Abstract:
A display control apparatus includes a main body and a display unit with a touch panel. The display control apparatus further includes a memory that stores a plurality of detection condition parameters for detecting a touch operation to the touch panel. The plurality of detection condition parameters are corresponding to each of a plurality of locations or a plurality of orientations of the touch panel. The display control apparatus further includes a state detector that detects a current location or a current orientation of the touch panel. The display control apparatus still further includes a condition selector that selects one of the plurality of detection condition parameters corresponding to the current location or the current orientation. Moreover, the display control apparatus includes a touch determiner that determines a touch to the touch panel by using the selected one of the plurality of detection condition parameters.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Japanese Patent Application No. 2008-079894, filed Mar. 26, 2008, the entire subject matter and disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a display control apparatus including a display unit with a touch panel. 
     2. Description of the Related Art 
     In recent years, a display control apparatus including a display unit with a touch panel having a sensor on a display so as to accept input through a touch operation on a screen of the display with a finger or a special pen is known. Since such a display control apparatus allows input operations by directly touching the screen, a direct and intuitive operation may be performed while visually identifying the screen. 
     Various types of touch panels included in display units with a touch panel are known. One type of the touch panel includes a capacitance touch switch using a capacitance sensor. The switch detects operational input while changing detection sensitivity from a high to low level. A touch operation may be reliably detected even when a thick glove is worn or when a finger is not covered by a glove. 
     The known display control apparatus including a display unit with a touch panel may intends to reliably detect a touch operation to a touch panel on the assumption that an installation location of a display unit with the touch panel in a display control apparatus is fixed. Specifically, sensitivity of a capacitance sensor is adjusted to compensate for a difference in a capacity change caused by existence of a glove etc. covering a finger reaching to the touch panel or thickness and material of the glove etc. being worn. 
     However, in a display control apparatus which allows a display unit with a touch panel to be connected to a plurality of locations on the display control apparatus or in different orientations, a direction and an amount of displacement of a contact area and a position of a finger during a touch operation generally differ for each installation location or each orientation of the display unit with the touch panel. For example, when a touch panel standing at an angle to a horizontal surface is operated from above, a contact area of a finger during a touch operation may become smaller than that on a touch panel placed flat on the horizontal surface. Moreover, when the touch panel is placed at a location higher or lower than an eye line of an operator, a contact position of the finger during the touch operation may be lower or higher than an intended contact position of the finger. 
     According to the known display control device, conditions such as a detection region and a detection area to detect the touch operation are fixed regardless of the installation location or the orientation of the touch panel. Therefore, the difference in the contact area of the finger or the displacement of the contact position during such a touch operation may cause a problem of not being able to reliably detect a touch operation on the display control apparatus which allows the display unit with a touch panel to be connected to a plurality of locations on the display control apparatus or in different orientations. 
     SUMMARY 
     A need has arisen to provide a display control apparatus which may increase reliability of detecting touch operations irrespective of the location or the orientation of the display unit with the touch panel connected to the display control apparatus. 
     A display control apparatus according to an embodiment of the invention comprises a main body and a display unit. The display unit includes a touch panel capable of being disposed at a plurality of locations or in a plurality of orientations with respect to the main body. The display control apparatus further comprises a memory that stores a plurality of detection condition parameters for detecting a touch operation to the touch panel. The plurality of detection condition parameters are corresponding to each of the plurality of locations or the plurality of orientations. The display control apparatus further comprises a state detector that detects a current location of the touch panel among the plurality of locations or a current orientation of the touch panel among the plurality of orientations. The display control apparatus still further comprises a condition selector that selects one of the plurality of detection condition parameters, corresponding to the current location or the current orientation detected by the state detector, from the plurality of detection condition parameters stored in the memory. Moreover, the display control apparatus comprises a touch determiner that determines a touch to the touch panel by using the selected one of the plurality of detection condition parameters. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a display control apparatus in accordance with first embodiment; 
         FIG. 2  shows a system structure of first embodiment; 
         FIG. 3  shows a flow chart indicating a processing of detection condition parameters; 
         FIG. 4  shows detection regions of the touch panel; 
         FIG. 5  shows an example of a table of the detection condition parameters of the touch operations according to a location; 
         FIG. 6  shows a partial perspective view of the display control apparatus in accordance with second embodiment; 
         FIG. 7  shows a system structure of second embodiment; 
         FIG. 8  shows a flow chart indicating a processing of detection conditions of the touch operations according to an orientation of the liquid crystal touch panel unit; and 
         FIG. 9  shows an example of a table of the detection condition parameters of the touch operations according to an orientation. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows the outer structure of a display control apparatus  1  in accordance with first embodiment.  FIG. 2  shows the system structure of the display control apparatus  1 . A liquid crystal touch panel unit  31  can be connected to a plurality of locations on the display control apparatus  1 . 
