Abstract:
A remote control is operative to transmit a remote control signal composed of a first portion and a second portion. The first and second portions are typically a pulse and a space. The pulse has a pulse width of a given duration within a pulse width range, while the space has a space width of a given duration within a space width range. An interrupt signal provided to indicate the end of transmission of the remote control signal is disabled when a space portion requires a space width greater than the space width range. The interrupt signal signaling the end of the remote control transmission is then disabled for a predetermined period of time essentially equivalent to a length of time that the additional space exceeds the space width. During the predetermined period of time, the remote control thus a space. The interrupt signal is then re-enabled after expiration of the predetermined period of time in order to allow for another remote control transmission.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to remote controls for electronic devices and, more particularly, to remote control transmissions.  
           [0003]    2. Description of the Related Art  
           [0004]    In modern consumer electronic devices such as television receivers, set-top boxes (e.g. cable boxes, satellite receivers, stereos, etc.) and the like (collectively, consumer electronic devices) many functions and/or features may be accessed and/or controlled via a remote control device. The remote control device may be user-actuated, as in the case of a hand-held remote control, or it may be device-actuated, in the case of a “relay” type remote control. In both cases, the remote control generates and transmits (wirelessly) a remote control signal that is received by the receiving electronic device. The control signal is encoded/coded in a manner appropriate for the receiving device. The receiving device receives the encoded/coded control signal and performs the requested command.  
           [0005]    The remote control may use a variety of wireless transmission mediums in order to send or transmit the generated control signal from the remote control to the receiving electronic device. One type of remote control uses bursts of infrared (IR) light or radiation as the medium/vehicle for transmission of the encoded signals, which are received by a suitable receiving device associated with the consumer electronic device. The consumer electronic device may include a microprocessor for performing many receiver functions in addition to decoding received IR coded command signals and generating appropriate control signals in response thereto. An IR encoded command signal generally consists of a binary data stream of given word length in which the presence of a burst of infrared energy represents a binary 1 and the absence of infrared energy represents a binary 0.  
           [0006]    IR transmissions from a remote control are typically made up of a series of pulses (high voltage/binary 1) and spaces (low voltage/binary 0) of varying lengths. Different combinations of the pulses and spaces are used to create unique IR codes. Each unique IR code represents a different key on the remote control. Consumer electronic devices may or may not use the same codes for the same or similar features. Thus, a remote control for one electronic device may not necessarily work with another electronic device.  
           [0007]    A typical remote control includes transmitter circuitry that may be part of an integrated circuit (IC) and, more particularly, an application specific integrated circuit (ASIC). For typical transmissions utilizing the IR circuitry, the length of the pulse and the length of the space are individually specified in separate registers. The registers are loaded with a pulse/space combination when a key on the remote control is actuated. When an IR sequence is being transmitted, an interrupt is generated at the end of each pulse-space combination. At the time of the interrupt, the next pulse-space sequence or combination is loaded from user registers to transmission registers. At this time, it is safe for the remote to reload the user pulse and space registers so they are set up for the next pulse-space combination, which is the loaded at the next interrupt.  
           [0008]    A problem with typical remote control circuitry that operates in the above manner, is that the IR transmitter only has a range of about ten microseconds (10 μsec) as a minimum to ten milliseconds (10 msec) as a maximum, in ten microsecond (10 μsec) increments, for each the pulse and space. However, some IR formats require space and pulse times greater than ten milliseconds. Since the minimum space or pulse time is only 10 microseconds instead of zero (0), the spaces or pulses cannot be concatenated to achieve spaces or pulses, respectively, greater than ten milliseconds.  
           [0009]    It has been determine that a pulse greater than ten milliseconds may be provided by two pulses with a single ten microsecond space therebetween without creating a problem for the receiving device. Particularly, as an example, a ten microsecond drop in a ten millisecond pulse is less than one cycle (assuming a carrier of 56 KHz, the period is 17 μsec). However, it has determined that providing just a ten microsecond pulse between two spaces causes a discrimination problem for the remote control transmission receiver.  
           [0010]    It is thus desirable to have a remote control that is operative to provide remote control transmissions of pulses and/or spaces that exceed the maximum pulse and/or space duration.  
