JPH075559A - Magnetic recorder for camera - Google Patents

Abstract

PURPOSE:To perform converting operation for data expressed by ASCII code so as to compress data capacity in order to express the data with small number of bits and record many data on a magnetically recording part. CONSTITUTION:An interface part 1 inputs/outputs the data expressed by the ASCII code between an information equipment on the external part of a camera and the camera. A data converting part 2 compresses the data expressed by the ASCII code. A recording/reproducing part 3 magnetically records the data converted by the data converting part 2 on the magnetically recording part 5 through a magnetic head 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording device for a camera using a film provided with a magnetic recording medium.

[0002]

2. Description of the Related Art In recent years, among commonly used cameras, a camera has been developed which records shooting information of the camera on a film. The film is provided with a magnetic recording portion for writing the various information. And
For example, in Japanese Unexamined Patent Publication No. 4-273238, when data is written in a personal computer, an electronic notebook, etc., ASCII code is used. By recording data using this ASCII code, it becomes highly versatile.

[0003]

However, since the above-mentioned ASCII code has a large data capacity, it is necessary to convert the data code, which complicates the equipment of the equipment and is not efficient. . In addition, the number of bits required to represent the data increases. However, since the number of bits that can be recorded by the camera is small, there is a problem in that the amount of data that can be stored becomes small when the data is represented by ASCII code.

The present invention has been made in view of the above problems, and provides a magnetic recording device for a camera which does not complicate the equipment and can represent data with a small number of bits and record a large number of data. The purpose is to do.

[0005]

That is, according to the present invention, as shown in FIG. 1, in a magnetic recording device of a camera using a film with a magnetic recording portion, an information code external to the camera is used to display an ASCII code. The interface unit 1 for inputting the converted data, the data changing unit 2 for compressing the data represented by the ASCII code, and the data changed by the data changing unit 2 via the magnetic head 4. The recording unit 5 is provided with a recording / reproducing unit 3 for magnetic recording.

[0006]

In the magnetic recording device of the camera of the present invention,
In a magnetic recording device for a camera that uses a film with a magnetic recording unit, the interface unit 1 inputs data represented by an ASCII code from an information device outside the camera. The data represented by the ASCII code is compressed by the data changing unit 2. Then, the data changed by the data changing unit 2 is
Magnetic recording is performed from the recording / reproducing unit 3 to the magnetic recording unit 5 via the magnetic head 4.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing an embodiment of a camera to which the magnetic recording device of this camera is applied. In the figure, 11 is a main microcomputer (M-μCOM; hereinafter abbreviated as M microcomputer) for performing the sequence and control of this camera. This M microcomputer 11
A known photometry circuit 12, distance measurement circuit 13, shutter control mechanism 14, focus adjustment mechanism 15, display circuit 16, storage circuit 17, and communication circuit 18 are connected to the.

The display circuit 16 displays various information such as photographing information and date data. In addition, the storage circuit 17
Is composed of a non-volatile memory such as an EEPROM, and stores the number of frames to be photographed, camera adjustment data, and the like.

The communication circuit 18 is a circuit for inputting a control signal from the outside of the camera and data created outside. A serial communication line of a personal computer (hereinafter abbreviated as PC) or the like can be connected to the communication circuit 18.

A magnetic information control circuit 19 is coupled to the M-microcomputer 11, and a data recording operation and a data reproducing operation are executed based on a command from the M-microcomputer 11. A photo interrupter (hereinafter abbreviated as PI) 20 is for detecting the moving amount and moving speed of the film. And
The signal of the PI 20 is converted into a pulse signal by the signal processing circuit 21, and then transferred to the M-microcomputer 11 to detect the moving amount and speed of the film.

The M microcomputer 11 is also provided with a date data imprinting circuit 22 and a driving circuit 23.
The date data imprinting circuit 22 is for creating date data and optically recording this data on the film 25. Then, the drive circuit 23 drives the motor included in the film feeding mechanism 24 for feeding the film 25 based on the control signal of the M-microcomputer 11. still,
Reference numeral 26 is a cartridge containing the film 25.

