Sensor detection system and image forming apparatus

Abstract

To provide a sensor detection system capable of performing a plurality of kinds of detection by one sensor, and an image forming apparatus.SOLUTION: The sensor detection system 20 includes an optical sensor 21 including a light projecting unit 211 and a light receiving unit 212, a first transmission actuator 22 having a first transmittance, a second transmission actuator 23 having a second transmittance different from the first transmittance, a first rotation shaft 30 that moves the first transmission actuator 22 between a position overlapping a sensor optical axis of the optical sensor 21 and a position not overlapping the sensor optical axis, and a second rotation shaft 32 that moves the second transmission actuator 23 between a position overlapping the sensor optical axis of the optical sensor 21 and a position not overlapping the sensor optical axis. The optical sensor 21 outputs a detection value corresponding to the amount of light received by the light receiving portion 212.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a sensor detection system using a transmission type optical sensor and an image forming apparatus using the same. [Background technology]

[0002] Various sensors are used in image forming apparatuses. For example, Patent Document 1 discloses a method for detecting the amount of remaining paper in multiple stages using a single optical sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-286604 Summary of the Invention [Problem to be solved by the invention]

[0004] In image forming apparatuses that use many sensors, there is a demand for reducing the number of sensors to cut costs. It is particularly useful if a single sensor can perform multiple types of detection.

[0005] The present disclosure has been made in view of the above-mentioned problems, and aims to provide a sensor detection system and an image forming apparatus that are capable of performing multiple types of detection using a single sensor. [Means for solving the problem]

[0006] In order to solve the above problems, a sensor detection system that is a first aspect of the present disclosure comprises a transmissive optical sensor including a light-projecting unit and a light-receiving unit, a first movable member having a first transmittance, a second movable member having a second transmittance different from the first transmittance, a first movement control unit that moves the first movable member between a position where it overlaps with and a position where it does not overlap with a sensor optical axis, which is the optical axis of light irradiated by the light-projecting unit toward the light-receiving unit, and a second movement control unit that moves the second movable member between a position where it overlaps with and a position where it does not overlap with the sensor optical axis, and is characterized in that the transmissive optical sensor outputs a detection value corresponding to the amount of light received by the light-receiving unit.

[0007] In addition, in the above sensor detection system, the first movement control unit and the second movement control unit can be rotation axes to which the first movement member and the second movement member are respectively attached, and the first movement member and the second movement member can be configured to move relative to the sensor optical axis by rotating around the respective rotation axes of the first movement control unit and the second movement control unit.

[0008] In addition, in the above sensor detection system, the second moving member may include a plurality of transparent sections having different transmittances, and the plurality of transparent sections may be controlled to move so as to overlap at different times relative to the sensor optical axis, and the first transmittance may be smaller than the transmittance of any of the plurality of transparent sections.

[0009] A sensor detection system according to a second aspect of the present disclosure comprises a transmission-type optical sensor including a light-projecting unit and a light-receiving unit, a plurality of movable members each having a different transmittance, and a plurality of movement control units provided corresponding to each of the movable members, for moving the corresponding movable member between a position overlapping with and a position not overlapping with a sensor optical axis, which is the optical axis of light irradiated by the light-projecting unit toward the light-receiving unit, and characterized in that the transmission-type optical sensor outputs a detection value corresponding to the amount of light received by the light-receiving unit.

[0010] An image forming apparatus according to a third aspect of the present disclosure is equipped with the sensor detection system according to the first aspect, and is characterized in that if the amount of light received by the light receiving unit is the amount of light that has passed only through the first movable member, it determines a detection state for only the first detection; if the amount of light received by the light receiving unit is the amount of light that has passed only through the second movable member, it determines a detection state for only the second detection; if the amount of light received by the light receiving unit is the amount of light that has passed only through the second movable member, it determines a detection state for both the first detection and the second detection; and if the amount of light received by the light receiving unit is the amount of light that has not passed through both the first movable member and the second movable member, it determines a non-detection state for both the first detection and the second detection.

