JP7552811B2 - Paper property detection device, paper information discrimination system, and image forming system - Google Patents

Description

The present invention relates to a paper property detection device, a paper information determination system, and an image forming system.

In recent years, image forming devices such as electrophotographic printers have come to be widely used in the color printing industry. In the field of PP (production print) corresponding to the color printing industry, there is a demand for adaptability to a wider variety of papers than those used in offices. In order to perform high-quality printing on these various papers, there are image forming devices that set multiple items of paper properties stored in a paper feed tray and print under image formation conditions according to the set items.

In order to set various types of paper, there is a technique for detecting the physical properties of the paper used for printing using an external sheet discrimination device, and reflecting the discrimination results in the image forming apparatus (for example, see Japanese Patent Application Laid-Open No. 2003-233664).

The sheet material discrimination device disclosed in Patent Document 1 discloses a configuration in which a sensor unit for detecting paper physical properties irradiates paper with coherent light as irradiation light from a laser irradiation unit, and detects the amount of specularly reflected light and diffusely reflected light from the paper surface. In addition, in the sheet material discrimination device of Patent Document 1, a user manually inserts paper to place it at the measurement position. At that time, an identification means (e.g., a protruding mark) is provided on the housing so that the user can visually identify whether the paper is inserted to the appropriate position.

JP 2015-108514 A

However, in the technology of Patent Document 1, the diameter of the irradiated light is small, and depending on the type of paper, the size and length of the pulp fibers are not uniform, and the surface property distribution varies greatly depending on the position (surface waviness). Therefore, when a small diameter irradiated light is irradiated from a laser irradiation unit as in Patent Document 1, the received light intensity varies greatly depending on the irradiation position, and there is a risk that the accuracy of determining the physical properties of the paper will decrease.

On the other hand, if the irradiation diameter is increased, the size of the entire device will increase. In this case, when the user manually inserts the paper, the entire paper is covered by the housing of the device,
It becomes difficult to check whether the paper has been inserted properly, which is particularly noticeable when determining the physical properties of small paper.

The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a paper physical property detection device that can easily check whether a small-sized recording medium is properly inserted and can accurately detect the physical properties of the recording medium, as well as a paper physical property discrimination system and image forming system equipped with the same.

The above object of the present invention is achieved by the following means:

(1) a second housing having a mounting surface on which a recording medium is placed;
a first housing arranged above the second housing and having a bottom surface facing the placement surface at a predetermined distance;
At least one detection unit that detects a physical property of the recording medium inserted on the placement surface;
Equipped with
a first width w2′ of an end portion of a bottom surface of the first housing on the side of the insertion opening is narrower than a width of a minimum size of paper that can be detected by the paper property detection device;
Paper property detection device.
(2) The paper physical property detection device described in (1) above, wherein the bottom surface of the first housing has a tapered or R-shaped shape in which the width in a width direction perpendicular to the insertion direction of the recording medium narrows toward the insertion opening.
(3) The paper physical property detection device according to (1) or (2) above, wherein the maximum width w1 of the first housing is greater than the width of a minimum size paper.
(4) The paper physical property detection device according to any one of (1) to (3), wherein the maximum width w2 of the bottom surface of the first housing is greater than the first width w2'.

( 5 ) A paper physical property detection device as described in any one of (1) to (4) above, further comprising a pressing mechanism that includes a pressing member and presses the recording medium inserted on the placement surface from below toward the bottom surface by lifting the pressing member upon detection.

( 6 ) The detection unit includes a second detection unit that is disposed inside the first housing, has an opening provided on the bottom surface as a detection area, and detects physical properties of the surface of the recording medium within the detection area;
The second detection unit is a paper physical property detection device described in any of (1) to (5) above, which is equipped with an emitter that irradiates light onto the detection area, a first light receiving unit that detects the amount of specularly reflected light that is specularly reflected on the surface of the recording medium in the detection area, and at least one second light receiving unit that detects the amount of diffusely reflected light that is diffusely reflected at at least one reflection angle on the surface of the recording medium in the detection area .

( 7 ) The paper physical property detection device described in (6) above, wherein the second detection unit is configured so that the irradiation diameter of the light irradiated from the light source of the light emitting unit in the detection area is set to an irradiation diameter that reduces the influence of unevenness in the fiber orientation of the recording medium .

(8) A paper physical property detection device described in any one of (1) to (7) above, wherein the detection unit includes a first detection unit that detects the basis weight of the recording medium, a second detection unit that detects the surface properties, and a third detection unit that detects the thickness as the physical properties.

(9) The second detection unit is a surface sensor, and a second opening provided on the bottom surface serves as a second detection area, and the paper physical property detection device described in (8) above is equipped with an emitter that irradiates light onto the second detection area, a light receiver that detects the amount of specularly reflected light that is specularly reflected on the surface of the recording medium in the second detection area, and at least one light receiver that detects the amount of diffusely reflected light that is diffusely reflected at at least one reflection angle on the surface of the recording medium in the second detection area.

(10) The paper physical property detection device described in (8) or (9) above, wherein the first detection unit is a basis weight sensor, and two opposing first openings provided on the bottom surface and the placement surface respectively form a first detection area, and the paper physical property detection device is equipped with one or more light-emitting units that irradiate light to the first detection area, a light- receiving unit that detects the amount of transmitted light that has passed through the recording medium in the first detection area, and a light-receiving unit that detects the amount of reflected light reflected on the surface of the recording medium in the first detection area.

(11) The third detection unit is a paper thickness sensor,
a contact portion that is biased to come into contact with the recording medium pressed by the pressing member and the bottom surface;
A paper physical property detection device described in any one of (8) to (10) above, comprising a position detection unit that measures the height direction position of the contact portion that contacts the recording medium, which changes depending on the thickness of the recording medium.

( 12 ) Further, a media set sensor is provided on the back side of the placement surface in the direction of insertion of the storage medium , for detecting the presence or absence of the recording medium,
a wall against which the recording medium is abutted is provided at the rear side of the mounting surface;
The paper physical property detection device described in (5) above, wherein the media set sensor determines whether the recording medium has hit the wall, and then the pressing mechanism is activated to press the recording medium with the pressing member, and then detection is performed by one or more of the detection units.

( 13 ) The detection unit includes a first detection unit that detects the basis weight of the recording medium, a second detection unit that detects surface properties, and a third detection unit that detects a thickness as the physical property,
The paper physical property detection device described in ( 12 ) above, wherein the detection performed while the recording medium is held down is detection of the surface property of the recording medium by a second detection unit, and detection of the thickness by a third detection unit.

( 14 ) A paper physical property detection device according to any one of (1) to ( 13 ) above;
a control unit that determines the paper type of the recording medium using the detection result obtained from the paper physical property detection device.

( 15 ) A paper physical property detection device according to any one of (1) to ( 14 ) above;
an image forming apparatus for forming an image on a recording medium;
a control unit that determines paper characteristics of the recording medium using a detection result obtained from the paper physical property detection device,
the control unit sets image forming conditions of the image forming apparatus using the determined paper characteristics of the recording medium.
Image forming system.

( 16 ) The image forming system described in ( 15 ) above, wherein the minimum size of the recording medium that can be detected by the paper physical property detection device is set to correspond to the minimum size of the recording medium that can be transported by the image forming device.

The paper physical property detection device according to the present invention includes a second housing having a mounting surface on which a recording medium is placed, a first housing arranged above the second housing and having a bottom surface facing the mounting surface at a predetermined distance, and at least one detection unit for detecting the physical properties of the recording medium inserted on the mounting surface, and the shapes of both sides formed by the second housing and the first housing are concave when viewed from the insertion direction of the recording medium. By doing so, it is possible to easily check whether a recording medium is properly inserted even in the case of a small-sized recording medium, and the physical properties of the recording medium can be detected with high accuracy.

1 is a diagram showing a schematic configuration of a paper information discrimination system including a paper physical property detection device according to a first embodiment; FIG. 1 is a block diagram showing a configuration of a paper information discrimination system. FIG. 2 is an external perspective view of the paper property detection device. FIG. 2 is a side view of the paper property detection device. FIG. 2 is a side view showing the internal configuration of the paper property detection device. FIG. 2 is a perspective view showing an internal configuration of a paper property detection device. FIG. 4 is a perspective view showing an example of a configuration of a paper pressing mechanism. 4 is a schematic diagram showing the positions of surface sensors and the like in the upper housing. FIG. FIG. 2 is a front view of the paper property detection device. 4 is a bottom view of the upper housing showing the size of the paper physical property detection device. FIG. FIG. 2 is a schematic diagram showing a state in which paper is inserted into the paper physical property detection device. 12A and 12B are diagrams for explaining the positioning of each detection unit, where FIG. 12A is a bottom view of the upper housing, FIG. 12B is a top view of the lower housing, and FIG. 12C is a schematic top view showing the detection areas, etc. FIG. 2 is a cross-sectional view of a surface sensor. FIG. 2 is a perspective view showing an internal configuration of a surface sensor. FIG. 2 is a schematic cross-sectional view of the surface sensor showing a state in which the shutter is open. 3 is a schematic diagram showing the arrangement positions of a light-emitting unit and a light-receiving unit. FIG. 4 is a schematic cross-sectional view showing the incident angle of irradiated light and the arrangement angle of a light receiving portion. FIG. FIG. 2 is a schematic diagram showing the state of pulp fibers on the surface of paper. FIG. 2 is a schematic diagram showing the microscopic variation in fiber orientation angle of paper. 4A and 4B are schematic diagrams showing the surface distribution of a sheet of paper and the diffusion state of irradiated light. 3 is a schematic diagram showing the irradiation diameter of irradiation light and the arrangement position of a light emitting unit (light source). FIG. 11 is a graph showing variations in the amount of detected light due to differences in the irradiation diameter when multiple points are measured on the surface of a sheet. FIG. 2 is a schematic diagram showing a configuration of a basis weight sensor. 4 is a flowchart showing a measurement process performed by the paper physical property detection device. 11 is a subroutine flowchart showing a paper physical property detection process (step S40). 25B is a subroutine flowchart showing a process subsequent to the process of FIG. 25A. FIG. 11 is a diagram showing the overall configuration of an image forming system including a paper physical property detection device according to a second embodiment. 4 is a flowchart showing a printing process of the image forming system. 13 is a subroutine flowchart showing a paper sheet determination process (step S612). FIG. 13 is a control block diagram showing the determination process (S612). 13 is an example of an operation screen showing a determination result (paper type/basis weight classification). 13 is an example of an operation screen showing a determination result (registered profile). 13 is an example of an operation screen displayed on an information processing device in the first modified example. 13 is an example of an operation screen displayed on an information processing device in the first modified example. 13 is an example of an operation screen displayed on an information processing device in the first modified example. 4 is a flowchart showing a measurement process and a paper type determination process performed in the paper information discrimination system (first example). 11 is a flowchart showing a measurement process and a paper type determination process performed in the paper information discrimination system (second example).

Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated description will be omitted. In addition, the dimensional ratios in the drawings are exaggerated for the convenience of explanation, and may differ from the actual ratios. In the drawings,
The vertical direction is the Z direction, the front and rear direction of the paper property detection device is the Y direction, and the direction perpendicular to these Y and Z directions is the X direction. The positive Y direction is the paper insertion direction, and the negative Y direction is the removal direction. The X direction is also called the width direction. In this embodiment, the recording medium includes printing paper (hereinafter simply referred to as paper) and various films. In particular, paper includes those made using mechanical pulp and/or chemical pulp derived from plants. Types of recording media include coated paper such as gloss coated paper and matte coated paper, and uncoated paper such as plain paper and fine paper.

FIG. 1 is a diagram showing a paper information discrimination system 1 including a paper property detection device 20 according to a first embodiment.
FIG. 2 is a block diagram showing the configuration of the paper information discrimination system 1000. FIG.

As shown in Fig. 1, the paper information discrimination system 1000 includes an information processing device 10 and a paper physical property detection device 20. These are communicatively connected by a USB cable or the like. In principle, the operation of the paper physical property detection device 20 is performed by the display unit of the information processing device 10, which functions as a host,
This is done through an input unit (user interface screen, keyboard, etc.), but it may also be done through a display unit or input unit provided in or attached to the paper physical property detection device 20 itself.

(Information processing device 10)
The information processing device 10 functioning as a host is a so-called PC (Personal Computer).
The information processing device 10 is an information processing device (computer) that controls the paper physical property detection device 20 in response to user operations. The information processing device 10 includes a control unit 11, which is composed of a CPU, RAM, ROM, etc., a storage unit 12, and a communication unit 15. The information processing device 10 communicates with the paper physical property detection device 20 via the communication unit 15. The control unit 11 executes various processes by executing programs stored in the ROM and the storage unit 12, and controls each unit of the device and performs various calculation processes according to the programs.

(Paper property detection device 20)
The paper physical property detection device 20 becomes ready in response to a request from the host, and in this state detects the physical properties of the paper 90 that is manually inserted by the user. The detection result is sent to the host side.

As shown in FIG. 2, the paper physical property detection device 20 includes a communication unit 25, a control unit 26, a memory unit 27, a display unit 28, a first media set sensor 30, a second media set sensor 40, a basis weight sensor 50, a surface property sensor 60, a paper thickness sensor 70, and a shutter opening/closing mechanism drive unit 655.
, a paper pressing mechanism drive unit 88 , and pressing mechanism position detection sensors 891 and 892 .
The basis weight sensor 50, the surface property sensor 60, and the paper thickness sensor 70 function as a "first detection unit," a "second detection unit," and a "third detection unit," respectively.
USB cable, wired LAN (Local Area Network), wireless LAN (
The control unit 26 communicates with other devices such as the information processing device 10 via, for example, a LAN conforming to the IEEE 802.11 standard. The control unit 26 executes various processes by executing programs stored in the ROM or the storage unit 27, and controls each part of the device and performs various calculation processes according to the programs. The display unit 28 is, for example, a plurality of LEDs, and indicates the state of the paper physical property detection device 20 by a combination of lighting states. Note that a liquid crystal display may be used as the display unit 28. The display unit 28 is, for example, disposed on the upper front side of the upper housing 21 (described later).
As another example, a speaker that emits warning sounds or operation sounds may be provided. A measurement start button that accepts a measurement start instruction may be provided, for example, on the upper front side of the upper housing 21. A light (LED) that weakly illuminates the paper insertion port on the upper housing 21 side near the paper insertion port so as not to affect the measurement may be provided.
Alternatively, a guide indicator (LED) indicating the paper entrance may be provided near the paper insertion opening on the placement surface S2 of the lower housing 22 (both of which will be described later). Other configurations will be described in detail later.

(Overall configuration of paper property detection device 20)
The overall configuration of the paper physical property detection device 20 will be described below with reference to Figures 3 to 6 in addition to Figure 2. Figures 3 and 4 are an external perspective view and a side view, respectively, of the paper physical property detection device 20. Figures 5 and 6 are a side view and a perspective view showing the internal configuration of the paper physical property detection device 20.

As shown in these figures, the paper property detection device 20 is made up of an upper housing 21 and a lower housing 22.
The upper housing 21 and the lower housing 22 are respectively referred to as the “first housing” and the “second housing.”
The upper surface of the lower housing 22 is a placement surface S2 on which the paper 90 inserted by the user is placed. The bottom surface S1 of the upper housing 21 faces the placement surface S2 with a predetermined gap therebetween. The space between the bottom surface S1 and the placement surface S2 is the paper passage area 200. When measuring, the user manually inserts the paper 90 into the paper passage area 200 from the insertion opening. At this time, the paper 90 moves along the insertion direction (Y direction) while sliding on the placement surface S2, and stops when it hits the back wall a3. The wall S3 spreads along the XZ plane and extends in the X direction (width direction).

The upper housing 21 includes a first upper portion 211 and a second upper portion 21
2. The bottom surface S1 is included in the second upper portion 212. The second upper portion 212 has a tapered shape (
or R-shaped) (see FIG. 9 described later).

As shown in Fig. 5 and Fig. 6, in the paper physical property detection device 20, a basis weight sensor 50, a first media setting sensor 30, a surface property sensor 60, a paper thickness sensor 70, and a second media setting sensor 40 are arranged in this order from the insertion opening toward the rear side.
is mounted on a pressure plate 81 of the paper pressing mechanism 80, and moves as the pressure plate 81 moves up and down. A board 20b1 on which components of the control unit 26 and memory unit 27 are mounted is disposed at the rear of the housing. The upper housing 21 houses a basis weight sensor 50, a first media set sensor 30, a surface property sensor 60, and a second media set sensor 40. The lower housing 22 houses a basis weight sensor 50, a paper thickness sensor 70, and a paper pressing mechanism 80. The basis weight sensor 50, which is a transmissive optical sensor, is disposed between the upper housing 21 and the lower housing 22.
It is placed across both.

(Basis weight sensor 50, surface property sensor 60, paper thickness sensor 70)
The basis weight sensor 50 is a transmission type optical sensor that detects the basis weight of the paper. The basis weight sensor 50 has a light emitting section and a light receiving section, and measures the basis weight based on the attenuation of light passing through the paper 90.
For example, a first substrate 50b1 having a light emitting unit mounted thereon (lower housing 22) and a second substrate 50b2 having a light receiving unit mounted thereon (upper housing 21) are disposed across the sheet passing area 200 of the basis weight sensor 50.
The detailed configuration of the basis weight sensor 50 will be described later (see FIG. 23).

The first media setting sensor 30 is, for example, a reflective sensor, and includes a light emitting section that irradiates light toward a detection area (detection area a30 described later) and a light receiving section that receives reflected light from the paper 90. These are mounted on a board 31 disposed above the paper passage area 200 (upper housing 21).
It will be installed in.

The surface property sensor 60 is a reflective optical sensor that detects the surface property of the paper. The surface property sensor 60 includes a first substrate 60b1 on which a light emitting unit is mounted, a second substrate 60b2 on which a first light receiving unit is mounted that receives specularly reflected light from the paper 90 of the light irradiated by the light emitting unit, and a third substrate 60b3 on which a second light receiving unit is mounted that receives diffusely reflected light of the irradiated light, and these are disposed above the paper passing area 200 (upper housing 21). A detailed configuration of the surface property sensor 60 will be described later (see FIGS. 13 to 22).

The paper thickness sensor 70 is movable in the vertical direction within a predetermined range, and is biased upward. The contact portion 72 comes into contact with the object to be measured (the lower surface or bottom surface S1 of the paper 90).
2, and a position detection unit that detects the movement of the arm. The position detection unit is composed of an encoder and a light emitting/receiving unit. This light emitting/receiving unit is mounted on a substrate 71 and disposed below the paper passing area 200 (lower housing 22). A contact unit 72 (see FIGS. 5 and 7) of the paper thickness sensor 70 is mounted on a pressing plate 81 of a paper pressing mechanism 80. As described below, in a state in which the pressing plate 81 is lifted toward the bottom surface S1 of the upper housing 21, the thickness of the paper 90 is detected from the difference (μm) in the height of the contact unit 72 when the paper 90 is present and when the paper 90 is not present.

The second media setting sensor 40 has the same configuration as the first media setting sensor 30 , and these are mounted on a substrate 41 arranged above the paper passage area 200 .

