Abstract:
In an electronic apparatus having a membrane switch and a touch panel switch at its entirety section, the touch panel switch is elastic and is laid over the membrane switch. The two-layered structure provides users with two operations: a “finger-sliding” operation and a “finger-depressing operation.” When a user slides a finger on the surface of the touch panel switch, the sliding force activates the touch panel switch. The “finger-sliding” is used for selecting a desired item. On the other hand, when the user presses down on the surface of the touch panel switch, the depression force through the touch panel switch activates the underlying membrane switch. The “finger-depressing” is used for numeric or symbolic information entry. It is thus possible to realize an electronic apparatus offering an excellent compromise between ease of operation and a wide display section.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an electronic apparatus, such as a video camera, an audio device or a mobile phone, having a plurality of entry switches arranged at its operating section. 
     BACKGROUND OF THE INVENTION 
     With advances in digital techniques, consumer-oriented electronic products including mobile phones, video cameras and audio devices have been highly integrated, and endowed with high performance in their downsized bodies. Besides, the-state-of-the-art has also accelerated an improvement in the user interface including a display and a keyboard. Here, taking a mobile phone as an example of such conventional consumer-oriented electronic products, its structure and operating characteristics are described below. 
     First of all, the structure of a mobile phone is described with reference to the accompanying drawings. FIG. 11 is a front view of a conventional mobile phone. On the front side of outer housing  1 , the sections, from top to bottom in the figure, arranged are: 
     (a) receiver  2  made of a loudspeaker; 
     (b) display  3  made of a LCD (liquid crystal display); 
     (c) touch panel switch  7 ; 
     (d) entry buttons made of numeric keys and confirmation keys; 
     (e) transmitter  5  made of a microphone. 
     FIG.  12  and FIG. 13 illustrate a cross-sectional view and an exploded perspective view of touch panel switch  7 , respectively. As shown in the figures, conductive films  12  and  13 , which are formed at face-to-face surfaces of touch panel switch  7 , are sandwiched between two properly shaped insulating pads  10  and  11 . Between conductive films  12  and  13 , adhesive spacer  30  is inserted, maintaining an interval in order to provide electrical insulation. Insulating pad  10  is formed to be elastic. When a user&#39;s finger depresses or slides on the pad, the applied force recesses a position and leads to electrical conduction between conductive films  12  and  13 . Each time condition is established, an output signal is obtained from electrode portion  14  via lead portions  15 A to  15 D and  16 . The structure adopted for touch panel switch  7  is generally called an analog type or a resistive film type. 
     As shown in FIG. 11, outer housing  1  accommodates extendible antenna  17  at its top. Display  3 , touch panel switch  7 , entry buttons  6 , and electric circuitry (not shown) which controls antenna  17 , are housed in outer housing  1 . The structure including the electric circuitry is shown in the block diagram in FIG.  14 . 
     In FIG. 14, Central Processing Unit (CPU)  18  performs various calculations and evaluations. More specifically, CPU  18  controls display  3  through Liquid Crystal Display (LCD) driver  19  and processes directly received signals from entry buttons  6 ; CPU  18  processes output signals from touch panel switch  7  via touch panel switch driver  20 ; CPU  18  controls antenna  17  via transmission-reception circuit  21 ; and CPU  18  also controls ROM  22  having pre-stored information, and RAM  23  in which the information items of a telephone directory can be added or deleted as required. 
     The placing-a-call procedure is now described. Suppose that the phone number of a party to be called is selected by a search function from the phone numbers pre-stored in a memory in the mobile phone. When the mobile phone is not in communication, as shown in FIG. 15, display  3  displays initial menu  24  comprising a plurality of items, and cursor  25  identifies distinctively which item is concurrently selected in the menu. 
