Abstract:
Disclosed are a camera module and a mobile terminal having the same, capable of simplifying the manufacturing process while reducing the fault rate and improving reliability of products. The camera module can include a camera housing having a support protrusion with an aperture formed at a center thereof and a predetermined mounting section provided at an inner portion; a plurality of lenses inserted and mounted in the mounting section of the camera housing so as to receive an optical image of a subject, where the support protrusion is provided at an upper portion of the lenses; an IR cut-off filter disposed below the lenses while sealing the mounting section; an image sensor; and a printed circuit board that digitalizes an image signal output from the image sensor.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit under 35 U.S.C. §119 to Korean Patent Application No. 10-2006-0042496, filed May 11, 2006, which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     The present document relates to a camera module. 
     A camera module is a device for photographing an image. The camera module may be provided in a mobile terminal in order to diversify applications of the mobile terminal. Here, the mobile terminal includes not only mobile phones, but also various wireless communication devices. 
     A camera module in the related art includes a lens unit, a lens holder, a housing, an IR cut-off filter, an image sensor and a printed circuit board. The lens unit receives an optical image of a subject and then transfers the optical image to the IR cut-off filter. Upon receiving the optical image, the IR cut-off filter cuts off infrared ray from the optical image and then transfers the optical image to the image sensor. The image sensor converts the optical image into an electric signal to output the electric signal. The printed circuit board is formed with predetermined electric patterns and a plurality of electrodes. The printed circuit board digitalizes the image signal output from the image sensor. 
     Focusing is performed by adjusting the distance between the lens unit and the image sensor to provide the clear image. The lens unit is coupled with the lens holder. Female/male screws are formed at coupling portions of the lens holder and the housing, respectively, so that the lens holder can be screw-coupled with the housing. That is, the focusing is performed by adjusting the distance between the lens unit and the image sensor using the screw mechanism. 
     According to a camera module in the related art using the screw mechanism, a worker sets the focal distance by rotatably coupling the lens holder with the housing using predetermined equipment. Therefore, if the torque value between the screw sections of the lens holder and the housing is out of a predetermined reference value, following problems may occur. 
     That is, if the torque value is less than the reference value, the lens holder cannot be securely coupled with the housing. In this case, the lens holder is randomly rotated when coupling the lens holder to the housing, causing the defocus phenomenon. 
     In addition, if the torque value is higher than the reference value, the focal distance can be precisely adjusted by rotating the lens holder. However, impurities are produced due to friction between the screw sections of the lens holder and the housing. Such impurities may degrade the image quality. 
     BRIEF SUMMARY 
     Embodiments of the present invention provide camera modules. 
     Embodiments of the present invention provide camera modules and mobile terminals equipped with the same, capable of simplifying the manufacturing processes and improving the image quality. 
     An embodiment of the present invention provides a camera module. The camera module can include a camera housing having a support protrusion with a perforation hole formed at a center thereof and a predetermined mounting section provided at an inner portion of the camera housing; a plurality of lenses inserted and mounted in the mounting section of the camera housing so as to receive an optical image of a subject, wherein the support protrusion of the housing is provided at an upper portion of the lenses so as to fixedly support the lenses; an IR cut-off filter disposed below the lenses while sealing the mounting section; an image sensor; and a printed circuit board that digitalizes an image signal outputted from the image sensor. 
     An embodiment of the present invention provides a mobile terminal. The mobile terminal can include a camera module, a communication device for making communication with external devices, and a controller for controlling the communication device and the camera module. The camera module can include a camera housing having a support protrusion with a perforation hole formed at a center thereof and a predetermined mounting section provided at an inner portion of the camera housing; a plurality of lenses inserted and mounted in the mounting section of the camera housing so as to receive an optical image of a subject, wherein the support protrusion of the housing is provided at an upper portion of the lenses so as to fixedly support the lenses; an IR cut-off filter disposed below the lenses while sealing the mounting section; an image sensor; and a printed circuit board that digitalizes an image signal outputted from the image sensor. 
     An embodiment of the present invention provides a camera module. The camera module can include a camera housing having an aperture at an outer surface and a predetermined mounting section provided at an inner portion, a plurality of lenses inserted and mounted in the mounting section of the camera housing so as to receive an optical image of a subject through the aperture of the camera housing, an IR cut-off filter disposed at an upper portion of the lenses, a support protrusion provided at a lower portion of the mounting section of the camera housing so as to fixedly support the lenses, an image sensor, and a printed circuit board that digitalizes an image signal output from the image sensor. 
