JP6966862B2 - Moisture detection device and image forming device - Google Patents

Description

The present invention relates to a moisture detection device for detecting a value related to the amount of moisture contained in a recording material and an image forming apparatus provided with the moisture detection device.

An electrophotographic image forming apparatus such as a copying machine or a laser printer transfers a toner image formed on an image carrier to a recording material, and heats and pressurizes the recording material to which the toner image is transferred to transfer the toner image to the recording material. To fix. Transfer conditions such as transfer bias and fixing conditions such as the fixing temperature during the fixing process and the transport speed of the recording material are controlled by the size and type of the recording material. One of the parameters that must be taken into consideration when setting image formation conditions such as transfer conditions and fixing conditions is the amount of water contained in the recording material. The amount of water contained in the recording material varies depending on the installation environment of the image forming apparatus and the storage condition of the recording material. Therefore, for example, it is conceivable to estimate the amount of water contained in the recording material based on the humidity detected by the humidity sensor provided in the image forming apparatus. However, since the estimation of the water content based on the humidity does not individually detect the water content contained in each recording material, it may differ significantly from the water content actually contained in the recording material. In this case, the set image formation conditions are not appropriate, image defects or the like may occur, or problems may occur in the transport of the recording material due to deformation of the recording material.

Therefore, Patent Documents 1 to 3 disclose a configuration for detecting the amount of water contained in each recording material. Patent Documents 1 to 3 irradiate a water content detection target with light in the absorption wavelength range and light in the non-absorption wavelength range of water, and detect the water content of the detection target based on the reflected light amount and the like. It is disclosed.

Japanese Unexamined Patent Publication No. 2013-57513 Japanese Unexamined Patent Publication No. 9-21902 Japanese Unexamined Patent Publication No. 9-61351

The recording material conveyed in the image forming apparatus may undergo fluctuations in a direction orthogonal to the image forming surface, that is, fluttering. When the recording material conveyed while fluttering is irradiated with light, the value related to the amount of water contained in the recording material cannot be accurately detected due to the fluctuation of the image forming surface due to the fluttering.

The present invention provides a moisture detection device and an image forming apparatus that can accurately detect a value related to the amount of moisture contained in a recording material.

According to one aspect of the present invention, the moisture detection device is provided in the transport path of the recording material, the light emitting means for emitting the light of the first wavelength and the light of the second wavelength different from the first wavelength, and the transport path. On the other hand, on the opposite side of the light emitting means, the light receiving means emitted by the light emitting means, the light receiving means arranged so as to receive the light of the second wavelength, and the light receiving means receive the light. A detection means for detecting a value related to the amount of water contained in the recording material based on the amount of light received by the first wavelength light transmitted through the recording material and the amount of light received by the second wavelength transmitted through the recording material. A rotating body provided between the light emitting means and the light receiving means and pressing the recording material to be conveyed in the transport path, and the rotating body is orthogonal to the transport direction of the recording material. The rotation includes two columnar members arranged at different positions in different directions and pressing the recording material, and a connecting member including the rotation axis of the rotating body and connecting the two columnar members. When viewed from the direction of the axis, the light path connecting the light emitting means and the light receiving means overlaps with the two columnar members and does not overlap with the connecting member .

According to the present invention, it is possible to accurately detect a value related to the amount of water contained in the recording material.

The block diagram of the image forming apparatus by one Embodiment. A perspective view of a moisture detection device according to an embodiment. The block diagram of the moisture detection apparatus by one Embodiment. The block diagram of the moisture detection apparatus by one Embodiment. An explanatory diagram of the positional relationship of each component of the moisture detection device according to one embodiment. The operation explanatory drawing of the moisture detection apparatus by one Embodiment. The operation explanatory drawing of the moisture detection apparatus by one Embodiment. The figure which shows the determination information by one Embodiment. The operation explanatory drawing of the moisture detection apparatus by one Embodiment. The operation explanatory drawing of the moisture detection apparatus by one Embodiment. The block diagram of the moisture detection apparatus by one Embodiment. The block diagram of the moisture detection apparatus by one Embodiment. The operation explanatory drawing of the moisture detection apparatus by one Embodiment.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. The following embodiments are examples, and the present invention is not limited to the contents of the embodiments. Further, in each of the following figures, components not necessary for the description of the embodiment will be omitted from the drawings.

