BACKGROUND

[0001] Printing systems may deposit printing fluid, such as ink, or another printing substance, such as three-dimensional printing powder, on print media. The print media may be stored in a media tray, from which the printing system may draw a sheet or portion of the print media for printing. The supply of print media within the media tray may be periodically filled or replaced when the supply reaches a certain level, or is depleted. The media tray may include an indicator to inform a user of the level of the print media remaining within the media tray.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Fig. 1A is a perspective view of an example indicator.

[0003] Fig. IB is a perspective view of an example indicator.

[0004] Fig. 1C is a partial back view of an example indicator.

[0005] Fig. 1 D is a partial perspective front view of an example indicator.

[0006] Fig. IE is a partial back view of an example indicator.

[0007] Fig. 1 F is a partial front view of an example indicator.

[0008] Fig. 1 G is a partial back view of an example indicator.

[0009] Fig. 1H is a partial front view of an example indicator.

[0010] Fig. II is a partial perspective front view of an example indicator.

[0011] Fig. 1J is a partial perspective front view of an example indicator.

[0012] Fig. IK is a partial back view of an example indicator.

[0013] Fig. 1L is a partial back view of an example indicator.

[0014] Fig. 2A is a partial perspective front view of an example indicator.

[0015] Fig. 2B is a partial perspective front view of an example indicator. DETAILED DESCRIPTION

(0016] Printing systems may deposit printing fluid, such as ink, for example, on media or print media. In some situations, printing systems may deposit other print substances on media, such as powder, for example, in a powder-based three-dimensional (3D) printer. The print media may be stored in a media tray, from which the printing system may draw a sheet or portion of the print media for printing. In some situations, the print media may be stored in a stack within the media tray. Additionally, in some situations, printing systems may have more than one media tray for storing multiple types or sizes of print media. Each of the media trays may have an external designation, shape, character, or other element to uniquely identify that particular tray to a user. The supply of print media within each media tray may be periodically filled or replaced when the supply reaches a certain level, or the supply is depleted.

(0017] In some situations, it may be desirable for the media tray to include an indicator to inform a user of the level or quantity of the print media left within the media tray. It may further be desirable that the indicator be an external alert, or, in other words, be visfcle to a user from the exterior of the media tray, or the printing system. Such an external indicator may be a continuous indicator, in some situations. A continuous indicator may be graduated, or continuously follow the current level or quantity of the print media within the media tray and display such a quantity or level to an external user of the printing system. In some situations, interpreting a continuous indicator may be difficult or confusing. A graduated or continuous indicator may be subject to a user's interpretation, and multiple users using the same printing system may have different interpretations of the level of print media left in the media tray based on any given external display of a continuous indicator. For example, a continuous print media indicator may, to some users, appear to indicate that the media tray needs to be refilled. To other users, however, the continuous indicator may indicate that a sufficient quantity of print media remains in the tray and it does not need to be refilled.

(0018] Implementations of the present disclosure provide an indicator for a media tray of a printing system In some implementations, the indicator may be a binary indicator, or, in other words, may only have two indicator positions and may operate in an ON/OFF fashion, with no intermediate position The indicator may provide an external indication to a user of the printing system that additional print media should be loaded into the media tray. Further, the external indication by the indicator of the level of print media left within the media tray may not be subject to different interpretations by different users of the printing system. An example indicator may provide only one of two different indications at a time. A first indication may inform a user that the media tray still has a sufficient quantity of print media remaining within. The second indication may inform a user that the media tray needs additional print media to be loaded within. Any user of the printing system may be able to look to the example indicator of the media tray and see one of the two possible print media level indications and know whether the tray needs to be loaded or not

