Patent Description:
Conventional camera lenses have been widely used in fields such as vehicle camera modules, access control monitoring systems, and field monitoring systems. However, when a camera lens is used in a cold environment, frost is easily formed on the lens due to the low temperature, which causes part of the lens field of view to be blocked by frost, so that the camera lens cannot capture a clear image through the lens.

Additionally, with advantages in vehicle technology in recent years, vehicle camera modules are also widely used in devices such as automatic driving monitoring devices, driving recorders, and reversing camera devices. When the lens frosting problem occurs in the lens of the vehicle camera module, it may cause the driving or automatic driving system to misjudge the environment or road conditions, and cause serious harm to the user's driving safety. Therefore, how to provide a camera lens that could improve the frosting phenomenon of the lens has become a major issue in the industry.

Some defrosting lenses in the prior art are disclosed in <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

According to the present invention, a defrosting lens according to claim <NUM> is provided. Preferred embodiments are further defined in the dependent claims.

In view of the reasons mentioned above, the primary objective of the present invention is to provide a defrosting lens that could improve a problem of frosting on the lens <NUM> of a camera lens.

The present invention provides a defrosting lens, including a lens barrel, a first lens, and a heating member, wherein the lens barrel has an opening toward an object side. The first lens is disposed in the lens barrel and is located at the opening. The heating member is adapted to provide a heat source and is disposed between an inner wall of the lens barrel and the first lens, wherein the heating member is arranged along a peripheral edge of the first lens.

With the aforementioned design, since the first lens located at the opening is the most likely to get frost due to low temperature, by providing the heating member on the peripheral edge of the first lens, the thermal energy generated by the heating member could raise the temperature of the first lens to remove the frost formed on the first lens. Additionally, the setting position of the heating member could facilitate the temperature of the whole first lens to be kept within a predetermined temperature difference range, without affecting a field of view of the defrosting lens. In this way, a definition of an image captured by the defrosting lens could be effectively improved, so that the defrosting lens could be applied in various environments without being limited by the change of climate temperature difference.

The present invention will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which.

A defrosting lens <NUM> according to an embodiment of the present invention is illustrated in <FIG>, which is applied to a vehicle camera and includes a lens barrel <NUM>, a first lens <NUM>, and a heating member <NUM>.

The lens barrel <NUM> has an opening <NUM> toward an object side of the defrosting lens <NUM>. The first lens <NUM> is disposed in the lens barrel <NUM> and is located at the opening <NUM> (i.e., the first lens <NUM> is disposed in the lens barrel <NUM> and is located closest to an outside, wherein the first lens <NUM> could be a convex lens, a concave lens, a filter, a spherical lens, an aspheric lens, a wide-angle lens, or a combination of the foregoing.

The heating member <NUM> is adapted to provide a heat source and is disposed between an inner wall of the lens barrel <NUM> and the first lens <NUM>, wherein the heating member <NUM> is arranged along a peripheral edge of the first lens <NUM>. The heating member <NUM> could be an electro-thermal heater, wherein the electro-thermal heater includes a substrate and an electro-thermal unit. The substrate could be a flexible insulating film. The electro-thermal unit is disposed on the substrate. The substrate could be selected from materials such as polyester film, polyimide (PI) film, polyethylene terephthalate (PET) film, polyvinyl chloride (PVC) film, or silicone rubber. The electro-thermal unit could be connected to an external power source through a conductive line, and then generate thermal energy by an electrothermal effect through an impedance loop of the electro-thermal unit. Preferably, the electro-thermal heater includes a thermistor chip or a temperature sensor chip, etc..

In the current embodiment, a film thickness of the heating member <NUM> ranges between <NUM> and <NUM>; a maximum heating temperature of the heating member <NUM> could preferably reach <NUM> degrees Celsius, and the heating member <NUM> could be controlled to reach a predetermined heating temperature at a predetermined time. In this way, a temperature of the first lens <NUM> could be increased through the heat source supplied by the heating member <NUM>, which could effectively remove frost formed on the first lens <NUM>. Additionally, the setting position of the heating member <NUM> could facilitate the temperature of the entire first lens <NUM> to be kept within a predetermined temperature difference range, without affecting a field of view of the defrosting lens <NUM>.

