Patent Publication Number: US-2006002203-A1

Title: Input device having activating means

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to input devices having an input section for detecting plane coordinates of positions during operations such as pushing an operational surface, and in particular, relates to input devices consuming lower amounts of power.  
      2. Description of the Related Art  
      Capacitive flat input devices are used in, for example, cellular phones as input devices for cursor movement such as menu selection or for handwriting, or as pointing devices of personal computers.  
      The capacitive flat input devices include operational surfaces formed of flat sheets or the like, and capacitances are varied when the surfaces of the sheets are operated by fingers or the like. Coordinate positions of the fingers on the operational surfaces can be detected by measuring the variations of the capacitances. According to this principle, coordinate data for moving cursors on display screens to desired positions can be obtained.  
      In Japanese Unexamined Patent Application Publication No. 2002-123363, one of such capacitive flat input devices is included in, for example, a remote controller of a television.  
      In Japanese Unexamined Patent Application Publication No. 2003-99185, one of such capacitive flat input devices reduced in thickness is used as a pointing device of a personal computer.  
      However, while the power is turned on, the capacitive flat input devices disclosed in Japanese Unexamined Patent Application Publication Nos. 2002-123363 and 2003-99185 always scan the variations of the capacitances with sensor circuits connected to the flat input devices even when the operational surfaces are not operated, resulting in an increase in power consumption.  
      In particular, remote apparatuses such as remote controllers use batteries as power sources, and usually do not have power switches for turning the power on or off. Accordingly, the remote apparatuses including the flat input devices keep scanning the variations of the capacitances of the flat input devices even when the remote apparatuses are not used (even when the operational surfaces are not operated). This leads to an increase in the power consumption of the batteries.  
     SUMMARY OF THE INVENTION  
      Accordingly, it is an object of the present invention to provide an input device consuming lower amounts of power.  
      The input device having activating means according to the present invention includes a face sheet, the upper surface of the face sheet functioning as an operational surface; and an input section for detecting plane coordinates of an operational position on the operational surface, the input section being disposed under the face sheet. The input device is characterized in that the activating means is disposed on a surface of the input section remote from the face sheet, and detects the operation on the operational surface; and the input section is activated on the basis of an operating signal output from the activating means.  
      According to the present invention, the input section is activated on the basis of the operating signal output from the activating means only when the operational surface is operated. Thus, the power consumption can be reduced compared with the known technology.  
      According to the present invention, it is preferable that the activating means and the input section be connected to controlling means, and that the controlling means output an activating signal to the input section in response to the operating signal output from the activating means.  
      Furthermore, according to the present invention, it is preferable that the activating means include a switch portion, that the switch portion enter an input state so as to output a push signal when the operational surface is pushed, and that the input section be activated on the basis of the push signal.  
      According to the description above, the structure of the activating means can be simplified. In particular, according to the present invention, there is no need to detect which switch portion was pushed, for example, and only an input state of the switch portion is required. Thus, the switching circuit can be simplified.  
      According to the present invention, it is preferable that the switch portion be a plurality of switch portions.  
      When the input device includes the plurality of switch portions, an operator can push any position on the face sheet of the input section such that one of the switch portions enters an input state. Thus, a push signal is output, and the input section can easily be activated.  
      Furthermore, according to the present invention, it is preferable that the activating means include an upper sheet having an upper electrode disposed on the lower surface of the upper sheet, and a lower sheet having a lower electrode disposed on the upper surface of the lower sheet, the lower sheet opposing the upper sheet with a predetermined spacing therebetween; and that the upper electrode and the lower electrode paired in the height direction form the switch portion.  
      Alternatively, according to the present invention, it is preferable that the activating means include a flexible plate and a detecting board, that a projection having a conductive element on the tip be disposed on the plate, that a pair of electrodes be disposed on the detecting board, and that the conductive element and the pair of electrodes opposing in the height direction form the switch portion.  
      With the above-described detecting means, the activating means can reliably enter an input state even with a small pushing force, and as a result, the input section can easily be activated.  
      According to the present invention, it is preferable that the input section be a capacitive sensor. Furthermore, according to the present invention, the power consumption can be appropriately reduced even when the input device is included in a remote apparatus. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view illustrating an electronic apparatus including an input device according to the present invention;  
       FIG. 2  is a cross-sectional view of the input device according to an embodiment of the present invention taken along line II-II in  FIG. 1 ;  
       FIG. 3  is a cross-sectional view taken at the same position as  FIG. 2  when the input device shown in  FIG. 2  is pushed by a finger or the like;  
       FIG. 4  is a block diagram illustrating operations of the input device;  
       FIG. 5  is an exploded perspective view illustrating an activating section according to a modification of the first embodiment of the present invention; and  
       FIG. 6  is a cross-sectional view of an input device according to a second embodiment of the present invention taken at the same position as  FIG. 2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      As shown in  FIG. 1 , an input device  1  according to the present invention is included in an electronic apparatus  100  having no power switch for turning the power on or off and driven by a battery or the like. The electronic apparatus  100  is, for example, a remote apparatus such as a remote controller.  
      The electronic apparatus  100  includes a display  101  for displaying various images such as menu panels, a plurality of buttons (push switches)  102 , and the input device  1 . Cursor movement such as menu selection on the display  101  is performed in response to operations on the input device  1 , and selected information is sent from a transmitting section  104  to external receiving apparatuses.  
      As shown in  FIG. 2 , the input device  1  includes an input section  2  and an activating section  3 . The lower surface of a control circuit board  29  of the input section  2  and the upper surface of an upper sheet  31  of the activating section  3  are bonded together with a bonding member such as an adhesive, and the activating section  3  is bonded to a base  5  composed of, for example, a glass epoxy resin with an adhesive or the like. Thus, the input section  2  and the activating section  3  are fixed to a casing  4 .  
      The input section  2  is a so-called capacitive flat input device, and specifically, a capacitive type known as GLIDEPOINT®.  
      In the input section  2 , a plurality of X electrodes  22  is formed on the upper surface of a film substrate  21  composed of, for example, a synthetic resin such as polyethylene terephthalate (PET), and a plurality of Y electrodes  24  is formed on the lower surface of the film substrate  21 . The X electrodes  22  and the Y electrodes  24  are arranged in a grid, and covered with insulating layers  26  and  27 , respectively. A face sheet  28  is disposed on the insulating layer  26 , and the upper surface of the face sheet  28  functions as an operational surface.  
      As shown in  FIG. 2 , the control circuit board  29  is disposed on the lower surface of the insulating layer  27 . The control circuit board  29  includes a sensor circuit containing, for example, a central processing unit (CPU) and an amplifier for amplifying outputs of detected signals (not shown) on a surface remote from the film substrate  21  (the lower surface).  
      In the input section  2 , through holes (not shown) for electrically connecting the X electrodes  22  and the Y electrodes  24  are formed in the film substrate  21 , insulating layer  27 , and the control circuit board  29 ; and coordinate signals based on the capacitances detected at the X electrodes  22  and the Y electrodes  24  are sent to the sensor circuit.  
      As shown in  FIG. 4 , the detected coordinate signals are amplified by the amplifier contained in a sensor circuit  50 , converted into digital signals at an analog-to-digital (A/D) converter, and sent to a CPU  51 . Subsequently, the coordinate signals are sent from the CPU  51  to the transmitting section  104  via a driver  52 , and then sent from the transmitting section  104  to external receiving apparatuses.  
      As shown in  FIG. 3 , when an electric conductor F such as a finger pushes the operational surface of the face sheet  28  of the input device  1 , part of electric lines of force flowing from the X electrodes  22  to the Y electrodes  24  is absorbed by the finger or the like of an operator at the X electrodes  22  and the Y electrodes  24 . As a result, the electric lines of force absorbed by the Y electrodes  24  are reduced, and the capacitances are varied. The coordinate positions of the electric conductor F such as a finger are detected on the basis of current outputs varied in response to these capacitances. This detection is performed by the CPU  51  or the sensor circuit  50  mounted on the backside of the control circuit board  29 .  
      As shown in  FIG. 2 , the activating section  3  is disposed on the surface of the input section  2  remote from the face sheet  28  (the lower surface).  
      In the activating section  3 , the upper sheet  31  and a lower sheet  32  opposing the upper sheet  31  are fixed to each other with a sheet spacer  33  interposed therebetween. Both the upper sheet  31  and the lower sheet  32  are composed of a flexible material such as a PET resin or a polyimide resin, and the spacer  33  is composed of a binding material. Alternatively, the sheets  31  and  32  and the spacer  33  all may be composed of a PET resin or the like, and may be fixed to each other.  
      Circular upper electrodes  31   a,    31   b,  and  31   c  composed of a metallic material such as copper or silver are formed on the surface of the upper sheet  31  facing the lower sheet  32 , and circular lower electrodes  32   a,    32   b,  and  32   c  composed of a metallic material such as copper or silver are formed on the surface of the lower sheet  32  facing the upper sheet  31 . Circular though holes  33   a,    33   b,  and  33   c  having a diameter larger than the external diameters of the upper and lower electrodes are formed in the spacer  33 . These upper and lower electrodes opposing each other in the height direction (Z direction) form switch portions S 1 , S 2 , and S 3 , respectively. In  FIG. 2 , only three switch portions S 1 , S 2 , and S 3  are shown. However, a number of switch portions are formed over the X-Y plane of the input device  1  of the electronic apparatus  100  in practice.  
