JPH087488A - Method of reading magnetic recording information - Google Patents

Abstract

PURPOSE:To reduce a read mistake by expanding a readable area of a data pulse. CONSTITUTION:When two data pulses DP exist between two clock pulses CP when information is recorded, the clock pulse (pseudo clock pulse CP') to exist between the two data pulses DP is set on operation, and the two data pulses DP are distributed to front/rear of the pseudo clock pulse. That is, by that the two data pulses DP are outputted closely, the matter that the clock pulse CP to output is not followed and is canceled is judged, and the clock pulse CP regarded as being canceled is revived apparently, and regular read is executed. The setting position of the pseudo clock pulse CP' is decided to an intermediate position between the two data pulses DP.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data recording depending on whether the position of one data pulse existing between clock pulses recorded on a magnetic recording layer is the first half or the second half of the distance between two clock pulses. The present invention relates to a magnetic recording information reading method for reading information by determining the state of a binary signal of a pulse.

[0002]

2. Description of the Related Art In recent years, a negative film provided with a magnetic recording layer capable of magnetically recording information has been proposed. In this negative film, since the shooting information is magnetically recorded,
A lot of information can be written in a narrow space, and most of the photographing information desired by the user can be recorded.

The photograph information recorded is binarized (0, 1).
The data is converted into recorded data and recorded. Normally, a clock signal is recorded for each data unit (1 bit).

That is, the clock signal is recorded on the negative film at equal time intervals, and the data signal is recorded between the clock signals. The determination of the data signal is determined by the recording position of the data signal. For example,
"0" if recorded before the intermediate position between clock signals, "1" if recorded after the intermediate position
Is.

FIG. 5A shows an example of a general data read signal. The pulse output to the + side of the 0 level is the clock pulse, and the pulse output to the-side is the data pulse. Comparing each data pulse with the intermediate position between the clock pulses (see the alternate long and short dash line in FIG. 5), this data signal can be read as "0, 1, 0, 1". The output interval between clock pulses is unfixed because the negative film transport speed varies during recording and reading.

[0006]

However, as shown in FIG.
As shown in (B), the data to be recorded is "1, 0".
In this case, when each data is closely recorded with one clock pulse interposed therebetween, the clock pulse to be recorded in the first data pulse recording is canceled by the next data pulse recording, As a result, the clock pulse may not be projected to the + side. Therefore, apparently, two data pulses are recorded between the two clock pulses.

That is, the data pulse outside the predetermined area (area close to the clock pulse) from the intermediate position of the two clock pulses is not compensated for the reading and causes a reading error.

In view of the above facts, an object of the present invention is to obtain a magnetic recording information reading method capable of reducing a reading error by expanding a readable area of a data pulse.

[0009]

According to a first aspect of the present invention, the position of one data pulse existing between clock pulses recorded in a magnetic recording layer is the first half of the distance between two clock pulses. 2 of the data pulse depending on whether it is the second half or the second half
A magnetic recording information reading method for reading information by determining the state of a binarized signal, wherein the two data pulses are detected when two data pulses are detected between the two clock pulses. It is characterized in that the state of the data pulse is discriminated on the assumption that a pseudo clock pulse exists between them.

The invention according to claim 2 is characterized in that the pseudo clock pulse is an intermediate position of two data pulse positions.

According to a third aspect of the present invention, the pseudo clock pulse is located at an intermediate position between the two clock pulses.

[0012]

According to the invention described in claim 1, two data pulses are detected between two clock pulses.
It is judged that the outputs of these two data pulses are close to each other and the clock pulse which should be in the middle of these two data pulses is canceled.

Therefore, each data pulse can be reliably read by determining the state of the data pulse assuming that the pseudo clock pulse exists between these two data pulses.

According to the second aspect of the present invention, by setting the pseudo clock pulse at the intermediate position of the two data pulse positions, one data pulse can always be present between the clock pulses. .

According to the third aspect of the present invention, the pseudo clock pulse is an intermediate position between two preexisting clock pulses. This is because, in general, clock pulses should be output at equal intervals, so that by setting this position as a pseudo clock pulse position, two data pulses can be distributed one by one between clock pulses. it can. If the data pulse cannot be distributed by this, it can be determined that there is some abnormality in the drive mechanism during reading.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows a camera 10 and a photo printing apparatus 12 according to this embodiment. The camera 10 is equipped with a cartridge 16 on one side of which the negative film 14 is wound around a spool 16A and accommodated therein. Camera 1
At 0, a drive reel 22 driven by a motor 20 connected to the control unit 18 is provided. The negative film 14 is frame-fed by locking the leading end of the negative film 14 to the drive reel 22.

