JP5754428B2 - Reflective optical sensor and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a laser beam printer, a facsimile machine, or a plotter apparatus.

  2. Description of the Related Art Conventionally, image forming apparatuses that form color images using a plurality of color toners have been widely implemented as analog or digital color copiers, printers, facsimile machines, and the like. Recently, it has been widely implemented as a multifunction printer (MFP) or the like (for example, see Patent Documents 1 to 3). In such an image forming apparatus, an electrostatic latent image is written on the surface of the image carrier, and a developer such as toner is attached to the electrostatic latent image to form an image. Next, the image-formed image is transferred to a recording material such as paper, and the image transferred to the recording material is fixed by fixing means such as a fixing belt, thereby forming an image.

  Then, by repeatedly fixing the image, the surface of the fixing unit may be worn or scratched. Specifically, for example, in an image forming apparatus capable of using A4 size paper and A3 size paper as recording materials, fixing is repeated in a state in which A4 size paper is vertically fed (referred to as sending the paper vertically long). Then, on the surface of the fixing belt as the fixing unit, vertical streak-like scratches are generated at the positions where both end portions of the A4 longitudinal paper in the sheet width direction are located. This is caused by the surface of the fixing belt being worn by paper dust adhering to both ends of the paper (debris such as additives generated by cutting the paper). When such vertical streak-like scratches are formed on the fixing belt, fixing is performed using A4 landscape paper (referred to as sending the paper in landscape orientation) or A3 portrait paper. A glossy streak appears on the image surface corresponding to the vertical streak. The appearance of the gloss streaks causes image quality degradation.

  In the inventions described in Patent Literature 1 to Patent Literature 3, measures for preventing such deterioration in image quality are disclosed. For example, the image forming apparatus described in Patent Document 1 includes an optical sensor that irradiates the surface of the fixing roller with light from a light source and receives reflected light from the fixing roller. Based on the intensity of the reflected light captured by the optical sensor, the reflectance of the surface of the fixing roller is calculated. When the reflectance is equal to or less than a predetermined value, the image forming apparatus issues a warning alarm because the surface of the fixing roller is scratched, offset, or the surface is deteriorated. By issuing this warning alarm, it is possible to determine when to replace the fixing roller.

  However, in the surface state detection device of Patent Document 1, the surface state of the fixing belt is roughly determined by simply detecting the reflectance of the reflected light from the surface of the fixing belt and comparing it with a preset set value. Therefore, it was impossible to accurately detect the presence / absence of an actual scratch, the position of the scratch, the width of the scratch, and the like.

The present invention
A reflective optical sensor for detecting the surface state of a moving object,
A plurality of illumination lenses corresponding to the plurality of irradiation system and the irradiation morphism system, an irradiation optical system for guiding the light emitted from the illumination system to the mobile,
A light receiving system having a plurality of light receiving portions, and the light receiving optical system having a light receiving lens for guiding the light reflected by the moving object to the light receiving system,
Equipped with a,
The irradiation system includes a plurality of light emitting units, and
The adjacent first irradiation system and second irradiation system are:
Among the light emitting units included in the first irradiation system, the light emitting unit positioned closest to the second irradiation system, and among the light emitting units included in the second irradiation system, the light emitting unit positioned closest to the first irradiation system. The interval between
The first irradiation system is arranged to be larger than the arrangement interval of the plurality of light emitting units,
Before KiTeru morphism lens, the optical axis position of those 該照 morphism lens has a optional feature that arranged so as to be between the two light receiving portions of the plurality of light receiving portions.

  According to the present invention, the following effects can be obtained by the above configuration.

In other words, each reflected light of light from a plurality of light emitting units is received by a plurality of light receiving units and compared with each other, so that the surface state at each position in the width direction of the moving body can be detected with higher accuracy. It becomes. For example, it is possible to detect in detail an accurate situation such as the presence or absence of an actual flaw on the moving body, the position of the flaw, the depth of the flaw, and the width of the flaw.
Moreover, irradiation morphism lens optical axis position of those 該照 morphism lens is by being arranged such that between any two light receiving portions of the plurality of light receiving portions, the moving direction around the moving body It is possible to suppress and stabilize the output fluctuation of the light receiving unit due to the fluctuation of the rotation angle (skew angle).
Further, the first irradiation system and the second irradiation system that are adjacent to each other are the light emitting unit that is located closest to the second irradiation system among the light emitting units that the first irradiation system has, and the light emission that the second irradiation system has. The intervals between the light emitting units located closest to the first irradiation system among the units are arranged to be larger than the arrangement intervals of the plurality of light emitting units included in the first irradiation system. Thereby, for example, since one irradiation lens can be associated with each irradiation system, it is possible to increase the amount of light incident on the moving body by increasing the lens diameter in the width direction of the irradiation lens.

1 is a longitudinal sectional view of a color printer as an example of an image forming apparatus. FIG. 2 is an enlarged side view showing the fixing device of FIG. 1. 1 is an overall configuration diagram of a surface state detection apparatus according to the present invention. It is the figure which looked at the surface state detection apparatus of FIG. 3 from the direction perpendicular | vertical to the rotating shaft of a heating roller. It is the side view which looked at the reflective optical sensor concerning Example 1 from the width direction. It is the front view which looked at the reflection type optical sensor of Drawing 5A from the light-emitting part side in the movement direction. It is the rear view which looked at the reflective optical sensor of FIG. 5A from the light-receiving part side in the moving direction. It is the top view which looked at the board | substrate which supports the light emission part and light-receiving part of the reflective optical sensor of FIG. 5A in the separation direction. It is a flowchart which shows operation | movement of a reflection type optical sensor. It is a flowchart which shows operation | movement of a surface state determination means. FIG. 5 is a graph showing the output of a reflective optical sensor and showing the relationship between the position in the main scanning direction and the intensity of reflected light. It is a graph which shows the relationship between a main scanning direction position and the differential value of reflected light intensity. It is the same graph as FIG. 8A which shows the relationship between the main scanning direction position and the reflected light intensity which show how to judge a damage level. It is a graph which shows the relationship between the light spot irradiation position n and the detection result R (n) of a reflective optical sensor. It is a graph which shows the relationship between the light spot irradiation position n and the differential value of detection result R (n). It is the same graph as FIG. 9B which shows how to obtain | require the position without a flaw. It is the same graph as FIG. 9A which considered the inclination component of the moving body. It is the graph which expanded the vertical axis | shaft of FIG. 9D to the up-down direction. It is the side view which looked at the reflective optical sensor concerning Example 2 from the width direction. It is the front view which looked at the reflective optical sensor of FIG. 10A from the light emission part side in the moving direction. It is the rear view which looked at the reflective optical sensor of FIG. 10A from the light-receiving part side in the moving direction. It is the top view which looked at the board | substrate which supports the light emission part and light-receiving part of the reflection type optical sensor of FIG. 10A in the separation direction. It is the side view which looked at the reflective optical sensor concerning Example 3 from the width direction. It is the front view which looked at the reflection type optical sensor of FIG. 11A from the light emission part side in the moving direction. It is the rear view which looked at the reflection type optical sensor of FIG. 11A from the light-receiving part side in the moving direction. It is the top view which looked at the board | substrate which supports the light emission part and light-receiving part of the reflection type optical sensor of FIG. 11A in the separation direction. Using the reflective optical sensor of Example 2 (LEDa (7)), the skew angle B is independently applied from 0 deg to ± 1.0 deg in increments of 0.25 deg to the fixing belt (moving body) as the test object. It is a graph which shows the mode of the output fluctuation of the light-receiving part at the time of doing. Using the reflective optical sensor of Example 3 (LEDb (7)), the skew angle B is independently applied from 0 deg to ± 1.0 deg in increments of 0.25 deg to the fixing belt (moving body) as the test object. It is a graph which shows the mode of the output fluctuation of the light-receiving part at the time of doing. Using the reflective optical sensor (LEDa (8)) of Example 2, a skew angle B is independently applied from 0 deg to ± 1.0 deg in increments of 0.25 deg to a fixing belt (moving body) as a test object. It is a graph which shows the mode of the output fluctuation of the light-receiving part at the time of doing. Using the reflective optical sensor (LEDb (8)) of Example 3, the skew angle B is applied independently from 0 deg to ± 1.0 deg in increments of 0.25 deg to the fixing belt (moving body) as the test object. It is a graph which shows the mode of the output fluctuation of the light-receiving part at the time of doing. It is the side view which looked at the reflective optical sensor concerning Example 4 from the width direction. It is the front view which looked at the reflection type optical sensor of FIG. 12A from the light emission part side in the moving direction. It is the rear view which looked at the reflection type optical sensor of FIG. 12A from the light-receiving part side in the moving direction. It is the top view which looked at the board | substrate which supports the light emission part and light-receiving part of the reflection type optical sensor of FIG. 12A in the separation direction. These are the side views which looked at the reflective optical sensor concerning Example 5 from the width direction. It is the front view which looked at the reflective optical sensor of FIG. 13A from the light emission part side in the moving direction. It is the rear view which looked at the reflective optical sensor of FIG. 13A from the light-receiving part side in the moving direction. It is the top view which looked at the board | substrate which supports the light emission part and light-receiving part of the reflection type optical sensor of FIG. 13A in the separation direction. It is the side view which looked at the reflective optical sensor concerning Example 6 from the width direction. It is the front view which looked at the reflection type optical sensor of FIG. 14A from the light emission part side in the moving direction. FIG. 14B is a rear view of the reflective optical sensor of FIG. 14A viewed from the light receiving unit side in the movement direction. It is the top view which looked at the board | substrate which supports the light emission part and light-receiving part of the reflection type optical sensor of FIG. 14A in the separation direction. It is a graph which shows distribution of the detection part output in a plurality of light sensing parts (PD_1-PD_18) when LED (2-3) concerning Example 8 lights up. It is a graph which shows the distribution of the detection part output about each of several light-receiving part (PD_1-PD_42) when LED (2-3), LED (5-3), and LED (8-3) are lighted simultaneously. . It is the figure which looked at the fixing belt from the perpendicular direction which shows the state which has arrange | positioned the reflection type optical sensor toward the width direction. FIG. 10 is a diagram of a fixing belt according to a ninth embodiment as seen from a perpendicular direction, showing a state in which the reflective optical sensor is disposed to be inclined with respect to the width direction and the moving direction. FIG. 14 is a diagram of the fixing belt as viewed from the perpendicular direction, showing the arrangement of the reflective optical sensor with respect to the width end position of various sizes of recording media (small size paper such as A4) according to Example 11. FIG. 14 is a diagram of the fixing belt as viewed from the perpendicular direction, showing the arrangement of the reflective optical sensor with respect to the width end position of various sizes of recording media (small size paper such as A5) according to Example 11. FIG. 12 is a diagram of the fixing belt as viewed from the perpendicular direction, showing the arrangement of the reflective optical sensor with respect to the width end position of various sizes of recording media (small size paper such as A6) according to Example 11. FIG. 14 is a diagram illustrating a state of a reflective optical sensor extending over the entire width of the fixing belt according to Example 12 when the fixing belt is viewed from a perpendicular direction.

  Embodiments of the present invention will be described below.