[0019] Referring now to Fig. 1 A, a perspective view of an example indicator 100 disposed within a media tray 102 of a printing system is illustrated. The media tray 102 may include an external portion 104. The external portion 104, in some implementations, may be an exterior panel or wall of the media tray 102. Additionally, the outside surface of the external portion 104 may be visible to a user of the printing system, and, in some situations, comprise an indicator window. Further, the media tray 102 may receive print media 106 wkhin the media tray 102. The print media 106, in some implementations, may comprise multiple sheets paper. The printing system may draw the multiple sheets of paper from the media tray for printing. In some implementations, the printing system may draw a single sheet of paper from the stack of print media 106 at a time. In other implementations, the print media 106 may be powder for use in a 3D printing system The powder may be disposed within a media tray 102 that may support the powder and a three-dimensional object as it is being printed. The print media 106, in further implementations, may be supported by a lift plate wkhin the media tray 102. The lift plate, in some implementations, may be biased in an upward direction, such that the hft plate constantly pushes the print media towards a pick element, roller, or portion of the printing system, wherein the pick element or portion is to draw a sheet of print media 106 from the print media 106 stack. The lift plate may be disposed at continuously different heights within the media tray 102, depending on the quantity of print media 106 in the tray 102. For example, a full stack of print media 106 may push the lift plate further down into the media tray 102 than half a stack of print media 106. Thus, the hft plate may move further ki the upward direction, as each sheet of print media 106 is removed by the pick element, roDer, or portion from the stack of print media 106.

[0020] Referring now to Fig. IB, a perspective view of an example indicator 100 disposed within a media tray 102 is illustrated, as taken along view line IB- IB of Fig. 1 A. The example indicator 100 may comprise an arm 108, a latch 116, and an indicator plate 1 18, in some implementations. The arm 108 may be a rigid strut or beam having a first end 1 19 and a second end 120, in some implementations. The arm 108 may be pivotally engaged with the media tray 102, or a fift plate within the media tray 102. The arm 108 may be pivotally disposed within the media tray 102, and comprise a pivot 121 disposed longitudinally along the length of the arm 108 in between the first end 1 19 and the second end 120. The pivot 121 may be disposed on the arm 108 such that, if the first end 1 19 were to move in a first direction, for example, a downward direction 1 10, the arm 108 would rotate in a corresponding direction 1 12 about the pivot 121, and the second end 120 may move in a direction opposite to the downward direction 1 10, such as an upward direction 1 14. Similarly, if the first end 1 19 were to move in an upward direction, the arm 108 may rotate about the pivot 121 in a corresponding direction, and the second end 120 may move in a direction opposite to the direction of movement of the first end 1 19.

[0021] The arm 108 may be pivotally engaged with the print media 106 itself within the media tray 102, or, in some implementations, with a lift plate supporting the print media 106 within the media tray 102. The arm 108 may be coupled to or engaged with the fift plate such that the first end 119 of the arm 108 travels with the lift plate, or in a corresponding manner as the lift plate. In other words, for example, print media 106 may push the lift plate in a downward direction upon being baded into the media tray 102, or upon the media tray 102 otherwise receiving the print media 106. The lift plate may concurrently move the first end 1 19 of the arm 108 in a corresponding downward direction 1 10. Further, as print media 106 is removed from the media tray 102, the lift plate may move either incrementally or continuously in an upward direction, thereby also causing the first end 1 19 of the arm 108 to move in a corresponding upward direction. Note, the first end 1 19 of the arm 108 may be directly engaged with the print media 106 in some implementations, instead of with a lift plate. Thus, in such an

