Abstract:
Provided is an antenna device for a portable terminal including a first housing and a second housing assembled with the first housing so as to slidingly move on the first housing. The antenna device includes an antenna pattern installed on an inner surface of the second housing; and at least one connecting terminal, which is installed on the outer surface of the first housing and is sliding by connected to the antenna pattern, wherein the second housing is assembled with the first housing to at least partially cover the first housing. The antenna device has few parts and has a simple structure, thus simplifying manufacture and reducing.

Description:
PRIORITY 
   This application claims priority under 35 U.S.C. § 119 to an application entitled “Antenna Device for Portable Terminal” filed in the Korean Intellectual Property Office on Oct. 26, 2004 and assigned Serial No. 2004-85874, the contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to portable terminals including digital communication devices such as cellular phones, personal digital assistants (PDAs), hand held phones (HHPs), camera phones, game phones, and Internet phones, and in particular, to an antenna device for a portable terminal, of which transmission/reception sensitivity is adjusted according to sliding movement on the portable terminal. 
   2. Description of the Related Art 
   The term portable terminal commonly refers to an electronic device with which a user can perform wireless communications. The design trend of portable terminals is geared towards portability and thus miniaturization light-weight designs. Moreover, multimedia compatibility is also desirable. Portable terminals are thus evolving into small, light-weight multi-function communication terminals which can also be adapted to various multimedia or Internet environments. Also, as portable terminals have become more prevalent they have transformed from being luxuries to being necessities throughout the world. 
   Conventional portable terminals are classified into several types by appearance. For example, according to the appearances of portable terminals, the conventional portable terminals are classified into bar type, flip type, and folder type terminals. The term bar-type terminal typically refers to a terminal in which a single housing is configured in a bar type manner, the term flip type terminal typically refers to a terminal in which a flip is rotatably assembled with a bar type housing by a hinge apparatus, and the term folder-type terminal typically refers to terminals in which a folder is rotatably assembled with a single bar type housing using a hinge apparatus so that the folder can be folded over the housing. 
   Also, according to wearing positions or methods, the portable terminals may be classified into neck-wearable type and wrist type terminals. The neck-wearable type terminal typically refers to a portable terminal which a user can wear around the user&#39;s neck using a string, and the wrist type terminal typically refers to a portable terminal which a user can wear around the user&#39;s wrist. 
   Also, according to the methods used to open/close the portable terminals, the portable terminals can be classified into rotation type and sliding type terminals. The rotation type terminal means a terminal in which two housings are rotatably assembled and open/closed while facing each other, and the sliding type terminal means a terminal in which two housings are open/closed by sliding movement in a longitudinal direction. Those skilled in the art will easily understand the variously classified portable terminals described above. 
   Conventional portable terminals thus are developing into advanced portable terminals which are capable of enabling high-speed data communication and/or voice communication functions. That is, in order to meet the increasing customer&#39;s demands, future portable terminals will provide services using a wireless communication technology for transmitting data at a high data rate. 
   Recently, conventional portable terminals have begun to adopt (internally and/or externally located) cameras, thus popularizing the transmission of digital images (e.g., photographs, graphics, icons, etc.). 
   However, antenna devices adopted by the conventional portable terminals have the following disadvantages. In a case where the conventional portable terminal adopts a retractable antenna comprised of a helical antenna and a rod antenna as an antenna device, its user must inconveniently pull out the retracted rod antenna to increase reception sensitivity when the reception sensitivity decreases, and retract the pulled-out rod antenna after a call. When the portable terminal is carried in a pocket, its portability is decreased due to protrusion of the antenna device. Moreover, when a portable terminal with an external antenna drops, the external antenna is more likely to be damaged. 
   Furthermore, in a case where a portable terminal incorporating a fixed built-in type antenna device, when antenna&#39;s reception sensitivity decreases due to geographical features, there is no way to cope with the decrease in reception sensitivity. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to substantially solve at least the above problems and/or disadvantages and to provide at least the advantages below. Accordingly, an object of the present invention is to provide an antenna device for a portable terminal, which is built in the portable terminal and can be popped in or out according to reception sensitivity. 
   Another object of the present invention is to provide an antenna device for a portable terminal, configured such that the antenna device can be slidingly located relative to the portable terminal, thereby adjusting reception sensitivity. 
