Heating device, camera system, external rear view device, motor vehicles and heating device

Abstract

A heating device for a lens barrel of an automotive camera assembly includes a heating element adapted to apply heat along the circumference of the lens barrel, and a tension socket and/or a tension ring adapted to press a ring-shaped part of the heating element against the lens barrel circumference. A camera system, an external rear view device, and a motor vehicle, each with at least one such heating device are also described.

Claims

1. A heating device for a lens barrel of an automotive camera assembly, comprising a heating element adapted to apply heat along the circumference of the lens barrel, wherein the heating element is L-shaped in a side view, with a first leg being provided by a ring-shaped first part, and a second leg being provided by a second part, wherein the ring-shaped first part establishes an open cylinder, wherein a lens is arranged inside the open cylinder of the ring-shaped first part; and a tension socket, which is adapted to press the ring-shaped first part of the heating element against the lens barrel circumference and comprises a recess through which a second part of the heating element can pass from the ring-shaped first part of the heating element to a connector.

2. The heating device of claim 1, further comprising at least one of: a heat transfer ring comprising aluminum; a heat transfer paste between the ring-shaped first part of the heating element and the lens barrel; or a heat transfer paste between the first ring-shaped part of the heating element and the tension socket and/or a tension ring.

3. The heating device of claim 1, wherein at least one of: the recess is selectable from a plurality of recesses, the second part is bar shaped, or the connector is adapted to be connected to an electronic control unit.

4. The heating device of claim 1, wherein the socket comprises connecting means for attaching the socket to a camera housing via a push and/or snap connection, and the connecting means at least one of: comprising at least one opening adapted to receive at least one projection or rib of the housing, or being adapted to interlock with the camera housing.

5. The heating device of claim 1, wherein the socket comprises at least one of: a rim embracing at least the first ring-shaped part and the lens barrel, or an inner ring extending from the inner surface of the socket and/or a shoulder provided by a S shaped cross-section at the end of the socket facing away from the housing, to snap fit around at least the ring-shaped first part and the lens barrel, with the heat transfer ring, the heat transfer paste and/or a tension ring interposed between the first ring-shaped part and the lens barrel.

6. The heating device of claim 1, wherein the socket at least one of: comprises an elastomer material made of rubber and formed as a rubber cap, has an inner diameter smaller than the outer diameter of the lens barrel carrying at least the ring-shaped first part of the heating element, or covers the lens barrel in a form-fit manner with a given preload.

7. The heating device of claim 1, further comprising: a tension ring adapted to press a ring-shaped first part of the heating element against the lens barrel circumference, with the socket being mounted on the tension ring, wherein preferably the tension ring is at least one of provided with a slit or made of metal.

8. The heating device of claim 7, wherein the slit is provided between two end pieces having a complementary geometry and/or forming together a projection or rib, and the two end pieces of the tension ring engage a further recess of the socket.

9. The heating device of claim 1, wherein at least one of: the second part of the heating element is at least one of adapted for connection with a plug or the electronic control unit, via at least the connector and/or a cable, or the heating element comprises a heating foil, at least in its first, ring-shaped first part.

10. The heating device of claim 1, further comprising at least one temperature sensor connected to a controller and/or the electronic control unit via a cable and/or a plug for controlling the heating of the heating element.

11. The heating device of claim 10, wherein the temperature sensor is arranged within the tension socket and/or a tension ring.

12. The heating device of claim 1, wherein the level of power applied to the heating element and/or the time of applying power to the heating element and/or a heating curve is controlled by an electronic control unit depending on an ambient temperature and/or a temperature measured by the temperature sensor, the ambient temperature or the temperature measured by the temperature sensor provided to the heating device by a CAN bus system, wherein, in case the temperature is below −5 degree Celsius, a higher power level is applied to the heating element in a first period of time, between 60 and 200 seconds, than in a second period of time, and wherein, in case the temperature is equal to or above +3 degree Celsius, there is only one power level applied to the heating element.

13. A camera system for a motor vehicle comprising: a heating device for a lens barrel of an automotive camera assembly, the heating device comprising: a heating element adapted to apply heat along the circumference of the lens barrel, wherein the heating element is L-shaped in a side view, with a first leg being provided by a ring-shaped first part, and a second leg being provided by a second part, wherein the ring-shaped first part establishes an open cylinder, wherein a lens is arranged inside the open cylinder of the ring-shaped first part; and a tension socket, which is adapted to press the ring-shaped first part of the heating element against the lens barrel circumference and comprises a recess through which a second part of the heating element can pass from the ring-shaped first part of the heating element to a connector.

