Optical rotary encoder

Abstract

An optical rotary encoder (1) comprises a light source (10), a rotating shaft (20), and an optical sensor array (30) comprising a plurality of optical sensors (31a,…, 31d, 32a, …, 32d) positioned to receive at least a portion of the light emitted by the light source (10) and reflected on the surface (23). The rotating shaft (20) has a longitudinal axis (25), and is configured to be rotatable around the longitudinal axis (25) by different rotating angles (α) and to be movable along the longitudinal axis (25) into different positions (P1, P2). The surface (23) of the rotating shaft (20) is configured so that a respective intensity of the portion of the reflected light received by each of the optical sensors (31a, …, 31d, 32a, …, 32d) of the optical sensor array is dependent on the rotating angles (α) of the rotating shaft (20) and on the positions (P1, P2) of the rotating shaft (20).

Description

[0001] Description

[0002] OPTICAL ROTARY ENCODER

[0003] Technical Field

[0004] The disclosure relates to an optical rotary encoder being configured to determine a rotating angle of a rotating shaft of the encoder and a movement of the encoder in a direction of a longitudinal axis of the rotating shaft . Furthermore , the disclosure relates to an electronic device comprising an optical rotary encoder for determining a rotating angle and a movement of a rotating shaft of the encoder in a direction of a longitudinal axis of the shaft .

[0005] Background

[0006] A rotary encoder is usually used in electronic devices to detect an angle of rotation of a rotating shaft of the encoder . The electronic device is , for example , controlled depending on the rotation angle of the rotating shaft set by a user . A typical example of such an electronic device is an electronic watch, for example a smartwatch or an electronic watch used for fitness tracking, in which settings can be made by mechanically rotating a crown coupled to a rotating shaft .

[0007] In such an electronic device , in addition to turning the rotating shaft , an adj ustment of operating parameters is often also made by moving the shaft in the direction of its longitudinal or rotational axis into di f ferent positions . For example , the rotating shaft can be moved into di f ferent locking positions by pushing it into the casing or pulling it out of the casing of the electronic device , i . e . by a translatory movement of the rotating shaft in the direction of its longitudinal or rotational axis . Depending on the selected locking position, various functions of the electronic device can be set , or operating parameters of the electronic device can be changed .

[0008] Optical rotary encoders , as their name suggests , use optical methods to detect a change in the angle of rotation of the rotating shaft from an original position . In such optical rotary encoders , mechanical switches can be provided to detect the position at which the rotating shaft is currently located in the direction of its longitudinal axis . For example , when the rotating shaft is pressed into the casing of the electronic device , a mechanical switch is triggered so that the position of the shaft in the direction of its longitudinal axis can be determined by monitoring the switching state of the mechanical switch . However, such rotary encoders require , in addition to the optical electronic components for determining the angle of rotation, in particular mechanical components and corresponding detectors in order to determine the displacement of the rotating shaft in its longitudinal direction .

[0009] It would be welcome in the art to provide an optical rotary encoder that , in addition to determining an angle of rotation of a rotating shaft about its longitudinal axis , also allows a displacement of the rotating shaft in the direction of the longitudinal axis of the shaft to be determined and requires only a few additional components for this purpose . Summary

[0010] An optical rotary encoder which enables both a measurement of a rotation of the shaft and the measurement of the movement of the shaft along its rotational axis by using an optical memory principle is speci fied in claim 1 .

[0011] The optical rotary encoder comprises a light source for emitting light , and a rotating shaft being positioned such that a surface of the rotating shaft is illuminable by the light source . The surface is configured to provide reflected light being at least a portion of the emitted light . The optical rotary encoder further comprises an optical sensor array . The optical sensor array comprises a plurality of optical sensors which are positioned to receive at least a portion of the reflected light . The rotating shaft has a longitudinal axis , and is configured to be rotatable around the longitudinal axis by di f ferent rotating angles and to be movable along the longitudinal axis into di f ferent positions . The surface of the rotating shaft is configured so that a respective intensity of the portion of the reflected light received by each of the optical sensors of the optical sensor array is dependent on the rotating angles of the rotating shaft and on the positions of the rotating shaft .

[0012] The proposed approach of the optical rotary encoder thus allows the measurement of two di f ferent movements of the rotating shaft , i . e . the measurement of rotating angles or of a change of rotation of the shaft as well as the measurement of a displacement of the shaft along its longitudinal or rotational axis , by an optical sensor array . That means that a single optical system is used to detect both a rotational movement of the shaft and a translational movement of the shaft , for example , by pressing the shaft into a casing of the optical rotary encoder or an electronic device which includes the optical rotary encoder .