  First, FIG. 1 is a longitudinal sectional view showing a color printer as an example of the image forming apparatus 1. Note that the image forming apparatus 1 is not limited to the above-described printer such as a color printer, but may include a copying machine, a facsimile machine, a printing machine, and a multifunction machine that combines these functions. .

  In FIG. 1, the image forming apparatus 1 includes an image forming unit 2 and a paper supply / discharge unit 3.

  Among them, the image forming unit 2 superimposes and transfers each visible image formed on the photosensitive drum 4 to the intermediate transfer body 6 of the transfer device 5 in the primary transfer process, and records the recording paper or the like in the secondary transfer process. The recording medium S is configured to be collectively transferred to a recording medium S (recording paper or recording paper, or a recording material or a recording member).

  The photosensitive drum 4 is an image carrier that can form images corresponding to the respective colors separated into four colors of yellow (Y), cyan (C), magenta (M), and black (K). There is a tandem structure in which four are arranged in parallel according to the number of colors. For convenience of illustration, only the yellow (Y) photosensitive drum 4 is provided with a reference numeral, but the same applies to cyan (C), magenta (M), and black (K).

  Further, the intermediate transfer body 6 described above is an endless belt (hereinafter referred to as a transfer belt 6) that can move in the transport direction 7 indicated by an arrow, facing each photosensitive drum 4.

  The above-described image forming unit 2 has various devices for performing image forming processing around the photosensitive drums 4 according to the rotation of the photosensitive drums 4. Now, the photosensitive drum 4 (K) that forms a black image will be described as an example. Around the photosensitive drum 4 (K), image forming processing is performed along the rotational direction of the photosensitive drum 4 (K). The charging device 8, the developing device 9, the primary transfer roller 10 (see the yellow (Y) primary transfer roller 10), and the cleaning device 11 are arranged in this order. Note that an optical scanning device 12 (exposure device), which will be described later, is used for writing performed on the photosensitive drum 4 (K) after the charging device 8 charges the photosensitive drum 4 (K).

  In the superimposing transfer to the transfer belt 6 described above, each visible image formed on each photosensitive drum 4 (Y, C, M, K) in the process of moving the transfer belt 6 in the transport direction 7 described above, The transfer is performed while shifting the timing from the upstream side to the downstream side in the transport direction 7 so that the transfer is performed at the same position on the transfer belt 6. This superimposed transfer is performed by applying a voltage from each primary transfer roller 10 disposed so as to face each photoconductor drum 4 with the transfer belt 6 interposed therebetween.

  The photosensitive drums 4 are arranged in this order from the upstream side in the transport direction 7. Each photosensitive drum 4 constitutes each image station for forming an image for each color of yellow, cyan, magenta, and black.

  The image forming unit 2 of the above-described image forming apparatus 1 further includes the above-described four image stations and a transfer belt unit 13 disposed above the respective photosensitive drums 4 constituting the respective image stations. A secondary transfer roller 14; a cleaning device 15; and the optical scanning device 12 as an optical writing device disposed opposite to and below the four image stations.

  Here, the transfer belt unit 13 includes the transfer belt 6 and the primary transfer roller 10 described above. In addition to the transfer belt 6 and the primary transfer roller 10 described above, the transfer belt unit 13 includes a driving roller 16 and a driven roller 17 around which the transfer belt 6 is wound.

  Among these, the driven roller 17 includes a tension applying unit 18 for applying a tension to the transfer belt 6, and the driven roller 17 is attached to the tension applying unit 18 in a direction away from the driving roller 16. A biasing means such as a spring for biasing is used.

  The secondary transfer roller 14 is a transfer member that is disposed so as to face the transfer belt 6 and that rotates along with the transfer belt 6.

  The cleaning device 15 described above is a device that is disposed to face the transfer belt 6 and cleans the transfer belt 6.

  The transfer belt unit 13, the primary transfer roller 10, the secondary transfer roller 14, and the cleaning device 15 constitute the transfer device 5 described above.

  The optical scanning device 12 is equipped with a semiconductor laser as a light source, a coupling lens, an fθ lens, a toroidal lens, a mirror, a rotary polygon mirror, and the like. Incident light 19 (in the figure, for convenience, a reference is given to an image station for a black image, but the same applies to other image stations) to form an electrostatic latent image on the photosensitive drum 4. Is.

  Although not shown in detail, the cleaning device 15 provided in the above-described transfer device 5 includes a cleaning brush and a cleaning blade disposed so as to face and contact the transfer belt 6. . The transfer belt 6 is cleaned by scraping and removing foreign matters such as residual toner on the transfer belt 6 with a cleaning brush and a cleaning blade. The cleaning device 15 also has discharge means (not shown) for carrying out and discarding the residual toner removed from the transfer belt 6.

  The sheet supply / discharge section 3 of the image forming apparatus 1 stores a sheet storage device 21 that stores recording media S such as paper (only the position is shown in the drawing) in a stacked state, and the sheet storage. The sheet conveyance path 22 that conveys the recording medium S accommodated in the apparatus 21 one by one, and the recording medium S that has been conveyed from the sheet accommodation apparatus 21 along the sheet conveyance path 22 are converted into a toner image by the image station described above. A pair of registration rollers 23 that are fed out toward an image station between each photosensitive drum 4 and the transfer belt 6 at a predetermined timing in accordance with the (image) formation timing, and a pair of registration rollers whose leading ends of the recording medium S are a pair. And a sensor (not shown) for detecting the arrival at 23.

  The sheet storage device 21 described above is a paper feed cassette disposed in the lower part of the apparatus main body 24 of the image forming apparatus 1, and abuts against the upper surface of the uppermost recording medium S stored in the paper feed cassette. A feeding roller 25 is provided as a sheet feeding roller, and the feeding roller 25 is driven to rotate counterclockwise in the figure, whereby the uppermost recording medium S is paired with the pair of registration rollers 23 described above. It is supposed to be sent to.

  Further, the paper supply / discharge unit 3 of the image forming apparatus 1 includes a fixing device 26 as a fixing unit for fixing the toner image on the recording medium S on which the toner image (image) is transferred, and a fixed recording medium S. Is discharged to the outside of the apparatus main body 24 of the image forming apparatus 1 and the recording medium S formed on the upper part of the apparatus main body 24 and discharged to the outside of the apparatus main body 24 by the paper discharge roller 27. And a paper discharge tray 28 for loading the paper.

  As the above-described fixing device 26, a belt fixing type is used.

  Further, inside the image forming apparatus 1, a toner bottle 29 filled with toner of each color of yellow, cyan, magenta, and black is provided in a lower portion of the paper discharge tray 28.

  In the image forming apparatus 1 shown in the figure, the images formed on the respective photosensitive drums 4 are sequentially transferred onto the transfer belt 6 so that the color image is superimposed on the recording medium S by the secondary transfer roller 14. However, instead of this, a recording medium S is carried on the transfer belt 6 and this recording medium S is opposed to each photosensitive drum 4 so that each color image is directly recorded on the recording medium. It is possible to superimpose on S.

  FIG. 2 is an enlarged side view showing the configuration of the fixing device 26 described above.

The fixing device 26 includes a fixing roller 31, a pressure roller 32 as a pressure member (pressure member) facing the fixing roller 31, a heating roller 33 (heating means) having a heat source H therein, And a fixing member (or a fixing member) such as a fixing belt 35 as a moving member wound between the heating roller 33 and the fixing roller 31.

  Further, the fixing device 26 performs recording in a tension roller 36 that applies tension to the fixing belt 35 and a nip portion (or a biting portion) between the fixing roller 31 (or the fixing belt 35) and the pressure roller 32 described above. A separation claw 37 provided on the downstream side in the conveyance direction of the medium S and a temperature sensor (not shown) that detects the temperature of the fixing belt 35 on the heating roller 33 are provided.

  Here, the above-described fixing roller 31 is one in which silicone rubber is arranged on the surface of a metal cored bar.

  The pressure roller 32 described above is provided with an elastic layer such as silicone rubber on the surface of a core metal such as aluminum or iron, and a PFA or PTFE release layer is provided on the surface layer.

  The heating roller 33 described above is constituted by a hollow roller of aluminum or iron, and has a heat source H such as a halogen heater therein.

  The fixing belt 35 is configured by a base material such as nickel or polyimide having a release layer such as PFA or PTFE, or an intermediate layer provided with an elastic layer such as silicone rubber. The fixing belt 35 is wound around the fixing roller 31 and the heating roller 33, and is kept at an appropriate tension by being pressed by the tension roller 36 from the outside.

  The separation claw 37 described above has a front end portion (top portion) in contact with the surface of the fixing roller 31 portion of the fixing belt 35, and a plurality of the separation claws 37 are arranged in the width direction (direction perpendicular to the paper surface) of the fixing belt 35. Yes.

  As the above-described temperature sensor, one non-contact temperature sensor (thermopile) that does not contact the fixing belt 35 is provided. It is also possible to use a contact temperature sensor (thermistor) that comes into contact with the fixing belt 35.

  The tension roller 36 has a metal core with silicone rubber.

  The fixing device 26 configured to include such a member performs recording from the lower side in the drawing toward the nip portion formed by the fixing roller 31 (or the fixing belt 35) and the pressure roller 32 and capable of nipping and conveying. When the medium S enters, a predetermined pressure and heat are applied at the nip portion to fix the image on the recording medium S.

  A surface state detection device 41 as shown in FIG. 3 is provided for such a fixing device 26. The surface state detection device 41 is for detecting the surface state of a moving body (fixing member) such as the fixing belt 35.

  The surface state detection device 41 includes a reflective optical sensor 42 and a surface state determination unit 43.

  The reflective optical sensor 42 described above is disposed in a state of being separated from the fixing belt 35 (moving body) at the portion of the heating roller 33 so as to face the fixing belt 35, and light 45 (detection light) toward the fixing belt 35. ) To irradiate and form a plurality of light spots 46 having different positions in the width direction on the surface of the fixing belt 35 and receive reflected light 47 from the light spots 46 of the fixing belt 35, respectively. This is a detection mechanism.

  Further, the surface state determination unit 43 described above is disposed inside the image forming apparatus 1 and is connected to the reflection type optical sensor 42 described above to input various detection signals 48 from the reflection type optical sensor 42. The surface condition of the fixing belt 35 is determined by performing the above arithmetic processing. The surface state determination means 43 also has a function as a control unit 44 that controls the reflective optical sensor 42 by sending a control signal 49 to the reflective optical sensor 42.

  4 is a view of the surface state detection device 41 of FIG. 3 as viewed from a direction perpendicular to the rotation axis of the heating roller 33 (in this case, upward).

  In this case, for example, the reflection type optical sensor 42 described above has a width end position 35 s on one side of the sheet passing portion of the recording medium S (for example, in the case of A4 lengthwise paper passing) in the width direction x of the fixing belt 35. Or only one is arrange | positioned with respect to the vicinity.

  As will be described later, the reflective optical sensor 42 irradiates and forms a plurality of light spots 46 sequentially or at a predetermined distance in the width direction x at different positions in the width direction x. As a result, a relatively long detection region A is formed on the surface of the fixing belt 35. In this way, by forming a relatively long detection region A, the relative positional relationship between the reflective optical sensor 42 and the width end position 35s of the recording medium S in the width direction x is relatively rough. It becomes possible.

