WO2010125114A1

WO2010125114A1 - Cassette for use in a label printer

Info

Publication number: WO2010125114A1
Application number: PCT/EP2010/055738
Authority: WO
Inventors: Dirk Van Britsom; Stefaan Van den Broecke; Kris Vandermeulen; Peter Van Pottelberghe; Jerry Roctus
Original assignee: Dymo
Priority date: 2009-04-28
Filing date: 2010-04-28
Publication date: 2010-11-04
Also published as: JP2012525282A; CN102458867A; US8939665B2; WO2010125126A1; JP5612669B2; WO2010125122A9; PL2246197T3; EP2416966B1; US20100272492A1; US20120057917A1; EP2246197A1; WO2010125128A1; WO2010125122A1; EP2246197B1; AU2010243577A1; EP2974874A2; EP2416966A1; CN102458867B; AU2010243573B2; US8469615B2

Abstract

A label printer cassette is provided. The label printer comprises at least one supply of printing medium and a housing in which said image receiving medium is received. The label printer further comprises a cover which is arranged in use to move between first and second positions and a clamping member for clamping said printing medium. The clamping member is arranged to have a first mode in which said printing medium is clamped and a second mode in which said printing medium can be drawn from said supply. The mode of the clamping member is controlled by the cover.

Description

Cassette for Use in a Label Printer

The present invention relates to a cassette for use in a label printer, to a label printer and to a combination of a cassette and a label printer.

A label printer generally comprises a print head which is controlled to print onto an image receiving tape medium or onto a consumable in the form of a continuous backing sheet on which pre-cut labels are provided. The image receiving medium is generally provided in the cassette which is received in a cassette receiving bay of the label printer.

Some cassettes are arranged such that the image receiving medium is drawn out of the cassette to a print zone defined between a print head and a platen of the label printer. Printing on the image receiving medium occurs at the print zone. In some cassettes, a print area is provided for accommodating at least part of the print head or the platen. Some cassettes may have an opening which allows the image receiving medium to exit the cassette housing on one side of the print zone, extend through the print zone and then to exit the cassette completely on the other side of the print zone..

Some cassettes also contain an ink ribbon. The ink ribbon thus may also pass across this print zone, following a similar path to the image receiving medium.

When the cassette is outside the label printer, the image receiving medium may become slack due to the user pulling the tape or general movement of the cassette. This is undesirable as when the cassette is then inserted in the label printer, this slack may have an adverse effect on the print quality. In some cases the image receiving medium may have gone completely back in the cassette so that printing is not possible.

According to a first aspect of the present invention, there is provided a label printer cassette comprising: at least one supply of printing medium; a housing in which said image receiving medium is received; a cover which is arranged in use to move between first and second positions; and a clamping member for clamping said printing medium, said clamping member arranged to have a first mode in which said printing medium is clamped and a second mode in which said printing medium can be drawn from said supply, wherein the mode of the clamping member is controlled by the cover.

According to a second aspect, there is provided a label printer comprising: a cassette receiving bay for receiving a cassette; a print head and platen at least partially provided in said cassette receiving bay; and a cassette cover operation mechanism arranged at least partially in said cassette receiving bay for engaging and moving a cover of a cassette, when said cassette is in said cassette receiving bay.

Some embodiments of the present invention will now be described, by way of example only, with reference to the accompanying Drawings in which:

Figure 1 shows a cross-section of a cassette embodying according to one embodiment of the present invention;

Figure 2 shows a perspective view of the cassette of Figure 1 ; Figure 3 shows part of the cassette of Figure 1 in more detail;

Figure 4 shows a perspective view of an unlocking mechanism in a label printer for unlocking a cover of the cassette of Figure 1 ;

Figure 5 shows a cross-sectional view of the unlocking mechanism of Figure 4, along line F-F of Figure 4; Figure 6 shows a perspective view of a cassette receiving bay of the label printer;

Figure 7 shows a cross section of part of the label printer showing the unlocking mechanism before the cassette of Figure 1 is inserted into the cassette receiving bay; Figure 8 shows a cross-section view of the part of the label printer shown in Figure 7 and the cassette of Figure 1 , as the cassette is inserted;

Figure 9 shows a cross-section view of the part of the label printer shown in Figure 7 and the cassette of Figure 1 , with the cover of the cassette in an unlocked configuration; Figure 10 shows a cross-section view of the part of the label printer shown in Figure 7 and the cassette of Figure 1 , with the cover of the cassette in an open position;

