DE102015202312A1 - Image acquisition system for a motor vehicle, method for producing an image recording system and injection molding tool - Google Patents

Abstract

The present invention relates to an image pickup system for a motor vehicle, an injection molding tool, and a method of manufacturing an image pickup system. The image recording system (100 ') comprises an optical holder (120) and an optical carrier (110), which is connected to the optical holder (120) such that an optical system carried by the optical carrier (110) optics to a with the object holder (120) connected to Bildaufnehmer (120). 130) is fixed optically adjusted. The imaging system is characterized in that the optic holder (120) comprises at least one transparent zero-shrinkage thermoset material by which the optics carrier (110) is connected to the optics holder (120). Fixed optically adjusted here means that the image recorder is firmly connected to the optical holder and thus to the optical carrier and the optics, that optical axes of the optics and the image recorder coincide and the image recorder is arranged in a focal point of the optics. The optical holder of the image recording system according to the invention can be easily manufactured on an injection molding machine.

Description

The present invention relates to an image pickup system for a motor vehicle, an injection molding tool, and a method of manufacturing an image pickup system.

State of the art

Imaging systems are used in many areas. An example is the application in motor vehicles. For example, optical camera systems (imaging systems) in motor vehicles capture the vehicle environment and provide information for other vehicle systems. Image acquisition systems are used, for example, for night vision applications (lane-departure warning) and for monitoring the front or rear of the vehicle.

Image recording systems comprise an optical holder, an optical carrier (lens) with a plurality of lenses and an image sensor on a carrier plate (imager chip).

The optics holder and the optics carrier are manufactured independently of each other. The elaborate lenses often have specially ground lenses.

When mounting the camera system, make sure that the optics carrier, including the optics, is optically aligned with the image recorder, as this is the only way to ensure that the image recorder acquires the correct image.

The optics holder has a passage opening which is fired on one side with the carrier plate. The slide carries an optic made of spaced-apart beam-forming components, so for example lenses. The optical axes of the beam-forming components coincide with each other, so they lie one above the other. The slide is arranged in the passage opening from the other side of the passage opening and connected to the object holder such that the optical axis of the optics coincides with the optical axis of the image recorder and the image recorder is arranged in the focus of the optics.

From the DE 102006008230 A1 For example, an image pickup system, particularly for automotive applications, is known with a substrate, an image sensor mounted on the substrate, an optical unit located in front of the image sensor, and an optical holder connected to the substrate in which the optical unit is housed.

A camera system with adjustment possibility, in which the optical carrier can be aligned with respect to the image sensor is in EP 1 716 018 B1 described. In EP 2054270 B1 In essence, a mounting system is described by a camera system.

Disclosure of the invention

According to the invention, an image acquisition system according to claim 1 for a motor vehicle, an injection molding tool according to claim 7 and a method according to claim 9 for the production of an image acquisition system are provided.

The image recording system comprises an optical holder and an optical carrier which is connected to the optical holder such that an optical system carried by the optics carrier optics is fixed to an image receptor connected to the object holder optically adjusted. The image recording system is characterized in that the optical holder comprises at least one transparent thermosetting material with zero shrinkage, by which the optical carrier is connected to the optical holder.

Fixed optically adjusted here means that the image recorder is firmly connected to the optical holder and thus to the optical carrier and the optics, that optical axes of the optics and the image recorder coincide and the image recorder is arranged in a focal point of the optics.

The optical holder of the image recording system according to the invention can be easily manufactured on an injection molding machine. Imager and optics holder are aligned in a cavity to each other so that optical axes of the optics and the image receptor coincide and the image sensor is arranged in a focal point of the optics. The cavity is a negative mold of the optical holder and can be filled after alignment with the thermosetting material to form the optical holder. During the curing of the material, the optics and the image recorder remain aligned due to the zero shrinkage, ie the absence of shrinkage and thus also a delay during curing. The finished image acquisition system can be removed from the cavity after curing. Gluing the optic holder to the optics carrier is unnecessary.

In a preferred embodiment, the optics carrier has at least one holding projection and / or at least one holding recess.

By means of the holding projection and / or the holding recess, the optical carrier can be held by an optical holder in position to a Bildaufnehmer.

The retaining projection and / or the retaining recess may form a ring perpendicular to the optical axis of the optics. This further improves the fixation.

The retaining projections may be like a spike and / or the retaining recesses may be blind hole-like and may be arranged annularly perpendicular to the optical axis of the optics.

In a preferred embodiment of the image recording system, the optical carrier is the optical carrier presented according to the invention.

The thermoset material may include a phenol-formaldehyde compound, an epoxy, and / or a bulk molding compound.

In a preferred embodiment, the thermoset material comprises from 50 to 70% thermally conductive particles. By means of the thermally conductive particles carrier plate and image sensor can be heated.

The thermally conductive particles may comprise boron nitride, aluminum hydroxide and / or magnesium hydroxide.

A fiber content of the thermosetting material may be formed to 10 to 30% of metal fibers. The metal fibers give the optics holder the required strength.

The metal fibers may comprise copper, aluminum and / or silver.

The injection molding tool according to the invention comprises a cavity, which is a negative mold of an optical holder and a receptacle for an image sensor and a further receptacle for a slide so that it at least partially protrudes into the cavity, wherein the receptacle and / or the further recording along a distance axis means of a drive can be shifted against each other.

Thus, by controlling the drive, a regulator or processor can shift the images relative to one another until an image shown in sharp-edged form on the projection surface is recognized by image processing connected to the image recorder. The imager is then in the focal point of the optics, and the cavity can now be filled with thermoset material with zero shrinkage to form the optics holder.

Then the optical alignment of optics and image sensor can be carried out automatically.

In a preferred embodiment of the injection molding tool, the drive comprises a mechanical drive, a piezo drive and / or an electric drive.

In the injection molding tool, a projection surface may be arranged such that an image imaged on the projection surface is imaged by an optical system in the slide in the further image onto the image recorder in the recording.

The method according to the invention serves to produce an image recording system. The method according to the invention comprises the steps:
Aligning an imager and an optics carrier in a cavity which is a negative mold of an optics holder such that optics carried by the optics carrier are optically aligned with the imager; Filling the cavity with a zero shrink thermoset material to form the optics holder; and curing the material.

This is a simple and inexpensive production process for an image acquisition system.

In a preferred embodiment of the method, the alignment comprises:
Processing an image displayed on a projection surface and transmitted through the optics carrier to the image receptor in an image processing system and driving a drive to advance and / or retract the optic with respect to the image receptor until the image is in focus.

Advantageous developments of the invention are specified in the subclaims and described in the description.

drawings

Embodiments of the invention will be explained in more detail with reference to the drawings and the description below. They show by way of example and schematically:

1 a picture-taking system according to the prior art,

2 an embodiment of the injection mold according to the invention in section with two cavities for object holder production, and

3 An embodiment of the image recording system according to the invention.

Embodiments of the invention

1 shows an image acquisition system 100 according to the prior art. The image acquisition system 100 includes an optics carrier (lens) 110 , one optical Mounts 120 and a imager 130 For example, a CCD or a CMOS chip (Charge Coupled Device or Complementary Metal Oxide Semiconductor). The optics carrier (lens) 110 carries a lens with multiple lenses 115 passing through spacers 116 are spaced from each other. The optics carrier 110 is from the optics holder 120 by means of a bond 125 held. The optics holder 120 continues to hold by means of another bond 125 a carrier plate 140 on which a picture recorder 130 is arranged.

The imager 130 is through bonding wires 150 covered with potting resin 155 are filled with tracks 160 connected.

The image acquisition system 100 is shown in a section. centering 117 make sure that optical axes of the lenses 115 and the imager 130 lie in the picture plane and coincide.

The optics carrier 110 is in the position along the common optical axis of lenses 115 and imagers 130 arranged at the image sensor 130 in the focus of optics is arranged.

