Coffee machine with basket size detection

Abstract

A coffee machine (100) for preparing a coffee beverage from ground coffee (10), the coffee machine (100) including: a controller (102) for controlling operation of the coffee machine (100), including the preparation of the coffee beverage according to a set of brewing parameters; a basket (110) for holding the ground coffee (10); a holder (120) for holding the basket (110) in a basket position (130); a transmitter (140) of an electromagnetic (EM) signal aimed at the basket position (130); a receiver (150) adapted to receive the EM signal when reflected by the basket (110) being in the basket position (130) and providing a basket signal to the controller (102) based on the reception of the EM signal.

Description

COFFEE MACHINE WITH BASKET SIZE DETECTIONRELATED APPLICATIONS

[0001] The present application claims convention priority from Australian Provisional Patent Application No. 2024901571, the contents of which are incorporated herein in their entirety by reference thereto.FIELD

[0002] The present invention relates to a coffee machine. In particular, the invention relates to coffee machine capable of detecting a size of a basket used with the coffee machine.BACKGROUND

[0003] Coffee machines are typically configured in some way to allow the production of coffee in different quantities. Coffee extraction is highly sensitive to the geometry of the brewing vessel, also called a basket, due to the different flow rates caused by deep narrow baskets compared to shallow wide baskets. The flow rate is more dependent on the depth of coffee grounds in the basket than the total volume of coffee grounds in the basket.

[0004] Thus, it is common practice to provide differently sized baskets for the purpose of brewing different amounts of coffee, so that the depth of coffee grounds in the basket may be modulated, by making a cavity of the basket a different shape to distribute the same volume of grounds with a different total depth.

[0005] Most coffee machines change their brewing parameters when extracting coffee from different baskets, in order to provide generally similar coffee beverages whether extracted from a small or a large basket. Thus, for most coffee machines, user input is required to identify the basket size before a brewing operation. The user input may be imperfect, resulting in undesirable beverage outcomes. It would be desirable if the coffee machine were capable of detecting the size of the basket, so that the brewing parameters may be adjusted accordingly.SUMMARY

[0006] It is an object of the present invention to substantially overcome, or at least ameliorate, one or more of the disadvantages of existing arrangements, or at least provide a useful alternative to existing arrangements.

[0007] There is disclosed herein a coffee machine for preparing a coffee beverage from ground coffee, the coffee machine including: a controller for controlling operation of the coffee machine, including the preparation of the coffee beverage according to a set of brewing parameters; a basket for holding the ground coffee; a holder for holding the basket in a basket position; a transmitter of an electromagnetic (EM) signal aimed at the basket position; a receiver adapted to receive the EM signal when reflected by the basket being in the basket position and providing a basket signal to the controller based on the reception of the EM signal.

[0008] Preferably, the basket has one of a variety of basket shapes; wherein the basket signal is processable by the controller to determine the basket shape of the basket in the basket position.

[0009] Preferably, the controller adjusts the set of brewing parameters based on the basket shape of the basket in the basket position.

[0010] Preferably, the basket has a rotational axis of symmetry and the transmitter is oriented at a non-parallel angle to the rotational axis of symmetry.

[0011] Preferably, one of the basket shapes includes a side wall perpendicular to the nonparallel angle of the transmitter.

[0012] Preferably, the basket is moved along a basket path toward the basket position, wherein the transmitter and receiver have a functional range, and wherein the transmitter is located such that the side wall is within the functional range when the basket is moved along the basket path.

[0013] Preferably, the transmitter is located such that the side wall is not within the functional range when the basket is in the basket position.

[0014] Preferably, the transmitter and receiver are located on a single circuit board, and wherein the coffee machine further includes a circuit board holder to hold the circuit board.

[0015] Preferably, the circuit board holder includes a signal divider between the transmitter and receiver that is substantially opaque to the EM signal.

[0016] Preferably, the EM signal is an infrared signal and the signal divider, preferably the circuit board holder, has a black surface.

[0017] Preferably, the coffee machine further includes a portafilter for receiving the basket, and the portafilter is received by the holder; wherein the basket signal is indicative of the portafilter being received by the holder without the basket.

[0018] Preferably, the holder includes a microswitch actuated by the basket when the basket is in the basket position; wherein actuation of the microswitch causes the controller to poll the basket signal for a time period prior to actuation of the microswitch, wherein the processor determines a presence of the basket in the basket position based on a steady state of the basket signal close to actuation of the microswitch, and wherein the processor determines a type of the basket based on a peak deviation of the basket signal further in the past from actuation of the microswitch.

