JP2000163832A - Mode detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve detective precision by optically detecting a rotary phase of a cam gear with an optical detection means arranging a gap in an optical path between a light emitting element and a light receiving element and in the optical path existing in a surface parallel to the radial direction of the cam gear. SOLUTION: When the cam gear 6 is rotated, a detecting beam through an input translucent body 14 is transmitted/interrupted repeatedly by a short width window 30 and a wide width window 31, and an output signal is obtained from the light receiving elements 24, 25, 26. The phases of the output signals 32, 33 are compared with each other. When the phase of the output signal 33 is delayed from the output signal 32, the cam gear 6 is rotated to left, and when the phase of the output signal 32 is delayed, the cam gear 6 is rotated to right is discriminated. At a power re-throw-in time, by arranging an optical guide part 19 on the edge of the short width window 30 adjacent to the wide width window 31 at the angle required for rotating the cam gear 6 to an initial position, the necessary/unnecessary of reset operation is detected. That is decided by the signal polarity of the output signals 32, 34 of the light receiving elements 24, 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mode detection apparatus applied to a mode detection of a mechanism operation in a recording / reproducing apparatus such as an audio disk, a video disk, and a video tape recorder.

[0002]

2. Description of the Related Art FIG. 14 to FIG.
FIG. 1 is a plan view showing a conventional mode detection device described in Japanese Patent No. 1569. In the figure, reference numeral 101 denotes a slider which moves in the a and b directions in the figure to control a mechanical mode;
Is a support shaft of the contact gear 103, 103 is a contact gear having a contact 141 on the back surface, 104 is a motor, 106 is a contact gear 1
03, a driving gear B for driving the slider 101;
Reference numeral 120 denotes a position detection board having an arc-shaped pattern 142 on the back surface; 121, a worm gear fixed to the rotating shaft of the motor 104; 122, a transmission gear train that meshes with the worm gear 121 to transmit the driving force of the motor 104; 130, drive gears A that mesh with the transmission gear train 122 to drive the contact gear 103, 137 is a support shaft of the drive gear B 106, 141 is a contact for position detection,
Reference numeral 2 denotes an arc-shaped pattern for position detection provided on the position detection substrate 120, G denotes a common electrode, and A, B, and C denote detection electrodes.

Next, the operation of the conventional mode detection device will be described. The rotational power of the motor 104 is transmitted from the worm gear 121 via the transmission gear train 122 to the drive gear A130.
To drive the contact gear 103. Next, the drive gear B 106 is rotated by the contact gear 103 to drive the slider 101. At this time, the stop position of the slider 101 is determined by the contact 141 provided on the back surface of the contact gear 103.
Slides on the arc-shaped pattern 142 on the position detection substrate 120 and conducts between the common electrode G and one or two of the detection electrodes A, B, and C to select a predetermined signal output and stop. This is to detect the position.

FIGS. 18 and 19 are views showing the configuration of a conventional mode detection device for performing optical detection. In both figures, 23 is a light emitting element that emits detection light, 24 is a light receiving element, 201 is a motor, 202 is a pulley provided on the rotating shaft of the motor 201, 203 is a window 205 for optical detection, A reduction gear for transmitting the driving force to the cam gear 204; 206, an optical path of the detection light; 207, a belt for transmitting the rotational force of the pulley 202 to the worm gear 209;
Reference numeral 208 denotes a second pulley on which a gear for transmitting the rotational force of the motor 201 to the worm gear 209 via the belt 207 is formed.

Next, the operation of the second conventional mode detection device will be described. An optical path 206 is formed between the light emitting element 23 and the light receiving element 24, and a window 205 for transmitting or blocking the detection light formed on the reduction gear 203 is provided in the optical path 206. When the switching of the operation mode is started, the rotational power of the motor 201 is changed to the pulley 202.
Then, the cam gear 204 is driven via the belt 207, the second pulley 208, the worm gear 209, and the reduction gear 203. At this time, the detection light reaching the light receiving element 24 is repeatedly transmitted and blocked by the window 205 because the reduction gear 203 rotates.

The light receiving element 24 detects when the detection light is input, that is, when the detection light is not blocked by the window 205, and when the detection light is not input, that is, when the detection light is blocked by the window 205. A binary signal in the form of a pulse is output by a detection circuit provided downstream of the light receiving element 24 (not shown). By counting this output signal, the cam gear 2
04 rotation phase is detected.

