JPS5850376B2 - display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device configured to enable functional testing of the display device without using a special tester.

Conventionally, it has been customary to use a dedicated tester to perform functional tests on general display devices, and when a failure occurs in the field, a dedicated tester is also required to find the location of the failure.

A conventional display device is shown in FIG. 1 and will be described.

In FIG. 1, 1 is a display device, which displays characters, symbols, etc., on a cathode ray tube (hereinafter referred to as CRT).

).

2 is a data input device (hereinafter referred to as K/B).

), it has a plurality of data input keys and a display data code generation circuit that generates a display data code signal for displaying characters or symbols on the CRTl in response to the key operations.

3 is a display control circuit (hereinafter referred to as CNT).

) performs various controls in response to external control code signals, while controlling external display data code signals or
This is for displaying characters, symbols, etc. on the CRTi corresponding to the display data code signal input from B2.

4 is an external connection interface (hereinafter referred to as LIF).

) for inputting external control code signals or display data code signals and for interconnecting with external equipment.

The operation of the device shown in FIG. 1 will be explained.

In operation as a normal display device, when a plurality of dekey keys provided on K/B2 are selected, a corresponding display data code signal is input to CNT3.

The display data code signal inputted to the CNT3 is displayed accordingly, and the characters or symbols corresponding to the data key /B2 are displayed on the CRTl.

The case where a display data signal is input from the outside to LIF4 is the same as the case where /B2 is operated as described above.

Next, if the display device needs to be tested due to a failure, etc., connect a dedicated tester to the LIF4, input various control code signals or display data code signals to the LIF4, and perform a function test of the display device to check. Was.

As described above, when performing a functional test on a conventional display device, a dedicated tester was used, so it was not possible to easily test the function of the display device.

The present invention has been made in view of the above-mentioned points, and by adding a mode switching circuit and a control code generation circuit for testing a general display device to a data input device, the display device can be used as needed. The present invention provides a display device that can perform functional tests.

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3.

In FIG. 2, the same reference numerals as in FIG. 1 indicate the same or corresponding parts.

5 is a data input device (hereinafter referred to as K/B).

), a circuit for performing a function test of the display device is added to the /B2 shown in FIG.

6 is a connection control circuit (hereinafter referred to as CON).

), according to the switching signal from the switching circuit 7, the display data code signal from /B5 is connected to CNT3 during normal operation, and the control code signal or display data from /B5 is connected to CNT3 during test mode. The code signal is selectively connected to CNT3 or LIF4.

Details of the /B5 shown in FIG. 2 are shown and explained in FIG. 3.

In Figure 3, 8 is various keys, 9 is a code generation circuit,
It generates display data code signals corresponding to various types of cows-8.

Reference numeral 11 denotes a mode switching circuit, which is used for a normal operation mode in which characters or symbols selected by key 8 are displayed on the CRTI, and a test for testing the function of the display device using a control code signal corresponding to the character or symbol selected by key 8. This is used to switch between the operating modes.

10 is a bit conversion circuit which does not operate in the normal operation mode and passes the display data code signal from the code generation circuit 9; in the test operation mode, it converts the display data code into a predetermined control code signal, and converts the display data code into a predetermined control code signal, It generates various control code signals accordingly.

The operation of this embodiment of the invention will be explained with reference to FIGS. 2 and 3.

When the mode switching circuit 11 of the K/BS is set to the normal operation mode, its operation is similar to that described above.
When various keys 8 provided on the screen are selected, characters or symbols corresponding to the keys 8 are displayed on the CRTl.

Next, when the mode switching circuit 11 of the K/BS is set to the test operation mode, the operation is as follows: While pressing or after pressing a specific key among the various keys 8 provided on the K/B 5, press another key 8. When is pressed, the code generation circuit outputs a display data code signal corresponding to the pressed key.

The display data code signal is input to the bit conversion circuit 10,
It is converted into a predetermined control code signal and input to C0N6.

The predetermined control code signal input to C0N3 is sent to the switching circuit 7.
The signal is output to the LIF4 or CNT3 according to various functional tests, and the functional test of the LIF4 or CNT3 is performed.

Further, if a specific key is not pressed but another key is pressed, the display is displayed on the CRTl in the same way as in the normal operation mode.

Here, the control code generation circuit is composed of a code generation circuit 9 and a bit conversion circuit.

As explained above, the present invention configures a display device in which a mode switching circuit and a control code generation circuit for performing a test are added to a data input device, so that the test can be performed as needed without using a special tester. Functional testing of display devices can be performed.

Here, in the detailed description of the present invention, key 8 was used in both the normal operation mode and the test operation mode.
It is clear that they may be provided independently.

Furthermore, the same applies to special keys.

Further, although the CRT has been described as a display device, it is obvious that a plasma display or the like can be used.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional display device, FIG. 2 is a block diagram of a display device according to an embodiment of the present invention, and FIG.
This figure is a block diagram showing the data input device shown in FIG. 2. In the figure, 1 is a cathode ray tube CRT as a display, 3 is a display control circuit CNT, 4 is an external connection interface circuit LIF, 5 is a data input device /B, and 6 is a control circuit C.
ON, 7 is a switching circuit, 8 is a key, 9 is a code generation circuit,
10 is a bit conversion circuit, and 11 is a mode switching circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. The display is controlled according to an external control code signal, and characters or symbols, etc. are displayed on the display surface in response to an external display data code signal or a plurality of key operations from a data input device. In the display device for displaying, the data input device is provided with a mode switching circuit for selecting a normal operation mode and a test operation mode, and a control code generation circuit for generating a control code signal equivalent to the control code signal. . A display device configured to perform a test operation based on signals from the control code generation circuit generated in response to operations of the plurality of keys when the mode switching circuit is set to the test operation mode. 2. A control code generation circuit consisting of a display code generation circuit that generates display data code signals corresponding to a plurality of keys provided on a data input device, and a bit conversion circuit that manually converts the display data code signals into control code signals. The display device according to claim 1, characterized in that the display device comprises: