Personal Care Devices

Abstract

Proposed are schemes, solutions, concepts, designs, methods, and systems related to assisting and / or improving image acquisition from a vibrating personal care device having an image capture device. In an embodiment, it is proposed to generate multiple pulses of illumination during a single vibration cycle of the personal care device. By illuminating a portion of the user multiple times during a single vibration cycle of the personal care device, improved images are obtained (e.g., images exhibiting less blur and / or distortion). In this manner, improved images are obtained from the vibrating personal care device.

Description

[Technical field]

[0001] The present invention relates to the field of personal care devices, and in particular to the field of personal care devices that capture a digital impression of one or more characteristics of a user. [Background technology]

[0002] It is known to provide personal care devices with the ability or functionality to capture digital impressions (e.g., images) of a user's characteristics or parts during use. For example, intraoral scanner (IOS) devices use projected light (e.g., laser or structured light) and an image sensor to capture images of dental and gingival tissues. These images can be processed to create a three-dimensional (3D) model of the scanned surface. Thus, the data provided by the IOS is useful for oral care, including detection of common dental diseases such as caries, tooth discolouration, and misalignment of the teeth. It is also advantageous to repeatedly capture and compare IOS images, for example to identify changes in dental and gingival tissues over time. Summary of the Invention [Problem to be solved by the invention]

[0003] Personal care devices, such as powered brushing or shaving devices, are used regularly (e.g., daily) and therefore provide a suitable means for regularly capturing images of the user. As such, there is a trend for cameras or image sensors to be integrated into personal care devices, such as toothbrushes. However, because a primary use characteristic of such personal care devices is their vibration, or cyclic / periodic motion, images captured by an image capture device integrated with the personal care device are typically distorted and / or blurred by the motion / vibration of the device.

[0004] While image stabilization techniques are known for portable handheld devices (e.g., smartphones, digital photo cameras, etc.), the design and optimization of such techniques is limited to low frequency (e.g., less than 10 Hz) irregular (e.g., non-periodic, random, etc.) motion caused by the user. Because personal care devices (e.g., toothbrushes) typically move or vibrate at much higher periodic frequencies (e.g., greater than 20-300 Hz), there remains a need to stabilize the image capture process and / or make the image acquisition process robust to device motion / vibration caused by personal care devices. [Means for solving the problem]

[0005] The invention is defined by the claims.

[0006] According to an embodiment of the present invention there is provided a personal care device comprising: an image capture device adapted to capture an image of one or more features of a user when in use; - vibration means adapted to vibrate the personal care device such that, in use, the personal care device (and the image capture device) vibrates in a periodic vibration cycle having a vibration frequency; an illumination device configured to generate pulsed illumination in use for illuminating a portion of a user; a control unit adapted to control the lighting device to generate two or more pulses of lighting during a single vibration cycle of the personal care device; and a processor unit configured to determine, as a target portion of the oscillation cycle, a first portion and a second portion of the oscillation cycle in which an angular velocity of the part of the personal care device satisfies a predetermined requirement; A personal care device is provided, wherein a control unit is adapted to control the lighting device to generate a first pulse of lighting during a first portion of an oscillation cycle and to generate a second pulse of lighting during a second portion of the oscillation cycle.

[0007] The proposed concept in this case aims to provide schemes, solutions, concepts, designs, methods and systems related to assisting and / or improving image acquisition from a vibrating personal care device having an image capture device, where the vibration of the personal care device affects the image of the image capture device. The image capture device can be a camera that is rigidly fixed to the vibrating device and therefore vibrates together with the device. Alternatively, the camera sensor itself may be located in a stationary part of the device (e.g. a brush handle), while the optics of the device (optical fiber, imaging lens of the optics, etc.) are subjected to the vibration of the device. In particular, in an embodiment of the invention, it is proposed to generate multiple pulses of illumination during a single vibration cycle of the personal care device. By illuminating a part of the user multiple times during a single vibration cycle of the personal care device, an improved image (e.g. less blur and / or distortion is seen in the image) is obtained. In this way, an improved image is obtained from the vibrating personal care device.

[0008] In particular, to reduce or minimize distortion in images acquired from a vibrating personal care device (during use), it is proposed to adapt the illumination pulse based on the vibration cycle. For example, the timing of illuminating a portion of the user's oral cavity can be synchronized with the vibration cycle, thereby ensuring that illumination occurs only during a preferred or optimal portion of the vibration cycle.

[0009] It is also proposed to determine a target portion of the oscillation cycle based on parameters of the periodic oscillation cycle. The lighting device is then controlled to synchronize the pulsed illumination to the target portion of the oscillation cycle. As an example, the movement and / or drive signal of the oscillation means can be monitored and then analyzed to determine the period / portion of the oscillation cycle during which there is low / zero movement of the personal care device.

[0010] The embodiments are particularly relevant to vibratory oral care devices, such as, for example, power toothbrushes. Thus, in one embodiment, the personal care device comprises an oral care device, the image capture device adapted to capture images of one or more features of a user's oral cavity, in use, and the lighting device configured to generate pulsed lighting for illuminating a portion of the user's oral cavity, in use.

[0011] In other words, some embodiments propose to adapt the pulsed illumination of the user's oral cavity based on one or more sensed operating parameters of the oral care device to provide improved quality images. Thus, embodiments facilitate stable, high-quality image acquisition during tooth brushing. Such embodiments are particularly relevant for remote dental care proposals, for example by enabling improved imaging of the user's teeth, gums, tongue, etc. For example, images obtained by the proposed embodiments may assist dental care procedures and / or decisions. Thus, embodiments are used in conjunction with dental treatment selection to assist dental care professionals in selecting a treatment for a subject.

[0012] Additionally, embodiments facilitate image-based diagnosis, superior position sensing, treatment planning (eg, orthodontics, aligners), and / or monitoring of dental procedures.