  Further, the surface state determination means 43 detects the surface state of the fixing belt 35 within a relatively long detection area A in the width direction x by inputting the detection signal 48 from the reflective optical sensor 42. can do.

  Then, by including the width end position 35 s of the recording medium S in the detection area A, the presence or absence of the vertical streak-like scratches 51 formed on the fixing belt 35 by the end surface of the recording medium S, and the position of the scratches 51. In addition, the level of the scratch 51 (scratch level) can be quantified as the surface state of the fixing belt 35.

  Here, the scratch level literally represents the degree of the scratch 51, and refers to the depth (roughness) of the scratch 51, the width (size) of the scratch 51, and the like.

  Hereinafter, before describing specific examples, an outline of a configuration that is characteristic in the present embodiment and its operation and effect will be described together.

  This embodiment relates to a reflective optical sensor 42 that is used in an image forming apparatus 1 that forms an image on a recording medium S and detects a surface state of a moving body (a fixing belt 35 described later).

Then, as shown in FIG 10A~ Figure 10D, the reflective optical sensor 42 has a plurality of illumination lenses 58 corresponding to the plurality of irradiation system and upper Symbol irradiation morphism system, emitted from the illumination system an irradiation optical system 53 for guiding light 45 to the mobile (see FIG. 5A), and guides the light receiving system having a plurality of light receiving portions 55, the light reflected on Symbol mobile (reflected light 47) to the light receiving system A light receiving optical system 56 having a light receiving lens 61 (see FIG. 5A) .

  Note that the irradiation optical system 53 and the light receiving optical system 56 are given the reference numerals only in the embodiments of FIGS. 5A to 5D because of the drawing, but the same applies to the other embodiments.

  As described above, the reflected light 47 of the light 45 from the at least two light emitting parts 52 is received by the at least two light receiving parts 55 and compared with each other, whereby the surface state at each position in the width direction x of the moving body is determined. Since it becomes possible to detect in more detail and more accurately in real time, it becomes possible to detect the surface state of the moving body with higher accuracy. For example, it is possible to detect in detail an accurate situation such as the presence / absence of the actual scratch 51 of the moving body, the position of the scratch 51, the depth of the scratch 51, and the width of the scratch 51.

Incidentally, when providing a plurality of light emitting portions 52, if as to the plurality of light emitting portions 52 provided one illumination lens 58 having a large lens diameter, smaller irradiation lens of lens diameter for each light emitting portion 52 Compared with the case where a plurality of individual 58 is provided, the intensity of the reflected light 47 from the light spot 46 can be increased while maintaining the interval (arrangement pitch) of the plurality of light spots 46, so It is possible to optimize the design of the detection unit 57 and increase the detection accuracy for the surface state of the moving body.

Then, as shown in FIG 11A~ Figure 11D, irradiation morphism lens 58, the optical axis position of the irradiation morphism lens 58 (optical axis 59), any two of the light receiving of the plurality of light receiving portions 55 It arrange | positions so that it may become between the parts 55. FIG .
At this time, the irradiation system includes a plurality of light emitting units 52. And the adjacent 1st irradiation system and 2nd irradiation system are the light emission part 52 located in the 2nd irradiation system side most among the light emission parts 52 which the said 1st irradiation system has, and said 2nd irradiation. It arrange | positions so that the space | interval with the light emission part 52 located in the 1st irradiation system side among the light emission parts 52 which a system has may become larger than the arrangement | positioning space | interval of the several light emission part 52 which the said 1st irradiation system has. The

  Thus, with respect to the arrangement direction of the irradiation system (width direction x of the moving body), the optical axis positions (optical axes 59) of the plurality of irradiation lenses 58 individually corresponding to the respective irradiation systems are the respective light receiving portions. By arranging each of the light receiving portions 55 so as to be at or near the position between any two light receiving portions 55 of 55, the above-mentioned movable body (of the recording medium S) It is possible to suppress and stabilize the output fluctuation of the light receiving unit 55 due to the fluctuation of the rotation angle (skew angle) around the transport direction. As a result, even if the position of the light spot 46 is different, the light receiving unit 55 exhibits the same behavior with respect to the fluctuation of the skew angle, so that the detection error can be reduced accordingly.

  12A to 12D, the light receiving lens 61 may be a cylindrical lens 62 that focuses light (reflected light 47) only in one axis direction.

  In this way, the light receiving lens 61 is a cylindrical lens 62 that focuses light (reflected light 47) only in one axial direction, so that the light receiving lens 61 can be compared with the case where a spherical lens or the like is used. It is possible to detect the surface state of the moving body with higher accuracy by suppressing the change in the received light amount distribution of the detection unit 57 (with respect to the width direction x).

  In addition, when the light receiving lens 61 is a cylindrical lens 62, for example, as compared with a case where a plurality of small lenses are arranged in parallel, parameters of each lens (small lens) (for example, lens radius of curvature, lens position, etc.). In addition, it is possible to eliminate the variation in the lens thickness and the like, so that the surface state of the moving body can be detected with higher accuracy.

  Further, as shown in FIGS. 13A to 13D, the irradiation lens 58 constituting the irradiation optical system 53 and the light receiving lens 61 constituting the light receiving optical system 56 may be integrally formed. Good (lens array 63).

  In this way, by integrating the irradiation lens 58 and the light receiving lens 61, workability when assembling each lens (the irradiation lens 58 and the light receiving lens 61) can be improved. As compared with the case of assembling, the arrangement accuracy between the lens surfaces can be improved.

Further, as shown in FIGS. 14A to 14D, a light shielding portion 65 may be provided between at least one of the adjacent irradiation optical systems or between the irradiation optical system and the light receiving system .

As described above, by providing the light shielding portion 65 between the adjacent irradiation optical systems or between the irradiation optical system and the light receiving system , the reflected light 47 from a portion other than the light spot 46 on the surface of the moving body. Or the reflected light on the lens surface of the irradiation lens 58 (irradiation lens 58 corresponding to the emitting light emitting part 52 or another irradiation lens 58 not corresponding to the emitting light emitting part 52) 47 or the like can be reduced or prevented from being received by the light receiving unit 55, and the surface state of the moving body can be detected with higher accuracy.

  Moreover, you may comprise so that the several light spot 46 may be irradiated sequentially.

  In this way, by sequentially irradiating the plurality of light spots 46, only one light spot 46 is always formed on the surface of the moving body. Therefore, at the same light receiving position, the plurality of light spots 46 are formed. Therefore, the detection accuracy for the reflected light 47 from each light spot 46 can be improved.

  Or you may comprise so that the several light spot 46 may be irradiated simultaneously (refer FIG. 15A and FIG. 15B).

  In this way, by irradiating a plurality of light spots 46 simultaneously, the scanning period in the width direction x of the light spot 46 can be shortened compared to the case where one light spot 46 is displaced sequentially. It becomes possible to detect the surface state of the body faster and more reliably.

Further, as shown in FIG. 16B, a plurality of light spots 46 may be irradiated with an arbitrary inclination with respect to the moving direction y (and the width direction x) of the surface of the moving body .

In this way, by irradiating the plurality of light spots 46 with an arbitrary inclination with respect to the moving direction y (and the width direction x) of the surface of the moving body , for example, the plurality of light emitting units 52 Even in the case where the light spots 46 are arranged at a constant interval, the interval between the plurality of light spots 46 with respect to the width direction x can be made smaller than the above-described constant interval, and the position resolution can be easily improved.

Then, a rotating fixing member (such as the fixing belt 35) and a pressure member (contacting the outer peripheral surface of the fixing member) and forming a nip portion for fixing the unfixed toner on the recording medium S passing through the recording medium S to the recording medium S are formed. The reflection type for detecting surface information of the fixing member with respect to the image forming apparatus 1 having the fixing device 26 having a pressure roller 32 and the like and a heating means (heating roller 33 and the like) for heating the fixing member. The reflective optical sensor 42 is arranged so as to irradiate a plurality of light spots 46 in a direction crossing the rotational movement direction of the fixing member on the outer peripheral surface of the fixing member. Also good.

  Thus, by providing the above-described reflective optical sensor 42, the image forming apparatus 1 can obtain the same effects as described above.

Further, with respect to the image forming apparatus 1 described above, the reflective optical sensor 42 may be disposed at least at the end position of the recording medium S as shown in FIGS . 17A to 17C or FIG. good.

  In this way, the reflective optical sensor 42 is partially installed with respect to the width end position 35s of the recording medium S conveyed by the moving body or in the vicinity thereof, so that the reflective optical sensor 42 is the most movable body. While being able to install efficiently in the place where the crack 51 is easy to generate | occur | produce or its vicinity, it becomes possible to reduce the size of the reflective optical sensor 42.

  In this case, the installation position of the reflective optical sensor 42 is at least one width end position in at least one of the recording media S having a maximum size that can be transported by the moving body or a standard size smaller than that. 35 s or its vicinity. The installation position of the reflective optical sensor 42 is at least one width end position in at least one of the recording media S having a standard size smaller than the maximum size that can be transported by the moving body. It is practically preferable to set it to 35 s or its vicinity.

  Alternatively, by installing the reflective optical sensor 42 over the entire width of the moving body, a plurality of types of scratches 51 generated at different positions depending on the size of the various recording media S conveyed by the moving body are once. Can be detected simultaneously, so that omission of detection can be eliminated.

  The moving body in the image forming apparatus 1 may be the fixing belt 35 (see FIGS. 2 to 4).

  As described above, since the moving body is the fixing belt 35, a material having a high surface hardness such as PFA is used for the fixing belt 35, and the fixing belt 35 is particularly easily damaged. It is possible to reliably detect the surface state of.

  The moving body may be the fixing roller 31 or the like instead of the fixing belt 35.

  Hereinafter, specific examples of the above-described embodiment will be described.

  5A to 5D show the most basic configuration of the reflective optical sensor 42. FIG.

  Here, in general, the width direction x of the moving body (the fixing member such as the fixing belt 35) is the main direction (or main scanning direction), and the moving direction y of the irradiated portion of the light spot 46 on the moving body (fixing member) The tangential direction) is the sub-direction (or sub-scanning direction), and the separation direction z between the moving body (fixing member) and the reflective optical sensor 42 is the emission direction of the light 45 or the reflection direction of the reflected light 47.

  FIG. 5A is a side view of the reflective optical sensor 42 viewed from the width direction x.

  FIG. 5B is a front view of the reflective optical sensor 42 of FIG. 5A viewed from the light emitting unit 52 side in the moving direction y.

  FIG. 5C is a rear view of the reflective optical sensor 42 of FIG. 5A viewed from the light receiving unit 55 side in the moving direction y.

  FIG. 5D is a plan view of the substrate 71 that supports the light emitting unit 52 and the light receiving unit 55 as viewed from the separation direction z.