           [0011]    It is thus also desirable to have a method of transmitting a remote control signal when a pulse and/or space exceeds the maximum pulse and/or space duration.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention is a remote control and associated method that provides a remote control transmission. In particular, the present invention is a remote control and associated method that provides an extended remote control transmission. More particularly, the present invention is a remote control and associated method that extends an operative range of pulse/space combination type remote control transmissions.  
           [0013]    In one form, the present invention is a remote control that comprises a first circuit and timer circuitry. The first circuit is operative to generate a transmission comprising first and second portions. The first portion is of a duration within a first time range. The second portion is of a duration within a second time range. The first circuit is further operative to generate a signal indicative of an end of transmission of the first and second portions. The timer circuitry is in communication with the first circuit and is operative to render the first circuit signal inactive when a time length of a second portion exceeds the second time range. The timer circuitry is further operative to generate a replacement signal for the first circuit signal after expiration of the time length of the second portion.  
           [0014]    In another form, the present invention is a method of generating a remote control transmission. The method includes the steps of: (a) generating a remote control transmission comprising first and second portions, the first portion of a duration that is within a first time range, and the second portion of a duration that is within a second time range; (b) generating a signal indicative of an end of transmission of the first and second portions; (c) inactivating the signal indicative of an end of transmission when a time length of a second portion exceeds the second time range; and (d) generating a replacement signal for the signal indicative of an end of transmission after expiration of the time length of the second portion.  
           [0015]    In yet another form, the present invention is a method of extending a remote control transmission beyond a space width range of a remote control, the remote control having an integrated circuit operative to generate a remote control transmission comprising a pulse and space, the pulse having a pulse width within a pulse width range, and the space having a space width within a space width range, the integrated circuit further operative to generate a signal indicative of an end of transmission. The method includes the steps of: (a) providing an interrupt signal to the integrated circuit after transmitting the remote control transmission, the interrupt signal operative to temporarily disable generation of another remote control transmission; (b) providing a timing interval equal to an amount of time that said space is to exceed the space width range, the timing interval equivalent to a space; and (c) enabling generation of another remote control transmission after expiration of the timing interval. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiment(s) of the invention taken in conjunction with the accompanying drawings, wherein:  
         [0017]    [0017]FIG. 1 is a representation of an exemplary system embodying the present invention;  
         [0018]    [0018]FIG. 2 is a simplified functional block diagram of the system of FIG. 1;  
         [0019]    [0019]FIG. 3 is a representation of another exemplary system embodying the present invention;  
         [0020]    [0020]FIG. 4 is a simplified functional block diagram of the system of FIG. 3;  
         [0021]    [0021]FIG. 5 is a graph of an exemplary remote control signal format;  
         [0022]    FIGS.  6 A-E are timing diagrams for various remote control signals in accordance with an aspect of the present invention;  
         [0023]    [0023]FIG. 7 is a block diagram of an embodiment of the present invention;  
         [0024]    [0024]FIG. 8 is a block diagram of a particular embodiment of the present invention;  
         [0025]    [0025]FIG. 9 is a flow diagram depicting a simplified overview of a manner of operation of the present invention; and  
         [0026]    [0026]FIG. 10 is a flow diagram depicting a more particular exemplary manner of operation of an embodiment of the present invention. 
     
    
       [0027]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate preferred embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0028]    Referring now to the drawings and, more particularly to FIG. 1, there is shown an exemplary electronic system, generally designated  10 , in which the present invention may be embodied. The electronic system  10  includes an electronic device  12  and a remote control  14 . The electronic device  12  is representative of any type of electronic device and, more particularly, any type of consumer electronic device. The consumer electronic device may be a television, television signal receiving device, VCR, DVD, or the like. The remote control  14  is representative of a typical, hand-held remote control that is operative to produce and send a transmission or control signal representing an action for the electronic device  12  to perform in response to actuation of a button or key  16  of the remote control  14 .  
         [0029]    The transmission of a remote control signal is preferably accomplished wirelessly and may take any form such as via radio frequency signals, infrared (IR) radiation or the like. The remote control signal may take any form, but is preferably a coded signal of a predefined or predetermined format. The electronic device  12  is operative to receive and decode the remote control signal. Once decoded, the electronic device  12  is operative to perform a particular command for the remote control signal.  