The inner wall of the lens barrel <NUM> has an abutting surface <NUM> that is annular. An image-side surface <NUM> of the first lens <NUM> has an abutting portion 201a. The heating member <NUM> is dispsoed between the abutting surface <NUM> and the abutting portion 201a. The lens barrel <NUM> includes a first lens barrel <NUM> and a second lens barrel <NUM>, wherein the first lens barrel <NUM> has the opening <NUM>, and the second lens barrel <NUM> has the abutting surface <NUM>. An inner wall of the first lens barrel <NUM> has an internal threaded section <NUM>, and an outer wall of an end of the second lens barrel <NUM> has an external threaded section <NUM> matching with the internal threaded section <NUM>, wherein the end of the second lens barrel <NUM> is disposed in the first lens barrel <NUM> by screwing the external threaded section <NUM> with the internal threaded section of the first lens barrel <NUM>. The first lens <NUM> is disposed between the opening <NUM> of the first lens barrel <NUM> and the abutting surface <NUM> of the second lens barrel <NUM>. In this way, when the end of the second lens barrel <NUM> is disposed in the first lens barrel <NUM> by screwing the external threaded section <NUM> with the internal threaded section of the first lens barrel <NUM>, the heating member <NUM> could be disposed between the abutting surface <NUM> of the second lens barrel <NUM> and the abutting portion 201a of the first lens <NUM>, thereby enhancing a heating efficiency that the heating member <NUM> heats the first lens <NUM>. The second lens barrel <NUM> has a wire hole <NUM> for being passed through by a conducting wire <NUM>, wherein the wire hole <NUM> communicates with an inside of the second lens barrel <NUM> and an outside. An inner opening of the wire hole <NUM> in the second lens barrel <NUM> is located at an outer edge of the abutting surface <NUM>, and a diameter of the wire hole <NUM> gradually decreases from the inner opening of the wire hole <NUM> in the second lens barrel <NUM> to an outside of the second lens barrel <NUM>.

In the current embodiment, the defrosting lens <NUM> includes a thermal insulating member <NUM> that could be made of a material with a lower thermal conductivity, wherein the thermal insulating member <NUM> is disposed in the lens barrel <NUM>. The heating member <NUM> is disposed between the thermal insulating member <NUM> and the first lens <NUM>, wherein a side of the heating member <NUM> is attached to the thermal insulating member <NUM>, and another side of the heating member <NUM> is in contact with the first lens <NUM>. With the thermal insulating member <NUM>, the thermal energy generated by the heating member <NUM> could be prevented from escaping to a direction away from the first lens <NUM>, thereby improving the heating efficiency that the heating member <NUM> heats the first lens <NUM>. Additionally, the thermal insulating member <NUM> could also block the thermal energy generated by the heating member <NUM> from being transferred to the abutting surface <NUM> of the second lens barrel <NUM>, which may cause damage or deterioration of the second lens barrel <NUM>.

In the invention, the defrosting lens <NUM> includes a thermoconductive member <NUM> that could be made of a material with a higher thermal conductivity. The thermoconductive member <NUM> is disposed in the lens barrel <NUM> and surrounds the first lens <NUM>, wherein the thermoconductive member <NUM> is located closer to an object-side surface <NUM> of the first lens <NUM> than the heating member <NUM>, and the heating member <NUM> is located closer to the image-side surface <NUM> of the first lens <NUM> than the thermoconductive member <NUM>. In this way, the thermal energy generated by the heating member <NUM> could be quickly transmitted to the object-side surface <NUM> of the first lens <NUM> through the conduction of the thermoconductive member <NUM>, thereby achieving the purpose of warming up the whole first lens <NUM>.

