Patent Application
20110211132
The present invention relates to a grid signal receiver and a wireless pointing system having the same.
With development of video household appliances such as a television (TV), a digital versatile disc (DVD), a set-top box, an internet protocol (IP) TV, etc., a pointing device such as a mouse for a personal computer (PC) has been urgently required. In particular, since the IPTV has been developed as an alternative to the PC in the average household, there is further needed the pointing device such as the PC mouse. However, a wired device like a general PC mouse cannot be proper for the video household appliances, and therefore the existing TV remote controller is utilized for achieving the pointing device.
There has been disclosed a patent related to a method in which the remote controller is used as the pointing device and generates and transmits light having a grid pattern and a receiver receives it and measures a moving direction, a moving speed, a size, etc of a grid line so as to drive a pointer (Korean Patent Publication No. 10-2008-0064074).
The grid signal receiver includes two pairs of sensors, i.e., includes a pair of sensors to determine left and right motions, and a pair of sensors to determine up and down motions. A method of determining the motion is as follows.
A) The remote controller having the grid signal transmitter moves to move a generated grid pattern
B) The grid signal receiver receives light of the grid pattern
C) Motion is determined according to received patterns
D) Determined motion is applied to a pointer
However, because such a grid-pattern wireless pointing method determines the motion on the basis of the light of the grid pattern, an error may occur in the motion as the grid pattern of the light is sloped or as the thickness and the interval of the grid line varies depending on the distance. Particularly, a user moves while holding the remote controller involving the grid signal transmitter by a hand, so that the slope of the grid pattern can frequently happen. The slope of the grid pattern is on the rise as a problem causing a malfunction.
To solve the problems of the prior art as described above, an aspect of the present invention is to provide a grid signal receiver, which can prevent a malfunction due to slope of a grid signal transmitter, and a wireless pointing system having the same. That is, an object of the present invention is to provide a grid signal receiver capable of compensating slope of a grid signal transmitter, and a wireless pointing system having the same.
In accordance with an aspect of the present invention, there is provided a grid signal receiver that receives a signal of a grid pattern from a grid signal transmitter and determines motion of the grid signal transmitter, the grid signal receiver including a slope sensor in addition to a motion sensor for sensing motion of a grid, the slope sensor sensing a slope of the grid to sense a slope of the grid signal transmitter.
The grid signal receiver may include: a pair of horizontal motion sensors which sense a vertical (Y-axis) pattern of the grid to sense horizontal (X-axis) motion; a pair of vertical motion sensors which sense a horizontal (X-axis) pattern of the grid to sense vertical (Y-axis) motion; and the slope sensor which senses the slope of the grid.
The slope sensor may be arranged not on the same line as the pair of horizontal motion sensors or the pair of vertical motion sensors.
The slope sensor may be arranged in a vertical direction with respect to one of the pair of horizontal motion sensors, or arranged in a horizontal direction with respect to one of the pair of vertical motion sensors.
The slope sensor may be arranged so that a distance between the slope sensor and one horizontal motion sensor arranged in the vertical direction is equal to a distance between the pair of horizontal motion sensors, or a distance between the slope sensor and one vertical motion sensor arranged in the horizontal direction is equal to a distance between the pair of vertical motion sensors.
The slope sensor senses the vertical (Y-axis) pattern together with the pair of horizontal motion sensors and compares relative sensing times of the sensors to calculate slope information of the grid, or the slope sensor senses the horizontal (X-axis) pattern together with the pair of vertical motion sensors and compares relative sensing times of the sensors to calculate slope information of the grid.
A vertical (Y-axis) pattern signal and a horizontal (X-axis) pattern signal of the grid may be different in a frequency band. Further, each sensor may include a photodiode to sense a grid signal; and an optical filter to pass the frequency band of the grid signal.
The vertical (Y-axis) pattern signal and the horizontal (X-axis) pattern signal of the grid may be different in the frequency band, the horizontal motion sensor and the vertical motion sensor may be provided with optical filters to pass the frequency bands of the vertical (Y-axis) pattern signal and the horizontal (X-axis) pattern signal, respectively, and the slope sensor may include an optical filter that passes either frequency band of the vertical (Y-axis) pattern signal or the horizontal (X-axis) pattern signal.