     The display control apparatus  1  includes a printer unit  2 , such as an ink-jet printer, and a scanner unit  3  at a lower part and an upper part of a frame. The liquid crystal touch panel unit  31  equipped with an electrostatic sensor  35  on a liquid crystal display section  36  is placed in the center of an operation panel section  4 , that is a location ( 1 ). In this embodiment, three more locations of the liquid crystal touch panel unit  31  are provided in addition to the location ( 1 ). The three locations include, at the lower front face of the frame, a location ( 2 ) located in the upper center part of the front face, a location ( 3 ) located in the left part of the front face, and a location ( 4 ) located in the right part of the front face. The liquid crystal touch panel unit  31  is removable and can be disposed at any of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ). 
     Input keys  40  include a power key for instructing the display control apparatus  1  to be turned on, for example. Various instructions can be given to the display control apparatus  1  by operating the input keys  40 . 
     The system structure of the display control apparatus  1  will now be described with reference to  FIG. 2 .  FIG. 2  shows an example of a system structure of the display control apparatus  1 . An ASIC (Application Specific Integrated Circuit)  26  centrally performs control processing in order to perform various kinds of functions of the display control apparatus  1  in accordance with instructions from a CPU  21 . The ASIC  26  is connected to a ROM  22 , a RAM  23 , and a MODEM  34  via an external bus  25 . An NCU  33  is connected to the MODEM  34 . The printer section  2  and the scanner section  3  are connected to the ASIC  26 . The input keys  40  are connected to the ASIC  26  via a panel gate array (panel GA)  27 . The panel gate array (panel GA)  27  controls operations for sending key signals to the ASIC  26  in accordance with operation of the input keys  40 . 
     The liquid crystal touch panel unit  31  includes an electrostatic sensor  35  including transparent electrodes (not shown) and the liquid crystal display section  36  disposed under the electrostatic sensor  35 . The liquid crystal touch panel unit  31  is connected to any one of connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49 , each of which is provided for each of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ) respectively. The connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49  are connected to a display control portion  28 , a touch detection portion  29 , and a location detector  45  provided within the ASIC  26 . The display control portion  28 , the touch detection portion  29 , and the location detector  45  are connected to the CPU  21 . Location sensors ( 1 )  41 , ( 2 )  42 , ( 3 )  43  and ( 4 )  44  are connected to the connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49 , respectively. 
     The electrostatic sensor  35  of the liquid crystal touch panel unit  31  is connected to the touch detection portion  29  via any one of the connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49 . The liquid crystal display section  36  of the liquid crystal touch panel unit  31  is connected to the display control portion  28  via any one of the connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49 . The location sensors ( 1 )  41 , ( 2 )  42 , ( 3 )  43  and ( 4 )  44  are connected to the location detector  45  via the connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49 , respectively. When a user touches a desired position on the electrostatic sensor  35  while looking at the display of the liquid crystal display section  36 , the touch detection portion  29  detects touched coordinates and outputs a touch position signal to the CPU  21 . 