(Paper Pressing Mechanism 80)
7 is a perspective view showing an example of the configuration of the paper pressing mechanism 80. As shown in the figure, the paper pressing mechanism 80 includes a pressing plate 81 having a pressing surface S8, a support member 82, an action shaft 83, a spring 84, a cam 85, a rotating shaft 86, a gear train 87, a drive motor 88, a height position detection sensor 891,
2 for the position detection sensor 892. The pressing plate 81 functions as a pressing member. When not measuring (before measurement), the pressing plate 81 is lowered to a predetermined position (home position) and does not prevent the paper 90 from being inserted into the paper passing area 200. When measuring, the pressing plate 81 is lifted and a predetermined biasing force is applied between the pressing plate 81 and the bottom surface S1 of the upper housing 21 to press the paper 90 against the bottom surface S1.
0 is pressed (clamped). The pressing plate 81 has an upper surface (pressing surface S8 (shown in gray in the figure)) parallel to the XY plane. The central area of the pressing surface S8 corresponds to the detection area a60 of the surface sensor 60. The contact portion 72 of the paper thickness sensor 70 is disposed on the end side of the pressing surface S8. During measurement when the cam 85 is not acting, the pressing plate 81 and the integral support member 82 that supports it move in the upward direction (the positive side of Z) indicated by the arrow, that is, toward the bottom surface S1, due to the biasing force of the spring 84, and the paper 90 is clamped and pressed between the pressing plate 81 and the bottom surface S1. This allows the surface of the paper 90 to be stably placed on the reference surface (see FIG. 16, etc., described later). On the other hand, when measurement by the surface property sensor 60 is not being performed, the driving motor 88 rotates a predetermined angle, and the driving force rotates the cam 85 via the gear train 88 and the rotating shaft 86, causing the cam 85 to press the action shaft 83 downward. As a result, the pressure plate 81 and the support member 82 move downward against the biasing force of the spring 84. The height of the pressure plate 81 is detected by height position detection sensors 891, 892 which detect the position of the encoder attached to the end of the rotating shaft 86.
These sensors detect whether the pressure plate 81 is in the pressing position (high position) or the release position (low position). When measurement using the surface sensor 60 or the like is not being performed, the corner of the pressure plate 81 on the upstream side in the conveying direction is shaped to have a beveled cut portion (inclined surface) so as not to prevent the user from inserting the paper 90, i.e., so as not to get caught on the corner of the paper 90, and the upper surface of the pressure plate 81 (excluding the cut portion) is in contact with the placement surface S of the lower housing 22.
It is located at the same height as 2 or slightly lower.

(Size of Paper Property Detection Device 20)
Next, the size of each component of the paper physical property detection device 20 will be described with reference to Figs. 8 to 11. Fig. 8 is a schematic diagram showing the arrangement of each detection unit, such as the surface property sensor 60, in the upper housing 21. Figs. 9 and 10 are a front view for explaining the size of the paper physical property detection device 20 and the detection area of each detection unit, and a bottom view of the upper housing 21. Fig. 10 is a bottom view of the A in Fig. 9.
This corresponds to the cross-sectional view taken along line -A.

As shown in FIG. 8, the longitudinal direction of the surface sensor 60 is in the X direction (
The surface property sensor 60 is arranged along the width direction (width direction) of the paper 90. The surface property sensor 60 has a large irradiation diameter of 6 mm or more so that the influence of non-uniform fiber orientation of the paper 90 is reduced as described below. Therefore, the overall size of the surface property sensor 60 is large in order to ensure a wide irradiation area (detection area a60 described below). For example, the overall length of the surface property sensor 60 in the longitudinal direction (X direction) is a maximum of 120 mm, and the first upper part 211 of the upper housing 21 is set to a size that can accommodate this.

In FIG. 9 and FIG. 10, w1 to w4, w2', and L1 are defined as follows.
Regarding the length in the width direction at the center c1 in the depth direction (Y direction),
w1: width (maximum width) of the first upper portion 221 of the upper housing 21,
w4: width of the upper end side of the second upper portion 212,
w2: width of the lower end side (corresponding to the bottom surface S1) of the second upper portion 212,
w3: the width of the placement surface S2 of the lower housing 22.
In addition, regarding the length of the insertion opening end in the depth direction,
w2': the width of the end of the lower end side (corresponding to the bottom surface S1) of the second upper portion 212 on the insertion opening side.
L1: the length in the depth direction on the lower end side of the second upper portion 212. Note that w2' is the region where the R-shape ends, that is, the length of the side where the ridge line runs along the width direction.

(Width and length examples)
As described above, the first upper portion 211 has a width w1>120 mm so as to accommodate the surface sensor 60 .

The minimum size of the paper 90 that can be measured by the paper property detection device 20 is a postcard size (1
The dimensions are set to 100 mm x 135 mm so that a paper size (00 mm x 148 mm) can be measured. That is, the minimum size of the paper 90 is 100 mm in the width direction. It is preferable that the position of the paper 90 can be visually confirmed when the user inserts the paper 90 into the paper passage area 200. For this reason, the second upper portion 212 of the upper housing 21 is formed so that the width of the bottom surface S1 of the second upper portion 212 of the upper housing 21 is as narrow as possible.
As shown in FIG. 9, the upper part 212 is tapered (or R-shaped) downward when viewed from the insertion direction (Y direction). That is, when viewed from the insertion direction (FIG. 9), the shape (profile) of both sides formed by the first and second housings 21 and 22 is concave. Also, as shown in FIG. 10, when viewed from the bottom, the shape is tapered (or R-shaped) in which the width in the width direction narrows from the back side toward the insertion opening. Also, as shown in FIG. 4, when viewed from the side (viewed from the X direction), the shape of the insertion opening in the area from the bottom surface S1 of the upper housing 21 (second upper part 212) to the front surface (front) is tapered (or R-shaped) toward the insertion opening side of the paper S so that the paper S can be easily inserted. This makes it easier to see the placement surface S2 of the lower housing 22 from the insertion opening side.

For this reason, w1>w2 and w2>w2' are satisfied. Also, w3≧w2 is set so that it is possible to visually confirm that the paper 90 has been placed on the placement surface s2.

As a specific example of these values, w1=140m
m, w2 = 114 mm, w2' = 85 mm, w3 = 136 mm. Also, L1 = 105
mm.

By making both sides concave in this way, the position of the paper 90 placed on the placement surface S2 can be easily confirmed visually. Fig. 11 is a schematic diagram showing a state in which a normal size paper 90 and a small size paper 90 are inserted on the placement surface S2.
Even if the thickness is 0, both sides of the paper 90 can be easily visually confirmed from the side.

In addition, when viewed from the bottom (FIG. 10), the width of the bottom surface S1 narrows toward the insertion opening.
By making the shape (or tapered shape) W2'< 100 mm (minimum size paper width)
Therefore, the user can visually confirm the position of the inserted paper 90 regardless of the size of the paper that is inserted.

(Configuration of each detection unit)
12 to 23, the configurations of each detection unit, particularly the surface property sensor 60 and the basis weight sensor 50, will be described in detail below. In particular, for the surface property sensor 60, a configuration in which an irradiation diameter is set to reduce the influence of the non-uniformity of the fiber orientation of the paper 90 described above will be described.

FIG. 12 is a diagram for explaining the arrangement of the detection units. FIG. 12(a) shows the upper housing 2.
12(a) is a bottom view of the lower housing 1, and FIG 12(b) is a top view of the lower housing 22. FIG 12(c) is a schematic top view showing the detection region and the like.

12C, in the paper physical property detection device 20, from the insertion opening toward the back side, there are arranged a detection area a50 (first detection area) of the basis weight sensor 50, a detection area a30 of the first media setting sensor 30, a detection area a60 (second detection area) of the surface property sensor 60, a detection area a70 (third detection area) of the paper thickness sensor 70, and a detection area a40 of the second media setting sensor 40. In addition, the pressing area a80 is a pressing surface S8 of the pressing plate 81.
Corresponds to.

As shown in FIG. 12(b), the detection area a30 of the first media set sensor 30 has a hole, and when no paper 90 is present, the light emitted from the first media set sensor 30 is absorbed into the hole and is not reflected. The second media set sensor 40 has a similar configuration. The first and second media set sensors 30, 40 are arranged at different positions in the X direction so that they are oblique to each other. This allows these sensors to detect paper 90 even when it is inserted at an angle (maximum of about 15°). The second media set sensor 40 is arranged in a position close to the wall S3, and the second media set sensor 40 is arranged in a position close to the wall S4.
By detecting 0, it is detected that the paper 90 hits the wall S3.

The pressure plate 81 has an opening corresponding to the detection area a70, and the contact portion 72 of the paper thickness sensor 70 is disposed inside the opening.

The detection area a60 of the surface sensor 60 is an opening provided in the bottom surface S1, and the pressing area a80 is disposed so as to surround the detection area a60. As a result, when the pressing plate 81 presses the paper 90, the entire periphery of the detection is covered.
When measurement is not being performed, the shutter 651 is closed by a shutter 651. When measurement is performed, the shutter 651 is opened by an opening/closing mechanism 65, as described later.

(Reflectance)
Moreover, the placement surface S2 is preferably made of a material with a reflectance of 35% or less (in the visible light region) in order to ensure the visibility of the white paper 90. The white paper 90 has the lowest reflectance of any paper type, such as rough paper/book paper used in books and comic magazines, and has a reflectance of 50 to 65%. In order to easily recognize the placement surface S2, which serves as the background, and the paper 90 placed thereon, it is preferable that the brightness difference between them is 1 or more. A reflectance of 50% corresponds to a brightness of 7.5, and in order to ensure a brightness difference of 1 or more from this brightness, that is, to ensure a brightness of 6.5 or less, the reflectance should be 35% or less. From this, the reflectance of 35% or less can be derived. For example, materials with a reflectance of 35% or less can be used not only for black, but also for red, green, blue, gray, and intermediate colors thereof. Among these, black is more preferable because it has a reflectance of about 4%, and therefore can ensure a large brightness difference. By forming the placement surface S2 from such a material with low reflectance, good visibility can be ensured even for paper of a type with low reflectance.