[0019] Preferably, the coffee machine includes a grinder for producing the ground coffee from coffee beans, and wherein the brewing parameters include a volume of ground coffee to produce.

[0020] Preferably, the actuation of the microswitch causes activation of the grinder to produce the volume of ground coffee.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a more complete understanding of the present invention, exemplary embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawing figures, in which like reference signs designate like parts and in which:

[0022] FIG. 1 is a perspective view of a coffee machine according to a preferred embodiment of the invention.

[0023] FIG. 2 is a side section view of the coffee machine of FIG. 1.

[0024] FIG. 3 is a schematic side section view of the coffee machine of FIG. 1 with a single size basket.

[0025] FIG. 4 is a schematic side section view of the coffee machine of FIG. 1 with a double size basket.

[0026] FIG. 5 is a schematic side section view of the coffee machine of FIG. 1 without a basket.

[0027] FIG. 6 is a schematic front section view of the coffee machine of FIG. 1 with the basket at the beginning of the basket path.

[0028] FIG. 7 is a schematic front section view of the coffee machine of FIG. 1 with the basket along the basket path.

[0029] FIG. 8 is a schematic front section view of the coffee machine of FIG. 1 with the basket in the basket position.

[0030] FIG. 9 is a trace of the basket signal used by the coffee machine of FIG. 1 with a single size basket moving to the basket position.

[0031] FIG. 10 is a trace of the basket signal used by the coffee machine of FIG. 1 with a single size basket moving in and out of the basket position.

[0032] FIG. 11 is a trace of the basket signal used by the coffee machine of FIG. 1 without a basket or with a double basket moving in and out of the basket position.

[0033] FIG. 12 is a chart showing an analysis of the basket signal of multiple beverage extractions by the coffee machine of FIG. 1.

[0034] FIG. 13 is a perspective view of a circuit board of the coffee machine of FIG. 1.

[0035] FIG. 14 is a detailed exploded perspective view of a circuit board holder of the coffee machine of FIG. 1.

[0036] FIG. 15 is a perspective view of the circuit board holder of FIG. 14.

[0037] FIG. 16 is a flow chart showing a method of interpreting the basket signal used by the coffee machine of FIG. 1.DETAILED DESCRIPTION

[0038] As shown in FIGS. 1 and 2, a preferred embodiment of a coffee machine 100 is used to prepare a coffee beverage (not shown) from ground coffee (not shown). The coffee machine 100 may include a grinder 200, fed by a hopper 202, to produce the ground coffee. The coffee machine 100 may include a basket 110 for holding the ground coffee. The basket 110 may take a variety of forms. In the preferred embodiment, which is an espresso coffee machine, the basket 110 may include a filter basket held by a portafilter 180. Water is pumped by a pump 220 from a water reservoir 210 at high pressure, preferably about 9 bar, through the ground coffee in the basket 110 to produce the coffee beverage. However, other embodiments are possible and do not affect the overall function and effect of the features disclosed herein. For example, the coffee machine 100 may be a pour over machine, wherein the basket 110 is a filter holder or indeed a filter, for holding the ground coffee through which water is moved in a largely unpressurised stream. The coffee machine 100 may be a drip filter machine, in which the basket 110 may be a filter or a filter holder. The coffee machine 100 may be a capsule coffee machine, in which the basket 110 is a coffee capsule that contains the ground coffee. The coffee machine 100 includes a controller 102 for controlling operation of the coffee machine 100, including the preparation of the coffee beverage according to a set of brewing parameters. The brewing parameters may include one or more of: a volume of coffee grounds to be produced by the grinder 200, for example by storing a time period for operating the grinder 200, an extraction pressure, an extraction volume, an extraction temperature, an extraction time, a pre-infusion pressure, a pre-infusion volume, a pre-infusion temperature, a pre-infusion time.

[0039] The basket 110 may have one of a variety of basket shapes, as shown in FIGS. 3 and 4.