     In this process, the touch detection portion  29  detects touch operations on the basis of detection sensitivities and detection regions which are set according to the location of the liquid crystal touch panel unit  31  detected by the location sensor ( 1 )  41 , ( 2 )  42 , ( 3 )  43  and ( 4 )  44  and the location detector  45 . A program for selecting one of detection condition parameters of the touch operations in accordance with the location of the liquid crystal touch panel unit  31  will be mentioned later. 
     The display control portion  28  controls the screen display of the liquid crystal display section  36  in accordance with the instructions from the CPU  21  in order to display various kinds of information related to the functions performed by the display control apparatus  1  on the liquid crystal display section  36 . 
     The location detector  45  detects that each of the connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49  is connected to the liquid crystal touch panel unit  31  on the basis of the signal from each of the location sensors ( 1 )  41 , ( 2 )  42 , ( 3 )  43  and ( 4 )  44  respectively. 
     The NCU (Network Control Unit)  33  is connected to the MODEM  34  to control facsimile communication. The MODEM  34  is connected to the ASIC  26  via the external bus  25 . 
     The ROM  22  stores various kinds of execution programs and data. An example of one of the execution programs is a program for selecting the detection conditions of the touch operations according to the location of the liquid crystal touch panel unit  31  (shown in  FIG. 3 ). An example of the data is a table of detection condition parameters for detecting the touch operations according to the location of the liquid crystal touch panel unit  31 . 
     The RAM  23  is a workspace to load the execution program and maintain calculated result data obtained while executing the program or as a result of a program execution when the CPU  21  executes the various kinds of execution programs stored in the ROM  22 . 
     Hereinafter, operations of the program for selecting one of the detection condition parameters of the touch operations according to the location of the liquid crystal touch panel unit  31  will be described (shown in  FIG. 3 ). 
     The location of the liquid crystal touch panel unit  31  of the display control apparatus  1  can be changed to any one of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ) when no electric power is supplied. Upon power-up, the program for selecting one of the detection condition parameters of the touch operation according to the location of the liquid crystal touch panel unit  31  shown in  FIG. 3  is activated and detects the location of the touch panel  31  in order to select one of the detection condition parameters of the touch operation according to the detected location. 
     When the program is activated, the location sensors ( 1 )  41 , ( 2 )  42 , ( 3 )  43  and ( 4 )  44  and the location detector  45  determine the location of the liquid crystal touch panel unit  31  (S 11 ). Subsequently, the CPU  21  judges whether the detected location is the same as the previous location (S 12 ). For example, in Step (S 12 ), the latest location is always maintained at a storage area (not shown) which is not erased even if the power is turned off, and upon power-up the previous location is compared with the location determined when activating the program. When the locations are different (S 12 : NO), one the detection condition parameters, e.g., a detection threshold (an example of a parameter of sensitivity) and detection region which are set for the corresponding location are selected and read from the table (shown in  FIG. 5 ) of the detection condition parameters of the touch operation, according to the locations, stored in the ROM  22  (S 13 ). 
       FIG. 5  shows an example of a detection condition parameter table for the touch operations for each of the locations.  FIG. 4  shows an example of a detection region map for the electrostatic sensor  35  of a button displayed on the liquid crystal display section  36 . In  FIG. 4 , a display region of one button is divided into eight regions (A), (B), (C), (D), (E), (F), (G) and (H) in order to control the detection region of the touch operations. The detection region herein means a region in which detection of touch operations is to be performed, and the electrostatic sensor  35 , for example, is placed at each section of the region. By selecting the detection condition parameter for one region or by combining a plurality of the regions, the detection region of the touch operations for the same button can be changed. Moreover, concerning the touch operations performed at each of the region, the sensitivity for the touch operation can be adjusted by changing a threshold signal level to detect electric information, such as a voltage, outputted from the electrostatic sensor provided at each section of the region. 
