (patches) TP is detected, the color information of the transmitted light can be accurately measured by calculating the average value and the like. .

Further, as in the above embodiment, the recording medium S
In addition to creating only the fixing test image, the fixing test image TP may be superimposed on the actual copy image GA as shown by the broken line in each figure by the selection of the operator. When the fixing test image TP is superimposed on the copy image GA, an image forming the fixing test image TP on the periphery of the recording medium as shown in FIGS. 9 to 11 may be selected. In the pattern as shown in FIG. 12, the copy image GA and the fixing test image T
This is because P overlaps.

(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 color information detecting unit and the color information of the transmitted light and the ideal color information Are different after the comparison with.
More specifically, as shown in FIG.
3, the CCD sensor 62 is disposed at a position deviated from the optical axis 41L of the halogen lamp 41 while allowing the intersection P between the optical axis 41L of the halogen lamp 41 and the recording medium S to be seen. And a recording medium S. Thus, the image color information detecting section 63 can detect the intensities IcR, IcG, and IcB of the refracted transmitted light of the fixing test image T after the color separation. Another difference is that the quality of the image is determined based on the determination result of the melting state of the toner and displayed on the operation panel. Note that the copy operation and the test image creation operation are the same as those in the first embodiment, and therefore description thereof is omitted, and the same components are denoted by the same reference numerals.

As described above, in the image color information detecting section 63, the intensity I of the refracted transmitted light after the color separation of the fixing test image T is obtained.
The reason why cR, IcG, and IcB are detected is that the quality 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.

The luminous intensity Ia of the halogen lamp 41
R and the like may also be detected to calculate the ratio of the two (IcR / IaR, etc.) and to use this to determine the quality of the image state. 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,
At the timing when the fixing test image T reaches the detection area of the image color information detection unit 63, the motor control unit 36 rotates the rotation motor 37, and thereby the RGB filter 39
To rotate. Then, the filters 39R, 39G, 39
B, the image color information detection unit 63 measures the intensity IbR, IbG, IbB of the straight transmitted light after color separation of the fixing test image T created on the recording medium S in order, and supervises these data. It is transmitted to the control unit 54. After that, the general control unit 5
Reference numeral 4 determines the melting state of each color toner CT, MT, YT based on table data stored in the ROM in advance.

Next, the toners CT, MT, and YT for each color are used.
Of the fixing test image T is determined based on the determination result of the melting state of the fixing test image T. 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
There is no need to view 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 the predetermined fixing test image T is created on the recording medium S, the image color information detecting section 63
Intensity Ic of refracted transmitted light after color separation of test image T after fixing
Measure R, IcG, IcB. And the overall control unit 54
Is the intensity Ic measured by the image color information detection unit 63
Based on R, IcG, and IcB, the melting state of each color toner CT, MT, and YT in the fixing test image T is obtained, and the quality of the image state 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 almost the same as that of the copying machine 1 according to the first embodiment, but as shown in FIG. The difference is that it can be moved in a direction intersecting the transport direction, specifically, in a direction orthogonal to the transport direction. Another difference is that the RGB filter 39 is arranged between the halogen lamp 41 and the recording medium S. That is, as shown in FIG. 15, the screw shaft 84 is provided in a direction orthogonal to the transport direction. A drive motor 85 is provided at the end, and an output shaft of the drive motor 85 and the screw shaft 84 are connected. Further, a CCD sensor 82 is attached to the screw shaft 84.

When the drive motor 85 is driven, the screw shaft 84 rotates, and the rotation causes the CCD sensor 82 to move. 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) as shown in FIG.
Is created, three (41A, 41A,
41B, 41C) are provided. In the present embodiment, the CCD sensor 82 is moved, but the halogen lamp 41 and the RGB filter 39 are moved, and the CCD sensor 82 is moved.
Three sensors 42 may be provided, or one set of the halogen lamp 41, the CCD sensor 42, and the RGB filter 39 may be moved with the relative positional relationship being fixed.

