Abstract:
An input apparatus allowing the improved operability of data entry without noticeable volume changes of a portable device itself and further allowing easy entry of a positional coordinate, a curve, and the like is disclosed. The input apparatus is detachably coupled to the portable device and is provided with a coordinate information generator for generating coordinate information depending on a movement on a flat surface to control a position of a cursor on a display of the portable device. Therefore, the input apparatus is removed from the portable device and the singly input apparatus can output coordinate information to the portable device by sliding it on a desk. The input apparatus preferably incorporates a battery for supplying power to the portable device when the input apparatus is coupled to the portable device.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an information input apparatus suitable for a compact device, and in particular to a portable information input apparatus for use in a portable information processing device such as a portable telephone terminal. 
   2. Description of the Related Art 
   There have been proposed and put into practical use various methods for inputting data to an information processing device such as a personal computer, a portable telephone set or the like. In the case of an information processing device relatively large in size like an ordinary desktop personal computer, a keyboard is often used for data entry. On the contrary, when it comes to a small information processing device like a portable telephone set, it is rather inconvenient from the viewpoint of portability to use a relatively large input apparatus like a keyboard even for entering characters. 
   Therefore, in such a compact size information processing device, a data entry method using a keypad and a display disposed in the main body of an apparatus has been employed in many cases. In such an information processing device, however, the keypad itself tends to have only a minimum number of keys required. Consequently, in the case where the number of characters to be used is larger than that of the keys on the keypad, a plurality of characters need to be allocated to one particular key. Therefore, some characters need to be selected and input by depressing a corresponding key the specified number of times. For example, to select a small letter “c” in the alphabet, the particular key allocated to the letters A, B and C is to be sequentially depressed to display “A”, “B”, “C”, “a”, “b”, and “c” in this order on a display unit. Then, at the time when the aimed letter “c” is displayed, the selection of one letter is completed. As a result, the entry of a plurality of letters constituting a name, an address or the like necessitates the complicated operation of the keypad, which has been a problem of notably low efficiency in data input processes. 
   There are two kinds of letters in the Japanese syllabary and each of them has 48 phonographs, which means there are 96 phonographs in total. Therefore, compared with English having 52 letters including the capital letters, the complexity of data entry of Japanese letters with the restricted numbers of keys on keypad is more significant. 
   Thus, for the compact information processing device of a certain kind, the incorporation of a wireless device such as an infrared transmission device or the like in its main body has been contrived. In such a device, merely by setting the compact information processing device in a wireless communication mode, data prepared in advance by using a computer or the similar type of device can be entered by wireless such as infrared rays or the like. 
   For example, in a system disclosed in Japanese Patent Application Unexamined Publication No. 9-298606, a radio base station is connected to a desktop computer by a cable and is further connected to a portable unit by radio. Accordingly, if data is entered beforehand to the desktop computer by using input means such as its keyboard or the like, then the data can be easily sent out to the portable unit by radio. 
   However, the wireless data entry method disclosed in the Publication No. 9-298606 is effective only under an environment where a device such as a desktop computer that is relatively large in size and easy for data entry can be used as an information input apparatus. Accordingly, in the case where new data entry is required outside an office, that is, under such an environment where a desktop computer is not available, such data needs to be created by using the concerned information processing device. This means that such data cannot be input without the above-described data entry method using a keypad and a display disposed in the main body of concerned information processing device, resulting in the difficulty of achieving an efficient operation. 
   Despite the recent progress in the miniaturization of an information processing device, the displaying contents on the display unit has been required wider and more complexed, and such forms of usage as on-line banking and as searching and obtaining information has been widely used. Under such circumstances, the method of performing data entry or operational designation using the keypad has been unsatisfactory in operability and thus a great obstacle to efficient information processing. Apparently, as far as data entry is concerned, an efficient operation can be performed by radio, but the information processing device itself needs to be provided with a circuitry for such wireless communications. In the case of a compact information processing device, in particular, it has been difficult to secure a space for the installation of such a circuitry. 
