JPH02163815A - Display device - Google Patents

Abstract

PURPOSE:To describe characters and patterns on a display screen by obtaining the locus of a beam spot detecting means from the detection output of the detecting means and the present position of a beam spot and showing the obtained locus on the screen. CONSTITUTION:A beam spot which scans a display screen 11 of a picture display means 1 is detected by a beam spot detecting means 5 containing a photodetecting element corresponding to the screen 11. Then a synchronizing signal is analyzed at the time point when the means 5 set opposite to a prescribed position on the screen 11 detects the beam spot under scanning. Thus the present position of the beam spot is recognized and stored successively in a locus memory means 3. As a result, a series of locus data are stored in the means 3 in response to the movement of the means 5. Then the locus data read out of the means 3 are displayed on the screen 11 via a display control means 4. Thus it is possible to obtain the same result as that obtained by describing the characters, etc., on the screen 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display device that uses an image display means such as a cathode ray tube display and can easily draw characters, figures, etc. on the display screen.

[Prior Art 1] Graphic processing techniques for drawing graphics on the display screen of a personal computer, word processor, or the like are realized, for example, by software such as a CAD system.

Normally, when performing graphical processing, an image to be displayed on a display screen is read in advance by an image sensor or the like and stored in an image memory, or a computer graphics device generates predetermined graphical data, and the image is used for display control. The information is output to a cathode ray tube display or the like via a circuit or the like.

In addition, when an operator creates a figure while looking at the display screen, he scans the cursor on the display screen using an input device such as a keyboard, and stores the resulting image in the image memory and displays it. I have to.

[Problems to be Solved by the Invention] However, in all conventional graphic processing, graphics are displayed through relatively complicated software. Therefore,
It is also necessary to provide a disk device for reading graphics processing programs, a processor for performing predetermined arithmetic processing, and the like.

However, conventional devices are relatively expensive and -
II It is not suitable for purposes such as easily attaching to a home television receiver or the like to depict characters or figures.

The present invention has been made with attention to the above points, and an object of the present invention is to provide a display device that can draw characters and figures on a display screen such as a cathode ray tube display using relatively simple hardware. That is.

(Means for Solving the Problems) A display device of the present invention includes an image display means, and a beam spot detection means for detecting a beam spot scanning a display screen of the image display means with a light receiving element facing the display screen. , trajectory storage means for determining and storing the trajectory of the beam spot detection means from the detection output of the beam spot detection means and the current position of the beam spot; The present invention is characterized by comprising a display control means for displaying information on a display screen.

[Function] In the above device, a beam spot scanning the display screen of the image display means is detected by a beam spot detection means using a light receiving element facing the display screen. Since the beam spot is scanned on the display screen by a constant synchronization signal, the beam spot detection means placed opposite a predetermined position on the display screen must analyze the synchronization signal at the time when it detects the beam spot being scanned. For example, the current position of the beam spot can be recognized. If the current positions recognized in this way are sequentially stored in the trajectory storage means, a series of trajectory data is stored in the trajectory storage means in accordance with the movement of the beam spot detection means. Thereafter, the locus data read from the locus storage means is displayed on the display screen via the display control means.

Therefore, if the beam spot detection means traces the display screen, the locus of the beam spot detection means will be immediately displayed on the display screen, and the same result will be obtained as if characters were drawn directly on the display screen6 [Example] Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 is a block diagram showing an embodiment of a display device of the present invention.

In the figure, this device includes an image display means 1 for displaying a predetermined image, a memory control means 2, a locus storage means 3, and a display control means 4. In addition to this, a beam spot detection means 5 and a ΔV detection section 6 are provided.

The image display means 1 is composed of a cathode ray tube display or the like, and displays a beam spot 1 on the display screen 11 at a predetermined period.
2 is being scanned. This scanning is controlled by a vertical synchronizing signal of frequency fv and a horizontal synchronizing signal of frequency ft+, similar to a normal television receiver.

The memory control means 2 includes a waveform shaping circuit 21 which shapes a vertical synchronizing signal having a frequency fv that was previously input to the image display means 1, and a waveform shaping circuit 21 which also has a frequency fv. A waveform shaping circuit 22 that shapes the horizontal synchronizing signal of
F) 24, Y coordinate counter 25, and X coordinate counter 2
It consists of 6.

The output of the waveform shaping circuit 21 is the D of the flip-flop 24.
It is input to the reset terminal R3T of the terminal and Y coordinate counter 25. Further, the output of the waveform shaping circuit 22 is connected to the reset terminal R3T of the Y coordinate counter 25 and the X coordinate counter 26.
Enter. Furthermore, the output of the clock generation circuit 23 is
Input into the coordinate counter 26.

That is, this memory control means 2 alternately inverts the output of the Q terminal or the mouth terminal to a high level every time the vertical synchronization signal (2) is input to the flip-flop 24 via the waveform shaping circuit 21, and the trajectory storage means 3 Image memory of 31.32
While writing/continuing control is performed, the Y coordinate counter 2
5 and the X coordinate counter 26, to the trajectory storage means 3,
It is a circuit configured to supply a write or read address for the image memory 31,32.

