JP2021177155A - Coverage detection device, image forming apparatus, coverage detection method, and coverage detection program - Google Patents

Abstract

To provide a coverage detection device that can accurately detect coverage of a grounding adhesive layer with powder.SOLUTION: A coverage detection device is to detect coverage of a grounding adhesive layer with powder adhered to the grounding adhesive layer, and comprises: a light source unit that irradiates an adhesion surface of the powder with rays of light different in reflectance on the grounding adhesive layer; a light receiving unit that individually receives rays of reflected light of the rays of light different in reflectance reflected on the adhesion surface of the powder; and a coverage detection unit that detects the coverage on the basis of quantities of the rays of reflected light received by the light receiving unit.SELECTED DRAWING: Figure 11

Description

The present invention relates to a coverage detection device, an image forming apparatus, a coverage detection method, and a coverage detection program.

As a technique for inspecting a toner image formed on a recording medium, there is a technique described in Patent Document 1 below. According to Patent Document 1, "From the irradiation light source 41, the blue toner image 43 on the intermediate transfer belt 2 is first irradiated with light having a wavelength of 550 nm, and then irradiated with light having a wavelength of 650 nm. The difference between the detection signal strength of only the transfer belt 2 (without the toner image 43) and the "difference in detection signal strength" of the magenta and cyan toner images of the "known adhesion amount" is plotted against the toner adhesion amount. Obtain as a "calibration line" for each toner color. From the thermoelastic wave signal intensity of only the intermediate transfer belt 2 and the thermoelastic wave signal intensity detected when irradiated with light of each wavelength, the amount of adhesion is calculated using the calibration curve and fed back to the development process. Then, "image density control" is performed. ".

Japanese Unexamined Patent Publication No. 2013-92691

By the way, there is a technique in which a toner image is used as a base adhesive layer and an image having a glossy feeling is formed by adhering powder to the base adhesive layer. In order to inspect whether or not the image formed in this way has a sufficient glossiness, it is necessary to detect the amount of powder adhered to the toner image. However, although the above-mentioned inspection technique can calculate the amount of adhesion of toners of a plurality of colors, it is not possible to accurately detect the amount of adhesion of powder to the toner image (coverage by powder), and the glossiness is visually observed. The coverage was detected by carrying out the inspection of.

Therefore, an object of the present invention is to provide a coverage detection device, an image forming device, a coverage detection method, and a coverage detection program capable of accurately detecting the coverage of the underlying adhesive layer by powder.

The present invention for achieving such an object is a coverage detection device for detecting the coverage of the undercoat adhesive layer by the powder adhering to the undercoat adhesive layer, and the reflectance of the undercoat adhesive layer is high. A light source unit that irradiates the adhering surface of the powder with different light, a light receiving unit that individually receives the reflected light of the light having different reflectances reflected by the adhering surface of the powder, and the reflected light received by the light receiving unit. The configuration is provided with a coverage detection unit that detects the coverage based on each light receiving amount.

According to the present invention, it is possible to provide a coverage detection device, an image forming apparatus, a coverage detection method, and a coverage detection program capable of accurately detecting the coverage of the underlying adhesive layer by powder.

It is a block diagram of the image forming apparatus which concerns on embodiment. It is a block diagram of the 1st sensor which the coverage detection apparatus which concerns on embodiment has. It is a figure which shows the spectroscopic reflection characteristic of an image pattern as a base adhesive layer. It is a block diagram of the 2nd sensor which the coverage detection apparatus which concerns on embodiment has. It is a figure which shows the spectral reflection characteristic of the powder holding surface as a base adhesive layer. It is a figure which shows the 1st modification of the 1st sensor which the coverage detection apparatus which concerns on embodiment has. It is a figure which shows the 2nd modification of the 1st sensor which the coverage detection apparatus which concerns on embodiment has. It is a figure which shows the 3rd modification of the 1st sensor which the coverage detection apparatus which concerns on embodiment has. It is a figure which shows the 4th modification of the 1st sensor which the coverage detection apparatus which concerns on embodiment has. It is a figure for demonstrating the calculation of the coverage of the powder which concerns on embodiment. It is a block diagram explaining the structure of the inspection information processing part which the coverage detection apparatus which concerns on embodiment has. It is a figure which shows the covering rate characteristic of the reflected light amount with respect to the covering rate of a powder. It is a figure which shows the difference characteristic of the reflected light amount with respect to the covering rate of a powder. It is a figure which shows the spectral reflection characteristic of each powder. It is a figure which shows an example of the correction coefficient of a coverage rate. It is a flowchart (the 1) which shows an example of the coverage | coverage detection method which concerns on embodiment. It is a flowchart (the 2) which shows an example of the coverage | coverage detection method which concerns on embodiment.

Hereinafter, embodiments of the coverage detection device, the image forming apparatus, the coverage detection method, and the coverage detection program of the present invention will be described in detail with reference to the drawings.

≪Image forming device≫
FIG. 1 is a schematic view showing a configuration of an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 shown in FIG. 1 is for forming a glossy image P1 by attaching a glossy powder Pd to an image pattern P formed on the main surface of the recording medium S.

The image pattern P is also a base adhesive layer for adhering the powder Pd. Such an image pattern P is made of a material that adheres powder Pd by melting by heating to develop adhesiveness and then curing. Further, the image pattern P may have adhesiveness regardless of heating. The image pattern P in this case is made of a material that is cured by heating or light irradiation after the powder P is transferred to the image pattern P. Such an image pattern P is, for example, a toner image or an ink image.

Therefore, although not shown here, the image forming apparatus 1 may be connected to an image pattern forming apparatus that forms an image pattern P on the recording medium S, and may be provided with an image pattern forming apparatus. ..

As an example, the image forming apparatus 1 for attaching the powder Pd to the image pattern P as described above to form the glossy image P1 includes a preheating member 11, a powder holding member 12, a powder supply member 13, and a rubbing member 14. It includes a transfer member 15, a cleaning member 16, a powder recovery member 17 on a medium, a drive control unit 18, and an operation unit 19. Further, the image forming apparatus 1 includes a covering rate detecting device 20 for detecting the covering rate of the powder Pd. Hereinafter, the details of each member constituting the image forming apparatus 1 will be sequentially described, and then the configuration of the powder Pd handled by the image forming apparatus 1 and the details of the coverage detection apparatus 20 provided in the image forming apparatus 1 will be described. do.
do.

<Preheating member 11>
The preheating member 11 is for melting the image pattern P formed on the main surface of the recording medium S by heating. Such a preheating member 11 is arranged on the transport path of the recording medium S supplied from the image pattern P forming apparatus in the transport direction x, for example. The image pattern P heated by the preheating member 11 develops adhesiveness by melting, and then has adhesiveness by curing.

The preheating member 11 may be provided as needed, and if the image pattern P has adhesiveness without being melted by heating, it is not necessary to provide the preheating member 11. However, in this case, the image forming apparatus 1 is provided with a heating unit or a light irradiation unit for curing the image pattern P after transferring the powder P to the image pattern P in the transfer member 15 described later. ..

<Powder holding member 12>
The powder holding member 12 has a cylindrical shape and is rotated around a cylindrical shaft by a drive motor, and the cylindrical side peripheral surface is a powder holding surface 12a. The powder holding surface 12a of the powder holding member 12 is formed of an elastic layer having adhesiveness, and holds the powder Pd described below by adhesiveness. Therefore, the surface layer constituting the powder holding surface 12a of the powder holding member 12 is also a base adhesive layer for adhering the powder Pd. Further, the powder holding member 12 is provided with a heating member 12b inside a cylindrical shape, and the powder holding surface 12a is heated.

As the material constituting such a powder holding surface 12a, it is preferable to have heat resistance, and silicon rubber is preferably used as an example.

Further, such a powder holding member 12 is arranged on the downstream side of the preheating member 11 in the transport direction x of the recording medium S and on the main surface side on which the image pattern P is formed in the recording medium S. The powder holding member 12 is configured to rotate in the forward direction along the transport direction x of the recording medium S on the side facing the recording medium S. The configuration of the powder P held on the powder holding surface 12a of the powder holding member 12 will be described in detail below.

<Powder supply member 13>
The powder supply member 13 is for supplying the powder Pd to the powder holding surface 12a of the powder holding member 12, and is provided along the axial direction of the cylindrical powder holding member 12. Such a powder supply member 13 has a storage container 13a for storing the powder Pd and a transport member 13b housed in the storage container 13a.

Of these, the storage container 13a has an opening of the cylindrical powder holding member 12 toward the powder holding surface 12a arranged along the axial direction of the powder holding member 12.

The transport member 13b is, for example, a rotating cylindrical brush or sponge, or a screw-shaped member. By rotating in the opposite direction to the powder holding member 12, the transport member 13b transports the powder Pd stored in the storage container 13a to the opening of the storage container 13a, and the powder holding surface 12a of the powder holding member 12 Is supplied with powder Pd.

The powder supply member 13 is not limited to such a configuration. For example, the powder supply member 13 has a configuration in which the powder holding surface 12a of the powder holding member 12 is in direct contact with the powder Pd stored in the storage container 13a. It may be.

