Portable terminal

Abstract

To provide a configuration that, even if the movement of a finger during an input operation on a keypad is peeped, makes it difficult to infer input information.SOLUTION: A storage unit 22 stores information for specifying a replaced character arrangement obtained by making the arrangement of at least some of the characters different from the key character arrangement of characters applied to keys of a numeric key 32 on a keypad 31, and a display unit 24 can be controlled so that, during a password input operation using the numeric key 32, a character arrangement image Pa corresponding to the replaced character arrangement is displayed superimposed on a part of a log-in image displayed on a display screen 24a. When any one key of the numeric key 32 is operated during the password input operation, input is received of a character on the replaced character arrangement corresponding to a character of the key on the key character arrangement.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a mobile terminal into which highly confidential information is input. [Background technology]

[0002] Conventionally, there are cases where highly confidential information such as passwords is input using the keypad of a mobile terminal. Since the keypad of a mobile terminal basically has the same arrangement, there is a problem that the input information can be easily guessed from the finger movement of the user when performing the input operation.

[0003] As a technique for solving such a problem, for example, a personal identification number input device disclosed in the following Patent Document 1 is known. In this personal identification number input device, a number arrangement image that is randomly rearranged so as to be different from the number arrangement printed on the numeric keypad is prepared, and when a personal identification number is input, the display state is switched to a screen that displays the number arrangement image. In this state in which the number arrangement image is displayed, input processing is performed so that when a key input operation is performed, a number in the number arrangement image corresponding to the arrangement of the key is input. As a result, since the number printed on the input key differs from the number actually input, even if the movement of the fingers during the input operation is peeked at, it is possible to make it difficult for a third party who does not know the number arrangement image to guess the input information. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-199581 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in many cases, due to miniaturization and other reasons, mobile terminals are configured so that the keypad and the display screen are located close to each other, which may allow someone to peek at the screen that displays the number layout image along with the finger movements during input operations. If this happens, a third party who peeks at both may be able to grasp the relationship between the keys operated for input and the numbers actually entered, and may be able to guess the input information.

[0006] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a configuration that makes it difficult to guess input information even if someone observes the movement of fingers during input operations on a keypad. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides A keypad (31) having a plurality of keys arranged thereon for inputting characters; a storage unit (22) for storing information specifying a replacement character arrangement in which at least some of the characters are arranged differently from the key character arrangement of the characters assigned to each key of the keypad; A display unit (24) for displaying information used in character input operations on a display screen (24a); a display control unit (21) capable of controlling the display unit so that a character arrangement image (Pa) corresponding to the replacement character arrangement is displayed over at least a portion of a predetermined display image displayed on the display screen during a predetermined character input operation using the keypad; an input control unit (21) that, when any key of the keypad is operated during the predetermined character input operation, accepts input of a character in the replacement character arrangement corresponding to the character in the key character arrangement of the key; A processing unit (21) that performs processing using the character string received by the input control unit; The present invention is characterized by comprising: The symbols in parentheses above indicate the corresponding relationship with the specific means described in the embodiments described later. Effect of the Invention

[0008] In the present invention, information specifying a replacement character arrangement in which at least some of the characters are arranged differently from the key character arrangement of the characters assigned to each key of the keypad is stored in a storage unit, and during a predetermined character input operation using the keypad, the display control unit can control the display unit to display a character arrangement image corresponding to the replacement character arrangement superimposed on at least a part of a predetermined display image displayed on the display screen. Then, when any key on the keypad is operated during the predetermined character input operation, input of a character in the replacement character arrangement corresponding to a character in the key character arrangement of the key is accepted by the input control unit.

[0009] As a result, during a predetermined character input operation for inputting highly confidential information such as a password, input of characters in a replacement character arrangement corresponding to characters in the key character arrangement of the input key is accepted, so that the characters attached to the keys inputted on the keypad can be made different from the characters actually input. In particular, since the character arrangement image corresponding to the replacement character arrangement is displayed superimposed on at least a part of the predetermined display image, even if the display screen is peeked at together with the finger movement during the input operation, it is difficult to accurately view the character arrangement image. Therefore, even if the finger movement during the input operation on the keypad is peeked at, it is difficult to guess the input information, and a mobile terminal with improved security can be realized.

