1. Field of the Invention
The present invention relates to a video apparatus, and more particularly, to a video apparatus simplifying the checking and adjustment of a specific single module which constitutes the video apparatus.
2. Description of the Related Art
In recent years, video apparatuses are manufactured (assembled) by combining a plurality of parts which have been modularized for every function unit. Accordingly, by changing the parts (modules) to be combined variously, many types of products can be designed and manufactured easily and efficiently.
At the same time, it is well-known that broadcasting is done in different broadcasting systems from country to country throughout the world. For example, there are three major television broadcasting systems: NTSC, PAL and SECAM. Each of these systems may still differ in minute details from country to country, particularly in the ex-Communist bloc, even though the same system is used. To cope with such circumstances, there is a need for video apparatus that is able to receive various broadcasts in different television broadcasting systems. At the same time, there is also a need to improve design efficiency and to develop products that have global usefulness by using modular parts to perform functions which differ from one broadcasting system to another. For example, the intermediate-frequency signal processing circuit part and the sound multiplex signal processing circuit part may be used as module parts, while circuit parts which are common regardless of the broadcasting systems remain part of the basic apparatus.
Meanwhile, for the adjustment of various devices comprising the module, a method to adjust by using a microcomputer through the BUS line is used. This technique is called the BUS control and replaces the conventional hand-operated volume adjustment.
FIG. 4 is a block diagram to show an example of an adjustable tester for modules controlled by the BUS control, and FIG. 5 is a flow chart of the checking and adjustment procedures for conventional modules.
In FIG. 4, the adjustable tester 25 carries out a temporary adjustment and the check of the operation on the module 7. The tester 25 has a microcomputer 3, an inputting/outputting means 4, a memory 8 and a BUS line 6.
The microcomputer 3 is provided with various test programs and test data which are necessary for the temporary adjustment of the module 7. The inputting/outputting means 4 inputs control commands and control data to the microcomputer 3, and at the same time, outputs responses to the control commands and control data. The memory 8 stores data for the temporary adjustment of the module 7 and the like. The BUS line 6 is connected to the microcomputer 3, the memory 8 and the module 7.
The module 7 comprises a TV receiver's intermediate frequency signal processing circuit, a sound multiplex signal processing circuit, a sound processor, etc. The BUS line 6 is connectable to each of these circuits. The module 7 is also provided with terminals to input to the intermediate frequency signal processing circuit, to output video signals from the intermediate frequency signal processing circuit, and to output sound signals from L (left) and R (right) of the sound processor.
On the other hand, the main unit of a TV receiver includes a tuner for receiving signals from the antenna and supplying intermediate frequency signals to the module 7, a video signal processing circuit to which the module 7 supplies video signals, a display which is supplied with the output from the video signal processing circuit, and a means to regenerate sound signals from the module. The main unit also has a channel selecting circuit which is connected to the tuner and selects received channels, a memory which is connected to this channel selecting circuit and can store channel data, etc., and a means to receive remote control signals. The channel selecting circuit is controlled by the microcomputer. This microcomputer is connectable to the tuner, video signal processing circuit, and each circuit of the module 7 through the BUS line.
The module 7 is a replaceable part corresponding to the difference in the broadcasting systems. Consequently, replacing this module 7 in accordance with the characteristic of a broadcasting system enables a user to use a main unit of a TV receiver for each of the broadcasting systems and thus, improve design efficiency.
Next, a description will be given on the conventional manufacturing process of video apparatuses based on the checking and adjustment process on a single module 7 shown in FIG. 5.
As shown in FIG. 5, in order to improve the reliability on the modularized parts, first of all, the module 7 is connected to the BUS line 6 of the adjustable tester 25 shown in FIG. 4, and the temporary adjustment of the single module 7 is performed by, for example, inputting some commands or data from the inputting/outputting means (adjusting means) 4 to the microcomputer 3. At this time, the data (offset value, etc.) for each adjustment (temporary adjustment) on each device which comprises the module 7, such as an intermediate-frequency signal processing circuit, a sound multiplex signal processing circuit and a sound processor are stored in the memory 8 of the adjustable tester 25. The temporary adjustment of the module 7 is carried out on each device. For example, the intermediate-frequency signal processing circuit adjustment is done on the AGC level, the sound multiplex signal processing circuit adjustment is done on the inputting level, on the separation of L (left) and R (right) signals, on the DC value of VCO at the PLL circuit, and on other filters, while the sound processor adjustment is carried out on the levels of bass, treble and balance. When the temporary adjustment of this single module 7 is finished, the check of the operation of the single module 7 follows using a prescribed means which is not shown in the figures (Step T1).
The module 7, which has been proved to be normal (good product) through the check of its operation, is mounted on the main unit of a video apparatus (television receiver) (Step T2), and as described above, each device constituting a module 7 is readjusted by, for example, inputting some commands or data to the microcomputer in the main unit from the remote controller. The data for adjustment of each device, including an intermediate-frequency signal processing circuit, a sound multiplex signal processing circuit and a sound processor, is stored in the memory of the main unit (Step T3).
After that, other devices of the main unit, that is, a tuner, a video signal processing circuit and the like are adjusted. The adjustment data on each device is stored in the memory of the main unit (Step T4). As for the adjustment of each device of the main unit, on the tuner, for example, the channel selection is adjusted, and on the video signal processing circuit, contrast, brightness and hue are adjusted.
As described above, according to the procedure of the checking and adjustment process on a single module which operates under the conventional BUS control, none of the modules have a dedicated memory (for example, EEPROM) to store the adjustment data on each device comprising the module 7. This requires the same adjustment twice. The first adjustment is performed before the shipment of modules as parts. The parts are adjusted module by module. The second adjustment is performed when the module is mounted and assembled on the set (the main unit). The module undergoes the same adjustment as the first adjustment, together with other devices of the main unit. The data for adjustment of each device is written in the memory which is built in the set (the main unit). In other words, the process which is carried out in Step T1 in FIG. 5 is repeated in Step T3, thus resulting in additional man-hours for adjustment.
As stated above, for a conventional video apparatus, a single module undergoes various adjustments at the time of manufacture to prepare the apparatus for proper operation before it is shipped. When the module is assembled into a video apparatus, various kinds of adjustments on the module are performed again. This adjustment must check more parts than in the previous adjustment of other circuit parts (for example, the video/chromaldeflection processing circuit), and thus, is time-consuming.