JP2020041935A - Toner deposition amount sensor - Google Patents

Abstract

To provide a toner deposition amount sensor that dispenses with a polarizing filter, which can suppress an increase in size of the whole sensor and in complexity of a structure.SOLUTION: Provided is a toner deposition amount sensor 100 that dispenses with a polarizing filter, comprising: a substrate 110; a lens holder 120; a light emitting element 130 for radiating irradiation light; a first light receiving element 140 for receiving regular reflection light and diffuse reflection light; a second light receiving element 150 for receiving only the diffuse reflection light; and a lens 160 having a light emitting lens part 162 and a light receiving lens part 163 on the underside. The lens holder 120 includes a light shielding wall 126 projecting to the inside of the lens 160. When it is assumed that θ represents the irradiation angle of irradiation light relative to a measurement object 10 and T represents height from the top face of the substrate 110 to the top face of the light shielding wall 126, the second light receiving element 150 is arranged in a first region that includes a region within Ttanθ from a projection region where the top face of the light shielding wall 126 is vertically projected to the top face of the substrate 110, and a region inside of said region.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a toner adhesion amount sensor that does not use a polarizing filter.

  As a toner adhesion amount sensor that does not use a polarizing filter, for example, those described in Patent Literature 1 or Patent Literature 2 are known. As shown in FIG. 5, a toner adhesion amount sensor 200 described in Patent Document 1 includes a substrate 210, a housing 220 disposed on the substrate 210, a light emitting element 230 disposed on the substrate 210 in the housing 220, A first light receiving element 240 and a second light receiving element 250.

  The first light receiving element 240 and the second light receiving element 250 are arranged apart from each other with the light emitting element 230 interposed therebetween. The first light receiving element 240 is disposed on the right side of the light emitting element 230, and the second light receiving element 250 is disposed on the left side of the light emitting element 230. The first light receiving element 240 mainly receives specularly reflected light, and the second light receiving element 250 mainly receives diffusely reflected light.

  The housing 220 has a first stop 221 on a path through which the irradiation light of the light emitting element 230 passes, a second stop 222 on a path through which the regular reflection light passes, and a third stop 223 on a path through which the diffuse reflection light passes. . Further, the housing has an inclined surface 224 on the upstream side of the first stop 221 for suppressing generation of stray light.

  As shown in FIG. 6, the toner adhesion amount sensor 300 described in Patent Document 2 includes a substrate 310, a housing 320 disposed on the substrate 310, a light emitting element 330 disposed on the substrate 310 in the housing 320, A first light receiving element 340 and a second light receiving element 350.

  The first light receiving element 340 and the second light receiving element 350 are arranged side by side in one package (mold resin). The first light receiving element 340 is arranged on a side far from the light emitting element 330, and the second light receiving element 350 is arranged on a side close to the light emitting element 330. The first light receiving element 340 receives specular reflection light and diffuse reflection light, and the second light reception element 350 receives only diffuse reflection light.

  The housing 320 has a first light shielding wall 321 and a second light shielding wall 322.

  The first light shielding wall 321 is provided between the light receiving element (the first light receiving element 340 and the second light receiving element 350) and the light emitting element 330. The first light shielding wall 321 prevents the irradiation light of the light emitting element 330 from being directly incident on the first light receiving element 340 and the second light receiving element 350.

  The second light shielding wall 322 is provided above the second light receiving element 350. The second light-shielding wall 332 guides the regular reflection light and the diffuse reflection light obtained from the first reflection area A1 of the measurement object to the first light receiving element 340, and obtains the light from the second reflection area A2 different from the first reflection area A1. Only the diffused reflected light is guided to the second light receiving element 350. That is, the second light-shielding wall 322 prevents the diffuse reflection light generated in the first reflection area A1 from being incident on the second light receiving element 350.

Japanese Patent No. 6272051 JP 2017-103497 A

  In the toner adhesion amount sensor 200 described in Patent Literature 1, the first light receiving element 240 and the second light receiving element 250 are arranged apart from each other with the light emitting element 230 interposed therebetween, so that the entire sensor becomes large. There is.