<First Embodiment>
FIG. 1 is a configuration diagram of an image forming apparatus 1 according to the present embodiment. In the figure, the letters Y, M, C, and K at the end of the reference numerals indicate that the colors of the toner image of the corresponding member are yellow, magenta, cyan, and black, respectively. However, when it is not necessary to distinguish the colors, the reference code excluding the character at the end of the reference code is used. The photoconductor 11 is an image carrier, and is rotationally driven in the clockwise direction in the figure at the time of image formation. The charging roller 12 charges the surface of the photoconductor 11 that is rotationally driven to a uniform potential. The exposure unit 13 exposes the surface of the charged photoconductor 11 to form an electrostatic latent image on the surface of the photoconductor 11. The developing unit 14 has toner of the corresponding color, and the toner is adhered to the electrostatic latent image of the photoconductor 11 by the developing bias output by the developing roller 15, thereby forming the toner image on the photoconductor 11. The primary transfer roller 16 outputs a primary transfer bias and transfers the toner image of the photoconductor 11 to the intermediate transfer belt 17 which is rotationally driven in the counterclockwise direction. A full-color toner image can be formed by superimposing the toner image of each photoconductor 11 on the intermediate transfer belt 17 and transferring the toner image.

The intermediate transfer belt 17 is stretched by a drive roller 18, a secondary transfer opposed roller 20, and a tension roller 25, and is rotationally driven depending on the rotation of the drive roller 18. As a result, the toner image transferred to the intermediate transfer belt 17 is conveyed to the opposite position of the secondary transfer roller 19. On the other hand, the recording material P stored in the cassette 2 has the feeding roller 4, the transport roller 5, and the toner image transferred to the intermediate transfer belt 17 at the timing when the toner image is transferred to the opposite position of the secondary transfer roller 19. It is conveyed to the facing position of the secondary transfer roller 19 by 6. The secondary transfer roller 19 outputs a secondary transfer bias to transfer the toner image of the intermediate transfer belt 17 to the recording material P. The toner that is not transferred to the recording material P and remains on the intermediate transfer belt 17 is removed from the intermediate transfer belt 17 by the blade 35 of the cleaning device 36. The recording material P to which the toner image is transferred is conveyed to the fixing unit 21. The fixing unit 21 heats and pressurizes the recording material P to fix the toner image on the recording material P. When an image is formed on only one side of the recording material P, the recording material P is discharged to the paper ejection tray 26 by the paper ejection roller 22 and the switchback roller 27 after the toner image is fixed. On the other hand, when an image is formed on both sides of the recording material P, the recording material P is sent out to the transport path shown by the dotted line in the figure by the reverse rotation of the switchback roller 27 and the switching of the flapper (not shown), and is secondary again. It is conveyed to the opposite position of the transfer roller 19 to form an image on another surface.

Further, the image forming apparatus 1 includes a moisture detecting device 30 that detects a value (including the moisture content itself) related to the moisture content of the recording material P. The moisture detection device 30 is arranged on the downstream side of the transfer rollers 5 and 6 and on the upstream side of the secondary transfer roller 19 in the transfer direction of the recording material P. The moisture detection device 30 has a light emitting unit 31 and a light receiving unit 32 arranged on the side opposite to the light emitting unit 31 with respect to the transport path for transporting the recording material P. The light emitting unit 31 is held by the secondary transfer unit 23 together with the secondary transfer roller 19. Further, the moisture detection device 30 has a pressing rotating body (not shown in FIG. 1) in order to stably convey the recording material.

The control unit 3 of the image forming apparatus 1 is a control unit of the entire image forming apparatus and includes a CPU 80. The CPU 80 executes a program held by the non-volatile memory (not shown) of the control unit 3, and controls the image forming apparatus by using the RAM (not shown) as a work area. Further, the control unit 3 includes a setting control unit 40 for setting image formation conditions. The setting control unit 40 sets image forming conditions, for example, transfer conditions and fixing conditions when forming a toner image on the recording material P, based on the value related to the water content of the recording material P detected by the water content detecting device 30.