[0011] The image forming apparatus may be configured such that the first detection is detection of paper passing through a paper transport path, and the second detection is detection of paper being full in a paper output tray.

[0012] An image forming apparatus according to a fourth aspect of the present disclosure is equipped with the sensor detection system according to the second aspect, and is characterized in that it determines the detection state for each of multiple types of detection based on the amount of light received by the light receiving element. [Effects of the Invention]

[0013] The sensor detection system and image forming apparatus of the present disclosure are capable of performing multiple types of detection using one optical sensor, thereby reducing the number of sensors and costs. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of an image forming apparatus according to an embodiment of the present disclosure. [Figure 2] 2 is a cross-sectional view taken along a paper transport path near a paper discharge port of the image forming apparatus. [Figure 3] 10 is a schematic perspective view showing a sensor detection system in which both paper passage detection and discharge full detection are in a non-detection state; FIG. [Figure 4]10 is a schematic perspective view showing a sensor detection system in which paper passage detection is in a detection state and discharge full paper detection is in a non-detection state. FIG. [Figure 5] 10 is a schematic perspective view showing a sensor detection system in which paper passage detection is in a non-detection state and discharge full paper detection is in a detection state; FIG. [Figure 6] 10 is a schematic perspective view showing a sensor detection system in which both paper passage detection and paper discharge full detection are in a detection state; FIG. [Figure 7] FIG. 2 is a block diagram showing a control system that performs detection and determination in the image forming apparatus. [Figure 8] FIG. 10 is a schematic perspective view showing a sensor detection system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] [First embodiment] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Fig. 1 is a schematic diagram showing an example of the configuration of an image forming apparatus 10 according to an embodiment of the present disclosure. Note that, although the image forming apparatus 10 in Fig. 1 is an example of a monochrome machine including only one image forming unit, the present invention can also be applied to a color machine including multiple image forming units.

[0016] The image forming apparatus 10 is configured to include a main body 11, a document reading unit 12, and a document transport device 13. The main body 11 has an internal image forming unit for forming (printing) an image on recording paper. The document reading unit 12 is disposed above the main body 11 and reads documents when copying the documents, etc. In the automatic reading mode, the document transport device 13 sequentially transports documents placed on a document set tray toward the document placement table of the document reading unit 12.

[0017] At least one paper feed cassette 110 for stocking paper is provided in the lower part of the main body 11, and paper is separated one by one from a selected paper feed cassette 110 and transported toward the image forming unit. The image forming unit forms an image on the paper fed from the paper feed cassette 110 using known electrophotographic technology. The paper on which the image has been formed is discharged from a paper discharge port 111 onto a paper discharge tray 112.

[0018] 2 is a cross-sectional view of the paper transport path near the paper discharge outlet 111 of the image forming apparatus 10 (a cross-sectional view of the paper transport path extending vertically as seen from the side indicated by arrow A in FIG. 1). In FIG. 2, the paper transport path is arranged along the paper surface, and the paper transport direction is from bottom to top. The paper discharge outlet 111 is located further above the portion shown in the figure.

[0019] As shown in FIG. 2, the image forming apparatus 10 includes a sensor detection system 20 near the paper discharge outlet 111. The sensor detection system 20 includes an optical sensor 21, a first transmissive actuator (first moving member) 22, and a second transmissive actuator (second moving member) 23. The sensor detection system 20 enables two types of detection using a single optical sensor 21. In this embodiment, a case is illustrated in which a paper passage detection (first detection) in the paper transport path near the paper discharge outlet 111 and a paper full detection (second detection) in the paper discharge tray 112 are performed. Because the paper passage detection near the paper discharge outlet 111 and the paper full detection in the paper discharge tray 112 are performed at nearby locations in the image forming apparatus 10, the use of the sensor detection system 20 is preferable. However, the type of detection to which the sensor detection system 20 can be applied is not particularly limited. Furthermore, since the type of detection is not limited, the type of device that uses the sensor detection system 20 is not particularly limited. That is, the sensor detection system 20 can be used in devices other than image forming devices.

