JP5990877B2 - Discriminating device and recording device - Google Patents

Description

  The present invention relates to a discriminating apparatus that discriminates a plurality of types of media having different degrees of light scattering, and a recording apparatus including the discriminating apparatus.

  2. Description of the Related Art Conventionally, an ink jet printer (hereinafter also referred to as “printer”) is widely known as a recording apparatus that performs a recording process on a recording medium (see, for example, Patent Document 1). In the printer described in Patent Document 1, a reflection type photosensor for detecting the presence or absence of a recording paper (recording medium) is provided on the recording paper conveyance path.

  The photosensor includes a light emitting element that makes light incident on the recording paper and a light receiving element that receives the light reflected from the recording paper. When the recording paper is arranged in the detection area of the photo sensor, the light emitted from the light emitting element is reflected by the recording paper and received by the light receiving element. As a result, since the amount of light received by the light receiving element exceeds a predetermined threshold, the photo sensor detects that the recording paper is arranged in the detection area.

  On the other hand, when no recording paper is disposed in the detection area of the photosensor, the light emitted from the light emitting element is not received by the light receiving element. As a result, since the amount of light received by the light receiving element is below a predetermined threshold, the photo sensor detects that no recording paper is disposed in the detection area. That is, in the above printer, the presence or absence of recording paper is detected based on whether or not the amount of light received by the light receiving element exceeds a predetermined threshold.

JP 2006-298532 A

  By the way, in the above printer, there is a case where another medium different from the recording paper is conveyed. In this case, if the light scattering mode of the recording paper and the other medium is significantly different, such as when the light scattering rate of the other medium is significantly larger than that of the recording paper, the light reflected from these media is reflected on the light receiving element. The amount of light received is clearly different. Therefore, based on whether or not the amount of light received by the light receiving element exceeds a predetermined threshold value, it is possible to determine which of the recording paper and the other medium is the medium being conveyed.

  However, if the light scattering mode on the recording paper and other media is a little different, the other media scatters some of the light incident from the light emitting element, but some degree is incident on the light receiving element. Therefore, the amount of light received by the light receiving element may exceed a predetermined threshold value. In this case, the photo sensor may erroneously detect that the recording paper is being transported even though the medium being transported is another medium different from the recording paper.

  An object of the present invention is to provide a discriminating apparatus and a recording apparatus that can discriminate a plurality of types of media having different degrees of light scattering.

In order to achieve the above object, a discrimination device according to the present invention is a discrimination device that discriminates between a first medium and a second medium having a light scattering rate larger than that of the first medium. The medium is transported in the transport direction, and the second medium is the upstream end portion of the preceding first medium before replacement and the downstream end of the subsequent first medium after replacement. A light-emitting unit that emits incident light on each medium, and a center position of a light-receiving surface that is shifted with respect to an optical axis of reflected light that is reflected from each medium. A light receiving unit that receives the reflected light, and a determination unit that determines that the medium to be determined is the second medium when the amount of light received by the light receiving unit is smaller than a predetermined threshold; The light emitting unit and the light receiving unit are spaced apart from each other in the transport direction. Vignetting and exit surface of the incident light is emitted in the light emitting portion, and a light receiving surface of the reflected light is received at the light receiving portion, upward gradient toward the downstream side in the transport direction of the first medium It is fixed in a tilted state.

  According to the above configuration, the reflected light reflected from the second medium is scattered relatively larger than the reflected light reflected from the first medium. Therefore, when the optical axis of the reflected light is deviated from the center position of the light receiving surface of the light receiving unit, the amount of light scattered without being received by the light receiving unit among the reflected light reflected from the second medium is Of the reflected light reflected from the first medium, the amount of light scattered without being received by the light receiving unit is larger. As a result, if the amount of reflected light reflected from the medium to be discriminated and received by the light receiving unit is smaller than a predetermined threshold, the medium is a second medium having a high light scattering rate. Can be determined.

Also, in the determination apparatus of the present invention, the light emitting portion, in the direction to reduce the amount of light received by the light receiving portion of the light reflected from the second medium, so that the optical axis of the incident light is inclined Be placed.