implementation, the print media 106 may directly push the first end 1 19 of the arm 108 in a downward direction upon being loaded into the media tray 102, and the first end 1 19 of the arm 108 may move in an opposite, upward direction upon print media 106 being removed from the media tray 102. In some implementations, the first end 1 19 of the arm 108 may be directly biased in an upward direction such that the first end 1 19 pushes the print media 106 in the upward direction upon print media 106 being removed from the stack of print media 106 within the media tray 102. [0022] Referring now to Fig. lC, a partial back view of an example indicator 100 is illustrated. Referring additionally to Fig. ID, a partial perspective front view of the example indicator 100 is illustrated. The example indicator 100 may comprise a latch 116 and an indicator plate 118. The indicator plate may be a movable component relative to the media tray 102, and comprise a latch post 122. The indicator plate 1 18 may be movably coupled to the media tray 102, or, in some implementations, the indicator plate 1 18 may be disposed within, and therefore movable within, a track, slot, or other orifice or aperture in the media tray 102. Further, in some implementations, the indicator plate 1 18 may be switchably disposed in one of a raised position and a lowered position. In some implementations, the indicator plate 118 may be sHdably coupled to or engaged with the media tray 102 such that the indicator plate 118 may slide from the raised position to the towered position, and vice versa. In further

implementations, the indicator plate 118 may be sbdably engaged with an exterior panel 104 of the media tray 102. The indicator plate 1 18 may be coupled to or engaged with the exterior panel 104 of the media tray 102 such that, when disposed in the towered position, a portion or all of the indicator plate 118 may be visible to the exterior of the media tray 102 or the printing system In further implementations, the indicator plate 118 may comprise a color, at least in part, other than the same or a similar color as the exterior of the media tray 102 or the printing system. In yet further implementations, the indicator plate 1 18 may comprise a color that contrasts with the exterior cobr of the media tray 102 or the printing system, so that the contrasting colors increase the visit ility of the indicator plate 118 when in the towered position.

[0023] The example indicator 100 may further comprise a latch 1 16. The latch 116 may be coupled to or engaged with each of the arm 108 and the indicator plate 118. In some implementations, the latch 116 may be pivotally coupled to the media tray 102 such that the latch 1 16 may toggle or pivot, relative to the media tray 102, between a latched position and a released positioa In further implementations, the latch 116 may be biased towards the latched position. The latch 1 16 may be biased towards the latched position by a resihent bias member, such as a spring or torsion spring. In further implementations, the latch 1 16 may be biased towards the latched position by gravity and having an unbalanced pivot point. The latch 1 16 may comprise a latch portion 124 to engage with the latch post 122 of the indicator plate 118, in some

implementations. The latch portion 124 may include complementary geometry, such as a slot, shelf, or channel, for example, to cradle or hold the latch post 122 in the latched position. [0024] Referring still to Figs. 1C-D, an example indicator is illustrated wherein the indicator plate 1 18 is disposed in the raised posidoa In such an implementation, the latch 1 16 may be disposed in the latched position, and therefore may support the indicator plate 118 in the raised position. The latch 1 16 may support the indicator plate 1 18 in the raised position by the latching portion 124 of the latch 1 16 engaging with the latch post 122 of the indicator plate 1 18 such that the latch post 122 fiiHy rests upon the latching portion 124, and the latch 1 16 can, therefore, support the entire weight of the indicator plate 1 18.

[0025] Referring to Fig. ID, the arm 108, in some implementations, may comprise a pivot tab 130 to engage with a pivot surface 132 of the latch 1 16. The pivot tab 130 may be a protrusion that extends laterally, or substantially orthogonally, from the longitudinal axis of the arm 108. The pivot tab 130 may, in some implementations, be a unitary part of the arm 108, or, in other implementations, the pivot tab 130 may be a separate component that is assembled to the arm 108. The pivot tab 130 may be disposed on the second end 120 of the arm 108 and, thus, move with the second end 120 of the arm 108. For example, should the arm 108 rotate or pivot about the pivot 121 in a direction such as direction 126, the second end 120 may move in a downward direction, thus also lowering or moving the pivot tab 130 in a downward direction 128. The pivot tab 130 may be disposed abng or spaced along the length of the arm 108 at an appropriate location such that, upon moving in a downward direction such as direction 128, the pivot tab 130 may contact the pivot surface 132 of the latch 1 16.

