Integrated adjustable core support and medium guide device

[0002] The present invention relates generally to an image forming machine and, more particularly, to an integrated adjustable core support and medium guide device adapted to be incorporated into a printer for properly holding medium rolls having different core diameters and for better aligning medium strips of the medium rolls moving from the core support to the medium guide of the integrated device.

[0003] Many conventional printers have certain medium holding mechanisms for supporting media mounted thereon. Typically, each of the media includes a medium strip wound on a support core forming a medium roll to be mounted on the medium holding mechanism of a conventional printer. The medium strip may be formed by a label strip, which includes a plurality of labels attached to a protective backing strip, or it may simply be formed by a paper strip. The protective backing of the label strip normally has a glossy surface attached to an adhesive surface of each label so that the labels could be easily peeled off from the protective backing. Each label also has a printable surface located opposite its adhesive surface.

[0004] Different conventional printers may have different kinds of medium holding mechanisms designed to fit their particular purposes. Ordinarily, the support core of the medium roll is tubular-shaped. The tubular support core could be made of plastic, cardboard, or any other materials that are suitable to hold the medium strip for mounting on the medium holding mechanism of the printer. The support core has an inner diameter and an outer surface where the medium strip is wrapped thereon. There are many different sizes of media used in the market for various business purposes. Thus, sizes of the support cores, e.g., the diameters and/or the lengths of the cylindrical support tubes,of the medium rolls have to be: accordingly varied in order to support different-sized medium strips. As a result, many commercially available medium rolls have different sizes of the inner diameters of their respective support cores.

[0005] As mentioned, commercially available medium rolls often come with different sizes. Therefore, medium holding mechanisms of most conventional printers have incorporated certain adjusting features to cope with the different-sized core diameters of the medium rolls. Typically, the medium holding mechanism of a conventional printer has a pair of support ears respectively positioned at opposite sides of the conventional printer. Each of the support ears respectively has a stepped shape for receiving different diameters of the support cores of the medium rolls. The stepped support ears of most conventional printers normally have at least two or three steps, but four-step support ears could also be found frequently.

[0006] Alternatively, the medium holding mechanism of a conventional printer may include a medium bar for supporting the medium rolls. The medium bar is normally secured to the conventional printer at one end, leaving an opposite end of the medium bar open for inserting and removing the medium rolls on the medium bar. Similar to the above-mentioned support ears, the medium bar often has a stepped shape to receive the medium rolls with different core diameters.

[0007] The conventional printer also has a medium guide mechanism for guiding and/or aligning the medium strip through the printer. Typically, the medium guide mechanism has a pair of pathway guides respectively positioned at opposite sides of a guide shaft. The pathway guides are positioned in the printer to guide the medium strip before the medium strip could reach a print head of the printer, thereby they help align the medium strip with the print head to provide better printing qualities. Each of the pathway guides often has a thin slot to allow the medium strip to pass through and both of the pathway guides are movably coupled to the guide shaft. Furthermore, the pathway guides are often equally spaced apart at opposite sides from a midpoint of the guide shaft. To accommodate medium strips having different dimensions, the pathway guides are configured to move toward or away from the midpoint of the guide shaft with. equal distance. Ordinarily, this is accomplished by a wheel-controlled sliding arrangement, where a user may adjust the distance between the pathway guides by turning an adjusting wheel. As a result, the pathway guides would always center the medium strip when the medium strip passes through the pathway guides. Alternatively, only one of the pathway guides is movably coupled to the guide shaft, while the other pathway guide is secured to an end of the guide shaft. Consequently, such pair of the pathway guides operates only to guide the medium strip and does not provide any centering function.

[0008] The above-mentioned stepped feature of the medium holding mechanism of the conventional printer provides a convenient solution to accommodate medium rolls having different core diameters of their support tubes. This feature, however, only partially solves the problems of holding the printable medium rolls having different core diameters. Particularly, a typical conventional printer has two or three steps on each support ear. As a result, only those medium rolls having core diameters fitted to these two or three steps will be held properly in the printer. Other medium rolls having different core diameter sizes will be, at best, loosely supported by the support ears. A loose medium roll mounted in the printer would potentially cause many problems during operation, such as the misalignment of the medium strip in the printer or the jamming of the printer due to uneven moving speed of the medium strip.

