JPS59164531A - Photoscanner - Google Patents

Abstract

PURPOSE:To make a scan with high density by providing a light source part which supplies plural pieces of luminous flux and a deflector which has plural deflection parts for deflecting selectively the pieces of luminous flux from said light source part. CONSTITUTION:Luminous flux li emitted from a light emission point 1i is deflected by a deflection part 2i to form an image on a medium 4 to be checked through a lens 3i. The image-formation point scans in an area 4i on the medium 4 to be scanned by the deflection of the deflection part 2i. The luminous flux li is deflected by the deflection part 2i simultaneously with and in the same direction against the image-formation point, so the modulated luminous flux li makes a high-density scan over the entire area of the medium 4 to be scanned.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical scanning device, and particularly to an optical scanning device using a light source capable of simultaneously supplying a plurality of beams of light.

Conventional optical scanning devices include devices that perform optical scanning by irradiating light from a single light emitting point onto a polygon mirror and reflecting it;
2. Description of the Related Art A device is known that performs optical scanning by independently modulating each light emitting point of a light source section having a plurality of light emitting points, such as a liquid crystal (LED) array, and by moving a medium to be scanned. However, in the latter device, the light source unit is imaged at the same magnification on the scanned medium using a compound eye lens system, so high-density scanning is not possible unless the density of each light emitting point of the light source unit is increased. be. As an improvement on these, a method is known in which two sets of light source units and compound lens systems are used, and images of the respective light emitting points of these two sets of light source units are shifted and imaged on the scanned medium. It is very difficult to arrange and adjust the components, and it lacks practicality.

Recently, it has been discovered that when heat is applied to a substance, the refractive index changes, and when light is incident on this heated substance, the emitted light is deflected.For example, Nikkei Electronics August 1, 1982
8th issue, pages 185 to 183, it is reported that a He-Ne laser is irradiated onto a rutile (Ti07.) crystal to which a DC voltage is applied, and that the deflection angle of the emitted light changes when the applied voltage is changed. It has been reported. The present inventor focused on the phenomenon of light deflection caused by heat, utilized the temperature dependence of the refractive index of a substance, discovered non-uniform changes in the refractive index due to thermal changes, and based on this knowledge, invented the present invention. I came to do this.

In view of the above points, the present invention provides a light source unit capable of supplying a plurality of independent light beams, a medium whose refractive index is temperature dependent, and a medium within the medium for deflecting the light beam from the light source unit. an optical scanning device comprising a deflector having a plurality of deflecting sections configured with means for controlling a refractive index distribution, and deflecting a light beam incident on the deflecting section by controlling the refractive index distribution within the medium. Our goal is to provide the following.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a principle sectional view of an embodiment of the present invention, and FIG. 2 is a detailed sectional view of the deflector 2 shown in FIG.

This optical scanning device consists of a light source section 14, a deflector 2, a compound eye lens 3, and a scanned medium 4. The light source section 1, the deflector 2, and the compound eye lens 3 each have a plurality of light emitting points 1i (i=1. 2
．． 3..., the same applies hereinafter), a deflection section 21, and a lens section 31. As the light source section 1, a known one such as a liquid crystal (LED) array can be used.

As shown in FIG. 2, the deflector 2 is composed of a plurality of transparent media 61 whose refractive index changes depending on the temperature, which are divided by a plurality of Vertier elements 51. The Beltier elements 51 are each connected to a power source (not shown) that applies a current in the same direction, and when a current is applied, the lower surface 5ia of the Beltier element 51 generates heat, and the upper surface 5ib is configured to absorb heat. There is. That is, the deflection section 21 includes the Bertier element 51
lower surface 5ib, medium 61, Bertier element 5 (i+1
) consists of the upper surface 5 (i+1)a.

Next, the operation of the above embodiment will be explained. When a current is applied to the Bertier element 51 from a power source, the upper surface 5ia of the element 51 absorbs heat, and the lower surface 5ib generates heat. Therefore, in the medium 81 of the deflection section 21, a continuous temperature gradient is formed from the lower surface 5ib to the upper surface 5(i+1)a.

Therefore, when the temperature coefficient of refractive index (dn/dT) of the medium 61 is negative, the surface 5 (i+1
) The refractive index gradually decreases from a toward the surface 5ib. The gradient of this refractive index becomes approximately constant, and the medium 61 has a prismatic action that deflects the incident light downward, as shown in FIG.

As shown in FIG. 1, the light beam emitted from the light emitting point 11 is deflected by the deflection section 21 and focused onto the scanned medium 4 by the lens section 31. This imaged point scans an area 41 on the scanned medium 4 by being deflected by the deflection unit 21 . The light emitting points 11 are each independently intensity-modulated, and the light beams are deflected by the deflection unit 21 and directed simultaneously and in the same direction with respect to the image forming point.
can be scanned by a modulated light beam. By changing the amount of current applied to the Bertier element 61, the temperature gradient of the medium 61 changes, and therefore the refractive index gradient changes, making it possible to greatly control the deflection angle.