(Configuration of Surface Sensor 60)
Fig. 13 is a cross-sectional view of the surface property sensor 60, and Fig. 14 is a perspective view showing the internal configuration of the surface property sensor 60. Note that in Fig. 14, the illustration of a cover (housing 61) that covers the entire surface property sensor 60 is omitted.

As shown in these figures, the surface property sensor 60 includes a housing 61 , a light emitting section 62 , a collimating lens 63 , a plurality of light receiving sections 64 (light receiving sections 641 , 642 ), and an opening/closing mechanism 65 .
The housing 61 covers the other components and blocks external light. The housing 61 is not on the bottom surface, and the plate constituting the bottom surface S1 of the upper housing 21 functions as a member that covers the bottom surface of the surface sensor 60 when the sensor is attached.
Details of the light receiving units 641 and 642 will be described later. In this embodiment, a collimator lens is used as an optical system between the light source and the irradiation area, but a lens other than a collimator lens may be used. For example, when a bullet-shaped LED is used, an optical lens is mounted on the LED. A convex lens or the like may be placed between the LED and the collimator lens.

The opening and closing mechanism 65 includes a shutter 651, a connection portion 652, a rotating shaft 653, and a worm gear 65
4, and a drive motor 655. The power of the drive motor 655 is provided by a worm gear 6
54, the rotation shaft 653, and the connection portion 652 are transmitted to the shutter 651.
51 moves around a rotation shaft 653 in the direction of the arrow. An opening corresponding to the detection area a60 is provided in the plate constituting the bottom surface S2 of the upper housing 21. An opening corresponding to the pressing area a80 is also provided in the plate constituting the placement surface S2 of the lower housing 22 so that the pressing plate 811 can move up and down. Figures 13 and 14 show a state in which the paper characteristics (physical property values) of the paper 90 are not measured, and in this case, the opening is closed by a plate-shaped shutter 651 which is a flat plate member. The opening and closing operation of the opening of the shutter 651 is performed by the control unit 26 controlling the drive motor (shutter opening and closing mechanism drive unit 655).

15 is a schematic cross-sectional view of the surface property sensor 60 with the shutter open. This Fig. 15 shows the state when measuring the paper properties. In Fig. 15, the shutter 65
The description of the configuration of the opening/closing mechanism 65 other than the opening 60 a60 is omitted.
The shutter 651 has a generally rectangular shape, and the size of the hole is, for example, several tens of mm in the horizontal direction (X direction) and a dozen or so mm in the vertical direction (Y' direction). In order not to impede the transport (insertion) of the paper 90 within the paper passage area 200, a plurality of ribs r1 (see FIG. 15) are provided on the lower surface of the shutter 651. Each rib r1 is
The rib r1 is inclined along the insertion direction so that it recedes on the upstream side of the insertion direction relative to the bottom surface S1 and protrudes slightly on the downstream side. This rib r1 allows the user to insert the paper 90 smoothly without getting caught. In addition, a reference plate 6501 is attached to the upper surface of the shutter 651 as a calibration member. The reference plate 6501 is, for example, a white plate with a predetermined surface property, and the surface property sensor 60 is calibrated by measuring the reference plate 6501 of the shutter 651 in the closed state before measuring the paper characteristics.

FIG. 16 is a schematic diagram showing the arrangement of the light-emitting unit 62 and the light-receiving units 64.
7 is a schematic cross-sectional view showing the angle of incidence (irradiation angle) of the light emitted by the light-emitting unit 62 and the arrangement angle of the light-receiving unit. In this embodiment, the arrangement angle of the light-emitting unit 62 is set so that the angle of incidence of the irradiated light with respect to the reference plane is 75°. This angle of incidence of 75° is the angle used in measuring white paper glossiness according to JIS, and is an angle that is less affected by the color of the object to be measured. The reference plane is a virtual plane corresponding to the bottom surface S1 of the upper housing 21, and during measurement, the surface of the paper 90, which is the object to be measured, is placed on the reference plane. The light-emitting unit 62 is placed on a substrate 60b1. The light-emitting unit 6
2 is an LED that emits light of a predetermined wavelength (for example, an average wavelength of 445 nm or more and 500 nm or less).
The light emitted from the light source (point light source) is converted into approximately parallel light by a collimator lens 63 and irradiated onto the irradiation area. The irradiation area corresponds to a detection area a60 when viewed from the Z direction, and the center (optical axis) of the irradiation area intersects with a reference plane parallel to the XY plane at an intersection p1. A surface-emitting LED or a bullet-shaped LED may be used as the light-emitting unit 62. In addition, when a bullet-shaped LED is used, a desired irradiation diameter (also called a beam diameter) can be obtained by designing a lens that matches the directivity of the bullet type.

Each of the light receiving sections 64 includes a light receiving element such as a photodiode or a phototransistor, and includes a first light receiving section 64 (light receiving section 641) that receives specularly reflected light from the irradiated area, and one or more second light receiving sections 64 (light receiving sections 642) that receive diffusely reflected light from the irradiated area. As shown in FIG. 16 (for angles of incidence and reflection, see also FIG. 17),
The first light receiving section 641 is disposed at a reflection angle of 75° corresponding to the incident angle of 75° of the light emitting section 62, and receives specularly reflected light. The second light receiving section 642 can be disposed at any reflection angle within a range of reflection angles of 0° or more and less than 90°, except for the position of 75°, and receives diffusely reflected light. The preferred positions for the positions are reflection angles of 60°, 30°, and 0°, and more preferably 60°.
There are two locations, 0° and 30°, or one location, 60°. The examples of Figures 13, 15, and 16 show an example in which a first light receiving unit 641 for receiving specularly reflected light with a reflection angle of 75° and a second light receiving unit 642 for receiving diffusely reflected light with a reflection angle of 30° are arranged. In these figures, the light receiving unit 641 is arranged on the substrate 60b2, and the light receiving unit 642 is arranged on the substrate 60b3.

The housing 61 is provided with openings a3 and a4 on the light receiving paths of the light receiving units 641 and 642. The openings a3 and a4 have the same structure, so the structure of the opening a3 will be described below as a representative example. The opening a3 is a circular slit with a diameter of 3 mm when viewed from the intersection p1 side, for example.

(Irradiation diameter)
Fig. 18 is a schematic diagram showing the variation in the microscopic fiber orientation of paper, and Fig. 19 is a schematic diagram showing the state of pulp fibers on the surface of paper. Generally, paper is made by randomly intertwining pulp fibers extracted from plants such as wood in all directions (isotropically), which results in an uneven surface and a distribution of surface irregularities (also known as "formation" in industry jargon). This formation varies depending on the length and thickness of the pulp fibers in the paper. Compared to Fig. 18A, Fig. 18B shows greater unevenness. Pulp fibers derived from coniferous and broadleaf trees are used as the material for paper, and the pulp fibers have an average length of 3.32 mm to 0.79 mm (maximum of about 5.7 mm),
The width (thickness) is 39 μm to 19 μm on average (maximum about 97 μm) (Reference: Paper "Measurement of Paper Surface Shape" (Paper and Pulp Technology Association Journal, Vol. 18, No. 2, February 1964), by Yukinori Hata, Central Research Institute, Oji Paper Co., Ltd.). In addition, as shown in Figure 19, the surface properties become non-uniform due to the length of the pulp fibers and the occurrence of bundling fibers (fiber entanglement) between the pulp fibers.

Therefore, if the irradiation diameter is narrowed too much compared to the length of the pulp fibers or the shape of the bundled fibers, the position of the reflected light on the paper, i.e., the unevenness of the paper surface, will cause differences in the amount of detected specular reflected light and diffused light, resulting in a sensor that is highly sensitive to the paper surface condition even on the same paper surface. This will cause errors in the amount of reflected light, and if the data containing these errors is used to determine the paper type, there is a risk of misidentifying the paper type. For example, matte coated paper will be misidentified as fine paper.

FIG. 20 is a schematic diagram showing the surface distribution of a sheet and the diffusion state of the irradiated light.
20(b) is a schematic diagram showing the irradiation diameter of the irradiation light and the arrangement position of the light emitting unit 62, FIG. 20(a) is a diagram showing a case where the irradiation diameter is small, and FIG. 20(b) is a diagram showing a state where the irradiation diameter is large. In this embodiment, in view of such a situation, irradiating a wide area as shown in FIG. 20(b) can reduce the influence of the distribution of the paper surface properties, rather than irradiating a narrow area as shown in FIG. 20(a). In other words, by setting the irradiation diameter of the irradiation light to a size that irradiates an area sufficiently larger than the area where the pulp fibers that cause the distribution of the paper surface properties are intertwined, the amount of reflected light of the paper surface properties including the unevenness of the paper surface can be averaged, and the influence of the distribution of the paper surface properties can be reduced. Specifically, the irradiation diameter in the irradiation area is set to a value equal to the maximum length of the pulp fibers described above, 5.
The irradiation diameter is set to 6 mm or more, which is larger than 7 mm. The irradiation diameter here is the diameter of the light (beam) on a plane perpendicular to the optical axis at the intersection p1 where the optical axis intersects with the irradiation surface (reference surface). In general, the focal length of the lens, the size of the light source, and the spread of the irradiation diameter are
It is expressed by the formula (1): (Spread of irradiation diameter) ≒ (Size of light source) / (Focal length of lens). From this formula, the longer the focal length, the closer the light can be to approximately parallel light, but the amount of light emitted decreases, so it is necessary to make the lens brighter. The formula for the brightness of a lens is generally as follows:
(Lens brightness) = (Lens focal length) / (Lens diameter)... (2) From formula (1), it is possible to widen the irradiation diameter by having a certain size of the light source. In other words, in order to set the irradiation diameter and irradiation light amount, the above-mentioned conditions are obtained from the optical design.

