JP2005314080A - Disk, encoder, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device provided with an encoder having a disk provided with a configuration capable of facilitating removal work of a member and preventing occurrence of improper image by preventing occurrence of dirt when removing the disk and suppressing reduction of detection precision using the disk. <P>SOLUTION: This image forming device is provided with the disk 148 mounted on a rotary shaft 141A and rotated and driven. This device is provided with the configuration 151 in which marking M is applied to a face in the vicinity of the outer periphery of the disk 148 by equal pitch and a grip part 148A or 148B constituted by a hole 148A1 or a projecting part 148B1 which opposes across the center of the disk 148 is provided at a position close to the center of the disk which is different from a marking M applied position to prevent coming-into-contact with the marking M when pulling it out of the rotary shaft 141A and prevent dust from adhering to the marking M. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a disk, an encoder, and an image forming apparatus, and more particularly to a disk attachment / detachment mechanism used for an encoder.

One of the devices used for starting timing and phase control of related members is an encoder.
For the configuration of the encoder, there is a case where a disk provided with a reading code marked with a predetermined arrangement pitch is used. The marking is detected by an optical element or the like, and the deviation position and the order position from the marking provided at the reference position are read as information, and the operation timing control and the position correction control between related members are performed based on this information.

One application of such an encoder is an image forming apparatus such as an ink jet printer.
Ink jet printers have a serial scan method in which printing is performed by scanning in a direction (main scanning direction) perpendicular to the recording sheet conveyance direction (sub-scanning direction). This method is as follows.

  After the recording sheet is guided to a predetermined recording position, an image is recorded by scanning the recording head mounted on the carriage moving along the recording sheet in the main scanning direction, and after recording by scanning for one line is completed. Recording of the entire recording sheet is performed by performing a predetermined amount of sheet feeding and then repeating the operation of starting recording again and recording for the next row (next scanning line in the sub-scanning direction) (see FIG. For example, Patent Document 1).

  In a line type ink jet printer that uses a method of recording only in the sub-scanning direction along the conveyance direction of the recording sheet, in addition to the serial scanning method described above, the recording sheet is set at a predetermined recording position. After the recording is collectively executed, the sheet is fed by a predetermined amount, and then the entire recording sheet is recorded by repeating the operation of collectively recording the next row (for example, patents). Reference 1).

It is necessary to match the recording sheet feed control and the recording start time by the recording head. Especially, when obtaining a full color image by superimposing multiple color images, the positions of the color images are aligned. It is extremely important to prevent color misregistration. In addition, it is necessary to match the start position return of the recording head and the recording sheet conveyance start timing.
For this reason, conventionally, in order to determine the conveyance speed and conveyance amount in the recording sheet conveying means, a member driven by a driving member of the conveying means, for example, an encoding plate with markings or markings on a disk or the like is provided. A configuration is used in which an inscription or marking is detected by an optical sensor (for example, Patent Document 1).

JP 2002-248822 (paragraphs “0003” to “0004” columns, “0008” columns)

  In an ink jet printer, as an arrangement configuration of a driving motor provided in a recording sheet conveying unit, a driving motor for the conveying unit is omitted in order to save an occupied space in a direction (main scanning direction) perpendicular to the moving direction of the conveying unit. May be stored in the occupied space of the conveying means in the main scanning direction.

  On the other hand, since it is necessary for the encoding plate to increase the conveying speed, the conveying amount, and the indexing accuracy of the conveying position, a configuration in which the angle with respect to the rotation amount can be reduced by relatively increasing the outer diameter may be adopted. For this reason, an encoder plate having a diameter larger than that of the drive motor cannot be accommodated in the space in the main scanning direction occupied by the conveyance means, as is the case with the drive motor. It is often arranged in the direction.

  However, in such an arrangement configuration of the encoder plates, there is a problem that the members and the devices arranged in the space in the main scanning direction of the conveying means cannot be taken out by the encoder plates.

  In other words, in an ink jet printer, a recording head, a carriage thereof, a carriage support rod, and the like are gathered together, and are stored in a unit that can be attached to and detached from a casing that forms the main body of the ink jet printer. There may be. For this reason, the unit taken out from the housing cannot be pulled out in one direction due to the presence of the encoder plate when replacing the conveying means, the recording head, and the carriage, etc. that are installed inside. By disassembling itself, a member that needs to be replaced is taken out. When such an operation is performed, even if only the parts in the unit need to be replaced, the unit itself must be disassembled one by one, and the maintenance and inspection work may become complicated. In addition, when the specification relating to the conveyance control of the recording sheet is changed, the marking format of the encoder plate may be changed. In this case, the encoder plate is replaced. For this reason, it is also required to remove the encoder plate itself.