By making the CCD sensor 82 constituting the image color information detecting section 83 movable as described above,
The color information of the transmitted light of the fixed image can be detected at a plurality of locations on one recording medium S without providing a plurality of D sensors 82. As a result, the average value can be calculated from the 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 IbRA of the nine linearly transmitted lights after color separation of the fixing test images TA, TB, and TC created on the recording medium S. , IbGA, IbBA and Ib
RB, IbGB, IbBB and IbRC, IbGC, I
bBC is sequentially moved and measured, and each data is transmitted to the overall control unit 54. Thereafter, the overall control unit 54 sets the average values IbRm, IbGm, and IbRm of the intensities of the test images TA, TB, and TC for each color filter.
IbBm is calculated, the melting state of the toner is determined with reference to the table data, and the control values of the drive control unit 55, the transport control unit 56, the high-pressure control unit 58, and the like are changed based on the determination result to determine the fixing conditions and the like. This is reflected in the imaging conditions.

As a result, 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 halogen lamp 41 is used.
The light emission intensity IaRA, IaGA, IaBA, etc., such as A, may also be detected, and the ratio of each to the transmitted light intensity 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 third embodiment, a plurality of fixing test images T
A to TC are created on the recording medium S. On the other hand, the intensities of the nine rectilinear transmitted lights after the color separation of the fixing test images TA to TC are sequentially measured while the CCD sensor 82 moves.
Then, the overall control unit 54 calculates an average value IbRm, for each color filter of nine intensities measured by the image color information detection unit 83,
By calculating IbGm and IbBm and reflecting the detection results in fixing conditions and the like based on the table data, a fixed image in a good image state can be formed. Therefore,
It is possible to avoid re-use of unnecessary copies and use of an OHP sheet having a poor appearance.

(Fourth Embodiment) Next, a fourth embodiment will be described. The copying machine according to the fourth embodiment has substantially the same configuration as the copying machine 1 according to the first embodiment, but does not create a fixing test image but copies a fixed image of a normal document. The difference is that color information of transmitted light is detected and processed. Another difference is that the RGB filter 39 is arranged between the halogen lamp 41 and the recording medium S. This color information processing program is executed after a predetermined number of copies have been made, after a predetermined operating time has elapsed, or when the operator has selected. Hereinafter, the processing of the color information 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 color information processing program is executed,
First, the image reading unit 2 obtains image data corresponding to an image of a document. Then, in the regions R1, R2, R3,... Where the image color information detecting section 43 can detect the color information of the transmitted light of the fixed image, it is checked which region has the fixed image (image data). For example, in the case shown in FIG. 16, it is found that the fixed image exists in the region R2. Then, the IR control unit 51 issues a command to the image color information detection unit 43 via the overall control unit 54 to detect the color 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.

Then, at the timing when the recording medium S is discharged from the fixing device 40 and the area R2 reaches the detection area of the image color information detecting section 43, the image color information detecting section 43
Intensities IgR, IgG, IgB of the straight transmitted light after color separation of
And transmits these data to the overall control unit 54. Then, the overall control unit 54 determines the melting state of the toner in the fixed image G based on the table data stored in the ROM in advance. Using the result of this determination, the overall control unit 54 changes the control values of the drive control unit 55, the transport control unit 56, the high-voltage control unit 58, and the like, and reflects the control values on the fixing conditions and the image forming conditions. Thereby, a fixed image in a good image state can be formed. 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. 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 fourth embodiment, when the processing program for transmitted light color 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 color 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 color information detecting unit 43 determines the intensity IgR, Ig of the color-separated linearly transmitted light of the fixed image in the region R2.
G and IgB are measured. Then, the overall control unit 54 determines the intensities IgR and Ig measured by the image color information detection unit 43.
The quality of the fixed image G on the recording medium S is determined by determining the melting state of the toner with reference to the table data based on G and IgB. 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.