[0007]

In the above-described conventional mode detection device, the arc-shaped patterns are arranged concentrically in the radial direction. Therefore, when the number of operation modes that need to be detected increases, the number of operation modes increases. There has been a problem that the number of patterns increases and the radius of the contact gear increases, which hinders downsizing of the device.

Further, in the conventional mode detection device for optically detecting, the arrangement of the optical system components restricts the structure of the switching mechanism, and the enlargement of the optical system causes an adverse effect on the miniaturization of the device. There are problems that workability is poor, detection accuracy varies because the cam gear for performing switching control and the rotation phase detection window are separate components, and the detection accuracy is low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has high detection accuracy and does not increase the size of the detection device even if there are many operation modes that need to be detected. An apparatus is provided.

[0010]

A mode detecting device according to the present invention has a light emitting element, at least two or more light emitting elements, and a gap provided in a circumferential direction of a cam gear of a mode switching mechanism for switching each operation mode. The rotation phase of the cam gear is optically detected by optical detection means in which the gap is arranged in an optical path existing in a plane parallel to a radial direction of the cam gear in an optical path between the light emitting element and the light receiving element. It is composed.

An optical system in which a plurality of types of gaps are arranged in the optical path between the light emitting element and the light receiving element in the optical path existing in a plane parallel to the radial direction of the cam gear and provided with steps in the direction of the rotation axis of the cam gear. The rotation phase of the cam gear is optically detected by the detection means.

Also, a plurality of light guide portions for guiding detection light are integrally formed, and an input light transmitting body facing one light emitting element is provided in an optical path between the light emitting element and the light receiving element. is there.

In addition, a rotation support shaft of the cam gear is disposed at a position apart from the end face of the two outer peripheral sides of the base of the mode switching mechanism for switching each operation mode of recording and reproduction by a radius distance of substantially the outermost circumference of the cam gear, and optical detection is performed. A light-shielding holder including at least a part of an optical path of the means is disposed at a corner portion adjacent to two sides of the outer periphery of the base.

Further, the rotation support shaft of the cam gear is disposed at a position separated from the end face of two sides of the outer periphery of the base by a radius distance of the outermost periphery of the cam gear, and the optical detection is performed. A light-shielding holder covering the entire optical path of the means is disposed at a corner portion adjacent to two sides of the outer periphery of the base.

Further, a motor for transmitting power to the cam gear, a worm gear, a reduction gear, and a rotation support shaft of the cam gear having a gap for use in mode detection formed in a circumferential portion thereof are held by one holder.

A cam gear having at least two kinds of gaps formed in a circumferential direction, wherein the first light guide portion and the second light guide portion are arranged in a short gap formed in the cam gear; The pitch of 1 / (4 × n) with respect to the arrangement pitch, and the long gap width formed in the cam gear;
The arrangement interval between the first light guide portion and the third light guide portion is the same as the arrangement pitch of the short gap.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments. Embodiment 1 FIG. 1 to 7 show a first embodiment of the present invention.
It is a figure which shows the mode detection apparatus which is. In each figure,
Reference numeral 1 denotes a base on which a movable member used for a power transmission mechanism is mounted, 2 denotes a holder fixed to the base 1, 3 denotes a motor fixed to the holder 2, 4 denotes a rotating shaft of the motor 3, and The worm 5, which has the shaft 41 rotatably held by the holder 2, forms a worm wheel 51 which engages with the worm 4, and a gear 52 having an outer shape smaller than that of the worm wheel 51. The rotation support shaft 43 is rotatable with respect to the holder 2. A reduction gear 6 is provided with a gear portion (not shown) that engages with the gear 52. A cam gear rotatably held by the holder 2 and the base 1 with the support shafts 62 and 63, respectively. , A notch formed in a lower portion of the slit 7, a cam groove 9 formed on an upper surface and a lower surface of the cam gear 6, and 10 represents a movable member used for a power transmission mechanism. One end Has Foroapin 11 which engages with the cam groove 9, a lever planted the tape guide 12 for controlling the magnetic tape traveling loop at the other end.