[0013] Thus , a signi ficant advantage of the proposed design of the optical rotary encoder is that no additional sensors or actuators are used, other than an optical detector / sensor system, to detect rotational and translatory motion of the shaft . In particular, no mechanical switches are included in the proposed design for measuring the translational displacement of the shaft along its rotational axis .

[0014] Therefore , there is no abrasion, which usually occurs when using a mechanical switch for detecting a translational movement of the rotating shaft . Moreover, since only one device / system is used for both the measurement of the rotation and the translational movement of the shaft , the proposed approach enables the encoder to be reali zed with a smaller system volume and to be produced with lower costs compared to a solution using an optical system for detecting a rotation of the shaft and using mechanical switches for detecting a movement of the shaft along its longitudinal axis .

[0015] According to a possible embodiment , the optical rotary encoder may include a crown arranged at an end of the rotating shaft for rotating the rotating shaft and moving the rotating shaft in the direction of the longitudinal axis of the rotating shaft .

[0016] According to an embodiment of the optical rotary encoder, the surface of the rotating shaft has a first area and a second area being arranged of fset to the first area in the direction of the longitudinal axis of the rotating shaft . The first area and the second area are configured to reflect the light of the light source in di f ferent angles of reflection, when the light of the light source hits the first area and the second area at the same angle of incidence .

[0017] The rotating shaft may be configured such that the light emitted from the light source is substantially incident on the first area of the shaft at a first translational position of the shaft and reflected from there onto a particular position of the optical sensor array . When the shaft is displaced in the direction of its longitudinal axis , the light emitted from the light source additionally falls on the second area and is reflected therefrom into other areas of the optical sensor array . By comparing or evaluating the ratio of the light intensities detected at the di f ferent positions of the optical sensor array, when the shaft is moved along its axis of rotation or its longitudinal axis , a change in the position of the shaft due to the translational movement of the shaft along its longitudinal axis can be determined .

[0018] According to a possible embodiment of the optical rotary encoder, the rotating shaft has a rotationally symmetrical shape with respect to the longitudinal axis of the rotating shaft . The first area of the surface of the shaft has a rotationally symmetrically di f ferent shape than the second area of the surface of the shaft . For example , the first area of the rotating shaft may be shaped cylindrically, and the second area of the shaft may be conically shaped . As a result , the light is reflected to a di f ferent position on the optical sensor array, when it strikes the conically shaped second area than when it strikes the cylindrically shaped first area of the shaft .

[0019] According to another possible embodiment of the optical rotary encoder, the surface of the rotating shaft has a first area and a second area being arranged of fset to the area in the direction of the longitudinal axis of the rotating shaft . The first area and second area are configured to scatter the light emitted from the light source to a di f ferent extent , when the light of the light source strikes the first area and the second area at the same angle of incidence .

[0020] In this embodiment , the light is scattered di f ferently depending on where it impinges on the rotating shaft . Therefore , as the rotating shaft moves along its longitudinal axis , the intensity of the reflected light detected at a position on the optical sensor array changes . By evaluating the change in the detected light intensity of the reflected light during a translatory movement of the rotating shaft along its longitudinal axis , the displacement of the rotating shaft along its longitudinal axis and thus the change of path can be determined .

[0021] According to a possible embodiment of the optical rotary encoder, the first area of the rotating shaft has zones of di f ferent light absorption and reflection . Depending on the angle of rotation of the rotating shaft , the light incident from the light source on the zones of the first area of the shaft is therefore absorbed or reflected at di f ferent strengths . The optical sensors thus detect di f ferent light intensities of the reflected light depending on their position in the optical sensor array and the angle of rotation of the shaft . By measuring the change in the light intensities detected by the optical sensors when the shaft is rotated, a change in the angle of rotation of the shaft can be determined .

[0022] According to a possible embodiment of the optical rotary encoder, the first area has first ones of the zones and second ones of the zones . The first area is patterned such that a respective one of the first zones is arranged between two of the second ones of the zones . Thus , when the rotating shaft rotates there are continuous changes in the detected light intensity at each position of an optical sensor in the optical sensor array, which are periodically repeated . By measuring the phase shi ft of the respective output signal of each optical sensor, when the shaft rotates , changes in the angle of rotation of the shaft can be determined .

[0023] According to a possible embodiment , the optical rotary encoder comprises a supporting substrate being positioned below the rotating shaft . The optical sensor array comprises first optical sensors and at least one second optical sensor . The first optical sensors and the at least one second optical sensor are positioned on the supporting substrate such that the at least one second optical sensor is positioned on the supporting substrate of fset to the first optical sensors in the direction of the longitudinal axis of the rotating shaft .

