JP3343839B2 - Display device with inspection function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device having a control means for controlling a display means by a plurality of input means.
Inspecting the functions of the plurality of input means and the display means,
Further, the present invention relates to a display device provided with a means for promptly detecting a wiring defect of the input means, the display means, and the control means.

[0002]

2. Description of the Related Art FIG. 1 is a block diagram showing an example of the configuration of a display device known as such. In FIG. 1, an input is made from a plurality of KEY blocks 1 as input means to a CPU 2 as control means, and the CPU 2 controls a fluorescent display tube 4 as display means via a display driver IC3. 1 is a CD stereo system, the CPU 2 also controls the CD system 5, tuner system 6, and tape system 7. FIG. 2 shows a wiring of a specific example of the display driver IC 3 and the fluorescent display tube 4 of FIG.

FIG. 3 shows the internal connection of the fluorescent display tube 4. As shown in FIG. 1A, a display tube divided into 1G to 9G grids is shown in FIG. like,
It has 16 P1 to P16 segments. The segments a to s therein correspond to the display segments in FIG. 3C, and the others correspond to the symbols in FIG. Here, in order to turn on the "ST" segment of the fluorescent display tube, for example, P4
And 9G are turned ON. P1, P3, P5, P7, P9, P
The rows indicated by 11, P13, P15 are called odd-numbered segments, and P2, P4, P6, P8, P10, P12, P1
4, P16 is called an even segment,
For example, “X-BASS” is an odd segment and “S
T "is an even segment.

FIG. 4 is a view showing a KEY input section from the front of a CD stereo system having a display device displayed in this example. In FIG. 4, each of KEYs 11 to 34 is
Input K used for the operation represented by the character or symbol attached thereto
EY. FIG. 10 shows a flowchart in a conventional test mode, and the display device is inspected according to the test mode. In the flowchart of FIG. 10, << TUNNING UP >> is determined in step S101.
The test mode (step S102) is entered by simultaneously pressing the KEY 24, the << TUNNING DOWN >> KEY 25 and the << POWER >> KEY 29. In step S103, the odd-numbered segments of the fluorescent display tube 4 are turned on for 4 seconds. In step S104, the even-numbered segments of the fluorescent display tube are turned on for 4 seconds.
Then, all the segments of the fluorescent display tube are turned on for 4 seconds, and then turned off in step S106. At this time,
MORY >> When the KEY 22 is received, the step S
According to the judgment of 107, the operation from step S103 to step S106 is performed again. The test mode is released by the << POWER >> KEY 29, and when the KEY is accepted, the mode is shifted to a normal POWER OFF state.

[0005]

By the way, in the conventional test mode in which the above-described display device is inspected,
After entering the test mode, odd segments, even segments, and all segments are automatically turned on and turned off.
Also, when the light is turned on again, the operation is performed by operating 1 key of << MEMORY >> KEY22. In the conventional test mode performed in this manner, the display mode may be changed or turned off during the function test of the display tube. In such a case, << MEMORY >> KEY2
It was necessary to confirm lighting again by the operation of 2. Then, in the conventional test mode, during the test mode, the <TUNING U> used to enter the test mode is used.
P >> KEY24, << TUNING DOWN >> KEY2
5, only a total of 4 keys including << POWER >> KEY 25 and << MEMORY >> KEY 22 used for re-lighting have been subjected to the function test as the input means. That is, the KEY block 1, the CPU 2, the display driver IC
3, it is impossible to perform all of the functional inspection of the fluorescent display tube 4 and the wiring inspection that connects each of them with the above-described conventional example.
There was no other choice but to let the actual operation be performed and inspected. The present invention
The present invention has been proposed in view of the above-described circumstances, and effectively performs all of the functional tests of the KEY block, the CPU, the display driver IC, and the fluorescent display tube, which are constituent elements of the display device, and the inspection of the wiring connecting them. It is intended to be performed.

[0006]

Means for Solving the Problems] This onset Ming, an input means such as a KEY blocks have a plurality of variable input element may set an input state of a wide by the action of the variable input elements, a plurality of variable display A display unit having an element and capable of generating various display states by the action of the variable display element, and performing operation control according to various operation modes including a test mode based on an input from the input unit, In a display device having control means for controlling display of each display element of the plurality of variable display elements to generate various display states in the display means, when the operation mode is set to a test mode, the control means , At least one of the plurality of variable display elements of the display means corresponding to various input states obtained by selecting at least one variable input element of the input means. By performing operation control for selecting and driving one, the function of each element of the input unit and the display unit and the abnormality of the wiring of the input unit, the display unit, and the control unit can be quickly inspected. to, as well as allows to perform simultaneously in a plurality of variable display elements and function test and the test mode each wiring inspection of the display driver of the plurality of variable input element and display means KEY blocks such as an input means, said input Directive of means
Mode in which all the variable display elements of the display means are turned on by
When it becomes, the drive starts blinking after a predetermined time elapses from lighting.
Control so that all variable display element segments
Display driver IC from thermal damage caused by lighting
And protect all the components of
Inspection of the light status can be performed for an arbitrary period of time even though it is blinking.
Function.

[0007]

[0008]

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The basic configuration of the display device of the present invention is the same as that of the above-described conventional example except that the function of the CPU 2 is different. Now, the operation in the test mode performed by the CPU 2 which characterizes the present invention will be described.