[0009] To reduce the loose-medium-roll problem, more, steps will have to be provided by the support ears. This arrangement would inevitably increase the overall width of the conventional printer due to the stepped feature of the support ears. As can be seen in FIG. 1, a conventional medium holding mechanism of a printer normally has two or more steps for each support ear (at least one step for each support ear is required). Each step of a support ear will need at least a certain amount of depth, e.g., 5 mm, on its rim in order to securely support the medium rolls. As a result, the overall width of the conventional medium holding mechanism will be increased by 2×D for each additional step of the support ear, where D is the depth of each step (supposed each step has the same depth D). The more steps adopted for each support ear, the wider medium holding mechanism, and thus the printer, is required. Furthermore, even though more steps may be able to fit more types of medium rolls, no conventional printer has an adjustable medium holding mechanism to fit many commercially available medium rolls with different core diameter sizes of their support tubes.

[0010] Another common problem to the conventional printer relates to the alignment of the medium strip between the medium guide mechanism and the medium holding mechanism. The medium guide mechanism in the conventional printer is separated and operated independently from the printer's medium holding mechanism. Ordinarily, the medium guide mechanism is located close to a front end of the printer, where the print head is located, while the medium holding mechanism is located close to a back end of the printer. After mounted on the medium holding mechanism, the medium strip of the medium roll is pulled forward and inserted through the slots of the pathway guides of the medium guide mechanism. Thereafter, the medium strip is threaded through between a platen and the print head, where the platen rotatably presses the medium strip tightly against the print head to move the medium strip forward for printing. As mentioned, at least one of the pathway guides is usually controlled by a wheel to adjust their relative positions. The wheel is coupled to the guide shaft and is positioned at one side of the printer near the front end. In the conventional printer, the adjusting wheel operates independently from the medium holding mechanism and is adapted to be manually, controlled.

[0011] Since the medium guide mechanism and the medium holding mechanism of the conventional printer are separately adjusted and operated independently from each other, misalignment problems, thus, often occur to the medium strip when it moves from the medium holding mechanism to the medium guide mechanism of the printer. For example, when mounting the medium roll in the printer, the user will have to adjust the pathway guides and/or the support ears to accommodate the newly installed medium roll. Moreover, the misalignment problems will be further deteriorated if the medium rolls are loosely mounted on the support ears. Since the pathway guides and the support ears are adjusted independently, the medium strip might not be precisely aligned between the support ears of the medium holding mechanism and the pathway guides of the medium guide mechanism. Even a slight misalignment of the medium strip between these two mechanisms might cause many potential problems to the conventional printer. The problems include, inter alia, the twisting of the medium strip, which may cause bad printing quality to the medium strip, or it may jam the conventional printer. An improved holding and guiding mechanism of the printer is, therefore, needed to resolve the above-mentioned problems.

[0012] An object of the present invention is to provide an improved holding mechanism to a printer for properly holding medium rolls having different core dimensions of their support tubes. Another object of the present invention is to provide an integrated, medium guiding mechanism for better aligning the medium strip of the medium roll mounted on the printer. These objects are met by providing an adjustable core support mechanism and an integrated medium holding and medium guiding device to a printer respectively according to the present invention, as indicated in the claims appended hereto.

[0013] In one embodiment of the present invention, the present invention comprises a medium holding mechanism having an adjustable core support ear for receiving medium rolls having different core dimensions. In another embodiment, the present invention comprises an integrated medium holding and medium guiding device. The integrated medium device includes a medium holding mechanism and a medium guiding mechanism integrally coupled to the medium holding mechanism forcing the medium guiding mechanism to remain aligned with the medium holding mechanism. In addition, the medium holding mechanism is adjustable of its width to hold medium rolls of different lengths.

[0014] In a preferred embodiment, the integrated medium device according to the present invention has a pair of side support members respectively positioned at opposite ends of the integrated medium device. The side support members are coupled to each other through a connecting gear mechanism. The connecting gear mechanism comprises a gear set meshing to a pair of tooth rails for moving both side support members away or toward each other. Each of the side support members respectively comprises an adjustable core support ear, a guiding rail, and a guiding wall, preferably integrated with a respective side support member. Moreover, each of the adjustable core support ears has an upper semi-circular half and a lower semi-circular half, wherein the lower semi-circular half is adapted to be adjusted vertically for supporting medium rolls having different core dimensions of their support tubes. Since the core support ear, the guide rail, and the guide wall are integrated. with respective side support members, the medium strip will remain aligned when it moves from the medium roll, which is mounted on the adjustable core support ears, to a pair of guide caps respectively positioned over, the top of the guide rails at the front end of each side support member.

