DE102021213003A1 - Transducer for generating sound waves and display - Google Patents

Abstract

The invention relates to a transducer (1) for generating sound waves, comprising a base substrate (9) on which a first template (8) is arranged, the first template (8) having at least one first recess (12a, .., 12d). , further having at least one first piezo element (7a,...,7d), which is arranged in a form-fitting manner in the at least one first recess (12a,...,12d), and a first electrode (6 ), which makes electrical contact with the at least one first piezo element (7a,...,7d) and a second template (4) arranged on the first electrode (6), which has at least one opening for the at least one first recess (12a,...,12d ) has a substantially identical second recess (13a,...,13d), wherein the at least one second recess (13a,...,13d) is aligned with the first recess (12a,...,12d) in the second template (4) is arranged and at least one second piezo element (5a,...,5d), which is arranged in the at least one second recess (13a,...,13d) in a form-fitting manner, so that the at least one second piezo element (5a,..., 5d) is aligned with the first piezoelectric element (7a,...,7d), and so that the at least one second piezoelectric element (5a,...,5d) makes electrical contact with the first electrode (6) and wherein the second template ( 4) a second electrode (3), which forms a pair of electrodes with the first electrode (6), is arranged, which makes electrical contact with the second piezo element (5a,...,5d) and a flywheel mass on the second electrode (3). (2) is arranged.Furthermore, the invention relates to a display.

Description

The invention relates to a converter for generating sound waves and a display with such a converter.

Touch panels/displays are often used in electronic devices and are used in particular to create touch screens, for example for mobile phones, or touch pads. There are currently various vibrating touch panels capable of modifying the tactile sensation of touch. In the process, vibrations in the ultrasonic range are coupled onto the rigid surfaces.

The glass surfaces of touch displays are excited to oscillate in such a way that if they are touched with a finger, the air or aerosol cushion and/or the slip-stick effect between the finger and the glass surface changes.

The touch panels use a physical principle that makes it possible to control the perceived coefficient of friction.

When the finger touches the touch display, an "air cushion" is created between the glass and the finger, thus reducing the coefficient of friction between the finger and the glass. The decrease in the coefficient of friction is a function of the amplitude of the vibration generated. In order to generate this vibration, piezoelectric cylindrical ceramics are used as transducers in the prior art.
Due to their cylindrical design, such converters generate ring-shaped waveforms on rigid surfaces, starting from the point of coupling. Such circular converters are used for a variety of tasks in displays.
Furthermore, currently only cylindrical transducers are known, which are used for the purpose of ultrasonic cleaning or for diagnostics.

The EP 1172019 B1 discloses a vibration exciter comprising: a curved piezoelectric device having a mounting portion for mounting the device to a substrate to be vibrated, and at least one free end or peripheral edge portion remote from the mounting portion and a mass load attached to the at least one or located at each free end or peripheral edge portion.

It is therefore an object of the invention to specify an improved converter for generating sound waves, which can be used in particular in displays, and a display with such a converter.

The object is achieved by a converter having the features of claim 1 and a display having the features of claim 13.

The object is achieved by a transducer for generating sound waves, comprising a base substrate on which a first stencil is arranged, the first stencil having at least one first cutout, further having at least one first piezo element which is arranged in a form-fitting manner in the at least one first cutout , and a first electrode arranged on the first stencil, which makes electrical contact with the first piezo element, and a second stencil arranged on the first electrode, which has at least one second cutout that is essentially identical to the at least one first cutout, the at least one second cutout being aligned to the first recess in the second template and at least one second piezo element, which is arranged in a form-fitting manner in the at least one second recess, so that the at least one second piezo element is aligned flush with the first piezo element, and so that the at least one second piezo element is the first Electrode electrically contacted and on the second template a second electrode, which forms a pair of electrodes with the first electrode, is arranged, which electrically contacts the second piezoelectric element and on the second electrode a flywheel is arranged.

Such a converter is easy to manufacture. In particular, a plurality of piezo elements can be arranged one behind the other and precisely in relation to one another through the recesses.

Such a converter is easily scalable in length, width, height and performance with the same manufacturing concept.

