HK1059120A - Small-size imaging apparatus, in particular photographic appliance or camera - Google Patents

Description

Small-sized imaging device, in particular a video camera or a video camera

The invention relates to a small-sized imaging device, in particular a video camera or a video camera, in which a sensor is provided which is formed by a plurality of pixels of a test image. The apparatus includes at least one focus adjustment lens having an optical axis passing substantially at the geometric center of the photosensitive surface of the sensor.

In particular, the imaging apparatus according to the invention is intended to be incorporated in a multifunctional portable device, in particular a mobile phone, a watch or a laptop.

An imaging device is known from US5,130,804, comprising a sensor, a lens arranged in a light-shielding compartment, and a holder with an opening against which the lens and a photosensitive surface of the sensor are arranged. The sensor itself is formed by a substrate defining a photosensitive surface, which is mounted on the bottom of a box to which the substrate is connected in a conventional electrical connection. The cartridge includes electrical connections connecting the base to external contact pads of the cartridge to allow electrical connection to a support on which the electronic device is mounted. Such an imaging device has a disadvantage in that it is not easy to precisely align the optical axis of the objective lens and the center of the opening when mounting. Also, the positioning of the sensitive element with respect to the opening cannot be assured. In addition, it is not easy to mount the sensitive elements on the support and to ensure that the corresponding contact pads are correctly aligned.

The object of the present invention is to solve the above mentioned drawbacks.

It is a further object of the invention to provide a small-sized imaging device in which, at the time of production of the imaging device, an electronic connection is easily established between the pixels of the sensitive element and the electronics of the use and/or processing of the electronic signals provided by the pixels.

The invention therefore relates to an imaging device as defined in the appended claim 1.

The invention will be described with the aid of the following description, with reference to the accompanying drawings, which are not limiting but exemplary, and in which:

FIG. 1 shows a simplified diagram of an embodiment of an imaging device according to the invention; and

fig. 2 shows a second embodiment of the device of fig. 1.

In fig. 1, an imaging device 2 is shown, which imaging device 2 forms a compact and autonomous module. However, it is intended to be integrated in a portable device, in particular a telephone or a portable object worn on the wrist, such as a watch. Such an imaging device is formed by an image sensor 4 having a light-sensitive surface 6 and an objective lens comprising at least focus adjusting lenses 8, 9, 10, 11 mounted in parallel in a light-shielding compartment 12 defining a tube 13, the tube 13 having a transverse opening and a side plate 14 at the inner end of the tube, i.e. close to the sensor. The outer end of the tube is closed by a lens 8. The sensor 4 is mounted on the inner surface 16 of a support 18, the support 18 having an opening 20 of a size approximately equal to or greater than the size of the photosensitive surface 6, which, by being approximately centered on the opening, is located opposite the opening 20.

It will be noted that some lenses may also have a function of filtering infrared or ultraviolet rays, in particular the lens 11. In a variant of embodiment, the optical element 11 consists of only one filter with two parallel flat surfaces. The optical element 11 can be fixed to the mask 12 of the objective or to the substrate by simply being inserted into the opening 20, or it can also be fixed directly to the sensor 4. These different possibilities allow the skilled person to carry out numerous implementation variants.

According to the invention, a plurality of positioning means of the objective lens with respect to the opening 20 and/or the sensor 4 are provided when the objective lens is mounted. In a preferred embodiment, these positioning means are also used to position the sensor relative to the opening so that the optical axis 24 of the objective lens and the center of the photosensitive surface of the sensor are substantially aligned.

In a first preferred embodiment, said positioning means are constituted by an optical element 11, which optical element 11, reaching through its lateral walls above the upper surface 22 of the support 18, is fixedly mounted in the opening 20. The opening 20 is dimensioned such that the optical element is positioned in the opening by its walls.

In a variant, the optical element 11 is fixed to the sensor 4 before mounting, and this optical element can be mounted with the sensor positioned on the substrate 18. Furthermore, in this case, the element 11 is used to position the light shield 12 and then the objective lens with respect to the sensitive element 4. For example, the element 11 is bonded to the photosensitive surface 6. This variant does not exclude the possibility that the size of the opening is larger than the size of the optical element 11.

It will also be noted that the shading grids 12, here illustrated in a simplified manner, may have different forms, in particular with a non-rectilinear inner or outer profile. The shade 12 can be designed by the skilled person to be fixed to the base body 18 in various ways, in particular adhesively.

The sensor 4 is constituted by a semiconductor substrate on the surface of which a plurality of pixels are arranged, which pixels define a light-sensitive surface 6. The pixels are connected by electrical pathways to electrically contacting studs 28 having corresponding plates mounted on the inner surface 16 of the support. On this surface 16, a plurality of conductive paths are mounted, which connect the contact pads to the sensitive element 4 with at least one electronic device 30. These edge contact pads 32 may also be designed to provide a processed or partially processed image to a user device, particularly a display device for images made by the imaging apparatus 2.

The sensitive element 4 and the electronic device 30 are protected by a resin 34. This resin 34 also hardens the rear part of the base body 18 and ensures the electrical connection between the contact pads, which are arranged on the base body 18, and the terminals of the sensor or the connection pads 28. It will be noted that in fact the sensitive element 4 may have only contact pads constituted by a thin surface metallization, the electrical connection being carried out by means of an anisotropic conductive adhesive or by intermediate means known to the skilled person.

In the second embodiment of the invention shown in fig. 2, the references already described in detail above will not be present again.

The imaging device 3 differs from the imaging device in fig. 1 in that the objective lens has a transparent optical element assembly inside the tube 13, the internal optical element 11 having no opening 20 through the base body 18. Here, when the objective is mounted, the positioning of the objective takes place by means of an inner part 40 of the light shield 12 relative to the opening 20, into which the light shield 12 penetrates and is adjusted relative to the opening.

Other means of positioning the objective lens with respect to the opening 20 may be devised when mounting the objective lens. The same applies to the sensor 4.

It is finally noted that the carriage 18 may advantageously have a foldably flexible portion located between a first portion supporting the sensitive element and the objective lens and a second portion supporting other devices, in particular the electronic device 30. It is thus possible to fold the second part under the first part in order to obtain a particularly compact device, in which the means 30 are located in particular opposite the sensitive element 4, in the extension of the objective lens.

Claims (6)

1. Small-sized imaging device, consisting of a sensor (4) and an objective (8, 9, 10, 12) mounted in correspondence with each other, and a support (18) having an opening (20) for the passage of the focused light of said objective, said sensor having a light-sensitive surface (6) located opposite the opening, characterized in that it comprises positioning means (11, 40) of said objective with respect to said opening and/or sensor when mounted.

2. The apparatus of claim 1, wherein said positioning means (11) is further adapted to position said sensor relative to said opening when said sensor is installed so that an optical axis (24) of said objective lens is substantially aligned with a center of said photosensitive surface.

3. Device according to claim 1 or 2, characterized in that the objective is formed by a light-shielding cell (12), in which light-shielding cell (12) at least one first optical lens (8, 9, 10) is arranged, which light-shielding cell has a transverse opening with an outer end closed off by the first lens and an inner end located opposite the opening.

4. A device according to claim 3, characterized in that it comprises a transparent optical element (11), which element (11) is fixedly mounted in said opening of said holder, said positioning means being constituted by the optical element.

5. The apparatus of claim 4 wherein said optical element is bonded to said photosensitive surface prior to mounting said sensor on said support.

6. A device according to claim 4 or 5, characterized in that the openings are dimensioned such that the optical elements are positioned in the openings by their respective transverse walls.