First, as shown in FIG. 5A, the reflective optical sensor 42 guides and fixes a light emitting unit 52 (for example, a light source unit such as a light emitting diode (LED)) and light 45 emitted from the light emitting unit 52. irradiating the belt 35, the irradiation optical system 53 having an irradiation lens 58 arranged so as to form a light spot 46 on the surface of the fixing belt 35, is reflected from the light spot 46 formed on the fixing belt 35 A light receiving system having a plurality of light receiving portions 55 (for example, light receiving elements such as photodiodes (PD)) that receive the reflected light 47 and one light receiving lens 61 corresponding to at least two light receiving portions. A light receiving optical system for guiding 47 to the light receiving section.

  The light emitting unit 52 and the light receiving unit 55 are supported (mounted and arranged) by the same substrate 71. The irradiation lens 58 and the light receiving lens 61 are integrated to form a lens array 63. The substrate 71 and the lens array 63 are held by a sensor main body 64 (case) of the reflective optical sensor 42. A light shielding portion 65 for preventing flare light is provided inside the sensor main body 64.

  The light shielding part 65 and the sensor body 64 can be integrated by resin molding.

  And as shown to FIG. 5B, the light emission part 52 is multiply arranged with respect to the width direction x, and comprises the irradiation system. The width direction x described above is the arrangement direction of the light emitting units 52 in the irradiation system.

  A plurality of irradiation lenses 58 are arranged in the width direction x. In this case, each irradiation lens 58 is provided in one-to-one correspondence with each light emitting unit 52.

  A constant arrangement pitch with respect to the width direction x of each light emitting section 52 at this time is P. Further, P is a constant arrangement pitch with respect to the width direction x of each irradiation lens 58.

  The light shielding unit 65 shields the space in the separation direction z between the corresponding light emitting unit 52 and the irradiation lens 58 from the space between the other corresponding light emitting unit 52 and the irradiation lens 58. In order to prevent flare light, a plurality of spaces are arranged in the width direction x at intervals between adjacent spaces.

  Further, the same light shielding unit 65 as described above is also provided between the irradiation unit 54 and the detection unit 57 described above.

In this case, the light shielding portion 65 may be a light shielding wall formed in the frame-shaped sensor main body 64, an opening (peripheral wall) formed in the thick plate-shaped sensor main body 64, or the like.

  Then, the light 45 emitted from each light emitting unit 52 is irradiated to the fixing belt 35 through the corresponding irradiation lens 58, and a light spot 46 is formed on the surface of the fixing belt 35. Accordingly, the reflective optical sensor 42 can appropriately form a plurality of light spots 46 on the fixing belt 35 with the arrangement pitch P in the width direction x.

  As shown in FIG. 5C, one or more light receiving portions 55 are arranged in the width direction x. In this case, as shown in FIG. 5D, a plurality of light receiving portions 55 are provided in one-to-one correspondence with the light emitting portions 52. At this time, the constant arrangement pitch with respect to the width direction x of the light receiving portion 55 is P. That is, the light emitting unit 52 and the light receiving unit 55 are both aligned at the same arrangement pitch P in the width direction x.

The above light receiving lens 61 does not have (lens) power in the width direction x.

  When the light spot 46 is irradiated on the surface of the fixing belt 35, reflected light 47 is generated from the surface of the fixing belt 35. Since the fixing belt 35 is not an optical mirror surface, reflected light 47 including a diffuse reflection component 47b in addition to the regular reflection component 47a is generated.

  A part of the reflected light 47 is guided to the light receiving lens 61, collected only in the moving direction y of the fixing belt 35, and received by the light receiving unit 55. The reflected light 47 is received by the light receiving unit 55 once for each of the light spots 46 having different positions in the width direction x.

  Next, the operation of the reflective optical sensor 42 will be described using the flowchart of FIG.

  First, assume that the N light emitting units 52 are LED (1), LED (2)... LED (N) in order from the left end of FIG. 5D, and similarly, each of the N light receiving units 55 is illustrated in FIG. PD (1), PD (2)... PD (N) in order from the left end.

  In this case, it is assumed that the plurality of light emitting units 52 perform so-called sequential lighting in which lighting / extinguishing is repeated one by one in order from the left end.

  When the control is started, first, in step 1 (S1), 1 is set as an initial value in the variable n, and in step 2 (S2), the nth LED (n) is turned on.

  Then, in step 3 (S3), in synchronization with the lighting of the nth LED (n), the reflected light 47 from the fixing belt 35 changes the PD (n) paired with the lit LED (n). The light is received by a plurality of light receiving portions 55 in the vicinity thereof.

  Here, for the sake of simplicity, it is assumed that the number of light receiving portions 55 that receive the same reflected light 47 from the same light spot 46 is an odd number, and the light is received by (2m + 1) light receiving portions 55. Here, m is an integer. That is, PD (n−m) to PD (n + m) receive the same reflected light 47 at the same time.

  When one reflected light 47 is received by the (2m + 1) light receiving units 55, the nth LED (n) is turned off in step 4 (S4).

  Then, in step 5 (S5), the reflected light 47 received by the (2m + 1) light receiving units 55 is photoelectrically converted and amplified to become detection signals 48. The detection signals 48 from the respective light receiving units 55 are Each time, it is sent to the surface state determination means 43 of FIG.

  Next, in step 6 (S6), the above n and N are compared. If n <N, n + 1 is substituted for n in step 7 (S7), and the process returns to step 1 (S1). The above operation is repeated until the rightmost LED (N) is turned on / off.

  When n = N and the rightmost LED (N) is turned on / off, this is set as one cycle, and the above-described sequential lighting ends.

  However, in some cases, in order to increase the detection accuracy, step 8 (S8) is added after step 6 (S6), and the above-described sequential lighting is performed over a plurality of cycles, and the average value processing of the detection results is performed. It can also be done.

  Further, it is not necessary to use all (N) light emitting units 52 from the left end to the right end, and it is possible to use only N ″ (≦ N) of them. . Alternatively, it is not always necessary to start lighting / extinguishing from the leftmost light emitting unit 52 (1) and end lighting / extinguishing at the rightmost light emitting unit 52 (N). The lighting / extinguishing may be started from the light emitting unit 52 (m) and the lighting / extinguishing may be terminated at the Nmth light emitting unit 52 (Nm) on the right side. The left and right may be reversed.

  Next, the operation of the surface state determination means 43 will be described using the flowchart of FIG.

  When the surface state determination means 43 receives the detection signals 48 from the (2m + 1) light receiving units 55 as described above in step 11 (S11), first, in step 12 (S12), (2m + 1) light receptions. The sum of the detection signals 48 of the unit 55 is taken, and the detection result R (n) corresponding to each LED (n) is calculated. Based on the detection result R (n), it is possible to obtain the reflected light intensity corresponding to each position in the width direction x on each light spot 46 irradiated in the width direction x, in other words, on the surface of the fixing belt 35.

  Next, the surface state of the fixing belt 35 is determined.

  In general, when the fusing belt 35 has a flaw 51, the reflected light 47 from the surface of the fusing belt 35 decreases the specular reflection component 47a and increases the diffuse reflection component 47b, compared to the case where there is no flaw 51. (See FIG. 5C).

  In the reflective optical sensor 42 shown in FIGS. 5A to 5D, when the regular reflection component 47a decreases, the amount of light received by PD (n) decreases correspondingly, and when the diffuse reflection component 47b increases, PD (n− m) to PD (n + m) partly increase the amount of light received. When the scratch 51 is present, the amount of light received by PD (n−m) to PD (n + m) is reduced as a whole as compared with the case without the scratch 51.

  By examining such a change in the amount of received light, the surface state, that is, the position and level of the scratch 51 can be calculated in real time.

  Therefore, first, the presence / absence and position of the scratch 51 are determined.

  In the reflective optical sensor 42, detection results R (n) indicating the reflected light intensity are obtained corresponding to the respective positions in the width direction x on the surface of the fixing belt 35. By comparing each reflected light intensity at each position in the direction x, it can be seen that there is a scratch 51 at a position where the reflected light intensity is reduced.

Here, FIG. 8A is a schematic diagram showing the reflected light intensity at each position in the width direction x (main scanning direction) obtained by the reflective optical sensor 42.
Then, as shown in FIG. 8B, the value of the reflected light intensity described above is differentiated with respect to the width direction x (step 13 (S13) in FIG. 7), and the zero cross position where the differential value greatly changes from negative to positive. , The presence / absence of the flaw 51 is determined (step 14 (S14) in FIG. 7), and the position of the flaw 51 can be determined (step 15 (S15) in FIG. 7).

  Note that when the absolute value of the differential value is smaller than a predetermined threshold value set in advance, it indicates that the decrease in reflected light intensity is small. If there is no flaw 51, the determination is terminated as it is.

  In FIG. 9A, the reflection type optical sensor 42 with N = 24, n = 3 to 22, m = 2, and array pitch P = 1 mm is used for the fixing belt 35 after passing 400,000 sheets of the recording medium S. An example of the detection result R (n) obtained in this way is shown. In this reflective optical sensor 42, the light spot 46 is irradiated on the surface of the fixing belt 35 at a pitch of 1 mm. Therefore, the horizontal axis of FIG. 9A corresponds to the LED spot n and also corresponds to the light spot irradiation position [mm]. To do.

  FIG. 9B shows the result of differentiating R (n) with respect to the width direction x, more specifically, the result of calculating the slopes at two points, R (n) and R (n + 1). . For the purpose of smoothing, the slopes at three points R (n−1), R (n), and R (n + 1) can also be calculated.

  According to FIG. 9B, when the zero-cross position is obtained, n = 12.5, and the scratch 51 is located at a position of 12.5 mm, which is the middle of the irradiation position of the light spot 46 corresponding to the LED (12) and the LED (13). It can be determined that there is.

  Next, the scratch level is determined.

  In step 16 (S16) of FIG. 7, it is determined whether or not the depth of the scratch 51 is to be determined. If the depth of the scratch 51 is not determined, the determination is terminated as it is.

  Qualitatively, it is considered that the depth (roughness) of the scratch 51 is deeper (coarse), so that the decrease in the reflected light intensity becomes larger. Will be obtained. A schematic diagram thereof is shown in FIG. 8C.

  In the case of FIG. 8C, the depth of the scratch 51 is obtained simply by obtaining the minimum value of the detection result R (n). However, the attachment state of the reflective optical sensor 42 and the inclination of the fixing belt 35 are obtained. It is conceivable that an inclination component or the like is superimposed on the detection result R (n) due to factors such as the above.

  Therefore, in order to remove the inclination component described above, the following is performed.

  That is, first, a position where there is a scratch 51 and a position where there is no scratch 51 (step 17 (S17) in FIG. 7) are obtained.

  The position where the scratch 51 is present can be determined as described above.

  The position where there is no flaw 51 is considered to be a position where the fluctuation of the detection result R (n) is small, that is, a position where the differential values gather around zero. Therefore, the position without the scratch 51 can be calculated based on the result of differentiation with respect to the width direction x.

  If the position where the scratch 51 is present is n0 and the positions where at least two scratches 51 are not present are n1 and n2, the detection result R (n0) at the position n0 where the scratch 51 is present and the positions n1 and n2 where the scratch 51 is not present. From the detection results R (n1) and R (n2), the reduction amount of the reflected light intensity can be obtained.

