CN114871160A

CN114871160A - Tape box

Info

Publication number: CN114871160A
Application number: CN202110167408.8A
Authority: CN
Inventors: 丁建文
Original assignee: AVE Science and Technology Co Ltd
Current assignee: AVE Science and Technology Co Ltd
Priority date: 2021-02-05
Filing date: 2021-02-05
Publication date: 2022-08-09

Abstract

The present invention relates to a tape cassette comprising: a housing provided with an accommodating cavity; the first winding piece and the second winding piece are at least partially arranged in the accommodating cavity; a wiping tape, one end of which is connected to the first winding member and the other end of which is connected to the second winding member, the wiping tape being moved relative to the housing by means of the first winding member and the second winding member; and the positioning block is arranged on the shell, the shell is also provided with a first opening communicated with the accommodating cavity, and the wiping belt passes through the first opening and abuts against the positioning block when being wound on the second winding piece from the first winding piece. According to the tape box, when the push piece of the push piece mechanism needs to be cleaned, the push piece is contacted with the wiping belt, and under the action force exerted on the wiping belt by the push piece, the wiping belt is clamped and positioned between the positioning block and the push piece, so that the friction force between the push piece and the wiping belt is increased, and under the condition that the friction force between the push piece and the wiping belt is increased, the cleaning effect on the push piece of the push piece mechanism is improved.

Description

Tape box

Technical Field

The invention relates to the technical field of medical equipment, in particular to a tape box.

Background

When observing a tiny object, the tiny object is often required to be made into a microscope slide specimen so as to be observed under a microscope. The microscopic slide specimen comprises a section, a loading piece and a smear, wherein the smear is a specimen which is prepared by uniformly smearing a liquid specimen (such as blood, marrow fluid and the like) collected from an organism on a glass slide, and is widely applied to the medical field.

For example, when examining a patient, it is sometimes necessary to test the blood of the patient. In this case, blood should be uniformly smeared on a slide glass to prepare a blood smear, and the prepared blood smear should be observed under a microscope. In order to avoid contamination of the sample by manual operation, a slide pushing mechanism is often used to push the drop of blood flat and uniformly smear the blood on the slide glass.

In order to avoid cross infection, after the push piece mechanism pushes blood once, the push piece of the push piece mechanism needs to be cleaned, and the cleaning effect of the traditional cleaning mechanism is poor.

Disclosure of Invention

Accordingly, it is necessary to provide a tape cartridge with a better cleaning effect in order to solve the problem of poor cleaning effect of the conventional cleaning mechanism.

A cartridge, said cartridge comprising:

a housing provided with an accommodating cavity;

the first winding piece and the second winding piece are at least partially arranged in the accommodating cavity;

a wiping tape having one end connected to the first winding member and the other end connected to the second winding member, the wiping tape being moved relative to the housing by means of the first winding member and the second winding member; and

the positioning block is arranged on the shell, a first opening communicated with the accommodating cavity is further formed in the shell, and the wiping belt passes through the first opening and abuts against the positioning block when being wound on the second winding piece from the first winding piece.

According to the tape box, when the push piece of the push piece mechanism needs to be cleaned, the push piece is contacted with the wiping belt, and under the action force exerted on the wiping belt by the push piece, the wiping belt is clamped and positioned between the positioning block and the push piece, so that the friction force between the push piece and the wiping belt is increased, and under the condition that the friction force between the push piece and the wiping belt is increased, the cleaning effect on the push piece of the push piece mechanism is improved.

In one embodiment, the positioning block is pivotally connected to the housing, and the positioning block can swing relative to the housing.

In one embodiment, the housing further includes a limiting member for limiting a swing position of the positioning block relative to the housing, the limiting member is disposed on the housing, the limiting member includes a first sub-limiting member and a second sub-limiting member, and the first sub-limiting member and the second sub-limiting member are respectively located at two sides of the positioning block in a swing direction of the positioning block relative to the housing.

In one embodiment, the first sub-limiting member is a torsion spring, the torsion spring includes a body and a first end and a second end respectively connected to the body, the body is connected to the housing, the first end abuts against the housing, and the second end abuts against the positioning block;

the second sub-limiting part is a protrusion convexly arranged on the shell.

In one embodiment, the positioning block has a right angle portion for abutting against the wiping strip.

In one embodiment, an elastic member is arranged on the positioning block and used for abutting against the wiping strip.

In one embodiment, the tape cassette further includes a first tape guide and a second tape guide, the first tape guide and the second tape guide being located upstream and downstream of the positioning block, respectively, in a moving direction of the wiping tape with respect to the housing.

