Abstract:
An operation panel which is applicable to an electronic device includes: a display having a plurality of display regions; a plurality of operating buttons connected to the display regions; a plurality of lights which illuminate the display regions; a timer which is adapted to detect whether or not a predetermined period has passed after any of the operating buttons is operated; and a control unit which is adapted to turn off or darken the lights in series each time the timer detects a passage of the predetermined period.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an operation panel which is applicable to electronic devices and a method for controlling the display of the operation panel.  
         [0003]     Priority is claimed on Japanese Patent Application No. 2005-74802, filed Mar. 16, 2005, the content of which is incorporated herein by reference.  
         [0004]     2. Description of Related Art  
         [0005]     In electronic devices, an operation panel is generally provided having a plurality of operating buttons performing for various kinds of operations. The operation panel is normally lit by a backlight at a predetermined illuminance. Several technologies to adjust the illuminance of an operation panel in accordance with illumination around the device have been disclosed (see Japanese Unexamined Patent Application, First Publications No. 2001-60080 and No. 2004-202759).  
         [0006]     However, adjustments of the illuminance of the operation panel disclosed in the above publications only depend on a factor which is outside the electronic device such as an illumination condition around the electronic device. Since these technologies do not adjust the illuminance in accordance with information about the electronic device itself, users may feel inconvenience in operation, for example, when using the electronic device in a dark room. In addition, there is a problem in that the electronic device wastes energy because the illuminance of the operation panel does not change until the illumination condition changes even though the electronic device is not operated for a predetermined period.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention has an object to provide an operation panel and a method of controlling a display thereof which are adapted to controlling the size of an illuminated area in accordance with an operating condition.  
         [0008]     The first aspect of the present invention is an operation panel which is applicable to an electronic device including: a display having a plurality of display regions; a plurality of operating buttons connected to the display regions; a plurality of lights which illuminate the display regions; a timer which is adapted to detect whether or not a predetermined period has passed after any of the operating buttons is operated; and a control unit which is adapted to turn off or darken the lights in series each time the timer detects a passage of the predetermined period.  
         [0009]     The second aspect of the present invention is a method of controlling display of an operation panel which is applicable to an electronic device, the operation panel including: a display having a plurality of display regions; a plurality of operating buttons connected to the display regions; and a plurality of lights which illuminate the display regions, the method including: a first step of displaying information on the display; a second step of measuring elapsed time after any of the operating buttons is operated; and a third step of turning off or darkening the lights in series each time the elapsed time reaches a predetermined period.  
         [0010]     Since the present invention controls the size of a display area or illuminated area based on the operating condition of the operation panel, a display which is suitable for the user&#39;s condition can be provided. In addition, frequent control of the size of the display area and illumination contributes to suppressing energy consumption.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a drawing showing an operation panel of a first embodiment of the present invention.  
         [0012]      FIG. 2  is a block diagram showing a display control unit of an electronic device to which the operation panel of the present invention is applied.  
         [0013]      FIG. 3  is an explanatory drawing showing a condition in which an illumination of one display region is turned off.  
         [0014]      FIG. 4  is a flowchart showing a process of the control of the display.  
         [0015]      FIG. 5  is a drawing showing an operation panel of a second embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     Embodiments of the present invention are described hereinbelow with reference to the drawings. In this embodiment, a display area of the operation panel is reduced when a predetermined period has passed after a user operates the operation panel.  
         [0017]      FIG. 1  is a block diagram generally showing an operation panel of a first embodiment of the present invention. In  FIG. 1 , an operation panel  1  has a display having liquid crystal display (LCD). The display is divided into two display regions,  1   a  and  1   b . Each display region has a plurality of operating buttons  2  (touch switches). The operating buttons  2  provided on the display region  1   a , for example, are major buttons which are frequently used, and the operating buttons  2  provided on the display region  1   b  are minor buttons which are not so frequently used.  
         [0018]     In addition, backlights  3   a  and  3   b  which illuminate the respective display regions  1   a  and  1   b  are provided on the edge of a substrate of the operation panel  1 . The light emitted from the backlights  3   a  and  3   b  illuminates the display through a light guide panel (not illustrated) provided on the substrate of the operation panel  1 . Since the operation panel  1  and the backlights  3   a  and  3   b  have an already known structure for attachment, a detailed explanation is omitted.  