Reference numeral 13 denotes a light-shielding holder fixed to the base 1, and 14 denotes a positioning and fixing inside the light-shielding holder 13.
An input light-transmitting body 18 having light guide portions 15, 16, 17 integrally formed radially of a transparent resin such as an acrylic resin, and 18 is positioned and fixed inside the light-shielding holder 13, and each is made of a transparent material such as an acrylic resin. An output light-transmitting member having light guide portions 19, 20, and 21 formed of resin;
Is a circuit board arranged opposite to the base 1, 23 is a circuit board 2
The light emitting elements mounted on 2 and the light receiving elements 24, 25 and 26 are light receiving elements mounted on the circuit board 22, respectively. Arrows 27, 28, and 29 indicate optical paths from the light emitted from the light emitting element 23 to the light receiving elements 24, 25, and 26, respectively.

Next, the operation will be described with reference to FIGS. The light for mode detection emitted from the light emitting element 23 is guided into the input light transmitting member 14, and is refracted at a right angle at each of the upper end portions (reflection surfaces) of the light guide portions 15, 16, 17 forming the input light transmitting member 14. And reaches the outside of the input light transmitting body 14,
The light is guided to the output light transmitting member 18. At this time, depending on the position of the slit 7 provided in the circumferential portion of the cam gear 6, there are a case where the mode detection light reaches the output light transmitting member 18 and a case where the mode detection light does not reach the output light-transmitting member 18.

When the light for mode detection passes through the slit 7 and reaches the output light transmitting member 18, the light is directed downward at the reflection surface at the upper end of the light guide portion 19, 20, 21 of the output light transmitting member 18. The light is refracted, and subsequently reaches the light receiving elements 24, 25, 26 through the paths indicated by arrows 27, 28, 29. When the light is blocked by the slit 7, the light receiving elements 24, 2
The detection light does not reach 5, 26. Light receiving element 2
Reference numerals 4, 25, and 26 denote internal resistance values that change when light is incident thereon, and an output signal corresponding to the presence or absence of the incident light can be obtained by a detection circuit (not shown) provided at a subsequent stage. .

Next, a more detailed description will be given with reference to FIGS. FIG. 8 is a development view in which the cam gear 6 is developed in the circumferential direction. The rotational driving force of the motor 3 rotates the cam gear 6 via the worm 4 and the reduction gear 5. For example, when the cam gear 6 rotates in the direction of arrow E as shown in FIG. 8, the optical path 27 shown in FIG. Modes 28 and 29 reach the light receiving elements 24, 25 and 26 according to the rotation phase of the cam gear because the slit 7 and the notch 8 are interposed between the rotation shafts 62 and 63 of the cam gear 6 in the radial direction. The detection light repeats blocking and transmission. Therefore, the mode detection light that reaches the light receiving elements 24, 25, and 26 is a light that is repeatedly intercepted and transmitted, and a signal synchronized with the rotation of the cam gear is obtained.

FIG. 9 shows an output signal waveform obtained from a detection circuit (not shown) provided at the subsequent stage of each of the light receiving elements 24, 25 and 26 when the cam gear 6 rotates in the direction of arrow E shown in FIG. FIG. In the figure, the vertical axis indicates the signal level, and the horizontal axis indicates time. 37 (upper) is a detection output signal waveform of the light receiving element 25 in the optical path 28, 38 (middle) is a detection output signal waveform of the light receiving element 24 of the optical path 27, and 39 (lower) is a detection output signal of the light receiving element 26 in the optical path 29. The waveform is shown. In this embodiment, the detection circuit is configured to detect L when the detection light is blocked by the slit 7 and detect H when the detection light is transmitted, but the polarity is opposite. It goes without saying that it does not matter.

Now, when the cam gear rotates in the direction of arrow E as shown in FIG. 8, the output signals 37 and 38 of the detection circuit at time T1 sequentially output (L, H). Further, in the present embodiment, the interval between the optical path 27 and the optical path 28 is arranged at an interval of ／ times the pitch of the slit 7, and then, from time T1, one pitch of the slit 7 (P in FIG. ), Ie, P / 4, the output signals 37 and 38 of the detection circuit at the time T2 when the cam gear 6 further rotates in the direction of the arrow E become (L, L). Further, the cam gear 6
At times T3, T4, and T5, each of which rotates by P / 4, the output signals of the detection circuit are (H, L), (H,
H) and (L, H).