14. An external rear view device comprising a camera system for a motor vehicle comprising: a heating device for a lens barrel of an automotive camera assembly, the heating device comprising: a heating element adapted to apply heat along the circumference of the lens barrel wherein the heating element is L-shaped in a side view, with a first leg being provided by a ring-shaped first part, and a second leg being provided by a second part, wherein the ring-shaped first part establishes an open cylinder, wherein a lens is arranged inside the open cylinder of the ring-shaped first part; and a tension socket, which is adapted to press the ring-shaped first part of the heating element against the lens barrel circumference and comprises a recess through which a second part of the heating element can pass from the ring-shaped first part of the heating element to a connector, wherein the heating element is adapted to be connected to the electronic control unit of the rear view device and/or the vehicle equipped with the rear view device via a bus system including a CAN bus system.

15. A motor vehicle, comprising at least one of: a heating device for a lens barrel of an automotive camera assembly, the heating device comprising: a heating element adapted to apply heat along the circumference of the lens barrel wherein the heating element is L-shaped in a side view, with a first leg being provided by a ring-shaped first part, and a second leg being provided by a second part, wherein the ring-shaped first part establishes an open cylinder, wherein a lens is arranged inside the open cylinder of the ring-shaped first part; and a tension socket, which is adapted to press the ring-shaped first part of the heating element against the lens barrel circumference and comprises a recess through which a second part of the heating element can pass from the ring-shaped first part of the heating element to a connector, a camera system comprising the heating device; or an external rearview device comprising the camera system.

16. The motor vehicle according to claim 15, wherein the heating element is controlled depending from at least one characteristic parameter of the vehicle, the heating element being activated only during a driving mode of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The foregoing summary, as well as the following detailed description, will be better understood when read in conjunction with the appended drawings. For the purpose of illustration, certain examples of the present description are shown in the drawings. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of system, apparatuses, and methods consistent with the present description and, together with the description, serve to explain advantages and principles consistent with the invention.

(2) FIG. 1a provides both an exploded view of a camera system of one embodiment of the present disclosure and a perspective view of the assembled camera system;

(3) FIG. 1b is a side view of the assembled camera assembly of FIG. 1a, with a socket in phantom;

(4) FIG. 1c is a perspective view of the camera assembly of FIG. 1b;

(5) FIG. 1d is another perspective view of the camera assembly of FIG. 1b, with the socket not shown in phantom;

(6) FIG. 2a is a perspective view of a heating element of an embodiment of the present disclosure to be used with the camera system shown in FIGS. 1a to 1d;

(7) FIG. 2b is a side view of the heating element of FIG. 2a;

(8) FIG. 2c is side view of an alternative socket of the camera system of FIGS. 1a to 1d;

(9) FIG. 3a is a perspective view of a camera system according to an alternative embodiment;

(10) FIG. 3b is a front view of the camera system of FIG. 3a;

(11) FIG. 4 is a perspective view of a camera system of a further embodiment;

(12) FIG. 5 is a flowchart of a heating method according to an embodiment; and

(13) FIG. 6 shows heating curves for five outside temperature ranges.

DETAILED DESCRIPTION

(14) As can be seen from FIGS. 1a to 1d showing a camera system 1 of one embodiment of the present disclosure, a camera assembly 10 is at one end surrounded by a socket 20 and at the opposite end inserted in a housing 30. In detail, the camera assembly 10 comprises a camera 12 with a lens barrel 14 having a heat transfer ring 16 attached to its circumference. A heating element 18 is mounted on the heat transfer ring 16, and the socket 20 encompasses the lens barrel 14, the heat transfer ring 16 and a ring-shaped part 18a of the heating element 18 to ensure a maximal contact area of said parts for optimizing a heat transfer from the heating element 18 via the heat transfer ring 16 to the lens barrel 14.

(15) The heating element 18 comprises, in addition to the ring-shaped part 18a, a bar-shaped part 18b as can be best seen in FIGS. 2a and 2b. As the ring-shaped part 18a is arranged substantially perpendicularly to the bar-shaped part 18b, the heating element 18 takes a L-shape in the side view of FIG. 2b.

(16) The heating element 18 can be connected to a connector 19 arranged outside the socket 20, see in particular FIG. ld. For that purposes, the socket 20 is provided with a recess 22 allowing the bar-shaped part 18b of the heating element 18 to enter into the socket 20, see e.g. FIG. 1b. Via the connector 19 and a cable 42 the heating element 18 is attached to a plug 40, see FIGS. 2a and 2b, in order to be connectable in particular to an electronic control unit of a vehicle, not shown.

(17) The socket 20 is also provided with an inner ring 21 projecting from its internal surface as shown in FIG. 1a to snap-fit around the housing 30 facing edge of the unit formed by the lens barrel 14, the heat transfer ring 16 and the ring-shaped part 18a of the heating element 18. Still further, the socket 20 is provided with openings 24 for engagement of ribs 32 provided by the housing 30, see FIGS. 1a and 1d.

(18) An alternative socket 20 shown in FIG. 2c, includes 4 recesses 22 to select one for the insertion of the bar-shaped part 18b of the heating element 18, a rim 26 for further securing the arrangement of the heat transfer ring 16 as well as the ring-shaped part 18a of the heating element 18 on the lens barrel 14, and a shoulder 28 provided by a S shaped cross-section at its end facing away from the housing 30 to snap fit around the unit formed by the lens barrel 14, the heat transfer ring 16 and the ring-shaped part 18a of the heating element 18.