[0024] Depending on the translatory movement of the shaft along its longitudinal axis or axis of rotation, the intensity of the light reflected onto the first sensors or the at least one second sensor changes . By evaluating the change in the detected light intensity of the reflected light received by the first optical sensors or the at least one second optical sensor, the movement of the shaft or the change in distance of the shaft during the translatory movement of the shaft can be determined .

[0025] According to a possible embodiment of the optical rotary encoder, the first area of the rotating shaft is configured so that a respective intensity of the portion of the reflected light received by each of the first optical sensors is dependent on the rotating angles of the rotating shaft . Thus , by evaluating the change in light intensity of the reflected light detected at the di f ferent positions of the first optical sensors , and thus by evaluating the phase shi ft of the sensor output signals , a change in the angle of rotation of the shaft can be determined .

[0026] According to an embodiment of the optical rotary encoder, the first area and the second area of the rotating shaft are configured so that , when the rotating shaft is moved in the direction of the longitudinal axis of the rotating shaft from a first position to a second position, the respective intensity of the portion of the reflected light received by each of the first optical sensors is decreased, and the respective intensity of the portion of the reflected light received by the at least one second optical sensor is increased . The change in the light intensity of the reflected light detected by the first optical sensors and the at least one second optical sensor is thus a measure of the distance by which the shaft of the optical rotary encoder has been moved along its longitudinal axis .

[0027] According to a possible embodiment of the optical rotary encoder, the optical sensor array comprises a plurality of the at least one second optical sensor . The first optical sensors are positioned on the supporting substrate next to each other in a first line . The second optical sensors are positioned on the supporting substrate next to each other in a di f ferent second line .

[0028] The evaluation of the light intensity detected by the optical sensors of a speci fic line during a rotational movement of the rotating shaft provides information about the rotation of the shaft by a certain angle of rotation . On the other hand, the evaluation of the light intensities of the reflected light detected by the second optical sensors of the second line in comparison to the light intensities detected by the first optical sensors of the first line during a translatory movement of the shaft provides information about the distance by which the rotating shaft has been displaced along its longitudinal direction .

[0029] According to a possible embodiment of the optical rotary encoder, the first line of the first optical sensors and the second line of the second optical sensors are arranged perpendicular to the direction of the longitudinal axis of the rotating shaft . Thus , the rotational movement of the rotating shaft in the direction of its longitudinal axis can be determined by evaluating and comparing the output signals of the first optical sensors of the first line with each other or by comparing the output signals of the second optical sensors of the second line with each other .

[0030] According to a further embodiment of the optical rotary encoder, the first line of the first optical sensors is positioned on the supporting substrate of fset to the second line of the second optical sensors in the direction of the longitudinal axis of the rotating shaft . Thus , the translatory movement of the rotating shaft in the direction of its longitudinal axis can be determined by evaluating the output signals of the first and second optical sensors of the first and second line , and comparing the output signals of the first optical sensors of the first line with the output signals of the second optical sensors of the second line .

[0031] According to a possible embodiment of the optical rotary encoder, the optical sensor array comprises a plurality of the at least one second optical sensor . The first optical sensors are positioned on the supporting substrate next to each other in a first line perpendicular to the direction of the longitudinal axis of the rotating shaft . The second optical sensors are positioned on the supporting substrate next to each other in a di f ferent second line that is in the direction of the longitudinal axis of the rotating shaft .

[0032] In this embodiment , the evaluation of the output signals of the first optical sensors enables the determination of a change in the angle of rotation of the shaft . The evaluation of the output signals of the second optical sensors makes it possible to determine a change in position of the shaft during a translational displacement of the shaft along its longitudinal or rotational axis .

[0033] An electronic device in which a function or operating parameters are adj ustable by rotating an actuator about an angle of rotation or by displacing the actuator along the axis of rotation or the longitudinal axis of the actuator is speci fied in claim 15 .

[0034] The electronic device comprises an optical rotary encoder being configured according to one of the embodiments described above . The electronic device may be embodied, for example , as one of a watch or a rotation sensor or a health monitoring device . By rotating the shaft on the crown or by pushing the shaft on the crown into the casing of the electronic device into di f ferent positions , operating conditions of the electronic device can be set or di f ferent functions of the electronic device can be activated .

[0035] Additional features and advantages of the optical rotary encoder and the electronic device are set forth in the detailed description that follows . It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework for understanding the nature and character of the claims .

