JP4945500B2 - Paper sheet thickness measuring apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a paper sheet thickness measuring apparatus and an image forming apparatus.

In order to optimize various conditions such as printing and fixing processes in printing machines such as laser printers that print on various types of paper sheets such as cardboard, copy paper, OHP film, etc. Information on how thick and what kind of paper is the paper-like medium to be obtained is necessary. Conventionally, such information has been made by the user specifying the type of paper sheet manually. However, since it is not convenient for the user to manually input the type of paper sheet, a method for automatically acquiring the type of paper sheet with high accuracy before the conveyance of the paper sheet is desired. .

A conventional optical paper sheet thickness measuring apparatus for measuring the thickness of a paper sheet in a state where the paper sheet is stacked on a tray of a printing press will be described (for example, see Patent Document 1). The optical paper sheet thickness measuring apparatus has, as its main configuration, a stacked bundle in which a plurality of paper sheets are stacked and aligned is placed on a tray, and the side surface of the stacked bundle is inclined upward or downward by a light source. In order to emphasize the unevenness on the side surface of the laminated bundle from obliquely below, light is irradiated. Reflected light from a region directly irradiated with irradiation light is imaged by a light receiving element, a peak-to-peak distance is obtained from a light and dark waveform formed by the paper sheet, and the paper sheet thickness is calculated. In this case, since the reflected light is strong at the edge of the paper sheet and the reflected light from the gap between the paper sheet and the paper sheet is weak, a peak in which the amount of light decreases at the gap appears.

However, it is difficult to obtain a sufficient contrast peak for accurately determining the thickness of the paper sheet by simply imaging the reflected light from the area directly irradiated on the side surface of the stack. It is difficult to reliably detect the thickness of the paper sheet, such as detecting false cycles for each of a plurality of sheets instead of each sheet. Also, the thickness of one sheet of paper is 60-300μ
Therefore, if the thickness of one sheet cannot be reliably detected, a plurality of thin papers overlap each other and are erroneously detected as thick papers.

JP 2005-104723 A

As described above, it has been difficult to accurately determine the thickness of the paper sheet by the conventional method. The present invention relates to a paper sheet thickness measuring apparatus capable of accurately measuring the thickness of a paper sheet in a state in which the paper sheets are stacked, and an image forming apparatus using the measurement result of the paper sheet thickness The purpose is to provide.

In order to solve the above-described problems, the present invention provides at least one of the upper surface, the lower surface, and the plurality of side surfaces of a stacked bundle having a top surface, a lower surface, and a side surface that is a surface along a plurality of stacking directions. An irradiating means for irradiating light so as to enter the laminated bundle from a first region on one surface, and propagating between the sheets among the light incident on the laminated bundle, A light amount distribution measuring means for obtaining light amount distribution information based on a light amount distribution of light that has reached a second region different from the first region on at least one side surface of the plurality of side surfaces of the bundle, and the light amount distribution information In accordance with the present invention, there is provided a paper sheet thickness measuring device comprising a thickness calculating means for calculating the thickness of the paper sheet.

In addition, light is emitted toward at least one of the upper surface, the lower surface, and the plurality of side surfaces of the stacked bundle having a top surface, a lower surface, and a side surface that is a surface along a plurality of stacking directions. A light amount distribution measurement for obtaining light amount distribution information by measuring a light amount distribution of light that is arranged on one side surface of the plurality of side surfaces different from the surface on which the irradiation unit is disposed and that reaches the side surface There is provided a sheet thickness measuring apparatus comprising: a means; and a thickness calculating means for calculating the thickness of the sheet based on the light amount distribution information.

Further, an irradiating unit that irradiates light toward one side surface of the plurality of side surfaces of the stack of bundles having a top surface, a bottom surface, and a side surface that is a surface along a plurality of stacking directions by laminating paper sheets;
Light quantity distribution measuring means for obtaining light quantity distribution information by measuring the light quantity distribution of light reaching the side surface, and light shielding means for blocking light directly incident on the light quantity distribution measuring means from the irradiating means and light reflected on the side surface And a paper sheet thickness measuring device for calculating the thickness of the paper sheet based on the light quantity distribution information.

In addition, the first region on at least one of the upper surface, the lower surface, and the plurality of side surfaces of the stacked bundle having a top surface, a lower surface, and a side surface that is a surface along a plurality of stacking directions on which the sheets are stacked. Of the light incident on the stacked bundle and propagating between the sheets, and at least one of the plurality of side surfaces of the stacked bundle. Light quantity distribution measuring means for obtaining light quantity distribution information based on the light quantity distribution of light that has reached one second side different from the first area, and the thickness of the paper sheet based on the light quantity distribution information A sheet thickness measuring device provided with a thickness calculating means for calculating the thickness, an image forming means for forming an image on the paper sheet, and the image formation based on the calculated thickness information of the paper sheet The image control means for controlling the means is provided. To provide an image forming apparatus.

According to the present invention, a paper thickness measuring apparatus capable of obtaining a high-contrast signal sufficient for accurately measuring the thickness of a paper sheet and capable of performing high-accuracy measurement, and a result of the measurement. It is an object to provide a used image forming apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, the same parts are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
A first embodiment will be described with reference to FIGS. 1 to 6 and FIG.

FIG. 1 shows an example in which a paper sheet type discriminating apparatus for discriminating types of paper sheets stacked in an image forming apparatus for forming an image on paper sheets is extracted.

First, the sheet thickness measuring device 26 will be described. As shown in FIG. 1, a plurality of paper sheets 13
Is stacked on a tray 12 having a drive unit (not shown) that can move up and down in the stacking direction. The stacked bundle 14 has a top surface, a bottom surface, and a side surface 16 that is a surface along a plurality of stacking directions. It has been placed. Irradiation light 11 is emitted toward the upper surface of the stacked bundle 14 from the light source 10 having the light amount adjusting unit 101 that is installed above the stacked bundle 14 and controls the amount of irradiation light. The upper surface is the surface of the paper sheet 13 that is the uppermost layer when the paper sheets 13 are stacked on the tray 12, and the lower surface is the tray 12.
This is the surface of the lowermost sheet 13 that is in contact with the sheet.

The side surface 16 is a plurality of end surfaces excluding the upper surface and the lower surface of the laminated bundle 14. The stacking direction is a direction in which the paper sheets 13 are stacked, and a plurality of surfaces of the stacked bundle 14 that are parallel to the direction are defined as side surfaces. The horizontal direction is a direction perpendicular to the stacking direction at the side surface 16. One side surface of the plurality of side surfaces 16 on which the light receiving element 19 is opposed is 16a.

A region on the surface of the stack 14 directly irradiated with the irradiation light 11 on the top surface of the stack 14 is a first region 30. The light enters the laminated bundle 14 from the light source 10 and propagates through the laminated bundle 14 so that the side surface 1
The propagating light 17 emitted from the second region 31 in 6a is measured by the imaging lens 18 and the light receiving element 19 arranged to face the side surface 16a of the laminated bundle 14. The light receiving element 19 is an area sensor in which elements such as a CCD image sensor and a CMOS image sensor are two-dimensionally arranged. The imaging lens 18 and the light receiving element 19 can be moved in the stacking direction and the horizontal direction by a drive unit (not shown).

The second region 31 on the side surface 16a of the laminated bundle 14 is propagated light 17 emitted from the side surface 16a.
Can be any of the plurality of side surfaces 16 in the stacked bundle 14, but is a different region that does not overlap with the first region 30 irradiated by the light source 10. In the present embodiment, the first region 30 is on the upper surface of the laminated bundle 14, and this is satisfied because it is different from the side surface 16 a of the laminated bundle 14 with the second region 31.

The light shielding member 15 is a rectangular resin plate, and the upper surface of the laminated bundle 14 is in contact with the upper surface of the laminated bundle 14 at a position 1 mm inside from the side end portion in contact with the side surface 16 a, and the light receiving element 19 can see the propagation light 17. The light other than the propagating light 17, for example, the irradiation light 11 from the light source 10,
The reflected light reflected by the irradiation light 11 in the first region 30 is not directly incident on the light receiving element 19. The propagating light 17 emitted from the second region 31 measured by the light receiving element 19 is output to the paper sheet thickness information calculation unit 20 as light quantity distribution information, and the paper sheet thickness information calculation unit 20 calculates from the light quantity distribution information. The thickness of the paper sheet 13 is calculated. This completes the description of the sheet thickness measuring device 26 in which the image forming apparatus of the present embodiment measures the thickness of the sheet 13.