Further, the M-microcomputer 11 is provided with a plurality of switches described below. That is, the rewind switch (REWSW) 27 is a switch operated when rewinding the film 25 which has been photographed to the film cartridge 26. The back cover switch (BKSW) 28 is a switch that is turned on when the back cover (not shown) is open.
By detecting the change in the state of the switch (from ON to OFF), the M-microcomputer 11 detects that the film cartridge 26 is loaded in the camera.

Further, a release switch (RELSW) 2
Reference numeral 9 is a switch for starting the exposure operation, and when the external control permission switch (EXTSW) 30 is turned on,
Communication with a PC becomes possible. Data playback switch (RE
The VSW) 31 is a switch operated when data is reproduced from the film 25 on which data has already been recorded on the magnetic track after the photographing is completed. Further, the power switch (PWSW) 32 is a switch linked to the power supply of the camera.

FIGS. 3 and 4 are views for explaining in detail the film feeding mechanism of the camera and its peripheral portion in the embodiment, and FIG. 5 is a perspective view showing the film cartridge. In FIGS. 3 and 4, the output shaft of the film winding / rewinding motor (M1) 33 provided in the camera body is
A pinion gear 34 is provided, and this pinion gear 34 meshes with the sun gear 35. The sun gear 35 meshes with the planet gear 36. Further, the planetary gear 36 is supported via a gear arm 37 so as to revolve around the rotation axis of the sun gear 35.

A take-up spool 38 for taking up a film is rotatably provided in a film take-up chamber (not shown) provided on the right side of the rear of the camera body. A spool gear 39 that meshes with the planetary gear 36 when the planetary gear 36 revolves counterclockwise is integrally provided on the upper end surface of the take-up spool 38. On the other hand, from the lower outer peripheral surface of the take-up spool 38, a locking claw 39a that engages with the perforation of the film to be described later is formed to project.

Further, an idle gear 40 is provided at a position where the planet gear 36 meshes with the planet gear 36 when the planet gear 36 revolves clockwise. At this time, the planetary gear 36 is
As shown, idle gears 40, 41, 42, 43
Via a coupler gear 44 described later.

On the other hand, a cartridge storage chamber (not shown) for storing the cartridge 26 is provided on the left side of the rear of the camera body. Further, above the cartridge 26, a coupler gear 44 having a coupler 45 whose tip projects in a minus (-) shape is rotatably provided. As shown in FIG. 5, the coupler 45 engages with the spool groove 46 provided on the upper end surface of the cartridge 26, and is integrated with the spool groove 46 about the axis.

A film feeding motor (M2) 47 is provided on the camera body. A pinion gear 48 is provided on the output shaft of the film feeding motor 47. The pinion gear 48 meshes with the sun gear 49. The planetary gear 50 meshes with the sun gear 49 and is supported via a gear arm 51 so as to be revolved around the rotation axis of the sun gear 49. Since the tension of the spring 52 acts on the gear arm 51, the planet gear 50 and the idle gear 43 mesh only when the film feeding motor (M2) 47 rotates counterclockwise.

Further, the film 25 is exposed by the light from the opening 53 formed in the camera body. Opening 5
Guide parts 54a and 54b for restricting the displacement of the film in the width direction are provided above and below 3. Also,
A sprocket 55 is arranged near the opening 53. The sprocket 55 meshes with the perforations 25 a of the film 25 and rotates in conjunction with the movement of the film 25. A gear 56 and a pressure roller 57 are integrated with the rotation shaft of the sprocket 55.
The gear 56 meshes with the gear 58. Further, a disc 59 having a slit is integrated with the rotary shaft of the gear 58.

When the sprocket 55 rotates, the disc 59 rotates at the rotational speed enlarged by the gears 56 and 57, and the PI of the disc 59 crosses the PI 20 each time.
20 outputs a signal. This signal is sent to the signal processing circuit 21.
Is converted into a pulse signal.

The magnetic head 60 is arranged at a position facing the pressure contact roller 57 so as to sandwich the film 25. The magnetic head 60 is fixed to a substrate 61 which is slidable in the directions of arrows A and B in FIG.

When the solenoid 62 is not driven, the tension of the spring 63 acts on the substrate 61, and the magnetic head 60
Does not press the film 25. And the solenoid 62
The output shaft of the substrate 6 is slidable in the directions of arrows C and D shown
It is fixed at 4. Pin 6 fixed to this substrate 64
5 is in the position shown in FIG. 3 because the tension of spring 66 acts on substrate 64. However, when the solenoid 62 is driven, the board 64 slides in the direction of the arrow D in the drawing, and the pin 65 slides along the side surface 67 of the board 61. Then, the substrate 6
1 slides in the direction of arrow A in the figure against the tension of the spring 63, and the magnetic head 60 presses the film 25.