  In the toner adhesion amount sensor 300 described in Patent Document 2, the first light receiving element 340 and the second light receiving element 350 are arranged side by side in one package. As compared with, the whole sensor can be downsized. However, the toner adhesion amount sensor 300 described in Patent Literature 2 has a problem that the housing 320 has the first light shielding wall 321 and the second light shielding wall 322, so that the structure of the housing 320 is complicated, which leads to an increase in cost. is there.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a toner adhesion amount sensor that does not use a polarizing filter and that can suppress an increase in the size of the entire sensor and complexity of the structure. is there.

In order to solve the above-mentioned problem, a toner adhesion amount sensor according to the present invention includes:
Irradiation of the irradiation light to the measurement object to which the toner is adhered without polarization, a toner adhesion amount sensor without using a polarizing filter to receive the reflection light from the measurement object with respect to the irradiation light without polarization,
Board and
A lens holder disposed on the substrate and forming a first housing space and a second housing space separated from each other on the substrate;
A light-emitting element that is arranged on the substrate in the first housing space and irradiates the irradiation light;
A first light receiving element that is disposed on the substrate in the second housing space and receives regular reflection light and diffuse reflection light included in the reflected light;
A second light receiving element disposed on the substrate in the second housing space and receiving the diffuse reflected light;
A lens disposed on the lens holder and having a light-emitting lens portion positioned above the light-emitting element and a light-receiving lens portion positioned above the first light-receiving element and the second light-receiving element on a lower surface side; ,
The lens holder has a light shielding wall projecting into the lens between the first housing space and the second housing space,
When the irradiation angle of the irradiation light to the object to be measured is θ, and the height from the upper surface of the substrate to the upper surface of the light shielding wall is T, the upper surface of the light shielding wall is vertically projected on the upper surface of the substrate. The second light receiving element is arranged in a first area including an area within Ttan θ from the projection area and an area inside the area, and the first light receiving element is arranged outside the first area. And

  In this configuration, since the first light receiving element and the second light receiving element are arranged on the substrate in the second housing space, the first light receiving element and the second light receiving element can be arranged close to each other, and the sensor The overall size can be easily reduced.

  Further, in this configuration, when the irradiation angle of the irradiation light to the measurement object is θ and the height from the upper surface of the substrate to the upper surface of the light shielding wall is T, the upper surface of the light shielding wall is vertically projected on the upper surface of the substrate. The second light receiving element is arranged in a first area including an area within Ttan θ from the projection area. Therefore, with this configuration, it is possible to prevent specularly reflected light from entering the second light receiving element without complicating the structure of the lens holder (for example, without providing a plurality of light shielding walls).

In the above toner adhesion amount sensor,
The lens obtains the specularly reflected light and the diffusely reflected light from the same reflection area of the object to be measured, and makes the diffusely reflected light perpendicularly incident on the second light receiving element or obliquely incident from the first light receiving element side. Preferably.

In the above toner adhesion amount sensor,
The light shielding wall may be configured to reach an upper surface of the lens.

In the above toner adhesion amount sensor,
The lens holder has a diaphragm portion above the first housing space,
The aperture section may be configured to limit an irradiation range of the irradiation light.

  According to the present invention, it is possible to provide a toner adhesion amount sensor that does not use a polarizing filter and can suppress an increase in the size of the entire sensor and a complicated structure.

FIG. 2 is a cross-sectional view illustrating a toner adhesion amount sensor according to an embodiment of the present disclosure. FIG. 2 is a plan view showing a toner adhesion amount sensor according to one embodiment of the present invention. It is a figure for explaining arrangement of the 1st light sensing element and the 2nd light sensing element concerning one embodiment of the present invention, and (A) is a sectional view and (B) is a top view. FIG. 7 is a cross-sectional view illustrating a main part of a toner adhesion amount sensor according to another embodiment of the present invention. FIG. 10 is a cross-sectional view illustrating a conventional toner adhesion amount sensor. FIG. 10 is a cross-sectional view illustrating another conventional toner adhesion amount sensor.

  Hereinafter, an embodiment of a toner adhesion amount sensor according to the present invention will be described with reference to the accompanying drawings.