     An embodiment of the present invention provides a mobile terminal. The mobile terminal can include a camera module, a communication device for making communication with external devices, and a controller for controlling the communication device and the camera module. The camera module can include a camera housing having an aperture at an outer surface and a predetermined mounting section provided at an inner portion, a plurality of lenses inserted and mounted in the mounting section of the camera housing so as to receive an optical image of a subject through the aperture of the camera housing, an IR cut-off filter disposed at an upper portion of the lenses, a support protrusion provided at a lower portion of the mounting section of the camera housing so as to fixedly support the lenses, an image sensor, and a printed circuit board that digitalizes an image signal output from the image sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view showing the coupling structure of a camera module according to an embodiment of the present invention; and 
         FIG. 2  is a cross-sectional view showing the coupling structure of a camera module according to another embodiment of the present invention. 
         FIG. 3  is a cross-sectional view of a camera module according to an embodiment of the present invention. 
         FIG. 4  is a cross-sectional view of a camera module according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, the present invention will be described with reference to accompanying drawings. 
       FIG. 1  is a cross-sectional view showing a coupling structure of a camera module according to an embodiment of the present invention. 
     As shown in  FIG. 1 , the camera module A according to an embodiment of the present invention includes a printed circuit board  10 , an image sensor  20 , and a camera housing  30 . A plurality of lenses  40  and an IR cut-off filter  50  are disposed in the camera housing  30 . 
     Predetermined electric patterns and a plurality of electrodes can be formed on the printed circuit board  10 . The printed circuit board  10  digitalizes the image signal output from the image sensor  20 . The image sensor  20 , which converts the image signal into an electric signal, can be attached between the electrodes by means of adhesive, such as epoxy, etc. In addition, coupling holes  10   b  can be formed outwardly of the electrodes along outer peripheral portions of the printed circuit board  10 , so that the camera housing  30  can be coupled with the printed circuit board  10 . 
     The image sensor  20  can include a pixel area having a plurality of pixels and a plurality of electrodes that serve as input/output terminals of the pixel area. The electrodes provided in the image sensor  20  can be electrically connected to the electrodes of the printed circuit board  10  through wire bonding. 
     The camera housing  30  can be a cylindrical plastic molding member. The camera housing  30  can be provided therein with a mounting section  31  for mounting the lenses  40  and a resting section  32  for resting the IR cut-off filter  50  therein. 
     A perforation hole  30   a  can be formed at the outer center portion of the camera housing  30  so as to allow the lenses  40  to be exposed to the exterior. Thus, the image can be obtained from the exterior by means of the lenses  40 . In addition, a coupling protrusion  30   b  can be provided at an outer end potion of the camera housing  30 . The coupling protrusion  30   b  can be inserted into the coupling hole  10   b  formed in the printed circuit board  10 . 
     In a state in which the coupling protrusion  30   b  is inserted into the coupling hole  10   b , the coupling protrusion  30   b  can be fixedly bonded to the printed circuit board  10  by means of adhesive, such as epoxy, etc. Thus, the camera housing  30  is sealed from the exterior. 
     The lenses  40  converge or diverge light to form the optical image. The lenses  40  may include a first lens  41  and a second lens  42 . The first and second lenses  41  and  42  may include aspheric lenses. In addition, the first lens  41  can be prepared as a convex lens and the second lens  42  can be prepared as a concave lens. Air may exist in a region between the first and second lenses  41  and  42 , or other medium can be provided in the region. The lenses  40  can be inserted and mounted into the mounting section  31  formed in the camera housing  30 . 
     The camera housing  30  can be designed such that the distance between the lenses  40  and the image sensor  20  may correspond to the total track of lens of the optical system. Thus, according to an embodiment of the present invention, it is not necessary to additionally adjust the focal distance between the lenses  40  and the image sensor  20 . The total track of lens signifies the distance between the lens center, onto which light is firstly incident, and the image sensor, that is, the distance when the focus is completed. 
     Meanwhile, the IR cut-off filter  50  can be attached to the resting section  32  formed in the camera housing  30  by means of adhesive. Accordingly, the lenses  40  can be fixedly installed in the resting section  31 , and the resting section  31  is sealed by means of the IR cut-off filter  50 . 
