JPS641842B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an arm position detection device for optically detecting the arm position of a pickup arm in a fully automatic record player. In conventional fully automatic record players, mechanical links, cams, etc. are used to determine the 30cm record introduction position, 25cm record introduction position, and 17cm record introduction position, and stop the pick-up arm. It was customary to use a link, cam, etc. to determine the moving speed of the pick-up arm. In recent years, fully automatic record players have come out that are equipped with an optical opening/closing system that opens and closes as the pick-up arm moves left and right to detect the introduction position and lead-out of various records, and perform the above-mentioned detection using the output signal of the optical opening/closing system. Ta. However, in either example, independent detection elements are provided for three record introduction positions and lead-out detection, and the output of each element is used for position detection, and in practical use, the pick-up is performed at the rest after return. A means of detecting that the arm has returned is typically required. For this reason, in the arm position detection device using the conventional optical opening/closing system, when the pick-up arm starts playing at a position other than the above-mentioned positions,
The initial position of the pick-up arm cannot be determined, so the pick-up arm must be returned to the rest and then moved to the required position, resulting in a lack of smooth use, and at the same time, the number of optical opening/closing systems used tends to increase. It was hot. Furthermore, even if the arm drive motor is stopped by the record introduction position signal, the actual stylus stop position varies due to inertia of the pick-up arm, and in order to reduce this, the moving speed of the pick-up arm must be reduced. However, there is a drawback that it takes time to move the pick-up arm from the rest position to the record introduction position. The object of the present invention is to eliminate the above-mentioned conventional drawbacks, to enable the initial position of the pick-up arm at the start of a performance to be determined, to enable high-speed movement of the arm at the time of lead-in, to reduce variations in the stop position, and to provide an optical opening/closing system. An object of the present invention is to provide an arm position detection device that reduces the number of arm position detection devices. Furthermore, another purpose is to be able to detect the speed of movement of the pick-up arm in order to detect the auto-lead-out simultaneously with the above-mentioned purpose, and to avoid false identifications (e.g. when picking-up in the auto-lead-out area, especially in the final groove). An object of the present invention is to provide an arm position detection device that does not perform the same identification as other areas, such as when the arm is not moving. In order to achieve the above object, in the present invention, three sets of optical switching systems are arranged within the movement range of the pick-up arm so that the three sets of optical switching systems open and close independently. The configuration is such that eight areas consisting of seven boundary positions are detected. Then, in the auto readout area, 3
The moving speed of the pick-up arm is detected as a continuous slit that repeats opening and closing of only one of the sets of optical systems, and is used as a readout signal. The configuration is the same as the introduction position, and even if the pick-up arm is not moving in the auto lead-out area, it is at least the same as when a 17cm record is being played, so that there is no malfunction. EMBODIMENT OF THE INVENTION Hereinafter, the arm position detection apparatus of this invention will be specifically explained by an Example. 1 and 2 show the structure of the pickup arm and its vicinity of a fully automatic record player equipped with an arm position detection device according to the present invention. They are a plan view and a side view, respectively. An arm vertical movement shaft 2 is fixed to the chassis 1. A threaded portion 2a is provided at the upper end of the arm vertical movement shaft 2, and an adjustment screw 3 is attached to the threaded portion 2a.
are screwed together. The arm bearing portion 4 is regulated in the vertical direction by an adjustment screw 3 via a notch 5, and in the lateral direction by a vertical hole 6 that slides on the arm vertical movement shaft 2. A left and right rotation shaft 8 is connected to the arm bearing portion 4 via a left and right rotation bearing 7, and a left and right rotation shaft 8 is connected to the arm bearing portion 4 via a left and right rotation bearing 7.
A pick-up arm 10 is rotatably supported through a vertical movement bearing 9. In addition, an arm chassis 1 is provided on the lower surface of the arm bearing portion 4.
1 is fixed, and a part of the arm chassis 11 is made of an elastic material such as polyacetal resin, and is approximately U.
The rotation stopper member 12 in the shape of a letter is attached to the chassis 1.