  According to the above configuration, when the light emitting unit is arranged so that the optical axis of the incident light is inclined, the incident angle of the incident light from the light emitting unit to each medium changes, so that the optical axis of the reflected light is that of the light receiving unit. The light receiving surface is arranged so as to be shifted from the center position. Therefore, it is possible to easily realize a configuration for discriminating between the first medium and the second medium having different degrees of light scattering based on the amount of reflected light received by the light receiving unit.

The discriminating apparatus of the present invention further includes a changing unit that changes a positional deviation amount of the optical axis of the reflected light with respect to a center position of the light receiving surface.
When the difference in the light scattering rate between the two media is large, when the optical axis of the reflected light is shifted with respect to the center position of the light receiving unit, the reflected light reflected from both media is scattered without being received by the light receiving unit. The difference in light quantity is relatively large. Therefore, even if the amount of positional deviation of the optical axis of the reflected light with respect to the center position of the light receiving unit is small, the difference between the amount of light reflected from both media and received by the light receiving unit is sufficiently large.

  In this regard, according to the above configuration, when the difference in the light scattering rate between the two media is large, the changing means reduces the positional deviation amount of the optical axis of the reflected light with respect to the center position of the light receiving surface of the light receiving unit. Therefore, the first medium and the second medium are accurately discriminated while the reflected light reflected from the first medium is reliably received by the light receiving unit and the presence or absence of the first medium is reliably detected. be able to.

Further, the recording apparatus of the present invention includes the determination device having the above-described configuration and a recording unit that performs a recording process on a medium whose type is determined by the determination device.
According to the said structure, the effect similar to invention of the said discrimination device is acquired.

1 is a schematic side view of an ink jet printer according to an embodiment of the present invention. (A) is a schematic diagram of a sensor before being tilted in the transport direction of continuous paper, and (b) is a schematic diagram of the sensor after being tilted in the transport direction of continuous paper. (A) is a schematic diagram of a sensor in which reflected light reflected from continuous paper is received by a light receiving unit, and (b) is a schematic diagram of a sensor in which reflected light reflected from a splice tape is received by a light receiving unit. (A) is a schematic diagram of a sensor in which the reflected light reflected from the upstream end portion of the continuous paper with curl is received by the light receiving unit, and (b) is reflected from the downstream end portion of the continuous paper with curl. The schematic diagram of the sensor by which the reflected light received by the light-receiving part. The schematic side view which shows the principal part of the ink jet type printer of another embodiment which concerns on this invention.

  Hereinafter, an embodiment in which the present invention is embodied in an ink jet printer (hereinafter, also referred to as “printer”) which is a kind of recording apparatus will be described with reference to FIGS. In the following description, when referring to “front-rear direction”, “left-right direction”, “up-down direction”, unless otherwise specified, “front-rear direction”, “left-right direction”, “up-down direction” indicated by arrows in each figure Direction.

  As shown in FIG. 1, the printer 11 includes a feeding unit 13 that feeds out the continuous paper S as a long medium, a recording unit 14 that performs recording processing by ejecting ink onto the fed continuous paper S, And a winding unit 15 that winds the continuous paper S that has been subjected to recording processing by the recording unit 14.

  In other words, the feeding unit 13 is disposed at a position closer to the rear side on the upstream side in the transport direction of the continuous paper S, and the winding unit 15 is disposed at a position closer to the front side on the downstream side. A recording unit 14 is disposed in the middle of the conveyance path between the feeding unit 13 and the winding unit 15.

  A winding shaft 16 extending in the left-right direction (a direction orthogonal to the paper surface) is rotatably provided in the feeding portion 13. The winding shaft 16 is supported so that the continuous paper S can be integrally rotated with the winding shaft 16 in a state where the continuous paper S is previously wound in a roll shape. That is, the continuous paper S is fed out of the winding shaft 16 by the rotation of the winding shaft 16 and is conveyed downstream in the conveying direction.

  The state shown in FIG. 1 shows a state immediately after the roll body of the continuous paper S is replaced with a new one with respect to the winding shaft 16. That is, the rear end (upstream end portion) of the preceding continuous paper S that is unwound from the used up old roll body and conveyed downstream, and the subsequent continuous paper S that is fed out from the new roll body. Are joined together by a splice tape T (see FIG. 3A). In addition, a first relay roller 17 that winds the continuous paper S fed from the winding shaft 16 and guides it toward the recording unit 14 is provided in a diagonally upper front direction of the winding shaft 16 so as to be rotatable in a left-right direction. It has been. Then, the continuous paper S fed from the winding shaft 16 is wound around the first relay roller 17 from the lower rear side, whereby the conveyance direction of the continuous paper S is changed to the horizontal direction, and the continuous paper S is transferred to the recording unit 14. Be transported.