[0020] The optical sensor 21 is a transmission type optical sensor including a light-projecting unit 211 and a light-receiving unit 212. That is, the light-projecting unit 211 emits light toward the light-receiving unit 212. The light-receiving unit 212 receives the light emitted from the light-projecting unit 211 and outputs a detection value corresponding to the amount of light received.

[0021] The first transparent actuator 22 is a transparent, flat-plate-like member and is attached (for example, by adhesive) to the first rotating shaft (first movement control section) 30 so as to protrude in the radial direction. The second transparent actuator 23 is a transparent, flat-plate-like member and is attached (for example, by adhesive) to the second rotating shaft (second movement control section) 32 so as to protrude in the radial direction. This allows the first transparent actuator 22 to rotate integrally with (about) the first rotating shaft 30, and the second transparent actuator 23 to rotate integrally with (about) the second rotating shaft 32. In addition, a first abutment piece 31 is provided on the first rotating shaft 30, and a second abutment piece 33 is provided on the second rotating shaft 32. In the above configuration, portions of the first rotating shaft 30 and the second rotating shaft 32 are also included in the sensor detection system 20.

[0022] The first transmissive actuator 22 and the second transmissive actuator 23 have transmittances set to different values. In this embodiment, the transmittance (first transmittance) of the first transmissive actuator 22 is set to a (%), and the transmittance (second transmittance) of the second transmissive actuator 23 is set to b (%).

[0023] The optical sensor 21 is installed so that the optical axis of the light emitted from the light projecting unit 211 (hereinafter referred to as the sensor optical axis) is parallel to the first rotation axis 30 and the second rotation axis 32. Therefore, the first transmissive actuator 22 and the second transmissive actuator 23 can rotate in a plane perpendicular to the sensor optical axis. The rotation planes of the first transmissive actuator 22 and the second transmissive actuator 23 exist between the light projecting unit 211 and the light receiving unit 212.

[0024] In the optical sensor 21, the first transmissive actuator 22 is used to detect paper passage. A first rotating shaft 30, to which the first transmissive actuator 22 is attached, is biased in a predetermined direction by a biasing means (such as a spring, not shown). The first contact piece 31 is positioned at a predetermined paper passage detection position within the paper transport path. While no paper is being transported at the paper passage detection position, the first rotating shaft 30 is at the first rotation position due to the rotation biasing force. Meanwhile, while paper is being transported at the paper passage detection position, the first contact piece 31 contacts the paper being transported, causing the first rotating shaft 30 to rotate against the rotation biasing force and reach the second rotation position. When the first rotating shaft 30 is at the first rotation position, the first transmissive actuator 22 is at a non-detection position (see FIGS. 3 and 5) where it does not overlap with the sensor optical axis. When the first rotating shaft 30 is at the second rotation position, the first transmissive actuator 22 is at a detection position (see FIGS. 4 and 6) where it overlaps with the sensor optical axis.

[0025] In the optical sensor 21, the second transmissive actuator 23 is used to detect whether the tray is full of paper. The second rotating shaft 32, to which the second transmissive actuator 23 is attached, is biased in a predetermined direction by a biasing means (such as a spring) (not shown). The second contact piece 33 is located on the upstream wall surface 112a of the paper output tray 112 in the paper transport direction (the wall surface where the paper output opening 111 is provided; see FIG. 1 ), protruding slightly below the paper output opening 111 toward the tray (the second contact piece 33 is not shown in FIG. 1 ). When the paper output tray 112 is not yet full of paper, the first rotating shaft 30 is rotated to the third rotation position by the above-mentioned rotation biasing force. On the other hand, when the paper output tray 112 is full of paper, the second contact piece 33 abuts against the paper stack on the paper output tray 112, causing the second rotating shaft 32 to rotate against the rotation biasing force and reach the fourth rotation position. When the second rotation shaft 32 is in the third rotation position, the second transparent actuator 23 is in a non-detection position (see Figures 3 and 4) where it does not overlap with the sensor optical axis, and when the second rotation shaft 32 is in the fourth rotation position, it is in a detection position (see Figures 5 and 6) where it overlaps with the sensor optical axis.