The above-described paper sheet thickness measuring device 26, the total thickness measuring device 27 for measuring the total thickness of the laminated bundle 14, the weight measuring device 28 for measuring the total weight of the laminated bundle 14, and the paper sheets The area information acquisition device 29 for acquiring area information 13 is arranged, and the sheet type discriminating unit 25 determines the basis weight of the sheet 13 from the information about the sheet 13 and the stack 14 output from each apparatus. And the type of the paper sheet 13 is determined from the basis weight. The paper sheet type discriminating unit 25 holds a table storing basis weights and paper types corresponding to the basis weights. Thereafter, important conditions such as the temperature of the fixing device that forms the image on the paper sheet 13 when printing the image on the paper sheet 13 are output. This completes the description of the paper sheet type discriminating apparatus for discriminating the type of the paper sheet 13 in the image forming apparatus of the present embodiment.

FIG. 2 shows how the irradiation light 11 incident on the inside of the laminated bundle 14 from the light source 10 is shown in FIG.
It is a figure showing whether it propagates inside. As shown in the figure, the irradiation light 11 incident on the upper surface of the laminated bundle 14 is diffusely reflected on the surface of the paper sheet 13a or penetrates into the paper sheet 13a, and a part of the paper sheet 13a. It penetrates 13a and reaches the surface of the lower paper sheet 13b. Here, since the light attenuation rate differs between the paper sheet and the air, the gap 2 between the paper sheet 13a and the paper sheet 13b.
3, the light repeats reflection and reaches the second region 31 on the side surface 16 a of the laminated bundle 14. The light that has reached the second region 31 exits from the second region 31 as propagating light 17.

Therefore, when the side surface 16a of the laminated bundle 14 is viewed, the gaps 23 between the paper sheets appear bright. Moreover, since the edge part of the paper sheet 13 is almost absorbed until the irradiation light 11 arrives at the side surface 16a, it looks dark. Therefore, when the second region 31 is imaged by the light receiving element 19, the gaps 23 of each paper sheet shine with a high light amount, and a clear peak appears in the light amount distribution information output from the light receiving element 19.

A part of the irradiation light 11 is reflected by the surface of the paper sheet 13, but the first region 30 and the second region 31.
Is on a different surface, and the light-shielding member 15 is arranged, so that it hardly reaches the light-receiving element 19.

The meaning of the first region 30 that is the region irradiated with the irradiation light 11 emitted from the light source 10 and the second region 31 in which the light receiving element 19 measures the propagation light 17 is another region that does not overlap is described. To do. The light measured by the light receiving element 19 enters the laminated bundle 14 from the first region 30, propagates through the gaps 23 between the sheets, and the second region 31 on the side surface 16 a of the laminated bundle 14.
This means that the propagating light 17 that has reached 1 and is reflected directly from the first region 30 is not measured. In this embodiment, the first region 3 and the second region 31 do not overlap each other.
0 and the second region 31 are on different surfaces on the stacked bundle, and light other than the propagating light 17 is received by the light receiving element 19.
The light shielding member 15 is installed so as not to be incident as much as possible. Even if the light shielding member 15 is not provided, the light source 10 and the light receiving element 19 may be arranged so that light other than the propagation light 17 does not enter the light receiving element 19 as much as possible.

Here, since the main area of the second area 31 means that the first area 30 does not overlap, the first area 30 irradiated by the irradiation light 11 emitted from the light source 10 is the second area. Even if it slightly overlaps 31 at each end, it cannot be said that the main region overlaps, so the first region 30 and the second region 31 can be said to be different.

FIG. 3 shows image data obtained by the light receiving element 19 picking up the light reaching the second region 31 by the paper thickness measuring apparatus of the present embodiment. A white portion where a large amount of light is imaged is an image of light emitted from the gap 23 of the paper sheet 13. Since the propagating light 17 propagating through the gap 23 of the paper sheet 13 and exiting from the side surface 16a is used, even if the side surface 16a of the laminated bundle 14 is not flat and has irregularities of several cycles, the paper sheet Since the light propagating inside the class 13 has already attenuated, the propagating light 17 is hardly affected by the unevenness of the side surface 16a. From the above results, it is possible to measure the peak for each sheet of paper very clearly compared to the prior art by using the sheet thickness measuring method of the sheet type discriminating apparatus of this embodiment. It can be seen that the thickness of one sheet of paper can be accurately measured.

FIG. 4 is a flowchart showing a processing procedure for calculating the thickness of the paper sheet 13 from the image data of the propagation light 17 in the second region 31 by the paper sheet thickness measuring device 26 of the present embodiment.

First, a light quantity distribution of the propagation light 17 incident on the inside of the laminated bundle 14 from the light source 10 and propagated through the laminated bundle 14 and emitted from the second region 31 on the side surface 16a is imaged by the light receiving element 19, and is shown in FIG. Such image data is acquired (ST1). In the image data acquired in (ST1), a light amount distribution in which brightness is repeated along the stacking direction is generated. This repetition interval corresponds to the thickness of the paper sheet 13. This image data has a width of one pixel and is divided into lines along the stacking direction. The light amount distribution based on the pixel value of each pixel of the line is integrated in the horizontal direction over the entire image data to obtain one-dimensional light amount distribution information along the stacking direction in the second region 31 (ST2). A reference point is set from the acquired light quantity distribution information waveform, and the first clear peak position is extracted from the reference point (ST3). Next, a second clear peak position is extracted from the reference point (ST4). The distance between these two peaks is calculated (ST5), and the thickness of the paper sheet is determined from the distance information between the peaks (ST6). The obtained paper sheet thickness information is output (ST7), and the process of calculating the paper sheet thickness is terminated (ST8).

In this processing procedure, the step (ST2) of integrating the light quantity distribution of the image data in the horizontal direction is incorporated, but one line along the stacking direction having a width of one pixel is extracted from the image data without integration. Then, the thickness of the paper sheet may be calculated from the light amount distribution information along the stacking direction in the line, and the paper sheet thickness information may be output. Experiments have shown that when two-dimensional image data is obtained, it is possible to more clearly see the light / dark cycle corresponding to the thickness of the paper sheet 13 after the step of integrating horizontally (ST2). .

Further, when integrating the light amount distribution in the horizontal direction (ST2), the propagation light 17 along the stacking direction is obtained.
It is also possible to extract a region where the brightness and darkness appear clearly and the repetition interval corresponds to the thickness of the paper sheet 13, and to perform the integration processing only in the region.

Further, the waveform of the light amount distribution in the stacking direction calculated in (ST2) is converted into a fast Fourier transform (FFT).
), The peak position of the power spectrum may be extracted, and the thickness of the paper sheet may be calculated from the peak position. By detecting the peak of the power spectrum, the average value of the thickness can be obtained accurately without obtaining the thickness of the paper sheet for each peak.

Moreover, you may obtain | require the method of calculating thickness, without actually calculating. For each paper sheet having various thicknesses in advance, the light quantity distribution information in the stacking direction of the propagation light 17 obtained in (ST2) and the thickness of the paper sheet at that time are stored in the database. When the thickness of the paper sheet is measured, the light amount distribution information obtained in (ST0) to (ST2) is compared with the light amount distribution information stored in the database. The ones with similar phases are selected.
You may output the thickness of the paper sheet matched with the selected light quantity distribution information from a database.

When the propagation light 17 is small, only a signal with a low S / N can be obtained, and it is considered difficult to correctly measure the thickness of the paper sheet 13. In addition, if too much light propagates inside the paper sheet 13 itself, the light receiving element 19 picks up light other than the light propagated through the gap 23 of the paper sheet 13, thereby causing noise. It is considered that it is difficult to accurately measure the thickness of the paper sheet 13.

When it is determined that the peak cannot be obtained from the light amount distribution information by the above procedure and is not optimal, the light amount adjusting unit 101 adjusts the light amount of the irradiation light 11 emitted from the light source 10 or a driving unit (not shown). 2), the image forming lens 18 and the light receiving element 19 are moved to adjust the measurement position, whereby an appropriate light amount distribution can be obtained. Specifically, when it is determined that the amount of light is too large, the drive unit (see FIG. 6) moves away from the light source 10 on the side surface 16a, and conversely, when it is determined that the amount of light is too small, the drive unit (see FIG. (Not shown) can be driven to obtain the same effect as adjusting the amount of the irradiation light 11 emitted from the light source 10. The drive unit (not shown) is attached to the imaging lens 18 and the light receiving element 19. However, if the relative positional relationship between the imaging lens 18 and the light receiving element 19 and the light source 10 can be changed, the driving unit (not shown) of this embodiment is used. Since an effect can be obtained, the same effect can be obtained even if a drive unit (not shown) is attached to the light source 10.

Further, the light source 10 is controlled to emit light with a plurality of light amounts, and the propagation light 1 emitted for each light amount
7 is imaged. Based on the image data from which the most appropriate light quantity distribution is obtained, the paper sheet 13
The thickness may be calculated.