[0036] Brief Description of the Drawings

[0037] The accompanying drawings are included to provide further understanding, and are incorporated in, and constitute a part of , the speci fication . As such, the disclosure will be more fully understood from the following detailed description, taken in conj unction with the accompanying figures in which :

[0038] Figure 1 shows an electronic device configured as a watch in which operating functions can be set by turning and pushing a rotating shaft into a casing of the electronic device ;

[0039] Figure 2 shows an embodiment of an optical rotary encoder for determining a rotational movement around a rotating axis and a translatory movement of the rotating shaft along its rotational axis by an optical sensor array; Figure 3 illustrates the determination of a change in an angle of rotation of a rotating shaft of an optical rotary encoder by optical sensors of an optical sensor array;

[0040] Figure 4 shows an optical rotary encoder for determining a change in the angle of rotation of a rotating shaft and for determining a change in positions of the rotating shaft during a translatory movement of the shaft along its rotational axis by a first embodiment of an optical sensor array;

[0041] Figure 5 shows an optical rotary encoder for determining a change in the angle of rotation of a rotating shaft and for determining a change in positions of the shaft during a translatory movement of the shaft along its rotational axis by a second embodiment of an optical sensor array; and

[0042] Figure 6 shows an embodiment of a rotating shaft of an optical rotary encoder for determining a change in an angle of rotation of the shaft during a rotational movement of the rotating shaft around its rotational axis and for determining a change in positions of the rotating shaft during a translatory movement of the shaft along its rotational axis .

[0043] Detailed Description of the Drawings

[0044] Figure 1 shows an electronic device 100 based on the example of a watch, for example a smartwatch or a fitness tracking watch, wherein operating parameters and functions of the electronic device can be set by turning a crown 24 which protrudes out of a casing of the electronic device and is coupled to a rotating shaft 20 . Depending on the position of the angle of rotation of a rotating shaft 20 or the change in the angle of rotation of the rotating shaft 20 , certain functions of the electronic device 100 can be activated, or operating parameters of the device 100 can be set or changed . In addition, operating conditions or parameters of the electronic device 100 can be changed by pushing or pulling on the crown 24 for moving the rotating shaft 20 along its longitudinal axis or axis of rotation to certain positions .

[0045] The change of the angle of rotation of the rotating shaft by a rotational movement of the shaft , and the change of the positions of the rotating shaft by a translatory movement of the shaft can be detected by an optical rotary encoder 1 that is included in the casing of the electronic device 1 .

[0046] Figures 2 to 5 show di f ferent embodiments of the optical rotary encoder 1 for determining a change in an angle of rotation of the rotating shaft 20 of the encoder caused by a rotation of the shaft , and for determining a change in the position of the rotating shaft 20 of the encoder caused by a translatory movement of the shaft along its rotational axis 25 . According to the proposed approach of the optical rotary encoder 1 , the change of the angle of rotation of the rotating shaft 20 and the change of the positions of the shaft 20 during a translatory movement of the shaft along its rotational or longitudinal axis is determined by a pure optical system of the encoder, as explained below . Referring to Figures 2 to 5 , the optical rotary encoder 1 comprises a light source 10 for emitting light , a rotating shaft 20 and an optical sensor array 30 . The light source can comprise one or more light emitting diodes . The rotating shaft 20 is positioned to be illuminated by the light emitted from the light source 10 . The rotating shaft 20 is positioned in respect to the light source 10 so that a surface 23 of the rotating shaft is illuminable by the light source 10 , when the light source 10 is turned on . The surface 23 reflects at least a portion of the light that is emitted by the light source 10 and strikes the surface 23 . The surface 23 is thus configured to provide reflective light which is at least a portion of the emitted light of the light source 10 that strikes the surface 23 .

[0047] The optical sensor array 30 comprises a plurality of optical sensors 31a, ..., 31d, 32a, ..., 32d . The optical sensors are positioned with respect to the rotating shaft 20 to receive at least a portion of the reflected light . The rotating shaft 20 is configured to be rotatable around its longitudinal or rotational axis 25 by di f ferent rotating angles . The rotating shaft 20 is further configured to be movable along the longitudinal or rotational axis 25 into di f ferent positions along the longitudinal or rotational axis .

[0048] According to the proposed approach of the optical rotary encoder, the surface 23 of the rotating shaft 20 is configured so that a respective intensity of the portion of the reflected light received by each of the optical sensors 31a, ..., 31d, 32a, ..., 32d of the optical sensor array 30 is dependent on the rotating angles a of the rotating shaft 20 around the longitudinal / rotational axis 25 and on the positions of the rotating shaft 20 along the longitudinal / rotational axis 25 .

[0049] As shown in Figures 2 to 5 , the optical rotary encoder 1 comprises a supporting substrate 40 that is positioned below the rotating shaft 20 . The optical sensor array 30 comprises first optical sensors 31a, ..., 31d being positioned on the supporting substrate 40 . The first optical sensors 31a, ..., 31d are positioned on the supporting substrate 40 next to each other in a first line . The first line of the first optical sensors 31a, ..., 31d is arranged perpendicular to the direction of the longitudinal or rotational axis 25 of the rotating shaft 20 .

