Abstract:
A call request control device, which in an offhook state, upon detecting a key input, checks the type of the key that was input. When the input key is a transmission/redial key, a determination is made of whether dial data is stored in the dial buffer. If dial data is stored in the dial buffer, then the dial data is set as a call destination number, and a call request message is sent. If dial data is not stored, then redial data is set as the call destination number, and a call request message is sent. Telephone sets incorporating such call request control device have enhanced functionality without corresponding increase in the number of keys.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an improved technology for multi-functioning of the keys provided on a telephone set.  
         [0003]     2. Description of the Related Art  
         [0004]     In a telephone set, such as a conventional IP telephone set or ISDN telephone set that sends the dial data integrally to a network when requesting a call, a dedicated transmission key, for instance, is provided as a means to determine the timing of sending the dial data integrally. By such arrangement, an input operation of this transmission key acts as the trigger for transmission of the data.  
         [0005]     If, however, a new dedicated transmission key is installed, the number of the keys to be provided on the telephone set increases. This is not desirable, since the telephone set has a limited number of keys.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention relates to the provision of multi-functioned keys on a telephone set to thereby provide a call request control device and an IP telephone set with a reduced number of keys.  
         [0007]     In one aspect, the invention relates to a call request control device, including: a dial buffer for storing dial data; a control unit for controlling a call request; and a transmission/redial key for requesting the control unit for a call request process, wherein, in cases where the transmission/redial key is input, if dial data is stored in the dial buffer, the control unit performs call request processing by using the dial data as a call destination number, whereas, if dial data is not stored in the dial buffer, the control unit performs call request processing by using redial data as the call destination number. Since the transmission/redial key functions as a combination of a transmission key and a redial key, it is possible to avoid increasing the number of the keys.  
         [0008]     In another aspect, the invention relates to a call request control device, including: a dial buffer for storing dial data; detection means for detecting onhook/offhook status; a control unit for controlling a call request; and a transmission/redial key for requesting the control unit for a call request process, wherein, in cases where the transmission/redial key is input in an offhook state, if dial data is stored in the dial buffer, the control unit performs call request processing by using the dial data as a call destination number, whereas, if dial data is not stored in the dial buffer, the control unit performs call request processing by using redial data as the call destination number. With such configuration, once inputting the transmission/redial key in an offhook state, if dial data is not input, redial transmission is carried out automatically. This arrangement provides a high level of convenience.  
         [0009]     In a still further aspect, the invention relates to a call request control device, including: a dial buffer for storing dial data; a display unit for displaying a call destination number; a detection means for detecting onhook/offhook status; a control unit for controlling a call request; and a transmission/redial key for requesting the control unit for a call request process, wherein, in cases where the transmission/redial key is input in an onhook state, if dial data is stored in the dial buffer, the control unit performs call request processing by using the dial data as a call destination number, whereas, if dial data is not stored in the dial buffer, the control unit displays redial data as the call destination number on the display unit, and, when the transmission/redial key is re-input, the control unit performs call request processing by using the redial data as the call destination number. With such configuration, redial transmission is possible by merely inputting the transmission/redial key twice in an onhook state. This arrangement likewise provides a high level of convenience.  
         [0010]     In yet another aspect, the invention relates to an IP telephone set including a call request control device of a type as described above. The keys are allowed to have multi-functionality and the number of the keys of the IP telephone set can be reduced by providing the call request control device to the IP telephone set. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a functional block diagram of an IP telephone set according to one embodiment of the invention;  
         [0012]      FIG. 2  is a plan view of a base unit of such IP telephone set;  
         [0013]      FIG. 3  is a flow chart explaining call request processing carried out in accordance with such embodiment of the invention; and  
         [0014]      FIG. 4  is a flow chart explaining call request processing carried out in accordance with such embodiment of the invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     An illustrative embodiment of the present invention will be described below with reference to the drawings.  
         [0016]      FIG. 1  is a functional block diagram of an IP telephone set  10  including a call request control device of the present embodiment. As shown in the figure, the IP telephone set  10  is constituted by a base unit  20  and a handset  40 . The base unit  20  is constituted as including an interface circuit  21 , a control unit  22 , a signal processing unit  23 , a codec  24 , a voice amplifier  25 , a voice amplifier  26 , a receiving buffer  27 , a sending buffer  28 , a dial buffer  29 , a hook switch  30 , dial keys  31 , a transmission/redial key  32 , and a LCD display unit  33 .  
         [0017]     The voice amplifier  26  is connected to a microphone  42  which is incorporated in the handset  40 , and a voice signal which was input to the microphone  42  is amplified in the voice amplifier  26  and is then input to the codec  24 . On the other hand, the voice signal which is output from the codec  24  is amplified in the voice amplifier  25 , whereby the reinforced sound is output through a speaker  41 . The codec  24  includes an A/D converter and D/A converter, in which an analog voice signal which is output from the voice amplifier  26  is converted into a digital voice signal (voice data) and supplied to the signal processing circuit  23 , and the voice data which is output from the signal processing circuit  23  is converted into an analog voice signal and output to the voice amplifier  25 .  
