JP2002132448A - Input device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an input device and a projector which have comparatively simple constitutions and can lay restraint on the influence of outer disturbance light. SOLUTION: This input device/projector has an indicating device 5 with a light source 5 blinking in a predetermined period, and a detector 1 that receives the light from the light source 5, detects a point or a trajectory indicated with the light source 5 and generates the coordinate information of the point or the trajectory. The detector 1, on the basis of the amount of light received while the light source 5 lights up and the amount of light received while lighted out, discriminates between the light from the light source 5 and the disturbance light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting points and trajectories drawn by a predetermined pointing device.

[0002]

2. Description of the Related Art As a conventional coordinate input device, a light spot on a screen is imaged using a CCD area sensor or a linear sensor, and image processing such as using barycentric coordinates or pattern matching is performed to calculate coordinate values. And a device using a position detecting element called PSD (an analog device that can obtain an output voltage corresponding to the position of the spot) are known.

[0003] For example, Japanese Patent Publication No. 7-76902 discloses an apparatus for detecting a coordinate by imaging a light spot with a parallel beam of visible light with a video camera and simultaneously transmitting and receiving a control signal with infrared diffused light. ing. Japanese Patent Application Laid-Open No. 6-274266 discloses an apparatus for detecting coordinates using a linear CCD sensor and a special optical mask.

Japanese Patent No. 2503182 discloses a configuration and a method of correcting output coordinates of an apparatus using a PSD. U.S. Pat. No. 5,235,363 discloses an apparatus for detecting, through the projection lens, the position of a spotlight projected on a projection image projected by a projection lens of a projector.

[0005]

In recent years, the brightness of a projection display has been improved, and it has become possible to use the display even in a brightly illuminated environment, and the demand is expanding. And, it is increasingly necessary that the coordinate input device be resistant to disturbance light so that it can be used in an environment combined with such a display. In recent years, devices using infrared light as wireless communication means have been increasing, and disturbance light is used for both infrared light and visible light.
Due to the increasing tendency, resistance to disturbance light is one of the important characteristics of the device.

However, the aforementioned Japanese Patent Publication No. 7-76902
As can be seen from the inventions described in Japanese Patent Application Laid-Open No. 6-274266 and Japanese Patent Application Laid-Open No. 6-274266, disturbance light can be suppressed only by an optical filter in a device using a conventional CCD sensor.

On the other hand, Patent Application No. 2503182
As shown in the figure, in the device using the PSD, the light intensity is frequency-modulated and the modulated wave is synchronously detected, so that the influence of the disturbance light can be suppressed. Has strong characteristics. However, a large-screen display has been improved in brightness as well as in resolution. Therefore, it is necessary to improve the resolution of the coordinate input device.
However, there is a problem in this point in an apparatus using a hologram.

That is, since the dynamic range of the sensor output voltage directly corresponds to the input range, for example, when the whole is decomposed into 1000 coordinates, at least 6
Since an S / N ratio of 0 dB or more is required, and digital correction of linearity error is indispensable, as described in the above-mentioned Patent No. 2503182, a high-precision analog circuit and a multi-bit AD converter are required. And an arithmetic circuit are required.

Further, since the S / N ratio of the sensor output signal depends on the amount of light and the sharpness of the light spot, suppression of disturbance light alone is not sufficient, and a bright and highly accurate optical system is also required. For this reason, the device itself is very expensive and large.

Further, as a technique for increasing the resolution by using a CCD sensor, Japanese Patent Publication No. 7-76902 discloses that a plurality of video cameras are used at the same time. become. Also,
In the case of a single video camera having a large number of pixels, the size and cost are further increased as compared with the case of using a plurality of cameras. In addition, to achieve higher resolution than the number of pixels by image processing, high-speed processing of huge image data is required,
For real-time operation, it is very large and expensive.

In Japanese Patent Application Laid-Open No. Hei 6-274266, high resolution is obtained by a special optical mask and signal processing.
If the N ratio can be secured, high resolution can be achieved. But,
Actually, the linear sensor forms an image in a linear shape and cannot separate it from disturbance light in the plane compared to an area sensor that becomes a point image. There is a problem that it becomes practical only in an environment.