2 shows an embodiment of the injection molding tool according to the invention 200 , The injection mold 200 includes two parts 200a . 200b , When assembling the parts 200a . 200b Two cavities form 210 that have a sprue 220 can be filled with a thermosetting material with zero shrinkage. To harden the thermosetting material are heating cartridges 250 in the injection mold 200 arranged. Each of the cavities 210 is a negative mold of an optical holder.

Each of the cavities 210 includes two opposing shots 230 . 240 , One of the shots 230 is in the part 200a arranged and used to record one with image sensor 130 equipped carrier plate 140 , The further shot 240 is in the other part 200b arranged and used to take one with lenses 115 equipped optics carrier 110 , The arrangement of the pictures 230 . 240 one another is such that in the case of assembled parts 200a . 200b , received optics carrier 110 and recorded support plate 14 optical axes of imagers 130 and lenses 115 coincide, so are identical.

In the embodiment, the further recording 240 with a drive 260 connected. The drive 260 allowed, the further recording 240 along the common optical axis of imager 130 and lenses 115 to move.

Alternatively or additionally, the recording 230 with another drive, such as an electric drive, a mechanical drive or a piezo drive connected. The further drive allows the recording 230 along the common optical axis of imager 130 and lenses 115 to move.

The further shot 240 also includes a projection screen 270 for example a screen. The projection screen 270 is perpendicular to the optical axis so arranged that the lenses one on the projection surface 270 shown image on the image sensor 130 depict.

An image processing unit 280 is with the imager 130 over a flexband 290 connected.

In an embodiment not shown, the injection mold has only one cavity.

With the injection mold, an image processing system according to an embodiment of the invention can be produced. To do this, the following steps are performed:
Inserting image sensors into the recordings;
Inserting the lens carriers equipped with lenses in the other shots;
Closing the parts of the injection mold;
Individual optical adjustment of the optical carriers with respect to the image sensors and / or the image sensors with respect to the optical carriers; and
Injection molding of a thermoset material with zero shrinkage into the cavities through the runner.

The optical adjustment can be done automatically. For this purpose, a sharp-edged image is displayed on the projection surface and the image processing attempts to recognize the displayed image in the image recorded by the image recorder. The drive is thereby moved forward and / or back until the recorded image is sharp and can be detected.

3 shows an embodiment of the image recording system according to the invention. Here is the optics carrier 110 still in the drive 260 sliding further recording 240 including projection screen 270 arranged. The optics holder 120 is already made. The optics carrier 110 has protruding retaining rings 118 perpendicular to the optical axis, which are enveloped by the thermosetting material and protrude into the material. This is the optics carrier 110 with respect to the image receptor 130 fixed optically adjusted. Instead of or in addition to projecting retaining rings can annular recesses, annularly arranged mandrels and / or annularly arranged blind holes on the optical carrier be present, which protrude into the thermosetting material or into which protrudes the thermosetting material.

A further embodiment of the invention describes a method for producing a camera system, for example for surroundings detection systems of vehicles, having an optics holder and an optics carrier, whose optics serve to guide incident light onto an image recorder and the media-tight implementation of the associated electronics including imager chip.

This further embodiment provides a method with which a cost-effective and environmentally friendly camera system can be produced. Targeted functional integration and functional use of materials mean that fewer process steps and individual parts are required. In addition, the structure is simple and space-saving and reduces the cost and time required for production and logistics.

The core of the further embodiment is the production of novel camera modules by an optical integration of the lens carrier equipped with optics carrier in the optical holder directly in the injection mold. Since the optics carrier is firmly locked to its retaining rings, no additional alignment and bonding processes are necessary.