It is fixed so as to sandwich the regulation shaft 13 fixed to. The above configuration constitutes a height adjustment mechanism for the pick-up arm 10, and by turning the adjustment screw 3, the arm bearing portion 4, the pick-up arm 10, and the arm chassis 11 are guided by the threaded portion 2a and can be moved up and down. Let's do it. A left-right motor 16 and a lifter motor 17 are also fixed to the chassis 1. On the underside of arm chassis 11,
A lifter input pulley 18 and a worm gear 19 are rotatably provided, and the worm gear 19 meshes with a lifter cam 20. FIG. 3 is a perspective view of the arm chassis 11. As shown in FIG. 3, the lifter cam 20 is rotatably supported on the arm chassis 11, and in order, the clutch cam part 20a, the discrimination cam part 20b, the lifter cam part 20c, and the discrimination cam part 20.
d. A wheel gear portion 20e is provided.
A rocker arm portion 22a of a clutch base 22 supported by a clutch shaft 21 is urged by a clutch spring 23 and abuts against the lower surface of the arm chassis 11 on the clutch cam portion 20a. A left-right input pulley 24 and a worm gear 25 are rotatably provided at the other end of the clutch base 22, and the worm gear 25 is also connected to the clutch base 22.
The clutch 26 is engaged with the clutch 26 which is rotatably supported by the clutch 26.
The clutch 26 is provided with a friction portion 26a and a wheel gear portion 26b.
It faces the fan-shaped portion 27a at the rear end, and comes into contact with the fan-shaped portion 27a by the clutch spring 23 when the rocker arm 22a is in the recess 20f of the clutch cam portion 20a as shown in FIG. The lifter input pulley 18 and the left-right motion input pulley 24 are coupled to an output pulley 29 fixed to the shafts of the lifter motor 17 and the left-right motion motor 16, respectively, via elastic belts such as a rubber belt 28. A lifter bearing 30 is fixed to the arm chassis 22, and a lifter shaft 33 having an arm guide 31 at the upper end and a guide pin 32 at the lower end slidably passes through the lifter bearing 30. As shown in FIG. 2, the guide pin 32 is supported by the arm chassis 11 and restrained by the lifter cam portion 20c via a lifter lever 35 biased by a lifter spring 34.
As the pick-up arm 10 is rotated, the arm guide 31 on which the pick-up arm 10 is mounted moves up and down. With the above-described configuration, the driving force of the left-right motor 16 and the lifter motor 17 is transmitted to the pick-up arm 10 via the rubber belt 28. A rest shaft 36 is fixed to the arm chassis 11, and the arm rest 3 is fixed to the upper end of the rest shaft 36.
7 has been made. The front end of the detection arm 27 fixed to the lower end of the left-right rotation shaft 8 is a detection section 43 bifurcated vertically, with a light-receiving substrate 44 fixed to the upper surface and a light-emitting substrate 45 fixed to the lower surface.
The light receiving board 44 and the light emitting board 45 have three sets of light receiving elements 46a, 46b, 4 at opposing positions, respectively.
6c, light emitting elements 47a, 47b, and 47c are provided, and a light guiding slit 48 is provided in the portion of the detection section 43 where each element faces each other. In the gap between the detection portions 43, a substantially arc-shaped detection plate 49 is approximately oscillated about the left and right rotation axis 8 by two studs 50 fixed to the chassis 1 and two elongated holes 51. It is designed to be able to move. The detection plate 49 is provided with a notch and a hole centered around the left-right rotation axis 8, and the detection portion 43 allows the pickup arm 10 to open and close sequentially and independently as the pick-up arm 10 rotates left and right. Three sets of optical opening/closing systems are constructed that repeat this process. The boundaries of the notch and the hole are arranged at the rest position 52 of the pick-up arm 10 so that they do not overlap with each other.
1st deceleration position 53, 30cm record introduction position 54,
25cm record introduction position 55, second deceleration position 56,
These are provided in areas corresponding to seven positions: the 17cm record introduction position 57 and the lead-out detection start position 58. From the lead-out detection start position 58 onwards, three sets of optical opening/closing systems are provided as the pick-up arm 10 rotates. Of these, only one set is a continuous slit portion 59 so as to repeat opening and closing, and the moving speed of the pick-up arm 10 is detected in the continuous slit portion 59. Moreover, one truth value pattern of the continuous slit section 59 has the same configuration as the introduction position of a 17 cm record, and the continuous slit section 5
If the pick-up arm is not moving at 9 (auto lead-out area), this is at least the same as when playing a 17cm record, so this is not a malfunction. Table 1 is a truth table of three sets of optical opening/closing systems as the pick-up arm 10 rotates. The optical paths a, b, and c in Table 1 are the first
The light receiving elements 46a, b, in the figure and FIG.
c, corresponding to the light emitting elements 47a, b, and c.