In the current embodiment, the second lens barrel <NUM> is made of metal. The thermoconductive member <NUM> is disposed between an inner wall of the first lens barrel <NUM> close to the opening and an end opening of the second lens barrel <NUM>, and the thermoconductive member <NUM> is in contact with the first lens barrel <NUM> and the second lens barrel <NUM>. In this way, the thermal energy generated by the heating member <NUM> could be quickly transmitted to the thermoconductive member <NUM> through the second lens barrel <NUM> and then be transmitted to the first lens <NUM> through the thermoconductive member <NUM>. In the current embodiment, the thermoconductive member <NUM> is disposed in a way surrounding an outer periphery of the first lens <NUM>. In other embodiments, the thermoconductive member <NUM> could be disposed in a way surrounding an outer periphery of the first lens <NUM> and in contact with the outer periphery of the first lens <NUM>, as shown in <FIG>, thereby further improving the heating efficiency that the heating member <NUM> heats the first lens <NUM>.

In the embodiment shown in <FIG>, the defrosting lens <NUM> includes a second lens <NUM>, wherein an inner wall of the second lens barrel <NUM> has a lens abutting surface <NUM> that is annular. The lens abutting surface <NUM> and the abutting surface <NUM> are arranged in order along an axial direction of the second lens barrel <NUM> toward the opening <NUM> of the first lens barrel <NUM>. A peripheral edge of an image-side surface of the second lens <NUM> abuts against the lens abutting surface <NUM>. In the current embodiment, the heating member <NUM> is not in contact with the second lens <NUM>.

In the current embodiment, the heating member <NUM> is disposed between the abutting surface <NUM> of the second lens barrel <NUM> and the abutting portion 201a of the first lens <NUM>. In practice, the heating member <NUM> could be disposed in a way surrounding the peripheral edge of the first lens <NUM>. For instance, a side of the heating member <NUM> is attached to a side edge of the first lens <NUM>, and another side of the heating member <NUM> is attached to the thermal insulating member <NUM>, as shown in <FIG>; alternatively, the heating member <NUM> is disposed on an inner wall of the first lens barrel <NUM> and is located on a peripheral edge of the opening <NUM>, and the thermal insulating member <NUM> is disposed between the inner wall of the first lens barrel <NUM> and the heating member <NUM>, as shown in <FIG>, which could achieve the purpose of raising the temperature of the first lens <NUM> as well.

Claim 1:
A defrosting lens (<NUM>), comprising:
a lens barrel (<NUM>) having an opening (<NUM>) toward an object side, wherein an inner wall of the lens barrel (<NUM>) has an abutting surface (<NUM>) that is annular; the lens barrel (<NUM>) comprises a first lens barrel (<NUM>) and a second lens barrel (<NUM>); the first lens barrel (<NUM>) has the opening (<NUM>); the second lens barrel (<NUM>) has the abutting surface (<NUM>); an end of the second lens barrel (<NUM>) is disposed in the first lens barrel (<NUM>);
a first lens (<NUM>) disposed in the lens barrel (<NUM>) and located at the opening (<NUM>), wherein the first lens (<NUM>) is disposed between the opening (<NUM>) of the first lens barrel (<NUM>) and the abutting surface (<NUM>) of the second lens barrel (<NUM>); an image-side surface (<NUM>) of the first lens (<NUM>) has an abutting portion (201a); and
a heating member (<NUM>) adapted to provide a heat source and disposed between the abutting surface (<NUM>) of the lens barrel (<NUM>) and the abutting portion (201a) of the first lens (<NUM>), wherein the heating member (<NUM>) is arranged along a peripheral edge of the first lens (<NUM>); and
a thermoconductive member (<NUM>) disposed in the lens barrel (<NUM>) and surrounding the first lens (<NUM>) and disposed between an inner wall of the first lens barrel (<NUM>) close to the opening (<NUM>) and an end opening of the second lens barrel (<NUM>).