TECHNICAL FIELD

The disclosure relates to an audio generating arrangement for an electronic device, the audio generating arrangement comprising a magnet actuator.

BACKGROUND

Electronic devices such as tablets, laptops, mobile phones, and panel speakers may be provided with audio generating arrangements comprising magnet actuators in order to generate sound waves via a panel, for example when providing audio via so-called singing displays. The quality of the audio is in strong correlation with the space available for the audio generating arrangement within the electronic device. However, the size of electronic devices is an important consideration when designing mobile devices and is usually aimed to be kept at a minimum. Therefore, the space available for the audio generating arrangement within the electronic device is also very limited.

As a consequence, prior art audio generating arrangements for electronic devices have either low-quality audio output, to keep the size of the electronic device relatively small, or have an increased size and, hence increased device size, to improve the quality of the audio.

SUMMARY

It is an object to provide an improved audio generating arrangement. The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description, and the figures.

According to a first aspect, there is provided an audio generating arrangement for an electronic apparatus comprising a movable element configured to form a surface of the electronic apparatus; and a magnet actuator configured to generate vibrations displacing the movable element along an actuation axis by means of a magnetic field, the displacement of the movable element generating audio waves; the magnet actuator comprising a first magnet arrangement comprising at least three magnets superimposed on top of each other along the actuation axis, a second magnet arrangement comprising at least three magnets superimposed on top of each other along the actuation axis, the second magnet arrangement being arranged concentrically with the first magnet arrangement along the actuation axis, the second magnet arrangement being separated from the first magnet arrangement by an air gap; a voice coil arrangement at least partially arranged within the air gap, manipulation of electrical current in the voice coil arrangement causing a change in the magnetic field such that the movable element is displaced, a first section of the voice coil arrangement being arranged in a first volume of the air gap, a second section of the voice coil arrangement being arranged in a second volume of the air gap, such that the first section of the voice coil arrangement is separated from the second section of the voice coil arrangement in the direction of the actuation axis.

This solution provides an improved audio generating arrangement for an electronic apparatus such as a tablet, a laptop, a mobile phone, or a panel speaker. The audio generating arrangement comprises a highly efficient magnet actuator that is more powerful with the same size and with the same power consumption than prior art magnet actuators, because the construction of the magnet actuator is able to provide more force. In fact, the actuator z-directional force is 40- 120% larger compared to prior art magnet actuators. The voice coil arrangement can also provide more force in the same size due to the longer wire length of the voice coil (Force = B x I x L). With the described arrangement, it is also possible to reduce the overall size of the actuator and thus also the audio generating arrangement and the electronic apparatus due to the good efficiency.

In a possible implementation form of the first aspect, the movable element is a display panel or a back cover. This facilitates providing electronic apparatuses with singing audio displays and/or back covers where instead of built-in speakers, at least a part of the surface of the displays and/or back covers is able to output audio.

In a further possible implementation form of the first aspect, the first magnet arrangement and the second magnet arrangement are arranged to form a Halbach array. This facilitates a magnet actuator providing more force in the same size/volume. Therefore, the audio generating arrangement comprising the magnet actuator will be able to generate higher quality audio without having to increase the size or volume of the arrangement.

In a further possible implementation form of the first aspect, the magnets of the first magnet arrangement and the magnets of the second magnet arrangement are annular, facilitating a compact-sized, yet highly efficient magnet actuator. Furthermore, the arrangement of the magnet arrangements facilitates reducing the overall size of the magnet actuator.

In a further possible implementation form of the first aspect, the magnet actuator further comprises at least one annular magnetic body, the body being concentrically arranged with the first magnet arrangement and the second magnet arrangement along the actuation axis and being separated from the voice coil arrangement by the first magnet arrangement or by the second magnet arrangement. This allows the magnetic body, such as an iron body, to be further away from the voice coil arrangement, facilitating the minimalization and optimization of the voice coil inductance, and improving especially high-frequency performance.