In this embodiment, the irradiation diameter is set to φ13 mm as shown in FIG. 21A. In order to achieve such an irradiation diameter, the lens specifications are set to a focal length of 20 mm based on optical design and optical simulation.
When the diameter of the light emitting portion 62 is 7.7 mm and the lens diameter is 7.5 mm, the distance from the light emitting portion 62 to the intersection point p1 is in the range of 50 to 70 mm, for example, 60 mm. When designed in this way, the irradiation diameter is, as shown in FIG. 21B, when viewed from above (on the XY plane), the short axis (length in the Y direction)
The diameter is φ13 mm, and the major axis (length in the X direction) is 50.2 mm (=13/cos 75°). By setting the irradiation area at this level (512.6 mm2), it becomes possible to detect the amount of specularly reflected light and diffused light with low sensitivity to the distribution of the surface properties of the paper, thereby reducing the influence of non-uniformity in fiber orientation. Note that in this embodiment, the light source 62 may be located at the focal length of the collimating lens 63 as in Example 1, but in order to ensure robustness in the installation accuracy during manufacturing,
It is preferable to place it inside the focal point as in the second embodiment.

22 is a graph showing the variation in the amount of detected light due to the difference in the irradiation diameter when measuring multiple points on the paper surface. The graph shows the variation in the amount of detected light due to the difference in the irradiation diameter between two levels, φ13 mm and φ1 mm, for sample N.
The figure shows the variation in the amount of detected light when measuring 10 different positions on a single sheet of plain paper, from No. 0.1 to No. 10. The ±8% shown in the figure is the threshold value at which false detection in paper discrimination is likely to occur, as determined through verification. If the irradiation diameter is small, it is easily affected by the texture of the paper 90,
As shown in Fig. 22, the variation in erroneous detection is smaller for an irradiation diameter of φ13 mm than for an irradiation diameter of φ1 mm, and is within the threshold of ±8%.

(Basis weight sensor 50)
23 is a schematic diagram showing the configuration of the basis weight sensor 50. The basis weight sensor 50 is a transmission type optical sensor that detects the basis weight of the paper, and includes a light emitting section and a light receiving section, and measures the attenuation (transmittance) of light that passes through the paper 90.

As shown in FIG. 23, the basis weight sensor 50 includes a plurality of light-emitting elements 51 and a single light-receiving element 5
The light emitting unit 51 includes a first light emitting unit 51 a, a second light emitting unit 51 b, and a third light emitting unit 51
The first, second, and third light emitting units irradiate the irradiation area with the first, second, and third irradiation light, respectively. This irradiation area (detection area a50) is a detection area a50 when viewed from the Z direction.
0. The pair of upper and lower openings are provided in the plate constituting the bottom surface S1 of the upper housing 21 and the plate constituting the placement surface S2 of the lower housing 22, respectively. The pair of openings have the same shape, for example, a rectangle. Transparent sheets 54a and 54b made of PET or the like that transmit the wavelengths of the irradiated light are attached to the detection area a50 in order to prevent foreign matter such as paper dust from the paper 90 passing through the paper passing area 200 from adhering to the detection area a50. Note that no sheet is attached to the opening corresponding to the detection area a60 for the surface sensor 60, and the adhesion of foreign matter is prevented by a shutter 651.

The first light-emitting unit 51a emits a first irradiation light having a first wavelength. The first wavelength is, for example, a near-infrared wavelength that is longer than the wavelength of visible light. More specifically, the first wavelength is
For example, the wavelength is between 750 nm and 900 nm. The second light-emitting unit 51b emits second irradiation light having a second wavelength. The second wavelength is, for example, the wavelength of blue light included in visible light. More specifically, the second wavelength is, for example, the wavelength is between 400 nm and 470 nm. Both the first light-emitting unit 51a and the second light-emitting unit 51b emit second irradiation light having a second wavelength.
0, the third light emitter 51c is disposed on the opposite side of the light receiver 52.
The third light-emitting unit 51c is provided on the same side as the first light-emitting unit 51a and in the vicinity of the light-receiving unit 52. The third light-emitting unit 51c irradiates the irradiation area (detection area a50) with third irradiation light having a third wavelength. The third wavelength is, for example, the wavelength of green light among visible light. More specifically, the third wavelength is, for example, 49
The third wavelength includes wavelengths between 5 nm and 570 nm.
a wavelength between 400 nm and 900 nm), and a second wavelength (e.g., between 400 nm and 4
70 nm) is a different wavelength.

The third irradiation light is irradiated toward the paper passage area 200 between the upper housing 21 and the lower housing 22. A reflecting portion 53 is provided on the placement surface S2 provided near the first light emitting portion 51a and the second light emitting portion 51b. The reflecting portion 53 is painted, for example, in green, which is the same color as the third irradiation light, and reflects the third irradiation light. Note that the reflecting portion 53 reflects the first irradiation light (near infrared ray) which is not the same color.
And the second illumination light (blue light) is not reflected.

In this embodiment, the control unit 26 controls the first light emitter 51a and the second light emitter 51b during measurement to emit the first irradiation light and the second irradiation light at different timings. The light receiver 52 receives the first irradiation light and the second irradiation light, detects the amount of each irradiation light, and outputs the detected amount of the first irradiation light and the amount of the second irradiation light to the control unit 26.
Similarly, the first irradiation light and the second irradiation light are irradiated onto the paper 90 transported to position a50. The light receiving unit 52 receives the transmitted light of the first irradiation light and the second irradiation light (first transmitted light, second transmitted light), detects the amount of each irradiation light, and outputs the detected amount of the first transmitted light and the second transmitted light to the control unit 26. That is, the light receiving unit 52 detects the first irradiation light and the second irradiation light when there is no paper 90, and the first transmitted light and the second transmitted light when the paper 90 is in the detection area a50.

Similarly, with respect to the third light emitting unit 51c, the light receiving unit 52 detects the first reflected light reflected by the reflecting unit 53 when the paper 90 is not present, and the second reflected light reflected by the surface of the paper 90 when the paper 90 is in the detection area a50. These detection data are transmitted to the host (
The image signal is sent to the information processing device 10 and used for paper type determination on the host side. In this embodiment, the third light emitting section 51c and the reflecting section 53 are provided, but these may be omitted.

(Paper property detection process)
Next, a paper property detection process performed by the paper property detection device 20 will be described with reference to Figures 24, 25A and 25B. Figure 24 is a flow chart showing the measurement process performed by the paper property detection device.

(Step S10)
Step S10 is a process that is performed after the initial operation associated with turning on the power of the main body of the paper physical property detection device 20. This initial operation includes initial communication associated with the establishment of communication with a host (the information processing device 10 or the image forming device 10b (described later)).

In step S10, the control unit 26 of the paper physical property detection device 20 controls the shutter opening/closing mechanism drive unit 655 to close the shutter 651. The fact that the shutter 651 is in the closed state may be determined by the output of a position detection sensor, or it may be estimated that the shutter 651 has been closed by driving the shutter for a sufficient period of time. At this time, a step-out may occur.

(Step S20)
Here, the control unit 26 calibrates each detection unit. For example, in the case of the surface sensor 60, the control unit 26 calibrates the surface sensor 60 by reading the reference plate on the back side of the shutter 651.

(Step S30)
If the paper physical property detection device 20 receives a measurement start instruction from the host (YES), the process proceeds to step S40.

(Step S40)
The control unit 26 starts the paper physical property detection process upon receiving the measurement start instruction.
FIG. 25B is a subroutine flowchart showing the process of step S40.

(Step S401)
Here, if there are any detected values, these are initialized (cleared).

(Step S402)
The control unit 26 calibrates the first to third detection units (the basis weight sensor 50, the surface property sensor 60, and the paper thickness sensor 70). For example, in the case of the paper thickness sensor 70, the pressing plate 81
is brought into contact with the bottom surface S1 of the upper housing 21 to obtain the output when no paper 90 is present.

(Step S403)
The control unit 26 activates the first detection unit (basis weight sensor 50) to detect the detection area 50 of the paper 90.
If the paper 90 is detected (YES), the process proceeds to step S404.

(Step S404)
The paper property detection device 20 notifies the host that the paper 90 has been inserted.

(Step 405)
In parallel with the process of step S404, the control unit 26 starts detecting the physical value of the basis weight (hereinafter referred to as "physical value 1") by the basis weight sensor 50. This detection is performed multiple times.

(Step S406)
Furthermore, when the user inserts the paper 90 further in, the paper 90 reaches the detection area 30,
If the first media set sensor 30 on the front side is ON (paper present) (YES), the control unit 26 advances the process to step S407.

(Step S407)
Similarly, when the second media set sensor 40 on the rear side is ON (paper present) (Y
ES), the control unit 26 advances the process to step S408.

(Step S408)
When the basis weight sensor 50 has completed multiple measurements and the detection of the physical property value 1 has been completed (YE
In step S409, the control unit 26 advances the process to the next step S409.
If the speed at which 0 is inserted is within a normal expected range, the detection of the physical property value 1 is completed before the second media setting sensor 40 is turned ON in step S407.

(Step S409)
Here, the control unit 26 waits for a predetermined delay time so that the paper 90 hits the wall S3 reliably, and if this delay time has elapsed (YES), the control unit 26 advances the process to step S410.

(Step S410)
The control unit 26 controls the shutter opening/closing mechanism driving unit 655 to open the shutter 651, and the process proceeds to step S501 in FIG. 25B.

(Step S411)
In steps S406 and S407, if the media set sensors continue not to be switched ON and a predetermined time has elapsed without detecting the presence of paper 90, resulting in a timeout (YES), the control unit 26 proceeds to step S412. Until the predetermined time has elapsed (NO), the control unit 26 repeats the processes of steps S406 and S407.

(Step S412)
The control unit 26 notifies the user of the warning through the display unit 28 etc. For example, the control unit 26 turns on a red LED of the display unit 28.

(Step S413)
The paper property detection device 20 also notifies the host of the current state, and the host may display a warning message on the display unit of the host in accordance with the received state.

