Patent Publication Number: US-2010110259-A1

Title: Multi-lens image sensor module

Description:
TECHNICAL FIELD 
     The present invention generally relates to an image sensor module and, more particularly, to a multi-lens image sensor module. 
     BACKGROUND 
     The current techniques of image sensor modules are broadly applied in various fields, such as a digital still camera, a digital video camera, a videophone, and a video conference, and the module has an image sensor semiconductor chip packaged inside an optical device to sense and to capture optical image signals, following that the module converts an optical image signal to an electric signal to be delivered to the circuit board and enables the optical image signals to be recognizable, processed, or stored. 
     A commonly used conventional image sensor module  100  is schematically depicted in the simplified illustration of  FIG. 1 . The image sensor module  100  comprises a lens  102 , a lens holder  104 , an image sensor chip  106 , and a base board  108 . The image sensor chip  106  having an image sensing area is formed on the base board  108 . The lens holder  104  covering the image sensor chip is mounted on the base board  108 . The lens  102  aligning with the image sensing area of the image sensor chip is set in the lens holder  104 . Through the lens  102 , the image sensor chip is able to capture the external image signals. 
     For example, similar image sensor module structure has been disclosed in TW425042. It discloses a CCD and CMOS image capturing module, which comprises a circuit board having a CCD and CMOS image sensor device and related electronic devices, and a lens holder, whose outer peripheral size is the same as that of the image sensor device, being set on the top surface of the said image sensor device. By aligning the lens holder with the outer edge of the image sensor device, and by the planar contact between the bottom surface of the holder and the top surface of the image sensor device, there is no position difference and no angle difference produced between the axis of the holder and the center of the image sensor device in order to prevent images from the aberration. 
     A compact camera module has been disclosed in TW-1297920, comprising mainly a substrate, a sensor chip and a lens module. The substrate has a surface defining a chip-attached region and a module-secured region for attaching the sensor chip and securing the lens module respectively, further defining a check point within the chip-attached region. Therein the module-secured region encloses the chip-attached region. The substrate includes a plurality of connecting pads and a plurality of check bars away from the chip-attached region, wherein the perpendicular bisectors of the check bars have a cross point aligned with the check point. Accordingly, a self-check step can be performed to check the center location of the sensor region of the sensor chip by the cross point after chip attaching. 
     An imaging module with chip on glass configuration has been disclosed in TW-M250470, comprising a filter and a lens holder with a base and a lens-fastening portion. The base combines a plurality of electrically connecting means. The filter disposes between the base and the lens-fastening portion. The filter has a plurality of circuits which are connecting to the electrically connecting means. An image sensing chip is a flip chip on the filter. A first sealing compound disposes between the image sensing chip and the filter for sealing sensing surface of the image sensing chip. 
     All the conventional techniques described above have not disclosed an image sensor module with a complete set of directions of a 360-degree visual angle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It is believed that the present invention and its several attendant advantages and features will be understood from the proceeding description and the accompanying drawings. 
         FIG. 1  is a schematic diagram of a preferred embodiment of a conventional image sensor module; 
         FIG. 2  is an illustration of a preferred embodiment of the multi-lens image sensor module of the present invention; 
         FIG. 3  is a parts breakdown illustration of the multi-lens image sensor module of the present invention; and 
         FIG. 4  is a parts breakdown illustration of the multi-lens image sensor module of the present invention. 
     
    
    
     SUMMARY 
     According to the description above, the aspect of the present invention herein is to provide a multi-lens image sensor module. 
     Another aspect of the present invention is to provide an image sensor module having a 360-degree large visual angle. 
     Another aspect of the present invention is to utilize an optical system as communication paths between the lenses and the image sensing area to transmit the image signals. 
     Another aspect of the present invention is to utilize a lid for image division to separate the image sensing area into a plurality of subareas. Each divided subarea of the sensing area is corresponding to one lens and one optical communication path. 
     The present invention herein is to disclose a multi-lens image sensor module, which comprises: a base board; an image sensor chip having an image sensing area formed thereon bonded to the base board; a lid formed on the base board, covering the image sensor chip thereon, and the lid having a plurality of openings corresponding to the image sensing area that is divided into a plurality of subareas according to the plurality of the openings; an optical system coupled to the lid; and a plurality of lenses coupled to the optical system, transmitting image signals to the image sensing area via the optical system. 
     The present invention herein also discloses a multi-lens image sensor module, which comprises: a base board; an image sensor chip having an image sensing area formed thereon bonded to the base board; a lid formed on the base board, covering the image sensor chip thereon, and the lid having a plurality of openings corresponding to the image sensing area that is divided into a plurality of subareas according to the plurality of the openings; a set of glasses arranged on the plurality of the openings; an optical fiber output fixed mount covering the plurality of the openings of the lid; a plurality of optical fiber input fixed mounts connected to the optical fiber output fixed mount via optical fibers; and a plurality of lenses separately arranged in the plurality of the optical fiber input fixed mounts, transmitting image signals to the image sensing area via optical fibers. 