[0010] The character arrangement image may be displayed over the predetermined display image so as to make at least a part of the image transparent. This makes it even more difficult for a third party trying to peek at the image to see the character arrangement image, thereby further improving security. In particular, since the user can see the predetermined display image through the character arrangement image, the user can perform input operations while checking the display contents of the predetermined display image, thereby improving security and convenience of input operations.

[0011] The display control unit may control the display unit so as to be able to switch between a state in which the character arrangement image is displayed and a state in which the character arrangement image is not displayed in response to a predetermined instruction made during a predetermined character input operation. Thereby, when the user remembers the character arrangement image, etc., the character arrangement image can be made non-displayable, so that the security can be further enhanced. Also, when it is desired to check the character arrangement image, etc., the character arrangement image can be temporarily displayed, so that both improvement in security and improvement in convenience regarding the input operation can be achieved.

[0012] The display control unit may control the display unit so as to be able to display information regarding the replacement character arrangement in a state where the character arrangement image is not displayed. Thereby, even in a state where the character arrangement image is not displayed, only a user who can recall the corresponding character arrangement image from the information regarding the replacement character arrangement displayed on the screen can perform the input operation correctly, so that the security can be further enhanced.

[0013] When the input of characters is accepted by the input control unit using one selected from among a plurality of types of replacement character arrangements stored in the storage unit, the display control unit may control the display unit so as to be able to display information regarding the selected replacement character arrangement in a state where the character arrangement image is not displayed. Thereby, even if a plurality of types of replacement character arrangements are prepared to improve security, only a user who can recall the corresponding character arrangement image from the information regarding the replacement character arrangement displayed on the screen can perform the input operation correctly, so that the security can be further enhanced.

[0014] The replacement character arrangement is set to replace the key character arrangement according to a predetermined replacement rule, and the display control unit may control the display unit so as to be able to display information regarding the predetermined replacement rule in a state where the character arrangement image is not displayed. Thereby, not only can a plurality of types of replacement character arrangements be prepared to follow the predetermined replacement rule, but also only a user who can recall the corresponding character arrangement image from the information regarding the predetermined replacement rule displayed on the screen can perform the input operation correctly, so that the security can be further enhanced.

[0015] The processing unit may perform a predetermined process as a failure of password authentication when the character string accepted by the input control unit does not match the predetermined password stored in the storage unit and when the pre-substitution character string corresponding to the input characters in the key character arrangement of the character string does not match the predetermined password. This makes it possible to prevent a predetermined process, such as an operation lock process, from being performed as a failure of password authentication even if a correct password is mistakenly input in the conventional key character arrangement instead of the substitution character arrangement.

[0016] The device may further include a notification unit that issues a predetermined notification when the pre-replacement character string matches a predetermined password. This allows a user who receives the notification to easily understand that although the correct password has been input using the conventional key character arrangement, the correct password is not input using the replacement character arrangement, and therefore password authentication is unsuccessful. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a front view of the mobile terminal according to the first embodiment. [Diagram 2] FIG. 2 is a side view of the mobile terminal of FIG. [Diagram 3] 2 is a block diagram illustrating an example of an electrical configuration of the mobile terminal of FIG. 1. [Figure 4] FIG. 4(A) is an explanatory diagram for explaining the key character arrangement of the numeric keypad in FIG. 1, and FIG. 4(B) is an explanatory diagram for explaining a character arrangement image of a replacement character arrangement corresponding to FIG. 4(A). [Diagram 5] FIG. 2 is an explanatory diagram illustrating a display example of a character arrangement image in the first embodiment. [Figure 6] FIG. 11 is an explanatory diagram for explaining a display example of a character arrangement image in the second embodiment. [Figure 7] FIG. 13 is an explanatory diagram illustrating a display example of a character arrangement image in a modified example of the second embodiment. [Figure 8]FIG. 8(A) is an explanatory diagram for explaining the key character arrangement of the numeric keypad in the third embodiment, and FIG. 8(B) is an explanatory diagram for explaining the character arrangement image of the replacement character arrangement corresponding to FIG. 8(A). [Figure 9] FIG. 13 is an explanatory diagram illustrating a display example of a hint display in the third embodiment. [Figure 10] 13 is a flowchart illustrating the flow of a key input acceptance process according to a modified example of the third embodiment. [Figure 11] FIG. 13 is an explanatory diagram illustrating a display example of a hint display in the fourth embodiment. [Figure 12] FIG. 12(A) is an explanatory diagram for explaining the key character arrangement of the numeric keypad in the fourth embodiment, and FIG. 12(B) is an explanatory diagram for explaining the character arrangement image of the replacement character arrangement corresponding to FIG. 12(A). [Figure 13] FIG. 13 is an explanatory diagram illustrating an example of highlighting a hint display in the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] [First embodiment] Hereinafter, a first embodiment of a mobile terminal according to the present invention will be described with reference to the drawings. The mobile terminal 10 according to this embodiment is configured as a mobile information reading device that optically reads information codes such as barcodes, QR codes (registered trademark), etc. As shown in Fig. 1 and Fig. 2, the mobile terminal 10 has an outer shell formed by a housing 11, and various electronic components are housed inside the housing 11.

