An MPEG downdecoder is to be provided which eliminates dephasing of pixels of moving picture data without losing properties inherent in a picture obtained on interlaced scanning. If an interlaced picture is inputted, and the DCT mode is the field mode, an interlaced picture accommodating picture decoding unit 3 executes 4xc3x974 decimating IDCT. If the DCT mode is the frame mode, the entire coefficients of the DCT block are IDCTed for separation into two pixel blocks associated with interlaced scanning. The separated two pixel blocks are DCTed. The coefficients of the low-frequency components are IDCTed and the two pixel blocks are synthesized together. A progressive picture accommodating picture decoding unit 2 is fed with a progressive picture. The coefficients of the low-frequency components of the DCT block are inverse orthogonal transformed.

1. Field of the Invention
This invention relates to a picture decoding method and apparatus for decoding compressed picture data of a first resolution obtained on predictive coding by motion prediction in terms of a pre-set pixel block (macro-block) as a unit and on performing orthogonally-transform in terms of a pre-set pixel block (orthogonal transform block) as a unit. More particularly, it relates to a picture decoding method and apparatus for decoding compressed picture data of the first resolution and for decimating the data to moving picture data of a second resolution lower than the first resolution.
2. Description of the Related Art
There is now going on the standardization of digital television signals employing the picture compression system, such as Moving Picture Experts Group Phase 2 (MPEG2). Among the standards for digital television broadcast, there are a standard for standard resolution pictures, such as those with the number of effective lines in the vertical direction of 576, and a standard for high-resolution pictures, such as those with the number of effective lines in the vertical direction of 1152. Recently, there is raised a demand for a downdecoder for decoding compressed picture data of a high-resolution picture and for reducing the resolution of the compressed picture data by xc2xd to generate picture data of the picture data of standard resolution to display the picture data on a television monitor adapted to cope with the standard resolution.
There is proposed in a publication entitled xe2x80x9cScalable Decoder free of low-range Driftxe2x80x9d (written by Iwahashi, Kanbayashi and Takaya, Shingaku-Gihou CS94-186, DSP 94-108, 1995-01) a downdecoder for decoding a bitstream of, for example, MPEG2, obtained on predictive coding with motion prediction of a high-resolution picture and compression coding by discrete cosine transform, and for downsampling the picture to a picture of standard resolution. This Publication, referred to below as Publication 1, shows the following first to third downdecoders.
Referring to FIG. 1, this first downdecoder includes an inverse discrete cosine transform unit 1001, for processing a bitstream of a high resolution picture with 8 (number of coefficients as counted from the dc component in the horizontal direction) xc3x978 (number of coefficients as counted from the dc component in the vertical direction), an adder 1002 for adding a discrete cosine transformed high resolution picture and a motion-compensated reference picture, and a frame memory 1003 for transient storage of the reference picture. The first downdecoder also includes a motion compensation unit 1004 for motion-compensating the reference picture stored in the frame memory 1003 with xc2xd pixel precision, and a downsampling unit 1005 for converting the reference picture stored in the frame memory 1003 to a picture of standard resolution.
This first downdecoder reduces an output picture, obtained on decoding as a high resolution picture by inverse discrete cosine transform, by the downsampling unit 1005, to output resulting picture data with the standard resolution.
Referring to FIG. 2, the second downdecoder includes an inverse discrete cosine transform unit 1011 for performing 8xc3x978 inverse discrete cosine transform, as it substitutes 0 for the high-frequency components of the discrete cosine transform (DCT) block of the high resolution picture, an adder 1012 for summing the discrete cosine transformed high resolution picture to the motion-compensated reference picture, and a frame memory 1013 for transient storage of the reference picture. The second downdecoder also includes a motion compensation unit 1014 for motion-compensating the reference picture stored in the frame memory 1013 with xc2xd pixel precision, and a downsampling unit 1015 for converting the reference picture stored in the frame memory 1013 to a picture of standard resolution.
This second downdecoder performs inverse discrete cosine transform to obtain a decoded output picture, as a high-resolution picture, as it substitutes 0 for coefficients of high-frequency components among the totality of coefficients of the DCT block, and reduces the output picture in size by the downsampling unit 1015 to output picture data of standard resolution.
Referring to FIG. 3, a third downdecoder includes a decimating inverse discrete cosine transform unit 102 for doing e.g., 4xc3x974 inverse discrete cosine transform, using only the coefficients of the low-frequency components of the DCT block of the bitstream of the high resolution picture, for decoding to a standard resolution picture, and an adder 1022 for summing the standard resolution picture processed with decimating inverse discrete cosine transform and the motion-compensated reference picture. The third downdecoder also includes a frame memory 1023 for transiently storing the reference picture and a motion compensation unit 1024 for motion-compensating the reference picture stored by the frame memory 1023 with a xc2xc pixel precision.
In this third downdecoder, IDCT is executed using only low-frequency components of all coefficients of the DCT block to decode a picture of low resolution from a picture of high resolution.
The above-described first downdecoder performs inverse discrete cosine transform on the totality of the coefficients in the DCT block to obtain a high-resolution picture on decoding. Thus, the inverse discrete cosine transform unit 1001 of high processing capability and the frame memory 1003 of high capacity are needed. The second downdecoder performs discrete cosine transform on the coefficients in the DCT block to obtain a high-resolution picture on decoding, as it sets the high-frequency components of the coefficients to zero, so that a lower processing capacity of the inverse discrete cosine transform unit 1011 suffices. However, the frame memory 1003 of high capacity is yet needed. In contradistinction from these first and second downdecoders, the third downdecoder performs inverse discrete cosine transform on the totality of the coefficients in the DCT block, using only coefficients of the low-frequency components of the coefficients in the DCT block, so that a low processing capability of an inverse discrete cosine transform unit 1021 suffices. Moreover, since the reference picture of the standard resolution picture is decoded, a lower capacity of the frame memory 1023 suffices.
Meanwhile, the display system of a moving picture in television broadcast is classified into a sequential scanning system and an interlaced scanning system. The sequential scanning system sequentially displays a picture obtained on sampling the totality of pictures in a given frame at the same timing. The interlaced scanning system alternately displays pictures obtained on sampling pixels in a given frame at different timings from one horizontal line to another.
In this interlaced scanning system, one of the pictures obtained on sampling pixels in a frame at different timings from one horizontal line to another is termed a top field or a first field, with the other picture being termed a bottom field or a second field. The picture containing the leading line in the horizontal direction of a frame becomes the top field, while the picture containing the second line in the horizontal direction of a frame becomes the bottom field. Thus, in the interlaced scanning system, a sole frame is made up of two fields.
With the MPEG2, not only a frame but also a field can be allocated to a picture as a picture compressing unit in order to compress the moving picture signals efficiently in the interlaced scanning system.
If, in the MPEG2, a field is allocated to a picture, the resulting bitstream structure is termed a field structure, whereas, if a frame is allocated to a picture, the resulting bitstream structure is termed a frame structure. In the field structure, a DCT block is constituted by pixels in the field and discrete cosine transform is applied on the field basis. The processing mode of performing field-based discrete cosine transform is termed the field DCT mode. In the frame structure, a DCT block is constituted by pixels in the frame and discrete cosine transform is applied on the frame basis. The processing mode of performing field-based discrete cosine transform is termed the frame DCT mode. In the field structure, a macro-block is constituted from pixels in a field and motion prediction is performed on the field basis. The processing mode of performing motion prediction on the field basis is termed the field motion prediction mode. In the frame structure, a macro-block is constituted from pixels in a frame and motion prediction is performed on the frame basis. The processing mode of performing motion prediction on the frame basis is termed the frame motion prediction mode.
Meanwhile, a picture decoding apparatus, adapted for decoding compressed picture data for the interlaced scanning system, using the third downdecoder shown in the Publication 1, is proposed in, for example, a Publication entitled in xe2x80x9cA Compensation Method of Drift Errors in Scalabilityxe2x80x9d written by N. Obikane, K. Tahara and J. Yonemitsu, HDTV Work Shop ""93. This Publication is hereinafter termed the Publication 2.
Referring to FIG. 4, the conventional picture decoding device, shown in Publication 2, includes a bitstream analyzer 1031, fed with a bitstream obtained on compressing a high resolution picture in accordance with the MPEG2, for analyzing this bitstream, a variable length encoding/decoding unit 1032 for variable length encoding data for allocating codes of lengths corresponding to the data occurrence frequency and for decoding the variable length encoded bitstream, and a dequantizer 1033 for multiplying the respective coefficients of the DCT block with quantization steps. The conventional picture decoding device also includes a decimating inverse discrete cosine transform unit 1034 for decoding a standard resolution picture by e.g., 4xc3x974 inverse discrete cosine transform using only coefficients of low-frequency components of the totality of the coefficients of the DCT block, and an adder 1035 for summing the standard resolution picture processed with decimating inverse discrete cosine transform to a motion-compensated reference picture. The conventional picture decoding device also includes a frame memory 1036 for transiently storing the reference picture and a motion compensation unit 1037 for motion compensating the reference picture stored in the frame memory 1036 to a xc2xc pixel precision.
The decimating inverse discrete cosine transform unit 1034 of the conventional picture decoding device, shown in the Publication 2, performs the inverse discrete cosine transform, using only the coefficients of the low-frequency components of the totality of the coefficients in the DCT block. It is noted that the positions of the coefficients of the frame DCT mode, processed with the inverse discrete cosine transform, differ from those of the field DCT mode.
Specifically, in the field DCT mode, the decimating inverse discrete cosine transform 1034 applies the inverse discrete cosine transform only on the 4xc3x974 of 8xc3x978 coefficients in the DCT block, as shown in FIG. 5. On the other hand, in the frame DCT mode, the decimating inverse discrete cosine transform 1034 applies the inverse discrete cosine transform only on the 4xc3x972+4xc3x972 of 8xc3x978 coefficients in the DCT block, as shown in FIG. 6.
Also, the motion compensation unit 1037 of the conventional picture decoding device performs motion compensation to xc2xc pixel precision, adapted to cope with the field motion prediction mode or with the frame motion prediction mode, based on the information (motion vector) on the motion prediction performed on the high resolution picture. Specifically, while the MPEG2 usually provides that the motion compensation be performed to xc2xd pixel precision, the number of pixels in a picture is thinned out to one-half if a standard resolution picture is to be decoded from a high resolution picture. Thus, the motion compensation unit 1037 performs motion compensation as it sets the pixel precision for motion compensation to xc2xc pixel.
Therefore, the motion compensation device 1037 performs linear interpolation on the pixels of the reference picture stored in the frame memory 1036 as a standard resolution picture to generate pixels to a xc2xc pixel accuracy.
Specifically, the processing for linear interpolation of pixels in the perpendicular direction for the field motion prediction mode and that for the frame motion prediction mode are explained with reference to FIGS. 7 and 8, in which the phase of pixels in the vertical direction is indicated in the perpendicular direction, with the phase of each pixel in a displayed picture being indicated by an integer.