Here, the light receiving element 19 measures the amount of light in the two-dimensional area in the second region 31 and performs processing based on the measurement result. However, it is only necessary to obtain a light amount distribution along at least the stacking direction. Therefore, when the light receiving element 19 outputs a light amount distribution of a one-dimensional line along the stacking direction, the step (ST2) of integrating the light amount distribution of the entire image data in the horizontal direction may be omitted.

FIG. 5 shows the second measured by the light receiving element 19 which is an area sensor in which the elements are two-dimensionally arranged.
4 shows the light amount distribution in the stacking direction including the thickness information of the paper sheet 13 obtained through the processing procedure from (ST1) to (ST2) shown in FIG. . Here, the horizontal axis indicates the length of the side surface 16a in the stacking direction, and the vertical axis indicates the normalized light quantity of the propagation light 17. For example, if the first peak from the reference extracted in (ST3) is the peak appearing near 120 μm in FIG. 5, the second peak from the reference extracted in (ST4) appears near 200 μm in FIG. Refers to the peak. In (ST5), the distance between the two peaks is determined to be about 80 μm, and in (ST6), the thickness of the paper sheet is determined to be 80 μm.

The propagation light 17 emitted from the second region 31 of the laminated bundle 14 is converted into the light receiving element 1 by the procedure as described above.
9, a peak corresponding to the thickness of one sheet is obtained.
Thickness per sheet is obtained.

Next, in the image forming apparatus according to the present embodiment, the type of the paper sheet is discriminated by the paper sheet type discriminating device based on the paper sheet thickness information obtained by the paper sheet thickness measuring device 26. A series of processes for outputting print parameters when forming an image on the paper sheet 13 will be described in detail with reference to FIG.

FIG. 6 shows functional blocks of the image forming apparatus including the processing procedure in the paper sheet type discriminating unit 25. The image data of the propagating light 17 emitted from the second region 31 can be obtained by the light detection block 200 by the method described above. The light detection block 200 corresponds to a combination of the imaging lens 18 and the light receiving element 19. The paper sheet thickness calculation block 201 obtains the light amount distribution information of the propagation light 17 along the stacking direction from the image data obtained by the light detection block 200, detects the peak interval of the light amount distribution, and It has a function to calculate the thickness of paper sheets from the distance.

The paper sheet thickness calculation block 201 is configured to irradiate the irradiation light 11 emitted from the light source 10 from the amount of the propagation light 17.
If the image data having the light amount distribution information that can calculate the thickness of the paper sheet 13 cannot be obtained, the drive control block 202 or the light adjustment block 203 adjusts the light amount. I do. The drive control block 202 has a function of controlling the drive unit 21 that is attached to the light detection block 200 and can be driven in the horizontal direction and the stacking direction. The light adjustment block 203 has a function of adjusting the amount of irradiation light 11 emitted from the light source 10. With the above function, the propagation light 17 having an optimum light amount distribution is imaged,
In the paper thickness calculation block 201, the thickness of the paper 13 is calculated. Then, various parameters corresponding to the thickness of the paper sheet 13 obtained by the paper sheet thickness calculation unit 201 are read from the paper sheet information database 209 and output to the image forming block 210.

The stacked bundle total thickness measuring unit 204 measures the total thickness of the stacked bundle 14. The stack bundle total weight measuring unit 205 measures the total weight of the stack bundle 14. The paper sheet area information acquisition unit 206 acquires the area information of the printing surface of the paper sheet 13.

The total thickness information of the laminated bundle 14 output from each block, the total weight information of the laminated bundle 14, and the area information of the printing surface of the paper sheet 13 are input to the basis weight calculation block 207, and the sheet 13 Calculate the basis weight. The basis weight is the weight per square meter of paper sheets. That is, the basis weight is obtained by dividing the weight per sheet 13 by the area of the printing surface of the sheet 13. That is, the total thickness of the laminated bundle 14 is divided by the thickness of one sheet 13 to obtain the number of laminated bundles 14, and then the total weight of the laminated bundle 14 and the number of laminated bundles 14 are used to determine the number of sheets 13. By calculating the weight per sheet, the basis weight can be determined.

The fixing parameter selection block 208 refers to the paper sheet information database 209 based on the basis weight and thickness of the paper sheet 13 and fixes the ink necessary for forming an image on the paper sheet 13. Important conditions in printing such as the temperature of the device are obtained and output to the image forming block 210.

In the paper sheet information database 209, the thickness of various parameters such as the pressing force of a transport roller (not shown) when the paper sheet 13 is transported to a printing unit (not shown) and the transfer bias for image formation, that is, printing, are stored in advance. The corresponding optimum value is stored in correspondence with the thickness and basis weight of the paper sheet 13.

FIG. 25 is a diagram illustrating an example of a lookup table held in the paper sheet information database 209. Corresponding to the thickness and basis weight of the paper sheet 13, the type of the paper sheet, the target temperature of the fixing device, and the paper conveyance speed from the image transfer section to the passage of the fixing device are stored.

The image forming block 210 controls a fixing unit (not shown) that actually forms an image on the paper sheet 13, that is, prints based on the input information.

The pressure contact force of the conveying roller corresponding to the thickness of the paper sheet 13 calculated in the paper sheet thickness calculation block 201 is output to the image forming block 210, and an operation corresponding to the value is performed to perform the operation of the paper sheet 13 The transport operation can be performed stably. In addition, the optimum value of the transfer bias is output to the image forming block 210, and an operation corresponding to the value is performed to prevent transfer failure of the toner image, retransfer of the transferred toner to the photosensitive drum, and the like. be able to.

A method for acquiring the area information of the printing surface of the sheets 13 constituting the stack 14 by the sheet area information acquisition unit 206 will be described. Dimensions of the paper sheets 13 constituting the laminated bundle 14 in advance (A
(4 size, L size, etc.) There is a method of inputting information and acquiring area information corresponding to the dimensions. Alternatively, a guide or the like (not shown) that is movable on the tray 12 and holds a plurality of side surfaces 16 of the laminated bundle 14 is attached, the laminated bundle 14 is installed on the tray 12, and the side surface 16 of the laminated bundle 14 is attached.
The paper sheet area information acquisition unit 2 is moved from the guide holding position at that time.
A method in which 06 obtains the area information of the paper sheet 13 is also conceivable. Alternatively, either a method of manually inputting a dimension and acquiring area information from the dimension, or a method of automatically measuring an area may be used.

Using the above functional blocks, parameters suitable for printing corresponding to the measured thickness and basis weight of the paper sheet 13 can be set before executing the print job.

When light other than the propagating light 17 such as the irradiation light 11 emitted from the light source 10 or the reflected light from the first region 30 is incident on the light receiving element 19, flare is caused and image data is deteriorated. Further, when the irradiation light 11 emitted from the light source 10 hits the second region 31 imaged by the light receiving element 19, the side surface 16a.
Is brightly illuminated, leading to a decrease in signal contrast in the light quantity distribution information. Therefore, a light shielding member 15 that does not transmit light is provided between the light source 10 and the light receiving element 19.

Here, the light shielding member 15 corresponds to the light shielding member 15 here even if it has an effect of preventing light other than the propagating light 17 from entering the light receiving element 19. For example, since an optical fiber propagates light that satisfies the total reflection condition, only light within a specific angle with respect to the central axis is emitted. Therefore, if the light receiving element 19 is arranged outside the specific angle, it is possible to prevent light from directly entering the light receiving element 19 from the fiber. Even in such a system, the optical fiber corresponds to the light shielding member 15 referred to herein.

The shape of the light shielding member 15 is not limited to a rectangular plate, and may be, for example, a cylindrical shape or a rectangular shape surrounding the light source 10. If the light source 10 is surrounded by a light shielding member and is in contact with the upper surface of the laminated bundle 14 so that light is incident on the laminated bundle 14, light other than the propagating light 17 does not enter the light receiving element 19, and the light quantity distribution information Increases signal contrast.

As the material of the light shielding member 15, for example, a resin, a metal plate, rubber, or the like can be used as long as it achieves the purpose of not transmitting light. Further, the light shielding member 15 may be integrated with the light source 10 instead of a single unit. Alternatively, the light shielding member 15 and the light receiving element 19 may be integrated.

The imaging lens 18 may be a gradient index lens or a cylindrical lens. When the light receiving element 19 such as a line sensor or an area sensor is combined with a gradient index lens, the imaging distance from the side surface 16a can be shortened, and the configuration becomes compact. When a cylindrical lens is combined with a line sensor, the cylindrical lens is a laminated bundle 1
Since the horizontal component of 4 is condensed and imaged on the line sensor, the propagation light 17 in the horizontal direction can be widely obtained, and the same effect as in the embodiment when the area sensor is used as the light receiving element 19 is obtained. It becomes possible to make it.

