Abstract:
An apparatus remotely controls, for example, door locking/unlocking and alarm activation of an automobile. A transmitting device transmits communication data, which includes synchronization data and identification data. The communication data is received by the control apparatus in which the identification data included in the received communication data is compared with already stored data. The locking and unlocking of the doors of the vehicle is carried out when the identification data matches the already stored data. A continuous reception condition is detected when the communication data is received for more than a predetermined period of time. When the continuous reception condition is detected, an alarm is actuated. As such, a common transmitting button of the transmitting device can be used to effect both control of the locking and unlocking of doors and alarm activation. The control apparatus may also include an erasable memory which is remotely settable in a writable status and in which identification data can be erased by remote control while in the writable status.

Description:
This is a Divisional of Ser. No. 08/838,049, filed Apr. 22, 1997 which is now U.S. Pat. No. 6,078,264 and is a Continuation of Ser. No. 07/921,618, filed Jul. 31, 1992 which is now U.S. Pat. No. 5,648,764 which is a Continuation of Ser. No. 07/566,231, filed Aug. 9, 1990 which is now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to an apparatus which receives control information sent from a transmitter, and which is ideally suited for use as a remote controller in applications such as the so called keyless entry system for automobiles. 
     2. Description of the Prior Art 
     The keyless entry system is an apparatus which can control the locking and unlocking of an automobile&#39;s doors by remote control, even from a location at some distance from the automobile. This apparatus makes it possible for someone such as the driver to carry the transmitter, and without using a key, to lock or unlock the doors and trunk etc. by remote control, through an operation such as the pressing of a push button switch on the transmitter. 
     In the keyless entry system, a specific set of identification data is established in advance between a transmitter and receiver which form a set. When the aforesaid push button switch is pressed, this identification data undergoes frequency modulation and is transmitted. 
     When the received electric field strength, detected by a squelch circuit in a standby mode, exceeds a preset threshold value, the receiver takes up the data and performs collation of the above mentioned identification data or the like. In this way, when the identification data match, the previously mentioned operations such as locking or unlocking of the doors are performed. 
     Thus, the receiver will produce a received response and perform door locking/unlocking control, only with respect to a control signal from a transmitter which matches the identification data registered in the receiver. Based upon this, improvements have been devised for security functions such as theft prevention. 
     On the one hand, theft prevention apparatuses have been extensively developed in recent years. This is the type of apparatus which detects the entry of a thief into the car without the use of a proper key, and which then generates an alarm. The current type of theft prevention apparatuses are constituted so that, for example, they detect the breaking of a window and then generate an alarm. However, a problem still remains that even if the car&#39;s owner discovers from a distance that a thief is prowling around and is about to break into the car, he is not able to sound the alarm and prevent damage to the car before it occurs. 
     Accordingly, there has been a desire for a theft prevention apparatus with further improved security functions, through a combination of the keyless entry system&#39;s transmitter and receiver with the current type of theft prevention apparatus. However, the addition of these extra functions to the transmitter and receiver would complicate their construction. 
     Furthermore, the previously mentioned identification data is, for example, stored in a ROM (Read Only Memory), and the transmitter and receiver are equipped with these ROM&#39;s. Therefore, when the transmitter is lost, it is necessary to exchange the ROM in the receiver with one that matches the identification data of a new transmitter, and maintenance operations become very troublesome. 
     Still further, in order to avoid malfunctions at places such as parking lots, a large number of identification data combinations are created. Because of this, there is also the problem of mounting costs for the management of maintenance parts, since it is necessary for the manufacturer to maintain a stock of ROM&#39;s which correspond to all of the identification data combinations. 
     SUMMARY OF THE INVENTION 
     Therefore, the object of the invention is to present a novel and improved receiving apparatus in order to solve the above-mentioned problems. 
     Another object of the invention is to present a receiving apparatus which can prevent the entry of a thief into a car before such entry occurs, by using the transmitter which controls the locking/unlocking of the car&#39;s doors. 
     In order to accomplish the abovementioned objects, the present invention provides a receiving apparatus which receives communication data including an identification data from a transmitter, 
     means for locking/unlocking doors, and 
     means for controlling the locking/unlocking means when communication data matching the identification data is received. The apparatus also includes 
     means for determining whether or not the communication data is being continuously received for more than a preset period of time, and 
     means for generating an alarm when the continuous receiving condition is determined in the determining means. 
     Therefore, when the owner of a car discovers that a thief is about to for the owner to break into his car, it is possible to prevent the break-in before it occurs, because the alarm will be generated if the communication data is transmitted for longer than a preset period of time. Furthermore, since the transmitter which controls the locking/unlocking of the doors serves a dual purpose, costs can also be reduced. 
     Moreover, when a determination of continuous receiving is to be made as described above, a squelch circuit is generally used, but if this kind of circuit is added to the receiving apparatus which controls the locking/unlocking of the doors, there would be an increase in cost. 
     Still another object of the invention is to present a receiving apparatus having a simple construction, which can make a reliable determination of continuous receiving. 