   Furthermore, in the conventional information input apparatus, it was practically impossible to enter handwritten characters by moving the cursor or to manually enter a positional coordinate, a curve, and the like. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide a portable information input apparatus and a portable device capable of improving the operability of data entry without noticeable volume changes of the portable device itself. 
   It is another object of the invention to provide an information input apparatus capable of facilitating the entry of a positional coordinate, a curve, and the like. 
   In order to achieve the above-described objects, according to an aspect of the present invention, an input apparatus for inputting information to an information processing device provided with a display, includes: a coupling mechanism for detachably coupling to a predetermined portion formed in the information processing device; a coordinate information generator for generating coordinate information depending on a movement on a flat surface to control a position of a cursor on the display of the information processing device; and a cable for electrically connecting the input apparatus to the information processing device. 
   The input apparatus preferably further includes a battery accommodating portion for accommodating a battery which is used to supply power to the information processing device when the input apparatus is coupled to the predetermined portion of the information processing device by the coupling mechanism. 
   The input apparatus may further include an electric contact portion for electrically connecting the battery to the information processing device when the input apparatus is coupled to the predetermined portion of the information processing device by the coupling mechanism. 
   The information processing device may include a secondary battery, which is charged by the battery of the input apparatus when the input apparatus is coupled to the predetermined portion of the information processing device by the coupling mechanism. 
   The cable may be pulled out from a rewinding mechanism provided in the information processing device when the input apparatus is removed from the predetermined portion of the information processing device. 
   The input apparatus may further include a connector connected to one end of the cable, for detachably connecting to the information processing device through the cable; and a cable accommodating space formed in the input apparatus, for accommodating the cable with the connector therein. 
   The input apparatus may further include at least two buttons which each functions as right-click and left-click buttons of a mouse when the input apparatus is separated from the predetermined portion of the information processing device and functions as right cursor key and left cursor key when the input apparatus is coupled to the predetermined portion of the information processing device by the coupling mechanism. 
   According to another aspect of the present invention, a portable telephone apparatus includes: a display; an information processing device; an input device for inputting coordinate information to the information processing device to control a position of a cursor on the display, the coordinate information varying depending on a movement on a flat surface; and a coupling mechanism for detachably coupling the input device to a predetermined portion of the portable telephone apparatus. 
   The input device nay include a battery accommodating portion for accommodating a battery which is used to supply power to the information processing device when the input device is coupled to the predetermined portion of the portable telephone apparatus by the coupling mechanism. 
   The input device may have a first electric contact portion and the predetermined portion of the portable telephone apparatus has a second electric contact portion, wherein the first and second electric contact portions are electrically connected to each other when the input device is coupled to the predetermined portion by the coupling mechanism. 
   The portable telephone apparatus may include a secondary battery, which is charged by the battery of the input device when the input device is coupled to the predetermined portion by the coupling mechanism. 
   The coordinate information may be transferred from the input device to the information processing device through a cable. The coordinate information may be transferred from the input device to the information processing device by wireless. 
   The information processing device may control the input device so that it functions as a keypad of the portable telephone apparatus when the input device is coupled to the predetermined portion by the coupling mechanism and functions as a pointing device when the input device is not coupled to the predetermined portion. 
   As described above, the input apparatus is detachably coupled to the predetermined portion formed in the information processing device by the coupling mechanism and is provided with the coordinate information generator for generating coordinate information depending on a movement on a flat surface to control a position of a cursor on the display of the information processing device. Therefore, the input apparatus is removed from the information processing device and the singly input apparatus can output coordinate information to the information processing device by sliding it, as a mouse, on a desk. This allows the improved operability of data entry without noticeable volume changes of the portable device itself and further allows easy entry of a positional coordinate, a curve, and the like. 