Referring to FIG. 7, the processing for interpolation of a picture motion-predicted in the field motion prediction mode is explained. For a high resolution picture (upper layer), motion compensation is independently performed to a xc2xd pixel precision, from field to field, as shown in FIG. 7A. On the other hand, for a standard resolution picture (lower layer), motion compensation is achieved by generating pixels dephased by xc2xc, xc2xd and xc2xe pixel in the perpendicular direction by linear interpolation in a field based on the pixel of an integer number precision, as shown in FIG. 7B. That is, in the standard resolution picture (lower layer), pixels with xc2xc pixel precision of the top field are generated by linear interpolation based on the pixels of the integer number precision of the top field, while those with xc2xc pixel precision of the bottom field are generated by linear interpolation based on the pixels of the integer number precision of the bottom field. It is assumed for example that the value of a pixel of the top field, having the phase in the perpendicular direction at the 0-position, is a, with the value of a pixel having the phase in the perpendicular direction at the 1-position being b. In this case, the pixel of the top field with the phase in the perpendicular direction of xc2xc is (3a+b)/4, while the pixel of the top field with the phase in the perpendicular direction of xc2xd is (a+b)/2, with the pixel of the top field with the phase in the perpendicular direction of xc2xe being (a+3b)/4.
Referring to FIG. 8, the processing of interpolation of a picture motion-predicted in the frame motion prediction mode is explained. For a high resolution picture (upper layer), interpolation processing is performed across the fields, that is across the bottom field and the top field, as shown in FIG. 8A, with the motion compensation precision being xc2xd pixel precision. For a standard resolution picture (lower layer), motion compensation is achieved by generating pixels dephased by xc2xc, xc2xd and 3/4 pixels in the perpendicular direction, based on the pixels of the integer number precision of two fields, that is the top field and the bottom field, as shown in FIG. 8B. For example, it is assumed that the value of a pixel of the bottom field having the phase in the perpendicular direction ofxe2x88x921 is a, the value of a pixel of the top field having the phase in the perpendicular direction of 0 is b, the value of a pixel of the bottom field having the phase in the perpendicular direction of 1 is c, the value of a pixel of the top field having the phase in the perpendicular direction of 2 is d, and a pixel of the top field having the phase in the perpendicular direction of 3 is e. In this case, the pixels of xc2xc pixel precision, having the phase in the perpendicular direction in a range from 0 and 2, may be found as follows:
The pixel having the phase in the perpendicular direction of xc2xc is (a+4b+3c)/8, while the pixel having the phase in the perpendicular direction of xc2xd is (a+3c)/4. The pixel having the phase in the perpendicular direction of xc2xe is (a+2b+3c+2d)/8, while the pixel having the phase in the perpendicular direction of 5/4 is (2b+3c+2d+e)/8. The pixel having the phase in the perpendicular direction of 3/2 is (3c+e)/4, while the pixel having the phase in the perpendicular direction of 7/4 is (3c+4d+e)/8.
With the above-described picture decoding device, disclosed in the Publication 2, the compressed picture data of the high resolution picture, associated with the interlaced scanning system, can be decoded to standard resolution picture.
However, with the conventional picture decoding device, shown in the above Publication 2, the pixels of the standard resolution picture obtained with the field DCT mode are dephased with respect to the pixels of the standard resolution obtained with the frame DCT mode. Specifically, with the field DCT mode, the phases of the pixels in the perpendicular direction of the respective pixels of the top field of the lower layer are xc2xd, {fraction (5/2)}, . . . , with the phases in the perpendicular direction of the respective pixels of the bottom field of the lower layer being 1, 3, . . . , as shown in FIG. 9. On the other hand, with the field DCT mode, the phases of the pixels in the perpendicular direction of the respective pixels of the top field of the lower layer are 0, 2, . . . , with the phases in the perpendicular direction of the respective pixels of the bottom field of the lower layer being 1, 3, . . . , as shown in FIG. 10. Thus, the pictures with different phases co-exist in the frame memory 1036, thus deteriorating the picture quality of the output picture.
With the conventional picture decoding device, shown in the Publication 2, correction is not made of phase deviations or dephasing of the pixels at the time of the motion compensation with the field motion prediction mode and the frame motion prediction mode resulting in the deteriorated picture quality.
It is therefore an object of the present invention to provide a picture decoding method and a picture decoding device for decoding standard resolution picture data from compressed picture data of the high resolution picture whereby phase deviations of pixels of output moving picture data may be eliminated without detracting from characteristics proper to a picture obtained on interlaced scanning.
In one aspect, the present invention provides a picture decoding apparatus for decoding moving picture data of a second resolution from compressed picture data of a first resolution, obtained on predictive coding by motion prediction in terms of a pre-set pixel block (macro-block) as a unit and on compression coding by orthogonal transform in terms of a pre-set pixel block (orthogonal transform block) as a unit, the second resolution being lower than the first resolution, wherein the decoding apparatus includes first inverse orthogonal transform means for inverse orthogonal transforming an orthogonal transform block of the compressed picture data, orthogonal transformed by an orthogonal transform system (field orthogonal transform mode) associated with the interlaced scanning, second inverse orthogonal transform means for inverse orthogonal transforming an orthogonal transform block of the compressed picture data, orthogonal transformed in accordance with an orthogonal transform system (frame orthogonal transform mode) associated with the sequential scanning, addition means for summing the compressed picture data, inverse orthogonal transformed by the first inverse orthogonal transform means or the second inverse orthogonal transform means, to motion compensated reference picture data, to output moving picture data of the second resolution, memory means for storing moving picture data outputted by the addition means as reference picture data, and motion compensation means for motion compensating the macro-block of the reference picture data stored in the memory means. The first inverse orthogonal transform means inverse orthogonal transforms coefficients of low-frequency components of the orthogonal transform block. The second orthogonal transforming means includes a first picture decoding unit for inverse orthogonal transforming coefficients of the entire frequency components of the orthogonal transform block, separating respective pixels of the inverse orthogonal transformed orthogonal transform block into two pixel blocks associated with interlaced scanning, orthogonal transforming the separated two pixel blocks, inverse orthogonal transforming the coefficients of the low-frequency components of the two orthogonal transformed pixel blocks and synthesizing the inverse orthogonal transformed two pixel blocks to generate an orthogonal transform block. The second orthogonal transforming means also includes third inverse orthogonal transform means for inverse orthogonal transforming the orthogonal transform block of compressed picture data, orthogonal transformed in the frame orthogonal transform mode, addition means for summing the compressed picture data, inverse orthogonal transformed by the third inverse orthogonal transform means, to motion compensated reference picture data, to output moving picture data of the second resolution, memory means for storing the moving picture data outputted by the addition means as reference picture data, and motion compensation means for motion compensating the macro-block of reference picture data stored in the memory means. The first inverse orthogonal transform means includes a second picture decoding unit for inverse orthogonal transforming coefficients of low-frequency components of the orthogonal transform block. If compressed picture data of the first resolution, encoded from the moving picture signals of the interlaced scanning system, are inputted, the moving picture data of the second resolution are decoded by the first picture decoding unit and, if compressed picture data of the first resolution, encoded from the moving picture signals of the sequential scanning system, are inputted, the moving picture data of the second resolution are decoded by the second picture decoding unit.
With this picture decoding device, when the compressed picture data of the first resolution, obtained on encoding the moving picture signals of the interlaced scanning system, is inputted, the coefficients of the entire frequency components of an orthogonal transform block, obtained on orthogonal transform by the frame orthogonal transform mode, are inverse orthogonal transformed and separated into two pixel blocks associated with the interlaced scanning. The separated two pixel blocks are respectively orthogonal transformed and coefficients of the low-frequency components are inverse orthogonal transformed to synthesize the two inverse orthogonal transformed pixel blocks. Also, in the present picture decoding device, if compressed picture data of the first resolution, obtained on encoding the moving picture signals of the sequential scanning system, is inputted, coefficients of the low-frequency components of the orthogonal transform block are inverse orthogonal transformed. The picture decoding device outputs moving picture data of the second resolution lower than the first resolution.
In another aspect, the present invention provides a picture decoding apparatus for decoding moving picture data of a second resolution from compressed picture data of a first resolution, obtained on predictive coding by motion prediction in terms of a pre-set pixel block (macro-block) as a unit and on compression coding by orthogonal transform in terms of a pre-set pixel block (orthogonal transform block) as a unit, the second resolution being lower than the first resolution, wherein the picture decoding apparatus includes first inverse orthogonal transform means for inverse orthogonal transforming an orthogonal transform block of the compressed picture data, orthogonal transformed by an orthogonal transform system (field orthogonal transform mode) associated with the interlaced scanning, second inverse orthogonal transform means for inverse orthogonal transforming an orthogonal transform block of the compressed picture data, orthogonal transformed in accordance with an orthogonal transform system (frame orthogonal transform mode) associated with the sequential scanning, addition means for summing the compressed picture data, inverse orthogonal transformed by the first inverse orthogonal transform means or the second inverse orthogonal transform means, to motion compensated reference picture data, to output moving picture data of the second resolution, memory means for storing moving picture data outputted by the addition means as reference picture data and motion compensation means for motion compensating the macro-block of reference picture data stored in the memory means. The first inverse orthogonal transform means inverse orthogonal transforms coefficients of low-frequency components of the orthogonal transform block, corrects the phase by xc2xc pixel with respect to the vertical direction of the respective pixels of the top field obtained on inverse orthogonal transform, and corrects the phase by xc2xe pixel with respect to the vertical direction of the respective pixels of the top field obtained on inverse orthogonal transform. The second inverse orthogonal transform means includes a first picture decoding unit for inverse orthogonal transforming coefficients of the entire frequency components of the orthogonal transform block, separating the inverse orthogonal transformed orthogonal transform block into two pixel blocks associated with the interlaced scanning, orthogonal transforming the separated two pixel blocks, inverse orthogonal transforming the coefficients of the low-frequency components of the orthogonal transformed two pixel blocks, correcting the phase of the respective pixels of the top field resulting from inverse orthogonal transform by xc2xc pixel, correcting the phase of the respective pixels of the bottom field resulting from inverse orthogonal transform by xc2xe pixel, and synthesizing the phase-corrected top and bottom fields. The second inverse orthogonal transform means also includes third inverse orthogonal transform means inverse orthogonal transforming an orthogonal transform block of the compressed picture data, orthogonal transformed in the frame orthogonal transform mode, addition means for summing compressed image data inverse orthogonal transformed by the third inverse orthogonal transform means to motion compensated reference picture data to output moving picture data of second resolution, memory means for storing the moving picture data outputted by the addition means as reference picture data, and motion compensation means for motion compensating a macro-block of the reference picture data stored in the memory means. The first inverse orthogonal transform means includes a second picture decoding unit for inverse orthogonal transforming the coefficients of low-frequency components of the orthogonal transform block. If compressed picture data of the first resolution, encoded from the moving picture signals of the interlaced scanning system, are inputted, the moving picture data of the second resolution are decoded by the first picture decoding unit and, if compressed picture data of the first resolution, encoded from the moving picture signals of the sequential scanning system, are inputted, the moving picture data of the second resolution are decoded by the second picture decoding unit.
In this picture decoding device, if compressed picture data of the first resolution, obtained on encoding moving picture signals of the interlaced scanning system, are inputted, the coefficients of the low-frequency components of the orthogonal transform block, obtained on orthogonal transform in the field orthogonal transform mode, are inverse orthogonal transformed, and the pixels of the top field, obtained on inverse orthogonal transform, are corrected in phase by xc2xc pixel in the vertical direction, while the pixels of the bottom field, obtained on inverse orthogonal transform, are corrected in phase by xc2xe pixel in the vertical direction. The coefficients of the entire frequency components of the orthogonal transform block, obtained on orthogonal transform in the frame orthogonal transform mode, are inverse orthogonal transformed, and the inverse orthogonal transformed orthogonal transform block is separated into two pixel blocks associated with the interlaced scanning. The separated two pixel blocks are respectively orthogonal transformed and the coefficients of the low-frequency components of the two orthogonal transformed pixel blocks are inverse orthogonal transformed. The pixels of the top field, obtained on inverse orthogonal transform, are corrected in phase by xc2xc pixel in the vertical direction, while the pixels of the bottom field, obtained on inverse orthogonal transform, are corrected in phase by xc2xe pixel in the vertical direction, and the phase-corrected top and bottom fields are synthesized together. In the present picture decoding device, if the compressed picture data of the first resolution, encoded from the moving picture signals of the sequential scanning system, is inputted, coefficients of the low-frequency components of the orthogonal transform block are inverse orthogonal transformed. The picture decoding device outputs moving picture data of the second resolution lower than the first resolution.
In still another aspect, the present invention provides a picture decoding method for decoding moving picture data of a second resolution from compressed picture data of a first resolution, obtained on predictive coding by motion prediction in terms of a pre-set pixel block (macro-block) as a unit and on compression coding by orthogonal transform in terms of a pre-set pixel block (orthogonal transform block) as a unit, the second resolution being lower than the first resolution, wherein, if compressed picture data of the first resolution, encoded from moving picture signals of the interlaced scanning system are inputted, an orthogonal transform block of the compressed picture data, orthogonal transformed in accordance with the orthogonal transform system associated with the sequential scanning (field orthogonal transform mode), is inverse orthogonal transformed, an orthogonal transform block of the compressed picture data, orthogonal transformed in accordance with the orthogonal transform system associated with the sequential scanning (frame orthogonal transform mode), is inverse orthogonal transformed, the inverse orthogonal transformed compressed picture data is summed to motion compensated reference picture data, reference picture data obtained on addition is stored as reference picture data, a macro-block of the stored reference picture data is motion compensated, coefficients of low-frequency components of the orthogonal transform block, orthogonal transformed in the field orthogonal transform mode, are inverse orthogonal transformed, coefficients of the entire frequency components of the orthogonal transform block, orthogonal transformed in the frame orthogonal transform mode, are inverse orthogonal transformed, pixels of the inverse orthogonal transformed orthogonal transform block are separated into two pixel blocks associated with interlaced scanning, the separated two pixel blocks are respectively orthogonal transformed, coefficients of the low-frequency components of the two orthogonal transformed pixel blocks are inverse orthogonal transformed, and the two inverse orthogonal transformed pixel blocks are synthesized to generate an orthogonal transform block, and wherein, if compressed picture data of the first resolution, encoded from the moving picture signals of the sequential scanning system, are inputted, the orthogonal transformed block of the compressed picture data, orthogonal transformed in the frame orthogonal transform mode, is inverse orthogonal transformed, the inverse orthogonal transformed compressed picture data and the motion compensated reference picture data are summed together, moving picture data resulting from the addition are stored as reference picture data, a macro-block of the stored reference picture data is motion compensated and coefficients of the low-frequency components of the orthogonal transform block are inverse orthogonal transformed.
With this picture decoding method, when the compressed picture data of the first resolution, obtained on encoding the moving picture signals of the interlaced scanning system, is inputted, the coefficients of the entire frequency components of an orthogonal transform block, obtained on orthogonal transform by the frame orthogonal transform mode, are inverse orthogonal transformed and separated into two pixel blocks associated with the interlaced scanning. The separated two pixel blocks are respectively orthogonal transformed and coefficients of the low-frequency components are inverse orthogonal transformed to synthesize the two inverse orthogonal transformed pixel blocks. Also, in the present picture decoding device, if compressed picture data of the first resolution, obtained on encoding the moving picture signals of the sequential scanning system, is inputted, coefficients of the low-frequency components of the orthogonal transform block are inverse orthogonal transformed. The picture decoding device outputs moving picture data of the second resolution lower than the first resolution.
In yet another aspect, the present invention provides a picture decoding method for decoding moving picture data of a second resolution from compressed picture data of a first resolution, obtained on predictive coding by motion prediction in terms of a pre-set pixel block (macro-block) as a unit and on compression coding by orthogonal transform in terms of a pre-set pixel block (orthogonal transform block) as a unit, the second resolution being lower than the first resolution, wherein, if compressed picture data of the first resolution, encoded from moving picture signals of the interlaced scanning system are inputted, an orthogonal transform block of the compressed picture data, orthogonal transformed in accordance with the orthogonal transform system associated with the sequential scanning (field orthogonal transform mode), is inverse orthogonal transformed, the inverse orthogonal transformed compressed picture data is summed to motion compensated reference picture data, and wherein, if compressed picture data of the first resolution, encoded from the moving picture signals of the sequential scanning system, are inputted, the orthogonal transformed block of the compressed picture data, orthogonal transformed in the frame orthogonal transform mode, is inverse orthogonal transformed, the inverse orthogonal transformed compressed picture data and the motion compensated reference picture data are summed together, moving picture data resulting from the addition are stored as reference picture data, a macro-block of the stored reference picture data is motion compensated and coefficients of the low-frequency components of the orthogonal transform block are inverse orthogonal transformed.
In this picture decoding method, if compressed picture data of the first resolution, obtained on encoding moving picture signals of the interlaced scanning system, are inputted, the coefficients of the low-frequency components of the orthogonal transform block, obtained on orthogonal transform in the field orthogonal transform mode, are inverse orthogonal transformed, and the pixels of the top field, obtained on inverse orthogonal transform, are corrected in phase by xc2xc pixel in the vertical direction, while the pixels of the bottom field, obtained on inverse orthogonal transform, are corrected in phase by xc2xe pixel in the vertical direction. The coefficients of the entire frequency components of the orthogonal transform block, obtained on orthogonal transform in the frame orthogonal transform mode, are inverse orthogonal transformed, and the inverse orthogonal transformed orthogonal transform block is separated into two pixel blocks associated with the interlaced scanning. The separated two pixel blocks are respectively orthogonal transformed and the coefficients of the low-frequency components of the two orthogonal transformed pixel blocks are inverse orthogonal transformed. The pixels of the top field, obtained on inverse orthogonal transform, are corrected in phase by xc2xc pixel in the vertical direction, while the pixels of the bottom field, obtained on inverse orthogonal transform, are corrected in phase by xc2xe pixel in the vertical direction, and the phase-corrected top and bottom fields are synthesized together. In the present picture decoding device, if the compressed picture data of the first resolution, encoded from the moving picture signals of the sequential scanning system, is inputted, coefficients of the low-frequency components of the orthogonal transform block are inverse orthogonal transformed. The picture decoding device outputs moving picture data of the second resolution lower than the first resolution.
According to the present invention, if the compressed picture data of the first resolution, obtained on encoding moving picture signals of the interlaced scanning system are inputted, coefficients of the low-frequency components of the orthogonal transform block, obtained on orthogonal transform by the frame orthogonal transform mode, are inverse orthogonal transformed and separated into two pixel blocks associated with the interlaced scanning. The two inverse orthogonal transformed pixel blocks are synthesized together. According to the present invention, if compressed picture data of the first resolution, obtained in encoding moving picture signals of the sequential scanning system, are inputted, the coefficients of the low-frequency components of the orthogonal transform block are inverse orthogonal transformed. According to the present invention, moving picture data of the second resolution lower than the first resolution are outputted.
Therefore, it becomes possible with the present invention to eliminate pixel dephasing between the field orthogonal transform mode and the frame orthogonal transform mode, and to improve the picture quality of the sequential scanned picture, without detracting from the properties inherent in the interlaced picture.
According to the present invention, if the compressed picture data of the first resolution, encoded from the moving picture signals of the interlaced scanning system, is inputted, the coefficients of the low-frequency components of the orthogonal transform block, obtained on orthogonal transform in the field orthogonal transform mode, are inverse orthogonal transformed, and the respective pixels of the top field, obtained on inverse orthogonal transform, are corrected in phase by xc2xc pixel in the vertical direction, while the respective pixels of the bottom field, obtained on inverse orthogonal transform, are corrected in phase by xc2xe pixel in the vertical direction, as described above. The coefficients of the entire frequency components of the orthogonal transform block, obtained on orthogonal transform by the frame orthogonal transform mode, are inverse orthogonal transformed. The orthogonal transform block, obtained on inverse orthogonal transform, are separated into two pixel blocks associated with the interlaced scanning, and the two separated pixel blocks are respectively orthogonal transformed. The coefficients of the low-frequency components of the two orthogonal transformed pixel blocks are inverse orthogonal transformed, and the pixels of the top field obtained on inverse orthogonal transform are corrected in phase by xc2xc, while those of the bottom field obtained on inverse orthogonal transform are corrected in phase by xc2xe. The phase-corrected top and bottom fields are synthesized together. According to the present invention, if the compressed picture data of the first resolution, obtained on encoding the moving picture signals of the sequential scanning system, are inputted, coefficients of the low-frequency components of the orthogonal transform block are inverse orthogonal transformed. According to the present invention, moving picture data of the second resolution lower than the first resolution are outputted.
Thus, according to the present invention, it is possible to reduce the processing volume and the recording capacity necessary for decoding, while pixel dephasing of the pixels of the output moving picture data of the second resolution can be eliminated without detracting from the properties inherent in the interlaced picture. That is, output moving picture data can be displayed without filtering processing, while the moving picture data of the second resolution can be improved in picture quality.