     In order to accomplish the abovementioned object, a receiving apparatus of the invention which receives a communication data including an identification data from a transmitting apparatus is characterized by determining the continuous receiving condition by repeatedly performing a comparison of at least a part of the communication data and previously stored data. 
     In a preferred embodiment, the receiving appratus is provided with means for determining the continuous receiving when all results of the comparisons within a present period of time are matches. 
     Further, in a preferred embodiment, the receiving apparatus is provided with means for determining the continuous receiving condition when, there is agreement for more than a preset number of times within a number of comparisons in that period of time. 
     Still further, in a preferred embodiment, the receiving apparatus is provided with means for determining the continuous receiving condition and for establishing a judgment standard for each classification of the communication data. The determining means determines the continuous receiving condition when all of the judgment standards for each classification are satisfied within a preset period of time as a result of the comparisons within the preset period of time. 
     In accordance with the invention, continuous the receiving condition is determined by a repeated comparison of at least a part of the communication data with the previously stored data, in a radiocommunication type receiving apparatus that does not have a squelch circuit. Therefore, the determination of the continuous receiving condition can be realized with a simple construction, without using a special construction such as a squelch circuit in a frequency modulation system. Further, since a comparison is performed between the communication data for which the continuous receiving condition determination is made, and the previously stored data, it is possible to prevent errors in the receiving of data. 
     Still another object of the invention is to present a receiving apparatus with a simple construction making possible easy performance of writing, clearing and reading out of identification data, which can reduce maintenance costs. 
     In order to accomplish the above-mentioned object, a which receives apparatus of the invention receiving a communication data including an identification data from a transmitting apparatus, comprises 
     means for storing, which makes possible the writing, clearing and reading out of the identification data, 
     means for status setting to set the storing means to writable status, clearable status or readable status, and 
     means for controlling in response to an output from the status setting means. 
     When the storing means is set to the writable status, the means for controlling receives the communication data from the transmitting apparatus, and writes the identification data contained in the received communication data to the storing means. 
     When the storing means is set to the clearable status, the means for controlling clears the identification data stored in the storing means. When the storing means is set to the readable status, the means for controlling reads out the identification data from the storing means, and when the identification data that is read out matches the identification data contained in the received communication data, the means for controlling outputs an output signal which responds to the received communication data. 
     In a preferred embodiment, the receiving apparatus is provided with means for reporting which reports over the period of the status that the storing means is in the writable status. 
     Further, in a preferred embodiment, the status setting means includes means for switching the writable status and the readable status, and means for clocking the period after the switching means has operated. 
     The status setting means sets into a status indicates that the switching means has been operated when a preset period of time has passed after the switching means is operated. The status setting means sets into the clearable status when, after the switching means is operated, the switching means is operated again before the time period has passed. 
     Still further in a preferred embodiment, the storing means is divided into a number of storing areas, and if the inputted identification data exceeds the number of divisions, the identification data is cleared in the order of the earliest input to the storing means. 
     In accordance with the invention, a storing means which can write, clear (i.e., erase) and read out the identification data, is provided in a receiving apparatus that receives a communication data, including an identification data, from a transmitting apparatus. A storing means is set to either a writable status, a clearable status or a readable status by a status setting means. 
     For example, when the storing means is set to the writable status, a controlling means receives the communication data from the transmitting apparatus, and registers the identification data contained in the received communication data by writing it into the storing means. 
     In this way the written identification data is read out each time the controlling means receives communication data when the storing means is set to the readable status. The written identification data is compared with the identification data contained in the received communication data. When, as a result of this comparison both are in agreement, the controlling means outputs an output signal based upon the received communication data. 
     Therefore, it is possible to write and register specific identification data with a simple construction. Based upon this, it is possible to devise maintenance cost reductions through the common use of parts, because it is not necessary to make the storing means correspond individually with identification data from the transmitting apparatus. It is also possible to make receiving apparatuses equipped with a common storing means to correspond individually with a number of transmitting apparatuses, each having different identification data. 
     Moreover, because it has been made possible to clear the stored contents of the storing means, when data communication is not needed, the response to communication from the transmitting apparatus can be stopped by clearing the stored contents. Based upon this, security functions can be improved since theft can be prevented before such theft occurs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein: 
     FIG. 1 is a block diagram that shows the electrical construction of a communication apparatus  20 , in which one example of the invention, the receiver  11 , is used, 
     FIG. 2 is a diagram that shows the type of data D transmitted from a transmitter  1 , 
     FIGS. 3 and 4 are flow charts that explain the operation of receiver  11  which is one example of the invention, 
     FIG. 5 is a flow chart that explains the data receiving operation for another example of the invention, 
     FIG. 6 is a flow chart that explains data the receiving operation for yet another example of the invention, 
     FIG. 7 is a block diagram that shows the electrical construction of a communication apparatus  30 , in which another example of the invention, the receiver  31 , is used, 
     FIG. 8 is a flow chart that explains the operation of the receiver  31 , 
     FIG. 9 is a block diagram that shows the electrical construction of a communication apparatus  50 , in which yet another example of the invention, the receiver  51 , is used, 
     FIG. 10 is a flow chart that explains the operation of the receiver  51 , 
     FIG. 11 is a block diagram that shows the electrical construction of a communication apparatus  60 , in which another example of the invention, the receiver  61 , is used, 
     FIG. 12 is a flow chart that explains the operation of the receiver  61 , 
     FIG. 13 is a block diagram that shows the construction of a receiving apparatus  70 , which is yet another example of the invention, 
     FIG. 14 is a drawing that explains the storing status of an EEPROM  72 , 
     FIG. 15 is a flow chart that explains the replacement operation for the stored contents of the EEPROM  72 , 
     FIG. 16 is a flow chart that explains the operation of a receiver  17 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Now referring to the drawings, preferred embodiments of the invention are described below. 