[0050] The surface 23 of the rotating shaft 20 has a first area 21 . The first area 21 is configured so that a respective intensity of the portion of the reflected light received by each of the first optical sensors 31a, ..., 31d is dependent on the rotating angles a of the rotating shaft 20 .

[0051] According to a possible embodiment of the optical rotary encoder, the first area 21 of the rotating shaft 20 may have zones 21a, 21b of di f ferent light absorption and reflection, i . e . the zones 21a, 21b have a di f ferent light absorption or reflection coef ficient . The first area 21 may have first zones 21a and second zones 21b . As illustrated in Figures 2 to 5 , the first area 21 may be patterned such that a respective one of the first zones 21a is arranged between two of the second zones 21b .

[0052] According to a possible embodiment , the first and second zones 21a and 21b may be configured as a black and white structure on the rotating shaft 20 . In particular, the patterned area 21 may include the first zones 21a configured as light stripes and the second zones 21b configured as dark stripes which extend on the surface 23 along the longitudinal axis 25 of the rotating shaft 20 . Nevertheless , the patterned area 21 is not intended to be limited to the light and dark stripe configuration shown . In principle , di f ferent designs of surface elements / zones with di f ferent absorption / reflection coef ficients or di f ferent reflective characteristics , for example high reflective and low reflective areas , are possible .

[0053] The operation of the optical rotary encoder 1 for detecting a rotation of the shaft 20 and for determining changes in the angle of rotation of the shaft 20 is explained below .

[0054] The light source 10 emits light to the rotating shaft 20 so that the zones 21a and 21b of di f ferent light absorption and reflection are illuminated with the emitted light . After reflection at the zones 21a and 21b, the reflected light is sent back to the optical sensor array 30 as light having modulated intensities that vary with the rotation angle a of the rotating shaft 20 . Rotating the shaft 20 will create a moving pattern of di f ferent light intensities on the optical sensor array 30 , in particular on the first optical sensors 31a, ..., 31d . The movement of the pattern of light intensities on the optical sensor array 30 that is caused by the rotation of the rotating shaft 20 is measured by the first line of the first optical sensors 31a, ..., 31d .

[0055] Figure 3 illustrates an example of output signals OS generated by the first optical sensors 31a, ..., 31d during rotational movement of the rotating shaft 20 . At each angular position / rotating angle a, the optical sensors 31a, ..., 31d receive di f ferent intensities of the reflected light due to the di f ferent degree of reflection at the first and second zones 21a and 21b of the rotating shaft 20 . The output signals OS of the optical sensors 31a, ... , 31d therefore have the characteristics shown in Figure 3 . As can be seen from the signal curves , the output signals OS of the optical sensors have a phase shi ft in relation to each other . The rotation angle a or the change of the rotation angle a of the rotating shaft during a rotational movement of the shaft 20 can be recalculated by a processing circuit that evaluates the output signals OS of the first optical sensors 31a, ..., 31d .

[0056] As already noted above , in addition to the determination of a rotation of the shaft 20 , the optical rotary encoder 1 allows to detect a translatory movement of the rotating shaft 20 along its longitudinal or rotational axis 25 . For this purpose , the optical rotary encoder 1 has further special f eatures / components which will be explained in the following .

[0057] Referring to the embodiments of the optical rotary encoder 1 shown in Figures 2 to 5 , the surface 23 of the rotating shaft 20 has a second area 22 that is arranged of fset to the first area 21 in the direction of the longitudinal or rotational axis 25 of the rotating shaft 20 . The first area 21 and the second area 22 are configured to reflect the light that is emitted by the light source 10 and strikes the areas 21 and 22 in di f ferent angles of reflection, when the light of the light source 10 hits the first area 21 and the second area 22 of the surface 23 at the same angle of incidence .

[0058] The rotating shaft 20 has a rotationally symmetrical shape with respect to its longitudinal axis 25 . The first area 21 of the surface 23 of the shaft 20 has a rotationally symmetrically di f ferent shape than the second area 22 of the surface 23 of the shaft . In other words , in a longitudinal section along the longitudinal axis of the rotating shaft 20 , the first area 21 of the outer surface 23 of the rotating shaft 20 has a di f ferent inclination with respect to the longitudinal axis than the second area 22 of the surface 23 of the shaft . In a longitudinal section through the shaft , in the first area 21 of the outer surface 23 of the shaft is parallel to the longitudinal axis of the shaft . In the longitudinal section through the shaft , the second area 22 of the outer surface 23 of the shaft is inclined to the longitudinal axis of the shaft . According to a possible embodiment , the first area 21 is cylindrically shaped, and the second area 22 is conically shaped .