In any case, the propagation light 1 emitted from the second region 31 on the side surface 16a of the laminated bundle 14
Any means can be used as long as it can capture an image of the image 7 without being limited to the above example.

The light shielding member 15 is disposed so as to be in contact with the laminated bundle 14. At this time, the light shielding member 15 is pressed to compress the laminated bundle 14 or stopped at a position in contact with the laminated bundle 14. According to the situation, it is configured to come into contact with the laminated bundle 14 with an appropriate pressing force.
If the light shielding member 15 blocks light other than the propagating light 17 from entering the light receiving element 19, the light shielding member 15 may be touched lightly or may be touched so as to be pressed.

The position of the light shielding member 15 is 1 mm inward from the end of the paper sheet 13 in the first embodiment, but is not limited to this example, and may be on the end of the paper sheet 13, for example. In any case, it may be installed in any place as long as it functions as the light shielding member 15.

Further, the light shielding member 15 itself may have a drive unit, and the distance from the end of the paper may be changed as appropriate. Thereby, the light quantity of the propagation light 17 emitted from the second region 31 can be adjusted.

The light receiving element 1 that measures the light amount distribution of the propagation light 17 emitted from the second region 31 of the laminated bundle 14
9 is not limited to the area sensor in which the image pickup elements are two-dimensionally arranged, but may be a line sensor in which the image sensors are one-dimensionally arranged.

Alternatively, the imaging system can be made more compact by devising such that the light receiving element 19 is directly brought into contact with the side surface 16a of the laminated bundle 14 to take an image.

As the light receiving element 19, any other element may be used as long as it can measure the light amount distribution of at least the side surface 16 a in the stacking direction, such as a photodiode or an optical sensor array.

The irradiation light 11 may be any of red light, ultraviolet light, blue light, green light, and near infrared light. When ultraviolet light having a wavelength of less than 380 nm or blue light having a wavelength of 380 nm to 500 nm is used, the light attenuation rate inside the paper sheet 13 is large, so that the amount of light emitted through the paper sheet 13 is reduced. A signal with a light quantity distribution with high contrast can be obtained. When green light having a wavelength of 500 nm to 600 nm, red light having a wavelength of 600 nm to 700 nm, or near infrared light having a wavelength of 700 nm to 1100 nm is used, the light has a small attenuation rate inside the paper sheet 13, so It penetrates deeply, and a signal of the light quantity distribution of the propagation light 17 can be obtained over a longer section.

The total thickness measuring device 27 of the laminated bundle 14 for measuring the total thickness of the laminated bundle 14 is provided separately in FIG. 1, but the function is applied to the light source 10 or the light shielding member 15 that is pressed against the upper surface of the laminated bundle 14. May be added.

In order to accurately measure the thickness of each sheet in a state where the sheets 13 are stacked, it is necessary to detect the gaps 23 of the sheets 13 one by one.

FIG. 24 shows a conventional example in which irradiation light is irradiated by a light source disposed obliquely with respect to the side surface of the stack of bundles, light reflected by the side surface is measured by a light receiving element, and the side surface of the paper sheet is measured. It is the light quantity distribution data of the lamination direction obtained by integrating the light and dark formed by the unevenness in the horizontal direction.

As can be seen from FIG. 24, when the irradiation light is irradiated obliquely from above and the irradiation area is imaged, the peak of the cycle of 2 to 4 sheets, which seems to be caused by the sheet cutting process, is conspicuous. Therefore, the frequency component of each sheet is more conspicuous. Therefore, the peak of the period corresponding to the thickness of one sheet of paper is very weak, and only a signal with a poor S / N can be obtained.

FIG. 7 is a diagram showing another configuration of the paper sheet thickness measuring apparatus according to the first embodiment. In FIG. 7, the laminated bundle 14 is placed on the tray 12, and the irradiation light 11 emitted from the light source 10 installed below the laminated bundle 14 irradiates the lower surface of the laminated bundle 14. Side 16 of the stack 14
In a, an imaging lens 18 and a light receiving element 19 are disposed opposite to each other, and the irradiation light 11 emitted from the light source 10 penetrates into the laminated bundle 14 and propagates inside the laminated bundle 14 and is on the side surface 16a of the laminated bundle 14. Second
The light amount distribution of the propagation light 17 emitted from the region 31 is measured by the light receiving element 19. The lower surface of the stacked bundle 14 is a printing surface that faces the bottom of the tray 12. In this case, since the light source 10 and the light shielding member 15 can be disposed on the bottom of the tray 12, the configuration becomes compact.

Further, even if the light source 10 is arranged on the plurality of side surfaces 16 where the light receiving elements 19 of the stacked bundle 14 are not arranged to face each other, it is only necessary to measure the propagation light 17.

In addition, the light source 10 is provided at two locations on the upper and lower surfaces of the laminated bundle 14, and these are irradiated simultaneously or alternately with the irradiation light 11 toward the inside of the laminated bundle 14, and light reception arranged on the side surface 16 a of the laminated bundle 14. The thickness of the sheets in the upper and lower parts of the stack 14 may be obtained by the element 19 (not shown).

In addition, if the surface where the light source 10 is opposed and the first region 30 is located is different from the side surface 16a where the second region 31 where the light receiving element 19 is opposed is disposed, the effect of the present embodiment can be obtained. Obtainable.

Note that the sheet thickness measuring device 26 and the sheet type discriminating device of this embodiment are MFP (M
It can be used as a means for obtaining information on the paper sheet 13 in a printer such as a bubble jet (registered trademark) printer or an ink jet printer, as well as a multifunction peripheral or laser printer.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS.

8 and 9 are structural diagrams of the paper sheet thickness measuring apparatus according to the second embodiment. FIG.
1, the irradiation light 1 from the light source 10 toward the side surface 16 a where the light receiving element 19 of the laminated bundle 14 is located.
1 is irradiated. The irradiated area is the first area 30. The irradiation light 11 irradiated toward the first region 30 on the side surface 16a penetrates into the inside of the stacked bundle 14, diffuses and propagates through the gaps 23 of the sheets constituting the stacked bundle 14, and reaches the side surface 16a. A certain second region 31 is reached.
The propagating light 17 emitted from the second region 31 is condensed on the light receiving element 19 through the imaging lens 18 installed toward the second region 31, and image data can be obtained. Shading member 1
5 is disposed between the first region 30 and the second region 31 so as to be in contact with the side surface 16 a of the stacked bundle 14, and the light directly incident on the light receiving element 19 from the light source 10 and the first region 30. The light directly reflected by is blocked. That is, the first region 30 irradiated by the light source 10 and the second region 31 imaged by the imaging lens 18 and the light receiving element 19 are different regions that do not overlap with each other, and the light receiving element 19 measures the propagation light 17. It is arranged so that it can.

Here, if the light shielding member 15 has a structure having a soft material such as rubber at its end, the soft material portion is deformed according to the unevenness present on the side surface 16a of the laminated bundle 14 to shield the light, and the laminated bundle 14 and the light shielded. Noise due to light leaking from the gap with the member 15 can be reduced.

Next, effects according to the second embodiment will be described. In the second embodiment, the irradiation light 11
Is transmitted to the side surface 16a of the laminated bundle 14, and propagated light 17 diffused and propagated inside the laminated bundle 14 and emitted from the second region 31 on the side surface 16a is obtained from the light receiving element 19 that images the same side surface 16a. . Thereby, the light source 10, the light shielding member 15, and the light receiving element 19 can be arrange | positioned on the same side surface 16a of the laminated bundle 14, and it can be set as a space-saving structure.
FIG. 9 is a diagram illustrating another configuration of the paper sheet thickness measuring apparatus according to the second embodiment. FIG.
Then, the light shielding member 15 on the side surface 16a and the light receiving element 19 as the light amount distribution measuring means are aligned in the stacking direction of the stacked bundle 14. In this case, there is a feature that light leakage from the light shielding member 15 due to the unevenness generated on the side surface 16a of the stack 14 is reduced by stacking the paper sheets 13.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS.

FIG. 10 is a diagram illustrating a configuration of a paper sheet thickness measuring apparatus according to the third embodiment. FIG.
In the embodiment shown in FIG. 2, the two light sources 10 are arranged opposite to the upper surface of the laminated bundle 14 so that the distances from the end sides of the upper surface of the laminated bundle 14 are different. Each light source 10 has side 1
A light amount control mechanism (not shown) that can adjust the light of the irradiation light 11 is provided so that the light amount of the propagating light 17 emitted from the second region 31 on 6a is optimized. It can be changed or can emit light simultaneously or mutually.