(Fifth Embodiment) Next, a fifth embodiment will be described. In the first to fourth embodiments, the color information of the transmitted light is obtained from one recording medium, and is processed and reflected on fixing conditions or the like, or the quality of the image on the recording medium is determined. . However, for example, cardboard or OHP that takes a large amount of heat from the fixing device 40 due to its large heat capacity
When sheets are continuously used, even if the image state of the first sheet is good, the supply of heat to the fixing device 40 cannot keep up, and the fixing temperature gradually decreases, and the image state deteriorates. There is. On the other hand, in the present embodiment, as shown in FIG. 17, the fixing test images T1, T2, and T2 on the plurality of recording materials S1, S2, S3,. The intensities Ib1R, Ib1G, Ib1B, Ib2R, and Ib1R, Ib1G, Ib1G,
Ib2G, Ib2B, Ib3R, Ib3G, Ib3B ...
Are sequentially detected. The overall control unit 54 processes the color information about the fixing test images T1, T2,... Of each of the recording materials S1, S2, and calculates the variation of the color information 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 color information of the fixing test images T1, T2,... Of the recording materials S1, S2,... Is processed, and the variation of the color information among the recording materials S1, S2,. By changing the fixing conditions to suit the recording paper to be used, it is possible to control so that a good fixed image having an image state of a certain level or more can be obtained even when fixing is performed continuously. Becomes In this embodiment, the intensity Ib1R of the straight transmitted light is measured, but it is apparent that the refracted transmitted light may be detected in the same manner as in the second embodiment.

(Sixth Embodiment) Finally, a sixth embodiment will be described. The copying machine according to the sixth embodiment has substantially the same configuration as the copying machine 1 according to the first embodiment, but differs in the configuration of an image color information detecting unit. Specifically, as shown in FIG. 18, the halogen lamp 101 is positioned diagonally on the right side of the recording material S (diagonally on the conveyance direction) in the figure.
And an RGB filter 109 for color-separating incident light incident on the fixing test image T from the halogen lamp 101.
Is provided coaxially with the optical axis 101L of the halogen lamp 101, and receives an incident angle α and a reflection with respect to the fixing test image T (recording medium S) so as to receive specularly reflected light with respect to the incident light that is color-separated by the RGB filter 109. The CCD sensor 1 is located diagonally upper left (diagonally upper in the transport direction) in the figure where the angle β is equal.
02 is provided.

As a result, the image color information detecting section 103 can detect the color information of the regular reflection light of the fixing test image T. As described above, by detecting the color information of the reflected light of the fixing test image T in the image color information detection unit 103, it is possible to detect the color information regardless of the paper type.
Another difference is that the quality of the image is determined based on the determination result of the melting state of the toner and displayed on the operation panel. Note that the copy operation and the test image creation operation are the same as those in the first embodiment, and therefore description thereof is omitted, and the same components are denoted by the same reference numerals.

When the fixing test image T is created,
The intensity IdR, Id of the specular reflected light after color separation of the fixing test image T created on the recording medium S by the image color information detecting unit 103.
G and IdB are measured, and these data are transferred to the general control unit 5.
Send to 4. Thereafter, the overall control unit 54 determines the melting state of the toner with reference to the table data stored in the ROM in advance. Further, utilizing that the determination result corresponds to the quality of the image state of the fixing test image T,
The overall control unit 54 determines whether the image state is good or not, and determines whether the image state is good or bad.
For example, the control result of the drive control unit 55, the transport control unit 56, the high-pressure control unit 58, and the like is changed and the obtained comparison result is reflected in the fixing condition and the image forming condition by changing the control temperature of the heating roller 40a.

As a result, 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 of the sixth embodiment, a predetermined fixing test image T is created on the recording medium S periodically or by an operator's selection. Then, the image color information detecting unit 103 sets the intensity IdR, IdR of the specular reflected light of the fixing test image T after color separation.
Measure dG and IdB. Then, the integrated control unit 54 determines the melting state of the toner with reference to the table data, and reflects this determination result in the fixing conditions and the like, so that 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 sixth embodiment, specular reflection light is used in place of using straight transmission light to detect color information of the fixing test image T in the first embodiment. It is not limited to this. For example, as a mode corresponding to that shown in the second embodiment, as shown in FIG. 19, the CCD sensor is located at a position where the diffuse reflection light of the fixing test image T with respect to the incident light from the halogen lamp 101 can be received. 112 may be arranged to use diffusely reflected light. Also, instead of using transmitted light in the third and fourth embodiments, reflected light can be used.