     In  FIG. 4 , the sections (C) and (D) located in the center of the display region of the button are assigned areas larger than the other sections (A), (B), (E), (F), (G), and (H) of the region. Assigning larger areas to the sections (C) and (D) in the center of the region is considered reasonable since users are expected to touch the center of the display region when touching the button. 
     In  FIG. 5 , the values  20 ,  50 ,  50 , and  50  are stored as a detection threshold level of the touch operations for each of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ). A lower detection threshold level herein means that lower signal levels can be detected and that the detection sensitivity is high. Moreover, two types of settings are stored for the detection region. In a first setting, four regions (E), (F), (G) and (H) located at the lower part of the display position of the button are set as the detection region of the location ( 1 ) and four regions (C), (D), (E) and (F) located in the center of the display position of the button are set as the detection region of the locations ( 2 ), ( 3 ) and ( 4 ). In a second setting, six regions (C), (D), (E), (F), (G) and (H) from the center to the lower part of the display position of the button are set as the detection region of the location ( 1 ) and four regions (C), (D), (E) and (F) in the center of the display position of the button are set as the detection region of the locations ( 2 ), ( 3 ) and ( 4 ). Thus, the first setting provides the detection region with different positions according to the locations. In addition, the second setting provides the detection region with different positions and sizes according to the location. In this manner, the detection region may be selected as a detection condition parameter for the process at Step (S 13 ) as shown in the first setting. Moreover, the detection region may be selected as shown in the second setting. In addition, a choice of whether to use the first or second setting may be given to users. 
     The table of  FIG. 5  shows a table of the detection condition parameters. Higher detection sensitivity is provided and the detection region is shifted to the front side of the display control apparatus  1  at the location ( 1 ) (in the case of the first setting) or a larger detection region is set (in the case of the second setting). 
     When the determined location is the same as the previous location (S 12 : YES), the CPU  21  judges whether the process is performed upon power-up (S 14 ). When the process is performed upon power-up (S 14 : YES), the previous detection condition parameter is read from the table ( FIG. 5 ) according to the location. 
     The detection condition read at Step (S 13 ) or Step (S 15 ) is maintained at the RAM  23  (S 16 ) and may also be stored in a non-volatile memory (not shown). 
     Then, while the process of the display control apparatus  1  is continued, the location detector  45  detects whether the location of the liquid crystal panel unit  31  has been changed with the electric supply to the display control apparatus  1  maintained (S 17 ). This can be detected if the electric supply to the liquid crystal panel unit  31  and the connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49  thereof is configured to be temporarily stopped while the electric supply to the body of the display control apparatus  1  is maintained. 
     If a change of the location is detected (S 17 : YES), the CPU  21  returns to Step (S 11 ) and reads again the connection condition corresponding to the location. While no change of the location is recognized (S 17 : NO), the process for detecting a change of the location is continued (S 17 ). 
     Next, second embodiment of the display control apparatus  1  will be described. A function to change a gradient angle (an example of an orientation) of a liquid crystal touch panel unit  31  when being connected to the display control apparatus  1  is provided. That is, the gradient angle can be changed when the liquid crystal touch panel unit  31  is connected. 
       FIG. 6  shows the liquid crystal touch panel unit  31  located at the operation panel section  4  of the display control apparatus  1  in a standing state. The gradient angle θ to the operation panel section  4  can be freely adjusted by users. Descriptions of an electrostatic sensor  35  and a liquid crystal display section  36  are the same as those of first embodiment (shown in  FIG. 1 ) and, therefore, will be omitted. 
     The system structure of the display control apparatus  1  of second embodiment will now be described with reference to  FIG. 7 . The system structure of  FIG. 7  includes a gradient angle detector  37  in place of the location detector  45  provided at the ASIC  26  in the system structure of first embodiment shown in  FIG. 2 , and an angle sensor  30  built in the liquid crystal touch panel unit  31  in place of the connection portions  46 ,  47 ,  48  and  49  and the location sensors  41 ,  42 ,  43  and  44 . The liquid crystal display section  36 , the electrostatic sensor  35 , and the angle sensor  30  built in the liquid crystal touch panel unit  31  are connected to a display control portion  28 , a touch detection portion  29 , and the angle detector  37 , respectively. Other structures are the same as those of the system structure of first embodiment (shown in  FIG. 2 ) and, therefore, descriptions thereof will be omitted herein. 