FIG. 5 shows a flowchart of the operation in the test mode of the present invention. First, step S1
Then, << TUNING UP >> KEY24 and << TUNI
NG DOWN >> KEY25 and << POWER >> KEY
29, and the test mode is entered (step S2). In step S3, all segments are turned on for 0.5 seconds to inform that the test mode has been entered. Next, if it is determined in step S5 that any key input has been performed after the light is turned off in step S4, the display segments are set to different display states corresponding to the key inputs shown in FIGS. Is turned on (step S6). For example, << REC >> KE
While the Y23 is pressed, the "REC" segment is turned on. By this inspection, the function inspection of the << REC >> KEY 23, the function inspection of the "REC" segment of the fluorescent display tube 4, the << REC >> KEY 23, the CPU2, the CPU2, the display driver IC3, the display driver IC3, and the fluorescent display tube 4 (in this case, 5G This means that the inspection of the wiring of (P1 connection) was performed at the same time. Here, as shown in FIGS.
In accordance with the Y number 23, 23 different display states are created.

Next, at step S7, << POWER >>
It is determined whether all of the 23 keys other than the KEY 29 have been input at least once, and if it can be determined that the input has been performed,
In step S8, "OK" is displayed. By this display, it can be confirmed that all inputs of 23KEY have been performed. This means that all of the 23KEY inspections have been completed. Thereafter, if it is desired to confirm the inspection of the arbitrary key and the display again, the arbitrary key is checked in step S9.
Input is performed, and display is performed in step S10. The test mode is released in the same manner as in the conventional example by using the << POWER >> KE
Performed by Y29, and when this key is received, the state shifts to a normal POWER OFF state.

FIG. 9 is an equivalent circuit diagram inside the display driver IC3. VCC or GN input from CPU2
The lighting of the fluorescent display tube is controlled by the D potential. G
When the ND potential is input, the switching element Q1 is turned on.
Then, VCC is applied to the terminal of the fluorescent display tube and grid 1
Display segments to which VCC is applied to both G to 9G and segments P1 to P16 are turned on. At this time, the resistance R
2 are applied to both ends of VCC2. If the value of the resistor R2 is 30 KΩ, VCC is 5V, and -V is -35V,

[0013]

(Equation 1)

In the case of lighting all segments, in this embodiment, dynamic lighting is used, so that 1G to 9G
Must be applied to one of them and all the terminals P1 to P16. At this time, the power consumption of the display driver IC becomes P ₀ = P _R × (16 + 1) = 906 mw, and if it continues for a long time, there is a possibility that thermal destruction may occur. Therefore, in steps S13 and S17, << CLOCK >> KEY 28
Then, when all segment lighting mode is set, after all lighting is performed for 4 seconds, driving to switch to blinking for 100 ms is performed.

[0015]

As described above, in the display device of the present invention, by entering the test mode by a predetermined operation in a place such as a production line inspection process of the display device, the input means, the control means, and the display means are provided. It is possible to simultaneously perform each function test and the test of the wiring connecting the input means, the control means, and the display means, and perform the flashing operation at any time even when the display mode is all on. It is also possible to confirm that the inspection has been performed without omission, and these can greatly reduce the time required for the inspection process of the production line and make it possible to perform the inspection reliably. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a configuration of a (conventional) display device on which the present invention is based.

FIG. 2 is a diagram showing wiring of a specific example of a fluorescent display tube and a display driver IC in FIG. 1;

FIG. 3 shows an internal connection of a fluorescent display tube.
(A) is a grid division diagram, (B) is a connection diagram of display segments, and (C) is a diagram showing a relationship between a code and a segment.

FIG. 4 is a diagram of a KEY input unit viewed from the front of a CD stereo system including a display device according to an embodiment of the present invention.

FIG. 5 shows a flowchart of an operation in a test mode according to the embodiment of the present invention.

FIG. 6 shows a step S1 in the test mode of FIG.
FIG. 3 is a diagram showing a display state for each KEY input in S17 and S17.

FIG. 7 shows a step S1 in the test mode of FIG.
FIG. 3 is a diagram showing a display state for each KEY input in S17 and S17.

FIG. 8 shows a step S1 in the test mode of FIG.
FIG. 3 is a diagram showing a display state for each KEY input in S17 and S17.

FIG. 9 shows a display driver IC according to an embodiment of the present invention.
FIG. 3 is a diagram showing an equivalent circuit inside the device.

FIG. 10 shows a flowchart of a conventional test mode operation.

[Explanation of symbols]

1 KEY block, 2 CPU, 3 Display driver I
C, 4 fluorescent display tube, 5 CD system, 6 tuner system, 7 tape system, 11 to 34 KEY,
S1 to S10, S101 to S107... Operation steps.

Claims (1)

(57) [Claims] 1. A key having a plurality of variable input elements and capable of setting various input states by the action of the variable input elements.
Input means such as blocks, display means having a plurality of variable display elements and capable of generating various display states by the action of the variable display elements, and various operations including a test mode based on input from the input means A display device having control means for performing operation control according to a mode and controlling display of each display element of the plurality of variable display elements in order to generate various display states in the display means,
When the operation mode is set to the test mode, the control unit controls a plurality of variable display elements of the display unit corresponding to various input states obtained by selecting at least one variable input element of the input unit. By performing operation control for selecting and driving at least one of them, the function of each element of the input unit and the display unit and the abnormality of the wiring of the input unit, the display unit, and the control unit are promptly inspected. And by the command of the input means
A mode in which all the variable display elements of the display means are turned on.
The drive switches to flashing after a predetermined time has elapsed
Has an inspection function characterized by controlling
Display device.