         [0030]    The remote control  14  includes a plurality of buttons or keys  16  that allow a user to control at least some of the functions/features of the electronic device  12 . Actuation or pressing of a button  16  causes the remote control  14  to produce and send a transmission corresponding to the button pressed. The button is associated with and initiates a function/feature of the electronic device  12 . Each button is associated with a unique signal that is received and interpreted by the electronic device  12 . When the electronic device  12  receives the unique signal, the unique signal is correlated to the appropriate feature/function and/or operation.  
         [0031]    In FIG. 2, a simplified functional block diagram of the electronic system  10  is shown. The electronic device  12  includes a processing unit, circuitry and/or logic  18 , a remote control signal receiver  20 , and other various circuitry/logic/components  22 . The processing unit  18  provides main processing for the electronic device  12 . The receiver  20  provides reception of remote control signals from the remote control  14 . Decoding of a remote control signal may be accomplished by the receiver  20  and/or by the processing unit  18 . The other circuitry/logic/components  22  is representative of the various circuitry, logic and/or other components of the particular electronic device  12 .  
         [0032]    The remote control  14  includes button/key circuitry/logic  24  that is operative to receive a button/key signal from a button/key  16  of the remote control  14 . The button/key circuitry/logic  24  interprets which button/key  16  of the remote control  14  was selected by the user. The remote control  14  further includes a transmission generator  26  that is operative to receive a button/key signal from the button/key circuitry/logic  24  and generate or produce an appropriate remote control signal (i.e. a remote control signal coded for the particular button/key selected). A transmitter  28  receives the coded remote control signal from the transmission generator  26  and transmits the coded remote control signal to the electronic device  12 .  
         [0033]    Referring now to FIG. 3, there is depicted another exemplary system, generally designated  40 , in which the present invention may be embodied. The electronic system  40  includes a television signal receiver  42  as an electronic device (typically and hereafter, television), a remote control  44  for the television  42 , an auxiliary electronic device  48 , and an auxiliary remote control  50 . The auxiliary electronic device  48  may be a set-top box (i.e. cable box, satellite receiver, or the like), a DVD, a VCR, or any other electronic device that utilizes and/or processes television signals. Thus, the auxiliary electronic device  48  is in communication with the television  42 . In addition, the electronic system  40  includes an auxiliary remote control  50  that is in communication with the television  42 .  
         [0034]    The remote control  44  includes a plurality of buttons/keys  46  and functions in like manner to the remote control  14  of the electronic system  10  of FIG. 1. The remote control  44  is operative to provide control signals to the television  42  in a predefined or predetermined format. The television  42  is operative to receive and interpret the remote control signals in order to perform the requested commands as provided by the remote control signals.  
         [0035]    The auxiliary electronic device  48  is also operative to receive and interpret remote control signals. While not shown, the auxiliary electronic device  48  typically has an associated remote control device. The auxiliary electronic device  48 , however, utilizes remote control signals of a predefined or predetermined format that is different than the predefined/predetermined format of the remote control  44 . Rather than using two remote controls, the auxiliary remote control  50  is operative to convert and transmit any remote control signal from the remote control  44  for use by the auxiliary electronic device  48 .  
         [0036]    More particularly, the television  42  provides the remote control signal received from the remote control  44  to the auxiliary remote control  50  when it is necessary and/or appropriate for the auxiliary electronic device  48  to receive/utilize the particular remote control signal that was generated by the remote control  44 . The auxiliary remote control  50  then provides an auxiliary remote control signal (preferably wirelessly) to the auxiliary electronic device  48 . The auxiliary remote control  50  may need to convert or reformat the remote control signal received from the television  42  for the particular format scheme of the auxiliary electronic device.  
         [0037]    In FIG. 4, a simplified functional block diagram of the electronic system  40  is shown. The remote control  44  includes button/key circuitry/logic  60 , a transmission generator  62  and a transmitter  64 . The button/key circuitry/logic  60  is operative to receive a button/key signal from a selected/pressed button/key  46 . The transmission generator  62  is operative to generate/produce a coded remote control signal for the particular button/key selected. The transmitter  64  is operative to transmit (preferably wirelessly, such as via IR) the coded remote control signal. The television  42  includes a display  52 , a processing unit  54 , a remote control signal receiver  56 , and other circuitry/logic/components  58 . The remote control receiver  56  is operative to receive a remote control signal from the remote control  44 . The processing unit  54 , along with the other circuitry/logic/components, processes the remote control signal appropriately.  