[0059] In addition to the first optical sensors 31a, ..., 31d, the optical rotary encoder 1 comprises at least one second optical sensor 32a, ..., 32d . The first optical sensors 31a, ..., 31d and the at least one second optical sensor 32a, ..., 32d are positioned on the supporting substrate 40 such that the at least one second optical sensor 32a, ..., 32d is positioned on the supporting substrate 40 of fset to the first optical sensors 31a, ..., 31d in the direction of the longitudinal / rotational axis 25 of the rotating shaft 20 . Even i f Figures 2 to 5 show a plurality of second optical sensor, an embodiment with only one second optical sensor is also possible .

[0060] The first area 21 and the second area 22 of the rotating shaft 20 are configured so that , when the rotating shaft 20 is moved in the direction of the longitudinal or rotational axis 25 of the rotating shaft 20 from a first position Pl to a second P2 , as illustrated in Figures 3 and 4 , the respective intensity of the portion of the reflected light received by each of the first optical sensors 31a, 31d is decreased, and the respective intensity of the portion of the reflected light received by the at least one second optical sensor 32a, ..., 32d is increased .

[0061] According to the embodiments of the optical rotary encoder 1 shown in Figures 2 to 4 , the optical sensor array 30 comprises a plurality of second optical sensors 32a, ..., 32d . The second optical sensors 32a, ..., 32d are positioned on the supporting substrate 40 next to each other in a second line being di f ferent from the first line of the first optical sensors 31a, ..., 31d . The first line of the first optical sensors 31a, ..., 31d and the second line of the second optical sensors 32a, ..., 32d are arranged perpendicular to the direction of the longitudinal or rotational axis 25 of the rotating shaft 20 . The first line of the first optical sensors 31a, ..., 31d is positioned on the supporting substrate 40 of fset to the second line of the second optical sensors 32a, ..., 32d in the direction of the longitudinal or rotational axis 25 of the rotating shaft 20 .

[0062] Figure 5 shows another embodiment of the optical rotary encoder 1 , wherein the optical sensor array 30 comprises a plurality of second optical sensors 32a, ..., 32d . The first optical sensors 31a, ..., 31d are positioned on the supporting substrate 40 next to each other in a first line perpendicular to the direction of the longitudinal or rotational axis 25 of the rotating shaft 20 . The second optical sensors 32a, ..., 32d are positioned on the supporting substrate 40 next to each other in a di f ferent second line that is in the direction of the longitudinal or rotational axis 25 of the rotating shaft 20 .

[0063] In the following, the operation of the optical rotary encoder 1 for determining the changes in the positions of the shaft 20 , when the shaft 20 is moved translationally along its longitudinal or rotational axis 25 , is explained .

[0064] Figure 3 shows the rotating shaft 20 located at position Pl . The light source 10 and the rotating shaft 20 are arranged so that only the first area 21 of the surface 23 is illuminated by the light of the light source 10 , when the shaft 20 is located at position Pl . The optical sensor array 30 is positioned below the rotating shaft 20 that , at position Pl of the rotating shaft 20 , only the first optical sensors 31a, ..., 31d are illuminated by the light reflected on the first area 21 of the surface 23 . A rotation of the rotating shaft by a certain rotating angle a can be determined, as explained above .

[0065] Figure 4 shows the rotating shaft 20 located at position P2 . As illustrated in Figure 4 , the second optical sensors 32a, ..., 32d of the second line are only illuminated by the light reflected at the surface 23 of the rotating shaft 20 , when the rotating shaft 20 is moved in a translatory movement along its longitudinal or rotational axis 25 from position Pl to position P2 . In this case , the light emitted from the light source 10 partly strikes the first area 21 and the second area 22 of the surface 23 of the rotating shaft . Due to the particular configuration of the second area 22 , the light gets reflected further away from the initial spot position on the first line of the first optical sensors 31a, ..., 31d and hits the second optical sensors 32a, ..., 32d that are distributed in the second line . The second optical sensors 32a, 32d receive higher intensities of reflected light in comparison to the first optical sensors 31a, ..., 31d the further the shaft 20 is moved from position Pl towards position P2 . By evaluating the changes in the light intensities received by the first optical sensors 31a, ..., 31d and the second optical sensors 32a, ..., 32d during the translatory movement of the rotating shaft 20 along its longitudinal or rotational axis 25 , it is possible to recalculate the change in position of the shaft 20 along its longitudinal axis by a processing circuit .

[0066] I f the shaft 20 is pressed against a spring having the spring force Fspring, as indicated in Figure 4 , it is also possible to calculate a pressing force FpreSs , i f the spring constant and the displacement distance of the shaft 20 are known .