[0013] Incorporating the embodiments into a user's regular brushing regimen (instead of using a separate device such as a smartphone, dental endoscope, or handheld intraoral scanner) helps improve dental care. The proposed concept thus provides improved image-based dental care.

[0014] However, the embodiments are also applicable to other vibrating personal care devices such as shavers, skin cleansing devices, etc.

[0015] It has been recognized that by controlling an image capture device based on a targeted portion of the vibration cycle of a personal care device, higher quality images can be obtained (in terms of reduced blur and / or distortion), thereby assisting in oral / dental treatment.

[0016] The embodiments thus provide the advantage of being able to improve decisions in the selection of therapeutic treatments through the use of images captured by the vibrating personal care device, for example, the embodiments may make available a greater number of oral therapeutic treatment options (e.g., through the provision of more and / or improved information about the subject's oral health).

[0017] The control is adapted to control the image capture device to synchronize the timing of the pulsed illumination with the oscillation cycle, which helps to ensure sufficient lighting conditions to reduce blurring and / or distortion of the image while ensuring a sufficient total illumination amount, i.e., activation of the lighting device for unnecessary periods of time is avoided.

[0018] In some embodiments, the control unit is adapted to control the lighting device to generate pulsed lighting during vibration at an integer multiple of twice the vibration frequency, for example 2x, 4x or 8x.

[0019] The control unit is adapted to set the illumination duration of the illumination device to be equal to or less than a quarter of the period of the vibration waveform, more preferably equal to or less than an eighth of the period of the vibration waveform, and even more preferably equal to or less than a sixteenth of the period of the vibration waveform. In this way, the illumination for capturing the image is set fast enough to reduce or minimize image distortion or blurring due to camera vibration. That is, the duration of the illumination pulse is set to be shorter than or equal to the duration / period of the minimum movement of the personal care device. For example, for a square wave drive vibration with a duty cycle of about 50%, it may be preferable to adapt the duration of the illumination pulse to be less than a quarter of the vibration period to ensure the acquisition of a useful image.

[0020] In some embodiments, it is proposed to identify a target portion of the vibration cycle (e.g., a portion with low speed / low motion) and then control the pulsed illumination based on the identified target portion of the vibration cycle. The control of the pulsed illumination according to the target portion of the vibration cycle results in improved images (e.g., less blur and / or distortion in the image). In particular, it is proposed to adapt the timing and / or settings of the pulsed illumination based on the vibration cycle to reduce or minimize distortion of the image acquired from the vibrating personal care device (in use). For example, the timing of the illumination pulse can be synchronized with the target portion of the vibration cycle, thereby ensuring that image capture occurs only during the preferred or optimal portion of the vibration cycle.

[0021] It is also proposed to determine the target portion of the vibration cycle by the sensed movement of the personal care device. By way of example, the motion, angular velocity and / or drive signal or means can be monitored and then analyzed to determine the period / portion of the vibration cycle where low / zero movement of the personal care device is observed.

[0022] For example, the vibration means may comprise a vibrator and a drive sensor may be employed to sense a drive signal of the vibrator. The processor unit is then adapted to determine a target portion of the vibration cycle based on a time period during which the sensed drive signal satisfies a pre-determined drive signal requirement. For example, the sensed drive signal may be representative of a drive current or drive voltage of the vibrator and the pre-determined drive signal requirement may be that the magnitude of the drive current or drive voltage exceeds a threshold. In this manner, sensing of the vibration signal is employed to determine the target portion of the vibration cycle (e.g., to identify the timing of low speed periods within the vibration cycle).

[0023] As a further example, a motion sensor may be employed to sense the angular velocity of a portion of the personal care device. The processor unit is then adapted to determine a target portion of the oscillation cycle based on a time period during which the sensed angular velocity meets a pre-determined velocity requirement. For example, the pre-determined velocity requirement may be that the magnitude of the sensed angular velocity does not exceed a velocity threshold. In this manner, a motion / movement sensing concept is employed to determine the target portion of the oscillation cycle (e.g., to identify the timing of low velocity periods within the oscillation cycle).

[0024] In another example, a Hall effect sensor may be employed to sense a magnetic field in a portion of the personal care device. The processor unit is then adapted to determine a target portion of the vibration cycle based on a time period during which the sensed magnetic field meets a pre-determined magnetic field requirement. Thus, for example, existing Hall sensors already incorporated in conventional personal care devices may be leveraged to provide new and / or enhanced functionality.

[0025] In yet another example, an accelerometer vibration sensor may be employed to sense the acceleration or excursion of the vibration of a part of the personal care device. The control unit is then adapted to determine a target portion of the vibration cycle based on a time period during which the magnitude of the sensed vibration meets a pre-determined vibration requirement. For example, the pre-determined vibration requirement may be that the acceleration of the sensed vibration exceeds a vibration threshold. Similarly, low speed is usually associated with both ends of the movement, in which case the pre-determined vibration requirement may be that the excursion of the sensed vibration exceeds a vibration threshold. In this way, a vibration sensing concept / apparatus is employed to determine the target portion of the vibration cycle (e.g., to identify the timing of the low speed period in the vibration cycle). Thus, existing and / or simple vibration sensing techniques and / or devices are employed to accurately identify the timing of the low speed of the personal care device.

[0026] Having outlined above that various techniques can be employed to determine the target portion of the oscillation cycle, it is noted here that some proposed embodiments employ the concept of identifying multiple portions of the oscillation cycle as the target portion of the oscillation cycle. That is, the target portion of the oscillation cycle includes multiple different sub-portions of the oscillation cycle separated in time. The number of sub-portions of the oscillation cycle that form the target portion of the oscillation cycle is equal to the number of pulses of illumination generated during a single oscillation cycle of the personal care device. In other words, each pulse of illumination is controlled to occur at a corresponding sub-portion of the period.