<Rubbing member 14>
The rubbing member 14 is for orienting the powder Pd on the powder holding surface 12a of the powder holding member 12 by rubbing the powder holding surface 12a of the powder holding member 12. Such a rubbing member 14 is arranged on the downstream side of the powder supply member 13 with respect to the rotation direction of the powder holding member 12.

The rubbing member 14 has a cylindrical shape, is arranged in a state of being in contact with the powder holding surface 12a, and rotates with a speed difference with respect to the rotation speed of the powder holding member 12. As a result, the rubbing member 14 is configured to rub the powder holding surface 12a of the rotating powder holding member 12. Further, the side peripheral surface of the rubbing member 14 that rubs the powder holding surface 12a is preferably made of a material having a gap for accommodating excess powder Pd on the powder holding surface 12a. .. As such a material, a porous material such as a brush, a sponge or a non-woven fabric is used.

Such a rubbing member 14 adheres to the powder holding surface 12a of the powder Pd supplied to the adhesive powder holding surface 12a by rubbing the powder holding surface 12a of the rotating powder holding member 12. Remove excess powder Pd that is not. At this time, excess powder Pd is captured in the voids on the side peripheral surface of the rubbing member 14.

As a result, the adhesive powder holding surface 12a holds one layer of powder Pd in a directly adhered state. At this time, if the powder Pd is non-spherical, the non-spherical powder Pd is in a state of being oriented in the same direction so as to be parallel to the powder holding surface 12a. As a result, the non-spherical powder Pd has a large contact area with respect to the powder holding surface 12a, and the adhesive force with respect to the powder holding surface 12a is secured. Therefore, the powder Pd falls from the powder holding surface 12a onto the recording medium S. Can be prevented. The composition of the powder Pd will be described in detail below.

Further, the rubbing member 14 includes a collection container 14a. The collection container 14a is arranged at least below the rubbing member 14, receives and stores the powder Pd that is removed from the powder holding surface 12a by the rubbing member 14 and falls, and causes the powder Pd to fall onto the recording medium S. To prevent.

<Transfer member 15>
The transfer member 15 is for transferring the powder Pd adhesively held on the powder holding surface 12a of the powder holding member 12 to the image pattern P formed on the main surface of the recording medium S. The transfer member 15 is arranged on the downstream side of the rubbing member 14 with respect to the rotation direction of the powder holding member 12.

The transfer member 15 has a cylindrical shape, and constitutes a nip portion that sandwiches the recording medium S between the transfer member 15 and the powder holding member 12. Further, the transfer member 15 is provided with a heating member 15b inside a cylindrical shape. Such a transfer member 15 is configured by using a metal roller or a rubber roller, and when a rubber roller is used, it is preferable that a silicon rubber or a fluorine layer is provided on the surface of the silicon rubber from the viewpoint of heat resistance.

The transfer member 15 as described above heats the image pattern P on the recording medium S nipped between the transfer member 15 and the powder holding member 12 and melts the image pattern P to make the image pattern P sticky. Further, the transfer member 15 presses the powder Pd, which is adhesively held in a state of being oriented toward the powder holding surface 12a of the powder holding member 12, against the image pattern P. As a result, the transfer member 15 transfers the oriented powder Pd from the powder holding surface 12a to the image pattern P.

The image pattern P passes through the nip portion between the powder holding member 12 and the transfer member 15, and then the temperature drops and hardens, and the powder Pd transferred from the powder holding member 12 is adhered and held. As a result, the image forming apparatus 1 forms a glossy image P1 in which the glossy powder Pd is attached to the surface of the image pattern P.

The glossy image P1 thus obtained is in a state of being attached with the powder Pd oriented with respect to the image pattern P, and becomes an image with high glossiness. Further, in the glossy image P1, since the contact area between the powder Pd and the image pattern P is large, the powder Pd is hard to be peeled off.

<Cleaning member 16>
The cleaning member 16 is a member for collecting the powder Pd remaining on the powder holding surface 12a of the powder holding member 12 that has passed through the nip portion between the transfer member 15 and cleaning the powder holding surface 12a. Such a cleaning member 16 has, for example, a cylindrical side circumference made of a brush or a sponge, and is left on the powder holding surface 12a by arranging the side circumference in contact with the powder holding surface 12a. Scrape the powder Pd. Further, the cleaning member 16 has a powder recovery member 16a which is arranged so as to face the side peripheral surface of the cleaning member 16 and collects the powder Pd scraped by the cleaning member 16. The powder recovery member 16a may be, for example, an air suction type. Further, the cleaning member 16 includes a collection container 16b. The collection container 16b is arranged at least below the cleaning member 16, receives and stores the powder Pd that is removed from the powder holding surface 12a by the cleaning member 16 and falls, and prevents the powder Pd from falling onto the recording medium S. ..

<Powder recovery member 17 on medium>
The powder recovery member 17 on the medium is for recovering excess powder Pd on the recording medium S that has passed through the nip portion between the powder holding member 12 and the transfer member 15. The powder recovery member 17 on the medium is arranged on the downstream side of the nip portion between the powder holding member 12 and the transfer member 15 in the transport direction x of the recording medium S, and on the side where the image pattern P is formed on the recording medium S. NS. Here, it is assumed that the extra powder Pd on the recording medium S is the powder Pd that is not adhered and held by the image pattern P.

Examples of such a powder recovery member 17 on a medium have a configuration in which powder Pd is sucked by air suction, but the present invention is not limited to this.

<Drive control unit 18>
The drive control unit 18 is a driver that controls the drive of each of the above-described units and the coverage detection device 20 described below based on the instruction from the operation unit 19 and the inspection result of the coverage detection device 20. It is composed of a computer. A computer is hardware used as a so-called computer. The computer may include a CPU (Central Processing Unit), a RAM (Random Access Memory), a non-volatile storage unit such as a ROM (Read Only Memory) or an HDD (hard disk drive), and a network interface. ..

<Operation unit 19>
The operation unit 19 is, for example, a part for inputting the setting of the job to be executed by using the image forming apparatus 1. The operation unit 19 may be a touch panel or operation buttons provided integrally with the display unit.

<Composition of powder Pd>
Next, the composition of the powder Pd will be described. The powder P has a non-spherical shape that is not a true sphere. It is preferable that such powder P has a scaly shape and a flat shape from the viewpoint of orientation along the powder holding surface 12a and the image pattern P.

The flat shape of the powder Pd means that the maximum length of the powder P is the major axis [L], and the maximum length in the direction orthogonal to the major axis [L] is the minor axis [W], the major axis [L], and the minor axis [W]. ], The ratio of the minor axis [W] to the thickness [t] is 3 or more, where the minimum length in the direction orthogonal to the thickness [t] is the thickness [t].

The thickness [t] of such a flat-shaped powder P is about 0.2 to 10 μm from the viewpoint of sufficiently expressing the glossiness of the powder Pd when the powder P is adhered to the image pattern 100 in an oriented state. It is preferably 0.2 to 5.0 μm, and more preferably 0.2 to 5.0 μm.

If the thickness [t] of the powder Pd is too small, it is difficult to recover the overlapped powder Pd, and the adhesion to the powder holding surface 12a and the image pattern P may not be ensured. In addition, the powder Pd is destroyed inside the image forming apparatus 1, and the size of the powder P tends to vary. On the other hand, if the thickness [t] of the powder Pd is too large, the powder P adhered to the image pattern 100 is likely to be separated from the image pattern 100.

The major axis [L] and minor axis [W] of the flat powder P are preferably about 1 to 50 μm, and more preferably 15 to 50 μm, respectively. If the major axis [L] and minor axis [W] are too small, handling becomes difficult. On the other hand, if the major axis [L] and the minor axis [W] are too large, it becomes difficult to form an image having a high resolution, which causes a factor of lowering the gradation of the image.

Further, the material of the powder P is not limited. The powder P is preferably composed of a metal or a metal oxide from the viewpoint of producing a desired gloss on the gloss image P1. Further, the powder P can be used by mixing particles of two or more kinds of materials. Further, the powder P may be a powder coated with particles, for example, a metal powder whose surface is coated with a metal oxide or a resin, or its surface is coated with a resin or a metal. It may be a metal oxide powder, or a resin powder whose surface is coated with a metal, a metal oxide or a resin.

Further, the powder may be a synthetic product or a commercially available product. Examples of commercially available products used as powder P are Sunshine Baby Chrome Powder, Aurora Powder, Pearl Powder (all manufactured by GG Corporation), ICEGEL Mirror Metal Powder (manufactured by TAT Co., Ltd.), Pika Ace MC Shine Dust, Effect C. (Made by Kurachi Co., Ltd., "Pika Ace" is a registered trademark of the company), PREGEL Magic Powder, Mirror Series (manufactured by Puri Anfa Co., Ltd., "PROGEL" is a registered trademark of the company), Bonnail Shine Powder (manufactured by K's Planning Co., Ltd., " "BONNAIL" is a registered trademark of the company), Metashine (manufactured by Nippon Sheet Glass Co., Ltd., "Metashine" is a registered trademark of the company), and LG neo (manufactured by Oike Kogyo Co., Ltd., "ELG neo" is a registered trademark of the company). included.

<< Coverage detection device 20 >>
Next, the coverage detection device 20 provided in the image forming device 1 will be described. The coverage detection device 20 is for detecting the coverage of the base adhesive layer by the powder Pd, and calculates the ratio of the base adhesive layer covered with the powder P. In the present embodiment, the base adhesive layer is the image pattern P and the powder holding surface 12a of the powder holding member 12. Such a coverage detection device 20 includes a first sensor 100a for detecting the coverage of the image pattern P by the powder Pd, and a second sensor 100b for detecting the coverage of the powder holding surface 12a by the powder Pd. , The information processing unit 200 is provided. The first sensor 100a and the second sensor 100b may be used alone, if necessary.

In the coverage detection device 20 provided with these members, the coverage of the powder Pd is detected based on the reflectance of light having different wavelengths. Lights having different wavelengths are absorption wavelength light absorbed by the underlying adhesive layer and non-absorbent wavelength light that is non-absorbent to the underlying adhesive layer and reflected by the underlying adhesive layer. Absorption wavelength light and non-absorption wavelength light are wavelength light set for each underlying adhesive layer.

In the following, first, the configuration of the first sensor 100a and the configuration of the second sensor 100b will be described, then the content of the coverage detection using the absorption wavelength light and the non-absorption wavelength light will be described, and then the information processing unit. The configuration of 200 will be described.

<First sensor 100a>
The first sensor 100a is the coverage of the powder Pd in the glossy image P1 and is for calculating the ratio of the image pattern P covered by the powder Pd. Such a first sensor 100a is arranged at a position facing the recording medium S that has passed through the nip portion of the powder holding member 12 and the transfer member 15.

FIG. 2 is a configuration diagram of the first sensor 100a included in the coverage detection device 20 according to the embodiment. As shown in this figure, the first sensor 100a includes an absorption wavelength light source 101a and a non-absorption wavelength light source 101n that form a light source unit, and two light receiving elements 102 that form a light receiving unit.

Of these, the absorption wavelength light source 101a is a light emitting element that generates absorption wavelength light Ha as light having a wavelength that is absorbed by the image pattern P that is the underlying adhesive layer. The non-absorbent wavelength light source 101n is a light emitting element that generates non-absorbent wavelength light Hn as light having a wavelength that is non-absorbent with respect to the image pattern P that is the underlying adhesive layer. The light emitting element may be, for example, an LED. The wavelength range of the absorption wavelength light Ha and the non-absorption wavelength light Hn may have a certain range.

From the viewpoint of the calculation accuracy of the coverage, it is preferable that the absorption wavelength light Ha and the non-absorption wavelength light Hn have a large difference in spectral reflectance with respect to the image pattern P. Specifically, the difference in spectral reflectance is preferably 40% or more, and more preferably 70% or more. The wavelengths of such absorption wavelength light Ha and non-absorption wavelength light Hn are set based on the spectral reflection characteristics of the image pattern P constituting the glossy image P1.

FIG. 3 is a diagram showing the spectral reflection characteristics of the image pattern P as the base adhesive layer, and is, as an example, the spectral reflection characteristics of the image pattern P using cyan toner. As shown in this figure, the image pattern P using cyan toner has a spectral reflectance of light having a wavelength of 632 nm of 5.85% and a spectral reflectance of light having a wavelength of 870 nm of 96.66%. The difference in spectral reflectance of light of these wavelengths is 90.81%, which is a sufficiently large difference.

Therefore, as an example of the case where the image pattern P uses cyan toner, light having a wavelength of 632 nm is set as absorption wavelength light Ha, and light having a wavelength of 870 nm is set as non-absorption wavelength light Hn.

Returning to FIG. 2, the absorption wavelength light source 101a and the non-absorption wavelength light source 101n irradiate the glossy image P1 with the absorption wavelength light Ha and the non-absorption wavelength light Hn from an oblique direction with respect to the main surface of the recording medium S. Is placed in. Further, the absorption wavelength light source 101a and the non-absorption wavelength light source 101n irradiate the absorption wavelength light Ha and the non-absorption wavelength light Hn on a certain area in the glossy image P1. The irradiation area of the absorption wavelength light Ha and the non-absorption wavelength light Hn is assumed to be a sufficiently large area with respect to the powder Pd from the viewpoint of the calculation accuracy of the coverage.

Further, the absorption wavelength light source 101a and the non-absorption wavelength light source 101n are sequentially arranged in the transport direction x of the recording medium S, and the absorption wavelength light Ha and the absorption wavelength light Ha and the absorption wavelength light Ha and the same region in the glossy image P1 are controlled by the drive control unit 18. It is driven to irradiate non-absorbent wavelength light Hn.

Each light receiving element 102 is arranged at a position where it receives the specularly reflected light Hra and Hrn that are irradiated from the absorption wavelength light source 101a and the non-absorption wavelength light source 101n and are specularly reflected by the image pattern P of the glossy image P1 and the powder Pd parallel thereto. Has been done. That is, one of the light receiving elements 102 is arranged at a position where it receives the specularly reflected light Hra that is specularly reflected by the glossy image P1 among the absorption wavelength light Ha emitted from the absorption wavelength light source 101a. The other light receiving element 102 is arranged at a position where it receives the specular reflected light Hrn that is specularly reflected by the glossy image P1 among the non-absorbing wavelength light Hn emitted from the non-absorbing wavelength light source 101n.

Each of these light receiving elements 102 photoelectrically converts the received light of all wavelengths and outputs the light, and outputs a voltage corresponding to the amount of light received. Such a light receiving element 102 may be, for example, a photodiode. The light receiving element 102 provided corresponding to the absorption wavelength light source 101a may receive at least a wavelength corresponding to the specular reflection light Hra of the absorption wavelength light Ha. Further, the light receiving element 102 provided corresponding to the non-absorbing wavelength light source 101n may receive at least a wavelength corresponding to the specular reflected light Hrn of the non-absorbing wavelength light Hn.

With the first sensor 100a having such a configuration, the recording medium S is conveyed once to irradiate the same location with the non-absorbent wavelength light Hn and the specularly reflected light Hrn, and these specularly reflected lights Hra and Hrn. Can receive light, so it is possible to detect the coverage with high accuracy.

<Second sensor 100b>
Returning to FIG. 1, the second sensor 100b is the coverage of the powder Pd on the powder holding surface 12a of the powder holding member 12 for calculating the ratio of the powder Pd covering the powder holding surface 12a. be. Such a second sensor 100b is arranged at a position facing the powder holding surface 12a on the upstream side of the nip portion between the powder holding member 12 and the transfer member 15 with respect to the rotation direction of the powder holding member 12. ..

FIG. 4 is a configuration diagram of the second sensor 100b included in the coverage detection device 20 according to the embodiment. The difference between the second sensor 100b and the first sensor 100a lies in the handling wavelength. That is, the fact that the second sensor 100b includes an absorption wavelength light source 101a'and a non-absorption wavelength light source 101n' that form a light source unit and two light receiving elements 102' that form a light receiving unit means that the first sensor 100a (FIG. 2) is the same.

Of these, the absorption wavelength light source 101a'is a light emitting element that generates absorption wavelength light Ha'as light having a wavelength that is absorbed by the powder holding surface 12a, which is the base adhesive layer. The non-absorbent wavelength light source 101n'is a light emitting element that generates non-absorbent wavelength light Hn'as light having a wavelength that is non-absorbent with respect to the powder holding surface 12a, which is a ground adhesive layer. It should be noted that the wavelength range of the absorption wavelength light Ha'and the non-absorption wavelength light Hn'may have a certain range, which is the same as that of the first sensor 100a.

As with the first sensor 100a, it is preferable that the absorption wavelength light Ha'and the non-absorption wavelength light Hn'have a large difference in spectral reflectance with respect to the powder holding surface 12a. The wavelengths of such absorption wavelength light Ha'and non-absorption wavelength light Hn'are set based on the spectral reflection characteristics of the powder holding surface 12a.

FIG. 5 is a diagram showing the spectral reflection characteristics of the powder holding surface 12a as the base adhesive layer, and as an example, is the spectral reflection characteristics of the powder holding surface 12a made of silicon rubber. The solid line in FIG. 5 shows the spectral reflection characteristics of the powder holding surface 12a made of silicon rubber without deterioration. On the other hand, the broken line in FIG. 5 shows the spectral reflection characteristics of the powder holding surface 12a made of silicon rubber that has deteriorated due to the influence of long-term use.

As shown in this figure, the powder holding surface 12a made of non-deteriorated silicon rubber has a spectral reflectance of 2% for light having a wavelength of 520 nm and a spectral reflectance of 51% for light having a wavelength of 730 nm. The difference in spectral reflectance of light of these wavelengths is 49%, which is a sufficiently large difference. The powder holding surface 12a made of deteriorated silicon rubber has a spectral reflectance of 4.8% for light having a wavelength of 520 nm and a spectral reflectance of 46% for light having a wavelength of 730 nm. The difference in spectral reflectance of light of these wavelengths is 41.2%, which is a sufficiently large difference.