[0067] Another embodiment of a rotating shaft 20 which allows to determine a displacement of the shaft 20 along its rotational or longitudinal axis 25 is shown in Figure 6 . The surface 23 of the rotating shaft 20 has areas 21 and 22 with di f ferent reflection characteristics . In the shown embodiment , the rotating shaft 20 comprises a first area 21 , as described with reference to Figures 2 to 5 , and additionally comprises a second area 22 that is arranged of fset to the first area 21 in the direction of the longitudinal or rotational axis 25 of the rotating shaft 20 . The areas 21 and 22 are configured to scatter the light emitted from the light source 10 to a di f ferent extent , when the light of the light source 10 hits the first area 21 and the second area 22 at the same angle of incidence . In the embodiment shown in Figure 6 , the second area 22 has , for example , the light / dark stripe pattern of the first area 21 , over which dark ring-shaped stripes are arranged circumferentially at a distance from one another .

[0068] The further the shaft 20 is moved from position Pl towards position P2 , the more light strikes the second area 22 . As a result , the light intensity of the light reflected at the surface 23 is decreased on the optical sensor array 30 that is positioned below the rotating shaft 20 , the further the shaft 20 is moved towards position P2 . By evaluating the changes in the light intensities received by the optical sensors of the optical sensor array during the translatory movement of the rotating shaft 20 along its longitudinal or rotational axis 25 , it is possible by processing circuit to recalculate the change in position of the shaft 20 along its longitudinal axis .

[0069] The optical rotary encoder 1 for determining a change in the rotational angle of the rotating shaft 20 and for determining a translatory movement of the shaft along its longitudinal or rotational axis can be included in an electronic device , for example a watch / smartwatch, a rotation sensor, a health monitoring device , etc . for setting operational parameters and activating functions of the electronic device . For these applications , the optical rotary encoder may include the crown 24 arranged at an end of the rotating shaft 20 for rotating the rotating shaft and moving the rotating shaft in the direction of its longitudinal or rotational axis 25 , as illustrated in Figures 1 to 6 .

[0070] The embodiments of the optical rotary encoder and the electronic device disclosed herein have been discussed for the purpose of familiari zing the reader with novel aspects of the optical rotary encoder and the electronic device . Although preferred embodiments have been shown and described, many changes , modi fications , equivalents and substitutions of the disclosed concepts may be made by one having skill in the art without unnecessarily departing from the scope of the claims .

[0071] In particular, the design of the optical rotary encoder and the electronic device is not limited to the disclosed embodiments , and gives examples of many alternatives as possible for the features included in the embodiments discussed . However, it is intended that any modi fications , equivalents and substitutions of the disclosed concepts be included within the scope of the claims which are appended hereto .

[0072] Features recited in separate dependent claims may be advantageously combined . Moreover, reference signs used in the claims are not limited to be construed as limiting the scope of the claims .

[0073] Furthermore , as used herein, the term "comprising" does not exclude other elements . In addition, as used herein, the article "a" is intended to include one or more than one component or element , and is not limited to be construed as meaning only one .

[0074] This patent application claims the priority of German patent application with application No . 10 2023 133 940 . 0 , the disclosure content of which is hereby incorporated by reference . References

[0075] 1 optical rotary encoder

[0076] 10 light source 20 rotating shaft

[0077] 21 first area

[0078] 22 second area

[0079] 23 surface

[0080] 24 crown 25 longitudinal / rotational axis of the rotating shaft

[0081] 30 optical sensor array

[0082] 31a, ..., 31d first optical sensors

[0083] 32a, ..., 32d second optical sensors 40 supporting substrate

Claims

Claims1. An optical rotary encoder, comprising:- a light source (10) for emitting light,- a rotating shaft (20) being positioned such that a surface (23) of the rotating shaft is illuminable by the light source (10) , wherein the surface (23) is configured to provide reflective light being at least a portion of the emitted light (23) ,- an optical sensor array (30) comprising a plurality of optical sensors (31a, ..., 31d, 32a, ..., 32d) positioned to receive at least a portion of the reflected light,- wherein the rotating shaft (20) has a longitudinal axis (25) , and is configured to be rotatable around the longitudinal axis (25) by different rotating angles (a) and to be movable along the longitudinal axis (25) into different positions (Pl, P2) ,- wherein the surface (23) of the rotating shaft (20) is configured so that a respective intensity of the portion of the reflected light received by each of the optical sensors (31a, ..., 31d, 32a, ..., 32d) of the optical sensor array is dependent on the rotating angles (a) of the rotating shaft (20) and on the positions (Pl, P2) of the rotating shaft (20) .

2. The optical rotary encoder of claim 1,- wherein the surface (23) has a first area (21) and a second area (22) being arranged offset to the first area (21) in the direction of the longitudinal axis (25) of the rotating shaft (20) ,- wherein the first area (21) and the second area (22) are configured to reflect the light of the light source (10) in different angles of reflection, when the light of the lightsource (10) hits the first area (21) and second area (22) at the same angle of incidence.