     In general, different from the eyes of human, the image sensor  20 , which can be a charge coupled device, can detect wavelength bands of near infrared ray and infrared ray. For this reason, the color of an image photographed by the image sensor  20  is closed to red. In order to solve this problem, the IR cut-off filter  50  is installed between the lenses  40  and the image sensor  20 . Thus, the image received through the lenses  40  is focused on the image sensor  20  after the infrared ray has been removed from the image by means of the IR cut-off filter  50 . 
     A spacer  51  can be provided at one surface of the IR cut-off filter  50  in order to support the lenses  40 . That is, the lenses  40  are supported by the spacer  51  in such a manner that the lenses  40  can fixedly adhere to the IR cut-off filter  50 . Due to the spacer  51  inserted into the mounting section  31  and the IR cut-off filter  50 , the mounting section  31  can be stably sealed. 
     The spacer  51  can be fabricated separately from the IR cut-off filter  50 , or can be integrally formed with the IR cut-off filter  50  ( FIGS. 3 and 4  show the spacer  51  integrally formed with the IR cut-off filter  50 ). If the spacer  51  is fabricated separately from the IR cut-off filter  50 , the spacer  51  fixedly makes contact with the IR cut-off filter  50 . In addition, the spacer  51  can be arranged to fixedly support the lenses  40 . 
     Further, a support protrusion  35  can be provided at an upper portion of the lenses  40 . The support protrusion  35  can be integrally formed with the camera housing  30 . In one embodiment, the support protrusion  35  can be fabricated separately from the camera housing  30 . 
     According to an embodiment of the present invention, the lenses  40  and the IR cut-off filter  50  can be integrally formed in the camera housing  30  while realizing the stable sealing structure. Accordingly, the lenses  40  can be installed as the camera housing  30  is assembled with the printed circuit board  10 . 
       FIG. 2  is a sectional view showing a coupling structure of a camera module according to another embodiment of the present invention. Hereinafter, an embodiment of the present invention will be described while focusing on the difference relative to the embodiment described with reference to  FIG. 1 . 
     According to the embodiment shown in  FIG. 2 , the IR cut-off filter  50  is positioned at front portions of first and second lenses  41  and  42 . In this case, an outer portion of a camera housing  30 ′ is expanded so as to install the IR cut-off filter  50  therein. In addition, different from the embodiment described with reference to  FIG. 1 , the spacer  51  supports an outer portion of the first lens  41 . 
     According to this structure, the spacer  51  adjacent to the IR cut-off filter  50  supports the first lens  41  instead of the second lens  42 . An additional support protrusion  33  can be provided at an end portion of a mounting section  31 ′ so as to support an outer portion of the second lens  42 . Thus, the first and second lenses  41  and  42  and the IR cut-off filter  50  can be stably and fixedly positioned in the camera housing  30 ′. 
     The camera housing  30 ′ can be designed in such a manner that the distance between the lenses  41  and  42  and the image sensor  20  may correspond to the total track of lens of the optical system. Thus, according to the present embodiment, it is not necessary to additionally adjust the focal distance between the lenses  41  and  42  and the image sensor  20 . 
     The above-described embodiments show the IR cut-off filter installed separately from the lenses. However, the IR cut-off filter can be integrally formed with the lenses by coating the IR cut-off filter on the surface of the lenses. 
     Different from the camera module of the related art, the camera module according to embodiments of the present invention does not require the assembling process for the lens holder, so impurities derived from mechanical friction between screw sections can be prevented from being produced. Accordingly, image degradation caused by the impurities can be minimized. In addition, the inability to work and focus distortion caused by the fault in the torque value can be inhibited. Further, since the camera module can be assembled matching with the predetermined optical distance, it is not necessary to additionally adjust the focal distance. Furthermore, the number of parts used for the camera module can be reduced, so that the manufacturing cost can be reduced. 
     The camera module according to the embodiments of the present invention is applicable for various mobile terminals. Here, the mobile terminals can include mobile phones as well as various wireless communication devices. 
     Such a mobile terminal includes a mobile communication terminal equipped with a camera module, a digital camera, or a complex terminal equipped with a camera module. In general, a communication device is separately provided in the mobile terminal so as to allow the user to make voice-communication with other users. In addition, the user can transmit the image obtained by using the camera module to other users through the communication device. Here, the mobile terminal may further include a controller for controlling the operation of the communication device and the camera module. 
     The camera module and the mobile terminal having the same according to the embodiments of the present invention can simplify the manufacturing process and improve the image quality. 
     Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.