JP2005091912A - Photodetector and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photodetector and an image forming apparatus that remove stains sticking on a plurality of marks formed on a surface of a belt and stains sticking on a sensor-side mark detection part (a light projection hole or a photodetection part, in the case of an optical sensor), without newly providing a driving device. <P>SOLUTION: A photosensor 101 detects the displacing or moving speed of a reflection scale 110 according to the quantity of reflected light from the reflection-type scale 110. A brush-driving part 131 drives a brush 131, by using the driving force of the driving source of the reflection type scale 110, to remove foreign matters on the optical sensor 101. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a photodetection device and an image forming apparatus, and more particularly to a photodetection device and an image forming apparatus that measure the amount of movement of a moving member.

  In an image forming apparatus provided with a rotating body for image formation such as a photoreceptor belt and an intermediate transfer belt, in order to perform high-precision alignment of an image on a transfer material conveyed by the rotation moving unit and the rotation moving unit In addition, it is required to accurately control the moving amount and moving position of the rotary moving part of the rotating body.

However, if the rotational angular velocity of the rotating body fluctuates for some reason, the moving amount and moving position of the rotary moving portion of the rotating body also changes, and the image on the transfer material conveyed by the rotary moving portion or the rotary moving portion. It was difficult to suppress the position error of the above with high accuracy.
As a conventional technique for solving such a problem, for example, a transfer belt or a paper transport belt is used in order to suppress an image position error due to fluctuations in the moving speed of the rotational movement portion of the rotating body with high accuracy. A rotary encoder is directly connected to the rotating shaft of the driving roller in the endless belt-shaped rotating body or the rotating shaft of a cylindrical member such as a photosensitive drum, and the rotating body is determined based on the rotational angular velocity of the rotating body detected by the encoder. There is known an image forming apparatus that controls the rotational angular velocity of a driving motor that is a driving means.
This image forming apparatus indirectly controls the amount of movement (moving position) of the rotationally moving portion of the rotating body by controlling the rotational angular velocity of the rotating body.
In addition, there is a conventional technique using a method of forming a mark on the belt surface, calculating a belt surface speed from a pulse interval obtained by detecting the mark with a sensor, and feeding back to the control. According to this prior art, since the behavior of the belt surface can be directly observed, the movement amount can be directly controlled.

But there is a further problem here. In particular, in the case of a method in which a mark is formed on the belt surface (detection object) and the mark is detected by a sensor, it is difficult to completely casing the mark and the sensor due to the structure, Since the mark is formed on the belt surface, the influence of the stain is increased because the mark and the sensor are installed in a place where the toner scattering is relatively large.
Here, “the influence of dirt becomes large” means that it becomes difficult for the sensor to detect the mark due to the dirt.
The reason why it is difficult to detect the mark with the sensor is that when the sensor is an optical sensor, the light transmittance or reflectance decreases due to contamination on the mark, the light exit of the optical sensor, or the light reception. The amount of light decreases due to contamination on the part, the sensor output (analog output) decreases or becomes zero, and the binarized signal converted from the sensor output (analog output) is not output. Because it will end up.

  As a prior art for solving the above problems, there has been a printer apparatus and a control method thereof disclosed in Japanese Patent Application Laid-Open No. H10-228707. In Patent Document 1, a cleaning operation is performed when the amount of received light is equal to or less than a predetermined value, and a warning is displayed when the amount of light does not return.

  Further, in the foreign matter removing apparatus of the image forming apparatus disclosed in Patent Document 2, air is periodically blown to the sensor to remove attached dust.

In the image forming apparatus disclosed in Patent Document 3, the detection surface of the toner concentration sensor is covered with a cover, and the detection surface of the toner concentration sensor is cleaned in conjunction with opening and closing of the cover.
JP-A-10-279129 JP 2000-280452 A JP 2002-031919 A

  However, in the conventional techniques including the above-described Patent Documents 1 to 3, it is necessary to provide a new driving device in the image forming apparatus in order to remove the foreign matter attached to the sensor, resulting in complicated apparatus configuration and increased power consumption. There was a problem.

  The present invention has been made in view of the above-described problem. Without newly providing a driving device, dirt attached to a plurality of marks formed on the belt surface, a mark detection unit on the sensor side (in the case of an optical sensor). An object of the present invention is to provide a photodetection device and an image forming apparatus for removing dirt adhering to a light emission port or a light receiving portion.

  In order to achieve such an object, according to the light detection device of the present invention, the light irradiation means for irradiating light, the light detection means for receiving and detecting the irradiation light, and driving the other mechanism, the light irradiation means And a light receiving means, and a removing means for removing foreign substances adhering to the light transmitting member on the optical path until the irradiation light is received.

  Further, according to the light detection device of the present invention, the removing means drives the other mechanism and attaches to the light irradiation means, the light receiving means, and the light transmitting member on the optical path until the irradiation light is received. Drive means for driving a drive member for removing foreign matter.

  Further, according to the light detection device of the present invention, the light detection means is based on the amount of received light, the amount of movement of the moving member, the amount of rotation of the rotating member, or the amount of movement of the moving member or the surface position of the rotating member. And the removing means drives the moving member or the rotating member.

  Further, according to the light detection apparatus of the present invention, the removing means is the moving member or the rotating member due to the friction between the surface of the moving member or the rotating member and the roller provided on the member contacting the surface of the member. The drive force of a member is transmitted to a roller, and the drive force which drives a drive member is obtained.

  Further, according to the light detection apparatus of the present invention, the removing means applies pressure or velocity to the fluid and moves the fluid to transport the fluid of another mechanism, and the light irradiating means, the light receiving means, or the irradiation light is received. The fluid around the light transmitting member on the optical path until it is discharged is ejected to the light irradiating means, the light receiving means, or the light transmitting member, or sucked to remove the foreign matter.

  In addition, according to the light detection apparatus of the present invention, the removal means has a removal control means for controlling the timing of executing the foreign substance removal.

  Further, according to the light detection apparatus of the present invention, the removal control means controls the removal means based on the amount of light detected by the light detection means.

  Further, according to the light detection apparatus of the present invention, the removal control means causes the removal means to remove foreign matter when the amount of light detected by the light detection means becomes smaller than a specified value. To do.

  Further, according to the light detection device of the present invention, when the amount of light detected by the light detection means becomes smaller than a specified value, the light detection means other than the removal of foreign matters by the removal means or the attachment of foreign matters is not possible. It is characterized by having a non-removable signal output means for outputting a non-removable signal indicating that a factor that hinders the detection by is generated.

  Further, according to the light detection device of the present invention, the non-removable signal output means has a light amount detected by the light detection means that is smaller than a specified value within a certain period from the end of the foreign substance removal operation by the removal means. In this case, a non-removable signal is output.

  Further, according to the light detection device of the present invention, when the non-removable signal is input, the light irradiation means detects the amount of the irradiation light from the light irradiation means detected by the light detection means to be equal to or greater than a specified value. It has the light quantity adjustment means which adjusts the light quantity of this irradiation light.

  Further, according to the light detection device of the present invention, when the light amount of the irradiation light from the light irradiation unit reaches the upper limit by the adjustment by the light amount adjustment unit, the adjustment limit signal indicating that the increase in the light amount of the irradiation light is the limit Adjustment limit signal output means for outputting.

  In addition, according to the light detection apparatus of the present invention, the one or more light irradiating means for irradiating light and the one or more light for receiving and detecting the irradiation light from one of the one or more light detecting means, respectively. The detecting means, driving the other mechanism, the light irradiating means, the light receiving means, the removing means for removing the foreign matter adhering to the light transmitting member on the optical path until the irradiated light is received, and the light detecting operation It is characterized by having a light detection switching means for switching the light detection means to be performed from the light detection means during the foreign substance removal operation by the removal means to the light detection means not performing the foreign substance removal operation.