In one embodiment, the first and second tape guides are each disposed adjacent to the first opening.

In one embodiment, the housing further has a second opening communicating with the accommodating cavity, and the tape cassette further includes a third tape guide provided on the housing, wherein the wiping tape passes through the second opening and abuts against the third tape guide when the first winding member is wound around the second winding member.

In one embodiment, the cross-sectional shape of the housing is a rectangle, and the first opening is disposed at a right-angle vertex of the rectangle.

Drawings

Fig. 1 is a structural view of a tape cassette according to an embodiment of the present invention;

fig. 2 is a structural view of the tape cassette shown in fig. 1 when the wiping tape abuts against the push piece;

fig. 3 is an isometric view of the cartridge shown in fig. 1 from a perspective;

fig. 4 is an isometric view of the cartridge of fig. 1 from another perspective;

fig. 5 is an isometric view of a positioning block and a resilient member of the cartridge shown in fig. 1;

fig. 6 is a structural view of a partial structure of the tape cassette shown in fig. 1.

100. A tape cassette; 10. a housing; 11. a first opening; 12. a second opening; 13. an observation window; 14. pressing and holding the opening; 15. a first half shell; 16. a second half shell; 20. a first winding member; 21. a first mounting hole; 30. a second winding member; 31. a second mounting hole; 40. wiping the tape; 41. a wiping section; 50. positioning blocks; 51. a right angle portion; 60. tabletting; 71. a first sub-limiting member; 72. a second sub-limiting member; 81. a first tape guide; 82. a second tape guide; 83. a third tape guide; 90. an elastic member; 91. a first abutment plane; 92. a second abutment plane; 110. a first shaft; 120. a second shaft; 200. and (7) pushing the sheet.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Fig. 1 is a view showing a structure of a tape cassette according to an embodiment of the present invention; fig. 2 is a view showing a structure in which the wiping tape of the tape cassette shown in fig. 1 abuts against the push piece.

Referring to fig. 1, an embodiment of the present invention provides a tape cartridge 100, and the tape cartridge 100 is capable of cleaning a blade 200 (see fig. 2) of a blade pushing mechanism. To facilitate understanding of the present invention, a blade pushing mechanism will first be briefly described, which generally includes a mounting base and a blade 200, the blade 200 being mounted to the mounting base, the blade 200 having a blade pushing position and a cleaning position relative to the mounting base. In the slide pushing position, the push piece 200 can contact with the slide, and when the push piece 200 and the slide generate relative motion, the push piece 200 can push flat the liquid (such as blood) in a drop shape to make a slide specimen; in the cleaning position, the push plate 200 can be in contact with the tape cassette 100, and the tape cassette 100 can clean the push plate 200 of the push plate mechanism.

With continued reference to fig. 1, the tape cartridge 100 includes a housing 10, a first winding member 20, and a second winding member 30, the housing 10 defining a receiving cavity, and at least a portion of the first winding member 20 and the second winding member 30 being disposed in the receiving cavity. The tape cartridge 100 further includes a wiping tape 40, one end of the wiping tape 40 is connected to the first winding member 20, and the other end of the wiping tape 40 is connected to the second winding member 20, and the wiping tape 40 is movable relative to the case 10 by means of the first winding member 20 and the second winding member 30.

The tape cartridge 100 further includes a positioning block 50, the positioning block 50 is disposed on the housing 10, the housing 10 is further provided with a first opening 11 communicating with the accommodating cavity, and the wiping tape 40 passes through the first opening 11 and abuts against the positioning block 50 when being wound 20 from the first winding member to the second winding member 30.

In the tape cartridge 100 of the present embodiment, when the push piece 200 of the push piece mechanism needs to be cleaned, the push piece 200 contacts the wiping tape 40, and the wiping tape 40 is clamped and positioned between the positioning block 50 and the push piece 200 under the action force applied to the wiping tape 40 by the push piece 200, so that the friction force between the push piece 200 and the wiping tape 40 is increased, and the cleaning effect on the push piece 200 of the push piece mechanism is improved under the condition that the friction force between the push piece 200 and the wiping tape 40 is increased.