In a further possible implementation form of the first aspect, the audio generating arrangement comprises at least a first magnetic body enclosed by at least part of the first magnet arrangement; and/or the audio generating arrangement comprises at least a second magnetic body enclosing at least a part of the second magnet arrangement. This also facilitates the minimalization and optimization of the voice coil inductance, improving especially high- frequency performance of the magnet actuator and the audio generating arrangement.

In a further possible implementation form of the first aspect, the first section of the voice coil arrangement and the second section of the voice coil arrangement are parts of one single-piece voice coil; or wherein the first section of the voice coil arrangement is a first single-piece voice coil and the second section of the voice coil arrangement is a second single-piece voice coil. On one hand, this allows the flexibility of using one or more pieces of voice coil. On the other hand, this enables longer wire length of the voice coil in the voice coil arrangement, making the magnet actuator and the audio generating arrangement more powerful and efficient without increasing the power consumption.

In a further possible implementation form of the first aspect, the audio generating arrangement further comprises an audio-signal generator configured to actuate the magnet actuator by means of audio signals, facilitating the output of high-quality audio signals with the audio generating arrangement.

In a further possible implementation form of the first aspect, an outer diameter of any one of the annular magnets of the first magnet arrangement is smaller than an inner diameter of any one of the annular magnets of the second magnet arrangement. This facilitates a compact magnet actuator with improved force and higher sound pressure level (SPL).

In a further possible implementation form of the first aspect, the voice coil arrangement is configured such that current travels through the first section and the second section of the voice coil arrangement in opposite current directions. This facilitates creating a strong magnetic field and thus an improved force of the magnet actuator and thus also the audio generating arrangement.

In a further possible implementation form of the first aspect, the magnet actuator further comprises a first spring arrangement and a second spring arrangement; the first spring arrangement and the second spring arrangements being configured to at least partially enclose opposite ends of the first magnet arrangement and the second magnet arrangement along the actuation axis, and to prevent the vibrations of the magnet actuator from generating a disintegration of the magnet actuator. The spring arrangements keep the magnet actuator together in every direction and provide spring-loaded freedom of movement. Furthermore, the spring arrangements control the distance between the voice coil arrangement and the magnet arrangements.

In a further possible implementation form of the first aspect, the magnet actuator further comprises a plunger arrangement enclosing the first magnet arrangement, the plunger arrangement being connected to the movable element, and the plunger arrangement being configured to move along the actuation axis. This can facilitate the movement of a display and/or a back cover connected to the plunger arrangement hence creating audio output through a display and/or a back cover.

In a further possible implementation form of the first aspect, the magnet actuator further comprises a base, the base being configured to at least partially accommodate the first magnet arrangement, the second magnet arrangement, and the plunger, the base being configured to be connected to a frame of the electronic apparatus. The base helps keeping the audio generating arrangement together from at least one direction and also provides an audio generating arrangement that can be built in an electronic apparatus and be connected to its frame. According to a second aspect, there is provided an electronic apparatus comprising a frame and the audio generating arrangement according to the above, the movable element of the audio generating arrangement forming a surface of the electronic apparatus, the magnet actuator of the audio generating arrangement being arranged between the frame and the movable element, and the magnet actuator being configured to generate vibrations displacing the movable element with respect to the frame in directions along the actuation axis of the magnet actuator. This solution provides an electronic apparatus capable of high-quality audio output via its movable surface element. Due to the improved magnet actuator, the electronic apparatus can either have a smaller size or a same size with an improved sound pressure level. The improvement, when compared to prior art magnet actuators, is 40-120 %.

According to a third aspect, there is provided a method of generating audio in an electronic apparatus, the method comprising the steps of generating a magnetic field along an actuation axis by a magnet actuator, the magnet actuator comprising a first magnet arrangement comprising at least three magnets superimposed on top of each other along the actuation axis, a second magnet arrangement comprising at least three magnets superimposed on top of each other along the actuation axis, the second magnet arrangement being arranged concentrically with the first magnet arrangement along the actuation axis, the second magnet arrangement being separated from the first magnet arrangement by an air gap; manipulating electrical current in a voice coil arrangement arranged within the air gap of the magnet actuator and causing a change in the magnetic field; the change in the magnetic field generating movement of a movable element, operably connected to the magnet actuator, along the actuation axis, the movable element forming a surface of the electronic apparatus.