  Further, according to the light detection device of the present invention, when the amount of light detected by the light detection means becomes smaller than a specified value, the light detection means other than the removal of foreign matters by the removal means or the attachment of foreign matters is not possible. It is characterized by having a non-removable signal output means for outputting a non-removable signal indicating that a factor that hinders the detection by is generated.

  Further, according to the light detection device of the present invention, the light detection switching means detects the light detection means for performing the light detection operation when the non-removable signal is input, and detects the light intensity at which the light amount is smaller than the specified value. The means is switched to another light detection means.

  In addition, according to the light detection device of the present invention, when the non-removable signal is input, the light irradiation unit detects that the amount of light emitted from the light irradiation unit detected by the light detection unit is equal to or greater than a specified value. It has the light quantity adjustment means which adjusts the light quantity of this irradiation light.

  Further, according to the light detection apparatus of the present invention, when the light amount of the irradiation light from the light irradiation unit reaches the upper limit by the adjustment by the light amount adjustment unit, the adjustment limit signal indicating that the increase in the light amount of the irradiation light is the limit Adjustment limit signal output means for outputting.

  Further, according to the light detection apparatus of the present invention, the light detection switching means, when the adjustment limit signal is input, the light detection means for performing the light detection operation from the light detection means whose amount of irradiation light has reached the upper limit. And switching to another light detection means.

  According to the invention, an image forming apparatus includes the above-described photodetecting device.

  According to the invention, the image forming apparatus includes a display unit that displays the light amount detected by the light detection device and the light amount emitted from the light detection device.

  According to the invention, there is provided an image forming apparatus having the above-described photodetecting device, and when a non-removable signal is input, foreign matter cannot be removed by the removing means, or foreign matter is not attached. And a display means for displaying that a factor that hinders detection by the light detection means has occurred.

  In addition, according to the present invention, the image forming apparatus having the above-described photodetecting device includes display means for displaying that the increase in the amount of irradiation light is a limit when an adjustment limit signal is input. Features.

  In addition, according to the present invention, there is provided a print output means for printing out the contents displayed on the display means.

  Further, according to the present invention, the removing means performs the removal of the foreign matter when the detection operation by the light detecting means is not performed.

  According to the present invention, even when a moving member cannot be measured because a foreign object adheres to the moving amount measuring mechanism that irradiates the moving member with light and measures the moving amount of the moving member based on the amount of reflected light. , It is possible to remove foreign matter that obstructs the passage of light by adhering to the light irradiating part, light detecting part or light transmitting member on the optical path of the moving amount measuring mechanism without providing a new driving means as a cleaning means It becomes.

The optical sensor according to the embodiment of the present invention adheres to a light irradiation unit, a light detection unit, or a light transmission member (such as transparent glass) on the optical path and removes dust that hinders the passage of light. In order to remove, a fiber member (such as a brush) and a drive means for driving the fiber member are provided, and the light irradiating unit, the light detecting unit, or the light transmitting member on the optical path of the optical sensor is connected to the fiber. Sensor cleaning means that can be wiped off (removed dust) with a material member. Furthermore, in the embodiment of the present invention, the driving means for driving the fibrous member is configured to also serve as the driving means of another mechanism.
Further, when the optical sensor is a detecting means for detecting the moving amount of the moving member, the rotating amount of the rotating member, or the moving amount of the moving member or the surface position of the rotating member, the drive for cleaning with the fibrous member The force is obtained from driving means for moving the moving member or rotating the rotating member.

  In the embodiment of the present invention, a movement amount measurement mechanism (a scale, a sensor, etc. on the movement member) for measuring the movement amount of the movement member, a drive control device equipped with this movement amount measurement mechanism, a copying machine, The description of an image forming apparatus such as a printer or a facsimile will be continued.

  FIG. 1A is a diagram showing an optical sensor and a reflective scale, and FIG. 1B is a diagram showing the reflective scale in more detail. Hereinafter, the configuration of the optical sensor and the reflective scale will be described with reference to FIG.

As shown in FIG. 1A, the image forming apparatus includes an optical sensor 101 and a reflective scale 110.
The optical sensor 101 is a device that measures the amount of movement of the reflective scale 110 by irradiating the reflective scale 110 moving in a certain direction with light and detecting the light intensity of the reflected light. The optical sensor 101 is installed so that the light irradiation direction and the irradiation surface of the reflective scale 110 are not perpendicular.

The optical sensor 101 includes a light source 102, a collimator lens 103, a slit mask 104, glass 105, and a light receiving element 106.
The light source 102 is a light emitting means such as an LED or a semiconductor laser.
The collimating lens 103 is a lens that optically corrects the light from the light source 102 substantially in parallel.
The light irradiation surface of the light source 102 of the slit mask 104 is provided with a portion that transmits light and a portion that blocks light at regular intervals, and transmits a part of the light irradiated from the light source 102 to the reflective scale 110. , Block the other irradiation light, split the light.
The glass 105 has light transmittance.
The light receiving element 106 receives light from the light source 102 reflected by the reflective scale 110.

As shown in FIG. 1B, a pattern in which the reflectance changes at a constant cycle is formed on the light source 102 light irradiation surface of the reflective scale 110 (that is, the light shielding portion 111 and the reflection portion 112 are provided). Repeated at regular intervals).
The slit mask 104 is for generating a split beam 107 having a pattern with the same period as the reflectance period of the reflective scale 110. Therefore, when the light from the collimating lens 103 is completely parallel light, It may be a transmission pattern having the same cycle as the reflection pattern on the irradiation surface of the light source 102 light of the reflective scale 110 (repetitive pattern of the light shielding unit 111 and the reflection unit 112). Further, even if the transmission pattern of the slit mask 104 is not exactly the same period as the reflection pattern of the reflective scale 110, the collimator lens 103 can be used if the light beam pattern can be adjusted to the same period as the reflective scale 110. can do.

In the optical sensor 101 and the reflective pattern 110 configured as described above, the light from the light source 102 is converted into a parallel beam by the collimator lens 103, and this is projected onto the reflective scale 110 through the slit mask 104.
At this time, as shown in FIG. 1B, on the irradiation surface of the reflective scale 110, the same pattern pitch as the pitch of the reflective pattern of the reflective scale 110 (interval between the light shielding portion 111 or the reflective portion 112). Split beams 107 are formed.
Of the split beam 107 on the reflective scale 110, only the one projected onto the reflecting portion 112 is reflected, passes through the glass 105, and enters the light receiving element 106. The split beam 107 projected on the blocking unit 111 is blocked here and is not incident on the light receiving element 106.
The reflective scale 110 moves in a direction parallel to the irradiation surface of the light source 102 light. Due to the movement of the reflective scale 110, the split beam 107 repeats blocking and reflection, and a light amount change due to the blocking or reflection is detected by the light receiving element.

As described above, the optical sensor 101 detects the change (movement amount) of the relative position between the slit mask 104 and the reflective scale 110 from the change in the light intensity of the reflected light (or transmitted light). The optical sensor 101 converts the change in light intensity into a change in electrical signal (analog signal), and then converts it into a binary signal.
2A is a diagram illustrating an analog signal converted from a change in light intensity by the optical sensor 101, and FIG. 2B is a diagram illustrating a binarized signal converted from the analog signal by the optical sensor 101. FIG. It is.
In FIG. 2 (a), when there is no foreign matter adhering to the slit mask 104 and the glass 105 (no dirt), when a small amount of foreign matter is attached (dirty (small)), a large amount of foreign matter adheres. The analog signal is shown in the case of being dirty (dirty (multiple)).
As shown in FIG. 2A, when a large amount of foreign matter adheres to the slit mask 104 and the glass 105, the light intensity of the reflected light received by the light receiving element 106 decreases, and the output of the analog signal also decreases. Detected. In this case, it is difficult to detect a change in light intensity when converted into a binary signal.