FIG. 2 is a perspective view showing the configuration of the moisture detection device 30. The recording material P is conveyed in the moisture detection device 30 in the direction indicated by the arrow T, and in the process, a value related to the moisture content is detected. As shown in FIG. 2, the pressing rotating body 33 presses the recording material P conveyed on the conveying path toward the conveying path side by the pressing force F by an urging mechanism (not shown). Further, the pressing rotating body 33 is a driven roller rotated in the R direction by the recording material P. That is, the recording material P is configured to be conveyed by the transfer rollers 5 and 6 and the secondary transfer roller 19 in a state of being narrowly held by the pressing rotating body 33, and to be rotated by the transfer of the recording material P. As a result, the recording material P is suppressed from fluttering in the moisture detection device 30, and is conveyed in a stable state.

FIG. 3 is a view of the moisture detection device 30 as viewed from the upstream side in the transport direction of the recording material P. The light emitting unit 31 has light emitting elements L1 and L2 on the electric substrate EB1 that emit light having different wavelengths such as 560 nm and 850 nm. The light receiving unit 32 has a line light receiving element LS provided on the electric substrate EB2. The line light receiving element LS has a plurality of light receiving elements arranged in a line (linearly) in a direction orthogonal to the transport direction of the recording material P. The line light receiving element LS is arranged so as to be able to receive the transmitted light of the light recording material P emitted by the light emitting elements L1 and L2, and each light receiving element of the line light receiving element outputs an electric signal according to the amount of light received. .. As each light receiving element included in the line light receiving element LS, an inexpensive element having light receiving sensitivity in the vicinity of visible light including light emitting wavelengths of the light emitting elements L1 and L2 and near infrared light region (about 400 to 1000 nm) can be used. Therefore, it is not necessary to use an expensive light receiving element made of InGaAs having a light receiving sensitivity at the absorption wavelength of water (1450 nm, 1940 nm, etc.). The pressing rotating body 33 includes two columnar members 331 and 332 having the same diameter for pressing the recording material P, and a connecting member 333 connecting the columnar members 331 and 332. The pressing rotating body 33 is composed of a member that sufficiently transmits the wavelength of the light emitted by the light emitting elements L1 and L2, for example, a transparent member. Further, the diameter of the connecting member 333 is shorter than the diameter of the columnar members 331 and 332. This is to prevent the connecting member 333 from directly contacting the glass surface forming a part of the transport path of the recording material P so that the connecting member 333 does not damage the glass surface. Here, the glass surface is provided at a position facing the connecting member 333 so that the light emitted from the light emitting elements L1 and L2 reaches the line light receiving element LS. By not damaging the glass surface, it is possible to suppress a decrease in the accuracy of detecting the amount of water, which will be described later.

FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3, and FIG. 5 is an explanatory view of the arrangement relationship of each member. As shown in FIG. 5, the light emitting elements L1 and L2, the rotation center axis of the pressing rotating body 33, and the line light receiving element Ls are substantially in the same plane (in the plane PI in FIG. 5, and in the vertical direction in FIG. 4). It is provided so as to exist in (corresponding to the one-dot chain line). Further, as shown in FIG. 5, three straight lines of a virtual line La connecting the light emitting elements L1 and L2, a rotation center axis Lb of the pressing rotating body 33, and an arrangement direction Lc of each element of the line light receiving element LS are formed. Each member is provided so as to be parallel to each other and in the plane PI. Further, the distance _{L b-c} of the distance _{L a-b} between the rotation center axis Lb and the virtual line La, and the rotation center axis Lb and the straight line Lc is substantially equal.

6 and 7 show a state in which the light emitting elements L1 and L2 are made to emit light. Note that FIGS. 6 and 7 are views viewed from the same positions as FIGS. 3 and 4, respectively. In FIGS. 6 and 7, the light emitted by the light emitting element L1 is indicated by L1L, and the light emitted by the light emitting element L2 is indicated by L2L. As shown in FIG. 6, the light L1L and the light L2L emitted by the light emitting elements L1 and L2 reach the line light receiving element LS with a spread in the direction orthogonal to the transport direction of the recording material P. Then, based on the electric signal output by each light receiving element of the line light receiving element LS, the light receiving amount of the light L1L and the light receiving amount of the light L2L can be determined respectively.

