JPH07269877A - Heat-cooking apparatus - Google Patents

Abstract

PURPOSE:To minimize and highly densify a printed-circuit substrate by providing key input circuit components for stabilizing a key scanning signal received and produced by a microcomputer in the interior of a key board. CONSTITUTION:A heat-cooking apparatus is provided with a heat-cooking unit 1 for heating and cooking foodstuffs to be heated, a control unit 2 having a microcomputer 21 for controlling the heat-cooking unit 1, and a key input unit 3 having a key board 31 for inputting heating information on the basis of a key scanning signal received and produced by the microcomputer 21. The key input unit 3 has, in its key board 31, an input protecting resistor 32 connected to the key board 31 for stabilizing the key scanning signal received and produced by the microcomputer 21. By this method, a number of key input circuits to be mounted on a printed-circuit substrate 22 of the control unit 2 can be reduced, and the printed-circuit substrate 22 can be minimized and highly densified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker, and more particularly, when a heating cooker is controlled by a microcomputer, key input circuit parts connected to an I / O port of the microcomputer are formed inside the keyboard. Regarding cookers.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing an example of a circuit configuration of a conventional heating cooker. As shown in FIG. 4, reference numeral 41 is a heating and cooking unit including a magnetron for heating and cooking an object to be heated, an infrared heater, and the like. 42 is a CPU, ROM, R
Microcomputer 42 consisting of AM and I / O ports
It is a control unit including a printed circuit board 42b on which a is mounted, and controls the heating and cooking unit 41 based on input heating information. Reference numeral 43 denotes a key input unit composed of a keyboard 43a composed of a tact switch, a flat switch and the like, a lead wire 43b for transferring a key scan signal and a connector 43c for connecting the lead wire 43b, and I of the microcomputer 42a of the control unit 42. Input heating information to the port (input port). The key input unit 43 is the connector 43
It is connected to the printed circuit board 42b of the control unit 42 by c. Reference numeral 44 denotes a display unit for displaying a cooking menu and cooking time, which is controlled by the microcomputer 42a.

In the control section 42 of the conventional cooking device, the limiting resistor 42c (which suppresses the influence of noise and static electricity entering the I / O port (input / output port) of the microcomputer 42a from the keyboard 43a of the key input section 43). 1), 4
2c (2), a key input circuit component 42c such as a pull-down / pull-up resistor 42c (3) for stabilizing the potential of a key scan signal input / output from a microcomputer 42a (for example, a carbon film resistor, A resistance array composed of resistance components such as a metal film resistor was formed on the printed circuit board 42b side on which the microcomputer 42a was mounted.

[0004]

However, in recent years,
Although the density of printed circuit boards is increasing, key control circuit components such as limiting resistors and pull-down / pull-up resistors that stabilize the key scan signals input / output from the microcomputer are mounted on the control unit mounted with the microcomputer. In order to be configured on the printed circuit board, a large component space is required, which has been a cause of hindering the high density and downsizing of the printed circuit board on which the microcomputer is mounted. Therefore, a large number of parts are required for the configuration of the key input circuit in the control unit. Therefore, the parts and manufacturing cost of the entire printed circuit board of the control unit are high.

The present invention has been made in consideration of the above circumstances, and is a key input circuit component for stabilizing a key scan signal input / output from the microcomputer when controlling the cooking with the microcomputer. By providing the inside of the keyboard, it is possible to significantly reduce the number of key input circuit components mounted on the printed circuit board of the control unit, and to provide a cooker that can achieve miniaturization and high density of the printed circuit board. To do.

[0006]

According to the present invention, there are provided a heating cooking section 1 for heating and cooking an object to be heated, a control section 2 having a microcomputer 21 for controlling the heating cooking section 1, and a control section 2. Enter from the microcomputer 21 /
A key input unit 3 having a keyboard 31 for inputting heating information based on an output key scan signal,
The key input unit 3 is a cooking device characterized in that a plurality of key input protection resistors 32 connected to the keyboard 31 are further provided inside the keyboard 31. According to the above configuration, the key scan signal input / output from the microcomputer 21 can be stabilized by the key input protection resistor 32.

