Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
165 words
An optical pick-up device which is capable of letting the laser beam emitted from a light emitting element focus through an optical system on a recording medium, also of focusing a reflected beam from said recording medium through said optical system on a photo-detecting element, and also capable of detecting a tracking error signal and a focusing error signal from the output signals of said photo-detecting element, characterized in that there is arranged a diffracting element before said light emitting element and said photo-detecting element, the region on said diffracting element is divided into two sub-regions by a parting line substantially perpendicular to the track direction, in one of these sub-regions there is formed a diffraction grating for separating two sub-spots in two directions from the laser beam emitted from the light emitting element for applying the so-called 3-spot method, and in the other sub-region there is arranged a diffraction grating causing the reflected beams from the recording medium focused on said photo-detecting element respectively.
Claim 2
Dependent Claim
165 words
An optical pick-up device which is capable of letting the laser beam emitted from a light emitting element focus through an optical system on a recording medium, also of focusing a reflected beam from said recording medium through said optical system on a photo-detecting element, and also capable of detecting a tracking error signal and a focusing error signal from the output signals of said photo-detecting element, characterized in that there is arranged a diffracting element before said light emitting element and said photo-detecting element, the region on said diffracting element is divided into two sub-regions by a parting line substantially perpendicular to the track direction, in one of these sub-regions there is formed a diffraction grating for separating two sub-spots in two directions from the laser beam emitted from the light emitting element for applying the so-called 3-spot method, and in the other sub-region there is arranged a diffraction grating causing the reflected beams from the recording medium focused on said photo-detecting element respectively.
Claim 3
Dependent Claim
56 words
An optical pick-up device according to claim 1, wherein there are provided two groups of photo-detecting elements and said two groups of photo-detecting elements are positioned at two points where the two first-order diffracted beams of the reflected beam from said recording medium diffracted by the aforementioned other sub-region of said diffracting element are focused respectively.
Claim 4
Dependent Claim
44 words
An optical pick-up device according to claim 1, wherein the so-called blaze property is imparted to said aforementioned other sub-region of said diffracting element, and there is positioned a group of photo-detecting elements where the first-order beam of higher in optical intensity is focused.
Claim 5
Dependent Claim
42 words
An optical pick-up device according to claim 1, wherein the aforementioned other sub-region of the diffracting element is of such composition that said diffraction grating is formed so as to diffract the beam in the direction substantially perpendicular to the track direction.
Claim 6
Dependent Claim
86 words
An optical pick-up device according to claim 1, wherein the aforementioned photo-detecting element for detecting the beam of the main spot reflected from said recording medium is divided into two elements by the parting line parallel to said parting line dividing the region on said diffracting element, and comprises an adding circuit which outputs the sum of the signals output from said respective elements of said photo-detecting element as the regenerative information signal, and a subtracting circuit which outputs a difference as said focusing error signal.
Claim 7
Dependent Claim
38 words
An optical pick-up device according to claim 1, wherein the aforementioned light emitting element and said photo-detecting element are housed in a common package and a cap seal window of said package is composed of said diffracting element.
Claim 8
Dependent Claim
126 words
An optical pick-up device for reading information recorded on a track on a recording medium, the device comprising a laser light source, means for focusing laser light from said light source on said recording medium, and detection means for detecting reflected laser light from said recording medium, wherein a first part of a diffracting element is adapted to split the incident light from the laser light source for the formation of a plurality of light spots said recording medium and a second part of said diffraction element is adapted to direct the reflected laser light from said light spots toward said detection means, and wherein said first and second parts are separated in a direction transverse to the direction of the track on said recording medium.
Claim 9
Dependent Claim
126 words
An optical pick-up device for reading information recorded on a track on a recording medium, the device comprising a laser light source, means for focusing laser light from said light source on said recording medium, and detection means for detecting reflected laser light from said recording medium, wherein a first part of a diffracting element is adapted to split the incident light from the laser light source for the formation of a plurality of light spots said recording medium and a second part of said diffraction element is adapted to direct the reflected laser light from said light spots toward said detection means, and wherein said first and second parts are separated in a direction transverse to the direction of the track on said recording medium.