Abstract:
A portable computer using a stylus for power control comprises a main body of the computer contained in a housing and provided with a stylus-holding means, a stylus for inputting data, and a means for detecting the combination and separation of the stylus and for controlling power supply to a system unit. The detecting and controlling means consists of a signal-generating unit and a power control unit. The signal-generating unit is positioned in the main body so as to detect the combination and separation of the stylus and generate a signal. The power control unit controls power supply to the system unit in response to the signal.

Description:
CLAIM OF PRIORITY 
     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from the inventor&#39;s application PORTABLE COMPUTER WITH FUNCTION OF POWER CONTROL BY COMBINATION OR SEPARATION OF STYLUS filed with the Korean Industrial Property Office on May 20, 1999 and there duly assigned Ser. No. 18307/1999. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates, in general, to portable computers and, more particularly, to a portable computer whose power supply is controlled by the combination and separation of a stylus. 
     2. Description of the Related Art 
     As computer technology has developed, portable computers such as wallet personal computers, Personal Digital Assistants (PDAs) and Handheld Personal Computers (HPCs) are increasingly used. Often, in order to reduce the thickness and weight of computers, they are made without any keyboard. Instead, data is input into the computer by manipulating a stylus on a screen. Such a stylus is referred to as a pen or a pen stylus. 
     Such a portable computer typically includes: a main body of the computer; a display, such as a Liquid Crystal Display (LCD), having a Touch Screen Panel (TSP) for inputting and outputting data on a screen; a stylus for inputting the data; a stylus-holding means formed in the housing of the main body, for holding the stylus; and a power switch located in the main body. 
     In such a portable computer, when the computer enters a low power mode (in which power is not supplied to the chief electronic elements of the computer), no need exists for using the stylus (it is used only for data input). At such times, a user may forget to put the stylus into the stylus-holding means, and therefore the stylus may get lost. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a portable computer that prevents a stylus from being lost, protects a display from being damaged, and eliminates inconvenience in operating the computer. 
     To accomplish the above objects, among others, the present invention provides a portable computer, comprising a main body of the computer contained in a housing and provided with a stylus-holding means, a stylus for inputting data, and means for detecting the combination and separation of the stylus and for responsively controlling power supply to a system unit. 
     In accordance with an embodiment of the invention, the detecting and controlling means consists of a signal-generating unit for detecting the combination and separation of the stylus and for generating a signal, the signal-generating unit being positioned in the main body of the computer, and a power control unit for controlling a power supply to the system unit in response to the signal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components. 
     FIG. 1 is a plan view of a portable computer showing a stylus to be put into a stylus-holding means of the portable computer in a first embodiment of the invention. 
     FIG. 2 is a plan view of the same portable computer, showing a stylus inserted into the stylus-holding means of the portable computer in the first embodiment. 
     FIG. 3 is a block diagram showing signal flow in accordance with the combination and separation of the stylus in the first embodiment. 
     FIG. 4 is a flowchart showing the operation of the portable computer of the present invention in accordance with the combination and separation of the stylus. 
     FIG. 5 is a partially cutaway perspective view showing a stylus taken out of a stylus-holding means of a portable computer in a second embodiment of the present invention. 
     FIG. 6 is a partially cutaway plan view showing a stylus taken out of a stylus-holding means of a portable computer in the second embodiment. 
     FIG. 7 is a partially cutaway plan view showing a stylus inserted into the stylus-holding means of a portable computer in the second embodiment. 
     FIG. 8 is a partially cutaway perspective view showing a portable computer of a third embodiment of the present invention. 
     FIG. 9 is an exploded view showing the portable computer of FIG.  8 . 
     FIG. 10 is a plan views showing a stylus being put into a stylus-holding means of the portable computer in the third embodiment. 
     FIG. 11 is a plan view showing a further aspect of a stylus being put into a stylus-holding means of the portable computer in the third embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a plan view showing stylus being inserted into a stylus-holding means of a portable computer of a first embodiment of the present invention, it is seen that a portable computer  10  includes a main body  12 , a display  14 , and a stylus  30 . (Other electronic components of the portable computer and a power unit are located in main body  12  although they are not illustrated in the drawings.) Display  14  is operated while being connected to the electronic units and the power unit. Commands are input into the computer by manipulating stylus  30  on display  14 . Therefore, display  14  is adapted to receive the commands by the manipulation of stylus  30 . 
