Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J11/00—Devices or arrangements  of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form
  • B41J11/20—Platen adjustments for varying the strength of impression, for a varying number of papers, for wear or for alignment, or for print gap adjustment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J11/00—Devices or arrangements  of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form
  • B41J11/66—Applications of cutting devices
  • B41J11/70—Applications of cutting devices cutting perpendicular to the direction of paper feed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J15/00—Devices or arrangements of selective printing mechanisms, e.g. ink-jet printers or thermal printers, specially adapted for supporting or handling copy material in continuous form, e.g. webs
  • B41J15/04—Supporting, feeding, or guiding devices; Mountings for web rolls or spindles
  • B41J15/042—Supporting, feeding, or guiding devices; Mountings for web rolls or spindles for loading rolled-up continuous copy material into printers, e.g. for replacing a used-up paper roll; Point-of-sale printers with openable casings allowing access to the rolled-up continuous copy material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J29/00—Details of, or accessories for, typewriters or selective printing mechanisms not otherwise provided for
  • B41J29/02—Framework
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J3/00—Typewriters or selective printing or marking mechanisms characterised by the purpose for which they are constructed
  • B41J3/36—Typewriters or selective printing or marking mechanisms characterised by the purpose for which they are constructed for portability, i.e. hand-held printers or laptop printers