   According to one aspect of the present invention, an antenna device for a portable terminal including a first housing and a second housing assembled with the first housing so as to slidingly move on the first housing including an antenna pattern installed on an inner surface of the second housing; and at least one connecting terminal, which is installed on the outer surface of the first housing and connected to the antenna pattern, wherein the second housing is assembled with the first housing to cover the first housing. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which: 
       FIG. 1  is a front view illustration of a portable terminal including an antenna device according to a preferred embodiment of the present invention; 
       FIG. 2  is a front view illustration of the portable terminal of  FIG. 1  with the second housing slidingly located in an extended position relative to the first housing; 
       FIG. 3  is a rear view illustration of the portable terminal shown in  FIG. 1 ; 
       FIG. 4  is a rear view illustration of the portable terminal shown in  FIG. 2 ; 
       FIG. 5  is a rear view illustration showing a state in which a rear cover of the second housing of the portable terminal shown in  FIG. 4  is disassembled; 
       FIG. 6  is a perspective view illustration of the inside of the rear cover of the second housing shown in  FIG. 5 ; 
       FIGS. 7 and 8  are cross-sectional view illustrations of the second housing further illustrating a configuration of the antenna device for the portable terminal shown in  FIG. 1  respectively taken along lines A-A and B-B of  FIG. 5 ; and 
       FIG. 9  is a partially exploded rear view illustration of a disassembled portable terminal in which a rear cover of a second housing of a portable terminal including an antenna device is separated from the portable terminal according to an alternative embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A preferred embodiment of the present invention will be described hereinbelow with reference to the accompanying drawings. In the drawings, the same or similar elements are denoted by the same reference numerals even though they are depicted in different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. 
     FIG. 1  is a front view illustration of a portable terminal  100  including an antenna device according to a preferred embodiment of the present invention,  FIG. 2  is a front view illustrating a state after a second housing  102  of the portable terminal  100  shown in  FIG. 1  is slidingly moved, and  FIGS. 3 and 4  are rear views of the portable terminal  100  shown in  FIGS. 1 and 2 , respectively. 
   As shown in  FIGS. 1 through 4 , the portable terminal  100  includes a bar shaped first housing  101 , in the front of which a keypad  111 , a mouthpiece  113 , and a display unit  115  are installed, and the second housing  102 , which is assembled with the first housing  101  to slidingly move on a top portion of the first housing  101  and opens/closes a portion of the display unit  115 . The second housing  102  is assembled with the first housing  101  to slidingly move in a longitudinal direction relative to the first housing  101 . The second housing  102  includes a front cover  102   a  and a rear cover  102   b,  and is configured to cover the top portion of the first housing  101 . An earpiece  121  is installed in the front cover  102   a  of the second housing  102 . A speaker  123  (refer to  FIG. 5 ) is installed on an inner surface  125  of the front cover  102   a  in which the earpiece  121  is installed, and the front cover  102   a  and the rear cover  102   b  are assembled using a plurality of latching pieces  127   a  and  127   b  (which are shown in  FIGS. 5 and 6 ) formed thereon, respectively. 
   When the second housing  102  is located such that it covers the first housing  101  and a portion of the display unit  115 , the portable terminal  100  is in a idle mode. When a user wishes to change an operation mode of the portable terminal  100  to a call mode, the user can manipulate the keypad  111  (e.g., by depressing a key) or slidingly move the second housing  102 . 
   Referring to  FIGS. 3 and 4 , a containing recess  117  for installing a battery pack (not shown) is formed in a rear surface of the first housing  101 , and a camera device  118  is located in an upper location from the containing recess  117 . A flash unit  119  is installed on the side of the camera device  118 , and the flash unit  119  and the camera device  118  are open/closed according to movement of the second housing  102  sliding on the first housing  101 . 
   An optional mirror  129  is installed on a rear surface of the second housing  102 . When the user wishes to photograph himself/herself using the camera device  118 , the user can preview an image of himself/herself using the mirror  129  before capturing a digital image. 
     FIG. 5  is a rear view illustration showing a state in which the rear cover  102   b  of the second housing  102  of the portable terminal  100  shown in  FIG. 4  is disassembled,  FIG. 6  is a perspective view illustration of the inside of the rear cover  102   b  of the second housing  102  shown in  FIG. 5 .  FIGS. 7 and 8  are cross-sectional view illustrations of the second housing further illustrating a configuration of the antenna device for the portable terminal  100  shown in  FIG. 1  respectively taken along lines A-A and B-B of  FIG. 5 . 
   As shown in  FIGS. 5 through 8 , the antenna device for the portable terminal  100  includes an antenna pattern  103  installed on an inner surface of the rear cover  102   b  of the second housing  102  and at least one of connecting terminals  135  and  137  for connecting the antenna pattern  103  with circuits (e.g., the portable terminal&#39;s internal circuitry, etc.) (not shown) of the portable terminal  100 . 
   The antenna pattern  103  is installed on the inner surface of the rear cover  102   b  of the second housing  102  and includes a connecting portion  131 , which is extended in a direction parallel to a sliding movement of the second housing  102  relative to the first housing  101 , and a radiating portion  133 , which is configured in an edge portion of the connecting portion  131 . The connecting portion  131  is extended along the sliding movement of the second housing  102 , and even if the second housing  102  slidingly moves, a state where a portion of the connecting portion  131  faces the rear surface of the first housing  101  is maintained. In contrast, the radiating portion  133  is located at a top portion of the second housing  102 . Therefore, in a state where the second housing  102  overlaps with the first housing  101 , the radiating portion  133  maintains a state of facing the rear surface of the first housing  101 . However, in a state where the second housing  102  is slidingly moved upward, the radiating portion  133  is spaced apart from the first housing  101 . 