Therefore, as an example of the case where the powder holding surface 12a is made of silicon rubber, light having a wavelength of 520 nm is set as absorption wavelength light Ha', and light having a wavelength of 730 nm is set as non-absorption wavelength light Hn'.

Returning to FIG. 4, the absorption wavelength light source 101a'and the non-absorption wavelength light source 101n' are oblique to the normal line of the powder holding surface 12a, and the absorption wavelength light Ha'and the non-absorption wavelength light Ha'and the non-absorption wavelength light with respect to the powder holding surface 12a. Arranged to irradiate Hn'. Further, the absorption wavelength light source 101a and the non-absorption wavelength light source 101n provide absorption wavelength light Ha'and non-absorption wavelength light Hn'with respect to a certain area on the powder holding surface 12a and a sufficiently large area with respect to the powder Pd. Irradiate. Further, the absorption wavelength light source 101a'and the non-absorption wavelength light source 101n' are sequentially arranged in the rotation direction of the powder holding member 12, and are controlled by the drive control unit 18 to have an absorption wavelength with respect to the same region on the powder holding surface 12a. It is driven to irradiate light Ha'and non-absorbent wavelength light Hn'.

Further, each light receiving element 102'is irradiated from the absorption wavelength light source 101a'and the non-absorption wavelength light source 101n', and is specularly reflected by the powder Pd parallel to the powder holding surface 12a and the powder holding surface 12a. Is located at a position to receive light. That is, one of the light receiving elements 102'is arranged at a position where the specular reflected light Hra', which is regularly reflected by the powder holding surface 12a, is received from the absorbed wavelength light Ha' radiated from the absorption wavelength light source 101a'. The other light receiving element 102'is arranged at a position where it receives the specular reflected light Hrn'reflected by the powder holding surface 12a among the non-absorbing wavelength light Hn'irradiated from the non-absorbing wavelength light source 101n'. There is.

Further, each light receiving element 102'of the second sensor 100b photoelectrically converts the received light of all wavelengths and outputs the light, and outputs a voltage corresponding to the received light amount. The light receiving element 102'provided corresponding to the absorption wavelength light source 101a' may receive at least a wavelength corresponding to the specular reflected light Hra'of the absorption wavelength light Ha'. Further, the light receiving element 102'provided corresponding to the non-absorbing wavelength light source 101n'is sufficient if it can receive at least a wavelength corresponding to the specular reflected light Hrn'of the non-absorbing wavelength light Hn'.

With the second sensor 100b having such a configuration, the powder holding member 12 is rotated once to irradiate the same location with the non-absorbent wavelength light Hn'and the specularly reflected light Hrn', and these specularly reflected light Hra. Since', Hrn'can be received, it is possible to detect the coverage with high accuracy.

<Modification example of the first sensor and the second sensor>
The first sensor 100a and the second sensor 100b are not limited to the configurations as described above, and the absorption wavelength light Ha or absorption wavelength light Ha'set for each and the non-absorption wavelength light Hn or non-absorption wavelength. Any configuration may be used as long as each reflectance of Hn'can be detected individually. A modified example of the first sensor 100a will be described below by exemplifying the first sensor 100a, but each of the modified examples described can be similarly applied to the second sensor 100b, and can be applied individually.

[First modification]
FIG. 6 is a diagram showing a first modification of the first sensor included in the coverage detection device according to the embodiment. The first sensor 100a-1 of the first modification shown in this figure includes one white light source 101w, two light receiving elements 102, an absorption wavelength filter 103a, and a non-absorption wavelength filter 103n.

The white light source 101w is a light emitting element that emits white light Hw, and the white light includes at least the above-mentioned absorption wavelength light Ha and non-absorption wavelength light Hn. Further, the white light source 101w is arranged so as to irradiate the glossy image P1 with white light Hw from an oblique direction with respect to the normal of the glossy image P1, and irradiates the white light W with respect to a certain area of the glossy image P1. do. Further, the white light source 101w irradiates the white light W on a sufficiently large area with respect to the powder Pd, which is a certain area in the glossy image P1.

Further, the two light receiving elements 102 are arranged at positions that receive the specular reflected light Hr that is irradiated from the white light source 101w and is specularly reflected by the glossy image P1. These light receiving elements 102 may be the same as the light receiving elements 102 of the first sensor 100a described in the embodiment.

The absorption wavelength filter 103a and the non-absorption wavelength filter 103n are arranged on the light incident surface of the light receiving element 102, and limit the light incident on each light receiving element 102. Of these, the absorption wavelength filter 103a is an optical filter that transmits the absorption wavelength light Ha and shields the non-absorption wavelength light Hn from the positively reflected light Hr that is irradiated from the white light source 101w and positively reflected by the glossy image P1. The absorption wavelength filter 103a causes only the absorption wavelength light Ha to be incident on one of the light receiving elements 102. The non-absorption wavelength filter 103n is an optical filter that transmits the non-absorption wavelength light Hn and shields the absorption wavelength light Ha from the positively reflected light Hr that is irradiated from the white light source 101w and positively reflected by the glossy image P1. The non-absorbent wavelength filter 103n causes only the non-absorbent wavelength light Hn to be incident on one of the light receiving elements 102.

In the configuration of such a first modification, since the specularly reflected lights Hra and Hrn having different wavelengths can be received from the same location at one timing, the light irradiation positions are different and the irradiation timings are different. It is possible to prevent the detection error of the coverage rate due to.

As a further modification of the first sensor 100a-1, two are changed to an absorption wavelength filter 103a, a non-absorption wavelength filter 103n, and a light receiving element 102, each of which receives only light in a specific wavelength region and performs photoelectric conversion. An example is a configuration in which a light receiving element is provided. In this case, one of the light receiving elements 102 does not include the non-absorption wavelength light Hn and receives only the light in the wavelength range including the absorption wavelength light Ha. Further, the other light receiving element 102 does not include the absorption wavelength light Ha and receives only the light in the wavelength range including the non-absorption wavelength light Hn.

[Second modification]
FIG. 7 is a diagram showing a second modification of the first sensor included in the coverage detection device according to the embodiment.
The first sensor 100a-2 of the second modification shown in this figure includes an absorption wavelength light source 101a, a non-absorption wavelength light source 101n, and one light receiving element 102.

The absorption wavelength light source 101a is an element that emits the above-mentioned absorption wavelength light Ha, and the non-absorption wavelength light source 101n is an element that emits the above-mentioned non-absorption wavelength light Hn. The absorption wavelength light source 101a and the non-absorption wavelength light source 101n are arranged so as to irradiate the glossy image P1 with the absorption wavelength light Ha and the non-absorption wavelength light Hn from an oblique direction with respect to the normal line of the glossy image P1. Further, the absorption wavelength light source 101a and the non-absorption wavelength light source 101n sequentially apply the absorption wavelength light Ha and the non-absorption wavelength light Hn to a certain area in the glossy image P1 and a sufficiently large area with respect to the powder Pd. Irradiate.

The light receiving element 102 receives light in a wavelength region including at least the above-mentioned absorption wavelength light Ha and non-absorption wavelength light H and performs photoelectric conversion. Such a light receiving element 102 is a specularly reflected light Hra, Hrn that is specularly reflected by the glossy image P1 among the absorption wavelength light Ha and the non-absorption wavelength light Hn that are sequentially emitted from the absorption wavelength light source 101a and the non-absorption wavelength light source 101n. Is arranged at a position to receive light.

[Third variant]
FIG. 8 is a diagram showing a third modification of the first sensor included in the coverage detection device according to the embodiment. The first sensor 100a-3 of the third modification shown in this figure includes one white light source 101w, one light receiving element 102, an absorption wavelength filter 103a, and a non-absorption wavelength filter 103n.

The white light source 101w may be the same as the white light Hw described in the first modification. Further, the light receiving element 102 may be the same as the light receiving element 102 described in the second modification.

The absorption wavelength filter 103a and the non-absorption wavelength filter 103n are the same as those described in the first modification. These absorption wavelength filters 103a and non-absorption wavelength filters 103n are arranged so as to be interchangeable on the light incident surface of the light receiving element 102, and the light incident on the light receiving element 102 is sequentially limited by the control of the drive control unit 18.

[Fourth variant]
FIG. 9 is a diagram showing a fourth modification of the first sensor included in the coverage detection device according to the embodiment. The difference between the first sensor 100a-4 of the fourth modification shown in this figure and that of the third modification is that the absorption wavelength filter 103a and the non-absorption wavelength filter 103n are arranged.

That is, in the first sensor 100a-4 of the fourth modification, the absorption wavelength filter 103a and the non-absorption wavelength filter 103n are arranged interchangeably on the light emission surface of the white light source 101w to limit the light emitted from the white light source 101w. do. Of these, the absorption wavelength filter 103a is an optical filter that transmits the absorption wavelength light Ha and shields the non-absorption wavelength light Hn from the light emitted from the white light source 101w. The non-absorption wavelength filter 103n is an optical filter that transmits the non-absorption wavelength light Hn and shields the absorption wavelength light Ha from the light emitted from the white light source 101w.