     FIG. 1 is a block diagram that shows the electrical construction of a communication apparatus  20 , in which one example of the invention, the receiver  11 , is used. The transmitter  1 , which is carried by someone such as the driver, includes and is composed of an antenna  2 , a transmitting circuit  3 , a push button switch  4 , and a read only memory (abbreviated below as ROM)  5 . 
     On the other side, the receiver  11  which is carried in a car body  10 , includes and is composed of an antenna  12 , a receiving circuit  13 , a waveform shaping circuit  14 , a ROM  15 , a processing circuit  16  which is realized by a microcomputer or the like, and a level conversion circuit  17 . 
     The same identification data is mutually stored in ROM&#39;s  5  and  15 , and this identification data is set individually for each car body  10 . When the push button switch  4  of the transmitter  1  is operated by the operator, the data stored in ROM  5 , which includes the identification data, undergoes amplitude modulation and is transmitted from the antenna  2  of the transmitter  1 . 
     In the receiving standby mode for times such as when the automobile is stopped, the data signal from transmitter  1  is received by the antenna  12 , goes through the receiving circuit  13 , is shaped into a data pulse in the waveform shaping circuit  14 , and is input to the processing circuit  16 . In the processing circuit  16 , when the identification data of the inputted data pulse matches the identification data stored in the ROM  15 , the operation mode, of an electromagnetic solenoid  21  as locking/unlocking means for the doors and trunk or the like of the car body  10 , is switched. 
     Namely, when the doors and trunk or the like are in an unlocked condition, they will be put into a locked condition by the operation of the push button switch  4 . Also at this time, the change to the locked condition is reported to the operator by performing the response operations of sounding a horn  22  one time, together with the lighting of a stop indicator lamp  23  one time. As opposed to this, when they are in a locked condition, they will be put into an unlocked condition by the operation of the push button switch  4 . Also, the change to the unlocked condition is reported to the operator by performing the response operations of sounding the horn  22  two times, together with the lighting of the stop indicator lamp  23  two times. The so called keyless entry is realized in this way. 
     Moreover, auto theft sensors, such as a hood switch  24  that turns on when a hood is opened, and a courtesy switch  25  that turns on when the door is opened, are connected to the processing circuit  16 . When a setting status of a security switch  26  is turned on, and then the hood switch  24  or courtesy switch  25  or the like are turned on, the processing circuit  16  activates a theft alarm sounding the horn  22 . Further, the output from all of the switches  24  through  26  is read into the processing circuit  16 , after being converted by a level conversion circuit  17  to correspond to the input level of the processing circuit  16 . 
     The data D of the data signal transmitted from the transmitter  1  to the receiver  11 , as shown for example in FIG. 2, is composed of a bit synchronization data D 1 , a frame synchronization data D 2 , and an identification data D 3 . When all of the data match, the door locking/unlocking operations are carried out. 
     Further, when the data receiving state as described above continues and lasts for longer than the preset time period W, then in response to the operation in the transmitter  1 , it is determined that the car body  10  is being exposed to theft and the security operation is performed. In other words with this operation, when the car is about to be stolen, or when a rider is about to get into the car and is assaulted by a thug, the person carrying the transmitter  1  activates the security operation and frightens the thug by operating the push button switch  4  for longer than the time period W. The security operation is, for example, the sounding of the horn  22  and the flashing of the stop indicator lamp  23  during a preset time period Wa. 
     FIG. 3 is a flow chart that explains the data receiving operation of the receiver  11 , which is one example of the invention. At step s 1 , it is determined whether or not the data D has been received, and when data D has been received flow moves to step s 2 . It is determined that data D has been received when the bit synchronization data D 1  and the frame synchronization data D 2  are correct. At step s 2 , it is determined whether or not the identification data D 3  is in agreement; when it is not in agreement flow returns to the step s 1 , and when the data is in agreement flow moves to step s 3 . 
     At step s 3 , setting or resetting of the security operation is performed. That is to say, if the present status is the “set” status, then resetting will be performed upon operation, and if it is the “reset” status, then setting will be performed upon operation. Next at step s 4 , the door locking/unlocking operation is performed. That is to say, if the present condition is the locked condition, then it will be unlocked upon operation, and if it is the unlocked condition, then it will be locked upon operation. Further, when setting is performed at step s 3  the door will be locked at step s 4 , and when resetting is performed at step s 3  the door will be unlocked at step s 4 . Also at this step s 4 , the response operation is performed which indicates that the operation in question has been performed. At step s 5 , from the point at which in this way the receiving of data D begins, the timer in the processing circuit  16  begins a counting operation. 
