Patent Application
20100060583
1. Field of the Invention
This invention relates to input devices such as keyboard and pointing devices to computers and other electronic systems such as phones and game machines that use keypad or pointing devices. More specifically, this invention relates to the keypads and pointing devices that can be operated by reflected light.
2. Description of the Related Art
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
There have been various attempts to use a beam of light to operate keyboard and pointing devices for computers. U.S. Pat. No. 3,761,877 discloses an optical graphic data tablet operated with a light pen. The position of the light spot on the plate indicated by a digital position indicator determines the signal to be sent to the computer. But its embodiments require the use of optical filters to shield the background light, and it is necessary either to maintain the intensity of light as received at the photocell at a constant level by means of a feedback circuit or correct for variations in light intensity. These requirements made the implementation expensive and difficult to build in the consumer market place. The light spot needs to be much brighter than the background or oscillating in itself, which are harmful for the eyes to look at for an extended period of time. Besides, no mechanisms similar to mouse operations such as selection and clicking was disclosed.
U.S. Pat. No. 4,713,535 discloses an optical keyboard which comprises an array of photo sensors that are arranged in an X-Y coordinate system. When a beam of light is cast onto a photo sensor, the photo sensor is actuated to transmit a coded signal to a microprocessor board, which then send a converted data to the computer. This design would significantly slow down the input speed as when the light beam moves from one sensor to another, special care and path need to be taken to avoid the sensors in between. Besides, the signal received is compared with a reference signal to check for validity, which means the intensity of the light beam needs to be significantly above the background light and may be harmful for the eyes to look at for an extended period of time.
U.S. Pat. No. 5,883,616, and U.S. Pat. No. 6,097,373 all disclosed computer input devices operated by a light beam for disabled people who can not operate manually a regular computer. The light sources in these inventions are all designed to be worn on the user's head. They all require an independent switching mechanism that can be used to select the desired sensor being illuminated.
My invention, U.S. Pat. No. 6,770,864, revealed a method of using a hand-held light beam to enter keyboard signals and control cursor movement on a display. The purpose of the endeavor is to develop a new but still manual operation method that can be a feasible alternative for today's keyboard and mouse, but with minimal or no injury effects on user's hands and bodies. In the process of reduction to practice, some issues were found to be expensive and inconvenient for the users: The light beam in the patent was chosen to be narrow and directional. However, to use any visible light, the light spot on the receiver box needs to be significantly brighter than the background light for the sensors to distinguish the two. It can be tiring for the eyes to look at the bright spot for a long time. When the background light is very bright, it's difficult for the light sensors to work well.
Another drawback of U.S. Pat. No. 6,770,864 is that it does not disclose methods for avoiding accidental “hits” on the keyboard entries that may trigger unintended signals to the computer. These undesired hits can be caused by accidental random light or the moving light beam, particularly when the light beam is moving fast.
All the inventions mentioned above and found in the searches that try to use light beams to operate input devices have one feature in common, i.e. the user needs to hold and move a source of light. This movable light source not only adds burden to the user, but also limits the speed of data entry as there has to be a movement of the light source.
The present invention includes specially arranged light sources, a receiver box that contains sensors for detecting light of the same wave length as that from the sources, a circuit inside the receiver box to process and transmit the signals to a connected digital processor. The light source or sources are arranged in such a way that enough photons from the source can be easily reflected by a finger or other reflective surfaces such as that of a plastic pen into the sensors and trigger some signals.
A primary object of the present invention is to enable light operated input devices to work without the need for the user to bear the weight of the light emitting devices, and thus reduce the factors of strain and fatigue from holding and moving a solid object for the user. Another object is to enable the uses of multiple fingers to increase the speed of data input. Yet another object is to enable the device to work well in various background lighting conditions without harmful effects on the eyes. Yet another object is to avoid forces on hands but enable fast and easy data input. Some arrangements of the light sources, sensor areas, and special operation mechanisms are also introduced to facilitate fast and easy usage of such devices.
In the drawings, closely related objects have the same number but different letters.
The purpose of this invention is to solve some problems that occurred in the process of reducing my invention of U.S. Pat. No. 6,770,864 to practice, and to improve the reliability, speed of data entry, and ease of use.
In general, when a reflector is approaching close to a sensor area and recognized by the system, a signal of keyboard or mouse button depressed or cursor movement is sent to the computer. When the reflector raises up or move out of the sensor area to stop the triggering, a button released or cursor movement stop signal is sent to the computer.
Items 30a, 30b, and 30c are optical isolating tubes inside which optical sensors 50a, 50b, 50c are protected from the light coming from sides. LEDs 40a, 40b, 40c emit light to be reflected to activate the sensors. While the wave length of the light can work in a wide range, it is found that Infrared light works better than visible light for optical stability and the ease on the eyes.
These light emitters and sensors are connected to a circuit 60 that includes a microprocessor, in this case a microcontroller to process the signals received. Item 70 is a frame or enclosure to contain all the circuits. Item 80 indicates a wire connection to any external entities.
Items 20a-20h are light sensitive areas of the inner ring. When these areas are triggered by reflected lights, the cursor will move in the direction from the center to the lit area. Items 30a-30h are also light sensitive areas and functions similarly to that of 20a-20h. However, the speed of the cursor can be determined when the reflector moves across different light sensitive areas.
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From the description above, a number of advantages of some embodiments of the input devices operable by reflected light revealed here become evident:
(1) The user no longer has to hold the light source in the hand or bear it with the body, and thus lead to less effort, less strain, and less tiring in the operation of the device.
(2) Multiple fingers or reflectors can be utilized for data entry and the speed is improved.
(3) Using Infrared emitters and sensors improves the optical stability.
(4) Using optical isolating tubes to improve the optical stability of the device.
(5) Dedicated light sensors for stopping the movement of the cursor improves usability.
(6) The integration of reflective optical keys with a display and other switches enables very small size input panels.
(7) Using light sensor triggering to function as mouse buttons and scrolling wheel avoids the use of finger touching the mouse, which further reduces the harmful effects on the fingers.
From the above description, the reader can see that this optical input interface can be reliable, fast, easy to use.
While the above description contains much specificity, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of several preferred embodiments thereof. Many other variations are possible. For example, the light sensors can be arranged in a matrix form and using the speed of the movement of the reflector to determine the movement of the cursor.
The spirit of the present invention provides a breadth of scope that includes all methods of using reflected light to operate keyboards and pointing devices reliably, fast, and easily so that the general public can use to avoid repetitive strain injuries and related pains. Any variation on the theme and methodology of accomplishing the same that are not described therein would be considered under the scope of the present invention.
