JPH0784207A - Light emitting element array device - Google Patents

Abstract

PURPOSE:To provide a light emitting element arrey device realizing a display device capable of obtaining high-picture quality in which light quantity shading is eliminated. CONSTITUTION:As to this light emitting element array device 2 constituted of housings 20, 26 and 27 housing at least a light emitting element array 22 inside and having an aperture part making a luminous flux radiated from the array 22 pass through, and a cover glass 28 covering the aperture part; reflection preventing treatment is performed on the cover glass 28, and also a light shielding member 30 whose width is larger on both ends in the longitudinal direction of a slit 29 than that on a central part is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting element array device used as a light source for writing to a spatial light modulator used in a video projector having high brightness and high resolution.

[0002]

2. Description of the Related Art As a light emitting element array device in which light emitting elements are integrated at high density, there is one which has been conventionally used for a printer, for example. This light emitting element array device is configured, for example, by arranging a large number of light emitting elements in a linear array and accommodating a driver IC for driving in parallel with the array in a package. There is. Further, since this light emitting element array device is provided as a print head in the vicinity of the surface of the photoconductor in the printer, a rod lens array for condensing the light emitted from each light emitting element on the photoconductor surface, The package is integrally formed so as to be interposed between the light emitting element array and the photoconductor.

By making a slight improvement to the light emitting element array device formed as described above, it can be used as a writing light source for a display device using an optical writing type spatial light modulator. FIG. 3 is a configuration diagram showing a schematic configuration of a display device in which the light emitting element array device of FIGS. 1 and 4 described later is used. The configuration of this display device will be described below with reference to FIG. In the figure, reference numeral 1 is a reflection type spatial light modulator, and as is well known, a photoconductive layer, a dielectric mirror layer and a light modulation layer are provided between a writing side transparent electrode and a reading side transparent electrode which face each other. At least a liquid crystal layer is laminated. Reference numeral 2 denotes a light emitting element array device configured to house a plurality of linearly arranged light emitting elements, a driver IC for driving these light emitting elements, and the like. When each light emitting element in the light emitting element array device 2 is modulated by image information and emits light at the same time for a predetermined period, the light emitted from each light emitting element emits light.
Is reflected by the oscillating mirror 4 driven by
It is guided to the imaging lens 5 and an image of illuminance corresponding to the emission intensity of each light emitting element is formed on the photoconductive layer of the spatial light modulator 1. As a result, the electric resistance value of the photoconductive layer changes in accordance with the amount of light irradiated, a charge image is formed at the boundary between the photoconductive layer and the dielectric mirror, and the charge image is formed on the liquid crystal layer. An electric field will be applied.

On the other hand, when the reading light in the visible range emitted from the reading light source 6 is incident on the deflecting beam splitter 7, the S-polarized light component of this reading light is reflected by the polarizing beam splitter 7 on the reading side of the spatial light modulator 1. And is incident on the read-out side transparent electrode of the spatial light modulator 1. The readout light incident from the readout-side transparent electrode passes through the liquid crystal layer, reaches the dielectric mirror layer, is reflected by the dielectric mirror layer, and passes through the liquid crystal layer again. At this time, as described above, the electric field due to the charge image is applied to the liquid crystal layer, and the alignment state of the liquid crystal layer changes according to the intensity of the electric field. The state of the polarization plane is changed corresponding to the linearly arranged pixel information. The read-out light whose polarization plane state has been changed, which has been emitted from the spatial light modulator 1 in this manner, is re-incident on the polarization beam splitter 7, and the P-polarized light of the read-out light whose polarization plane state has been changed by the polarization beam splitter 7. The components are transmitted and imaged as a plurality of light spots linearly arranged on the screen 9 by the projection lens 8.

FIG. 4 is a cut perspective view showing an example of a conventional light emitting element array device. In the figure, reference numeral 20 is
The base of the light emitting element array device 42 is made of aluminum in consideration of the heat dissipation effect, and the surface exposed to the outside is subjected to black satin finish. A board 21 on which a light emitting element array 22 in which a plurality of light emitting elements are linearly arranged and a driver IC 23 for driving the light emitting element array 22 are mounted is housed in a central recess of the base 20. It is like this. Further, a flexible board 24 is connected to the board 21 so as to connect the driver IC 23 and a signal circuit (not shown). The substrate 21 is clamped and fixed together with the flexible substrate 24 by screwing the clamper 26 to the base 20 via the pressure contact rubber 25 at both ends in the direction perpendicular to the longitudinal direction. Further, spacers 27 are similarly screwed to the base 20 at both ends in the longitudinal direction of the substrate 21 (FIG. 4 is a cutaway view, so only one end is shown), and together with the clamper 26, the light emitting element array 22 is provided. It is designed to surround the circumference of.