     At step s 6 , in the same way as step s 1 , it is determined whether or not the receiving of the data D is being continued; when it is not, this step s 6  is repeated, and when the receiving of the data D is being continued, flow moves to step s 7 . At step s 7 , collation of the identification data D 3  is performed again; when there is agreement flow moves to step s 8 , and when there is not agreement flow returns to step s 1 . 
     At step s 8 , it is determined whether or not a timer&#39;s counting time W 1  is more than the preset time W, for example, about 2 seconds; when flow is not, it returns to the step s 6 , and when the time W has elapsed, flow moves to step s 9 . At step s 9 , flow returns to the step s 1  after the security operation is performed. In this way with steps s 6  through s 9 , the security operation is realized by means of operation in the transmitter  1 . 
     When data D is not received at the step s 1 , flow moves to step s 10   a  where it is determined whether or not security is set, and if set, it is then determined whether or not theft is occurring at step s 10   b . If theft is occuring, flow then moves to the step s 9  and the security is performed. In this way with steps s 10   a , s 10   b , and s 9 , the security operation is realized by means of the car&#39;s theft sensors. Further, when security is not set at step s 10   a , and when it is determined at step s 10   b  that theft is not occurring, flow returns to step s 1 , and when in this way data D is not received and theft is not detected, these steps s 1 , s 10   a , and s 10   b  are repeated. 
     FIG. 4 is a flow chart that explains the security operation. At step s 41 , the timer&#39;s counting operation is started. At step s 42  the horn  22  is blown, and at step s 43  flashing of the stop indicator lamp  23  is performed. At step s 44 , it is determined whether or not the timer&#39;s counting time W 1   a  has elapsed only as far as the preset time Wa, for example about 60 seconds; when it has not, flow returns to the step s 42  continuing the security operation, and when it has, the operation is finished. 
     In this way, with the receiver  11  which conforms to the invention, simplification of construction together with a marked improvement in functionality are made possible, because two operations, the door locking/unlocking operation and the security operation, have been realized in accordance with the operational state of the push button switch  4 , without using a special construction such as a squelch circuit, as in the prior art. 
     FIG. 5 is a flow chart that explains the data receiving operation of another example of the invention, and as this example is similar to the previously discussed example, the same reference numbers will be given for the corresponding parts. In this example, when the data D is in agreement at step s 7 , flow moves to step s 8  after performing the counting operation for the count value N 1  of the counter in the processing circuit  16  at step s 11 . Further, when the receiving of data D is not detected at step s 6 , and when the data D is not in agreement at step s 7 , flow moves directly to step s 8 . 
     At step s 8 , when the timer&#39;s counting time W 1  passes the preset time W, flow moves to step s 12  where it is determined whether or not the count value N 1  is greater than the preset value N; when flow is greater, it moves to the step s 9  and the security operation is performed, and when it is not greater, the counter&#39;s count value is reset at step s 13  and flow then returns to the step s 1 . 
     Further, for example, data D is transmitted from the transmitter  1  about 20 times during the time period W of 2 seconds, and for this reason the value of N is set to about 16. 
     Therefore, even in cases where some receiving errors are generated due to noise or other factors, it is possible to determine the continuous receiving condition and to realize a greater degree of accuracy in the security operation. 
     FIG. 6 is a flow chart that explains the data receiving operation of yet another example of the invention, and as this example is similar to the previously discussed example, the same reference numbers will be given for the corresponding parts. In this example, at step s 19 , it is determined the that continuous receiving is taking place if the bit synchronization data D 1  is in agreement, and at that time it is determined at steps s 20  and s 21  respectively, up to what point the data contained in the data D has been received error free, and based upon the results of that determination, the counting operation is performed at steps  22  through  24  respectively. 
     In other words, when all of the data D up to the identification data D 3  is received error free, flow moves from step s 20  to step s 22 , and all of the count values, the count value Na of the bit synchronization data D 1 , the count value Nb of the frame synchronization data D 2 , and the count value Nc of the identification data D 3 , are added together. 
     Further, when the reception up to the frame synchronization data D 2  is error free, flow moves from step s 21  to step s 23 , and the count value Na of the bit synchronization data D 1  and the the count value Nb of the frame synchronization data D 2  are added together. Still further, when only the bit synchronization data D 1  is received, flow moves from step s 21  to step s 24 , and the count value Na of the bit synchronization data D 1  is added. 
     From the steps s 22  through s 24  flow moves to step s 25 , and after the count value W 11 , which indicates the fact that data D has not been received, has been reset, flow moves to the step s 8 . Further, when continuous receiving of data D is not detected at the step s 19 , and after adding the count value W 11  at step s 26 , flow moves to step s 27 . 