A method and apparatus are provided for warning when the amplitude of conversations exceeds certain values. The apparatus includes a microphone and related circuitry which continuously produce a signal related to the amplitude of the conversation while the apparatus is operational. A comparator continuously compares the signal to a pre-set first value and produces an output as long as the signal indicates that the conversation exceeds a certain amplitude. There is a discriminator responsive to the comparator output which provides a discriminator output when the duration of the comparator output exceeds a pre-determined value. The discriminator is connected to an alarm which produces a warning signal when the discriminator provides the discriminator output. There may also be a second comparator which produces a visual signal when the amplitude of the conversation is above an amplitude which may be below the amplitude which activates the alarm.

1. Field of the Invention
This invention relates to devices which provide a warning when sound levels exceed a certain level and, in particular, to devices which warn parties to a conversation when their voice levels become louder than normal.
2. Description of Related Art
When people engaged in a conversation begin to get emotional, their voice levels typically rise. Therefore, the rise in voice levels can be a warning sign that they are becoming angry. Sometimes this becomes a pattern of behavior between closely related persons, including spouses. They begin talking at normal levels, but one or both of them become emotional, their voice levels rise, and this leads to irrational shouting and possibly even violence.
Therefore, it would be desirable to provide some means for monitoring the level of the conversation and providing a warning when the participants in the conversation begin to raise their voices. Providing a suitable warning can break the pattern of behavior leading to disputes.
Various electronic devices have been developed in the past to provide a warning when certain sounds are detected. A well-known example would be intruder alarms, which typically provide an audible alarm when loud noises are detected such as the sound of breaking glass.
Devices have also been proposed which arc specifically adapted to monitor conversation levels. For example, U.S. Pat. No. 4,481,504 to Scott discloses a sound alarm device which listens to the sound level in an enclosure or other area for a predetermined interval of time. Subsequently, it does not listen for another predetermined interval of time. An alarm is sounded if a sound level of a predetermined magnitude is monitored during the first interval. The circuit is designed to omit alarms upon receiving quick, sharp noises such as a cough, hand clap, book dropping or the like. Proposed uses include classroom monitoring. The listening time is 0.5-0.7 seconds, while the off time is 5-6 seconds. Accordingly, it is a matter of probability whether a particular sound will occur during the listening time. Many angry words can be said in 5-6 seconds, and potentially this device would not provide any warning.
Another related device is the classroom noise alarm found in U.S. Pat. No. 4,346,374 to Groff. With this device, two time delay circuits are utilized, one with a 14 second delay and the other with a 5 second delay. When a noise beyond a certain threshold is detected, nothing happens for the next 14 seconds. However, if a loud sound occurs at any time within the next five seconds, then a warning is given by the device. While this may be suitable for classroom monitoring purposes, it renders the device totally unsuitable for avoiding arguments as intended by the present invention. Any prolonged period, particularly one as long as 14 seconds, gives ample opportunity for the parties to raise their voices and engage in verbal fights.
Accordingly, while various devices have been developed in the past, they are not ideally suited for purposes of monitoring conversations and avoiding arguments by giving a warning when voice levels rise.