[0026] Referring now to Fig. IE, a partial back view of an example indicator 100 is illustrated. Referring additionally to Fig. IF, a partial front view of the example indicator 100 is illustrated. In Figs. 1E-F, an example indicator 100 is illustrated wherein the indicator plate 1 18 is still disposed in the raised position, and the arm 108 has rotated abng direction 126. In some implementations, the first end 1 19 of the arm 108 may have moved in an upward direction as depicted in Fig. IB, thereby causing the arm 108 to rotate abng direction 126 and the second end of the arm 120 to move in a downward direction 128. The arm 108, and thus the pivot tab 130, has moved in the downward direction 128 to the point where the pivot tab 130 makes contact with the pivot surface 132 of the latch 1 16. The arm 108 may cause the latch 1 16 to start to pivot upon the pivot tab 130 coming into contact with the pivot surface 132 of the latch 1 16. As illustrated in Figs. lE-F, the latch 1 16 is still in the latched position and, therefore, still supports the indicator plate 1 18 in the raised position. [0027] Referring now to Fig. 1G, a partial back view of an example indicator 100 is illustrated. Referring additionally to Fig. 1H, a partial front view of the example indicator 100 is illustrated. In Figs. 1G-H, an example indicator 100 is illustrated wherein the arm 108 has continued to rotate along direction 126, the latch 116 has pivoted to the released position, and the indicator plate 118 has fallen or slid to the lowered positioa The arm 108 may have continued to rotate along direction 126 due to print media continuing to be removed from the media tray 102 and, therefore, causing the first end 1 19 of the arm 108 to continue to move in the upward direction. Further, the arm 108 may have moved along the direction 126 far enough to cause the latch 116 to release the indicator plate 118 due to a certain, or specific quantity, or predetermined amount of print media remaining within the media tray 102. In other words, the second end 120 of the arm 108, and thus the pivot tab 130, has continued to move in the downward direction 128. The pivot tab 130, therefore, has pushed upon the pivot surface 132 of the latch 116 such that the latch 1 16 has pivoted about its pivot point 133. The pivot tab 130 has caused the latch 1 16 to pivot such that the latch portion 124 has translated in a direction 129, away from the latch post 122 of the indicator plate 118. As illustrated in Figs. 1G-H, the pivot tab 130 has continued in the direction 128, pushing on pivot surface 132 so that the latch portion 124 has completely disengaged from the latch post 122. Upon disengagement of the latch post 122 with the latching portion 124, the latch 1 16 has fully pivoted from the latched position to the released position, and the indicator plate 1 18 is no longer supported in the raised position by the latch 1 16. Thus, the latch 116 has released the indicator plate 1 18 to slide in a direction 134 to the lowered positioa Therefore, the indicator plate 1 18 may be supported in the raised position until a predetermined, or specific amount of print media 106 is removed from the media tray, thereby moving the arm 108 a sufficient amount to contact and pivot the latch 1 16 to a degree where the latch 116 releases the indicator plate 1 18.

[0028] Referring now to Figs. II- J, partial perspective views of an example indicator 100 disposed within a media tray 102 are illustrated. The media tray 102 may have an exterior panel 104 comprising an indicator window 136, in some implementations. The indicator plate 1 18 may be visfcle to the exterior of the media tray 102 or printing system through the window 136 when in the lowered positioa Further, the indicator plate 118 may not be visfcle to the exterior of the media tray 102 or printing system through the indicator window 136 when in the raised positioa Fig. II may represent the situation illustrated ki Figs. C-F, where the indicator plate 1 18 is disposed in the raised position, supported by the latch 1 16. Further, Fig. 1J may represent the situation illustrated in Figs. 1G-H, where the latch 1 16 has pivoted from the latched position to the released position, and the indicator plate 1 18 has moved from the raised position to the lowered position. The indicator plate 118 may now be visible through the window 136 to an external user, signifying to the user that the predeteirnined, or specific amount of print media is remaining within the media tray 102, and that additional print media 106 should be added to the tray 102.