     The present invention discloses the multi-lens image sensor module, wherein the base board is a multilayer PCB (Printed Circuit Board). The said image sensor chip may include a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor chip. The number of the said lenses is at least three to enable a 360-degree visual angle of the image sensor module. 
     The multi-lens image sensor module of the present invention divides the image sensing area into a plurality of individual subareas, and each divided subarea of the sensing area is corresponding to one lens and one optical fiber communication path. In this way, only one image sensor module is required to obtain a 360-degree large visual angle, hence saving the number of the image sensor modules. Furthermore, the multi-lens image sensor module of the present invention uses optical fibers as communication paths between the lenses and the image sensing area of the image sensor module to transmit optical signals, thus extending the distance between the image sensor module and the lenses. 
     DETAILED DESCRIPTION 
     The invention hereinafter will be described in greater detail with preferred embodiments of the invention and accompanying illustrations. Nevertheless, it should be recognized that the preferred embodiments of the invention are not provided to limit the invention but to illustrate it. The present invention can be practiced not only in the preferred embodiments herein mentioned, but also in a wide range of other embodiments besides those explicitly described. Further, the scope of the present invention is expressly not limited to any particular embodiments except what is specified in the appended Claims. 
     An embodiment is an implementation or example of the invention. Reference in the specification to “an embodiment,” “one embodiment,” “some embodiments,” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments. The various appearances of “an embodiment,” “one embodiment,” or “some embodiments” are not necessarily all referring to the same embodiments. It should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. 
     The multi-lens image sensor module of the present invention uses the lid for image division to separate the image sensing area of the image sensor chip into a plurality of subareas. Each lens will capture the image from only one divided subarea, and then the established algorithm is operated to process or synthesize the image from all the divided subareas, therefore obtaining a large visual angle (up to 360°). The present invention requires only one image sensor module to reach the same field of view as that obtained from several image sensor modules, consequently saving the number of the image sensor modules. 
     The image sensor module of the present invention couples a plurality of lenses via an optical system, extending the distance between the image sensor module and the lenses to enable a wider range of the practical application, and a farther image can be captured based on a farther-distanced lens of the image sensor module. A plurality of lenses is horizontally arranged within the visual angle respectively in order to obtain a complete image of the 360-degree field of view. 
     According to a preferred embodiment, the illustration of the multi-lens image sensor module  200  of the present invention is shown in  FIG. 2 . The image sensor module  200  comprises an image sensor chip  202 , an optical system  206 , a set of glasses  208 , and a plurality of lenses  216 . 
     Image signals from outside are transmitted to the image sensor chip  202  via the optical system  206 . The image signals transmitted by the optical system  206  will be divided into separate signals with no mutual interaction through the lid (not shown). The lid will divide the image sensing area of the image sensor chip  202  into a plurality of subareas. Each subarea is corresponding to one lens  216 . External image signals sequentially pass through the lenses  216 , the optical system  206 , the set of glasses  208 , and the lid to arrive at the image sensing area of the image sensor chip  202 . Each of the said plurality of optical communication paths is individually independent without mutual interaction amongst one another. After the image sensor chip  202  receives the image signals, the optical image signals will be delivered to an analog-digital converter (A/D Converter)  218  to convert the image signals into digital image signals. 
     In a preferred embodiment, the optical system may be a combination of a convex lens, a concave lens, and a plane mirror. The arrangement of the optical system is well known in the art, therefore the detailed description being omitted. In one embodiment, the optical system may be an optical fiber communication system. 
     According to a preferred embodiment of the present invention, the parts breakdown illustration of the multi-lens image sensor module  300  is shown in  FIG. 3 . The multi-lens image sensor module  300  comprises an image sensor chip  302 , a base board  304 , an image sensor module lid  306 , a set of glasses  308 , an optical fiber output fixed mount  310 , optical fibers  312 , a plurality of optical fiber input fixed mounts  314 , and a plurality of lenses  316 . 
     The image sensor chip  302  is set on the base board  304 , having an image sensing area  303  formed thereon to capture images. The base board  304  is, but not limited to, a multilayer PCB (Printed Circuit Board), and any appropriate circuit board can be applied to the present invention herein. The base board  304  may also include analog and digital circuitry formed thereon (not shown), for example, a DSP (digital signal processor), a memory chip, an ASIC (Application Specific Integrated Circuit) chip, and passive components. The image sensing area  303  of the image sensor chip  302  receives optical signals, and the analog image signals are converted into digital image signals by the DSP and the ASIC chip, then the digital image signals will be stored in the memory chip. 