The key input protection resistor 32 is preferably a thin film resistor formed inside the keyboard 31. According to the above configuration, since the key input protection resistor 32 is a thin film resistor, even if it is formed inside the keyboard 31,
It is not necessary to increase the external dimensions and thickness of the keyboard 31.

The control unit 2 includes a CPU, ROM, RA
It is preferable that the M and I / O ports are composed of a printed circuit board 22 on which a microcomputer 21 having one chip is mounted. According to the above configuration, the number of peripheral circuit parts of the microcomputer 21 can be reduced, so that the printed circuit board 22 can be downsized and the reliability can be improved.

The key input protection resistor 32 is a limiting resistor connected to the I / O port of the microcomputer 21,
It is preferably configured as a pull-up / pull-down resistor. According to the above configuration, the key input protection resistor 32 can stabilize the key scan signal input / output to / from the keyboard 31 and prevent noise and static electricity from entering the microcomputer 21 on the key input unit 3 side. Therefore, the reliability of the control unit 2 is further improved and the heating and cooking unit 1 can be stably controlled.

The key input section 3 is further provided with a flexible wiring board 33 for connecting the keyboard 31 and the I / O port of the microcomputer 21 and an FPC socket terminal 34 for connecting the flexible wiring board 33. According to the above configuration, the keyboard 31 of the key input unit 3
Since the printed circuit board 22 of the control section 2 and the printed circuit board 22 of the control section 2 can be separated and connected flexibly, it is possible to design freely.

In the present invention, the heating / cooking section 1 is composed of a magnetron or infrared heater that oscillates a high frequency and a load control circuit that drives them. The control unit 2 is composed of a printed circuit board 22 on which a microcomputer 21 having a CPU, a ROM, a RAM, and an I / O port formed by one chip is mounted. As the key input unit 3, a keyboard 31, a limiting resistor connected to the keyboard 31, and a key input protection resistor 32 such as a pull-up / pull-down resistor are integrally formed on the flexible wiring board 33 as a thin film resistor. In particular, as the flexible wiring board 33 on which the key input protection resistor 32 is formed, for example, an FPC (flexible printed circuit board) in which a conductor is printed on a film such as polyimide or polyester is used.

[0012]

The present invention will be described in detail below based on the embodiments shown in the drawings. The present invention is not limited to this. INDUSTRIAL APPLICABILITY The present invention is mainly suitable for use in a heating cooker that controls heating with a microcomputer. Each component can be applied to household appliances using a microcomputer, in addition to achieving the "compact and reliable heating cooker" of the present invention.

FIG. 1 is a block diagram showing an embodiment of the circuit configuration of the heating cooker according to the present invention. As shown in FIG.
Is a heating and cooking section for heating and cooking an object to be heated, which is composed of a magnetron, an infrared heater and the like and a load control circuit for driving them. 2 is CPU, ROM, RAM,
A control unit including a printed circuit board 22 on which a microcomputer 21 having an I / O port formed of one chip is mounted. The heating and cooking unit 1 is controlled based on the input heating information and the heating information is displayed on the display unit 4. . 3 is a keyboard 31 composed of flat panel switches and the like, and a flexible wiring board (FPC) 3 for transferring a key scan signal.
3 and a plurality of key input protection resistors (thin film resistors) 32 integrally formed on the flexible wiring board 33, and an FPC socket terminal 34 connected to the flexible wiring board 33.
Is a key input section. Further, the FPC socket terminal 34 of the key input unit 3 is provided on the printed circuit board 22 of the control unit 2.
Is provided with an FPC plug terminal (not shown). Reference numeral 4 is a display unit for displaying a cooking menu and heating time, and a fluorescent display tube is used.

The key scan signal input / output from the microcomputer 21 on the printed board 22 is the FPC socket terminal 34 and the flexible wiring board 3.
It is supplied to the keyboard 31 via 3. For example, in the flexible wiring board 33 connected to the keyboard 31, the limiting resistor 32a is provided at the output port 1 to 5 of the microcomputer 21 and the limiting resistor 32a is provided at the input port 6 to 10 of the microcomputer 21. 32b and a pull-down resistor 32c for stabilizing the potentials of the pin 6 to the pin 10 of the key scan signal input port are incorporated (see FIGS. 2 and 3). The common line of the pull-down resistor 32c is connected to the 11th pin of the FPC socket terminal 34 and is connected to the ground (GND) of the microcomputer 21.