In addition, when the encoder plate is removed because it interferes with the removal of the member, the encoder plate may be directly gripped, so that the encoder plate, particularly when the marking is applied near the outer periphery In some cases, the part becomes a place to be gripped, so that it may be soiled with fat or dust transferred from the finger when gripped.
If the markings on the encoder plate are soiled, the detection accuracy of the optical sensor will deteriorate, and the recording sheet conveyance state cannot be accurately determined, resulting in inaccurate alignment between images. As a result, a defective image such as a color shift is obtained.

  In view of the problems with the disk used in the conventional encoder described above, the object of the present invention is to facilitate the removal of the member and to prevent the occurrence of contamination when the disk is removed and to improve the detection accuracy using the disk. An object of the present invention is to provide a disk, an encoder, and an image forming apparatus having a configuration capable of preventing the occurrence of a defective image by suppressing the decrease.

  The invention according to claim 1 is a disk that is mounted on a rotating shaft and is driven to rotate, and a cord portion formed by marking at an equal pitch is provided on a surface near the outer periphery, and a finger is disposed on a surface near the center. The disc is provided with a gripping portion that can be gripped by the disc.

  According to a second aspect of the present invention, in the disk according to the first aspect, the grip portion is provided at a position at least opposite to the center other than the center.

  According to a third aspect of the present invention, in the disk of the first or second aspect, the gripping portion is formed by a hole penetrating in the thickness direction on a surface near the center.

  According to a fourth aspect of the present invention, in the disk according to the first or second aspect, the gripping portion is constituted by a protruding portion that protrudes from a surface near the center.

  According to a fifth aspect of the present invention, in the disk according to one of the first to fourth aspects, an anti-slip portion is provided on the surface of the grip portion.

  According to a sixth aspect of the present invention, in the disc according to the fourth aspect, the projecting portion constitutes a wing portion capable of generating an airflow in a predetermined direction near the surface of the disc.

  A seventh aspect of the invention is characterized in that, in the disk of the fourth or sixth aspect, a dust collecting portion is provided in the vicinity of the protruding portion.

  According to an eighth aspect of the present invention, in the disk according to one of the first to seventh aspects, the disk is a transparent body.

  A ninth aspect of the invention is characterized in that, in the disk according to one of the first to seventh aspects, the disk has a reflective surface on one side in the thickness direction.

  According to a tenth aspect of the present invention, the image forming apparatus is provided with an optical sensor capable of detecting markings on the disk according to one of the first to ninth aspects. .

  The invention described in claim 11 is characterized in that, in the encoder described in claim 10, a cover capable of covering at least the area of the disk where the marking is provided is provided.

  According to a twelfth aspect of the present invention, in the encoder according to the tenth or eleventh aspect, the cover is provided with an axial movement restricting portion that restricts the disk from being displaced in the axial direction. .

  According to a thirteenth aspect of the present invention, in the encoder according to one of the eleventh and twelfth aspects, the cover is provided with an opening corresponding to a grip portion provided on the disk side. It is characterized by.

  According to a fourteenth aspect of the present invention, in the encoder according to the thirteenth aspect, an opening / closing member is provided in an opening provided in the cover.

  According to a fifteenth aspect of the present invention, in the encoder according to any one of the tenth to fourteenth aspects, the cover is provided with a cleaning member for cleaning the marking portion of the disk.

  According to a sixteenth aspect of the present invention, the encoder according to any one of the tenth to fifteenth aspects is used for a recording engine unit.

  According to a seventeenth aspect of the present invention, in the image forming apparatus according to the sixteenth aspect, the recording engine unit includes at least a recording sheet conveying unit, a recording head, and a unit including a carriage component member therein. It is characterized by being.

  According to an eighteenth aspect of the present invention, in the image forming apparatus according to the sixteenth or seventeenth aspect, the unit constituting the recording engine unit has a casing having a space in which the disk and a part of the rotation shaft thereof can be built. The casing is provided with an optical sensor capable of detecting the marking of the disk, and a bearing capable of supporting both axial ends located in the casing in the axial direction of the rotating shaft, and the rotating shaft Is provided such that an end portion extended from one of the bearings is detachably attached to an end portion extended from the unit side, and the engagement state between the end portions of the rotating shaft is released. The casing can be removed from the unit.