   The antenna pattern  103  may be printed on the inner surface of the second housing  102  such as like a printed circuit pattern formed on a substrate or configured as an antenna plate attached to the inner surface of the second housing  102  after being constructed in a predetermined pattern by sheet metal working. Here, the antenna pattern  103  should be shaped and sized such that it is suitable for a transmission/reception frequency band of the portable terminal  100 . In the present embodiment, the antenna pattern  103  is an antenna plate in which a pattern shape is constructed by sheet metal working. 
   The connecting terminals  135  and  137  are installed on the rear surface of the first housing  101 . At least one of the connecting terminals  135  and  137  is a power feeding terminal  135  connecting the antenna pattern  103  with a circuit device of the portable terminal  100 , to be specific, transmission/reception circuit devices (not shown) of the portable terminal  100 . Also, as illustrated in this embodiment, the other of the connecting terminals  135  and  137  is a ground terminal  137  connecting the antenna pattern  103  with the ground of the circuit device of the portable terminal  100 . 
   The power feeding terminal  135  includes a plate spring maintaining a state of protruding from the rear surface of the first housing  101  and installed within a range in which the connecting portion  131  passes according to the sliding movement of the second housing  102  relative to the first housing  101 . Therefore, regardless of whether the second housing  102  slidingly moves, the power feeding terminal  135  always maintains a state of being connected with the antenna pattern  103  within a range of the sliding movement of the second housing  102 . Also, since the power feeding terminal  135  is made of a plate spring and protrudes from the outer surface of the first housing  101 , when the second housing  102  slidingly moves, the power feeding terminal  135  slidingly contacts the connecting portion  131  of the antenna pattern  103 . 
   The ground terminal  137  protrudes from the outer surface of the first housing  101 , located in parallel to the power feeding terminal  135 , and is made of a plate spring like the power feeding terminal  135 . Here, preferably, the ground terminal  137  is properly spaced apart from the power feeding terminal  135  so that it does not interfere with the connecting portion  131 . The ground terminal  137  selectively contacts the antenna pattern  103  according to the sliding movement of the second housing  102 . That is, in the state where the second housing  102  overlaps with the first housing  101 , the ground terminal  137  contacts the radiating portion  133  of the antenna pattern  103 , and in the state where the second housing  102  is slidingly moved upward from the first housing  101 , the ground terminal  137  is located apart from the first housing  101 . 
   When the second housing  102  overlaps with the first housing  101 , the connecting portion  131  and the radiating portion  133  contact the power feeding terminal  135  and the ground terminal  137 , respectively. Here, the antenna pattern  103  operates as a flat plate type inverted-F antenna or a loop antenna. 
   When the second housing  102  is slidingly moved upward from the first housing  101 , the radiating portion  133  does not contact the ground terminal  137 , while the connecting portion  131  maintains a connection with the power feeding terminal  135 . Here, the antenna pattern  103  operates as a monopole antenna. 
     FIG. 9  is a partially exploded rear view illustration of a disassembled portable terminal in which a rear cover of a second housing of a portable terminal including an antenna device is separated from the portable terminal according to an alternative embodiment of the present invention. Like reference numbers are used to refer to like elements through at the preceding drawings. The antenna device for the portable terminal  100  according to this embodiment of the present invention includes the power feeding terminal  135  and does not include the ground terminal  137  (which is included in other embodiments of the invention). In this embodiment, because the configuration of the antenna device for the portable terminal  100  has fewer parts, it is less expensive and easier to manufacture the portable terminal  100 , contributing to a commensurate reduction in manufacturing costs. However, since the ground terminal  137  is not installed, the antenna pattern  103  also operates as a monopole antenna regardless of the position of the first housing  101 . For example, when the second housing  102  overlaps with the first housing  101 , the antenna pattern  103  operates as a monopole antenna. 
   As described above, in the antenna device according to a preferred embodiment of the present invention, which includes the power feeding terminal  135  and the ground terminal  137  for connecting the antenna pattern  103  with the circuit device, the antenna pattern  103  operates as a flat plate type inverted-F antenna or a loop antenna in the state where the second housing  102  overlaps with the first housing  101 , and the antenna pattern  103  operates as a monopole antenna in the state where the second housing  102  is slidingly moved upward from the first housing  101 . Also, in the antenna device according to another preferred embodiment of the present invention, in which the antenna pattern  103  operates as a monopole antenna regardless of the sliding movement of the second housing  102 , it is easier to manufacture the portable terminal  100 . 
   As described above, in the inventive antenna device for a portable terminal, by forming an antenna pattern on an inner surface of a second housing, which is assembled with a first housing so as to slidingly move on the first housing in a state of covering the first housing, and installing a power feeding terminal on the first housing, a configuration of the antenna device is simplified. Therefore, product manufacture is simplified and costs are reduced. 
   Also, when transmission/reception sensitivity decreases, excellent transmission/reception sensitivity can be secured by extending an antenna against the power feeding terminal by slidingly moving the second housing. 
   While the invention has been shown and described with reference to a certain preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.