  1 and 2 show a toner adhesion amount sensor 100 according to an embodiment of the present invention. The toner adhering amount sensor 100 is a sensor that does not use a polarization filter that irradiates the measurement target 10 with the toner adhered thereto without irradiating the irradiation light with the polarization, and receives the reflection light of the irradiation light from the measurement target 10 without the polarization. It is. The measurement object 10 is, for example, a transfer belt or a photoconductor.

  The toner adhesion amount sensor 100 includes a substrate 110, a lens holder 120, a light emitting element 130, a first light receiving element 140, a second light receiving element 150, and a lens 160. Since the toner adhesion amount sensor 100 does not include a polarization filter, it is more advantageous in cost than a polarization separation type sensor.

  The substrate 110 is, for example, a rectangular printed wiring board. On an upper surface (mounting surface) of the substrate 110, a lens holder 120, a light emitting element 130, a first light receiving element 140, and a second light receiving element 150 are arranged. As shown in FIG. 2, the light emitting element 130, the first light receiving element 140, and the second light receiving element 150 are arranged in a line in the longitudinal direction of the substrate 110 at the center of the substrate 110.

  The lens holder 120 is made of a material that is opaque to light emitted from the light emitting element 130. The lens holder 120 has a lens fixing portion 121 (concave portion) on the upper surface side of the central portion, and has a first concave portion 122 and a second concave portion 123 on the lower surface side of the central portion.

  The lens fixing part 121 is formed in a shape that can fix the lens 160. The first recess 122 is configured to have a rectangular shape in plan view, and forms a first housing space surrounding the light emitting element 130 arranged on the substrate 110. The second concave portion 123 is configured to have a rectangular shape in a plan view, and forms a second housing space surrounding the first light receiving element 140 and the second light receiving element 150 arranged on the substrate 110. The first storage space and the second storage space are separated from each other.

  The lens holder 120 has a first opening 124 above the first recess 122, has a second opening 125 above the second recess 123, and has the first opening 124 and the second opening 125. And a light shielding wall 126 between them.

  The first opening 124 has an elliptical cross section and is configured to be connected to the first housing space. The first opening 124 is located above the light emitting element 130 and functions as a diaphragm that limits the irradiation range of the light emitted from the light emitting element 130. Thus, the first opening 124 can narrow the irradiation area on the measurement target 10.

  The second opening 125 has a rectangular cross section substantially the same size as the second recess 123 and is configured to be connected to the second housing space. The second opening 125 does not function as a stop. The second opening 125 and the second recess 123 may be constituted by one through hole.

  The light blocking wall 126 is configured to protrude into the lens 160 between the first housing space and the second housing space. The light shielding wall 126 is provided to prevent specularly reflected light from entering the second light receiving element 150.

  The light shielding wall 126 extends perpendicular to the upper surface of the substrate 110, and the upper surface of the light shielding wall 126 reaches the upper surface of the lens 160. Accordingly, the light shielding wall 126 can prevent the irradiation light (stray light) of the light emitting element 130 reflected on the upper surface of the lens 160 from being incident on the first light receiving element 140 and / or the second light receiving element 150.

  The side surface of the light shielding wall 126 on the side of the second housing space is flush with the side surface of the second opening 125. Further, as shown in FIG. 2, the light shielding wall 126 is configured to be rectangular in plan view, and the length of the light shielding wall 126 in the width direction (transverse direction of the substrate 110) is equal to that of the first recess 122 and The length is the same as the length of the second recess 123 in the width direction.

  The light emitting element 130 is arranged on the substrate 110 in the first accommodation space and emits irradiation light. As the light emitting element 130, for example, an infrared light emitting diode (infrared LED) that emits infrared light or a red light emitting diode (red LED) that emits red light can be used.

  The first light receiving element 140 is arranged on the substrate 110 in the second accommodation space, and receives the regular reflection light and the diffuse reflection light included in the reflection light. The specularly reflected light is light reflected by the light emitted from the light emitting element 130 which is mainly specularly reflected in a region of the measurement object 10 where the toner is not attached. The diffusely reflected light is light reflected by the light emitted from the light emitting element 130, which is irregularly reflected mainly by the toner attached to the measurement object 10.

