JP3066711U - Video deck - Google Patents

Abstract

(57) [Summary] [Problem] When a sensor or the like is used to detect a dew condensation state, it is necessary to adopt a hardware configuration for detecting the dew condensation. Had been done. SOLUTION: In a state where a video tape is loaded on a head cylinder, a rotational driving force is given only to a take-up reel motor. Then, the occurrence of dew condensation is detected by detecting the tape running speed at this time and determining whether or not the tape running speed is abnormal. Therefore, it is possible to provide a video deck capable of performing highly reliable dew detection with a simple configuration.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a video deck, and more particularly to a video deck capable of detecting condensation on a head cylinder and a video tape.

[0002]

[Prior art]

 A general VCR adopts a method in which a video tape is pulled out of a video cassette, wound around a head cylinder at a predetermined angle, and the video signal of the video tape is recorded and reproduced. If dew condensation occurs on the head cylinder or video tape, the video tape wraps around the head cylinder and normal recording and reproduction cannot be performed. Also, if the video tape is wound around the head cylinder, the video tape, the head cylinder and the like will be damaged.

In order to prevent such inconvenience, conventionally, a sensor for detecting a dew condensation state is provided near the head cylinder so that the device cannot be operated when the dew condensation state is detected. Further, in the technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-150444, a rotation detecting means for detecting the rotation of a tape reel in a video cassette, and the head cylinder in a state where the tape reel is freed upon completion of the tape loading. A control means for rotating the reel for a very short time is constituted, and the presence or absence of condensation is detected by detecting whether or not the reel rotates by the rotation detecting means when the head cylinder rotates for a very short time.

[0004]

[Problems to be solved by the invention]

 The conventional video deck described above has the following problems. That is, in the former conventional example, dew condensation on the head cylinder can be detected, but if dew condensation occurs on the video tape, no countermeasure can be taken. In addition, it is necessary to configure hardware such as a sensor for detecting the dew condensation state, which has resulted in an increase in cost and an increase in the number of assembling steps.

In the latter technique disclosed in Japanese Patent Application Laid-Open No. Hei 6-150444, the head cylinder must once wind the video tape at the time of dew condensation. It is difficult to control the rotation of the head cylinder for a short time. Furthermore, since the rotation direction of the head cylinder is not parallel to the running direction of the video tape, sending the video tape in a dew condensation state may cause the video tape to come off the guide. Also, in the case of a head cylinder where the upper drum rotates and the lower part is fixed, dew condensation may occur only at the lower part and the dew state may not be detected even if the video tape is stuck to the head cylinder . The present invention has been made in view of the above problems, and has as its object to provide a video deck capable of performing highly reliable dew detection with a simple configuration.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the invention according to claim 1 is a video deck provided with a function of detecting dew condensation, in which a take-up reel motor generates a rotational driving force while a video tape is loaded on a head cylinder. The motor driving means, the tape running speed detecting means for detecting the tape running speed while generating the rotational driving force by the motor driving means, and the tape running speed detected by the tape running speed detecting means are always constant. And a dew detecting means for detecting that dew has occurred when the speed is different from the speed.

In the invention according to claim 1 configured as described above, the video deck according to the invention has a function of detecting condensation on a head cylinder, a video tape, and the like. In order to realize such a function, the motor driving means generates a rotational driving force on the take-up reel motor in a state where the video tape is loaded on the head cylinder, and the motor driving means applies the rotation to the take-up reel motor. When the rotational driving force is generated, the tape traveling speed detecting means detects the tape traveling speed while generating the rotational driving force by the motor driving means.

When the tape running speed detecting means detects the tape running speed, the dew detecting means detects that dew condensation has occurred when the tape running speed detected by the tape running speed detecting means is different from the normal speed. Is detected. That is, in the present invention, the motor driving means generates the rotational driving force only on the take-up reel motor and does not apply the rotational driving force to the cylinder head. At this time, if the video tape sticks to the cylinder head due to dew condensation, the running of the tape is hindered, and the video tape is sent at a speed different from the normal speed. Therefore, the occurrence of dew condensation is detected by detecting such an abnormality in the tape running speed.

