JPS6095485A - Crt display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a CRT that connects a personal computer to a television receiver and simultaneously displays data images from the personal computer by superimposing them on a CRT screen with television broadcast images. The present invention relates to a display device.

Recently, personal computers have come to be used in ordinary households. Attempts are now being made to connect a home color television receiver as a CRT display device to a personal computer and display data from the personal computer on the color television receiver.

<Prior Art> FIG. 1 is a schematic diagram of a general CRT display device showing a state in which a personal computer is connected to a color television receiver. Referring to Figure 1, the data entered from the keyboard 1 is transferred to the personal computer 2.
, the R, G, and N signals for displaying the data on the color television receiver 3 are sent to the television 117.
The signal is applied to a signal mixing circuit 32 included in a circuit 31. Then, the R, G, and n signals are converted to CR via the signal mixing circuit 32.
It is given to T33, and characters or graphs are displayed.

By configuring the CRT display device in this manner, data images such as various characters and graphs can be displayed using the color television receiver 3 as a monitor. Furthermore, recently, a CRT display device has been devised that displays data from a personal computer superimposed on a color television broadcast screen.

<Problem> By the way, such a CRT display device does not superimpose data images from a digital computer on television images (not only broadcast images (including images reproduced by a VTR or video disk player, etc.)). Therefore, depending on the content of the television image, for example, characters and graphs in news programs and educational programs may have gold scraps, and in such cases, users may confuse them with data images from a personal computer. However, it had the disadvantage that it was difficult to immediately identify which image it was.

Purpose> The present invention has been made in view of these points, and is intended to improve CR
In a device that can simultaneously project and display a television image and a data image from a personal computer on one screen, there is no possibility that the user will confuse the two images.
The present invention provides an RT display device.

Particularly, the present invention provides a CRT display device that allows a user to easily identify an image by adding shading with appropriate contrast to a data image from a personal computer.

<Examples> The present invention will be described below according to examples shown in the drawings. Second
The figure shows a block diagram of one embodiment of the invention, in which the first
The same parts as those in the figure are given the same reference numerals. In particular, we will focus on ORGATE 4. Monostable multivibrator5. Bumper amplifier 6. A shadow signal creation circuit 9 consisting of a transistor 7, a variable resistor 8, etc., a shadow contrast adjustment variable resistor 10 for adjusting the magnitude of the shadow signal created by the shadow signal creation circuit 9, and further transistors 11, 12, and A shadow signal mixing circuit 15 consisting of a buffer amplifier 1314 and the like is added to form 11 circuits.

Now, in the CRT display device of the above embodiment, CR1 is used as data output from the personal computer 2.
The operation when the R, G, T3 Ill forces that project the character image "Una[Fll" shown in FIG. 3(, )] on the screen are derived will be described.

In this case, at least one of the R, G, and B outputs of the personal computer 2 is 11
Therefore, a rectangular wave pulse as shown in FIG. 3(1)) is derived from the OR gate 4, and is supplied to the monostable multivibrator 5. At this time, the monostable multivibrator 5 is triggered by the falling edge of this pulse, and outputs a positive one-shot pulse with a constant pulse r1t TO as shown in FIG. supplied to the base. The transistor 7 is turned on only during this pulse period, and an inverted pulse signal of negative polarity is derived from the collector as shown in FIG. 3(d), and this is supplied to the shadow signal mixing circuit 15 as a shadow signal. At this time, the shadow signal mixing circuit 1
5, the buffer amplifier 1 is connected to the base of the transistor 12.
3 through which the aforementioned shadow signal is supplied. Note that a television brightness signal (Y signal) obtained from a trench television circuit 31 is inverted and inputted to the base of this transistor 12, and when the negative polarity shadow signal is added, that is, In the shadow area, the Y signal is temporarily blocked. On the other hand, the shadow signal obtained via the buffer amplifier 14 is suitably adjusted in magnitude by a variable resistor 10 for adjusting shadow contrast, and then supplied to the signal mixing circuit 32 in the television circuit 3I. Note that when there is no shadow signal, the Y signal obtained from the television circuit 31 is amplified by the transistors I+ and +2 and then returned to the signal mixing circuit 32 of the television circuit 31. That is, in the above-mentioned shadow signal mixing circuit 15, the shadow signal is mixed with the Y signal, and the Y signal mixed with this shadow signal is mixed with the Y signal.
Signal (Y signal signal mixing circuit 32 of television circuit 3I
will be supplied to

As a result, the rear edge of the character image area from the personal computer 2 is shaded in black or gray, and becomes the background, as shown in Figure 3(a). It is difficult to add any kind of shading to the television image.

In the above embodiment, the width of the shadow projected on the screen is determined by varying the value of the pulse width adjustment pulse rljT o of the multivibrator 5 using the variable resistor 8 for adjusting the pulse width attached to the monostable multivibrator 5. Can be set arbitrarily.

However, in this case, when the pulse width To is set so wide that the shadow of the character on the screen overlaps with a part of the adjacent character image, or when the galactor white size or the horizontal spacing between adjacent characters is narrow, Even if a positive polarity one-shot Halus is output from the monostable multivibe 1/-5, the output of the OR gate 4 will be ``H'' due to the character output of Puzusiri (7).
'' level, and the output of the amplifier 6 also becomes ``I ('' level. At this time, the transistor 7 is in the cut-off state, and therefore no shadow signal is derived from the collector. As a result, the shadow of one character on the screen is It does not erode parts of neighboring characters.

Furthermore, in this embodiment, by appropriately adjusting the value of the variable resistor IO for adjusting shadow contrast, it is possible to arbitrarily set the brightness of the shadow added to the trailing edge of the character image on the CR7 screen.

In the above embodiment, a color television receiver and a personal computer are connected, and the color characters from the personal computer are shaded in black on the CR7 screen, but it is of course possible to shade in color as appropriate. This is possible, and can also be implemented when a black-and-white television receiver and a personal computer are connected.

(8) <Effects> As described above, according to the present invention, a personal computer is connected to a television image machine, and the data image from the personal computer is superimposed on the CR7 screen with the television image. In a CRT display device that can project and display data on a personal computer, in particular, the data image of a personal computer is shaded with arbitrary contrast. can be immediately identified,
Therefore, even if characters and data are displayed on the screen in TV broadcasts such as News Kagawa, it is unlikely that confusion will occur.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a CRT display device in which a personal computer is connected to a color television receiver, Fig. 2 is a block diagram of an embodiment of the present invention, and Fig. 3 is a CRT screen for explaining the operation of the embodiment. 2 is an example and a signal waveform diagram at that time. 2...Par7-)-le computer, 3...Color television receiver, 32...Signal mixing circuit, 33...
CRT, 9...shading signal creation circuit, 10...variable resistor for adjusting shadow contrast, 15...shading signal creation circuit. Agent Patent attorney Aihiko Fuku (and 2 others) +X
++% ) (q () -1 1N-\, \-

Claims (1)

[Claims] 1. In a CRT display device in which a personal computer is connected to a television receiver and data images from the personal computer can be simultaneously projected and displayed on the CRT screen by superimposing the television image, The apparatus comprises means for creating a shadow signal, a means for arbitrarily adjusting the magnitude of the shadow signal, and a means for mixing the adjusted shadow signal with a television image signal, the data image being on a CRT screen. (7) A CRT display device characterized in that the contrast of the shadow can be adjusted as appropriate.