The light shielding member 15 is disposed in contact with the upper surface of the stacked bundle 14 so that light other than the propagation light 17 does not enter the light receiving element 19, and the first region 30 irradiated with the irradiation light 11 emitted from the light source 10;
The second regions 31 captured by the light receiving element 19 do not overlap each other.

Irradiation light 11 applied to the upper surface of the laminated bundle 14 penetrates into the laminated bundle 14 and the laminated bundle 14.
Is diffused and propagated through the gaps 23 of the paper sheets constituting the sheet to reach the side surface 16a of the laminated bundle 14. The propagating light 17 on the side surface 16a of the laminated bundle 14 is the imaging lens 1 installed toward the side surface 16a.
Then, the light is focused on a light receiving element 19 which is an area sensor in which elements such as a CCD image sensor and a CMOS image sensor are two-dimensionally arranged. The imaging lens 18 and the light receiving element 19 can be moved in the horizontal direction and the stacking direction by a driving unit (not shown).

In the present invention, since measurement is performed using light propagating through the gap 23 of the paper sheet 13, it is preferable to adjust the position of the light source 10 and the light receiving element 19 according to the thickness and density of the paper sheet 13. At this time, a difference occurs in the light amount of the propagation light 17 due to the difference in the illumination position of the light source 10. For example, 1 from the end
. Even if the amount of propagating light 17 when the light source 10 disposed at a position of 5 mm is emitted is large, it is 3 from the end.
When the light source 10 disposed at a position of mm is caused to emit light, the attenuation of light increases as the distance from the end increases, the amount of the propagation light 17 decreases, and the peak due to the propagation light 17 emitted from the gap 23 of each paper sheet. Can be detected. The position from this end may be adjusted according to the implementation. Light source 1
The light emission of 0 may be performed one by one, and if the light quantity is still insufficient, a plurality of light sources 1
The amount of light can be compensated by emitting 0 simultaneously.

Further, when the thickness of the paper sheet 13 is thick, the irradiation light 11 incident on the upper surface of the laminated bundle 14 is absorbed when propagating through the inside of the paper sheet 13, and from the second region 31 on the side surface 16a. The amount of propagating light 17 to be emitted is reduced. Therefore, it is conceivable that a sufficient amount of light for measuring the thickness of the paper sheet 13 cannot be obtained.

On the contrary, when the thickness of the paper sheet 13 is thin, the irradiation light 11 incident on the upper surface of the laminated bundle 14 is not easily absorbed when propagating through the paper sheet 13 and is transmitted through the paper sheet 13 itself. More light to do. Then, it is conceivable that the light receiving element 19 picks up images other than the light that has propagated through the gap 23 of the paper sheet 13, and noise is added to make it impossible to measure the thickness of the paper sheet 13.

The ease of light transmission inside the paper sheet also varies depending on the material and density of the paper sheet 13.

Therefore, when the light amount of the propagation light 17 is small, the position where the light receiving element 19 measures the light amount is moved horizontally by a drive unit (not shown), and the light source 10 is located near the side of the stack 14. It is considered that a sufficient amount of light can be obtained by measuring the propagating light 17 emitted from 31. On the contrary, when the amount of the propagation light 17 is too large, the propagation light 17 emitted from the second region 31 located far from the side of the stack 14 may be measured. From the above, when the image pickup position on the side surface 16a of the stack 14 is adjusted in the horizontal direction by a drive unit (not shown), a mechanism for picking up an image at an optimum amount of light according to the thickness of the paper sheet 13 is provided. it can. Using this, the propagation light 17 measured by the light receiving element 19 in the second region 31 of the side surface 16a.
Thus, it is possible to obtain a signal having a light quantity distribution with high contrast by extracting an area where the quantity of light is appropriate. Further, the density of the paper sheet 13 may be calculated by measuring the light attenuation rate in the stacked bundle 14 from the light amount distribution information. The light source 10 may be provided not only on the upper surface of the laminated bundle 14 but also on the lower surface and the side surface 16.

After determining that the measured light quantity is optimal, the image data captured by the light receiving element 19 can obtain the thickness information of the paper sheet 13 through the processing procedure described in the first embodiment.

Of the two light sources 10, the one far from the end of the paper sheet 13 may be an LED that emits red light, and the one near the end of the paper sheet 13 may be an LED that emits blue light. Since the blue light is easily attenuated inside the paper sheet 13, the amount of light propagating through the paper sheet 13 is reduced, so that a signal having a sufficient light amount distribution for measuring the thickness of the paper sheet 13 is obtained. However, since it penetrates only to a shallow part of the stack 14, there is a possibility that the second region 31 that can be imaged becomes narrow. The red light is hard to attenuate within the paper sheet 13 and penetrates deep into the stacked bundle 14, but the light is not easily attenuated even inside the paper sheet 13, and thus is emitted from the second region 31. Since the propagating light 17 is likely to include not only the light propagating through the gap 23 but also the light propagating through the inside of the paper sheet 13, it is possible to obtain a signal with sufficient contrast for measuring the thickness of the paper sheet 13. It may not be possible. Therefore, each light source 10 is controlled to take advantage of the characteristics of two different emission center wavelengths and adjust the amount of each other, so that the second is selected according to the paper sheet to be measured.
It is possible to adjust the light amount of the propagation light 17 emitted from the region 31, and it is possible to obtain a light amount distribution signal with high contrast. Further, the combination is not limited to the combination of an LED that emits red light far from the end of the stacked bundle 14 and an LED that emits blue light near the end, and any combination can be used as long as a signal with a high contrast light quantity distribution can be obtained. May be.

Alternatively, two LEDs may be arranged at the same distance from the end of the stacked bundle 14, and the light emitted from each of them may be blue light and red light. The blue light and the red light have different transmittances inside the paper sheet 13, and therefore the amount of the propagation light 17 emitted from the second region 31 is also different. Moreover, the light quantity of the irradiation light 11 which each LED emits can also be controlled so that the suitable propagation light 17 can be measured using the difference in the transmittance | permeability by the difference in wavelength.

Further, the number of LEDs is not limited to two, and may be three or more. The light source 10 is an LED.
Not limited to this, a laser or other light source may be used.

FIG. 11 is a diagram illustrating another configuration of the paper sheet thickness measuring apparatus according to the third embodiment. In FIG. 11, the light source 10 having a linear irradiation surface such as an elongated fluorescent tube is arranged so as to form an angle θ with the end side of the laminated bundle 14. The light source 10 having a line-shaped irradiation surface is located on the side surface 16a of the laminated bundle 14 when it is close to the edge formed by the side surface 16a where the second region 31 of the laminated bundle 14 is located and the upper surface where the first region 30 is located. Although the amount of propagating light 17 emitted from the second region 31 is large, the light source 1
As the distance from the edge of 0 increases, the amount of propagating light 17 emitted from the second region 31 decreases.

By moving the positions of the imaging lens 18 and the light receiving element 19 in the horizontal direction when it is determined that the image data obtained by the light receiving element 19 is not optimal for obtaining the thickness information of the paper sheet 13. The amount of the propagation light 17 to be measured can be adjusted.

From the above, according to FIG. 11, a mechanism for obtaining an optimal light amount can be achieved by simply adjusting the imaging position on the side surface 16a of the stacked bundle 14 in the horizontal direction with a simple configuration of the line-shaped light source 10.

  Further, the light source 10 may be provided not only on the upper surface of the laminated bundle 14 but also on the lower surface and side surfaces.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIGS.

FIG. 12 is a diagram illustrating a configuration of a paper sheet thickness measuring apparatus according to the fourth embodiment. FIG.
The light source 10 of the sheet thickness measuring apparatus shown in FIG. 1 is composed of a light guide 152 using a halogen lamp and an optical fiber. The irradiation light 11 emitted from the irradiation surface of the light guide 152 is the tray 1
2 is irradiated toward the upper surface of the stacked bundle 14 placed on the sheet 2 and stacked with the paper sheets 13. The irradiation position is 1 mm inward from the end of the top surface of the laminated bundle 14. The light shielding member 15 is a metal tube that shields the periphery of a circular optical fiber that guides light from the halogen lamp, and since this is lightly pressed against the laminated bundle 14, the irradiation light 11 irradiated on the upper surface of the laminated bundle 14 is: A part of the light is reflected by the surface of the paper sheet 13 but is blocked by the light shielding member 15 and does not reach the light receiving element 19.
The other light penetrates into the laminated bundle 14, propagates through the gaps 23 of the sheets constituting the laminated bundle 14, and reaches the side surface 16 a of the laminated bundle 14.