In US Pat. No. 5,235,363, the position of the spot light is detected by TTL using the projection lens of the projector. However, since there is a beam splitter disposed behind the projection lens, the back focus of the lens is extended and the size of the lens is increased. Invite.

Particularly, when a color synthesizing system using a dichroic prism as in a three-plate type projector is located behind a lens, there is a problem that there is almost no space for disposing the beam splitter. In addition, strong reflected light is scattered in the lens, and the coordinate position detecting ability is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an input device and a projector which can suppress the influence of disturbance light with a relatively simple configuration.

[0015]

According to the present invention, there is provided an indicator having a light source which blinks at a predetermined cycle, receiving light from the light source, detecting a point or a locus indicated by the light source,
Detecting means for creating coordinate information of the point or the trajectory, wherein the detecting means detects light from the light source and disturbance light based on a light receiving amount when the light source is turned on and a light receiving amount when the light source is turned off. An input device characterized in that the input device is distinguished from each other.

According to the present invention, an indicator having a light source that blinks at a predetermined cycle receives light from the light source,
Detecting means for detecting a point or a locus indicated by the light source and creating coordinate information of the point or the locus, wherein the detecting means comprises: A light source and a disturbance light are distinguished based on the amount of received light.

[0017]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a system using a projector 8 according to one embodiment of the present invention.

The projector 8 includes an image signal processing unit 81 to which an image signal from the external computer 9 is input,
A liquid crystal panel 82, which is a light valve controlled by this, includes an illumination optical system including a lamp 83, a reflector 84, and a condenser lens 85, and a projection lens 86 that projects an image of the liquid crystal panel 82 onto the screen 10.

Screen 1 which is a screen on which an image is projected
The diffused light is emitted toward the detector 1 from the light emitting unit 5 at the tip of the pointing tool 4 in the optical path projected from the projection lens 86 to 0.

The detector 1 includes a coordinate detecting sensor unit 2, a controller unit 3 for controlling the coordinate detecting unit 2 and calculating coordinates, a control signal detecting sensor unit 6 and a signal processing unit 7, and emits light from the light emitting unit 5. By receiving light and operating the indicating tool 4, the point indicated by the light emitting unit 5 or the trajectory is detected,
A control signal corresponding to the state of each button of the pointing tool 4 is detected, coordinate information and control information are created, and the controller 3 communicates the information to the computer 9.

Thus, input operations such as writing characters and line drawings on the display screen, button operations and icon selection decisions can be freely performed by the pointing tool 4.

FIG. 2 is a block diagram showing the internal structure of the detector 1 and the pointing device 4, which constitute a coordinate input device. The configuration of the indicator 4, the configuration of the detector 1, and the operation of each unit will be described in order with reference to FIG. 2. (Explanation of the Indicator 4) The indicator 4 includes a light emitting unit 5 having a light emitting element 41 as a diffused light source, a light emitting control means 42 for driving and controlling the light emission, a switch 43, and buttons 44A and 44.
B. Infrared LE as the light emitting element 41
D or the like can be used. In the present embodiment, an element that emits infrared light is assumed.

The light emission control means 42 turns on the light emitting element 41 according to the state of the switch 43 and the buttons 44A and 44B.
A drive signal for performing / OFF is generated, the light emitting element 41 is turned on and off at a predetermined cycle, and light emission control is performed by superimposing a control signal by a modulation method described later.

FIG. 3 is an external view of the pointing device 4. When the operator grips the indicating tool 4 and turns on the switch 43, the light emitting section 5 emits light. The diffused light from the light emitting unit 5 is received by the detector 1, and a coordinate signal starts to be output by the processing described later. When the control signal is OFF, only the indication of the designated position to the operator is performed on the screen by the movement of the cursor or the switching of the highlight of the button on the display screen.

When the buttons 44A and 44B are pressed, the control signals assigned to them are superimposed on the drive signal, for example, the input of characters and line drawings is started, and the buttons on the image projected on the screen 10 are selected and determined. Screen control can be executed. With such a configuration, the operator can quickly and accurately operate an arbitrary position on the screen with one hand by drawing a character or a figure or selecting a button or menu.