Figure 11 shows a perspective view of the cassette of Figure 1 , with the cover in an open position; and

Figure 12 shows the underside of the part of the cover marked A in Figure 11

Figure 13 shows schematically parts of a label printer;

Figure 14 shows an exploded view of a cassette; Figure 15 shows a platen lock member and the cover where the platen lock member is in a lock position where the platen roller is locked;

Figure 16 shows the platen lock member of Figure 15 in an unlock position such that the platen can move;

Figure 17 shows a perspective view of the underside of the cassette receiving bay showing the platen lock member in the unlock position;

Figure 18 shows in detail the interaction between the platen lock member with the platen support member in the lock position;

Figure 19 shows a view of the underside of the cover of the cassette;

Figure 20a shows an enlarged view of a the clamping member of the cassette in a clamped position; and

Figure 20b shows an enlarged view of the clamping member is in the undamped position.

In the Figures, like reference numerals indicate like parts. The cassette shown in the Figures is arranged to house one or more supplies of print medium. The print medium may be an ink ribbon and/or may be an image receiving medium. An image receiving medium may be in the form of an image receiving tape having an upper image receiving layer for receiving an image and a removable backing layer secured to the upper image receiving layer by a layer of adhesive such that after an image has been printed the backing layer can be removed and the image receiving layer can be stuck to a surface. This image receiving tape may be a continuous supply. Accordingly, the cassette may be used with a label printer which includes a cutter for cutting off a length of image receiving tape after the image has been printed. Alternatively, the image receiving medium may comprise a continuous backing layer whilst an image receiving layer is in the form of pre-cut labels. In this example, the label can be printed and then peeled off from the backing layer. Alternatively, the labels may be connected together with no backing layer. The labels may be separated by lines indicating where a user should cut or lines of weakness such as perforations.

As mentioned, the cassette may hold an image receiving medium or an ink ribbon. In some embodiments, the cassette may house an image receiving medium and an ink ribbon.

Some cassettes may be used with a thermal label printer where an image is generated by the activation of a thermal print head against the ink ribbon such that ink from the ink ribbon is transferred onto the image receiving medium at a print zone.

It should be appreciated that in some embodiments of the present invention, where the cassette just houses an image receiving medium, that image receiving medium may be in the form of a direct thermal image receiving medium. A direct thermal image receiving medium is such that an image can be created directly onto or within the direct thermal image receiving medium by a thermal print head, without the requirement of an ink ribbon.

It should be appreciated that in an alternative embodiment, the cassette may only house an image receiving medium. An ink ribbon may be housed in a separate cassette.

Alternative embodiments of the invention may have different image receiving medium structures. For example a protective layer may in some embodiments be applied to the printed surface after printing. In other embodiments of the invention, a protective layer may be provided on the image receiving surface and printing occurs through the protective layer. In yet another embodiment, an image is applied to a surface of an image receiving medium and then the image receiving medium is adhered to the backing layer, with the printed image being on the side of the image receiving medium being adhered to the backing layer. In some embodiments, there may be not backing layer. These embodiments may have a layer of adhesive. In alternative embodiments, there may not be any adhesive. These are just some examples of the possible structure of the image receiving medium and other structures are of course possible.

In some embodiments of the invention, a particular label printer may be arranged to receive a range of different cassettes housing different image receiving mediums and/or ink ribbons. The printing media may be different in type and/or width. The cassettes may differ in their thickness depending on the size of the printing media accommodated therein.

Mention has been made of the use of a thermal print head. It should be appreciated that alternative embodiments may use different printing technologies such as ink jet or any other suitable printing technique. Some cassettes and label printers embodying the present invention will now be described with reference to the accompanying Figures.

Referring first particularly to Figure 1 , the cassette 2 has a housing 4. The housing 4 is arranged to contain a supply of image receiving medium 6 and an ink ribbon 8. The ink ribbon 8 is provided on an ink ribbon supply spool 12 and is, when used, taken up by the ink ribbon take-up spool 10. The image receiving medium 6 and ink ribbon 8 are arranged to pass in overlap past a print head 22 which acts against a rotatable platen 24. The print head 22 and platen 24 can be seen from Figure 6.