  The second light receiving element 150 is disposed on the substrate 110 in the second housing space and closer to the light shielding wall 126 than the first light receiving element 140. The second light receiving element 150 receives only diffuse reflection light without receiving regular reflection light. The diffusely reflected light enters the second light receiving element 150 vertically or obliquely from the first light receiving element 140 side.

  As the first light receiving element 140 and the second light receiving element 150, a photodiode or a phototransistor can be used. In the present embodiment, since the first light receiving element 140 and the second light receiving element 150 are mounted on the substrate 110 as bare chips that are not packaged (resin-sealed), the first light receiving element 140 and the second light receiving element 150 Can be shortened. This facilitates downsizing of the entire sensor. Further, the first light receiving element 140 and the second light receiving element 150 can receive substantially the same amount of diffuse reflected light, and output errors of both can be reduced.

  The first light receiving element 140 and the second light receiving element 150 perform photoelectric conversion and output an electric signal corresponding to the amount of received light to an arithmetic circuit (not shown) mounted on the substrate 110. The arithmetic circuit calculates the difference between the output of the first light receiving element 140 and the output of the second light receiving element 150, thereby obtaining an output proportional to the amount of specularly reflected light, that is, an area where no toner is attached. . The output value increases when the toner adhesion amount is small (the area where no toner is attached), while the output value decreases when the toner adhesion amount is large (the area where the toner is not attached is small). The arithmetic circuit may be provided outside the toner adhesion amount sensor 100.

  The lens 160 is made of a material that is transparent to light emitted from the light emitting element 130, and is disposed on the lens fixing portion 121 on the upper surface of the lens holder 120. The lens 160 has a convex lens portion 161 on the upper surface side, and has a light emitting lens portion 162 and a light receiving lens portion 163 on the lower surface side.

  The convex lens portion 161 faces the light emitting lens portion 162 and the light receiving lens portion 163 on the lower surface side. The upper surface of the convex lens portion 161 is flat, and the length of the convex lens portion 161 in the width direction is larger than the length of the light shielding wall 126 in the width direction.

  The light-emitting lens unit 162 is located above the light-emitting element 130 and condenses the irradiation light of the light-emitting element 130, while the light-receiving lens unit 163 is located above the first light-receiving element 140 and the second light-receiving element 150. Collects specularly reflected light and diffusely reflected light. The light emitting lens part 162 is formed at a position higher than the light receiving lens part 163.

  The light-emitting lens unit 162 and the light-receiving lens unit 163 obtain specularly reflected light and diffusely reflected light from the same reflection area of the measurement object 10 and make the specularly reflected light and diffusely reflected light incident on the first light receiving element 140. The second light receiving element 150 is configured such that only diffusely reflected light is vertically incident or obliquely incident from the first light receiving element 140 side.

  With this configuration, the first light receiving element 140 and the second light receiving element 150 can receive diffusely reflected light from the same reflection area, so that an output error between them becomes small. As a result, the detection accuracy of the toner adhesion amount is improved.

  Further, according to this configuration, the diffuse reflection light is vertically incident on the second light receiving element 150 or obliquely incident from the first light receiving element 140 side, so that the second light receiving element 150 is disposed near the light shielding wall 126 and the sensor is disposed. The entire height can be reduced (a first region L1 described below is reduced), and specularly reflected light can be reliably prevented from entering the second light receiving element 150.

  Next, a preferred arrangement of the first light receiving element 140 and the second light receiving element 150 will be described with reference to FIG.

  Assuming that the irradiation angle of the irradiation light of the light emitting element 130 is θ, the incident angle of the regular reflection light is also θ. Here, assuming that the height from the upper surface of the substrate 110 to the upper surface of the light-shielding wall 126 is T, the first region L1 within Ttanθ from the projection region in which the upper surface of the light-shielding wall 126 is vertically projected on the upper surface of the substrate 110 is specularly reflected. This is a region where light does not enter.

  In the present embodiment, the second light receiving element 150 is arranged in the first area L1 (hatched area in FIG. 3B), while the first light receiving element 140 is arranged in the second area L2 outside the first area L1. . Note that the heights of the second light receiving element 150 and the first light receiving element 140 are much smaller than the height T and can be ignored.

