JPS595713A - Trimming device of crystal oscillator - Google Patents

Abstract

PURPOSE:To shorten a trimming time and to form a crystal oscillator of good quality at high yield by carrying out the cutting and frequency measurement of the crystal oscillator alternately, and adjusting the rotating speed of a motor and the extent of feeding very finely under the control of a control circuit during operation. CONSTITUTION:A main body 1 is provided with two cylindrical diamond grindstones 2 closely at an interval and they are driven in the opposite rotation directions. When a pulse motor 3 is put in associative operation, a sliding plate 6 and a sliding main body 7 start moving linearly and the free end of a chuck holding member 9 also moves linearly at the same time to press the tip part of a chuck 12, which rotates around a fulcrum 13 as a center axis, so that the crystal oscillator 14 moves until a part of the crystal oscillator contacts one grindstone. At this time, the part of the crystal oscillator is cut by the grindstone 2 rotating in a direction (a). Once the operation of the chuck 12 is stopped temporarily, the oscillation frequency of the crystal oscillator 14 is measured to detect whether an adjustment to a desired frequency is made or not and when an adjustment is required again, the other part of the crystal oscillator is cut by the other grindstone rotating in a direction (b) through similar moving operation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel automatic trimming device for a crystal resonator.

Conventionally, as a method for trimming crystal resonators used in crystal watches, communication equipment, etc., for example, a reading metal film is deposited on the tip of the crystal resonator in advance, and the film is gradually trimmed by irradiating the film with a laser. The desired frequency of vibration was obtained by removing the vibrator, or by sandblasting, by spraying an abrasive such as carborundum on the end faces and corners of the vibrator and cutting it.

・However, with the method using a laser, the metal film deposited on it is removed without cutting the crystal that makes up the crystal resonator body, so the amount of frequency change due to removal is small, and it is suitable for fine adjustment. Coarse adjustment is not possible. Therefore, a separate rough adjustment process must be provided, and the trimming operation is complicated because coarse adjustment and fine adjustment cannot be performed continuously. In addition, in the sandblasting method, the abrasive is expensive and it is not reused after spraying, which increases the cost.Furthermore, the spray nozzle is often clogged with the abrasive, resulting in frequent failures, and it is difficult to attach and remove the crystal unit. Some manual work was required, and the trimming work was complicated and work efficiency was low.

In view of this situation, the inventor of the present invention has conducted intensive studies on an automatic trimming method, and the result is that two grindstones that rotate in opposite directions at the same rotational speed are arranged close to each other, and the end closest to the grindstone is Two leaf spring members are prepared, one free end and the other fixed end. Both free ends converge in the direction of the gap between the grinding wheels, and both fixed ends open in the tangential direction of the adjacent grinding wheels. The tips of the chaffs, which are fixed to a movable member that moves parallel to the grinding wheel and hold the crystal resonator, are interposed between the free ends, and the pulse motor is rotated so that both sides of the crystal resonator can be cut. A control circuit is installed that converts the motion into linear motion and moves the movable member in a direction parallel to the grindstone, and after cutting one side, measures the frequency, determines whether readjustment is necessary, and issues subsequent work instructions. It has been found that by doing this, it is possible to automatically trim a crystal resonator with high precision, reliably and efficiently.

The present invention will be further described in detail based on examples, but the present invention is not limited to the following examples within the scope of the gist.

FIG. 1 is a plan view of the main parts of an automatic trimming device showing one embodiment of the present invention.

Two cylindrical diamond grindstones 2 are provided adjacent to each other with a gap in an automatic trimming device main body 1, and are directly or indirectly driven by a motor in the directions of arrows a and b in the figure so as to rotate in opposite directions.

Next, a pulse motor 8 is prepared, and the rotational movement of the motor shaft 4 is transmitted to the rotational movement of the slide ball 5 in the direction of arrow C. The motor shaft 4 and the slide plate 6 are connected via the slide ball 5 so that the motor shaft 4 and the slide plate 6 move linearly in the direction of the arrow d. FIG. 2 is a sectional view showing the connection structure. The slide plate 6 is connected to the slide body 7, and moves linearly in the d direction using the slide shaft 8 as support.

The end of the chuck holding member 9 is fixed to the chuck holding member mounting surface 7a, which is obtained by cutting the upper part of the slide body 7 diagonally toward the gap between the grindstones 2, with a screw 1o. The other end of the chuck holding member 9 is a free end and extends in the direction of the gap between the grindstones.

The chuck fixing member 11 is fixed with a fulcrum 18 so that the chuck can rotate left and right about the fulcrum 13 as a central axis. After holding the crystal oscillator 14 at the tips of the chaffs 12, as shown in this figure (Fig. Set the vibrator 14 and at the same time chuck 12
The chuck fixing member 11 is moved so that the leading end of the chuck holding member 9 is held from both sides by the free end of the chuck holding member 9.

When the pulse motor 3 is driven, the slide plate 6 and the slide body 7 begin to move linearly, and the free end of the chuck holding member 9 also moves linearly at the same time to press the tip of the chuck 12, and the chaffs 12 move around the fulcrum 18. It rotates around the central axis and a part of the crystal oscillator touches one of the grindstones fi! The crystal resonator 14 moves to (the crystal resonator is on line B).