[0027] Furthermore, the image capture device comprises a camera. The control unit is then adapted to control the camera to capture a first image during a first portion of the vibration cycle and a second image during a second portion. In this way, image capture is synchronized with the pulses of illumination, thereby ensuring optimal lighting conditions for short / fast image capture (and thus reducing image blurring and / or distortion). The embodiment is then employed in conjunction with different types of image capture devices, including, for example, global shutter cameras or free-running rolling shutter cameras that are not synchronized with the vibration of the personal care device.

[0028] In some embodiments, the image capture device comprises a rolling shutter camera, where image acquisition is synchronized with the pulses of illumination, resulting in image data with reduced blur and / or distortion that is combined with image data from different portions of different frames of the camera, facilitating the construction of a single high quality image (from multiple captured frames).

[0029] The embodiments may then be employed in conjunction with different types of image capture devices, including, for example, cameras that are not synchronized with the vibrations of the personal care device.

[0030] The device further comprises an image processor configured to generate a reconstructed image based on the first image and the second image.

[0031] For example, the predetermined requirement may be that the magnitude of the sensed angular velocity not exceed a first velocity threshold. In this manner, two or more images with less blurring of the image can be produced during the duration of the vibration.

[0032] In a further development, the image processor is therefore configured to process the first image and the second image with an image processing algorithm to identify target regions in each of the first image and the second image, extract image data from the identified target regions, and generate a reconstructed image including the extracted image data.

[0033] In another example, the predetermined requirement may be that the magnitude of the sensed angular velocity exceeds a second velocity threshold. Optionally, the image processor is then configured to process the first image and the second image with an image combination algorithm to generate a reconstructed image based on the first image and the second image. Such a reconstructed image has the benefit of providing a wider field of view and / or improved image quality (e.g., reduced blurring).

[0034] The personal care device may comprise a toothbrush, preferably an electric toothbrush adapted to vibrate when in use. In other embodiments, the personal care device comprises a mouthpiece, a shaver, or a skin cleaning brush adapted to vibrate when in use. One or more of the proposed concepts may thus be employed in a wide variety of personal care devices. The embodiments thus have broad application in the field of personal care devices (as well as image capture and / or processing concepts for images captured by vibrating personal care devices).

[0035] According to another aspect of the present invention, there is provided a method of controlling a personal care device comprising vibration means adapted to vibrate the personal care device such that, in use, the personal care device vibrates in a periodic vibration cycle having a vibration frequency; an image capture device adapted to capture images of one or more features of a user, in use; and a lighting device configured to generate pulsed lighting for illuminating a part of the user, in use, the method comprising the steps of determining as target parts of the vibration cycle a first part and a second part of the vibration cycle in which an angular velocity of the part of the personal care device satisfies a predetermined requirement; and controlling the lighting device to generate two or more pulses of lighting during a single vibration cycle of the personal care device, wherein the step of controlling the lighting device comprises controlling the lighting device to generate a first pulse of lighting during the first part of the vibration cycle and a second pulse of lighting during the second part of the vibration cycle.

[0036] According to yet another aspect of the invention there is provided a computer program comprising computer program code means adapted to perform a method according to the proposed embodiments when said computer program is run on a computer.

[0037] There is therefore also provided a computer system comprising a computer program product according to the proposed embodiments and one or more processors adapted to perform the method according to the proposed concepts by execution of computer readable program code of said computer program product.

[0038] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0039] For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings in which: [Brief description of the drawings]

[0040] [Figure 1] FIG. 1 is a simplified schematic block diagram of an electric toothbrush 10 according to a proposed embodiment. [Figure 2A] 2 is a graph showing an exemplary change over time in the (displacement) angle Θ and angular velocity associated with vibration of the brush head of FIG. 1, where the change in the brush head displacement angle Θ is plotted as a solid line and the change in the angular velocity v of the brush head 14 is plotted as a dashed line. [Figure 2B] 2B illustrates an exemplary alignment (i.e., synchronization) of pulses of illumination from a lighting device with respect to the oscillation cycle illustrated in FIG. 2A. [Diagram 3] FIG. 1 is a simplified schematic block diagram of a mouthpiece according to a proposed embodiment. [Figure 4] FIG. 1 is a simplified block diagram of a computer in which one or more portions of the embodiments may be employed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] The present invention will be described with reference to these figures.

[0042] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems, and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the devices, systems, and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. The mere fact that certain techniques are recited in mutually different dependent claims does not indicate that a combination of these techniques cannot be used to advantage.

[0043] In practicing the claimed invention, those skilled in the art can understand and realize variations of the disclosed embodiments, from a study of the drawings, the disclosure, and the appended claims. In the claims, the words "comprises," "including," "having," "including" do not exclude other elements or steps, and singular elements do not exclude a plurality.

[0044] It should be understood that these figures are only schematic and are not drawn to scale, and it should also be understood that the same reference numbers have been used throughout the figures to denote the same or similar parts.

[0045] The present invention proposes a concept to assist and / or improve image acquisition from a vibrating personal care device having an image capture device. In particular, embodiments provide a system, device, and / or method for controlling a lighting device to generate two or more pulses of lighting during a single vibration cycle of the personal care device, where control of the image capture device is responsive to the pulses of lighting during the vibration cycle. Illuminating the user's oral cavity in this manner results in improved images (e.g., images that are less blurred and / or distorted).

[0046] In particular, it is proposed to control the lighting device to generate multiple pulses of illumination during a single vibration cycle of the personal care device (in use) in order to reduce or minimize distortion of images acquired from a vibrating personal care device. More specifically, it is recognized that one or more parts of the vibration cycle may be more suitable for image capture, for example due to reduced motion / movement exhibited. By illuminating the user's oral cavity during such parts of the vibration cycle, the length of exposure required to capture a sufficient amount of unblurred images is reduced. For example, when using two captures at the same position, the two images can be combined, thus requiring less light, improving the signal-to-noise ratio and overall exposure, and requiring less power. Such an embodiment thus helps to reduce or minimize power consumption, while still ensuring suitable illumination to facilitate a reduction / shortening of the exposure duration of the image capture device.