[0026] Fig. 3 is a schematic perspective view showing sensor detection system 20 in which both paper passing detection and paper full detection are in a non-detection state. Fig. 4 is a schematic perspective view showing sensor detection system 20 in which paper passing detection is in a detection state and paper full detection is in a non-detection state. Fig. 5 is a schematic perspective view showing sensor detection system 20 in which paper passing detection is in a non-detection state and paper full detection is in a detection state. Fig. 6 is a schematic perspective view showing sensor detection system 20 in which both paper passing detection and paper full detection are in a detection state. Note that Figs. 3 to 6 only show light-emitting unit 211 of optical sensor 21, and light-receiving unit 212 is not shown.

[0027] When both the paper passage detection and the paper discharge full detection are in the non-detection state, both the first transmissive actuator 22 and the second transmissive actuator 23 are in the non-detection position. That is, as shown in Fig. 3, neither the first transmissive actuator 22 nor the second transmissive actuator 23 overlaps with the sensor optical axis, and the light emitted from the light-emitting unit 211 is received by the light-receiving unit 212 without being attenuated by transmission.

[0028] When the paper passage detection is in the detection state and the paper discharge full detection is in the non-detection state, only the first transmissive actuator 22 is in the detection position (the second transmissive actuator 23 is in the non-detection position). That is, as shown in Fig. 4, only the first transmissive actuator 22 overlaps with the sensor optical axis, and the irradiated light from the light-emitting unit 211 is attenuated as it passes through the first transmissive actuator 22, and then is received by the light-receiving unit 212.

[0029] When the paper passage detection is in the non-detection state and the paper discharge full detection is in the detection state, only the second transmissive actuator 23 is in the detection position (the first transmissive actuator 22 is in the non-detection position). That is, as shown in Fig. 5, only the second transmissive actuator 23 overlaps with the sensor optical axis, and the irradiated light from the light-emitting unit 211 is attenuated as it passes through the second transmissive actuator 23, and then is received by the light-receiving unit 212.

[0030] When both the paper passage detection and the paper discharge full detection are in the detection state, the first transmission actuator 22 and the second transmission actuator 23 both reach the detection positions. That is, as shown in FIG. 6, both the first transmission actuator 22 and the second transmission actuator 23 overlap the sensor optical axis, and the irradiation light from the light projection unit 211 passes through the first transmission actuator 22 and the second transmission actuator 23 and is attenuated, and then is received by the light receiving unit 212.

[0031] Here, when both the paper passage detection and the paper discharge full detection are in the non-detection state (the state in FIG. 3), the received light amount of the light receiving unit 212 is set to 100%. Also, assume that the transmittance a (%) of the first transmission actuator 22 is greater than the transmittance b (%) of the second transmission actuator 23 (a > b). Note that both the transmittance a (%) and the transmittance b (%) are less than 100% (and greater than 0%). However, the magnitude relationship between the transmittance a (%) and the transmittance b (%) is not limited to the relationship of a > b, and it may also be the relationship of a < b.

[0032] In this case, as shown in Table 1 below, when only the paper passage detection is in the detection state, the received light amount is a%, when only the paper discharge full detection is in the detection state, the received light amount is b%, and when both the paper passage detection and the paper discharge full detection are in the detection state, the received light amount is ab%. Also, the magnitude relationship of the received light amount is 100(%) > a > b > ab > 0(%). For example, if a = 67(%) and b = 50(%), then ab = 33.5(%).

[0033]

Table 1

[0034] The control circuit 40 performs detection determination by comparing the output (detection value) of the light receiving unit 212 with threshold values. In this embodiment, the control circuit 40 compares the output of the light receiving unit 212 with first to third threshold values.

[0035] The first threshold is set to a threshold that is smaller than the detection value for a received light amount of 100(%) and larger than the detection value for a received light amount of a(%). Thus, when the output of the light receiving unit 212 is larger than the first threshold, the control circuit 40 can determine that both the paper passage detection and the paper discharge full detection are in a non-detection state.