  According to a nineteenth aspect of the present invention, in the image forming apparatus according to the eighteenth aspect, the optical sensor provided in the casing can be connected to the electrical component on the unit side or the image forming apparatus main body side via a connector. It is characterized by that.

  According to the first to fifth and eighth and ninth aspects of the present invention, the gripping portion provided on the surface in the vicinity of the center, which is a position different from the disk marking position, can be gripped. Finger contact with the part can be avoided. In particular, in the invention described in claim 2, it is possible to facilitate gripping by being provided at positions facing each other across the center, and in the invention described in claim 3, the grip portion is formed by a hole penetrating in the thickness direction of the disk. By being provided, a simple configuration can be achieved without increasing the thickness of the disk itself. In the invention according to claim 4, it is possible to facilitate the removal of the disk by making it possible to increase the area that receives the force when grasping. In the invention according to the fifth aspect, the removal can be surely performed without the finger slipping inadvertently during the removal. As a result, the situation in which the disk cannot be taken out due to the presence of the disk is solved, and the member arranged on the inner side of the disk arrangement position can be taken out, so that the maintenance and replacement work can be simplified. In addition, even when a disk on which such marking is applied uses a transparent body or a reflective surface that is relatively easily soiled, it is possible to reduce the dirt on the marking.

  According to the sixth aspect of the present invention, since the protrusion as the grip provided on the disk as the rotating member is a wing that generates an airflow in a predetermined direction on the disk surface, the airflow floats near the marking by the airflow. It is possible to prevent contamination due to adhesion to the marking by scattering the dust. As a result, it is possible to prevent a drop in detection accuracy due to marking contamination.

  According to the seventh aspect of the invention, dust scattered by the air current generated near the outer periphery or near the surface due to the rotation of the disk itself can be collected, so that it is possible to suppress inadvertent adhesion of dust to the marking, It is possible to prevent a decrease in marking detection accuracy.

  According to the tenth and eleventh aspects of the present invention, when an optical sensor capable of detecting marking is used, the cover member that can cover the area where the marking is applied is provided. It is possible to reduce the detection error when the optical sensor is used.

  According to the twelfth aspect of the present invention, since the axial movement restricting portion for restricting the axial displacement is provided, it is possible to optimize the facing relationship with the optical sensor and reduce the detection error.

  According to the thirteenth aspect of the present invention, since the opening is provided at the position on the cover side corresponding to the holding portion of the disk, the disk can be removed by inserting a finger from the opening without removing the cover. As a result, the disk removal operation can be facilitated.

  According to the fourteenth aspect of the present invention, since the opening / closing member is provided in the opening of the cover, it is possible to prevent the dust from entering the marking portion of the disk from the opening to prevent the marking from being stained.

  According to the fifteenth aspect of the present invention, since the cleaning member for cleaning the marking portion of the disk is provided on the cover, the marking portion can be prevented from being soiled and soiled.

  According to the sixteenth and seventeenth aspects of the present invention, when the members in the unit constituting the recording engine unit are taken out to the outside, it is possible to prevent the members from being in the way of being taken out by simply grasping and removing the disk. One constituent member in the unit can be replaced, and the life of the unit itself can be extended.

  According to the invention of claim 18, the unit constituting the recording engine unit is provided with a casing having a space in which a part of the optical sensor, the disc and the rotating shaft of the unit can be incorporated, and the casing is provided with respect to the unit. Since the detachable relationship is established, the disc can be removed while maintaining dust-proofing against the disc. In particular, since the optical sensor for detecting the marking on the disc is also provided on the casing, it is possible to prevent the optical system from being contaminated at once, thereby eliminating the detection error of the arking.

  According to the nineteenth aspect of the present invention, since the optical sensor provided in the casing and the unit or the electrical component on the image forming apparatus side can be connected by the connector, when the casing is removed, the connector is connected. Unlike the case where a harness is used between the optical sensor and the optical sensor, it is possible to eliminate the operation of removing the harness and simplify the operation of taking out the constituent members in the unit.

  The best mode for carrying out the present invention will be described below with reference to the illustrated embodiments.

  FIG. 1 is a schematic diagram showing a schematic configuration of an ink jet printer which is one of image forming apparatuses using a disk and an encoder according to an embodiment of the present invention. The present invention is not limited to the above-described inkjet printer, and a copying machine, a printer, or a printing machine that uses an electrophotographic method can be used as an object of the image forming apparatus.