[0047] Furthermore, by synchronizing image acquisition with multiple illumination pulses, multiple images are acquired for a single vibration cycle. The multiple images are advantageously analyzed separately, where more images are realized due to the use of multiple pulses if the camera is imaging different parts of the scene. Furthermore, data from these multiple images is then used (e.g., combined, integrated, selected) to generate a reconstructed image of further improved quality. For example, a first image may be captured during a first portion of the vibration cycle and a second image during a second portion, and a reconstructed image may be generated based on the first and second images. In this way, multiple portions of image data are used to facilitate the construction of a single high quality image (or wide field image).

[0048] It is further recognized that the timing of such portions of the vibration cycle that are preferred (or optimal) for image capture is determined based on operational parameters of the personal care device. Examples of such operational parameters include vibrator / motor current, magnetic field, device motion, and angular velocity of parts of the personal care device. Thus, simple detection of the motion of the personal care device is employed to determine the preferred, optimal, or target timing for image capture, thereby enabling improved or optimized image capture.

[0049] In other words, embodiments propose to control the timing of the illumination pulses based on the vibration of the personal care device (and thus the image capture device) so that an improved quality image is provided.

[0050] Thus, embodiments facilitate stable, high-quality image acquisition during tooth brushing. Such embodiments may be particularly relevant for remote dental care recommendations, for example, by enabling improved imaging of the user's teeth, gums, tongue, etc. For example, images obtained by the proposed embodiments may assist dental care treatment and / or decision-making. For example, images obtained by the proposed embodiments may assist dental care procedures and / or decisions. Thus, embodiments are used in connection with dental treatment selection to assist dental care professionals in selecting a treatment for a subject.

[0051] Referring to Figure 1, there is shown a simplified schematic block diagram of an electric toothbrush 10 according to a proposed embodiment. The electric toothbrush 10 comprises vibration means 12 (in particular a motor) adapted to vibrate a brush head 14 of the electric toothbrush 10 in use (at a frequency of about 200Hz).

[0052] The electric toothbrush 10 also includes an image capture device 16 (eg, a digital camera) that is adapted to capture images of one or more features of a user's oral cavity during use.

[0053] To assist in reducing the exposure duration required to capture a properly exposed image, the oral care device (i.e., electric toothbrush) 10 also includes an illumination device 19 (e.g., an LED) that is configured to illuminate a portion of a user's oral cavity during use. That is, when the sensitivity (e.g., ISO) and / or lens aperture of the image capture device 16 is fixed and / or limited, illumination of the user's oral cavity by the illumination device 19 results in a reduction in the length of exposure required to capture a sufficient amount of light.

[0054] The electric toothbrush 10 also comprises a sensor arrangement 17 adapted to sense operational parameters of the personal care device and a control unit 18 adapted to control the image capture device based on a target portion of the oscillation cycle.

[0055] Furthermore, the control unit 18 is adapted to control the lighting device 19 to synchronize the timing of illumination by the lighting device 19 with the vibration cycle. More particularly, the control unit 18 is adapted to control the lighting device 19 to generate two or more pulses of illumination during a single vibration cycle of the personal care device.

[0056] The motor 12 is configured to periodically rotate the brush head 14 clockwise and then counterclockwise from a rest position by approximately 10°-25°, so that the brush head 14 vibrates in a periodic oscillatory waveform.

[0057] 2A illustrates an exemplary change in the angle (displacement) Θ and angular velocity of the brush head 14 over time as the brush head 14 oscillates. The change in the displacement angle Θ of the brush head 14 is plotted as a solid line, while the change in the angular velocity v of the brush head 14 is plotted as a dashed line.

[0058] From the evolution depicted in FIG. 2A, it can be seen that "slow" periods 20, i.e., time periods during which the magnitude of the angular velocity v of the brush head 14 is below a predetermined threshold Vth, can be identified. More specifically, it can be seen that the angular velocity v of the brush head 14 is close to zero when the absolute value of the displacement angle Θ reaches a maximum value such that the time derivative of the displacement angle Θ changes polarity (i.e., when the solid line changes direction). It is proposed that these slow periods 20 provide the best opportunity for image capture using an image capture device with limited speed and exposure adjustment capabilities. Some embodiments are therefore based on the proposal that the illumination provided by the illumination device 19 is synchronized to two slow periods 20 of a single oscillation cycle.

[0059] By way of illustration, Fig. 2B depicts such an alignment (i.e. synchronization) of a pulse of illumination from lighting device 19 with respect to the oscillation cycle depicted in Fig. 2A. In Fig. 2B, the lower graph depicts the variation in illumination intensity provided by lighting device 19 on the same time scale as the graph of Fig. 2A (reproduced as the upper graph in Fig. 2B). From the lower graph of Fig. 2B, it can be seen that a first pulse 25A of illumination provided by lighting device 19 is synchronized with a first slow period 20A of a single oscillation cycle, and that a second pulse 25B of illumination provided by lighting device 19 is synchronized with a second slow period 20B of a single oscillation cycle.

[0060] By illuminating a portion of the user's oral cavity multiple times during a single vibration cycle of the oral care device, and then synchronizing image acquisition with the multiple illumination pulses, multiple images are acquired for a single vibration cycle. Alternatively, if a free-running camera is employed to continuously capture images, image data is acquired / stored only during the illumination pulses. Data from these multiple images is then used (e.g., combined, integrated, selected) to generate a reconstructed image with improved quality. In this way, multiple portions of image data are used to facilitate the construction of a single high-quality image or wide-field-of-view image.

[0061] Returning to the particular embodiment of FIG. 1, the control unit 18 is adapted to control the pulsed illumination based on parameters of the periodic oscillatory waveform.

[0062] In this embodiment, the control unit 18 is adapted to control the illumination device 19 to generate two pulses of illumination during a single vibration cycle of the oral care device. In particular, the control unit 18 is adapted to synchronize the two pulses of illumination with the slow period 20 of the vibration cycle. In this manner, image capture is synchronized with both the pulsed illumination and the slow period 20, thereby reducing the amount of movement that causes blurring and / or distortion of the captured image.