The light L1L and L2L are attenuated by internal reflection, loss, etc. when passing through the transparent pressing rotating body 33. Further, the light L1L and L2L are greatly attenuated by the transmission of the recording material P and reach the line light receiving element LS. However, as shown in FIG. 7, the pressing rotating body 33 having a circular cross section has a lens-like effect, and in the transport direction of the recording material P, the spread of the light irradiated by the light emitting elements L1 and L2 is suppressed, and the line Light can be focused on the light receiving element LS. Further, the transparent pressing rotating body 33 allows the line light receiving element LS to detect the amount of light received while holding the recording material P narrowly. Therefore, it is possible to suppress the influence of the local unevenness of the water content in the transport direction of the recording material P and detect the average water content in the plane of the recording material.

In the following, how to detect the value regarding the water content (water content) contained in the recording material P based on the received light amount of the light L2L having the first wavelength of 560 nm and the light L2L having the second wavelength of 850 nm different from the first wavelength. I will explain. First, it is assumed that the light emitting elements L1 and the light emitting element L2 have the same light emitting intensity. Further, the amount of light emitted by the light emitting element L1 and transmitted through the recording material P is referred to as a first transmitted light amount, and the amount of light emitted by the light emitting element L2 and transmitted through the recording material P is referred to as a second transmitted light amount. At this time, the difference in the amount of transmitted light, which is the difference between the amount of the first transmitted light and the amount of the second transmitted light, changes according to the water content of the recording material P, as shown in FIG. Note that FIG. 8 shows the measurement results of the water content and the transmitted light amount difference when plain paper (60 g paper) having a basis weight of 60 g / m ^{2 is used as the recording material P.} The water content is the ratio (%) of the water content contained in the recording material P to the basis weight of the recording material P, and is a value related to the water content of the recording material P.

Hereinafter, the reason why the difference in the amount of transmitted light changes depending on the water content of the recording material P will be described. The amount of light transmitted through the recording material P is affected by both the change in the surface property of the recording material P due to moisture absorption and the absorption by water contained in the recording material P. That is, when the water content of the recording material P changes, the transmitted light amount changes accordingly. However, the fluctuation of the transmitted light amount due to the change in the surface property has a small wavelength dependence, and therefore, the fluctuation amount of the transmitted light amount due to the change in the surface property due to the change in the water content of the recording material P is almost the same regardless of the wavelength. Yes, the difference in the amount of transmitted light hardly changes. On the other hand, the absorption by water contained in the recording material P has a wavelength dependence, and the longer the wavelength, the larger the absorbance. Therefore, the amount of change in the amount of transmitted light due to absorption due to the change in the water content of the recording material P differs depending on the wavelength, and the difference in the amount of transmitted light changes. Therefore, the fluctuation of the transmitted light amount due to the change of the water content of the recording material P is wavelength-dependent as a whole, and therefore the difference changes according to the water content of the recording material P.

In the present embodiment, as shown in FIG. 8, the relationship between the water content and the difference in the transmitted light amount is measured in advance, and the determination information showing the relationship between the water content and the difference in the transmitted light amount is stored in the control unit 3. .. Then, the control unit 3 obtains the water content of the recording material by using the determination information based on the difference in the amount of transmitted light between the light L1L and the light L2L. It should be noted that the determination information may be obtained for each basis weight of the recording material used for image formation. In this case, the image forming apparatus 1 determines the water content of the recording material based on the determination information corresponding to the basis weight of the recording material to be image-formed. Subsequently, a method for obtaining the first transmitted light amount and the second transmitted light amount will be described. For example, when the light emitting intensity of the light emitting element L1 and the light emitting element L2 are equal and the light receiving sensitivity of each light receiving element of the line light receiving element LS is constant regardless of the wavelength, the first transmitted light amount and the second transmitted light amount are respectively. , Can be obtained as the amount of light received by the light L1L and the light L2L transmitted through the recording material P. However, in general, the light-receiving sensitivity of each light-receiving element of the line light-receiving element LS is wavelength-dependent, and the light-emitting intensities of the light-emitting element L1 and the light-emitting element L2 may not be equal. Therefore, first, the light receiving amount of the light L1L detected by the line light receiving element LS without transmitting the recording material P (hereinafter referred to as the paper non-light receiving amount) is obtained. Subsequently, the light receiving amount of the light L1L detected by the line light receiving element LS when the recording material P is transmitted (hereinafter referred to as the light receiving amount with paper) is obtained. Then, the ratio of the light receiving amount on paper to the light receiving amount on paper multiplied by the adjustment coefficient can be obtained as the transmitted light amount of the light L1L, that is, the first transmitted light amount. The same applies to the amount of second transmitted light. Here, the adjustment coefficient is a coefficient for correcting the difference between the sensitivity of each element of the line light receiving element LS with respect to the first wavelength and the sensitivity with respect to the second wavelength, and the difference in the emission intensity between the light emitting element L1 and the light emitting element L2. Is.

