JP2013080176A - Recording material discriminating device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve discrimination accuracy by preventing variation in position of recording materials by a recording material detecting unit and adhesion of powder of recording materials to the recording material detecting unit.SOLUTION: A recording material discriminating device includes a sled-shaped protrusion 5 that is integrally formed with a diffuser panel 4 and presses a recording material against glass 2. The sled-shaped protrusion 5 is arranged on the surface of the diffuser plate 4 at a position different from an area A where light radiated from a light radiation element 3 and detected by a detecting unit 1 transmits; and the area A is separated from the recording material in a state where the recording material is pressed by the sled-shaped protrusion 5.

Description

  The present invention relates to a recording material discriminating apparatus for discriminating the type of recording material, and an image forming apparatus provided with the same.

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a laser printer, the size and type (hereinafter also referred to as paper type) of a recording material are set by a user on an operation panel or the like provided in the image forming apparatus main body. The following control is performed according to the setting. That is, control is performed to change development conditions, transfer conditions, fixing processing conditions (for example, a fixing temperature and a conveyance speed of a recording material passing through the fixing device), or image processing. Alternatively, when the user sets a paper type at the time of printing (image formation) from the host computer, the image forming apparatus changes development conditions, transfer conditions, fixing processing conditions, or image processing according to the designated paper type. Control is performed.
Here, in Patent Document 1, a surface image of a recording material is captured by a CMOS sensor, the type of the recording material is determined by a method of detecting the surface smoothness of the recording material, and development conditions, transfer conditions, or fixing conditions are variable. It has been proposed to control.
Further, there is provided an apparatus for discriminating the type of recording material by providing a light emitting source at a position facing a sensor for discriminating the recording material and detecting the basis weight of the recording material by the transmitted light by detecting the transmitted light. Proposed.
In such a recording material discriminating device that detects the surface smoothness and the basis weight due to transmitted light, in order to eliminate the positional variation of the recording material, the recording material is sandwiched between mechanical members and the recording material is prevented from floating. Was detected and the recording material was discriminated.

JP 2002-182518 A

However, the conventional image forming apparatus as described above has the following problems.
When the recording material is sandwiched between mechanical members and the recording material is detected as in the past, in some cases, foreign matter such as fine paper dust or oil stains adhering to the recording material when the recording material is sandwiched. There is a risk of being stuck to the mechanical member. As a result, there has been a concern that the reliability of the detection result of the surface smoothness and the detection result of the basis weight may be impaired.
Further, if a mechanical member that wipes off the powder adhering to the mechanical member is separately provided, it is possible to improve the detection result of the surface smoothness and the basis weight. However, in order to keep the detection result good, a special mechanical member has to be provided.
The present invention has been made in view of the circumstances as described above, and prevents the recording material powder from adhering to the recording material detection unit while preventing the recording material position variation in the recording material detection unit. The purpose is to improve.

In order to achieve the above object, the present invention provides:
A mounting member on which the recording material is mounted;
Irradiation means for emitting light to the recording material placed on the placement member,
A transmissive member through which the light emitted by the irradiating means is transmitted;
Detecting means for detecting light from the recording material;
In the recording material discriminating apparatus for discriminating the type of the recording material based on the output of the detecting means,
It is formed integrally with the transmission member, and has a pressing part that presses the recording material onto the mounting member.
The pressing portion is disposed at a position different from a transmission region through which light irradiated by the irradiation unit and detected by the detection unit is transmitted on the surface of the transmission member, and the pressing unit pressed the recording material. In the state, the transmission region is separated from the recording material.

  According to the present invention, it is possible to improve the discrimination accuracy by preventing the recording material powder from adhering to the recording material detection unit while preventing the recording material position variation in the recording material detection unit.

Sectional drawing which shows schematic structure of the recording material discrimination apparatus of Example 1. FIG. Sectional drawing which shows schematic structure of the image forming apparatus of Example 1. FIG. Schematic diagram showing an image detected by the detection unit in the first embodiment. Sectional drawing which shows schematic structure of the recording material discrimination apparatus of Example 2. FIG. Sectional drawing which shows schematic structure of the recording material discrimination device of Example 3. Sectional drawing which shows schematic structure of the recording material discrimination device of a prior art example Schematic showing the image detected by the detector in the conventional example

DETAILED DESCRIPTION Exemplary embodiments for carrying out the invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.
The present invention relates to a recording material discriminating apparatus that has a detecting means for detecting the surface smoothness and basis weight of a recording material and discriminates the type of the recording material based on the output of the detecting means. The present invention also relates to an image forming apparatus that controls image forming conditions from the surface smoothness of the recording material and the basis weight detection result (discrimination result of the recording material discrimination device).