         [0038]    The auxiliary remote control  50  includes processing circuitry/logic  66 , a transmission generator  68 , and a transmitter  70 . The processing circuitry/logic  66  is operative to receive the remote control signal from the television  42  which received the remote control signal from the remote control  44 . The transmission generator  68  is operative to provide an auxiliary remote control signal that is coded for the format of the auxiliary electronic device  48 . The transmitter  70  is operative to transmit the auxiliary remote control signal to the auxiliary electronic device  48 .  
         [0039]    The auxiliary electronic device  48  includes a processing unit  74 , a remote control receiver  72 , and other circuitry/logic/components  76 . The remote control receiver  72  is operative to receive an auxiliary remote control signal from the auxiliary remote control that is formatted for the auxiliary electronic device  48 .  
         [0040]    Referring to FIG. 5, there is shown a graphical representation of an exemplary is remote control signal, generally designated RCS (Remote Control Signal), produced and/or generated by any one of the remote control devices  14 ,  44 , and/or  50 . The RCS consists of a first portion P, and a second portion S. The first portion P is a pulse portion of the remote control signal, while the second portion S is a space portion of the remote control signal. The first portion P is constrained to be within a first or pulse time range, duration, or pulse width designated as between t 1  and t 2 , while the second portion S is constrained to be within a second or space time range, duration, or space width designated as between t 2  and t 3 . Each time range has a non-zero duration or minimum duration and a maximum duration. Typically, the pulse time range is between about ten microseconds (10 μsec) to ten milliseconds (10 msec), while the space time range is between about ten microseconds (10 μsec) and ten milliseconds (10 msec). Each button/key of the remote control thus has a unique pulse-space combination (a pulse of a predetermined time range plus a space of a predetermined time range) that is generated and transmitted.  
         [0041]    Referring to FIG. 8, there is depicted a simplified block diagram of an auxiliary remote control, generally designated  80 , and known as an IR Blaster. The IR Blaster is manufactured by Thomson Consumer Electronics of Indianapolis, Ind. The IR Blaster  80  is typical of “IR blaster” devices in which an incoming signal (here a remote control signal) is amplified and/or retransmitted in an IR format to control another electronic device (see FIGS. 3 and 4). In this embodiment, the IR Blaster  80  is utilized to receive, amplify, and retransmit incoming IR remote control signals. The retransmitted IR remote control signals are in an IR/remote control format that is compatible with an auxiliary electronic device. The IR Blaster  80  has IR receiver circuitry/logic  82 , an application specific integrated circuit (ASIC)  86 , and other circuitry/logic  84 . The ASIC  86  is operative to generate/produce and output/transmit IR remote control signals.  
         [0042]    The ASIC  86  includes, among other circuitry/logic  98 , a clock cell  88 , an IR transmitter block/cell  90 , an output compare block/cell  92 , an IR transmitter control register  94 , and an output compare control register  96 . For IR transmissions that do not need modifying, the ASIC provides a pulse and space combination to the IR transmitter control register  94  before the IR remote control signal (the pulse and space combination signal) is transmitted by the IR transmitter cell  90  (i.e. a “normal” is IR transmission). Because of various design considerations, the ASIC  86  is normally constrained to provide a pulse and space combination within pulse and space durations such as described above. When a pulse is to exceed the maximum pulse width, the ASIC provides a space of minimum space width after the pulse of maximum pulse width before another pulse of the remaining pulse time width. The receiving electronic device is typically not affected by the minimum width space within the extended pulse. However, when a space is to exceed the maximum space width, such as that shown in FIG. 6A, the addition of a pulse of minimum pulse width will not generally be accepted by the receiving electronic device. As shown in FIG. 6B, the normal IR output (IR_OUTA UNMODIFIED) from the ASIC produces an unwanted “glitch” pulse at the end of the maximum space width.  
         [0043]    In accordance with an aspect of the present invention, when it is necessary for the ASIC to produce and transmit an IR remote control signal that has a space that is greater than the maximum space width, the ASIC is disabled in order to generate an extended space. In particular, the ASIC IR transmitter cell  90  is disabled while an extended space is generated/produced. The generation/production of the extended space remote control IR signal is provided via a “hardware” embodiment/implementation and/or a “software” embodiment/implementation.  