[0009] Here, the motor driving means only needs to be able to run the tape in the loading state without applying a rotational driving force to the head cylinder, and is supplied in the same loading state as during normal recording / reproducing. For example, only the rotation of the reel or the take-up reel may be performed. At this time, in order to prevent the video tape from wrapping around the capstan, it is preferable to send the tape with the capstan and the video tape in a non-contact state.

The tape running speed detecting means only needs to be able to detect the tape running speed, and its configuration is various. As an example of such a configuration, the invention according to claim 2 is the video deck according to claim 1, wherein the tape traveling speed detecting means detects a rotation cycle of a supply reel and a take-up reel of the traveling video tape. Thus, the tape running speed is detected.

In the invention according to claim 2 configured as described above, the tape running speed detecting means detects a rotation cycle of a supply reel and a take-up reel of the running video tape. Then, the tape traveling speed is detected based on the rotation cycle of the reel. That is, a normal video deck is configured to generate a pulse corresponding to the rotation speed of the reel by, for example, providing a reflection plate or the like on the lower surface of the reel to detect the remaining amount of tape.

Therefore, in the present invention, the tape running speed is detected by adopting a configuration similar to the above configuration. Of course, in a video deck originally equipped with such a pulse detection mechanism, this mechanism can be used for detecting the tape running speed in the dew detection according to the present invention, and the pulse is not necessarily generated by the reflector. Also, various configurations such as utilizing a Hall element can be adopted.

Further, the configuration for detecting the tape traveling speed as the tape traveling speed detecting means does not necessarily have to be the above-described configuration, and the invention according to claim 3 is an example of another configuration. Alternatively, in the video deck according to claim 2, the tape running speed detecting means detects a tape running speed by detecting a control signal recorded on a video tape.

In the invention according to claim 3 configured as described above, the tape traveling speed detecting means detects a control signal recorded on a video tape. Then, the tape running speed is detected based on the timing of the control signal. That is, in a normal video deck, a control signal is recorded on a control track of a video tape for controlling a tape running speed or the like. Therefore, the tape traveling speed is detected by detecting the timing of generation of the pulse based on the control signal.

[0015] Since the tape running speed is detected in this manner, the dew detecting means grasps the tape running speed at normal times based on the reel pulse timing when no condensation has previously occurred and the control pulse timing. If this is done, the presence or absence of condensation can be determined by comparison with the normal tape traveling speed. If it can be determined that condensation has occurred, it is better not to perform operations such as recording and playback until the condensation is removed. Therefore, as an example of such a configuration, the invention according to claim 4 is a device according to any one of claims 1 to 3, wherein the cassette EJECT is provided when the dew detection unit detects the occurrence of dew. It is configured so that operations other than the above are impossible.

In the invention according to claim 4 configured as described above, when the dew detection unit detects the occurrence of dew, operations other than the cassette EJECT are disabled. In other words, the video deck does not respond to the user's operation even if the user wants to perform the operation such as recording / playback when condensation occurs, so that it is possible to prevent accidental recording / playback. it can. Further, since no inconvenience occurs even if the cassette EJECT is performed, only such an operation can be executed.

In addition, dew condensation occurs when a video deck is suddenly brought from a cold outdoor place in winter to a warm room with heating. Therefore, it is preferable to detect the occurrence of dew condensation when such a sudden change in situation occurs, and the invention according to claim 5 is configured as described above according to any one of claims 1 to 4. In this VCR, the detection of the occurrence of dew condensation by the dew detection means is performed only once after the power plug of the VCR is inserted into the power tap.

That is, when the video deck is used after the above-mentioned sudden change of the external environment occurs, it is considered that the power supply plug of the video deck is often inserted. Therefore, the dew detection means performs dew detection only once after inserting the power plug of this VCR into the power tap. Needless to say, since a cassette must be inserted here, if the cassette is inserted when the power plug is inserted into the power strip, dew condensation detection can be performed as it is, and if no cassette has been inserted, it can be inserted. The dew condensation may be detected at the point of time.

As described above, if the dew condensation is detected each time the power plug is inserted into the power tap, it is possible to cope with a sudden change in the external environment. On the other hand, specifications for places where dew condensation is likely to occur, and a configuration that enables detection every time the VCR is turned on and enables the user to provide detection support in order to more reliably detect dew condensation Needless to say, this is also possible.