Here, the wiping tape 40 passes through the first opening 11 and abuts against the positioning block 50 when being wound around the second winding member 30 from the first winding member 20, and includes the following cases:

referring to fig. 1, in one embodiment, the wiping tape 40 is wound around the first winding member 20 and is wound around the second winding member 30, passes through the first opening 11, and out of the accommodating cavity to abut against the positioning block 50, and is re-inserted into the accommodating cavity from the first opening 11. In another embodiment, the wiping strip 40 is wound from the first winding element 20 onto the second winding element 30 through the first opening 11 out of the receiving cavity and into abutment with the positioning block 50, and is re-threaded from the other opening into the receiving cavity. In yet another embodiment, the wiping strip 40 is threaded from the first winding member 20 around the second winding member 30 through the other opening out of the receiving cavity into abutment with the positioning block 50 and threaded back into the receiving cavity from the first opening.

Here, the fact that the wiping tape 40 is wound around the second winding element 30 from the first winding element 20 and is passed out of the accommodating chamber through the first opening 11 to be in contact with the positioning block 50 means that: the wiping tape 40 abuts against a portion of the positioning block 50 so that the wiping tape 40 is sandwiched and positioned between the positioning block 50 and the push piece 200 when the push piece 200 is cleaned.

With continued reference to fig. 2, in one embodiment, the tape cartridge 100 is capable of reciprocating in the width direction of the wiping tape 40 while wiping the push piece 200, so that the wiping tape 40 wipes the push piece 200. It should be understood that in other embodiments, the tape cartridge 100 may also reciprocate in other directions to wipe the blade 200, and is not limited herein.

In one embodiment, the housing 10 is a hollow rectangular parallelepiped structure, that is, the cross-sectional shape of the housing 10 is a rectangle, the first winding element 20 and the second winding element 30 are both in a flat disk shape, the axial directions of the first winding element 20 and the second winding element 30 are parallel to the thickness direction of the housing 10, and the first winding element 20 and the second winding element 30 are arranged in the housing 10 side by side.

Fig. 3 shows an isometric view of the tape cassette shown in fig. 1 from a perspective; fig. 4 shows an isometric view from another perspective of the tape cassette shown in fig. 1; fig. 5 is an isometric view of the positioning block and the resilient member of the cartridge shown in fig. 1; fig. 6 is a structural view showing a partial structure of the tape cassette shown in fig. 1.

Referring to fig. 3 and 4, in particular, the housing 10 includes a first housing half 15 and a second housing half 16, which are separately disposed, and the first housing half 15 and the second housing half 16 are spliced to form the housing 10. So configured, assembly of the first winding member 20, the second winding member 30 and the wiping tape 40 is facilitated.

In an embodiment, all of the first winding element 20 and the second winding element 30 are disposed in the accommodating cavity, the first winding element 20 is provided with a first mounting hole 21, the second winding element 30 is provided with a second mounting hole 31, a first through hole is disposed at a position of the housing 10 corresponding to the first mounting hole 21, and a second through hole is disposed at a position corresponding to the second mounting hole 31. So set up, be convenient for external drive mechanism locate in first mounting hole 21 from first through-hole, locate in second mounting hole 31 from the second through-hole to drive and wipe area 40 and rotate for casing 10. It should be understood that in other embodiments, portions of the first winding element 20 and the second winding element 30 may be disposed in the accommodating cavity, and the remaining portion of the first winding element 20 passes through the first through hole, and the remaining portion of the second winding element 30 passes through the second through hole to be connected to an external driving mechanism, so as to drive the wiping strip 40 to rotate relative to the housing 10.

Further, during the movement of the wiping tape 40 relative to the housing 10, one of the first winding member 20 and the second winding member 30 for winding up the wiping tape 40 serves as a driving member, and the other serves as a driven member by the pulling action of the wiping tape 40.

If external drive mechanism can include driving motor and driven shaft, driving motor includes main part and driving shaft, and the driving shaft passes first perforation and locates in first mounting hole 21, and the driven shaft passes the second perforation and locates in second mounting hole 31, and driving motor's main part makes the driving shaft drive first coiling member 20 and does the coiling action, and second coiling member 30 releases under the effect of dragging of wiping area 40 and wipes area 40 this moment. That is, at this time, the first winding member 20 serves as a driving member, and the second winding member 30 serves as a driven member.

In another embodiment, the second winding member 30 can be connected to a driving motor, and the driving motor drives the second winding member 30 to wind the wiping strip 40, and the first winding member 20 releases the wiping strip 40 under the pulling action of the wiping strip 40. That is, at this time, the second winding member 30 serves as a driving member, and the second winding member 30 serves as a driven member.

Specifically, a plurality of wiping portions 41 (see fig. 2) are formed on the wiping belt 40, and the wiping belt 40 can be moved relative to the housing 10 by the first winding member 20 and the second winding member 30, so that the plurality of wiping portions 41 can alternatively abut against the positioning block 50, i.e., one wiping portion 41 is replaced for each wiping of the push plate 200, thereby avoiding cross infection.