   Further, the input apparatus preferably includes a battery accommodating portion. A battery accommodated in the portion is used to supply power to the information processing device when the input apparatus is coupled to the information processing device. Since the battery is accommodated in the input apparatus, space saving is achieved in the case where the input apparatus is coupled to the information processing device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing an appearance of a portable telephone set equipped with an input apparatus according to a first embodiment of the present invention; 
       FIG. 2  is a perspective view showing an operation unit taken out of the portable telephone set and placed on a desk according to the first embodiment; 
       FIG. 3  is a backside view of the operation unit as the input apparatus according to the first embodiment; 
       FIG. 4  is a side view of the operation unit when it is singly lifted according to the first embodiment; 
       FIG. 5  is a side view showing a side face of a telephone set main body when the operation unit is removed according to the first embodiment; 
       FIG. 6  is a flow chart showing an input mode switch operation in the portable telephone set according to the first embodiment; 
       FIG. 7  is a perspective view showing a portable telephone set according to a first modified example of the first embodiment; 
       FIG. 8  is a perspective view showing an operation unit and a telephone set main body with the operation unit removed according to a second modified example of the first embodiment; 
       FIG. 9  is a magnified perspective view showing a partition wall of the second modified example; 
       FIG. 10  is a backside view of the operation unit of the second modified example; 
       FIG. 11  is a perspective view showing a use status of an operation unit separated from a portable telephone set main body according to a second embodiment of the invention; 
       FIG. 12  is a perspective view showing an appearance of a portable telephone set using an input apparatus according to a third embodiment of the invention; 
       FIG. 13  is a perspective view showing an operation of a mouse incorporating a battery, which is pulled out of a second telephone set main body according to the third embodiment; 
       FIG. 14  is a perspective view showing a process of removing the battery from the mouse according to the third embodiment; 
       FIG. 15  is a perspective view showing another example of removing the battery from the mouse as a modification of the third embodiment; and 
       FIG. 16  is a perspective view showing an appearance of a portable telephone set using an input apparatus according to a fourth embodiment of the invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Next, the preferred embodiments of the present invention will be described with reference to the accompanying drawings. 
   First Embodiment 
   Referring to  FIG. 1 , a portable telephone set denoted by reference numeral  100  comprises a telephone set main body  102  having a display unit  101  disposed in its front face. The telephone set main body  102  includes an antenna  103  disposed in its upper end portion so as to be freely expanded/contracted. 
   An operation unit  105  capable of functioning as a pointing device (here, a mouse) is detachably coupled to a level difference portion  102 A located one-step lower in the telephone set main body  102 . Right and left buttons  107  and  108  corresponding to right and left buttons of an ordinary mouse are disposed in the upper end portion of the front face of the operation unit  105 . Further, the operation unit  105  is provided with a rotary wheel  109  located in the center portion thereof and a part of the rotary wheel  109  is protruded from the front face of the operation unit  105 . 
   An operation unit locking mechanism  111  is attached near the lower end portion of the operation unit  105 . The operation unit locking mechanism  111  is capable of holding the operation unit  105  on the level difference portion  102 A to prevent its falling-off. In the remaining portion of the front face of the operation unit  105 , as in the case of an ordinary portable telephone set, a keypad  112  composed of various keys including ten keys is disposed. Between the keypad  112  and the operation unit locking mechanism  111 , a microphone hole  114  is bored to enter a voice of a user. 
   In the case of the operation unit  105  united with the telephone set main body  102  as shown in  FIG. 1 , the operation unit  105  allows all the normal operations of a telephone set. In this state, however, pressing of the right and left buttons  107  and  108  of the mouse cannot bring about the above-described functions. In addition, the coupling of the operation unit  105  with the level difference portion  102 A prevents the operation unit  105  from horizontal movement independently with the telephone set main body  102 . Consequently, the operation unit  105  cannot provide the function of instructing a cursor direction as a mouse. 
   The portable telephone set  100  includes a speaker hole  110  bored near the tip above the display unit  101  to output a voice. From this hole, a voice of a communication party, necessary voice guidance, and so on, are outputted. 