Definitions

• the present invention relates generally to printers and, in particular, to a compact, clam shell style printer that is easily loaded and includes a construction that minimizes the cabling required between a printhead, control switches and connectors, and the associated circuit board.
• Printers of the type to which this invention pertains have many applications and uses. They may be used as part of a point-of-sale terminal to print receipts, etc. Printers of this type may also be used to generate labels on which alphanumeric characters or symbology, i.e., barcodes are printed.
• Thermal printing involves a thermal printhead which uses heating elements to produce localized heating on thermal reactive print media to produce indicia on the print media.
• the print medium In order to effect the printing process, the print medium must be clamped between a platen and the thermal printhead.
• the printhead is normally spring biased towards the print roller in order to provide the required clamping force.
• the present invention provides a new and improved printer apparatus in which the loading of print media is greatly facilitated and, in which modular construction is used in order to substantially reduce the number of parts normally needed for this type of printer.
• the printing apparatus includes a base and an associated cover for enclosing an interior region of the apparatus.
• the cover is movable between opened and closed positions.
• the printing apparatus defines a print media path that extends from the interior region to a discharge opening.
• the platen roller is rotatably supported by the cover, such that when the cover is moved to its opened position, the platen roller is spaced from the print media path.
• a substantially fixed printhead is supported by the base and is engageable by the platen roller when the cover is in its closed position.
• a biasing arrangement urges the platen roller towards the printhead when the cover is in its closed position.
• a cutter mechanism forms part of the printing apparatus and has one portion carried by the cover and another portion carried by the base, such that when the cover is moved to its opened position, the one portion of the cutter mechanism moves to a spaced location along with the platen roller to facilitate the loading of print media into the printing apparatus.
• the printing apparatus also includes a thermal printhead which together with associated control components and electronics forms a printhead and control module that is mounted within the printing apparatus.
• the control module preferably comprises a circuit board assembly to which the thermal printhead is secured and is fixed relative to the base.
• the circuit board assembly also mounts one or more switches which provide a cover position detector function, as well as a print media advancement function.
• the circuit board assembly also mounts connectors by which the printer is interfaced to other equipment.
• the printer incorporates a clam shell design in which a pivotally mounted cover mounts a spring biased platen roller.
• a print media compartment is exposed, as well as the complete media feed path.
• Print media is installed in the printer by placing the print media supply in a compartment defined within the printer and then pulling the lead end of the print media so that it extends beyond an ejection point in the printing apparatus. Closing the cover causes the platen roller to re-engage the printhead thus clamping the print media between itself and the printhead.
• the printer includes a cutter in which a portion is carried by the cover and another portion is mounted in the base.
• opening the cover also separates the cutter elements so that print media need not be fed through a cutter mechanism when the print media is loaded.
• the one cutter portion comprises a fixed blade that is attached to and is movable with the cover.
• the other portion of the cutter includes a reciprocally movable blade and is located in the base unit.
• one of the cutter portions is resiliently biased to the other portion when the cover is closed. This biasing urges the cutter portions into an aligned relationship to promote uniform blade contact in order to improve cutter performance.
• the disclosed printer is compact and is easily manufactured. Cabling normally required between the printhead, the control switches, the connectors and the associated circuit board, is eliminated or at least substantially reduced. In addition, the susceptibility of damage to the electronics of the printer due to electrostatic discharge is substantially reduced since the electronic control module assembly is located entirely within the printer and except for the interface connectors is not accessible from outside the printer.
• Figure 1 is a perspective view of a printer apparatus constructed in accordance with the preferred embodiment of the invention
• Figure 1A is an exploded view of the printer shown in Figure 1, showing separation of removable covers from a base portion of the printer;
• Figure 2 is a side cross-sectional view of the printer
• Figure 3 is another side cross-sectional view of the printer;
• Figures 4-6 show three different views of a control module assembly forming part of the printer;
• Figure 7 is a perspective view of an intermediate or internal housing member forming part of the present invention
• Figure 7A is a fragmentary, perspective view of the internal housing member shown in Figure 7 showing a media feed switch mechanism
• Figure 8 is a perspective view of a removable cover forming part of the printer
• Figure 9 is a fragmentary, perspective view of the printer cover shown in Figure 8;
• Figure 9A is an exploded view of the printer cover shown in Figure 9 ;
• Figure 10 is a side view of an internal housing member forming part of the printer
• Figure 10A is a fragmentary side view showing a cover unlatching mechanism
• Figure 11A and 11B are fragmentary side views showing a cover open detector switch arrangement constructed in accordance with a preferred embodiment of the invention.
• Figure 12 is a fragmentary side view, partially in section showing an alternate cover latching mechanism of the present invention.
• Figure 13 is a perspective view of an alternate printer cover
• Figure 14 is a perspective view of a cutter mechanism forming part of the present invention.