The Y-coordinate counter 25 is reset by the vertical synchronization signal ■, counts the horizontal synchronization signal ■, and counts the coordinate of the display screen 11 in the Y-axis direction. Further, the X coordinate counter 26 is reset by the horizontal synchronization signal ■, and the clock generation circuit 2
3 is counted, and the coordinates of the display screen 11 in the X-axis direction are counted.

On the other hand, the trajectory storage means 3 includes two image memories 31.3.
2 is provided. Both image memories 31.
32 is alternately and exclusively set to a write state and a read state by a signal output from the flip-flop 24 of the memory control means 2. Furthermore, both image memories 31.3
2 includes a Y coordinate counter 25 and an X coordinate counter 25 of the memory control means 2.
Coordinate data (address signal) output from the coordinate counter 26 is input at the same time. That is, the image memories 31 and 32 store image data (referred to as locus data in the present invention) having a resolution of fH horizontal synchronizing signal frequencies in the Y-axis direction and n resolutions in the X-axis direction.

On the other hand, a light receiving element 51 is attached to the tip of the beam spot detecting means 5, and wiring is connected so that the detection signal ■ outputted from the light receiving element 51 is inputted to the display control means 4 via the △■ detecting section 6. has been done. The V detection unit 6 captures the rising edge of the detection signal ■ output by the light receiving element 51, and
It consists of a known rising edge detection circuit that outputs a position detection pulse (2) to the display control means 4.

The display control means 4 writes the position detection pulse (■) output from the ΔV detection section 6 into either the image memory 31 or 32, and simultaneously displays it together with a human input signal (RGB signal in this embodiment) from an external circuit (not shown). It consists of a circuit that controls the display on the screen 11. The configuration of the display control means 4 of this circuit will be explained in detail later using FIG.

The display device shown in FIG. 1 is used as shown in FIG. 2.

In FIG. 2, for example, the letter "A" 7 is drawn on the display screen ll of the image display means 1. Image display means l
The case includes the memory control means 2 shown in FIG.
Circuits such as trajectory storage means 3 are housed therein.

Here, the light receiving element 51 of the beam spot detection means 5 is
When the user traces the display screen 11 while facing the display screen 11, the letter "A" 7 as shown in the figure is projected on the display screen.

The above operation is realized as follows.

FIG. 3 shows a specific wiring diagram of the display control means shown in FIG. 1, and the specific operation of the display device of the present invention will be explained using this FIG.

In FIG. 3, the display control means 4 is composed of an OR gate 41, a latch circuit 42, and two AND gates 43 and 44.

The OR gate 41 is wired so that the position detection pulse (2) output from the HV detection section 6 and the output of, for example, the image memory 31 on the read-out side of the locus storage means 3, which is in the read-out state, are input. The output of the OR gate 41 is output towards the latch circuit 42.
The output is connected to the inverting input terminal of the AND gate 43 and to the writing double image memory 32 in the writing state in the locus storage means 3.

Furthermore, an RGB input signal 8 for color display is input to the display control means 4 from an external circuit. Of the input signals 8, G
The (green) signal is input to the AND gate 43, the R (red) signal is input to the AND gate 44, and the B (blue) signal is input to the AND gate 44.
The signal is configured to be output directly to the image display means 1.

The signals of each part in Fig. 1 and Fig. 3 are marked with ■~■,
Each signal is illustrated in FIGS. 4(a) to (h), respectively.

First, the waveform shaping circuit 21 shown in FIG. 1 outputs a shaped vertical synchronizing signal (2) as shown in FIG. 4(a). Further, the waveform shaping circuit 22 shown in FIG. 1 outputs a shaped horizontal synchronizing signal (2) as shown in FIG. 4(b). That is, as shown in FIGS. 4(a) and 4(b), between two vertical synchronizing signal pulses, exactly the same number of horizontal synchronizing signal pulses as the number of scanning lines is output. Further, the clock generating circuit 23 in FIG. 1 outputs a clock (2) which is the horizontal synchronizing signal multiplied by five, as shown in FIG. 4(C).

Now, the beam spot detection means 5 shown in FIG.
When the light-receiving element 51 faces the display screen 11 in the manner described in FIG. 2, the light-receiving element 51 outputs a detection signal (2) at the timing when the beam spot 12 is scanned in front of the light-receiving element 51. As shown in FIG. 4(d), this signal (2) rises at time "t" when facing the beam spot, and then gradually attenuates.

The Δvl output unit 6 receives the detection signal ■ output from the light receiving element and outputs the position detection pulse ■ shown in FIG. 4(e).

Here, the timing at which the position detection pulse ■ is output is
Assuming time to as shown in FIG. 1, at that point, the Y coordinate counter 25 shown in FIG. 1 counts the number of pulses Y of the horizontal synchronization signal ■ from time t1 to time t0 shown in FIG. are doing. Further, the X-coordinate counter 26 counts the number X of clocks output from the clock generation circuit 23 from time t2 to time t after being reset by the immediately preceding horizontal synchronization signal ■. Therefore, at the time when the position detection pulse ■ is output from the ΔV detection section 6, the address signals (X, Y) are input to the image memories 31 and 32.