FIG. 3 is a diagram showing the optical sensor 101 and the reflective scale 110 when dust (foreign matter) adheres to the slit mask 104 and the glass 105.
As shown in FIG. 3, if dust adheres to the slit mask 104 and the glass 105, light from the light source 102 is blocked, so that the light intensity (light quantity) wave detected by the light receiving element 106 decreases. End up. As shown in FIG. 2A, the magnitude of the converted electric signal (analog signal) is also reduced accordingly.

FIG. 4 is a diagram illustrating the light detection device 130 according to the first embodiment of the present invention.
As shown in FIG. 4, the light detection device 130 includes the optical sensor 101, the reflective scale 110, the brush drive unit 131, and the brush 132. The configurations of the optical sensor 101 and the reflective scale 110 are the same as those described above with the same reference numerals.
In this embodiment, as shown in FIG. 4, the brush drive unit 131 drives the brush 132 (fibrous member) to remove the dust 120 attached to the slit mask 104 and the glass 105. The brush drive unit 131 drives the brush 132 and also drives other mechanisms. For example, the brush drive unit 131 may be a drive unit for the moving member (the reflective scale 110) that is the detection target of the optical sensor 101.

FIG. 5 is a diagram illustrating an example of the configuration of the image forming apparatus according to the first exemplary embodiment of the present invention.
FIG. 5 shows an example in which the movement amount of the endless moving member such as the belt 10 is detected by the optical sensor 101 (light detection device 130) and the movement amount of the moving member is controlled.

  As shown in FIG. 5, the image forming apparatus includes a light detection device 130, a motor 141, a drive control device 142, a drive roller 143, a belt 144, and a support roller 146. The

The belt 144 is an endless moving member (corresponding to the reflective scale 110) installed in the image forming apparatus, and may be, for example, a transfer belt, an intermediate transfer belt, a paper conveyance belt, or a photosensitive belt.
On the belt 144, a mark 145 is formed by repeating portions having different reflectivities at regular intervals. The mark 145 corresponds to a reflection pattern formed by periodically repeating the blocking portion 111 and the reflecting portion 112.
The belt 144 is in contact with the drive roller 143 and the plurality of support rollers 146 and is wound around.

  The motor 141 is in contact with the driving roller 143 and transmits its rotational motion to the driving roller 143. The motor 141 transmits its driving force to the brush driving unit 131. The brush drive unit 131 drives the brush 131 with the driving force transmitted from the motor 141.

  The driving roller 143 is in contact with the motor 141 and the belt 144, and rotates itself by the rotational motion transmitted from the motor 141, and the belt 144 is moved by transmitting the rotational motion of the driving roller 143 to the belt 144.

  The optical sensor 101 detects the position of the mark 145 on the belt 144 and outputs a binary signal indicating the detected position of the mark 145 (or the moving speed of the belt 144) to the drive control device 142.

  The drive control device 142 controls the drive speed (rotational speed) of the motor 141 based on the binarized signal input from the optical sensor 101. Accordingly, the moving speed of the belt 144 can be controlled so that the passing speed of the mark 145 with respect to the optical sensor 101 is constant.

As described above, in this embodiment, the optical sensor 101 detects the position of the mark 145 on the belt 144 that is an endless moving member, and the brush driving unit 131 uses the driving force of the motor 141 that is the driving source of the belt 144. Using this, the brush 131 was driven to remove foreign matters on the optical sensor 101.
In addition, the optical sensor 101 detects the position of a mark on a rotating member such as a photosensitive drum, and the brush driving unit 131 drives the brush 131 using the driving force of the driving source of the rotating member. The foreign matter on the top may be removed.

FIG. 13 is a diagram showing the configuration of the image forming apparatus in Embodiment 1 of the present invention. FIG. 14 is a diagram showing a configuration around the intermediate transfer belt in the first embodiment of the present invention. FIG. 15 is a diagram showing a configuration in which a light detection device is installed around the intermediate transfer belt in the first embodiment of the present invention.
Hereinafter, an application example of the light detection device 130 in the present embodiment in the image forming apparatus will be described.

  In the tandem image forming apparatus as shown in FIG. 13, the photodetecting device 130 in this embodiment is installed. FIG. 14 shows the periphery of the intermediate transfer belt 10 in the image forming apparatus of FIG. 13 in more detail. In the present embodiment, the light detection device 130 is installed at a position facing the intermediate transfer belt 10 in order to detect the displacement or moving speed of the intermediate transfer belt 10.

As shown in FIG. 15, the image forming apparatus of FIG. 13 includes an intermediate transfer belt 10, a driving roller 14, a light detection device 130, a motor 171, and a speed reducer 172. In the example of FIG. 15, the optical sensor 101 detects the displacement or moving speed of the intermediate transfer belt 10 using the intermediate transfer belt 10 as a reflective scale 110.
A toner image formed on the photosensitive drums 40, 40M, 40C, and 40Y that can be contacted is transferred to the intermediate transfer belt 10. The intermediate transfer belt 10 is an endless belt that is in contact with a driving roller 14 that is rotationally driven by a motor 171 and travels by the rotational driving of the driving roller 14. The motor 171 is decelerated by the speed reducer 172.
On the surface of the intermediate transfer belt 10 on the photosensitive drum contact side, marks 173 are provided at regular intervals in the circumferential direction (running direction). The optical sensor 101 displays the marks 173 on the oblique light portion 111 or the reflection portion 112. Detect as.
As described above, by installing the light detection device 130 in the present embodiment in the image forming apparatus, it is possible to perform image forming operation and the like stably without being affected by the contamination of the optical sensor 101. Also, the number of maintenance is reduced.

The image forming apparatus also detects the light amount (or the level of an electric signal [voltage or current] converted from the light amount) detected by the light detection unit (light receiving element 106) of the optical sensor 101 or the light irradiation unit ( Display means such as a display capable of displaying the amount of light emitted from the light source 102) (or the level of an electric signal [voltage or current] applied to irradiate the amount of light) is provided.
Therefore, the operator of the image forming apparatus can know the degree of contamination of the optical sensor 101. In addition, cleaning (maintenance) can be performed in advance before a maintenance instruction is issued.

As described above, according to the present embodiment, the light detection device 130 moves the moving member (belt 144) with the driving force for cleaning with a fibrous member such as the brush 132, or the rotating member. It is configured to be obtained from driving means (motor 141) for rotating (photosensitive drum).
In this embodiment, the image forming apparatus includes a roller (a driving roller 143 and a support roller 146) that contacts the surface of the moving member or the rotating member, and the surface of the moving member or the rotating member and the roller described above. The driving force is transmitted to the roller by the frictional force between the two and the fibrous member is driven by the driving force, and the foreign matter on the slit mask 104 and the glass 105 of the optical sensor 101 is removed.
Therefore, it is possible to remove the foreign matter attached to the optical sensor 101 with a simple configuration without providing a new drive source.