Next, an example of the communication circuit of the camera of the embodiment will be described with reference to FIG. In the figure, PC68
The RS232C port is provided as standard. Using the four signal lines in this RS232C, P
It is possible to control the M microcomputer 11 from C68.
The PC 68 uses the SD line to transfer data to the M microcomputer 1
Transfer to 1.

This data is input from the serial data receiving port RXD of the M microcomputer 11. M microcomputer 1
1 transfers the data to the PC 68 using the RD line. This data is output from the serial data transmission port TXD of the Mmicrocomputer 11. The serial communication method is asynchronous communication that does not require a synchronous clock. D
TR and DSR are control lines used to time data transmission and reception. Since the signal level of the RS232C standard is different from the signal level of the Mmicrocomputer 11, the level converter 69 is required.

Next, the configuration and operation of the magnetic information control circuit 19 will be described with reference to FIG. Sub-microcomputer (S-μCOM; hereinafter abbreviated as S-microcomputer) 70
Performs a data recording operation and a data reproducing operation based on the command from the M microcomputer 11. Port CS, DAT
A and CLK are used for communication between the S microcomputer 70 and the M microcomputer 11. The communication is a serial communication method.
The SYNC of the port is used to send a synchronous clock necessary for recording data on the magnetic track.

The output of the S-microcomputer 70 is the control circuit 71,
It is supplied to the magnetic head 60 via the buffers 72a and 72b. Then, the signal from the magnetic head 60 is
Head amplifier 73, differentiating circuit 74, comparator 75,
It is supplied to the S-microcomputer 70 via the edge detection circuit 76. In addition, the control circuit 71, the buffers 72a and 72
b, head amplifier 73, differentiating circuit 74, comparator 7
5, the edge detection circuit 76, the interface circuit 77
Are configured.

In this way, the interface circuit 77
Is a reproducing circuit for converting a signal output from the magnetic head 60 into a signal that can be input to the S-microcomputer 70;
It includes a recording circuit for supplying a current to the magnetic head 60 according to the output of the. DATA backup memory is M
The data transferred from the microcomputer 11 is stored until the recording operation is started. As this memory, a non-volatile memory that does not lose data even when the power of the camera is turned off is required. Reference numeral 78 is a DATA backup memory, and Q1 is a transistor for driving the solenoid 62.

FIGS. 8A to 8C are time charts when data is recorded by the FM modulation method. FM
In the modulation, two synchronous clocks input to the port SYNC are used to form 1-bit data on the magnetic body. When the data is "1", the current supplied to the head is inverted every time the synchronous clock is input. On the other hand, when the data is "0", the current supplied to the head is inverted for the first synchronous clock. It does not respond to the second sync clock. By the above operation, the magnetic track is magnetized in the same shape as the current waveform.

The current flowing to the magnetic head 60 is output from the buffers 72a and 72b of the interface circuit 77. The control circuit 71 controls the buffers 72a and 72b according to the states of the ports DTOUT and EN. When the operation of passing a current to the magnetic head 60 is not executed, the buffer 72
The outputs of a and 72b are held at high impedance.
Therefore, the outputs of the buffers 72a and 72b do not collide with the signals of the magnetic head 60 during data reproduction.

FIGS. 9A to 9E are time charts for reproducing the data recorded by the FM modulation from the magnetic track. As the film moves, the playhead
A signal is generated according to the magnetization state of the magnetic track. When the reproducing head passes through the changing position from the N pole to the S pole (or the S pole to the N pole) in the magnetized state, the reproduction signal reaches a peak. In order to read the data recorded on the magnetic track, it is necessary to detect the peak of this signal. The reproduced signal is amplified by the head amplifier in the interface circuit. The amplified reproduction signal is input to the differentiating circuit 74. The output of the differentiating circuit 74 rapidly crosses GND at the peak position of the reproduction signal.