(19) FIGS. 3a and 3b show a further camera system making usage of a tension ring 50 around the heat transfer ring 16, with the tension ring 50 being provided with a slit 52 to provide a C-shape facilitating the mounting thereof. In addition, the two end pieces 54 and 56 on both sides of the slit 52 are provided with a complimentary geometry in order to facilitate attachment to each other to secure the mounting of the tension ring 50 on the heat transfer ring 16.

(20) The tension ring 50 can be made from metal, whereas the socket 20 preferably is provided in form of a rubber cap. Such a rubber cap can even be mounted around the metal tension ring.

(21) The camera assembly 10 shown in FIG. 4 provides a further embodiment of this disclosure and illustrates the attachment of a temperature sensor within the socket 20 and being connected to a plug 44 via a cable 46. The temperature sensor is of particular importance with respect to realizing a heating method.

(22) FIG. 5 depicts a heating method 100 according to an embodiment, with heating curves for outside temperatures far below 0° C. using a two-stage heating strategy. In the first stage a heat is generated which aims to melt an icing (melting enthalpy), and in a second stage, which starts after a defined time t(switch), the heating power is reduced to prevent icing or to evaporate droplets.

(23) The method can have steps as follows:

(24) The first step 110 is to check whether the vehicle status is correct. That is, it is checked whether the vehicle is in a driving mode during which a defrost function can only be active. A driving mode can be in form of a forward driving mode or reverse driving mode. The vehicle status is cyclically monitored.

(25) If the vehicle is in a valid condition, i.e. in a driving mode, the second step 120 is to determine the ambient or rather outside temperature. Depending on the determined temperature, a heating curve index is set to determine the appropriate heating curve, with one or two stages.

(26) For example there can be 5 heating curves defined by 5 heating curve indices as shown in FIG. 6, with the following heating curve indices:

(27) HC0 for temperatures above 25° C.,

(28) HC1 for temperatures from 25° C. to 3° C.,

(29) HC2 for temperatures below 3° to −5° C.,

(30) HC3 for temperatures below −5° to 15° C. and

(31) HC4 for temperatures below −15° C.; with only the heating curve index HC3 and HC4 resulting in a 2 level heating. The power levels of the heating curves defined by the heating curve indices can also differ from each other.

(32) The power jump can take place after 60 sec.

(33) Thus, every power level has to be applied for a specific temperature range. The first set of power levels is melting ice in case of an icing on the surface of the cover glass or lens and are called “Power Heating”. The second set of power levels are for avoiding an icing or fogging on the surface of the cover glass or lens and are called “Long Term Heating”.

(34) The power levels also depend on whether a cover glass as described in PCT/EP2019/077092 or a lens barrel as described above is to be heated. The respective data can be provided via CAN (Controlled Area Network) from the vehicle to the heating device.

(35) When the heating curve index has been determined, the third step 130 is to check when the vehicle has last left the status in which a heating was allowed, and the respective time span is compared with a calculated time in order to avoid that a short interruption of a journey, such as for refueling or a short shopping trip, leads to a new heating cycle with high heat input. Said calculated time t(min) depends on the outside temperature T(outside) and represents a minimum holding time: t(min)=12 sec/° C. [40° C.+T(outside)].

(36) If t(min) is longer than the measured holding time, the heating cycle cannot be carried out with a high heat input from the start. As a result of this “Check last ECU Reset” the answer “NO” is set.

(37) If t(min) is less than the measured holding time, the heating cycle can start from the beginning. As a result of “Check last ECU Reset” the answer “YES” is set.

(38) In the fourth step 140 “Heater Control 1”, the time for the second stage is checked.

(39) If the active heating time is less than t(switch), heating can be carried out with a higher power. As a result of this “Heater Control 1” the answer “YES” is set.

(40) When t(switch) has expired in the current heating cycle, the second stage is to be used to heat with a lower power. As a result of this “Heater Control 1” the answer “NO” is set.

(41) In the fifth step 150 “Heater Control 2”, it is checked whether the results of “Check last ECU Reset” and “Heater Control 1” both have received the answer “YES”. If this is the case, the heating cycle can be started from the beginning.

(42) In the sixth step “Set time stamp”, t(switch) is set to 0.

(43) It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that the invention disclosed herein is not limited to the particular embodiments disclosed, and is intended to cover modifications within the spirit and scope thereof.

REFERENCE SIGNS

(44) 1 camera system 10 camera assembly 12 camera 14 lens barrel 16 heat transfer ring 18 heating element 18a ring-shaped part 18b bar-shaped part 19 connector 20 socket 21 inner ring 22 recess 24 opening 26 rim 28 shoulder 30 housing 32 rib 40 plug 42 cable 44 plug 46 cable 50 tension ring 52 slit 54 end piece 56 end piece 100 heating method 110-160 method steps