  The recording unit 14 is provided with a support plate 18 having a support surface capable of supporting the continuous paper S. Further, a line head type recording head 19 as recording means is provided at a position facing the support plate 18 in the recording unit 14. The lower surface of the recording head 19 is a nozzle forming surface in which a plurality of nozzles (not shown) that eject ink are opened. The recording head 19 extends in a direction perpendicular to the conveyance direction of the continuous paper S in the horizontal direction, and has a length in the longitudinal direction corresponding to the maximum paper width of the continuous paper S. Then, the recording head 19 performs recording by ejecting ink to the recording area of the conveyed continuous paper S in the middle of the conveying path.

  An optical for detecting a splice tape T that joins the paper ends of the front and rear continuous sheets S at a position behind the recording head 19 upstream of the recording unit 14 in the transport path of the continuous sheet S. A sensor 20 of the type is provided. A control unit 21 is electrically connected to the sensor 20, and a detection signal output from the sensor 20 is transmitted to the control unit 21. In addition, a heater unit 22 that performs a drying process on the continuous paper S that has been ejected with ink from the recording head 19 is provided at a position in front of the recording head 19 that is downstream of the recording unit 14 in the conveyance direction of the continuous paper S. It has been. A controller 21 is electrically connected to the heater unit 22, and the controller 21 controls the temperature of the heater unit 22.

  Further, on the front side of the support plate 18, a second relay roller 23 facing the first relay roller 17 in the front-rear direction with the support plate 18 interposed therebetween is provided so as to extend in parallel with the first relay roller 17. Further, a pair of transport rollers 24 and 25 are disposed at a front and rear positions at a position on the front side of the support plate 18 and on the rear side of the second relay roller 23. The conveying roller pair 24, 25 is configured by driving rollers 24a, 25a and driven rollers 25b, 25b. The drive rollers 24a and 25a each extend in the left-right direction and abut on the surface of the continuous paper S on which the recording process is performed. On the other hand, the driven rollers 24b and 25b extend in parallel with the driving rollers 24a and 25a, and abut the surface of the continuous paper S opposite to the surface on which the recording process is performed. Then, the continuous paper S is sandwiched between the driving rollers 24a and 25a and the driven rollers 24b and 25b, and the driven rollers 24b and 25b are driven to rotate along with the driving rotation of the driving rollers 24a and 25a. S is transported.

  In addition, the 1st relay roller 17 and the 2nd relay roller 23 are located in the same height as the upper surface which is a support surface of the support plate 18 in the top part of each peripheral surface. Therefore, the continuous paper S is conveyed to the front side which is the downstream side while being in sliding contact with the support surface of the support plate 18. Then, the continuous paper S is wound around the second relay roller 23 from the front upper side, whereby the transport direction of the continuous paper S is changed from the horizontal direction to the front diagonally lower side and transported to the winding unit 15.

  In the winding unit 15, a winding shaft 26 is rotatably provided obliquely in front of the second relay roller 23. Then, the leading end that is the downstream end in the conveyance direction of the continuous paper S is wound around the winding shaft 26.

Next, the sensor 20 will be described.
As shown in FIG. 2A, a light emitting unit 30 and a light receiving unit 31 are provided on the lower surface 20a of the sensor 20 with an interval in the front-rear direction. The light emitting unit 30 emits incident light incident on the continuous paper S. The optical axis AX1 of the incident light is inclined so as to form a downward gradient with an inclination angle θ0 in the front-rear direction, which is the conveying direction of the continuous paper S, with respect to the lower surface 20a of the sensor 20 arranged to face the continuous paper S. When the lower surface 20a of 20 is opposed to the continuous paper S, the incident light is incident on the continuous paper S from obliquely upward and rearward. The light receiving unit 31 receives reflected light incident on the continuous paper S from the light emitting unit 30 and reflected obliquely upward and forward. That is, on the lower surface 20 a of the sensor 20, an emission surface 30 a on which incident light is emitted from the light emitting unit 30 and a light receiving surface 31 a on which reflected light is received by the light receiving unit 31 are formed. 2A, when the lower surface 20a of the sensor 20 is arranged parallel to the paper surface of the continuous paper S, the optical axis AX2 of the reflected light is at the center position P of the light receiving surface 31a of the light receiving unit 31. To position.