The output of the comparator 75 is inverted at a position where it crosses GND. Therefore, the comparator 75
Output is the same as the magnetic pattern of the magnetic track. The output of the comparator 75 is further fed to the edge detection circuit 7
6 is input. The edge detection circuit 76 outputs the signal Hi
(High level) to Lo (Low level) or Lo
The change from HI to Hi is detected, and a pulse signal is generated.

This pulse signal is output to the port DTIN of the S-microcomputer 70. This pulse signal includes a clock pulse (“C” on the time chart) that separates data from each other and a data pulse (“D” on the time chart) for distinguishing “1” from “0”. Mixed. The S-microcomputer 70 determines that it is "1" when there is a data pulse between clock pulses. When there is no data pulse, it is determined to be "0".

Next, the communication protocol between the M-microcomputer 11 and the PC 68 will be described with reference to the time chart of FIG. First, when the PC 68 opens the RS232C line, the DRT bar (inverted signal of DRT) of the M-microcomputer 11 expressed by the relational expression 1 is "H".
It changes from i "to" Lo ".
When detecting that the DRT bar has become “Lo”,
The DSR bar (inverted signal of DSR) represented by the relational expression is set from "Hi" to "Lo".

[0034]

[Equation 1]

[0035]

[Equation 2]

On the PC68 side, the DSR bar is "L".
When it becomes “o”, it is determined that the M-microcomputer 11 is in a communicable state.
The M microcomputer 11 outputs command data used for identifying the communication mode. Therefore, in any communication mode, the command data is located at the beginning of the communication data. M microcomputer 11 is PC6
By transferring the end code toward 8, the communication mode ends. When the above PC 68 inputs the end code,
Close the RS232C line. The DTR bar is
It changes from "Lo" to "Hi". Upon detecting this change, the M-microcomputer 11 changes the DSR bar from "Lo" to "Hi".
Set to to prohibit communication operation.

FIG. 10A is a time chart of the a mode. The a mode is a mode in which the data transferred from the PC 68 is stored in the DATA backup memory 78 in the magnetic information control circuit 19. The PC 68 outputs the number of frames following the command a. This piece number is PC68
Specify the area of the backup memory that stores the data output by. The number of data (N) is added in consideration of convenience when the M microcomputer 11 inputs data. M
The microcomputer 11 compresses the capacity of the input data DT _{1 to} DT _N by a conversion operation. Then, the converted data is stored in the backup memory. When the storage of the data ends, the M-microcomputer 11 outputs the end code.

FIG. 10B is a time chart of the b mode. This b mode is for the PC 68 to read the data stored in the DATA backup memory 78. Following the command b, the PC 68 outputs the number of frames indicating the area of the backup memory. The M-microcomputer 11 reads the data in the designated area from the backup memory and performs a conversion operation on the read data.
The converted data DT _{1 to} DT _N are output toward the PC 68. The number of data (N) is added in consideration of convenience when the PC 68 inputs data. PC6
The data output by 8 or the data input by the PC 68 is formed based on the ASCII code table shown in FIG.

Next, the operation of the M-microcomputer 11 will be described with reference to the flow charts of FIGS.
FIG. 12 shows a main routine of the M-microcomputer 11. When the PWSW 32 is turned on, the M-microcomputer 11 is power-on reset. Then, in step S1, I / O
Port initialization Memory initialization is performed. Next, in step S2, the state of the BKSW 28 is determined. Here, if the BKSW 28 changes from off to on, it means that the film is loaded and the back cover of the camera changes from open to closed. In this case, the process proceeds to step S3 and the motor M2 is driven to feed the film 25 from the cartridge 26. Further, the motor M1 is driven to wind the film 25 on the spool by a predetermined amount.

In step S2, the BKSW 28
If there is no change, go to step 4 and REWSW2
State 7 is determined. Here, when the REWSW 27 is operated, the process proceeds to step S5, and the film 25 that has been photographed is rewound to the cartridge 26. In conjunction with this operation, the S-microcomputer 70 records the data stored in the DATA backup memory 78 on the magnetic material of the film 25.

If there is no change in REWSW27 in step S4, the process proceeds to step S6 and REVSW3
A state of 1 is determined. Here, if the REVSW 31 is operated, the process proceeds to step S7. In this step S7, the entire film 25 is wound up. Then, in conjunction with this operation, the S-microcomputer 70 reproduces the data recorded on the film 25. The reproduced data is DAT
It is stored in the A backup memory 78.