In this embodiment, the print head 22 is fixed in position and the moveable platen 24 is able not only to rotate about its axis but also to move between a non-printing position in which the platen is spaced apart from the print head and a printing position in which the platen 24 acts against the print head 22. It should be appreciated that in alternative embodiments of the present invention, the platen may be fixed into position, for example only able to rotate about its axis and the print head moves between the printing and non-printing positions. In a further alternative embodiment, both the print head 22 and the platen 24 may be arranged to be moved one towards the other so as to, for example move from a non-printing position to a printing position.

The print head 22 is arranged, when the cassette is in the cassette receiving bay to be accommodated in a print area 16 defined in the cassette. This print area can be seen from Figures 1 and 2. The print head 22 is arranged to be accommodated in the print area 16 with the image receiving medium 6 and ink ribbon 8 passing in overlap between the print head 22 and the platen 24. A print zone is thus provided between the print head 22 and the platen 24.

The ink ribbon 8 is taken from the ink ribbon supply spool 12 and after passing through the print zone is taken up by the ink ribbon take-up spool 10. As can be seen from Figure 2, the housing of the cassette has a first opening 20 aligned with the ink ribbon supply spool. This first opening is provided on the underside of the cassette and is arranged to receive a first member 25 provided in the cassette receiving bay. The underside of the cassette has a second opening 18 aligned with the ink ribbon take up spool 10. This second opening 18 is arranged to receive a second member 26 provided in the cassette receiving bay. These first and second members 25 and 26 engage the ink ribbon supply spool 12 and the ink ribbon take-up spool 10. One or both of the engagement members 25 and 26 may be driven so as to be able to drive the ink ribbon 8 forwards and/or in the reverse direction.

A cover 28 is provided on a cover side 30 of the cassette 2. The cover side 30 is one of the four sides which extend between an upper surface 31 and a lower surface 29. These four sides are parallel to the axes defined by the first and second members and the axis about which an image receiving medium supply 104 and the ink ribbon supply 12 rotate. The cover side 30 is the side which has an opening 33 through which the image receiving medium 6 and the ink ribbon 8 exits the cassette 2. The cover side 30 is the side which generally defines the print zone and which defines (with the cover 28) an exit 35 of the cassette. The cover 28 is arranged to move along the plane of side 30 between a closed position, which is shown in Figure 2 and an open position which is shown in Figure 11. The cover is thus arranged to move in the plane of side 30, in the direction of arrow B. The cover 28 is arranged to move back and forth along the length direction of the side 30.

When cover 28 is in the closed position, the image receiving medium 6 and ink ribbon 8 adjacent to the print area 16 are covered and hence protected from the exposure to foreign matter. When the cover 28 is open, as shown in Figure 11 , the image receiving medium 6 and ink ribbon 8 are exposed so that the platen 24 can contact the image receiving medium 6, when acting against the print head 22 and printing can be performed.

The movement of the cover 28 will now be described in more detail. Reference is made to Figure 3 which shows part of the cassette 2 of Figure 1 in greater detail. The cover 30 has an opening 32. The opening 32 is arranged, when the cover 28 is in the closed position to engage a locking projection 34 of the cassette 2. The projection 34 engages, that is received in, the opening 32 in the cover 28 and thus prevents the cover 28 from being opened when the cassette 2 is outside the label printer. The projection may also engage step 36 of cover 28 when received in opening 32.

The projection 34 is provided on a generally planar member 38 which extends generally parallel to the cover side 30. This member 38 is made of a resilient material such that it is normally biased to the position shown in Figure 3. Alternatively or additionally the member 38 itself maybe supported or mounted such that the projection 34 is biased to the position shown in Figure 3. In this scenario, the member 38 may be relatively rigid. Alternatively or additionally, the projection 34 itself may be of a resilient material.

The member 38 is supported at one end 101 at the end of the cover side 30 remote from the cassette exit 35. The member 38 is arranged to also provide an image receiving medium clamping function. The member 38, at the end 100 which is opposite the supported end 101 , is arranged to press against a guide post 102. The image receiving medium is drawn from the tape supply 104 and passes between the end 100 of the member 38 and the guide post 102, when no clamping of the image receiving medium 6 is provided. This is shown in an enlarged view in Figure 20b. When the member 38 provides a clamping force, the image receiving medium 6 is clamped between the member 38 and the guide post 102. This is shown in the enlarged view in Figure 20a.