[0029] Referring now to Fig. IK, a partial back view of an example indicator 100 is illustrated, wherein the arm 108 has rotated along direction 1 12, after the indicator plate 118 has moved from the raised position to the lowered positioa The arm 108 may rotate along direction 1 12 due to the first end 1 19 of the arm 108 moving in a downward direction, such as direction 110, for example. The first end 1 19 may move in a downward direction, in some

implementations, due to additional print media 106 being disposed within or added to the media tray 102. In other words, after the print media 106 reaches the predetermined, or specific quantity or level, a user may refill the media tray 102, thereby moving the first end 1 19 of the arm 108 in a downward direction 1 10, and the second end 120 of the arm 108 in an upward direction, such as direction 114. The latch post 122 of the indicator plate 118 may be engaged with, or resting upon, in some implementations, a surface of the second end 120, such that, as the second end 120 moves in upward direction 1 14, the second end 120 pushes the latch post 122, and thus the indicator plate 1 18 upwards towards the raised positioa

[0030] Referring additionally to Fig. 1 L, a partial back view of an example indicator 100 is illustrated, wherein the arm 108 has continued to rotate along direction 1 12, thereby pushing the latch post 122 in an upwards direction 1 14 so that the latch post 122 comes into contact with the latching portion 124 of the latch 1 16. The latch post 122 of the indicator plate 1 18 may contact and engage with a surface or feature of the latching portion 124 of the latch 1 16 such that the post 122 pushes the latching portion 124 in a lateral direction, such as direction 129, for example. As the arm 108 continues to push the latch post 122 along an upward direction, the latch post 122 may continue to push the latching portion 124 along the lateral direction such that the latch 1 16 pivots from the latched position back to the released positioa Once the latch 1 16 reaches the released position, the latch post 122 may continue moving in the upward direction until it has moved beyond and stopped contact with the surface or feature of the latching portion 124. In some implementations, the latch post 122 may stop contact with the latching portion 124 once the indicator plate 1 18 is back in the raised position Additionally, the latch post 122, in some implementations, may stop contact with the latching portion 124 upon a predetermined amount or quantity of print media 106 being baded into the media tray 102. At this point, the latch 1 16 may, once again, pivot from the released position back to the latched position due to the latch 1 16 being biased in the latched directioa Once in the latched position, the latch post 122 may, again, be engaged with the latching portion 124 so that the latch 1 16 supports the indicator plate 1 18 in the raised position, as illustrated in Figs. 1C-D. In other words, upon receiving a refill or another predetermined quantity of print media 106, the arm 108 may push the indicator plate 1 18 back up to the raised position, where the latch post 122 may pivot the latch 1 16 from the latched position to the released position so that the latch post 122 may move past the latching portion 124 of the latch 1 16, and wherein the latch 1 16 may then pivot back to the latched position to support the indicator plate 1 18 in the raised position

[0031] Referring now to Figs. 2A-B, partial perspective views of an example indicator

200 disposed within a media tray 202 are illustrated. Example indicator 200 may be similar to example indicator 100. Further, the similarly named elements of example indicator 200 may be similar in function and/or structure to the elements of example indicator 100, as they are described above. The media tray 202 may have an exterior panel 204 comprising an indicator window 236, in some implementations. In further implementations, the indicator window 236 may comprise the shape of a symbol or character to identify the media tray 202 and differentiate the media tray 202 from other media trays disposed within the same printing system. In yet further implementations, the indicator window 236 may comprise the shape of an alphanumeric character, such as a letter or number in order to identify the media tray 202. Additionally, an indicator plate may be visible to the exterior of the media tray 202 when the indicator plate is in a lowered position, which may be behind the indicator window 236. Further, the indicator plate may be disposed behind the indicator window 236 when in the lowered position such that the character or symbol is visible to the exterior of the media tray 202.