         [0018]     The signal processing circuit  23  is a compressing/expansion circuit for voice data, which is constituted as including a DSP (Digital Signal Processor) or the like, in which: voice data supplied from the codec  24  is compressed and stored in the sending buffer  28 ; the compressed voice data which is supplied from the control unit  22  is subjected to expansion processing; and the expanded voice is supplied to the codec  24 . The interface circuit  21  is a circuit that is constituted as including a MAC (Media Access Control) circuit and PHY (Physical Protocol) circuit, in which: a transmission code sent from a transmission path such as an IP network is subjected to decoding processing and stored in the receiving buffer  27 ; and the voice data supplied from the control unit  22  is encoded and sent to the transmission path. The control unit  22  is a circuit that executes call control, in which: the voice data stored in the sending buffer  28  is read and then packetized into predetermined frames; the packetized voice data is supplied to the interface circuit  21 ; the voice data is retrieved from the received data accumulated in the receiving buffer  27  and then supplied to the signal processing circuit  23 .  
         [0019]     The base unit  20  further comprises the dial buffer  29  for accumulating dial data, hook switch (detection means)  30  for detecting onhook/offhook status of the handset  40 , dial keys  31  for dial inputs, transmission/redial key  32  for requesting for a call (including a redial call request), and LCD display unit  33  for displaying the dial data and the like.  
         [0020]      FIG. 2  is a plan view of the base unit  20 . As shown in the figure, in addition to the hook switch  30 , dial keys  31 , transmission/redial key  32 , and LCD display unit  33  as described above, the base unit  20  is also equipped with volume controlling keys, a setting key, a cancellation key, a transfer/hook key, a speaker key, a hold key, and the like. The transmission/redial key  32  is a key functioning as a combination of the conventional transmission key and redial key, and can request a call to the dialed number or can redial by performing an input operation of this key.  
         [0021]      FIG. 3  is a flow chart explaining call request processing executed by the control unit  22 . As shown in the figure, in an offhook state, when a key input is detected (step S 1 ), the type of the key that was pressed is checked (step S 2 ). If the pressed key is a dial key, the dial data is stored in the dial buffer  29  (step S 3 ), whereby the procedure returns to the step S 1 . If the pressed key is the transmission/redial key  32 , it is checked whether there is dial data stored in the dial buffer  29  (step S 4 ).  
         [0022]     If there is dial data stored in the dial buffer  29  (step S 4 ; YES), the dial data is set as a call destination number (step S 5 ), and a call request message is sent (step S 6 ). On the other hand, if dial data is not stored in the dial buffer  29  (step S 4 ; NO), redial data is set as the call destination number (step S 7 ), and a call request message is sent (step S 6 ). Preferably, the redial data is of the terminal number in the outgoing to which a call was made most recently, but it is not limited to this. For example, it may be constituted such that a caller can select a terminal number from among the list in the outgoing history or incoming history.  
         [0023]     If the pressed key is the speaker key, the dial buffer  29  is cleared (step S 8 ), and the procedure moves on to a standby mode. If the pressed key is the cancellation key, the dial buffer  29  is cleared (step S 9 ), and the procedure returns to the step S 1 .  
         [0024]      FIG. 4  is a flow chart explaining call request processing executed by the control unit  22 . As shown in the figure, in an onhook state, when a key input is detected (step S 10 ), the type of the key that was pressed is checked (step S 11 ). If the pressed key is a dial key, the dial data is stored in the dial buffer  29  (step S 12 ), and the procedure returns to the step S 10 . If the pressed key is the transmission/redial key  32 , it is checked whether there is dial data stored in the dial buffer  29  (step S 13 ).  
         [0025]     If there is dial data stored in the dial buffer  29  (step S 13 ; YES), the dial data is set as a call destination number (step S 14 ), and a call request message is sent (step S 15 ). On the other hand, if dial data is not stored in the dial buffer  29  (step S 13 ; NO), the redial data is set in the dial buffer  29  and further displayed on the LCD display unit  33  (step S 16 ). The procedure then returns to the step S 10 . With such configuration, when pressing the transmission/redial key  32  twice in the onhook state, by the first input operation, the redial data is displayed on the LCD display unit  33  and is stored in the dial buffer  29 , and, by the second input operation, the redial data stored in the dial buffer  29  can be used as a call destination number to request a call. Preferably, the redial data is of the terminal number in the outgoing history to which a call was made most recently, but it is not limited to this. For example, it may be constituted such that a caller can select a terminal number from among the list in the outgoing history or incoming history.  
         [0026]     If the pressed key is the speaker key, it is checked whether there is dial data stored in the dial buffer  29  (step S 17 ), and if dial data is stored (step S 17 ; YES), the dial data is set as a call destination number (step S 18 ), and a call request message is sent (step S 19 ). On the other hand, if dial data is not stored (step S 17 ; NO), the procedure moves on to an offhook state. If the pressed key is the cancellation key, the dial buffer  29  is cleared (step S 20 ), and the procedure moves on to a standby mode.  
         [0027]     According to the present embodiment, the transmission/redial key  32  is enabled to function as a combination of conventional transmission and redial keys, and hence the IP telephone set  10  is also enabled to have an increased number of functions. Furthermore, redial transmission is possible only by operating the transmission/redial key  32  once (in the offhook state) or twice (in the onhook state) even if data is not stored in the dial buffer  29 . This provides a high level of convenience.  
         [0028]     The present invention has been explained, taking the IP telephone set  10  as an illustrative example hereinabove, however, the call request control device of the present invention can be applied to a digital telephone set such as an ISID telephone set that sends dial data in batch mode. Other variations, modifications and alternative embodiments of the invention will readily suggest themselves to those of ordinary skill in the art based on the disclosure herein, and therefore are to be regarded as being within the spirit and scope of the invention.