The member 38 is thus arranged to have a first clamping mode and a second clamping mode. In the first clamping mode of Figure 20a, the member 38 is arranged to press against the guide post 102 to clamp the image receiving medium 6 between the end 100 of the member 38 and the guide post 102. In the second clamping mode of Figure 20b, the member 38 still contacts the image receiving medium 6 but the force, if any, applied by the member 38 is reduced so that the image receiving medium 6 can be drawn from the supply 104. In the second clamping mode the member 38 and the guide post 102 provide a guiding function for the image receiving medium 6 as the image receiving medium 6 is drawn from the supply 104.

In an alternative embodiment, in the second clamping mode there is no contact between the member 38 and the image receiving medium 6 or a limited contact.

Reference is now made to Figure 14 which shows an exploded view of a cassette 2 embodying the present invention. The cassette 2 comprises a first part 202 and a second part 204. The first part 202 and the second 204 define the housing 4 of the cassette.

The cassette 2 is arranged to house the supply of image receiving medium 6. As can be seen, the image receiving medium 6 is provided on a spool 212. The spool 212 is arranged to spool engagement members 216 provided in the first part 202. Similar spool engagement members may be provided in the second part 204. These spool engagement members 216 are arranged to fit inside the spool 212 to position the spool 212 in the cassette 2. The spool engagement members 216 are positioned such that the image receiving medium spool 212 is held in place but the spool 212 is arranged to rotate about the spool engagement members 216. In an alternative embodiment the image receiving medium is not provided on a spool but wound on his own.

5 The cassette 2 is also provided with the cover 28. The member 38 has the first locking projection 34 which is arranged to engage the opening 32 of the cover 28 to hold the cover in the closed position. The cassette 2 also has an ink ribbon subassembly 214 which supports the ink ribbon take up spool 10 and the ink ribbon supply spool 12.

I O

Reference is now made to Figures 4, 5 and 6 which show parts of the label printer which are arranged to cause the unlocking of the cover member 28. In particular, Figure 6 shows a cassette receiving bay 40. On the side 42 of the cassette receiving bay 40 which faces the cover 28 is an unlocking

15 mechanism 50 for unlocking the cover 28. A perspective view of this mechanism is shown in Figure 4 whilst a cross-sectional view of this mechanism along line F-F is shown in Figure 5. The unlocking mechanism 50 has a sliding part 52 which is arranged to move with respect to a housing 60. The sliding part 52 is configured to move in the direction of arrow C. This 0 direction is parallel to the longitudinal length of the cover 28. The sliding part 52 moves in the same back and forth directions as the cover 28. The housing 60 is fixed in position in the tape printer and does not move.

The sliding part 52 has an opening 53 through which an unlock member 54 5 projects. When the unlocking mechanism 50 is in the cassette receiving bay 40, the unlock member 54 projects through the opening and extends into the cassette receiving bay. This unlock member 54 is arranged to control the unlocking of the cover 28 in the cassette 2. The unlock member 54 is biased to the position in which the unlock member 54 projects through the opening 0 53. This biasing may be achieved as a result of the material which comprises the unlock member 54 and/or as a result of the mounting of the unlock member 54. The unlock member 54 may be separate from a main body 55 of the sliding part 52. The unlock member 54 is arranged to be mounted on the main body 55 of the sliding part 52. The unlock member 54 may be of the same or different material to the main body 55.

The interaction of the cover 28 of the cassette 2 and the cassette receiving bay 40 of the label printer will now be described in more detail.

Reference is now made to Figure 7 which shows the unlocking mechanism 50 and in particular the unlock member 54 extending to the cassette receiving bay 40. Figure 7 shows the cassette receiving bay 40 before a cassette 2 is inserted in the cassette receiving bay 40. When inserting the cassette 2, the unlock member 54 deflects in the direction of arrow D that is so that it is no longer extending into the cassette receiving bay 40. The area behind the unlocking mechanism 50 of the label printer has an opening 57. This opening 57 is configured such that when the unlock member 54 is moved in the direction of arrow D, at least a part of the unlock member 54 can be accommodated in that opening 57. The sliding part 52 is in the initial position and the main body 55 of the sliding part has not moved. The unlock member 54 is such and /or is mounted so that the unlock member 54 is sufficiently flexible so that it can move in the direction of arrow D.