  The sensor 20 is configured to be rotatable about an axis (not shown) extending horizontally in the left-right direction. In the present embodiment, as shown in FIG. 2B, the lower surface 20a of the sensor 20 forms an upward gradient with an inclination angle θ in the forward direction that is the conveyance direction of the continuous paper S with respect to the paper surface of the continuous paper S. Thus, the tilt angle θ of the sensor 20 is fixed. In this case, when the incident angle θ1 of the incident light incident on the continuous paper S from the light emitting unit 30 increases with the rotation of the sensor 20, the reflection angle of the reflected light that is reflected obliquely forward and upward on the paper surface of the continuous paper S. θ2 also increases. For this reason, the optical axis AX2 of the reflected light reflected from the continuous paper S is displaced forward from the center position P of the light receiving surface 31a of the light receiving unit 31. That is, in the present embodiment, the light receiving unit 31 of the sensor 20 is disposed such that the center position P of the light receiving surface 31a is shifted forward in the front-rear direction with respect to the optical axis AX2 of the reflected light reflected from the continuous paper S. .

  Next, regarding the operation of the printer 11 configured as described above, in particular, the sensor 20 has the continuous paper S as the first medium and the splice as the second medium having a light scattering rate larger than that of the continuous paper S. The following description will be made focusing on the action when discriminating from the tape T.

  3A, when incident light emitted from the light emitting unit 30 of the sensor 20 enters the continuous paper S, the incident light is scattered by unevenness on the paper surface of the continuous paper S. Then, the reflected light scattered on the surface of the continuous paper S spreads radially around the optical axis AX2. In this case, since the degree of scattering of incident light on the continuous paper S is small, the size of the region where the reflected light reflected from the continuous paper S spreads radially is small. Therefore, almost the entire amount of the reflected light that spreads radially is received by the light receiving surface 31 a of the light receiving unit 31. Accordingly, the light receiving unit 31 outputs an ON value to the control unit 21 as a detection signal because the amount of light received from the light emitting unit 30 and reflected on the surface of the continuous paper S exceeds a predetermined threshold. Then, when the output value of the light receiving unit 31 is the ON value, the control unit 21 determines that the medium located in the detection area of the sensor 20 is the continuous paper S.

  On the other hand, as shown in FIG. 3B, when incident light emitted from the light emitting unit 30 of the sensor 20 enters the splice tape T, the incident light is scattered by unevenness on the surface of the splice tape T. The reflected light scattered on the surface of the splice tape T spreads radially around the optical axis AX2. In this case, the incident light scattering degree on the splice tape T is larger than the incident light scattering degree on the continuous paper S. That is, the size of the region where the reflected light reflected from the splice tape T spreads radially is larger than the size of the region where the reflected light reflected from the continuous paper S spreads radially. Therefore, a part of the reflected light that spreads radially is not received by the light receiving surface 31 a of the light receiving unit 31.

  In particular, in this embodiment, the lower surface 20a of the sensor 20 is disposed so as to be inclined with respect to the paper surface of the continuous paper S. The light emitting unit 30 is arranged such that the optical axis AX1 of incident light is inclined in the direction in which the amount of reflected light reflected from the splice tape T is reduced by the light receiving unit 31. As a result, the optical axis AX2 of the reflected light reflected from the splice tape T is shifted from the center position P of the light receiving surface 31a. For this reason, the amount of reflected light that is not received by the light receiving surface 31a of the light receiving unit 31 when the reflected light spreads radially is larger than when the optical axis AX2 of the reflected light is located at the center position P of the light receiving surface 31a. Is relatively large. Therefore, the light receiving unit 31 outputs an OFF value as a detection signal to the control unit 21 because the amount of light emitted from the light emitting unit 30 falls below a predetermined threshold. Then, when the output value of the light receiving unit 31 is an OFF value, the control unit 21 determines that the medium located in the detection region of the sensor 20 is the splice tape T. In this respect, the control unit 21 according to the present embodiment determines which of the continuous paper S and the splice tape T the medium to be determined is based on whether the amount of light received by the light receiving unit 31 is below a predetermined threshold. It functions as a determination unit that determines whether the medium is used.