The light receiving element 19 is a line sensor. The light receiving element 19 has an imaging lens 18 made of a gradient index lens, and is approximately equal to the size of the light receiving element of the sensor, and the side surface 1 of the laminated bundle 14.
The propagating light 17 emitted from the second region 31 in 6a can be measured. Thereby, the stack 1
The propagation light 17 emitted from the four side surfaces 16a can be imaged with a simple optical system and high resolution. The drive unit 21 can move the light receiving element 19 of the line sensor in which the light receiving elements are arranged in the stacking direction of the stacked bundle 14 in the horizontal direction of the stacked bundle 14 by a motor and a belt.

By moving the light receiving element 19 in the horizontal direction of the stacked bundle 14 by the driving unit 21, it is possible to obtain image data of a wide area with a small number of pixels. Further, the propagation light 17 emitted from the second region 31 on the side surface 16a of the stacked bundle 14 can be measured over a wide area with a high resolution of the line sensor.

The image data output by the light receiving element 19 is obtained by extracting the interval between the peak amounts of light in the stacking direction for each line by the paper sheet thickness calculation unit 20 and integrating the obtained results to obtain the peak interval. Based on the obtained peak interval, the sheet thickness information is obtained.

Next, the effect of the fourth embodiment will be described. The light source 10 is a halogen lamp whose light intensity can be adjusted, and the irradiation light 11 from the halogen lamp is extended to an irradiation position by a light guide 152 using an optical fiber. The irradiation part of the light guide 152 is covered with a metal cylindrical case, and if the irradiation part of the light guide 152 is pressed against the laminated bundle 14,
The irradiation light 11 can be penetrated into the laminated bundle 14 at any place without leaking.

Here, the light source 10 is a halogen lamp, but the light source 10 may be a metal halide lamp or other types of lamps, for example. Irradiation light 11 is not limited to white light. For example, blue light, green light, red light, or near infrared light may be irradiated by combining a halogen lamp and a bandpass filter.

Moreover, although the shape of the irradiation surface of the light guide 152 is circular, for example, it may be a line-shaped irradiation surface or a semicircular irradiation surface. In any case, any configuration may be used as long as the periphery of the optical fiber is shielded by the light shielding member 15.

In FIG. 12, the light source 10 irradiates the upper surface of the laminated bundle 14. However, the light source 10 may irradiate the lower surface of the laminated bundle 14, or may irradiate any one or more side surfaces 16 of the laminated bundle 14.

Moreover, although the position of the sensor was moved to the horizontal direction by the drive part 21, not only this but the lamination | stacking bundle | flux 14 may be moved and the equivalent result may be obtained.

  FIG. 13 is a diagram illustrating another configuration of the paper sheet thickness measuring apparatus according to the fourth embodiment.

In FIG. 13, if the photodiode having the imaging lens 18 focused on one point on the side surface 16a of the stack 14 is moved in the stacking direction using the drive unit 21 composed of a motor and a belt, The propagating light 17 can be detected with a simple configuration.

Further, in the present embodiment, the light receiving element 19 and the like are moved in the horizontal direction or the vertical direction by the drive unit 21; however, a structure may be adopted in which the distance from the side surface 16a is changed. As a result, the focusing of the imaging lens 18 can be adjusted so that it is correctly aligned with the side surface 16a.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to FIGS.

FIG. 14 is a diagram illustrating a configuration of a paper sheet thickness measuring apparatus according to the fifth embodiment. FIG.
The tray 12 is a paper sheet separating means that blows air onto any one of the side surfaces 16 of the stacked bundle 14 by a blower mechanism and blows air into the gaps 23 of the stacked bundle 14 so that the sheets 12 are in close contact with each other. A ventilation separation mechanism 221 for separating the classes 13 from each other is provided.

Next, effects of the fifth exemplary embodiment will be described. The stacked paper sheets 13 may be adsorbed between adjacent paper sheets 13 due to factors such as burrs at the time of cutting, and being in close contact with each other for a long time. When the paper sheets 13 are attracted to each other, the paper sheet gap 23 necessary for obtaining the thickness information of the paper sheets 13 disappears, which is sufficient for measuring the thickness of the paper sheets 13. May not be obtained. The air blown by the blower separation mechanism 221 hits the side surface 16 of the stacked bundle 14, and the air is blown into the gaps 23 of the paper sheets 13. As a result, the closely attached paper sheets 13 can be separated. A gap 23 in the paper sheet 13
If this occurs, the light propagating through the inside easily reaches the side surface 16a, and the thickness of the paper sheet 13 can be easily detected.

FIG. 15 is a diagram showing another configuration of the paper sheet thickness measuring apparatus according to the fifth embodiment. FIG.
5, as a paper sheet separating mechanism, a vibrator is pressed against the upper surface of the laminated bundle 14 to apply ultrasonic waves to the laminated bundle 1.
4 is provided with an ultrasonic vibration mechanism 22 that creates a gap 23 between the paper sheets 13. The ultrasonic vibration mechanism 22 causes the paper sheets 13 to vibrate, thereby separating the paper sheets 13 that are in close contact with each other. If a gap 23 is formed in the paper sheet 13, light propagating through the inside easily reaches the side surface 16a, and the thickness of the paper sheet 13 can be easily detected.

FIG. 16 is a diagram showing another configuration of the paper sheet thickness measuring apparatus according to the fifth embodiment. FIG.
6 includes a spatula 233 that creates a gap 23 between the paper sheets 13 by pressing against the upper surface of the stack 14 as a paper sheet separating mechanism. The spatula 223 has a shape that becomes thinner as it goes to the tip, and the tip is rounded. The tray 12 may have a concave structure 224 on a part of the bottom surface in contact with the lower surface of the laminated bundle 14. The position where the concave structure 224 and the spatula 223 are pressed is a corresponding position with the stacked bundle 14 interposed therebetween. By pressing the tip of the spatula 223 against the upper surface of the laminated bundle 14, the end of the laminated bundle 14 is warped and a gap 23 can be formed in the paper sheet 13. If a gap 23 is formed in the paper sheet 13, light propagating through the inside easily reaches the side surface 16a, and the thickness of the paper sheet 13 can be easily detected.

Further, the paper sheets 13 may be separated from each other by moving the paper sheets 13 and the stacked bundle 14 by a mechanism for conveying the paper sheets 13, and a gap 23 between the paper sheets 13 may be generated.

(Sixth embodiment)
Next, a sixth embodiment will be described with reference to FIG.

FIG. 17 is a diagram illustrating a configuration of a paper sheet thickness measuring apparatus according to the sixth embodiment of the present invention. In the embodiment shown in FIG. 17, the light source 10, the light shielding member 15, the imaging lens 18, and the light receiving element 19 are configured as one unit. Irradiation light 11 emitted from the light source 10 is irradiated toward the upper surface of the stacked bundle 14 in which the paper sheets 13 are stacked on the tray 12. The light shielding member 15 is integrated with the light source 10 and the light receiving element 19 and has a shape covering the periphery of each of the light source 10 and the light receiving element 19, and restricts the illumination area so that the irradiation light 11 does not enter the light receiving element 19. Yes. The irradiation light 11 irradiated on the upper surface of the laminated bundle 14 penetrates into the laminated bundle 14, diffuses and propagates through the gaps 23 of the sheets constituting the laminated bundle 14, and reaches the side surface 16 a of the laminated bundle 14. The propagating light 17 emitted from the second region 31 on the side surface 16a of the laminated bundle 14 is transmitted through the side surface 16a.
The light is condensed on the light receiving element 19 through the imaging lens 18 installed toward the surface.

The image data picked up by the light receiving element 19 is subjected to processing for calculating the thickness of the paper sheet 13 by the paper sheet thickness calculating unit 20 that calculates the paper sheet thickness, and outputs the paper sheet thickness information. To do.

Next, the effect of the sixth embodiment will be described. In the sixth embodiment, the light source 10, the light shielding member 15, the imaging lens 18, and the light receiving element 19 are configured as one unit. The light source 10 is disposed at a position 1 mm from the end of the paper sheet 13. An area sensor having a gradient index lens is used as the light receiving element 19, and a frame for holding and shielding these is formed of resin. By pressing a unit composed of these components against the laminated bundle 14, the propagation light 17 that diffuses and propagates inside the laminated bundle 14 and exits from the second region 31 on the side surface 16 a of the laminated bundle 14 is transmitted outside. Measurement can be performed while suppressing the influence of noise caused by light. Further, a single moving means (not shown) for pressing against the laminated bundle 14 can be provided, and a simple configuration can be realized.

The light source 10 may be arranged on the lower surface and the side surface to constitute a unit. The light source 10 may be other than the LED.

(Seventh embodiment)
Next, a seventh embodiment will be described with reference to FIG.

The upper part of FIG. 18 is a diagram illustrating a configuration of a paper sheet thickness measuring apparatus according to the seventh embodiment.
The lower part of FIG. 18 is a diagram showing the tray 121 and the light shielding member 151 extracted.