     In order to place a call with the search function, a user usually selects the “Calling telephone number” item in the initial menu. With the finger-sliding motion on the surface of touch panel switch  7 , the user can put cursor  25  in display  3  on the “Calling telephone number” item. When the user slides the finger on the surface of elastic insulating pad  10 , a contact point between conductive films  12  and  13  changes its position, following the wake of the finger-sliding motion. Referring to now FIG. 13, lead portion  15  ( 15 A through  15 D) is extended from electrode portion  14  ( 14 A through  14 D). Lead portion  16  is electrically connected to conductive film  12  with contact portion  16 A, which is laid beneath insulating pad  10 . In response to the position changed by the finger motion on the surface, touch panel switch  7  produces an output signal (i.e., an output voltage value) with its magnitude varying between lead portions  15  and  16 . Obtained from two orthogonal directions, the output signal is converted from analog to digital by touch panel switch driver  20 . Then the converted signal is entered into CPU  18 . Processing the received signal in time sequence, CPU  18  determines in which direction the finger slid on the touch pad surface of touch panel switch  7 , and moves cursor  25  in a proper direction based on the determination. 
     With the cursor sitting on the desired item, the user depresses confirmation key  6 A. Through this action, a decision signal is sent to CPU  18 . The decision signal informs CPU  18  of completion of selecting and confirming the desired item. Receiving the decision signal, CPU  18  recognizes that the “Calling telephone number” item is selected, and fetches the pre-stored telephone directory information from RAM  23  or ROM  22 . CPU  18  then sends the information to LCD  4  via LCD driver  19 , so that the telephone directory appears on the display  3 . 
     With another finger-sliding motion on the touch pad surface of touch panel switch  7 , the user now moves cursor  25  to identify a telephone number to be selected, then depresses confirmation key  6 A. In response to this action, CPU  18  recognizes that the selection is validated and performs the predetermined procedure: CPU  18  not only transmits a transmission signal through transmission-reception circuit  21  and antenna  17  to the selected phone number of the party to be called, but also activates receiver  2  and transmitter  5 . 
     As described above, the finger-sliding motion on the touch panel surface of touch panel switch  7  is a quick-and-easy manner of selection in conventional mobile phones. The users can thereby pick out the desired item easily among many items on the display. 
     The ease of use mentioned above; however, is impaired on a smaller touch panel: the area requires enough space for the finger-sliding motion. Due to recent technological advances, electronic apparatus are getting smaller and smaller. On the other hand, the display area of such apparatus requires more space to cope with a higher volume of information to display thereon. In turn, it has become difficult to reserve enough space for a touch pad in a limited space. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the problems discussed above and aims to provide an electronic apparatus without any space occupied exclusively by the touch panel switch on its entry section. It is a further object to provide an electronic appartus that offers an improved finger-sliding operation with positive response to the touch panel switch. 
     In the structure of the entry section of an electronic apparatus according to the present invention, a touch panel switch with elasticity is placed over a depression switch with tactile feedback (similar to a clicking response.) The depression switch comprises a plurality of switch elements disposed in a planar arrangement. When a user slides the finger on the surface of the touch panel switch structured above, an output signal from the touch panel switch changes in response to the finger-sliding operation. From the output changes, the apparatus detects in which direction the finger moves and how far the finger moves on the touch panel. The detected moving direction and amount are associated with the items appearing on the display, so that the user can select a desired item and then enter it. 
     This two-layered structure thus offers a user-friendly electronic apparatus having two ways of operation: finger-sliding with a light touch enables the user to select a desired item; and finger-depressing with a force sufficient to activate the lower-layered depression switch enables the user to enter preset information including characters, numerals, and symbols. 
     According to the present invention, the apparatus comprises a display section displaying a plurality of items and identifying an item to be selected from among the items, and a depression switch with tactile feedback. The depression switch is made up a plurality of switch elements, and different information for data entry is assigned to each of them. 
     An elastic touch panel switch is laid over the depression switch with tactile feedback. Due to the elasticity, the force applied on the surface of the touch panel switch can also operate the lower-layered depression switch. When a user now slides the finger on the upper-layered touch panel switch, an output signal from the touch panel switch changes in response to the finger-sliding operation. From the output changes, the apparatus detects which direction the finger moves and how far the finger moves on the touch panel. The detected moving direction and amount are associated with the items appearing on the display, so that the user can select a desired item and then enter it. This two-layered structure not only eliminates the space allocated for a touch panel switch from the entry section, but also maintains enough area for easily performing the finger-sliding operation, it is thus possible to provide an electronic apparatus with ease of operation. 
