JP2006145946A - Detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detecting device capable of increasing an upper-limit value of the quantity of light for securely detecting dirt of a detecting means when two couples of detecting means are provided side by side. <P>SOLUTION: The detecting device is constituted so that two detecting means which are each composed of a light emission portion and a light reception portion provided opposite a body to be detected and detect the body to be detected from variation in quantity of light of an optical path are arranged side by side, wherein the detecting means is characterized in that one light emission portion and one light reception portion are on the same side with the body to be detected and the light reception portions opposed to the body to be detected are at different positions. The storage amount of a developer in a storage means of storing the developer removed by a cleaning means of removing a developer on an image carrier is detected step by step. Further, the light emission portion arranged on the same side with the body to be detected is a light emitting element and the light reception portion is a light receiving element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a detection device that detects the presence or absence of an object to be detected.

  FIG. 11 shows a cross section of a conventional image forming apparatus, and the configuration thereof will be described and explained in the order of image formation.

  The image forming apparatus sequentially transfers the toner images formed by the image forming unit 201 to the intermediate transfer unit 202 at the primary transfer point N1.

  On the other hand, the sheet S is conveyed to the secondary transfer point N2 by the transfer material conveying unit 203, and the toner image is transferred from the intermediate transfer unit 202 at the secondary transfer point N2.

  Thereafter, the toner image is fixed on the sheet S by the fixing unit 204 and discharged onto the discharge tray 260 by the discharge unit 205.

  Here, when the toner image is transferred onto the sheet S at the secondary transfer point N 2 by the intermediate transfer unit 202, the toner remaining on the surface of the intermediate transfer belt 208 without being completely transferred is in contact with the intermediate transfer belt 208. It is removed by the cleaning blade 224 of the disposed cleaner unit 223 and collected in the cleaner container 227.

  The toner collected in the cleaner container 227 is a container for storing waste toner that is transported by the screw 228 in the cleaner container 227 of the cleaner unit 223 and connected and disposed at the end of the cleaner unit 223. Accumulated in the waste toner bottle 250 as needed. In the waste toner bottle 250, when the toner accumulated inside reaches a certain amount, two pairs of optical sensors arranged in parallel are detected step by step.

  As shown in FIG. 12, the two pairs of the first and second detection sensors arranged side by side have two light emitting portions 75a and 76a attached to the substrate 99 as detection means A and B, respectively, as objects to be detected. On the same side, two light receiving portions 75b and 76b attached to the substrate 98 are disposed on the same side with respect to the object to be detected (for example, see Patent Document 1).

JP-A-2002-139971

  However, in the above-described conventional method, for example, one countermeasure against false detection in which the vicinity of the detection means is contaminated with a powdery object (toner) and the light from the light emitting unit does not reach the light receiving unit and cannot be detected. As shown in FIG. 9, the light amount on the light-emitting side is increased so that the light reaches the opposite light-receiving part even if some dirt 77 is attached (see FIG. 9).

  However, when the amount of light is increased as shown in FIG. 12, the light emitting portions 75a and 76a of the detecting means A and B are attached to the substrate 98, and the light receiving portions 75b and 76b of the detecting means A and B are attached to the substrate 99. Since it is on the same side with respect to the detected object, light 75d other than the light 75c emitted from the light emitting portion 75a that should be detected only by the light receiving portion 75b of the detecting means A reaches the light receiving portion 76b of the detecting means B. For this reason, the amount of light has an upper limit, and it has not been possible to sufficiently prevent erroneous detection. Similarly, since light 76d other than light 76c emitted from the light emitting unit 76a that should be detected only by the light receiving unit 76b of the detecting unit B reaches the light receiving unit 75b of the detecting unit A, there is an upper limit on the amount of light. , Could not sufficiently prevent false detection.

  Therefore, an object of the present invention is to provide a detection device that can increase the upper limit of the amount of light for reliably detecting the contamination of the detection means when two pairs of detection means are arranged in parallel. It is.

  In order to achieve the above object, a typical configuration of the present invention is a detection in which a light emitting unit is not arranged in parallel on the same side with respect to a detected object, and similarly, a light receiving unit is not arranged in parallel on the same side with respect to the detected object. A detection method characterized by adopting a configuration.

  According to the present invention, when two pairs of detection means are arranged in parallel, the light emitting unit and the light receiving unit are mounted on the same substrate, and the two sets are arranged upside down without complicating the configuration. It is possible to increase the upper limit value of the amount of light for dirt near the detection means.