     FIG. 2  shows the case where the operation unit  105  is taken out of the above-described portable telephone set and is placed on a desk. One end of a thin but strong mouse cable  121  is attached to the head of the operation unit  105 . The other end of the mouse cable  121  is pulled out of a cable outlet  124  bored almost in the center part of a partition wall  122 , which is in contact with one end of the level difference portion  102 A. Inside the cable outlet  124 , a rewinding mechanism (not shown) is provided for rewinding the mouse cable  121 . This rewinding mechanism has a well-known function of locking or holding the mouse cable  121  pulled out by a desired length. In addition, by pulling the mouse cable  121  in a particular angular direction, this locked state is released to enable the rewinding mechanism to rewind the cable completely. Accordingly, the mouse cable  121  can be pulled out by a length requested by the user for use, and after a desired operation using the operation unit  105  has been completed, the mouse cable  12 ′ can be completely contained in the telephone set main body  102 . A first projection portion  125  is protruded from the partition wall  122  immediately above the cable outlet  124 . 
   The level difference portion  102 A has a second projection portion  126  formed at a position thereof corresponding to the operation unit locking mechanism  111 . The second projection portion  126  is protruded from the face of the level difference portion  102 A to lock the operation unit  105 . The second projection portion  126  has a tapered shape as if the arrow shape is cut by halt along the centerline in axial direction. In the vicinity of the second projection portion  126 , a group of electrodes  127  is disposed to be supplied with power from the operation unit  105  and exchange signals with the operation unit  105 . 
   A main portion inside the operation unit  105  is used to accommodate a charging battery (not shown), which is designed to supply power to the telephone set main body  102  through the group of electrodes  127 . The charging battery may be a secondary (rechargeable) battery. However, the telephone set main body  102  has a relatively small-capacity secondary battery (not shown) disposed therein to be charged by the charging battery accommodated in the operation unit  105 . While the operation unit  105  is separated from the level difference portion  102 A, this secondary battery supplies power to the display unit  101  and other necessary circuits, allowing the operation result of the operation unit  105  to be input and displayed on the display unit  101 . 
   The level difference portion  102 A also includes an operation unit detecting sensor  128  disposed on its upper surface. The operation unit detecting sensor  128  is provided to detect the setting of the operation unit  105  on the level difference portion  102 A and, in the described embodiment, a pressure detecting sensor is used. An on/off switch operating depending on the setting of the operation unit  105  on the level difference portion  102 A may be used as the pressure detecting sensor. Not only the pressure type but also various other sensor types may be used. 
   The functions of key switches and buttons may be changed depending on whether the operation unit  105  is used as a single mouse or as a part of the portable telephone set  100 , and also some of the functions may be inhibited depending on the use status. Thus, the presence and absence of the operation unit  105  needs to be detected. 
     FIG. 3  shows the backside of the operation unit used as an input apparatus. The operation unit  105  functions as a mouse, and therefore includes a track ball  131  rotatably contained to detect a moving direction. The surface of the track ball  131  is gradually stained as it is used and, thus, a track ball removing plate  132  is provided to enable the track ball to be removed and cleaned. The track ball removing plate  132  can be removed front the operation unit  105  by rotating it in a predetermined direction. In this removed state, the track ball  131  may also be removed, and the inside of the operation unit  105  may be cleaned. 
   The operation unit  105  also includes, in its backside, the operation unit locking mechanism  111  engaged with the second projection portion  126  shown in  FIG. 2 , and a group of electrodes  134  respectively connected to the electrodes  127 . 
     FIG. 4  shows the side face of the operation unit when it is singly lifted. A part of the track ball  131  is exposed from the lower end surface of the main body of the operation unit  105 . In addition, a part of the rotary wheel  109  is protruded from the upper end surface. In the case of the single use of the operation unit  105 , the rotary wheel  109  is used when an additional instruction is made to scroll a screen displayed on the display unit  101  or the like. Depending on the constitution of the operation unit  105  as the input apparatus, the rotary wheel  109  may be omitted. 
   The operation unit locking mechanism  111  indicated by a broken line in  FIG. 4  is provided to the rear end portion of the operation unit  105  opposite its tip portion where the mouse cable  121  has been pulled out. The operation unit locking mechanism  111  is supported by the main body of the operation unit  105  so that it is rotatable around a spindle  141  vertically disposed on the paper surface of the drawing. 
