JPH0472250B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a device that remotely determines arbitrary coordinates within an image display surface and inputs an interrupt signal from the coordinates, and particularly relates to a device that remotely determines arbitrary coordinates within an image display surface and inputs an interrupt signal from the coordinates. The present invention relates to a screen coordinate input device.

[Background of the invention]

2. Description of the Related Art A screen coordinate input device using a light pen is one of the means for inputting data directly from the image display surface of an image displayed on an image display device. This is the required coordinate N on the image display surface 2 of the image display device 1 shown in FIG.
If you want to obtain information on (x, y), coordinates N(x, y)
The light pen 3 detects the light of the scanning line 51 that scans the coordinate information. That is, when the scanning line 51 passes the scanning start point A on the image display surface 2, the scanning line synchronization signal shown in FIG. 14B is generated. The period T of this scanning line synchronization signal is the same as the time it takes for the scanning line to scan the image display surface 2 once. When the necessary coordinates N (x, y) of the image display surface 2 are pressed with the light pen 3 that has a built-in light receiving element, the light pen 3 is switched on and the optical input signal shown in FIG. The data is input to pen 3. Therefore, by detecting the time difference t between the scanning line synchronization signal and the light pen light input signal, the scanning time between the scanning start point A and the required coordinate N (x, y) can be found, and from the scanning speed of the scanning line 51, the coordinate N(x,y)
is determined. Once the coordinates N(x,y) are determined,
Data input, including interrupt signals, can be input from these coordinates.

Usually, there is only one operator of this type of image display device 1 or one person who monitors the images, and only one person inputs the coordinates from the image display surface 2. However, in the case of important images, the images must be monitored and manipulated by multiple people to prevent misidentification or erroneous operation, and the images may be projected onto a large screen for monitoring. At this time, there is a distance between the image on the large screen and the operator or supervisor, so if you want to input coordinates from the large screen, you cannot use a screen coordinate input device such as a light pen that contacts the image display surface. ,
The functionality of large screens is limited.

An example of a conventional device for inputting coordinates using a light-emitting pen is Japanese Patent Application Laid-open No. 57134/1983. This conventional example includes a light-emitting pen for specifying the display screen 2 that emits light in four directions, a light-detecting section including a light-receiving element arranged around the display screen to detect light from the light-emitting pen, and a light-emitting pen for specifying the display screen 2 that emits light in four directions. This figure shows a position specifying device including a coordinate calculating section 7 that calculates a position on a display screen specified by a light-emitting pen based on a signal from a detecting section.

This conventional light-emitting pen emits crosshair-shaped light at the same time when the push-button switch is pressed, so there is a drawback that there is no intersection in the screen, which will be explained later in Figure 4B. There is a problem of misrecognition.

In addition, the conventional example merely shows a method in which the light-emitting pen 1 is brought into contact with the screen and intersecting linear light is emitted at the same time. The optical path or slit of the pen is not extremely tilted and opposed to each other. In other words, because they are used in contact or in close proximity, the projected slit pattern becomes blurred and enters multiple light receiving elements, making it unclear which is the true position of the light. Not planned.

If the light-emitting pen having the structure of Cited Example 1 is used as is in the method of indicating a position on the screen from a remote location, which is the object of the present invention, it is generally not possible to bring the light-emitting pen into contact with the screen. Therefore, it is difficult to irradiate linear light from the correct perpendicular direction at that point on the screen, causing blurring in which the width of the linear light increases, increasing the possibility that the light will be received by multiple light-receiving elements. . As a result, unless special measures are taken during calculation, accurate and quick coordinate calculation cannot be realized.

Furthermore, in the conventional example described above, the crosshair is displayed only when the light-emitting pen is touched on the display screen.

When this is applied to a large screen, which is the object of the present invention, it is not possible to position the screen while touching any part of the entire screen area, so it is necessary to project light as a guide to aim at a desired point.

If a light beam displaying a cross line for coordinate capture is used as this guide light, the cross line will always be displayed, which is troublesome.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a screen coordinate input device that is free from the possibility of capturing coordinates as if the linear lights were intersecting even though they were not intersecting within the screen.