[0063] Furthermore, in this embodiment, the control unit 18 is also adapted to set the illumination duration of the illumination pulse to be equal to or less than one-quarter of the period of the oscillatory waveform. In practice, by choosing the threshold Vth to be a value less than half the maximum angular velocity, the illumination duration of a single illumination pulse is controlled to be equal to or less than one-eighth of the period of the oscillatory waveform. However, it may be preferable to limit the illumination duration to a shorter period (i.e., a lower duration value) in order to limit the duration of image acquisition to a small, low-velocity period 20 where the angular velocity v of the brush head 14 is close to zero (i.e., the threshold Vth is close to zero).

[0064] For example, it may be preferable to adapt the control unit 18 to set the illumination duration to less than one tenth, and more preferably less than one sixteenth, of the period of the oscillatory waveform.

[0065] Furthermore, for example in the case of a rolling shutter camera, it may be further preferred to further limit the illumination duration, line by line, to be equivalent to a shift of less than one pixel on the image capture device, i.e., a shift within the pixel resolution of the moving image. References to a pixel herein may encompass a single sensing element of an image sensor, or a sensing element (single sensor) of an image sensor array. That is, a pixel may be considered to be a single element of a sensed image, where the sensed image is formed from a plurality of sensed elements (i.e., pixels).

[0066] In this way, the total illumination duration is shared (i.e., divided) across all the rows of the camera sensor such that light is incident on the sensor in short pulse periods for each row, and the cumulative total duration of all the pulses adds to the exposure duration. This is accomplished by exposing each row of the sensor to the incident light for only a fraction of the exposure duration, or by pulsing the illumination source for only a fraction of the exposure duration, where the pulsing is synchronized with the row exposure time of each row of the sensor in a rolling shutter camera.

[0067] As an example, one may calculate the speed of pixel shift with a fixed distance to the object and a fixed motion. For example, if an image capture device has a sensor with 1024x768 pixels, the captured image area is 10 mm wide, the moving image area is 2 mm left and 2 mm right, and the vibration period is 2 ms, the exposure duration may be 1 ms. The movement is therefore 4 mm in 1 / 2 period (1 ms), and 4 mm is covered by 4 / 10x1024=410 pixels. A single pixel image movement takes 1 ms / 410=2.4 μs. Considering the shift of 1 / 2 pixel during the exposure, it is 1.2 μs. Therefore, an exposure of 1 ms means an exposure less than 1 ms / 768=1.3 μs per row.

[0068] Short illumination durations may also prevent pixel shift during exposure, for example by ensuring that exposures of pixels in an image camera are from the same location and therefore do not bleed into the next pixel location. It will be appreciated that while the embodiment of FIG. 1 has been described as employing a brush head 14 that periodically and repeatedly rotates from a rest position by approximately 10°-25° clockwise and then counterclockwise, it may be appreciated that other embodiments may employ brush heads that oscillate in different ways. For example, alternative embodiments may include a brush head that repeatedly oscillates (side to side or up and down), i.e., is repeatedly displaced (laterally or vertically) in opposite directions from a rest position. In such embodiments, a periodic vibration pattern with changes in displacement and velocity over time will still be seen, forming a periodic waveform as depicted in FIG. 2A, and thus having identifiable and repeating "slow" periods (e.g., following control of the drive parameters and / or vibration means).

[0069] That is, although the proposed concepts have been described above with reference to rotational / angular motion of a vibrating portion of an oral care device, the proposed concepts may also be employed with other vibrating personal care devices that exhibit repetitive vibratory motion, and in the case of multi-dimensional motion, periods of low / zero speed are identified with respect to multiple dimensions and used to control the timing of multiple illumination pulses in a single vibration cycle of the personal care device.

[0070] Also, although the proposed concept has been described above with a lighting device controlled to generate two pulses of lighting during a single vibration cycle of the personal care device, alternative embodiments are not limited to generating just two pulses of lighting during a single vibration cycle of the personal care device. In other embodiments, the control unit is adapted to control the lighting device to generate pulsed lighting at integer multiples of twice the vibration frequency (e.g., two, four, six, eight, etc. pulses of lighting during a single vibration cycle of the personal care device).

[0071] In embodiments, therefore, it is proposed to use strobe lighting that flashes (i.e., pulses) at twice the frequency of the vibration (or harmonics thereof) of the personal care device. A short duty cycle of the lighting pulse (e.g., 10% or less) helps to minimize vibration blur in the captured image.

[0072] By pulsing / flashing at twice the frequency of the vibration, different possibilities exist depending on the timing of the pulse (i.e., the phase of the pulsed illumination) relative to the vibration motion.

[0073] In a first example, if the illumination pulse is controlled to occur during a slow period (i.e., when the displacement angle amplitude is close to a maximum), the phase of the vibration is such that no two illumination positions appear at the same device position. In this example, two different images are captured, one when the displacement angle is positive and the other when the displacement angle is negative. That is, the two images are captured at two different orientations. Combining these images produces an improved single image with a wider viewing angle.

[0074] In a second example, if the illumination pulse is controlled to occur when the displacement angle is substantially zero (i.e., when there is a displacement angle close to zero), then the two illumination positions will occur at substantially the same location; that is, the two images will be captured at the same orientation. The data from these images is processed to produce a single image of higher quality. This example shows the advantage of pulsing illumination during the high velocity portion of the vibration.

[0075] 3, there is shown a simplified schematic block diagram of a cleaning or treatment mouthpiece 40 according to a proposed embodiment. The mouthpiece 40 is adapted to be inserted into a user's mouth and to vibrate (in use) for oral cleaning purposes.

[0076] The mouthpiece 40 is provided with vibration means 42 (in particular an electric motor) adapted, in use, to vibrate the mouthpiece with a periodic vibration waveform (eg having a frequency in the range 50 Hz to 500 Hz).

