Optical projection system of microlens array

Abstract

The invention provides an optical projection system of a micro-lens array. The system comprises a light source, a collimating lens, a first micro-lens array, a projection source, a positive lens module, a second micro-lens array and a receiving surface which are arranged in sequence, wherein the first micro-lens array comprises n first micro-lens units arranged in an array, the projection source comprises n projection image units arranged in an array, the second micro-lens array comprises n second micro-lens units arranged in an array, the first micro-lens unit and the second micro-lens unit which are opposite to each other have a common optical axis, a distance between the projection source and the positive lens module is s, a distance between the second micro lens array and the receivingsurface is L', the equivalent focal length f0 of the positive lens module is equal to L', the focal length f1 of the first micro lens unit is approximately equal to s, and the focal length f2 of thesecond micro lens unit is equal to s. According to the system, the sub-real image units can be compounded and superposed on the receiving surface, and optical crosstalk between adjacent optical channels can be avoided.

Description

technical field [0001] The invention relates to a projection system, and specifically discloses an optical projection system of a microlens array. Background technique [0002] The projection system is an optical system that illuminates the object and images it on the projection screen. The short-distance projection system can be applied to the side of the car to welcome guests, or it can be applied to the front and rear of the car as a warning reminder, and it can also be used for desktop projection, such as the projection of keyboard images. [0003] A projection system mainly includes three important components: a light source, a projection source, and an imaging unit. Based on whether the image in the projection source repeatedly appears on the receiving surface, it is divided into a single-channel projection system and a multi-channel projection system. [0004] Single-channel projection systems such as figure 1 As shown in Fig. 1, a multi-chip imaging unit is set up...

AI Technical Summary

Problems solved by technology

[0005] Multi-channel projection systems such as figure 2 As shown, including the light source, collimating lens, first microlens array, projection source and second microlens array, far-field imaging can be realized, but when the distance between the receiving surface is relatively short, the height of the microlens unit is higher than that of the projected real image The image height is too large and cannot be ignored. For example, when the ratio of the height of the microlens unit to the height of the projected real image is greater than 1 / 50, due to the offset of each imaging optical path, multiple staggered real image units will be formed on the receiving surface, resulting in In the end, a clear and single projected real image cannot be formed

[0006] In order to solve the above problems, the prior art patent No. 201480039253.8 discloses a multi-aperture projection display and a single image generator for the multi-aperture projection display. figure 2 The center of the second microlens array is offset so that the corresponding optical axis does not coincide with the optical axis of the first microlens array, thereby realizing overlapping and superposition of multi-channel images, and finally realizing short-distance projection and a single projected real image, but Because the optical axis offset of the first microlens array and the second microlens array is staggered, that is, part of the light in a certain unit in the first microlens array enters the adjacent unit of the second microlens array, the distance between adjacent channels The optical information will crosstalk with each other, and eventually cause the projected real image to form a ghost

[0007] The projection system in the prior art cannot ensure that the projected real image is clear and free of ghosting when obtaining close-range projection

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