Another object of the present invention is to provide a screen coordinate input device that does not cause blurring of light rays even when light is projected onto the screen from an oblique direction.

Another object of the present invention is to provide a screen coordinate input device that eliminates the trouble of constantly displaying a crosshair on the screen.

[Summary of the invention]

In order to achieve the above object, the present invention includes a transmitter that projects intersecting linear light beams onto a screen for calculating coordinates within the screen surface on which an image is displayed;
a plurality of light receiving elements disposed around the image display surface of the screen to receive the straight intersecting light beams from the transmitter; and a coordinate calculation device for calculating the coordinates of the intersection of the intersecting light beams based on signals from the light receiving elements that have detected the intersecting light beams. In the screen coordinate input device, the transmitter includes means for emitting each linear light at different timing, and the coordinate calculation device first calculates the coordinates of each linear light, and calculates the two sets of coordinates obtained. A screen coordinate input device is proposed that includes means for determining the intersection coordinates of intersecting rays based on the values.

The optical system of the transmitter preferably includes a columnar lens that collimates the linear light in the width direction in order to prevent blurring when the light is projected.

In addition, in order to avoid the trouble of having a crosshair always displayed on the screen, it is necessary to change the transmitter's light emitting means to a means that emits linear light outside the visible range, and a means that emits linear light that is visible at the intersection of this linear light. Combined with means for projecting light.

[Embodiments of the invention]

Hereinafter, specific embodiments of the present invention will be described in detail.

FIG. 1 is a conceptual diagram showing an embodiment of a coordinate input device in which the present invention is applied to a large screen.

In FIG. 1, the required coordinates within the large screen surface are assumed to be P(x _P , y _P ). Light receiving elements 4 are arranged around the large screen 5 at intervals corresponding to the required resolution of the large screen 5.
Each of the light receiving elements 4 has unique coordinates, so by specifying the coordinates of the light receiving element 4, arbitrary coordinates of the image on the large screen 5 can be determined. To specify the coordinates of the light receiving element 4, a transmitter 9 having built-in light emitting diodes 81 and 82 is used as a light source. Here, 71 is a power supply and drive circuit for the light emitting diodes 81 and 82, and 6 is a condensing optical system. Intersecting linear lights are extracted from the transmitter 9 and projected onto the large screen 5. large screen 5
The position of the linear light projected onto the screen changes depending on the angle at which the operator of the transmitter 9 holds the transmitter 9 and the relative relationship between the large screen 5 and the operator. The light projected onto the large screen 5 is detected by the light receiving elements 4 arranged around the large screen 5, and the coordinates of each light receiving element 4 at that time are P ₁ (x ₁ , y ₁ ), P ₂ (x ₂ , _y2 ),
If P ₃ (x ₃ , y ₃ ), P ₄ (x ₄ , y ₄ ), then the straight line
The intersection point P (x _P , y _P ) of P ₁ P ₂ and P ₃ P ₄ is given by the following equation.

That is, the unique coordinates P ₁ , P ₂ ,
An arbitrary coordinate P (x _P , y _P ) within the image plane of the large screen 5 is determined by P ₃ and P ₄ .

FIG. 2 is a diagram showing the optical system 6 of the transmitter 9. The light from the light emitting diodes 81 and 82 is linearly focused by columnar lenses 101, 102, 103, and 104. These linear lights 131, 13
2 is reflected by reflecting mirrors 111 and 112, and is further synthesized by a reflecting mirror 121 and a reflecting mirror 122 having a slit that transmits the reflected light from the mirror,
The light is extracted to the outside as intersecting linear light 133.

Here, let us consider the conditions required for the light beam condensed by the optical system 6. The longitudinal direction of the linear light needs to be long enough to sufficiently cover the large screen and simultaneously illuminate the light receiving elements 4 on the opposite side.
On the condensing side, which is perpendicular to that, the beam must be narrow enough to illuminate only one photodetector on each side. When light enters multiple light receiving elements on each side,
This is because the position of point P cannot be uniquely determined.