[0077] The mouthpiece 40 also includes an image capture device 44 disposed on the mouthpiece tray and adapted to capture images of one or more features of a user's oral cavity in use. The mouthpiece tray is also provided with flashing LEDs 46 for illuminating the user's oral cavity in use. The image capture device 44 and LEDs 46 are configured to be controlled by a mouthpiece control unit (i.e., controller) 48.

[0078] In particular, the control unit 48 is configured to control the exposure parameters of the camera 44 and activate the flash LED 46 based on the parameters of the periodic vibration waveform of the mouthpiece 40. To determine the parameters of the periodic vibration waveform of the mouthpiece 40, the mouthpiece 40 is equipped with a sensor arrangement 50 adapted to detect the characteristics of the movement / vibration of the mouthpiece. In particular, in this embodiment, the sensor arrangement 50 comprises an accelerometer and a gyroscope (inertial measurement unit) for detecting changes in the displacement and velocity of the mouthpiece 40. Information about the detected changes in the displacement and velocity of the mouthpiece 40 is provided to the control unit 48, and based on this information, the control unit 48 determines the parameters of the periodic vibration waveform of the mouthpiece 40 (e.g., period, frequency, amplitude, timing of zero crossings, etc.).

[0079] As already explained above with reference to the embodiment of Figure 1, the control unit 48 determines the "slow / slow" periods of mouthpiece 40, i.e. the time periods during which the magnitude of the velocity of mouthpiece 40 is below a pre-determined threshold. The control unit 48 then controls the lighting device 46 to generate pulses of illumination during the two "slow / slow" periods of a single oscillation cycle of mouthpiece 40. The control unit 48 also controls the exposure parameters of the camera such that image capture is timed to occur during the pulses of illumination.

[0080] However, it is noted that in this embodiment, the image capture device 44 comprises a rolling shutter camera configured to operate at the image capture frame rate. With respect to such a rolling shutter camera, trade-offs in operational characteristics may be necessary. For example, a rolling shutter camera may be more cost-effective (e.g., cheaper), but may take longer to perform a complete image capture depending on the acquisition settings and / or capabilities. The time period during which data is acquired from the rolling shutter camera is then considered to be an "exposure period". For example, image data from the rolling shutter camera 44 may be acquired for one-tenth of a frame, in which case the effective exposure duration is one-tenth of the period of a frame of the rolling shutter camera. Thus, the control unit 48 is further adapted in this case to control the exposure parameters taking into account the frame rate of the rolling shutter camera.

[0081] In this example, the first exposure parameter includes exposure start timing (i.e. the time when capture of image data from the rolling shutter camera begins / commences), and the control unit 48 is adapted to control the start of the capture of image data from the rolling shutter to be synchronized with the pulse of illumination. In particular, the control unit 48 is adapted to synchronize the start of the capture of image data from the rolling shutter camera to both the pulse of illumination and the slow period of the oscillation cycle (determined based on information from the sensor arrangement 50). In this manner, the image capture device 44 is controlled to synchronize the capture of image data with the pulse of illumination (and the slow period), thereby reducing the amount of movement that causes blurring and / or distortion of the captured image.

[0082] Further, in this example, the second exposure parameter includes an exposure duration of the image capture device 44 (i.e., the length of image data capture from a rolling shutter camera), and the control unit 48 is adapted to set the image data capture duration depending on the duration of the illumination pulse. By way of example, it may be preferred to adapt the control unit 48 to set the exposure duration of the image data capture to be less than or equal to the duration of the illumination pulse.

[0083] That is, for image acquisition using rolling shutter camera 44, it is proposed to adapt the exposure duration to be fast relative to the camera vibration, e.g., the effective exposure time (i.e., image data acquisition time from rolling shutter camera 44) is adapted to be at most equivalent to the duration / period of the smallest movement of mouthpiece 40. For example, for a square wave driven vibration with a duty cycle of about 50%, the exposure duration may be less than or equal to one quarter of the vibration period.

[0084] As a further example, the embodiment may comprise a processor device configured to determine a target portion of the oscillation cycle based on the parameters of the periodic oscillation cycle. More specifically, the processor device is configured to determine a first portion and a second portion of the oscillation cycle in which the angular velocity of the part of the personal care device satisfies a pre-determined requirement as the target portion of the oscillation cycle. In such an embodiment, the control unit then controls the lighting device to generate a first pulse of illumination during the first portion of the oscillation cycle and to generate a second pulse of illumination during the second portion of the oscillation cycle. Furthermore, the control unit also controls the image capture device to capture a first image during the first portion of the oscillation cycle and a second image during the second portion. Optionally, an image processor can then be employed to generate a reconstructed image based on the first image and the second image. In this way, high quality regions of the captured images are identified and then the identified high quality regions of the multiple different images are utilized to build (i.e., construct) a single high quality image.

[0085] For example, the pre-determined requirement may be defined to require that the magnitude of the sensed angular velocity does not exceed a first velocity threshold (i.e., require a low velocity). Again, both images can be used independently of each other. In such an embodiment, the image processor further processes the first image and the second image with image processing algorithms to identify target regions in each of the first image and the second image, extract image data from the identified target regions, and generate a reconstructed image including the extracted image data. That is, a portion of the image from the low velocity period of the vibration cycle is used to build and generate an optimized image.

[0086] Alternatively, the pre-determined requirement may be defined to require the magnitude of the sensed angular velocity to exceed a second velocity threshold (i.e., require a medium or high velocity occurring at a particular time period within the vibration cycle). In such an embodiment, the images will be captured with the brush head in substantially the same position, e.g., zero displacement. Again, both images can be used independently of each other. The image processor then further processes the first image and the second image with an image combination algorithm to generate a reconstructed image based on the first image and the second image. That is, if the images are captured from the same angle / position, they are combined to form a new improved image.

[0087] In this manner, image segments containing higher quality image data than the reference image are identified and used to construct an improved / optimum image from a number of different captured images.