The absorption wavelength filter 103a and the non-absorption wavelength filter 103n are interchangeably arranged on the light emitting surface of the white light source 101w under the control of the drive control unit 18.

<Calculation of coverage using absorption wavelength light and non-absorption wavelength light>
FIG. 10 is a diagram for explaining the calculation of the coverage of the powder according to the embodiment, and illustrates the case where the base adhesive layer is the image pattern P. In this figure, the absorption wavelength light Ha and the non-absorption wavelength are shown with respect to the image pattern P and the glossy image P1 formed on the recording medium S from the absorption wavelength light source 101a and the non-absorption wavelength light source 101n described above. Schematic examples (a) to (d) when light Hn is irradiated from an oblique direction are shown. Further, in this figure, when the incident light amount of the absorption skin wavelength light Ha and the non-absorption wavelength light Hn is 100, the absorbed light, the diffusely reflected light, and the specularly reflected light in the respective schematic examples (a) to (d) are shown. The ratio is schematically shown.

In FIG. 10, the schematic example (a) illustrates a case where an image pattern P having a coverage rate of 0% is irradiated with absorption wavelength light Ha. In this case, most of the absorption wavelength light Ha irradiated to the image pattern P is the absorption light (1) in the image pattern P, and a part is the diffusely reflected light (2) in the image pattern P or the image pattern P. It becomes the specularly reflected light (3) in. Of these, the specularly reflected light (3) becomes the specularly reflected light Hra received by the light receiving element 102.

The schematic example (b) exemplifies the case where the image pattern P having a coverage rate of 0% is irradiated with the non-absorbent wavelength light Hn. In this case, the non-absorption wavelength light Hn irradiated on the image pattern P is not absorbed by the image pattern P, and most of it is diffusely reflected light (2) in the image pattern P or specularly reflected light (2) in the image pattern P. 3). Of these, the specularly reflected light (3) becomes the specularly reflected light Hrn received by the light receiving element 102.

The schematic example (c) illustrates the case where the glossy image P1 is irradiated with the absorption wavelength light Ha. In this case, most of the absorption wavelength light Ha irradiated to the exposed portion of the image pattern P is the absorption light (1) in the image pattern P, and a part is the diffusely reflected light (2) in the image pattern P, or It becomes the specularly reflected light (3) in the image pattern P. Of these, the specularly reflected light (3) is received by the light receiving element 102 as a part of the specularly reflected light Hra.

Further, in this case, the absorption wavelength light Ha irradiated to the powder Pd is hardly absorbed by the powder Pd and becomes specular light (4) in the powder Pd or diffusely reflected light (5) in the powder Pd. Of these, the specularly reflected light (4) is received by the light receiving element 102 as a part of the specularly reflected light Hra.

The schematic example (d) exemplifies the case where the glossy image P1 is irradiated with the non-absorbent wavelength light Hn. In this case, the non-absorption wavelength light Hn applied to the exposed portion of the image pattern P is not absorbed by the image pattern P, and most of it is diffusely reflected light (2) in the image pattern P or positive in the image pattern P. It becomes the reflected light (3). A part of the specularly reflected light (3) is received by the light receiving element 102 as the specularly reflected light Hrn.

Further, in this case, most of the non-absorbent wavelength light Hn irradiated on the powder Pd is not absorbed by the powder Pd and becomes specular light (4) on the powder Pd or diffusely reflected light (5) on the powder Pd. .. Of these, the specularly reflected light (4) is received by the light receiving element 102 as a part of the specularly reflected light Hra. This is the same as the schematic example (c) in the case of irradiating the absorption wavelength light Ha.

Here, the glossy powder Pd reflects both the absorption wavelength light Ha and the non-absorption wavelength light Hn with respect to the image pattern P with almost no absorption. Therefore, between the above-mentioned schematic examples (c) and (d), the difference between the total amount of light received by the specularly reflected light Hra of the absorbed wavelength light Ha and the total amount of light received by the specularly reflected light Hrn of the non-absorbed wavelength light Hn. It can be seen that ΔH corresponds to the difference of the specularly reflected light (3) in the image pattern P. The magnitude of this difference ΔH is a value corresponding to the magnitude of the exposed area of the image pattern P and is a value corresponding to the coverage by the powder Pd, but is a value that is not affected by the orientation state of the powder Pd. .. Therefore, based on this difference ΔH, the coverage of the powder Pd can be detected by removing the error due to the orientation state of the powder Pd.

That is, most of the diffusely reflected light (5) on the powder Pd is light that is specularly reflected on the powder Pd that is not sufficiently oriented with respect to the image pattern P and is obliquely adhered to the surface of the image pattern P. Therefore, it is the reflected light that is not received by the light receiving element 102. Therefore, the generation of diffusely reflected light (5) in such powder Pd becomes an error component in the calculation of the normal coverage using single wavelength light. However, since the above-mentioned difference ΔH is a value obtained by subtracting this error component, the coverage by the powder Pd calculated based on this difference ΔH is a value that does not include the error component due to the orientation state of the powder Pd. Therefore, the coverage of the powder Pd can be detected with good accuracy based on the difference ΔH.

<Information Processing Department 200>
Returning to FIG. 1, the configuration of the information processing unit 200 constituting the coverage detection device 20 will be described. The information processing unit 200 detects the coverage based on the difference ΔH described above. Such an information processing unit 200 detects the coverage of the powder Pd based on the signals obtained from the first sensor 100a and the second sensor 100b and the information obtained from the operation unit 19. Further, the information processing unit 200 gives a correction instruction to each unit of the image forming apparatus 1 based on the calculated coverage.

Such an information processing unit 200 is composed of a computer. A computer is hardware used as a so-called computer. The computer may include a CPU (Central Processing Unit), a RAM (Random Access Memory), a non-volatile storage unit such as a ROM (Read Only Memory) or an HDD (hard disk drive), and a network interface. .. The information processing unit 200 configured by such a computer stores a coverage detection program for calculating the coverage and a correction instruction in a non-volatile storage unit, and executes processing based on the stored coverage detection program. By doing so, the coverage rate is calculated and the correction instruction is performed.

FIG. 11 is a block diagram illustrating the configuration of the information processing unit 200 included in the coverage detection device 20 according to the embodiment. As shown in this figure, the information processing unit 200 is connected to the first sensor 100a, the second sensor 100b, the drive control unit 18, and the operation unit 19. Such an information processing unit 200 includes a characteristic holding unit 201, a correction coefficient holding unit 202, a light source adjusting unit 203, a covering ratio detecting unit 204, and as each functional unit that executes a stored coverage detection program. A correction indicating unit 205 is provided. Each of these functional parts is as follows.

[Characteristic holding unit 201]
The characteristic holding unit 201 holds the amount of reflected light with respect to the coating rate of the powder as the covering rate characteristic. The characteristic holding unit 201 holds the respective coverage characteristics for each base adhesive layer, that is, for each type of image pattern P, and for each configuration of the powder holding surface 12a of the powder holding member 12. These coverage characteristics are information acquired experimentally in advance, and are, for example, information input from the operation unit 19.

FIG. 12 is a diagram showing the coverage characteristics of the amount of reflected light with respect to the coverage of the powder, and is an example in the case where the base adhesive layer is the image pattern P. The sensor output value on the vertical axis in FIG. 12 is the output value of the light receiving element that has received the specularly reflected light Hra and Hen, and corresponds to the above-mentioned light receiving amount. Such coverage characteristics are obtained as follows.

With reference to FIGS. 1 and 2 above, first, a plurality of types of glossy images P1 in which the coverage with the powder Pd is changed are prepared. In these glossy images P1, the coverage by the powder Pd is changed by changing the supply amount of the powder Pd by the powder supply member 13, the rubbing condition of the rubbing member 14, and the cleaning condition of the cleaning member 16. Next, the prepared glossy image P1 is read by using an image reading device, and by observing the scanned image, the powder Pd does not overlap and the powder Pd is parallel to the surface of the image pattern P and is well oriented. Only the glossy image P1 is selected. Then, the scanned image is binarized by image processing software, and the coverage of the powder Pd in each selected glossy image P1 is detected.

Further, each glossy image P1 is irradiated with absorption wavelength light Ha to detect its specular reflection light Hra, and is irradiated with non-absorption wavelength light Hn to detect its specular reflection light Hen. Then, the detected values of the specularly reflected lights Hra and Hen are plotted against the coverage ratio calculated for each glossy image P1. As a result, the relationship between the coverage of the powder Pd and the detected values of the specularly reflected lights Hr and Hen (that is, the amount of received light and the amount of output from the sensor) is obtained.