When the columnar lenses 101, 102, etc. focus on the light receiving elements 4 around the large screen 5 as shown in FIG. The position changes, and the above conditions are no longer necessarily met.

Therefore, on the light condensing side, it is preferable to use a collimator system to make the irradiated light beam into parallel light beams. Figure 3B
3C shows an example in which parallel light is made into a beam and then focused into a beam by a reflecting mirror 122 having a slit, and FIG. 3C shows an example in which the parallel light is focused into a beam by a relay lens system. The third beam narrows the beam width by blocking light with the slit 122.
It is clear that the optical system shown in Fig. C has less light loss than the example shown in Fig. B.

Note that when figures and characters are displayed on the screen, the movement of cross-shaped lights on them is a nuisance, so the oscillation wavelengths of the light-emitting diodes 81 and 82 are selected to be in the near-infrared region. In this way, the light projected within the plane of the large screen 5 will not be bothersome to the operator's eyes and will be detected by the light receiving element 4 with high sensitivity.

Now, depending on the direction indicated by the transmitter 9, as shown in FIG. 4A, the intersection P of the straight lines P ₁ P ₂ and P ₃ P ₄ is always
(x _P , y _P ) are not necessarily within the plane of the large screen 5, and may be off the large screen 5, for example, as shown in FIG. 4B. Even at this time, the coordinates P ₁ , P ₂ , P ₃ , and P ₄ are detected, so the point of intersection P between straight lines P ₁ P ₂ and P ₃ P ₄ is calculated, and the points of intersection P ₁ P ₃ and P ₂ It is necessary to avoid mistaking the intersection Q with P ₄ as the point P. If the drive circuit 71 is controlled so that the drive currents of the light emitting diodes 81 and 82 of the transmitter 9 do not flow simultaneously as shown in FIG.
Since P ₁ P ₂ and P ₃ P ₄ are received at different timings by the light receiving element 4, they can be reliably determined, and no misidentification will occur due to the combination of P ₁ P ₃ and P ₂ P ₄ .

In order to reduce power consumption, the drive currents for the light emitting diodes 81 and 82 of the transmitter 9 are usually amplitude modulated and the duty ratio is made as small as possible.

The light from the transmitter 9 thus obtained is received by the light receiving element 4 arranged around the large screen 5, but light from other light sources is also received at the same time. Therefore, it is necessary to effectively receive and amplify only the amplitude-modulated light from the transmitter 9. Figure 6 shows
An example of an amplifier circuit for separating and amplifying general light and light from the transmitter 9 is shown, and FIG. 7 shows an example of the input to the light receiving element 4 and the output of the amplifier circuit. In FIG. 6, from the general light and the light from the transmitter 9, only the oscillation wavelength components of the light emitting diodes 81 and 82 are selected by the wavelength filter 14. This light is input to a light receiving element (photodiode) 4. As shown in FIG. 7A, this consists of the light from the light emitting diodes 81 and 82 and a direct current component D due to a wavelength component in general light having the same oscillation wavelength as the light from the light emitting diodes 81 and 82. For this direct current D, the capacitance C ₁ of the amplifier does not work, and the resistors 17 and 18 work as conversion constants for the operational amplifier 15. For the light from the transmitter 9 that has been subjected to amplitude modulation, the capacitance C ₁ acts, and the resistance 1
Since 6 acts as a conversion constant for this light, the output of the amplifier circuit shown in FIG. 7B is finally obtained.