Example 1 will be described below.
FIG. 2 is a schematic cross-sectional view illustrating a schematic configuration of an image forming apparatus 101 as an example that suitably illustrates the image forming apparatus according to the present exemplary embodiment.

  As shown in FIG. 2, the image forming apparatus 101 includes a recording material cassette 102, a feeding roller 103, a transfer belt driving roller 104, a transfer belt 105, photosensitive drums 106 to 109 as an image carrier, and a transfer roller as a transfer unit. 110-113. The photosensitive drums 106 to 109 constitute cartridges 114 to 117 integrally with process means (charging means, developing means, etc.) acting on the photosensitive drum, respectively. The image forming apparatus 101 includes optical units 118 to 121, a fixing unit 122 as a fixing unit, and the like. Here, the photosensitive drums 106 to 109, process means (charging means, developing means, etc.) acting on the photosensitive drum, the transfer rollers 110 to 113, the optical units 118 to 121, and the fixing unit 122 constitute image forming means. .

  In the image forming apparatus 101, toner images of respective colors of yellow, magenta, cyan, and black are transferred onto the surface of the recording material by using an electrophotographic process. Thereafter, the recording material is heated at a predetermined temperature and pressed by a fixing roller (not shown) of the fixing unit 122 to fix the toner image on the recording material.

The optical units 118 to 121 of the respective colors are configured to form an electrostatic latent image by exposing and scanning the surfaces of the photosensitive drums 106 to 109 with a laser beam. These series of operations are scanning-controlled in synchronization with the recording material conveyance operation so that the image is transferred from a predetermined position on the recording material to be conveyed.
The electrostatic latent images formed on the surfaces of the respective photosensitive drums 106 to 109 are visualized as toner images by toners as developers of the respective colors by a developing device (not shown) provided in the cartridges 114 to 117.

  The image forming apparatus 101 also includes a motor for feeding and conveying the recording material, a motor for driving the transfer belt driving roller 104, a motor for driving the photosensitive drums 106 to 109 and the transfer rollers 110 to 113, and a fixing roller. And a driving motor.

Further, the image forming apparatus 101 includes a reading unit (recording material detection unit, image reading unit) 23 for determining a recording material.
The reading unit 23 irradiates light onto the surface of the recording material fed and conveyed from the recording material cassette 102 by the feeding roller 103, collects the reflected light and forms an image, and forms a specific area with the recording material. Detect video of. Further, the reading unit 23 detects the transmitted light of the light irradiation unit 24 disposed at a position facing the reading unit 23.

Next, the operation of the recording material will be described with reference to FIG.
First, when a print instruction is sent to the image forming apparatus 101 from a host computer (not shown) or the like, the recording material is picked up and fed by the feed roller 103. Then, the recording material is temporarily stopped between the reading unit 23 and the light irradiation unit 24, and the surface smoothness and basis weight of the recording material are measured by the reading unit 23 and the light irradiation unit 24. By measuring the surface smoothness and basis weight of the recording material, the type of the recording material can be identified.
The print control is changed (image forming conditions are controlled) based on the measurement results of the surface smoothness and basis weight of the recording material (results of determining the type of recording material). For example, the print speed is changed to 1/2 speed or 1/3 speed.

Thereafter, the conveyance of the recording material, that is, the image forming operation is resumed by the print control determined based on the measurement result of the surface smoothness and the basis weight of the recording material.
The recording material on which the toner images of yellow, magenta, cyan, and black are superimposed and transferred on the surface of the recording material, and the recording material on which the unfixed toner image is formed is heated and pressurized by the fixing unit 122 at a predetermined temperature. As a result, the toner image is fixed on the recording material. Thereafter, the recording material on which the toner image is fixed is discharged from the image forming apparatus 101, and printing is completed.

Next, a characteristic configuration of the present embodiment will be described.
FIG. 1 is a cross-sectional view showing a schematic configuration of a recording material discriminating apparatus that detects the amount of transmitted light in order to detect the surface smoothness and basis weight of the recording material in this embodiment, and the apparatus shown in FIG. FIG. 1 (b) shows a cross-section taken by changing the direction by 90 degrees. FIG. 1B shows an image forming surface of the recording material (a surface parallel to the mounting surface 2a on which the recording material is placed in the glass 2 described later) with respect to the recording material conveyance direction (paper passing direction). It is a view seen from the orthogonal direction (width direction of the recording material).