3. The optical rotary encoder of claim 1 or 2,- wherein the rotating shaft (20) has a rotationally symmetrical shape with respect to the longitudinal axis (25) ,- wherein the first area (21) of the surface (23) of the rotating shaft (20) has a rotationally symmetrically different shape than the second area (22) of the surface (23) of the rotating shaft (20) .

4. The optical rotary encoder of any of the claims 1 to 3,- wherein the surface (23) has a first area (21) and a second area (22) being arranged offset to the first area (21) in the direction of the longitudinal axis (25) of the rotating shaft (20) ,- wherein the first area (21) and the second area (22) are configured to scatter the light emitted from the light source (10) to a different extent, when the light of the light source (10) hits the first area (21) and the second area (22) at the same angle of incidence.

5. The optical rotary encoder of any of the claims 1 to 4, wherein the first area (21) has zones (21a, 21b) of different light absorption and reflection.

6. The optical rotary encoder of claim 5,- wherein the first area (21) has first ones of the zones (21a) and second ones of the zones (21b) ,- wherein the first area (21) is patterned such that a respective one of the first zones (21a) is arranged between two of the second ones of the zones (21b) .

7. The optical rotary encoder of any of the claims 2 to 6, comprising :- a supporting substrate (40) being positioned below the rotating shaft (20) ,- wherein the optical sensor array (30) comprises first optical sensors (31a, ..., 31d) and at least one second optical sensor (32a, ..., 32d) , the first optical sensors (31a, ..., 31d) and the at least one second optical sensor (32a, ..., 32d) being positioned on the supporting substrate (40) such that the at least one second optical sensor (32a, ..., 32d) is positioned on the supporting substrate (40) offset to the first optical sensors (31a, ..., 31d) in the direction of the longitudinal axis (25) of the rotating shaft (20) .

8. The optical rotary encoder of claim 7, wherein the first area (21) is configured so that a respective intensity of the portion of the reflected light received by each of the first optical sensors (31a, ..., 31d) is dependent on the rotating angles (a) of the rotating shaft (20) .

9. The optical rotary encoder of the claim 7 or 8, wherein the first area (21) and the second area (22) are configured so that, when the rotating shaft (20) is moved in the direction of the longitudinal axis (25) of the rotating shaft (20) from a first position (Pl) to a second position (P2) , the respective intensity of the portion of the reflected light received by each of the first optical sensors (31a, ..., 31d) is decreased, and the respective intensity of the portion of the reflected light received by the at least one second optical sensor (32a, ..., 32d) is increased.

10. The optical rotary encoder of any of the claims 7 to 9,- wherein the optical sensor array (30) comprises a plurality of the at least one second optical sensor (32a, ..., 32d) ,- wherein the first optical sensors (31a, ..., 31d) are positioned on the supporting substrate (40) next to each other in a first line and the second optical sensors (32a, ..., 32d) are positioned on the supporting substrate (40) next to each other in a different second line.

11. The optical rotary encoder of claim 10, wherein the first line of the first optical sensors (31a, ..., 31d) and the second line of the second optical sensors (32a, ..., 32d) are arranged perpendicular to the direction of the longitudinal axis (25) of the rotating shaft (20) .

12. The optical rotary encoder of claim 10 or 11, wherein the first line of the first optical sensors (31a, ..., 31d) is positioned on the supporting substrate (40) offset to the second line of the second optical sensors (32a, ..., 32d) in the direction of the longitudinal axis (25) of the rotating shaft (20) .

13. The optical rotary encoder of any of the claims 7 to 9,- wherein the optical sensor array (30) comprises a plurality of the at least one second optical sensor (32a, ..., 32d) ,- wherein the first optical sensors (31a, ..., 31d) are positioned on the supporting substrate (40) next to each other in a first line perpendicular to the direction of the longitudinal axis (25) of the rotating shaft (20) ,- wherein the second optical sensors (32a, ..., 32d) are positioned on the supporting substrate (40) next to each other in a different second line that is in the direction of the longitudinal axis (25) of the rotating shaft (20) .

14. The optical rotary encoder of any of the claims 1 to 13, comprising : a crown (24) arranged at an end of the rotating shaft (20) for rotating the rotating shaft (20) and moving the rotating shaft (20) in the direction of the longitudinal axis (25) of the rotating shaft (20) .

15. An electronic device, comprising:- an optical rotary encoder (1) as claimed in any of the claims 1 to 14,- wherein the electronic device (100) is embodied as one of a watch or a rotation sensor or a health monitoring device.

Images