     At step s 27 , it is determined whether or not the count value W 11  is greater than the preset value W 10 , and when it is, that is to say when the nonreceiving condition continues, for example, for longer than the count value W 10  of about 0.4 seconds, all of the count values are reset at step s 28  and flow returns to the step s 1 . 
     Moreover, when the count value W 11  at step s 27  is less than the value W 10 , flow moves to step s 8 . At step s 8 , it is determined whether or not the timer&#39;s counting time W 1  has become greater than the preset time W, and when it has not, flow returns to the step s 19 , and when flow has, it moves to step s 31 . 
     At steps s 31  through s 33 , conditions are determined as to whether or not all of the count values N 1   a , N 1   b , and N 1   c  are respectively greater than the preset values Na, Nb, and Nc, and only when all of those conditions are satisfied, flow moves to the step s 9  and  20  the security operation is performed; when any one of those conditions is not satisfied, flow returns to step s 1  after all of the count values are reset at the step s 28 . Further, for example, the value Na is set to 16, the value Nb is set to 10, and the value Nc is set to 6. 
     According to this example, with the continuation of a favorable receiving state, all of the conditions indicated in the steps s 31  through s 33  are satisfied, and moreover, since the security operation is performed only when the count value W 11  of the nonreceiving condition at step s 27  is less than the preset value W 10 , it is possible to improve accuracy still further based upon this. 
     FIG. 7 is a block diagram that shows the electrical construction of the communication apparatus  30 , in which another example of the invention, the receiver  31 , is used, and as this example is similar to the previously discussed example, the same reference numbers will be given for the corresponding parts. In this example, when the push button switch  4  is operated, a transmission circuit  33  of a transmitter  32  performs FSK (Frequency Shift Keying) modulation on, for instance, a 30 MHz carrier wave and then transmits it from the antenna  2  in accordance with the data stored in ROM  5 , which includes the identification data. 
     The receiver  31  which is carried in a car body  40  receives the data from the transmitter  32  with the antenna  12 , and reads the data into the processing circuit  36  after it is demodulated in a receiving circuit  34  and formed into a data pulse in a waveform, shaping circuit  35 . When the identification data of the read-in data matches the identification data stored in an EEPROM (Electrically Erasable Programmable ROM)  37 , a processing circuit  36  changes the operating state of the electromagnetic solenoid  21 , in response to the output from a switch group  38  which will be discussed later. 
     Switch group  38  is a group of switches for establishing which door&#39;s locking/unlocking is to be controlled, and for example, is composed of switches such as a door switch  38   a  for setting the door control, a hood switch  38   b  for setting the engine hood control, and a trunk switch  38   c  for setting the trunk control. The output of this switch group  38  is read into the processing circuit  36  after being converted to correspond with the input level of the processing circuit  36 , in a level conversion circuit  39 . 
     Further, a status setting switch  41  is provided in conjunction with the processing circuit  36 . When this status setting switch  41  is turned on, the EEPROM  37  is set to a writable status, and it is possible to register the identification data D 3  of the received data D, which is input by way of the receiving circuit  34  from the antenna  12 . As opposed to this, when the status setting switch  41  is turned off, a EEPROM  37  is set to the readable status, and each time a data signal is received from the transmitter  32 , the identification data is read out from the EEPROM  37  and compared with the identification data D 3  from the transmitter  32 . As a result of the comparison, in the case where the two sets of identification data are the same, the regular keyless entry control is performed, which controls the locking/unlocking of the doors. 
     Moreover, switches  24  through  26  for the security may also be connected to the processing circuit  36 . 
     Further, a reporting means  42  is connected to the processing circuit  36 . Means such as a LED (Light Emitting Diode)  43  and a horn  44  are given as examples of the reporting means  42 . Further for this horn  44 , the horn  22  which generates the alarm sound may be used in common, or a buzzer or the like may be used. The reporting means  42 , reports on such conditions as whether or not the EEPROM  37  is in a writable status, and further, whether or not the writing of the identification data has been completed. For example, the LED  43  may light up or flash while set to the writable status, and the horn  44  may blow when the writing of the identification data into the EEPROM  37  is completed. 
     FIG. 8 is a flow chart that explains the operation of receiver  31 . At step l 1 , it is determined whether or not the status setting switch  41  is turned on. In other words, it is determined whether or not the EEPROM  37  is set to the status in which the identification data can be written, and when flow is not, it proceeds to step l 6  and regular keyless entry control is performed. That is to say, the identification data D 3  which is transmitted from the transmitter  32  is compared with the identification data stored in the EEPROM  37 , and as a result, if the door is in a locked condition, the unlocking control is performed, and if the door is in an unlocked condition, the locking control is performed. In this way the door&#39;s locking/unlocking control is performed in response to the data signal from the transmitter  32 . 