As described above, in the present embodiment, the recording material is pressed by the transparent pressing rotating body 33 to suppress the fluttering of the recording material. Then, the recording material is irradiated through the transparent pressing rotating body 33, and the value related to the water content of the recording material is detected by the amount of transmitted light. Therefore, it is possible to suppress the fluctuation of the transmitted light amount due to the fluttering of the recording material, and it is possible to accurately detect the value related to the water content of the recording material. It should be noted that the pressing rotating body 33 may not be entirely composed of a transparent member, but may be configured such that only the region through which the light L1L and L2L pass is a transparent member. Further, in the present embodiment, it is possible to detect a value related to the water content of the recording material without using an expensive light receiving element having a light receiving sensitivity at the absorption wavelength of water (1450 nm, 1940 nm, etc.). The present invention can also be used to detect the amount of water using the absorption wavelength of water. In addition, since the water content can be detected with high accuracy, it is possible to set image forming conditions suitable for the water content of each recording material. For example, the control unit 3 of the image forming apparatus appropriately sets transfer conditions such as transfer voltage (transfer bias) and transfer current when transferring an image to the recording material based on the detected value regarding the water content of the recording material. can do. Further, the control unit 3 of the image forming apparatus appropriately sets the fixing conditions such as the fixing temperature and the transport speed of the recording material when fixing the image on the recording material based on the detected value regarding the water content of the recording material. be able to.

<Second embodiment>
Subsequently, the second embodiment will be described focusing on the differences from the first embodiment. 9 and 10 are block diagrams of the moisture detection device 30 according to the present embodiment, and are diagrams corresponding to FIGS. 6 and 7 of the first embodiment. The same reference numerals are given to the same components as those of the moisture detection device 30 of the first embodiment, and the description thereof will be omitted. In the present embodiment, the pressing rotating body 34 is used instead of the pressing rotating body 33 of the first embodiment. Similar to the first embodiment, the pressing rotating body 34 includes two columnar members 331 and 332 having the same diameter for pressing the recording material, and a connecting member 343 for connecting the columnar members 331 and 332. There is. The two columnar members 331 and 332 are arranged at different positions in the direction orthogonal to the transport direction of the recording material, and the connecting member 343 is a member extended in the direction orthogonal to the transport direction of the recording material and is a pressing rotating body. Includes 34 rotation axes. However, the thickness of the connecting member 343 is made thinner than that of the connecting member 333 of the first embodiment. That is, the area of the cross section orthogonal to the rotation axis of the connecting member 343 is made smaller than the area of the cross section orthogonal to the rotation axis of the columnar members 331 and 332. Further, in the first embodiment, the rotation center of the pressing rotation 33 is located on the line connecting the light emitting elements L1 and L2 and the line light receiving element LS in the transport direction of the recording material. In the present embodiment, as shown in FIG. 10, the position 38 in the transport direction of the recording material at the center of rotation of the pressing rotating body 34 is located upstream of the position 37 of the first embodiment by a predetermined distance in the transport direction of the recording material. Shift.