A method for making a release agent suitable for use in the baking industry, along with examples of the release agent made according to the method. The method comprises heating a food grade oil to between about 100 and about 130 degrees Celsius, then adding water heated to near its boiling point. Agitation is used during the process to convert the mixture to a stable oil-in-water emulsion. A relatively small volume of emulsifying agent may also be added. The preferred embodiment uses a silicone oil, which leaves very little solid residue on the baking pans.

1. Field of the Invention
This invention relates to the field of baking. More specifically, the invention comprises a method for making a composition for releasing baked products from baking pans, along with the composition made by the method.
2. Description of the Related Art
Industrial baking operations involve the repeated use of a set of baking pans. These pans may go through many baking cycles per day. Release agents have been used for many years to enable the easy extraction of the bread from the pans.
Baking release agents must be safe for human consumption, since some of the agent will inevitably be present in the food being baked. Thus, many prior art release agents have used edible oils. Edible oils, typically vegetable oils, have been used in this role for many years. Examples are soybean oil, corn oil, sunflower oil, olive oil, peanut oil, safflower oil, cottonseed oil, and palm oil. Glycerides, as well as other animal fat derivatives, are often included.
The edible oil is generally mixed with water prior to spraying or painting the composition onto the baking pans. A typical composition includes (by volume) about 30% edible oil and about 3% emulsifiers, with the balance being water. These components are typically mixed under ambient conditions (about 25 degrees Celsius). However, under some circumstances they may be mixed at mildly elevated temperatures of approximately 60 degrees Celsius.
The percentages vary according to market requirements and desired shelf life. The prior art formulations have limited stability, meaning that the oil and water will separate over time. They are referred to as an "emulsion," but are in reality more accurately deemed a water-in-oil suspension. The stability of the suspension is limited. Thus, the selection of the percentages may depend in part on how long the product must be stored prior to use.
The selection of the appropriate edible oil is driven in part by market forces, including local availability. Well-refined cotton seed oil is cleaner burning than badly refined sunflower oil, but the price difference may nevertheless favor the sunflower oil.
Mixing in more water increases the viscosity of the prior art formulations, but not the stability. Adequate stability can be achieved by adding the correct type and percentage of emulsifier. However, a certain amount of stability is gained past a certain concentration point due to the viscosity itself, as the molecules that are not linked by the emulsifier cannot float apart.
A highly viscous product eventually becomes too thick to spray. It can be thinned of course, but adding more water will eventually result in far too few links between the molecules and the viscosity will actually decrease, resulting in a low viscosity product with no stability and extremely poor release properties. Once the initial mixing is complete, it is very difficult to add more water to the prior art formulations.
Thus, the baking release agent is typically manufactured in the form in which it will ultimately be applied to the baking pans. The release agent is not made as a "concentrate" designed to be diluted prior to use. The prior art formulations contain about ⅔ water by volume. A purchaser buying such products is paying to transport a large volume (and weight) of water. A large portion of the storage volume is obviously also consumed by the water. It would be desirable to provide a release agent which could be "cut" with water in the bakery just prior to its use. This would result in a substantial reduction in transportation and storage costs.
There is a second inherent problem in the prior art formulations. All the organic oils discussed (cotton seed oil, sunflower oil, etc.) contain a significant amount of carbon. Residual carbon tends to accumulate on the pans over the baking cycles. Vegetable oils undergo significant oxidation and solid deposition at around 180 degrees Celsius. The average baking oven temperature is around 250 degrees Celsius. Thus, carbon fouling is a given in current baking operations.
This carbon fouling becomes a significant problem, as it is quite difficult to remove. Anyone who has cleaned a household bread baking pan is familiar with the problem of carbon deposits. They must often be scraped off in a very laborious fashion.
One solution is simply to discard a set of pans once the carbon deposition becomes significant. As several hundred or several thousand pans may comprise the set, this solution is unsatisfactory. A second solution is to pull the pans out of service and clean them. This option often requires the use of toxic chemicals, such as carbon tetrachloride. Such cleaning operations must generally be conducted in a separate facility equipped to handle such chemicals. Thus, the pan set must be shipped away and taken out of service for days if not weeks. This fact necessitates the use of two or three pan sets for a single baking line. The use of carbon-depositing pan release agents is therefore problematic.
The present invention seeks to address these concerns with the prior art formulations by providing a release agent which (1) can be diluted with additional water just prior to its use; and (2) significantly reduces deposits on the baking pans.

Release agent and method for use in baking applications


A gentle acting blast media comprising glass-like polysaccharide grit suspended in a compressible carrier component.