This solution provides a method of generating higher-quality audio. This method enables an electronic apparatus capable of producing higher SPL without having to increase the size of the actuator or the apparatus.

These and other aspects will be apparent from the embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the aspects, embodiments and implementations will be explained in more detail with reference to the example embodiments shown in the drawings, in which: Fig. 1 shows a cross-sectional view of an audio generating arrangement built into an electronic apparatus in accordance with an example of the present invention;

Fig. 2 shows a perspective view of a partial magnet actuator of an audio generating arrangement in accordance with an example of the present invention;

Fig. 3 shows a perspective view of a partial magnet actuator of an audio generating arrangement in accordance with an example of the present invention;

Fig. 4 shows a cross-sectional view of a partial magnet actuator of an audio generating arrangement in accordance with an example of the present invention;

Fig. 5 shows a cross-sectional view of a partial magnet actuator of an audio generating arrangement in accordance with an example of the present invention;

Fig. 6a shows a perspective view of the bottom of the magnet actuator shown in Fig. 5;

Fig. 6b shows a bottom view of the magnet actuator shown in Fig. 5 and 6a;

Fig. 7a shows a perspective view of the top of the magnet actuator shown in Fig. 5 and 6a;

Fig. 7b shows a top view of the magnet actuator shown in Fig. 5 and 7a;

Fig. 8 shows an exploded perspective view of a magnet actuator of an audio generating arrangement in accordance with an example of the present invention.

DETAILED DESCRIPTION

Fig. 1 shows a cross-sectional view of an audio generating arrangement 11 built into an electronic apparatus 13, such as a tablet, a laptop, a mobile phone, or a panel speaker. Fig. 1 shows a movable element 10 of the electronic apparatus 13, such as a display panel or a back cover. The electronic apparatus further comprises an internal frame 12 also shown in Fig. 1. The movable element 10 forms a surface of the electronic apparatus 13 and is able to function in a similar way to a speaker. The electronic apparatus 13 further comprises a magnet actuator 1, the magnet actuator 1 being arranged between the frame 12 and the movable element 10. The magnet actuator 1 is able to generate vibrations displacing the movable element 10 with respect to the frame 12 in directions along the actuation axis A of the magnet actuator 1.

The magnet actuator 1 and the movable element 10 form part of an audio generating arrangement 11. As mentioned above, the movable element 10 forms a surface of the electronic apparatus 13, and the magnet actuator 1 generates vibrations displacing the movable element 10 along an actuation axis A by means of a magnetic field. The displacement of the movable element 10 generates audio waves and produces high-quality audio output with improved SPL. The audio generating arrangement 11 may further comprise an audio-signal generator configured to actuate the magnet actuator 1 by means of audio signals.

The magnet actuator 1 shown in Fig. 1 preferably comprises a first magnet arrangement 2 comprising at least three magnets 2a, 2b, 2c superimposed on top of each other along the actuation axis A, and a second magnet arrangement 3 comprising at least three magnets 3a, 3b, 3c superimposed on top of each other along the actuation axis A. The magnets 2a, 2b, 2c of the first magnet arrangement 2 and the magnets 3a, 3b, 3c of the second magnet arrangement 3 are preferably annular. The second magnet arrangement 3 is arranged concentrically with the first magnet arrangement 2 along the actuation axis A. Advantageously, the first magnet arrangement 2 and the second magnet arrangement 3 are arranged such that an outer diameter of any one of the annular magnets 2a, 2b, 2c of the first magnet arrangement 2 is smaller than an inner diameter of any one of the annular magnets 3a, 3b, 3c of the second magnet arrangement 3. Optionally, the first magnet arrangement 2 and the second magnet arrangement 3 form a Halbach array. The second magnet arrangement 3 is separated from the first magnet arrangement 2 by an air gap 4. The magnet actuator 1 comprises a voice coil arrangement 5 that is at least partially arranged within the air gap 4. Manipulation of electrical current in the voice coil arrangement 5 causes a change in the magnetic field and displaces the movable element 10. The air gap 4 may have at least two volumes 4a, 4b; a first section 5a of the voice coil arrangement 5 can be arranged in the first volume 4a of the air gap 4, and a second section 5b of the voice coil arrangement 5 can be arranged in the second volume 4b of the air gap 4. Preferably, the first section 5a of the voice coil arrangement 5 is separated from the second section 5b of the voice coil arrangement 5 in the direction of the actuation axis A. The voice coil arrangement 5 is preferably configured such that current travels through the first section 5a and the second section 5b of the voice coil arrangement 5 in opposite current directions. The voice coil arrangement may for example utilize a coil wire length of about 5.53 m, DC R 6.4 Ohm, 0.152 mm diameter wire, and have 102 rounds total, 17 rounds in z-stack (2.6mm Z- height coil), 3 rounds in x-stack (0.46mm x- width). The air gap 4 is optionally about 0.5 mm, while the thickness of the coil chassis is optionally about 0.2 mm (e.g. made of plastic). The coil inductance is 74.5 pH per coil in the air gap 4.