     FIG. 5  shows the side face of the main body of the telephone set with the operation unit removed. The first and second projection portions  125  and  126  are protruded in a space of the telephone set main body  102  for containing the operation unit  105  as shown in FIG.  4 . The user fits the first projection portion  125  into a concave (not shown) formed in the tip portion of the operation unit  105 , and presses the rear end portion toward the level different portion  102 A. This causes the operation unit locking mechanism  111  to be rotated by a predetermined angle against a spring mechanism (not shown) to engage the second projection portion  126 . As a result, the operation unit  105  is fixed to the telephone set main body  102  as shown in FIG.  1 . 
   Conversely, when the operation unit  105  is to be removed from the telephone set main body  102 , the upper end portion of the operation unit locking mechanism  111  is moved toward the outside by finger against the spring mechanism. This causes the second projection portion  126  to be unlocked. By lifting the rear end portion of the operation unit  105  in the unlocked state of the second projection portion  126 , the operation unit  105  can be separated from the telephone set main body  102 . 
   The telephone set main body  102  shown in  FIG. 1  includes a program-controlled processor such as a central processing unit (CPU, not shown), and the functions of a portable telephone set are realized by a program stored in a read-only memory (ROM, not shown) running on the CPU. When the operation unit  105  is operated, the input processing mode is varied depending on whether the operation unit detecting sensor  128  has detected the operation unit  105  or not. 
   To detect the setting of the operation unit  105  on the level difference portion  102 A, a sensor may be provided to detect the rotation of the operation unit locking mechanism  111 . Based on the detecting result of this sensor, determination may be made as to the setting of the operation unit  105  in the level difference portion  102 A. 
     FIG. 6  shows the outline of switching control steps for the input mode of the operation unit provided in the portable telephone set according to the described embodiment. When it is determined that the operation unit detecting sensor  128  shown in  FIG. 2  has detected the operation unit  105  (YES at step S 151 ). The operation mode of the operation unit  105  is set to the normal mode of the telephone set (step S 152 ). On the other hand, when it is determined that the operation unit detecting sensor  128  shown in  FIG. 2  has not detected the operation unit  105  (NO at step S 151 ), the operation mode of the operation unit  105  is set to a mouse mode using the operation unit  105  as a mouse. 
   In the mouse mode, a function of detecting an operation performed by one of the right and left buttons  107  and  108  and the rotary wheel  109  of the operation unit  105  becomes active. Two-dimensional information associated with movement of the operation unit  105  detected by the rotation of the track ball  131  shown in FIG.  3  and so on, also becomes active. These kinds of information are sent out through the mouse cable  121  to the telephone set main body  102 . On the other hand, since the keypad  112  such as ten keys or the like is not needed in a usual mouse operation, even when these keys are depressed, information generated by such a key operation is ignored in the telephone set main body  102 . 
   However, some users may be desired to use parts or all of the keypad  112  each as ten keys even in the singly use state of the operation unit  105 . In such a case, the use of these keys may be permitted under certain conditions. For example, if a “0” key and a “#” key are simultaneously depressed, the depressing of the keypad  112  entered within a predetermined time period thereafter may be validated. Or if the “0” key and the “#” key are simultaneously depressed, the depressing of the keypad  112  may be validated until the rotation of the track ball  131  is commenced again. In this way, the burdensome work of attaching the operation unit  105  to the telephone set main body  102  may be eliminated in every occasion when the various key operations are required. 
   In the normal mode, the similar input processing will be implemented as the case where the operation unit  105  is firmly attached to the telephone set main body  102 . A problem inherent in this case is how to handle the right and left buttons  107  and  108  and the rotary wheel  109 . The input processing of these three input sections may be ignored in the normal mode, or functions different from those in the mouse mode may be allocated to these input sections. For example, the rotary wheel  108  may be used as an execution key, and the right and left buttons  107  and  109  may be used respectively as right-direction and left-direction cursor keys. 
   FIRST MODIFIED EXAMPLE 
     FIG. 7  shows a first modified example of the first embodiment of the invention. In  FIG. 7 , members similar to those described with reference to  FIG. 1  are denoted by the same reference numerals, and the descriptions thereof will be omitted. In the first modified example, an upper-direction cursor key  161  is disposed immediately below the display unit  101  of the telephone set main body  102 . A lower-direction cursor key  162  is also disposed adjacently to the rotary wheel  109  included in the keypad  112  of the operation unit  105 . These upper-direction and lower-direction cursor keys  161  and  162  are not functioned in the mouse mode but in the normal mode. In this case, the right and left buttons  107  and  108  are used respectively as right-direction and left-direction cursor keys. 
