KR20020007351A - Flash memory card adapter for stereo systems - Google Patents

Abstract

The present invention provides an adapter 10 for reproducing or recording a selection and other audio programs stored in a digital medium such as a flash memory card 18 using a conventional stereo system. And an adapter using the cassette mechanism of the stereo system as an interface for the digital medium.

Description

Flash memory card adapter for stereo system {FLASH MEMORY CARD ADAPTER FOR STEREO SYSTEMS}

Rapid advances in computer technology and related fields have resulted in the development of data storage media such as flash memory cards that are extremely compact, energy efficient and inexpensive. Although such media are primarily designed for use as memory for storing digital data, for example in laptop computers, digital cameras and other similar uses, such media can also be used to digitally store selections or other audio programs. Can be. For example, using MPEG2 or other data compression techniques, about four minutes of selection can now be stored in two megabytes of digital memory and reproduced in an acceptable manner. Moreover, in the near future, it is expected that flash memory cards with capacities up to 16 megabytes and even more will be released.

Therefore, using such a flash memory card, it is possible to distribute music to the general public not only using a conventional stage such as a record store, mail order catalog, etc., but also an unusual stage such as the Internet.

A significant problem in introducing new media such as flash memory cards is that such flash memory cards are not compatible with the currently available stereo systems. The public who plays music has a conventional stereo system, i.e. a system capable of playing music from live broadcasts such as AM or FM radio or TV or from pre-recorded media such as records, CDs or analog or digital cassettes. Used to play music. It is no surprise that a typical hi-fi enthusiast has many pre-recorded selections in one or more of these formats and tends to antagonize new types of pre-recorded media that are incompatible.

The present invention relates to an adapter for playing or recording a selection and other audio programs stored in a digital medium such as a flash memory card using a conventional stereo system. To an adapter using the cassette mechanism of the stereo system as an interface.

1 shows a block diagram of the main elements of the invention.

Fig. 1A is a diagram showing in detail how information on a conventional flash memory card can be formatted.

2 is a block diagram showing a conventional cassette player / recorder.

3 is a plan view of a cassette adapter constructed in accordance with the present invention.

4 is a schematic plan view of a cassette adapter according to the present invention.

5 is a flow chart illustrating the basic operation of the adapter of FIG.

6 is a flow chart illustrating the fast forward / reverse function.

7 is a block diagram of the battery charger and brake assembly for the adapter of FIG.

Figure 8 shows the stop / power down subroutine in a flow chart.

9 is a flow chart illustrating an alternative fast forward / reverse function.

10 shows a variant embodiment with a replaceable output module.

Figure 11 shows a variant embodiment with a digital recording module.

It is a first object of the present invention to provide an adapter for a replaceable flash memory card that can be used in a cassette or an existing stereo system having the same magnetic storage medium interface.

It is a second object of the present invention to provide a cassette adapter that can be easily used by a consumer without requiring any special training or any additional expensive equipment.

It is a third object of the present invention to provide an adapter which is constructed and arranged to be connected with a conventional stereo system in order to maintain the full functionality of the integrated cassette player even when used with the adapter.

It is a fourth object of the present invention to provide a cassette adapter comprising a battery and a charging device.

Other objects and advantages of the present invention will become apparent from the following description. In short, the adapter constructed according to the invention comprises a housing similar to that of a conventional cassette. Within such a housing, a flash memory card or other solid state memory containing digital data is disposed.

Audio data is retrieved from such a card, compressed, converted into corresponding analog signals, and supplied to the playback head of a conventional cassette player. Means are provided for maintaining almost all the functions of the cassette player including the functions of fast forward, fast reverse and the like.

Preferably, a generator is also provided that recharges the battery that powers the adapter. Advantageously, the same generator can be used to load the cassette player's motor to simulate the end of the tape. Optionally, the output assembly of the adapter is modular and may be suitable for outputting signals to other devices such as earphones. The recording head may also be provided to record data in the flash memory.

