JPS6253588A - Image display device - Google Patents

Abstract

PURPOSE:To improve a maintenance and a service with attaching a self- diagnostic function on an image display device itself by comparing a synchronizing signal outputted from a picture information output means with a driving signal outputted from a driving means. CONSTITUTION:In addition to the same signal process circuit 10 as a normal image display device, a device is equipped with a comparison circuit 30, a decision circuit 32 and an informing lamp 34. As the comparison circuit 30, a phase comparison circuit is used, and phases between a vertical/horizontal synchronizing signal from a television video signal and a vertical/horizontal deflection output signal actually impressed on a deflecting coil are compared and when both phases are in consistent with each other without being shifted, the output of a level Low is sent and when either phase is different, the output of a level High to a decision circuit 32 at the next stage. The decision circuit 32 is a general switching circuit, supplying an electric power for a lamp illumination to the informing lamp 34 only when the output from the comparison circuit 30 is at the level High.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image display device having a self-diagnosis function.

[Prior Art] Conventionally, image display devices have been widely used as display units in information processing systems. For example, CRT, which is one of them, is inexpensive, has high resolution, and has excellent high-speed response, and is widely used in various fields. In addition, in recent years, many image display devices using solid display media such as plasma displays and liquid crystal displays have been proposed in order to become thinner and more compact, and these image display devices are being applied more widely.

[Problems to be Solved by the Invention] However, the conventional image display devices are still not satisfactory and have the following problems.

As mentioned above, image display devices have a solid position as display devices that are the easiest for humans to use.

However, when some kind of failure or malfunction occurs, it is difficult for the operator to determine whether the problem is with the image display device itself or with the image information transmitted to the image display device, making it difficult to deal with the problem. Ta. For example, when the image display device does not display any information, to repair it, first check whether the image information is normal or not, and if the information is normal, then check which part inside the image display device. It was necessary to investigate whether an abnormality had occurred, and the investigation and repair were inconvenient. Additionally, in cases where the image display device is inputting image information from another mechanically separated device, it is easy to determine whether an abnormality has occurred in the image information or the image display device. If this cannot be determined, it is not possible to determine which of the other devices or the image display device should be repaired, which is extremely inconvenient.

The present invention was made in view of the above problems, and by providing the image display device itself with a self-diagnosis PR function, maintenance and
The purpose is to provide an image display device that is easier to use and more convenient in terms of service.

[Means for Solving the Problems] In order to solve the above problems, the hydrogen cyanide means of the present invention, as shown in the basic configuration diagram of FIG. Image information output means S and 1 output an image signal and a synchronization signal based on the image information, and output a drive signal based on the image signal and synchronization signal from the image information output means VS to the image display means VD. In an image display device having a driving means VC, a comparing means C for comparing a synchronization signal outputted by the image information outputting means S with a driving signal outputted by the driving means VC.
1; and determining means C2 for determining the quality of the image display device based on the comparison result of the comparing means.

[Operation] The comparison means C1 in the present invention refers to the image information output means v
The synchronization signal of the S output and the drive signal of the drive means VC output are compared.

As is well known, in order to display an image on a two-dimensional plane, a synchronization signal is usually used as one of the image information to determine timing such as the end of one display screen or the end of one horizontal scan. These timing signals are synchronization signals,
It is output from the image information output means vS either in combination with the image signal which is the information of the image to be displayed or singly.

On the other hand, the driving means VC inputs the above-mentioned synchronization (rM number) and image signal, and outputs a driving signal for the image display means VD necessary for displaying an image faithful to these signals on the image display means VD. This drive signal is the image display means VD
The purpose of this is to convert the image signal and synchronization signal into a type corresponding to the configuration of the image display means VD. Therefore, various types are available depending on the configuration of the image display means VD. For example, if the image display means VD is
In the case of RT, beam scanning sawtooth waves for vertical and horizontal synchronization are generated, and a synchronization signal is generated like a liquid crystal display (s! If the display means VD has a matrix configuration, a synchronization signal is generated by sequentially applying a driving voltage to the rows or columns. Convert.

