Crystal Vibrator
By positioning the thermistor inside the housing and matching expansion coefficients, the crystal oscillator accurately measures temperature while minimizing volume and thermal mismatch effects.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TXC CORP
- Filing Date
- 2024-11-22
- Publication Date
- 2026-04-27
AI Technical Summary
Conventional crystal oscillators face issues with inaccurate temperature measurement of the resonant crystal piece due to the thermistor being disposed outside the housing, leading to increased volume and mismatched thermal expansion coefficients between different materials.
The thermistor is positioned inside the housing, close to the resonant crystal piece, with sealed spaces created between the housing and the crystal piece, allowing accurate temperature measurement and reduced volume through the use of thin-film thermistors and matching expansion coefficients.
Accurate temperature measurement of the resonant crystal piece is achieved, reducing the oscillator's volume and minimizing frequency changes during thermal cycles.
Smart Images
Figure 2026070430000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a vibration device, and particularly to a crystal oscillator.
Background Art
[0002] Conventional crystal oscillators include a housing, a resonant crystal piece, and a thermistor. Since the resonant crystal piece is disposed inside the housing and the thermistor is disposed outside the housing, the thermistor cannot accurately measure the temperature of the resonant crystal piece, and the volume of the crystal oscillator becomes excessively large.
Summary of the Invention
Problems to be Solved by the Invention
[0003] The present invention provides a crystal oscillator capable of accurately measuring temperature.
Means for Solving the Problems
[0004] The crystal oscillator of the present invention includes a housing, a pad, a resonant crystal piece, and a thermistor. The housing includes a first housing and a second housing. The pad is disposed on the outer surface of the second housing. The resonant crystal piece includes two thick portions and a thin portion whose both ends are respectively connected to the two thick portions. The two thick portions are disposed between the first housing and the second housing. A sealed first space is formed between the inner surface of the first housing and the thin portion of the resonant crystal piece, and a sealed second space is formed between the inner surface of the second housing and the thin portion of the resonant crystal piece. The thermistor is disposed in the first space or the second space and is electrically connected to the pad.
Advantages of the Invention
[0005] Based on the above, the thermistor of the crystal oscillator of the present invention is disposed inside the housing and is close to the resonant crystal piece inside the housing, so that the temperature of the resonant crystal piece can be accurately measured. The volume of the crystal oscillator can also be reduced through the thermistor disposed inside the housing.
Brief Description of the Drawings
[0006] [Figure 1] This is a schematic diagram of a quartz crystal oscillator according to one embodiment of the present invention. [Figure 2] This is a schematic diagram of a quartz crystal oscillator according to another embodiment of the present invention. [Figure 3] This is a schematic diagram of a quartz crystal oscillator according to another embodiment of the present invention. [Figure 4] This is a schematic diagram of a quartz crystal oscillator according to another embodiment of the present invention. [Modes for carrying out the invention]
[0007] Figure 1 is a schematic diagram of a quartz crystal oscillator according to one embodiment of the present invention. Referring to Figure 1, the quartz crystal oscillator 100 includes a housing 110, a pad 120, a resonant crystal element 130, and a thermistor 140. The housing 110 includes a first housing 111 and a second housing 112. The pad 120 is located on the outer surface 115 of the second housing 112. The resonant crystal element 130 includes two thick portions 132 and a thin portion 133, with both ends of the thin portion 133 connected to the two thick portions 132, respectively. The two thick portions 132 are positioned between the first housing 111 and the second housing 112.
[0008] A sealed first space P1 is formed between the inner surface 113 of the first housing 111 and the thin portion 133 of the resonant quartz crystal 130, and a sealed second space P2 is formed between the inner surface 114 of the second housing 112 and the thin portion 133 of the resonant quartz crystal 130. The inner surface 114 of the second housing 112 corresponds to the outer surface 115. The thermistor 140 is placed in either the first space P1 or the second space P2 and is electrically connected to the pad 120. The pad 120 is located outside the second space P2.