     When the status setting switch  41  is turned on at the step l 1 , the LED  43  of the reporting means  42  lights up at step l 2 . At step l 3 , it is determined whether or not the identification data D 3  which is to be registered has been received by the receiving circuit  34 , and when it has not been received, flow proceeds to step l 4  and it is determined whether or not the status setting switch  41  has been turned off, or in other words, whether or not the writable status of the EEPROM  37  has been released. In the case that the status setting switch  41  has not been turned off, the processing returns to step l 3  and the determination is repeated. In this way, when the status setting switch  41  is turned off, flow proceeds from step l 4  to step l 5 , and with the release of the writable status the LED  43  turns off, and the regular keyless entry control is returned to. 
     On the other hand, while the EEPROM  37  is set to the writable status, when the identification data D 3  which is to be registered is received at the step l 3 , flow proceeds to step l 7 , the processing circuit  36  is set to the write mode, the identification data D 3  is written into the EEPROM  37  at step l 8 , after the writing is completed the horn  44  of the reporting means  42  is blown one time, and then after determining the conclusion of the writable status at step l 4 , the regular keyless entry control is returned to. 
     Therefore, according to the example described above, the writable status of the EEPROM  37 , which is connected to the processing circuit  36 , is set by changing the status setting switch  41 , and when in the writable status, reading and registering can be easily accomplished by receiving the identification data D 3  which is to be registered from the transmitter  32 . Consequently, for example, even when the transmitter  32  is lost and it is necessary to register the identification data for a new transmitter  32 , registering into the EEPROM  37  of the receiver  31  can be accomplished easily. 
     In other words, there is no need for troublesome operations such as the replacement of memory parts in order to register new identification data, as has been the case up until now, and it is possible to hold down the cost of maintenance part management. Still further, because the reporting means  42  is provided, it is possible for the operator to easily confirm factors such as the writable status and the completion of writing, which makes for excellent operability. Further, since the status setting switch  41  is constructed with two stable positions, the operator can operate it while fully confirming the status, and malfunction can be prevented. 
     FIG. 9 is a block diagram that shows the electrical construction of the communication apparatus  50 , in which yet another example of the invention, the receiver  51 , is used, and the same reference numbers are used for parts which correspond to the previous example. In this receiver  51 , timer  53  is provided in a processing circuit  52  which controls the locking/unlocking of the doors, and further, a status setting switch  54  is composed of two switches  54   a  and  54   b . The status setting switch  54  does not have two stable positions like the previously mentioned status setting switch  41 , but is constructed so that, as with a so called push switch, a single pressing operation outputs a one pulse signal. 
     In this example, once switch  54   a  is operated, the EEPROM  37  is set to the writable status and the timer  53  begins to count, from that point of operation. When the count value t of the timer  53  reaches the preset value T, for example 5 seconds, the writable status of the EEPROM  37  is automatically released. 
     Further, the processing circuit  52  has a function for clearing the stored contents within the EEPROM  37 . In other words, it is constructed so as to clear the stored contents of the EEPROM  37  after the switch  54   a  is operated, and when the switch  54   b  is operated before the count value t of timer  24  passes the preset value T. The time for determining that the switch  54   b  has been operated is selected, for example, to be about 2 seconds. 
     FIG. 10 is a flow chart that explains the operation of receiver  51 . At step m 1 , it is determined whether or not the operation of switch  54   a , for the registering of the identification data, has been performed, and when it has not, flow proceeds to step m 7  and the kind of regular keyless entry control previously mentioned is performed. Further, when switch  54   a  has been operated at step m 1 , flow proceeds to step m 2 , sets the EEPROM  37  is set to the writable status, and together with the lighting or flashing of LED  43 , counting with the timer  53  begins. 
     After that, it is determined at step m 3  whether or not switch  54   b  has been operated. In case the determination is negative, the identification data D 3  which is to be registered at step m 4  is transmitted from the transmitter  32 , and it is determined in the receiving circuit  51  whether or not the data has been received. In case the determination at the step m 4  is negative, the processing proceeds to step m 5  and it is determined whether or not the count value t of the timer  53  has exceeded the preset value T. In case the determination at the step m 5  is negative, the processing returns again to step m 3 , and the processing of the above mentioned steps m 3  through m 5  is repeated. 
     When the count value t exceeds the preset value T, the processing proceeds to step m 6 , it is determined that the write registration of new identification data was not performed within the preset time period, the writable status of the EEPROM  37  is released, together with the turning off the LED  43 , the count value t of timer  53  is cleared, and at step m 7  regular keyless entry control is performed similar to that mentioned above. 
     On the other hand, when it is determined that the switch  54   b  has been operated before the count value t of the timer  53  has reached the preset value T at the step m 3 , the EEPROM  37  is set to the clear mode at step m 8 , all of the stored contents are cleared at step m 9 , the horn  44  is blown once at step m 10 , and the processing proceeds to the above mentioned step m 6 . 
     Further, when the identification data D 3  which is to be registered at the step m 4  is received before the count value t of the timer  53  reaches the preset value T, the processing moves to step m 11 , the EEPROM  37  is set to the write mode, the received identification data D 3  is written at step m 12 , the horn  44  is blown twice at step m 13 , and the processing proceeds to the above mentioned step m 6 . 
