Description TECHNICAL FIELD

This disclosure relates to an imaging device in a vehicle instrument cluster. In particular, the imaging device is arranged within an instrument of an instrument cluster. More in particular, the imaging device is concealed within a pointer.

BACKGROUND ART

The global automotive industry has been utilizing cameras for monitoring both an exterior and an interior of the vehicle for many years. One particular application is the use of camera to monitor the condition of a passenger compartment or cabin of a passenger vehicle. An interior camera may also be used for monitoring the state of a subject within a vehicle, which is of particular importance for autonomous or semi-autonomous driving, for example, the monitoring of the subject for potential driving hazard such as fatigue, so that the vehicle may alert the subject to switch to autonomous or semi-autonomous driving.

One of the challenges of designing a vehicle interior camera for monitoring subject's state is the space constraints of positioning the interior camera within the passenger compartment or cabin, since the camera has to be strategically positioned to get a field of view of subject's facial features, for example the eyes . Conventional methods include placing or mounting the camera at a location that is visible to the subject, such as an instrument cluster, which is normally in line-of-sight of the subject. To meet the requirements of monitoring a subject in an interior of a vehicle, US 6927674 B2 proposes a setup involving two cameras integrated into an instrument cluster, with the two cameras displaced at least 8cm apart. However, space is required to mount the cameras of US 6927674 B2 on the cluster surface, which may be difficult to allocate without sacrificing other contents desired to be displayed on the cluster.

In another example, EP 2664476 Al proposes an instrument cluster with a detector for monitoring a driver inside the vehicle, by using a combination of a detector for monitoring the subject and a reflector to redirect radiation from the subject to the detector, both of which are arranged in an instrument cluster. The proposed setup of EP 2664476 Al does not solve the problem of space constraints on an instrument cluster as it is still necessary to position camera modules on surface of an instrument cluster. Furthermore, the setup of EP 2664476 Al is complex as a reflector is required.

None of the above prior art documents proposes a design that improves the efficiency of space allocation within an instrument cluster. While a potential solution to the problem may be to increase the size of the instrument cluster, there may be other disadvantages such as having an over bulky instrument cluster, thereby losing aesthetic appeal and inviting other potential hazards .

In summary, with the increasing demand for both aesthetic and functional information and contents to be displayed on instrument clusters, there is a need to better utilize the space of an instrument cluster such that all vehicle information may be efficiently allocated within the space of an instrument cluster. SUMMARY

The above objective is achievable in a first aspect, by providing an imaging device arranged within an instrument in an instrument cluster of a motor vehicle. Advantageously, allocating a dedicated space to position an imaging device on an instrument cluster is not required. The instrument may comprise a pointer, the pointer comprising a column configured to attach the pointer to the instrument cluster, wherein the imaging device is arranged within the column. The pointer may further comprise a pointer needle having a hub and a shaft, wherein the hub may be configured to receive light rays from a light source and wherein the shaft extends from the hub, the shaft having an aperture aligned to the column. Advantageously, the objective of efficiently utilizing space on an instrument cluster is achieved.

Preferably, the pointer needle may be operable as a light guide for propagating light rays received from the light source towards a distal end of the shaft. To operate as a light guide, an internal surface of the pointer needle, including the shaft, may be reflective, allowing light rays to propagate towards a specific direction. An example of achieving a reflective surface is to layer the shaft with a printed foil. The shaft may include an aperture aligned to the column to thereby reveal the imaging device. This arrangement facilitates the imaging device, which may be positioned in the column below the shaft, to receive light rays for processing images.

The pointer needle may further comprise a cover, the cover having an aperture or ancillary aperture correspondingly disposed to the aperture of the shaft, to receive a filter mechanism. Where the pointer needle does not comprise a cover, the aperture of the shaft may receive the filter mechanism. The filter mechanism may be configured to conceal the imaging device. This arrangement allows the imaging device to be hidden from view.