The reading unit 23 includes a detection unit (image reading sensor, detection unit) 1 (for detecting an image formed on the recording material) 1 for determining the type of the recording material, and a transparent cover that covers the detection unit 1. It is comprised by providing with the glass 2 which is. Here, the glass 2 corresponds to a mounting member (second transmitting member).
A light irradiation unit 24 is disposed at a position facing the detection unit 1. The light irradiation unit 24 is provided with a light irradiation element 3 as an irradiation unit that emits light to a recording material placed on the glass 2 (on the placement member). In addition, a diffusion plate 4 is provided between the light irradiation element 3 and the reading unit 23 in the light irradiation unit 24 to diffuse the light and make the light uniform. Thus, the reading unit 23 is disposed so as to face the light irradiation element 3 with the diffusion plate 4 and the glass 2 interposed therebetween.
The light irradiated by the light irradiation element 3 passes between the coil springs 31 held by the holding member 32, passes through the diffusion plate 4, and is irradiated to the reading unit 23.

  The diffusing plate 4 is integrally formed with a warped projection 5 as a pressing portion for pressing the recording material against the glass 2. The diffusion plate 4 is pressed against the glass 2 by a coil spring 31. The coil spring 31 is made so as to exhibit a force necessary to bring the recording material into close contact with the glass 2 and an appropriate force that does not overpress the diffusion plate 4 against the glass 2.

When the recording material is conveyed, the recording material is passed between the diffusion plate 4 and the glass 2, and the recording material is placed on the glass 2. It is configured to suppress.
The type of the recording material is determined by irradiating the light radiating element 3 with the recording material pressed against the glass 2 by the warped projection 5 of the diffusing plate 4 and passing through the diffusing plate 4, the recording material and the glass 2. This is performed by detecting the detected light by the detection unit 1.

  FIG. 6 is a cross-sectional view showing a schematic configuration of a conventional recording material discriminating apparatus. In FIG. 6, the constituent members are shown corresponding to FIG. 1 so as to be easily compared with the configuration of the present embodiment, and the same members as the constituent members of the present embodiment are denoted by the same reference numerals. Also in FIG. 6, as in FIG. 1, FIG. 6B is a cross-sectional view of the apparatus shown in FIG. 6A with the orientation changed by 90 degrees, and FIG. 6B shows the image forming surface of the recording material. FIG. 5 is a diagram viewed from a direction (recording material width direction) orthogonal to the recording material conveyance direction (paper passing direction).

A light irradiation unit 24 is disposed at a position opposite to the detection unit 1. The light irradiation unit 24 is provided with a light irradiation element 3, and a diffusion plate 6 for diffusing light is provided between the light irradiation unit 24 and the reading unit 23.
FIG. 7 is a schematic diagram showing an image G2 detected by the detection unit 1 in the conventional example shown in FIG.
In the configuration of FIG. 6, light that is located on a straight line connecting the detection unit 1 and the light irradiation element 3 on the surface of the diffusion plate 4 that faces the glass 2, and is detected by the detection unit 1 irradiated by the light irradiation element 3. Since the region through which the light passes is in contact with the glass 2, there is a concern that paper dust adheres to the glass 2 or the diffusion plate 4. In the image detected by the detection unit 1, as shown in FIG. 7, a black portion corresponding to paper dust has been detected.

On the other hand, in this embodiment, the difference between this embodiment shown in FIG. 1 and the conventional example shown in FIG. 6 is in the shapes of the diffusion plate 4 and the diffusion plate 6 for diffusing light.
Hereinafter, the shape of the diffusion plate 4 will be described.
As described above, the warped projection 5 is integrally formed on the diffusion plate 4.
The warped projection 5 is located at a position different from the area (transmission area) A through which the light irradiated by the light irradiation element 3 and detected by the detection unit 1 is transmitted on the surface of the diffusion plate 4 facing the glass 2. It is arranged. For this reason, in a state where the recording material is pressed against the glass 2 by the warped projection 5, the recording material is separated from the region A on the surface of the diffusion plate 4.
In this embodiment, as shown in FIG. 1A, the warped projection 5 is a projection such as projections at both ends in a concave shape when viewed from the sheet passing direction. In other words, the warped projection 5 has both end portions (area A) in the diffusion plate 4 in the direction parallel to the placement surface 2a on which the recording material is placed on the glass 2 and perpendicular to the recording material conveyance direction. The projections are provided on both sides of the projection. Further, as shown in FIG. 1B, the warped projection 5 is a flat projection extending in the paper passing direction (recording material conveyance direction).