     The liquid crystal touch panel unit  31  is located at the operation panel section  4  of the display control apparatus  1  in a standing state, and the gradient angle θ is adjustable. 
     The electrostatic sensor  35  of the liquid crystal touch panel unit  31  is connected to the touch detection portion  29 . The liquid crystal display section  36  of the liquid crystal touch panel unit  31  is connected to the display control portion  28 . The angle sensor  30  of the liquid crystal touch panel unit  31  is connected to the angle detector  37 . The angle sensor  30  may include a volume (not shown) that outputs a voltage corresponding to the gradient angle θ. The volume may comprises one of axes about which the liquid crystal touch panel unit  31  is rotates. When a user touches a desired position on the electrostatic sensor  35  while looking at the display of the liquid crystal display section  36 , the touch detection portion  29  detects the touched coordinates and outputs a position signal to a CPU  21 . 
     In this process, the touch detection portion  29  detects touch operations on the basis of the detection sensitivity and the detection region which have been set in accordance with the gradient angle θ of the liquid crystal touch panel unit  31  detected by the angle sensor  30 . A program for selecting one of the detection condition parameters (shown in  FIG. 8 ) of the touch operations according to the gradient angle θ (an example of an orientation) of the liquid crystal touch panel unit  31  will be mentioned later. 
     Hereinafter, the program for selecting one of the detection condition parameters of the touch operations according to the gradient angle θ of the liquid crystal touch panel unit  31  will be described (shown in  FIG. 8 ). In first embodiment (shown in  FIG. 3 ), the one of the detection condition parameters of the touch operation is selected according to the location of the liquid crystal touch panel unit  31 . In the flowchart of  FIG. 8 , the one of the detection condition parameters is selected according to the gradient angle θ (an example of an orientation) in place of the location of the liquid crystal touch panel unit  31 . 
     The gradient angle θ of the liquid crystal touch panel unit  31  of second embodiment can be appropriately changed. When the program is activated upon power-up etc., the angle detector  37  determines the gradient angle θ of the liquid crystal touch panel unit  31  (S 21 ). Subsequently, the CPU  21  judges whether the determined gradient angle θ is the same as the previous gradient angle θ (S 22 ). When the gradient angles θ are different (S 22 : NO), the detection conditions concerning the detection threshold (sensitivity) and the detection region which are set for the corresponding gradient angle θ are selected and read (S 23 ) from the table (shown in  FIG. 9 ) of the detection condition parameters of the touch operations, in accordance with the gradient angle θ, stored in the ROM  22 . 
       FIG. 9  shows an example of the table of detection condition parameters of the touch operation for each of the gradient angles θ. The gradient angles θ of range from 10 degrees to 90 degrees and the values from 70 to 20 as the detection threshold levels of the touch operation are stored. Moreover, two types of settings are stored for the detection region. In a first setting, four regions (E), (F), (G) and (H) located at the lower pair of the display position of the button are set as the detection region when the gradient angles θ are 10 degrees and 20 degrees, and four regions (C), (D), (E) and (F) in the center of the display position of the button are set as the detection region when the gradient angles θ are 40 degrees and 60 degrees, and four regions (A), (B), (C) and (D) located at an upper part of the display position of the button is set as the detection region when the gradient angles θ are 80 degrees and 90 degrees. In a second setting, four regions (E), (F), (G) and (H) located at the lower part of the display position of the button are set as the detection region when the gradient angles θ are 10 degrees and 20 degrees, and four regions (C), (D), (E) and (F) in the center of the display position of the button are set as the detection region when the gradient angle θ is 40 degrees, and six regions (C), (D), (E), (F), (G) and (H) from the center to the lower part of the display position of the button are set as the detection region when the gradient angle θ is 60 degrees, and six regions (A), (B), (C), (D), (E) and (F) from the upper part to the center of the display position of the button are set as the detection region when the gradient angles θ are 80 degrees and 90 degrees. Thus, in the same manner as in first embodiment, the first setting provides the detection region with different positions in accordance with the gradient angle. In addition, the second setting provides the detection region with different positions and sizes in accordance with the gradient angle. In this manner, the detection region may be selected as detection condition parameters at Step (S 23 ) as shown in the first setting. Moreover, the different positions and sizes of the detection region may be set as shown in the second setting. In addition, a decision of whether to use the first or second setting may be given to users. 