FIG. 1 is a diagram (front view) viewed from a direction (main scanning direction) orthogonal to the recording sheet conveyance direction.
The ink jet printer 1 according to the present embodiment includes an image reading unit (scanner) 200 and a paper feeding unit 300 at the top and bottom with the printing unit 100 as a boundary.
The sheet feeding unit 300 stores recording sheets such as recording sheets in a stacked state, and the separating and conveying unit 301 provided with a pickup roller sequentially stores the stacked recording sheets from the highest one. By feeding out, the recording sheet is conveyed toward the printing unit 100 side.

  The image reading unit 200 includes a document placing table (contact glass) 201 on which a document other than a sheet such as a book document can be placed, and a scanner having a plurality of optical lens groups disposed below the document placing table 201. The original placed on the contact glass 201 can be read by a CCD (photoelectric conversion element) 203 when the reading optical system 202 reads and scans the original.

The printing unit 100 is positioned between the image reading unit 200 and the paper feeding unit 300 in the vertical direction, and includes a plurality of conveying rollers 101, 102, 103, a reverse roller 104, and a discharge roller 105 group, and a recording. A printing unit 110 configured as an engine unit and an ink tank 106 are provided.
Although the configuration of the printing unit 110 will be described later, the sub-scanning conveyance mechanism unit 140, the maintenance mechanism unit 150 (see FIG. 2), and the idle driving mechanism unit 160 (see FIG. 2), which are used as the conveyance mechanism for the printing mechanism unit 120 and the black wire. 2).

  In the inkjet printer 1 having the above-described configuration, the uppermost recording sheet separated from the sheet feeding unit 300 by the separation / conveyance unit 301 is guided to the printing unit 110 by the conveyance roller 101.

The printing unit 110 is provided with a recording sheet by a sub-scanning direction conveyance mechanism unit 140 in which a predetermined feed amount is set based on a printing width of an inkjet head mounted on a carriage of the printing mechanism unit 120 and capable of reciprocating in the main scanning direction. The operation of printing a predetermined number of lines in the main scanning direction of the recording sheet conveyed while being conveyed in the sub-scanning direction is repeated at the time of forward movement, backward movement or reciprocation of the recording sheet, and is read by the image reading unit 200. An image is formed by printing on a sheet of recording paper based on the image data.
The recording sheet on which the image is formed is sent to the reverse roller 104 by the conveying rollers 102 and 103. The recording sheet whose conveyance direction has been reversed by the reversing roller 104 is discharged above a printing unit 110 to a paper discharge tray 107 provided inside the inkjet printer 1. Since the paper discharge tray 107 is provided inside the inkjet printer 1, unlike the case where it is provided outside, the installation space of the apparatus can be reduced.

2 is a right side view of FIG. 1, and FIG. 3 is a perspective view showing a schematic configuration of a printing unit constituting the recording engine unit.
2 and 3, the printing unit 110 is a single unit that collectively stores the printing mechanism unit 120, the sub-scanning conveyance mechanism unit 140 used as a recording sheet conveyance unit, the maintenance mechanism unit 150, and the idle driving mechanism unit 160. The recording paper conveyance path 111 is provided between the printing mechanism unit 120 and the sub-scanning conveyance mechanism unit 140.

  The maintenance mechanism 150 includes mechanical caps necessary for maintaining the operation capability of the inkjet, such as a cap for preventing the nozzle of the inkjet head from drying, a wiper that wipes the nozzle surface of the inkjet head, and removes ink on the nozzle surface. It is provided on the home position side of the inkjet head. In addition, a blanking mechanism 160 is provided at the end of the home position opposite to the main scanning direction, and ink blanking is performed at the start of printing or at a preset timing in order to prevent ink clogging. Can be done. Reference numeral 161 denotes an idle receiving ink discharge receiver provided opposite to the ink jet head. Since the maintenance mechanism 150 and the blanking mechanism 160 may use a known mechanism, detailed description thereof is omitted.

  The ink jet head of the ink jet printer according to the present embodiment is a system in which ink is ejected by a pressurizing force generated when a vibration plate forming a liquid chamber wall surface is vibrated by an electro-mechanical conversion element such as a piezoelectric element, or a heating resistor. A system that pressurizes ink with pressure applied by bubbles generated by film boiling caused by film, and a system that pressurizes ink by displacing the diaphragm with an electrostatic force between the diaphragm that forms the wall surface of the liquid chamber and the electrode facing it Etc. are used. In addition, the ink jet head in this embodiment has a predetermined number of discharge ports on the lower surface, and each discharge port is provided for each color of YMCK. Ink is supplied to the carriage 121 from the ink tank 106 shown in FIG.

