JPH0411389Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an electronic tuning tuner device used in miniaturized devices such as 8 mm VTR devices or liquid crystal televisions.

[Prior art] Conventional electronic tuning tuners for televisions, etc.
By installing UHF and VHF circuit elements and separating each circuit with a shield plate set up on a flat board,
It comprised a VHF combination electronic tuning tuner. For example, in the plan view of the tuner device shown in FIG. 5, which shows a conventional example, the tuner device 1 houses a flat board 3 in a shield case 2, and each circuit element 4 and circuit elements are arranged on the flat board 3 for each predetermined circuit. A shield plate 5 is provided to separate UHF and VHF.
The circuit is partitioned by a central shield plate 5a.

[Problems to be solved by the invention] However, in the tuner device with this conventional configuration, the circuit configuration is provided on a flat board, and the UHF circuit section and the VHF circuit section are separated by a shield plate. Therefore, there is a problem in that even if circuit elements and the like are mounted on both sides of a flat substrate to increase the mounting density of the substrate, there is a limit and it is difficult to achieve miniaturization.

An object of the present invention is to provide a tuner device that solves the above problems.

[Means for Solving the Problems] In order to solve the above problems, the tuner device of the present invention includes a flat circuit board inside the shield case of the tuner device, and an upright circuit board installed on the flat circuit board. A flat circuit board is provided with a tuned circuit element, and a vertical circuit board is formed of a ceramic substrate with UHF active circuit elements arranged on one side and VHF active circuit elements arranged on the other side, The structure is such that it is located approximately at the center inside the shield case.

[Function] The above configuration increases the mounting density of the tuner device to make the tuner device smaller, and the UHF and VHF tuning circuit portions are each provided with dedicated portions on the flat circuit board, so the tuning portion This eliminates variations in inductance and allows the circuit to have a high Q value.

[Embodiment] Next, an embodiment of the tuner device according to the present invention will be described.

1 is a perspective view of the tuner device according to the present invention, FIGS. 2a and 2b are front and side views showing a part of the circuit board, FIG. 3 is a circuit diagram showing the circuit configuration of the tuner device, and FIG. Figure 4 shows the main circuit diagram.

As shown in the figure, the tuner device 10 that receives the UHF-VHF band includes a shield case 11 and a UHF
Input terminal 12 and VHF input terminal 13,
AGC, AFC, UB, Vt, HB, IMB and IF OUT
consists of 14 terminals, UB is the power supply for the UHF circuit,
HB is VHF High Band switching power supply,
IMB is the power supply for the VHF mixer circuit and IF circuit, and VB is the VHF circuit power supply.

Further, inside the shield case 11, a planar circuit board 15 made of a printed circuit board and an upright circuit board 16 made of ceramic or the like are provided with slit holes 15a and 15b provided approximately in the center of the planar circuit board 15. It is structured as follows.

Next, the upright circuit board 16 shown in FIG. Chip parts 19 serving as semiconductors, resistors, and capacitors are arranged here, and the semiconductor parts are coated with resin 20 as shown in FIG. 2b. Reference numeral 21 indicates conductive contact terminals provided on the lower end protrusions 22 and 23 of the ceramic substrate 17, which serve as input and output terminals. The parts are soldered to the circuit network of the planar circuit board 15 to eliminate inductance.

Next, to explain the circuit configuration in Figure 3, the part surrounded by dotted line A in the circuit diagram is the UHF part, and the part B is the UHF part.
This is the VHF section. Here, the semiconductors Q ₁ , Q ₂ , Q ₃ , and Q ₇ operate during VHF reception and are a circuit for receiving the VHF band, and the switching diodes D ₁ , D ₄ , D ₅ , and D ₁₄ is the low band of the VHF band,
It is a high band selector switch and the operating voltage HB is +
When voltage B is applied, current flows through L ₂ , L ₄ , L ₆ , L ₁₃ , which is grounded at high frequency, and L ₁ , L ₄ , L ₅ and L ₉
and the variable capacitance diode D ₂ included in each circuit,
D ₃ and D ₆ are variable, and a tuning voltage Vt tuned to the receiving frequency is applied. Also, Q ₁ ,
The AGC voltage is constantly applied to G ₂ of Q ₄ 's FET through a resistor, and the gains of Q ₁ and Q ₄ are automatically set depending on the magnitude of the receiving state electric field strength connected from the PIF output, and the AFC voltage is changed. is being applied.