The relationship shown in FIG. 12 is an actual measurement example in the following cases.
Recording medium S: Esprit FP (trade name manufactured by Nippon Paper Industries, Ltd.)
Base adhesive layer (image pattern P): Cyan toner (toner for production print products manufactured by Konica Minolta)
Powder Pd: Silver Powder: LG neo # 325 (manufactured by Oike Kogyo Co., Ltd.)
Absorption wavelength light source 101a: Bullet-shaped LED (manufactured by Nichicon: peak wavelength 632 nm: incident angle 20 degrees)
Non-absorbent wavelength light source 101n: Bullet-shaped LED (manufactured by Stanley: Peak wavelength 870 nm: Light receiving angle 20 degrees)

The characteristic holding unit 201 may hold the difference between the sensor output values (light receiving amount) thus obtained as the difference characteristic. This difference corresponds to the above-mentioned difference ΔH with reference to FIG.

FIG. 13 is a diagram showing the difference characteristic of the amount of reflected light with respect to the coverage of the powder, and is an example in the case where the base adhesive layer is the image pattern P. The output difference on the vertical axis in FIG. 13 is the output value (sensor output value) of the light receiving element that receives the specularly reflected light Hra of the absorption wavelength light Ha and the light receiving element that receives the specularly reflected light Hrn of the non-absorption wavelength light Hn. It is a difference from the output value (sensor output value) and corresponds to the above-mentioned difference ΔH.

[Correction coefficient holding unit 202]
The correction coefficient holding unit 202 shown in FIG. 11 holds a correction coefficient for correcting the coverage characteristic held by the characteristic holding unit 201. This correction coefficient is a numerical value for making the received amount of the positively reflected light of the absorbed wavelength light and the non-absorbed wavelength light in the powder about the same, and is for each powder and each wavelength of the absorbed wavelength light and the non-absorbed wavelength light. It is assumed that the information is acquired in advance and input from, for example, the operation unit 19. Next, the details of this correction coefficient will be described.

FIG. 14 is a diagram showing the reflectance characteristics of each powder so that the spectral reflectance characteristics of the three types of glossy powders, red powder, silver powder, and blue powder, have the same integrated reflectance values. It is a figure standardized to. The red powder, silver powder, and blue powder are Elgi neo # 325Blue, Silver, and Red (trade names manufactured by Oike Kogyo Co., Ltd.).

As shown in FIG. 14, each powder has a spectral reflection characteristic peculiar to each type, and the reflectance of absorbed wavelength light and the reflectance of non-absorbed wavelength light are not always the same. Then, in order to ignore the orientation state of the powder in the above-mentioned difference ΔH, the amount of light received by the positively reflected light of the absorption wavelength light and the non-absorption wavelength light is set to be about the same, so that the absorption wavelength light and the non-absorption wavelength light of the powder are not received. It is necessary to exclude the numerical value related to the received amount of the positively reflected light of the absorption wavelength light from the difference ΔH.

For example, it is assumed that the coverage of the blue powder is detected by using the absorption wavelength light having a wavelength of 520 nm and the non-absorption wavelength light having a wavelength of 730 nm as the absorption wavelength light and the non-absorption wavelength light for the underlying adhesive layer.

As shown in FIG. 14, the reflectance of the absorption wavelength light having a wavelength of 520 nm is 19%, and the reflectance of the non-absorption wavelength light having a wavelength of 730 nm is 11% with respect to the blue powder. Therefore, when the coverage of the powder is 100%, the amount of light received by the specularly reflected light of the absorption wavelength is 19% ÷ 11% = 1.73 times the amount of light received by the specularly reflected light of the non-absorption wavelength, which is relative. The amount of light received is large. On the other hand, when the coverage of the powder is 0%, the received amount of the positively reflected light of the absorption wavelength light and the received amount of the positively reflected light of the non-absorption wavelength are not affected by the spectral reflectance characteristics of the powder. The amount of light received by the positively reflected light of the absorption wavelength light is one times the amount of light received by the positively reflected light of the non-absorption wavelength.

From these values, a correction coefficient is calculated so that the amount of light received by the specularly reflected light of the absorption wavelength and the amount of light received by the specularly reflected light of the non-absorption wavelength are always 1 times, regardless of the coverage. .. FIG. 15 is a diagram showing an example of the correction coefficient of the coverage, and is calculated so that the received amount of the specularly reflected light of the absorption wavelength light is 1 times the received amount of the specularly reflected light of the non-absorption wavelength. This is the correction coefficient. The correction coefficient holding unit 202 holds such a correction coefficient for each powder and for each wavelength of absorption wavelength light / non-absorption wavelength light.

However, as seen in the spectral reflection characteristics of the silver powder in FIG. 14, if the spectral reflectance is almost constant between the absorption wavelength and the non-absorption wavelength, it is necessary to make a correction in consideration of the spectral reflection characteristics of the powder. No. It is not necessary to prepare a correction coefficient for such a powder.

The correction coefficient holding unit 202 retains the spectral reflectance characteristics of each powder, and when the type of powder and the wavelengths of absorption wavelength light and non-absorption wavelength light are input in the operation unit 19, each powder The correction coefficient may be calculated by reading the corresponding reflectance from the reflectance characteristics.

Further, the spectral reflection characteristics of each powder may be obtained by extracting a powder having an area larger than the irradiation area of the light source of the sensor, measuring it with the sensor in the device, and holding it in the correction coefficient holding unit 202 at the time of commercializing the powder.

[Light source adjustment unit 203]
The light source adjusting unit 203 shown in FIG. 11 adjusts the outputs of the absorption wavelength light sources 101a and 101a'and the non-absorption wavelength light sources 101n and 101n'. The light source adjusting unit 203 outputs the absorption wavelength light sources 101a and 101a'and the non-absorption wavelength light sources 101n and 101n' so that the reflectance of the underlying adhesive layer becomes a predetermined value when the powder coverage is 0%. To adjust. In this case, the reflectance of the base adhesive layer may be the sensor output value of the specularly reflected light of the absorption wavelength light and the non-absorption wavelength light with respect to the base adhesion layer.

Here, for example, as shown in FIG. 5, when the underlying adhesive layer is a powder holding member, the spectral reflection characteristics of the powder holding member vary depending on the deterioration of the powder holding member over time and the device environment. When the base adhesive layer is an image pattern, the spectral reflection characteristics of the image pattern vary depending on the type of toner constituting the image pattern and the type of the recording medium used as the base of the image pattern. Further, the absorption wavelength light source and the non-absorption wavelength light source vary in the amount of light actually emitted even if the same current is applied due to deterioration over time, the device environment, contamination in the device, and the like.

Therefore, the light source adjusting unit 203 sets the absorption wavelength light source so that the sensor output values of the positively reflected light of the absorption wavelength light and the non-absorption wavelength light in the base adhesive layer in which the coating ratio of the powder is 0% become a predetermined value. And adjust the output of the non-absorption wavelength light source. For example, referring to FIG. 12, the sensor output value of the positively reflected light of the absorption wavelength light is 0.1 [V], and the sensor output value of the positively reflected light of the non-absorption wavelength light is 0.3 [V]. , Adjust the output of absorption wavelength light source and non-absorption wavelength light source. The procedure for adjusting the light source by the light source adjusting unit 203 will be described later in the method for detecting the coverage.

[Coverage detection unit 204]
The coverage detection unit 204 shown in FIG. 11 includes information from the operation unit 19, the first sensor 100a, and the second sensor 100b, the coverage characteristic or difference characteristic held in the characteristic holding unit 201, and the correction coefficient holding unit. The coverage by the powder is detected based on the correction coefficient held in 202. The procedure for detecting the coverage by the coverage detection unit 204 will be described in the following method for detecting the coverage.

[Correction indicator 205]
Based on the coverage detected by the coverage detection section 204, the correction instruction unit 205 sets the coverage of the image pattern P by the powder Pd and the coverage of the powder holding surface 12a to the desired coverage set for each. As described above, the drive control unit 18 is instructed to correct the drive conditions of each drive unit. The target of the correction of the driving condition is, for example, the amount of powder Pd supplied by the powder supply member 13, the rubbing condition of the rubbing member 14, the cleaning condition of the cleaning member 16, and the like. It is assumed that the correction instruction by the correction instruction unit 205 is predetermined by the coverage rate detected by the coverage rate detection unit 204.

The coverage detection device 20 described above may include at least the characteristic holding section 201 and the coverage detection section 204, and does not need to include all of the described sections. Further, the coverage detection device 20 may be provided as a personal computer or another external device external device independent of the image forming device 1.

≪Coverage detection method≫
Next, the coverage detection method implemented by the coverage detection device 20 as described above will be described. FIG. 16 is a flowchart (No. 1) showing an example of the coverage detection method according to the embodiment, and shows a procedure for adjusting the light source. Further, FIG. 17 is a flowchart (No. 2) showing an example of the coverage detection method according to the embodiment, and shows the procedure for detecting the coverage. These flowcharts show the procedure of the coverage detection method carried out by the coverage detection program included in the coverage detection device 20. Hereinafter, the image processing method of the embodiment will be described with reference to FIGS. 1 to 15 with reference to the flowcharts of FIGS. 16 and 17.