• Figure 14A schematically illustrates an alternate embodiment of a cutter mechanism.
• FIG 1 illustrates the overall construction of a printing apparatus embodying the present invention.
• the printing apparatus comprises a clam shell-type printer.
• the printer includes a base 10, a hinged cover 12 which, when opened, provides access to a paper supply compartment 13 (shown in Figure 1A) , and a fixed, but removable cover 14 that encloses a printhead assembly and an optional cutter 15 (shown best in Figures 1A and 2.
• a feed button 16 is actuatable by a user and is operative to advance print media out of an ejection slot indicated generally by the reference character 18.
• a cover release button 20 is provided for releasing a latch mechanism that maintains the cover 12 in its closed position as illustrated in Figure 1.
• connectors to be described and indicated generally by the reference character 22 are provided by which the printer is connected to power and a host system such as a cash drawer of a point of sale terminal (not shown) .
• the connectors 22 are accessible underneath the printer by means of a recess 24 formed in the base 10 of the printer.
• the cover 12 is rotatable between opened and closed positions about a pivot axis 28.
• the opened position is shown in phantom and is indicated by the reference character 26.
• the cover is separable from the rest of the printer after it is moved to the opened position.
• this feature is facilitated by a pair of J-shaped hinge members 30, which are engageable with slots 32 formed in the base 10 (shown in Figure 1A.
• the cover mounts a spring biased platen roller 40 (see Figure 1A and 9A) which is operably engageable with a thermal printhead 50 mounted at a fixed position within the base 10 of the printer.
• print media such as paper
• Figure 2 Figure 2
• Heating elements forming part of the printhead are selectively energized to produce indicia, i.e., alphanumeric characters, symbology, barcodes, etc. on the print media 52.
• the thermal printhead 50 itself is not moveably biased towards the platen roller 40.
• the print medium in order for the thermal printing process to perform properly, the print medium must be clamped tightly between the platen roller 40 and the printhead 50, as the print medium moves past the printhead.
• the platen roller 40 in the device of the present invention, is spring biased in order to produced the required clamping force.
• the thermal printhead 50 forms part of a control module or circuit board assembly 54 that also mounts the control electronics and may even include the power supply for the electronics and the printhead.
• the power supply does not form part of the assembly 54 due to space constraints.
• the printhead 50 is attached to a circuit board 54a by solder connections 55a, 55b made between connecting pins of the thermal printhead 50 and contacts or circuit traces made on a circuit board 54a.
• a support bracket 60 is secured to the circuit board 54a by fasteners 62 and serves as a mechanical support and rigidizes the mounting of the thermal printhead 50.
• the circuit board is electronically coupled to, and mechanically mounts the connectors 22, which may include a power connector 56, a communications port in the form of a parallel port connector 58, and a cash drawer connector 59 by which the printer is interfaced to a host system, such as a point of sale machine.
• the parallel port 58 may be in the form of a DB25 connector.
• the power connector is adapted to receive a removable jack or plug forming part of a "power cube" which is usually plugged into an A.C. outlet.
• the connector 59 may be in the form of a RJ11 or RJ45 jack. It should be noted that other forms of connectors are contemplated by the present invention.
• the communications port may a serial port or alternatively may be a more generic communications port to which a serial or parallel module (not shown) is attached, which determines the type of communication that will be used by the printer.
• the circuit board 54a also rigidly mounts a cover open icroswitch 70 which is mechanically actuated by an actuating protrusion (to be described) forming part of the cover 12.
• the board assembly 54 also includes a print media feed switch 72
• the feed switch 72 is mechanically actuated by the feed button 16, shown in Figures 1, 1A, as will be explained.
• the assembly also includes a LED 73 directly mounted to the board 54a and which is visible through an opening 73a (See Figure 1) in the housing 14. In the preferred embodiment the light from the LED 73 is transmitted to the opening 73a by a light pipe (not shown) that is mounted at the location indicated by the reference character 75 in Figure 1A.
• the mounting arrangement eliminates cabling between the LED 73 and the board 54a.
• the disclosed control module assembly 54 substantially reduces the manufacturing costs of the printer, since it eliminates connectors and cabling between the printhead 50 and the control electronics, which are typically found in thermal printers.
• the platen roller 40 is rotatably supported in the cover 12 and includes a driven gear 80 located at one end. Referring in particular to Figure 3, when the cover is moved to its closed position (shown in Figure 1) , the driven gear 80 engages a gear train, indicated generally by the reference character 82 located within the base 10.
• the gear train 82 is coupled to a drive motor 84 and includes a cluster gear 85 directly driven by the motor 84 having an output gear 84a which in turn rotates a drive gear 86 that couples with the platen gear 80 when the cover 12 is closed.
• the driven gear 80 of the platen roller 40 engages the drive gear such that the engagement occurs at a tangent line that is substantially parallel to the line of action defined by the platen roller mounting in the cover.
• the platen roller 40 is spring loaded and is laterally movable with respect to the fixed printhead 50.
• the platen roller 40 is supported by spaced apart slots 88a, 88b (see also Figure 8) formed in the hinged cover 12. The slots allow the platen roller 40 to move towards and away from the printhead 50 along a line of action indicated by the reference character 89 in Figure 2.
• the platen roller 40 As seen best in Figures 9 and 9A, the platen roller
• the bushings include a narrow diameter portion 93a which is sized to fit within an associated slot.
• An enlarged portion 93b defining a side surface 93c.