[0040] The coffee machine 100 includes a holder 120 for holding the basket 110 in a basket position 130. The basket position 130 is a position in which the basket 110 is required to belocated in order for the coffee beverage to be successfully extracted from the ground coffee. In the preferred embodiment, the basket position 130 is a successful engagement of the portafilter 180 holding the basket 110 with a group head 230 of the coffee machine, which typically includes a bayonet fitting 232. However, the basket position 130 may also refer to a position required for the production of coffee grounds and their deposition in the basket 110. In the preferred embodiment, this may be an engaged position underneath a chute 204 of the grinder 200, which may include a bayonet fitting, or another means of indicating a desired physical position to the user inserting the portafilter 180.

[0041] As shown in FIG. 3, the coffee machine 100 includes a transmitter 140 of an electromagnetic (EM) signal aimed at the basket position 130. The transmitter 140 preferably emits the EM signal along a signal path 144. The coffee machine 100 correspondingly further includes a receiver 150 adapted to receive the EM signal. In particular, the EM signal is received by the receiver 150 when the signal is reflected by the basket 110 being in the basket position 130. The receiver 150 is adapted to provide a basket signal 190, shown for example in FIG. 9, to the controller 102. The basket signal 190 may be processable by the controller 102 to determine the basket shape of the basket 110 in the basket position 130. The controller 102 may adjust the set of brewing parameters based on the basket shape of the basket 110 in the basket position, as determined by the controller 102 based on the basket signal 190. The basket signal 190 may also be indicative of the portafilter 180 being received by the holder 120 without the basket 110 being installed in the portafilter 180, as shown in FIG. 5, referred to as “no basket”. The controller 102 may prevent operation of the coffee machine 100 if the basket signal 190 indicates no basket.

[0042] As shown in FIGS. 3 and 4, the basket 110 may have a rotational axis of symmetry 112. The transmitter 140 may be oriented at an angle 142 to the axis 112, preferably a non-parallel angle 142. Preferably, the angle 142 is about 45°. One of the possible basket shapes, as shown in FIG. 3, may include a side wall 134 that is perpendicular to the angle 142, such that the EM signal emitted by the transmitter 140 is reflected strongly by the side wall 134 to the receiver 150, with a comparatively short time of flight between emission of the EM signal by the transmitter 140 and reception of the EM signal by the receiver 150. Other embodiments are possible where the side wall 134 is not perpendicular to a path of the EM signal along the angle 142, but where the side wall 134 causes a bisection of the angle 142 between the transmitter 140and the receiver 150, again resulting in a relatively strong reception of the EM signal by the receiver 150 with a short time of flight.

[0043] In the embodiment shown in FIG. 3, the side wall 134 is aligned with the transmitter 140 the basket 110 is in the basket position 130. In this embodiment, the transmitter 140 may be driven using a current of about 80 mA, the basket signal 190 may require amplification by about 80 M (or 2 x 107), the basket signal 190 output by the transmitter 140 may be on the order of about 1 to 100 nA, using the amplification, this is converted to a voltage signal between about 0 and 3.3 V. The difference in basket signal 190 between basket shapes may be about 0.3 V. However, in another embodiment shown in FIGS. 6 to 8, the transmitter 140 may be located such that the side wall 134 is within the functional range 152 of the transmitter 140 and receiver 150 as the basket 110 is moved along a basket path 132 toward the basket position 130, as shown in FIG. 7. The transmitter 14 may even be located such that the side wall 134 is not within the functional range 152 when the basket 110 is in the basket position 130, as shown in FIG. 8.

[0044] Turning to FIGS. 9, 10, and 11 in more detail to discuss the processing of the basket signal 190 by the controller 102 to determine the basket shape or no basket. FIG. 9 shows the basket signal 190 as the basket 110 moves along the basket path 132. As can be seen in FIG. 9, a peak deviation 194, or a minimum 194, exists corresponding to the position shown in FIG. 7. This peak deviation 194 would not exist if the basket 110 had a basket shape without the side wall 134 that interacts with the angle 142 to create the peak deviation 194 in that position. It is therefore possible for the controller 102 to determine that the basket 110 has a basket shape including the side wall 134 angled to complement angle 142. FIG. 10 shows the basket signal 190 for repeated movement of a single dose basket 110, having the side wall 134 angled to complement angle 142, while FIG. 11 shows the basket signal 190 for repeated movement of a double dose basket 110, having a side wall 134 that does not complement angle 142. The peak deviations 194 of the basket signal 190 in FIG. 10 are clearly apparent. The controller 102 may determine a peak deviation 194 to be present in the basket signal 190, if the minimum value of the basket signal 190 is below 1 V.