Further, the wiping part 41 can carry cleaning media, the cleaning media are injected onto the wiping part 41, and the cleaning media dissolve the liquid adhered to the push sheet 200, so that the cleaning effect of the push sheet 200 of the push sheet mechanism is further improved. Of course, in other embodiments, the cleaning medium may be directly injected onto the push-piece 200, the cleaning medium dissolves the liquid adhered to the push-piece 200, and the wiping portion 41 only has a wiping effect.

The type of the cleaning medium is not limited, and the cleaning medium may be a solution capable of dissolving blood when the liquid on the slide 200 is blood pressure.

With continued reference to fig. 3, the cartridge 100 further includes a resilient tab 60, the tab 60 bearing against the follower to prevent the follower from spinning, causing the wiping strip 40 to be automatically released from the follower. In one embodiment, when all of the driven member is accommodated in the accommodating cavity, the housing 10 is further provided with a pressing port 14 communicating with the accommodating cavity, and the pressing sheet 60 is pressed and held on the driven member through the pressing port 14.

In an embodiment, the first opening 11 is opened at a right-angled vertex of the housing 10, the positioning block 50 is disposed at the same right-angled vertex of the housing 10, a right-angled portion 51 (see fig. 5) is formed on the positioning block 50, and the wiping portion 41 can be bent under the action force applied by the push-piece 200 and abut against the right-angled portion 51, so as to position the wiping portion 41 and the push-piece 200, thereby further facilitating the wiping of the push-piece 200.

With continued reference to fig. 1 and fig. 6, in an embodiment, the positioning block 50 is pivotally connected to the housing 10, and the positioning block 50 can swing relative to the housing 10. Specifically, the positioning block 50 is pivotally connected to the housing 10 by a first shaft 110, and a rotation axis of the positioning block 50 relative to the housing 10 is parallel to rotation axes of the first winding element 20 and the second winding element 30. With reference to fig. 1, the tape cartridge 100 further includes a limiting member (not shown) for limiting a swing position of the positioning block 50 relative to the housing 10, the limiting member includes a first sub-limiting member 71 and a second sub-limiting member 72, and the first sub-limiting member 71 and the second sub-limiting member 72 are respectively disposed on two sides of the positioning block 50 in a swing direction of the positioning block 50 relative to the housing 10. With this arrangement, when the pushing piece 200 applies an acting force to the wiping portion 41, since the positioning block 50 can rotate relative to the housing 10, the pushing piece 200 can push the wiping portion 41 to abut against the right-angled portion 51, so that the wiping portion 41 can be positioned conveniently, and the self-adaptive capacity of the positioning block 50 is improved.

The first sub-limiting member 71 and/or the second sub-limiting member 72 have elasticity. When the first sub-limiting member 71 and/or the second sub-limiting member 72 have elasticity, the positioning block 50 can automatically return under the action of the elastic restoring force when the pushing sheet 200 releases the positioning block 50.

The first sub-limiting member 71 has elasticity, and specifically, the first sub-limiting member 71 is a torsion spring, which includes a body and a first end and a second end respectively connected to the body, and the body is connected to the housing 10. More specifically, the body is sleeved on a second shaft 120 protruding from the housing 10, and the first end abuts against the housing 10 and the second end abuts against the positioning block 50. Thus, when the pushing piece 200 applies an acting force to the wiping strip 40, the positioning block 50 swings relative to the housing 10 under the driving of the wiping strip 40, and the positioning block 50 causes the torsion spring to elastically deform, so that the position of the positioning block 50 relative to the housing 10 is finely adjusted, the pushing piece 200 is abutted against the wiping part 41 and the straight corner part 51, the wiping part 41 is conveniently positioned, and the self-adaptive capacity of the positioning block 50 is improved.

The second sub-limiting member 72 is a protrusion protruding from the housing 10 to cooperate with the first sub-limiting member 71 to limit the position of the positioning block 50 relative to the housing 10. Specifically, the second sub-limiting member 72 is disposed on the second half-shell 16 in a protruding manner.

Referring to fig. 5, in an embodiment, the positioning block 50 is provided with an elastic member 90, and the elastic member 90 is used for abutting against the wiping strip 40. Further, the elastic member 90 has a first abutting surface 91 and a second abutting surface 92 located on both sides of the right angle portion 51, respectively, and the wiping tape 40 abuts both the first abutting surface 91 and the second abutting surface 92. With such an arrangement, when the push plate 200 needs to be cleaned, the elastic member 90 is elastically deformed to apply an elastic restoring force to the push plate 200, so that the wiping belt 40 is more tightly clamped between the positioning block 50 and the push plate 200, thereby increasing the friction force between the push plate 200 and the wiping portion 41 and improving the wiping effect.