Preferably, the filter mechanism may be configured to filter a predetermined spectrum of light. Configuring the filter mechanism to filter a predetermined spectrum of light allows scalability and flexibility in design. For example, selection of the predetermined spectrum of light may be infrared radiation. This selection may be made compatible with an imaging device such as an infrared imaging device, thus enabling processing of infrared images, data of which may be used to determine other factors, for instance body temperature of the subject. Having an infrared filter allows for infrared light rays to pass through and into the infrared imaging device. However, visible light rays would be blocked, thus an infrared filter conceals the infrared imaging device within the pointer, hidden from view of a subject such as the driver.

Preferably, the imaging device comprises of a plurality of lenses stacked along a coincidental optical axis, the stacked lenses operable to receive light rays captured within a first angle of view. This setup achieves the objective of efficiently utilizing space within an instrument of an instrument cluster, yet achieving a practical depth of view. Advantageously, since the lenses are stacked along a coincidental optical axis, only a single imaging device is utilized in operation. This is in contrast with US 6927674 B2, which utilizes two cameras. The benefit of achieving better depth of view results in sharper images, i.e. accuracy in monitoring the subject.

Ideally, where the instrument comprises a pointer, the column of the pointer houses the plurality of lenses . An advantage of having a housing to house the plurality of lenses is that the housing keeps the lenses in place, thereby compensating adverse lens effects, for example unintentional displacement of lenses due to thermal effects.

Preferably, one or more of the plurality of lenses may be displaced from the coincidental optical axis of the plurality of lenses. This freedom of displacing one or more of the plurality of lenses facilitates the imaging device to capture light rays within a second angle of view. Advantageously, the imaging device may possess a wider angle of view to track the subject' s movement for instance, when the subject is looking away from the imaging device or outside the first or original angle of view. This freedom of displacing one or more of the plurality of lenses allows flexibility when designing the imaging device. For instance, in the event that an instrument is placed on the left or right side of the instrument cluster, one or more of the plurality of lenses may be displaced at an angle to capture an angle of view of the subject.

The hub of the pointer may or may not be in direct communication with the light source, to receive light rays emitting from the light source. Direct communication means that a substantial amount of light rays is not lost to the surroundings but is transmitted to and received by the hub. Where the hub of the pointer is in direct communication with the light source, the hub itself may be extended to be closer to the light source.

The hub of the pointer may also be in direct communication with the light source by means of an ancillary light guide, for re-directing light rays emitting from the light source towards the hub. Depending on the size of an imaging sensor comprised in the imaging device, there may not be space on the cluster to place the light source near the hub of the pointer. Therefore, the additional ancillary light guide may be beneficial for re-directing light into the hub of a pointer and yet achieve the objective of integrating an imaging device within an instrument of an instrument cluster. The ancillary light guide may be straight or curved or any other shape, for example, a L-shape light guide, as long as light from the light source is received by the hub.

Alternatively, the light source may be located at an elevated location compared to the imaging device. The light source may thus be closer to the hub, thereby reducing the loss of light rays to the surroundings. This may be an alternative to finding a space on the cluster to place the light source.

The pointer may be operable to rotate about the column by means of a motor shaft. Since the column may not have space to house the motor shaft due to the imaging device already arranged therein, the motor shaft may be configured to rotate about a rotational axis that is parallel to the column. The motor shaft may be located away from the column, but may be capable of rotating the pointer about the column by means of a motor gear connecting the motor shaft to the column. Preferably the imaging device includes a motor gear and a motor shaft. The motor gear supports a change in speed, torque and/or direction of the pointer's rotational movement about the column, while the motor shaft may be powered by a power source so that it can rotate about a rotational axis parallel to the column. The motor gear may be separately connected to the column or may be manufactured as part of the column . The motor gear may comprise one or more gears driven by the motor shaft. The motor gear and motor shaft may be designed according to design preference and requirement.

The imaging device as disclosed herein may be implemented in any types of motor vehicles having an instrument cluster. Thus, in a second aspect, there is provided a motor vehicle having an imaging device as disclosed herein.

BRIEF DESCRIPTION OF DRAWINGS

Other objects and aspects will become apparent from the following description of embodiments with reference to the accompany drawings in which:

Fig. 1 shows a side view of an instrument cluster having an imaging device arranged within an instrument of the instrument cluster according to a preferred embodiment.

Fig. 2 shows an imaging device arranged within a pointer of an instrument cluster according one of the preferred embodiments.