  When the continuous paper S joined by the splice tape T is stiff, as shown in FIGS. 4 (a) and 4 (b), the upstream end portion S1 which is the rear end of the preceding continuous paper S and the succeeding continuous paper S are shown. Each downstream end portion S2 which is the front end of the continuous paper S may have a curl.

  That is, the upstream end portion S1 of the preceding continuous paper S has just been unwound from the small-diameter roll state where the remaining amount of the continuous paper S is small, so that a relatively large curl is caused by the strong curl. Has occurred. On the other hand, the downstream end portion S2 of the succeeding continuous paper S is new and is drawn from a large-diameter roll state in which the continuous paper S is wound up with a large amount of remaining winding. Has occurred.

  Therefore, as shown in FIG. 4A, when the sensor 20 detects the upstream end portion S1 of the preceding continuous paper S, the incident light emitted from the light emitting unit 30 is the upstream end portion S1 of the continuous paper S. After being reflected by the upper surface S1a, the light receiving unit 31 receives the light. In this case, the upper surface S1a of the upstream end portion S1 of the continuous paper S is inclined so as to form an upward gradient toward the downstream side in the transport direction of the continuous paper S. Further, the lower surface 20a of the sensor 20 is inclined so as to form an upward gradient toward the downstream side in the conveyance direction of the continuous paper S. That is, the lower surface 20a of the sensor 20 is inclined so that the angle intersecting the upper surface S1a of the upstream end portion S1 of the continuous paper S is small.

  As a result, the optical axis AX2 of the reflected light reflected from the upstream end portion S1 of the preceding continuous paper S is compared with the case where the upper surface S1a of the upstream end portion S1 of the continuous paper S is horizontally disposed. Of the light receiving surface 31a. That is, the optical axis AX2 of the reflected light reflected from the upstream end portion S1 of the continuous paper S is displaced in the direction approaching the center position P of the light receiving surface 31a of the light receiving unit 31. Therefore, when the upstream end portion S1 of the continuous paper S is curled, the reflected light reflected from the upstream end portion S1 of the continuous paper S is easily received by the light receiving unit 31. Accordingly, the sensor 20 can more reliably detect the boundary between the upstream end portion S1 of the preceding continuous paper S and the splice tape T.

  On the other hand, as shown in FIG. 4B, when the sensor 20 detects the downstream end portion S2 of the subsequent continuous paper S, the incident light emitted from the light emitting unit 30 is the downstream end portion S2 of the continuous paper S. After being reflected by the upper surface S <b> 2 a, the light is received by the light receiving unit 31. In this case, the upper surface S2a of the downstream end portion S2 of the continuous paper S is inclined so as to form a downward gradient toward the downstream side in the conveyance direction of the continuous paper S. Further, the lower surface 20a of the sensor 20 is inclined so as to form an upward gradient toward the downstream side in the conveyance direction of the continuous paper S. That is, the lower surface 20a of the sensor 20 is inclined such that the angle intersecting the upper surface S2a of the downstream end portion S2 of the continuous paper S is increased.

  As a result, the optical axis AX2 of the reflected light reflected from the downstream end portion S2 of the subsequent continuous paper S is compared with the case where the upper surface S2a of the downstream end portion S2 of the continuous paper S is disposed horizontally. A position shift occurs in front of the light receiving surface 31a. That is, the optical axis AX2 of the reflected light reflected from the downstream end portion S2 of the continuous paper S is displaced in the direction away from the center position P of the light receiving surface 31a of the light receiving unit 31. However, since curl generated in the downstream end portion S2 of the continuous paper S is relatively small, almost all of the reflected light reflected from the downstream end portion S2 of the continuous paper S is received by the light receiving unit 31. Therefore, the sensor 20 can reliably detect the boundary between the splice tape T and the downstream end portion S2 of the subsequent continuous paper S.

According to the present embodiment, the following effects can be obtained.
(1) The reflected light reflected from the splice tape T is scattered relatively larger than the reflected light reflected from the continuous paper S. Therefore, when the optical axis AX2 of the reflected light is deviated from the center position P of the light receiving surface 31a of the light receiving unit 31, the reflected light reflected from the splice tape T is scattered without being received by the light receiving unit 31. Of the reflected light reflected from the continuous paper S is larger than the amount of light scattered without being received by the light receiving unit 31. As a result, if the amount of reflected light reflected from the medium to be discriminated and received by the light receiving unit 31 is smaller than a predetermined threshold, the medium is a splice tape T having a high light scattering rate. Can be determined.