(Step S501)
In step S501 in FIG. 25B, the control unit 26 controls the paper pressing mechanism 80 to lift the pressing plate 81 and press the paper 90 between the pressing surface S4 of the pressing plate 81 and the bottom surface S1 of the upper housing 21.

(Steps S502 and S503)
The control unit 26 controls the surface property sensor 60 (second detection unit) and the paper thickness sensor 70 (third detection unit) to start measuring the physical properties of the paper 9.
While holding the surface roughness at 0, the surface roughness sensor 60 (second detection unit) measures the surface roughness (hereinafter, “physical property value 2”).
The paper thickness sensor 70 (third detection unit) starts detecting the paper thickness (hereinafter referred to as "physical property value 3").

(Step S504)
If the detection of the physical property values 2 and 3 by each detection unit is completed (YES), the control unit 26 advances the process to step S505.

(Step S505)
The paper physical property detection device 20 transmits the detection results (physical property values 1 to 3) obtained in steps S408 and S504 to the host.

(Steps S506 and S507)
The process thereafter is the end process. The control unit 26 controls the paper pressing mechanism 80 to press the pressing plate 81.
The shutter 6 is lowered to a predetermined position.
The closing operation of 51 is performed.

(Steps S508 and S509)
If the second media set sensor 40 and the first media set sensor 30 turn OFF in this order as a result of the user pulling out the paper 90, the control unit 26 determines that the process has been performed normally, and the process proceeds to step S510.

(Step S510)
The paper property detection device 20 notifies the host of the normal end state. In this state, the next paper 90 can be measured (acceptable state), and the process ends and returns to the process of FIG. 24 (end, return).

(Steps S511, S512, S513)
Here, the control unit 26 performs processing similar to that of steps S411 to S413, and determines that the measured paper 90 has not been removed and remains stuck in the paper passage area 200 when a predetermined time has elapsed and timed out. Depending on the determination result, the control unit 26 notifies the user of a warning via the display unit 28 and notifies the host of the condition.

(Step S514)
The control unit 26 notifies the user of the completion of the measurement by, for example, turning on the green LED of the display unit 28.

(Step S50)
In step S50 of FIG. 24, if the control unit 26 receives a stop request from the host side or if the power of the paper physical property detection device 20 itself is turned off (YES), it stops the device and terminates (END).

In this manner, in the present embodiment, when viewed from the recording medium insertion direction, the paper physical property detection device 20 has both side surfaces formed by the second housing and the first housing that are concave in shape. With this configuration, the user can easily recognize whether the recording medium is inserted properly.

In addition, when viewed from the insertion direction, the first housing has a tapered shape (or R shape) that narrows toward the bottom. As a result, even if the size of the detection unit (surface sensor 60) is large and the width of the upper part of the first housing is wide, but the width is narrow on the bottom side, the user can easily recognize whether the recording medium is inserted properly, even if a small-sized recording medium is inserted.

The paper physical property detection device 20 also includes a paper pressing mechanism 80. This allows the pressing plate 81 to be lowered when inserting paper, so that the insertion of the paper 90 is not impeded.
Since the paper S is pressed between the bottom surface S1 of the upper housing and the paper feed roller 1, the position of the surface of the paper S can be stabilized, so that the physical properties of the paper can be detected with high accuracy.

Second Embodiment
Next, a paper physical property detection device 20 according to a second embodiment will be described with reference to Fig. 26 to Fig. 29. The paper physical property detection device 20 according to the second embodiment is incorporated in an image forming system 1000b. The image forming system 1000b includes the paper physical property detection device 20 and an image forming apparatus 10b that functions as a host for the paper physical property detection device 20.

(Image forming apparatus 10b)
The image forming apparatus 10b includes a control unit 11b, a storage unit 12b, an image forming unit 13, and a paper feed unit 14.
4, a communication unit 15, a post-processing unit 17, an operation panel 18, and a discharge unit 19. A paper physical property detection device 20 is connected to the image forming apparatus 10b via the communication unit 15.

The communication unit 15 has the same configuration as in the first embodiment, and so a description thereof will be omitted.

(Control unit 11b, storage unit 12b)
The control unit 11b controls the operation panel 18 and a network-connected PC operated by the user.
When a print job is input by an instruction sent from an external terminal such as a printer, the control unit 11b executes the print job based on the print setting information of the input print job. The control unit 11b executes a paper type determination process using a paper type discrimination engine (trained model) and a paper profile stored in the storage unit 12b. Here, the "paper profile" is a pre-registered profile that corresponds to the measured values and calculated values of the measured values of the paper physical properties obtained from the paper physical property detection device 20 for a certain paper, as well as the characteristic data, paper size, and an arbitrary identification name (e.g., paper brand) input by the user. Note that the measured values (physical property values) and calculated values from the paper physical property detection device 20 include, for example, the measured values of reflected light at 75° and 30° by the surface property sensor 60 of the paper physical properties, the calculated value of basis weight and/or the calculated value of basis weight difference based on the measured value of the basis weight sensor 50, and the calculated value of paper thickness based on the measured value of the paper thickness sensor 70, which will be described later. In addition, the characteristic data input by the user includes transport system characteristic data (front and back adjustment value,
offset correction value, etc.), image formation characteristic data (fixing temperature value, density adjustment value, gamma correction value, etc.)
, paper feed system characteristic values (air flow rate adjustment value of the paper feed tray handling fan), and various other control parameter values.

The “paper type discrimination engine” is also called a trained model, and is a paper property detection device 2 for detecting the paper 90.
The trained model is generated by supervised learning using training data, with the detection output of 0 as the input value and the paper type information of the paper 90 set by the user as the correct label. As training data, data from other image forming devices 10b connected to the network may be aggregated by a server on the network. The learning machine (not shown) can generate the trained model by a learning method using a neural network configured by combining perceptrons. Note that the learning method is not limited to this, and various methods can be used as long as they are supervised learning methods. For example, random forest, support vector machine (SVM), boosting, Bayesian, etc.
A network linear discrimination method, a nonlinear discrimination method, etc. can be applied.
This can be performed using a standalone high-performance computer using a GPU (Graphics Processing Unit) processor, or a cloud computer.

(Image forming unit 13)
The image forming unit 13 forms an image by, for example, an electrophotographic method.
The printer is equipped with a writing section corresponding to each of the basic colors of (yellow), M (magenta), C (cyan), and K (black), a photosensitive drum, and a developing unit that contains a two-component developer consisting of toner and carrier of each color, and forms a full-color image on paper 90.

(Paper feeding and conveying section 14)
The paper feed conveying unit 14 is equipped with a plurality of paper feed trays. The paper feed trays also include a manual feed unit (not shown). Various types of paper 90 and various sizes of paper 90 can be fed from the paper feed trays of the paper feed conveying unit 14. The minimum size of paper 90 that can be fed and conveyed is, for example, postcard size (100 mm×148 mm) for standard paper and 100 mm for non-standard paper.
×135mm.

(Operation panel 18)
The operation panel 18 is equipped with a touch panel, a numeric keypad, a start button, a stop button, etc., and is used to display the status of the image forming apparatus 10b or the image forming system 1000b, and to allow the user to set the type of paper placed in the paper feed tray, etc., and to input instructions.

(Post-processing section 17)
The post-processing section 17 performs processes such as stapling, cutting, and punching (punching holes) on the paper 90 on which an image has been formed by the image forming section 13 and which has been conveyed from the image forming device 10b.

(Printing process)
Next, the print process including the paper type determination process will be described with reference to Fig. 27. In Fig. 27, steps S61 to S63 correspond to the print preparation process. The user performs this print preparation process before carrying out actual printing of a print job.

(Step S61)
The user operates a paper setting button on an operation screen (not shown) displayed on the operation panel 18. The control unit 11b starts paper setting by accepting this operation from the user. Specifically, the image forming apparatus 10b functioning as a host controls the paper physical property detection device 20 to detect the physical property values of the paper 90. Details of this paper setting process will be described later with reference to FIG. 28.

(Step S62)
Upon completion of the paper setting, the image forming conditions are set according to the set paper characteristics, and a test print (trial print) of the print job is performed.

(Step S63)
If the user is not satisfied with the results of the test print, or if multiple types of paper are used in one print job, the user can repeat the process from step S61 onwards for another type of paper (
Step S63: NO). On the other hand, if the test printing results are satisfactory and all paper types have been checked (YES), the control unit 11b accepts a preparation completion operation from the user and causes the process to proceed to step S64.

(Step S64)
The control unit 11b controls the image forming unit 13 and the like to execute the print job (main printing), thereby completing the print process (END).

(Paper setting process)
(Step S611)
28 is a subroutine flowchart showing the paper setting process (step S61). For example, the user loads a stack of papers 90 to be used for printing into the paper feed tray, and
One of the sheets of paper 90 is used to perform a process of measuring the physical properties by the paper physical property detection device 20. The measurement process on the paper physical property detection device 20 side is the process described above in Figures 24, 25A, and 25B. The paper physical property detection device 20 measures the paper 90 inserted by the user, obtains the detection results of the physical properties 1 to 3, and transmits these to the image forming device 10b (corresponding to step S505 in Figure 25B). The image forming device 10b receives the detection results of the physical properties 1 to 3 sent from the paper physical property detection device 20.

(Step S612)
The control unit 11b performs paper type determination and basis weight classification determination using the physical property values 1 to 3 (or their average data) acquired in step S611, the trained model (paper type discrimination engine), and basis weight classification probability calculation processing.
(or the average data thereof) and a profile selection process are used to determine candidate paper profiles with high similarity from registered paper profile data.

The paper type determination and basis weight classification determination processes will be described in more detail with reference to Fig. 29. Fig. 29 is a control block diagram showing the determination process (step S612).
In No. 1, in addition to the paper type determination and basis weight classification determination processes, a registration profile candidate determination process determined using a paper profile created for each user (for each device) is also shown.