In reality, there are as many light receiving elements 4 as are sufficient to express each coordinate of the large screen 5. FIG. 8 shows a block diagram of a processing circuit for the light received by the light receiving element 4. Light receiving element 4 indicating each coordinate of large screen 5
are connected to the scanning circuit 20 and sequentially scanned by the start pulse S. The scanned signal from the light receiving element 4 is amplified by an amplifier circuit 21 and then sent to a waveform shaping circuit 22 including an integrating circuit.
is input. The output from the waveform shaping circuit 22 is
It is input to the counter circuit 23. Here, as shown in FIG. 9, a time difference t ₁ between the start pulse S and the first pulse, and a time difference t ₂ between the start pulse S and the second pulse are detected by counting the clock pulses φ. Note that the start pulse S and clock pulse φ are controlled by the microcomputer 24. The microcomputer 24 calculates the period T of the start pulse S and the time difference.
From t ₁ and t ₂ , it is determined which light receiving element 4 the light from the transmitter 9 has entered, and the light receiving element 4 is
memorize the coordinates of In the next cycle T, two more coordinates are detected in the same way, and the intersection coordinates P (x _P , y _P ) of the linear lights in the plane of the large screen 5 are determined by equations (1) and (2). It is determined. Furthermore, in the next period T, the coordinates of the light receiving element 4 obtained in the immediately previous period T are used. The intersection coordinates P (x _P , y _P ) are incorporated into the image display information of the projection control device 25 of the large screen 5, and a mark is displayed to indicate where the intersection point is located in the coordinates of the intersection point. As a result, the operator of the transmitter 9 or the person monitoring the image on the large screen 5 can easily know the required coordinates.

As shown above, when determining arbitrary coordinates within the plane of the large screen 5 by receiving and detecting the amplitude-modulated light from the transmitter 9 with the light receiving element 4,
As shown in FIG. 10A, a drive current for coordinate calculation is applied to the light emitting diodes 81 and 82. If it is necessary to input data such as an interrupt signal from within the plane of the large screen 5, determine the coordinates for that input, input the interrupt signal I to the drive circuit 71 in FIG. The interrupt signal I coded within the light emission period of 81 and 82 is
Light is transmitted from the transmitter 9 as shown in Figure 0B. This light is detected by the light receiving element 4 and coordinates are input. When the interrupt signal is received and detected, the mark indicating the coordinates of the intersection point on the large screen 5 is made to blink, thereby notifying the operator of the transmitter 9 or the person monitoring the image that the interrupt signal has been received.

The signal processing flow of the screen coordinate input device which inputs an interrupt signal from arbitrary coordinates within the large screen 5 is shown in FIG. 11. That is, first, input of an interrupt signal from within the large screen 5 is permitted. Next, light is transmitted from the transmitter 9 to the large screen 5, arbitrary coordinates within the surface of the large screen 5 are determined from the coordinates of the light receiving elements 4 installed around the large screen 5, and a mark is displayed at the coordinates. The mark display averages the coordinate information from several past times to make it easier to see. The interrupt signal input from the coordinates encodes the light transmitted by the transmitter 9 to distinguish it from the light for coordinate calculation. The light receiving element 4 receives the interrupt signal, processes the contents of the interrupt signal in the subsequent processing circuit, and blinks the input coordinate mark displayed on the large screen 5 to receive the interrupt signal. Let me know.

Such a large screen coordinate input device using light allows coordinate input on the image surface without contact, and also allows multiple people to monitor and operate the image, and has a function of monitoring images using a large screen. and improved operational functions. Furthermore, since the transmitter is comprised of an optical system and there are no moving parts, the reliability of the coordinate input device is increased, and since it is a wireless screen coordinate input device, coordinate input from any location can be performed with simple operations.

In the above embodiment, the method of changing the light transmission pattern of the transmitter as an interrupt signal for inputting coordinates on a large screen has been described. That is, this is a direct coordinate input method from the image plane of a large screen. Alternatively, data can be input from arbitrary coordinates within the large screen surface by directly sending an interrupt signal from the transmitter to the projection control device.