     In order to input commands into the computer  10 , various technologies are employed. One such technology uses a conductive stylus to input the commands. The conductive stylus is connected to the portable computer  10  via a cord (not shown). The cord has an internal conductor that connects the stylus with the portable computer  10  so as to allow the write function to be performed on display  14 . 
     Touch-screen technology may also be used. In a touch-screen embodiment, a stylus-holding hole  16  is formed in main body  12  of portable computer. The stylus-holding hole  16  holds stylus  30  therein. The stylus-holding hole  16  has an opening  20  at its outer end. In order to allow the stylus  30  to be held in the stylus-holding hole  16 , stylus  30  is inserted into stylus-holding hole  16  through opening  20 . A slot  28  is formed to be so connected to the stylus-holding hole  16  as to engage with a flange  34  of the stylus  30  when stylus  30  is put into the stylus-holding hole  16 . Slot  28  extends from an outer end portion of the stylus-holding hole  16  to one side end of the main body  12 . The shape of slot  28  is complementary to that of flange  34  of stylus  30 . A push button switch  25  for sensing the insertion of the stylus  30  into the main body  12  and the extraction of the stylus  30  therefrom is mounted on a printed circuit board  23 . A portion of the push button switch  25  projects toward the central axis of stylus-holding hole  16 . Also, the stylus  30  is provided with a recess  31 . When the stylus  30  is put into stylus-holding hole  16 , the projecting portion of push button switch  25  is pushed by the external surface of the stylus  30  until the projecting portion of the push button switch enters recess  31  as seen in FIG.  2 . When the push button switch  25  is pushed, it generates a signal. 
     Referring now to FIG. 3, a power control unit  102  receives the signal from the switch  25  of FIGS. 1 and 2 and stops power supply to a system unit  106 . Consequently, the power mode of the portable computer  10  goes from ON to LOW POWER mode (or STANDBY MODE), or if preferred an OFF mode in which power is completely off. When the stylus  30  is fully inserted into stylus-holding hole  16 , power is restored. 
     The push button switch  25  may be replaced with a different sensor, such as a photo sensor or need switch. When push button switch  25  is pushed physically, or the photo sensor senses the insertion of stylus  30 , push button switch  25 , or the photo sensor, generates a signal and transmits the signal to power control unit  102 . When power control unit  102  receives the signal, the power control unit  102  controls power supply  104  to stop power supply to system unit  106 . A signal representative of the current operating state of system unit  106  is sent to the power control unit  102  every predetermined period. 
     By the same token, when stylus  30  is taken out of stylus-holding hole  16 , the push button switch  25  generates a signal and transmits the signal to power control unit  102 . When power control unit  102  receives the signal, power control unit  102  controls power supply  104  to supply power to the system unit  106 . 
     Hence, in accordance with the present invention, the stylus  30  can perform the function of a power switch instead of a power switch. Thus, when stylus  30  is inserted into main body  12  of the computer  10 , power supply to system unit  106  is turned off and the computer  10  goes into STANDBY mode. On the other hand, when stylus  30  is extracted from main body  12  of the computer  10 , power supply to system unit  106  is effected, and the computer  10  goes into ON mode. 
     Referring now to FIG. 4, if stylus  30  is in stylus-holding hole  16  of portable computer  10  (step S 110 ) while portable computer  10  is in ON mode (step S 100 ), power supply to system unit  106  stops (S 120 ). Hence, the portable computer  10  goes into STANDBY mode or OFF mode. On the other hand, if stylus  30  is out of stylus-holding hole  16  (S 130 ) while portable computer  10  is in a STANDBY or LOW POWER mode (S 100 ), or is in OFF mode, power control unit  102  allows power supply  104  to supply power to system unit  106  (S 140 ). Hence, the portable computer  10  goes to ON or operating mode. The “A” of the flowchart of FIG. 4 may be either a low power (STANDBY) mode or an operating (ON) mode. The mode of the portable computer  10  may be converted from one of the two modes to the other mode continually by use of the stylus  30 . 