[0045] Turning to FIG. 12, as the single dose basket 110 may be detected using the peak deviation 194, the question remains how the controller 102 processes the basket signal 190 to determine the difference between the double dose basket 110 and the no basket case. The steadystate 192 condition of the basket signal 190 is shown in FIG. 12, may be the value of the basket signal 190 some time after the basket 110 has reached the basket position 130. In the preferred embodiment, the steady state 192 condition of the basket signal 190 is an average value calculated over a set time range of the basket signal 190. As seen in FIG. 12, the value of the steady state 192 is usefully different between the no basket condition, which results in a higher value, and the double dose basket 110, which results in a lower value. FIG. 12 shows a conversion of the 0 to 3.3 V basket signal 190 to a digital scale with 10 bits of resolution (1024 possible values). The higher value is between 77.5% to 82.5% of the digital scale, while the lower value is between 725% to 77.5% of the scale. This difference is due to the different reflectivity of the material of the basket 110 compared to an inside surface of the portafilter. Preferably, the inside surface of the portafilter is less reflective than the material of the basket 110. Neither have a peak deviation 194, which is shown for the single dose basket 110 along the X-axis of FIG. 12.

[0046] The holder 120 may include a microswitch 122 that is located to be actuated by the basket 110, or the portafilter 180, when the basket 110 is in the basket position 130. The basket signal 190 may be stored in a memory module (not shown) of the controller 102 using a first-in first-out method, also referred to as a circular memory buffer, such that a store period backwards of any particular moment of the basket signal 190 is maintained in the memory module. Actuation of the microswitch 122 may cause the controller 102 to process the store period of the basket signal 190, or a portion thereof, in order to identify the peak deviation 194, and / or the steady state 192 value of the basket signal 190, in order to determine the basket shape and / or presence of the basket 110. The store period may be about 1000 -2000 ms, in the preferred embodiment the last 100 ms of the store period are used to identify the peak deviation 194 and the steady state 192. Actuation of the microswitch 122 may also cause actuation of the grinder 200 to produce the volume of ground coffee, as determined by the set of brewing parameters, which may have been altered by the controller 102 in response to processing of the basket signal 190 following actuation of the microswitch 122.

[0047] As shown in FIG. 13, the coffee machine 100 may include a circuit board 160. The transmitter 140 and the receiver 150 are preferably located on the same or a single circuit board 160. The circuit board 160 may further include driving circuit 162 for powering the transmitter 140. The circuit board 160 may also include an amplifier circuit 164 for amplifying the basket signal 190 produced by the receiver 150. As shown in FIGS. 14 and 15, the coffee machine 100may also include a circuit board holder 170 to hold the circuit board 160 in the desired position relative to the coffee machine 100 and / or the basket position 130. The circuit board holder 170 may include a signal divider 172 between the transmitter 140 and the receiver 150 that is substantially opaque to the EM signal. In one embodiment, the EM signal is an infra red signal, and the signal divider 172, in fact preferably the entire circuit board holder 170, has a black coloured surface.

[0048] FIG. 16 shows a method of using the coffee machine 100. At step S 101, the coffee machine 100 is powered. At step S103, the coffee machine 100 is idle, the transmitter 140 is continuously sending the EM signal and the receiver 150 is continuously providing the basket signal 190 to the controller 102, which stores the basket signal 190 for the store period in the circular memory buffer. At step S105, the portafilter 180 is inserted into the holder 120, moving along the basket path 132. The microswitch 122 is triggered by the portafilter 180, causing the controller 102 to poll the basket signal 190 of the store period. At step SI 07, the controller 102 determines whether the peak deviation 194 of the basket signal 190 of the store period is below 1 V. If the peak deviation 194 has been detected, the controller 102, at step SI 09, causes a user interface 104 of the coffee machine 100 to indicate that the basket shape is a single dose basket 110. The controller 102 may adjust the set of brewing parameters. If the peak deviation test of step SI 07 has failed, the controller 102, at step Si l l determines the steady state 192 value of the basket signal 190 of the store period, by taking an average of the basket signal 190. At step SI 13, the controller 102 tests whether the average of the basket signal 190 is above or below a threshold. Depending on the outcome of the test, the controller 102 determines the basket 110 to be a double dose basket 110, or that there is no basket in the portafilter 180. In the case of the double dose basket 110, the controller 102 proceeds to step SI 09, except indicating the double dose basket and adjusting the set of brewing parameters accordingly. In the no basket case, the controller 102, at step SI 09, indicates an error on the user interface 104. The controller 102 may further prevent operation of the grinder 200 and / or the coffee machine 100.