  FIG. 3 shows a printing unit 110 that forms a recording engine unit. The printing unit 110 is equipped with a carriage 121 equipped with an inkjet head and a pair of guide members 120A for guiding the carriage 121 in the main scanning direction (one in FIG. 3). Only, a main scanning motor (not shown) for moving the carriage 121 in the main scanning direction, and conveying members 142 and 143 (see FIG. 1) equipped in the sub-scanning direction conveying mechanism 140. It has. The sub-scanning direction conveyance mechanism unit 140 will be described later with reference to FIG.

  The main scanning motor is provided on the idle driving mechanism portion 160 side (the front side in the drawing direction described later), and the output end of the main scanning motor is connected to the carriage 121 via a timing belt (not shown). Thus, the rotation of the main scanning motor is converted into a linear motion of the carriage 121, and the carriage 121 can be moved in the main scanning direction. As a configuration for moving the carriage 121 in the main scanning direction, one of the guide members is a screw shaft, a ball screw structure is interposed between the carriage 121 and the carriage 121 is driven to rotate by being driven by a main scanning motor. A configuration is also possible.

  The printing unit 110 is supported so as to be detachable with respect to the casing of the inkjet printer 1. As a configuration for this, a pair of rails 115 (see FIG. 1) provided on the printing unit 110 side is inkjet. A configuration that can move along a guide portion 109 (see FIG. 1) provided on the housing side of the printer 1 is used.

  In FIG. 1, the sub-scanning transport mechanism unit 140 uses a belt wound around a pair of pulleys 141 (see FIG. 1) arranged along the sub-scanning direction as a transport member (hereinafter referred to as a transport belt for convenience) 142. In addition, a conveyance roller 143 is provided at a position facing the pulley 141 so that the recording sheet can be nipped and conveyed. In this case, the conveying belt 142 is configured to electrostatically attract the recording sheet or to suck negative pressure so that the recording sheet can be conveyed while maintaining the flatness of the recording sheet.

  The conveyance belt 142 is driven by a sub-scanning motor denoted by reference numeral 145 in FIG. In other words, a driven pulley 142A around which the drive belt 146 is wound is integrated with a rotating shaft of a pulley provided as a driving side of the pair of pulleys 141 (for convenience, indicated by reference numeral 141A in FIG. 3). The drive belt 146 is wound around a drive pulley 145A provided on the output shaft of the sub-scanning motor 145 so that the rotation of the sub-scanning motor 145 is transmitted and the recording sheet can be conveyed in the sub-scanning direction. Yes.

The sub-scanning transport mechanism unit 140 is provided with a configuration for determining the transport speed and transport amount of the transport belt 142.
In this embodiment, an encoder 147 is used as a configuration for determining the conveyance speed and conveyance amount of the conveyance belt 142.
The encoder 147 has a disk 148 made of a transparent resin body that is press-fitted into the rotating shaft 141A of the pulley on the drive side of the conveyor belt 142, and an equal pitch along the circumferential direction in the vicinity of the outer periphery of the disk 148 in FIG. And an optical sensor 149 for detecting the marking M formed by. The optical sensor 149 in this embodiment uses a transmission type when the disk 148 is a transparent resin body and the marking is formed by printing. Further, as shown in FIG. 3, the optical sensor 149 is supported on the printing unit 110 side and maintained in an immobile state.

As shown in FIGS. 4 and 5, the disk 148 has a hole 148A1 formed in a surplus area between the vicinity of the outer periphery and the center of the disk 148 where the marking M is formed, penetrating in the thickness direction. A grip portion 148 </ b> A configured by the above is provided.
The gripping part 148A is provided at a position facing the center of the disk 148, and the disk 148 can be gripped by inserting, for example, a finger of one hand across the center.

  In FIG. 4, reference numeral 1500 denotes a backing member of the disk 148, reference numeral 142B denotes the driven pulley described in FIG. 3, and reference numeral 148B in FIG. 5 denotes an embossed portion 142A1 formed on the driven pulley 142A side. It is a hole to be fitted.