Here, the surface of the clamper 26 and the spacer 27 is treated with a black satin finish like the base 20, and a step 26a which forms the same plane as the base 20 is attached to the base 26. , 27a are provided.
The cover glass 2 is attached to the step portions 26a and 27a.
8 is placed and fixed with an adhesive. Both the front and back surfaces of the cover glass 28 are subjected to an antireflection film treatment, and the back surface thereof is subjected to a black satin treatment in parallel with the light emitting element array and having a slit 39 of a predetermined width just above the light emitting element array. A light blocking member 40 is provided.

Here, the black matte treatment and the antireflection film treatment applied prevent any reflection and contribute to writing in the spatial light modulation element 1 of the luminous flux emitted from the light emitting element array 22. It allows only the effective luminous flux to pass,
Light as noise that reaches the photoconductive layer of the spatial light modulator 1 is significantly reduced to prevent image deterioration such as contrast deterioration. Further, as the light shielding member 40, a metal or organic substance deposited by vapor deposition, etching, or the like, a substance coated with a paint, a black paper, a cloth, a filter, or the like is used. Front or back,
Or it is provided on both front and back sides.

[0008]

By the way, according to the light-emitting element array device 42 having the above-described structure, when an image of the light-emitting surface is formed on the photoconductive layer of the spatial light modulator 1 by using the optical system. Even if the emission of the light emitting element array 22 is uniform at the center and the periphery, the imaging optical system usually causes vignetting of the lens and deterioration of the peripheral light amount as is known by the cosine fourth law. There is a problem that light amount shading occurs at the central portion and both end portions of the image, and shading occurs on the screen 9 even in the projection image of the reading light.
Further, as a method of electrically correcting this shading, in the drive circuit device of the light emitting element array 22, a method of weakening the light emitting state of the light emitting element array 22 in the central portion as compared with the both end portions can be considered. However, for example, when the light emission amount of the light emitting element is digitally driven, there is a problem that a smooth correction cannot be obtained unless a sufficient number of bits is given for the correction. Therefore, the present invention has been made in view of the above points, and an object of the present invention is to provide a light emitting element array device that realizes a high-quality display device without light amount shading.

[0009]

A light emitting element array according to the present invention comprises a housing having at least an opening for accommodating the light emitting element array therein and allowing a light beam emitted from the light emitting element array to pass therethrough, A light emitting element array device comprising a window member for closing an opening, and a light shielding member provided in the window member and having a slit parallel to the light emitting element array for passing only an effective light beam of the emitted light beam,
The above-mentioned object is achieved by configuring the slit and / or the window member so that the amount of light passing through the slit and the window member is different in the longitudinal direction of the slit.

Further, the light emitting element array device of the present invention is configured such that, in the light emitting element array device as described above, the amount of light passing through the slit and the window member is variable by the slit and / or the window member. By doing so, the above-mentioned object is achieved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same components as those described in the conventional example or components corresponding to those in the conventional example are denoted by the same reference numerals, and the description thereof may be omitted. Figure 1
FIG. 1 is a cut perspective view showing an embodiment of a light emitting element array device of the present invention. In the figure, the light emitting element array device 2 of the present invention is substantially the same as the above-mentioned conventional example,
Is a light-shielding member and has a slit 29, and the width of the slit 29 is set so as to correct the deterioration of the peripheral light amount due to the imaging lens 5, and the width of the central portion is narrower than the width of both end portions in the longitudinal direction. The difference is. Since the light emitting element array device 2 of the present embodiment is configured as described above, when the light emitting element array device 2 is used in the display device shown in FIG. 3, the light emitted from the light emitting element ( Writing light)
Above the vicinity of the light emitting element array device 2, since the width of the central portion is narrower than the width of both ends of the slit 29 in the longitudinal direction, the light is stronger at both ends. However, when the light is guided to the image forming lens 5 and imaged on the spatial light modulator 1, the peripheral light amount deterioration of the lens causes the light amount at both ends and the central part to be uniform on the spatial light modulator 1. To be imaged. Therefore, the shading of the projected image on the screen, which is caused by the shading of the writing light amount, can be corrected well.