FIG. 12 shows an example of the configuration of a transmitter used in this other embodiment. Along with crossed linear light 133 from the light emitting diodes 81 and 82 whose oscillation wavelength is in the near-infrared region, light 134 from the light emitting diode 83 whose oscillation wavelength is in the visible region is projected onto the image plane of the large screen 5. Ru. At this time,
Since the visible light 134 is located at the intersection of the crossed near-infrared lights 133, the operator of the transmitter 9 or the person monitoring the image can easily know the position of the required coordinates. When inputting data such as interrupts from within the image plane of the large screen 5, the transmitter 9
The interrupt signal I is inputted to the drive circuit 72 of the controller. This interrupt signal I causes the light emitting diode 8 to
3 is made to blink, for example, to confirm the input of the interrupt signal I, and the interrupt signal I is sent to the microcomputer 241 via the signal line 251. When the microcomputer 241 receives the interrupt signal I, the microcomputer 241 detects the intersecting linear near-infrared light 133 projected onto the screen of the large screen 5 with each light receiving element 4, and according to the apparatus and procedure shown in FIG. The coordinates of the intersection are determined and the information content of the interrupt signal I at those coordinates is processed.

Although the coordinate input device for a large screen has been described above as an embodiment of the present invention, it is clear to those skilled in the art that the present invention can be applied to various image display devices. In addition, non-contact input is possible not only on large screens but also on small screens. Furthermore, it is clear that the two straight lines of light do not have to be exactly orthogonal.

〔Effect of the invention〕

According to the present invention, a light-receiving element is installed around a large screen, linear light that intersects the screen is projected, and the light is detected by the light-receiving element, thereby allowing arbitrary coordinates within the image display surface to be detected. Since it can be determined remotely, data can be entered from a large screen, improving image monitoring and manipulation capabilities using the large screen. Furthermore, since it is a wireless transmitter, coordinates can be input easily from any location, and it can be applied to various image-based monitoring systems.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing an embodiment of the large screen coordinate input device of the present invention, FIG. 2 is a diagram showing the optical system of the transmitter, FIG. 3 is a diagram showing the light condensing situation of the optical system, and FIG. Figure 5 shows the light projection pattern of a large screen, Figure 5 shows the driving current pattern of the light emitting diode, Figure 6 shows an example of the amplifier circuit, and Figure 7 shows the input and output waveforms of the amplifier circuit. FIG. 8 is a block diagram of the coordinate calculation device; FIG. 9 is a diagram showing pulse waveforms for determining coordinates; FIG. 10 is a diagram showing light transmission patterns during normal and interrupt times; 1
Fig. 1 is a diagram showing the flow of signal processing of the screen coordinate input device according to the present invention, Fig. 12 is a diagram showing another embodiment of the transmitter, and Fig. 13 is a diagram showing a conventional example of the coordinate input device from the image display screen. The figure shown in FIG. 14 is a diagram showing the principle of the coordinate calculation. 1... Image display device, 3... Light pen, 4...
... Light receiving element, 5 ... Large screen, 6 ... Condensing optical system, 71, 72 ... Power supply and drive circuit, 8
1, 82, 83... Light emitting diode, 9... Transmitter, 101-105... Column lens element, 14...
...Filter, 20...Scanning circuit, 21...
...Amplification circuit, 22 ... Waveform shaping circuit, 23 ... Counter circuit, 24, 241 ... Microcomputer, 25 ... Projection control device.

Claims (1)

[Scope of Claims] 1. A transmitter that projects intersecting linear light beams onto the screen for calculating coordinates within the screen surface on which an image is displayed, and a transmitter that is arranged around the image display surface of the screen and transmits light from the transmitter. A screen coordinate input device comprising a plurality of light-receiving elements that receive straight-line intersecting light rays, and a coordinate calculation device that calculates the intersection point coordinates of the intersecting rays based on a signal from the light-receiving element that detects the intersecting rays, the coordinate calculating device first determines the coordinates of each of the linear lights, and calculates the coordinates of the intersection of the intersecting rays based on the two sets of coordinate values obtained. A screen coordinate input device comprising: means. 2. The screen coordinate input device according to claim 1, wherein the optical system of the transmitter includes a columnar lens that collimates linear light in the width direction. 3. In the screen coordinate input device according to claim 1 or 2, the light projecting means of the transmitter includes means for projecting linear light outside the visible range, and A screen coordinate input device comprising: means for projecting visible light onto an intersection point.