(Steps S701 to S703)
The control unit 11b obtains a basis weight conversion value, a surface property measurement value, and a paper thickness conversion value using the physical property values 1 to 3 acquired in step S611. Here, the basis weight conversion value is calculated from the first and second basis weights using a coefficient and a formula determined by the surface property measurement value of measurement value 3 (S703) and the ambient environment information (temperature, humidity) of the image forming system 1000b. Here, basis weight difference = first basis weight - second basis weight. The basis weight sensor 50 is equipped with multiple LEDs that irradiate light of different wavelengths, as shown in FIG. 23. The first basis weight is calculated using a wavelength (7
A first LED that outputs irradiation light of 50 nm to 900 nm is used, and the paper 90 of this irradiation light is
The second basis weight is calculated based on the amount of light transmitted through the wavelength (400 nm to 470 nm).
The basis weight is calculated by the amount of transmitted light of the irradiated light passing through the paper 90 using a second LED that outputs an irradiated light of 10 ...
The process is sent to steps S713 and S714. The paper thickness is sent to steps S712 and S713. The surface property measurement values are sent to steps S701, S713 and S714.

(Step S711)
The control unit 11b calculates a basis weight category probability from the basis weight calculated in step S701. Examples of basis weight categories include the following 12 categories.
~61g/m2
62-75 g/m2
76-81 g/m2
82-92 g/m2
93-106 g/m2
107-136 g/m2
137-177 g/m2
178-217 g/m2
218-257 g/m2
258-301 g/m2
302-351 g/m2
352 g/m2~
The calculated basis weight is assumed to follow a normal distribution and vary with a predetermined standard deviation, and the probability of each division is determined. For example, if the basis weight is close to the center of one of the divisions, the probability of that division is high and is set to 100.
%. On the other hand, the further away from the center of the division, i.e., the closer to the boundary, the lower the probability. The division probability is sent to step S721 as the basis weight division score.

(Step S712)
The control unit 11b uses the basis weight and the paper thickness to calculate the density (=basis weight/paper thickness). The calculated density is sent to step S713.

(Step S713)
The control unit 11b performs paper type discrimination using the paper characteristic data of the measured values of density, basis weight difference, and surface property, and the trained model. The discrimination result is sent to step S721 as a paper type score.

(Step S714)
The control unit 11b uses paper characteristic data of measured values of density, paper thickness, and surface properties, and a list of paper profiles registered in advance by a user, etc., to select a registered profile with a high compatibility rate from among them. The list of paper profiles includes basis weight, paper thickness,
The control unit 11b has data representing the paper properties including the basis weight difference value and the surface property measurement value (for example, the measurement value from the light receiving units 641 and 642).
3 (or the calculated data thereof) is used to select a candidate paper profile from among the registered paper profiles in order of closestness to the registered data of the paper physical properties.
The selection results are sent to step S722 as a list of candidate paper profiles to which a relevance score has been assigned.

(Step S721)
The control unit 11b displays one or more candidates for paper type/basis weight in descending order of probability according to the basis weight category score and the paper type score, and presents them to the user.

FIG. 30 is an operation screen 1 showing the judgment result (paper type/basis weight classification) displayed on the operation panel 18.
81. In the operation screen 181, two candidates for paper type/basis weight are displayed in descending order of score. When the user wishes to accept the judgment result of the first candidate, column 81 (coated paper/basis weight 177-216), the user operates button 84, and the judgment result of the selected column 81 is applied to tray 1 (one of the multiple paper feed trays). When the user wishes to apply the second candidate, column 82 (plain paper/basis weight 172-216), the user operates button 84 after selecting column 82. On the other hand, when the user wishes to apply the selected judgment result to both trays 1 and 2, the user operates button 85. Also, by operating button 83,
The judgment result can be discarded without being adopted. The judgment result selected by the user can be stored in a server or the like as correct answer data and used as training data for subsequent machine learning.

(Step S722)
The control unit 11b displays one or more candidates for registered profiles in descending order of score according to the relevance score, and presents them to the user.

FIG. 31 is an example of an operation screen 182 that displays the judgment results (registered profile) on the operation panel 18. On the operation screen 182, three registered profile candidates are displayed in descending order of score. A registered profile is a registered profile that is a paper characteristic that the user previously measured using the paper physical property detection device 20 or the like, or a paper characteristic that the user manually inputs via the operation panel 18, associated with a media name. If the paper characteristic is the same as that previously measured, the registered media name is displayed as the first candidate. The first candidate, column 86 (paper profile data 21
) is accepted, the judgment result of the selected column 86 is applied to the tray 1, etc. by operating buttons 84, 85, etc.

(Step S613)
Referring again to Fig. 28, the control unit 11b displays the determination result. This process corresponds to Fig. 30, Fig. 31, and steps S721 and S722 described above.

(Step S614)
If the user wishes to change the paper type (YES), the process proceeds to step S617; if the user wishes to accept the determination result without making any changes (NO), the process proceeds to step S615.

(Step S615)
The control unit 11b accepts an input operation from the user via the operation panel 18, and sets the accepted changed paper type as the paper type information of the selected tray.

(Step S616)
If there is no change in the setting (for example, when the operation of the button 84 in FIG. 30 is accepted), the control section 11b sets the result of the determination made in step S613 as the paper type information of the selected tray.

(Step S617)
The printing conditions for the selected tray are set to the printing conditions corresponding to the set paper type, and then the process returns to the process in FIG. 27, and the processes from step S61 onwards are carried out (return).

In this manner, in the image forming system 1000b according to the present embodiment, the paper physical property detection device 2
The paper type of the recording medium is determined using the detection results from 0. This allows the paper type to be determined with high accuracy.

The above-described paper property detection device 20 and the image forming system 1000 including the same
The configuration of b has been described as the main configuration in explaining the features of the above embodiment, but is not limited to the above configuration and can be modified in various ways within the scope of the claims.

(Paper Determination Process in Paper Information Discrimination System 1000 According to the First Embodiment)
In the paper information discrimination system 1000 (see FIG. 1), the control unit 11 also performs the steps shown in FIGS.
In this case, the result of the determination of the paper type is sent directly or indirectly (for example, via a server on the network) to the image forming apparatus 10b, and is used for print settings. For example, the paper information determination system 100
When using the printer 10 as a standalone printer, the paper determination result (selection candidates) is sent to the image forming apparatus 10.
In this case, the paper information discrimination system 1000 may be connected to the image forming apparatus 10b for communication and display contents equivalent to those shown in Figs. 30 and 31 on the display unit of the information processing apparatus 10, so that the paper feed tray of the image forming apparatus 10b can be set directly from the information processing apparatus 10. In this case, paper setting processing using the measurement results of the paper physical property detection device 20 added later can be performed on the image forming apparatus 10b already on the market.

(First Modification)
Also, as shown below, original display contents different from the display contents of the image forming apparatus 10b may be used. Figs. 32 to 34 are examples of operation screens displayed on the display unit of the information processing apparatus 10. On operation screen 1 in Fig. 32, a "Connect" button 801, a "Scan" button 802, a "Clear" button 803, and a "Disconnect" button 804 are arranged. On operation screen 1, the paper physical property detection apparatus 20 and the information processing apparatus 10 are connected by a cable, but are not connected for communication. In this state, when "Connect
By operating the "ct" button 801, communication is established, the information processing device 10 functions as a host for the paper physical property detection device 20, and the display switches to the operation screen 2 shown in FIG.

In the operation screen 2 of FIG. 33, a “Measurement” tab 811 and a “Pred
The user selects the "Selection Paper Type" tab 812 and then operates the "Scan" button 802. This operation causes the information processing device 10 as the host to send a measurement start instruction to the paper physical property detection device 20 (corresponding to step S30 in FIG. 24). Thereafter, the paper physical property detection device 20 performs the processes of FIG. 25A and FIG. 25B while performing a handshake (sending and receiving communication data) with the information processing device 10, and measures the physical property values of the paper 90. The results (physical property values 1 to 3) are sent to the information processing device 10. The information processing device 10 performs processes such as those in FIG. 28 and FIG. 29 to determine the paper type, determine the basis weight classification, and the like. The determined paper type determination result is then displayed in an area 813 (corresponding to FIG. 30). The user selects one of the multiple candidates.

Also, the product name or unique name of the selected paper type can be entered in the “Profile” field 814.
After keying in the “FileName”, the “FileName” can be registered in the storage unit 12 by operating the “Save” button 815 .

In addition, when the "Disconnect" button 804 is operated, a request to stop measurement is sent from the information processing device 10 to the paper physical property detection device 20 (corresponding to step S50 in FIG. 24).
This ends the measurement and disconnects the communication connection.

On the other hand, by operating the “User Profile” button 816 on the operation screen 2,
The screen switches to the operation screen 3 in Fig. 34. In this operation screen 3, candidates for paper profiles that are similar to the user paper profile within a predetermined range based on the measurement values of the paper 90 are displayed (similar to Fig. 31). In this way, the information processing device 10 can also perform the same processing as the image forming device 10b.

(Measurement process and paper type determination process performed in the paper information discrimination system 1000 in the first embodiment and the first modified example)
The measurement process and the paper type determination process performed by the paper information discrimination system 1000 will be described below with reference to FIGS.

(First Example)
FIG. 35 is a flowchart showing the measurement process and the paper type determination process performed in the paper information discrimination system 1000 in the first example.

(Steps S10b, 20b)
Here, the paper property detection device 20 performs the same processes as steps S10 and S20 in FIG.

(Step S30b)
In the information processing device 10 , a measurement start instruction is sent to the paper physical property detection device 20 when the user operates the “Scan” button 802 (see FIG. 33 ).

When the paper physical property detection device 20 receives a measurement start instruction from the host (information processing device 10) (YES), the process proceeds to step S40b.

(Step S40b)
Here, the paper physical property detection device 20 performs the same process as step S40 in FIG. 24 to detect the paper physical property.