Referring now to Figure 1, a cassette adapter 10 constructed in accordance with the present invention includes a microprocessor 12 used to control the operation of the adapter. The microprocessor receives information from a reel sensor 14, which is used to monitor the movement of one or two dummy reels, as will be described in more detail below. The adapter 10 further comprises an address pointer 16, which addresses the leakage of information from the replaceable flash memory card 18 and the transfer of information to the replaceable flash memory card 18. Used to control inflow.

As shown in more detail in Fig. 1A, the flash memory card 18 is divided into several sections. This section comprises a plurality of data sections 20, which hold actual data for the audio program, for example a plurality of selections. The flash memory card 18 further includes a table of contents 22, which is used to recognize the address of each of the numerical selections. Finally, section 24 may also be provided for control data, which is used by the adapter 10 for various control functions.

As can be seen above, it is believed that the data corresponding to the audio selection are preferably compressed during recording to ensure that the data storage capability of the flash memory card 18 is maximized. When data is retrieved from the flash memory card 18, the data is first decompressed or expanded by the pressure reducer 26. Next, digital-to-analog conversion is performed by the D / A converter 28.

The converter 28 converts the digital signal from the replaceable card 18 into a corresponding analog signal. Amplifier 30 is used to amplify the analog signal. Finally, analog output stage 32 is used to transmit the analog signal to the cassette player section of a conventional stereo system. Analog output stage 32 may also include other processing circuitry, which processing circuitry, as will be described below, may be compatible with cassette players of conventional stereo systems and signals expected by cassette players of conventional stereo systems. It may be necessary to convert the analog signal.

As shown in Fig. 2, a typical stereo system includes a tape cassette player 34 having a mechanical section 36 for controlling the mechanical function of the tape cassette player, and an electrical section 38 for controlling signal processing. do. The machine section 36 comprises a plurality of control switches or other similar control means 40, which are typically associated with cassette players such as playback, record, fast forward, fast reverse, and the like. It is activated by the user or automatically to perform the associated function. The machine section 36 further comprises a spindle motor 42 and a capstan motor 44. It should be appreciated that the motors 42 and 44 are shown for illustrative purposes and that in some tape cassette players one or more motors may be used for a designated purpose. Moreover, other mechanical and electromechanical elements are also commonly present in tape cassette players, and these other mechanical and electromechanical elements are not shown since they do not serve the present invention.

The electrical section 38 includes an audio function controller 46, a playback head 48, an amplifier 50, a de-emphasis circuit 52, a signal processor circuit 56 and one or more speakers 58. . If the stereo player 34 is also a recorder, the electrical section 38 is a sound source 62, i.e. a microphone, any other component of the system such as a jack for inputting a signal to be recorded, a radio or a CD player. It may further include a coupling for connecting to. The signal from the sound source 62 is transmitted to the record head 68 via the emphasis circuit 64 and the signal processor 66. On the other hand, although only a single circuit is shown in Fig. 2, it should be appreciated that two or more circuits may be used for each of the functions described above for stereo and multi-channel systems. The audio function controller 46 controls the various circuits of the electrical section 38.

Usually, when a regeneration controller (not shown) is activated, the spindle motor 42 starts to rotate the spindle in a conventional cassette and the capstan motor rushes into the cassette and passes over the regeneration head 48 at a constant speed. The magnetic tape contained in the cassette is moved in a predetermined direction. At this time, the playhead reads the analog signal stored on the tape and transfers the signal to the amplifier 50. Audio signals on magnetic tape are very noisy and in most cases may not be acceptable for high fidelity selection. Therefore, over the years, various approaches have been developed to remove or reduce noise, including, for example, by emphasizing certain frequency components. After amplification is performed, the signal is passed through circuit 52 which de-emphasizes the signal at a particular frequency and generally corrects the signal for some processing effect that may be added to remove noise. After passing through the circuit 52, a signal is supplied to the signal processor 56, which separates the supplied signal into a suitable channel and supplies the signal to the speaker 58. Volume control, and other adjustments required by the user via the audio function control 46 may also be implemented by the signal processor 56.