     The reason that the horn  44  is blown a different number of times at the steps m 10  and m 13 , is that the respective objectives of blowing the horn  44  are to clearly report to the operator the difference between the clearing of the EEPROM  37  and the completion of writing to the EEPROM  37 . Therefore, the number of times the horn  44  is blown, is not limited in this example. 
     In this way based upon the above example, it is possible to easily register the identification data D 3  of the transmitter  32  into the receiver  51 , with a simple operation similar to the examples shown in FIGS. 7 and 8 above. Further, forgetting to change the switch, such as when the operator leaves the EEPROM  37  set to the writable status through carelessness or the like, can be prevented, because when the identification data D 3  to be registered is not received within the time period clocked in advance using the clocking means, timer  53 , the writable status of the EEPROM  37  is released automatically. Moreover, the selection of the write mode and clear mode for the EEPROM  37  can be implemented with a simple operation of the status setting switch  54 , making for very high operability. 
     Furthermore, because a clear mode is provided for the EEPROM  37 , when for example, the operator leaves the automobile for a long period of time, by clearing the stored contents of the EEPROM  37  it becomes impossible to release the door locks with a transmitter having any kind of identification data, and security is improved greatly. 
     FIG. 11 is a block diagram that shows the electrical construction of a communication apparatus  60 , in which another example of the invention, the receiver  61 , is used, and the same reference numbers are used for parts which correspond to the previous example. In this receiver  61 , a status setting switch  63 , which is connected to a processing circuit  62  that controls the locking/unlocking of the doors, is composed of one push switch. 
     In other words, the example shown in FIG. 9 above is constructed so that the switch  54   a  is operated when the EEPROM  37  is set to the writable status, and furthermore the switch  54   b  is operated when the EEPROM  37  is set to the clear mode during the preset period T, however, one common status setting switch  63  can be used for these switches  54   a  and  54   b.    
     That is to say, it should be constructed so that when the EEPROM  37  is set to the writable status, and once the status setting switch  63  is operated, at that time the counting of timer  53  is started, and by a second operation of the status setting switch  63  during the preset period T, it is set to the clear mode. Further, the EEPROM is constructed so that in case the second operation of the status setting switch  63  is not performed by the time the count value t of timer  53  exceeds the preset value T, the writable status of the EEPROM  37  is released automatically. 
     FIG. 12 is a flow chart that explains the operation of receiver  61 , and the same reference numbers are used for parts that correspond to the previous FIG.  10 . Since as before, the two switches  54   a  and  54   b  are replaced with a single status setting switch  63 , step m 1  which is indicated in FIG. 10 is replaced with step m 1   a  of FIG. 12, and becomes the determination of whether or not the status setting switch  63  has been operated once. Further, the determination of the operation for switch  54   b  at step m 3  of the FIG. 10, is replaced with the determination of whether or not the second operation of the status setting switch  63  has been performed at step m 3   a  in FIG.  12 . The other processing operations are the same as the processing shown in FIG. 10, and are omitted here. 
     Based on the above receiver  61 , since the two operation switches  54   a  and  54   b  used in receiver  51  are combined in the common status setting switch  63 , the space occupied by the status setting switch  63  in the apparatus is reduced together with a curtailment of the number of parts. 
     Further, for all of the switches  54   a ,  54   b , and  63 , momentary switches may be used. 
     FIG. 13 is a block diagram that shows the construction of a receiver apparatus  70 , which is yet another example of the invention, and the same reference numbers are used for parts which correspond to the previous example. In this example, a number of transmitters (indicated as “n” in the example) are provided, and it is supposed in this case that mutually different identification data R 1  through Rn (indicated by the reference number “R” when generalized below) are stored in the ROM&#39;s M 1  through Mn of the receivers U 1  through Un (indicated by the reference number “U” when generalized below). 
     In a case such as this where a number of transmitters U is provided, it is necessary for all of the identification data R 1  through Rn, which are assigned to the transmitters U, to be registered in an EEPROM  72  of a receiver  71 , so that any of the transmitters U can perform the keyless entry control. 
     The interior of the EEPROM  72  is divided into a number of storage areas. In this example, as one illustration it is supposed that the EEPROM has been divided into “k” areas, and it is possible to write and register “k” sets of identification data R. In this example the registration order is established so that in the case of registering identification data R which exceeds the number of areas k, priority is given to the most recently registered identification data: 
     FIG. 14 is a drawing that explains the storing status of the EEPROM  72 . There are k storage areas for which the reference numbers M 1  through Mk are given. FIG. 14A shows the condition of the first identification data R 1  registered in the storage area M 1 . Continuing, when the status setting switch  63  etc. is operated so that the identification data R 2  will be registered, as is shown in FIG. 14B, the identification data R 1  which was registered in the storage area M 1  is shifted to the adjacent storage area M 2 , and then the new identification data R 2  which is to be registered, is written and registered into the storage area M 1  that has been cleared. 
     Thereafter in the same way, with each new registration, the previously registered identification data R is shifted consecutively to the adjacent storage area. In this way, when k sets of identification data are registered, as is shown in FIG. 14C, identification data R is registered respectively in all of the k number of storage areas M 1  through Mk. 