Furthermore, the geometry of the piezo elements can be freely selected; for example, they can be selected to be rectangular and thus generate a straight wave front. After such a linear excitation, the waves propagate perpendicularly to the wavefront.

Such a wavefront is particularly advantageous if the converter is arranged in a display, ie between a cover, in particular a glass, and the display unit. With such a configuration, since a display is usually rectangular, the complete display can be achieved with such a straight (rectilinear wavefront) wavefront. For larger displays, two opposing converters can be arranged. This has particular advantages over commercially available converters, which have ring-shaped pie have zo elements and therefore propagate in a circular fashion (circular wave front).

Due to the free scalability of such a converter, the power of the converter can easily be increased or decreased; by using thicker piezo elements and a thicker upper centrifugal mass, the performance of the converter can easily be increased with almost the same design.

Such a converter also has the advantage that it is robust in relation to disturbances, that is to say both the electrical and the mechanical connection of the piezo elements are robust in relation to external disturbances.

Furthermore, such a converter can dissipate the heat loss of the piezo elements on both sides.

By using the templates with the defined cut-outs, the piezo elements can be positioned precisely.

Depending on the application, several such cutouts and thus piezo elements can also be arranged and the remaining geometry, for example that of the electrodes and the templates, can be adapted.

In this case, a pair of electrodes is formed by a negative and a positive electrode.

Preferably, the first electrode is a positive electrode and the second electrode is a negative electrode.

In a further embodiment, at least the one first piezo element and the corresponding first recess and the at least one second piezo element and the corresponding second recess are essentially rectangular, so that the transducer generates a straight wave front during operation.

This makes the converter particularly suitable for use in a display.

If such a converter is arranged on a right and/or opposite left side or an upper and a lower side, the wavefront thus covers the entire display surface evenly without any problems.

In a further development, several first piezo elements are provided as well as corresponding first recesses arranged in a row and closely adjacent to one another in the first template, so that the several first piezo elements are arranged closely adjacent to one another in the first template through the first recesses, as well as several second ones Piezo elements and corresponding second recesses in the second stencil that are closely adjacent to one another and arranged in a row are provided, so that the plurality of second piezo elements are arranged closely adjacent to one another in the second stencil through the second recesses, the first piezo elements and the second Piezoelectric elements are circular or elliptical or oval in shape, so that the transducer generates a straight wavefront during operation due to the closely spaced arrangement of the first piezoelectric elements and the second piezoelectric elements.

This makes the converter particularly suitable for use in a display. When such a converter is arranged on a right and/or opposite left side or an upper and a lower side, the wave front thus covers the entire display surface without any problems.

In a further development, both the base substrate and the first and second templates and also the first electrode and the second electrode and the centrifugal mass are designed in the form of strands.

Such a string-shaped transducer is therefore long and narrow. Such a narrow and elongated strand design allows the transducer to be easily positioned at the edge of a rigid surface such as a rectangular display. Such a strand-shaped transducer, for example an ultrasonic transducer, is therefore particularly suitable for injecting vibrations into rigid surfaces such as rectangular displays.

In a further development, guide passages are provided on the base substrate, on the first template and the second template, as well as on the first electrode and the second electrode and on the centrifugal mass as well as the first template and the second template as well as the first electrode and the second electrode as well as the centrifugal mass to each other and thus also the at least one first piezoelectric element and the at least one second piezoelectric element is made possible.

As a result, the individual elements can easily be arranged in the exact position during production and do not slip during operation.

In a further development, both the base substrate and the first template and the second template as well as the first electrode and the second electrode and the centrifugal mass have Poka-Yoka elements, so that the base substrate and the first template and the second template as well as the first electrode and the second electrode as well as the centrifugal mass to each other and thus also the at least one first piezoelectric element and the at least one second piezoelectric element is made possible.

For example, the poka-yoka elements can be selected from the group: pin element and corresponding opening and/or latching elements such as pins/projections and corresponding depressions. As a result, such a transducer can be manufactured in a simple, position-accurate manner.

For example, in the case of a pin element and a corresponding opening, the pin element is attached to one element and the corresponding opening is attached to the other element, so that the individual elements can be arranged in a precise position. Furthermore, the individual elements are prevented from slipping during operation.