Fig. 3 shows an imaging device according to an alternative embodiment .

Fig. 4 shows an imaging device with a light source arranged at an alternative position according to one of preferred embodiment.

DESCRIPTION OF DETAILED EMBODIMENT

Hereinafter, various terms such as "first", "second", and the like may refer to modifying various different elements of various embodiments of the present disclosure, but do not limit the elements. The expressions may be used to distinguish one element from another element. For instance, "a first angle of view" and "a second angle of view" shall be construed to refer to two separate or independent angles of view or fields of view regardless of the order or the importance, without departing from the scope of the present disclosure.

The term "field of view" (FOV) or more in particular, "angle of view" (AOV) shall refer to an operational angle or space which an imaging device is sensitive to light rays or electromagnetic radiation, where the imaging device may receive light rays or capture images .

An explanation on an imaging device arranged in an instrument of an instrument cluster according to one or more preferred embodiments will be discussed in detail below.

Fig. 1 shows a side view of an imaging device 104 arranged within an instrument 100 of an instrument cluster according to a preferred embodiment . The instrument 100 comprises a pointer 108. The pointer 108 has a pointer needle 106, which is commonly used as an indicator for pointing towards reading of parameters on an instrument. The pointer 108 has a hub 110 and a shaft 112. The hub 110 is configured to receive light rays from a light source 120. The shaft 112 extends from the hub 110. The shaft has an aperture 114 configured to receive a filter mechanism 116. A column 118 is configured to attach the pointer 108 to a bottom surface 142 of the instrument cluster. The column 118 is correspondingly disposed to or aligned with the aperture 114 of the shaft 112 so that the aperture 114 reveals the imaging device 104 concealed within the column 118. In practice, the column 118 is concealed within a top surface 102 of the instrument cluster, as shown in Fig. 1.

In an alternative embodiment, the column 118 comprises of two parts, one part extending from the pointer 108, another part extending from the bottom surface 142 of the instrument cluster, thereby creating the column 118 for attaching the pointer 110 to the instrument cluster. It shall be understood by a practitioner skilled in the art that the column may also be a single piece of device for attaching the pointer to the instrument cluster.

The pointer needle 106 is operable as a light guide for propagating light rays received from the light source 120 towards a distal end A of the shaft 112. The shaft 112 has an aperture or hollow portion 114, for revealing the imaging device 104 such that the imaging device is capable of receiving light rays from a field of view or angle of view. The aperture or hollow portion 114 may be a cavity cored out from a part of the shaft aligned with the column 118, such that light rays will still propagate through an outer rim of the cored out portion (not shown) to the imaging device 104 in the column 118. In an alternative embodiment, the pointer needle 106 may further comprise a cover 124, such as a housing or a pointer cap. The cover 124 is configured to have an aperture 114', correspondingly disposed to or aligned with the aperture or hollow portion 114of the pointer needle 106, to receive the filter mechanism 116. Thus , where the pointer comprises cover 124, the filter mechanism 116 is received by the aperture 114' of the cover 124, instead of the aperture 114 of the shaft 112. The filter mechanism 116 is configured to conceal or hide the imaging device 104 from view. The filter mechanism 116 may also function to prevent dust or particles from settling on the lenses of the imaging device 104.

For design flexibility and scalability, the filter mechanism 116 is configured to filter a desired or predetermined spectrum of light. In a preferred embodiment, the predetermined spectrum selected is an infrared radiation within an electromagnetic spectrum. This allows the imaging device 104 to capture images of a subject but at the same time, conceal the imaging device 104 from view of the subject . A compatible form of imaging device 104 , such as an infrared camera is selected for use in conjunction with the selection of predetermined spectrum of light. In this given example, infrared images may be produced to monitor, say, a body temperature of the subject.

Turning now to Fig. 2 which shows an imaging device concealed within a pointer of an instrument cluster according to one of the preferred embodiments, the imaging device 104 comprises a plurality of lenses 126 stacked along a coincidental optical axis X. The stacked lens are operable to receive light rays captured within a first angle of view 128 (as shown in Fig. 1) . The instrument 100 comprises a pointer 106 and the column 118. The column 118 houses the plurality of lenses 126. Although it is possible to eliminate column 118 when designing the imaging device, the use of column 118 has the benefit of ensuring stack lenses remain stacked along a coincidental optical axis. It shall be apparent to a practitioner skilled in the art other work around designs such as use of partitions on two or more sides of the stacked lenses may achieve the same effect.