Reference is now made to Figure 8. This shows that the cassette 2 is being inserted into the cassette receiving bay 40 but has not been completely received. For example, the cassette 2 may be two thirds of the way in. The unlock member 54 is shown as having extended into the opening 57 of the label printer. This insertion of the cassette 2 moves the unlock member 54 out of the cassette receiving bay 40 so that the cassette 2 can be inserted in the cassette receiving bay 40. In contrast to the figure shown in Figure 7, the cassette is now partially shown.

Reference is now made to Figure 9, the cassette 2 is now completely received in the cassette receiving bay 40. The unlock member 54 has moved back to the position in which the unlock member 54 extends into the cassette receiving bay 40. However, because the cassette in now in the cassette receiving bay 40, the unlock member 54 is aligned with the opening 32 of the cover 28. The unlock member 54 is thus arranged to extend through the opening 32 to move locking projection 34 in a direction towards the inside of the cassette 2 and away from the cover 28. The locking projection 34 no longer engages the opening of the cover 32 and the cover 28 can now be moved. However, the unlock member 54 is now engaged with the cover 32 such that if the sliding part 52 is moved, the cover 28 will move with the sliding part 52.

It should be appreciated that at this point, the image receiving medium 6 is still clamped . A cover 80 of the cassette receiving bay 40 is still completely open in Figure 9.

Before starting to pull with unlock member 54 on the cover 28 in opening 32, it has to be ensured that unlock member 54 does not move into the opening 57. Therefore, the size of opening 32 in the cover 28 is such that the unlock member 54 can move first over such a distance that the unlock member 54 does not move into opening 57 before it interacts with the side of the opening 32 to pull on the cover 28. This ensures that the unlock member 54 does not move into opening 57 when it starts to pull on the cover 28.

Reference is made to Figure 12 which shows that the cover 28 of the cassette 2 is being moved towards the open position. The cover 28 is not completely in the open configuration. The tape is still clamped as longitudinal ribs 110 of the cover 28 are still interacting with projection 112 on member 38. The unlock member 54 is thus engaged with the opening 32 of the cover. Accordingly, when the sliding part 52 is moved in the direction of arrow E, the cover 28 of the cassette 2 is also moved in the direction of arrow E. This movement moves the cover 28 along the plane of the side 30, out of the cassette receiving bay 40 into the body of the label printer. The cover 28 is moved in the direction away from the print area of the cassette 2 and accordingly when in the open position a portion of the cassette cover 28 will be received inside the label printer, but outside the cassette receiving bay 40. It should be appreciated that the sliding part 52 is guided by the housing 60 which is sized to allow the sliding mechanism to move in the direction of arrow C. The housing 60 defines a pair of guide rails 62 which guide the movement of the sliding part 52. The sliding part has correspondingly shaped stepped parts 64 which engage the guide rails 62 such that the sliding part 52 is arranged to move in a defined path. Movement of the sliding part 52 may be mechanically controlled or may be controlled by a motor.

In one embodiment, the movement of the sliding part 52 is controlled by the cover 80 of the cassette receiving bay 40. As the cover 80 of the cassette receiving bay 40 closes, the sliding part 52 moves in the direction of arrow C.

In one embodiment, the sliding part 52 is mechanically coupled to the cover of the cassette receiving bay 80 so that when the cover of the cassette receiving bay 40 is closed, the cover 28 of the cassette 2 is open. Likewise when the cover of the cassette receiving bay 80 is open, the cover 28 of the cassette 2 is closed.

Alternatively or additionally the sliding part 52 may moves against the force of a spring 66 or other biasing member. The spring 66 is located inside the label printer and is not in the cassette receiving bay 40. In one embodiment, the spring 66 is located in label printer behind the sliding part 52 and the housing 60. The spring 66 is biased to urge the slider 52 to the position shown in Figure 6 which corresponds to the cover 28 of the cassette 2 being in the closed position. Accordingly, when the cover 80 of the cassette receiving bay 40 is opened, the cover 28 of the cassette 2 will be urged to the closed position by the sliding part 52, the sliding part 52 being moved by the biasing spring 66.