As is clear from the above explanation, the synchronization signal is always converted into a drive signal in some way, and only when the conversion is complete can a desired image be displayed on the image display means VD. Therefore, the comparison means C1 of the present invention compares this synchronization signal and the drive signal to create material for determining the quality of conversion. Here, comparison means that if the conversion of the synchronization signal by the driving means VC is performed accurately, it is clear that the synchronization signal and the drive signal after conversion have the same phase difference. This is done by detecting the

The determining means C2 determines the quality of the image display device based on the comparison result of the comparing means C1. That is, since the comparing means C1 compares the same lv1 signal and the drive signal after its conversion, it is determined based on the comparison result whether or not the synchronization signal is faithfully converted into the drive signal. Therefore, if the conversion is being performed accurately, the image display device is operating normally; on the other hand, if the conversion is not accurate, it can be easily determined that the image display device is not functioning properly.

Note that the determining means C2 is configured in various ways, such as notifying the above-mentioned determination results, or operating a safety circuit to stop power supply to the image display device in the event of an abnormality.

EXAMPLES Hereinafter, in order to explain the present invention more specifically, the present invention will be described in detail by giving examples.

[Embodiment 2] FIG. 2 is an electric circuit block diagram of an image display device according to an embodiment. A circuit 10 surrounded by a dotted line in the figure is similar to a normal television receiver circuit, and is used to transmit image information transmitted from other information processing equipment such as a microcomputer to a CRT.
It has a function to convert to a type suitable for displaying on L1.

First, these circuits 10 will be briefly explained.

The image processing circuit 20, which receives image information from another information processing device, converts the image information into a television video signal in which an image signal and a synchronization signal overlap. For example, when the image information is a digital signal or an RGB separated signal, it plays the role of a kind of decoder that converts this into a type suitable for a normal television receiver. As a result, the following circuit up to CRT1 may be the same as that of a normal television receiver as described above, and existing equipment can be used. The television video signal created in this way is amplified by the video amplification circuit 12 and the CRT1
The signal is sent to an input terminal of 1, a synchronizing signal separation circuit 13, and a comparison circuit 30, which will be described later. The synchronization signal separation circuit 13 separates the vertical synchronization signal and the horizontal synchronization signal from the amplified television video signal and outputs them to the vertical synchronization oscillation circuit 14 and the horizontal synchronization oscillation circuit 15, respectively, to determine the frequencies of the vertical synchronization oscillation and horizontal synchronization oscillation. decide. This ensures synchronous oscillation faithful to the television video signal. Based on these oscillation signals for vertical and horizontal synchronization, a sawtooth wave for vertically and horizontally scanning the electron beam of the CRTl 1 is generated by the vertical deflection output circuit 16 and the horizontal deflection circuit 17, and is applied to the deflection coil 11C of the CRTl 1. be done. Also, horizontal deflection output circuit 1
The output of 7 is also output to a high-voltage rectifier circuit 1B mainly composed of a flyback transformer, and is used as an anode voltage of the CRTll and a voltage source for each of the above-mentioned circuits.

In addition to the signal processing circuit similar to that of a normal image display device as described above, the image display device of this embodiment includes a comparison circuit 30, a determination circuit 32, and a notification lamp 34.

Next, the operations of these circuits will be explained in detail.

The comparator circuit 30 inputs the amplified television video signal and the vertical/horizontal deflection output signal among the above-mentioned image processing signals, and compares them. As shown in Figure 3, vertical
The horizontal deflection output signal performs two vertical scans (frame scans) in the vertical direction to display one screen (frame).
Further, it is a normal interlaced scanning signal in which an odd or even numbered horizontal scan (field scan) is performed for each vertical scan.

