1. Field of the Invention
The present invention relates to an algorithm for rebuilding 1D information acquired when an object to be measured makes a motion relative to an image input device into 2D information and, more particularly, to an algorithm used when an object to be measured is a skin pattern and an image input device thereof.
2. Description of Related Art
Fingerprint reading methods and devices are more and more appreciated in recent years. In practical life, because the fingerprint recognition technology has become more and more mature, its applications are more and more widespread. For example, the fingerprint recognition technology has early applied in private entrance guard and security systems or in large fingerprint recognition systems of specific organizations. Recently, it has been applied in identity recognition systems of entry and exit control organizations and household registration organizations. Along with gradual popularity of portable electronic devices, there have been some portable electronic products such as mobile phones or personal digital assistants (PDAs) that have adopted this technology.
A conventional skin pattern reading method utilizes a skin pattern sensor composed of capacitive sensors arranged in a 2D array. Its advantage is that users need not to wait for a relative motion generated between a skin pattern to be measured and the sensing module. It is only necessary to directly contact the skin pattern with the sensor to get lumpy 2D image information of the skin pattern. This method, however, has the problem that the electrostatic protection capacity of the capacitive sensor is bad to cause a too low production yield. Moreover, the capacitive sensor is easily damaged by electrostatic charges during usage. Besides, because the 2D sensor has a large area, it is not suitable for applications in small-size portable electronic products.
Another conventional skin pattern reading method utilizes a skin pattern sensor having an optical sensing module composed of sensing elements arranged in a 2D array. The optical 2D sensing module comprises a light source, a light guide (reflector, lens, diffuser, and so on), an optical window (transparent sheet, prism, and son on), an optical imager (aperture, lens, and so on), and a 2D image sensor. Delicate setup and fine tuning of optical path are required for the light source, the light guide, the optical window, and the optical imager, hence having a higher cost. Moreover, the occupied volume is too large to be suitable for integration into portable electronic products.
U.S. Pat. No. 6,381,347 disclosed an optical 2D image sensing device shown in
Yet another conventional skin pattern reading method utilizes a 1D band type skin pattern sensor with a width of generally more than 4 rows. The generally adopted width is 8, 12, or 16 rows. It is necessary for users to generate a relative motion between a skin pattern to be measured and the 1D band type skin pattern sensor to acquire continuous 1D band type information for rebuilding 2D information of the skin pattern. This 1D band type skin pattern sensor occupies a less area than that occupied by the above 2D sensors and thus has the opportunity of being integrated into portable electronic products. The common 1D band type sensors are of thermal sensing type, capacitive type, and optical type. Thermal sensing type sensors cannot touch a skin pattern for a too long time. That is, the relative motion between the skin pattern and the thermal sensing type sensor cannot be too slow to lose spatial resolution of the thermal sensing type sensor owing to thermal conductance. On the other hand, the relative motion between the skin pattern and the thermal sensing type sensor cannot be too fast to generate artifact due to thermal effect caused by fast friction, hence affecting the imaging quality. The drawbacks of the capacitive type sensors are described above. Because the optical type sensors still required optical machinery for lighting and imaging, the shrinkage of their size is limited. In summary, although 1D band type sensors are superior to the above 2D sensors in size, area, and cost, they can be further improved.
Still yet another conventional skin pattern reading method utilizes a 1D band type skin pattern sensor with a width of less than 4 rows (e.g., 2 or 3 rows of optical sensors). In this method, optical machinery for lighting, light guiding, and imaging is still required to occupy a large volume. Moreover, the algorithm adopted by this method for rebuilding 1D information into 2D information bases on the similarity between the information obtained by each row of sensors at a certain time and the information obtained by other rows of sensors at a different time to determine the speed of the skin pattern. The rebuilding quality of the 2D information depends strongly on the uniformity and similarity of each sensing element of each row of sensors. Because of manufacturing factors, there is still slight difference between the characteristics of each sensing element of each row of sensors. Added with the factors of optical machinery for lighting, light guiding, and imaging, the total difference of characteristics between each sensing element of each row of sensors becomes larger, hence affecting the rebuilding quality of 2D information. An extra pre-calibration can be used to compensate the above difference in characteristics, but the pre-calibration requires optical machinery for lighting and imaging to occupy some space. In summary, although this skin pattern reading method has a smaller area and a lower cost of sensor than those of the above 1D band type skin pattern reading method, it also can be further improved.
An object of the present invention is to provide an algorithm for rebuilding 1D information into 2D information and a 1D skin pattern sensing module thereof, which rebuild 1D linear image into recognizable and high-precision 2D planar image.
Another object of the present invention is to provide an algorithm for rebuilding 1D information into 2D information and a 1D skin pattern sensing module thereof, which make use of primary 1D sensing elements matched with secondary sensing elements to rebuild good-quality images without being affected by the problem of sensitivity uniformity of the sensing elements.