  With this configuration, the toner adhesion amount sensor 100 according to the present embodiment allows specular reflection light to the second light receiving element 150 without complicating the structure of the lens holder 120 (for example, without providing a plurality of light shielding walls). It is possible to prevent incidence.

  The embodiment of the toner adhesion amount sensor according to the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, the lens holder of the present invention forms a first housing space and a second housing space separated from each other on the substrate 110, and projects into the lens 160 between the first housing space and the second housing space. If the light shielding wall 126 is provided, the configuration can be appropriately changed.

  When the diffuse reflection light is obliquely incident on the second light receiving element 150 from the first light receiving element 140 side, the second light receiving element 150 is positioned on the inner side of the light shielding wall 126 with respect to the top of the light shielding wall 126 (light emission). (The element 130 side). That is, the first region L1 in the present invention includes the region within Ttan θ of the above embodiment and the region inside the region.

  FIG. 4 is a cross-sectional view of a main part of a toner adhesion amount sensor according to another embodiment of the present invention. By making the lower part of the side surface of the light shielding wall 126 an inclined surface, the second light receiving element 150 can be arranged inside the light shielding wall 126. Thus, only the diffusely reflected light obliquely incident from the first light receiving element 140 side can be received by the second light receiving element 150 without preventing the diffused reflected light from being incident. Further, by disposing the second light receiving element 150 inside the light shielding wall 126 and separating the first light receiving element 140 and the second light receiving element 150 in this manner, the size of the toner adhesion sensor 100 can be reduced. Even if the measurement object 10 is inclined with respect to the optical axis, it is possible to reliably prevent specular reflection light from entering the second light receiving element 150.

  The upper surface of the light shielding wall of the present invention does not have to reach the upper surface of the lens 160, and the upper surface may be higher than the upper surface of the lens 160.

Reference Signs List 10 Measurement object 100 Toner adhesion amount sensor 110 Substrate 120 Lens holder 121 Lens fixing part 122 First concave part 123 Second concave part 124 First opening 125 Second opening 126 Light shielding wall 130 Light emitting element 140 First light receiving element 150 Second Light receiving element 160 Lens 161 Convex lens 162 Light emitting lens 163 Light receiving lens

Claims (4)

Irradiation of the irradiation light to the measurement object to which the toner is adhered without polarization, a toner adhesion amount sensor without using a polarizing filter to receive the reflection light from the measurement object with respect to the irradiation light without polarization,
Board and
A lens holder disposed on the substrate and forming a first housing space and a second housing space separated from each other on the substrate;
A light-emitting element that is arranged on the substrate in the first housing space and irradiates the irradiation light;
A first light receiving element that is disposed on the substrate in the second housing space and receives regular reflection light and diffuse reflection light included in the reflected light;
A second light receiving element disposed on the substrate in the second housing space and receiving the diffuse reflected light;
A lens disposed on the lens holder and having a light-emitting lens portion positioned above the light-emitting element and a light-receiving lens portion positioned above the first light-receiving element and the second light-receiving element on a lower surface side; ,
The lens holder has a light shielding wall projecting into the lens between the first housing space and the second housing space,
When the irradiation angle of the irradiation light to the object to be measured is θ, and the height from the upper surface of the substrate to the upper surface of the light shielding wall is T, the upper surface of the light shielding wall is vertically projected on the upper surface of the substrate. The second light receiving element is arranged in a first area including an area within Ttan θ from the projection area and an area inside the area, and the first light receiving element is arranged outside the first area. Toner amount sensor. The lens obtains the specularly reflected light and the diffusely reflected light from the same reflection area of the object to be measured, and makes the diffusely reflected light perpendicularly incident on the second light receiving element or obliquely incident from the first light receiving element side. The toner adhesion amount sensor according to claim 1, wherein 3. The toner adhesion amount sensor according to claim 1, wherein the light shielding wall reaches an upper surface of the lens. The lens holder has a diaphragm portion above the first housing space,
4. The toner adhesion amount sensor according to claim 1, wherein the aperture unit limits an irradiation range of the irradiation light. 5.

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