The present invention relates to carrier-based glass-like polysaccharide abrasive grit and, more particularly, to reusable glass-like, polysaccharide abrasive grit suspended within compressible carrier particles and to methods of using such materials in gently cleaning, polishing, and abrading particularly difficult to remove elastomeric materials from delicate bare and coated surfaces.
Highly abrasive grit materials are well known in the art and are commonly used as blast media in sandblasting operations. Typical applications for highly abrasive grit blast media include cleaning building exteriors and removing surface coatings such as surface oxides on castings. In applications such as these, minor surface damage caused by the blasting operation is not of concern and abrasive grit which is relatively aggressive in removing surface coatings may be used. However, other applications exist in which the surface damage which results from the use of traditional highly abrasive grit blast media is unacceptable.
One example of a particularly sensitive application for abrasive grit materials is in the military and commercial aircraft industry. The removal of paint from exterior aircraft surfaces is periodically required for cosmetic purposes and to allow technicians to inspect the underlying metal and other surfaces for corrosion. However, aircraft surfaces clad with aluminum or made of composite materials are particularly sensitive to damage caused by conventional blast media.
Aircraft surfaces are typically clad with pure aluminum, which is softer than the underlying aluminum alloy the cladding is designed to protect. The soft layer of aluminum cladding is particularly susceptible to damage and erosion by traditional blast stripping operations, which can leave a very rough and unacceptable surface finish. Such damage to the aluminum cladding can result in premature corrosion that could necessitate the replacement of whole sections of an aircraft""s skin. Furthermore, methods used for stripping aluminum clad structures may not be acceptable for structures made of composite materials such as fiberglass, graphite and aramid (Kevlar(copyright)), which are even more sensitive than aluminum to damage from blast media.
Prior art blast media used in aircraft applications include synthetic hard abrasive grit materials composed of thermosetting resins such as epoxy resin, urea resin, unsaturated polyester resin, alkyd resin, or harder resins such as polystyrene, polycarbonate or acrylic. Although less aggressive than conventional blast media, plastic blast media are sufficiently aggressive when used in paint stripping applications that skilled handling by trained personnel is required in order to avoid permanent damage to aircraft skins. Moreover, even skilled use of such blast media can result in reduced fatigue life, increased crack propagation and high surface roughness to the extent that such media is unacceptable for repeated use on aluminum clad or composite structures.
Gentler methods of paint removal involve the use of chemical solvents such as methylene chloride or phenol. However, health dangers and stringent environmental laws associated with the use of such volatile organic chemicals in paint stripping operations has made the use of such solvents impractical and undesirable. In some cases, companies have postponed aircraft exterior surface maintenance programs rather than attempt to deal with the regulations and costs associated with chemical stripping.
A series of related patents, owned by the assignee of the present invention, describe entirely new types of less destructive abrasive grit material. U.S. Pat. Nos. 5,066,335; 5,360,903; 5,367,068; 5,780,619; and 6,159,257 describe glass-like polysaccharide abrasive grit particles made from conventional starches, such as wheat and corn starches. These abrasive grit particles comprise a particulate polysaccharide glass-like solid in which moisture is occluded within the interstices of a matrix of polysaccharide molecules. The polysaccharide molecules may be partially cross-linked to increase the complexity of the matrix of polysaccharide molecules within the glass-like polysaccharide grit particles.
The glass-like polysaccharide abrasive grit compositions described in these patents enjoy several advantages over the prior art abrasive grit. Polysaccharide abrasive grit particles are less aggressive than plastic blast media, thereby avoiding the damage to aluminum clad structures caused by traditional blast stripping methods. As a result, use of polysaccharide abrasive grit is more forgiving and requires less skill in handling than plastic blast media. Use of polysaccharide abrasive grit allows aluminum clad aircraft skins to be subjected to repeated paint-and-strip operations. This is in contrast to plastic blast media which some aircraft manufacturers limit in paint stripping operations to only once in the lifetime of an aircraft, due to the potential damage to the aircraft""s surface. Furthermore, polysaccharide abrasive grit particles are acceptable for use with both aluminum and composite materials, allowing for complete nose-to-tail paint stripping operations of aircraft. Finally, abrasive grit particles made of polysaccharides such as wheat and corn starch are non-toxic and biodegradable, reducing the health risks and disposal problems often associated with paint stripping operations. These advantages over other methods have allowed the glass-like polysaccharide starch grit particles described in these patents to gain wide acceptance in the industry for removing coatings from aircraft.
Additionally, the polysaccharide grit particles described in the aforementioned U.S. Pat. No. 6,159,257 have an additional advantage in that they maintain their integrity particularly well when placed in contact with liquid water and retain their usability as blast media particularly well after they are dried. In addition, the abrasive blast media described in this patent facilitate detection and clean up of particles that infiltrate the joints and seams present in blast-treated surfaces.
Certain applications relating to cleaning, polishing, and abrading delicate surfaces found in aircraft and elsewhere call for a blast media which is particularly gentle-acting. Such a gentle-acting blast media should produce cleaning, polishing, and abrading results as rapidly and efficiently as the polysaccharide grit media described above. If the previously patented polysaccharide grit media could be modified to achieve such a result, the art would be substantially advanced.
Additionally, the effective removal of certain elastomeric coatings from delicate substrates without damage to the substrate presents a particular challenge. Examples of such elastomeric coatings include, from the aerospace industry, the following: high strength aircraft integral fuel tank sealant (polysulfide); high strength, high temperature aerospace grade acetoxy paste sealants (silicone rubber); rapid cure primeness aircraft integral fuel tank sealant (alcohol/solvent-based); low density, high temperature aircraft integral fuel tank sealant (polysulfide); vertical surface sealant and bonding (silicone rubber); fuel and solvent resistant paste adhesive sealant (fluorosilicone); and medium density ablator/insulator aircraft thermal protection coating (filled elastomeric silicone (MA-25)). Such elastomeric coatings have Shore A hardness of about 40 to 60. A gentle-acting abrasive particle that would remove such materials with a Shore A hardness of about 40 to 60 without damaging delicate substrates would be a welcome addition to the armamentarium of abrasive grit products.
Finally, polysaccharide grit would be usable in cleaning and abrading interior surfaces of enclosed vessels such as the inner walls of the fuel tanks, for removing elastomeric sealants while leaving the underlying protective primer coat intact, it could be insured that the grit particles will be easily and completely removed from the vessels when the cleaning and abrading is complete. Thus, if the polysaccharide grit particles could be modified to float out on water or other solvents used to rinse such vessels, another substantial advance in the art would be at hand.
It is an object of the present invention to provide a particularly gentle-acting blast media.
A further object of the present invention is to provide a gentle-acting blast media that can effectively remove materials having a Shore A hardness of about 40 to 60 from delicate substrates without damaging the substrate.
Yet another object of the invention is to provide a gentle-acting blast media in which dust created during use of the media is minimized.
A further object of the invention is to provide a gentle-acting blast media that has substantially less rebound energy than conventional media upon impacting a surface being treated, thereby facilitating collection of the media.
A still further object of the invention is to provide gentle-acting carrier-based blast media in which the carrier component remains substantially intact after numerous blasting cycles.
Another object of the invention is to provide carrier-based gentle-acting blast media in which the carrier component breaks down as the blast process proceeds, exposing additional underlying blast media.
A still further object of the present invention is to provide a glass-like polysaccharide abrasive grit suspended or securely attached in a carrier component comprising compressible closed or open cell matrices.
Another object of the present invention is to provide gentle-acting blast media which floats in water or other solvents to facilitate removal of the media particularly after use in the interior of enclosed vessels.
These and other objects of the invention will be better understood, by one skilled in the art, by having reference to the appended drawings and following description.
The invention thus comprises gentle-acting blast media comprising carrier-based glass-like polysaccharide abrasive grit particles which exhibits the above-described desirable characteristics. The glass-like polysaccharide abrasive grit is described in the aforementioned U.S. Pat. Nos. 5,066,335; 5,360,903; 5,367,068; 5,780,619; and 6,159,257, which are incorporated by reference. The carrier may be any suitable compressible material capable of being compressed when it strikes a surface between about 5% and 95% (preferably between about 50% and 90%) of its original cross-section and returning generally to its original dimension. Such carriers include, among others, compressible closed or open celled matrices in which the glass-like polysaccharide abrasive grit can be suspended or secured. Particularly preferred compressible materials are described in U.S. Pat. Nos. 5,529,589; 5,243,470; 5,256,703; and 5,146,716, which are incorporated by reference. To the extent that these references generally teach methods for suspending and securing abrasives, these teachings will apply as well to the suspension or securement of the glass-like polysaccharide abrasive grit of this invention in the carrier component. Additionally, where water is present in the carrier component or in the process used in suspending or securing the grit in the carrier, it is preferred that the polysaccharide material of the aforesaid U.S. Pat. No. 6,159,257 be used.