The grid signal receiver may further include a motion vector processor that receives a sensed signal from the respective sensors to process a motion vector, and calculates slope information of the grid to compensate the motion vector.
The motion vector processor may include a direction detector to detect a moving direction of the grid; a line detector to generate a pulse every time when one grid line moves; a slope detector to detect a slope of the grid; a motion vector extractor to receive information about the moving direction of the grid from the direction detector and a pulse from the line detector and extract an X-axis motion vector (horizontal motion vector) and a Y-axis motion vector (vertical motion vector); and a slope-based motion vector compensator to compensate the X-axis motion vector and the Y-axis motion vector on the basis of the slope information received from the slope detector.
The motion vector processor may further include a low-pass filter that receives output of the slope-based motion vector compensator and performs low-pass filtering to suppress variation of a motion vector due to noise and shaking generated in a transmitting terminal or a receiving terminal.
The motion vector processor may further include a low-pass filter that performs low-pass filtering by receiving the X-axis motion vector and the Y-axis motion vector of the motion vector extractor to reduce an error that may occur under acceleration or negative-acceleration conditions, and outputs the filtered X-axis and Y-axis motion vectors to the slope-based motion vector compensator.
The motion vector processor may further include an anti-shaking decision unit to estimate shaking, so that the motion vector extractor is halted depending on the decision of the anti-shaking decision unit.
The motion vector processor may include: a direction detector to detect a moving direction of the grid; a line detector to generate a pulse every time when one grid line moves; a slope detector to detect a slope of the grid; a motion vector extractor to receive information about the moving direction of the grid from the direction detector and a pulse from the line detector and extract an X-axis motion vector and a Y-axis motion vector; a pulse width demodulator to convert a certain cycle about the motion of the grid into a digital value; a pulse-based motion vector compensator to compensate the X-axis motion vector and the Y-axis motion vector received from the motion vector extractor on the basis of the converted digital value; and a slope-based motion vector compensator to compensate the X-axis motion vector and the Y-axis motion vector received from the pulse-based motion vector compensator on the basis of the slope information received from the slope detector.
The plurality of sensors may be provided as a first chip, and the motion vector processor may be provided as a second chip different from the first chip.
The plurality of sensors and the motion vector processor may be provided as a single chip.
In accordance with another aspect of the present invention, there is provided a wireless pointing system including: a grid signal transmitter to generate and output a signal having a grid pattern signal; and a grid signal receiver to process a motion vector to receive the signal of the grid pattern and calculate motion, the grid signal receiver including a slope sensor in addition to a motion sensor to sense motion of a grid, so that a slope of the grid signal transmitter is sensed and the motion vector is compensated on the basis of slope information.
In a grid signal receiver according to exemplary embodiments of the present invention and a wireless pointing system having the same, a wireless pointing function absolutely required in the next-generation video household appliances such as the IPTV or the like.
Particularly, the slope of the grid signal transmitter is sensed and compensated to prevent a malfunction due to the slope of the remote controller. Further, shaking compensation, smooth pointing, etc. can be achieved through various signal processes.
Hereinafter, embodiments of the present invention will now be described with reference to the accompanying drawings so that a person having an ordinary skill in the art can easily realize the present invention.
This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
A grid signal receiver according to an exemplary embodiment of the present invention and a wireless pointing system having the same can sense a slope of a grid signal transmitter and compensate a motion vector according to sensed results, thereby performing a reliable wireless pointing function.
The grid signal transmitter 100 includes a light source (a light emitting diode (LED) may be used by way of an example), and a grid generator, so that it can transmits light of a grid pattern to implement a pointing function. The transmitted light of the grid pattern is sensed in the form of a grid line by the grid signal receiver 200, and a moving direction and a moving speed thereof are calculated to obtain a motion vector, thereby operating a pointer on a screen of the video house hold appliances such as the digital TV or the like. Below, the wireless pointing system 10 in this embodiment will be described in more detail with reference to
The grid signal transmitter 100 includes a microcomputer 120, an X-grid generator 140, a Y-grid generator 145, a first lens 160, and a second lens 165. The grid signal transmitter 100 may generate an infrared signal having a grid pattern (light other than the infrared light may be used as long as it is within the scope of the present invention).