Since the disk 148 has a smaller thickness than the installation space of the sub-scanning motor 145 in the width direction of the transport belt 142, the drive that the output shaft has when the sub-scanning motor 145 is installed inside the wall surface of the printing unit 110. Due to the opposing relationship with the pulley 145A, as shown in FIG. 3, the print unit 110 is positioned outside the wall surface. Therefore, the disk 148 becomes an obstacle when a member located inside the printing unit 110, for example, the guide member 120A shown in FIG.
In the present embodiment, the gripping portion 148A is used to remove the disk 148 from the state where it is press-fitted into the rotating shaft 141A.

  Since the present embodiment is configured as described above, when the disk 148 is removed from the rotating shaft 141A, the finger M is inserted into the gripping portion 148A and the mark M is deviated from the position where the center of the disk 148 is sandwiched. By grasping the position, the disk 148 can be extracted from the press-fitted rotary shaft 141A.

  In the present embodiment, a hole is used as the configuration of the gripping portion 148A. However, the present invention is not limited to this, and a gripping portion 148B using a protrusion 148B1 protruding in the thickness direction may be used as shown in FIG. Is possible. The surfaces of the gripping portions 148A and 148B, that is, the surface that the finger touches are not shown, but the surface roughness is roughened or a non-slip portion such as a notch is provided so that the disc 148 slides down when the disc is gripped. It is preferable for eliminating slippage when 148 is extracted.

  According to the embodiment as described above, by providing the grip portions 148A and 148B provided at positions where the marking M is not directly touched, it is possible to reliably prevent adhesion of dirt due to finger contact with the marking M. This can prevent erroneous detection by the optical sensor 149 due to marking contamination.

Next, a modification of the main part of the sub-scanning transport mechanism unit 140 will be described.
In FIG. 6, the protrusion 148 </ b> B <b> 1 provided as the gripping part 148 </ b> B takes in air in the vicinity of the protrusion 148 </ b> B <b> 1 in the rotation direction of the disk 148 and flows toward the center (indicated by a one-dot chain line in FIG. 6). ).

  On the other hand, at the center of the disk 148, a dust collecting portion 148D made of electrostatic flocking or the like is provided in a ring shape on the same surface as the surface on which the protrusion 148B1 is formed.

In this configuration, when the disk 148 rotates, the air striking the protrusion 148B1 generates an air flow toward the center according to the shape of the protrusion 148B1, and comes into contact with the recovery part 148D. As a result, the ink particles and dust floating in the vicinity of the disk 148 and adhering to the collecting portion are prevented from moving toward the marking M of the disk 148, and the dirt on the marking M is suppressed. .
With such a configuration, generating the airflow is effective when the disk 148 performs continuous steady rotation. For example, the marking M can be performed by executing the initialization process when the ink jet printer 1 is started. It is also possible to cause the dust adhering to the droplets to drop off from the marking M due to the air flow and to go to the recovery unit 148D.

  In the above embodiment, a configuration using a transparent resin body as the disk 148 is shown. However, the present invention is not limited to this, and a configuration in which a reflective material is vapor-deposited on one side can be used, and a reflection type can be used as an optical sensor. It is.

Next, another embodiment of the present invention will be described.
The present embodiment is characterized in that a cover 151 that can cover the area of the disk 148 where the marking M is applied is provided.
FIG. 7 is a diagram showing this configuration, in which the cover 151 can cover the outer periphery of the disk 148 except for the position of the optical sensor 149 provided on the wall portion of the printing unit 110. It is composed of a cup-shaped member.

  The cover 151 is provided with an elongated hole-shaped opening 151A having a slightly longer circumference than the gripping portion at a position corresponding to the gripping portion 148A or 148B provided on the disk 148, and the inside of the opening 151A, That is, a flexible opening / closing member 152 is provided in a cantilever shape on the surface facing the disk 148. The cover 151 has an amount of protrusion of the peripheral wall including an axial length of the disk 148 and the driven pulley 142A, and a part of the peripheral wall is fixed to the wall portion of the printing unit 110 by fastening or the like (not shown). It is like that.

On the other hand, the cover 151 is provided with an axial movement restricting portion 151B that prevents the driven pulley 142A from being biased in the axial direction under the influence of the tension from the belt.
The axial direction movement restricting portion 151 </ b> B is configured by a claw member that can lock one surface of a locking flange 148 </ b> C provided at one end in the width direction of the driven pulley 142 </ b> A at a position opposed to the center of the inner surface of the cover 151.

Since the present embodiment is configured as described above, the disk 148 mounted on the rotary shaft 141A is in a state where the outer periphery is covered by the cover 151.
When the cover 151 is attached to the wall portion of the printing unit 110, for example, the axial movement restricting portion 151B is fitted from one side so as to be positioned on one surface of the locking flange 148C of the driven pulley 142A. Attached to.