In one embodiment, the carrier component of the present invention comprises a compressible lattice structure formed by a plurality of interconnected fibrous strands forming open or closed cells. In this embodiment, a plurality of discrete glass-like polysaccharide abrasive grit particles are present along with an adhesive component which attaches the discrete glass-like polysaccharide abrasive grit particles to the carrier component. This compressible lattice structure facilitates gentle contact of the discrete grit particles with the surface to be treated while resisting wear of the carrier component during use, so that the carrier component remains substantially intact after numerous blast cycles. The resulting carrier-based blast media has the ability to be propelled against a surface to be treated to produce minimal surface damage while limiting the creation of dust or fine particulate matter. The carrier component used in this embodiment of the invention and its manufacture are described in U.S. Pat. No. 5,529,589, the disclosure of which is incorporated by reference.
Another carrier for producing a gentle-acting compressible blast media comprises a lipophilic/hydrophilic, flexible, open cell water-foamable polymeric material such as a polyurethane-Wollastonite and/or staurolite interpolymer obtained by a chemical reaction under foam forming and interpolymer conditions, as described in detail in U.S. Pat. Nos. 5,243,470, 5,256,703, and 5,146,716, the disclosures of which are also incorporated by reference.
The gentle-acting carrier-based blast media of the present invention includes a carrier component having a plurality of glass-like polysaccharide abrasive grit, securely bonded or fastened thereto throughout the carrier material and optimally on the carrier surface by a suitable adhesive, resin, binder or the like. The glass-like polysaccharide abrasive grit particles may be bonded or fastened to the compressible carrier component secured at the intersection of fibers forming the lattice structure of the carrier component. It is to be appreciated, however, that the glass-like polysaccharide abrasive grit particles bonded or fastened to the carrier component may be secured however practical at any location within or on the surface of the carrier component.
The synergetic effects of suspending or attaching glass-like polysaccharide abrasive grit particles to the compressible carrier component will be evident by adding by weight from as little as 5% to as much as 95% by weight of the polysaccharide particles to the carrier. The optimal percentage of carrier versus grit will be dependent on the application, since increasing the concentration of grit in the carrier increases aggressiveness and dust production when the blast media is used. For example, the preferred range for removing elastomeric coatings and certain hard shell coating systems is 50% to 90% by weight glass-like polysaccharide abrasive grit particles.
The mesh size of the abrasive grit added to the carrier can vary between 8 and 120 mesh (U.S. standard). The preferred range of polysaccharide grit mesh sizes for removing elastomeric coatings and certain hard shell coatings is 16 to 80 mesh size. The compressible carrier particles should typically have an average axial length or diameter ranging from about 1 to 12 mm, with particle sizes between about 2 to 8 mm currently being preferred.
The method of manufacturing the above-noted carrier component, which is described in detail in U.S. Pat. No. 5,529,589, generally comprises providing a waste product or material, for example, a by-product from the die-cutting of fibrous packaging material, which is ground up into a plurality of fibrous particles ranging in length from approximately xc2xcxe2x80x3 (0.635 mm) to xe2x85x9xe2x80x3 (0.318 mm). The overall shape and dimensions of the ground-up particles are not critical as long as the particles are sufficiently large in size to facilitate attachment or bonding of the polysaccharide grit.
The ground fibrous material sprayed or otherwise coated with an adhesive binder in a mixing device. Once the ground fibrous material and the applied adhesive are thoroughly mixed and the adhesive becomes sufficiently tacky, the desired quantity of polysaccharide grit is added, mixed in and allowed to set for a predetermined period of time appropriate to the adhesive binder and the ambient conditions, e.g. a few seconds to three (3) minutes.
If it is desirable for the carrier component to be slightly softer or more absorbent, a prepolymer can be added to the mixed components and reacted with steam and/or hot water. Since these prepolymers are moisture activated materials, when the prepolymer is exposed to steam and/or hot water, the moisture functions as a catalyst to speed up the reaction of the prepolymer with the fibrous carrier 4 and the added glass-like polysaccharide abrasive grit particles (preferably as in U.S. Pat. No. 6,159,257) to form a plurality of particles each incorporating a substantially uniform mixture of the ground carrier component, the abrasive component(s), and/or the prepolymer. The mixture is thereafter allowed to react for a necessary period of time, e.g. a few minutes, depending on the type of the prepolymer employed and/or the amount of steam. Finally, the mixture is conveyed to and processed by a second grinder. The prepolymer typically fills and occupies the space between adjacent glass-like polysaccharide abrasive grit abrasive particles of each particle and is bonded or otherwise attached to such components to form a generally unitary structure.
The carrier component as described above comprises a plurality of strands, threads and the like which are interwoven, intermeshed, and/or attached with one another to form an open lattice support structure. The carrier component is very porous and this tends to increase the flowability of the carrier-based blast media through suitable blasting equipment. The lattice structure also tends to generally uniformly space the glass-like polysaccharide abrasive grit abrasive grit particles from one another.
Another possible carrier, component comprises a compressible lipophilic/ hydrophilic, flexible, open cell water-foamable polymeric materials such as a polyuretbane-Wollastonite and/or staurolite interpolymer as described in U.S. Pat. Nos. 5,243,470, 5,256,703, and 5,146,716. The term xe2x80x9cinterpolymerxe2x80x9d is used in these patents to indicate that the polyurethane is bound to the polysaccharide grit by a bonding mechanism which may be hydrogen bonding, chemical bonding, complex, or adsorptive or absorptive bonding, rather than being merely an admixture of the components. The bonding can be combinations of the above. The interpolymer of the invention can be for example the cured product of a mixture of substantially linear isocyanate capped polyether polyol prepolymer, having an average functionality of less than 2, a cell formation regulating amount of surfactant and water.
The above-referenced lipophilic flexible open cell urethane-Wollastonite interpolymer is obtained by reacting, under interpolymer and urethane forming conditions, (a) a substantially linear isocyanate capped prepolymer having a reactive functionality of less than 2 mixed with (b) an aqueous solution comprising Wollastonite and surfactant. Preferably the interpolymer has an active functionality of from about 1.3 to about 1.9, and more preferably of from about 1.5 to about 1.8. The linear polyether polyol is derived from a difunctional, active hydrogen-containing initiator and one or more 1,2-epoxides which will impart hydrophilic properties to the resulting polyol, or from ethylene glycol and ethylene oxide or prepared from a substantially linear polyether polyol.
As explained in the above-referenced patents, the prepolymer may be prepared with a toluene disocyanate (TDI); the acrylic is preferably an acrylic latex, the gypsum may be US Hydrostone gypsum and the surfactant is a preferably non-ionic surface active agent with from about 0.5 to about 5.0 percent surface active agent by weight of prepolymer added to the interpolymer, preferably from about 1.0 to about 2.0 percent surface active agent by weight of prepolymer. Generally from about 6.5 to about 400 moles of water are reacted with the prepolymer, preferably from about 20 to about 200 moles of water. This differs from other urethanes where stoichiometric amounts of water are used.
The prepolymer is chemically reacted with a large molar excess of water. The water is provided as an aqueous solution containing other components, such as Wollastonite and/or Staurolite and a surfactant which are all readily dispersed or soluble within the water. If desired, the prepolymer and/or the aqueous mixture can contain one or more other active ingredients. For example, an activated carbon or aqueous mixture for absorption of specific contaminant materials may also be included in the aqueous phase to be mixed with prepolymer.
A variety of different compressible materials having different lattice structures will function very well as the above described carrier components. For example, lattice structures made from urethane, nylon, polypropylene and polyvinyl alcohol should work well. Also, the lattice structure may be chosen so that it does not readily break down upon impacting the surface being cleaned, polished or abraded while still exposing the glass-like polysaccharide abrasive grit. Such a lattice structure that remains substantially intact after a plurality of blasting cycles will minimize the amount of fiber waste generated by using the fiber media according to the present invention. Alternatively, the lattice may be one which wears during use, exposing additional underlying polysaccharide grit for treating the surface.
The porosity of the carrier will facilitate suspending or securing the glass-like polysaccharide abrasive grit while promoting uniformed dispersion of the grit within the carrier. Any glass-like polysaccharide abrasive grit carried on the surface of the carrier is available for direct contact with the surface to be treated. Due to the compressibility of the lattice structure of the carrier, the grit located below the surface will be able to contact the surface being treated as the carrier compresses and flattens out upon impacting the surface being cleaned, polished or abraded. The above and other characteristics of the carrier component result in a media which gently cleans, polishes or abrades at an acceptable cutting rate and in a way not know in the prior art.
The carrier may be two dimensional, e.g. planar, or it may be three dimensional. In addition, the lattice structure may have a uniform repeating pattern, similar to a screen, or it may have an arbitrary or random arrangement of interconnected fibers.
Bactericide or fungicide can also be included in the carrier to prevent bacterial or mold growth.
The media of the invention can be used to clean oil or contaminants from industrial equipment such as in machine shops, blow molds, paper mills, ducts, manufacturing plants, paint, restaurants etc. The polysaccharide grit of the aforementioned U.S. Pat. No. 6,159,257 is presently preferred for such applications.
Although the polysaccharide grit is incorporated into larger carrier component particles, the grit still has a substantially unaffected surface profile. This allows the grit to impact the surface to be treated and achieve maximum penetration into that surface.
Finally, if the media is used to blast without a nozzle, larger compressible carrier component particles could be used.