     In a preferred embodiment, a plurality of entry buttons may be arranged between the outer housing and the top surface of the touch panel switch. As the user&#39;s finger slides along the face of the arranged buttons, the bottom of the button depresses a specified position of the touch panel switch. That is, a staircase-shaped signal is obtained from the touch panel switch, which is reliable, easy to detect and control. 
     As another preferred embodiment, a transparent material may be employed for the touch panel switch and the entry buttons disposed thereon, and an illuminator may be disposed beneath the touch panel switch. The illuminator makes the surface of the touch panel switch glow for increased visibility, when the user operates the apparatus in the dark. 
     In still another preferred embodiment of the present invention, the apparatus comprises a display section displaying a plurality of items and identifying an item to be selected from among the items, and an elastic membrane switch with tactile feedback. The membrane switch is made up of a plurality of switch elements, and different information for data entry is assigned to each of them. 
     The membrane switch is laid over the touch panel switch. As a user slides the finger horizontally along the surface of the membrane switch, an output from the touch panel switch changes in response to the finger-sliding operation. From the output changes, the apparatus detects in which direction the finger moves and how far the finger moves on the membrane switch. The detected moving direction and amount are associated with the items appearing on the display, so that the user can select a desired item and then enter it. This two-layered structure thus not only eliminates the space allocated for a touch panel switch from the entity section, but also maintains enough area for easily performing the finger-sliding operation. It is thus possible to provide an electronic apparatus with ease of operation. In addition, a plurality of entry buttons may be disposed between the membrane switch and the outer housing laid thereon. This structure secures a positive depression on the membrane switch, providing users with a tactile response. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a front view of a mobile phone in accordance with a first preferred embodiment of the present invention. 
     FIG. 2 shows a side cross-sectional view of the mobile phone. 
     FIG. 3 shows a partial enlarged cross-sectional view of a touch panel switch and a membrane switch, which are the essential parts of the mobile phone. 
     FIG. 4 shows an exploded perspective view of the touch panel switch, which is essential part of the mobile phone. 
     FIG. 5 shows a block diagram of the mobile phone. 
     FIG. 6 shows a front view of the display section of the mobile phone before operation. 
     FIG. 7 shows a front view of the display section of the mobile phone during operation. 
     FIG. 8 shows a front view of a mobile phone in accordance with a second preferred embodiment of the present invention. 
     FIG. 9 shows a side cross-sectional view of the mobile phone. 
     FIG. 10 shows a side cross-sectional view of a mobile phone in accordance with a third preferred embodiment of the present invention. 
     FIG. 11 shows a front view of a conventional mobile phone. 
     FIG. 12 shows a cross-sectional view of a touch panel switch, which is an essential part of the conventional mobile phone. 
     FIG. 13 shows an exploded perspective view of the touch panel switch, which is essential part of the conventional mobile phone. 
     FIG. 14 shows a block diagram of the conventional mobile phone. 
     FIG. 15 shows a front view of the periphery of the display section of the conventional mobile phone before operation. 
     FIG. 16 shows a front view of the display section of the conventional mobile phone during operation. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments of the present invention are described hereinafter with reference to the accompanying drawings, FIG.  1  through FIG.  10 . 