FIG. 2 is an explanatory view showing the external appearance of the key input unit for heating and cooking according to the present invention. FIG. 2 shows a key input protection resistor (thin film resistor) 32 including a keyboard 31, limiting resistors 32a and 32b, and a pull-down resistor 32c, a flexible wiring board 33, and an FPC socket terminal 34. In particular,
FIG. 3 is an enlarged view of the key input protection resistance (cover film resistor) 32 of the flexible wiring board 33 of the key input unit 3.
FIG. 3 is an explanatory view showing the internal structure of the key input unit for heating and cooking according to the present invention. The internal structure of the flexible wiring board 33 of the key input unit 3 will be described with reference to FIG. In particular, as the flexible wiring board 33, for example, an FPC (flexible printed circuit board) in which a conductor is printed on a film such as polyimide or polyester is used.

As shown in FIG. 3, the flexible wiring board (FPC) 33 includes a lower film 33a and an insulating sheet 3.
3b and the upper film 33c are bonded together. A conductive line (for example, thin copper) for transmitting a key scan signal is printed on the lower film 33a, and a microcomputer 21 is provided in the middle thereof.
Limiting resistor 32a from the output port of the
The limiting resistor 32b from the input port is vapor-deposited. Then, a connection terminal portion 32d for connecting to the conductive line of the upper film 33c is printed, and an insulating sheet 33b is attached to insulate the pull-down resistor 32c of the upper film 33c.

The upper film 33c includes the lower film 3
The connection terminal portion 3 is provided at a position where the connection terminal portion 32d of 3a is connected.
Print 2e and pull down resistor 3 in the middle of the conductive line.
2c is vapor-deposited. The common line of the pull-down resistor 33c appears on the 11th pin. Upper film 33
The notch portion of c and the lower film 31c is for connecting the FPC socket terminal 34 and the conductive line.

In the above embodiment, the limiting resistors 32 (a), 32 are used as the key input protection resistors 32 for stabilizing the key scan signals input / output from the microcomputer 21.
(B) and the pull-down resistor 32 (c) are all built in the flexible wiring board 33, but depending on the circuit configuration, it is not necessary to provide all of them, and any one or two key input protections Only the resistor 32 may be implemented. Further, the key input protection resistor 32 has been described as being integrally formed with the flexible wiring board 33 in order to make it easy to understand the configuration location, but it can be configured inside the keyboard 31. , The location is not specified.

[0019]

According to the present invention, key input circuit parts such as a limiting resistor and a pull-down / pull-up resistor for stabilizing the key scan signal input / output from the microcomputer are formed inside the keyboard. Since the number of components of the key input circuit can be greatly reduced, the component space can be significantly reduced, and the external dimensions of the printed circuit board of the control unit can be reduced in size and density. Therefore, the cost of the material and manufacturing cost of the printed circuit board can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a circuit configuration of a heating cooker according to the present invention.

FIG. 2 is an explanatory diagram showing an appearance of a key input unit for heating and cooking according to the present invention.

FIG. 3 is an explanatory diagram showing an internal structure of a key input unit for heating and cooking according to the present invention.

FIG. 4 is a block diagram showing an example of a circuit configuration of a conventional heating cooker.

[Explanation of symbols]

 1 Heating / Cooking Section 2 Control Section 3 Key Input Section 4 Display Section 21 Microcomputer 22 Printed Circuit Board 31 Keyboard 32 Key Input Protection Resistor 33 Flexible Wiring Board 34 FPC Socket Terminal

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H03M 11/20

Claims (1)

[Claims] 1. A cooking unit for heating and heating an object to be heated,
The key input unit includes a control unit having a microcomputer for controlling the heating and cooking unit, and a key input unit having a keyboard for inputting heating information based on a key scan signal input / output from the microcomputer of the control unit. Is a cooker characterized by further comprising a plurality of key input protection resistors connected to the keyboard inside the keyboard.