By adopting such a configuration, the recording material is not strongly pressed against the area A on the surface of the diffusion plate 4 and the area A facing the area A of the glass 2, so that foreign matters such as fine paper dust and oil stains are present. However, it becomes difficult to adhere to these. Accordingly, it is possible to prevent the recording material powder from adhering to the recording material detection unit and improve the discrimination accuracy while suppressing the positional variation of the recording material in the recording material detection unit.
In addition, compared to the configuration in which the pressing portion is formed on another member integrated with the diffusion plate 4, the pressing portion is formed in the region A by forming the warped projection 5 as the pressing portion integrally on the diffusion plate 4 itself. It can be placed as close as possible. For this reason, it is possible to suppress the floating of the portion facing the region A of the recording material as much as possible.

Further, a curved portion 7 is provided in the warp-like projection 5 of the diffusion plate 4 in the sheet passing direction so that the front end portion of the recording material easily enters under the diffusion plate 4 (between the glass 2 and the diffusion plate 4). It has become. Without this part, there is a concern that the recording material may be caught on the end of the diffusing plate 4 and easily jammed.
Although the paper dust is generated when the warped projection 5 rubs the recording material, even if the paper dust is conveyed to the recording material and accumulates in the diffusion plate 4, the downstream end of the warped projection 5 in the recording material conveyance direction. And does not collect in the optical path irradiated by the light irradiation element 3.

  FIG. 3 is a schematic diagram showing an image G1 detected by the detection unit 1 in the present embodiment. In this embodiment, the glass 2 and the region A of the diffusion plate 4 are not in contact with each other through the recording material on the straight line connecting the detection unit 1 and the light irradiation element 3 as shown in FIG. As a result, no foreign matter is attached. Therefore, as shown in FIG. 3, the image detected by the detection unit 1 is clear.

As described above, by using the diffusing plate 4 of the present embodiment, the light irradiated by the light irradiation element 3 on the surface of the diffusing plate 4 and detected by the detecting unit 1 while preventing the position variation of the recording material in the reading unit 23. It is possible to prevent foreign matter from adhering to the region A through which the light passes and the portion of the glass 2 facing the region A. As a result, the recording material discrimination accuracy can be further improved.
Here, in this embodiment, the diffusion plate 4 is applied as a pressing member that presses the recording material against the glass 2. However, the present invention is not limited to this, and the pressing member may be a light transmissive member such as glass. There may be.
Further, in this embodiment, the recording material discriminating apparatus shown in FIG. 1 has a configuration in which the light irradiation element 3 and the detection unit 1 are arranged with the recording material interposed therebetween, and the detection unit 1 detects light transmitted through the recording material. . However, the recording material discrimination device is not limited to this. For example, the detection unit 1 is arranged on the same side as the light irradiation element 3, and the light irradiated by the light irradiation element 3 and reflected by the recording material is detected by the detection unit 1. Even if it is a structure, this invention is applicable.

  Example 2 will be described below. In the present embodiment, the basic configuration other than the configuration for preventing the position variation of the recording material and the shape of the diffusion plate is the same as that of the first embodiment. Omitted.

  FIG. 4 is a cross-sectional view showing a schematic configuration of the recording material discriminating apparatus according to the present embodiment. FIG. 4B is a cross-sectional view of the apparatus shown in FIG. It is. FIG. 4B is a view as seen from the direction (width direction of the recording material) orthogonal to the recording material conveyance direction (paper passing direction) on the image forming surface of the recording material.

As shown in FIG. 4B, the diffusion plate 21 is integrally formed with a convex portion 21 a as a pressing portion provided on the downstream side of the diffusion plate 21. The convex portion 21 a is configured to be in contact with the glass 2, and the recording material is sandwiched between the convex portion 21 a on the downstream side of the diffusion plate 21 and the glass 2. Further, the convex portion 21a on the downstream side of the diffusing plate 21 is located on the downstream side in the recording material transport direction from the region A through which the light irradiated by the light irradiation element 3 on the surface of the diffusing plate 4 is transmitted. To position.