Gentle-acting carrier-based glass-like polysaccharide abrasive grit


A work machine, preferably a mobile work machine, has an attachment device, in particular a trench cutter. The attachment device has at least two adjustable hydraulic motors for driving independent, individually controllable loads. The hydraulic supply of the adjustable hydraulic motors takes place by a hydraulic drive unit arranged externally from the attachment device, in particular by a drive unit of the work machine. The at least two adjustable hydraulic motors of the attachment device are connected to a constant pressure network provided by the hydraulic drive unit.

The invention relates to a work machine having an attachment device, in particular a trench cutter, wherein the attachment device comprises at least two adjustable hydraulic motors for driving independent, individually controllable loads, and wherein the hydraulic supply of the hydraulic motors takes place by a hydraulic drive unit arranged external to the attachment device, in particular by a hydraulic drive unit of the work machine.
Certain work machines in the construction industry can be flexibly equipped—depending on their deployment—with different installation devices, in particular in the sector of special civil engineering. Examples for different attachment devices are vibrators, drill drives, or trench cutters. The latter serve to excavate trenches in the earth to erect a concrete wall. A mobile work machine such as an excavator, preferably a cable-operated excavator, that receives the trench cutter via the cantilever or excavator arm and controls it accordingly preferably serves as the work machine. Further work machines that can be considered are special civil engineering machinery or also cranes.
A known excavation process with the aid of a so-called trench cutter is schematically shown in FIG. 1. The cut trench 1 is filled with a support liquid 2 during its creation and the excavation tool in the form of the trench cutter is sunk therein. The support liquid 2 filled in primarily has the task of preventing the collapse of the wall being created and thus to obtain the desired geometry of the trench 1. Conventional trench cutters such as shown in FIG. 1 comprise a guide frame 3 at whose lower end one or more driven cutting wheels 4 are arranged. In addition, the trench cutter optionally comprises one or more pumps 5 to convey the excavated material to the surface. The cutter is suspended at a suitable work machine such as a cable-operated excavator and is supplied with energy by a drive unit of the work machine or of the cable-operated excavator located on the surface via hydraulic supply lines.
In cutting operation, the cutting wheels 4 detach and comminute the material to be excavated (sand, soil, crushed rock, rock, etc.) and mix it with the support liquid 2 introduced to the trench 1. The resulting mixture is supplied to the suction opening 6 of the pump 5 and is conveyed by it for further processing on the surface. The individual drives of known cutting systems are hydraulically operated as a rule. Examples for known hydraulic circuits for driving the hydraulic motors of the trench cutter can be seen from FIGS. 2a and 2b.
Hydraulic motors 10 having adjustable displacement volumes are used as rotary drives of the cutting wheels 4 and of the pump 5 to be able to react to different conditions of use by changing the achievable speed and the drive torque. The energy supply of the hydraulic motors 10 is provided via a drive unit 11, 12 of the piece of working equipment. In accordance with FIG. 2a, it can here be a piece of equipment 11 having an open hydraulic circuit or, in accordance with FIG. 2b, a piece of equipment 12 with a closed hydraulic circuit. The existing solutions provide controlling the quantity and the direction of the oil flow from the drive unit 11, 12 to the consumer 10 with hydraulic components that are located on the surface and are in particular a component of the drive units 11, 12 by an adaptation of the conveying quantity. An individual operation pressure for each single consumer 10 results in dependence on the load.
Very different operating pressures result with a given speed of the hydraulic drives 10 depending on the load state. The individually used pump 13 in the unit 11 always has to deliver the highest present pressure level. The pressure difference from the low load drives 10 has to be reduced in the hydraulic control block 14 where it arises as thermal energy and is not further usable. To improve the efficiency here, a plurality of mutually separate hydraulic circuits are used in the drive unit 12—as shown in the embodiment of FIG. 2b—advantageously with a respective pump 13a, 13b, 13c each for each consumer 10.
It is further disadvantageous in the previous solution concepts that they require a high number of hydraulic lines between the attachment tool and the drive unit 11, 12. They are led from the respective drive unit 11, 12 to the cutter via a complex hose winch system 15. These hydraulic lines are at greatly varying operating pressures independently of one another. This constant variance of the operating pressures results due to the structure in deformations and relative movements between the individual hydraulic lines and as a consequence in increased wear and damage which has to be dealt with using complex technical measures.
In addition, the cutting system in accordance with FIGS. 2a, 2b provides that the control 16 of the cutter communicates with the control 17 of the drive unit 11, 12 to coordinate the power feed by the drive unit 11, 12 and the setting of the consumers 10 with one another. This makes increased demands on the compatibility of the control 17 of the drive unit 11, 12 since it does not as a rule have to be compatible with a plurality of attachment devices that do not necessarily originate from the same manufacturer of the work machine.

Work machine having adjustable hydraulic motors


Disclosed is a method and an apparatus enabling water-conditioning processes to be performed using a heater initially equipped with an aquarium tank for the purpose of supplying heat. Instead of allowing heat to propagate globally, reactor housing is introduced in the tank enclosing the heater so as to form a localized hot zone. The temperatures of the hot zone are maintained at high degrees sufficient to initiate various water-conditioning processes with efficiency, including alga control, ammonia control, water-hardness control, and sterilization. The construction of the reactor housing is simple and inexpensive, and its geometry is compatible to a heater which can be purchased commercially. In short, multiple functions are added to a heater installed in an aquarium, performing water-conditioning processes in addition to the basic task of supplying heat, allowing water quality of the aquarium to be improved and maintained.

1. Field of Invention
This invention is directed to a method and an apparatus to obtain water conditioning utilizing a localized hot zone. By making use of a conventional heater installed with an aquarium tank a localized hot zone can be established, making it possible to perform other tasks to improve and maintain water quality of the aquarium, including water softening, decreasing ammonia content, alga controlling, and sterilizing.
2. Prior Art
A heater is generally used in an aquarium tank to raise water temperatures to relatively high degrees so as to keep the enclosed fish and invertebrates happy and healthy. More precisely, the prior art considers the heater to be an instrument whose function is merely to supply heat to an aquarium tank. Other tasks required under water-conditioning purposes are deemed by the prior art as irrelevant to the role of a heater, such as water softening, alga control, sterilization, and the de-ammonia process. Even by employing other instruments available in the current markets the aforementioned water-conditioning tasks are nevertheless difficult to perform. To lower total hardness of tank water ion-exchange resins may be used, but at elevated costs. To sterilize water UV irradiation can be employed, requiring care to be exercised at the same time. To obtain alga control one has to lower the nutrition level in the water plus reducing the lighting conditions. The only efficient way to decrease the ammonia content in an aquarium tank is to insist on frequent water change. Ozone may be used to perform both alga control and sterilization, however, excessive dose can be harmful to fish as well as to humans. Simple, efficient, and economic instrumentation performing water conditioning tasks in an aquarium tank is thus still lacking by the prior art.
Accordingly, it is an object of the invention to address one or more of the foregoing disadvantages or drawbacks of the prior art, and to provide such an improved method and apparatus to obtain water conditioning via the use of a heater. That is, water-conditioning tasks can be performed simultaneously by using the same heater instrument supplying heat to the aquarium tank. By establishing a localized hot zone, water conditioning processes, such as to soften water hardness, to sterilize, to reduce the ammonia content, and to control the population of microalgae, can be thereof initiated, thereby rendering an effective use of the heater instrument.
Other objects will be apparent to one of ordinary skill, in light of the following disclosure, including the claims.
In one aspect, the invention provides a method which sets up a localized hot zone in an aquarium via the use of a heater contained in the prior art. The temperatures at hot zone reach barely the boiling points of water, thereby enabling a plurality of water-conditioning processes to take place with efficiency and effectiveness, including alga control, sterilization, ammonium de-ionization, and water softening.
In another aspect, the invention discloses an apparatus which allows a heater instrument contained in the prior art to provide additional services to an aquarium tank, besides performing the basic task supplying heat to the aquarium. A localized hot-zone is thus established in the aquarium so as to enable the other beneficial processes on water conditioning to occur, such as sterilization, water softening, ammonium de-ionizing, and alga control.

Method and apparatus of obtaining water conditioning utilizing localized hot zone