(Step S45)
The information processing device 10 uses the measurement results (physical property values 1 to 3) of the paper physical property detection device 20 to determine the paper type, the basis weight classification, and select the paper profile. This process is shown in FIG.
This is the same process as step S612), and these determinations and selections are made using the paper profile and the paper type discrimination model (trained model) stored in the storage unit 12 (or the server) of the information processing device 10.

(Step S50b)
The paper property detection device 20 performs the same process as step S50 in FIG.
When the control unit 26 receives a stop request sent from the host side in response to the operation of the "isconnect" button 804 (YES), the device is stopped and the process is terminated (END).
.

(Second Example)
36 is a flowchart showing the measurement process and the paper type determination process performed by the paper information discrimination system 1000 in the second example.
In the previous embodiment, operating button 802 resulted in measurement of a single sheet of paper 90, but in the second example, switching to a "paper measurement mode" enables continuous measurement of multiple sheets of paper 90.

(Steps S10c, 20c)
Here, the paper property detection device 20 performs the same processes as steps S10 and S20 in FIG.

(Step S30c)
In the information processing device 10 , a measurement start instruction is sent to the paper physical property detection device 20 when the user operates the “Scan” button 802 (see FIG. 33 ).

When the paper physical property detection device 20 receives a measurement start instruction from the host (information processing device 10) (YES), the process proceeds to step S40c and transitions to the "paper measurement mode."

(Step 40c)
Here, the paper physical property detection device 20 performs the same process as step S40 in FIG.

(Step S45c)
The information processing apparatus 10 performs the same process as step S45 in Fig. 35. It determines the paper type, the basis weight category, and selects the paper profile.

(Step S55)
When the user operates the "Clear" button 803 (see FIG. 33), the information processing device 10 transmits a request to cancel the "paper measurement mode" to the paper physical property detection device 20. When the paper physical property detection device 20 receives the request to cancel the "paper measurement mode" (YES), it ends the process. On the other hand, when the paper physical property detection device 20 does not receive the request to cancel (NO), it repeats the process of step S40c. In this case, the insertion of paper 90 by the first detection unit (paper thickness sensor 50) is used as a trigger, and the paper physical property detection process (S40c) is performed every time the insertion is detected.

(Third Example)
As another example, the information processing device 10 of the paper information discrimination system 1000 may not have a paper type discrimination function, and may only have a function of passing the measured values (physical property values 1 to 3) to the image forming device 10b. In this case, the paper type discrimination model (trained model) may be
The paper type can be determined by using an individual paper type determination model stored on the side.

In addition, an example has been shown in which the control unit 11b of the image forming device 10b has a trained model, but the trained model may be stored on the server side and the server may determine the paper type. In this case, the image forming device 10b transmits data on the measured paper characteristics to the server, and the server, upon receiving the data, determines the paper type based on the data and transmits the determination result back to the image forming device.

In this embodiment, the paper type determination result is displayed in order of priority (score) as shown in Fig. 30, but the display of the priority may be omitted. If there is only one candidate (or if the difference between the second and subsequent candidates is a predetermined value or more), the selected paper feed tray may be automatically applied to improve operability, and an operation screen may be displayed that allows the test printing (step S62) to be performed immediately (with one touch).

10 Information processing device 20 Paper property detection device 21 Upper housing (first housing)
S1 Bottom surface 22 Lower housing (second housing)
S2 Placement surface 30 Media set sensor (front)
40 Media set sensor (rear)
50 Basis weight sensor (first detection unit)
60 Surface sensor (second detection unit)
61 Housing a3, a4 Opening 61a Inclined surface b1, b2, b3 Substrate 62 Light emitting portion 63 Collimator lens 64, 641, 642 Light receiving portion 70 Paper thickness sensor (third detection portion)
72 Contact portion 80 Paper pressing mechanism 81 Pressing plate 88 Paper pressing mechanism driving portion (motor)
891, 892 Pressing mechanism height position sensor 65 Opening/closing mechanism 651 Shutter 655 Shutter opening/closing mechanism drive unit (motor)
a20, a30, a40, a50, a60 Detection area a80 Pressing area 1000 Paper information discrimination system 1000b Image forming system

Claims (14)

a second housing having a mounting surface on which a recording medium is placed;
a first housing arranged above the second housing and having a bottom surface facing the placement surface at a predetermined distance;
At least one detection unit that detects a physical property of the recording medium inserted on the placement surface;
Equipped with
the detection unit includes a plurality of detection units that detect different physical properties, and a detection region of each of the plurality of detection units is disposed within a detection range set on the placement surface of the second housing;
A minimum size of the recording medium that can be detected by the paper physical property detection device is set, and the minimum size in a width direction perpendicular to the insertion direction of the recording medium is a paper width w0;
The set minimum size is a size larger than the detection range so as to cover the detection range,
When viewed from above, a bottom surface of the first housing is larger than the detection range and is disposed so as to cover the entire detection range, and a maximum width w1 of the first housing is larger than a width w0 of the paper of a minimum size,
the bottom surface of the first housing has a tapered or R-shaped shape in which the width in a width direction perpendicular to the recording medium insertion direction becomes narrower toward the insertion opening,
The width w2' of the end of the bottom surface of the first housing on the insertion opening side is narrower than the width w0 of the paper of the minimum size detectable by the paper property detection device.
Paper property detection device. the detection unit includes a first detection unit that detects a basis weight of the recording medium, a second detection unit that detects a surface property, and a third detection unit that detects a thickness, as the physical property;
The paper property detection device according to claim 1 , wherein the first, second and third detection areas of the first, second and third detection units, respectively, are arranged within the detection range set on the loading surface of the second housing. The first housing is composed of two parts, an upper housing on the upper side and a lower housing on the lower side, the bottom surface is the bottom surface of the lower housing, and the lower housing has a tapered shape or an R shape whose width narrows from the top to the bottom surface on the lower side,
The maximum width w1 of the first housing is the width of the upper housing,
3. The paper physical property detection device according to claim 2 , wherein a maximum width w2 of the bottom surface of the first housing is greater than the width w2', and the maximum width w2 is greater than a width w0 of the paper of a minimum size . The paper physical property detection device according to claim 2 or claim 3, further comprising a pressing mechanism which includes a pressing member and which presses the recording medium inserted on the placement surface from below toward the bottom surface by lifting the pressing member upon detection . the second detection unit is disposed inside the first housing, and detects a physical property of a surface of the recording medium within the detection area by using an opening provided on the bottom surface as a detection area;
A paper physical property detection device as described in any one of claims 2 to 4, wherein the second detection unit comprises an emitter that irradiates light onto the detection area, a first light receiving unit that detects the amount of specularly reflected light that is specularly reflected off the surface of the recording medium within the detection area, and at least one second light receiving unit that detects the amount of diffusely reflected light that is diffusely reflected at at least one reflection angle on the surface of the recording medium in the detection area. The paper physical property detection device according to claim 5, wherein the second detection unit is configured such that the irradiation diameter of the light irradiated from the light source of the light emitting unit in the detection area is set to an irradiation diameter that reduces the influence of unevenness in the fiber orientation of the recording medium . The paper physical property detection device of claim 2, wherein the second detection unit is a surface sensor, and a second opening provided on the bottom surface serves as a second detection area, and the paper physical property detection device comprises: an emitter that irradiates light onto the second detection area; a light receiver that detects the amount of specularly reflected light that is specularly reflected on the surface of the recording medium within the second detection area; and at least one light receiver that detects the amount of diffusely reflected light that is diffusely reflected at at least one reflection angle on the surface of the recording medium in the second detection area. The paper physical property detection device described in claim 2 or claim 7, wherein the first detection unit is a basis weight sensor, and two opposing first openings provided on the bottom surface and the placement surface respectively form a first detection area, and the paper physical property detection device is equipped with one or more light-emitting units that irradiate light onto the first detection area, a light-receiving unit that detects the amount of transmitted light that has passed through the recording medium in the first detection area , and a light-receiving unit that detects the amount of reflected light that has been reflected by the surface of the recording medium in the first detection area. a pressing mechanism including a pressing member, which, when detected, lifts the pressing member to urge the recording medium inserted on the placement surface toward the bottom surface from below, thereby pressing the recording medium;
the third detection unit is a paper thickness sensor,
a contact portion that is biased to come into contact with the recording medium pressed by the pressing member and the bottom surface;
The paper physical property detection device according to claim 2 , further comprising: a position detection unit that measures a height direction position of the contact portion that contacts the recording medium, the height direction position changing depending on a thickness of the recording medium . a media set sensor disposed on the inner side of the placement surface in a direction in which the storage medium is inserted within the detection range , the media set sensor detecting the presence or absence of the storage medium;
a wall against which the recording medium is abutted is provided at the rear side of the mounting surface;
The paper physical property detection device according to claim 4, wherein the media set sensor determines whether the recording medium has hit the wall, and then the pressing mechanism is activated to press the recording medium with the pressing member, and then detection is performed by one or more of the detection units. 11. The paper physical property detection device according to claim 10 , wherein the detections performed while the recording medium is held down are detection of the surface property of the recording medium by a second detection unit and detection of the thickness by a third detection unit. A paper physical property detection device according to any one of claims 1 to 11 ,
a control unit that determines the paper type of the recording medium using the detection result obtained from the paper physical property detection device. A paper physical property detection device according to any one of claims 1 to 11 ,
an image forming apparatus for forming an image on a recording medium;
a control unit that determines paper characteristics of the recording medium using a detection result obtained from the paper physical property detection device,
the control unit sets image forming conditions of the image forming apparatus using the determined paper characteristics of the recording medium.
Image forming system. The image forming system according to claim 13, wherein the paper width w0 of the smallest size of the recording medium that can be detected by the paper physical property detection device is set to correspond to the paper width of the smallest size of the recording medium that can be transported set in the image forming device.