The production takes place completely on only one injection molding machine and only in one injection mold. For this, the encapsulated circuit carrier is deposited with handling on the pins in the receptacle in the part of the heated to 130 ° C to 170 ° C injection mold. At the same time, the flex band is positioned, the contacting for the image sensor is plugged in and connected to an image processing system. In the same or another step, the optical carrier equipped with lenses is inserted into the further receptacle in the other part of the cavity on the nozzle side (runner side) and in front of a projection surface, for example with a slight pressure. The further receptacle is displaceable, for example rotatable, and can be moved very accurately back and forth by a drive. When the tool is closed, the image of the projection surface is transmitted through the optics carrier to the imager and processed in the image processing system. The drive is moved back and forth until the image is sharp. At this time, the system sends a signal to the injection molding machine, and the thermosetting material for the optical holder is injected around the retaining rings of the optical carrier, for example, with an internal mold pressure less than 50 bar injected. The optics holder is shaped.

The thermoset material is preferably a Bulk Molding Compound (BMC) set at zero shrinkage. This means that the distance and the position of the optical carrier to the image sensor remain constant even after removal from the tool without shrinkage and distortion in the cooled state.

The thermosetting plastic may also be an epoxy resin (EP) or a phenolic molding compound (PF).

After a given curing time, the injection mold can be opened and the sprue can be automatically separated from the optical holders. The finished image acquisition systems can be removed from the handling of the nozzle side of the injection mold and packaged in blisters.

Due to the low viscosity of the surrounding thermoset occur during the injection process, only low pressures, so that the optics carrier is not compressed and the lenses are not moved.

In addition to the use of low-cost materials, the functional integration of design and optical properties can save labor and system costs as well as manufacturing costs and logistics time.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006008230 A1 [0007]
• EP 1716018 B1 [0008]
• EP 2054270 B1 [0008]

Claims (10)

Imaging system ( 100 ' ) for a motor vehicle with an optical holder ( 120 ), an optical carrier ( 110 ), so with the optics holder ( 120 ), that one of the optical carrier ( 110 ) worn optics to one with the optics holder ( 120 ) associated image sensor ( 130 ) is fixed optically adjusted, characterized in that the optics holder ( 120 ) comprises at least one transparent thermoset material with zero shrinkage through which the optics carrier ( 110 ) with the optics holder ( 120 ) connected is. Image recording system according to claim 1, wherein the optics carrier at least one retaining projection ( 118 ) and / or has at least one retaining recess. Image recording system according to claim 2, wherein the retaining projection ( 118 ) and / or the retaining recess form a ring perpendicular to the optical axis of the optics. Image recording system according to claim 2, wherein the retaining projections are like a spike and / or the retaining recesses blind-hole-like and are arranged annularly perpendicular to the optical axis of the optics. An imaging system according to any one of claims 1 to 4, wherein the thermosetting material comprises a phenol-formaldehyde compound, an epoxy and / or a bulk molding compound. Injection mold ( 200 ) comprising a cavity ( 210 ), which is a negative mold of an optical holder, and a receptacle ( 230 ) for one image recorder and another image ( 240 ) for a slide, so that this at least partially into the cavity ( 210 ), wherein the receptacle ( 230 ) and / or the further recording ( 240 ) by means of a drive ( 260 ) can be shifted against each other along a distance axis. Injection mold according to claim 6, wherein the drive ( 260 ) comprises a mechanical drive, a piezo drive and / or an electric drive. Injection mold according to claim 6 or 7, further comprising a projection surface ( 270 ), which is arranged such that an image imaged on the projection surface of an optical system in the slide in the further receptacle ( 240 ) on the image sensor in the receptacle ( 230 ) is displayed. Method for producing an image acquisition system ( 100 ' ) according to one of claims 1 to 5, comprising steps: aligning the image recorder ( 130 ) and the optics carrier ( 110 ) in a cavity ( 210 ) of an injection molding tool ( 200 ), which is a negative mold of the optical holder ( 120 ), so that the optics to the image sensor ( 130 ) is optically adjusted, Spritzvergießen the cavity ( 210 ) with the thermosetting material to the optics holder ( 120 ) and curing the material. The method of claim 9, wherein the aligning comprises: processing one on a projection surface ( 270 ) and by the optics on the image sensor ( 130 ) in an image processing system ( 280 ) and driving a drive ( 260 ) for advancing and / or retracting the optics carrier ( 110 ) with respect to the image sensor ( 130 ) until the picture is sharp.

Images