[0019] 1, a display screen 24a is disposed on one longitudinal end (top side) of a surface 11a of a housing 11, and a keypad 31 is disposed on the other longitudinal end (bottom side). The keypad 31 is configured by arranging a plurality of physical keys, such as numeric keys and function keys, for inputting characters, etc. Characters corresponding to a general key character arrangement are provided on the top surface of each key of the keypad 31 by printing or the like.

[0020] As shown in FIG. 2, a reading port 12 for taking in reflected light from the information code into the housing 11 is provided at one longitudinal end of the back surface 11b of the housing 11, and a cover 13 for closing an accommodation port for inserting and removing the battery is attached to the other longitudinal end.

[0021] As shown in FIG. 3, the mobile terminal 10 includes a control unit 21 consisting of a CPU or the like, a memory unit 22 consisting of a semiconductor memory or the like, an imaging unit 23 configured as a camera for imaging an information code or the like through the reading port 12, a display unit 24 in which information to be used for character input operations is displayed on a display screen 24a, an alarm unit 25 including light-emitting elements such as LEDs, a speaker, a buzzer, etc., the light emission state and alarm state of which are controlled by the control unit 21, an operation unit 30 which outputs signals corresponding to key operations on a keypad 31 or the like to the control unit 21, and a communication unit 26 for communicating with a higher-level device or the like.

[0022] In the control unit 21 of the mobile terminal 10 thus configured, a reading process is performed to decode the information code imaged by the imaging unit 23 through the reading port 12 in response to a predetermined operation on the operation unit 30. The reading result of this reading process is temporarily stored in the storage unit 22 together with related information such as the reading time, and is then transmitted to a higher-level device or the like via the communication unit 26 at a predetermined timing.

[0023] Next, a key input reception process performed by the control unit 21 when inputting a login password (hereinafter, also referred to as a password input operation) will be described. In the mobile terminal 10 according to the present embodiment, in order to prevent third parties other than a designated user from executing a predetermined function, a login image requesting input of a login password is displayed on the display screen 24a in a key input reception process performed by the control unit 21, as shown in FIG. 1. The password input operation corresponds to an example of a "predetermined character input operation" using the keypad 31, and the login image displayed on the display screen 24a during this password input operation can correspond to an example of a "predetermined display image." The above-mentioned predetermined function is a function that should be restricted in the event of unauthorized use by a third party, and is assumed to be, for example, an output process or display process of read information to the outside.

[0024] In this embodiment, as one of the measures against peeping, a replacement character arrangement is prepared for the four-row, three-column keys (hereinafter simply referred to as numeric keypad 32) on which the numbers "0" to "9" and "·" are printed among the keys constituting keypad 31, in which at least some of the characters are arranged differently from the key character arrangement of the printed characters. For example, for the key character arrangement shown in FIG. 4(A), a replacement character arrangement is prepared in which the characters are arranged randomly, as shown in the character arrangement image Pa in FIG. 4(B). The replacement character arrangement is prepared so as to be generated for each password input operation, and information specifying the replacement character arrangement is stored in storage unit 22 each time.