     The table of  FIG. 9  shows detection conditions under which the touch operations are assumed to be ineffective as the gradient angle θ of the liquid crystal touch panel unit  31  increases and the touch positions are assumed to be focused on the upper part of the button display. As the gradient angle θ increases, a higher detection sensitivity is provided, and at the same time, the detection region is shifted to the upper side of the button display (in the case of the first setting), or the detection region is shifted to the upper side of the button display, and at the same time, a larger detection region is set (in the case of the second setting). 
     When the determined gradient angle θ is the same as the previous gradient angle θ (S 22 : YES), the CPU  21  judges whether the process is performed upon power-up (S 24 ). When the process is performed upon power-up (S 24 : YES), the previous detection condition is read from the table (shown in  FIG. 9 ) in accordance with the gradient angle θ. 
     The detection condition read at Step (S 23 ) or Step (S 25 ) is maintained in the RAM  23  (S 26 ) and may also be stores in a non-volatile memory (not shown). 
     Then, while the process of the display control apparatus  1  is continued, the angle detection section  37  detects whether the gradient angle θ of the liquid crystal panel unit  31  has been changed with the electric supply to the display control apparatus  1  maintained (S 27 ). In second embodiment, although the electricity can be supplied to the liquid crystal panel unit  31  and the connection portion  32  thereof while the electric supply to the body of the display control apparatus  1  is maintained, the electric supply to the liquid crystal panel unit  31  and the connection portion  32  thereof may be temporarily stopped while the electric supply to the body of the display control apparatus  1  is maintained. 
     If a change of the gradient angle θ is detected (S 27 : YES), the CPU returns to Step (S 21 ) and reads again one of the detection condition parameters corresponding to the gradient angle θ. While no change of the gradient angle θ is recognized (S 27 : NO), the process for detecting a change of the gradient angle θ is continued (S 27 ). 
     As described in detail above, according to first embodiment, when the liquid crystal touch panel unit  31  can be connected to a plurality of locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ), the table (shown in  FIG. 5 ) of the detection condition parameters of the touch operation according to the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ) is stored at the ROM  22 ; therefore, the detection sensitivity (threshold level of signals) of the touch operation and the detection region on the button display to accept touch inputs, etc. can be optimized for the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ) of the liquid crystal touch panel unit  31 . Even when characteristics of the touch operation are different for each of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ), the touch operations can be reliably detected irrespective of the difference of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ). Therefore, the operability of the touch panel in the display control apparatus may be improved. 
     In this case, the display control apparatus  1  is provided with a plurality of connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49 , to which the liquid crystal touch panel unit  31  can be connected. Thereby, the location of the liquid crystal touch panel unit  31  can be detected based on which of the connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49  is connected. 
     In this case, the detection condition parameter, e.g., the detection threshold (sensitivity) and the detection region which are set for each of the detected location is selected and read from the table (shown in  FIG. 5 ) of the detection condition parameters of the touch operation, in accordance with the locations, stored in the ROM  22 . In the display control apparatus  1  which allows the liquid crystal touch panel unit  31  to be connected to a plurality of connection portions ( 1 )  46 , ( 2 )  47 , ( 3 )  48  and ( 4 )  49 , the location of the liquid crystal touch panel unit  31  is automatically detected and one of the plurality of detection condition parameters is set according to the location; therefore, the touch operation may be reliably detected irrespective of the location of the liquid crystal touch panel unit  31 . 