  Further, in order to subtract the slope component superimposed on the detection result R (n), the distance of the detection result at the position where the scratch 51 is located with respect to the approximate straight line connecting the detection results at the position where there are no multiple scratches 51 can be obtained. It ’s fine.

  Actually, a method of obtaining the decrease amount of the reflected light intensity with respect to the result of FIG. 9B will be described.

  FIG. 9C shows the position where a plurality of points are gathered within a range of ± 20 where the differential value is small with respect to the position n0 where the scratch 51 is present from FIG. 9B. Accordingly, n1 = 6 and n2 = 15 can be selected as the positions n1 and n2 having no scratch 51.

  Using the detection results R (n) of the position n0 = 12.5 where the scratch 51 is extracted and the positions n1 = 6 and n2 = 15 where the scratch 51 is not extracted, the depth of the scratch 51 (roughness) ) Is calculated.

  That is, as shown by a broken line in FIG. 9D, R (n1) and R (n2) are connected by a straight line to obtain an approximate straight line. Then, as shown by the arrows in the figure, the depth of the scratch 51 is obtained (step 18 (S18) in FIG. 7). In this example, the depth of the scratch 51 is 63.1. The ratio of decrease in reflected light intensity is 0.16 (16%).

  From FIG. 9D, it can be seen that there is an inclination component indicated by a broken line, and the depth of the scratch 51 is superimposed on this.

  As the scratch level increases, the decrease in the reflected light intensity increases.

  As another surface condition parameter, a method for determining the width (size) of the scratch 51 will be described.

  In step 19 (S19) of FIG. 7, it is determined whether or not the width (size) of the scratch 51 is to be determined. If the width (size) of the scratch 51 is not determined, the determination is terminated as it is.

  The center position of the scratch 51 (the position where the scratch 51 is present) can be determined as described above.

  As for the width of the scratch 51, for example, from a detection result R (n) at a position where the scratch 51 is present, a predetermined amount out of the amount of decrease in reflected light intensity corresponding to the depth (roughness) of the scratch 51, for example, What is necessary is just to calculate the position which has the reflected light intensity used as the fall amount of 50%. However, the predetermined amount of reduction described above is not limited to 50% and can be arbitrarily set.

  FIG. 9E is an enlarged view of the vertical axis of FIG. 9D in the vertical direction for easy understanding. From this figure, it can be determined that the half width of the scratch 51 is 3 mm.

  Note that all of these surface condition parameters may be determined, or only necessary parameters may be determined.

  10A to 10D show the reflective optical sensor 42 (reflective optical sensor 42a) of the present embodiment.

  FIG. 10A is a side view of the reflective optical sensor 42 viewed from the width direction x.

  FIG. 10B is a front view of the reflective optical sensor 42 of FIG. 10A viewed from the light emitting unit 52 side in the movement direction y.

  FIG. 10C is a rear view of the reflective optical sensor 42 of FIG. 10A viewed from the light receiving unit 55 side in the movement direction y.

  FIG. 10D is a plan view of the substrate 71 that supports the light emitting unit 52 and the light receiving unit 55 as viewed in the separation direction z.

  First, as shown in FIG. 10A, the reflective optical sensor 42 (reflective optical sensor 42a) guides the light emitting part 52 (light emitting part 52a) and the light 45 emitted from the light emitting part 52 to move the moving body. An irradiation lens 58 (irradiation lens 58a) arranged so as to irradiate (fixing member such as the fixing belt 35) and form a light spot 46 on the surface of the fixing belt 35, and a fixing member (such as a moving body). A light receiving lens 61 (light receiving lens 61a) arranged so as to guide the reflected light 47 reflected from the light spot 46), and a light receiving portion for receiving the reflected light 47 guided by the light receiving lens 61. 55 (light receiving portion 55a).

  The light emitting unit 52 and the light receiving unit 55 are supported (mounted and arranged) by the same substrate 71. The substrate 71, the irradiation lens 58, and the light receiving lens 61 are held by a sensor body 64.

  As shown in FIG. 10B, a plurality of (in this case, four) light emitting units 52 are arranged close together in the width direction x, thereby forming an irradiation system. A plurality are provided.

Then, a plurality (four) illumination optical system corresponding to each irradiation system consisting of the light emitting portion 52 of each one of the irradiation lens 58 (irradiation lens 58a) of is as provided (many-to-one ). At this time, the lens diameter in the width direction x of the irradiation lens 58 is, for example, about four times the lens diameter of the irradiation lens 58 shown in FIG. 5B. Lens parameters other than the lens diameter are as follows. These are the same as those of the irradiation lens 58 shown in FIG. 5A. At this time, the arrangement pitch of the four light emitting units 52 in the width direction x is Pa (<P).

  The irradiation lens 58 is an anamorphic lens having different powers in the width direction x and the movement direction y.

  When the surface state of the fixing belt 35 is detected by the reflective optical sensor 42, the fixing belt with respect to the reflective optical sensor 42 is influenced by the influence of the wave of the fixing belt 35, flapping, curling of the fixing belt 35, and the like. There may be variations in the distance and angle of the 35 detection surfaces. These variations are difficult to eliminate completely, and the surface state of the fixing belt 35 is detected when variations in distance and angle occur between the reflective optical sensor 42 and the detection surface of the fixing belt 35. At this time, since a correct output (detection signal 48) cannot be read, accurate detection cannot be performed.

  At present, the influence of angular variation (hereinafter referred to as tilt angle) caused by the wave of the fixing belt 35 among the variation in the distance and angle of the detection surface generated in the reflective optical sensor 42 is particularly large.

  Therefore, in this embodiment, an anamorphic lens having different powers in the width direction x and the movement direction y is used as the irradiation lens 58. Thus, while maintaining the beam diameter in the width direction x in the light spot 46 on the fixing belt 35 in a desired state, the curvature radius with respect to the moving direction y of the anamorphic lens is optimized and is incident on the light receiving lens 61. The beam diameter of the reflected light 47 with respect to the moving direction y is reduced. As a result, it is possible to reduce fluctuations in the output of the detection unit and prevent deterioration in the detection accuracy of the sensor when a variation in the tilt angle caused by the wave of the fixing belt 35 occurs.

  Further, a combination of each irradiation system by the plurality of light emitting units 52 and one irradiation lens 58 corresponding to each irradiation system is used as one irradiation unit 75, and the irradiation unit 75 is a plurality of units in the width direction x. By arranging, the irradiation part 54 ((each irradiation system + irradiation lens 58) × number of units) of the reflective optical sensor 42 is configured.

  The arrangement pitch in the width direction x of each irradiation unit 75 at this time is P′a. In this case, the number of the light emitting units 52a constituting the irradiation system of one irradiation unit 75 is four, but any number may be used as long as it is two or more.

  In this embodiment, for the sake of simplicity, for example, the number of irradiation units 75 is set to nine. However, the number of irradiation units 75 is not limited to nine, and may be less than nine or more than nine.

  In one irradiation unit 75, the light 45 emitted from each light emitting unit 52 forms a light spot 46 on the surface of the fixing belt 35 via the corresponding irradiation lens 58. 42, a plurality of light spots 46 are formed on the fixing belt 35 at an arrangement pitch P ″ a in the width direction x.

  As shown in FIG. 10C, a plurality of light receiving portions 55 are arranged in the width direction x.

  At this time, as shown in FIG. 10D, there are a plurality of light receiving portions 55 in which the optical axis 59 of the irradiation lens 58a and the position in the width direction x are arranged at substantially the same position. The arrangement pitch in the width direction x of the light receiving portions 55 at this time is P ′ ″ a.

  Here, in the reflective optical sensor 42 of the present embodiment, the relationship of P ′ ″ a≈P ″ a≈P′a / 4 (≈P) is satisfied.

  One light receiving lens 61 corresponds to all the light receiving portions 55 arranged. The light receiving lens 61 is also an anamorphic lens having different powers in the width direction x and the movement direction y.

  A plurality of light spots 46 are formed in the width direction x on the surface of the fixing belt 35, and each reflected light 47 from each light spot 46 is generated on the surface of the fixing belt 35. Here, since the fixing belt 35 is not an optical mirror surface, reflection including a diffuse reflection component 47b occurs in addition to the regular reflection component 47a, and a part of the reflected light 47 is guided by the light receiving lens 61. Light is received by the light receiving unit 55.

Then, in FIG. 10D, the light emitting unit 52, in the interior of one irradiation unit 75 are aligned with de minimis arrangement pitch Pa to the width direction x, the arrangement pitch with respect to the width direction x is between the illumination unit 75 adjacent Aligned with P'a.

  The light receiving portions 55 are aligned at a constant arrangement pitch P ′ ″ a with respect to the width direction x. In addition, the space | interval of the light emission part 52 and the light-receiving part 55 in the said moving direction y is set to P '' '' a.

  Then, the light emitting units 52 are LEDa (1), LEDa (2)... LEDa (N) in order from the left end, and similarly, each light receiving unit 55 is in order PDa (1), PDa (2) from the left end. ... PDa (N ').

  As described above, the reflective optical sensor 42a of the present embodiment has a configuration in which one irradiating lens 58 is associated with a plurality of (in this case, four) light emitting units 52. The lens diameter in the width direction x of the lens 58 can be increased, thereby maintaining the arrangement pitch P ″ a of the plurality of light spots 46 on the fixing belt 35 to be the same as the arrangement pitch P in FIG. On the other hand, the amount of light incident on the fixing belt 35 can be increased by about four times as compared with the reflective optical sensor 42 of FIG.

  As is clear from FIG. 10B, at least two lights 45 emitted from a plurality of (in this case, four) light emitting units 52 in the same irradiation unit 75 are related to the optical axis 59 of the irradiation lens 58. They are configured so as to be substantially line symmetrical with each other. That is, for each irradiation unit 75, the correspondence relationship between the light emitting portion 52 and the light spot 46 formed on the fixing belt 35 is opposite to the left and right. For example, in the left irradiation unit 75 in the figure, the leftmost light emitting section 52 corresponds to the fourth light spot 46 from the left, and the fourth light emitting section 52 from the left corresponds to the leftmost light spot 46. The correspondence is reversed so as to correspond. The four light emitting units 52 in the irradiation unit 75 are arranged symmetrically on both sides of the optical axis 59 of the irradiation lens 58.

  The lens parameters in this case are specifically described. The radius of curvature of the irradiation lens 58 in the width direction x is 4.6 mm, the conic constant of the width direction x is 0, and the curvature of the irradiation lens 58 in the movement direction y. The radius is 4.3 mm, the cone constant in the moving direction y of the irradiation lens 58 is −2.0, the lens diameter in the width direction x of the irradiation lens 58 is 2.4 mm, and the lens diameter in the moving direction y of the irradiation lens 58. Is 10.5 mm, and the lens thickness of the irradiation lens 58 is 6.6 mm.

  The light receiving lens 61 has a radius of curvature in the width direction x of 50 mm, the conical constant in the width direction x of −1.0, the light receiving lens 61 has a radius of curvature in the moving direction y of 4.8 mm, and the light receiving lens 61. The conical constant in the moving direction y is −1.6, the lens diameter in the width direction x of the light receiving lens 61 is 17 mm, the lens diameter in the moving direction y of the light receiving lens 61 is 10.1 mm, and the lens thickness of the light receiving lens 61 Is 6.6 mm.