[0015] The foregoing and other objects, features and advantages of the invention will be apparent from the more particular description of preferred embodiments of the present invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

[0016] FIG. 1ashows the prospective view of a conventional printer having a pair of support ears for holding a medium roll.

[0017] FIG. 1billustrates a connecting mechanism coupling both support ears of FIG. 1a.

[0018] FIG. 2 shows the perspective view of a conventional printer having a pair of pathway guides.

[0019] FIG. 3 shows a perspective view of an integrated medium device incorporated into a printer according to the present invention.

[0020] FIG. 4 shows a detailed perspective view of the integrated medium device of FIG. 3.

[0021] FIG. 5ashows a right part of the integrated medium device of FIG. 4 with a connecting mechanism.

[0022] FIG. 5bshows a left part of the integrated medium mechanism of FIG. 4 with the connecting mechanism.

[0023] FIG. 3 shows a preferred embodiment of the present invention having an integrated medium device 10 being incorporated into a printer 1. The integrated medium device 10 includes a pair of side support members 12aand 12bcoupled to each other through a connecting mechanism 30. The side support members 12aand 12bare respectively positioned at the inner left and right sides of the printer 1 and are substantially parallel to each other, where medium holding sections 14aand 14brespectively of the side support members 12aand 12bare located near a back end of the printer 1, and medium guiding sections 16aand 16bare located near a front end of the printer 1. In the preferred embodiment, the side support members 12aand 12bare made of molded plastic materials. In alternative embodiments, other suitable materials may be used to make the side support members 12aand 12b.

[0024] As mentioned, each of the side support members 12a, 12bof the integrated medium device 10 has a medium holding section 14a, 14band a medium guiding section 16a, 16bintegrated with the respective medium holding sections 14a, 14b, as shown in FIG. 4. Each of the medium holding sections 14a, 14bcomprises an adjustable core support ear 18a, 18brespectively positioned on a shallow elliptic recess 20a, 20bof the respective left and right side support members 12a, 12b. In the preferred embodiment, the medium holding sections 14a, 14b, which include an adjustable core support ear respectively, are integrated with respective medium guiding sections 16a, 16b. In an alternative embodiment, the medium holding sections 14a, 14b, which respectively comprises an adjustable core support ear 18a, 18b, are separated from the medium guiding sections 16a, 16b. In yet another alternative embodiment, the medium holding sections 14a, 14b, which includes no adjustable core support ear, are respectively integrated with the medium guiding sections 16a, 16b.

[0025] The core support ears 18a, 18bare respectively divided into an upper and a lower semi-circular ear parts (22a, 24a) and (22b, 24b), and diameters of the core support ears 18a, 18bare approximately equal to the short diameter of the elliptic recesses 20a, 20b. The upper ear parts 22a, 22bof each core support ears 18a, 18bare securely coupled to the left and right side support members 12a, 12brespectively, while the lower ear parts 24a, 24bare vertically movable along the respective elliptic recesses 20a, 20b.

[0026] In the preferred embodiment, the upper and lower ear parts (22a, 24a) and (22b, 24b) of the core support ears 18a, 18brespectively has a two-step stepped support rim, i.e., a larger base step and a smaller inner step on top of the base step. The outer diameter of the base step is approximately 1.125 inches wide and the outer diameter of the inner step is approximately 1 inch wide. The rim thickness of the inner step is approximately 0.1 inches, and the depth of both steps are also approximately 0.1 inches. In an alternative embodiment, the multiple-step feature of the core support ears 18a, 18bcould be saved, leaving only one step to each core support ear 18a, 18b.