The elements 62-68 reverse this process so that sound can be recorded on magnetic tape.

In the present invention, since there is no magnetic tape, it is provided to mimic all the usual functions performed by a normal cassette player. Therefore, when the adapter 10 is inserted into a conventional cassette player, the player, via all or at least a majority of the functions of the controllers 40 and 46, operates the flash memory card 18 through the speaker 58. Plays a selection of songs stored digitally on the computer.

Referring now to FIGS. 3 and 4, the adapter 10 comprises a housing 70, which is substantially the same as the housing of a conventional cassette, and consequently the housing 70. There are two holes 72 and 74. Two dummy reels 76 and 78 are disposed inside the housing 70, and the reels 76 and 78 are concentrically mounted in the holes 72 and 74, respectively. The reels 76 and 78 are dummy reels in that these reels do not loosen or constrain the magnetic tape as in the case of conventional cassettes. Coupled with the reels 76 and 78 are sensors 80 and 82 which are used to monitor the respective movement of the reels 76 and 78, as will be described below. .

On one side of the housing 70, such as the top side 84, two removable panels 86, 88 are provided. These panels allow for access into the interior space of the housing 70. Panel 88 is used to access flash memory card 18, and panel 86 is used to exchange read / write head 90, which is described in more detail below. In the simplest embodiment, the read / write head 90 includes an output stage 32.

The housing 70 further includes a battery 100, a battery charger 102, a digital circuit 106 and an analog circuit 108. The battery 100 supplies power to various electrical components contained in the housing 70.

The operation of the adapter will now be described in relation to the flow chart starting from FIG.

First, the adapter 10 is inserted into the cassette player 34 so that the spindle (not shown) extends through the holes 72 and 74 to engage the reels 76 and 78. Sensors 80 and 82 are used to determine the functionality required by the user. Initially, the spindle is idle and no function is required from the adapter. Thus, the adapter 10 is idle.

At regular intervals, microprocessor 12 queries the sensor to check if the reel has started to move (step 200). In step 202, if an exercise is detected, it is assumed that the user has activated the PLAY control. Alternatively, individual sensors can be used to detect the playhead 48, which is responsive to the operation of the play button or in response to the play button, as shown in FIG. Forward toward the housing 70.

Next, the rotational speed of the reel moving in step 204 is measured. As mentioned above, the flash memory card 18 includes a table of contents section, which contains not only the information that each selection starts and ends, but also the entire audio program of the flash memory card 18. Include length or duration. In step 206, this total length is used in conjunction with the reel's speed of movement to search or inspect to establish an index number (step 208). This index will be described below but is used for the fast forward and reverse functions.

Next, the address pointer 16 is set to an address for starting the first music selection on the flash memory card 18, as defined in the table of contents (step 210). In step 212, as described above in connection with FIG. 1, the first byte of music at the first location is retrieved and played (step 214). As a result, the output stage 32 generates an electromagnetic signal similar to the signal generated by a conventional cassette.

Within the cassette player, the playback head 48 senses the signal from the output end 32 and acts as if the playback head 48 operates in a conventional cassette, thereby starting to play back the tape. As the first data byte is processed and reproduced, the next group of bytes is retrieved by the address pointer 16 in step 216 and converted during operation to be reproduced as described above. In step 218 the table of contents table is checked to see if the current byte is the last byte. If the current byte is the last byte, the playback process ends after the last byte is played (step 220) and the stop subroutine is started. If the current byte is not the last byte, the playback process continues. Between each individual selection (assuming flash memory card 18 includes one or more selections), the microprocessor can insert artificial gaps of 1-3 seconds, as is common with conventional tape.

As described above, the volume and frequency are adjusted by the user using the cassette player control unit in accordance with normal operation functions.

The adapter is also designed to fulfill other common functions. For example, Fig. 6 is a flowchart showing the fast forward and fast reverse functions in a flow chart. While regeneration is normally performed (step 214), the reels are monitored by sensors 80 and 82 to determine the direction and speed of rotation of the reels (step 230). (For most cassette players, only one reel of the reels is rotated for playback and high speed forward, and the other reels are rotated in the opposite direction for high speed reverse). If the reel is rotating at normal speed (step 232), normal playback continues. If a fast rotational reel is detected in step 232, a determination is made as to whether a fast forward or reverse function is required in step 234.

When fast forward is detected, playback is paused in step 236 and the address pointer 16 is advanced. More specifically, the address pointer is advanced at a speed proportional to the rotational speed of the moving reel. For example, if at step 204 (see Fig. 5) a pulse is detected from the reel 76 every four seconds, and at step 206 it is determined that the flash memory card 18 contains 1000 seconds of music, step 208 In, if each exponent (1 ... 250) corresponds to the bytes of the group over the entire time, a maximum exponent of 1000/4 = 250 is established. As normal playback continues, for each pulse from the sensor, the exponent slowly increments with the address pointer so that 4 seconds of music is played. While fast forward is being implemented, the exponent is incremented faster according to the pulse from the sensor and the address pointer is advanced at a faster rate from one group of bytes to the next group of bytes, so for every pulse 4 bytes Is skipped (step 236). The reel speed is sampled at regular intervals (step 238). If the reel is slower than normal speed, normal playback resumes at the last position of the address pointer. If the reel continues to rotate at high speed, the position of the address pointer is checked against the background of the table of contents to ensure that the end of the recorded program has not been reached. If the end of the recorded program has been reached, a stop subroutine is started in step 242. If the end of the recorded program has not been reached, the address pointer continues to advance.

If fast reverse (or rewind) is detected in step 234, the address pointer is decelerated or decremented at high speed in the same manner as the address pointer is incremented (accelerated) in step 236. In step 246 the reel speed is checked. If the reel speed returns to the normal speed, normal playback resumes (step 214). If the reel speed remains high, then at step 248 the location of the address pointer is checked to determine if the first byte has been reached. If the first byte has not been reached, step 244 is continued. If the first byte has been reached, a stop subroutine is initiated at step 250.

Power to the components of the adapter 10 is mainly supplied by the battery 100. While substantially no mechanical operation is performed within the adapter 10, the life of the battery 100 can last for a fairly long time, but the battery charger system 102 is provided within such an adapter, thereby improving the life of the battery. It would be advantageous to extend it to almost infinite.

As shown in more detail in FIG. 7, battery charger 102 includes a generator coil 104 for this purpose, which is connected to one of the reels, namely reel 76. Furthermore, the reel 76 is provided with a plurality of permanent magnets 110 and the generator coil 104 is disposed adjacent to the reel 76 such that reel is rotated by the spindle motor 42, or During the fast forward transition, electricity is generated in the generator coil 104. This current is rectified by a full wave rectifier 120, the rectified current is supplied to a DC / DC converter 122, and the DC / DC converter 122 supplies the rectified current to the battery 100. Convert to a voltage level compatible with. Finally, the output of the DC / DC converter 122 is supplied to a voltage regulator 124, which regulates the voltage from the DC / DC converter 122 and then adjusts that voltage. To charge the battery 100. In most cases, only a single coil 104 may be sufficient, as only the reels associated with the forward movement of the tape in a conventional cassette are driven. However, if desired, a second coil, rectifier and a DC / DC converter (not shown) may be provided, which is connected to the other reel 78. In this case, the voltage regulator 124 supplies the charging current generated by the reel of either the reel 76 or the reel 78 to the battery 100.