  The distance between the irradiation lens 58 and the light receiving lens 61 in the moving direction y is 2.53 mm, the distance between the light emitting portion 52 and the irradiation lens 58 in the optical axis direction (separation direction z), and the optical axis. The distances between the light receiving portion 55 and the light receiving lens 61 in the direction are equal to each other and are 10.37 mm.

  11A to 11D show the reflective optical sensor 42 (reflective optical sensor 42b) of the present embodiment.

  FIG. 11A is a side view of the reflective optical sensor 42 viewed from the width direction x.

  FIG. 11B is a front view of the reflective optical sensor 42 of FIG. 11A viewed from the light emitting unit 52 side in the movement direction y.

  FIG. 11C is a rear view of the reflective optical sensor 42 of FIG. 11A viewed from the light receiving unit 55b side in the movement direction y.

  FIG. 11D is a plan view of the substrate 71 that supports the light emitting unit 52 and the light receiving unit 55 as viewed in the separation direction z.

10A to 10D described above, a plurality of light receiving portions 55a of the reflective optical sensor 42a are arranged to face the light emitting portion 52a and have an arrangement pitch P ′ ″ a in the width direction x. As shown in FIG. 10C, there are a plurality of light receiving portions 55a arranged at substantially the same position as the optical axis 59 of the irradiation lens 58a in the width direction x.

  On the other hand, in the present embodiment, the position in the width direction x of the optical axis 59 of the irradiation lens 58b when viewed from the movement direction y is located in the middle or in the vicinity of any two light receiving portions 55b. The feature is that the arrangement of the light receiving portion 55b is changed.

  First, as shown in FIG. 11A, the reflective optical sensor 42 (reflective optical sensor 42b) guides the light emitting part 52 (light emitting part 52b) and the light 45 emitted from the light emitting part 52 to move the moving body. (Fixing belt 35) is irradiated and reflected from irradiation lens 58 (irradiation lens 58b) arranged to form light spot 46 on the surface of fixing belt 35 and fixing belt 35 (light spot 46). A light receiving lens 61 (light receiving lens 61b) arranged to guide the reflected light 47, and a light receiving portion 55 (light receiving portion 55b) for receiving the reflected light 47 guided by the light receiving lens 61. ,have.

  The light emitting unit 52 and the light receiving unit 55 are supported (mounted and arranged) by the same substrate 71. The substrate 71, the irradiation lens 58, and the light receiving lens 61 are held by a sensor body 64.

As described above, the only change from the above embodiment is the position of the light receiving portion 55 (light receiving portion 55b), and the arrangement pitch P ′ ″ a between the adjacent light receiving portions 55 is not changed. Therefore, the lens parameters are also the same as those in the above embodiment.

11E to 11H , a skew angle B is applied to the fixing belt 35 (moving body) that is a test object by using the reflective optical sensor 42a of the above embodiment and the reflective optical sensor 42b of this embodiment. Is a state of output fluctuation of the light receiving unit 55 when 0 is applied from 0 deg to ± 1.0 deg in increments of 0.25 deg. Here, the skew angle B is a rotation angle of the fixing belt 35 around the moving direction y described above.

  Here, the light emitting section 52 to be lit is the seventh light emitting section 52 (LEDa (7) and LEDb (7)) from the left side (FIGS. 11E and 11F, respectively), and the eighth light emitting section 52 (LEDa (8)). And LEDb (8)) (FIGS. 11G and 11H, respectively). The output of the light receiving unit 55 is set so that the output when the skew angle B = 0 deg is 1 (relative light receiving unit output), and as described above, the sum of the detection signals 48 in the plurality of light receiving units 55. The value is used as the detection result as the detection unit output (or reflected light intensity). Here, for the sake of simplicity, the total number of light receiving portions 55 is 10 or 8.

  In the range of the skew angle B = ± 1.0 deg, the absolute value of the difference between the maximum value and the minimum value of the detection unit output is set as the PV value, and the PV value when the different light emitting units 52 are turned on is represented by each reflective optical sensor. Comparison is made for each of 42a and 42b. In addition, even if the light emission part 52 to light is different, it is an ideal state that PV value becomes equal, and it becomes so good that the difference of PV value becomes small. And it can be judged that the detection error by the difference in the light emission part 52 to light is small because PV value is small.

  As is apparent from the results of FIGS. 11E to 11H, the PV value is smaller when the reflective optical sensor 42b of this embodiment is used than when the reflective optical sensor 42a of the above-described embodiment is used. ing.

  As described above, in the reflective optical sensor 42b of the present embodiment, the variation in the detection unit output caused by the variation in the skew angle, which is the rotation about the moving direction y of the fixing belt 35, is different even if the light emitting unit 52 to be lit is different. By configuring so as to behave in a similar manner, it is possible to suppress detection errors due to differences in the light emitting units 52 that are lit.

  12A to 12D show a reflective optical sensor 42 (reflective optical sensor 42c) of the present embodiment.

  FIG. 12A is a side view of the reflective optical sensor 42 viewed from the width direction x.

  FIG. 12B is a front view of the reflective optical sensor 42 of FIG. 12A viewed from the light emitting unit 52 side in the movement direction y.

  FIG. 12C is a rear view of the reflective optical sensor 42 of FIG. 12A viewed from the light receiving unit 55 side in the movement direction y.

  FIG. 12D is a plan view of the substrate 71 that supports the light emitting unit 52 and the light receiving unit 55 as viewed in the separation direction z.

  11A to 11D, the light receiving lens 61b of the reflective optical sensor 42b is an anamorphic lens, but in this embodiment, light (reflected light 47) is applied to the light receiving lens 61c of the reflective optical sensor 42c. Is characterized by using a cylindrical lens 62 that focuses only in one axial direction (note that although not specifically described, the cylindrical lens 62 may be used in other embodiments as well). . In this case, for example, the cylindrical lens 62 has no power in the width direction x or the arrangement direction of the light spots 46 (including the case where the arrangement direction of the light spots 46 is inclined as described later).

As shown in FIGS . 12A and 12B , the reflective optical sensor 42 (the reflective optical sensor 42c) guides and moves the light emitting unit 52 (the light emitting unit 52c) and the light 45 emitted from the light emitting unit 52. An irradiation lens 58 (irradiation lens 58c) arranged to irradiate the body (fixing belt 35) and form a light spot 46 on the surface of the fixing belt 35, and reflected from the fixing belt 35 (light spot 46). The light receiving lens 61 (light receiving lens 61c) arranged to guide the reflected light 47, and the light receiving portion 55 (light receiving portion 55c) for receiving the reflected light 47 guided by the light receiving lens 61. And have.

  The light emitting unit 52 and the light receiving unit 55 are supported (mounted and arranged) by the same substrate 71. The substrate 71, the irradiation lens 58, and the light receiving lens 61 are held by the sensor main body 64.

As shown in FIGS. 12C and 12D , the reflective optical sensor 42 has a configuration in which a plurality of light receiving portions 55 (PDc) are arranged in the width direction x. Therefore, regarding the moving direction y described above, it is necessary to narrow the reflected light 47 incident on the light receiving unit 55 in the moving direction y in consideration of the position of the light receiving unit 55 and the size of the light receiving unit 55. Since a plurality of light receiving portions 55 are arranged, it is not necessary to squeeze the reflected light 47 by applying power in the width direction x of the light receiving lens 61. Therefore, as described above, the cylindrical lens 62 having no power in the width direction x is used as the light receiving lens 61.

  Since the light-receiving lens 61 is a cylindrical lens 62 having no power in the width direction x, the width of the light-receiving portion 55 due to the difference in the light-emitting portion 52 that is turned on compared to the case where an anamorphic lens is used as the light-receiving lens 61. A change in the received light amount distribution in the direction x can be suppressed, and the surface state of the fixing belt 35 can be detected with higher accuracy.

  When the lens parameters of this embodiment are specifically described, the irradiation lens 58 is not changed from the case of each of the above embodiments. For the light receiving lens 61, only the curvature radius in the width direction x and the conical constant in the width direction x are changed from those in the first embodiment, and the curvature radius in the width direction x of the light receiving lens 61 is ∞ and the width direction x. The conic constant is zero.

  The arrangement positions and pitches of the light emitting unit 52 and the light receiving unit 55 are the same as those in the second embodiment.

  13A to 13D show a reflective optical sensor 42 (reflective optical sensor 42d) of the present embodiment.

  FIG. 13A is a side view of the reflective optical sensor 42 viewed from the width direction x.

  FIG. 13B is a front view of the reflective optical sensor 42 of FIG. 13A viewed from the light emitting unit 52 side in the movement direction y.

  FIG. 13C is a rear view of the reflective optical sensor 42 of FIG. 13A viewed from the light receiving unit 55 side in the movement direction y.

  FIG. 13D is a plan view of the substrate 71 that supports the light emitting unit 52 and the light receiving unit 55 as viewed in the separation direction z.

  In the reflective optical sensor 42 of each of the above embodiments, the irradiation lens 58 and the light receiving lens 61 can be arranged at their desired positions. In this embodiment, the irradiation lens The lens array 63 in which the lens 58 and the light receiving lens 61 are integrated is characterized by the fact that the lens array 63 is used in the other embodiments as well. Of course it is good).

  As shown in FIG. 13A, the reflective optical sensor 42 (reflective optical sensor 42d) guides the light emitting section 52 (light emitting section 52d) and the light 45 emitted from the light emitting section 52 to move the moving body (fixing). The irradiation lens 58 (irradiation lens 58d) arranged to irradiate the belt 35) and form the light spot 46 on the surface of the fixing belt 35, and the reflection reflected from the fixing belt 35 (the light spot 46). A light receiving lens 61 (light receiving lens 61d) arranged to guide the light 47, and a light receiving portion 55 (light receiving portion 55d) for receiving the reflected light 47 guided by the light receiving lens 61. Have.

  The light emitting unit 52 and the light receiving unit 55 are supported (mounted) by the same substrate 71. The substrate 71 and the lens array 63 described above are held by the sensor body 64.

  According to this embodiment, as described above, by using the lens array 63, it is possible to improve workability of assembling each lens (the irradiation lens 58 and the light receiving lens 61) to the reflective optical sensor 42. In addition, the arrangement accuracy between the lens surfaces can be increased. Thereby, fluctuations in the output of the detection unit are further reduced, and it can be expected to detect the surface state of the fixing belt 35 with higher accuracy.

  14A to 14D show the reflective optical sensor 42 (reflective optical sensor 42e) of the present embodiment.

  FIG. 14A is a side view of the reflective optical sensor 42 viewed from the width direction x.

  FIG. 14B is a front view of the reflective optical sensor 42 of FIG. 14A viewed from the light emitting unit 52 side in the moving direction y.

  FIG. 14C is a rear view of the reflective optical sensor 42 of FIG. 14A viewed from the light receiving unit 55 side in the movement direction y.

  FIG. 14D is a plan view of the substrate 71 that supports the light emitting unit 52 and the light receiving unit 55 as viewed in the separation direction z.