  Further, in the configuration of this example, as a result of observing the state after passing a large number of recording materials, the paper dust was found on the diffusion plate 21 at the portions facing the convex portions 21a and the convex portions 21a of the glass 2. Is attached, but is not attached to the region A where the light irradiated by the light irradiation element 3 on the surface of the diffusion plate 21 and the light detected by the detection unit 1 is transmitted and the portion facing the region A of the glass 2 It was.

As described above, also in this embodiment, the recording material is sandwiched between the diffusing plate 21 and the glass 2 so that the positional variation of the recording material can be reduced, and further, the light irradiation element 3 on the surface of the diffusing plate 21 is irradiated. It becomes possible to prevent foreign matter from adhering to the region A where the light detected by the detection unit 1 is transmitted and the region A of the glass 2 facing the region A. Therefore, the same effect as in the first embodiment can be obtained.
Here, although the present Example demonstrated the structure which the convex part 21a of the downstream of the diffusion plate 21 contact | connects the glass 2, it is not restricted to this, The part of the upstream of the area | region A among the diffusion plates 21 The structure which touches the glass 2 may be sufficient.

Example 3 will be described below. In the present embodiment, the basic configuration other than the configuration for preventing the position variation of the recording material and the shape of the diffusion plate is the same as the above-described embodiment. Omitted.
FIG. 5 is a cross-sectional view showing a schematic configuration of the recording material discriminating apparatus according to the present embodiment. FIG. 5 (b) shows a cross-section of the apparatus shown in FIG. It is. FIG. 5B is a diagram viewed from a direction orthogonal to the recording material conveyance direction on the image forming surface of the recording material.

  As shown in FIG. 5 (b), the diffusion plate 22 as a pressing member is located upstream of the region A through which light irradiated by the light irradiation element 3 on the surface of the diffusion plate 22 and detected by the detection unit 1 is transmitted. Sledge-like protrusions 22a are formed on the part and the downstream part so as to protrude from the diffusion plate main body so as to be in contact with the glass 2. Then, the recording material is sandwiched between the warped projection 22 a and the glass 2 in the diffusion plate 22.

In the configuration of this embodiment, as a result of observing the state after passing a large number of recording materials, the foreign matter is irradiated by the light irradiation element 3 on the surface of the diffusion plate 22 and the region A through which the light detected by the detection unit 1 is transmitted. And a region A through which the light irradiated by the light irradiation element 3 on the surface of the diffuser plate 22 and transmitted by the detection unit 1 is transmitted, although attached to a portion other than the portion facing the region A of the glass 2 The glass 2 was not attached to the portion facing the region A.
Thus, also in the present embodiment, the same effects as those of the first and second embodiments can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Detection part, 2 ... Glass, 3 ... Light irradiation element, 4 ... Diffusing plate, 5 ... Sled-like protrusion, A ... Area | region (transmission area | region)

Claims (5)

A mounting member on which the recording material is mounted;
Irradiation means for emitting light to the recording material placed on the placement member,
A transmissive member through which the light emitted by the irradiating means is transmitted;
Detecting means for detecting light from the recording material;
In the recording material discriminating apparatus for discriminating the type of the recording material based on the output of the detecting means,
It is formed integrally with the transmission member, and has a pressing part that presses the recording material onto the mounting member.
The pressing portion is disposed at a position different from a transmission region through which light irradiated by the irradiation unit and detected by the detection unit is transmitted on the surface of the transmission member, and the pressing unit pressed the recording material. The recording material discriminating apparatus according to claim 1, wherein the transmission region is separated from the recording material.   The pressing portion is arranged on both sides of the transmission region in a direction parallel to the mounting surface on which the recording material is placed and perpendicular to the recording material conveyance direction. The recording material discrimination device according to claim 1.   The recording material determination apparatus according to claim 1, wherein the pressing portion is disposed downstream of the transmission region in the recording material conveyance direction.   The mounting member is a second transmitting member through which light emitted from the irradiation unit and transmitted through the recording material is transmitted, and the detection unit detects light transmitted through the second transmitting member. Item 4. The recording material discrimination device according to any one of Items 1 to 3. A recording material discrimination device according to any one of claims 1 to 4,
Image forming means for forming an image on a recording material;
And an image forming condition of the image forming means is controlled based on a discrimination result of the recording material discrimination device.

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