What determines the timing of each scan, that is, the frequency of vertical scanning and horizontal scanning, is the synchronization signal included in the amplified television video signal. In general, the Domei signals are overlapped, and the black level value is taken so as not to cause blanking on the display screen. Therefore, the synchronization signal and deflection signal in this television video signal must have exactly the same frequency.
It is clear that this is a signal that changes repeatedly with the same phase. Therefore, a phase comparison circuit is used as the comparison circuit 30, and a phase comparison circuit is used as the comparison circuit 30. The phase of the vertical/horizontal synchronization signal and the vertical/horizontal deflection output signal actually applied to the deflection coil is compared, and if both phases match without any deviation, a LOW level output is output. When the phases are different, a high level output is sent to the next stage determination circuit 32. The determination circuit 32 is a normal switching circuit, and supplies lamp lighting power to the notification lamp 34 only when the output from the comparison circuit 30 is at a high level.

According to the image display device of this embodiment configured as described above, even if some abnormality occurs and no image is displayed on the CRTll, unless the abnormality is caused by the image display device itself, Since all the internal signal processing is executed smoothly, the notification lamp 34 does not light up, and it can be easily determined visually that there is an abnormality in another information processing device that is outputting image information. Furthermore, if there is an abnormality in the image display device itself, the internal signal will naturally be disturbed, and the notification lamp 34 will surely turn on, thereby notifying the existence of an abnormality inside the image display device. .

Therefore, the image display device of this embodiment is equipped with a so-called self-diagnosis function, and it is extremely easy to determine whether an abnormality has occurred in the 8N device.

In this embodiment, the comparator circuit 30 is constructed of a circuit that performs phase comparison, but as described above, it is determined whether the internal signal processing is normal or not by comparing the frequencies and the ground. It's okay.

Further, the abnormality notification is not limited to the visual one using a lamp, but may be one that appeals to the auditory sense such as a buzzer sound.

Furthermore, in this embodiment, the configuration is such that only the notification is made to tell whether the abnormality is internal to the image display device, but whether the abnormality is observed in the vertical synchronization signal, horizontal synchronization signal, or both synchronization signals is notified. It is also possible to notify in detail. In this way, it is easier to determine where the abnormality is inside the image display apparatus, which is effective from the standpoint of service and maintenance.

[Effects of the Invention] As described above in detail with reference to the embodiments, the image display device of the present invention includes: an image display unit that displays an image; and an output unit that outputs an image signal and a synchronization signal based on image information to be displayed. In an image display device comprising an image information output means and a drive means for outputting a drive signal filled with an image signal and a synchronization signal from the image information output means to the image display means, the output of the image information output means The apparatus is characterized by comprising a comparison means for comparing the same signal and a drive signal outputted from the drive means, and a determination means for determining the quality of the image display device based on the comparison result of the comparison means. .

Therefore, the image display device also has a so-called self-diagnosis function for determining its own abnormality, and a significant improvement in workability in terms of service and maintenance can be achieved. This also improves the ease of use of the image display device, and has significant secondary effects such as enabling wider use.

[Brief explanation of the drawing]

Fig. 1 is a basic configuration diagram of the present invention, Fig. 2 is an electric circuit block diagram of the embodiment, Fig. 3 is an explanatory diagram of its vertical and horizontal deflection output signals, and Fig. 4 is the synchronization in the TV video signal. An explanatory diagram of the signal is shown. VD... Image display means vs. Image information output means VC... Driving means

Claims (1)

[Claims] Image display means for displaying an image; image information output means for outputting an image signal and a synchronization signal based on image information to be displayed; and an image signal and a synchronization signal from the image information output means. a drive means for outputting a drive signal based on the image information to the image display means, a comparison means for comparing a synchronization signal outputted by the image information output means and a drive signal outputted from the drive means; An image display device characterized by comprising: a determination device that determines whether the image display device is good or bad based on the comparison result of the comparison device.