[0025] Then, when any key on the numeric keypad 32 is operated during the key input reception process (when a password is input), the control unit 21 performs an input control process for accepting input of a character in the replacement character arrangement corresponding to a character in the key character arrangement of the relevant key. In the example of FIG. 4, when the key on which "1" is printed is pressed, input of "2" is accepted, and when the key on which "2" is printed is pressed, input of "5" is accepted. In this way, the character attached to the key operated for input on the numeric keypad 32 can be made different from the character actually input. The control unit 21 that performs the above input control process can correspond to an example of an "input control unit".

[0026] For this reason, it is necessary to operate the numeric keypad 32 after grasping the replacement character arrangement, and in this embodiment, a predetermined operation for temporarily displaying the character arrangement image Pa on the screen (hereinafter also referred to as a character arrangement image display operation) is performed on the operation unit 30, and the control unit 21 performs a display control process in which the character arrangement image Pa corresponding to the replacement character arrangement is displayed overlaid on the login image. That is, the character arrangement image Pa is displayed as an overlay on the login image. Note that the character arrangement image display operation can be, for example, a long press of a predetermined function key or a continuous press of a predetermined number of times or more.

[0027] In particular, in this embodiment, as one of further measures against peeking, the character arrangement image Pa is displayed so as to overlap a part of the login image from above. Specifically, for example, the character arrangement image Pa is displayed so as to be arranged in a smaller size with respect to the entire screen range at a position that is the lower left of the login image, as exemplified in Fig. 5. The control unit 21 that performs the display control process can correspond to an example of a "display control unit" that can control the display unit 24.

[0028] If a user can perform the character arrangement image display operation, while the character arrangement image Pa is displayed as described above, the user can operate the numeric keypad 32 to input the login password. For example, if the login password to be input is "1234" and the character arrangement image Pa is displayed as shown in Fig. 5, the user operates the numeric keypad 32 to input "7", "1", "6", and "3" in that order. During this input operation, the character arrangement image Pa is displayed in a reduced size at the bottom left of the login image, so that the user can perform the input operation while checking the contents displayed by the login image.

[0029] By performing the above-described input operation, the input of "1234" is accepted as the login password in the input control process, and password authentication is successful. This allows the user to execute the above-described predetermined functions of the mobile terminal 10. Note that the control unit 21, which performs authentication processing related to password authentication, can correspond to an example of a "processing unit" that performs processing using the character string accepted by the input control process.

[0030] On the other hand, a third party who cannot perform the character arrangement image display operation cannot display the character arrangement image Pa on the screen even if the password is peeked at by the third party, and therefore the password authentication is not successful. Even if the display screen 24a is peeked at in conjunction with the movement of the user's finger during the password input operation, in this embodiment, the character arrangement image Pa is arranged so as to be small at the lower left of the login image. Therefore, a third party who is at an angle or distance from the display screen 24a has difficulty recognizing the existence of the character arrangement image Pa itself, and it is possible to make it impossible to accurately view the arrangement of the characters.

[0031] As described above, in the mobile terminal 10 according to the present embodiment, information specifying a replacement character arrangement in which at least some of the characters are arranged differently from the key character arrangement of the characters assigned to each key of the numeric keypad 32 in the keypad 31 is stored in the storage unit 22, and the display unit 24 can be controlled so that a character arrangement image Pa corresponding to the replacement character arrangement is displayed superimposed on a part of the login image displayed on the display screen 24a during a password input operation using the numeric keypad 32. Then, when any key of the numeric keypad 32 is operated during a password input operation, input of a character in the replacement character arrangement corresponding to a character in the key character arrangement of the key is accepted.

[0032] As a result, input of characters in a replacement character arrangement corresponding to characters in the key character arrangement of the input key is accepted, so that the characters attached to the input key on the numeric keypad 32 can be made different from the characters actually input. In particular, since the character arrangement image Pa is displayed superimposed on a part of the login image, even if the display screen 24a is peeked at together with the finger movement during the input operation, it is difficult to accurately view the character arrangement image Pa. Therefore, even if the finger movement during the input operation on the numeric keypad 32 is peeked at, it is difficult to guess the input information, and a mobile terminal 10 with enhanced security can be realized.