     Referring now to FIGS. 5 to  7 , which show a portable computer according to a second embodiment of the present invention, it is seen that a portion of the push button switch  25  projects toward the central axis of stylus-holding hole  16  near which a locking member is positioned. The locking member consists of a resilient tongue  22  and a locking projection  26 . The resilient tongue  22  is defined by a cut  24  in the sidewall  18  of stylus-holding hole  16 , so as to be moved resiliently. One narrow side of the tongue  22  is connected integrally to the sidewall  18  and the other side is separated from the sidewall  18 . Locking projection  26  is formed linearly on the end portion of the free end of resilient tongue  22 , which is projected toward the central axis of stylus-holding hole  16 . 
     Furthermore, an annular groove  32  is formed around the external surface of stylus  30 . In accordance with this construction, when the stylus  30  is put into the stylus-holding hole  16 , locking projection  26  and annular groove  32  are engaged with each other, thereby locking stylus  30  within stylus-holding hole  16 . This construction keeps stylus  30  in place in stylus-holding hole  16 . 
     A push button switch  25  is mounted on a printed circuit board  23  with a portion of the push button switch  25  projecting toward the central axis of the stylus-holding hole  16 . Stylus  30  is provided with a recess  31 . This construction causes stylus  30 , when it is put into stylus-holding hole  16 , to turn on switch  25 , and the projecting portion of push button switch  25  is pushed by the external surface of stylus  30  until the projecting portion of push button switch  25  enters recess  31 . When push button switch  25  is pushed, it generates a signal and thereby changes the power mode of the portable computer  10 . 
     Referring now to FIG. 7, the projecting portion of push button switch  25  is engaged with recess  31  when locking projection  26  is engaged with annular groove  32 . In order to remove stylus  30  from the stylus-holding hole  16 , a user may push the stylus  30  out of the stylus-holding hole  16  while pressing its flange  34 . At this time, locking projection  26  is extracted from the stylus-holding hole  16  while being pushed resiliently. Thus, when the stylus  30  is put into and taken out of the stylus-holding hole  16 , power is turned off and on to the portable computer  10 . 
     Referring to FIGS. 8 to  11 , a portable computer  40  of a third embodiment of the present invention includes a top housing  50 , a bottom housing  60 , a frame  70 , a board  71 , a stylus  90 , and a display (not shown). The top housing  50  and the bottom housing  60  are engaged with one other. Top housing  50  has a top face and four side faces; its bottom is open. Bottom housing  60 , as shown here, engages with top housing  50  so as to cover the bottom of top housing  50 . (Of course, the housing used for the portable computer  40  may have various alternative constructions.) Frame  70  is positioned in an internal space defined by the top and bottom housings  50  and  60 , respectively. The frame  70  is connected to board  71 , to which are mounted a power unit and electronic units for performing the various functions of the portable computer. The display is constructed to allow the stylus  90  to input data into the computer via the display. The screen of the display is positioned within the opening  56  of top housing  50 . 