  On the other hand, when the disk 148 is removed, the disk 148 can be removed together with the cover 151 by making the position of the grip 148A or 148B of the disk 148 correspond to the opening 151A with the cover 151 removed from the wall.

  According to the present embodiment, since the cover 151 covers the outer periphery of the disk 148, entry of dust from the outside to the marking M formed in the vicinity of the outer peripheral portion is prevented, and the marking M is contaminated. Will be prevented. Moreover, the cover 151 is not only dust-proof for the marking M, but also regulates the displacement of the driven pulley 142A in the axial direction, so that it can be used as a multifunctional member by a single member.

Next, another embodiment of the present invention will be described.
The present embodiment is characterized in that it has a structure for preventing and eliminating contamination of the marking M on the disk 148 in advance.
FIG. 8 is a view corresponding to FIG. 7 showing the above-described configuration. In FIG. 8, the cover 151 is provided with a cleaning member 153 using a felt, a sponge pad, or the like at a position facing the vicinity of the outer periphery of the disk 148.
The cleaning member 153 is configured to be pressed to some extent when it is fixed at a position facing the marking M or when the cover 151 is attached to the wall of the printing unit 110. In addition to this, the configuration is such that the marking M of the disk 148 that is set in advance at the start of the ink jet printer and rotates within the time range contacts the marking M, and is kept away from the marking M after a predetermined time. It is also possible to do.

  Since the present embodiment is configured as described above, when the cleaning member 153 contacts the marking M of the disk 148, when the disk 148 rotates, dust and ink particles adhering to the marking M are wiped off. Dirt will be eliminated. It is desirable that the contact pressure of the cleaning member 153 should be set so as not to promote wear of the marking M. Further, the cleaning method of the cleaning member 153 is not limited to wiping by contact, and for example, dust may be removed by an electrostatic adsorption method using electrostatic force.

Next, another embodiment of the present invention will be described.
The present embodiment includes a casing having a space in which the disk 148 and members provided therewith can be collectively accommodated, and the dust on the disk can be removed when performing the illustration. It is characterized by that.
FIG. 9 is a schematic diagram showing this configuration, in which the casing 180 is configured by a separable casing having a space that can accommodate a part of the disk 148 and the rotating shaft 141A. An optical sensor 149 is attached to a part. The dividing form of the casing 180 is a form that can be divided along the axial direction of the rotary shaft 141A, and is integrated by fastening (indicated by a one-dot chain line in FIG. 9) or the like in a combined state.

  The rotating shaft 141A is divided into a portion having an axial length located in the casing 180 and a portion to which the drive pulley of the conveyor belt 142 is attached outside the casing 180. The end portions can be attached to and detached from a rotating shaft (indicated by reference numeral 141A ′ for convenience) supported on the printing unit 110 side by a joint J provided on each end face.

  A bearing 161 is provided at a position where both ends of the rotating shaft 141A in the casing 180 are inserted in the axial direction. The rotating shaft 141A is supported by the bearing 161, and the driven pulley 142A attached to the rotating shaft 141A. The disk 148 can rotate independently of the casing 180. Although not shown, the casing 180 is not cut off at the peripheral wall corresponding to the position through which the drive belt 146 passes to prevent the movement of the drive belt 146.

  The casing 180 is attached to the wall portion of the printing unit 110 by fastening or the like as in the case of the cover shown in FIG.

  On the other hand, the optical sensor 149 attached to the casing 180 that is kept stationary is connected to the electrical unit of the printing unit 110 or the inkjet printer 1 by the connector C, and between these electrical units. There is no connection using a harness.

  Since the present embodiment is configured as described above, the casing 180 attached to the wall of the printing unit 110 includes the disk 148 and the optical sensor 149 to form an encoder unit. When the member in the printing unit 110 needs to be taken out, it is removed from the wall of the printing unit 110.

When the casing 180 is removed, first, the connector C to the optical sensor 149 is removed, and then the rotation shaft 141A located on the casing 180 side and the rotation shaft 141A ′ located on the print unit 110 side are connected to the joint J. It is separated by releasing the match.
When the casing 180 is separated from the wall portion of the printing unit 110, the rotating shaft 141A is maintained in a supported state, so that the built-in members such as the disk 148 may be accidentally dropped in the casing 180. Is prevented.

  In the present embodiment, although not described and illustrated, an opening 180A and an opening / closing member (reference numeral 152 is used for convenience) are provided at a location corresponding to the grip portion of the disk 148, as in the cover shown in FIG. Alternatively, it is possible to obtain the same state as the case where the disk 148 is removed by grasping the peripheral wall of the casing 180 without intentionally providing a grip portion.

1 is a schematic diagram illustrating an example of an image forming apparatus to which an encoder using a disk according to an embodiment of the present invention is applied. FIG. 2 is a schematic side view of the image forming apparatus illustrated in FIG. 1. FIG. 2 is a perspective view of a printing unit forming a recording engine unit according to an embodiment of the present invention. It is a perspective view which shows the structure of the disc by the Example of this invention. It is a perspective view which shows the structure on the opposite side of the disk shown in FIG. It is a perspective view which shows the principal part modification in the disc shown in FIG. It is a schematic side view showing an embodiment of an encoder according to an embodiment of the present invention. It is a side view schematic diagram which shows the structure of the encoder by another Example of this invention. It is a side view schematic diagram which shows the structure of the encoder by the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 110 Printing unit 1411, 141A 'Rotating shaft 142 Conveying belt 147 Encoder
148 Disc 148A, 148B Gripping part 148B1 Projection part also serving as wing part 148D Recovery part 149 Optical sensor 151 Cover 151A Opening 151B Axial movement restricting part 152 Opening / closing member 153 Cleaning member 180 Casing 181 Bearing J Joint C Connector

Claims (19)

A disc mounted on a rotating shaft and driven to rotate;
A disc characterized in that a cord portion composed of markings at an equal pitch is provided on a surface in the vicinity of the outer periphery, and a grip portion that can be gripped with a finger is provided on a surface in the vicinity of the center. The disc of claim 1, wherein
The disc is characterized in that the gripping portion is provided at a position at least opposite to the center other than the center. The disk according to claim 1 or 2,
The disk according to claim 1, wherein the gripping portion is formed by a hole penetrating in a thickness direction on a surface near the center. The disk according to claim 1 or 2,
The disc according to claim 1, wherein the gripping portion is constituted by a protruding portion protruding from a surface near the center. The disk according to one of claims 1 to 4,
A disc having a non-slip portion provided on a surface of the grip portion. The disc of claim 4, wherein
The disc is characterized in that the protrusion constitutes a wing that can generate an airflow in a predetermined direction in the vicinity of the surface of the disc. The disk according to claim 4 or 6,
A disc, wherein a dust collecting portion is provided in the vicinity of the protruding portion. The disk according to one of claims 1 to 7,
The disk is a transparent body. The disk according to one of claims 1 to 7,
The disk is characterized in that one surface in the thickness direction is a reflecting surface.   An encoder comprising an optical sensor capable of detecting markings on a disk according to any one of claims 1 to 9. The encoder according to claim 10, wherein
An encoder comprising a cover capable of covering at least a range of the disk on which the marking is applied.   The encoder according to claim 10 or 11, wherein the cover is provided with an axial movement restricting portion for restricting the disc from being displaced in the axial direction. The encoder according to one of claims 11 or 12,
An encoder according to claim 1, wherein the cover is provided with an opening corresponding to a grip provided on the disk side. The encoder according to claim 13,
An encoder characterized in that an opening / closing member is provided in an opening provided in the cover. The encoder according to one of claims 10 to 14,
The encoder according to claim 1, wherein the cover is provided with a cleaning member for cleaning the marking portion of the disk.   An image forming apparatus using the encoder according to claim 10 in a recording engine unit. The image forming apparatus according to claim 16.
2. The image forming apparatus according to claim 1, wherein the recording engine unit includes at least a recording sheet conveying unit, a recording head, and a unit including a carriage component member therein. The image forming apparatus according to claim 16 or 17,
The unit constituting the recording engine unit is provided with a casing having a space in which the disk and a part of the rotating shaft of the disk can be incorporated, and the casing includes an optical sensor capable of detecting the marking of the disk. And a bearing capable of supporting both axial ends located in the casing in the axial direction of the rotating shaft, and the rotating shaft has an end portion extended from one of the bearings extended from the unit side. An image forming apparatus, wherein the casing is detachably attached to the end portion, and the casing can be detached from the unit by releasing the engaged state between the end portions of the rotating shaft. The image forming apparatus according to claim 18.
An image forming apparatus, wherein the optical sensor provided in the casing is connectable to an electrical component on the unit side or the image forming apparatus main body side via a connector.

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