As shown in FIG. 1, the negative film 14
Is provided with two perforations 24A and 24B for each image frame 14A. The perforations 24A and 24B are preliminarily drilled and are used for positioning, for example, when the camera 10 is loaded. Therefore, the position of the image frame 14A is determined by the perforations 24A and 24B, and each image frame 14A and the two perforations 24A and 24 corresponding thereto are positioned.
The relative position with B is always the same. Further, the two perforations 24A and 24B are located at both ends of the corresponding image frame 14A in the negative film transport direction.

A magnetic recording layer 26 is provided along the longitudinal direction of the negative film 14 at the widthwise end of the negative film 14 opposite to the side where the perforations 24A and 24B are provided. This magnetic recording layer 2
In 6, various information regarding photographing can be magnetically recorded.

As shown in FIG. 2, the camera 10 is provided with a recording head 28 connected to the control section 18 corresponding to the magnetic recording layer 26 of the negative film 14, and the negative head automatically driven by the driving means. Predetermined information based on the captured image is recorded on the magnetic recording layer 26 when the film 14 is conveyed.

Further, two photoelectric sensors 30 are installed on the conveyance path of the negative film 14 of the camera 10. This photoelectric sensor 30 has the above-mentioned perforation 2
4A and 24B are provided, a light projecting portion and a light receiving portion are provided so as to straddle the front and back of the negative film 14, and photoelectric is generated when a light beam from the light projecting portion is received by the light receiving portion. The sensor 30 outputs a high level signal to the control unit 18.

As shown in FIG. 2, two photoelectric sensors 3 are provided.
The pitch size of 0 is the same as the pitch size of two adjacent perforations 24A and 24B provided on the negative film 14. Here, when the negative film 14 passes between the light projecting section 32 and the light receiving section 34 and two approaching perforations 24A and 24B are simultaneously detected, the recording head 28 is controlled to record the above information. It is supposed to do.

This information is recorded by binarized data. That is, the information is recorded after being converted into bit signals (0, 1).

As shown in FIG. 5 (A '), the recording signal is represented by a pulse signal protruding from the 0 level to the-side (hereinafter referred to as data pulse D _P ), and has a constant time interval (negative film). Clock pulse C output from the 0 level to the + side at equal distances with respect to the 14 transports)
It will be recorded between _P. Here, if recording is performed before the intermediate position of this clock pulse C _P ,
The data pulse D _P indicates “0” and indicates “1” when recorded on the rear side of the intermediate position.

The negative film 14 which has been photographed is rewound into the cartridge 16 again, taken out from the camera 10 and brought into the lab through the DPE store. In this lab, the negative film 10 is developed and placed at a predetermined position of the photo printing device 12.

As shown in FIG. 2, the photo printing apparatus 12
The negative carrier 54 is disposed on the optical axis of the light source 52 that is irradiated during printing. The negative carrier 54 is provided with a drive roller (not shown) that is rotated by the drive force of the drive unit 58 connected to the control device 56, so that the negative film 14 is conveyed in the direction of arrow A in FIG. It has become. Further, the negative carrier 54 has a solenoid 60.
Is provided, and the negative film 14 can be clamped and pressed at the printing position by a signal from the control device 56.

C is provided between the light source 52 and the negative carrier 54.
Each MY filter 62 is interposed so that the MY filters are projected and retracted on the optical axis according to the exposure amount of each color.

The light rays that have passed through the negative film 14 are irradiated onto the photographic printing paper 66 through the lens 64, and the image is printed on the photographic printing paper 66. A shutter 68 is interposed between the photographic paper 66 and the lens 64,
A signal from the control device 56 is used to retract from the optical axis during exposure.

On the conveying path of the negative film 14,
A reading head 70 is arranged on the upstream side of the negative carrier 54 so that the information recorded by the recording head 28 of the camera 10 can be read. The controller 56 has
A memory is provided for recording the information read by the read head 70.

Here, a photoelectric sensor 72 having the same structure as the photoelectric sensor 30 attached to the camera 10 is provided on the path of passage of the perforations 24A and 24B corresponding to the reading head 70 (that is, Two photoelectric sensors 72 are arranged at the same pitch as described above.). Therefore, by the detection signal of the photoelectric sensor 72,
The position of the magnetic recording layer 26 can be recognized.

As described above, the data read by the read head 70 (for example, the data shown in FIG. 5A) indicates whether each data pulse D _P is before the intermediate position between the two clock pulses C _P. The bit signal is deciphered as it is determined whether or not it is later.

Here, as shown in FIG. 3A, two clock pulses C _P are recorded at the time of recording information in the camera 10.
There may be two data pulses D _{P in} between.

In this embodiment, such a waveform is detected.
If these two data pulses D _PKu which should exist between
Lock pulse (pseudo clock pulse C_P')
2 data pulses D_PThis pseudo clock pal
I'm trying to sort before and after.