Furthermore, both the base substrate and the first template and the second template as well as the first electrode and the second electrode and the centrifugal mass can each have at least one aligned threaded hole for fixing the base substrate with the first template and the first electrode and the second Template and second electrode as well as the flywheel together with a screw. Alternatively, both the base substrate and the first electrode and the first template and the second electrode and the second template and the centrifugal mass can be glued together.

This allows the elements to be easily fixed to one another.

Furthermore, the first template and the second template can be made of a soft plastic. Since the templates represent a bypass for the vibrations, the damping is kept low by the soft plastic. Furthermore, several first recesses and second recesses and several first piezoelectric elements and second piezoelectric elements can be arranged in a row, and with both the base substrate and the first template and the second template and the first electrode and the second electrode as well as the centrifugal mass in their Length are adjusted accordingly. The converter can thus be adapted to the width or length of a display, for example.

As a result, such a converter can be used in a variety of ways.

Furthermore, the object is achieved by a display with a substantially rectangular display unit for displaying images and a corresponding transparent rectangular front, wherein a converter as described above is arranged between the display unit and the transparent front.

The converter can have first piezo elements and second piezo elements, the first piezo elements and the second piezo elements being rectangular or essentially rectangular. This results in a straight wave front, which propagates completely on the rectangular display.

Furthermore, the converter can be designed in the form of a strand. This means that the converter can easily be arranged on the left and right edge under the front, for example. The wavefront can thus propagate straight across the display.

Further properties and advantages of the present invention emerge from the following description with reference to the enclosed figures.

• 1: ein erfindungsgemäßer Wandler als Explosionszeichnung,
• 2: ein erfindungsgemäßer Wandler.

It shows schematically:

• 1 : a converter according to the invention as an exploded view,
• 2 : a converter according to the invention.

1 shows a converter 1 according to the invention as an exploded drawing. In this case, a lower strand forms a base substrate 9 as a lower centrifugal mass. The base substrate 9 is made of metal, for example, for example steel, aluminum or comparable conductive materials.

The base substrate 9 has a few threaded holes 11 and guide holes 10a or guide grooves 10b at each end.

A first lower template 8 is arranged on the base substrate 9 . The lower template 8 is preferably made of soft plastic and is provided with first identical recesses 12a, .., 12d arranged in a row, into which the lower first piezo elements 7a, ..7d, here with the negative pole, are then inserted downwards, ie in Towards the base substrate 9, are inserted (integrated) in a form-fitting manner. Depending on the number of desired length of the transducer 1 more or less first pie zo elements 7a,...,7d or their length can be varied.

The piezoelectric elements 7a, .

Since the first template 8 represents a bypass for the vibrations, the damping is kept low by being made of soft plastic. Alternatively, hard rubber can also be used for the first template 8 . Furthermore, corresponding threaded holes 11 are provided in the first lower template 8 for later screwing to the base substrate 9 .

A first electrode 6, here a positive electrode 6, preferably made of copper, is then arranged on the first template 8 and the first piezo elements 7a, . . . , 7d integrated therein. The piezo elements 7a,...,7d make electrical contact with the first positive electrode 6.

Furthermore, corresponding threaded holes 11 are provided in the first electrode 6 for later screwing to the base substrate 9 and the first template 8 .

A second upper template 4 is then placed on the positive electrode 6 . This is also preferably made of soft plastic because of the damping to be kept low; can alternatively be made of hard rubber.

The second template 8 has second recesses 13a, . . . These are preferably identical to the first piezo elements 7a,...,7d.

The first piezoelectric elements 7a,...,7d and the second piezoelectric elements 5a,...,5d are thus directly one above the other in the vertical direction.

The upper piezo elements 5a,...,5d are placed with the positive pole down,
ie inserted in the direction of the positive electrode 6 in the second recesses 13a, ..., 13d of the upper second template 8.

Furthermore, corresponding threaded holes 11 are provided in the second upper template 4 for later screwing to the base substrate 9 and the first lower template 8 and the first positive electrode 6 . A second electrode, here a negative electrode 3, is then arranged on the upper second template 4 and the upper second piezo elements 5a,...,5d.