• the side surface 93c is engageable and rides against a side surface of the associated slot and locates the axial position of the platen roller with respect to the cover 12 so that lateral movement (i.e., movement in a direction 90° to the line of action 89 is inhibited) .
• Each bushing 93 also includes an extension 93d which is sized to fit within its associated spring 91 and serves to maintain the position of the spring between its associated bushing 93 and the abutment 95.
• the line of action 89 defined by the slots 88a, 88b is substantially parallel to a tangent line located at the engagement point between the driven gear 80 and drive gear 86.
• biasing the platen roller 40 using spring elements directly acting between the cover and the platen roller 40 is a preferred embodiment, the present invention contemplates other arrangements for producing a biasing force on the platen roller 40.
• Cover constructions/mountings may be employed which indirectly generate a biasing force on the platen roller 40, for urging it towards operative contact with the printhead 50.
• the illustrated springs which act between the cover and the platen roller 40, via the bushings 93 may be replaced with components that indirectly bias the platen roller 40 towards the printhead 50.
• the cover open switch 70 mounted to the printhead board assembly 54 is actuated by a protrusion 90a formed on the end of a cover latch member 90 (see Figure 8) on the cover 12 which is operative to actuate the switch 70 as the cover moves to its closed position.
• the cover includes another latch member 91 that does not include a similar protrusion.
• the latch members 90, 91 from at least part of the slots 88a, 88b, which as described above movably supports the platen roller 40 for movement towards and away from the printhead 50.
• the latch members 90, 91 form part of a cover latching system by which the cover 12 is maintained in its closed position.
• a tolerance compensating member 94 (see Figures 1A, 11A and 11B) is located intermediate the cover open switch 70 and the protrusion 90a, when the cover 12 is closed.
• the tolerance compensating member 94 is a foam element which is compressible. The foam element is used to compensate for variations in the gap between the actuating protrusion 90a of the cover latch member 90 and the position of the cover open detect switch 70. With the disclosed construction, precise adjustments between the cover actuating protrusion 90a and the microswitch 70 in order to effect proper operation when the cover is closed, are not required.
• the foam member located between the latch member 90 and switch 70 compensates for variations in gap distances between the protrusion 90a and switch 70 which normally occur in manufacture.
• a rectangular- shaped foam member 94 is located in an opening 98a defined by an interior housing 98 of the printer.
• the foam member is positioned such that it overlies the cover open switch 70 mounted to the control module assembly 54.
• a portion 94a of the underside of the foam element 94 is secured to a shelf 97 as by adhesive or other suitable means.
• the remaining portion 94b of the element 94 is cantilevered above the switch 70.
• Variations in the final gap between the protrusion 90a and the microswitch 70 are taken up by the foam.
• the cover 12 is latched in its closed position by the latch members 90, 91.
• the latch members 90, 91 include latching surfaces 97.
• the intermediate housing 98 as seen best in Figures 10A and 11B, includes a pair of latch pawls 101, 102 having a complemental latch surfaces 99 which are engageable with the latching surfaces 93 formed on the cover latch members 90, 91.
• the engagement between the latch surface 97 and the latch surface 99 is best shown in Figure 11B and is indicated by the reference character 100.
• a mechanism is provided for releasing the latch pawls 101, 102 without requiring excessive application force by the operator.
• a cover unlatching mechanism comprising a pair of spaced apart lever arms 110, 112 is located and pivotally supported in the internal housing 98.
• the lever arms 110, 112 are interconnected by a shaft 118, so that they rotate in unison about an axis
• the latch arm 110 defines a first actuating lever portion 110a, which receives forces from the cover open button 20 via tab 20a. The application of force to the first lever portion 110a rotates the lever 110 and hence the lever 112 (see Figure 1A) in a counterclockwise direction as viewed in Figure 10A.
• Each lever arm 110, 112 includes a second lever portion 120 located on the other side of the pivot axis 121. Downward movement in the first lever portion 110a causes the second lever portions 120 to move upwardly.
• the second lever portions each include a vertically extending pin-like portion 120a and a laterally extending finger portion 120b.
• the pin-like portion 120a is operative to engage a earning surface 130 on its associated latch pawl causing the latch pawl to move or bend leftwardly (as viewed in Figure 10A) .
• This movement tends to disengage the latch pawl surface 99 from the latch surface 97 located on its associated cover mounted latch member.
• the laterally extending finger 120b of each lever 110, 112 tends to exert upward forces on an abutment surface 123 formed on the cover mounted latch members 90, 91 thereby effecting opening of the cover 12.
• the combination action provided by the lever arrangement reduces the effort needed to open the cover by depressing the cover open button 20.
• Figures 12 and 13 illustrate an alternate embodiment for the cover latching mechanism.
• a spring arrangement is used to pop open a cover 12 ' when the cover open button 20 is pressed.
• a latch arm 110 • is rotated about a pivot 121 whenever the button 20 is depressed. The forces from the button 20 are applied to a first lever portion 110a 1 via tab 20a.
• a second lever portion 120' operates like the lever portion 120 in Figure 10a to move the latch paw 101 leftwardly in order to disengage the cover 12 ' .
• a pair of spring members indicated generally by the reference character 160 operate to raise the cover 12 • upwardly so the operator can grasp and lift the cover to its opened position.
• the spring members comprise compression springs 162 which act between the cover 12' and a cup 164.
• the assemblage is maintained by a screw 165 and washer 166 which holds the cup 164 to a stanchion 168 formed in the cover 12'.