As the indicating tool 4, a remote control 2 for proximity is used.
It is also possible to use two types of pointers, to operate two pointers at the same time by two or more persons, or to use a plurality of pointers with different attributes such as color and thickness. In addition, the light emission control means 42 has an I
The D number is transmitted together with the control signal.

According to the transmitted ID number, attributes such as the thickness and color of the drawn line can be determined by software or the like on the externally connected device side, so that the setting can be changed using buttons or menus on the screen. can do. For this operation, an operation button or the like may be separately provided on the indicator 4 to transmit a change instruction signal. For these settings, the ID is maintained by holding the state inside the indicator 4 or the detector 1. It is also possible to configure so that attribute information instead of the number is transmitted to the externally connected device.

In this case, it is sufficient to provide the indicating tool 4 or the detector 1 with a function of retaining the setting data. When one indicating tool is used by two or more devices, the attribute can be switched at a time or a plurality of attributes can be changed. When the screen of the external connection device is displayed, the setting can be shared, and a convenient usage can be achieved. In addition,
Needless to say, such additional operation buttons can be used to perform other functions such as blinking of the display device, switching of the signal source, operation of the recording device, and the like. (Explanation of Detector 1) The detector 1 includes a control signal detection sensor 6 for detecting a scene with high sensitivity by a condenser lens 61.
0 and two linear sensors 20X and 20Y for detecting the direction of arrival of light by the cylinder lenses 90X and 90Y, and the diffused light from the light emitting section 5 of the indicator 4 is transmitted through the visible light cut filter 100 to disturb the light. After excluding light, each receives light.

Condensing lens 61, control signal detection sensor 6
0, cylinder lens 90X, 90Y, linear sensor 2
0X and 20Y are arranged, for example, as shown in FIG.
A condensing lens 61 is mounted on the control signal detection sensor 60, and detects a light amount of a predetermined wavelength with high sensitivity from the entire range on the screen. The output is detected by the frequency detection means 71, and a digital signal including data such as a control signal superimposed by the light emission control means 42 is demodulated.

On the other hand, two linear sensors 20X, 20Y
Is the indicator 4 by the cylinder lenses 90X and 90Y.
The light emitted from the light emitting unit 5 is collected, and the photosensitive unit 21 of each sensor is collected.
An image is linearly formed on X and 21Y. As shown in FIG. 4, the two sensors are accurately arranged at right angles, and the photosensitive section 21X of the linear sensor 20X for X coordinate detection is arranged on the optical axis of the projection lens 86, so that the linear sensors 20X and 20Y respectively Can obtain an output having a peak at a pixel reflecting the X coordinate and the Y coordinate.

These sensors are controlled by a sensor control means 31, and output signals thereof are output from the sensor control means 3.
The A / D converter 31A provided in 1 sends the digital signal as a digital signal to the coordinate calculator 32 to calculate the output coordinate value on the sensor.

For example, as shown in FIG. 5, the cylinder lenses 90X and 90Y are integrally formed by plastic molding so that the X axis and the Y axis can be set accurately.

The condenser lens 61 is connected to the linear sensor 20.
By arranging the X, 20Y and the cylinder lenses 90X, 90Y in the same direction and substantially on the same plane and on the same straight line, the space efficiency of the projector 8 can be improved. (Control Signal Demodulation Operation) FIG. 6 is a timing chart showing a signal waveform representing an operation of restoring a control signal from an output signal of the control signal detection sensor 60. As described above, when the switch 43 of the pointing device 4 is turned on, light emission is started, and a header signal including a leader portion, which is a relatively long continuous pulse train, and a code (such as a maker ID) following the leader portion is first output. A transmission data sequence such as a control signal follows in a predefined order and format.

Each data bit is formed such that "1" is modulated so as to have a double interval with respect to "0".
The frequency detecting means 71 is tuned to the pulse cycle of the highest frequency of the first frequency in this waveform, and when used together with the visible light cut filter 100, is modulated like the waveform CMD without being affected by disturbance light. Demodulate the signal,
The control signal is interpreted as digital data by the control signal detecting means 72 and the control signal is restored.