[0009] Since the thermistor 140 is positioned closer to the resonant crystal element 130 within the housing 110, the temperature of the resonant crystal element 130 can be measured more accurately. The thermistor 140 is, for example, a thin-film thermistor 140, which can reduce the volume of the crystal oscillator 100. The number of pads 120 is, for example, two, but is not limited to this.
[0010] The crystal oscillator 100 further includes a circuit structure 150, the ends 151 and 152 of the circuit structure 150 being connected to a pad 120 and a thermistor 140, respectively. The circuit structure 150 penetrates a portion of the housing 110. The thermistor 140 is electrically connected to the pad 120 via the circuit structure 150. In this embodiment, the thermistor 140 is located in a first space P1, between the first housing 111 and the resonant crystal 130. The housing 110 includes an internal flat surface 117, which is the inner surface 113 of the first housing 111. The thermistor 140 is positioned on the internal flat surface 117 (inner surface 113) of the first housing 111, facing the resonant crystal 130. Because the thermistor 140 is closer to the resonant crystal 130, the temperature of the resonant crystal 130 can be measured more accurately. The intermediate portion 153 between the two ends 151 and 152 of the circuit structure 150 penetrates at least one of the two thick portions 132 of the resonant crystal piece 130 and the second housing 112. In this embodiment, the intermediate portion 153 penetrates the two thick portions 132.
[0011] A groove 131 is formed between the two thick and thin sections 132 and 133 of the resonant quartz crystal 130, forming a neck structure. The thermistor 140 corresponds to the groove 131. Since the housing 110 and the resonant quartz crystal 130 are made of quartz, the expansion coefficients of the sealing housing 110 (housing 110) and the resonant quartz crystal 130 can be made the same.
[0012] In conventional quartz oscillators, the sealing housing and the resonant quartz crystal are made of different materials, resulting in different expansion coefficients. During the heating and cooling process, the frequency changes of the sealing housing and the resonant quartz crystal become mismatched, causing a delay (hysteresis) that affects the accuracy of conventional quartz oscillators. In this embodiment, the housing 110 and the resonant quartz crystal 130 of the quartz oscillator 100 have the same expansion coefficient (i.e., they are made of the same material). Therefore, during the heating and cooling process, the frequency changes of the housing 110 and the resonant quartz crystal 130 of the quartz oscillator 100 match, resulting in a more desirable accuracy for the quartz oscillator 100.
[0013] Furthermore, the crystal oscillator 100 further includes two sealing rings 160. One sealing ring 160 is positioned between the first housing 111 and the two thickened portions 132 of the resonant crystal element 130, and the other sealing ring 160 is positioned between the second housing 112 and the two thickened portions 132 of the resonant crystal element 130, thereby sealing the space between the housing 110 and the resonant crystal element 130.
[0014] Figure 2 is a schematic diagram of a quartz crystal oscillator according to another embodiment of the present invention. Referring to Figures 1 and 2 together, the quartz crystal oscillator 100a in this embodiment is similar to that of the previously described embodiment, the difference being that the inner surface 113a of the first housing 111a in this embodiment includes a groove 116 recessed toward the interior of the first housing 111a, away from the resonant crystal element 130. The thermistor 140 is located within the groove 116. The groove 116 provides the housing 110a with a larger space to facilitate the assembly of the quartz crystal oscillator 100a by an engineer. The circuit structure 150a located within the first space P1 extends along the surface of the groove 116 and is connected to the thermistor 140. The quartz crystal oscillator 100a in this embodiment has the same effects as the previously described embodiment, and therefore will not be described further here.
[0015] Figure 3 is a schematic diagram of a quartz oscillator according to another embodiment of the present invention. Referring to Figures 1 and 3 simultaneously, the quartz oscillator 100b in this embodiment is similar to that of the previously described embodiment, the difference being that the thermistor 140 in this embodiment is located in the second space P2. Here, the internal flat surface 117 of the housing 110 is the inner surface 114 of the second housing 112. The thermistor 140 is located on the inner surface 114 (internal flat surface 117) of the second housing 112. The intermediate portion 153 between the ends 151 and 152 of the circuit structure 150b penetrates only the second housing 112. The quartz oscillator 100b in this embodiment has the same effects as the previously described embodiment, so its explanation is omitted here.