  In this embodiment, the light-shielding portion 65 is provided in the reflection type optical sensor 42 of each of the above-described embodiments (there is no particular description, but in other embodiments as well, the light-shielding portion is the same). Of course, the portion 65 may be provided).

  As shown in FIG. 14A, the reflective optical sensor 42 (reflective optical sensor 42e) guides the light emitting part 52 (light emitting part 52e) that emits near infrared light and the light 45 emitted from the light emitting part 52. An irradiation lens 58 (irradiation lens 58e) disposed so as to irradiate and irradiate the moving body (fixing belt 35) and form a light spot 46 on the surface of the fixing belt 35; 46), a light receiving lens 61 (light receiving lens 61e) arranged so as to guide the reflected light 47 reflected from the light receiving lens 61, and a light receiving unit 55 (see FIG. 6) for receiving the reflected light 47 guided by the light receiving lens 61. Light receiving portion 55e).

  The light emitting unit 52 and the light receiving unit 55 are supported (mounted and arranged) by the same substrate 71. The substrate 71 and the lens array 63 are held by the sensor body 64.

  In the present embodiment, a light blocking portion 65 is provided to prevent flare light.

  Here, the flare light is light other than the reflected light 47 from the light spot 46. The light other than the reflected light 47 from the light spot 46 is, for example, reflected light 47 from a portion other than the light spot 46 on the surface of the moving body or an irradiation lens 58 (for irradiation corresponding to the emitted light emitting section 52). Reflected light 47 on the lens surface of the lens 58 or another irradiating lens 58) that does not correspond to the light emitting section 52 that is emitting the light.

  In this case, the light shielding unit 65 is provided so as to shield between the adjacent irradiation units 75.

  More specifically, in order to partition the space between the corresponding light emitting unit 52 and the irradiation lens 58 and the external space, the space is provided as appropriate for the boundary portion of each space.

  Further, the light shielding unit 65 is installed between the irradiation unit 54 and the detection unit 57.

  The light shielding portion 65 described above can be a light shielding wall provided inside the frame-shaped sensor main body 64 or an opening formed in the thick plate-shaped sensor main body 64.

  In addition, the light shielding part 65 and the sensor main body 64 can be integrated by resin molding.

  As described above, by providing the light shielding unit 65 inside the sensor main body 64, the fixing belt 35 is irradiated through the irradiation lens 58 other than the irradiation lens 58 corresponding to the arbitrary light emitting unit 52 (LED) to be lit. The reflected light from the emitted light and the direct reflected light from the lens surface of the irradiating lens 58 or other irradiating lens 58 corresponding to the arbitrary light emitting section 52 to be lit (hereinafter, these lights are referred to as flare light). However, the surface state of the fixing belt 35 can be detected with higher accuracy by preventing direct incidence on the light receiving portion 55.

  In the reflective optical sensor 42 shown in the above embodiments, as described in this embodiment, a plurality of light emitting units 52 (LEDs) are turned on / off one by one so that a plurality of light emitting units 52 (LEDs) are sequentially turned on. The light spot 46 is sequentially irradiated so that the position of the scratch 51 on the surface of the movable body (a fixing member such as the fixing belt 35) in the width direction x can be accurately specified.

  Here, the light emitting unit 52 is sequentially turned on when, for example, the light spot 46 is scanned on the moving body (the fixing belt 35) in the positive direction of the width direction x (for example, the direction from the left to the right). Repeats the operation of turning on / off the light emitting units 52 in one irradiation unit 75 one by one in order from the right end. Similarly to the above, the operation of turning on / off one by one from the right end is repeated for the light emitting units 52 in the irradiation unit 75 arranged adjacent to the positive side in the width direction x of the irradiation unit 75. Like that. This is because, as described above, the correspondence between the light emitting section 52 in the irradiation unit 75 and the light spot 46 formed on the moving body (fixing belt 35) is reversed with respect to the width direction x. Is due to. In the case of the embodiment of FIGS. 5A to 5D, it goes without saying that the light emitting sections 52 may be turned on / off one by one in order from the left side to the right side.

  Then, by repeating such a series of operations, when all the light emitting units 52 to be turned on are turned on / off, the above-described sequential lighting is ended with this as one cycle.

  By sequentially lighting in this way, the light spot 46 irradiated and formed on the fixing belt 35 can be scanned in the detection region A toward the positive side in the width direction x.

  The operation of the light receiving unit 55 (PD) when the light spot 46 is scanned to the positive side in the width direction x will be described. The fixing belt is synchronized with the lighting of the LED (n) which is the nth light emitting unit 52. The plurality of light receiving portions 55 receive the reflected light 47 from the light 35.

  Here, for simplification, it is assumed that the number of light receiving portions 55 that simultaneously receive light is an even number (2 m), and light is received by 2 m light receiving portions 55. Here, m is an integer. Next, a method of selecting 2m light receiving units 55 will be described.

  It is not always necessary to use all the light emitting units 52 that are turned on / off from the left end to the right end (N from 1 to N), and any N ′ ″ (N ″) of them. '≦ N) may be used.

  When the LED (n), which is the nth light emitting unit 52, is turned on, the light receiving unit 55 that receives the largest amount of light among the N ′ ″ light receiving units 55 and the light receiving unit 55 (PD Next, the light receiving unit 55 having the next largest received light amount is extracted.

  Probably, the two light receiving portions 55 are arranged adjacent to each other, and if the center in the width direction x of these two light receiving portions 55 is set to X = 0, the remaining 2m (2) light receiving portions 55 (PD). Are extracted at positions X = 0 ± 1.5l × P ′ ″ (l = 1, 2,... (M−1)).

  The detection signal 48 from each light receiving unit 55 received by the 2m light receiving units 55, photoelectrically converted and amplified is sent to the surface state determination means 43 each time.

  In some cases, in order to increase the detection accuracy, the above-described sequential lighting is performed over a plurality of cycles, and an average value process or the like can be performed on the detection results.

  The plurality of light emitting units 52 (LEDs) are sequentially turned on based on a control signal 49 from the surface state determination unit 43 (control unit 44).

  In this embodiment, a plurality of light spots 46 are simultaneously illuminated by simultaneously turning on a plurality of light emitting portions 52 (LEDs) with respect to the reflective optical sensor 42 of each of the above embodiments, and optical scanning in the width direction x is performed. This is characterized in that the line period is shortened.

  For example, when the number of irradiation units 75 described above is 9, irradiation units 75 (1), irradiation units 75 (2)..., Irradiation units 75 (9) are arranged in order toward the positive side in the width direction x. If the surface state of the moving body (a fixing member such as the fixing belt 35) is detected, the light emitting units 52 (LEDs) of the irradiation units 75 (2) to 75 (8) are turned on. To do. In this case, in each irradiation unit 75, four light emitting units 52 are arranged in the order of LED (1), LED (2), LED (3), and LED (4) toward the positive side in the width direction x. Shall be. Here, for example, the light emitting unit 52 (3) of the irradiation unit 75 (2) is referred to as an LED (2-3).

  FIG. 15A shows a distribution of detection unit outputs in a plurality of light receiving units 55 (PD) when the LED (2-3) is turned on. The detection unit output is defined to be 1 at the maximum value, and the detection unit outputs in the light receiving units 55 (PD_1) to (PD_4) and the light receiving units 55 (PD_15) to (PD_18) are zero. Therefore, when the LED (2-3) (or LED2-2) is turned on, it can be considered that the number of the light receiving portions 55 that receive the reflected light 47 is ten.

  For example, when two light emitting units 52 are turned on simultaneously, when any one light emitting unit 52 is turned on, the other ten light receiving units 55 used to obtain the detection result Therefore, it is necessary to prevent the reflected light 47 due to the lighting of the light emitting unit 52 from being received.

  Therefore, when the plurality of light emitting units 52 are turned on simultaneously, it is necessary to turn on the light emitting units 52 located at some distance from the width direction x.

  FIG. 15B shows the distribution of the detection unit output for each of the plurality of light receiving units 55 when the LED (2-3), the LED (5-3), and the LED (8-3) are turned on simultaneously.

According to this figure, by simultaneously lighting three light emitting units 52 at sufficiently separated positions, three detection unit outputs similar to those when the light emitting unit 52 is lit alone are obtained simultaneously. be able to.
In the example shown in FIG. 15B,
The light emitting part 52 (LED (1)) of the irradiation unit 75 (2, 5, 8),
Light emitting unit 52 (LED (2)) of irradiation unit 75 (2, 5, 8),
The light emitting unit 52 (LED (3)) of the irradiation unit 75 (2, 5, 8),
The light emitting unit 52 (LED (4)) of the irradiation unit 75 (2, 5, 8) can be turned on simultaneously,
The light emitting unit 52 (LED (1)) of the irradiation unit 75 (3, 6),
The light emitting unit 52 (LED (2)) of the irradiation unit 75 (3, 6),
The light emitting unit 52 (LED (3)) of the irradiation unit 75 (3, 6),
The light emitting unit 52 (LED (4)) of the irradiation unit 75 (3, 6) can be turned on simultaneously,
The light emitting unit 52 (LED (1)) of the irradiation unit 75 (4, 7),
The light emitting part 52 (LED (2)) of the irradiation unit 75 (4, 7),
The light emitting unit 52 (LED (3)) of the irradiation unit 75 (4, 7),
It turns out that the light emission part 52 (LED (4)) of the irradiation unit 75 (4, 7) can be lighted simultaneously.

  In this way, by simultaneously lighting the plurality of light emitting units 52 at positions sufficiently separated from each other, the line period of optical scanning in the width direction x can be shortened. If the line cycle can be shortened, the conveyance speed of the fixing belt 35 can be increased, and the time required for the image forming operation can be shortened more than before.

  The configuration of the irradiation unit 75 is preferably set in consideration of the relationship of the light emitting units 52 that are turned on simultaneously. For example, the light emitting units 52 having the same arrangement in different irradiation units 75 are turned on simultaneously. In this case, the light emitting parts 52 having the same arrangement in the irradiation units 75 located every other two are simultaneously turned on so that the plurality of reflected lights 47 from the plurality of light spots 46 are not simultaneously received by the same light receiving part 55. It is constituted so that.

  The plurality of light emitting units 52 (LEDs) are simultaneously turned on based on a control signal 49 from the surface state determination unit 43 (control unit 44).

  In each of the above-described embodiments, as shown in FIG. 16A, the light spot 46 is formed side by side in the width direction x with respect to the moving body (a fixing member such as the fixing belt 35). In the embodiment, as shown in FIG. 16B, the light spot 46 is formed to be inclined at an arbitrary angle with respect to the width direction x and the movement direction y with respect to the moving body (fixing belt 35). There is the feature.

  Thus, by forming the light spot 46 in an inclined manner, the arrangement pitch of the light spots 46 with respect to the width direction x can be reduced.

  More specifically, in each of the above-described embodiments, the reflective optical sensor 42 is arranged in the width direction x, whereas in this embodiment, the reflective optical sensor 42 is arranged in the width direction x. It arrange | positions so that it may incline with respect to the moving direction y.

  Thus, by arranging the reflective optical sensor 42 in an inclined manner, the arrangement pitch of the light spots 46 in the width direction x can be reduced as described above.