In an alternative embodiment of the present invention, movement of the cover 28 may be caused by a motor. The motor can be controlled that when the printer is ready for printing, the sliding member 52 is moved to the open position. In Figure 12, the cover 80 of the cassette receiving bay 40 is being moved towards the closed position but has not yet reached the completely closed position. At this point, the image receiving medium 6 is still being clamped between the end of the member 38 and the guide post 102, The inside of the cover 28 which can be seen from Figure 19 of the cassette 2 has a pair of guide surfaces 110 provided by a pair of ribs 111 extending along the part of the length of the cover 28. The guide surfaces 110 interact with a clamping projection 112 of the member 38. The clamping projection 112 may be provided at any suitable location and in the arrangement shown in the Figures, the clamping projection 1 12 is provided adjacent the locking projection 34, on the side of the locking projection 34 remote to the end 101 of the member 38. When the clamping projection 112 acts against the guide surface 110, the end 100 of the member 38 is pressed against the post 102 with sufficient force such that the image receiving medium 6 is clamped. As the cover 28 of the cassette 2 is moved from the open position to the almost completely closed position, the clamping projection 112 acts against the guide surface 111 to provide the clamping of the image receiving medium 6.

Reference is now made to Figure 10 which shows the arrangement when the cover of the cassette receiving bay 80 is completely closed and to Figure 20b which shows part of the cassette 2 with the clamp in an undamped position.

In one embodiment of the invention, the clamping of the image receiving medium 6 is only removed when the cover 80 of the cassette receiving bay 40 is completely closed. In Figure 10 and 20b, the clamping of the image receiving medium 6 has been removed. As can be seen from Figure 20b the clamping projection 112 has moved down a ramp surface 116 towards the cover 28 of the cassette 2 and away from image receiving medium supply

104. This has the function of allowing the clamping projection 112 to reduce the pressure applied by the end 100 of the resilient member 38 against the guide post 102 such that the image receiving medium 6 is no longer clamped and can be drawn from the supply 104.

As can be seen from Figure 19, the underside of the cover includes a rib 160 which defines the maximum distance that the cover 28 can be moved in the direction of opening. This rib 160 extends in the width direction of the cassette 2. Once the locking projection 34 is lifted out of opening 32 and the cover 28 is moved, the locking projection 34 is biasing on the inside of the cover 28. The rib 160 on the inside of the cover 28 interacts with the locking projection 34 when the cover 28 is in the maximum opened position, as can be seen from Figure 20b. The inside of the cover 28 also has the pair of parallel longitudinal guide rails 110 which guide the movement of the locking projection 34 to thereby guide the movement of the cover 28.

The movement of the cover 28 is also arranged to control a platen roller lock 400 as will be described with reference to Figures 15 to 18. The platen roller lock 400 is arranged to have a first end 402. The first end 402 is arranged to be actuated by the cover 28. When the cover 28 is in the closed position, the first end 402 of the platen roller lock 400 is in a position which causes the platen roller lock 400 to prevent the platen 24 from being moved towards the print head 22. The platen roller locking member 400 is mounted to pivot about a pivot point 404. The pivot point 404 is between the first end 402 and a second end 406 of the platen roller locking member 400.

Figure 15 shows the first end 402 in the position such that the platen roller is prevented from moving by the second end 406. The first end 402 is arranged to extend into the part of the label printer which receives the cover 28 when the cover 28 is in the open position.

Initially, as shown in Figure 18 and Figure 15, the second end 406 engages a stop 405 of a platen roller support 408. Because the second end 406 engages against the stop 405, the platen roller is prevented from moving towards the print head 22.

Reference is made to Figure 16 and 17 which show the cover 28 in the open position. As can be seen, the cover 28 has moved the first end 402 in the direction of arrow M, away from the space which accommodates the cover 28 when in the open position. When the cover 28 moves the first end 402 in the direction of arrow M, the second end 406 is moved in the direction of arrow N, that is in an opposite direction to arrow M, about the pivot point 404.

When the cover has moved the first end 402 in the direction of arrow M, the second end 406 is moved to the position as shown in Figures 16 and 17. The second end 406 is moved in the direction of arrow N out of contact with the stop 405 of the platen roller support 408. Accordingly, the platen 24 is then able to move towards the print head 22. Thus, as the cover 28 is opened the platen 24 can be moved towards the print head 22. When the cover 28 is closed or there is no cassette 2 present, the platen roller support 408 is prevented from moving by the stop 405.

The platen locking member 400 is biased to the position in which the platen roller support 400 is prevented from moving.