[0016] FIG. 4 is a schematic diagram of a crystal oscillator according to another embodiment of the present invention. Referring to FIGS. 3 and 4 simultaneously, the crystal oscillator 100c in this embodiment is similar to the previous embodiment, and the difference between the two is that the inner surface 114c of the second housing 112c in this embodiment has a concave groove 116c recessed in a direction away from the resonance crystal piece 130 toward the inside of the second housing 112c. The thermistor 140 is disposed in the concave groove 116c. The circuit structure 150c located in the second space P2 extends along the surface of the concave groove 116c and is connected to the thermistor 140. The crystal oscillator 100c in this embodiment has the same effects as the previous embodiment, so the description is omitted here.
[0017] In summary, the thermistor of the crystal oscillator of the present invention is disposed in the housing and is close to the resonance crystal piece in the housing, so that the temperature of the resonance crystal piece can be accurately measured. The volume of the crystal oscillator can also be reduced through the thermistor disposed in the housing.
Industrial Applicability
[0018] The crystal oscillator of the present invention can accurately measure temperature.
Description of Reference Numerals
[0019] P1: First space P2: Second space 100, 100a, 100b, 100c: Crystal oscillators 110, 110a, 110c: Housings 111, 111a: First housings 112, 112c: Second housings 113, 113a, 114, 114c: Inner surfaces 115: Outer surface 116, 116c: Concave grooves 117: Inner flat surface 120: Pads 130: Resonance crystal pieces 131: Concave groove [[ID=4-3]] 132: Thick portions 133: Thin portions 140: Thermistors 150, 150a, 150b, 150c: Circuit structure 151, 152: Edge 153: Middle section 160: Sealing ring
Claims
1. A housing including the first housing and the second housing, A pad located on the outer surface of the second housing, A resonant quartz crystal comprising two thick portions and thin portions connected to the two thick portions, wherein the two thick portions are sandwiched between the first housing and the second housing, forming a sealed first space between the inner surface of the first housing and the thin portions of the resonant quartz crystal, and forming a sealed second space between the inner surface of the second housing and the thin portions of the resonant quartz crystal, A thermistor disposed within the first space or the second space and electrically connected to the pad, A crystal oscillator, including a quartz crystal oscillator.
2. The circuit structure further includes, the ends of which are connected to the pad and the thermistor, respectively. The crystal oscillator according to claim 1.
3. The thermistor is placed in the first space, and the intermediate portion between the two ends of the circuit structure penetrates at least one of the two thick portions of the resonant crystal piece and the second housing. The crystal oscillator according to claim 2.
4. The thermistor is disposed on the inner surface of the first housing. The crystal oscillator according to claim 3.
5. The inner surface of the first housing has a recessed groove that is recessed toward the interior of the first housing and away from the resonant crystal piece, and the thermistor is disposed within the recessed groove. The crystal oscillator according to claim 4.
6. The thermistor is placed in the second space, and the intermediate portion between the two ends of the circuit structure penetrates the second housing. The crystal oscillator according to claim 2.
7. The thermistor is positioned on the inner surface of the second housing. The crystal oscillator according to claim 6.
8. The inner surface of the second housing has a recessed groove that is recessed toward the interior of the second housing and away from the resonant crystal piece, and the thermistor is disposed within the recessed groove. The crystal oscillator according to claim 7.
9. The material of the housing and the resonant crystal piece is quartz. The crystal oscillator according to claim 1.
10. The present invention further includes two sealing rings, one of which is positioned between the first housing and the two thick portions of the resonant crystal, and the other of which is positioned between the second housing and the two thick portions of the resonant crystal. The crystal oscillator according to claim 1.