Further, for example, when the cam gear 6 rotates in the direction opposite to the arrow E, the signal patterns output by the detection circuit are (L, H) → (H,
H) → (H, L) → (L, L) → (L, H). That is, the output signals 37 and 3 depend on the rotation direction of the cam gear 6.
The order in which the combination of the cam gears 8 changes is different, whereby the rotation direction of the cam gear 6 can be detected.

Considering, for example, the case where an unsteady operation such as a power failure occurs during the operation of the circuit and the rotational phase of the cam gear 6 stored in the memory is erased, the current supplied to the motor 3 when the power is turned on again Detection signals 37 and 38 detected when the cam gear 6 rotates again even if the polarity of
The rotation direction of the cam gear 6 can be recognized by monitoring the order in which the combination changes.

The rotation phase of the cam gear 6 can be detected by counting the rectangular wave which is one of the output signals 37 and 38. For example, if the mode switching control is programmed according to the rotation phase of the cam gear 6, the light receiving element 24 or 25
A mode detection device capable of controlling mode switching by an output signal of a detection circuit provided at a subsequent stage is obtained.

The cam gear 6 is shifted to a phase other than the initial phase.
In some cases, if the phase of the cam gear 6 is erased from the memory due to a power failure or the like, it can be identified from the output signal 39 of the light receiving element 26 that the phase of the cam gear 6 needs to be reset to the initial position.

Further, as described above, the cam gear 6
Since the cam groove 9 and the slit 7 are integrally formed as one part by integrally forming the slit 7 on the outer periphery of the cam gear 6 and the slit 7, the cam gear 6 and the slit 7 are separately formed when the mode detection device according to the first embodiment is mass-produced. Compared to what is a part,
There is an effect that there is no variation in the mounting position due to the assembly, and at the same time, the detection accuracy does not vary. Further, since the slit 7 is arranged so as to transmit or block the light used for detection in the radial direction of the cam gear 6, only a small thickness necessary for transmitting or blocking the detection light is added to the diameter of the cam gear 6. Thus, a cam gear integrated with the slit used for detection can be formed, so that there is no adverse effect on miniaturization of the apparatus.

Next, a description will be given of a mold structure in which the above-described cam gear 6 is manufactured by injection molding. FIG. 10 is a cross-sectional view taken along the line FF shown in FIG. 8, and FIG. 11 is a cross-sectional view taken along the line GG shown in FIG. In the figure, reference numeral 35 denotes an upper mold of a mold used when the cam gear 6 is formed by injection molding.
Reference numeral 6 denotes a lower die used for injection molding of the cam gear 6 similarly to the upper die 35.

Generally, the mold setting direction (FIGS. 10, 1)
1 (a direction indicated by an arrow in FIG. 1) (in this embodiment, the slit 7 corresponds to this) is a slide core other than the upper die 35 and the lower die 36 shown in FIG. (Not shown) or the like, a member that moves in a direction perpendicular to the die-cutting direction is required, so that the number of dies increases. In the cam gear 6 used in the present embodiment, the slit 7 and the notch 8 provided in the circumferential direction are provided with a step in the radial direction, so that the slit 7 and the notch 8 affect the other. The upper mold 35 and the lower mold 36 can be formed without using a slide core or the like as shown in FIG.
The cam gear having the slit 7 can be formed only with the slit.

Embodiment 2 In FIGS. 1 and 2,
The lever 10 is moved to a pre-designed angle in accordance with the rotation phase of the cam gear by the shape of the cam groove 9 formed in the cam gear 6, and the tape guide 12 is used to move the magnetic tape, which is not shown, to the lever 10. It is possible to control an operation mode such as attaching the magnetic tape to a tape path loop or leaving an interval until the magnetic tape does not contact the tape path system. In addition to the above, the cam groove 9 formed in the cam gear 6 includes a lever for mounting and discharging a tape cassette (not shown) and a control lever for a pinch roller for pressing a magnetic tape to a capstan shaft. A tape guide control lever or the like for pulling out the magnetic tape from the tape cassette and winding the tape at a predetermined angle around the cylinder is provided similarly to the lever 10, and controls these operations.