         [0044]    According to the software embodiment of the present invention, when the ASIC  86  is to produce a space of greater duration than the minimum space width, the output compare timer cell  92  is utilized as an internal software timer while the associated output pin of the ASIC is not used. The IR transmitter cell  90  is utilized to generate the pulse, while the output compare timer cell  92  generates/provides the space. More particularly, when a current pulse-space sequence expires, the IR transmitter cell  90  is rendered inactive by not reloading the pulse and space register  94  for a next sequence. While the IR transmitter cell  90  is inactive, a (logic) low (0 volts) is output on the associated IR_OUT pin of the ASIC  86 . The output compare cell  92  is then set up to expire (i.e. generate an interrupt) at the end of the desired space extension duration (see FIG. 6E). Once the desired extended space duration expires, an output compare timer interrupt is generated. The output compare timer interrupt activates the IR transmitter cell  90  wherein a pulse and space sequence is then loaded into the IR transmitter control register  94  for transmission of the next pulse-space combination.  
         [0045]    According to a hardware embodiment/implementation of the present invention and referring additionally to FIG. 7., when the ASIC  86  is to produce a space of greater duration than the minimum space width, the IR transmitter cell  90  is rendered inactive in preferably the same manner as the “software” implementation. However, an output/output pin of the out compare timer is set up to drive the desired space (or unmodulated pulse) on the associated output pin. When driven, the output of the output compare timer cell  92 , via the output compare control register  96 , will override the IR transmitter output based on the resistance value selected for associated signals as described below. The output compare is thus set up as an “oopen drain” which would not have any effect in the (logic) high state, but would ground the IR-OUT signal in a (logic) low condition. The output compare timer  92  can be triggered or started on either the rising or falling edge of the IR pulse. In the case that the falling edge is used, the output compare timer cell  92  is used to hold the IR_OUT low until a timeout is reached, at which point an interrupt is generated. The interrupt then disables the output compare timer  92  and enables the IR_OUT for the next pulse. This is graphically illustrated by the timing diagrams of FIGS. 6C, 6D, and  6 E.  
         [0046]    [0046]FIG. 7 illustrates in block diagram form, the use of the output compare block/cell  92  to provide a space to the buffer  100  to provide a modified IR_OUT signal. The output compare register  96  provides an output compare enable signal to the output compare block  92  in order to have the output compare block  92  provide the extended space width. The various blocks of the output compare cell  92  provide timing and output of the extended space width to the buffer  100 . The signal from the output compare cell  92  overrides any output from the IR transmitter block  90  by the resistor R 2 . The value of the resister R 2  is chosen to be in the ratio of 10:1 to ensure that the IR-OUT signal can be overdriven by the output compare.  
         [0047]    Referring to FIG. 9, there is shown a flowchart, generally designated  120 , of an exemplary general manner of operation of the present invention. Initially, in step  122 , the remote control determines the space length of the remote control signal (RCS) to be sent. Once the space length of the RCS is determined, it is determined whether the space length exceeds the maximum space width, step  124 . If the RCS does not exceed the maximum space width, then the remote control continues with normal transmission of the RCS by the IR transmitter, step  126 . However, if it is determined that the RCS needs to exceed the maximum space width, RCS generation by the IR transmitter is disabled for a predetermined time corresponding substantially to the length of time of the extended portion of the space, step  128 . This process occurs whether the present invention is implemented in hardware or software.  
         [0048]    Referring to FIG. 10, there is shown a flowchart, generally designated  130 , illustrating an exemplary manner of operation of the present invention with respect to the hardware implemented embodiment of the present invention. In step  132 , the space structure (i.e. the length of the space) is determined. If the space structure is not greater than the maximum space width, step  134 , then the normal transmission scheme is used by the IR transmitter, step  136 . Else, if in step  134  it is determined that the space structure is greater than the maximum space width, the IR transmit pin of the ASIC is set to a general purpose port, step  138 . In step  140 , the general purpose pin is set to make a space. The output compare timer of the output compare cell is set to time the length of the desired extended space, step  142 . Any other software is allowed to be executed until the output compare timer generates an interrupt, step  144 . Thereafter, the IR transmit pin is set to use the IR transmit cell, step  146 . As well, the IR transmitter is set to set up the next pulse-space sequence.  
         [0049]    While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, of adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.