1. A multivalued information reproducing apparatus comprising:
a light source which emits linear polarized light having a prescribed polarization direction;
a first optical system which generates first linear polarized light and second linear polarized light that have different polarization directions using the linear polarized light which is emitted from the light source and makes the two polarized lights input to an optical recording medium in which the polarization directions of recording light are recorded as multivalued information;
a second optical system which has a transmission light selecting element that selectively transmits emission light generated when the light passes the first optical system is input to the optical recording medium and by which the emission light that passes the transmission light selecting element is directed to a photo detecting portion in a state where first emission light that has a same polarization direction as the first linear polarized light and second emission light that has a same polarization direction as the second linear polarized light are separated; and
a polarization direction judging portion which judges the polarization direction that is recorded in the optical recording medium based on amount of light of the first emission light and amount of light of the second emission light that are obtained by the photo detecting portion.
2. The multivalued information reproducing apparatus according to claim 1, wherein the first optical system makes the first linear polarized light and the second linear polarized light input simultaneously to the optical recording medium.
3. The multivalued information reproducing apparatus according to claim 1, wherein the first optical system makes the first linear polarized light and the second linear polarized light input to the optical recording medium with a time interval.
4. The multivalued information reproducing apparatus according to claim 1, wherein the first linear polarized light and the second linear polarized light have the polarization directions that are orthogonal with each other.
5. The multivalued information reproducing apparatus according to claim 2, wherein the first optical system includes:
a first light separating element which separates the linear polarized light that is emitted from the light source into two lights;
a polarization direction converting element which is arranged so as to converts the polarization direction of at least one of the two lights that are separated by the first light separating element and to make one of the two lights be the first linear polarized light and the other of the two lights be the second linear polarized light;
an optical axis aligning element which aligns the optical axes of the first linear polarized light and the second linear polarized light; and
a light shielding element which is arranged in front of the optical axis aligning element to shield a part of the respective lights such that the first linear polarized light and the second linear polarized light are not superimposed when the optical axes of them are aligned.
6. The multivalued information reproducing apparatus according to claim 2, wherein the second optical system includes a second light separating element which separates the first emission light and the second emission light into different light paths, and the photo detecting portion is composed of two photo detectors that are arranged in different positions.
7. The multivalued information reproducing apparatus according to claim 2, wherein the second optical system directs the first emission light and the second emission light to the photo detecting portion with a time interval.
8. The multivalued information reproducing apparatus according to claim 2, wherein the first linear polarized light and the second linear polarized light have the polarization directions that are orthogonal with each other.
9. The multivalued information reproducing apparatus according to claim 3, wherein the first optical system includes a liquid crystal element which contains a liquid crystal and two transparent electrodes to sandwich the liquid crystal.
10. The multivalued information reproducing apparatus according to claim 3, wherein the first linear polarized light and the second linear polarized light have the polarization directions that are orthogonal with each other.
11. The multivalued information reproducing apparatus according to claim 5, wherein the second optical system includes a second light separating element which separates the first emission light and the second emission light into different light paths, and the photo detecting portion is composed of two photo detectors that are arranged in different positions.
12. The multivalued information reproducing apparatus according to claim 5, wherein the second optical system directs the first emission light and the second emission light to the photo detecting portion with a time interval.
13. The multivalued information reproducing apparatus according to claim 7, wherein the second optical system includes a liquid crystal element which contains a liquid crystal and two transparent electrodes to sandwich the liquid crystal, and a polarizing plate.
14. The multivalued information reproducing apparatus according to claim 12, wherein the second optical system includes a liquid crystal element which contains a liquid crystal and two transparent electrodes to sandwich the liquid crystal, and a polarizing plate.
15. A multivalued information reproducing method to reproduce an optical recording medium on which multivalued information is recorded, comprising:
a first step to irradiate simultaneously or with a time interval first linear polarized light and second linear polarized light which have different polarization directions on the optical recording medium in which the polarization directions of recording light are recorded as multivalued information;
a second step to extract only emission light which is generated from the optical recording medium by the irradiation of the first step;
a third step to direct the emission light that is extracted by the second step to a photo detecting portion in a state where first emission light that has a same polarization direction as the first linear polarized light and second emission light that has a same polarization direction as the second linear polarized light are separated; and
a fourth step to judge the polarization direction that is recorded in the optical recording medium based on amount of light of the first emission light and amount of light of the second emission light that are obtained in the photo detecting portion by the third step.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A grocery listing system comprising:
a. a sheet of lightweight, rigid, magnetic receptive material about 12 cm high, 12 cm wide and about 1.5 mm thick and,
b. a magnetic strip about 10 cm wide, 1.5 cm high and about 1.5 mm thick mounted to the reverse side of said sheet at a spaced location and,
c. a plurality of magnets about 1.2 cm high, 2.5 cm wide, 1.5 mm thick, with grocery item nouns printed thereon and,
d. a plurality of magnets about 1.2 cm high, 2.5 cm wide, 1.5 mm thick with adjectives printed thereon and,
e. a plurality of magnets about 1.2 cm high, 2.5 cm wide, 1.5 mm thick with numbers printed thereon and,
e. a plurality of magnets about 1.2 cm high, 2.5 cm wide, 1.5 mm thick with common household activity verbs of printed thereon and,
f. a plurality of magnets about 1.2 cm high, 2.5 cm wide, 1.5 mm thick with manufacturer’s logos printed thereon and,
g. a plurality of magnets about 1.2 cm high, 2.5 cm wide, 1.5 mm thick with a blank space allowing a user to write a description of a desired household item thereon.
2. A method for using a grocery listing system, comprising:
a. providing a list system of the type comprising a sheet of magnetic receptive material having a magnetic strip mounted on the reverse side thereof,
b. means for magnetically attaching said sheet to a refrigerator door,
c. providing a multitude of magnets with words printed thereon,
d. means for magnetically attaching said magnets to said refrigerator door,
e. means for magnetically attaching said magnets to said sheet,
f. arranging said magnets on said sheet so that said magnets form word groups indicating specific qualities and quantities of items to be purchased andor word groups indicating common household activities to be performed,
g. disposition of any of said word magnets on said sheet being indicative of a reminder to purchase a product or perform some task in conjunction with a shopping trip,
h. transfer of any of said word magnets to the said sheet being indicative of a request to purchase or perform some task in conjunction with a shopping trip,
i. means for removal and transport of said sheet with said word magnets magnetically attached from said refrigerator door,
j. means for reviewing said sheet and said magnets while on a shopping trip,
k. means to remove said magnets from said sheet upon return from a shopping trip,
whereby someone can easily keep, compile, carry, refer to, and reuse said grocery listing system.