     First Preferred Embodiment 
     FIG. 1 shows a front view of a mobile phone in accordance with a first preferred embodiment of the present invention. In FIG. 1, outer housing  31  has a touch panel surface on its front, and is also an enclosure for accommodating electric circuitry therein. Above the touch panel surface, receiver  32  and display  33  formed by an LCD  34  are disposed, and disposed below the touch panel surface is transmitter  35 . FIG.  2  and FIG. 3 show a cross-sectional view and a partial enlarged cross-sectional view, respectively. Entry section  36  is responsible for entry and selection when the mobile phone is in operation. As shown in FIGS. 2 and 3, touch panel switch  37  formed to be elastic is arranged at the top surface of the entry section  36 , and membrane switch with tactile feedback  38  is laid beneath the touch panel switch  37 . On the entry section side of the touch panel switch  37 , as shown in FIG. 1, button markings  37 A to  37 N are arranged at positions which correspond to each switch element of the membrane switch  38 . Markings  37 A to  37 N indicate each position and function of each switch element. 
     When a user depresses some positions of the markings for numerical or symbol data entry, thanks to the two-layered structure described above, the depression at each position activates the corresponding switch element of the membrane switch  38 . For example, when the user depresses marking  37 C marked “1” (FIG.  1 ), the depression recesses, as shown in FIG. 3, the part beneath marking  37 C in the elastic touch panel switch  37 , and further the force is transmitted through the touch panel switch  37  to conductive diaphragm  38 A. If the depression force is beyond a predetermined value, conductive diaphragm  38 A flips its shape vertically, thereby conducting the switch circuit having diaphragm  38 A, which is formed on printed circuit board  38 B. In this way, the numerical value “1” is accepted as the entry data. For good tactile response and operability, the depression force, i.e., a repulsive force required to flip diaphragm  38 A is preferably set to approximately 100-gram force (gf). 
     Touch panel switch  37  is generally called an analog type or a resistive film type. FIGS. 3 and 4 illustrate a partial cross-sectional view and an exploded perspective view of touch panel switch  37 , respectively. Conductive films  42  and  43  are formed on face-to-face sides of rectangular insulating pads  40  and  41 , respectively. Adhesive spacer  60  is inserted between conductive films  42  and  43  to maintain an interval for electric insulation. This structure is the same as that in the prior art, with the exception that insulating pads  40 ,  41  and conductive films  42 ,  43  are all elastic. 
     On the periphery of conductive film  43  placed over insulating pad  41 , four electrode portions  44  ( 44 A through  44 D) are disposed in the middle of each edge. Each electrode portion is sided shorter than the edges of the conductive film, and arranged in an orthogonal orientation relative to each other. Lead portions  45  ( 45 A through  45 D) are connected to each of electrode portions  44  ( 44 A through  44 D), respectively. Lead portions  46  are electrically connected to conductive film  42  laid beneath insulating pad  40  with contact portion  46 A. As shown in FIG. 4, lead portions  45  and  46  are both extended out from touch panel switch  37 . 
     In addition, touch panel switch  37  is arranged within outer housing  31  such that electrode potions  44 A through  44 D are placed in parallel with each edge of the touch pad surface and, the area surrounded by the four electrode portions  44 A through  44 D works as the touch pad surface. 
     In order to obtain an output signal, touch panel switch  37  works in the same manner as does the conventional type: the finger-sliding operation with a depression force on the surface of insulating pad  40  leads to electrical conduction between conductive films  42  and  43 . Touch panel switch  37  is adjusted so as to produce a predetermined output signal when a depression force of approximately 10 gf is applied. 
     According to the touch panel surface as described above, in which touch panel switch  37  is correctly associated with each element of membrane switch  38 , and the depression force is adjusted to a predetermined value, when a relatively small depression force of approximately 10 gf is exerted on the surface of switch  37  by the finger-sliding operation, an output signal corresponding to the force can be obtained easily. On the other hand, when a positive downward depression force, for example, approximately 100 gf, is applied to one of markings  37 A through  37 N on touch panel switch  37 , the switch  37  can transmit the force, due to its elasticity, to membrane switch  38 . As a result, an output signal associated with the depressed marking position is now easily obtained. 
     In response to the depression force of 100 gf, touch panel switch  37  also reacts and produces an output signal. For avoiding a malfunction, it is preferable to employ a software-controlled evaluation such that any output signal from switch  37  is ignored when membrane switch  38  produces an output signal. 
     Referring now to FIG. 1, accommodating expandable antenna  47  at its top, outer housing  31  is the enclosure for display  33 , touch panel switch  37 , membrane switch  38 , and electric circuitry (not shown in FIGS. 1 and 2) for controlling antenna  47 . 
     The structure including the electric circuitry of the mobile phone according to the preferred embodiment of the present invention is briefly described below. CPU  48 , as shown in FIG. 5, executes a various kind of calculation and evaluation. As is similar to conventional structure, display  33 , touch panel switch  37 , membrane switch  38 , and antenna  47  are coupled directly or via specific circuits to CPU  48 : display  33 , touch panel switch  37  and antenna  47  are coupled to CPU  48  via LCD driver  49 , touch panel switch driver  50  and transmission-reception circuit  51 , respectively, while membrane switch  38  is directly connected to CPU  48 . CPU  48  also controls ROM  52  and RAM  53 , ROM  52  holds pre-stored specific information therein, and RAM  53  allows users to add/delete telephone directory information as required. 
     Now described are about the operating principles of the mobile phone according to the preferred embodiment. FIG. 6 illustrates a mobile phone which is not in communication. Display  33 , like the display in the prior art, displays initial menu  54  comprising a plurality of items, and cursor  55  that highlights a currently selected item from among the items appearing on the display. In the conventional display, however, the structural limitation that an area for the touch panel has to be allocated between the display and the entry section inevitably “eats” the area for the display. When selecting a desired item from the initial menu with long lists, a user inconveniently scrolls hidden items to view. As opposed to the conventional design with such inconvenience, according to the embodiment, the structure in which touch panel switch  37  is laid over membrane switch  38  in FIG. 3 realizes a large display  33 . Thanks to the two-layered structure, display  33  can display several lines of information items more than the conventional display. 
     Here will be discussed how to place a call. In order to select a desired function from the initial menu, with the finger-sliding operation on the surface of touch panel switch  37 , a user moves cursor  55  on display  33  toward a desired item. The depression force by the finger-sliding operation is relatively small, approximately 10 gf. In response to the force touch panel switch  37  works as follows. Touch panel switch  37  comprises, as mentioned earlier, insulating pads  40 ,  41 , and conductive films  42 ,  43 . Conductive films  42  and  43  are formed on the facing surfaces of insulating pads  40  and  41 , respectively. Two insulating pads are placed at a predetermined interval for electrical insulation. When the user slides the finger on the top surface of insulating pad  40 , a contact point between conductive films  42  and  43  changes its position, following the wake of the finger-sliding motion. According to the positional changes, an output signal obtained through electrode portions  44 A to  44 D and lead portions  45 A to  45 D,  46  (i.e., an output voltage value) also varies. The output voltage value is detected from the signals having two orthogonal directions, that is, from the signals occurred between electrode portions  44 A and  44 B, and from the signals occurring between electrode portions  44 C and  44 D. 
     Now will be discussed in a little more detail how to obtain the output voltage value from touch panel switch  37 . On conductive film  43 , as shown in FIG. 4, two pairs of electrode portions are arranged in orthogonal orientation. Now, between one pair of electrode portions,  44 A and  44 B (that is, between lead portions  45 A and  45 B) and, between the other pair of electrode portions,  44 C and  44 D (that is, between lead portions  45 C and  45 D), a voltage is applied alternately, so that conductive film  43  is energized. The depression force applied to elastic insulating pad  40  recesses conductive film  42 , making a contact point with energized conductive film  43 . At the same time, an output voltage value is obtained between lead portions  45 A ( 45 B) and  46 , or between lead portions  45 C ( 45 D) and  46 . Touch panel switch driver  50  shown in FIG. 5 converts the obtained output signal from analog to digital, and sends it to CPU  48 . Processing the received signal in time sequence, CPU  48  determines in which direction the finger slides, and how fast the finger moves on the surface of touch panel switch  37 , to thereby move cursor  55  shown in FIG. 6 according to the direction and speed. 
     With cursor  55  highlighting a desired item, the user depresses marking  37 A downwardly with a depression force of approximately 100 gf. The depression on marking  37 A, which validates the selection, activates a corresponding switch element of membrane switch  38 , so that a decision signal for the selected item is sent to CPU  48 . Receiving the decision signal, CPU  48  recognizes the item highlighted by cursor  55  on display  33  in FIG.  6 . CPU  48  then invokes the corresponding menu data from ROM  52  or RAM  53  and transmits the menu data through LCD driver  49  to display  33 . As a result, the user views the desired menu called up on display  33 . 
     The mechanism will be explained in some detail, taking a case in which the phone number of a party to be called is searched from pre-stored information as an example. First of all, a user selects the “Calling telephone number” item from the initial menu  54 . For this selection, as shown in FIG. 7, with the finger-sliding motion in up-to-bottom direction on touch panel switch  37 , the user moves cursor  55  appearing on display  33  to the “Calling telephone number” item. With “Calling telephone number” being highlighted, the user depresses marking  37 A for validating the selection. In response to this operation, CPU  48  invokes telephone directory information that is pre-stored in ROM  52  or RAM  53 , and sends the information through LCD driver  49  to display  33 . Then, with another finger-sliding motion on touch panel switch  37 , the user moves cursor  55  to a desired phone number and depresses marking  37 A for validating the selection. Receiving this decision signal, CPU  48  recognizes the selection of the desired phone number and performs the predetermined procedures: CPU  48  transmits a transmission signal through transmission-reception circuit  51  and antenna  47  to the selected and validated phone number of the party to be called, and enables receiver  32  and transmitter  35  as well. 
     In order to place a call, a user may enter a series of numerals indicating a phone number through membrane switch  38  shown in FIG.  2 . In this case, an output signal from touch panel switch  37  can be detected, as well as from membrane switch  38 . CPU  48  can cope successfully with the situation, executing pre-programmed software, in which any output signal from switch  37  is ignored when membrane switch  38  produces an output signal. 
     According to the embodiment, touch panel switch  37  is placed over membrane switch  38  for numerals and symbols entry. The two-layered structure not only enables the use of an area-limited touch pad surface to be maximized, but also reserves the area of display  33  to be broader. Display  33  can therefore display can additional 3-4 lines of information items as compared with the conventional display. With this structural improvement, it is possible to provide a user-friendly mobile phone with good visual recognition. In addition, on the wide area of touch panel switch  37 , changes of an output voltage can be “magnified” to be read. In other words, a fine-adjusted control becomes possible. It is possible to control a moving speed of the operation, as well as a moving direction. 
     In selecting-item operation, the moving direction of cursor  55  is not limited to top-to-bottom: in response to the finger-sliding operation in side-to-side or diagonal direction on the touch pad surface of touch panel switch  37 , it is possible to control cursor  55  to follow this direction. 
     As an application for the embodiment, in selecting-item operation, it is possible to make the items move, with the cursor sitting on a position, instead of moving the cursor onto desired item. 
     Touch panel switch  37  is not limited to the type described above. As an application of the embodiment, it is effective to employ, for example, a digital type touch panel switch. In this case, an ON-state output signal is produced, following the wake of the finger-sliding operation. The CPU can detect a series of ON-state signals for the evaluation. A static capacitance type touch panel is also available with effect. As another application of the embodiment, the touch panel switch may be made of a transparent material, and an illuminator, such as an electroluminescent (EL) element of a light-emitting diode (LED), may be arranged at the bottom of the touch panel switch. With the help of the illuminator, the user can easily operate the switch even in the dark. As still another application of the embodiment, a normal type switch such as a depression switch with tactile feedback may be employed, instead of using membrane switch  38 . In addition, the depression force applied to touch panel switch  37  and membrane switch  38  is not limited to the value mentioned earlier. It may be adjusted to an appropriate value if necessary. 