The tray 121 of the seventh embodiment has a groove 122 at the bottom that is in contact with the lower surface of the laminated bundle 14.
The light shielding member 151 has a slit 152 at an end portion that is in contact with the laminated bundle 14 on the upper surface.

The irradiation light 11 emitted from the light source 10 irradiates the upper surface of the laminated bundle 14 with light. Although most of the irradiation light 11 emitted from the light source 10 is blocked by the light blocking member 151, some of the light is slit 1.
The light passes through 52 and enters the light receiving element 19. Further, a part of the light that has propagated through the laminated bundle 14 and reached the lower surface of the laminated bundle 14 passes through the groove 122 and enters the light receiving element 19. Therefore, the light receiving element 19 can obtain light serving as a reference indicating the positions of the uppermost surface and the lowermost surface of the laminated bundle 14.
The paper sheet thickness calculation unit 20 can measure the thickness of the paper sheet 13 and the number of the paper sheets 13 based on the reference light and the propagation light 17 emitted from the gap 23 of the paper sheet 13.

Further, when the number of stacked paper sheets 13 is small, the number of peaks of propagating light 17 emitted from the gaps 23 between the paper sheets 13 also decreases. Therefore, by forming appropriate gaps such as grooves and slits on the bottom surfaces of the light shielding member 151 and the tray 121, reference light indicating the upper and lower surfaces of the stacked bundle 14 can be obtained. The number of peaks can be increased by the reference light, and the thickness of the paper sheet 13 can be measured even with a small number of sheets.

For example, even if the number of sheets 13 is one, the light receiving element 19 can obtain light amount distribution information having two peak values by the reference light emitted from the slit 152 and the groove 122. Therefore, the paper sheet thickness information calculation unit 20 can obtain the thickness of the paper sheet 13 from the two peak values.

In addition, the groove 122 and the slit 152 can be distinguished from the reference light emitted from the groove 122 and the slit 152 and the propagation light 17 emitted from the second region 31 on the side surface 16a of the stacked bundle 14.
May be formed into a characteristic shape. By storing the light quantity distribution pattern based on the reference light in the paper sheet information database 209 in advance, it is possible to easily distinguish it from the propagation light 17.

Moreover, the clearance gap provided in the light-shielding member 15 and the bottom face of the tray 12 may acquire the same effect by roughening the surface irrespective of a groove | channel. Moreover, you may acquire the same effect by sticking the thin plate of the transparent or translucent material which permeate | transmits light like an OHP sheet.

(Eighth embodiment)
Next, an eighth embodiment will be described with reference to FIGS. This embodiment has been made to enable measurement of the light amount distribution of the propagating light 17 that does not depend on errors in the stacking condition.

FIG. 19 is a diagram showing a configuration of a paper sheet thickness measuring apparatus according to the eighth embodiment of the present invention. The light receiving element 19 is an area sensor in which elements such as a CCD image sensor and a CMOS image sensor are two-dimensionally arranged. The imaging lens 18 and the light receiving element 19 are arranged so as to image the side surface 16a from an angle shifted by θ from the vertical direction of the side surface 16a. The paper sheet thickness information calculation unit 20 calculates the thickness of the paper sheet 13 using the light amount distribution information in the stacking direction in which the image contrast is the highest among the image data.

FIG. 20 is a diagram showing an extracted configuration of the paper sheet thickness calculation block 201 of the present embodiment. The paper sheet thickness calculation block 201 of this embodiment includes a focus area determination unit 2010 and a thickness calculation unit 2011.

The focusing area determination unit 2010 determines a focusing area that is an area in the stacking direction in which the imaging lens 18 is estimated to be best in focus from the two-dimensional image data captured by the light detection block 200. The thickness calculation unit 2011 calculates the thickness of the paper sheet 13 based on the image data of the focus area.

FIG. 21 is a flowchart illustrating a process in which the paper thickness measuring apparatus according to the present embodiment calculates the thickness and basis weight of the paper 13.

First, the light quantity distribution of the propagating light 17 emitted from the second region 31 on the side surface 16 a by the irradiation light 11 emitted from the light source 10 penetrating into the laminated bundle 14 and propagating through the laminated bundle 14 is expressed as follows. An image is picked up by the imaging lens 18 and the light receiving element 19 arranged non-parallel to the side surface 16, and image data is acquired (ST11). The in-focus area determination unit 2010 divides the image data into an image area having a width corresponding to 0.2 mm if the depth of field of the camera is 0.2 mm (ST).
12). The absolute value of the difference between adjacent pixels in the stacking direction is calculated for all the pixels in the image (S
T13). Then, the sum of absolute values of differences is calculated for each region (ST14), and the region having the maximum value is selected as the focus region (ST15). The thickness calculating means 2011 adds the pixel values in the in-focus area in the horizontal direction (ST16), estimates the local background level from the waveform obtained by viewing the added value in the vertical direction, and subtracts (ST17), The coordinate positions of the points having the peak likeness are recorded from the waveform obtained by subtracting the background level (ST18), the peak intervals are obtained from the coordinate positions of the peaks, the thickness is estimated from the peak intervals and the camera resolution, and Calculates the basis weight of the paper sheet 13 from the density (0.75 to 0.85 g / cm ³ ) of a general paper sheet (ST19).
). Parameters such as the thickness and basis weight of the paper sheet 13 are output to the fixing parameter selection block 208 (ST20), and the process ends (ST21).

In this process, the image area is vertically divided in (ST12) in order to cope with the positional deviation of the entire stack 14 but the image area is divided vertically and horizontally in order to deal with the misalignment of the laminated bundle 14 itself. May be processed.

The effect of this embodiment will be described. The laminated bundle 14 is not always at a constant distance from the light receiving element 19, and an error occurs depending on the laminated state. Moreover, the side surface 16 of the laminated bundle 14 is not necessarily aligned so as to be parallel to the vertical direction, and some undulation may occur.
According to the present embodiment, the imaging region 18 and the light receiving element 19 capture an image of the side surface 16a of the stacked bundle 14 from an angle deviated from the vertical direction, so that an in-focus area is easily generated in the image. As a result, stable measurement that is not affected by errors due to the stacking condition of the stack 14 can be performed. Therefore, an imaging system with a wide depth of field can be realized.

In the embodiment described above, the in-focus area in the image is detected by obtaining a high-frequency component. However, for example, the stacking position of the stacked bundle 14 is detected using a rangefinder, and the focused position in the image is not detected. The focus area may be selected from the distance from the light receiving elements 19 arranged in parallel.

(Ninth embodiment)
Next, a ninth embodiment will be described with reference to FIG.

FIG. 22 is a diagram illustrating a configuration of a paper sheet thickness measuring apparatus according to the ninth embodiment. Paper sheets 1
3 are stacked so as to be substantially parallel to the direction of gravity. The light source 10 irradiates light toward the lower surface of the laminated bundle 14. The tray 123 is provided with an opening 124 on the lower surface.
Due to the opening 124, the stacked bundle 14 is bent downward due to its own weight, and a gap 23 is generated between the paper sheets 13.

Next, effects of the ninth embodiment will be described. The tray 12 has an opening formed on the bottom surface thereof, so that the stacked bundle 14 stacked on the tray 12 bends downward from the opening 124.

The amount of deflection of the deflection is limited by the light source 10, thereby suppressing the amount of deflection due to the weight of the stack 14 itself. For this reason, the gap 23 caused by the deflection becomes appropriate, and the propagating light 17 emitted from the gap 23 can be easily observed. Moreover, the structure which digs down a part of bottom face of the tray 12 as a means to form the clearance gap 23 may be sufficient.

(Tenth embodiment)
Next, a tenth embodiment will be described with reference to FIG.

FIG. 23 is a diagram illustrating a position where a light source is arranged in the paper thickness measuring apparatus according to the tenth embodiment.

The paper sheet thickness device of the present embodiment has two LEDs 102 and 103 as light sources. L
The ED 102 irradiates light toward the upper surface of the stacked bundle 14. Further, the LED 103 irradiates light toward the side surface 16 different from the side surface 16a to which the light receiving element 19 of the stacked bundle 14 faces and images. The light receiving element 19 irradiates the LEDs 102 and 103 and images the propagation light 17 propagating through the gap 23 and exiting from the side surface 16a. A light shielding member that shields light directly incident on the light receiving element 19 from the light source is omitted.

In the present embodiment, the light receiving element 19 can image the propagating light 17 over a wide range in the stacking direction and the horizontal direction of the stacked bundle 14 by irradiating the LEDs 102 and 103 simultaneously or alternately from the upper surface and the side surface.

The wavelengths of light emitted by the LEDs 102 and 103 may be the same wavelength or different wavelengths. By combining LEDs that emit light of different wavelengths, the propagation light 17 can be imaged over a wider range.