Further, according to the present embodiment, the light detection device 130 includes the light irradiation unit (light source 102), the light detection unit (light receiving element 106), or the light transmission member (slit mask 104 and transparent glass) on the optical path. 105) and the like, and a fibrous member (brush 132, etc.) and a driving means (brush driving unit 131) for driving the fibrous member are provided. And a sensor cleaning means capable of wiping (removing dust) the light irradiating part, the light detecting part or the light transmitting member on the optical path of the optical sensor 101 with a fibrous member.
In the light detection device 130, the driving means for driving the fibrous member is configured to also serve as the driving means of another mechanism, so that it is not necessary to provide a new driving means as the sensor cleaning means. The dust 120 that adheres to the light irradiation part, the light detection part, or the light transmission member on the optical path and hinders the passage of light can be removed.

Further, according to the present embodiment, the optical sensor 101 detects the amount of movement of the moving member (reflective scale 110, belt 144), the amount of rotation of the rotating member, or the amount of movement of the moving member or the surface position of the rotating member. In the case of the detecting means, the driving force for cleaning with the fibrous member is obtained from the driving means for moving the moving member or rotating the rotating member.
Accordingly, it is not necessary to provide a new driving unit as the sensor cleaning unit, and the dust 120 that adheres to the light irradiation unit, the light detection unit, or the light transmission member on the optical path of the optical sensor 101 and obstructs the passage of light. Can be removed.

Further, according to the present embodiment, the light detection device 130 is configured to obtain the driving force for cleaning with the fibrous member from the driving means for moving the moving member or rotating the rotating member. Has been. Further, the light detection device 130 includes rollers (a driving roller 143 and a support roller 146) that come into contact with the surface of the moving member or the rotating member. Due to the friction between the surface of the moving member or rotating member and the roller, the moving member or rotating member transmits a driving force to the roller, and the fibrous member is driven by the driving force.
Accordingly, it is not necessary to provide a new driving unit as the sensor cleaning unit, and the dust 120 that adheres to the light irradiation unit, the light detection unit, or the light transmission member on the optical path of the optical sensor 101 and obstructs the passage of light. Can be removed.

  Hereinafter, unless otherwise specified, in the present embodiment, the components denoted by the same reference numerals as those in the first embodiment will be described assuming that the configuration and operation thereof are the same as those in the first embodiment.

FIG. 6 is a diagram illustrating a configuration of the photodetecting device 130 according to the second embodiment of the present invention.
As shown in FIG. 6, the light detection device 130 includes the optical sensor 101, the reflective scale 110, the nozzle 151, the valve 152, the fan 153, and the flow paths 154a and 154b. Is done.
As in the first embodiment, it is assumed that the light detection device 130 is provided in an image forming apparatus such as a copying machine.
The optical sensor 101 measures the light intensity of the reflected light of the light irradiated on the reflective scale 110.
The fan 153 applies pressure or speed to the fluid (for example, air) and sends it to the flow path 154a.
The valve 152 is connected to the fan 153 via the flow path 154a, to the nozzle 151 via the flow path 154b, and to the cooling target 155 by the fan 153 via the flow path 154c. The valve 152 selects a flow path for sending the fluid sent from the fan 153 (such as at least one of the flow paths 154b and 154c, or both).
The nozzle 151 removes the fluid sent from the fan 153 to the flow path 154 a by spraying the dust 120 attached to the slit mask 104 and the glass 105.
The cooling target 155 is a member or device that is provided in the image forming apparatus and needs to be cooled by the fan 153.
In this embodiment, the dust 120 attached to the cooling target 155 is sprayed on the optical sensor 101 (the slit mask 104 and the glass 105) by spraying a fluid sent by a fan 153 provided in the image forming apparatus. Remove.

In this embodiment, a fluid (for example, air) is applied to the fluid around the optical sensor 101 by using a means (pump, fan 153, etc.) for transporting the fluid by applying pressure or speed to the fluid and the nozzle 151. By spraying on the light transmission member (slit mask 104, glass 105) on the detection unit or the optical path, the light is attached to the light irradiation unit, the light detection unit, or the light transmission member on the optical path of the optical sensor 101, and the light is transmitted. The obstructing dust 120 is removed.
Further, the light detection device 130 has a sensor cleaning unit that can remove the dust 120 along with the movement of the fluid by sucking the fluid around the light irradiating unit, the light detecting unit, or the light transmitting member on the optical path by the nozzle 151. It is good. Also in this case, the means for transporting the fluid by applying pressure or velocity to the fluid is configured to also serve as a means for transporting the fluid of another mechanism (such as a fan).

As described above, according to the present embodiment, the light detection device 130 includes a fluid (usually normal) around the optical sensor 101 by means of means (pump, fan 153) for transporting the fluid by applying pressure or speed to the fluid and the nozzle 151. Is blown onto the light irradiating part, the light detecting part or the light transmitting member on the optical path. In addition, the light detection device 130 sucks the fluid around the optical sensor 101 by means (pump, fan 153) and a nozzle 151 for applying pressure and speed to the fluid and transporting the fluid. As a result, it is possible to remove the dust 120 that adheres to the light irradiation part, the light detection part, or the light transmission member on the optical path of the optical sensor 101 and hinders the passage of light.
In this embodiment, the means (pump, fan 153, etc.) for transporting the fluid by applying pressure or speed to the fluid is also configured to serve as a means for transporting the fluid of other mechanisms. Since electronic devices often use a fan as a heat countermeasure, it is not necessary to provide a new driving unit as a sensor cleaning unit by utilizing this, and the light irradiation unit, the light detection unit or the optical sensor 101 The dust 120 that adheres to the light transmitting member on the optical path and hinders the passage of light can be removed.

Hereinafter, unless otherwise specified, in the present embodiment, the components denoted by the same reference numerals as those in the first embodiment will be described assuming that the configuration and operation thereof are the same as those in the first embodiment.
In the present embodiment, the sensor cleaning unit performs cleaning of the optical sensor when the amount of light detected by the optical sensor falls below a specified value.

FIG. 7 is a diagram showing an outline of the configuration of the light detection device 130 according to the third embodiment of the present invention.
As shown in FIG. 7, in this embodiment, a sensor cleaning control means 133 is further added to the light detection device 130 of the first embodiment.
The sensor cleaning unit 133 outputs a control signal for controlling the brush driving unit 131 based on the measurement result of the light intensity of the reflected light from the optical sensor 101.

FIG. 8 is a diagram illustrating a configuration of the light detection device 130 according to the third embodiment of the present invention.
As shown in FIG. 8, the light detection device 130 includes the optical sensor 101, the reflective scale 110, the brush drive unit 131, the brush 132, and the sensor cleaning control unit 133. .
As in the first embodiment, it is assumed that the light detection device 130 is provided in an image forming apparatus such as a copying machine.
The optical sensor 101 measures the light intensity of the reflected light of the light irradiated on the reflective scale 110.

The sensor cleaning control unit 133 controls the brush driving unit 131 based on the light amount detected by the light detection unit (light receiving element 106) of the optical sensor 101.
The sensor cleaning control unit 133 includes an LPF (Low Pass Filter) 134, a comparator 135, and a switch 136.
The LPF 134 outputs only the low frequency component of the analog signal (FIG. 2A) output from the optical sensor 101 (light receiving element 106) as the input voltage Vin to the comparator 135.
The comparator 135 receives the input voltage Vin from the LPF 134 and the reference voltage Vc, and compares the two voltage values.
The switch 136 is a switch for switching on / off the driving of the brush drive unit 131.

  The light receiving element 106 receives reflected light from the reflective scale 110, but at this time, light other than the reflected light component may also be received. In such a case, the light receiving element 106 outputs an offset analog signal as shown in FIG.