Another object of the present invention is to provide an algorithm for rebuilding 1D information into 2D information and a 1D skin pattern sensing module thereof, which simplify a 2D planar image sensor to a 1D linear sensor. Matched with the relative speed information between the sensor and a skin pattern to be measured, a 2D image can be rebuilt with a reduced size and a lower cost. The 1D skin pattern sensing module is therefore more suitable for applications in personal mobile electronic products, and its competitiveness in the market can be enhanced.
Another object of the present invention is to provide an algorithm for rebuilding 1D information into 2D information and a 1D skin pattern sensing module thereof, in which the light guiding part and the optical imaging part that occupy most volume of a 2D image sensing device are saved, and the skin pattern is directly imaged onto sensing elements based on the near field principle. Therefore, the volume can be shrunk to apply to personal mobile electronic products.
Another object of the present invention is to provide an algorithm for rebuilding 1D information into 2D information and a 1D skin pattern sensing module thereof, in which the 1D skin pattern sensing module comprises a primary 1D sensing element array and a secondary sensing element set to improve the drawback of a 2D sensor array that has a higher cost and occupies a larger area. The skin pattern is directly imaged onto sensing elements by means of near field imaging to improve the light guiding part and the optical imaging part that occupy most volume of a common optical sensor. The time relationship between 1D information obtained by part of the sensing elements of the primary 1D sensing element array and the sensing elements of the secondary sensing element set at continuous and specific intervals is utilized to determine the speed of the skin pattern, thereby rebuilding 2D information of the skin pattern.
The present invention provides an algorithm for rebuilding 1D information obtained by a 1D skin pattern sensing module into 2D information. The algorithm comprises:
providing a 1D skin pattern sensing module comprising a substrate, a 1D skin pattern sensing array set disposed on the substrate, a transparent film covering on the 1D skin pattern sensing array set, an operational unit, and a light source, the 1D skin pattern sensing array set comprising:
providing the operational unit to rebuild the 1D information obtained by the 1D skin pattern sensing module into 2D information, the operation of the operational unit comprising:
The present invention provides an algorithm for rebuilding 1D information into 2D information and a 1D skin pattern sensing module thereof. The 1D skin pattern sensing module detects information of the skin pattern by means of near field imaging to shrink the volume. The algorithm can prevent the quality of 2D information from being affected by the problem of sensitivity uniformity of the sensing elements. In other words, the present invention provides an algorithm that is barely affected by the problem of sensitivity uniformity of the sensing elements and a sensing module of small size and low cost to apply to portable electronic products, increase the functions of product, and enhance the competitiveness of product.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which:
The present invention provides an algorithm and a 1D skin pattern sensing module thereof. The 1D skin pattern sensing module shown in
The skin pattern 4 directly contacts the transparent film 3, and makes a vertical motion relative to the long axis of the 1D skin pattern sensing array set 2. The 1D skin pattern sensing array set 2 thus acquires continuous 1D information of the skin pattern 4 by means of near field imaging though the transparent film 3. The transparent film 3 can provide the functions of etch resistance, scrape resistance, contamination resistance, sufficient light transmission, and protection of the 1D skin pattern sensing array set 2. Besides, the transparent film 3 has a thickness smaller than 1 mm so that the skin pattern 4 and the 1D skin pattern sensing array set 2 can be as close as possible. The present invention needs no optical elements such as prism, lens, and reflector, and delicate setup and fine tuning of optical path are therefore not required. Moreover, because a linear sensing element array is adopted, the whole size can be reduced, and the cost can be lowered.
As shown in
The 1D skin pattern sensing module provided by the present invention can utilize a light source 6 disposed on the substrate 1 or an external light source (e.g., sunlight, indoor lamp) not disposed on the substrate 1 for lighting of the skin pattern 4. The light source, however, ought to provide uniform and stable photons incident to the skin pattern 4. In this embodiment, the light source is disposed on the substrate 1 to be projected onto the skin pattern 4 with a predetermined height and a predetermined angle. The predetermined height and angle can be adjusted to match the position where the 1D skin pattern sensing array set 2 is placed on the substrate. A filtering film with a wavelength characteristic corresponding to the light source can be coated onto the 1D skin pattern sensing array set 2 to increase the signal to noise ratio so as to enhance the resistance to outside light pollution. The 1D skin pattern sensing module can further comprise a polarizer, a waveplate, a diffuser, or a reflector, or a predetermined assembly of the above components between the light source 6 and the skin pattern 4. In order to have a larger penetration depth for bio-tissues, red light and near infrared light of wavelength of 650 to 1300 nm can be selected.
When the present invention operates, the skin pattern 4 tightly presses close to the transparent film 3, and makes a vertical motion relative to the 1D skin pattern sensing array set 2 to acquire continuous 1D information of skin pattern at specific intervals. Matched with the algorithm for rebuilding 1D information into 2D information, the 2D information of the skin pattern 4 can be obtained intact.
To sum up, the present invention provides an algorithm for rebuilding 1D information into 2D information and a 1D skin pattern sensing module thereof to accomplish the following effects:
Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 94125231 | Jul 2005 | TW | national |