• the spring forces act between the cover 12 ' and side plates 172 forming part of the internal housing member 98 (see Figure 7) .
• the print media feed switch 72 located on the control module assembly is, in the preferred embodiment, directly actuated by the feed button 16 shown in Figure 1.
• the button 16 includes a finger receiving portion 16a and an elongate arcuate segment 16b.
• the button 16 is slidably held within a channel 140 defined in a locating rib 142 molded into the internal housing 98.
• the arcuate segment is rectangular in cross-section and is therefore inhibited from rotating with respect to the rectangular shaped channel 140.
• the coaction between the channel 140 and the segment 16b operates to transfer the finger forces applied to the button 16a in one direction to a switch closing force exerted by the distal end 16c of the button 16 in another direction which is substantially 70° different from the direction of the finger applied force.
• a remotely mounted print media advancing switch is avoided eliminating the need for cabling and other componentry to connect an actuating button to the switch and, in turn, connect the switch to the control electronics.
• susceptibility to electrostatic discharge damage to the circuit board and/or switch is reduced since, in the preferred embodiment, the feed button 16 is molded from a non-conducting, plastic material.
• the switch 72 may be used for other functions, such as triggering a self test mode when the printer is first turned on or used as means to initiate a printer configuration mode.
• the switch 72 should not be limited to a print media advancing function.
• the disclosed printer may be outfitted with the cutter 15.
• the cutter 15 includes a fixed blade 15a mounted to the cover 12.
• a moving blade assembly 15b is mounted in the base 10 and is enclosed by the removable cover 14.
• the moving cutter assembly includes a reciprocating blade 150 which moves towards and away from the fixed blade 15a.
• a drive motor 152 forming part of the cutter assembly effects the required reciprocating movement in the blade 150.
• a print media portion 52a extending through the slot 12 is severed from the remainder of the print media 52.
• FIG. 7 illustrates the overall construction of the internal housing 98.
• the housing is preferably a molded product and includes latches 103 by which it is removably held within the base 10.
• the internal housing 98 defines, at least partially, the paper supply compartment 13 in which a roll of print media is placed.
• the cover 12 is opened and a roll of print media is placed within the compartment 12.
• the leading end of the print media is passed over the printhead and laid atop the cover 14.
• the cover 12 is then rotated to its closed position at which time the platen roller 40 re-engages the printhead and clamps the print media between itself and the printhead.
• the paper does not have to be fed between paper paths components, i.e., rollers or between components of the cutter (since the fixed blade 15a moves out of the paper path when the cover 12 is opened) .
• the fixed blade of the cutter is attached and moves with the cover 12 , whereas the reciprocating blade portion of the cutter remains with the base 10.
• Figure 14 illustrates, in detail, the preferred cutter mechanism 15.
• the mechanism includes a fixed blade 15a which is mounted to the cover 12.
• a reciprocating blade 150 is carried by the moving blade assembly 15b which is mounted to the base 10 of the printing apparatus.
• the fixed blade 15a moves upwardly with respect to the reciprocating blade 150.
• the blade 150 includes a pair of spaced apart laterally extending ears 180 which contact the underside of the fixed blade 15a whenever the cover is closed.
• the blade 150 itself is at least partially held to a cutter mounting plate 184 by a compression spring and fastener 190, 192 respectively.
• the spring 190 exerts an upward force on the blade 150 so that contact with the fixed blade 15a is maintained while allowing the blade to move (and even rotate slightly) in order to align itself with the blade 15a, even if there are slight misalignments between the cover 12 and the base 10.
• reliable cutting of the print media which passes between a cutting edge 196 of the fixed blade 15a and a V-shaped cutting edge 198 of the blade 150 is improved.
• the motor 152 is energized to move the blade 150 towards and away from the fixed blade 15a.
• a slot 200 formed in the blade 150 allows relative movement between the blade and the fastener 192.
• the alignment ears 180 remain in sliding contact with the underside of the blade 15a throughout the cutting cycle. It should be noted that this aspect of the invention also contemplates a spring loaded fixed blade 15a to provide the self-alignment function.
• Figure 14A illustrates an alternate arrangement for biasing the blades towards uniform cutting contact.
• a fixed blade 15a 1 is biased towards a reciprocating blade 150' by a spring 190 ' that acts between the fixed blade 15a 1 and a cover portion 12a''.
• the fixed blade 15a* is urged into contact with the reciprocating blade 150' whenever the cover 12 ' ' is closed.
• the disclosed invention provides a very compact and cost effective printer that is easily loaded. Costly and complex cabling between a printhead, control components and interfacing connectors is eliminated or substantially reduced.
• the disclosed construction also facilitates servicing and component replacement in the printer.
• the internal mounting of all of the electronic components including control switches reduces the risk of damage to electronic components due to electrical discharges, etc.

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• Handling Of Sheets (AREA)
• Accessory Devices And Overall Control Thereof (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=21845375

Family Applications (1)

Country Status (3)

Cited By (22)

Families Citing this family (8)

Citations (2)

Family Cites Families (3)

• 1997
  • 1997-10-17 EP EP97946274A patent/EP1011974A1/de not_active Withdrawn
  • 1997-10-17 WO PCT/US1997/018977 patent/WO1998017475A1/en not_active Application Discontinuation
  • 1997-10-17 CA CA002269061A patent/CA2269061A1/en not_active Abandoned

Patent Citations (2)

Non-Patent Citations (1)

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