The start or stop timing of each operation control by each lever is determined according to the rotation phase of the cam gear 6, and illustration of detecting signals output from the light receiving elements 24, 25 and 26 is omitted. Control is performed by instructing the motor 3 by the output signal of the detection circuit. Here, in the present embodiment, since the cam groove 9 and the slit 7 are integrally formed as one part, the second embodiment is used.
When the mode detection device is mass-produced, compared with the case where the cam gear 6 and the slit 7 are separate parts, there is no variation in the mounting position due to the assembling, and at the same time, the detection accuracy of the rotational phase does not vary. The variation in the amount of deviation of the distance is reduced. Further, since the slit 7 is disposed so as to transmit or block the light used for detection in the radial direction of the cam gear 6, the thickness of the input light transmitting body 14 and the diameter required for forming the cam groove 9 are reduced. Since a cam gear integrated with the slit used for detection can be configured by adding only a small thickness necessary for blocking light, there is no adverse effect on miniaturization of the apparatus.

In the mode detecting device according to the present embodiment as shown in FIG. 3, the holder 2 on which the worm 4 and the motor 3 are mounted is fixed to the base 1 in advance from the cam gear 6, and the light emitting element 23 is Light receiving element 24,
The circuit board 22 on which the substrates 25 and 26 are mounted is positioned opposite to the base 1 while being aligned. Therefore, the configuration is simple,
The light emitting element 23 and the light receiving elements 24, 25 and 26 are mounted on the circuit board 2
2, when the circuit board 22 is removed from the base 1 of the mode switching mechanism, such as when the circuit board is repaired or inspected later during assembly, or the like, the light emitting element 23 and the light receiving element 24, 25, 2
6) Since there is no connector or wiring for electrical connection to the part, workability is improved.

Embodiment 3 As means for branching light emitted from one light emitting element 23 to obtain optical paths of a plurality of detection lights, a plurality of light guides 15 and 1 shown in FIG.
The input light-transmitting body 14 in which 6 and 17 are formed radially is used.
Since the operation of transmitting or blocking the detection light and the detection method are the same as those in the above-described embodiments, the description of the operation is omitted.

The input light transmitting member 14 is formed of a material having a high light transmittance, and has a shape in which the number of refraction of the light beam is reduced in the middle of the optical path, so that the light transmitted through the input light transmitting member 14 is refracted. It is possible to transmit the light to the output light transmitting member 18 while suppressing the decrease (loss) of the light amount due to the light. Further, the fact that the loss in the optical path can be suppressed means that the light receiving element 24,
Even if the amount of received light at 25 and 26 is the same, the light emitting element 2
The light emission amount of No. 3 can be reduced. Therefore, by reducing the light emission amount of the light emitting element 23, the light emitting element 2
3 can achieve lower power consumption, lower heat generation, and longer life.

Embodiment 4 FIG. For example, in FIG. 5, assuming that the diameter of the cam gear 6 is 100 mm, about 50 mm downward from the upper end of the base 1 provided with each member of the drive transmission mechanism.
When the support shaft 62 of the cam gear 6 is arranged at a position about 50 mm away from the right end direction and the light-shielding holder 13 is arranged at the upper right end corner of the base 1, the area occupied by the mode detection device is equal to that of the cam gear 6. Only the upper right corner of the base 1, that is, 50 × 50 × π × 3/4 + 50 × 5
0 = approximately 8390 mm ² , which means that the area occupied by the cam gear 6 (approximately 7850 mm ² ) requires only an increase of about 7%.

A circuit board 2 disposed opposite to the base 1
By forming the projection 2 in substantially the same shape as the base 1, the position where the light emitting element 23 and the light receiving elements 24, 25, and 26 are mounted can be located below the light shielding holder 13. That is, these photoelectric elements are also concentrated on the corners of the circuit board 22, and other electronic circuit components (not shown) can be effectively arranged on the circuit board 22.

Embodiment 5 An assembling method according to an embodiment of the present invention will be described with reference to FIG. First, the light shielding holder 13 to which the input light transmitting member 14 and the output light transmitting member 18 are fixed is attached to the base 1. Next, the cam gear 6 and the reduction gear 5 are inserted into the base 1. Here, the slit 7 for transmitting and blocking an optical path installed perpendicular to the optical path in the radial direction of the cam gear 6 is arranged in a gap existing between the input light transmitting member 14 and the output light transmitting member 18. However, when the cam gear 6 is inserted into the base 1, each component does not physically interfere with each other and can be easily attached.

Next, the motor 3, the worm 4, and the reduction gear 5 are fixed to the holder 2 in advance, and the cam gear 6 is also fixed to the holder 2 by attaching the holder 2 to the base 1 in the rotation axis direction of the cam gear 6. Therefore, it is rotatably supported. By attaching the holder 2 to the base 1, the assembly according to the embodiment of the present invention is completed. That is, assembling can be performed with a small number of steps as described above.

Embodiment 6 FIG. FIG. 12 is a diagram in which the outer periphery of the cam gear 6 which is a main part of the mode detection device according to the embodiment of the present invention is developed in the circumferential direction. In the figure, reference numeral 30 denotes a short width window corresponding to a narrower slit among slits of different widths formed on the outer periphery of the cam gear 6;
Reference numeral 31 is a wide window corresponding to a wider slit formed on the outer periphery of the cam gear 6.

FIG. 13 is a diagram showing an output signal waveform output by a detection circuit (not shown) provided at the subsequent stage of each of the light receiving elements 24, 25 and 26 shown in FIG. 12 in the present embodiment. is there. In the figure, 32 is a detection signal waveform of the light receiving element 24, 33 is a detection signal waveform of the light receiving element 25, 34
Represents a detection signal waveform of the light receiving element 26.

Next, the operation of this embodiment will be described. The light guide section 19 and the light guide section 20 are arranged at an interval P / 4 at a ratio of 1/4 with respect to the arrangement pitch P of the short windows 30. The light guide 19 and the light guide 21 are arranged at the same interval P as the arrangement pitch P of the short windows 30.
Further, the arrangement pitch of the short windows 30 and the slit width of the wide windows 31 are the same as the distance P between the light guides 19 and 21. When the cam gear 6 rotates in the direction of arrow H shown in FIG. 12, the detection light passing through the input light transmitting body 14 repeatedly transmits and blocks through the short width window 30 and the wide width window 31, and the light receiving elements 24, 25, 26 An output signal as shown in FIG. 13 is obtained from the detection circuit.

Here, the phases of the output signals 32 and 33 are compared. As shown in FIG. 13, the phase of the output signal 33 is
2, the cam gear 6 is rotating to the left (in the direction of arrow H) in FIG. 12, and conversely, if the phase of the output signal 32 is behind the output signal 33, At 12, it can be recognized that the cam gear 6 is rotating to the right (in the opposite direction of the arrow H).

Further, the light guide section 19 is arranged at the edge of the short window 30 adjacent to the wide window 31 at an angle at which it is necessary to rotate the cam gear 6 to the initial position when the power is turned on again (reset operation is required). Thus, the necessity of the reset operation can be detected. The principle is determined by the signal polarities of the output signals 32 and 34 of the light receiving elements 24 and 26. In the example shown in FIG. 13, it is determined that reset is not necessary in the region R1 in which the output signals 32 and 34 are both H or L, and reset is necessary in the region R2 in which the polarities of the output signals 32 and 34 are different.
For example, considering the case where an unsteady operation such as a power failure occurs while the circuit is operating and the power is once turned off and then turned on again, the polarities of the output signals 32 and 34 are determined as described above. This makes it easy to determine whether to rotate the cam gear 6 to the reset position.

As described above, in this embodiment, even if the notch 8 as shown in FIG. 8 described in the first embodiment is not provided in the cam gear 6, the rotation direction of the cam gear 6 when the power is turned on again, and The need for rotation to the reset position can be identified. For this reason, it is possible to reduce the thickness of the cam gear 6 in the rotation axis direction, for example, including the case where all the cam grooves 9 formed in the cam gear 6 are integrated on one surface.

In the above description, the present invention is applied to a video tape recorder. However, in an audio disk, a video disk, a DAT, and other devices, if the operation mode is switched by a cam gear, these devices are used. It is needless to say that the mode detection can be performed in.

[0047]

Since the present invention is configured as described above, it has the following effects.

Optical detection in which a gap is provided in a circumferential direction of a cam gear for controlling each operation mode of recording and reproduction, and a gap of the cam gear is arranged in an optical path parallel to a radial direction of the cam gear in an optical path between a light emitting element and a light receiving element. Since the rotation phase of the cam gear is detected by the means, there is no variation in the mounting position of the cam gear due to assembly, and at the same time, the rotation phase of the cam gear can be detected without variation in detection accuracy. Since the gap is arranged to transmit or block the light to be used in the radial direction of the cam gear, it is only necessary to add a small thickness necessary for transmitting or blocking the detection light to the diameter of the cam gear. It is possible to obtain a cam gear integrally formed with a gap for transmitting or blocking light, which has the effect of eliminating the disadvantage of downsizing the device.

Further, a plurality of types of gaps having different phases are provided in the circumferential direction of the cam gear for controlling each operation mode of recording and reproduction, and the plurality of types of gaps are provided with steps provided in the radial direction of the cam gear to emit light. Since the rotation phase of the cam gear is detected by optical detection means in which a gap between the cam gear is disposed in an optical path existing in a plane parallel to the radial direction of the cam gear in the optical path between the element and the light receiving element, the cam gear is mounted by assembly. It is possible to detect the rotation phase of the cam gear without any variation in the position and at the same time without varying the detection accuracy, and the gap is arranged so that the light used for the detection is transmitted or blocked in the radial direction of the cam gear. So
Since it is only necessary to add a small thickness necessary for transmitting or blocking the detection light to the diameter of the cam gear, it is possible to obtain a device which does not adversely affect the miniaturization of the device. Has the effect that can be eliminated. In addition, since a plurality of types of gaps are provided on the circumferential portion of the cam gear with a step, even if the cam gear is formed by injection molding or the like, the mold needs only one core and one cavity, and the mold configuration is reduced. There is an effect that a cam gear that is easy and inexpensive to manufacture can be obtained.

Further, a plurality of light guide portions are formed integrally,
In addition, since the input light-transmitting member facing the one light-emitting element is provided in the optical path between the light-emitting element and the light-receiving element, the number of times of refraction of the detection light transmitted through the light guide portion is reduced, and the amount of light reaching the light-receiving element Is reduced, the amount of light emitted from the light-emitting element can be reduced, whereby the current supplied to the light-emitting element can be suppressed, and an apparatus with low power consumption can be obtained.

Further, the rotation shaft of the cam gear is disposed at a position apart from the end face of the outer periphery of the base of the mode switching mechanism by a radial distance substantially at the outermost periphery of the cam gear, and at least a part of the optical path of the optical detecting means. Since the light-shielding holder is disposed at the corner adjacent to the two sides of the outer periphery of the base, an apparatus having a small space occupancy including the optical detection element can be obtained.

Further, the rotation support shaft of the cam gear is disposed at a position separated from the end face of the two sides of the outer periphery of the base body of the mode switching mechanism by a radial distance of substantially the outermost circumference of the cam gear, and the light shielding covering the entire optical path of the optical detection means. Since the holders are arranged at the corners adjacent to the two sides of the outer periphery of the base, an apparatus having a small space occupancy including the optical detection element can be obtained.

Further, the motor for transmitting the power to the cam gear, the worm gear, the reduction gear, and the rotation support shaft of the cam gear in which the gaps used for detecting the operation mode are formed in the circumference thereof are held by one holder, so that the number of parts is reduced. Therefore, there is an effect that a device which is easy to assemble with a small number of steps and can be easily obtained.

[0054] In addition, a cam gear having at least two kinds of gaps formed in the circumferential direction is provided, and the first light guide portion and the second light guide portion are arranged in a short gap formed in the cam gear. Are arranged at an interval of 1 / (4 × n) with respect to the arrangement pitch, and the long gap width formed in the cam gear, and the arrangement interval between the first light guide portion and the third light guide portion Are arranged at the same pitch as the arrangement pitch of the short width gap, so that the gap is arranged in only one row in the rotation direction of the cam gear, and it is possible to identify the rotation direction of the cam gear and the necessity of rotation to the reset position, and at the same time, it is thin Is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a mode detection device according to Embodiments 1 to 6 of the present invention.

FIG. 2 is a plan view of a mode detection device according to Embodiments 1 to 6 of the present invention.

FIG. 3 is a cross-sectional view taken along the line AA in FIG.

FIG. 4 is a side view of the mode detection device according to the first to sixth embodiments of the present invention.

FIG. 5 is a sectional view taken along line BB in FIG. 4;

FIG. 6 is a sectional view taken along line CC in FIG. 5;

7 is a sectional view taken along line DD in FIG. 5;

FIG. 8 is a development view of a cam gear outer peripheral portion of the mode detection device according to the first to sixth embodiments of the present invention.

FIG. 9 is a diagram showing an output signal waveform of a light receiving element in the mode detection device according to the first to sixth embodiments of the present invention.

FIG. 10 is a sectional view taken along line FF in FIG. 8;

11 is a sectional view taken along line GG in FIG.

FIG. 12 is a development view of an outer peripheral portion of a cam gear of a mode detection device according to a sixth embodiment of the present invention.

FIG. 13 is a diagram showing an output signal waveform of a light receiving element in the mode detection device according to the sixth embodiment of the present invention.

FIG. 14 is a plan view showing a conventional mode detection device.

FIG. 15 is a plan view showing a position detection board of a conventional mode detection device.

FIG. 16 is a cross-sectional view showing a conventional mode detection device.

FIG. 17 is a sectional view taken along line VV in FIG. 12;

FIG. 18 is a diagram illustrating a conventional mode detection device that performs optical detection.

FIG. 19 is a side view showing a conventional mode detection device that performs optical detection.

[Explanation of symbols]

2 holder, 3 motors, 4 worm gears, 5 reduction gears, 6 cam gears, 7 slits, 8 cutouts, 9 cam grooves, 13 light shielding holders, 14 input translucent members, 15, 1
6, 17, 19, 20, 21 light guide portion, 18 output light transmitting member, 23 light emitting element, 24, 25, 26 light receiving element,
30 short windows, 31 wide windows

Claims (7)

[Claims] 1. A mode switching mechanism for switching between recording and reproducing operation modes by a cam gear provided with a cam groove, comprising: a light emitting element; at least two or more light receiving elements;
An optical element having a gap provided in a circumferential direction of the cam gear, wherein the gap is arranged in an optical path existing in a plane parallel to a radial direction of the cam gear in an optical path between the light emitting element and the light receiving element. 1. A mode detecting device comprising a dynamic detecting means, wherein a rotational phase of the cam gear is optically detected. 2. A mode switching mechanism for switching each operation mode of recording and reproduction by a cam gear provided with a cam groove, comprising: a light emitting element; at least two or more light receiving elements;
A plurality of gaps having different phases provided in a circumferential direction of the cam gear; and the plurality of kinds of gaps are arranged with a step in a radial direction of the cam gear, and the light emitting element and the light receiving element are provided. A mode in which the optical path detecting means includes optical detecting means in which the gap is disposed in an optical path existing in a plane parallel to a radial direction of the cam gear in an optical path between the optical discs, and optically detects a rotation phase of the cam gear. Detection device. 3. A light-emitting device according to claim 1, wherein a plurality of light guides for guiding the detection light are integrally formed, and an input light-transmitting member disposed to face one light-emitting element is provided in an optical path between the light-emitting element and the light-receiving element. The mode detection device according to claim 1 or 2, wherein: 4. A rotation support shaft of the cam gear is disposed at a position apart from an end face of two sides of a base outer periphery of the mode switching mechanism for switching each operation mode of recording / reproduction by a radius distance of a substantially outermost periphery of the cam gear, and optically. 4. The mode detecting device according to claim 1, wherein a light-shielding holder including at least a part of an optical path of the detecting means is disposed at a corner portion adjacent to two sides of the outer periphery of the base. 5. The mode detection device according to claim 4, wherein the light-shielding holder includes the entire optical path of the optical detection means. 6. A motor for transmitting power to a cam gear, a worm gear, a reduction gear, and a rotating shaft of the cam gear having a gap used for detecting an operation mode formed in a circumferential portion thereof are held by one holder. The mode detection device according to claim 4. 7. A cam gear having a gap formed in a circumferential direction and having at least two kinds of widths, wherein a first light guide portion and a second light guide portion are arranged in a short width formed in the cam gear. The gaps are arranged at an interval of 1 / (4 × n) with respect to the arrangement pitch of the gaps, and the width of the long gap formed in the cam gear and the distance between the first light guide and the third light guide are adjusted. 2. The mode detection device according to claim 1, wherein the arrangement intervals are arranged at the same pitch as the arrangement pitch of the short gaps.