The first section 5a of the voice coil arrangement 5 and the second section 5b of the voice coil arrangement 5 can be parts of one single-piece voice coil arrangement 5 separated into two sections 5a, 5b, or they can also be multiple, e.g. two different single-piece voice coils 5a, 5b. For example, both voice coil sections 5a, 5b may have about 51 rounds adding up to 102 rounds total.

The magnet actuator 1 may further comprise at least one annular magnetic body 6, such as an iron part. The magnetic body 6 is preferably concentrically arranged with the first magnet arrangement 2 and the second magnet arrangement 3 along the actuation axis A. Moreover, the magnetic body 6 is preferably separated from the voice coil arrangement 5 by the first magnet arrangement 2 or by the second magnet arrangement 3. By not placing the magnetic body 6, such as an iron part, close to the voice coil arrangement 5, the voice coil inductance can be minimized, and as a result, high-frequency performance can be achieved. Preferably, there is at least a first magnetic body 6a and a second magnetic body 6b in the magnet actuator 1. The first magnetic body 6a, such as an iron part, might be enclosed by at least part of the first magnet arrangement 2. The first magnetic body 6a can be separated from the voice coil arrangement 5 by the first magnet arrangement 2. For example, there might be two annular first magnetic bodies 6a as in the embodiment shown in Fig. 1. The second magnetic body 6b, such as an iron part, is advantageously enclosed by at least part of the second magnet arrangement 3. The second magnetic body 6b can be separated from the voice coil arrangement 5 by the second magnet arrangement 3. For example, there might be two annular second magnetic bodies 6b as in the embodiment shown in Fig. 1.

As shown in Fig. 1, there may be an upper first magnetic body 6a located next to the magnet 2a, and a lower first magnetic body 6a located next to the magnet 2c. In this example, the outer diameter of any one of the first magnetic bodies 6a is smaller than an inner diameter of any one of the annular magnets 2a, 2b, 2c of the first magnet arrangement 2. Furthermore, there may be an upper second magnetic body 6b located next to the magnet 3a, and a lower second magnetic body 6b located next to the magnet 3 c. The inner diameter of any one of the second magnetic bodies 6b is larger than an outer diameter of any one of the annular magnets 3 a, 3b, 3 c of the second magnet arrangement 3. This, as mentioned before, is only an optional arrangement of the magnetic bodies 6.

Fig. 1 also illustrates the magnet actuator 1 having a spring arrangement 7, a plunger arrangement 8, connectors and a base 9.

The spring arrangement 7 may have at least two parts: a first spring arrangement 7a and a second spring arrangement 7b. The function of the spring arrangement 7 is keeping the actuator 1 together from all directions and preventing the vibrations of the magnet actuator 1 from causing the magnet actuator 1 to disintegrate, i.e., separate. The first spring arrangement 7a and the second spring arrangement 7b at least partially enclose opposite ends of the first magnet arrangement 2 and the second magnet arrangement 3 along the actuation axis A. As shown in Fig. 1, the first spring arrangement 7a and the second spring arrangements 7b may partially also enclose the magnetic bodies 6b. The first spring arrangement 7a and the second spring arrangement 7b are preferably arranged on the outside of the magnet actuator 1.

