JPH0460626A - Projection device - Google Patents

Abstract

PURPOSE:To improve the picture quality by providing an optical path changing means which changes the path of the light from a screen and an irradiation position control means which moves a position which is projected on an object surface. CONSTITUTION:The screen 7 is so formed that the contacting/leaving intervals where no-picture-element areas 7b are formed between respective picture elements 7a are nearly equal to the size of each picture element 7a in the contacting/leaving direction, and this device is provided with the optical path changing means which changes the path of the light form the screen 7 and the irradiation position control means which moves the position irradiating the object surface to a position corresponding to a no-pciture-element area 7b before driving. Then an irradiated area irradiated corresponding to an image on the screen moves by all picture elements and enters an area which does not irradiates the object surface because of the no-picture-element area 7b. Consequently, repeated irradiation of only a specific range of the surface is prevented and the picture quality is improved.

Description

[Detailed Description of the Invention] Object of the Invention [Industrial Application Field] The present invention relates to a projection device, and more specifically, a projection device that has a screen made up of a plurality of pixels and irradiates light from the screen onto a projection surface. Regarding.

[Prior Art] This type of projection device has conventionally been used in optical printers and the like, and for example, it exposes a photoreceptor by irradiating a photosensitive paper or the like with transmitted light emitted from the back of an LCD panel. something is known. The screen of an LCD panel is made up of a plurality of pixels. An image is formed by turning each pixel on and off (transparent/non-transparent), and a photosensitive paper is exposed to transmitted light according to the image. That is, it is an optical switch array that allows light emitted from the back side to pass only in areas where the pixels are transparent. Therefore, the image exposed on the photosensitive paper corresponds to the image displayed on the LCD panel.

There are also known devices in which photosensitive paper is exposed to light emitted from a CRT instead of light transmitted from an LCD panel.

There are also devices that project images by irradiating light from the screen onto a screen or the like.

[Problems to be Solved by the Invention] However, in a device in which a screen is constituted by a plurality of pixels and a projection surface is irradiated with light from the screen, the following problems have occurred.

For example, when an LCD panel is used, a wiring pattern provided between each pixel blocks light, making it impossible to irradiate that area at all times. That is, in the area where the wiring pattern is provided, which is a non-pixel area, it becomes impossible to control the transmitted light, and as shown in FIG. (Hatching)
exists. Therefore, a problem arises in that the wiring pattern is always projected in black, resulting in a decrease in contrast and image quality.

Even when a CRT is used, there are areas between each pixel that cannot be irradiated due to the shadow mask, causing the above-mentioned problem.

The projector of the present invention aims to solve the above problems and improve image quality.

Structure of the Invention [Means for Solving the Problem] As illustrated in FIG. The projection surface is irradiated with light emitted from the screen, transmitted light of light emitted from the back of the screen, or reflected light of light emitted from the front of the screen, using a screen color consisting of non-pixel areas. In the projection device,
The screen is set such that the adjacent interval between each pixel and the size of each pixel in the adjacent direction are approximately equal, and the screen is provided between the screen and the projection surface, and an optical path changing means for changing the path of light from the screen; and irradiation position control for driving the optical path changing means to move a position of irradiating the projection surface to a position corresponding to the non-pixel area before the driving. The gist is that it has the means.

[Function] The projection device of the present invention having the above configuration uses a screen consisting of a plurality of pixels that can control transmission, reflection, and light emission of light, and a non-pixel area existing around the pixels. of light is irradiated onto the projection surface. In this screen, the interval between adjacent pixels in which a non-pixel area is formed is set to be approximately equal to the size of each pixel in the adjacent direction. An optical path changing means is provided between the screen and the projection surface, and the irradiation position control means drives the optical path changing means to change the course of the light from the screen and set the position at which the light is irradiated onto the projection surface. is moved to a position corresponding to the non-pixel area before driving. As a result, the irradiation area, which is irradiated according to the image on the screen, simultaneously moves and enters the area where the projection surface is not irradiated due to the non-pixel area. Furthermore, since the interval between adjacent pixels is approximately equal to the size of the pixels in the adjacent direction, it is possible to prevent only a specific range from being overlappingly irradiated.