[0027] Two sets of three elongated slots 26aand 26bare vertically positioned respectively on the elliptic recesses 20aand 20b. Each vertical slot of the sets 26a, 26bis substantially parallel to each other, wherein a left and a right slot of each set 26a, 26brespectively has the length of approximately 0.75 inches and both middle slots have the length of approximately 1 inch. Moreover, both middle slots respectively have a pair of curved recess sections respectively located near the top and the bottom of each middle slot and respectively have a narrower straight intermediate section in between the top and the bottom curved recess sections. Thus, the wall-to-wall distances of each top and each bottom curved recess sections of both middle slots are wider than the wall-to-wall distances of the straight sections of the middle slots. A handle post is perpendicularly coupled to and extending backward from respective backsides of the lower ear parts 24aand 24bthrough the middle slots. The diameters of the handle posts are slightly larger than the wall-to-wall widths of the straight sections of the middle slots but are narrower than the wall-to-wall widths of the top or the bottom curved recess sections of the middle slots. Furthermore, the position of the top recess section of each middle slot is chosen to make each lower ear part 24a, 24bmeet with the upper ear part 22a, 22bto form a respective circular core support ear 18a, 18bwhen the handle post of each core support ear 18a, 18bis rested on the respective top recess section. Likewise, the position of the bottom recess section of each middle slot is chosen to allow the lower ear parts 24aand 24bposition at its lowest position within the elliptic recesses 20aand 20bwhen the handle post of each core support ear 18a, 18bis rested on the respective bottom recess section of each middle slot. As illustrated in FIG. 5, the right lower ear part 24bis at its lowest position in the recess 20b(FIG. 5a), and the left lower ear part 24ais at its uppermost position in the recess 20a(FIG. 5b).

[0028] A pair of adjusting nobs 28aand 28bare respectively coupled to the handle posts of the lower ear parts 24aand 24bfor manually adjusting vertical positions of the lower ear parts 24aand 24b. One of the middle slot walls, such as the wall between the middle and the left slots or between the middle and the right slots, of the left side support member 12ais broken at just above the top recess section. Similarly, one of the middle slot walls of the right side support member 12bis broken at just above its top recess section. As a result, the broken slot walls of the middle slots could be pushed sideways to allow the handle posts of the lower ear parts 24aand 24bto move up and down along their respective middle slots. As mentioned, the diameters of the handle posts are slightly larger than the wall-to-wall widths of the straight sections of the middle slots but are smaller than the wall-to-wall widths of the top and the bottom curved recess sections. Therefore, when the handle posts are pushed by the adjusting nobs 28a, 28bto move up and down the middle slots, the broken slot walls of each middle slot will be urged sideways to give way to the handle posts until the handle posts are rested on the top or the bottom curved recess sections of the middle slots. However, although the broken slot walls would be pushed aside to allow movements of the handle posts, the straight sections between the top and the bottom recess sections of both middle slots would clamp the handle posts tightly when the handle posts are positioned between their respective recess sections. The broken slot walls, thus, respectively function like a pivoted leaf spring for pressing the handle posts tightly. As a result, the lower ear parts 24aand 24brespectively of the support ears 18a, 18bcould be held stationary at any vertical positions from the very top positions directly adjacent to the upper ear parts 22aand 22bto the lowest points of the elliptic recesses 20a, 20b.

[0029] The pairs of the upper ear parts and the lower ear parts (22a, 24a) and (22b, 24b) together hold the tubular cores of the medium rolls to be mounted on the support ears 18aand 18b. Since positions of the lower ear parts 24aand 24brespectively of each support ear 18aand 18bcould be vertically adjusted, the support ears 18aand 18bof the present invention could hold medium rolls with a wide variety of core diameter sizes sufficiently tight. Therefore, the integrated medium device 10 according to the present invention prevents the medium rolls from being held loosely on the support ears 18a, 18b, as commonly happened to the conventional printers, and it also prevents many problems associated with the loose medium rolls. Moreover, the integrated medium device 10 of the present invention also minimizes the necessary thickness for the support ears 18aand 18b, as compared to the conventional printer which requires multiple steps of their support ears for holding medium rolls having different diameters of their support tubes. The present invention, thus, makes it possible for a small dimension printer to have a medium holding mechanism adapted to support a wide variety of medium rolls.

[0030] The left and right side support members 12aand 12bare coupled to each other by a connecting mechanism 30, as partially shown in FIGS. 5aand 5b. Similar to FIG. 1bof the conventional printer, the connecting mechanism 30 of the present invention includes a rear and a front saw-like tooth arms 32a, 32brespectively secured to the bottom of the left and right side support members 12a, 12band extending perpendicularly to their respective inner surfaces. In the preferred embodiment, the rear and the front tooth arms 32a, 32brespectively has wedge-like coupling parts 34a, 34bcoupled to the tooth arms 32a, 32bat their respective ends. Correspondingly, the left and right side support member 12a, 12brespectively has receptive caps such as receptive cap 36b(FIG. 4) for receiving the wedge coupling parts 34a, 34b, as illustrated in FIG. 4. In addition, each of the wedge parts 34a, 34bhas two holes perpendicularly located at the top of the wedge parts 34a, 34b. Likewise, each of the receptive caps such as receptive cap 36b(FIG. 4) respectively has two matching holes through the top of the receptive caps 36a, 36b. Thus, when the wedge parts 34a, 34bare wedged into the respective receptive caps 36a, 36b, two securing poles (not shown) could be inserted into the holes of the wedge parts 34a, 34bthrough the receptive caps 36a, 36bfor holding the wedge parts 34a, 34bfirmly in place.