  (2) When the lower surface 20a of the sensor 20 is disposed so as to be inclined with respect to the paper surface of the continuous paper S, the incident angle of the incident light from the light emitting unit 30 to the medium changes, so that the optical axis AX2 of the reflected light is received. The light receiving surface 31 a of the part 31 is arranged so as to be shifted from the center position P. Therefore, it is possible to easily realize a configuration for discriminating between the continuous paper S and the splice tape T having different degrees of light scattering based on the amount of reflected light received by the light receiving unit 31.

In addition, you may change the said embodiment into another embodiment as follows.
In the above embodiment, as shown in FIG. 5, a pair of upper and lower guides that guide the conveyance of the continuous paper S fed from the winding shaft 16 to the position upstream of the recording unit 14 in the conveyance path of the continuous paper S. Plates 40 and 41 may be provided. Further, by forming the opening 42 in the upper guide plate 40, incident light may be incident on the continuous paper S passing between the guide plates 40 and 41 through the opening 42.

  In this case, the continuous paper S fed out from the winding shaft 16 is curled by the curl. Therefore, the continuous paper S forms a downward slope between the guide plates 40 and 41 toward the downstream side in the transport direction while contacting the inner surface of the upper guide plate 40 in the vicinity of the carry-in port of the guide plates 40 and 41. After being conveyed in such a tilted state, it contacts the inner surface of the lower guide plate 41 in the vicinity of the carry-out port of the guide plates 40 and 41. When the sensor 20 detects the splice tape T that joins the paper ends of the continuous paper S, incident light emitted from the light emitting unit 30 enters the upper surface of the splice tape T through the opening 42.

  Here, in the same manner as the continuous paper S, the splice tape T is conveyed between the guide plates 40 and 41 while being inclined so as to form a downward gradient toward the downstream side in the conveying direction. Further, the lower surface 20a of the sensor 20 is inclined so as to form an upward gradient toward the downstream side in the conveyance direction of the continuous paper S. That is, the lower surface 20a of the sensor 20 is inclined so that the angle intersecting the upper surface of the splice tape T becomes larger.

  As a result, the optical axis AX2 of the reflected light reflected from the splice tape T is displaced toward the front of the light receiving surface 31a of the light receiving unit 31 as compared with the case where the upper surface of the splice tape T is horizontally disposed. That is, the optical axis AX2 of the reflected light reflected from the splice tape T is displaced in the direction away from the center position P of the light receiving surface 31a of the light receiving unit 31, so that the reflected light not received by the light receiving surface 31a of the light receiving unit 31 is received. The amount of light becomes larger. Therefore, the light receiving unit 31 easily determines that the medium located in the detection region of the sensor 20 is the splice tape T because the amount of light emitted from the light emitting unit 30 is easily below a predetermined threshold. be able to.

  In the above embodiment, a tilting mechanism that changes the tilt angle of the lower surface 20a of the sensor 20 may be provided. In this case, if the inclination angle of the lower surface 20a of the sensor 20 is changed, the incident angle of the incident light from the light emitting unit 30 of the sensor 20 to the medium changes, so that the reflected light with respect to the center position P of the light receiving surface 31a of the light receiving unit 31 is changed. The positional deviation amount of the optical axis AX2 changes. Therefore, the tilt mechanism functions as a changing unit that changes the amount of positional deviation of the optical axis AX2 of the reflected light with respect to the center position P of the light receiving surface 31a.

  In the embodiment described above, the lower surface 20a of the sensor 20 may be greatly inclined to a position where a part of the reflected light reflected from the continuous paper S is not received by the light receiving surface 31a of the light receiving unit 31. That is, the lower surface 20a of the sensor 20 may be tilted within a range in which the amount of light received by the light receiving unit 31 that receives the reflected light reflected from the continuous paper S does not fall below a predetermined threshold.

In the above embodiment, the lower surface 20a of the sensor 20 may be inclined in the width direction of the continuous paper S that intersects the transport direction of the continuous paper S.
In the above embodiment, the light emitting unit 30 may be tilted without tilting the sensor 20. That is, only the light emitting unit 30 of the light emitting unit 30 and the light receiving unit 31 may be tilted.