Reference is made to Figure 13 which shows basic circuitry for controlling the label printer. There is a microprocessor chip 300. In practice there may be more than one chip. This chip is shown diagrammatically as having read-only memory 302, a processing part 301 , random access memory capacity indicated diagrammatically by RAM 304 and an external memory 330. However, this is by way of example and different memory and processing arrangements may be used in alternative embodiments. The microprocessor chip or chips are arranged to receive label data from a data input device such as a keyboard. Alternatively or additionally, the data input device may comprise a touch screen and/or a data port (e.g. a USB port) arranged to receive data from a PC or the like.

The microprocessor chip or chips 300 are arranged to output data to drive a display 310 via a display driver 309. That display may display a label to be printed (or a part thereof) and/or a message for the user. This display may for example be a LCD display or a touch screen. The display driving capacity may be provided as part of the microprocessor chip or chips. The microprocessor chip or chips are also arranged to output data to drive the print head 22 so that label data is printed onto the image receiving medium 6 to form a label.

The microprocessor chip or chips 300 may also control a motor 307 for driving the image receiving medium 6.

Finally, the microprocessor chip or chips 300 may also control a cutting mechanism 358 to allow a length of tape to be cut off. In alternative embodiments of the present invention, a manual cutter may alternatively be provided.

In one embodiment of the present invention, the label printer is a stand-alone printer. This stand-alone printer may operate independently or may be connected to receive data from a PC. In alternative embodiments of the present invention, the label printer may be a PC printer and as such, the keyboard and display may be omitted as the data may be input and displayed on the PC. The PC then acts as an input device for the printer.

The present invention may include any feature or combination of features disclosed herein either implicitly or explicitly or any generalisation thereof without limitation to the scope of any of the present claims. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention as defined by the claims.

Claims

1. A label printer cassette comprising: at least one supply of printing medium; a housing in which said image receiving medium is received; a cover which is arranged in use to move between first and second positions; and a clamping member for clamping said printing medium, said clamping member arranged to have a first mode in which said printing medium is clamped and a second mode in which said printing medium can be drawn from said supply, wherein the mode of the clamping member is controlled by the cover.

2. A cassette as claimed in claim 1 , wherein the cover is arranged such that when the cover is in the first position, the cover is configured to cover said printing medium at a printing location of said cassette.

3. A cassette as claimed in claim 1 or 2, wherein said cover is arranged such that when the cover is in the second position, the cover is configured to expose the printing medium at a printing location of said cassette.

4. A cassette as claimed in any preceding claim, wherein said clamping member is in the first mode when the cover is in the first position and in the second mode when the cover is in the second position.

5. A cassette as claimed in claim 4, wherein said clamping member is in the first mode when the cover is moved from the first position to the second position.

6. A cassette as claimed in any preceding claim, wherein said cassette has a part with which said clamping member cooperates.

7. A cassette as claimed in claim 6, wherein said printing medium is configured to pass between the clamping member and said part.

8. A cassette as claimed in claim 6 or 7, wherein said part is fixed.

9. A cassette as claimed in any of claims 6 to 8, wherein said part comprises a post.

10. A cassette as claimed in any of claims 6 to 9, wherein said clamping member in configured in the first mode, to act against the part such that said printing medium is clamped and in the second mode, the clamping member is configured to allow the printing medium to be drawn between the clamping member and the part.

11. A cassette as claimed in any preceding claim, wherein said clamping member is configured to have a first position in the first mode and a second different position in the second mode.

12. A cassette as claimed in any preceding claim, wherein said clamping member comprises a resilient member.

13. A cassette as claimed in any preceding claim, wherein said clamping member is biased to have the first mode.

14. A cassette as claimed in any preceding claim, wherein said cover has a control surface which causes the clamping member to be in the first position.

15. A cassette as claimed in claim 14, wherein when the cover is in the second position, the control surface is not in contact with said clamping member.

16. A cassette as claimed in any preceding claim wherein said at least one supply of printing medium comprises at least one of an image receiving medium and an ink ribbon.

17. A cassette as claimed in claims 14 or 15, wherein when the control surface is the surface of at least one rib on an inside of the cover.

18. A cassette as claimed in claims 17, wherein when the control surface is the surface of two ribs on the inside of an cover.

19. A label printer in combination with a cassette as claimed in any preceding claim.

20. A label printer comprising: a cassette receiving bay for receiving a cassette; a print head and platen at least partially provided in said cassette receiving bay; and a cassette cover operation mechanism arranged at least partially in said cassette receiving bay for engaging and moving a cover of a cassette, when said cassette is in said cassette receiving bay.