     The image sensor chip  302  may include a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor chip. A CCD is a semiconductor that can record the change of the light in a digital still camera, usually denoted as megapixel, and its material is primarily silicon semiconductor, which is capable of converting the light on the surface of a photosensitive element into storage electric charges. As the surface of a CCD senses the light illuminating, an electric charge is correspondingly produced thereon, following that it is transmitted to an amplifying and decoding element to restore all the signals produced by the photosensitive element on a CCD, and a full picture is thus constructed. A CMOS image sensor chip is a semiconductor that can record the change of the light in a digital still camera as well. But the manufacturing technology of a CMOS is different from that of a CCD, and it is closer to that of common computer chips instead. The material of a CMOS is primarily made of silicon and germanium, and its image sensor module utilizes the current to process the chip in order to record and interpret signals as an image. 
     The image sensor module lid  306  is arranged on the image sensor chip  302 , and it is mounted on the base board  304 . The image sensor module lid  306  has an opening  307  corresponding to the image sensing area  303  of the image sensor chip  302 . The image sensor chip  302  captures external images via the opening  307 . The lid  306  has a plurality of sidewalls  309  to divide the opening  307  into a plurality of openings  307 , the image sensing area  303  consequentially being divided into a plurality of subareas. In this embodiment, the image sensing area is divided into four subareas by the image sensor module lid  306 , but not necessarily four. 
     A set of glasses  308  and an optical fiber output fixed mount  310  are arranged on the openings  307  of the lid  306 . The set of the glasses  308  having a plurality of glasses corresponds exactly to the plurality of the openings  307  respectively. The space amongst the optical fiber output fixed mount  310 , the set of glasses  308 , the lid  306 , and the base board  307  may be a vacuum or filled with low humidity gases (nitrogen or argon) to prevent the moisture from entering it, which avoids affecting the sensing capability of the image sensor chip. The optical fiber output fixed mount  310  is connected to the individual optical fiber input fixed mounts  314  via optical fibers  312 . The openings  315  of optical fiber input fixed mounts  314  have internal threads to screw in the lenses  316 . 
     External optical signals are transmitted via the optical fibers to the image sensing area  303  on the image sensor chip  302  by the multi-lens image sensor module  300 . Excellent communication efficiency can be achieved by transmitting optical signals via optical fibers. The paths between the lenses  316  and the image sensing area  303  are separate, not interfering with one another during signal transmission. 
     The multi-lens image sensor module of the present invention has extended the distance between the lenses and the image sensing area, hence enabling the optical fiber input fixed mounts  314  and the lenses  316  to be located at a far distance from the image sensor chip  302  and the base board  304 , consequently, any desired position being able to be chosen for the lenses, particularly those too narrow a space to be equipped with an entire image sensor module. 
     The image sensing area  303  on the image sensor chip  302  is divided into a plurality of subareas by the image sensor module lid, and each lens  316  is merely responsible for the partial sensing area, therefore enabling a 360-degree large visual angle to be obtained. In this embodiment, the number of the lenses is four, but not necessarily four, and any suitable number of lenses is applicable in the present invention herein. 
     According to an embodiment of the present invention, the parts breakdown illustration of the multi-lens image sensor module  300  is shown in  FIG. 4 . In a preferred embodiment, the multi-lens image sensor module  300  is applicable in equipments requiring a 360-degree visual angle, such as a walkable and orienting robot or any measuring distance occasions. In the horizontal direction, each lens  316  is arranged by the optical fiber at a specific position to share a 90-degree visual angle respectively, thus enabling the multi-lens image sensor module  300  to obtain a 360-degree visual angle as a whole. In a preferred embodiment, the multi-lens image sensor module  300  may also harness three lenses with each lens&#39; sharing a 120-degree visual angle respectively. 
     Optical fibers are utilized to transmit optical signals in the present invention, and the lenses are able to be set at any position desired therein. If a complete set of directions of a visual angle is desired in the prior art, then a plurality of image sensor modules is required to be arranged in many directions individually. Only one image sensor module is necessary to fulfill a complete set of directions of a visual angle in the multi-lens image sensor module of the present invention herein. 
     The preferred embodiments are described above to illustrate the invention herein, but are not provided to limit the Claims declared in the present invention. What is claimed depends on the Claims appended and the equivalent field. It will be apparent to those skilled in the art that changes or modifications may be made from any of the described messages without departing from the spirit of the invention, but are included in the equivalent design or modifications under the scope of the present invention, being circumscribed by the following Claims.