[0088] From the above description of various concepts and embodiments, it will be understood that there is proposed a method of controlling a personal care device, the personal care device comprising vibration means adapted to vibrate the personal care device such that, in use, the personal care device vibrates in a periodic vibration cycle having a vibration frequency, an image capture device adapted to capture images of one or more features of a user, in use, and a lighting device configured to generate pulsed lighting for illuminating a part of the user, in use. The method comprises the step of controlling the lighting device to generate two or more pulses of lighting during a single vibration cycle of the personal care device.

[0089] 4 shows an example of a computer 50 in which one or more parts of the embodiment are employed. The various operations discussed above utilize the capabilities of the computer 500. For example, one or more parts of the system for providing a subject-specific user interface can be incorporated into any element, module, application, and / or component discussed herein. In this regard, it should be understood that the system functional blocks may be executed on a single computer or may be distributed across several computers and locations (e.g., connected via the Internet), such as a cloud-based computing infrastructure.

[0090] The computer 50 includes, but is not limited to, a PC, a workstation, a laptop, a PDA, a palm device, a server, a storage, and the like. In general, from a hardware architecture perspective, the computer 50 includes one or more processors 51, a memory 52, and one or more I / O devices 53 communicatively coupled via a local interface (not shown). The local interface can be, for example, but is not limited to, one or more buses or other wired or wireless connections, as known in the art. The local interface has additional elements, such as controllers, buffers (caches), drivers, repeaters, receivers, etc., to enable communication. Additionally, the local interface includes address, control, and / or data connections to enable appropriate communication between the aforementioned components.

[0091] Processor 51 is a hardware device for executing software that may be stored in memory 52. ​​Processor 51 may be virtually any custom or commercially available processor, central processing unit (CPU), digital signal processor (DSP), or coprocessor of any number of processors associated with computer 50, and processor 51 may be a semiconductor-based microprocessor (in the form of a microchip) or microprocessor.

[0092] The memory 52 may include any one or combination of volatile memory elements (e.g., random access memory (RAM), such as dynamic random access memory (DRAM), static random access memory (SRAM), etc.) and non-volatile memory elements (e.g., ROM, erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), programmable read only memory (PROM), tape, compact disk read only memory (CD-ROM), disk, diskette, cartridge, cassette, or the like). Additionally, the memory 52 incorporates electronic, magnetic, optical, and / or other types of storage media. It should be noted that the memory 52 may have a distributed architecture, with various components located remotely from one another but accessible by the processor 51.

[0093] The software in memory 52 includes one or more individual programs, each of which comprises an ordered list of executable instructions for implementing a logical function. The software in memory 52, according to an exemplary embodiment, includes a suitable operating system (O / S) 54, a compiler 56, source code 55, and one or more applications 57. As shown, the applications 57 include a number of functional components for implementing the features and operations of the exemplary embodiment. The applications 57 of computer 50, according to an exemplary embodiment, represent various applications, computational units, logic, functional units, processes, operations, virtual entities, and / or modules, although the applications 57 are not intended to be limiting.

[0094] Operating system 54 controls the execution of other computer programs and provides scheduling, input / output control, file and data management, memory management, and communication control and related services. The inventors contemplate that application 57 for implementing the exemplary embodiment is applicable to any commercially available operating system.

[0095] The application 57 may be a source program, an executable program (object code), a script, or any other entity comprising a set of instructions to be executed. In the case of a source program, the program is typically translated via a compiler (such as compiler 56), assembler, interpreter, etc., which may or may not be contained in memory 52, to be connected to the O / S 54 and to operate appropriately. Furthermore, the application 57 may be written as an object-oriented programming language with classes of data and methods, or a procedural programming language with routines, subroutines, and / or functions, such as, but not limited to, C, C++, C#, Pascal, BASIC, API calls, HTML, XHTML, XML, ASP script, JavaScript, FORTRAN, COBOL, Perl, Java, ADA, .NET, etc.

[0096] The I / O devices 53 include input devices such as, but not limited to, a mouse, keyboard, scanner, microphone, camera, etc. The I / O devices 53 further include output devices such as, but not limited to, a printer, display, etc. Finally, the I / O devices 53 further include devices that communicate both input and output such as, but not limited to, a NIC or modulator / demodulator (for accessing remote devices, other files, devices, systems, or networks), radio frequency (RF) or other transceivers, telephone interfaces, bridges, routers, etc. The I / O devices 53 also include components for communicating over various networks such as the Internet or an intranet.

[0097] If computer 50 is a PC, workstation, intelligent device, etc., the software in memory 52 further includes a Basic Input Output System (BIOS) (omitted for simplicity). The BIOS is a set of essential software routines that initializes and tests the hardware at power-on, starts O / S 54, and supports data transfers between hardware devices. The BIOS is stored in some type of read-only memory, such as ROM, PROM, EPROM, EEPROM, etc., so that the BIOS can be executed when computer 800 is powered on.

[0098] Processor 51 is configured, when computer 50 is operating, to execute software stored in memory 52, to communicate data to and from memory 52, and to generally control the operation of computer 50 in accordance with the software. Applications 57 and O / S 54 are read, in whole or in part, by processor 51, possibly buffered within processor 51, and then executed.

[0099] It should be noted that if the application 57 is implemented in software, the application 57 may be stored on virtually any computer-readable medium for use by or in connection with any computer-related system or method. In the context of this document, a computer-readable medium is an electronic, magnetic, optical, or other physical device or means that can contain or store a computer program for use by or in connection with a computer-related system or method.

[0100] The application 57 may be embodied in any computer readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-based system, or other system capable of fetching instructions from and executing instructions on an instruction execution system, apparatus, or device. In the context of this document, a "computer readable medium" may be any means capable of storing, communicating, propagating, or transporting a program for use by or in connection with an instruction execution system, apparatus, or device. A computer readable medium may be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium.