[0031] Each of the tooth arms 32a, 32bhas teeth only at one side wherein the teeth of both arms 32aand 32bface each other when mounted. As in the conventional printer, the connecting mechanism 30 further comprises a gear means 48 positioned between the tooth arms 32a, 32band meshing with the teeth of the tooth arms 32a, 32b. As a result, when it rotates, the gear means 48 will pull the side support members 12aand 12bcloser or will push them away from each other, depending on the rotational directions of the gear means 48. Preferably, the gear means 48 is positioned at the center between the side support members 12aand 12b. Therefore, the gear means 48 will pull or push both side support members 12aand 12bwith equal distance. The gear means 48 of the present invention is similar to a gear means of the conventional printer shown in FIG. 1b. In the preferred embodiment, the gear means 48 is coupled to a rotational wheel (not shown) for the user to rotate the gear means to adjust the positions of the side support members 12a, 12b. The rotational wheel is also conventional. In an alternative embodiment, no rotational wheel is provided. The user then adjusts the positions of the side support members 12a, 12bby manually pressing them together or by pulling them away from each other.

[0032] As noted, each side support member 12a, 12bof the preferred embodiment has an integrated medium guide section 16a, 16brespectively located at the front part of the side support member 12a, 12b. The medium guide section 16a, 16brespectively has a curved shape guide rail 40a, 40b. Each curved guide rail 40a, 40bextends from the bottom of the medium holding section 14a, 14bfrontward and upward until the horizontal position of the front end of the guide rail 40a, 40bis approximately 0.25 inches lower than the bottom of the lower ear part 24a, 24bat its uppermost position and approximately 0.25 inches higher than the bottom of the lower ear part 24a, 24bat its lowest position in the recesses 20a, 20b. Thus, the front ends of the guide rails 40a, 40bare approximately at the height in the middle of the swing span of the bottoms of the respective lower ear parts 24a, 24b.

[0033] The medium guide sections 16a, 16balso have flat cover hats 42a, 42brespectively located at the front end of the medium guide sections 16a, 16b. Each cover hat 42a, 42bextends perpendicularly inward from side walls 44a, 44bof the side support member 12a, 12brespectively and is substantially parallel to their corresponding guide rails 40a, 40bat the front end, as shown in FIG. 4. The flat cover hat 42a, 42bis approximately angled 10°-20° downward to its front, making the front end opening of the medium guide section 16a, 16bsmaller and forcing the medium strip to move downward toward a print head (not shown) of the printer 1.

[0034] The medium guide sections 16a, 16bare respectively rigidly integrated to the medium holding sections 14a, 14bthrough the side walls 44a, 44bof the side support members 12a, 12baccording to the present invention. When the medium holding sections 14aand 14bare adjusted to receive a medium roll, the medium guide sections 16a, 16bwill be adjusted accordingly. As a result, the medium guide sections 16a, 16b, particularly at their respective front ends, will always align with the medium holding sections 14a, 14bno matter how the latter would move. The present invention, thus, provides an integrated medium device 10 for assuring the medium strip of the medium roll mounted thereon will remain aligned when the medium strip moves from the medium roll toward the front ends of the medium guide sections 16a, 16b. In addition, when the user mounts the medium roll on the printer 1, the user needs only to adjust the medium holding sections 14a, 14band doesn't need to worry about the alignment of the medium guide sections 16a, 16bsince they are self-aligned. In contrast, users of conventional printers need to independently adjust both their medium holding mechanism and the medium guiding mechanism to align both mechanisms with respect to each other. This would potentially cause many undesirable misalignment problems.

[0035] From the foregoing, it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made by persons skilled in the art without deviating from the spirit and/or scope of the invention. Particularly, the dimensions of the various parts of the present invention are for illustrative purposes only. Any persons skilled in the art may modify the dimensions of the present invention according to their particular purposes for different imaging devices. In addition, the present invention could also be used in all kinds of imaging machines, including but not limited to printers and fax machines, etc. The present invention may also be used in other medium-roll-mounting devices for better aligning the medium strips with respect to the medium rolls when the medium strips move through the devices.