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 the third and fourth embodiments, the image color information detection units 83 and 43 detect the color information of the straight transmitted light of the fixed image, but instead of detecting the color information of the straight transmitted light, The color information of the refracted transmitted light may be detected as exemplified in the second embodiment, or one of the color information of the regular reflected light and the color information of the diffuse reflected light may be detected. In the above embodiment, an example in which the present invention is applied to a copying machine has been described. However, the present invention is applicable to any apparatus having an image creating unit and a fixing unit such as a printer such as a page printer and a facsimile. be able to.

[0076]

As described above, according to the image forming apparatus of the present invention, the image color information detecting means detects the color information of the fixed image. Next, the image color information processing means processes the color information detected by the image color information detection 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 O
This avoids having to use an HP sheet.

[Brief description of the drawings]

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

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

FIG. 3 is a perspective view illustrating another configuration of the color 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 an explanatory diagram illustrating a relationship between a molten state of toner and color information.

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

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

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

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

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

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

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

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

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

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

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

FIG. 17 is an explanatory diagram for describing a detection method and a processing method in an image color information detection unit when a color information fluctuation of a fixed image is also processed in the copying machine according to the fifth embodiment. is there.

FIG. 18 is a perspective view illustrating a configuration of an image color information detection unit in a copying machine according to a sixth embodiment.

FIG. 19 is a schematic configuration diagram showing another configuration of the image color information detection unit in the copying machine of FIG. 18;

FIG. 20 is an explanatory diagram for explaining a state of transmitted light when fixing is performed favorably.

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

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

FIG. 23 is an explanatory diagram for explaining a state of transmitted light when fixing is not properly performed.

[Explanation of symbols]

 5 Image Processing Unit 30 Photosensitive Drum 32Y, 32C, 32M, 32K Developing Device 33 Transfer Charger 34 Transfer Drum 39 RGB Filter 40 Fixing Unit 41 Halogen Lamp 42 CCD Sensor 43 Image Color Information Detecting Unit 54 Overall Control Unit S Recording Medium T Fixing Test image

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsuneshi Takahashi 2-13-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka International Building Minolta Co., Ltd. 2G020 AA08 DA13 DA43 2H027 DA32 DA50 DC05 DE02 DE07 DE09 EA12 EB04 EB06 EC03 EC06 EC19 EF09 HA02 HA03 HA12 ZA07 2H030 AA02 AD04 AD16 2H033 AA02 AA11 AA35 CA01 CA30

Claims (3)

[Claims] 1. An image forming apparatus comprising: an image forming unit that forms an image on a recording medium; and a fixing unit that fixes the image generated by the image forming unit on the recording medium. A light emitting element for irradiating light to a fixed image fixed on a recording medium, a light receiving element for detecting color information of light emitted from the light emitting element and transmitted or reflected through the fixed image, the light emitting element and the light receiving element An image forming apparatus comprising: an image color information detection unit including a spectral filter provided between the image color information detection unit; and an image color information processing unit that processes color information detected by the image color information detection unit. 2. The image forming apparatus according to claim 1, wherein the image color information detecting unit is configured to detect color information of light transmitted or reflected on each of the fixed images on the plurality of recording materials fixed in succession. The image forming apparatus according to claim 1, wherein the image color information processing unit also processes a change in color information of each of the fixed images. 3. A test image data memory according to claim 1, wherein said image creating means stores test image data for creating a predetermined test image on said recording medium. Wherein the image color information detecting means detects color information of light transmitted or reflected by the fixing test image fixed on the recording medium, and the image color information information processing means detects the color information of the fixing test image. An image forming apparatus for processing color information.