JP6071005B2 - Structure of watch pointer position detection sensor - Google Patents

Description

  The present invention relates to a pointer position sensor used for detecting a pointer position in a radio-controlled timepiece or the like that automatically corrects the time by obtaining a time signal by radio waves, and in particular, a light emitting element that constitutes a pointer position detection sensor and The present invention relates to a structure that shields between light receiving elements.

  Conventionally, in a timepiece that automatically corrects the time by obtaining a time signal, in order to detect the position of the pointer from the rotation of the pointer wheel that drives the pointer, a hole is provided in a predetermined portion of the pointer wheel, and the light emitting element changes to the pointer wheel. The pointer position was detected by irradiating light and receiving the light transmitted through the hole with a light receiving element (see Patent Document 1).

  Normally, the light emitting element and the light receiving element in the conventional timepiece are arranged to face each other with the pointer wheel in between, but a circuit board on which the light emitting element and the light receiving element are mounted is required. For this reason, there has been a case where a light receiving element is mounted on the same circuit board as the light emitting element by guiding light transmitted through the pointer wheel toward the circuit board on which the light emitting element is mounted.

Japanese Patent No. 4781800

  As described above, when the light emitting element and the light receiving element are mounted on the same circuit board, the light from the light emitting element may directly strike the light receiving element from the lateral direction and receive light. For this reason, an attempt was made to attach a shielding member such as rubber between the light emitting element and the light receiving element, but light may leak from the gap between the shielding member and the circuit board or case, and accurate position detection is performed. There was a case that could not be. In addition, a circuit board made of resin or the like may serve as a light guide, and light may be guided inside the light receiving element, and the light receiving element may receive the light. was difficult. Furthermore, when a separate shielding member is attached, there is a problem that the number of parts and man-hours increase, resulting in an increase in cost.

  In addition, when the movement is downsized, the circuit board also becomes smaller, the distance between the light emitting element and the light receiving element becomes closer, and light leakage occurs significantly, making it more difficult to prevent light leakage. there were.

  The problem to be solved by the present invention is to solve the above-mentioned problems of the prior art and provide a structure of a pointer position detection sensor for a watch that securely shields the light emitting element and the light receiving element without providing a separate shielding member. There is to do.

The structure of the pointer position detection sensor of the timepiece according to the present invention includes a case, a pointer wheel having a through hole formed at a predetermined position supported by the case, and a circuit board attached to the case. A structure of a pointer position detection sensor for detecting a position, a light emitting element mounted on the circuit board and irradiating light to the pointer wheel, and mounted on the circuit board side by side with the light emitting element and of the pointer wheel A light-receiving element that receives light passing through the through-hole by rotation; a light guide that guides light that has been emitted from the light-emitting element and transmitted through the through-hole to the light-receiving element; and the light-emitting element in the circuit board; A through-hole provided between the light-receiving element and the case that protrudes from the case and is inserted into the through-hole by attaching the circuit board to the case. A shielding unit for shielding, is made of.

  Further, the case in the structure of the pointer position detection sensor of the timepiece is provided with a recess adapted to each of the light emitting element and the light receiving element, a partition wall of the recess is formed by the shielding portion, and the bottom of the recess is A light emitting hole and an incident hole facing the light emitting element and the light receiving element are provided. Moreover, the said shielding part is penetrated by the said through-hole, without closely_contact | adhering to the inner surface of the said through-hole.

  In the structure of the timepiece position detection sensor of the timepiece of the present invention, since the shielding portion is provided in the case to which the circuit board is attached, and the shielding portion is inserted into the through hole of the circuit board, the light emitting element and the light receiving element are shielded. There is no need to attach a separate shielding member. In particular, since the shielding part is provided integrally with the case, no gap is generated between the shielding part and the case, and the shielding can be ensured.

  In addition, since the through hole is provided between the light emitting element and the light receiving element in the circuit board, the circuit board serves as a light guide and does not guide the light from the light emitting element in the direction of the light receiving element. Can be shielded.

  Further, the distance between the light-emitting element and the light-receiving element only needs to be such that a through-hole and a shielding portion can be provided, so that the light-emitting element and the light-receiving element can be disposed extremely close to each other, and the movement can be reduced in size.

It is principal part sectional drawing of the movement for radio timepieces which shows the structure of the pointer position detection sensor of the timepiece which concerns on one Embodiment of this invention. It is a front view of the 3rd case shown in FIG. It is sectional drawing of the 3rd case shown in FIG. It is a rear view of the circuit board shown in FIG. It is a side view of the circuit board shown in FIG.

  In the radio timepiece movement shown in FIG. 1, the case 4 includes a first case 1 that covers the pointer driving mechanism from the back side of the watch, and an intermediate plate that supports the pointer driving mechanism from the back side of the watch in the first case 1. And a third case 3 such as a lower plate that supports the pointer driving mechanism from the front side of the watch.

  The pointer wheel in the pointer drive mechanism in this embodiment includes an hour hand wheel 5, a minute hand wheel 6, and a second hand wheel 7. At this time, the hour hand wheel 5, the minute hand wheel 6 and the second hand wheel 7 are respectively provided with circular or circular through holes 5a, 6a and 7a at positions where the gears overlap. The through holes 5a, 6a, and 7a are set so as to communicate or be shielded in a predetermined pattern by the rotation of each gear.