[0033] In particular, in this embodiment, the display unit 24 is controlled to switch between a state in which the character arrangement image Pa is displayed and a state in which the character arrangement image Pa is not displayed, in response to an instruction by a character arrangement image display operation performed during a password input operation. This allows the character arrangement image Pa to be hidden when the user remembers the character arrangement image Pa, thereby further improving security. In addition, when the user wants to check the character arrangement image Pa, the character arrangement image Pa can be temporarily displayed, thereby improving both security and convenience regarding input operations. The instruction by the character arrangement image display operation can be an example of a "predetermined instruction."

[0034] The character arrangement image Pa is not limited to being placed in a small size at the bottom left of the login image, but may be placed in a small size in a display area that is not effectively utilized in the login image, for example, in the bottom right or top left of the login image. Also, the size and position of the character arrangement image Pa may be arbitrarily changeable in response to a predetermined change instruction from a user or the like.

[0035] In addition, the replacement character arrangement is not limited to being randomly generated so that each character is randomly arranged with respect to the key character arrangement for each password input operation, and information specifying the replacement character arrangement generated in advance may be pre-registered in the memory unit 22.

[0036] [Second embodiment] Next, a mobile terminal according to a second embodiment of the present invention will be described with reference to the drawings. The second embodiment differs from the first embodiment mainly in that the character arrangement image Pa is made transparent and displayed on the screen. Therefore, the same components as those in the first embodiment are given the same reference numerals and the description thereof is omitted.

[0037] As shown in FIG. 6, the character arrangement image Pa according to this embodiment is displayed over and transparently on the login image displayed on the display screen 24a.

[0038] This makes it even more difficult for a third party trying to peek at the character arrangement image Pa to see, thereby further improving security. In particular, since the user can see the login image through the character arrangement image Pa, the user can perform input operations while checking the contents displayed by the login image, thereby improving security and convenience regarding input operations.

[0039] The character arrangement image Pa displayed transparently is not limited to being arranged so as to be overlaid from above with an area equivalent to a part of the login image, but may be arranged so as to be overlaid from above with an area equivalent to the entire region of the login image. Also, the character arrangement image Pa may be displayed in a reduced size so as to make at least a part of the login image transparent, as exemplified in Fig. 7. Also, the size and position of the character arrangement image Pa may be configured to be arbitrarily changeable in response to a predetermined change instruction from a user or the like.

[0040] [Third embodiment] Next, a mobile terminal according to a third embodiment of the present invention will be described with reference to the drawings. The third embodiment is different from the first embodiment in that the character arrangement image is not displayed on the screen, but information related to the replacement character arrangement is displayed on the screen. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0041] In this embodiment, the replacement character arrangement is not generated randomly, but a specific pattern is designated by the user or the like, and information for specifying the replacement character arrangement and information related to the replacement character arrangement are registered in advance in the storage unit 22. For this reason, a character arrangement that is easy for the user to remember can be registered in advance.

[0042] When the character arrangement image Pa is not displayed on the screen, information related to the replacement character arrangement is displayed on the login image. This display of information related to the replacement character arrangement is a so-called hint display (hereinafter also referred to as hint display Pb), and can be registered so that the user can recall the character arrangement image corresponding to the replacement character arrangement registered as described above.

[0043] Specifically, for example, the user can register a replacement character arrangement in which the key character arrangement of the numeric keypad 32 shown in Fig. 8(A) is upside down as in the character arrangement image shown in Fig. 8(B). In this case, if the user registers a hint display Pb of "upside down" as a display of information related to the "replacement character arrangement in which the key character arrangement is upside down", the hint display Pb is displayed on the login image during the key input acceptance process, as shown in Fig. 9, without the character arrangement image Pa being displayed on the screen.

[0044] This allows only a user who can recall the corresponding character arrangement image Pa from the hint display Pb displayed on the screen to perform a correct input operation even when the character arrangement image Pa is not displayed, thereby further improving security.

[0045] It should be noted that a plurality of types of substitute character arrangements may be registered. In this case, a different hint display Pb is also registered for each substitute character arrangement and stored in the storage unit 22.

[0046] When character input is accepted during input operation of the numeric keypad 32 using one selected from a plurality of types of replacement character arrangements, a hint display Pb of the selected replacement character arrangement is displayed on the login image during key input acceptance processing without displaying the character arrangement image Pa.