      Distinctive features of the present invention will now be described. As shown in  FIG. 2 , when the operational surface of the face sheet  28  of the input device  1  is not pushed by a finger or the like, the upper electrodes  31   a,    31   b,  and  31   c  and the lower electrodes  32   a,    32   b,  and  32   c  of the activating section  3  oppose each other with a predetermined spacing therebetween, and switching signals (operating signals) are not output. At this time, the sensor circuit  50  connected to the input section  2  shown in  FIG. 4  does not receive power from a battery  53 , and is not activated. In other words, the sensor circuit  50  in the state shown in  FIG. 2  does not scan coordinate signals of the X electrodes  22  and the Y electrodes  24  of the input section  2 .  
      As shown in  FIG. 3 , when the operational surface of the face sheet  28  of the input device  1  is pushed by the electric conductor F such as a finger, the pushing force is transmitted to the interior of the input device  1 , and the control circuit board  29  of the input section  2  is deformed downward. Then, the upper sheet  31  of the activating section  3  bonded to the control circuit board  29  is also deformed downward, and the upper electrode  31   b  comes into contact with the lower electrode  32   b.  In this manner, the electrodes are connected to each other, and the operating signals (push signals) are output.  
      As shown in  FIG. 4 , the push signals output from the activating section  3  interrupt the CPU  51 . The CPU  51  sends an activating signal for activating the input section  2  to the sensor circuit  50  in response to the interrupting signals. The sensor circuit  50  then receives power from the battery  53 , and is activated.  
      In this manner, the sensor circuit  50  is activated on the basis of the activating signal from the CPU  51 , and scans and detects the coordinate signals output from the X electrodes  22  and the Y electrodes  24 .  
      The detected coordinate signals are, for example, converted into digital signals at the A/D converter contained in the sensor circuit  50 , and sent to the CPU  51 . The coordinate signals are then sent from the CPU  51  to the transmitting section  104  via the driver  52 , and received by external receiving apparatuses.  
      In this manner, according to the present invention, the input section  2  is activated on the basis of the push signals output from the activating section  3 . In other words, the input section  2  is not activated unless the push signals are not output. That is to say, when the electric conductor F such as a finger does not push the operational surface of the face sheet  28  as shown in  FIG. 2 , the input section  2  is not activated, and the sensor circuit  50  does not perform a scan. Thus, unnecessary power supply to the circuit is cut, and the power consumption of the battery  53  can be reduced.  
      Moreover, the CPU  51  controls the activation of the input section  2  on the basis of the push signals from the activating section  3  as shown in  FIG. 4 . This leads to an easy circuit design.  
      According to the control by the CPU  51 , for example, the activated input section  2  can easily be deactivated when the coordinate signals are not detected from the input section  2  within a predetermined period of time by cutting the power supply to the input section  2 . Also, the input section  2  can be activated depending on the amplitudes of the outputs from the activating section  3 . For example, when the outputs from the activating section  3  do not exceed a threshold level, the outputs are determined as misoperations, and the input section  2  is not activated. In this case, the input section  2  can be activated only when the outputs exceed the threshold level.  
      The input section  2  is activated when any one of the switch portions S 1 , S 2 , and S 3  of the activating section  3  is pushed. However, there is no need to detect which switch portion was pushed at this time, and only a push signal output from the activating section  3  is required. Thus, the circuit can be simplified by, for example, connecting the switch portions S 1 , S 2 , and S 3  in series.  
      Alternatively, the pushed switch portion may be detected such that the CPU  51  performs a predetermined control when a predetermined switch portion is pushed. For example, when a menu panel is shown on the display  101 , an operator operates the input section  2  so as to move a cursor onto an icon displayed in the menu panel. When one of the switch portions S 1 , S 2 , and S 3  is pushed, a push signal is output, and the CPU  51  outputs a command signal for opening the icon.  
      In this case, the switch portions S 1 , S 2 , and S 3  must be wired separately, or a change-over switch or the like for detecting the pushed switch portion must be prepared.  
      It is preferable that marks indicating the positions of the switch portions S 1 , S 2 , and S 3  be printed on the operational surface of the face sheet  28 .  
      The activating section  3  shown in  FIG. 2  is a so-called membrane switch. Therefore, the upper electrodes and the lower electrodes reliably come into contact with each other and become conductive even when the input section  2  is pushed with a small pushing force. As a result, the input device  1  can easily be activated.  
       FIG. 5  is an exploded perspective view illustrating an activating section according to a modification of the first embodiment of the present invention. The spacer is omitted, and the arrangement of a plurality of upper electrodes  31   a,    31   b,  and  31   c  formed on an upper sheet  31  and a plurality of lower electrodes  32   a,    32   b,  and  32   c  formed on a lower sheet  32  in the X-Y plane is shown by the dotted lines on both sheets.  
      In this modification, the structure of the input device is the same as that shown in  FIG. 2  except for an activating section  3 A.  