  The LPF 134 processes the analog signal from the light receiving element 106 and outputs it to the comparator 135. When the electrical signal from the light receiving element 106 is an alternating analog signal (an analog signal having a waveform symmetric with respect to a constant sensor output serving as a reference), the alternating analog signal processed by the LPF 134 is input to the comparator 135.

The comparator 135 compares the electric signal level (input voltage Vin) from the LPF 134 with a specified value (reference voltage Vc), and when the input voltage Vin becomes smaller than the reference voltage Vc (slit mask 104 and glass). When dust 120 adheres to 105 and the amount of reflected light decreases), a control signal for driving the brush drive unit 131 is output.
Note that the comparison process between the input voltage Vin and the reference voltage Vc (specified value) by the comparator 135 is performed when the normal optical sensor 101 is used, and at a timing when the optical sensor 101 detects reflected light. Done.

The switch 136 is turned on when a “signal for instructing light amount confirmation” is input, and a control signal from the comparator 135 is input to the brush drive unit 131. This “signal for instructing light amount confirmation” is a signal for permitting the start of cleaning of the optical sensor 101, and the switch 136 is detected after the detection processing of the reflected light from the reflective scale 110 by the optical sensor 101 is completed. Is input. This “signal for instructing light amount confirmation” may be input to the switch 136 by pressing a predetermined key switch on an operation panel provided in the image forming apparatus, for example.
When the “signal for instructing light amount confirmation” is not input, the switch 136 is turned off. Therefore, even if a control signal is output from the comparator 135, it is not input to the brush drive unit 131, and the optical sensor 101 is not cleaned. .

  Further, the brush drive unit 131 may drive the brush 132 at regular intervals when a control signal is input, or may drive the brush 132 along with the drive of the drive unit of another mechanism.

As described above, according to the present embodiment, the light detection device 130 includes the sensor cleaning control unit 133 that controls the timing at which the sensor cleaning unit (the brush driving unit 131 and the brush 132) performs the cleaning.
The sensor cleaning control unit 133 performs control based on the amount of light detected by the light receiving element 106 of the optical sensor 101. The sensor cleaning unit 133 performs cleaning of the optical sensor 101 when the amount of light detected by the light receiving element 106 falls below a specified value.
Therefore, the optical sensor 101 can be accurately cleaned at a necessary timing without interfering with detection of reflected light by the optical sensor 101.

Hereinafter, unless otherwise specified, in the present embodiment, the components denoted by the same reference numerals as those in the first embodiment will be described assuming that the configuration and operation thereof are the same as those in the first embodiment.
In this embodiment, the light detection device is a factor that impedes detection of a detection object other than sensor cleaning impossible or light sensor contamination when the amount of light detected by the light detection unit of the light sensor falls below a specified value. A means for outputting a signal notifying that the occurrence of

FIG. 9 is a diagram illustrating a configuration of the photodetecting device 130 according to the fourth embodiment of the present invention.
As shown in FIG. 9, the light detection device 130 includes a light sensor 101, a reflective scale 110, a brush drive unit 131, a brush 132, and a sensor cleaning impossibility signal output unit 160. Is done.
As in the first embodiment, it is assumed that the light detection device 130 is provided in an image forming apparatus such as a copying machine.
The optical sensor 101 measures the light intensity of the reflected light of the light irradiated on the reflective scale 110.

The sensor cleaning impossibility signal output means 160 is based on the amount of light detected by the light detection unit (light receiving element 106) of the optical sensor 101, and causes the reduction in the amount of reflected light from the reflective scale 110 due to the slit mask 104 and the glass. A sensor cleaning impossible signal for notifying that the ink is not dirty is output.
The sensor cleaning impossibility signal output unit 160 includes an LPF 161, a comparator 162, and a switch 163.
The LPF 161 outputs only the low frequency component of the analog signal ((a) in FIG. 2) output from the optical sensor 101 (light receiving element 106) as the input voltage Vin to the comparator 162.
The comparator 162 receives the input voltage Vin from the LPF 161 and the reference voltage Vc, and compares the two voltage values.
The switch 163 is a switch for switching on / off of the sensor cleaning impossible signal output.

  The light receiving element 106 receives reflected light from the reflective scale 110, but at this time, light other than the reflected light component may also be received. In such a case, the light receiving element 106 outputs an offset analog signal (alternate analog signal) as shown in FIG.

  The LPF 161 processes the analog signal from the light receiving element 106 and outputs it to the comparator 162. When the electrical signal from the light receiving element 106 is an alternating analog signal, the alternating analog signal processed by the LPF 161 is input to the comparator 162.

The comparator 162 compares the electric signal level (input voltage Vin) from the LPF 161 with a specified value (reference voltage Vc), and when the input voltage Vin becomes smaller than the reference voltage Vc (slit mask 104 and glass). When the amount of reflected light from the reflective scale 110 received by the light receiving element 106 decreases due to factors other than the contamination 105, a sensor cleaning impossible signal is output.
Note that the comparison process between the input voltage Vin and the reference voltage Vc (specified value) by the comparator 162 is performed when the normal optical sensor 101 is used, and at a timing when the optical sensor 101 detects reflected light. Done.

The switch 163 is turned on when a “signal for instructing light amount confirmation” is input, and a sensor cleaning impossible signal is output from the comparator 162.
When the “signal for instructing light amount confirmation” is not input, the switch 163 is turned off, so that the sensor cleaning disable signal from the comparator 162 is not output.

The optical sensor 101 is cleaned periodically by sensor cleaning means (the brush drive unit 131 and the brush 132) or with the drive of a drive device of another mechanism. Even immediately after cleaning, the amount of light received by the light receiving element 106 decreases because dust that cannot be removed by the sensor cleaning means has adhered to the optical sensor 101 or dust has adhered to the optical sensor 101. However, the amount of light has decreased due to another factor.
Therefore, in this embodiment, when the amount of light detected by the light receiving element 106 falls below a specified value, the amount of light received by the light receiving element 106 decreases due to factors other than dust that can be removed by the sensor cleaning unit as described above. It is configured to output a signal informing that it is in progress.
The image forming apparatus in which the light detection device 130 is installed has display means such as a display and sound output means for outputting sound such as a speaker. The light detection device 130 cannot be cleaned or the optical sensor 101 is dirty. In addition, a signal notifying that a factor that hinders detection of the detected object has occurred is input to the display means and the sound output means. When the sensor cleaning disable signal is input, the display means displays that cleaning is not possible or a factor that hinders detection of the detected object other than contamination of the optical sensor 101 has occurred. In addition, when the above signal is input, the audio output means notifies the user of the fact that the cleaning is impossible or that a factor that prevents detection of the detected object other than the contamination of the optical sensor 101 has occurred.
Therefore, it becomes possible to easily notify that cleaning by the sensor cleaning means is impossible or that a factor that hinders detection of the detected object other than the contamination of the optical sensor 101 has occurred.
Furthermore, the image forming apparatus according to the present exemplary embodiment may include a unit that prints out the display content on the display unit. This makes it possible to store the above display content on a paper medium or the like.

Hereinafter, unless otherwise specified, in the present embodiment, the components denoted by the same reference numerals as those in the third embodiment will be described assuming that the configuration and operation thereof are the same as those in the third embodiment.
In the present embodiment, the sensor cleaning unit performs cleaning of the optical sensor when the amount of light detected by the optical sensor falls below a specified value.

FIG. 10 is a diagram illustrating the configuration of the light detection device 130 according to the fifth embodiment of the present invention.
As shown in FIG. 10, the light detection device 130 includes the optical sensor 101, the reflective scale 110, the brush driving unit 131, the brush 132, and the sensor cleaning control unit 138. .
As in the first embodiment, it is assumed that the light detection device 130 is provided in an image forming apparatus such as a copying machine.
The optical sensor 101 measures the light intensity of the reflected light of the light irradiated on the reflective scale 110.