Each of the above embodiments can be variously modified, but all these modifications are included in the present invention without departing from the gist of the present invention.

The figure which shows the structure of the paper sheet thickness measuring apparatus by 1st Embodiment. The figure which shows typically the propagation phenomenon of the light inside a laminated bundle. The figure which imaged the propagation light which reached the 2nd field in the side of a lamination bundle. The flowchart which showed the process sequence which calculates the thickness of paper sheets from the image data of propagation light. The graph of the light quantity distribution along the lamination direction of the propagation light in the side surface of the lamination | stacking bundle | flux obtained by integrating the image of FIG. 3 in a horizontal direction. The functional block diagram of the paper sheet kind discrimination | determination apparatus regarding 1st Embodiment. The figure which shows another structure of the paper sheet thickness measuring apparatus regarding 1st Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 2nd Embodiment. The figure which shows another structure of the paper sheet thickness measuring apparatus regarding 2nd Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 3rd Embodiment. The figure which shows another structure of the paper sheet thickness measuring apparatus regarding 3rd Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 4th Embodiment. The figure which shows another structure of the paper sheet thickness measuring apparatus regarding 4th Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 5th Embodiment. The figure which shows another structure of the paper sheet thickness measuring apparatus regarding 5th Embodiment. The figure which shows another structure of the paper sheet thickness measuring apparatus regarding 5th Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 6th Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 7th Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 8th Embodiment. The figure which extracts and shows the structure of the paper sheet thickness calculation block of the paper sheet thickness measuring apparatus regarding 8th Embodiment. The flowchart which shows the process of the paper sheet thickness measuring apparatus regarding 8th Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 9th Embodiment. The figure which shows the structure of the paper sheet thickness measuring apparatus regarding 10th Embodiment. The graph of the light quantity distribution of the lamination direction obtained by integrating the image of the side surface of the lamination | stacking bundle imaged with the prior art in the horizontal direction. The figure which shows the example of the table which a paper sheet information database hold | maintains.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light source 101 Light quantity adjustment part 11 Irradiation light 12,121 Tray 13 Paper sheet 14 Laminated bundle 15,151 Light shielding member 16, 16a Side surface 17 of laminated bundle 14 Propagation light 18 Imaging lens 19 Light receiving element 20 Paper sheet thickness information Calculation unit 21 Drive unit 22 Ultrasonic vibration mechanism 23 Gap between paper sheets and paper sheet 25 Paper sheet type discrimination unit 26 Paper sheet thickness measuring device 27 Total thickness measuring device 28 of laminated bundle 14 Laminated bundle 14 Total weight measuring device 29 Area information acquisition device 30 for one sheet of paper First region 31 irradiated by light source 10 Second region 102, 103 LED captured by light receiving element
122 Groove 152 Slit 124 Opening 152 Light Guide 200 Light Detection Block 201 Paper Sheet Thickness Calculation Block 202 Drive Control Block 203 Light Adjustment Block 204 Laminated Bundle Whole Thickness Measuring Unit 205 Laminated Bundle Whole Weight Measuring Unit 206 Paper Area information acquisition unit 207 Basis weight calculation block 208 Fixing parameter selection block 209 Paper sheet information database 210 Image formation block 221 Air separation mechanism 223 Spatula 224 Concave structure 2010 Focus area determination means 2011 Thickness calculation means

Claims (24)

From the first region on at least one of the upper surface, the lower surface, and the plurality of side surfaces of the stacked bundle having a top surface, a lower surface, and a side surface that is a surface along a plurality of stacking directions. An irradiating means for irradiating light so as to be incident on the laminated bundle;
Of the light incident on the laminated bundle, the light propagates between the paper sheets, and is emitted from a second region different from the first region on at least one of the plurality of side surfaces of the laminated bundle. A light amount distribution measuring means for obtaining light amount distribution information based on the light amount distribution of the light to be
A paper thickness measuring apparatus comprising a thickness calculating means for calculating the thickness of the paper based on the light quantity distribution information.
2. The paper sheet thickness measuring apparatus according to claim 1, wherein the irradiating unit and the light quantity distribution measuring unit are arranged to face different surfaces.
3. The paper sheet thickness measuring apparatus according to claim 2, wherein the irradiating means irradiates light toward an upper surface or a lower surface of the laminated bundle.
4. The paper sheet thickness measuring apparatus according to claim 3, further comprising a light blocking unit that blocks light directly incident on the light amount distribution measuring unit from the irradiation unit.
5. The paper sheet thickness measuring device according to claim 4, further comprising a light amount control unit for controlling a light amount of light emitted by the irradiation unit.
The light amount control unit controls the irradiation unit to irradiate a plurality of light beams.
6. The light quantity distribution measuring unit obtains the light quantity distribution information for each light quantity.
The paper sheet thickness measuring apparatus as described.
6. The paper sheet thickness measuring apparatus according to claim 5, wherein the light quantity control means controls the light quantity of the light emitted by the irradiation means in accordance with the light quantity distribution information.
6. The paper sheet thickness measuring apparatus according to claim 5, wherein the light quantity distribution measuring means is arranged non-parallel to the side surface.
Further comprising a driving means for changing a relative positional relationship between the irradiation means and the light quantity distribution measuring means,
6. The paper sheet thickness measuring apparatus according to claim 1, wherein the driving unit changes the positional relationship in accordance with the light quantity distribution information.
The thickness calculating unit extracts a peak position with a large amount of light based on the light amount distribution information along the stacking direction, and calculates a thickness of the paper sheet from the peak position. The paper sheet thickness measuring apparatus according to any one of 1 to 5.
5. The paper sheet thickness measuring apparatus according to claim 4, wherein the light shielding means includes first emission means for emitting a part of light from the irradiation means.
Comprising a tray on which the stack is loaded;
5. The paper sheet thickness measuring apparatus according to claim 4, further comprising: a second emitting unit that emits a part of the light reaching the lower surface on a surface of the tray in contact with the lower surface.
6. The paper sheet thickness measuring apparatus according to claim 1, wherein the irradiation unit includes two or more light sources arranged on two or more surfaces of the stacked bundle.
6. The paper sheet thickness measuring apparatus according to claim 1, wherein the irradiating means has two or more light sources and has different emission center wavelengths.
5. The paper sheet thickness measuring apparatus according to claim 4, wherein the irradiating means has two or more light sources arranged at different distances from the edges of the upper surface or the lower surface.
5. The paper sheet thickness measuring device according to claim 4, wherein the irradiating means is a linear light source arranged so as to be non-parallel to the edge of the upper surface or the lower surface.
Further comprising a driving means for changing a relative positional relationship between the irradiation means and the light quantity distribution measuring means,
2. The paper sheet thickness measuring apparatus according to claim 1, wherein the light quantity distribution measuring unit obtains the light quantity distribution information in a plurality of the positional relationships.
2. The paper sheet thickness measuring apparatus according to claim 1, further comprising paper sheet separating means for forming a gap between the paper sheets.
The first region and the second region are on the same side surface of the stacked bundle, and light from the irradiation means is prevented from reaching the second region without entering the stacked bundle. 2. The paper sheet thickness measuring apparatus according to claim 1, further comprising a light shielding means.
The paper sheet thickness measuring device according to claim 1,
An image forming means for forming an image on the paper sheet;
An image forming apparatus comprising: an image control unit that controls the image forming unit based on the calculated thickness information of the paper sheet.
21. The image according to claim 20, wherein the image control unit further includes a basis weight calculating unit that calculates a basis weight of the paper sheet, and controls the image forming unit based on the basis weight information. Forming equipment.
The image forming apparatus according to claim 21, further comprising a discriminating unit that discriminates a type of the paper sheet based on the basis weight.
Irradiation that irradiates light toward at least one of the upper surface, the lower surface, and the plurality of side surfaces of the stacked bundle having a top surface, a lower surface, and a side surface that is a surface along a plurality of stacking directions. Means,
A light amount distribution measuring unit that obtains light amount distribution information by measuring a light amount distribution of light that reaches one side of the plurality of side surfaces different from the surface on which the irradiation unit is disposed;
A paper thickness measuring apparatus comprising a thickness calculating means for calculating the thickness of the paper based on the light quantity distribution information.
Irradiation means for irradiating light toward one side surface of the plurality of side surfaces of the stack of bundles having a top surface, a bottom surface, and a side surface that is a surface along a plurality of stacking directions in which paper sheets are stacked;
A light amount distribution measuring means for obtaining light amount distribution information by measuring the light amount distribution of the light reaching the side surface;
A light shielding means for blocking light directly incident on the light quantity distribution measuring means from the irradiation means and light reflected by the side surface;
A paper sheet thickness measuring device comprising paper sheet thickness calculating means for calculating the thickness of the paper sheet based on the light quantity distribution information.