Specifically, the elastic member 90 is made of a rubber material, and the elastic member 90 is integrally formed with the positioning block 50. It should be understood that in other embodiments, the elastic member 90 is not limited to being made of rubber, and the elastic member 90 may be provided separately from the positioning block 50.

Referring to fig. 1, 4 and 6, in an embodiment, the tape cassette 100 further includes a first tape guide 81 and a second tape guide 82, and the first tape guide 81 and the second tape guide 82 are respectively located upstream and downstream of the positioning block 50 in a moving direction of the wiping tape 40 relative to the housing 10. With this arrangement, when the wiping tape 40 enters and exits the first opening 11, the first tape guide 81 and the second tape guide 82 can restrict the angle of the wiping tape 40 and facilitate tensioning of the wiping tape 40. Specifically, the first tape guide 81 and the second tape guide 82 are both disposed adjacent to the first opening 11.

In one embodiment, the housing 10 further has a second opening 12 communicating with the receiving cavity, the tape cartridge 100 further includes a third tape guide 83, the third tape guide 83 is disposed on the housing 10, and the wiping tape 40 passes through the second opening 12 and abuts against the third tape guide 83 when the first winding member 20 is wound on the second winding member 30. In this way, the third tape guide 83 can not only function as a support for the wiping tape 40 in cooperation with the first tape guide 81 and the second tape guide 82; meanwhile, the third tape guide 83 can be engaged with an external counting wheel so that the wiping tape 40 is held between the counting tape guide 80 and the counting wheel, and when the wiping tape 40 rotates relative to the housing 10, the counting wheel rotates by a frictional force applied thereto by the wiping tape 40, thereby depending on the number of rotations thereof or the length of movement of the wiping tape 40.

In one embodiment, the third guiding component 83 and the positioning block 50 are respectively disposed at two right-angle vertices of the housing 10 in the length direction of the housing 10. Of course, in other embodiments, the arrangement position of the counting tape guide 80 and the positioning block 50 is not limited.

With continued reference to fig. 1, in particular, the housing 10 is provided with an observation window 13, and the amount of the wiping tape 40 wound on the first winding member 20 and the second winding member 30 can be observed through the observation window 13. It should be understood that in other embodiments, the entire housing 10 may be made of transparent material to facilitate observing the amount of the wiping tape 40 wound on the first winding member 20 and the second winding member 30.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A tape cassette, characterized in that the tape cassette comprises:

a housing provided with an accommodating cavity;

2. The cartridge of claim 1, wherein the positioning block is pivotally coupled to the housing, the positioning block being pivotable relative to the housing.

3. The cartridge as claimed in claim 2, wherein the housing further includes a limiting member for limiting a swing position of the positioning block relative to the housing, the limiting member being disposed on the housing, the limiting member including a first sub-limiting member and a second sub-limiting member, the first sub-limiting member and the second sub-limiting member being respectively located at two sides of the positioning block in a swing direction of the positioning block relative to the housing.

4. The cartridge of claim 3, wherein the first sub-stop is a torsion spring including a body and first and second ends respectively connected to the body, the body being connected to the housing, the first end abutting the housing, the second end abutting the positioning block;

the second sub-limiting part is a protrusion convexly arranged on the shell.

5. The cartridge of claim 1, wherein the positioning block has a right angle portion for abutting the wiping tape.

6. The cartridge as claimed in claim 1, wherein an elastic member is provided on the positioning block, the elastic member being adapted to abut against the wiping tape.

7. The cartridge of claim 1, further comprising a first tape guide and a second tape guide, the first tape guide and the second tape guide being located upstream and downstream of the positioning block, respectively, in a direction of movement of the wiping tape relative to the housing.

8. The cartridge of claim 7, wherein the first and second tape guides are each disposed adjacent to the first opening.

9. The tape cassette according to claim 1, wherein a second opening communicating with the housing chamber is further provided in the housing, the tape cassette further comprises a third tape guide provided in the housing, and the wiping tape passes through the second opening and abuts on the third tape guide when the first winding member is wound around the second winding member.

10. The cartridge of claim 1, wherein the housing has a rectangular cross-sectional shape, and the first opening is disposed at a right-angled vertex of the rectangle.