   SECOND MODIFIED EXAMPLE 
     FIG. 8  shows a second modified example of the first embodiment of the invention. In  FIG. 8 , members similar to those described with reference to  FIG. 2  are denoted by the same reference numerals, and the descriptions thereof will be omitted. In the second modified example, an operation unit  105 A has a cable  171  connected thereto and the cable  171  has a first connector  172  connectable to the telephone set main body  102 . Therefore, the telephone set main body  102  and the operation unit  105 A are connected to each other by the cable  171 . 
   As shown in  FIG. 9 , in the second modified example, a second connector  174  is disposed in the partition wall  122 . The connection of the first connector  172  to the second connector  174  allows not only a power-supply line connection but also a signal line connection between the telephone set main body  102  and the operation unit  105 A. 
     FIG. 10  shows the backside of the operation unit in the second modified example. In  FIG. 10 , members similar to those described with reference to  FIG. 3  are denoted by the same reference numerals, and the descriptions thereof will be omitted. As shown in  FIG. 10 , a relatively large space portion  177  is disposed in the backside of the operation unit  105 A. When the operation unit  105 A is mounted and fixed on the level difference portion  102 A, the cable  171  and the first connector  172  pulled out of the second connector  174  are contained in the space portion  177 . 
   According to the second modified example, the cable  171  may be used for transmitting not only a mouse control signal but also other signals. Thus, without providing any special power source or charging battery in the telephone set main body  102 , it is possible to enter necessary information, e.g., positional information, by moving the operation unit  105 A while displaying the display unit  101 . 
   Second Embodiment 
     FIG. 11  shows a use status of an operation unit removed from a portable telephone set main body according to a second embodiment. In  FIG. 11 , members similar to these described with reference to  FIG. 1  are denoted by the same reference numerals, and the descriptions thereof will be omitted. 
   A portable telephone set denoted by a reference numeral  200  has a telephone set main body  202  including the display unit  101  disposed in the front face. In the upper end portion of the telephone set main body  202 , the antenna  103  is disposed so as to be freely expanded/contracted. 
   A bottom portion below an operation region having the keypad  112  of the telephone set main body  202  disposed therein is hollowed, constituting a thin operation plate  102 B having a space to accommodating a mouse unit  205  incorporating a battery. The mouse unit  205  is turned upside down and then fixed to the operation plate  102 B. Accordingly, in the second embodiment, the disposition of various keys such as ten keys in the mouse unit  205  is not always necessary, and it is enough to dispose one or more buttons like the right and left buttons  107  and  108 . In the embodiment, as in the case of the first embodiment, the rotary wheel  109  is provided in addition to the right and left buttons  107  and  108  of the mouse. 
   Third Embodiment 
     FIG. 12  shows the appearance of a portable telephone set using an input apparatus according to a third embodiment of the invention. In the third embodiment, members similar to those described with reference to  FIG. 1  are denoted by the sane reference numerals, and the descriptions thereof will be omitted. 
   A portable telephone set  300  according to the third embodiment has a first telephone set main body  301  including the display unit  101  and the speaker hole  110 , and a second telephone set main body  302  including keypad  112  such as ten keys, a microphone hole  114 , and so on. These first and second main bodies  301  and  302  are connected to each other by a hinge mechanism  303  so as to be freely opened/closed. 
   The second telephone set main body  302  has a hollow portion  307  formed inside extending toward the hinge mechanism  303  to accommodate a mouse  305  incorporating a battery. Therefore, the portable telephone set  300  can be carried in a state where the mouse  305  is inserted into the hollow portion  307 . In the side portion of the second telephone set main body  302 , a latch releasing slicer  306  is disposed so as to freely slide. The mouse  305  incorporating the battery is latched by a latch mechanism (not shown) when it is inserted the full depth into the hollow portion  307  of the second telephone set main body  302 . Accordingly, to take out the mouse  305  incorporating the battery again, the latch releasing slider  306  needs to be slid to release latching. 