【table】

[Table] As explained above, in the arm position detection device according to the present invention, three sets of optical opening/closing systems are arranged so as to open and close independently within the movement range of the pick-up arm. By detecting eight areas consisting of boundary positions, it is possible to determine the initial position of the pick-up arm at the start of a performance and to move the pick-up arm at high speed during lead-in, while reducing variations in stop positions. Furthermore, in order to detect auto-readout, in the auto-readout area, the moving speed of the pick-up arm is detected as a continuous slit that repeats opening and closing of only one of the three optical opening/closing systems, and the continuous slit that occurs due to this. By making the truth value pattern (0, 1, 0) on one side of the slit the same as the pattern (0, 1, 0) at the introduction position of a 17cm record, for example, if the pick-up arm is in the auto lead-out area, When the power is turned off and restarted, the truth value pattern (0, 0, 0)
Or (0, 1, 0). Here, (0, 0,
0) is correctly determined to be a lead-out area.
Also, when it is (0, 1, 0), it is determined that a 17cm record is being played, the calculation operation continues, and the moving speed is detected by the opening and closing of the continuous slit, and it is correctly determined that it has reached the lead-out area. Therefore, it is not erroneously determined that the pick-up arm is in another area, so that a configuration without malfunction can be achieved.

[Brief explanation of drawings]

FIG. 1 is a plan view of an arm portion of a record player equipped with an arm position detection device according to the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a perspective view thereof. DESCRIPTION OF SYMBOLS 1... Chassis, 10... Pick-up arm, 11... Arm chassis, 16... Lateral movement motor, 17... Lifter motor, 27... Detection arm, 43... Detection section, 46... Light receiving element, 47...
...Light emitting element, 49...Detection plate.

Claims (1)

[Claims] 1. In the arm position detection device of a fully automatic record player waiting for the auto lead-in and auto read-out functions, a light emitting section and Three sets of optical opening/closing systems 46a, 46b, each consisting of a light receiving section.
46c; 47a, 47b, 47c, and the left and right positions of the pick-up arm are determined from the combination of the 3-bit output signal obtained by the optical opening/closing system, the rest position 52 of the pick-up arm 10,
First deceleration position 53, 30cm record introduction position 54.
25cm record introduction position 55, second deceleration position 56.
When the 17cm record introduction position 57 and the lead-out detection start position 58 are detected, and the first and second deceleration positions 53 and 56 are detected, the movement of the pick-up arm is decelerated. As the arm 10 rotates, only one of the three sets of optical opening/closing systems repeats opening and closing, so that the moving speed of the pick-up arm is detected, and one truth value of the truth value pattern generated by this repetition is detected. By making the pattern the same configuration as the truth value pattern at the introduction position of a 17cm record, even if the pick-up arm is not moving in the auto lead-out area, it is at least the same as when the 17cm record is being played, and there is no malfunction. An arm position detection device characterized by having the following configuration.