[0036] The second threshold is set to a threshold that is smaller than the detection value for the amount of received light of a (%) and larger than the detection value for the amount of received light of b (%). Thus, when the output of the light receiving unit 212 is smaller than the first threshold and larger than the second threshold, the control circuit 40 can determine that the paper passage detection is in a detected state and the paper discharge full detection is in a non-detected state.

[0037] The third threshold is set to a threshold that is smaller than the detection value for the amount of received light of b (%) and larger than the detection value for the amount of received light of ab (%). Thus, when the output of the light receiving unit 212 is smaller than the second threshold but larger than the third threshold, the control circuit 40 can determine that the paper passing detection is in a non-detection state and the paper discharge full detection is in a detection state. When the output of the light receiving unit 212 is smaller than the third threshold, the control circuit 40 can determine that both the paper passing detection and the paper discharge full detection are in a detection state.

[0038] As described above, the sensor detection system 20 of the present disclosure makes it possible to perform two types of detection using one optical sensor 21, and in equipment using this sensor detection system 20, the number of sensors can be reduced, thereby reducing costs.

[0039] In this embodiment, two types of detection (paper passage detection and paper discharge full detection) are performed by combining two actuators with one optical sensor 21. However, in principle, it is also possible to perform more types of detection by combining more actuators. In other words, it is also possible to determine the detection state for each of three or more types of detection based on the amount of light received by the light receiving unit 212.

[0040] For example, when using three actuators with transmittances a (%), b (%), and c (%) respectively, by setting the transmittances so that the relationship 100 (%) > a > b > c > ab > bc > ac > abc > 0 (%) is satisfied, three types of detection are possible using the same principle as explained above. Furthermore, four or more types of detection are also possible using the same principle.

[0041] In the above description, the movement of the actuator relative to the optical axis sensor is by rotational movement, but the method of movement of the actuator is not particularly limited. For example, the movement of the actuator relative to the optical axis sensor may be by linear reciprocating movement.

[0042] Second Embodiment As described above, the sensor detection system 20 is capable of two types of detection using one optical sensor 21. In this embodiment, a configuration that enables multi-stage detection in one type of detection will be described.

[0043] FIG. 8 is a schematic perspective view showing a sensor detection system 20 according to the second embodiment. The sensor detection system 20 shown in FIG. 8 has a second transmissive actuator 23 that includes a plurality of transmissive flat members. Specifically, the second transmissive actuator 23 includes a plurality of (five in this example) transmissive sections 231 to 235 attached to the second rotating shaft 32 so as to protrude in the radial direction. The transmissive sections 231 to 235 are attached at different positions relative to the second rotating shaft 32 along the axial direction, and protrude in different directions from the second rotating shaft 32 in the circumferential direction. Therefore, the tip ends of the transmissive sections 231 to 235 are arranged so as not to overlap with each other when viewed in the axial direction. The configuration of the first transmissive actuator 22 is the same as that of the first embodiment.

[0044] Here, the transmissive portions 231 to 235 of the second transmissive actuator 23 have different transmittances. In this embodiment, the transmittances of the transmissive portions 231 to 235 are b1 to b5 (%), respectively. The magnitude relationship of the transmittances b1 to b5 (%) is not particularly limited, but here, it is assumed that b1>b2>b3>b4>b5. Furthermore, in this embodiment, the transmittance a (%) of the first transmissive actuator 22 is smaller than any of the transmittances b1 to b5 (%). That is, it is assumed that b1>b2>b3>b4>b5>a.

[0045] In this embodiment, when the second transmissive actuator 23 is used to detect whether the image forming apparatus 10 is full of discharged paper, the amount of discharged paper in the discharge tray 112 can be detected in multiple stages. Specifically, as the amount of discharged paper in the discharge tray 112 increases from a non-detection state, the rotation amount of the second rotation shaft 32 also increases, and the transmissive portions 231 to 235 sequentially overlap with the sensor optical axis. That is, the transmissive portions 231 to 235 included in the second transmissive actuator 23 are controlled to move so as to overlap with the sensor optical axis at different times (two or more different transmissive portions among the transmissive portions 231 to 235 will not overlap with the sensor optical axis at the same time). As a result, the amount of discharged paper in the discharge tray 112 can be detected by detecting which of the transmissive portions 231 to 235 overlaps with the sensor optical axis. Here, assuming that the discharged paper amounts when the transparent portions 231 to 235 are detected are levels 1 to 5, the discharged paper amount increases as the level increases from 1 to 5, and at level 5, fullness is detected.