As mentioned earlier, one of the features to be implemented is the STOP function. A stop is necessary when the user activates the corresponding push button or when the end of the program on the flash memory card is reached. The first case is relatively simple to implement, because in a typical cassette player, the spindle motor and capstan motor stop when the user presses the stop push button. Therefore, this case can be easily recognized by the sensor monitoring the movement of the reels 76 and 78, and is processed as shown in the flow chart of FIG. In step 214, the normal playback order is implemented as described above. In step 400, a test is performed to detect a STOP command from the cassette player 34. If either one of the reels is not in motion, a stop command may be taken and the microprocessor 12 may stand-down with a low power supply to the adapter 10 as follows. )) Mode. First, preferably, the current position of the address pointer 16 representing the last music byte to be played is maintained or stored by the microprocessor 12 (step 402), so that when the playback is resumed, the adapter continues to select the current tune. Enable playback. Next, in step 404 the microprocessor directs a power-down sequence to conserve energy. In step 406 the reel's movement is monitored to detect a playback command. When such a command is detected, the playback mode is resumed at the position where the playback mode was interrupted, as indicated by the address pointer 16 (step 214).

The end of the music table of contents of the provided flash memory card has little difficulty to manipulate, since there is no direct connection between the adapter 10 (or cassette) and the cassette player 34. As used herein, the term "end" refers to the front or beginning portion of a program reached in response to a fast reverse or rewind operation, or the last part of a table of contents reached by a normal playback or fast forward operation. . In a cheaper cassette player, there is no provision for detecting the end of the tape. Instead, it is believed that the user will soon press the stop button knowing that the music is no longer playing. However, in the case of the present invention, it is extremely undesirable to wait for a stop command, because waiting for a stop command wastes energy. Therefore, as shown in step 408 or FIG. 8, if a stop command is not received but an end portion is detected, i.e., if the address pointer indicates the beginning or end of the program, the adapter ( 10) is powered down (step 404).

In more advanced systems, the load on the spindle motor can be monitored by the cassette recorder 34, and if a sudden increase in the load is detected, the tape end (or tape jam) is assumed to automatically stop. In a variant embodiment, the present invention mimics this function by applying a load or 'brake' to a suitable reel as follows (step 410.) Referring again to Figure 7, an electronic switch for a shunt. 130 is provided, and this shunt electronic switch 130, when in the closed state, shunts the coil 104. This switch 130 is operated by the microprocessor 12. Step 408 Is detected, the microprocessor 12 outputs a command to close the switch 130. Thus, the switch 130 shunts the coil 104. Kigo should take the, unexpected jeokyigodo relatively large load is similar to the load generated by the end portion of the ordinary tape to the spindle motor. Cassette player to generate an automatic stop command as described interpret this as a tape end event described above.

Also shown in Figure 7 is a modifying means that provides a brake mechanism, which comprises a solenoid 140, a brake shoe 142 and a solenoid driver 144. In this embodiment, when the end of the program is detected at step 408, microprocessor 12 sends a command to solenoid driver 144. In response, solenoid driver 144 actuates solenoid 140. Thus, the solenoid causes the brake shoe 142 to be in frictional contact with the reel 76. Thus, when applied as above, the brake shoe 142 effectively decelerates the reel 76 or even stops the reel 76. This suddenly increases the load on the spindle motor in the same way as when the tape reached its end.

The functions described so far are imitations or duplicates of the usual functions related to cassette players. However, the adapter 10 contains more information than a simple magnetic tape in a conventional cassette, and the operation of such an adapter can be modified to operate more effectively using this information. For example, often a user may want to skip a particular selection, or may want to replay a selection that has already been played. For most cassette players, the user can only achieve this by roughly advancing or reversing the tape and then playing the tape at a new location on the tape. Spending most of this time using this method results in a user not listening to any selection, or reaching the desired selection to listen to the previous selection, because the user has made a gap between the selection and the selection. Or the desired selection is over, which results in the user listening to the middle part of the selection.

More complex cassette players exist that can detect the beginning and end of a selection from the silence gap between the selection and the selection. In such a player, when the user presses the fast forward button, for example, the player uses the playhead to monitor the tape until a gap is detected, and the player stops if it indicates that the next selection is located. Of course, this feature is still a waste of time, especially if the current selection is quite long. Moreover, passages of silence, in which the volume in selection is extremely low, are often mistaken as gaps.