The plunger arrangement 8 may enclose the first magnet arrangement 2 and is connected to the movable element 10. The plunger arrangement 8 is a moving part of the magnet actuator 1, being able to move along the actuation axis A. Since the plunger arrangement 8 is connected to the movable element 10, it also makes the movable element 10 move.

The base 9 may at least partially accommodate the first magnet arrangement 2, the second magnet arrangement 3, and the plunger 8. The base 9 is preferably arranged at the bottom of the magnet actuator 1, and is configured to be connected to an internal frame 12 of an electronic apparatus 13, such as a tablet, a laptop, a mobile phone or a panel speaker. There might be any number of connectors attached to the base 9, the connectors being arranged between the base 9 and the frame 12.

Fig. 2 and 3 show a part of the audio generating arrangement 11 in perspective view. The figures do not illustrate the electronic apparatus 13 but only parts of the magnet actuator 1. Fig. 2 shows the first magnet arrangement 2 and the second magnet arrangement 3 with the first spring arrangement 7a and the base 9. Fig. 3 shows the first spring arrangement 7a and the second spring arrangement 7b enclosing a plunger arrangement 8. Figs. 2 and 3 both illustrate the spring arrangement 7 which has a mechanical function: keeping the assembly together in every direction (x, y, z) and giving spring-loaded freedom of movement. The spring arrangement 7 can also control the distance of the voice coil arrangement 5 from magnets 2a, 2b, 2c and 3a, 3b, 3c.

Fig. 4 shows an example of the three magnets 2a, 2b, 2c of the first magnet arrangement 2 and the three magnets 3 a, 3b, 3 c of the second magnet arrangement 3, when the magnets are annular. Fig. 4 also illustrates the air gap 4 including the voice coil arrangement 5 and the plunger arrangement 8. The plunger arrangement 8 preferably has an annular segment enclosed within the air gap 4, providing a wall-like support structure for the voice coil arrangement 5.

Fig. 5 shows a cross-sectional view of the magnet actuator 1 as shown in Fig. 1, without the movable apparatus 10 and the frame 12.

Fig. 6a, 6b and 7a, 7b show perspective views of an example of an embodiment of the magnet actuator 1. Figs. 6a and 6b show the bottom of the magnet actuator 1 where the connectors might be arranged, while Figs. 7a and 7b show the top of the magnet actuator 1 with the plunger arrangement 8.

Fig. 8 shows an exploded perspective view of a possible embodiment of the magnet actuator 1. This figure illustrates the different annular magnets 2a, 2b, 2c and 3a, 3b, 3c and the first 6a and second magnetic bodies 6b.

When generating audio in an electronic apparatus 13, the method comprises the steps of generating a magnetic field along an actuation axis A by a magnet actuator 1, manipulating electrical current in a voice coil arrangement 5 within the magnet actuator 1 and causing a change in the magnetic field. The change in the magnetic field then generates movement of a movable element 10 of the electronic apparatus along the actuation axis A, the movable element 10 forming a surface of the electronic apparatus. 13 The movable element 10 is preferably a display panel and/or a back cover of an electronic apparatus. The moving part in the magnet actuator 1 is preferably a plunger arrangement 8 connected to the movable element 10. As described above, the magnet actuator 1 comprises a first magnet arrangement 2 comprising at least three magnets 2a, 2b, 2c superimposed on top of each other along the actuation axis A, a second magnet arrangement 3 comprising at least three magnets 3a, 3b, 3c superimposed on top of each other along the actuation axis A, the second magnet arrangement 3 being arranged concentrically with the first magnet arrangement 2 along the actuation axis A, the second magnet arrangement 3 being separated from the first magnet arrangement 2 by an air gap 4.

The various aspects and implementations have been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject-matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

The reference signs used in the claims shall not be construed as limiting the scope. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this disclosure. As used in the description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.