When an address signal is input, the pre-stored trajectory data of the address (x, y) is directed to the image display means 1 via the display control means 4 from, for example, the image memory 31 which is in the read state at that time. is output. Further, the position detection pulse ■ is stored as locus data at the address (X, Y) of the image memory 22 in the writing state.

In the image display means 1, the beam spot 12 is synchronously controlled by the same synchronization signals as the vertical synchronization signal ■ and the horizontal synchronization signal ■ input to the memory control means 2, and as a result, the beam spot 12 is stored in the image memory 31. The image thus obtained will be displayed as is on the image display means 1.

By the way, in FIG. 3, the position detection pulse (2) output from the ΔV detection section 6 is stored in the latch circuit 42 via the OR gate 41 together with the output of the read-side image memory 31. Therefore, when there is no output from the ΔV detection unit 6, the output signal from the read-side image memory 31 is directly transmitted to the latch circuit 4.
2. The latch circuit 42 has its data latch timing controlled by the nXfn clock signal from the clock generation circuit 23.

The output signal of this latch circuit 42 is the AND gate 43.4
Enter 4. One AND gate 43 is the latch circuit 4
Since the output of 2 is inverted and accepted, AND gate 43 and AND gate 44 perform exclusive operations such that when one closes the gate, the other opens the gate. Since the G signal is input to the AND gate 43 and the R signal is input to the AND gate 44, when the output of the latch circuit 42 becomes, for example, a high level, the AND gate 43 closes the gate and the G signal is input to the image display means l. There is no output towards , and the AND gate 44 opens the gate,
The R signal is output towards the image display means 1.

As a result, as shown in FIGS. 4(f), (g), and (h), for example, the position detection pulse
At the timing when it is latched by the latch circuit 42 via
On the display screen 11 of the image display means 1, an R signal (2), that is, a red dot, is displayed, and at this time, a G signal (2), that is, a green signal, is blocked. As a result, red dots are displayed on the display screen 11 against a green background.

In this embodiment, it is assumed that the B signal (2) is not input.

Already stored locus data is transferred from the read-out image memory 31 in FIG. 3 to the latch circuit 42 via the OR gate 41.
A similar result is obtained when latched to . Therefore, the locus data already stored in the read-out image memory 31 and the device detection pulse (2) constituted by the ΔV detection section 6 are superimposed and displayed on the image display means 1.

Incidentally, when the position detection pulse (■) output from the ΔV detection section 6 is latched by the latch circuit 42 via the OR gate 41,
The output of the latch circuit 42 is input to the write-side image memory 32 and stored therein. The stored write address of the write-side image memory 32 is (X, Y) as shown in FIG.

If a similar operation is performed by moving the light receiving element 51 as shown in FIG. 2, the trajectory will be stored in the writing side image memory 32.

In FIG. 3, just as the beam spot finishes scanning one screen, the next vertical synchronizing pulse is input to the flip-flop 24 and the Y-coordinate counter 25 via the waveform shaping circuit 21 of FIG. As a result, the flip-flop 24 switches the read side and write side of the image memories 31 and 32 of the trajectory storage means 3. Thereafter, the replaced image memory on the reading side and the output of the ΔV detection section 6 are combined again, stored in the image memory on the writing side, and displayed on the image display means l.

The present invention is not limited to the above embodiments.

For example, instead of using trajectory data as is as described above,
If the image is encoded and stored in the image memory, the above circuit can be realized using a memory with a smaller capacity. Furthermore, the configurations of the memory control means 2 and the display control means 4 may be replaced with various circuits having equivalent functions as necessary.

〔Effect of the invention〕

By adding simple hardware to a television receiver or the like, the display device of the present invention described above allows a user to arbitrarily draw characters and figures on the display screen. For example, it can be used as a message board, It can be used to edit designs, etc. Therefore, the present invention can be widely applied to various devices using cathode ray tube displays and the like.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the display device of the present invention, FIG. 2 is a perspective view showing how the display device of the present invention is used, and FIG. 3 is a wiring diagram of display control means of the display device of the present invention. , FIG. 4 is a signal waveform diagram of each part explaining the operation of the display device of the present invention. l...Image display means, 2...Memory control means, 3.
...Trajectory storage means, 4.Display control means, 5.Beam spot detection means, 6.ΔV detection section, 11..
・Display screen, 12...beam spot. Figure]' Figure

Claims (1)

[Claims] an image display means, a beam spot detection means for detecting a beam spot scanning a display screen of the image display means with a light receiving element facing the display screen, a detection output of the beam spot detection means and a current position of the beam spot; and a trajectory storage means for determining and storing the trajectory of the beam spot detection means from the above, and a display control means for displaying an image corresponding to the trajectory data read from the trajectory storage means on the display screen. display device.