This arrangement means that the upper first piezoelectric elements 5a, . . . , 5d are electrically conductively connected to the first plus electrode 6 and the second minus electrode 3.

Furthermore, corresponding threaded holes 11 are provided in the second negative electrode 3 for later screwing to the base substrate 9 , the second upper template 4 and the first lower template 8 and the first positive electrode 6 .

A metallic upper flywheel mass 2, preferably made of steel or aluminum, is then arranged on the negative electrode 3 with corresponding threaded holes 11.

Finally, the centrifugal mass 2 and the base substrate 9 are screwed together with screws 14, as a result of which all other components are pressed together. The first piezoelectric elements 7a,...,7d and the second piezoelectric elements 5a,...,5d are thus mechanically prestressed and electrically contacted.

The first lower stencil 8 with the first recesses 12a, 5a,...,5d.

Except for the first piezoelectric elements 7a,...,7d and the second piezoelectric elements 5a,...,5d, all components are provided at their ends with guide holes 10a or guide grooves 10b, in which the elements are precisely positioned in the manufacturing process using the described sequence using centering pins be plugged together.

2 shows a transducer 1 in the finished state.

This is in particular in the form of a strand. However, the dimensions such as length, width, height of all components and/or the length and width of the first piezoelectric elements 7a,...,7d and second piezoelectric elements 5a,...,5d can vary. The transducer 1 may consist of more or less than the four segments shown. Furthermore, the structure can consist of more or less than the two layers shown, consisting of first and second electrodes 3, 6 and templates 4, 8.

In particular, the piezo elements 5a, ., 5d, 7a, . . . , 7d are rectangular, so that a rectilinear wavefront is achieved.

Reference List

1

converter

2

flywheel

3

second negative electrode

4

second template

5a,...,5d

second piezo elements

6

first positive electrode

7a,...,7d

first piezo elements

8th

first template

9

base substrate

10a

guide holes

10b

guide grooves

11

threaded hole

12a,..,12d

first recesses

13a,..,13d

second recesses

14

screws

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 1172019 B1 [0006]

Claims (15)

Transducer (1) for generating sound waves, comprising a base substrate (9) on which a first template (8) is arranged, the first template (8) having at least one first recess (12a, .., 12d), further having at least a first piezo element (7a,...,7d), which is arranged in a form-fitting manner in the at least one first recess (12a,...,12d), and a first electrode (6) arranged on the first template (8), which electrically contacts at least a first piezo element (7a,...,7d) and a second stencil (4) arranged on the first electrode (6), which has at least one substantially identical to the at least one first recess (12a,...,12d). second recess (13a, .., 13d), wherein the at least one second recess (13a, .., 13d) is arranged aligned with the first recess (12a, .., 12d) in the second template (4) and at least a second piezoelectric element (5a,...,5d) which is arranged in a form-fitting manner in the at least one second recess (13a,...,13d), so that the at least one second piezoelectric element (5a,...,5d) is aligned with the first piezoelectric element (7a,...,7d) is aligned, and so that the at least one second piezoelectric element (5a,...,5d) electrically contacts the first electrode (6) and wherein on the second stencil (4) a second Electrode (3), which forms an electrode pair with the first electrode (6), is arranged, which makes electrical contact with the second piezo element (5a,...,5d) and a centrifugal mass (2) arranged on the second electrode (3). is. Converter (1) after claim 1 , characterized in that the at least one first piezo element (7a, ..., 7d) and the at least one second piezo element (5a, ..., 5d) is at least identical in shape or essentially identical. Converter (1) after claim 1 or 2 , characterized in that the at least one first piezoelectric element (7a, ..., 7d) and the corresponding first recess (12a, ..., 12d) and the at least one second piezoelectric element (5a, ..., 5d) as the corresponding second recess (13a, .., 13d) is also essentially rectangular in shape, so that the transducer (1) generates a straight wavefront during operation. Converter (1) after claim 1 or 2 , characterized in that several first piezo elements (7a,...,7d) as well as corresponding first recesses (12a,...,12d) are provided in the first template (8) which are closely adjacent to one another and arranged in a row, so that the several first piezoelectric elements (7a,...,7d) are arranged closely adjacent to one another in the first stencil (8) through the first recesses (12a,...,12d) and also several second piezoelectric elements (5a,... ., 5d) as well as corresponding second recesses (13a,..., 13d) which are closely adjacent to one another and arranged in a row in the second template (4) are provided, so that the plurality of second piezoelectric elements (5a,..., 5d) are arranged closely adjacent to one another in the second template (4) through the second recesses (13a,...,13d), the first piezoelectric elements (7a,...,7d) and the second piezoelectric elements (5a,. ..,5d) are circular or elliptical or oval in shape, so that the closely adjacent arrangement of the first piezoelectric elements (7a,...,7d) and second piezoelectric elements (5a,...,5d) to one another means that the transducer (1st ) generates a straight wavefront during operation. Transducer (1) according to one of the preceding claims, characterized in that both the base substrate (9) and the first template (8) and second template (4) and the first electrode (6) and second electrode (3) as well the centrifugal mass (2) are designed in the form of strands. Transducer (1) according to one of the preceding claims, characterized in that both on the base substrate (9) and on the first template (8) and the second template (4) and on the first electrode (6) and the second electrode (3 ) and the centrifugal mass (2) are provided with guide passages that are aligned at the ends to accommodate guide pins in the manufacturing process, so that the base substrate (9) as well as the first template (8) and the second template (4) as well as the first electrode (6) and the second electrode (3) as well as the centrifugal mass (2) to each other and thus also the at least one first piezoelectric element (7a,...,7d) and the at least one second piezoelectric element (5a,..., 5d) is enabled. Transducer (1) according to one of the preceding claims, characterized in that both the base substrate (9) and the first template (8) and the second template (4) and the first electrode (6) and the second electrode (3) and the centrifugal mass (2) have Poka-Yoka elements, so that the base substrate (9) as well as the first template (8) and the second template (4) as well as the first electrode (6) and the second template (4) can be precisely positioned Electrode (3) as well as the centrifugal mass (2) to each other and thus also the at least one first piezoelectric element (7a,...,7d) and the at least one second piezoelectric element (5a,...,5d) is made possible. Converter (1) after claim 7 , characterized in that the poka-yoka elements from the group: pin element and corresponding opening and/or latching elements such as pegs/projections and corresponding depressions can be selected. Transducer (1) according to one of the preceding claims, characterized in that both the base substrate (9) and the first template (8) and the second template (4) and the first electrode (6) and the second electrode (3) and the centrifugal mass (2) each have at least one aligned threaded hole (11) for fixing the base substrate (9) with the first template (8) and the first electrode (6) and the second template (4) and second electrode ( 3) and the flywheel (2) together by means of a screw (14). Transducer (1) according to one of the preceding claims, characterized in that both the base substrate (9) and the first electrode (6) and the first template (8) and the second electrode (3) and the second template (4) and the flywheel (2) are glued together. Transducer (1) according to one of the preceding claims, characterized in that the first template (8) and the second template (4) consist of a soft plastic. Transducer (1) according to one of the preceding claims, characterized in that a plurality of first cutouts (12a,...,12d) and second cutouts (13a,...,13d) and a plurality of first piezoelectric elements (7a,...,7d) and second piezo elements (5a, ..., 5d) are arranged in a row, and wherein both the base substrate (9) and the first template (8) and the second template (4) and the first electrode (6) and the second electrode (3) and the centrifugal mass (2) are adjusted accordingly in their length. A display comprising a substantially rectangular display unit for displaying images and a corresponding transparent rectangular face, wherein a transducer (1) according to any one of the preceding claims is arranged between the display unit and the transparent face. screen after Claim 13 , characterized in that the transducer (1) first piezo elements (7a, ..., 7d) and second piezo elements (5a, ..., 5d), wherein the first piezo elements (7a, ..., 7d) and the second piezoelectric elements (5a,...,5d) are rectangular or substantially rectangular. screen after Claim 13 or 14 , characterized in that the converter (1) is in the form of a strand.

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