The microcomputer 120 may generate a signal having a carrier frequency in each axis (X axis and Y axis). Here, the X axis refers to an axis where the grid signal transmitter 100 generates a grid line in a horizontal direction, and the Y axis refers to an axis where the grid signal transmitter 100 generates a grid line in a vertical direction. The signal generated at this time may be converted into the infrared signal through an infrared LED. At this time, the X-axis carrier frequency signal and the Y-axis carrier frequency signal may use the same frequency, but preferably use different frequencies to prevent interference. For example, the X-axis carrier frequency signal may be generated within a range from 30 to 40 KHz, and the Y-axis carrier frequency signal may be generated within a range from 41 to 50 KHz.
The X-grid generator 140 may receive the X-axis carrier frequency signal and generate an X-axis pattern (IRX). That is, the X-axis generator 140 transmits the light emitted from the LED, thereby generating the X-axis pattern (IRX). The Y-grid generator 145 may receive the Y-axis carrier frequency signal and generate a Y-axis pattern (IRY). That is, the Y-axis generator 145 transmits the light emitted from the LED, thereby generating the Y-axis pattern (IRY). The X-grid generator 140 and the Y-grid generator 145 may be provided as plates etched to have the X-axis pattern and the Y-axis pattern, respectively, and may be made of glass or the like which can transmit the light (infrared light).
The first lens 160 transmits the X-axis pattern (IRX) and projects it onto the grid signal receiver 200. The second lens 165 transmits the Y-axis pattern (IRY) and projects it onto the grid signal receiver 200. Here, the first and second lenses 160 and 165 are made of a material capable of transmitting the light (infrared light).
In this embodiment, the grid signal transmitter 100 generates the X-axis pattern signal and the Y-axis pattern signal individually as described above, but not limited thereto. Alternatively, the X-axis pattern and the Y-axis pattern may be generated at the same time (in this case, an XY-grid generator is used as the grid generator), or the grid pattern may be generated using one carrier frequency signal.
Referring to
Contrary to the prior art, the signal receiver 220 further includes a slope sensor E to sense the slope of the grid, and the motion vector processor 240 compensates the motion vector in accordance with the slope sensed by the signal receiver 220. Thus, the direction or the size of the motion vector can be prevented from distortion.
The signal receiver 220 includes horizontal motion sensors A and B to determine the left and right motion (motion in the X-axis), vertical motion sensors C and D to determined the up and down motion (motion in the Y-axis), and the sensor E to determine the slope.
In this embodiment, a method of determining the motion is as follows. The grid signal transmitter 100 moves and thus the grid pattern generated by the grid signal transmitter 100 also moves. The signal receiver 220 of the grid signal receiver 200 may receive the grid light. Then, the direction is determined according to the received patterns. The determined direction is applied to the pointer.
Each sensor A, B, C, D, E is provided as a photo diode capable of sensing the light and converting it into an electric signal. Here, to prevent interference between the horizontal (X) axis and the vertical (Y) axis of the grid, the grid signal transmitter 100 generates the light of the horizontal (X) axis and the vertical (Y) axis to have different frequencies. Thus, each sensor A, B, C, D, E may employ a corresponding optical filter.
The horizontal motion sensors A and B are sensors for determining the left and right (X-axis) motion. The vertical motion sensors C and D are sensors for determining the up and down (Y-axis) motion. The slope sensor E is a sensor for determining the slope of the grid.
The slope sensor E is configured to have the same optical filter as the horizontal motion sensors A and B or the vertical motion sensors C and D, so that the slope sensor E can sense the slope together with the horizontal motion sensors A and B or sense the slope together with the vertical motion sensors C and D.
The horizontal motion sensors A and B are arranged in a horizontal direction, and the vertical motion sensors C and D are arranged in a vertical direction. In the case that the slope sensor E receives the same frequency signal as the horizontal motion sensors A and B (i.e., senses the slope together with the horizontal motion sensors A and B), the slope sensor E can be arranged in any position except a horizontal position on the same line as the horizontal motion sensors A and B.
Also, if the slope sensor E receives the same frequency signal as the vertical motion sensors C and D (i.e., senses the slope together with the vertical motion sensors C and D), the slope sensor E can be arranged in any position except a vertical position on the same line as the vertical motion sensors C and D. Here, whether it is vertical or horizontal is based on the X-axis and the Y-axis of the grid generated in the grid signal transmitter 100.