Next, another embodiment of the present invention will be described. The configuration of the present embodiment is approximately the same as the above-described conventional example, but instead of the cover glass 28 of the conventional example, both ends in the longitudinal direction of the slit that correct the peripheral light amount deterioration due to the imaging lens 5. The difference is that the window member is set so that the transmittance at the central portion of the slit is lower than the transmittance at 1. FIG. 2 is a diagram showing a light transmittance distribution of a window member in another embodiment of the light emitting element array device of the present invention,
The vertical axis represents the light transmittance, and the horizontal axis represents the slit longitudinal direction. For this window member, for example, a metal thin film may be coated by vacuum deposition to use an ND filter having a transmittance distribution as shown in FIG. Since the light emitting element array device of the present embodiment is configured as described above, when the light emitting element array device is used in the display device shown in FIG. 3, the light emitted from the light emitting element (writing light) is used. In the upper part near the light emitting element array device, since the transmittance of the window member in the central portion is smaller than the transmittance of the window member in both end portions of the slit, light is stronger in both end portions. However, when the light is guided to the image forming lens 5 and imaged on the spatial light modulator 1, the peripheral light amount deterioration of the lens causes the light amount at both ends and the central part to be uniform on the spatial light modulator 1. To be imaged.
Therefore, the shading of the projected image on the screen, which is caused by the shading of the writing light amount, can be corrected well.

The present invention is not limited to the above embodiment. For example, instead of the light blocking member of the above embodiment, a light blocking member having a variable slit shape may be used. As a method of changing the shape of the slit, for example, a mechanical shutter may be provided on the window member to change the shape of the slit. Alternatively, a plurality of liquid crystal shutters that are finely separated may be provided and each of them may be driven to change the shape of the slit. According to this structure, the amount of light passing through the slit can be arbitrarily changed, so that the peripheral light amount ratio can be corrected by the lens and the correction amount can be arbitrarily changed.

Further, for example, the window member of the embodiment may be a window member whose transmittance is variable in the slit so that the amount of light passing through the slit and the window member is variable. As the window member with variable transmittance, for example, liquid crystal (TN liquid crystal, polymer liquid crystal composite film, etc.) can be used. When this window member is provided in the vicinity of the light emitting surface of the light emitting element array, a liquid crystal shutter is formed as a window member for each light emitting element, and the transmission amount of the light flux emitted from each light emitting element is modulated. In this case, not only the peripheral light amount ratio of the optical system can be corrected but also the variation in the light emission output of the light emitting element can be corrected. The variation of the light emission output and the correction of the peripheral light amount ratio need only be kept at the initial setting, so that the response of the liquid crystal does not matter. Further, since it is not necessary to correct the peripheral light amount ratio and variations on the light emitting element side, it is easy to express multi-gradation in the light emitting element, and the liquid crystal shutter drive circuit is not required to have high speed, so multi-gradation correction is performed. It's also easy. Moreover, the position of the window member with respect to the light emitting element is set to a distance (several tens of μm) which is sufficiently larger than the depth of focus (several tens of μm) on the light emitting element side of the writing lens.
(about mm) When set apart, the effect of unnecessary light is small,
It is possible to correct the peripheral light amount ratio and change the correction amount.

[0015]

As described above, according to the light emitting element array device of the present invention, it is possible to correct the shading of the light quantity and realize the display device of high image quality. Also, by varying the effective light quantity of the luminous flux from the light-emitting element array device, variations in the light-emitting element output can be suppressed, light quantity shading can be corrected, and this correction amount can be changed. The device can be realized.

[Brief description of drawings]

FIG. 1 is a cut perspective view showing an embodiment of a light emitting element array device of the present invention.

FIG. 2 is a diagram showing a light transmittance distribution of a window member in another embodiment of the light emitting element array device of the present invention.

FIG. 3 is a configuration diagram showing a schematic configuration of a display device in which the light emitting element array device of the present invention is used.

FIG. 4 is a cut perspective view showing an example of a conventional light emitting element array device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spatial light modulator 2 Light emitting element array device 5 Imaging lens 6 Readout light source 8 Projection lens 9 Screen 20 Base (housing) 22 Light emitting element array 26 Clamper (housing) 27 Spacer (housing) 28 Cover glass (window member) 29 Slit 30 Light blocking member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichiro Negishi 3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi Kanagawa Japan Victor Company of Japan, Ltd.

Claims (2)

[Claims] 1. A housing having at least a light emitting element array therein and having an opening through which a light beam emitted from the light emitting element array passes, a window member closing the opening, and the window member. A light-emitting element array device comprising: a light-shielding member having a slit in parallel with the light-emitting element array for allowing only an effective light beam of the radiated light beam to pass therethrough; A light emitting element array device, wherein the amount of light passing through the window member is made different in the longitudinal direction of the slit. 2. A housing having at least a light emitting element array therein and having an opening through which a light beam emitted from the light emitting element array passes, a window member closing the opening, and the window member. A light-emitting element array device comprising: a light-shielding member having a slit in parallel with the light-emitting element array for allowing only an effective light beam of the radiated light beam to pass therethrough; A light emitting element array device, wherein the amount of light passing through the window member is variable.