  In FIG. 16B, the reflective optical sensor 42 is disposed with an inclination of 45 °.

  Thus, by tilting the reflective optical sensor 42 by 45 °, the length of the detection region A ′ in the width direction x is shortened to 1 / √2, but the arrangement pitch of the light spots 46 in the width direction x is also reduced. Since it can be reduced to 1 / √2, the position resolution of the detection result can be increased as compared with the case where the reflective optical sensor 42 is not tilted with respect to the width direction x as shown in FIG. 16A.

  However, the inclination angle of the reflective optical sensor 42 is not limited to the above, and it may be inclined smaller than 45 ° (0 ° to 45 °) or larger than 45 ° (45 ° to 90 °). ) It may be inclined and is optional. In addition, the reflective optical sensor 42 is inclined to the lower right in FIG. 16B, but may be inclined to the lower left.

  In the above description, the light spot 46 is inclined by directly inclining the reflective optical sensor 42 itself. However, for example, the reflective optical sensor 42 is arranged in parallel with the width direction x. In this state, the light spot 52 is obliquely installed inside the reflective optical sensor 42, or the light 45 is deflected by the irradiation lens 58, so that the light spot 46 is tilted and the arrangement direction of the light emitters 52 is set. The arrangement pitch of the light spots 46 in the width direction x may be narrower than the interval of.

  Further, the reflection type optical sensor 42 in which the light spot 46 is inclined by installing the light emitting unit 52 obliquely inside the reflection type optical sensor 42 or deflecting the light 45 by the irradiation lens 58 is provided. Further, it may be arranged in an inclined manner.

  In addition, when installing the light emission part 52 diagonally in the reflective optical sensor 42, it can be made to incline and arrange for every irradiation system (irradiation unit 75).

 In this embodiment, the reflective optical sensor 42 described in each of the above embodiments is installed inside the image forming apparatus 1 (see FIG. 1).

  As described above, by installing the reflection type optical sensor 42 with respect to the image forming apparatus 1, real time detection of the scratch 51 on the moving body (fixing member such as the fixing belt 35), which has been impossible in the past, is possible. In addition, the position of the scratch 51 on the fixing belt 35 and the width of the scratch 51 can be detected.

  As described in the above embodiments, the light receiving / emitting device (light emitting unit 52 and light receiving unit 55) for the reflective optical sensor 42 and the optical system (irradiation optical system 53 and light receiving optical unit) for the reflective optical sensor 42 are used. By optimizing the system 56), the reflected light 47 from the fixing belt 35 is maintained while maintaining the interval between the adjacent light spots 46 on the moving body (fixing member such as the fixing belt 35) as the test object. By increasing the strength, it is possible to improve the detection accuracy for the scratch 51 on the surface of the fixing belt 35.

  In this embodiment, in the image forming apparatus 1 described above, the reflective optical sensor 42 of each of the embodiments described above has a small size (for example, A4, A5, A6) as shown in FIGS. 17A, 17B, and 17C. ) Paper (recording medium S) in the vicinity of the width end position 35s.

  Thereby, even when the length of the detection area A in the width direction x is shortened, the width end position 35s of the sheet can be included in the detection area A.

  As described above, the fact that the detection region A can be shortened has an advantage that the reflective optical sensor 42 can be downsized particularly in the width direction x.

  Generally, the width of the scratch 51 is about several hundred μm to several mm, and the fluctuation range of the position of the scratch 51 is about several mm. Therefore, the detection region A is set to about 5 mm to 15 mm in the width direction x. This is suitable for reducing the size of the reflective optical sensor 42.

  Generally, the image forming apparatus 1 can use a plurality of sizes of paper such as A3 size, A4 size, and A5 size.

  Since the paper that can be passed through in most cases is generally A3 vertical paper, the small-size paper width is smaller than the A3 paper.

  If the image forming apparatus 1 is capable of A2 longitudinal paper, a paper size smaller than the A2 paper is the small size paper width.

  Note that the reflective optical sensor 42 can be structurally disposed at the width end position 35 s of the paper that can be maximally passed.

  In addition, since there are two width end positions 35s on both ends of the small size paper, one reflection type optical sensor 42 is provided for each width end position 35s of the paper, that is, in the width direction x. Although it is possible to arrange two, the vertical streak 51 caused by the end face of the paper is uniformly generated on both sides of the paper, and generally there is no significant difference in the scratch level. It is sufficient to provide it for either one of the end positions 35s.

  In this embodiment, in the image forming apparatus 1, the reflection type optical sensor 42 of each of the above embodiments is large so as to cover the entire area in the width direction x as shown in FIG. You may do it.

  For example, when the image forming apparatus 1 is capable of A1 longitudinal paper, the width end portion of each paper such as A2, A3, A4, A5, B3, B4, B5, and B6 sizes is used. The reflection type optical sensor 42 is enlarged in the width direction x so that the position 35 s can be irradiated by the reflection type optical sensor 42.

  In this embodiment, a fixing member such as the fixing belt 35 is used as the moving body.

  By using the fixing belt 35 as the moving body in this way, it is possible to detect the surface state of the fixing belt 35 with high accuracy using the reflective optical sensor 42 of the present embodiment.

  Note that the moving body may be a fixing member such as the fixing roller 31.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the embodiments are only examples of the present invention, and the present invention is not limited to the configurations of the embodiments. Needless to say, design changes and the like within a range not departing from the gist of the invention are included in the present invention. Further, for example, when each embodiment includes a plurality of configurations, it is a matter of course that possible combinations of these configurations are included even if not specifically described. Further, when a plurality of embodiments and modifications are shown, it is needless to say that possible combinations of configurations extending over these are included even if not specifically described. Further, the configuration depicted in the drawings is of course included even if not particularly described. Further, when there is a term of “etc.”, it is used in the sense that the equivalent is included. In addition, when there are terms such as “almost”, “about”, “degree”, etc., they are used in the sense that they include those in the range and accuracy recognized by common sense.

  As a supplementary explanation, the form of the reflective optical detection means is not limited to the reflective optical sensor described in this embodiment. In short, it is sufficient that a plurality of light spots can be irradiated in the main direction on the surface of the fixing belt and the reflected light can be received.

  The reflective optical sensor described in this embodiment is an array type in which a plurality of LEDs and a plurality of PDs face each other in a one-to-one relationship. However, the reflected light from the surface of the fixing belt is deflected by an optical deflector. May be a light deflection type in which light is received by one or a plurality of PDs, or a sensor drive type in which an optical sensor comprising one LED and one PD is moved in the main direction by a drive means. May be.

1 Image forming apparatus 31 Fixing roller (moving body)
35 Fixing belt (moving body)
35s Width end position 41 Surface state detection device 42 Reflective optical sensor 42a Reflective optical sensor 42b Reflective optical sensor 42c Reflective optical sensor 42d Reflective optical sensor 42e Reflective optical sensor 44 Controller 45 Light 46 Light spot 47 Reflection Light 49 Control signal 51 Scratch 52 Light emitting part (irradiation system)
52a Light emitting part (irradiation system)
52b Light emitting part (irradiation system)
52c Light emitting part (irradiation system)
52d Light emitting part (irradiation system)
52e Light emitting part (irradiation system)
53 Irradiation optical system 54 Irradiation part 55 Light reception part (light reception system)
55a Light receiving part (light receiving system)
55b Light receiving part (light receiving system)
55c Light-receiving part (light-receiving system)
55d Light receiving part (light receiving system)
55e Light receiving part (light receiving system)
56 Light-receiving optical system 57 Detection unit 58 Irradiation lens (irradiation optical system)
58a Irradiation lens (irradiation optical system)
58b Irradiation lens (irradiation optical system)
58c Irradiation lens (irradiation optical system)
58d Irradiation lens (irradiation optical system)
58e Irradiation lens (irradiation optical system)
59 Optical axis 61 Light receiving lens (light receiving optical system)
61a Lens for receiving light (receiving optical system)
61b Lens for receiving light (receiving optical system)
61c Lens for receiving light (receiving optical system)
61d Light receiving lens (light receiving optical system)
61e Lens for receiving light (receiving optical system)
62 Cylindrical lens 64 Sensor body 65 Light-shielding part A Detection area S Recording medium x Width direction (arrangement direction of irradiation system)
y Movement direction

Japanese Patent Laid-Open No. 5-113737 (paragraph numbers [0001] [0002], FIG. 1) JP-A-2006-251165 ([Claim 1], paragraph number [0003], FIG. 3) JP 2007-34068 (Claim 2; paragraph number [0004], FIG. 2)

Claims (10)

A reflective optical sensor for detecting the surface state of a moving object,
A plurality of illumination lenses corresponding to the plurality of irradiation system and the irradiation morphism system, an irradiation optical system for guiding the light emitted from the illumination system to the mobile,
A light receiving system having a plurality of light receiving portions, and the light receiving optical system having a light receiving lens for guiding the light reflected by the moving object to the light receiving system,
Equipped with a,
The irradiation system includes a plurality of light emitting units, and
The adjacent first irradiation system and second irradiation system are:
Among the light emitting units included in the first irradiation system, the light emitting unit positioned closest to the second irradiation system, and among the light emitting units included in the second irradiation system, the light emitting unit positioned closest to the first irradiation system. The interval between
The first irradiation system is arranged to be larger than the arrangement interval of the plurality of light emitting units,
Before KiTeru morphism lens, the optical axis position of those 該照 morphism lens is reflective of any characterized in that arranged so as to be between the two light receiving portions of the plurality of light receiving portions Optical sensor. The reflective optical sensor according to claim 1 , wherein the light receiving lens is a cylindrical lens that focuses light only in one axial direction. The reflective optical sensor according to claim 1 or 2 , wherein the irradiation lens constituting the irradiation optical system and the light receiving lens constituting the light receiving optical system are integrally formed. The reflection type according to any one of claims 1 to 3 , wherein a light shielding part is provided between at least one of the adjacent irradiation optical systems or between the irradiation optical system and the light receiving system. Optical sensor. The reflective optical sensor according to any one of claims 1 to 4, wherein a plurality of light spots are sequentially irradiated. Reflective optical sensor according to any one of claims 1 to 5, characterized in that illuminating the plurality of light spots simultaneously. Reflective optical sensor according to any one of claims 1 to 6, characterized in that irradiation with respect to the moving direction of the surface of the movable body, a plurality of light spots have any inclination. A rotating fixing member;
A pressure member that forms a nip that contacts the outer peripheral surface of the fixing member and fixes the unfixed toner on the recording medium passing therethrough to the recording medium;
An image forming apparatus having a fixing device having heating means for heating the fixing member,
The reflective optical sensor according to any one of claims 1 to 7 , which detects surface information of the fixing member.
The image forming apparatus, wherein the reflective optical sensor is arranged to irradiate a plurality of light spots on a peripheral surface of the fixing member in a direction intersecting a rotational movement direction of the fixing member. The reflective optical sensor;
The image forming apparatus according to claim 8 , wherein the image forming apparatus is disposed at least at an end position of the recording medium. It said moving body, the image forming apparatus according to claim 8 or claim 9, characterized in that a fixing belt.