That is, since the two data pulses D _P are output close to each other, it is determined that the clock pulse C _P to be output cannot be followed and is canceled, and the clock which seems to be canceled. The pulse C _P is apparently restored (pseudo clock pulse C _P '), and normal reading is executed.

In this embodiment, the set position of the pseudo clock pulse C _P 'is set to the intermediate position between the two data pulses D _P.

The operation of this embodiment will be described below. When shooting and recording of information are completed, the negative film 14 (cartridge 16) is taken out from the camera 10, and when the DPE store is requested to print, it is transported to the laboratory from the DPE store. It is placed at 12 predetermined positions.

In this state, the drive unit 58 is driven by the control of the control device 56, and the negative roller 1 is rotated by the rotation of the drive roller.
4 conveys in the direction of arrow A in FIG.

At this time, the photographing information recorded for each image frame 14A is read by the reading head 70 and stored in the memory of the control device 56. The procedure of reading the photographing information will be described later.

When the predetermined image frame 14A reaches the printing position, the solenoid 60 is driven to sandwich and press the negative film 14 at the printing position.

In this state, the shutter 68 is opened and C
By making each of the MY filters 62 appear and disappear on the optical axis according to the exposure amount, the light rays that have passed through the negative film 14 are irradiated onto the photographic paper 66 through the lens 64, and the image is printed on the photographic paper 66. At this time, the stored information about the corresponding image frame 14A is printed, for example, on the back side of the photographic paper 66, or printed on a different subject together with the frame number.

Here, the recorded information is as shown in FIG.
As shown in (A ′), a clock pulse (a group of pulses projected to the + side of the 0 level) C _P , a data pulse (a group of pulses projected to the − side of the 0 level) D _P ,
And is usually recorded so that one data pulse D _P exists between two clock pulses C _{P as} shown in FIG. 5A, and each clock pulse C _P is recorded.
The data pulse D _P existing before the intermediate position between them represents “0”, and the data pulse D _P existing after the intermediate position represents “1”. Therefore, the read data in FIG. 5A is “0, 1, 0, 1”.

By the way, as shown in FIG. 3A, the data to be actually recorded is "1, 1, 1, 0, 1, 0,
In some cases, recording is performed such that there are only nine intervals between the clock pulses C _P , while there are 12 “1, 1, 0, 0, 1, 0”. This is a phenomenon that the negative film transport speed fluctuates and tends to occur at the time of outputting data of "0, 1". The cause is that the first data pulse D _P of data that follows "0, 1" is output in the vicinity of the clock pulse C _P , and then the next data pulse D _P is also output in the vicinity of the clock pulse C _P. As a result, the clock pulse C _P to be output in the middle is canceled. In such a case, it was conventionally unreadable. However, in this embodiment, the information can be read reliably. The information reading procedure will be described below with reference to the flowchart of FIG.

First, in step 100, the counter is reset, and then in step 102, it is judged whether or not the clock pulse C _P is detected.

When the clock pulse C _P is detected, the process proceeds to step 104 to reset and start the clock counter C _c , the first data counter Cd ₁ and the second data counter Cd ₂ .

In the next step 106, the data pulse D
_If it is determined whether _P is detected or not, and if an affirmative determination is made, the process proceeds to step 108, the first data counter Cd ₁ is stopped, the count value at this time is substituted into td ₁ , and step 110 is performed. Move to.

Next, step 110 and step 112
Is a routine for determining whether the pulse detected next is the clock pulse C _P or the data pulse D _P , and the one detected first is affirmatively determined. Here, if the affirmative determination is made in step 110, it is determined that one data pulse D _P exists in the normal form, that is, between the two clock pulses C _P , and the process proceeds to step 114 and the clock counter C _c is stopped, and the count value at this time is substituted for t _c in step 116.

At the next step 118, the clock counter C _c , the first data counter Cd ₁ and the second data counter Cd ₂ are reset and started, and the routine proceeds to step 120.

In step 120, the value of 1/2 of the count value tc of the clock counter C _c (that is,
The intermediate position) is compared with the count value td ₁ of the first data counter Cd ₁ .

As a result of this comparison, when it is judged that td ₁ <tc / 2, the routine proceeds to step 122, where it is judged that the data pulse D _P is in front of the intermediate position, and it is recognized as "0", Returning to step 106, the next data pulse D _P
Wait for detection. When it is determined that td ₁ ≧ tc / 2, the process proceeds to step 124, it is determined that the data pulse D _P is on the rear side of the intermediate position, and it is recognized as “1”,
Returning to step 106, the detection of the next data pulse D _P is waited for.

By the way, in the loop of steps 110 and 112, if the affirmative judgment is made in step 112, it is judged that there are two data pulses D _P between the two clock pulses C _P , and the routine proceeds to step 126. Second to move
Stop the data counter Cd ₂ , then step 1
At 28, the count value at this time is substituted for td ₂ .