This problem is solved as follows in the present invention. As mentioned above, the beginning and end portions of each selection on the flash memory card 18 are known from the table of contents (section 24). Therefore, the adapter can be programmed to use this information. Referring to Fig. 9, during normal regeneration (step 214), the reel is monitored as described above. If a fast forward command is detected in step 500, then in step 502 the address of the beginning of the next song selection is examined in the table of contents. In step 504, this address is loaded into the address pointer 16. Thus, playback can be resumed with a new selection. The same process can be used to return to the previous selection when a fast reverse is detected.

This mode of operation can be preprogrammed. Alternatively, a manual selection switch 150 may be provided on the housing 70 (see FIG. 6) to select the mode described by the flow chart of FIG. 6 or the mode described by the flow chart of FIG. Can be. Alternatively, this mode of operation may be a selectable parameter stored in the control data section 27 of the flash memory card 18.

Referring back to FIG. 1, the main embodiment of the present invention is shown in which a D / A converter provides data to a cassette regeneration coil module 170, which mimics a magnetic analog tape. It is configured and arranged to. As shown in Fig. 10, the cassette regeneration coil module 170 includes an amplifier 30, an emphasis circuit 31, a coil driver 33, and a coil 35. The emulation circuit 31 emulates a specific frequency component of the signal according to a conventional noise reduction scheme. The purpose of this circuit 31 is to ensure that the sound from the cassette player 34 is not distorted due to the operation of the de-emphasis circuit 52. The signal from the emphasis circuit 31 is applied to the coil 35 by the coil driver 33.

However, the adapter 10 may be used independently or may be used in connection with other systems. For this purpose, the cassette regeneration coil module 170 can be replaced via a panel 86 (see FIG. 4) to be replaced with another module. Several such modules are also shown in FIG.

For example, module 170 is a headphone module. It consists of an amplifier 180 and a headphone jack 182. When such a module 172 is installed, the adapter 10 is a stand alone music player, which directly flash memory card 18 through a pair of earphones (not shown) connected to the headphone jack 182. Can be used to play a program on the

Module 178 is a stereo output module. It consists of an amplifier 184 and a conventional stereo jack 186. When such a module is installed, the program on the flash memory card 18 can be played through a conventional stereo system by connecting the audio jack 186 to one of the external input ports of the conventional stereo system.

Module 187 is an RF module, which consists of an amplifier 188 and an RF transmitter 190. In this configuration, the adapter is used as a standalone transmitter for transmitting analog signals originating from the flash memory card 18 via a radio frequency link, for example to a stereo receiver tuned to a specific frequency.

Finally, the embodiment of Figure 11 shows a recording module 190, which is preferably suitable for receiving audio information in the form of digital data. Data received from the digital interface 192 is stored in the buffer 194 and then loaded into the flash memory card 18 for later playback. Such digital data can be received from the digital output of a conventional stereo system, or from a CD player or the like. Alternatively, analog data may be received. In such a cassette, analog data can still be sampled and the corresponding digital data can be stored in flash memory.

Preferably all such models, shown collectively in FIG. 3 as the read / write head 90, are inserted into the housing through the panel 84. In the configuration with the module of FIG. 10 or FIG. 11, the adapter 10 can be operated, or can be a standalone unit, in which the adapter 100 is not connected to a motor, so that the battery 100 It may not be charged.

While the present invention has been described with reference to various preferred embodiments, it should be appreciated that these embodiments are merely illustrative of the present invention and that the same object may be achieved by other means. Accordingly, the embodiments described above are illustrative rather than restrictive of the appended claims.

Claims (1)

In a digital adapter inserted into an analog cassette player to replace a conventional analog cassette, A replaceable digital data storage medium storing digital data indicative of audio sound; A controller for retrieving the digital data from the storage medium; A converter for converting the digital data into an analog signal; And An interface for extending the analog signal to the external head of the cassette player in a conventional analog cassette format Digital adapter comprising a.