  By mounting the light emitting unit and the light receiving unit on the same substrate and forming two pairs of detection means with the same unit, the accuracy of the positional relationship between the light emitting unit and the light receiving unit can be improved compared to the case of mounting individually, and an error can occur. The possibility of detection can be reduced. Furthermore, it can be realized at a low cost by using the same unit.

  As a result, a device configuration having a detection reliability with a simple configuration is possible.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
As shown in FIG. 2, the laser scanner unit (1Y, 1M, 1C, 1K) corresponding to each color of yellow, magenta, cyan, and black has a laser beam (2Y, 2M, 2C, 2K) according to the image data of each color. ). This laser beam is applied to each color on a photosensitive drum (4Y, 4M, 4C, 4K) as an image carrier of each color whose surface is uniformly charged by a charging roller (3Y, 3M, 3C, 3K). Draw a latent image corresponding to the image data. Then, the developing devices (5Y, 5M, 5C, 5K) corresponding to the respective colors use the toners as the developer of the respective colors contained therein and the latent images through the developing sleeves (6Y, 6M, 6C, 6K) of the respective colors. Are sequentially developed in the order of yellow, magenta, cyan, and black.

  At this time, the intermediate transfer belt 8 as an intermediate transfer member is simultaneously held so that the upper surface thereof is in horizontal and uniform contact with the photosensitive drums of the four colors, and belt driving rollers (7a, 7b, 7c). ) Is rotated clockwise (in the direction of the arrow). At the primary transfer points (T1Y, T1M, T1C, T1K) on the upper surface of the intermediate transfer belt 8, the primary is sequentially performed by the backup rollers (9Y, 9M, 9C, 9K) that urge the belt from the inside to the respective photosensitive drums. Transcribed. As a result, the toner images on the respective photoconductive drums 4 are transferred onto the intermediate transfer belt 8 as a developer carrier by superimposing four color images in the order of yellow, magenta, cyan, and black. A toner image in which the images overlap is formed.

  After the secondary transfer, the sheet S on which an image is formed has a fixing roller 19 including a halogen heater 18 and a pressure roller 20 that rotates while being pressed against the fixing roller 19 with a predetermined pressure. The toner image transferred by heat and pressure is fixed on the sheet S by passing through the nip portion N which is a contact point of these two rollers 21 and then conveyed by the discharge roller pair (22a, 22b). It is discharged onto the discharge tray 60.

  On the other hand, the sheet S passes from the feeding cassette 10 to the secondary transfer point T2 through the feeding roller 11, the conveying roller pair (12a, 12b), the conveying roller pair (13a, 13b), and the conveying roller pair (14a, 14b). It is conveyed. At the secondary transfer point T2, the toner image formed on the intermediate transfer belt 8 by being sandwiched and conveyed by the transfer roller 15 in which a foam is wound around a metal shaft and the secondary transfer counter roller 7b is collectively transferred (secondary). The toner that has been transferred and is not completely transferred and remains on the surface of the intermediate transfer belt 8 is removed from the intermediate transfer belt 8 by a cleaning device described later.

  The cleaning device removes the toner on the intermediate transfer belt 8 and removes the toner removed by the cleaner unit 23 as a cleaning means that can be attached to and detached from the apparatus main body. The apparatus includes a waste toner bottle 50 as a means and two pairs of optical sensors as a plurality of detection means for detecting the amount of toner stored in the waste toner bottle 50.

  The toner that is not completely transferred and remains on the surface of the intermediate transfer belt 8 is removed by the cleaning blade 24 of the cleaner unit 23 disposed so as to be in contact with the intermediate transfer belt 8 and collected in the cleaner container 27. The toner collected in the cleaner container 27 is transported in the cleaner container 27 toward the front surface of the apparatus main body by a screw 28, and is connected to the end of the cleaner unit 23 to be disposed in a waste toner storage container. The waste toner bottle 50 is stored as needed.

  FIG. 3 is a configuration diagram of the intermediate transfer belt unit and the cleaner unit.

  In the intermediate transfer belt unit 40, the intermediate transfer belt 8 is supported by three belt drive rollers including a drive roller 7a, a secondary transfer counter roller 7b, and a tension roller 7c. The bearing member 17 of the tension roller 7c is pressed by a compression spring 17a to absorb changes in the peripheral length of the intermediate transfer belt 8 due to temperature and humidity in the intermediate transfer unit 40 body and changes with time. In addition, by transmitting the driving force of a driving motor (not shown) to the driving roller 7a, the intermediate transfer belt 8 is rotated clockwise at a predetermined peripheral speed in accordance with the image forming operation.