[0047] In this way, even if multiple types of replacement character layouts are prepared to improve security, only a user who can imagine the corresponding character layout image Pa from the hint display Pb displayed on the screen can perform a correct input operation, so that security can be further improved. Note that the hint display Pb may also be controlled so as to be switchable between a state in which the hint display Pb is displayed and a state in which the hint display Pb is not displayed in response to a predetermined instruction from the user.

[0048] As a variation of this embodiment, in the key input reception process, the user may be able to select between a process in which a hint display Pb is displayed with the pre-registered replacement character arrangement not being displayed (a process that is a characteristic configuration of this embodiment), and a process in which a character arrangement image Pa of a randomly generated replacement character arrangement is displayed (a process that is a characteristic configuration of the other embodiments described above).

[0049] That is, as shown in the flowchart of FIG. 10, when the key input reception process is started in the control unit 21, in the judgment process of step S101 of FIG. 10, it is judged whether or not to select a pre-registered replacement character arrangement. Here, when an operation or the like is performed by the user not to select the pre-registered replacement character arrangement (No in S101), a replacement character arrangement is randomly generated as described in the first embodiment and the like (S102). Then, a character arrangement image Pa corresponding to the replacement character arrangement generated as described above is generated so as to be displayable on the screen (S103). Then, when a predetermined character arrangement image display operation is performed (Yes in S104), the character arrangement image Pa is displayed on the screen (S105), and an input control process is performed to accept input of characters in the replacement character arrangement (S106). On the other hand, when the character arrangement image display operation is not performed (No in S104), the character arrangement image Pa is not displayed on the screen, and the input control process is performed (S106). The character arrangement image display operation may include an instruction for the size and position of the character arrangement image Pa, an instruction for transparency, and the like.

[0050] On the other hand, when the user performs an operation to select one of the multiple types of replacement character arrangements that have been preregistered (Yes in S101), information specifying the selected replacement character arrangement and the hint display Pb are read from the storage unit 22 (S107) as described in the present embodiment. Then, the hint display Pb read as described above is displayed on the screen without displaying the character arrangement image Pa on the screen (S108), and an input control process is performed to accept input of characters in the replacement character arrangement (S106). Note that while the hint display Pb is displayed on the screen, the character arrangement image Pa may be temporarily displayed on the screen by performing a character arrangement image display operation or the like.

[0051] In this way, the user can select the display (character arrangement image Pa or hint display Pb) to be overlaid on at least a portion of the login image depending on the usage environment, etc., thereby improving the convenience of the mobile terminal 10 while increasing security.

[0052] [Fourth embodiment] Next, a mobile terminal according to a fourth embodiment of the present invention will be described with reference to the drawings. The fourth embodiment is different from the first embodiment in that the replacement character arrangement is set and registered according to a predetermined replacement rule. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

[0053] In the configuration in which multiple types of replacement character arrangements are registered as described above, if the number of registered replacement character arrangements is small, a third party who is peeking at the finger movements during the password input operation may enter the password correctly by repeating the finger movements. For example, if three types of replacement character arrangements are registered, the password will be entered correctly in the above-mentioned case with a probability of 1 / 3. On the other hand, if the number of replacement character arrangements to be registered is simply increased, the number of patterns that the user must remember increases, which causes a problem in that the password input operation becomes complicated.

[0054] For this reason, in this embodiment, a replacement character arrangement is set by a terminal administrator or the like so that the key character arrangement is replaced in accordance with a specified replacement rule, and while the character arrangement image Pa is not displayed, information regarding the specified replacement rule is displayed as a hint display Pc in part of the login image.

[0055] Specifically, for example, a pattern generation rule that adds a natural number displayed in the hint display Pc to the numbers in the key character layout (default character layout) of the numeric keypad can be set and registered as the specific pattern generation rule that serves as the above-mentioned predetermined replacement rule. If the natural number to be added is "2", then, as shown in FIG. 11, the character layout image Pa is not displayed on the screen, and "2" is displayed as the hint display Pc on the login image.