Below, a method that the slope sensor E senses the slope together with the horizontal motion sensors A and B will be described according to an exemplary embodiment of the present invention.
In this embodiment, the slope may be determined through the sensor A and the sensor E. If the grid is sloped, the sensor A and the sensor E are different in time of receiving the vertical grid patterns. Thus, the slope of the grid signal transmitter 100 is determined. This case is possible if the sensors A and the sensor E are arranged in the vertical direction. Even if they are not arranged in the vertical direction, the slope can be determined by comparing the sensors A, B and E with respect to the sensing time.
Also, the direction and the angle of the sloped grid signal transmitter 100 are determined through the sensors A, B and E.
First, the slope direction of the grid signal transmitter 100 can be determined on the basis of order that the sensors are turned “on”.
Table 1 shows information that can be obtained according to order of sensing the infrared signal. In the following, a reference of 45 degrees can be determined when a distance between the sensors A and B is equal to that between the sensors A and E.
s=vt, v=constant Equation 1
Therefore, a ratio of tEA and tAB is equal to that of dA and dB. Further, if the distance between the sensor A and the sensor E is equal to that between the sensor A and the sensor B, dB is equal to dE. Therefore, a ratio of dA and dE is calculated. Through this, a gradient can be calculated by operation of a trigonometrical function.
The gradient calculated by this is used in compensating the motion vector through the rotation transformation.
If one or more light lines are positioned between the sensors, it faces a trouble in determining the direction of the motion. Thus, if the thickness of the grid line within the transmitting and receiving distance of the grid signal transmitter 100 is larger than the distance between the sensors, there is no problem in determining the direction of the motion. Here, a method of intercepting the light is used in forming the grid light, and it is thus easy to increase the thickness of the line.
A direction detector 241 may sense the moving direction of the grid signal transmitter 100. A line detector 242 may generate a pulse every time when one line moves. Then, a motion vector extractor 244 may generate a motion vector with respect to the horizontal and vertical directions and transmit it to a slope-based motion vector compensator 245.
The motion vector compensator 245 may compensate the motion vector according to the slope angles θ. At the same time, the slope detector 243 may transmit the slope angle θ of the transmitter based on the sensed signals 2H, 2V, 1E from the horizontal motion sensors A and B and the slope sensor E to the slope-based motion vector compensator 245. Here, the signal 2H is a vertical pattern infrared signal (IRX) received from the horizontal motion sensors A and B, and the signal 1E is a vertical pattern infrared signal (IRX) received from the slope sensor E.
The slope-based motion vector compensator 245 takes two motion vectors and θ, and then performs the above-described rotation transform to thereby output the compensated motion vector.
At this time, the predetermined cycle Twdith may be generated from a pulse width demodulator (PWDM) 248 that converts a pulse signal into a digital signal. A pulse-based motion vector compensator 249 may compensate the motion vector according to the predetermined cycle given by the pulse width demodulator 248. Such a compensated motion vector may be transmitted to the slope-based motion vector compensator 245.
According to an embodiment of the present invention, two methods may be considered in realizing the method of receiving the grid signal and calculating the motion vector. One is to achieve the motion vector processor in the form of hardware, and the other is to convert/achieve the inner function of the motion vector processor in the form of software (firmware) using a micro control unit (MCU).
The software type is divided into a case where the MCU is externally provided (see
Such a software type has an advantage that an independent board can be flexibly developed in consideration of the MCU corresponding to the application. On the other hand, the MCU feature of the independent board has to be dependent on the application, and thus an evaluation and a test about whether the selected MCU is suitable may be required whenever the application changes.
Although some embodiments have been provided to illustrate the present invention, it will be apparent to those skilled in the art that the embodiments are given by way of illustration, and that various modifications and equivalent embodiments can be made without departing from the spirit and scope of the present invention. Accordingly, the scope of the present invention should be limited only by the accompanying claims and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2008-0106175 | Oct 2008 | KR | national |
| 10-2009-0102252 | Oct 2009 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR2009/006240 | 10/27/2009 | WO | 00 | 4/28/2011 |