     In addition, according to second embodiment, when the gradient angle θ of the liquid crystal touch panel unit  31  can be changed, the table (shown in  FIG. 9 ) of the detection condition parameters of the touch operation according to the gradient angle θ is stored in the ROM  22 ; therefore, the detection sensitivity (threshold level of signals) in the touch operations and the detection region on the button display to accept touch inputs, etc. can be optimized on the basis of the gradient angle θ of the liquid crystal touch panel unit  31 . Even when characteristics of the touch operations are different for each of the gradient angles θ, the touch operations may be reliably detected irrespective of the difference in the gradient angle θ. Therefore, the operability of the touch panel in the display control apparatus may be improved. 
     In this case, the detection condition parameters, e.g., the detection threshold (sensitivity) and the detection region for the detected gradient angle θ is selected and read from the table (shown in  FIG. 9 ) of the detection condition parameters of the touch operation, in accordance with the gradient angle θ, stored in the ROM  22 . The display control apparatus  1  (shown in  FIG. 6 ) which allows the liquid crystal touch panel unit  31  to be located at the operation panel section  4  of the display control apparatus  1  in a standing state automatically detects the gradient angle θ of the liquid crystal touch panel unit  31  and selects the one of detection condition parameters according to the gradient angle θ; therefore, the touch operations may be reliably detected irrespective of the gradient angle θ of the liquid crystal touch panel unit  31 . 
     As to the display button of the liquid crystal touch panel unit  31  in first and second embodiments, the display region is divided into a plurality of sections (for example, eight regions (A), (B), (C), (D), (B), (F), (G) and (H)) to control the detection region of the touch operations. An electrostatic sensor, for example, is placed at each region. By setting the detection condition with one region or by combining the regions, the position and dimensions of the detection region of the touch operation for the same button can be changed. Moreover, concerning the touch operation performed at each region, the sensitivity for the touch operation can be adjusted by changing the threshold signal level to detect electric information, such as a voltage, outputted from the electrostatic sensor provided at each region. 
     By absorbing differences in the characteristics of the touch operation caused by differences in the connection states during the touch operation, position information corresponding to the detection information appropriate for each state can be selected and set even when contact areas, contact conditions, etc. of fingers touching the liquid crystal touch panel unit  31  are different irrespective of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ) of the liquid crystal touch panel unit  31  or the orientation, e.g., the gradient angle θ. In addition, the detection region can be appropriately selected and set. Therefore, the touch operation may be reliably detected irrespective of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ) of the liquid crystal touch panel unit  31  or the gradient angle θ. 
     Moreover, by compensating for differences in the strength of the detection signals caused by differences in the characteristics of the touch operation, the touch operation may be reliably detected irrespective of the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ) of the liquid crystal touch panel unit  31  or the gradient angle θ. 
     The display control apparatus  1  which may includes both the locations ( 1 ), ( 2 ), ( 3 ) and ( 4 ) and the structure to detect the orientation, e.g., the gradient angle θ, and the one of detection condition parameters may be selected based both on the location and the orientation. 
     Moreover, in  FIG. 4 , although the detection region of the display button is divided into eight regions and the regions in the center are given larger areas, the number of regions of the button display and the size of each region can be appropriately changed. 
     In addition, setting of the threshold levels and setting of the detection region in the tables (in  FIG. 5  and  FIG. 9 ) can be appropriately optimized. Furthermore, a plurality of other detection condition parameters may be stored in the tables in addition to the first and second settings to allow users to select desired parameters. Moreover, statistics of touch positions, touch areas, and optimal touch sensitivities of the touch operations by users may be gathered to automatically change the settings based on the statistics. Thereby, misoperations of the touch panel may decrease and the operability may be improved.