     Furthermore, in the case when new identification data R (k+1) is registered, the identification data R 1 , which was registered the earliest, is cleared from the last storage area Mk, as is shown in FIG.  14 D. After that, the data are shifted in sequence as stated above, and the newest identification data R (k+1) is written and registered into the storage area M 1 . In this way, EEPROM is constructed so that identification data can be registered into EEPROM  72  while giving priority to the newest data. 
     FIG. 15 is a flow chart that explains the replacement operation for registered contents as mentioned above. When the replacement processing begins, the stored contents in the last storage area Mk are cleared at step a 1 . That is to say, the identification data which was entered the earliest and which has been shifted to the last storage area Mk, is cleared. At step a 2 , the stored contents of the storage area M(k−1) is shifted to the adjacent storage area Mk which has been cleared, and thereafter the shifting process is sequentially repeated. After that at step ak, the stored contents of the first storage area M 1  is shifted, and in this way the identification data to be newly registered secures the storage area M 1  in which it should be registered, and the replacement processing of the stored contents is completed. 
     FIG. 16 is a flow chart that explains the operation of receiver  71 . At step b 1 , it is determined whether or not the operation of the status setting switch  63  has been performed for the first time, and when it has not been operated, processing proceeds to step b 17 , the above mentioned regular keyless entry control is performed, and step b 1  is executed again. On the other hand, if the determination is affirmative, the processing proceeds to step b 2 , the EEPROM  72  is set to the writable status, and together with the lighting or flashing of the LED  43 , the counting of timer  53  starts, and at step b 3  it is determined whether or not the count value t has exceeded the preset value T. 
     In case the determination is negative, processing proceeds to step b 4  and it is determined whether or not the second operation of the status setting switch  63  has been performed. In case the determination at the step b 4  is negative, the processing proceeds further to step b 5  and it is determined whether or not the identification data R to be registered has been received. In case the determination is negative, the processing returns again to step b 3  where the determination of the count value t and the preset value T is performed, and the processing of steps b 3  through b 5  is repeated. 
     When the identification data R to be registered is received at the step b 5 , it is preset into the processing circuit  62  at step b 6 , +1 is added to replace “0” as the count value C of a receiving counter, and at step b 7  it is determined whether or not the count value C is “1”. In case the count value C is “1”, processing proceeds to step b 8  where the processing circuit  62  is set to the write mode, the received identification data R is written to the EEPROM  72  at step b 9 , and the processing returns again to step b 3 . 
     In general, the identification data R which is sent from a transmitter U is sent a number of times at the same level, and the construction is such that at the receiver  71 , the identification data R can be evaluated and registered with certainty. Therefore, in case the count value C is not “1” at the step b 7  while the processing of the steps b 3  through b 7  is being repeated, the processing proceeds to step b 10 . At step b 10 , it is determined whether or not the identification data R received at a current time is the same as the identification data R received the previous time, and when it is, the count value C at step b 11  is newly set to “1”, the processing returns to step b 3 , and the processing of the above steps b 3  through b 7 , b 10  and b 11  is repeated. 
     When it is determined at the step b 10 , that the identification data R received at a current time is different than the identification data R registered in the EEPROM  72  the previous time, processing proceeds to step b 12  where the replacement processing shown in the above mentioned FIG. 16 is performed, and secures the first storage area M 1  in a writable status. At step b 13 , the EEPROM  72  is set to the write mode, and the new identification code data R is written to the storage area M 1  at step b 14 . 
     After that, the horn  44  is blown once at step b 15 , and at step b 16  the writable status of the EEPROM  72  is released, and together with the turning off of the LED  43 , the count value t of timer  53  is cleared. As a result, the processing circuit  62  performs regular keyless entry control at step b 17 , and the processing returns again to step b 1 . 
     On the other hand, when at the step b 3 , the count value t of timer  53 , from the point of the first operation of the status setting switch  63 , exceeds the preset value T, the processing proceeds to step b 16  and the writable status of the EEPROM  72  is automatically released. 
     Furthermore, at the step b 4 , when the second operation of the status setting switch  63  is performed before the count value t of the timer  53  reaches the value T, processing moves to step b 18  where the processing circuit  62  is set to the clear mode, all of the stored contents of the EEPROM  72  are cleared at step b 19 , reporting is performed by blowing the horn  44  twice at step b 20 , and then processing proceeds to step b 16 . 
     Therefore according to the above example, operability is markedly improved, because apparatus is constructed so that in registering to the EEPROM  72 , greater priority is given to the most recently registered identification data, than to the earliest registered identification data, which can be considered to be less in demand. 
     Therefore based upon the above example, it is possible to greatly simplify the control and registering of the identification data-R from the transmitters U to the receiver  71  at the manufacturing stage. Also for example, even in the case where a transmitter is lost and a transmitter with new identification data is procured, maintenance is simple because write registration of the new identification data to the receiver can be carried out easily. 
     The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and the range of equivalency of the claims are therefore intended to be embraced therein.