In the above embodiment, even if the light-emitting point 11 of the hot water part 1 is imaged at the same magnification on the scanned medium 4 through the deflector 2 and the compound lens 3, the scanning density on the scanned medium 4 is It is possible to improve the density several times compared to 1i. For example, when an LED array is used as the light source part 1, there is no need to increase the light emitting point density of this LED array, and an inexpensive and high-brightness one can be used. can do. Therefore, it is possible to perform high-density scanning without performing reduction using an optical system, and it is possible to utilize equal-magnification imaging using a compound eye lens, making it possible to downsize the entire optical scanning device.

In the above embodiment, the light emitting point 11 of the light source section 1, the deflection section 21 of the deflector 2, and the lens section 3X of the compound eye lens 3 correspond to each other, but this is not necessarily necessary. may correspond to the light emitting parts 11 and 12, and the lens part 32 may correspond to the light emitting parts 13 and 14. Further, although the deflector 2 is arranged between the light source section 1 and the compound eye lens 3 in FIG. 1, it may be arranged between the compound eye lens 3 and the scanned medium 4 instead.

31Z is a principle sectional view of another embodiment of the present invention, and FIG. 4 is a detailed sectional view of the deflection imaging system 8 of FIG. 3. This optical scanning device includes a light source part l having a plurality of light emitting points 1i, cylindrical lenses 7a and 7b each having power (refractive power) in a cross section perpendicular to the plane of the paper, and a deflection imaging part 81 to be described later. It consists of a deflection imaging system 8 and a scanned medium 4. The medium 91 of the deflection imaging system 8 is made of a material whose refractive index changes with temperature, and is formed in advance so that the refractive index decreases as the optical axis moves away from the medium. That is,
Each of the media 81 has a cylindrical lens effect that has power within a cross section that includes the plane of the paper. The medium 91 is further divided alternately by resistors 10i and metal plates 11i. That is, the deflection imaging section 81 includes a resistor 101, a medium 91, and a metal plate 111, and the deflection imaging section 82 includes a metal plate 111, a medium 82, and a resistor 102. Resistor 10
i are each connected to a controllable power source, and metal plate +1i has a heat dissipation function.

To explain the operation of the embodiment shown in FIGS. 3 and 4, when a current is applied to the resistor 10i from the power source, the resistor 10i generates heat and the metal plate 11i radiates heat.
A continuous temperature gradient is formed in the medium 81 from the resistors 10i and 10(j+1) toward the metal plate 11i. Therefore, if the temperature coefficient of refractive index (dn/dT) of the medium 91 is negative, In the media 81 and 92, the portion having the maximum refractive index is deflected by the resistor 111, so that the incident light can be deflected as shown in FIG. In this case, the adjacent media 81 and 9(i+1) have deflection effects in opposite directions, but this inconvenience can be easily eliminated by converting the brightness modulation signal for each light emitting point of the light emitting section l.

In this example, the imaging effect in the cross section perpendicular to the plane of the paper is cylindrical 7δ, ? b is shared by the deflection imaging section 8 itself in the cross section including the plane of the paper.

As explained above, by forming a deflector having a plurality of deflecting parts each consisting of a medium and a heat generating part, each of which has a temperature dependence of its refractive index, and controlling the amount of heat generated by the heat generating part, the medium Since the refractive index within the deflection section is made non-uniform and the light beam incident on the deflection section is changed, high-density scanning becomes possible, and the arrangement and adjustment of the various components of the apparatus are facilitated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, and FIG. 2 is a cross-sectional view of one embodiment of the present invention.
FIG. 3 is a detailed cross-sectional view of the deflector shown in the figure, FIG. 3 is a cross-sectional view of another embodiment of the present invention, and FIG. 4 is a detailed cross-sectional view of the deflection imaging system of FIG. 3. DESCRIPTION OF SYMBOLS 1... Light source part, 2... Deflector, 8... Deflection imaging system, 11.12.13-... Light emitting point (part), 21
．． 22.23~... Deflection section, 51.52.53~... Peltier element, 61.62.
63~. 91.92.83~...Refractive index temperature dependent medium, 101, 102~...Resistance pair. III Figure

Claims (1)

[Scope of Claims] A light source unit capable of supplying a plurality of light beams, and a deflector having a plurality of deflection units for selectively deflecting the light beams from the light source unit, each of the deflection units being , each having a medium having a temperature dependence of refractive index, and means for controlling the refractive index distribution within the medium, and making the refractive index within the medium non-uniform by the control means,
An optical scanning device characterized in that a light beam from the light source unit that enters the deflection unit is deflected.