  In the cleaner unit 23, a cleaning blade 24 for cleaning the intermediate transfer belt 8 is disposed at a portion facing the tension roller 7c. The cleaning blade 24 is held so as to contact the intermediate transfer belt 8 at a predetermined angle with the swing shaft 25 as a rotation center. The cleaning blade 24 is in contact with the intermediate transfer belt 8 with a predetermined contact pressure by a compression spring 29 and is fixed to the blade holding plate 26.

  The bearing member 17 ′ is provided with a round long hole 42 into which the screw drive input portion 34 of the cleaner unit 23 is fitted. The round oblong hole 42 serves as a detent when the cleaner unit 23 is set. Further, the bearing member 17 has a boss 43 for positioning the detent member 30 of the cleaner unit 23. The bosses 41 and 41 ′ are fitted into the positioning grooves 31 and 31 ′ provided in the cleaner unit 23. Further, the cleaner unit 23 is positioned on the intermediate transfer unit 40 by the latches 32 and 32 ′.

  Next, the mounting method of the cleaner unit 23 will be described with reference to FIGS. 6 to 8 are diagrams showing how the cleaner unit and the intermediate transfer unit are mounted, and FIG. 5 is a top view of the cleaner unit.

  The cleaner unit 23 is inserted into the image forming apparatus main body in the direction of arrow A in FIG. 5, which is perpendicular to the conveying direction, and is pushed in until it hits a not-shown abutting portion in the intermediate transfer unit 40. As shown in FIGS. 6 to 8, the cleaner unit 23 is held in the state where the cleaner unit 23 is pushed in, and the lever 36 is rotated around the axis of the screw 28 for transporting the waste toner. The latches 32 and 32 'are pushed up until 41 and 41' are caught. On the contrary, when removing, the latches 32 and 32 'are released from the bosses 41 and 41' by rotating the lever 36 counterclockwise in the drawing, and the cleaner unit 23 is separated and pulled out in the direction of arrow B in FIG.

  In FIG. 5, the waste toner removed by the cleaning blade 24 is conveyed in the direction of arrow B by the screw 28 disposed at the lowermost part of the cleaner container 27. The waste toner falls into the waste toner bottle from the connecting portion between the cleaner container 27 and the waste toner bottle and is collected (see FIG. 9). The screw 28 is rotated by the driving force transmitted to the screw driving input unit 34.

  As shown in FIGS. 9 and 10, the waste toner bottle 50 is detachably held by a user by a snap fit or the like on a waste toner bottle holding member 70 disposed on the apparatus side plate 53. The waste toner bottle 50 is positioned by fitting the upper waste toner intake γ and the discharge port δ of the cleaner unit 23 together. At this time, the waste toner bottle 50 is held by the waste toner bottle holding member 70 while keeping a gap, and does not affect the positioning portion of the cleaner unit 23 and the waste toner bottle 50, and the posture of the waste toner bottle 50 is changed. It can be held.

  The waste toner bottle holding member 70 is provided with two optical sensors shown in FIG. 1 as detection means for detecting the capacity of the waste toner 51 in the waste toner bottle 50 in two stages. The two units of the detection unit 98 ′ in which the light emitting unit 75a and the light receiving unit 76b are attached to the substrate 98 and the detection unit 99 ′ in which the light emitting unit 76a and the light receiving unit 75b are attached to the substrate 99 are the same unit and are arranged upside down. Has been. The unit 98 'and the unit 99' are arranged so that the light emitting unit 75a and the light receiving unit 75b face the object to be detected, and the light emitting unit 76a and the light receiving unit 76b face the object to be detected.

  Next, the actual waste toner detection operation will be described.

  The light detection unit 75a and the light receiving unit 75b form an optical path 75c, and the detection unit B forms a light detection unit 76a and the light receiving unit 76b. The first detection sensor is a stage where the waste toner 51 of the waste toner bottle 50 is almost full, and the second capacity detection sensor pair is a stage where the waste toner 51 of the waste toner bottle 50 is completely full. Detect. The two pairs of toner capacity detection sensors 75, 75b, 76a, and 76b are light transmission sensors, and light emitting portions 75a and 76a and light receiving portions 75b and 76b are disposed on both sides near the lower side of the waste toner intake port γ, respectively. ing. The waste toner bottle 50 is formed of a transparent member at a portion where light paths 75c and 76c connecting the light emitting portions 75a and 76a and the light receiving portions 75b and 76b pass, and can transmit sensor light.