         [0019]      FIG. 2  is a block diagram showing a display control unit of the operation panel  1  of the electronic device. The same reference numerals are provided for the elements which are identical to the elements shown in  FIG. 1  and explanations thereof are omitted. In  FIG. 2 , drivers  5  and  6  controls the backlights  3   a  and  3   b  of the operation panel  1 . The drivers  5  and  6  are controlled by a control unit  4 . When any one of the operation buttons  2  is operated, the control unit  4  starts a timer  7  and measures an elapsed time.  
         [0020]     Next, the processing carried out by the above structure is described with reference to  FIG. 4 . In a state in which the electronic device is in operation and the display regions  1   a  and  1   b  are illuminated (this means that the backlights  3   a  and  3   b  are lit herein below) (step S 1 ), when any one of the operation buttons  2  provided in the display regions  1   a  and  1   b  (step S 2 ) is operated, the control unit  4  makes the timer  7  start (step S 3 ). While the timer  7  measures the elapsed time, the display regions  1   a  and  1   b  are illuminated. When any one of the operation buttons  2  is operated (YES in step S 4 ), the process returns to step S 3  and the timer  7  restarts.  
         [0021]     When a predetermined period has passed without further operation (YES in step S 5 ), the display region  1   b  is turned off. At this time, the operation panel  1  is like the one shown in  FIG. 3  (step S 6 ). Then the timer  7  starts (step S 7 ). While the timer  7  measures the elapsed time, only the display region  1   a  is illuminated as shown in  FIG. 3 . When the operation button  2  of the display region  1   b  is operated (YES in step S 8 ), the process returns to step S 1  and the display region  1   b  is illuminated again. When the operation button  2  of the display region  1   a  is operated (YES in step S 9 ), the process returns to step S 7  and the timer  7  restarts. When a predetermined period has passed without further operation (YES in step S 10 ), the display region  1   a  is turned off (step S 11 ).  
         [0022]     As described above, the display regions are reduced when a predetermined period has passed without the user&#39;s further operation in this embodiment. Therefore, energy consumption can be saved based on the operating condition of the electronic device, regardless of the surroundings thereof.  
         [0023]     In this embodiment, although the display regions are adapted to be turned off when a predetermined period has passed without further operation, the display regions may be adapted to be darkened in the aforementioned condition. In addition, although the predetermined period is the same in step S 5  and step S 10  in  FIG. 4 , different periods may be respectively set in these steps. Furthermore, the predetermined period may be set by the user.  
         [0024]     Next, a second embodiment of the present invention is described. This embodiment shows an image forming device such as a copying machine to which the present invention is applied.  
         [0025]      FIG. 5  is a drawing which shows a display of an operation panel  11 . The display is divided into four display regions: a display region for copying function information  1   c , a display region for scanning function information  1   d , a display region for printing function information  1   e , and a display region for facsimile function information If. Backlights  3   c ,  3   d ,  3   e , and  3   f  are also provided in the operation panel  11 . Backlights  3   c ,  3   d ,  3   e , and  3   f  illuminates display regions  1   c ,  1   d ,  1   e , and  1   f , respectively.  
         [0026]     In this embodiment, the display is reduced when a predetermined period has passed after a user operates any one of the operating buttons of the operation panel without further operation, the same as in the first embodiment. Specifically, the image forming device stops power supply to a printer engine unit and shifts to an energy-saving mode when the predetermined period has passed. At the same time, the display region for copying function information  1   c , and the display region for printing function information  1   e  are turned off. The display region for scanning function information  1   d , and the display region for facsimile function information  1   f  are turned off in series as the predetermined period has passed. Although the operating buttons are provided outside the operation panel  1 l in this embodiment, they may be provided in each display region.  
         [0027]     The display region for printing function information  1   e  may be adapted to be turned off (or be darkened) usually, regardless of whether the device is in energy-saving mode or not, and to be illuminated only when receiving print datum and printing.  
         [0028]     The display region for facsimile function information If may be adapted to be turned off (or be darkened) usually, and to be illuminated only when receiving and printing facsimile datum. It may also be adapted to be illuminated and stop energy-saving mode by touching the display region when sending a facsimile.  
         [0029]     In addition, the display region for copying function information  1   c  and the display region for scanning function information  1   d  may also be adapted to be illuminated and stop the energy-saving mode by touching each display region when operating.  
         [0030]     Furthermore, in a case where literal notation is used in each display region  1   c ,  1   d ,  1   e , and  1   f , information may be displayed in a reduced state in the illuminated display regions when the display is reduced by turning off some of the display regions.  
         [0031]     This embodiment makes it possible to provide a display condition based on actual operation of the operation panel to the user of the image forming device. In addition, energy consumption can be saved by reducing illumination of the operation panel.  
         [0032]     While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.