When there is no change in REVSW 31, the process proceeds from step S6 to step S8, and the state of EXTSW 30 is determined. If the EXTSW 30 is turned on, the process proceeds to step S9 and the subroutine "communication" is executed. On the other hand, if the EXTSW 30 is off, the process proceeds from step S8 to step S10, and the state of the PWSW 32 is determined. If the PWSW 32 is off, the operation of the M-microcomputer 11 is stopped. On the other hand, if the switch is on, the process proceeds to step S11.

In step S11, the aperture value is calculated at the shutter speed based on the data input from the photometric circuit 12. Next, in step S12, the calculated data is displayed by the display circuit 16. Then, in step S13, the state of the RELSW 29 is determined. Here, if there is no change in the RELSW 29, the process proceeds to step S2. When the switch is operated, the process proceeds to step S14, and the focus adjusting mechanism 15 is controlled based on the data from the distance measuring circuit 13.

In step S15, data to be recorded on the magnetism of the film 25 is created. Then, this data is transferred to the S-microcomputer 70. The S-microcomputer 70 stores this data in a predetermined area of the DATA backup memory 78. Next, in step S16, the shutter control circuit 14 is controlled to expose the film 25. Then, in step S17, the film 25 is wound by one frame.

Next, the subroutine "communication" will be described with reference to FIG. This subroutine is shown in Figure 1.
0 shows the operation of the time chart shown in FIG. First, in step S21, command data from the PC 68 is input. Then, in step S22, it is determined whether or not the command is the "a mode". here,
If the command is "a mode", the process proceeds to step S23,
The number of pieces is input. Next, in step S24, the number of data N is input. Then, the N data DT _{1 to} D
T _N is input in step S25. Here, PC6
DT ₁ to DT _N from 8 are data represented by ASCII code that forms one character with 8 bits.

Then, in step S26, DT ₁ -D
T _N is converted to dt ₁ to dt _n . By this conversion operation, the data described in ASCII code is converted into a data format convenient for recording on the magnetic material on the film 25. The data conversion method will be described later.
By this conversion, the data capacity is compressed. Then
In step S27, the compressed data dt ₁ to DT _n
Are transferred to the S microcomputer 70. The S-microcomputer 70 stores this data in the area of the DATA backup memory 78 designated by the number of frames. Then, in step S28, the end code is output to the PC 68. As a result, the communication in the a mode ends and the process is returned.

On the other hand, the above steps S22 to S
When shifting to 29, it is determined whether or not the command is the “b mode”. If the command is not "b mode", the process proceeds to step S28 and the operation ends. If the command is "b mode", the flow advances to step S30 to input the number of frames. Then, in step S31, data dt ₁ to DT _n is inputted through S microcomputer 70 from the backup memory. The above data dt _{1 to} dt _n
Is data stored in a predetermined area designated by the number of frames. This data has been compressed in the process of step S26.

In step S32, this data is converted into DT ₁ to DT _N based on the ASCII code. In step S32, the reverse operation of the data conversion operation of step S26 is performed. Then, in step S33,
The data number N is output to the PC 68. Then, after DT ₁ to DT _N are output to the PC 68 in step S34, the process proceeds to step S28.

Here, steps S26 and S2 in FIG.
The data conversion operation of No. 7 will be described. In the table of FIG. 14A, data transferred from the camera to the PC 68,
Alternatively, the data transferred from the PC 68 to the camera is shown, and this data is described in ASCII code. Representing the data in ASCII code facilitates connection with an information device such as a PC.

Further, each data includes a character for identifying the type of data. For example, in the figure, the data I indicates that it is "TV" and the data I is the shutter speed. The expression method of such data is
Although it is convenient for using data, it has a drawback that the amount of data is large. However, the amount of data that can be recorded on the magnetic material on the film is not large. Therefore, such a data representation method is not preferable.

The table shown in FIG. 14B is a data-compressed version of the table shown in FIG. The data shown in the table of FIG. 9B is recorded on the magnetic material of the film. Characters that identify the type of data to compress the data are removed. This is because the data can be identified if the recording order is known. Numerical data following the identifying character can also be expressed without using the ASCII code.

