Light beam recording device

Claim 2

A light beam recording device comprising a light source which emits a light beam of high intensity which is able to deform a thermoplastic material, an optical system for focusing the light beam on the thermoplastic recording medium, a photoelectric sensing means provided behind the recording medium for receiving light passing through the recording medium, and means for controlling said optical system to focus the light beam accurately on the recording medium in accordance with the output of said photoelectric sensing means.

Claim 3

A light beam recording device as claimed in claim 1 wherein said photoelectric sensing means is located behind the recording medium to receive only the light diffracted by the deformed part of the recording medium.

Claim 4

A light beam recording device as claimed in claim 2 wherein a light intercepting means is provided to prevent the light passing straight through the recording medium from being received by the photoelectric sensing means.

Claim 5

A light beam recording device as claimed in claim 1 wherein said photoelectric sensing means comprises a first photodetector which receives light passing straight through the recording medium and a second photodetector which receives light diffracted by the recording medium.

Claim 6

A light beam recording device as claimed in claim 4 wherein a logical circuit is connected with the first and second photodetectors to make an output which indicates the direction in which the optical system is to be moved by said optical system controlling means for focusing the light beam accurately on the recording medium.

Claim 7

A light beam recording device as claimed in claim 4 wherein said second photodetector to receive light diffracted by the recording medium is provided with means for converging the diffracted light thereonto.

Claim 8

A light beam recording device as claimed in claim 6 wherein said diffracted light converging means is a convergent lens.

Claim 9

A light beam recording device as claimed in claim 6 wherein said diffracted light converging means is a light diffusing plate and a convergent lens to focus the image of the light diffusing plate on the second photodetector.

Claim 10

A light beam recording device as claimed in claim 8 wherein said light diffusing plate has an aperture which passes the light passing straight through the recording medium.

Claim 11

A light beam recording device as claimed in claim 6 wherein said diffracted light converging means is a mirror to reflect the diffracted light and a convergent lens to receive the light reflected by the mirror and converge the light onto the second photodetector.

Claim 12

A light beam recording device as claimed in claim 10 wherein said mirror has an aperture which passes the light passing straight through the recording medium.

Claim 13

A light beam Recording device as claimed in claim 1 wherein said means for controlling the optical system comprises a control circuit connected with said photoelectric sensing means for generating an output signal which indicates that the light beam is focused on the recording medium, and an electric motor associated with the optical system to move the focusing lens in the optical system in the direction normal to the face of the recording medium in accordance with the signal from the control circuit.

Claim 14

A light beam recording device for recording information on a thermoplastic recording medium with a high intensity light beam comprising in combination, a light source which emits a light beam of high intensity which is able to deform a thermoplastic material, an optical system for focusing the light beam on the thermoplastic recording medium, a photoelectric sensing means provided behind the recording medium for receiving light passing through the recording medium, means for controlling said optical system to focus the light beam accurately on the recording medium in accordance with the output of said photoelectric sensing means, an information generating means for generating information to be recorded on the recording medium, means for moving the recording medium in a plane in accordance with the information given by said information generating means, and means for intercepting the light beam emitted by the light source in accordance with the information given by said information generating means, said optical system controlling means being connected with said information generating means and provided with information for operating said light beam intercepting means, whereby the optical system controlling means is operated to stop the optical system when the light beam is intercepted by the light beam intercepting means.

Claim 15

A light beam recording device for recording information on a thermoplastic recording medium with a high intensity light beam comprising in combination, a light source which emits a light beam of high intensity which is able to deform a thermoplastic material, an optical system for focusing the light beam on the thermoplastic recording medium, a photoelectric sensing means provided behind the recording medium for receiving light passing through the recording medium, means for controlling said optical system to focus the light beam accurately on the recording medium in accordance with the output of said photoelectric sensing means, an information generating means for generating information to be recorded on the recording medium, means for moving the recording medium in a plane in accordance with the information given by said information generating means, and means for intercepting the light beam emitted by the light source in accordance with the information given by said information generating means, said optical system controlling means being connected with said information generating means and provided with information for operating said light beam intercepting means, whereby the optical system controlling means is operated to stop the optical system when the light beam is intercepted by the light beam intercepting means.