The sensor cleaning control unit 138 performs control based on the amount of light detected by the light detection unit (light receiving element 106) of the optical sensor 101.
The sensor cleaning control unit 138 includes an LPF 134, a comparator 135, and switches 136 and 137.
The LPF 134 outputs only the low frequency component of the analog signal (FIG. 2A) output from the optical sensor 101 (light receiving element 106) as the input voltage Vin to the comparator 135.
The comparator 135 receives the input voltage Vin from the LPF 134 and the reference voltage Vc, and compares the two voltage values.
The switch 136 is a switch for switching on / off the driving of the brush driving unit 131.
The switch 137 is a switch for switching on / off the sensor cleaning impossibility signal output. This sensor cleaning impossibility signal is used to notify that the cause of the reduction in the amount of reflected light from the reflective scale 110 by the light receiving element 106 is not the contamination of the slit mask 104 and the glass 105, as in the fourth embodiment. Signal.

  The LPF 134 processes the analog signal from the light receiving element 106 and outputs it to the comparator 135. When the electrical signal from the light receiving element 106 is an alternating analog signal, the alternating analog signal processed by the LPF 134 is input to the comparator 135.

The comparator 135 compares the electric signal level (input voltage Vin) from the LPF 134 with a specified value (reference voltage Vc), and when the input voltage Vin becomes smaller than the reference voltage Vc, the brush driving unit 131. A control signal for driving the sensor or a sensor cleaning impossible signal is output.
Note that the comparison process between the input voltage Vin and the reference voltage Vc (specified value) by the comparator 135 is performed when the normal optical sensor 101 is used, and at a timing when the optical sensor 101 detects reflected light. Done.

The switch 136 is turned on when a “signal for instructing light amount confirmation” is input, and a control signal from the comparator 135 is input to the brush drive unit 131. This “signal for instructing light amount confirmation” is a signal for permitting the start of cleaning of the optical sensor 101, and the switch 136 is detected after the detection processing of the reflected light from the reflective scale 110 by the optical sensor 101 is completed. Is input.
When the “signal for instructing light amount confirmation” is not input, the switch 136 is turned off. Therefore, even if a control signal is output from the comparator 135, it is not input to the brush drive unit 131, and the optical sensor 101 is not cleaned. .
Further, the brush drive unit 131 may drive the brush 132 at regular intervals when a control signal is input, or may drive the brush 132 along with the drive of the drive unit of another mechanism.

The switch 137 is turned on when a cleaning execution signal (a signal indicating that the optical sensor 101 has been cleaned) is input from the brush drive unit 131, and an output signal from the comparator 135 is output as a sensor cleaning impossible signal.
When the cleaning execution signal is not input, the switch 137 is turned off, so that the output signal from the comparator 135 is not output as a sensor cleaning impossible signal.

  In this embodiment, as in the fourth embodiment, when the amount of light detected by the light receiving element 106 falls below a specified value, the amount of light received by the light receiving element 106 is caused by factors other than dust that can be removed by the sensor cleaning means. It is configured to output a signal notifying that the number is decreasing.

The comparator 135 compares the voltage value Vin of the analog signal indicating the light quantity level input from the light receiving element 106 via the LPF 134 with the reference voltage Vc. If the voltage value Vin is smaller than the reference voltage Vc, the comparator 135 Output.
Here, when a signal for instructing light amount confirmation is input to the switch 136, an output signal from the comparator 135 is input to the brush drive unit 131 as a control signal for driving the brush drive unit 131. When the control signal is input, the brush driving unit 131 drives the brush 132 to start cleaning the optical sensor 101.
When the cleaning of the optical sensor 101 is completed, the brush drive unit 131 outputs a cleaning execution signal to the switch 137.
When a cleaning execution signal is input to the switch 137, an output signal from the comparator 135 is output as a sensor cleaning impossible signal via the switch 137.

As described above, according to the present embodiment, even when the sensor cleaning is performed, the amount of light detected by the light detection unit (the light receiving element 106) of the optical sensor 101 does not increase (even after the sensor cleaning is performed, the optical sensor). When the amount of light (voltage value Vin) detected by the light detection unit 101 (light receiving element 106) is less than the specified value (reference voltage value Vc), sensor cleaning is not possible or the optical sensor 101 is not contaminated. A signal (cleaning impossible signal) is output to notify that a factor that hinders detection of the detection object (reflection type scale 110, mark 145) has occurred.
Therefore, it becomes possible to easily notify that cleaning by the sensor cleaning means is impossible or that a factor that hinders detection of the detected object other than the contamination of the optical sensor 101 has occurred.

Hereinafter, unless otherwise specified, in the present embodiment, the components denoted by the same reference numerals as in the fourth embodiment will be described assuming that the configuration and operation thereof are the same as those in the fourth embodiment.
In the present embodiment, the light detection device 130 further includes a light amount adjusting means in addition to the configuration of the fourth embodiment. Other configurations are the same as those in the fourth embodiment, and thus the description thereof is omitted.

FIG. 11 is a diagram illustrating a configuration of the photodetecting device 130 according to the sixth embodiment of the present invention.
As shown in FIG. 11, the light detection device 130 includes a light sensor 101, a reflective scale 110, a brush drive unit 131, a brush 132, a light amount adjustment unit 139, and a sensor cleaning impossible signal output unit 160. And is configured.
The sensor cleaning impossibility signal output means 160 includes an LPF 161, a comparator 162, and a switch 163.
As in the fourth embodiment, it is assumed that the light detection device 130 is provided in an image forming apparatus such as a copying machine.

Similar to the fourth embodiment, the comparator 162 outputs a signal when the input voltage value Vin becomes smaller than the reference voltage value Vc. When a signal for instructing light amount confirmation is input, the switch 163 is turned on and outputs an output signal from the comparator 162 to the light amount adjusting means 139 as a sensor cleaning impossible signal.
When the sensor cleaning impossibility signal is input, the light amount adjusting unit 139 determines that the light amount of light to be irradiated to detect the displacement or moving speed of the reflective scale 110 is insufficient, and is irradiated from the light source 102. A light amount adjustment instruction signal for increasing the amount of light is output to the light source 102.
When the light amount adjustment instruction signal is input, the light source 102 increases the amount of irradiation light by a preset amount. The increase in the amount of irradiation light from the light source 102 is executed until the input voltage value Vin becomes equal to the reference voltage value Vc (until the light amount adjustment instruction signal is not input to the light source 102).

As described above, according to the present embodiment, the light amount adjusting unit 139 detects the detection object (reflection type scale 110, mark 145) other than the sensor cleaning of the optical sensor 101 or the contamination of the optical sensor 101. The amount of light detected by the light detection unit (light receiving element 106) is determined by the light detection unit (light receiving element 106) based on a signal (sensor cleaning impossibility signal) that informs that an obstructing factor has occurred. Adjust so that it exceeds the specified value.
Therefore, even if a factor that hinders detection of the detection object (reflective scale 110, mark 145) other than the sensor cleaning or the contamination of the optical sensor 101 occurs, the displacement or movement speed of the detection object is increased by increasing the amount of light. It becomes possible to detect.

Hereinafter, unless otherwise specified, in the present embodiment, the components denoted by the same reference numerals as those in the sixth embodiment will be described assuming that the configuration and operation thereof are the same as those in the sixth embodiment.
In the present embodiment, in addition to the configuration and functions of the sixth embodiment, the light amount adjusting unit 139 further outputs a signal indicating that the light amount adjustment is the limit.
Other configurations and functions are the same as those in the sixth embodiment, and thus description thereof is omitted.