      The activating section  3 A includes the upper sheet  31  and the lower sheet  32  linked together via a flexible sheet  33 A composed of a flexible resin such as a PET resin or a polyimide resin.  
      The upper electrodes  31   a,    31   b,  and  31   c  formed on the upper sheet  31  are connected in series by lead wires, and are connected to an extension pattern  35  composed of a metallic material such as copper and silver. The extension pattern  35  is exposed on the surfaces of the upper sheet  31  and the lower sheet  32  opposing each other, and is preferably insulated so as to avoid a contact. The extension pattern  35  is extended to the exterior of the activating section  3 A via the flexible sheet  33 A and the lower sheet  32 . Resistors R 1 , R 2 , and R 3  are printed adjacent to the respective lower electrodes of the lower sheet  32 . Therefore, when the upper electrodes and the lower electrodes come into contact with each other and become conductive, a voltage output by this conduction is detected.  
      In this modification, all of the upper sheet  31 , the lower sheet  32 , and the flexible sheet  33 A are composed of the same flexible material such as a PET resin or a polyimide resin. That is to say, the activating section  3 A is produced by forming the upper sheet  31  and the lower sheet  32  linked to the flexible sheet  33 A from the same material, and then by bending the flexible sheet  33 A such that the upper sheet  31  and the lower sheet  32  oppose each other as shown in  FIG. 5 . Thus, the activating section  3 A can easily be produced.  
       FIG. 6  is a cross-sectional view of an input device according to a second embodiment of the present invention taken at the same position as  FIG. 2 . In this embodiment, the structure of the input device is the same as that of the first embodiment except for an activating section  3 B. In contrast to the first embodiment, the activating section  3 B is not a so-called membrane switch.  
      The activating section  3 B includes a plate  301  of a film composed of a synthetic resin such as a PET resin and a detecting board  302 .  
      A plurality of projections  303  composed of, for example, an ultraviolet (UV) curable resin is printed on the backside of the plate  301 . In  FIG. 6 , only three projections  303  are shown. However, a number of projections are formed over the X-Y plane of an input section  1  of an electronic apparatus  100  in practice.  
      Pairs of electrodes  304   a  and  304   b  are disposed on the upper surface of the detecting board  302  with a predetermined spacing therebetween at positions opposing the respective projections  303 . Moreover, a conductive element  305  (electrode) containing, for example, carbon is disposed on each tip of the projections  303  formed on the plate  301 . In this embodiment, the conductive element  305  and the pair of electrodes  304   a  and  304   b  form a switch portion.  
      Operations of an input device  1  according to this embodiment are similar to those according to the first embodiment. When the input device  1  is pushed by a finger or the like at, for example, a position P, the pushing force is transmitted to the interior of the input device  1 , and a control circuit board  29  of an input section  2  is deformed downward. Then, the plate  301  of the activating section  3 B bonded to the control circuit board  29  is also deformed downward, and a conductive element  305 A disposed on the tip of a projection  303 A comes into contact with both the electrodes  304   a  and  304   b  opposing the conductive element  305 A so as to become conductive. At this conduction, a push signal generated at the switch portion interrupts a CPU  51  included in the input section  2 . The CPU  51  activates the input section  2  on the basis of this interrupting signal.  
      In this manner, the input section  2  is activated on the basis of the push signals output from the activating section  3 B. In other words, the input section  2  is not activated unless the push signals are not output. That is to say, when the electric conductor such as a finger does not push the operational surface of the face sheet  28 , the input section  2  is not activated, and the sensor circuit  50  does not perform a scan. Thus, unnecessary power supply to the circuit is cut, and the power consumption can be reduced.  
      According to the activating section  3 B of this embodiment, the conductive elements disposed on the tips of the projections come into contact with the respective pairs of electrodes opposing the conductive elements and become conductive even when the input section  2  is pushed with a small pushing force as in the case for the first embodiment. As a result, the input device  1  can easily be activated.  
      In contrast to the description above, the input device according to the present invention may include only one switch portion. However, it is preferable that the input device include the plurality of switch portions as above. When the input device includes the plurality of switch portions, an operator can push any position on the face sheet of the input section such that one of the switch portions enters an input state. Thus, a push signal is output, and the input section can easily be activated.  
      According to the present invention, the input device  1  is included in a remote apparatus such as a remote controller shown in  FIG. 1 , and powered by the battery  53  or the like without a power switch for turning the power on or off. However, the input device  1  may also be included in a remote apparatus with a power switch as long as the power is supplied by the battery  53  or the like.  
      Furthermore, the present invention is applicable not only to remote controllers but also electronic apparatuses such as cellular phones and personal computers.  
      The activating section  3  includes the plurality of switch portions, and outputs the push signals when the operational surface is pushed and the switch portions enter an input state. However, the activating section  3  may have a structure other than this.