This configuration is similar to the technology used in infrared remote controllers and the like, and is a highly reliable wireless communication system. If the first modulation frequency is higher than that of a generally used infrared remote controller, for example, 60 KHz, no malfunction occurs even when the first modulation frequency is used at the same time. The detection output signal CMD of the frequency detection means 71 is interpreted as digital data by the control signal detection means 72, and the control signal is restored and sent to the communication control means 33.

Next, the phase synchronization of the sensor will be described. The code modulation cycle, which is the second frequency included in the waveform CMD, is detected by the sensor control means 31 and used for sensor control.

That is, by generating a signal LCK reset at the timing of the header portion and phase-synchronized with the trailing edge of the subsequent CMD signal, the sensor control means 31 has a signal of a constant frequency synchronized with the presence or absence of light emission. Become. In addition, a signal LON indicating the presence or absence of an optical input and a sensor reset signal RCD activated by the LON are generated from the signal CMD. While the signal RCL is at H, the two sensors are reset, and a synchronous integration operation described later is started at the timing of the falling edge of RCL in synchronization with the rising edge of LCK.

On the other hand, when the control signal detecting means 72 detects the header and confirms that the input from the pointing tool 4 is started instead of other equipment or noise, this is transmitted to the sensor control means 31 and the sensor operation is enabled. Signal CON indicating H
And the operation of the coordinate calculation means 32 is started.

FIG. 7 shows a timing chart when the light input signal LSG is lost and a series of operations is completed. When the demodulated signal CMD detected from the LSG keeps L for a certain period of time or more, the signal LON indicating presence or absence of optical input becomes L, and CON
Also becomes L, and the coordinate output operation ends.

Next, the synchronous integration operation of the linear sensors 20X and 20Y will be described. In the present embodiment, it is assumed that the linear sensors 20X and 20Y are array-shaped and capable of performing a synchronous integration operation.

FIG. 8 is an internal configuration diagram of the linear sensors 20X and 20Y. Since the details of this sensor are described in Japanese Patent Application Laid-Open No. 08-233571 of the same applicant, only the portions related to the present embodiment will be described here. Since the two for X and Y are the same,
The following description is for only one of them.

The sensor array 21 serving as a light receiving section is composed of N pixels, and charges corresponding to the amount of received light are stored in the integrating section 22. The integrator 22 can be reset by applying a voltage to the gate ICG, thereby enabling an electronic shutter operation. The electric charge stored in the integration section 22 is transferred to the storage section 23 by applying a pulse voltage to the electrode ST.

There are 2N storage units 23, and charges are separately stored corresponding to H and L of the LCK signal synchronized with the blinking of light. Thereafter, the charges accumulated in the 2N-stage linear CCD unit 25 are transferred via a shift unit provided to simplify the transfer clock. Thus, the linear C
Charges corresponding to the blinking of the sensor output light of the N pixels are arranged adjacent to the CD portion.

The electric charges arranged in the linear CCD section 25 are sequentially transferred to the ring CCD section 26. The ring CCD 26 is operated by the CLR unit 27 in response to the RCL signal.
Then, the charge from the linear CCD 25 is sequentially accumulated. Reference numeral 29 denotes an amplifier for reading out this charge, which outputs a non-destructive voltage proportional to the amount of accumulated charge.

FIG. 9 is a diagram showing an example of this output waveform. When only the signal at the time of lighting is read out, the waveform of B becomes a waveform at the time of non-lighting, that is, the signal of only disturbance light becomes the waveform of A, and the waveform becomes A. The charges of these corresponding pixels are stored in the ring CCD 26.
, The amplifier 29 is actually designed to non-destructively amplify and output the difference between the adjacent transfer stages, and its output waveform is such that the disturbance light component is canceled out as indicated by B-A. Thus, noise is suppressed, and an image signal of only the blinking light from the indicator 4 is obtained.