At the next step 130, it is judged whether or not the clock pulse C _P is detected, and if an affirmative judgment is made,
In step 132, the clock counter C _c is stopped, and in step 134, the count value at this time is substituted for t _c .

At the next step 136, the clock counter C _c , the first data counter Cd ₁ and the second data counter Cd ₂ are reset and started, and the routine proceeds to step 138.

In step 138, the position of the pseudo clock pulse (count value tc ') is calculated. That is, in the present embodiment, since it is set to the intermediate position of the two data pulses D _P , it can be obtained by the following formula.

Tc '= (td ₁ + td ₂ ) / 2 In the next step 140, in order to read the first detected data pulse D _P , 1/2 of the count value tc' of the position of the pseudo clock pulse is read. value (i.e., the first intermediate position between the clock pulses C _P and the pseudo clock pulses C _P ') and the value of the count value td ₁ according the first data counter Cd ₁ are compared.

As a result of this comparison, when it is judged that td ₁ <tc '/ 2, the routine proceeds to step 142, where it is judged that the data pulse D _P is on the front side of the intermediate position and "0".
Is recognized and the process proceeds to step 146. Also, td ₁ ≧
If it is determined to be tc '/ 2, the process proceeds to step 144, it is determined that the data pulse D _P is on the rear side of the intermediate position, it is recognized as "1", and the process proceeds to step 146.

Next, in step 146, the count value tc "between the position of the pseudo clock pulse and the clock pulse C _P on the rear side is calculated in order to read the second detected data pulse D _P. This tc "is tc-t
It can be obtained by c '.

[0056] count value tc 1/2 value "between the clock pulses C _P position and the rear side of the next step 148 the pseudo clock pulses (i.e., the rear side of the pseudo clock pulses C _P 'clock Intermediate position with pulse C _P )
And a value obtained by subtracting the count value tc ′ indicating the position of the pseudo clock pulse from the second data counter Cd ₁ (that is, the count value at the time of detecting the second data pulse D _P counted from the pseudo clock pulse C _P ′). Are compared.

As a result of this comparison, td ₂ -tc '<tc "
If it is determined to be / 2, the process proceeds to step 150, it is determined that the data pulse D _P is on the front side of the intermediate position, "0" is recognized, the process returns to step 106, and the next data pulse D _P Wait for detection. Also, td ₂ −tc ′ ≧ t
If it is determined to be c ″ / 2, the process proceeds to step 152, it is determined that the data pulse D _P is behind the intermediate position, it is recognized as “1”, the process returns to step 106, and the next data pulse is returned. Wait for D _P to be detected.

[0058] Thus, when the two data pulses D _P exists between one clock pulse C _P, in other words, even if the clock pulse C _P between two data pulses D _P did rise Therefore, it is possible to reliably read each data pulse D _P.

Therefore, the clock pulse C _{P is different from the} conventional one.
The readable area can be expanded to the side closer to, and reading mistakes and misreading can be reduced.

In this embodiment, the pseudo clock pulse C _P 'is set as the intermediate position of the two data pulses D _P , but it may be the intermediate position of the two clock pulses C _P.

[0061]

As described above, the magnetic recording information reading method according to the present invention has an excellent effect that read errors can be reduced by expanding the readable area of the data pulse.

[Brief description of drawings]

FIG. 1 is a plan view of a negative film according to this embodiment.

FIG. 2 is a schematic configuration diagram of a camera and a photo printing apparatus according to the present embodiment.

3A is a characteristic diagram of magnetically recorded data according to the present embodiment, and FIG. 3B is an enlarged view of a part of FIG. 3A.

FIG. 4 is a control flowchart according to the present embodiment.

FIG. 5A is a general characteristic diagram of magnetically recorded data for explaining the conventional technique, and FIG. 5B is a characteristic diagram showing a waveform generated when data pulses are output close to each other. .

[Explanation of Codes] 14 Negative Film (Photographic Film) 26 Magnetic Recording Layer 28 Recording Head 56 Controller 70 Reading Head

Claims (3)

[Claims] 1. A binary signal of a data pulse depending on whether the position of one data pulse existing between clock pulses recorded on a magnetic recording layer is the first half or the second half of the distance between two clock pulses. Is a magnetic recording information reading method for reading information by determining the state of No. 1, wherein when two data pulses are detected between the two clock pulses, a pseudo recording is performed between the two data pulses. A magnetic recording information reading method, characterized in that the state of a data pulse is determined as if a clock pulse exists. 2. The magnetic recording information reading method according to claim 1, wherein the pseudo clock pulse is at an intermediate position between two data pulse positions. 3. The magnetic recording information reading method according to claim 1, wherein the pseudo clock pulse is at an intermediate position between the two clock pulses.