     FIG. 13  shows the use state of the mouse incorporating the battery as a pointing device, which is pulled out of the second telephone set main body of the third embodiment. When pulled out directly from the hollow portion  307 , the mouse  305  incorporating the battery can be moved freely on the desk within the length of a cable  311 , enabling the entry of coordinate data. In the tip of the mouse  305  incorporating the battery, a latch mechanism  312  is attached to perform latching inside the second telephone set main body  302 . 
     FIG. 14  shows the process of removing the battery from the mouse incorporating the battery of the embodiment. The mouse  305  incorporating the battery may include a group of electrodes  134  (as shown in  FIG. 10 ) disposed in its outside. Therefore, by setting the mouse  305  in a charger (not shown), it is possible to charge the battery included in the mouse  305 . In the third embodiment, however, the battery is taken out of the mouse  305  and is charged. The battery denoted by a reference numeral  321  is taken out by sliding a battery cover  322  located in the rear end portion of the main body of the mouse  305 . 
     FIG. 15  shows another exemplary mouse incorporating a battery. A battery cover  341  provided in the rear end portion of the main body of the mouse  305  incorporating the battery is freely opened/closed. In the open state of this cover  341 , the battery  321  can be removed. 
   Fourth Embodiment 
     FIG. 16  shows the appearance of a portable telephone set using an input apparatus according to a fourth embodiment. In  FIG. 16 , members similar to those described with reference to  FIG. 1  are denoted by the same reference numerals, and the descriptions thereof will be omitted. 
   A portable telephone set  400  according to the fourth embodiment includes a mouse unit  403  disposed in the center part of the backside of a telephone set main body  402 . The mouse unit  403  contains a cable  404  freely fed to transmit a signal to the telephone set main body  402 . A concave  406  is provided in the rear end portion of the mouse unit  403 . The projection (not shown) of a battery  407  attached to the telephone set main body  402  is fitted in this concave  406  and latched by the latch mechanism  312 , and thereby the mouse unit  403  is fixed to the telephone set main body  402 . To remove the mouse unit  403 , first, the latch mechanism  312  is released, and then the side portions of the right and left buttons  107  and  108  are gripped and lifted to the upper side shown in the drawing. 
   In the foregoing embodiments and the modified examples, the input apparatus as the pointing device and the information processing main body of the portable telephone set or the like are connected to each other by the cable. However, these can be connected by wireless using an infrared wave, and so on. 
   As apparent from the foregoing, the present invention is advantageous in the following respects. 
   First, the input apparatus incorporates the battery and is allowed to be removed from a main body of an information processing device. Further, the input apparatus includes coordinate information output means for outputting coordinate information to the main body of the information processing device. The coordinate information is generated by the input apparatus sliding on a flat plate such as the desk. Therefore, the space required for operations of the apparatus can be effectively utilized, contributing to the miniaturization of the apparatus. 
   Second, since the main body of the information processing device and the input apparatus are connected to each other by a cable, a communication device using infrared rays or the like may be eliminated, which enables the apparatus to be miniaturized and power consumption to be reduced. 
   Third, since the main body of the information processing device and the input apparatus are connected to each other by wireless, it is not necessary to provide any cable containing portions, and there is no possibility of disconnection. 
   Fourth, since the input unit is held to be freely detached in the portable telephone set, the removed use of the input unit facilitates the input processing of the portable telephone set, enabling a complex entry to be carried out quickly in combination with the display unit. 
   Fifth, the main body of the portable telephone set described above in the fourth respect includes a detecting means for detecting the setting of the input unit in the apparatus main body, and an input switching means for switching between the normal input mode and the pointing device input mode depending on whether the input unit is fixed to the apparatus main body. In other words, the input unit operates in the normal input mode when the input unit is attached to the portable telephone set, and operates in the pointing device input mode when the input unit has been removed from the apparatus main body. Accordingly, the functions of the input unit can be automatically switched depending on the presence and absence of the input unit in the apparasus main body.