  As shown in FIG. 3, when the removed waste toner 51 is stored in the waste toner bottle 50 and the sensor light of the first capacity detection sensor pair 75a, 75b is blocked, the control means 120 of the apparatus main body 120 It is considered that 50 replacement periods have been reached. At this time, the control means 120 of the apparatus main body displays a message or a warning prompting the user to replace with a new waste toner bottle 50 on the display panel (see FIG. 2), and continues to notify the user. The recording operation of the apparatus main body is possible, and the recording operation is continued.

  As shown in FIG. 9, when the waste toner 51 blocks the sensor light of the second capacity detection sensor pair 76a, 76b, the control unit 120 of the apparatus main body disables the recording operation for the first time. The recording operation is stopped unless the waste toner bottle 50 is replaced. For this reason, for example, the waste toner 51 blocks the first capacity detection sensor pair 75 during the execution of the recording operation for several hundred sheets, and the control means 120 of the apparatus main body reaches the replacement time of the waste toner bottle 50. The recording operation of the apparatus does not stop suddenly even when it is considered. That is, when the replacement warning is issued for the first time, it is possible to guarantee the continuation of the recording operation issued by the user.

It is a figure which shows the relationship between the light emission part of the capacity | capacitance detection sensor pair which concerns on Embodiment 1 of this invention, and a light-receiving part. 1 is a cross-sectional view of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 3 is a configuration diagram of an intermediate transfer belt unit and a cleaner unit. FIG. 6 is a perspective view of an intermediate transfer unit and a cleaner unit. It is a top view of a cleaner unit. FIG. 5 is a diagram illustrating a method for mounting the cleaner unit and the intermediate transfer unit. FIG. 5 is a diagram illustrating a method for mounting the cleaner unit and the intermediate transfer unit. FIG. 5 is a diagram illustrating a method for mounting the cleaner unit and the intermediate transfer unit. It is a figure which shows the position of the capacity | capacitance detection sensor pair which concerns on Embodiment 1 of this invention. It is a figure which shows the position of the capacity | capacitance detection sensor pair which concerns on Embodiment 1 of this invention. It is sectional drawing of the image forming apparatus explaining a prior art example. It is a figure explaining the detection method explaining a prior art example.

Explanation of symbols

A 1st detection sensor B 2nd detection sensor 1 Laser scanner unit 2 Laser beam 3 Charging roller 4 Photosensitive drum 5 Developing device 6 Cleaner unit, waste toner bottle fitting part 7 Belt drive roller 7a Drive roller 7b Secondary transfer Counter roller 7c Tension roller 8 Intermediate transfer belt 9 Backup roller 10 Feed cassette 15 Transfer roller 19 Fixing roller 20 Pressure roller 21 Fixing device 23 Cleaner unit 50 Waste toner bottle 51 Waste toner 75a First detection sensor light emitting part 75b First Detection sensor light receiving portion 75c optical path of first detection sensor pair 76a second detection sensor light emitting portion 76b second detection sensor light receiving portion 76c optical path of second detection sensor pair 77 toner contamination 98 light emitting portion, light receiving portion mounting substrate 98 'detection unit 99 light emitting part, Light-receiving part mounting substrate 99 'detection unit 110 display panel 120 control means

Claims (4)

  Two detection means for detecting the detected object from the change in the amount of light in the optical path composed of the light emitting portion and the light receiving portion provided at positions opposed to the detected object are provided in parallel, and the detecting means is the same as the detected object. A detecting device characterized in that each side is a light emitting portion and a light receiving portion, and the light receiving portions facing the object to be detected are arranged at different positions.   2. The detection device according to claim 1, wherein the storage amount of the developer in the storage means for storing the developer removed by the cleaning means for removing the developer on the developer carrying member is detected stepwise.   The detection device according to claim 1, wherein the light emitting unit disposed on the same side of the object to be detected is a light emitting element, and the light receiving unit is a light receiving element.   4. The detection apparatus according to claim 3, wherein the light emitting element and the light receiving element disposed on the same side with respect to the object to be detected are configured in the same detection unit.

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