[0020]

[Effect of the invention]

 As explained above, the present invention detects the occurrence of dew condensation by detecting the tape running speed without rotating the head cylinder, so a video deck that can perform highly reliable dew detection with a simple configuration is provided. Can be provided. Further, according to the present invention, the tape traveling speed can be detected with a simple configuration.

Further, according to the present invention, the tape running speed can be detected with a simple configuration. Further, according to the invention of claim 4, it is possible to prevent the inconvenience of the video deck which may be caused by the occurrence of dew condensation. Furthermore, according to the invention of claim 5, it is possible to detect whether or not dew condensation has occurred when the external environment changes rapidly.

[0022]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a video deck according to an embodiment of the present invention. Referring to FIG. 1, the video deck includes a video mechanism 10, a system controller 20, and a signal processing circuit 30. The system controller 20 has a predetermined program execution environment including a CPU, a memory, and the like (not shown), and controls the connected video mechanism 10 and the signal processing circuit 30.

That is, the signal processing circuit 30 includes a tuner, a VIF, an RF converter, and the like. The VIF and the like in the signal processing circuit 30 are controlled in an appropriate order under the control of the system controller 20, and video recording / reproducing is performed. Is generated. The video mechanism 10 includes various mechanisms for recording and reproducing signals on a video tape, which will be described later, and for running the tape. The video signal is recorded and reproduced under the control of the system controller 20, and the dew condensation is detected. Is performed.

The video mechanism 10 mainly includes a head system circuit for recording and reproducing signals on and from a video tape, and a motor system circuit for running the video tape. The head system circuit includes a full erase head 11, a head cylinder 12, and an AC (audio control) head 13, and each head is connected to a signal processing circuit 30.

The motor system circuit includes a capstan 14, a drum motor 15, and a reel motor 19, and each motor is controlled by the system controller 20. The capstan 14, the drum motor 15 and the AC head 13 are connected to a servo circuit 16, and the servo circuit 16 is connected to a system controller 20 together with a reel motor 19.

The servo circuit 16 performs a feedback control of the capstan 14 and the drum motor 15 in accordance with a PG pulse indicating the rotation of the head cylinder 12, an FG pulse indicating the rotation of the capstan, and a control pulse output from the AC head 13. The tape drive is controlled by the system controller 20 together with the reel motor 19, so that the tape can run in a predetermined form. The video deck according to the present embodiment is provided with rotation cycle sensors 18a and 18b for detecting the rotation cycle of the take-up reel 17a and the supply reel 17b, and is used for detecting the remaining amount of tape.

FIG. 2 shows the travel route of the video tape and the arrangement of various heads. The full erase head 11, the head cylinder 12, and the AC head 13 are arranged in this order with respect to the travel route of the video tape. I have. At the time of video recording / reproduction, the video tape is pulled out by the tape guide post and the back tension post, and the video tape is brought into contact with the full erase head 11, the head cylinder 12, and the AC head 13. At this time, the capstan 14 and the pinch roller are pressed against each other in the capstan 14, and the video tape is sent out by the rotation of the capstan 14.

At the time of video recording, the video signal generated via the antenna is subjected to predetermined processing by the signal processing circuit 30 and sent to the head cylinder 12 and the AC head 13, and the video signal in the loading state is loaded by the head cylinder 12. A video track is recorded on the tape, and an audio track and a control pulse are recorded on the video tape by the AC head 13. Further, at this time, the full erase head 11 is driven, and full-width erasing is performed on the video tape before recording the video track or the like.

Also, when dew condensation is detected, as shown in the figure, the video tape is pulled out by the tape guide post and the back tension post, and the video tape comes into contact with the full erase head 11, the head cylinder 12, and the AC head 13. Is done. In the capstan 14, as shown in FIG. 2, the capstan 14 and the pinch roller are not pressed against each other in order to prevent the video tape from being entangled.

In this case, the tape travel is performed by transmitting the rotational driving force of the reel motor 19 to the take-up reel 17 a via the reel base, and the rotational driving force is applied to the head cylinder 12. Not to be. Therefore, the system controller 20 for controlling the reel motor 19 constitutes the motor driving means. Here, the system controller 20 detects the tape running speed, and determines whether or not the tape running speed is abnormal by detecting whether or not the tape running speed is abnormal. It is performed as follows.

FIG. 3 is a schematic diagram showing a signal recording pattern of a video tape. In FIG. 1, a video tape signal is written in a head cylinder 12 after the entire width of the video tape is erased by a full erase head 11, and an audio signal is written in an upper part by an AC head 13 and a control signal is written in a lower part. This control signal is recorded once for one frame of video signal. Therefore, the tape traveling speed is detected by detecting the control pulse output from the AC head in the loading state. That is, the AC head 13 and the system controller 20 constitute the tape running speed detecting means.

In the configuration described above, the system controller 20 controls each unit in accordance with a flowchart shown in FIG. 4 for detecting dew condensation. In step S100, it is determined whether or not the power plug of the video deck according to the present embodiment has been inserted into the power tap. If not, the process exits the control routine for detecting dew condensation described below. That is, in the present embodiment, dew condensation is detected at least once after the power plug is inserted into the power tap. When it is determined in step S100 that the power plug has been inserted into the power tap, it is determined in step S110 whether or not the cassette is in the inserted state.

If it is determined in step S110 that the cassette is not inserted, the process waits until it is determined that the cassette is inserted. Next, in step S120, the video tape is brought into a loading state. That is, as shown in FIG. 2, the video tape is pulled out by the tape guide post and the back tension post, and the video tape is brought into contact with the full erase head 11, the head cylinder 12, and the AC head 13.

In this state, in step S130, the reel motor 19 is controlled to apply a rotational driving force to the take-up reel 17a. Then, in step S140, it is determined whether or not the tape running speed obtained from the timing of the control pulse is abnormal as compared with a previously obtained normal tape running speed. If it is not determined in step S140 that the tape traveling speed is abnormal, the process exits the dew condensation detection routine.

If it is determined in step S140 that the tape running speed is abnormal, it is determined in step S150 whether or not the user has given a cassette EJECT instruction, and the process waits until the cassette EJECT is performed. That is, at this stage, operations other than the cassette EJECT are not accepted. If it is determined in step S150 that the cassette eject instruction has been given, the process returns to step S110 and waits until a cassette is inserted again. That is, once the condensation is detected, the next time the cassette is inserted, the condensation is detected again. As described above, the system controller 20 constitutes the dew condensation detecting means.

Next, the operation of the present embodiment in the above configuration will be described. FIG. 5 shows an example of a control pulse when the video deck according to the present embodiment is normal and when dew condensation occurs, with respect to a time axis. In the figure, a control pulse is detected for a time T in order to detect the tape running speed. During the time T, eight control pulses are output in a normal state, and "8 / T" is held in advance as a normal tape running speed.

If the user plugs the power plug into the power tap when the user brings the video deck from outdoors to indoors, it is determined that the power plug has been inserted in step S100 in FIG. Enter the detection routine. Here, it is assumed that dew condensation has occurred on the head cylinder 12 when the video deck is brought from indoors to outdoors.

Here, when the user inserts the cassette into the video deck, the system controller 20 drives the tape guide post in step S120 through the determination in step S110. As a result, the video tape is pulled out from the cassette, and a loading state as shown in FIG. 2 is obtained. Further, in step S130, the system controller 20 controls the reel motor 19 to apply a rotational driving force to the take-up reel 17a via the tape base.

At this time, since no rotational driving force is applied to the head cylinder 12 and dew condensation occurs on the head cylinder 12 as described above, the video tape sent in the loading state is Stick to 12. Therefore, the video tape is not fed smoothly as compared with a state in which no condensation occurs, and the video tape fed while being in contact with the AC head 13 does not run smoothly. Of course, the video tape will not run if the head cylinder is stuck to such an extent that it opposes the running force of the video tape.

In any case, as shown in FIG. 5, only a smaller number of control pulses are detected during the time T than in the normal state. In this example, the tape running speed is represented by "3 / T", which is smaller than the normal speed [8 / T]. That is, the tape running speed in this case is abnormal, and it is determined by the determination in step S140 that dew condensation has occurred, and the flow shifts to standby for the cassette EJECT in step S150. As a result, it is not necessary to configure a dew condensation detection sensor or the like, and it is possible to detect dew condensation without causing entrainment in the head cylinder.

In this embodiment, the tape running speed is based on the control pulse. However, it is sufficient that the tape running speed can be compared with a predetermined normal speed. Various embodiments can be adopted. For example, the tape running speed may be detected based on the detection of the rotation of the tape reel, which is used for detecting the remaining amount of the tape.

FIG. 6 is a perspective view showing the lower part of the reel base of the take-up reel 17a and the supply reel 17b. The take-up reel base 17a1 and the supply reel base 17b1 are respectively connected to the rotation shafts 17a2 and 17b2. Four substantially fan-shaped reflectors 17a3 and 17b3 are arranged on the bottom surface at equal intervals in the peripheral direction, and below the respective reflectors 17a3 and 17b3, phototransistors 18a1 and 18b1 and light emitting diodes 18a2 and 18a2 are provided. 18b2 are provided. The light emitting diodes 18a2 and 18b2 are directed toward the reflection plates 17a3 and 17b3, and the phototransistors 18a1 and 18b1 detect the reflected light from the reflection plates 17a3 and 17b3.

As a result, each time the rotation shafts 17a2 and 17b2 make one rotation, four pulses are output from the phototransistors 18a1 and 18b1. The output pulses of the phototransistors 18a1 and 18b1 are input to the system controller 20, where the rotation periods of the take-up reel base 17a1 and the supply reel base 17b1 are detected, and the tape running speed is calculated. Is done. If the tape running speed is detected by such a configuration, and other configurations and controls are performed in the same manner as in the above-described embodiment, the dew condensation can be detected using the rotation detection of the tape reel.

As described above, in the present invention, the video tape is loaded on the head cylinder, and only the take-up reel motor is given a rotational driving force. Then, the occurrence of dew condensation is detected by detecting the tape running speed at this time and determining whether or not the tape running speed is abnormal. Therefore, it is possible to provide a video deck capable of performing highly reliable dew detection with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a video deck according to an embodiment of the present invention.

FIG. 2 is a diagram showing a travel route of a video tape and an arrangement of various heads.

FIG. 3 is a schematic diagram showing a signal recording pattern of a video tape by a schematic diagram.

FIG. 4 is a flowchart of a system control for detecting dew condensation.

FIG. 5 is a diagram showing an example of control pulses when the video deck according to the embodiment is normal and when dew condensation occurs.

FIG. 6 is a diagram showing a mechanism for detecting a rotation cycle at a lower portion of the reel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Video mechanism 11 ... Full erase head 12 ... Head cylinder 13 ... AC head 14 ... Capstan 15 ... Drum motor 16 ... Servo circuit 17a ... Take-up reel 17b ... Supply reel 18a, b ... Rotation cycle sensor 19 ... Reel motor 20 ... Syscon 30 ... Signal processing circuit

Claims (5)

[Utility model registration claims] 1. A video deck having a function of detecting dew condensation, comprising: a motor drive means for generating a rotational drive force on a take-up reel motor in a state in which a video tape is loaded on a head cylinder; A tape running speed detecting means for detecting the tape running speed while generating a rotational driving force, and a notice that dew condensation has occurred when the tape running speed detected by the tape running speed detecting means is different from a normal speed. A video deck comprising: a dew detecting means for detecting dew condensation. 2. The video deck according to claim 1, wherein said tape running speed detecting means detects a tape running speed by detecting a rotation cycle of a supply reel and a take-up reel of a running video tape. A video deck characterized by the following. 3. The video deck according to claim 1, wherein said tape running speed detecting means detects a tape running speed by detecting a control signal recorded on a video tape. VCR characterized by doing. 4. The video deck according to any one of claims 1 to 3, wherein when the dew detection means detects the occurrence of dew, operation other than cassette EJECT is disabled. VCR featuring. 5. The video deck according to any one of claims 1 to 4, wherein the detection of dew condensation by the dew detection means is performed only once after a power plug of the video deck is inserted into a power tap. A video deck characterized by performing.