Therefore, the lights L1L and L2L received by the line light receiving element LS do not pass through the connecting member 343. As shown in FIG. 9, the light L1L and L2L received by the line light receiving element LS include those that have passed through the columnar members 331 and 332. However, it is also possible to adjust the arrangement region of the line light receiving element LS so that the line light receiving element LS receives only the light L1L and L2L that do not pass through the pressing rotating body 34. As a result, the line light receiving element LS can receive light in which the attenuation of light by the pressing rotating body 34 is suppressed. Since the amount of light received by the line light receiving element LS becomes large, the amount of water contained in the recording material P can be accurately detected.

The amount of shift of the center of rotation to the upstream side in the recording material transport direction is determined within a range in which the fluttering of the recording material P in the optical path from the light emitting elements L1 and L2 to the line light receiving element LS can be suppressed. As an example, the shift amount is 5 mm or less. Alternatively, as shown in FIG. 10, the rotation center of the pressing rotating body may be shifted within the range in which the line connecting the light emitting elements L1 and L2 and the light receiving element LS penetrates the columnar members 331 and 332. Further, the direction in which the center of rotation is shifted may be on the downstream side in the recording material transport direction.

As described above, the connecting member 343 including the rotation axis of the pressing rotating body 34 is arranged at a position that does not interfere with the optical path from the light emitting elements L1 and L2 to the line light receiving element LS. With this configuration, it is possible to suppress the attenuation of light by the pressing rotating body 34, and thus to accurately detect the value related to the water content of the recording material. In this embodiment, the pressing rotating body 34 does not have to be a transparent member.

<Third embodiment>
Subsequently, the third embodiment will be described focusing on the differences from the first embodiment. 11 and 12 are block diagrams of the moisture detection device according to the present embodiment. 11 is a view seen from the upstream side in the transport direction of the recording material P, and FIG. 12 is a cross-sectional view taken along the line AA of FIG. The same reference numerals are given to the same components as those described in the first embodiment, and the description thereof will be omitted. As shown in FIG. 11, in the present embodiment, the arrangement positions of the light emitting elements L1 and L2 are shifted in a direction orthogonal to the transport direction as compared with the configuration of the first embodiment. In FIG. 11, it is shifted to the right side, but it may be on the left side. Further, instead of the pressing rotating body 33, the pressing rotating body 36 composed of the transparent member 36A and the black member 36B (shaded portion) is used. The black member 36B is provided so as to be located on a side different from the side on which the light emitting elements L1 and L2 are shifted. Further, on the same substrate as the line light receiving element LS, a light emitting element L3 and a light guide LG for guiding the light emitted by the light emitting element L3 to the recording material P are provided.

The light emitting element L3 and the light guide LG are provided to determine the surface property of the recording material. The principle of determining the surface property is described in, for example, Japanese Patent Application Laid-Open No. 2014-114131. Briefly, the light emitted by the light emitting element L3 irradiates the surface of the recording material P via the light guide LG, and the reflected light is received by the line light receiving element LS. There is a correlation between the degree of unevenness on the surface of the recording material P and the amount of reflected light. Therefore, a table showing the relationship between the degree of unevenness and the amount of reflected light is set in advance in the image forming apparatus, and the control unit 3 is based on the table and the line light receiving element LS of the reflected light of the light emitted by the light emitting element L3. The surface property of the recording material is determined based on the amount of light received.

FIG. 13 shows a state in which the light emitting elements L1, L2, and L3 are made to emit light, and corresponds to FIG. 6 of the first embodiment. The light emitted by the light emitting elements L1 and L2 is received by the line light receiving element LS via the transparent member 36A of the pressing rotating body 36 as in the first embodiment. However, in the present embodiment, since the light emitting elements L1 and L2 are shifted to the right side in the drawing, the light L1L and the light L2L are received by the light receiving element in the right half of the line light receiving element LS in the drawing. On the other hand, the light emitted by the light emitting element L3 irradiates the surface of the recording material P from the lower side in the drawing via the light guide LG. The light receiving element of the line light receiving element LS in a region different from the region that receives the light L1L and L2L receives the reflected light of the light emitted by the light emitting element L3. The black member 36B of the pressing rotating body 36 is located above the light receiving region of the line light receiving element LS of the light emitted by the light emitting element L3. That is, the black member 36B of the pressing rotating body 36 is arranged at a position facing the light receiving region of the line light receiving element LS of the light emitted by the light emitting element L3 via the recording material P. The amount of light transmitted by the black member 36B is weaker than that of the transparent member 36A. Therefore, due to the black member 36B, the transmitted light from the recording material P emitted by the light emitting elements L1 and L2 and the external light are transmitted to the light receiving element of the line light receiving element LS that receives the reflected light of the light emitted by the light emitting element L3. It is possible to suppress the incident. Therefore, it is possible to suppress deterioration of the determination accuracy of the surface property of the recording material P.