At this time, a part of the crystal resonator is cut by the grindstone 2 rotating in the direction a. Thereafter, the slide plate 6 and the slide body 7 linearly move in opposite directions, and the free end of the chuck holding member 9 moves to suppress the tips of the chaffs 12 until the crystal oscillator 14 returns to the position on line A. At this point, the operation of the chaffs temporarily stops, and the oscillation frequency of the crystal oscillator 14 is measured to determine whether or not it has been adjusted to the target frequency.If adjustment is necessary again, the crystal oscillation The same movement operation as described above is performed so that the other part of the child is cut by the grindstone rotating in direction b, and the crystal resonator 14 is moved again to the position on line A, and the operation is temporarily stopped.

Then, the oscillation frequency is detected in the same manner as described above to further control subsequent movement operations.

Note that metal, resin, ceramic, etc. are used for the chuck holding member 9, but there is no particular limitation as long as the material can hold the chuck. In addition, in this device, the chuck holding member 9 is removed, and the chaffs 12 are attached to the chuck fixing member 11.
When installing the chuck 12, the chuck 12 may be completely fixed so that it does not rotate due to external force, or another holding member may be interposed between the slide body 7 and the chuck 12 to connect and fix the chuck 12. In this case, by finely adjusting the pulse input timing of the pulse motor, the reaction when the crystal oscillator 14 contacts the grinding wheel 2 can be prevented in advance, thereby preventing cracks and chips during cutting. Furthermore, since the accuracy of cutting can be reliably controlled, trimming can be completed with fewer cuts.

Although the crystal resonator 14 is automatically trimmed in this manner, a control circuit is essential for the trimming process in the present invention.

Figures 2 and 3 are block diagrams showing one embodiment of the trimming control circuit.

The crystal resonator 14 is oscillated by an oscillation circuit 15, and compared with a reference oscillation output from a reference oscillation circuit 18, the oscillation frequency is measured by a frequency measurement circuit 19.

The frequency is displayed on the display 20. The measured oscillation frequency and the frequency setting circuit 21 that sets the target frequency are compared in a comparator 22, and the detection symbols are the swing control circuit 17 and the motor rotation speed control circuit 2.
8 or input to the adjustment completion detector. In the case of a detection result that requires re-detection of JN, the frequency of the crystal resonator oscillated by the oscillation circuit 15 is level-detected by the oscillation level detection circuit 16, and the output signal and the output signal from the comparator 22 are detected by a chaff. Input to the control circuit 17 t'1
, drives the pulse motor 3. At the same time, comparator 22
The output signal from is input to the motor rotation speed control circuit section,
The rotation speed of the motor 24 is controlled and transmitted to the grindstone 2, and the rotation speed of the grindstone is adjusted. On the other hand, when the frequency is adjusted to the target frequency, the adjustment completion detector 25 detects it.

As described above, in the automatic trimming of a crystal oscillator, the present invention allows for soft and fine adjustment of changes in feed amount, and as an automatic device, there is no wasted movement, resulting in a significant improvement in work efficiency. .

In addition, while cutting the crystal resonator and measuring the frequency, the control circuit very delicately adjusts and operates the motor rotation speed and feed amount, reducing trimming time and making it possible to cut high-quality crystal resonators into smaller sizes. This is something that can be provided in a timely manner.

[Brief explanation of drawings]

FIG. 1 is a plan view of the main parts of an automatic trimming device showing an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the connection structure between the pulse motor and the slide body in the embodiment, and FIG. 2 is a block diagram showing an embodiment of a trimming control circuit which is one component. 1... Automatic trimming device body 2...
Grinding wheel 8...Pulse motor 4...Motor shaft 5...Slide ball 6...Slide plate 7...Slide body 7a... ...
Chuck holding member mounting surface 8...Slide shaft
9... Chuck holding member 10... Screw 11... Chuck fixing member V...
Chuffs 13...Fully point I4...Crystal oscillator 15...--Oscillation circuit 16...
・Oscillation level detection circuit 17... Oscillation "control circuit 18..."
・Reference oscillation circuit 19...Frequency measurement circuit Addition...Display 21...Frequency setting circuit
Safety...Comparator 23...Motor rotation speed control circuit Thorn...--Motor 25...
...adjustment completion detector patent applicant Rico Ichitoki Co., Ltd. Sakaki off phrase 88 progress nm Agency & t ZP/p husband A to vl, -V shout display B Nakada 7/#1 last time to pierced 11 phantom G3 No. 2 Bone B11/1 Name Crystal rM@h3-q)') Dirt device 3, Nagisa Noriyoshi and 6 close f!・, 4 people live in Takekota 〒4
G+ Usuzenbeikasho

Claims (1)

[Claims] 1. Trimming of a crystal oscillator, which consists of a mechanism that linearly moves two grindstone holding members that rotate in opposite directions at approximately the same speed in a direction parallel to the grindstone, and a chuck that holds the crystal oscillator and moves in the direction of the grindstone. Device.