[0056] In this case, if the login password to be entered is "1234", a user who has seen the hint display Pc can input the numeric keys 32 in the order of "9", "0", "1", "2", and the input of "1234" as the login password will be accepted, and the password authentication will succeed. Also, if the "3" serving as the hint display Pc is shown on the login image, by inputting the numeric keys 32 in the order of "8", "9", "0", "1", the input of "1234" as the login password will be accepted, and the password authentication will succeed. Note that, in a state where "2" is shown as the hint display Pc on the screen, by performing a character arrangement image display operation or the like, in the above example, with respect to the key character arrangement in Fig. 12(A), the character arrangement image Pa illustrated in Fig. 12(B) may be temporarily displayed on the screen.

[0057] Thus, in this embodiment, the replacement character arrangement is set to replace the key character arrangement according to a predetermined replacement rule. At the time of the password input operation, the hint display Pc (information regarding the above-mentioned predetermined replacement rule) is displayed on the login image in a state where the character arrangement image Pa is not displayed.

[0058] Thereby, not only can a plurality of types of replacement character arrangements be prepared according to the above-mentioned predetermined replacement rule, but only a user who can recall the corresponding character arrangement image Pa from the hint display Pc shown on the screen can perform the correct input operation, so the security can be further enhanced. In particular, for the user, in the above example, it is only necessary to remember "adding the number of the hint display Pc to the key character arrangement", so while suppressing the burden on the user to remember each character arrangement image Pa, the number of character arrangement images Pa (the types of replacement character arrangements) can be increased for improving security.

[0059] Note that the above-mentioned predetermined replacement rule (specific pattern generation rule) is not limited to being set and registered to add the natural number displayed on the hint display Pc. For example, it may be set and registered to subtract the natural number displayed on the hint display Pc. In that case, the hint display Pc may be displayed as an integer including positive and negative numbers.

[0060] The above-mentioned predetermined substitution rule (specific pattern generation rule) may be set and registered so that when the natural number displayed in the hint display Pc is "x", the key character arrangement (default character arrangement) of the numeric keypad is shifted by "x" spaces. In this case, when the hint display Pc "1" is displayed on the login image, by inputting "3", "1", "2", and "6" in that order on the numeric keypad 32, the input of "1234" is accepted as the login password, and password authentication is successful.

[0061] In addition, the above-mentioned predetermined replacement rule (specific pattern generation rule) may be set and registered so that when the natural number displayed in the hint display Pc is "x", the xth character onwards of the input characters will be accepted as input characters, or so that the input characters will be accepted skipping x characters.

[0062] [Fifth embodiment] Next, a mobile terminal according to a fifth embodiment of the present invention will be described with reference to the drawings. The fifth embodiment is different from the fourth embodiment in that the pre-replacement character string corresponding to the input character in the key character arrangement is also taken into consideration when inputting a password. Therefore, the same reference numerals are used for the components substantially the same as those in the fourth embodiment, and the description thereof will be omitted.

[0063] When the password authentication fails, the control unit 21 can perform a predetermined process such as an operation lock process that does not accept input operations by a third party, etc., in order to restrict a predetermined function as described above. However, there is a possibility that the user will mistakenly input the correct password with the conventional key character arrangement instead of the replacement character arrangement. For example, when the login password to be input is "1234" and a replacement character arrangement is selected as described above, if the user overlooks the hint display Pc and inadvertently inputs "1", "2", "3", and "4" in that order on the numeric keypad 32, password authentication will fail. In that case, even if the input operation is performed by a user who has memorized the correct login password, there is a possibility that an operation lock process or the like will be performed due to the failure of password authentication as described above.

[0064] For this reason, in the authentication process in this embodiment, the process also takes into consideration the pre-substitution character string that corresponds to the input characters in the key character arrangement of the character string entered when the password authentication fails. That is, not only does the character string accepted in the substitution character arrangement as described above not match the login password, but also the pre-substitution character string does not match the login password, password authentication is deemed to have failed.

[0065] For this reason, as described above, even if the character string accepted in the replacement character arrangement does not match the login password because the user inadvertently inputs "1," "2," "3," and "4" in that order on numeric keypad 32, password authentication will not be considered a failure if the pre-replacement character string "1234" matches the login password.

[0066] In this way, even if the correct password is mistakenly entered using the conventional key character arrangement instead of the replacement character arrangement, by taking into consideration the character string before replacement, it is possible to prevent predetermined processing such as operation lock processing from being performed as a result of password authentication failure.