[0101] The proposed image capture and / or processing method may be implemented in hardware or software, or in a mixture of both (e.g., as firmware running on a hardware device). To the extent that an embodiment is implemented partially or entirely in software, the functional steps illustrated in the process flow charts are performed by appropriately programmed physical computing devices, such as one or more central processing units (CPUs) or graphic processing units (GPUs). Each process, and its individual constituent steps as illustrated in the flow charts, may be performed by the same computing device or by different computing devices. According to an embodiment, a computer readable storage medium has stored thereon a computer program comprising computer program code, which is configured to cause one or more physical computing devices to perform an encoding or decoding method as described above when said program is executed on said one or more physical computing devices.

[0102] Storage media include volatile and non-volatile computer memories such as RAM, PROM, EPROM, and EEPROM, optical disks (such as CDs, DVDs, BDs, etc.), magnetic storage media (such as hard disks and tapes, etc.) Various storage media may be fixed within a computing device or may be transportable such that one or more programs stored thereon may be loaded into a processor.

[0103] To the extent that the embodiments are implemented partially or entirely in hardware, the blocks shown in the block diagrams of Figures 1 and 3 may be separate physical components or logical subparts of a single physical component, or may all be implemented in an integrated form within a single physical component. The functionality of a block shown in the figures may be divided among multiple components in an implementation, or the functionality of multiple blocks shown in the figures may be combined into a single component in an implementation. Examples of hardware components suitable for use in embodiments of the present invention include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs). One or more blocks may be implemented as a combination of dedicated hardware to perform some functions and one or more programmed microprocessors and associated circuitry to perform other functions.

[0104] In practicing the claimed invention, those skilled in the art can understand and realize variations of the disclosed embodiments by studying the drawings, the disclosure, and the appended claims. In the claims, the words "comprises, includes, has" do not exclude other elements or steps, and singular elements do not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain methods are recited in mutually different dependent claims does not indicate that a combination of these methods cannot be advantageously used. Where a computer program is discussed above, it may be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium, provided together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. It is noted that when the term "adapted to" is used in the claims or description, the term "adapted to" is intended to be equivalent to the term "configured to". Any reference signs in the claims should not be construed as limiting the scope thereof.

[0105] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or part of instructions comprising one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions noted in the blocks may be executed in a different order than that noted in the figures. For example, two blocks shown in succession may in fact be executed substantially in parallel, or the blocks may sometimes be executed in reverse order depending on the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart diagrams, as well as combinations of blocks in the block diagrams and / or flowchart diagrams, may be implemented by a dedicated hardware-based system that performs the specified functions or operations or executes a combination of dedicated hardware and computer instructions.

Claims

1. 1. A personal care device comprising: an image capture device that, when in use, captures an image of one or more features of a user; vibration means for vibrating the personal care device such that, in use, the personal care device vibrates in a periodic vibration cycle having a vibration frequency; an illumination device that generates pulsed illumination in use for illuminating a portion of the occupant; a control unit for controlling the lighting device to generate two or more pulses of lighting during a single vibration cycle of the personal care device; and a processor unit configured to determine as a target portion of the oscillation cycle a first portion and a second portion of the oscillation cycle in which an angular velocity of a portion of the personal care device satisfies a predetermined requirement; A personal care device, wherein the control unit controls the lighting device to generate a first pulse of lighting during the first portion of the oscillation cycle and to generate a second pulse of lighting during the second portion of the oscillation cycle.

2. 10. The personal care device of claim 1, wherein the personal care device comprises an oral care device, and the lighting device, in use, provides pulsed lighting for illuminating a portion of the user's oral cavity.

3. 3. The personal care device of claim 1 or 2, wherein the control unit controls the lighting device to produce pulsed lighting at integer multiples of two of the vibration frequency of the vibration cycle.

4. 4. A personal care device according to any one of claims 1 to 3, wherein the control unit sets the illumination duration of the lighting device to be no more than a quarter of the period of the vibration waveform, more preferably no more than an eighth of the period of the vibration waveform, and even more preferably no more than a sixteenth of the period of the vibration waveform.

5. 5. The personal care device of claim 1, wherein the image capture device comprises a camera, and the control unit controls the camera to capture a first image during the first portion of the vibration cycle and a second image during the second portion.

6. The personal care device comprises:

6. The personal care device of claim 1, further comprising an image processor configured to generate a reconstructed image based on the first image and the second image.

7. The personal care device of claim 6 , wherein the predetermined requirement is that the magnitude of the sensed angular velocity not exceed a first velocity threshold.

8. 8. A personal care device according to claim 6 or 7, wherein the image processor processes the first image and the second image with an image processing algorithm to identify target areas in each of the first image and the second image, extract image data from the identified target areas, and generate a reconstructed image including the extracted image data.

9. 7. The personal care device of claim 6, wherein the predetermined requirement is that the magnitude of the sensed angular velocity exceeds a second velocity threshold, and the image processor processes the first image and the second image with an image combination algorithm to generate a reconstructed image based on the first image and the second image.

10. 10. The personal care device of claim 1, wherein the personal care device comprises a toothbrush, a mouthpiece, a shaver, or a skin cleaning brush.

11. 1. A method of controlling a personal care device comprising an image capture device for capturing images of one or more features of a user, in use; vibration means for vibrating the personal care device such that, in use, the personal care device vibrates in a periodic vibration cycle having a vibration frequency; and a lighting device for generating pulsed lighting, in use, for illuminating a part of the user, the method comprising: determining as a target portion of the oscillation cycle a first portion and a second portion of the oscillation cycle in which an angular velocity of a portion of the personal care device satisfies a predetermined requirement; and controlling the lighting device to generate two or more pulses of lighting during a single vibration cycle of the personal care device; The method of claim 1, wherein controlling the lighting device comprises controlling the lighting device to generate a first pulse of illumination during the first portion of the oscillation cycle and to generate a second pulse of illumination during the second portion of the oscillation cycle.

12. A computer program comprising computer program code means for performing the method according to claim 11 when the computer program is executed on a computer.

Images