The PEAK signal which is the maximum value of this waveform is
Since the signal is sequentially accumulated in the ring CCD 26 and becomes larger due to the repetition of the blinking, by detecting that this level has reached the predetermined value TH1, an output waveform of a constant quality is always obtained. Note that this determination may be made separately for the two sensors for X and Y. However, when the sensors are arranged very close to each other, almost the same amount of light is incident, so the peak of the output is also reduced. Almost the same. For this reason, in the present embodiment, the circuit is simplified by performing the determination with only one output and performing exactly the same control for both sensors.

On the other hand, if the disturbance light is very strong, the ring CCD must be driven before the peak of the differential waveform becomes sufficiently large.
There is a possibility that the transfer charges of 26 may be saturated. For such a case, the linear sensors 20X and 20Y have a skim function.

FIG. 10 is a diagram showing the operation. The skim unit 28 monitors the level of the non-lighting signal. If the signal level exceeds a predetermined value at the n-th time (dotted line in FIG. 10), a certain amount of charge is extracted from each of the A and B pixels. Works. Therefore, a waveform like An + 1 is obtained at the next (n + 1) -th time, and by repeating this, even if there is extremely strong disturbance light, signal charges can be accumulated without being saturated. As a result, it is possible to obtain a sufficiently large signal waveform by continuing the integration operation many times even if the amount of blinking light is weak.

The two linear sensors 20 thus obtained are
The X and 20Y signals (difference signals) are
Are sent as digital signals to the coordinate calculation means 32 to calculate the coordinates.

In the coordinate calculation, first, coordinate values (X1, Y1) on the sensor are obtained for output data in the X and Y directions. Since X and Y are the same, a flowchart for only X is shown in FIG.

First, the difference data Dx (1) to Dx of each pixel
x (N) is read (step S202) and stored in the buffer memory. Next, S / S
Pre-filtering is performed to improve N (step S203). This is the neighborhood operation operator (1, 2,
This is a very simple addition, well known as 1).

Next, the largest pixel is searched for between the maximum value and the pixels before and after the maximum value, and the pixel numbers are set to nx and nx + 1 (step S204). The exact position between peak pixels is a type of differential operator (1, 1, 0, -1,-
Determined using 1). This calculation is for finding the zero crossing of the differential waveform, but the expression has a very simple form shown in step S205 by rearranging the expression.

[0054]

(Equation 1)

The sum of the inter-pixel coordinate Gx and the pixel number nx thus obtained is the sensor output coordinate X1 (step S20).
6). Also for Y1, similarly to X1, Y1 = Gy + ny
Can be requested.

Next, calibration is performed using a user calibration function to obtain output coordinate values (X, Y). This user calibration is a conversion by a simple linear function, and when the user specifies three points (or more) on a predetermined screen in a calibration value setting mode such as when the installation state is changed, the user calibration is performed. The coefficient of the function is determined as a solution of the ternary simultaneous equation (in the case of four or more points, a fitting method such as the least square method may be used).

The installation calibration by the user is a method generally performed by a coordinate input device, and a detailed description is omitted. However, if the installation is frequently changed, such as a projector, this function is used. It is desirable to have.

The output coordinate values (X,
Y) and data such as control signals are transmitted to the computer 9 by the communication control means 33 by a predetermined communication method, and input of a cursor, a menu, a character or a line drawing on the screen projected by the projection display device 8 according to an instruction from the computer 9. Various operations such as can be performed.

Next, FIG. 12 is a view of the projector 8 as viewed from the front, and shows the visible light cut filter 10 which is a light receiving window.
The linear sensor 20X built in the inside of the projector 8 is configured such that the photosensitive section 21X is located on the optical axis of the projection lens 86 of the projector 8, and the linear sensor 20Y and the photosensitive section 2
1Y are arranged near the same plane as the linear sensor 20X and the photosensitive section 21X, respectively.
0 is disposed near the same plane as the linear sensors 20X and 20Y.

A plurality of control signal detection sensors 60 may be arranged as shown in FIG. 12 to increase the sensitivity. The visible light cut filter is, for example, Clarex (T
57006) can be used. Further, a bandpass filter that matches the emission wavelength of the light emitting element 41 of the pointing tool 4 may be used. Reference numeral 51 denotes a light receiving sensor that receives infrared rays from a remote controller for controlling the projector 8 using infrared rays, and the arrangement is shown in FIG. The above-mentioned visible light cut filter 100 is shared and arranged inside. 52 is a sensor control means.