When in operation, one or more of the plurality of lenses 126 may be displaced from the coincidental optical axis X of the plurality of lenses 126 such that the imaging device 104 is able to capture a second angle of view 130. There is no restriction as to the displacement of the coincidental optical axis X leans towards, i.e. left or right lateral direction. The displacement of the one or more plurality of lenses 126 may be implemented during the designing stage. By way of example, when deciding the placement of instruments on an instrument cluster, an instrument may be placed directly in front and in the centre of a driver' s seat, in which case the plurality of lenses 126 will be stacked along the coincidental optical axis X to receive light rays captured within the first angle of view 128. Alternatively, the instrument may be placed on either left or right side of the instrument cluster, with the imaging device having only a partial field of view of the subject, in which case the plurality of lenses 126 will be displaced from the coincidental optical axis X to receive light rays captured within the second angle of view 130, i.e. displaced to the right (if the instrument is placed on the left side) or to the left (if the instrument is placed on the right side) . One of the design consideration may be the displacement of one or more of the plurality of lenses 126 to provide an alternative angle of view (or second angle of view) when im- plementing the imaging device.

Referring to Fig. 1, the hub 110 of the pointer needle 108 is in direct communication with the light source 120 by means of a straight ancillary light guide 132. With reference now to Fig. 3 which shows an imaging device according to an alternative embodiment, the hub 110 of the pointer needle 108 is in direct communication with the light source 120 by means of a curved ancillary light guide 132. The ancillary light guide 132 may re-direct light rays emitting from the light source 120 towards the hub 110. Depending on size of the imaging device, the light source 120 may not be in line with the hub 110. In such circumstances, a curved ancillary light guide 132, as shown in Fig. 3, will be necessary to converge and re-direct light rays emitting from light source 120 into the hub 110. The ancillary light guide 132 may also be combined with the hub 110, as shown in Fig. 2, or the hub 110 itself may be extended to directly communicate with the light source 120. Alternatively, the hub 110 of the pointer needle 108 may not be in direct communication with the light source 120, as shown in Fig. 4.

Alternatively, Fig. 4 shows the light source 120 at an elevated location 134 with respect to the bottom surface 142 of the instrument cluster to be nearer or closer to the imaging device 104, to reduce complexity of design. An example of elevating the location of the light source 120 is by means of electrical connectors 140. In yet another alternative embodiment, the light source 120 may be supported on the image sensor or around the column 108 since the image sensor is typically wider than the column 108 which houses the plurality of lenses 126. As such, it is possible to place light sources closer to the hub 110 so that light is substantially completely received by the hub 110 and not lost to the environment. To enable the light source 120 to be electrically controlled, the light source 120 may be placed on a printed circuit board at the elevated location 134, e.g. on the image sensor or on a flexible circuit board wrapping the column 108.

The imaging device 104 may be implemented in any form of motor vehicle having an instrument cluster.

In operation, a motor gear 136 and motor shaft 138 is required to drive the pointer 108, and rotate the pointer 108 about a rotational axis when in operation. As shown in any one of Fig. 1 to 4, the motor shaft 138 shall have a rotational axis parallel to the coincidental optical axis X. In prior art pointers, i.e. pointers without an imaging device integrated in column 118, the motor shaft is typically located in column 118 to drive the pointer's movement around axis X. Due to integration of the disclosed imaging device 104 in column 118, the motor shaft 138 has to be displaced from column 118. In best case scenario, the motor shaft 138 may be allocated near to the imaging device 104 away from axis X, but may still be able to rotate pointer 108 about axis X by the motor gear 136 attached or connected to the column 118. When driven by power, the motor shaft 138 shall rotate the motor gear 136, thereby rotating the pointer 108.

While the preferred embodiment and alternative embodiments of the invention have been disclosed and described in detail herein, it may be apparent to practitioners skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope thereof.