[0046] The sensor detection system 20 of this embodiment is capable of multi-level detection (detection at levels 1 to 5) for paper passage detection and paper discharge full detection, and the relationship between the combinations of these detection results and the amount of received light is shown in Table 2 below. In this case, the control circuit 40 in the image forming apparatus 10 must determine 12 possible results, so the control circuit 40 can determine all results by comparing the amount of received light with 11 threshold values.

[0047] [Table 2] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present disclosure should not be interpreted solely by the above-described embodiments, but should be determined based on the claims. [Explanation of symbols]

[0048] 10 Image forming device 20 Sensor Detection System 21 Optical sensor (transmissive optical sensor) 211 Light projector 212 Light receiving part 22 First transmission actuator (first moving member) 23 Second transmission actuator (second moving member) 231~235 Transparent part 30 First rotation axis (first movement control section) 31 1st contact piece 32 Second rotation axis (second movement control section) 33 Second contact piece 40 Control circuit

Claims

1. a transmission type optical sensor including a light emitting portion and a light receiving portion; a first moving member having a first transmittance; a second moving member having a second transmittance different from the first transmittance; a first movement control unit that moves the first moving member between a position where the first moving member overlaps with a sensor optical axis, which is an optical axis of irradiation light that the light projector irradiates toward the light receiver, and a position where the first moving member does not overlap with a sensor optical axis; a second movement control unit that moves the second moving member between a position where the second moving member overlaps with the sensor optical axis and a position where the second moving member does not overlap with the sensor optical axis, The sensor detection system is characterized in that the transmission type optical sensor outputs a detection value according to the amount of light received by the light receiving portion.

2. 10. The sensor detection system of claim 1, the first movement control unit and the second movement control unit are rotation shafts to which the first moving member and the second moving member are respectively attached, A sensor detection system characterized in that the first moving member and the second moving member move relative to the sensor optical axis by rotating around the respective rotation axes of the first movement control unit and the second movement control unit.

3. 10. The sensor detection system of claim 1, the second moving member includes a plurality of transmitting portions having different transmittances, The plurality of transmission portions are controlled to move so as to overlap with each other at different timings relative to the sensor optical axis, A sensor detection system, characterized in that the first transmittance is smaller than the transmittance of any of the plurality of transmittance portions.

4. a transmission type optical sensor including a light emitting portion and a light receiving portion; A plurality of moving members each having a different transmittance; a plurality of movement control units provided corresponding to the plurality of moving members, each moving the corresponding moving member between a position overlapping with a sensor optical axis, which is an optical axis of irradiation light emitted by the light projecting unit toward the light receiving unit, and a position not overlapping with the sensor optical axis; The sensor detection system is characterized in that the transmission type optical sensor outputs a detection value according to the amount of light received by the light receiving portion.

5. A sensor detection system according to any one of claims 1 to 3, The amount of light received by the light receiving unit is When the amount of light transmitted through only the first moving member is determined to be a detection state only for the first detection, When the amount of light transmitted through only the second moving member is determined, the second detection is determined to be in a detection state only; determining a detection state for both the first detection and the second detection when the amount of light transmitted through both the first moving member and the second moving member is equal to the amount of light; an image forming apparatus that determines a non-detection state for both the first detection and the second detection when the amount of light is such that the light does not pass through both the first moving member and the second moving member;

6. 6. The image forming apparatus according to claim 5, the first detection is detection of paper passing through a paper transport path, The image forming apparatus is characterized in that the second detection is detection of a full stack of discharged sheets in a discharge tray.

7. A sensor detection system according to claim 4, An image forming apparatus, characterized in that a detection state is determined for each of a plurality of types of detection based on the amount of light received by the light receiving section.

Images