FIG. 12 is a diagram illustrating a configuration of the light detection device 130 according to the seventh embodiment of the present invention.
As shown in FIG. 12, the light detection device 130 includes the optical sensor 101, the reflective scale 110, the brush drive unit 131, the brush 132, the light amount adjustment unit 139, and the sensor cleaning impossible signal output unit 160. And is configured.
The sensor cleaning impossibility signal output means 160 includes an LPF 161, a comparator 162, and a switch 163.
As in the sixth embodiment, it is assumed that the light detection device 130 is provided in an image forming apparatus such as a copying machine.

When the sensor cleaning impossibility signal is input from the comparator 162, the light amount adjusting unit 139 outputs a light amount adjusting signal to the light source 102 as in the sixth embodiment. The light amount adjusting unit 139 monitors the current light amount of the irradiation light from the light source 102 at regular intervals, and stores information indicating the current light amount in the own unit. The light amount adjusting unit 139 stores information indicating the upper limit of the amount of light that can be emitted by the light source 102 in advance.
Here, when the sensor cleaning impossibility signal is input, the light amount adjusting means 139 determines whether or not the current light amount of the irradiation light from the light source 102 has reached the upper limit value that can be irradiated, and sets the upper limit value to the upper limit value. If it is determined that the light amount has not been reached, the light amount adjustment instruction signal is output to the light source 102 as before, and an instruction to increase the light amount of the irradiation light is given.
On the other hand, when it is determined that the current light amount of the irradiation light from the light source 102 has already reached the upper limit value, the light amount adjustment unit 139 indicates that the light amount adjustment is a limit (a further increase in the light amount is impossible). Is output).

As described above, according to the present embodiment, the light detection device 130 includes means for outputting a signal notifying that the adjustment is possible when the light quantity adjustment means 139 reaches the limit that can be adjusted. The signal is input to information output means such as a display means (display) and a sound output means (speaker).
When the signal is input, the display means displays a notification that the light amount is within the limit that can be adjusted. In addition, when the above signal is input, the audio output means notifies the user of the fact that the amount of light can be adjusted similarly.
Therefore, the user of the image forming apparatus can easily recognize that the factor that hinders the detection of the detection object (the reflective scale 110 and the mark 145) cannot be eliminated only by adjusting the light amount from the light source 102. It is possible to perform an appropriate measure for.
Furthermore, the image forming apparatus according to the present exemplary embodiment may include a unit that prints out the display content on the display unit. This makes it possible to store the above display content on a paper medium or the like.

Hereinafter, unless otherwise specified, in the present embodiment, the components denoted by the same reference numerals as those in the seventh embodiment will be described assuming that the configuration and operation thereof are the same as those in the seventh embodiment.
In the light detection device 130 according to the present embodiment, in addition to the configuration of the seventh embodiment, another light sensor as an alternative means having the same function as that of the light sensor 101 is provided, and one of the two light sensors is provided. An optical sensor switching means for switching to operate is provided.
Other configurations and functions are the same as those of the seventh embodiment, and thus description thereof is omitted.

FIG. 16 is a diagram illustrating the configuration of the light detection device 130 according to the eighth embodiment of the present invention.
As shown in FIG. 16, the light detection device 130 includes optical sensors 101 and 201, a reflective scale 110, a brush driving unit 131, a brush 132, a light amount adjusting unit 139, and an optical sensor switching unit 140. And a sensor cleaning impossibility signal output means 160.

  The optical sensor 201 has the same function as the optical sensor 101. Assume that one of the optical sensors 101 and 201 detects the displacement or moving speed of the reflective scale 110 based on the amount of reflected light from the reflective scale 110.

The brush drive unit 131 drives the brush 132 to perform cleaning of one of the optical sensors 101 and 201 for which cleaning has been instructed.
The brush drive unit 131 outputs a drive notification signal indicating which optical sensor is currently being cleaned to the optical sensor switching unit 140.

The optical sensor switching unit 140 switches so that one of the optical sensors 101 and 201 is operated.
When the drive notification signal is input from the brush drive unit 131, the optical sensor switching unit 140 changes the optical sensor that performs the light receiving operation of the reflected light from the reflective scale 110 from the optical sensor currently being cleaned by the brush drive unit. Switch to an uncleaned optical sensor.

  The sensor cleaning impossible signal output means 160 informs that the optical sensor cannot be cleaned, or that a factor that hinders detection of the detected object other than the contamination of the optical sensor has occurred, and in which optical sensor it has occurred. Is output to the optical sensor switching means 140.

  The light amount adjusting unit 139 outputs a signal indicating that the light amount adjustment is the limit to the optical sensor switching unit 140. It is assumed that the signal indicating that the light amount adjustment is the limit includes information indicating in which optical sensor the light amount adjustment is the limit.

  When the sensor cleaning disable signal is input from the sensor cleaning disable signal output means 160, the light sensor switching means 140 turns the optical sensor that performs the reflected light receiving operation from the reflective scale 110 into the detection object other than the cleaning impossible or dirt. Switch from one of the optical sensors in which a factor that hinders detection occurs to another optical sensor.

  In addition, when the light sensor switching unit 140 receives a signal indicating that the light amount adjustment is limited from the light amount adjusting unit 139, the light sensor switching unit 140 detects the light sensor that performs the reflected light receiving operation from the reflective scale 110, and the light amount adjustment is limited. Switch from one photosensor to another.

As described above, according to the present embodiment, the optical sensor alternative means is provided, and while the optical sensor is performing cleaning, the operation is switched to the alternative means. An alternative is a sensor that plays a similar role or the same optical sensor.
The optical sensor switching unit 140 temporarily switches to the other optical sensor so that the operation can be continued while one optical sensor is performing cleaning, or without the sensor analog signal from the optical sensor. The procedure is switched to a procedure capable of controlling the traveling speed of the reflective scale 110.
As a result, even when the optical sensor is being cleaned, the detection operation of the displacement or movement speed of the reflective scale 110 can be continued by another optical sensor, and a stable image forming operation by the image forming apparatus is realized. It becomes possible to do.

Further, according to the present embodiment, the image forming apparatus includes an alternative means of the optical sensor, and a signal notifying that the sensor cleaning is impossible, or that a factor that prevents detection of the detected object other than the contamination of the sensor unit has occurred, or Based on a signal notifying that the limit that can be adjusted by the light amount adjusting means is reached, the operation is switched to the alternative means.
If the signal is output, recovery of the optical sensor cannot be expected unless maintenance is performed. In this embodiment, even during maintenance of the optical sensor, the operation can be continued by switching to the alternative means, and a stable image forming operation by the image forming apparatus can be realized.

In this embodiment, one photosensor as an alternative means is provided, but a plurality of photosensors may be provided.
In the present embodiment, another optical sensor 201 and an optical sensor switching unit 140 are provided in the configuration of the seventh embodiment. However, the configuration further includes the configurations of the first to sixth embodiments. There may be.

  The above-described Examples 1 to 8 are examples of preferred embodiments of the present invention, and the embodiments of the present invention are not limited to these, and various modifications can be made without departing from the scope of the present invention. It becomes possible to carry out.