[Embodiments] In order to clarify the structure and functions of the present invention described above, preferred embodiments of the projection apparatus of the present invention will be described below.

FIG. 2 is a schematic configuration diagram of a projection device used in an IcD printer as an example. The projector] includes a lamp 3 as a light source for exposing the photosensitive paper P, and a condenser lens 5 provided in order from the light source side. LCD panel 7, glass flat plate 9° imaging lens] 1, and glass flat plate X
Axial rotation mechanism (hereinafter referred to as X-axis rotation mechanism)] 3,
A glass flat plate X-axis rotation mechanism (hereinafter referred to as Y-axis rotation mechanism) 15 and a projection control device 17 are provided.

The condenser lens 5 converts the light from the lamp 3 into parallel light and allows it to pass therethrough. Therefore, the LCD panel 7 is irradiated with parallel light.

The LCD panel 7 is a liquid crystal display device that performs dot matrix display, and controls the orientation of liquid crystal molecules depending on whether or not each pixel is energized, thereby changing the bright state (transparent) and dark state (non-transparent) according to image data. (transparent) to form and display an image. The irradiated light from lamp 3 is
If the pixel is bright, it passes through; if it is dark, it is blocked. Therefore, the projected image passing through the LCD panel 7 is
This corresponds to the image displayed on panel 7.

As shown in FIG. 3, the screen of this LCD panel 7 has one wiring pattern 7 between each pixel 78 for driving the liquid crystal.
b (hatched in the drawing) is provided. still,
The pixel 7a used here refers to the effective display area of the liquid crystal I, that is, the area where the passage of light can be controlled.

Each pixel 7a has a square shape when viewed from the irradiation direction, and is arranged in a matrix. The width of the wiring pattern 7b between each pixel 78, that is, the adjacent interval between each pixel 7a in the vertical and horizontal directions is set equal to the length of one side of each pixel 7a. The wiring pattern 7b does not transmit light from the light source and always blocks it. Therefore, the aperture ratio (effective display area for the entire screen) of this LCD panel 7 is 25%.

The flat glass plate 9 is a rectangular glass plate that is slightly larger than the screen of the LCD panel 7, and is usually used as a reference position.
It is provided parallel to the D panel 7 (perpendicular to the optical axis).

It is rotatable in the directions of arrows XI and X2 around its lateral central axis
It is rotatably provided in the l and Y directions.

The projected image of the light transmitted through the glass flat plate 9 is formed by the imaging lens]1
An image is formed on the photosensitive paper P. Therefore, the photosensitive paper P is exposed to this transmitted light and records the image displayed on the LCD panel 7.

X-axis rotation mechanism 13. [Y-axis rotation mechanism] 5 each includes a stepping motor (not shown), and rotates the glass flat plate 9 independently in the XI and X2 directions and in the Yl and Y2 directions in the drawing, respectively, according to signals from the projection control device] 7. It is a drive mechanism that allows

Projection control device] 7 is an electronic control device 19 and an x-axis rotation mechanism]3. Y-axis rotation mechanism] X-axis motor driver 21 that outputs a drive signal to the stepping motor 5. A Y-axis motor driver 23, an LCD driver 25 that drives the LCD panel 7, and a lighting driver 27 that lights the lamp 3.
An operation switch 29 is provided.

The electronic control unit 19 includes a CPU 19a, a RAM 19b, a ROM 19c configured as an arithmetic and logic circuit, and a video RAM (V-RAM) 19d that stores image data.
and the various types of fibers mentioned above 21°23, 25. 27.
It includes an input/output interface 19e for exchanging signals with the operation switch 29, and a bus 19f for interconnecting these.