Next, UHF circuits Q ₄ , Q ₅ , and Q ₆ are composed of RF amplification, mixer circuit, and UHF oscillation circuit.
D ₇ , D ₈ , D ₉ , and D ₁₁ are variable capacitance diodes used when receiving the UHF band, and L ₁₂ , L ₁₄ , L ₁₇ , and L ₂₀ are tuning circuits of the circuit, and resonance with the cupacitor of the variable capacitance diodes Variable capacitance diode D ₇ which is a circuit,
It is tuned by the applied voltage from Vt at D ₈ , D ₉ , and D ₁₁ .

In addition, here, the variable capacitance diodes D ₁₂ and D ₁₃ are
When an AFC circuit is configured and a voltage is applied to the AFC terminal, the frequency of the local oscillation circuit is automatically connected to the PIF circuit, and then the tuner local oscillation circuit is set.

In addition, _Q5 is a VHF band mixer circuit, where two signals are input to each transistor emitter and mixed, and the mixed and mixed signals are passed through a filter and then passed through a SAW filter F to VHF.
It is input to _G2 of the IF amplification circuit in the circuit section.

Conventionally, the signal was input through a diode switching circuit, but by connecting the SAW filter F, the switching circuit is not required. This means that the frequency applied to SAW filter F while receiving the VHF band is the VHF local oscillation frequency,
This is because the relationship between the frequency characteristics of the SAW filter F can be ignored.

Therefore, in the circuit configuration explained above, as shown in the figure by the dotted line parts A and B, part A is UHF.
part and the VHF local oscillation part, and this part A is the local oscillation part of VHF.
One side 1 of the ceramic substrate 17 has a circuit configuration including active elements made of semiconductors Q ₄ , Q ₅ , Q ₆ and Q ₇ .
7a, and the other side 17b is provided with a circuit configuration including active elements made of semiconductors of circuit portions Q ₁ , Q ₂ , and Q ₃ of the VHF portion.

Next, Figure 4 shows the main parts of the VHF mixer circuit and IF amplifier circuit, including the FET transistor.
The PF signal from the VHF circuit is applied to G ₁ , and the frequency from the local oscillation circuit is applied to G _2. However, by combining SAW filter F here, a difference in frequency occurs, and the respective circuits are It has a circuit configuration that does not require switching and does not require a switching diode circuit.

In addition, as a means of constructing a circuit on the ceramic substrate 17, the semiconductor parts of the tuner device 1, such as the RF amplifier section, mixer section, local oscillation section, and IF amplifier circuit section, are directly bonded to semiconductor chips on the ceramic substrate 17. A circuit is formed on 17a and 17b, or a pattern is printed to attach a semiconductor directly to the plate surfaces 17a and 17b of the ceramic substrate 17, and the semiconductor part is printed, and the resistor part is also printed and fired. . Here, Ag−Pt
In the case of only printed wiring, the Q of the circuit decreases due to the resistance of the printed electrodes, resulting in poor characteristics. Therefore, the film printed circuit board is bonded onto the ceramic substrate 17 to reduce the electrical resistance and Q of the circuit. It is something that improves and composes.

[Effect] Therefore, as described above, according to the tuner device according to the present invention, on one surface of one ceramic substrate,
A semiconductor partial circuit of a UHF circuit section and a VHF local oscillation circuit section, a VHF circuit section and an IF amplification circuit section are formed on the other side, and these are installed in the center of a flat circuit board that constitutes a tuning circuit section of a tuner device. The tuner device has a configuration in which the circuits are inserted into cut-out slit holes and connected to the respective circuits, which increases the circuit packaging density and allows the tuner device to be miniaturized. Since each tuning circuit has a dedicated section, it is possible to provide a tuner device that eliminates variations in the inductance of the tuning section, increases the Q of the circuit, and improves the characteristics.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIGS. 2a and b are front and side views showing a part of the circuit board, FIG. 3 is a circuit diagram showing the circuit configuration of the tuner device, and FIG. FIG. 4 is a circuit diagram of the main part thereof, and FIG. 5 is a perspective view showing a conventional example. 10... Tuner device, 11... Shield case, 12... UHF input terminal, 13... VHF input terminal, 14... Terminal, 15... Planar circuit board, 1
5a, 15b...slit hole, 16...standing circuit board, 17...ceramic board, 18...printed circuit, 19...chip component, 20...resin, 21...
...Contact terminal, 22, 23...Protrusion part.

Claims (1)

[Scope of utility model registration request] It consists of a flat circuit board installed inside the shield case and an upright circuit board installed upright on the flat circuit board.A tuning circuit element is arranged on the flat circuit board, and a UHF circuit board is installed on one side of the upright circuit board. A tuner device characterized in that it is formed from a ceramic substrate with active circuit elements arranged on one side and a VHF active circuit element arranged on the other side, and is located in the center of the case.