(A) is a figure which shows an optical sensor and a reflection type scale, (b) is the figure which showed the reflection type scale in detail. (A) is a figure which shows the analog signal converted from the change of light intensity by the optical sensor, (b) is a figure which shows the binarization signal converted from the analog signal by the optical sensor. It is a figure which shows a photosensor and a reflective scale when dust (foreign matter) adheres to a slit mask and glass. It is a figure which shows the photon detection apparatus in Example 1 of this invention. 1 is a diagram illustrating an example of a configuration of an image forming apparatus in Embodiment 1 of the present invention. It is a figure which shows the structure of the photon detection apparatus in Example 2 of this invention. It is a figure which shows the outline of a structure of the photon detection apparatus in Example 3 of this invention. It is a figure which shows the structure of the photon detection apparatus in Example 3 of this invention. It is a figure which shows the structure of the photon detection apparatus in Example 4 of this invention. It is a figure which shows the structure of the photon detection apparatus in Example 5 of this invention. It is a figure which shows the structure of the photon detection apparatus in Example 6 of this invention. It is a figure which shows the structure of the photon detection apparatus in Example 7 of this invention. 1 is a diagram illustrating a configuration of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 3 is a diagram illustrating a configuration around an intermediate transfer belt according to the first exemplary embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration in which a light detection device is installed around an intermediate transfer belt according to the first exemplary embodiment of the present invention. It is a figure which shows the structure of the photon detection apparatus in Example 8 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Intermediate transfer belt 14,143 Driving roller 40, 40M, 40C, 40Y Photosensitive drum 101, 201 Photosensor 102 Light source 103 Collimating lens 104 Slit mask 105 Glass 106 Light receiving element 107 Split beam 110 Reflective scale 111 Light shielding part 112 Reflecting part DESCRIPTION OF SYMBOLS 130 Photodetector 131 Brush drive part 132 Brush 133,138 Sensor cleaning control means 134,161 LPF
135, 162 Comparator 136, 137, 163 Switch 139 Light quantity adjusting means 140 Optical sensor switching means 141, 171 Motor 142 Drive control device 144 Belt 145, 173 Mark 146 Support roller 151 Nozzle 152 Valve 153 Fan 154a, 154b, 154c Flow path 155 Cooling target 160 Sensor cleaning impossible signal output means 172 Reducer

Claims (24)

Light irradiation means for irradiating light;
Light detecting means for receiving and detecting the irradiation light;
Removing means for driving the other mechanism and removing foreign matter adhering to the light irradiating means, the light receiving means, and the light transmitting member on the optical path until the irradiated light is received;
A photodetection device comprising: The removing means includes
Driving means for driving other mechanisms and driving the light irradiating means, the light receiving means, and a driving member for removing foreign matter adhering to the light transmitting member on the optical path until the irradiation light is received When,
The light detection device according to claim 1, further comprising: The light detection means detects the amount of movement of the moving member, the amount of rotation of the rotating member, or the amount of movement of the surface position of the moving member or rotating member based on the amount of received light,
The removing means includes
The photodetecting device according to claim 2, wherein the moving member or the rotating member is driven. The removing means includes
The driving force of the moving member or the rotating member is transmitted to the roller by the friction between the surface of the moving member or the rotating member and the roller provided on the member contacting the surface of the member. The light detection device according to claim 3, wherein a driving force for driving the driving member is obtained. The removing means includes
Applying pressure or velocity to the fluid to move the fluid to transport the fluid of another mechanism, and the fluid around the light transmitting member, the light receiving device, or the light transmitting member on the optical path until the irradiation light is received 2. The light detection device according to claim 1, wherein the foreign matter is removed by spraying or sucking the light irradiation means, the light receiving means, or the light transmitting member.   The photodetecting device according to claim 1, further comprising a removal control unit that controls a timing at which the removal unit performs foreign matter removal. The removal control means includes
The light detection apparatus according to claim 6, wherein the removal unit is controlled based on a light amount detected by the light detection unit. The removal control means includes
8. The light detection device according to claim 7, wherein when the light amount detected by the light detection means becomes a value smaller than a predetermined value, the removal means is caused to remove the foreign matter.   When the amount of light detected by the light detection means is smaller than a specified value, the removal means cannot remove the foreign matter, or a factor that prevents the detection by the light detection means other than the attachment of the foreign matter has occurred. 9. The photodetecting device according to claim 1, further comprising a non-removable signal output unit that outputs a non-removable signal indicating The non-removable signal output means includes
10. The non-removable signal is output when the amount of light detected by the light detecting means becomes smaller than a predetermined value within a predetermined period from the end of the foreign substance removing operation by the removing means. The light detection apparatus as described.   When the non-removable signal is input, the amount of irradiation light from the light irradiation unit is adjusted so that the amount of irradiation light from the light irradiation unit detected by the light detection unit is equal to or greater than a predetermined value. The light detection device according to claim 9, further comprising a light amount adjustment unit.   An adjustment limit signal output means for outputting an adjustment limit signal indicating that the increase in the light amount of the irradiation light is a limit when the light amount of the irradiation light from the light irradiation means reaches an upper limit by the adjustment by the light amount adjustment means; The photodetection device according to claim 11, further comprising: One or more light irradiation means for irradiating light;
One or more light detection means for receiving and detecting each irradiation light from one of the one or more light detection means;
Removing means for driving the other mechanism and removing foreign matter adhering to the light irradiating means, the light receiving means, and the light transmitting member on the optical path until the irradiated light is received;
And a light detection switching means for switching the light detection means for performing the light detection operation from the light detection means during the foreign matter removal operation by the removal means to the light detection means for which the foreign matter removal operation is not performed. Photodetector.   When the amount of light detected by the light detection means is smaller than a specified value, the removal means cannot remove the foreign matter, or a factor that prevents the detection by the light detection means other than the attachment of the foreign matter has occurred. 14. The photodetecting device according to claim 13, further comprising a non-removable signal output means for outputting a non-removable signal indicating The light detection switching means is
When the non-removable signal is input, the light detection means for performing the light detection operation is switched from the light detection means whose light quantity is smaller than a specified value to the other light detection means. The photodetection device according to claim 14.   When the non-removable signal is input, the amount of irradiation light from the light irradiation unit is adjusted so that the amount of irradiation light from the light irradiation unit detected by the light detection unit is equal to or greater than a predetermined value. The light detection device according to claim 13, further comprising a light amount adjustment unit.   An adjustment limit signal output means for outputting an adjustment limit signal indicating that the increase in the light amount of the irradiation light is a limit when the light amount of the irradiation light from the light irradiation means reaches an upper limit by the adjustment by the light amount adjustment means; The photodetection device according to claim 16, further comprising: The light detection switching means is
When the adjustment limit signal is input, the light detection means for performing the light detection operation is switched from the light detection means for which the amount of the irradiated light reaches the upper limit to the other light detection means. Item 18. The light detection device according to Item 17.   An image forming apparatus comprising the photodetection device according to claim 1.   The image forming apparatus according to claim 19, further comprising a display unit configured to display a light amount detected by the light detection device and a light amount irradiated from the light detection device. An image forming apparatus comprising the photodetection device according to any one of claims 9 to 11,
When the removal impossible signal is input, it has a display means for displaying that the removal means cannot remove the foreign matter, or that a factor that prevents detection by the light detection means other than the attachment of the foreign matter has occurred. Image forming apparatus. An image forming apparatus comprising the photodetection device according to claim 12,
An image forming apparatus comprising: display means for displaying that the increase in the amount of irradiation light is a limit when the adjustment limit signal is input.   The image forming apparatus according to claim 20, further comprising a print output unit that prints out the content displayed on the display unit. The removing means includes
The image forming apparatus according to any one of claims 19 to 23, wherein foreign matter removal is performed when a detection operation by the light detection unit is not performed.

Images