Hologram Reproducing Device Lens Orientation Control
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Solution Overview
Problem
Current hologram recording devices are large and expensive due to the need for precise control of light wavelength and irradiation angle for data multiplexing, which is typically achieved using expensive galvanometer mirrors.
Innovation Solution
A hologram information reproducing device with a light source unit, an optical system including a lens and mirror, and driving means that can independently change the orientation of the lens or cylinder in multiplex and arrangement directions, allowing precise reproduction of hologram information even when the light source unit is switched.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a galvanometer mirror is used to control the irradiation angle for wavelength or angle multiplexing, then the precision of angle control is improved, but the device size and cost increase
Solution Approach 1:
The patent replaces the mechanical galvanometer mirror system with an optical system comprising a lens and a rotating prism. The lens focuses the light beam, and the rotating prism changes the irradiation angle by rotating around the optical axis. This substitution eliminates the need for a galvanometer mirror while achieving the same angle control function, thereby reducing device size and cost.
Solution Approach 2:
The patent changes the control parameter from mechanical mirror deflection angle to rotational angle of the prism. By rotating the prism around the optical axis, different irradiation angles are achieved through parameter change (rotation angle), which simplifies the mechanical structure compared to using a galvanometer mirror that requires precise angular deflection control.
2Quantity of substance
If multiple disks are used to record a large amount of data, then the data storage capacity is improved, but the operation complexity and time increase due to disk replacement
Solution Approach 1:
The patent enables a single recording medium to serve multiple functions by implementing both wavelength multiplexing and angle multiplexing on the same medium. This allows one disk to store multiple datasets with different wavelengths and angles, eliminating the need for multiple disks and disk replacement operations, thereby improving operation efficiency while maintaining large storage capacity.
Solution Approach 2:
The patent adds angular dimension to the traditional wavelength multiplexing approach. By controlling both the wavelength and the irradiation angle independently, the system creates an additional dimension for data separation and storage, allowing multiple datasets to be recorded and reproduced on the same area of the recording medium without requiring multiple disks.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device enables precise reproduction of hologram information with angle multiplexing, reducing the size and cost by concentrating optical components on one side of the recording medium and using magnetic or piezoelectric circuits for precise lens or cylinder movement.
Implementation Method 1
a light source unit that emits reference light; an optical system that irradiates with the reference light
Implementation Method 2
detecting means that is disposed on the same side as the light source unit with respect to the recording medium and that detects reproduction light that is obtained as a result of diffracting the reference light at the recording medium
Implementation Method 3
first driving means that changes the orientation of the lens. The first driving means changes the orientation of the lens in accordance with a multiplex direction of the information recorded on the recording medium
Implementation Method 4
a mirror that directs the light transmitted through the lens towards the recording medium
Data Source
AI summary
A hologram information reproducing device is described which can reproduce information from a recording medium on which hologram information is recorded, and which can be downsized. In one aspect, when light from a light source is emitted, the light is converted into parallel reference light, by a lens of an optical system. A mirror changes the orientation of the reference light so that it is oriented obliquely downward towards a recording medium. More specifically, as viewed from the top, the mirror changes a path of the light from the light source unit by approximately 90 degrees. In addition, as viewed from the side, the mirror changes the path of the light from the light source unit downward by approximately 45 degrees. Since an interference pattern recorded on the recording medium is a Bragg grating, when the reference light illuminates a recording area of the recording medium, a reproduction light is obtained by Bragg diffraction. The reproduction light is reflected by a reflecting layer of the recording medium and is detected by a photodetector 13.