As described above, in the present embodiment, the moisture detection device can be provided with a function for discriminating the surface property of the recording material, the image forming device does not need to be separately provided with the function for discriminating the surface property of the recording material, and the image forming layer is miniaturized. can.

[Other embodiments]
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

31: light emitting unit, 32: light receiving unit, 3: control unit, 33: pressing rotating body

Claims (10)

Recording material transport path and
A light emitting means for emitting light having a first wavelength and light having a second wavelength different from the first wavelength.
A light receiving means that receives the light of the first wavelength and the light of the second wavelength emitted by the light emitting means on the side opposite to the light emitting means with respect to the transport path.
The amount of water contained in the recording material based on the amount of light received by the light receiving means of the first wavelength transmitted through the recording material and the amount of light received by the second wavelength light transmitted through the recording material. A detection means that detects the value of
A rotating body provided between the light emitting means and the light receiving means and pressing the recording material carried through the transport path, and a rotating body.
Equipped with
The rotating body is arranged at a different position in a direction orthogonal to the transport direction of the recording material, and includes two columnar members for pressing the recording material and a rotation axis of the rotating body, and the two columns. It is equipped with a connecting member that connects the members.
When viewed from the direction of the rotation axis, the optical path of light connecting the light emitting means and the light receiving means overlaps with the two columnar members and does not overlap with the connecting member. Detection device. The moisture detection device according to claim 1, wherein the rotating body is configured to rotate depending on the transport of the recording material. The detecting means receives light received by the light receiving means while the rotating body is rotating depending on the transport of the recording material, and the light receiving amount of the light of the first wavelength transmitted through the recording material and the recording material. The moisture detection device according to claim 2, wherein the value relating to the amount of water contained in the recording material is detected based on the amount of received light of the second wavelength light transmitted through the recording material. Further, another light emitting means is provided on the same side as the light receiving means with respect to the transport path.
The rotating body has a first region for transmitting light and a second region for transmitting light weaker than the first region, and is provided on the side of the light emitting means with respect to the transport path.
The light receiving means further receives the reflected light of the light emitted by the other light emitting means by the recording material.
The detection means further detects the surface property of the recording material based on the reflected light of the light emitted by the other light emitting means received by the light receiving means by the recording material.
The second region is characterized in that it is located at a position facing the region of the light receiving means that receives the reflected light of the light emitted by the other light emitting means by the recording material via the recording material. The moisture detection device according to any one of 1 to 3. The moisture detection device according to claim 4 , wherein the second region is a region composed of a black member. The aspect according to any one of claims 1 to 5 , wherein the area of the cross section of the connecting member orthogonal to the rotation axis is smaller than the area of the cross section of the two columnar members orthogonal to the rotation axis. Moisture detector. The moisture detection device according to any one of claims 1 to 6 , wherein the light receiving means includes a plurality of light receiving elements arranged along a direction orthogonal to the transport direction of the recording material. The moisture detection device according to any one of claims 1 to 7.
An image forming means for forming an image on the recording material,
A control means for controlling an image formation condition when an image is formed on the recording material based on a value related to the water content of the recording material detected by the detection means.
An image forming apparatus characterized by being equipped with. The image forming means includes a transfer means for transferring an image to the recording material.
The image according to claim 8 , wherein the control means controls a transfer voltage or a transfer current when the transfer means transfers an image to the recording material based on a value relating to a water content of the recording material. Forming device. The image forming means includes a fixing means for fixing an image on the recording material.
The image forming according to claim 8 or 9 , wherein the control means controls a fixing temperature when the fixing means fixes an image on the recording material based on a value relating to a water content of the recording material. Device.

Images