     Second Preferred Embodiment 
     FIG. 8 is a front view, and FIG. 9 is a cross-sectional view of a mobile phone in accordance with a second preferred embodiment of the present invention. As illustrated in FIG. 9, the difference between the structures shown in the first and second embodiments is in the arrangement of entry button member  62 , which is inserted between touch panel switch  37  and outer housing  61 . The rest of the configuration is the same as that in the first preferred embodiment, and hence the description is omitted here. 
     On entry button member  62 , an array of entry protrusions  62 A are formed, each of which penetrates outwardly through a corresponding hole  61 A perforated in outer housing  61 . Each person of protrusions  62 A corresponds to the position of each switch element of membrane switch  38 . As a user&#39;s finger horizontally slides on the face of protrusions  62 A one after another, the bottom entry button member  62  depresses a specified position of the touch panel switch continuously. That is, a staircase-shaped signal is obtained from the touch panel switch. Such a signal is easy to recognize without amplification. It is therefore possible that the moving direction by the finger-sliding operation is easily detected and controlled with high reliability. 
     The structure promises an easy-to-view wide display  33  capable of displaying more information, and enhances a detecting accuracy of moving direction and speed during the finger-sliding operation. 
     In addition, as described in the first period embodiment, the touch panel switch  37  and entry button member  62  may be made of a transparent material, and an illuminator may be employed to light up the top of entry protrusions  62 A. With the help of the structure, as is the case in the first preferred embodiment, the user can easily recognize the protrusions  62 A in the dark. 
     In each of the first and second embodiments, the membrane switch  38  is activated without displacement of the touch panel switch  37  towards the membrane switch  38 . 
     Third Preferred Embodiment 
     FIG. 10 is a cross-sectional view of a mobile phone in accordance with a third preferred embodiment of the present invention. It is apparent from FIG. 10 that in the structure of this embodiment the position of the membrane switch is interchanged with the touch panel switch as shown the second preferred embodiment. That is, as shown in FIG. 10, elastic membrane switch  71  is laid over touch panel switch  37 . Entry button member  62 , which has an array of entry protrusions  62 A thereon, is inserted between membrane switch  71  and outer housing  61 . Each of protrusions  62 A is disposed at a position that corresponds to each switch element of membrane switch  71 . Each of protrusions  62 A, as is the case of the second preferred embodiment, protrudes outwardly through a corresponding hole  61 A perforated in outer housing  61 . 
     In the third embodiment, when a user depresses any of protrusions  62 A, the depression force activates the corresponding switch element of underlying membrane switch  71 . On the other hand, when the user slides the finger horizontally on the face of some protrusions  62 A, membrane switch  71  can apply a depression force, due to its elasticity, to a series of contact points on touch panel switch  37 . Following the wake of the finger-sliding operation, the contact point changes its position on touch panel switch  37 . As a result, an output signal corresponding to the positional changes is obtained from touch panel switch  37 . 
     In response to the depression force applied to protrusions  62 A, touch panel switch  37  also produces an output signal. As is the case of the first preferred embodiment, for avoiding a malfunction, it is preferable to employ a software-controlled evaluation such that any output signal from switch  37  is ignored when membrane switch  71  produces an output signal. 
     A wide space for display  33  is promised, similar to the case of the first preferred embodiment. As another advantage, entry button member  62  not only ensures a positive depression onto membrane switch  71 , but also provides the user with a clicking tactile response with ease of use. 
     It is possible to configure the entry section without entry button member  62 . In the case, membrane switch  71  is placed in exposed arrangement on outer housing  61 . This configuration is also effective, as is the case described above. 
     In this embodiment, the touch panel switch  37  is activated without displacement of the membrane switch  71  toward the touch panel switch  37 . 
     The present invention, as described in the embodiments, eliminates a space exclusive to a touch panel switch and, configures the touch panel switch and a depression switch with tactile feedback in a two-layered structure. A wide display area can thus be allocated at the entry section. Besides, the two-layered structure realizes an easy and quick selection with reliability by the finger-sliding/depressing operation on the wide touch panel surface. Employing the structure provides an electronic apparatus with greatly improved operability.