FIG. 13 is a view showing another embodiment of the projector 8, and shows a mode in which the extendable pointing tool 4 is attached to a detachable storage section 8 a provided in the projector 8. Reference numeral 8b denotes a belt for fixing the pointing device 4.

As described above, according to the above-described embodiment, the difference signal is obtained by separately integrating the signals at the time of lighting and the time of non-lighting of the light spot blinking at a predetermined cycle by the pointing rod. Since the signal is digitized with a data width of n bits or more and coordinate operation processing is performed to output a coordinate value with a resolution of about 2 times the number of sensor pixels, the position of the peak pixel is obtained with high accuracy. Since the quality of the image signal is good and the pixels can be divided to obtain high-resolution coordinate values,
The effect of disturbance light can be suppressed, and a high-resolution, small-sized, light-weight, low-cost coordinate input device can be realized. By incorporating this coordinate input device in the projector and disposing it at a position on the side of the projection lens, a small presentation system with less parallax can be provided.

[0063]

As described above, according to the present invention,
With a relatively simple configuration, the influence of disturbance light can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a system using a projector 8 according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal structure of a detector 1 and an indicator 4;

FIG. 3 is an external view of a pointing tool 4;

FIG. 4 shows a condenser lens 61, a control signal detection sensor 60, cylinder lenses 90X and 90Y, a linear sensor 20X,
It is an outline view showing an example of arrangement of 20Y.

FIG. 5 is a diagram showing integration of a cylinder lens.

FIG. 6 is a timing chart showing signal waveforms representing an operation of restoring a control signal from an output signal of a control signal detection sensor 60.

FIG. 7 is a timing chart at the end of a series of operations for restoring a control signal.

FIG. 8 is an internal configuration diagram of the linear sensors 20X and 20Y.

FIG. 9 is a diagram illustrating an example of output waveforms of the linear sensors 20X and 20Y.

FIG. 10 is a diagram illustrating a skim operation of the linear sensors 20X and 20Y.

FIG. 11 is a flowchart of a coordinate calculation.

FIG. 12 is a front view of the projector 8;

FIG. 13 is a perspective view of another embodiment of the projector 8.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 5/00 550 G09G 5/00 550C H01L 31/16 H01L 31/16 B H04N 5/74 H04N 5/74 Z F term (reference) 5B068 AA04 AA22 AA36 BB18 BC03 BD09 BD17 BE03 BE08 CC17 CD06 5B087 AA02 AC09 CC09 CC21 CC25 CC26 CC33 DD03 DD17 5C058 BA33 BA35 EA02 EA26 EA33 5C082 AA03 AA21 AA24 CA85 CA81 CA85

Claims (6)

[Claims] An indicator having a light source that blinks at a predetermined cycle, a light receiving the light from the light source, detecting a point or a locus indicated by the light source, and generating coordinate information of the point or the locus. Means, wherein the detecting means distinguishes light from the light source from disturbance light based on the amount of light received when the light source is turned on and the amount of light received when the light source is turned off. 2. The input device according to claim 1, wherein the light source emits infrared light. 3. The input device according to claim 2, wherein said detection means has a light receiving window formed of a material that blocks visible light and transmits infrared light. 4. A driving signal generating means for generating a driving signal for causing the light source to blink on and off in the cycle, and a control signal generating means for generating a control signal for instructing execution of a predetermined process. The input device according to claim 1, further comprising: a unit configured to superimpose the control signal on the drive signal. 5. The input device according to claim 1, further comprising: means for sending the coordinate information to an external computer. 6. An image projecting means for projecting an image, receiving light from the light source of an indicator having a light source that blinks at a predetermined cycle, detecting a point or a locus indicated by the light source, and Detecting means for creating coordinate information of the trajectory;
Wherein the detecting means distinguishes light from the light source from disturbance light based on the amount of light received when the light source is turned on and the amount of light received when the light source is turned off. .