  In the above embodiment, the sensor 20 has a moving mechanism that moves at least one of the light emitting unit 30 and the light receiving unit 31 back and forth so as to change the distance in the front and rear direction between the light emitting unit 30 and the light receiving unit 31. You may prepare. In this case, when the distance in the front-rear direction between the light emitting unit 30 and the light receiving unit 31 is changed, the positional deviation amount of the optical axis AX2 of the reflected light with respect to the center position P of the light receiving surface 31a of the light receiving unit 31 changes. Therefore, the moving mechanism functions as a changing unit that changes the positional deviation amount of the optical axis AX2 of the reflected light with respect to the center position P of the light receiving surface 31a.

  In the above embodiment, the medium to be discriminated by the sensor 20 is not limited to the continuous paper S and the splice tape T, and any medium may be employed as long as the light scattering rates are different from each other.

In the above embodiment, the medium is not limited to a long medium wound in a roll shape, and a single-cut medium may be adopted.
In the above-described embodiment, the recording apparatus adopting the inkjet method as the recording method is described. However, the recording device can be changed to a recording device of an arbitrary recording method such as an electrophotographic method or a thermal transfer method. Further, the recording apparatus is not limited to a printer, but may be a FAX apparatus, a copying apparatus, or a multifunction machine having a plurality of these functions. Further, as the recording apparatus, a liquid ejecting apparatus including a liquid ejecting head that ejects or ejects a small amount of liquid droplets other than ink may be employed. In addition, a droplet means the state of the liquid discharged from the said liquid ejecting apparatus, and shall also include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And liquids as one state of the substance, as well as particles in which functional material particles made of solid materials such as pigments and metal particles are dissolved, dispersed or mixed in a solvent. Further, representative examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, or a color filter in a dispersed or dissolved form. It may be a liquid ejecting apparatus for ejecting, a liquid ejecting apparatus for ejecting a bio-organic matter used for biochip manufacturing, a liquid ejecting apparatus for ejecting a liquid used as a precision pipette, a printing apparatus, a microdispenser, or the like.

  In the above-described embodiment, the determination device is not limited to the one provided in the recording device, and may be a medium determination device provided in various processing devices that perform arbitrary processing on the medium.

  DESCRIPTION OF SYMBOLS 11 ... Inkjet printer as recording apparatus, 19 ... Recording head as recording means, 21 ... Control part as discrimination | determination part, 30 ... Light emission part, 31 ... Light receiving part, 31a ... Light receiving surface, AX1, AX2 ... Optical axis, P: center position, S: continuous paper as the first medium, T: splice tape as the second medium.

Claims (4)

A discriminating apparatus for discriminating between a first medium and a second medium having a light scattering rate larger than that of the first medium,
The first medium is a medium conveyed in a conveyance direction,
The second medium is a medium that joins the upstream end portion of the preceding first medium before replacement with the downstream end portion of the subsequent first medium after replacement,
A light emitting unit for emitting incident light to each medium;
A light receiving unit configured to receive the reflected light by being arranged so that a center position of a light receiving surface is shifted with respect to an optical axis of the reflected light reflected from the respective mediums,
A discriminating unit for discriminating that the medium to be discriminated is the second medium when the amount of light received by the light receiving unit is smaller than a predetermined threshold;
With
The light emitting unit and the light receiving unit are provided at an interval in the transport direction , and an emission surface from which incident light is emitted in the light emitting unit, and a light receiving surface from which reflected light is received by the light receiving unit are provided. The discriminating apparatus is fixed in an inclined state so as to form an upward gradient toward the downstream side in the transport direction of the first medium . The discrimination device according to claim 1 ,
The light emitting unit is arranged such that an optical axis of the incident light is inclined in a direction in which the amount of the reflected light reflected from the second medium is decreased in the light receiving unit. . In the discrimination device according to claim 1 or 2 ,
The discriminating apparatus further comprising changing means for changing a positional deviation amount of the optical axis of the reflected light with respect to a center position of the light receiving surface. The discrimination device according to any one of claims 1 to 3 ,
A recording apparatus comprising: a recording unit configured to perform a recording process on a medium whose type is determined by the determination device.

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