Next, a method of compressing numerical data will be described with reference to FIGS. In FIG. 15, I
The shutter speed of is expressed in the apex system.
Considering the shutter speed range, 1 byte (8bi
Numerical data can be represented by t). As shown in FIG. 16, one byte is divided into two, and the upper 4 bi
Let t be an integer part and the lower 4 bits be a decimal part. Then, it may be assumed that the decimal point exists between bit4 and bit3. That is, the upper 4 bits represent 0 to 15, and the lower 4 bits represent 0.0 to 0.9. Therefore, "TV15.5" becomes A5 [HEX] and is compressed to 1 byte.

AVs, BVs, and SVs represented by the II, III, and IV apex systems can be similarly compressed to 1 byte. V is the focal length of the lens. The focal length can be expressed by 2 bytes. VI is data indicating the subject distance, and may be considered in the same manner as I above. The date data of VII, VIII, and IX, and the number of frames of X can be represented by 1 byte each. Furthermore, the data of XI is data that cannot be compressed.

The data following "ASCII" can be arbitrarily recorded by the user. Therefore, the expression form of the data is unknown and the data cannot be compressed. When reproducing the data recorded on the film and transferring the data to the PC 68, the reverse operation of the data conversion is executed.

[0055]

As described above, according to the present invention, the ASC
Since the data capacity is compressed by converting the data described by the II code, the data can be efficiently recorded on the magnetic material on the film having a small recording capacity.

[Brief description of drawings]

FIG. 1 is a block diagram showing the concept of a magnetic recording device for a camera of the present invention.

FIG. 2 is a block diagram showing an embodiment of a camera to which the magnetic recording device of this camera is applied.

FIG. 3 is a diagram illustrating in detail the film feeding mechanism of the camera and its peripheral portion in the embodiment.

FIG. 4 is a diagram illustrating in detail the film feeding mechanism of the camera and its peripheral portion in the embodiment.

FIG. 5 is a perspective view showing a film cartridge.

FIG. 6 is a diagram illustrating an example of a communication circuit of the camera of the embodiment.

FIG. 7 is a block configuration diagram showing details of a magnetic information control circuit 19 of FIG.

8A to 8C are time charts when data is recorded by the FM modulation method.

9A to 9E are time charts for reproducing data recorded by FM modulation from a magnetic track.

10A and 10B are an M microcomputer 11 and a PC 6.
8 is a time chart explaining a communication protocol with 8.

FIG. 11 is a diagram showing an ASCII code table.

FIG. 12 is a main flowchart explaining the operation of the M microcomputer 11.

FIG. 13 is a subroutine of “communication” for explaining the operation of the M-microcomputer 11.

14A is a table of data transferred from the camera to the PC 68 or data transferred from the PC 68 to the camera, described in ASCII code. FIG.
(B) is a table obtained by compressing the table of FIG.

FIG. 15 is a diagram showing an example of compression of numerical data.

FIG. 16 is a diagram showing an example in which 1-byte (8-bit) numerical data is divided into two and expressed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Interface part, 2 ... Data conversion part, 3 ... Recording / reproducing part, 4 ... Magnetic head, 5 ... Magnetic recording part, 11 ... Main microcomputer (M microcomputer), 12 ... Photometric circuit, 13 ... Distance measuring circuit, 14 ... Shutter control mechanism, 15 ...
Focus adjusting mechanism, 16 ... Display circuit, 17 ... Memory circuit, 18
... communication circuit, 19 ... magnetic information control circuit, 20 ... photointerrupter (PI), 21 ... signal processing circuit, 22 ... date data imprinting circuit, 23 ... driving circuit, 24 ... film feeding mechanism, 25 ... film, 26 ... Patrone, 27 ... Rewind switch (REWSW), 28 ... Back cover switch (B
KSW), 29 ... Release switch (RELSW), 3
0 ... External control permission switch (EXTSW), 31 ... Data reproduction switch (REVSW), 32 ... Power switch (PWSW).

Claims (1)

[Claims] 1. In a magnetic recording device for a camera using a film with a magnetic recording portion, an interface means for inputting data represented by an ASCII code from an information device outside the camera, and the above-mentioned ASCII code. A magnetic recording device for a camera, comprising: data changing means for compressing the obtained data, and magnetic recording means for magnetically recording the data changed by the data changing means in the magnetic recording portion.