[0049] It will also be appreciated that in this document the terms “comprise”, “comprising”, “include”, “including”, “contain”, “containing”, “have”, “having”, and any variations thereof, are intended to be understood in an inclusive (i.e. non-exclusive) sense, such that the process, method, device, apparatus or system described herein is not limited to those features or parts or elements or steps recited but may include other elements, features, parts or steps not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the terms “a” and“an” used herein are intended to be understood as meaning one or more unless explicitly stated otherwise. Moreover, the terms “first”, “second”, etc. are used merely as labels, and are not intended to impose numerical requirements on or to establish a certain ranking of importance of their objects.

[0050] Integers:10 ground coffee 152 functi onal range100 coffee machine 160 circuit board104 user interface 170 circuit board holder102 controller 172 signal divider110 basket 180 portafilter112 rotational axis of symmetry 190 basket signal120 holder 192 steady state122 microswitch 194 peak deviation130 basket position 200 grinder132 basket path 202 hopper134 side wall 204 chute140 transmitter 210 water reservoir142 non-parallel angle 220 pump144 signal path 230 group head150 receiver 232 bayonet fitting

Claims

CLAIMS:

1. A coffee machine for preparing a coffee beverage from ground coffee, the coffee machine including: a controller for controlling operation of the coffee machine, including the preparation of the coffee beverage according to a set of brewing parameters; a basket for holding the ground coffee; a holder for holding the basket in a basket position; a transmitter of an electromagnetic (EM) signal aimed at the basket position; a receiver adapted to receive the EM signal when reflected by the basket being in the basket position and providing a basket signal to the controller based on the reception of the EM signal.

2. The coffee machine of claim 1, wherein the basket has one of a variety of basket shapes; wherein the basket signal is processable by the controller to determine the basket shape of the basket in the basket position.

3. The coffee machine of claim 2, wherein the controller adjusts the set of brewing parameters based on the basket shape of the basket in the basket position.

4. The coffee machine of any one of claims 1 to 3, wherein the basket has a rotational axis of symmetry and the transmitter is oriented at a non-parallel angle to the rotational axis of symmetry.

5. The coffee machine of claim 4, when dependent from claim 2, wherein one of the basket shapes includes a side wall perpendicular to the non-parallel angle of the transmitter.

6. The coffee machine of claim 5, wherein the basket is moved along a basket path toward the basket position, wherein the transmitter and receiver have a functional range, and wherein the transmitter is located such that the side wall is within the functional range when the basket is moved along the basket path.

7. The coffee machine of claim 6, wherein the transmitter is located such that the side wall is not within the functional range when the basket is in the basket position.

8. The coffee machine of any one of claims 1 to 7, wherein the transmitter and receiver are located on a single circuit board, and wherein the coffee machine further includes a circuit board holder to hold the circuit board.

9. The coffee machine of claim 8, wherein the circuit board holder includes a signal divider between the transmitter and receiver that is substantially opaque to the EM signal.

10. The coffee machine of claim 9, wherein the EM signal is an infrared signal and the signal divider, preferably the circuit board holder, has a black surface.

11. The coffee machine of any one of claims 1 to 10, wherein the coffee machine further includes a portafilter for receiving the basket, and the portafilter is received by the holder; wherein the basket signal is indicative of the portafilter being received by the holder without the basket.

12. The coffee machine of claim 11, wherein the holder includes a microswitch actuated by the basket when the basket is in the basket position; wherein actuation of the microswitch causes the controller to poll the basket signal for a time period prior to actuation of the microswitch, wherein the processor determines a presence of the basket in the basket position based on a steady state of the basket signal close to actuation of the microswitch, and wherein the processor determines a type of the basket based on a peak deviation of the basket signal further in the past from actuation of the microswitch.

13. The coffee machine of any one of claims 1 to 12, wherein the coffee machine includes a grinder for producing the ground coffee from coffee beans, and wherein the brewing parameters include a volume of ground coffee to produce.

14. The coffee machine of claim 13, wherein the coffee machine includes a grinder for producing the ground coffee from coffee beans, and wherein the brewing parameters include a volume of ground coffee to produce wherein the actuation of the microswitch causes activation of the grinder to produce the volume of ground coffee.

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