  As shown in FIGS. 2 and 3, a light emitting element 8 and a light receiving element 9 which will be described later are fitted to the front surface of the third case on the front side of the movement, and the hour hand wheel 5, the minute hand wheel 6 and the second hand wheel 7. Recesses 3a and 3b are provided so as to face each other. Between the recesses 3a and 3b, there is provided a substantially elongated rectangular shielding part 3c protruding forward so as to isolate the recesses 3a and 3b. The shield 3c is formed so as to protrude forward from the end face of a boss 3d or the like for positioning a circuit board 10 to be described later. In addition, at the bottom of the recesses 3a and 3b, an emission hole 3e and an incident hole 3f are provided so as to face the light emitting element 8 and the light receiving element 9, respectively. The emission hole 3e is provided at a position communicating with the through holes 5a, 6a, and 7a of the hour hand wheel 5, the minute hand wheel 6, and the second hand wheel 7. In addition, the incident hole 3f is provided at a position facing the light guide 11 provided in the first case 1 so as to guide light transmitted through the through holes 5a, 6a, and 7a forward.

  On the circuit board 10 attached to the front side of the third case 3, the light-emitting element 8 such as a light-emitting diode and the light-receiving element 9 such as a phototransistor are positioned so as to fit the recesses 3 a and 3 b of the third case 3. Mounted. The circuit board 10 is provided with an elongated rectangular through-hole 10a facing and matching the shielding portion 3c of the third case 3 between the light emitting element 8 and the light receiving element 9.

  In the present embodiment, the circuit board 10 is positioned by the boss 3d provided on the front surface of the third case 3 having the above configuration and fixed by the screws 12 or the like, so that the circuit board 10 is fixed to the third case 3. Is attached. At this time, the light emitting element 8 and the light receiving element 9 mounted on the circuit board 10 are accommodated in the recesses 3 a and 3 b of the third case 3 and are shielded by the shielding part 3 c of the third case 3. Further, the shielding portion 3c is inserted through the entire through hole 10a so that the tip thereof reaches the front surface of the circuit board 10, and reaches not only between the light emitting element 8 and the light receiving element 9 but also the thickness portion reaching the front surface of the circuit board 10. Shielded.

  When the light emitting element 8 and the light receiving element 9 are shielded as described above, the lateral direction of the adjacent light emitting element 8 and light receiving element 9 is shielded from the bottom of the recesses 3a and 3b from the bottom of the recesses 3a and 3b to the inside of the through hole 10a of the circuit board 10 by the shielding part 3c. Will be. In addition, the through hole 10a provided between the light emitting element 8 and the light receiving element 9 blocks light guided to the inside of the circuit board 10, thereby leaking light through the circuit board 10. Nothing will happen.

  In addition, the shielding part 3c in this embodiment is penetrated by the through-hole 10a, without contacting the inner surface of the through-hole 10a. This prevents stress from being applied to the vicinity of the light-emitting element 8 and the light-receiving element 9 when the circuit board 10 is attached, and prevents the position thereof from shifting, and prevents the inner surface of the through-hole 10a and the shielding portion 3c from being in close contact with each other. The light inside the circuit board 3 is surely blocked.

  The detection of the pointer position using the structure of the pointer position detection sensor of the present embodiment is performed as follows. Light emitted from the light emitting element 8 passes through the through holes 5a, 6a, and 7a of the hour hand wheel 5, the minute hand wheel 6, and the second hand wheel 7 from the emission hole 3e, is guided by the light guide 11, and is emitted from the incident hole 3f. The light receiving element 9 is irradiated.

  The light emitted from the light emitting element 8 passes through the through holes 5a, 6a and 7a to reach the light guide 11, and is guided by the light guide 11 to reach the light receiving element 9, and the hour hand wheel 5 and the like. May be blocked by rotation. In this way, the position of the hour hand attached to the hour hand wheel 5 is detected from the on / off intervals when the light reaches the light receiving element 9 and when it is blocked. The position of the minute hand wheel 6 and the second hand wheel 7 can be similarly detected.

  In the present embodiment, as described above, since the light from the light emitting element 8 is not directly received by the light receiving element 9, the light is shielded and blocked by the shielding portion 3c and the through hole 10a. Such a pointer position can be reliably detected.

DESCRIPTION OF SYMBOLS 1 1st case 2 2nd case 3 3rd case 3a, 3b Recess 3c Shielding part 3d Boss 3e Outgoing hole 3f Incident hole 4 Case 5 Hour hand wheel 5a Through hole 6 Minute hand wheel 6a Through hole 7 Second hand wheel 7a Through hole 8 Light-emitting element 9 Light-receiving element 10 Circuit board 10a Through hole 11 Light guide 12 Screw

Claims (3)

A structure of a pointer position detection sensor for detecting a pointer position in a timepiece having a case, a pointer wheel having a through hole formed at a predetermined position supported by the case, and a circuit board attached to the case. ,
A light emitting element mounted on the circuit board and irradiating the pointer wheel with light;
A light receiving element that is mounted on the circuit board in line with the light emitting element and receives light passing through the through hole by rotation of the pointer wheel;
A light guide that guides the light emitted from the light emitting element and transmitted through the through hole to the light receiving element;
A through hole provided between the light emitting element and the light receiving element in the circuit board;
A shielding part that protrudes from the case and is inserted through the through-hole by attaching the circuit board to the case and shields between the light emitting element and the light receiving element;
A structure of a pointer position detection sensor of a watch characterized by comprising:
The case is provided with a recess adapted to each of the light emitting element and the light receiving element, a partition wall of the recess is formed by the shielding portion, and light of the light facing the light emitting element and the light receiving element is formed at the bottom of the recess. The structure of the watch position detecting sensor for a timepiece according to claim 1, wherein an exit hole and an entrance hole are provided. The timepiece position detection sensor structure for a timepiece according to claim 1 or 2, wherein the shielding portion is inserted into the through hole without being in close contact with the inner surface of the through hole.

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