     Stylus  90  is positioned in the internal space defined by top housing  50  and bottom housing  60 . A first notch  52  and a second notch  62  are respectively formed on the bottom end portion of a sidewall of top housing  50  and the top end portion of a sidewall of bottom housing  60 . When top and bottom housings  50  and  60  are engaged with one other, first and second notches  52  and  62  form an opening  63  as is shown in FIG.  8 . Stylus  90  is inserted through opening  63  into the internal space defined by top and bottom housings  50  and  60 . The shape of opening  63  corresponds to the contour of the cross section of the stylus  90 . Therefore, the shapes of first and second notches  52  and  62 , respectively, are two half-contours of the cross section of stylus  90 . A conventional means (e.g., a detent) for holding stylus  90 , when it is inserted into the internal space, is formed in frame  70  and/or bottom housing  60 . The holding means may be formed in frame  70 , or in top housing  50  and the frame  70 . The mounting position of the holding means is determined depending upon the desired portion in the internal space of the housing  50 ,  60 . In this embodiment, as shown here, the holding means is a holding trough  72  formed in frame  70  and ribs  66 ,  66 ′ and  68  (FIG. 9) formed in bottom housing  60 . Holding trough  72  is partially cylindrical-shell-shaped, and its cross-sectional shape corresponds to that of first notch  52  and a half-contour of the cross section of stylus  90 . Additionally, holding trough  72  is extended to such a length that it sustains the length of stylus  90 . A resilient portion  74 , a cut  76 , and a projection  78  are formed in holding trough  72 . Resilient portion  74  is defined by cut  76  to have a free end. Since resilient portion  74  has a free end, the resilient portion  74  can be resiliently moved forward and rearward. Projection  78  is so formed on the free end of resilient portion  74  as to be engaged with an annular groove  91  formed on the external surface of stylus  90 . When the stylus  90  is put into the stylus-holding means, projection  78  locks the stylus  90  in place. By means of projection  78 , stylus  90  is kept in the stylus-holding means. When holding the stylus  90  in the stylus-holding means, the holding trough  72  sustains one side of the stylus  90 . The other side of the stylus  90  can be sustained by first ribs  66  and  66 ′ and by second rib  68  formed in bottom housing  60 . The first ribs  66  and  66 ′ extend along a direction through which the stylus  90  is inserted. When top housing  50  is engaged with bottom housing  60  and stylus  90  is inserted into the stylus-holding means, the first ribs  66  and  66 ′ together with holding trough  72  sustain the stylus  90 , as is shown in FIGS. 8 and 9. Second rib  68  extends to connect the internal ends of the ribs  66  and  66 ′ to each other. The second rib  68  is provided with a notch whose shape corresponds to the contour of the cross section of stylus  90 . When the stylus  90  is put into the stylus-holding means, the second rib  68  sustains stylus  90  on the side opposite to holding trough  72 . A first depression  54 , a second depression  64 , and a third depression  80  are respectively formed on top housing  50 , bottom housing  60 , and frame  70  at a corner of the housing. When top housing  50 , bottom housing  60 , and frame  70  are assembled into a main body, first, second, and third depressions  54 ,  64 , and  80  form a slot  82 , as seen in FIG. 8. A flange  94  of stylus  90  maybe inserted into slot  82  with a portion of the flange  94  projecting out of the housing. The slot  82  and the flange  94  facilitate the insertion of stylus  90  into the housing and the extraction of stylus  90  from the housing. A push button switch  75  is mounted on board  71 ; a portion of switch  75  projects into a valley defined by holding trough  72  so as to be pushed by the stylus  90  and thus generate a signal when the stylus  90  is inserted into the housing or is separated therefrom. 
     FIGS. 10 and 11 illustrate a process in which the stylus  90  is put into the stylus-holding means. A first annular groove  91 , a second annular groove  92 , and a recess  93  are formed on the external surface of stylus  90 , in that order. Although first and second annular grooves  91  and  92  are formed ahead of recess  93 , the sizes of the first and second annular grooves  91  and  92  are small. Hence, first and second annular grooves  91  and  92  do not cause the pushed projected portion of push button switch  75  to move while the pushed projected portion passes first and second annular grooves  91  and  92 ; hence, the pushed projected portion continues to be pushed. However, when stylus  90  has been inserted to a position where the pushed projected portion is exactly over recess  93 , the pushed projected portion is restored because the recess  93  has sufficient space to receive the pushed projected portion. Recess  93  may be positioned ahead of first and second grooves  91  and  92 . Since the operation of this embodiment, in which power supply is controlled while the stylus  90  is inserted into the stylus-holding means, is comparable to the first and second embodiments, detailed description of the operation is omitted here. 
     As described above, the present invention provides a portable computer that prevents a stylus from being lost, protects a display from being damaged, and eliminates inconvenience in operating the computer. 
     While the invention has been described in connection with specific and preferred embodiments thereof, it is capable of further modifications without departing from the spirit and scope of the invention. This application is intended to cover all variations, uses, or adaptations of the invention, following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains, or as are obvious to persons skilled in the art, at the time the departure is made. It should be appreciated that the scope of this invention is not limited to the detailed description of the invention hereinabove, which is intended merely to be illustrative, but rather comprehends the subject matter defined by the following claims.