<Light source adjustment>
[Step S101]
In step S101 of FIG. 16, the light source adjusting unit 203 (see FIG. 11) irradiates the image pattern P having a coverage of 0% of the powder Pd with the absorption wavelength light Ha and the non-absorption wavelength Hn. The sensor output values of the two light receiving elements 102 are acquired (see FIG. 2). Similarly, the light source adjusting unit 203 irradiates the powder holding surface 12a of the powder holding member 12 having a coverage of 0% of the powder Pd with the absorption wavelength light Ha'and the non-absorption wavelength Hn'. The sensor output value of the light receiving element 102'is acquired (see FIG. 4). These sensor output values may be values input from the operation unit 19.

The sensor output of the image pattern P having a coverage of 0% of the powder Pd is formed in the image forming apparatus 1 (see FIG. 1) with the heat sources of the end holding member 12 and the transfer member 15 stopped. It is a value obtained by supplying the recorded recording medium S to the first sensor 100a. Alternatively, it is a value obtained by supplying the recording medium S on which the image putter P is formed to the first sensor 100a in a state where the rotation of the powder holding member 12 is stopped or separated.

Further, the sensor output of the powder holding surface 12a of the powder holding member 12 having a coverage of 0% of the powder Pd is such that the powder holding member 12 is attached to the second sensor 100b after rotating the powder holding member 12 in at least the following states. It is a value obtained by rotating. That is, in the image forming apparatus 1 (see FIG. 1), the transport member 13b of the powder supply member 13 is stopped, and the supply of the powder Pd to the powder holding member surface 12a is stopped. Further, in the image forming apparatus 1 (see FIG. 1), the powder Pd adhesively held on the powder holding surface 12a of the powder holding member 12 by the transfer member 15 is formed on the main surface of the recording medium S as an image pattern P. State to be transferred to. Further, in the image forming apparatus 1 (see FIG. 1), the cleaning member 16 scrapes the powder Pd remaining on the powder holding member surface 12a.

[Step S102]
In step S102, the light source adjusting unit 203 instructs the drive control unit 18 to adjust the light source so that the acquired sensor output value becomes each preset sensor output value. As a result, the drive control unit 18 uses the absorption wavelength light source 101a and the non-absorption wavelength light source 101n of the first sensor 100a so that the sensor output value when the coverage of the powder Pd is 0% becomes a preset output value. Further, the outputs of the absorption wavelength light source 101a'and the non-absorption wavelength light source 101n' of the second sensor 100b are adjusted.

It should be noted that such light source adjustment may be performed each time prior to the detection of the coverage rate described below, or may be performed at a predetermined timing.

<Detection of coverage>
[Step S201]
In step S201, the coverage detection unit 204 acquires information on the powder Pd and wavelength information. The information regarding the powder Pd may be the type of the powder Pd, and is the type of the powder Pd with which the correction coefficient is associated in the correction coefficient holding unit 202. The wavelength information is information corresponding to the wavelengths of the absorption wavelength light Ha and the non-absorption wavelength light Hn handled by the first sensor 100a, and further the absorption wavelength light Ha'and the non-absorption wavelength light Hn'handled by the second sensor 100b. These pieces of information may be, for example, information input from the operation unit 19 when detecting the coverage.

[Step S202]
In step S202, the coverage detection unit 204 performs a correction coefficient acquisition process. At this time, the coverage detection unit 204 refers to the correction coefficient holding unit 202 and acquires the correction coefficient associated with the type and wavelength information of the powder Pd acquired in step S201. This correction coefficient corresponds to the absorption wavelength light Ha and the non-absorption wavelength light Hn handled by the first sensor 100a, and the correction coefficient corresponding to the absorption wavelength light Ha'and the non-absorption wavelength light Hn'handled by the second sensor 100b. It is a coefficient.

[Step S203]
In step S203, the coverage detection unit 204 performs a correction process of the coverage characteristic. At this time, the coverage detection unit 204 first acquires the coverage characteristics of the underlying adhesive layer from the property holding unit 201. The coverage characteristics to be acquired are the coverage characteristics of the image pattern P (see FIG. 12) and the coverage characteristics of the powder holding surface 12a of the powder holding member 12 (not shown).

The coverage detection unit 204 corrects each of the acquired coverage characteristics with the correction coefficient acquired in step S202. For example, in the case of the coverage characteristic shown in FIG. 12, each value of the absorption wavelength is corrected by the correction coefficient of FIG.

[Step S204]
In step S204, the coverage detection unit 204 calculates the difference characteristic from the corrected coverage characteristic. In this case, with respect to the coverage characteristic of the image pattern P and the coverage characteristic of the powder holding surface 12a of the powder holding member 12, the coverage characteristic of the non-absorption wavelength is subtracted from the corrected coverage characteristic of the absorption wavelength, and the image is imaged. The difference characteristic regarding the pattern P and the difference characteristic regarding the powder holding surface 12a are obtained.

If it is not necessary to correct the coverage characteristics, for example, when the powder is a silver powder, steps S202 and S203 are not performed, and in this step S203, the characteristics holding unit 201 corresponds to the above. The difference characteristic may be acquired.

[Step S205]
In step S205, the coverage detection unit 204 acquires the sensor output values of the two light receiving elements 102 when the glossy image P1 is irradiated with the absorption wavelength light Ha and the non-absorption wavelength Hn (see FIG. 2). .. Similarly, the coverage detection unit 204 irradiates the powder holding surface 12a of the powder holding member 12 with the absorption wavelength light Ha'and the non-absorption wavelength Hn', and the sensor output values of the two light receiving elements 102'. (See Fig. 4).

At this time, it is assumed that the glossy image P1 is formed by the image forming apparatus 1 in which the light sources of the first sensor 100a and the second sensor 100b are adjusted in steps S101 and S102.

Further, the powder holding surface 12a of the powder holding member 12 is the powder holding surface 12a of the powder holding member 12 in which the light source of the second sensor 100b is adjusted in steps S101 and S102. At this time, it is preferable that the acquisition region of the sensor output value on the powder holding surface 12a coincides with the acquisition region of the sensor output when adjusting the light source. Thereby, the variation in the rotation direction of the powder holding member 12 can be suppressed.

[Step S206]
In step S206, the coverage detection unit 204 calculates the difference in the sensor output acquired in step S205. At this time, the coverage detection unit 204 calculates the difference between the sensor output values of the two light receiving elements 102 of the first sensor 100a, and similarly calculates the difference between the sensor output values of the two light receiving elements 102'of the second sensor 100b. calculate.

[Step S207]
In step S207, the coverage detection unit 204 refers to each difference characteristic (for example, FIG. 13) calculated in step S204, and detects a coverage corresponding to the difference in the sensor output calculated in step S206. At this time, the coverage detection unit 204 refers to the difference characteristic regarding the image pattern P, and sets the coverage corresponding to the difference between the sensor output values of the two light receiving elements 102 of the first sensor 100a to the image pattern P by the powder Pd. Detected as the coverage of. Further, the covering ratio detection unit 204 refers to the difference characteristic regarding the powder holding surface 12a, and holds the covering ratio corresponding to the difference between the sensor output values of the two light receiving elements 102'of the second sensor 100b by the powder Pd. It is detected as the coverage of the surface 12a.

<< Effect of the embodiment >>
According to the embodiment described above, as described with reference to FIG. 10, the coverage of the powder Pd can be detected without being affected by the orientation state of the powder Pd. Therefore, even if there is powder adhered to the surface of the image pattern P or the powder holding surface 12a at an angle, it is possible to detect the coverage with high accuracy without being affected by the powder. In particular, the higher the spectral reflectance of the powder Pd being metallic, the higher the coverage due to the influence of the orientation state of the powder in the detection of the coverage when a normal reflective sensor that does not use light of different wavelengths is used. It will be detected low. Therefore, this embodiment is particularly effective when powder Pd having a high spectral reflectance is used.

When the present invention is applied and the glossy image P1 is formed by using the image forming apparatus 1 shown in FIG. 1, the coverage of the image pattern P by the powder Pd and the coverage of the powder holding surface 12a by the powder Pd are detected. went.

The configurations of the samples 1 to 6 for which the coverage was detected are as shown in Table 1 below.

The materials constituting Samples 1 to 3 are as follows.
-Recording medium: Smooth recording medium (Nippon Paper Industries: Esprit FP), recording medium with uneven surface (Nippon Paper Industries: npi woodfree paper)
-Image pattern: Cyan toner (for production print products made by Konica Minolta)

The materials constituting Samples 4 to 6 are as follows.
-Powder holding member: Silicon rubber for both new and deteriorated products (manufactured by Showa Densen Co., Ltd .: Silicon rubber XH279)
-Powder type: silver, red (manufactured by Oike Kogyo Co., Ltd .: LG neo # 325)

By changing the rubbing strength of the rubbing member 14 for the samples 1 to 6 having the above-mentioned configurations, three levels of powder Pd having different orientation states and covering ratios were prepared. These three levels are as follows.
・ Level 1: Coverage 26%, less powder adhered diagonally ・ Level 2: Coverage 49%, powder adhered diagonally Medium ・ Level 3: Coverage 50%, adhered diagonally A large amount of powder This coverage is a value calculated by image processing of the scanned image.