[0067] As a modified example of this embodiment, when the pre-replacement character string matches the login password, a predetermined notification may be issued to notify that character input is being accepted in the replacement character arrangement. As the predetermined notification, for example, a notification that highlights the hint display Pc may be adopted as illustrated in Fig. 13, or a notification by the notification unit 25 emitting light or making an alarm sound may be adopted. The display unit 24 and the notification unit 25 that highlight the hint display Pc may correspond to an example of a "notification unit" that issues a predetermined notification when the pre-replacement character string matches the predetermined password.

[0068] As a result, a user who receives the notification can easily understand that although the correct password has been entered using the conventional key character arrangement, the correct password is not entered using the replacement character arrangement, and therefore password authentication will not be successful.

[0069] The present invention is not limited to the above-described embodiments, and may be embodied as follows, for example. (1) The present invention is not limited to a case where a replacement character arrangement is prepared for the numeric keypad 32 of four rows and three columns among the keys constituting the keypad 31, but a replacement character arrangement may be prepared for keys of a predetermined arrangement. For example, a replacement character arrangement may be prepared for keys of a predetermined arrangement to which alphabets or the like are attached.

[0070] (2) The above-described key input reception process is not limited to being performed when a login password is input, and may be performed when highly confidential information, such as other types of passwords, is input.

[0071] (3) The present invention is not limited to application to portable terminals that optically read information codes, but may also be applied to information reading terminals that further have other functions, such as a wireless tag communication function for reading and writing wireless tags, etc. [Explanation of symbols]

[0072] 10 Mobile devices 21 Control unit (display control unit, input control unit, processing unit) 22 Memory section 24 Display 24a display screen 25. Notification Department 30 Control section 31 Keypad 32 Numeric keypad Pa character layout image Pb.Pc Hint Display

Claims

1. a keypad having a plurality of keys arranged thereon for inputting characters; A storage unit that stores information specifying a replacement character arrangement in which at least a part of characters is arranged differently from a key character arrangement of characters assigned to each key of the keypad; a display unit that displays information used for character input operation on a display screen; a display control unit capable of controlling the display unit so that, when a predetermined character input operation is performed using the keypad, a character arrangement image corresponding to the replacement character arrangement is displayed superimposed on at least a portion of a predetermined display image displayed on the display screen; an input control unit that, when any key of the keypad is operated during the predetermined character input operation, accepts input of a character in the replacement character arrangement corresponding to the character in the key character arrangement of the key; a processing unit that performs processing using the character string accepted by the input control unit; A mobile terminal comprising:

2. 2. The mobile terminal according to claim 1, wherein the character layout image is displayed superimposed on the predetermined display image so as to make at least a part of the predetermined display image transparent.

3. The mobile terminal according to claim 1, characterized in that the display control unit controls the display unit to be switchable between a state in which the character arrangement image is displayed and a state in which the character arrangement image is not displayed, in accordance with a specified instruction given during the specified character input operation.

4. The mobile terminal according to claim 1 , wherein the display control unit controls the display unit so as to be able to display information regarding the replacement character arrangement in a state in which the character arrangement image is not displayed.

5. The storage unit stores a plurality of types of the replacement character arrangements, the input control unit accepts input of a character using one selected from the plurality of types of replacement character arrangements; The mobile terminal according to claim 1 , wherein the display control unit controls the display unit so as to be able to display information relating to a selected replacement character arrangement in a state in which the character arrangement image is not displayed.

6. The replacement character arrangement is set to replace the key character arrangement according to a predetermined replacement rule; The mobile terminal according to claim 1 , wherein the display control unit controls the display unit so as to be able to display information regarding the predetermined replacement rule in a state in which the character arrangement image is not displayed.

7. A predetermined password is stored in the storage unit, The mobile terminal according to claim 1, characterized in that the processing unit performs a predetermined process as a failure of password authentication when the character string accepted by the input control unit does not match the specified password and when a pre-substitution character string corresponding to an input character in the key character arrangement of the character string does not match the specified password.

8. 8. The mobile terminal according to claim 7, further comprising a notification unit that issues a predetermined notification when the pre-substitution character string matches the predetermined password.

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