The configuration of the first sensor 100a is as follows.
Absorption wavelength light source 101a: Peak wavelength 632 nm (Nichicon bullet type LED)
Non-absorbent wavelength light source 101n: Peak wavelength 870 nm (Stanley bullet type LED)
・ Incident angle: 20 degrees ・ Light receiving angle: 20 degrees

The configuration of the second sensor 100b is as follows.
-Absorption wavelength light source 101a': Peak wavelength 520 nm (Kingbright: L-7113VGC-H)
-Non-absorption wavelength light source 101n': Peak wavelength 730 nm (Everlight Electronics: ELSH-Q61F1-0LPNM-JF3F8)
・ Incident angle: 20 degrees ・ Light receiving angle: 20 degrees

In the detection of the coverage of Samples 1 to 6, in Examples 1 to 3, the light source adjustment and the correction by the powder type were carried out in advance as follows.
-Example 1: No prior light source adjustment / no correction by powder type-Example 2: No prior light source adjustment / correction by powder type-Example 3: With prior light source adjustment / correction by powder type

Further, as a comparative example, the coverage was detected using only one wavelength light. The light used had a peak wavelength of 870 nm (Stanley bullet-shaped LED), and both the incident angle and the light receiving angle were set to 20 degrees. No prior light source adjustment / no correction by powder type.

The coverage detected as in Examples 1 to 3 and Comparative Examples described above was compared with the coverage calculated by image processing. In the evaluation, when the difference between the coverage calculated by image processing and the coverage detected in Examples 1 to 3 or Comparative Example is 5% or less, the deviation is considered to be small and the deviation is determined at all three levels. It was considered good only when was small. The evaluation results are shown in Table 1 above.

As shown in Table 1, since the comparative example is affected by the powder adhered at an oblique angle, the detected value of the covering ratio in all the samples deviates from the calculated value by the image processing, and the covering is highly accurate. The rate could not be detected.

On the other hand, in Example 1, although the condition was that there was no light source adjustment / no correction by the powder type, the coverage of Sample 1 and Sample 4 using silver powder having constant spectral reflection characteristics had a higher coverage. The detection result did not deviate from the value calculated by the image processing, and good results were obtained. As a result, the effect of applying the present invention to detect the coverage using absorbed wavelength light and non-absorbed wavelength light for the underlying adhesive layer was confirmed.

Further, Example 2 is the detection under the condition that the light source is not adjusted and the powder type is corrected, and the detection result of the coverage is obtained in the samples 1, 2, 4 and 5 in which the surface state of the underlying adhesive layer is smooth. Good results were obtained with no deviation from the values calculated by image processing. As a result, the effect of correction by powder type was confirmed.

Further, in Example 3, the detection is performed under the condition that the light source is adjusted in advance and the powder type is corrected, and the detection result of the covering ratio in all of the samples 1 to 6 deviates from the calculated value by the image processing. No, good results were obtained. Here, the sample 3 uses a recording medium S having an uneven surface, and the unevenness is several tens of μm. The image pattern P formed on the upper portion had a thickness of about 4 μm, and the surface of the image pattern P also had large irregularities. Further, in the sample 6, the powder holding member 12 which is the base adhesive layer was a long-term use product and had a surface state with large irregularities. However, it was confirmed that by adjusting the amount of light in advance, it is possible to detect the coating rate with high accuracy without being affected by the surface condition of the underlying adhesive layer.

1 ... Image forming apparatus 12 ... Powder holding member 12a ... Powder holding surface (base adhesive layer)
15 ... Transfer member 20 ... Coverage detection device 101a, 101a'... Absorption wavelength light source 101n, 101n' ... Non-absorption wavelength light source 101w ... White light source 102, 102'... Light receiving element 103a ... Absorption wavelength filter 103n ... Non-absorption wavelength filter 201 ... Characteristic holding unit 202 ... Correction coefficient holding unit 203 ... Light source adjustment unit 204 ... Coverage detection unit 205 ... Correction indicator Ha, Ha'... Absorption wavelength light (light with different reflectance)
Hn, Hn'... Non-absorbent wavelength light (light with different reflectance)
Hra, Hra'... Specular reflected light (absorption wavelength light)
Hrn, Hrn'... Specular reflected light (non-absorbent wavelength light)
Pd ... Powder P ... Image pattern (base adhesive layer)
S ... Recording medium

Claims (15)

It is a coverage detection device for detecting the coverage of the base adhesive layer by the powder adhering to the base adhesive layer.
A light source unit that irradiates the adhesion surface of the powder with light having different reflectances in the base adhesive layer, and
A light receiving unit that individually receives reflected light of light having different reflectances reflected by the powder adhesion surface, and a light receiving portion.
A coverage detection device including a coverage detection unit that detects the coverage based on the amount of each reflected light received by the light receiving section. The coating according to claim 1, wherein the light having different reflectances is an absorption wavelength light absorbed by the base adhesive layer and a non-absorption wavelength light absorbed by the base adhesive layer less than the absorption wavelength light. Rate detector. A characteristic holding unit that retains the characteristics of each received light amount with respect to the covering rate is provided.
The coating rate detecting unit calculates the difference between the received light amounts, and detects the covering rate based on the calculated difference and the characteristic held in the characteristic holding unit according to claim 1 or 2. Coverage detector. A correction coefficient holding unit for holding a correction coefficient in which the received amount of each reflected light is 1: 1 regardless of the covering ratio is provided for each type of powder and for each wavelength of light having different reflectance.
The coverage detection unit
Based on the type of the powder when detecting the coverage and the wavelength of light having different reflectances, the correction coefficient used for detecting the coverage is obtained from the correction coefficient holding unit.
The coverage detection device according to claim 3, wherein the characteristic held by the characteristic holding unit is corrected by the acquired correction coefficient, and the coverage is detected based on the corrected characteristic. The light having different reflectances is light emitted from an oblique direction with respect to the adhesion surface of the powder.
The coverage detection device according to any one of claims 1 to 4, wherein each reflected light is specularly reflected light obtained by specularly reflecting the light having different reflectances on the adhesion surface of the powder. The coverage detection device according to any one of claims 1 to 5, wherein the light source unit includes a plurality of light sources that irradiate light having different reflectances. The light source unit
A light source that irradiates all of the light with different reflectances,
A plurality of filters for individually passing light having different reflectances are provided.
The coverage detection device according to any one of claims 1 to 5, wherein the plurality of filters are interchangeably provided on the light emitting surface of the light source. The coverage detection device according to any one of claims 1 to 7, wherein the light receiving unit includes a plurality of light receiving elements that individually receive the reflected light reflected by the powder adhering surface. .. The light receiving portion includes a light receiving element that receives all of the reflected light reflected by the powder adhering surface.
A plurality of filters for individually passing each of the reflected light are provided.
The coverage detection device according to any one of claims 1 to 7, wherein the plurality of filters are interchangeably provided on the light receiving surface of the light receiving element. From the light source unit corresponding to the light-receiving amount so that the light-receiving amount obtained by irradiating the base adhesive layer to which the powder does not adhere with light having different reflectances becomes a predetermined value. The coverage detection device according to any one of claims 1 to 9, further comprising a light source adjusting unit for adjusting the output. Claims 1 to 10 include a correction instruction unit for instructing a drive control unit of an apparatus for adhering the powder to the base adhesive layer to correct driving conditions based on the coating ratio detected by the coverage detection unit. The coverage detection device according to any one of the above. An image forming apparatus for forming an image in which powder is adhered to an image pattern formed on one main surface of a recording medium.
An image forming apparatus including the coverage detection device according to any one of claims 1 to 11. A powder holding member having a powder holding surface that holds the powder by adhesion,
By sandwiching a recording medium provided at a position facing the powder holding surface of the powder holding member and having the image pattern formed between the powder holding member, the powder holding member is held by adhesion on the powder holding surface. A transfer member for transferring powder to the image pattern is provided.
The image forming apparatus according to claim 12, wherein the covering rate detecting device detects the covering rate of the powder by using at least one of the powder holding surface or the image pattern as the base adhesive layer. A coating rate detection method for detecting the coverage of the base adhesive layer by the powder adhering to the base adhesive layer.
The light source unit irradiates the adhesion surface of the powder with light having different reflectances in the base adhesive layer.
The light receiving unit individually receives the reflected light of the light having different reflectances reflected on the adhesion surface of the powder.
A coating rate detecting method in which the covering rate detecting unit detects the covering rate based on the amount of each received light of the reflected light received by the light receiving section. It is a coverage detection program for detecting the coverage of the base adhesive layer by the powder adhering to the base adhesive layer.
The light source portion is irradiated with light having a different reflectance in the base adhesive layer on the adhesion surface of the powder.
The light receiving portion is individually received with the reflected light of the light having different reflectances reflected on the adhesion surface of the powder.
A coverage detection program for causing the coverage detection unit to detect the coverage based on the amount of each of the reflected light received by the light receiving section.

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