Therefore, in the projection device configured in this way,
The rotational position of the glass flat plate 9 is determined by X according to the projection control device]7.
Shaft rotation mechanism 13. It is set by drive control of the Y-axis rotation mechanism 15.

Next, the deviation of the optical path when the glass flat plate 9 rotates and tilts from the reference position perpendicular to the optical axis will be explained.

As shown in FIG. 4, the inclination of the glass flat plate 9 with respect to the reference position is θ], and the thickness of the glass flat plate 9 is d.

The refractive index of air is nl, and the refractive index of the glass flat plate 9 is n2.
Then, the deviation α between the incident light and the output light is α=d(si
nθ1−CO2O3・tanθ2) sinθ1
nl However, 3. . θ2 n2 . Therefore, when the glass flat plate 9 is tilted by θ] with respect to the reference position by the X-axis rotation mechanism 13 or the Y-axis rotation mechanism 15, the projected image transmitted through the glass flat plate 9 is different from the projected image at the reference position. It shifts by α. That is,
By driving and controlling the X-axis rotation mechanism 13 or the Y-axis rotation mechanism 5 to tilt the glass flat plate 9, the glass flat plate 9
The transmitted light can be shifted parallel to any position.

Next, the exposure control process executed by the electronic control unit] 9 will be described. FIG. 5 is a flowchart showing an exposure control routine, which is activated when a print mode is selected.

First, read image data for frames (S100
), it is determined whether the start button (as shown) of the operation switch 29 is turned on (S110). The process waits until the start button is turned on, and when it is turned on, the lamp 3 is then turned on (S120). Subsequently, the LCD is driven by a drive signal according to the image data, and one frame worth of image is displayed on the LCD panel 7 (S130). next,
It is determined whether or not a predetermined period T for exposing the photosensitive paper P has elapsed (5140), and the process of step 130 is executed until the predetermined period T has elapsed. When it is determined that the predetermined period T has elapsed, driving of the LCD is stopped (S150). At this time, all the pixels 7a of the LCD panel 7 are in a dark state, and the irradiation light from the lamp 3 is blocked by the LCD panel 7. That is, the transmitted light from the LCD panel 7 is irradiated onto the photosensitive paper P for a predetermined period T, and the projected image is exposed.

FIG. 6(a) shows an exposure area R1 where the light that has passed through each pixel 7a of the LCD panel 7 is exposed to the photosensitive paper P. still,
Here, it is assumed that each pixel 7a is all in a bright state (transparent).

When the process in step ]50 is completed, a drive signal is output to the X-axis rotation mechanism 15 to rotate the glass flat plate 9 as shown in FIG.
It is rotated by a predetermined angle θ in one direction (S160). This rotation angle θ is set in advance so that the deviation α of the emitted light with respect to the incident light of the LCD panel 7 is equal to the length of one side of each pixel 7a.

When the glass flat plate 9 is rotated by a predetermined angle θ, the LCD is rotated for a predetermined period T, similar to steps 130 to 150 above.
and exposes the projected image onto the photosensitive paper P (3170
~190). Therefore, as shown in FIG. 6(b), the exposure area R2 where the photosensitive paper P is exposed through each pixel 7a is
Step ] The exposure area R1 (FIG. 6(a)) is shifted to the right by one pixel.

Next, a drive signal is output to the X-axis rotation mechanism 13 to rotate the glass flat plate 9 by a predetermined angle θ in the ×1 direction in FIG.
S200). Then, drive the LCD only for a predetermined period of time,
Expose the projected image color to light-sensitive paper P (3210-230)
. Therefore, as shown in FIG. 6(C), the exposure area R3 for exposing the photosensitive paper P is the same as the exposure area R2 (
It is shifted upward by one pixel from FIG. 6(b)).

Subsequently, a drive signal is output to the X-axis rotation mechanism 15 to rotate the glass flat plate 9 by a predetermined angle θ in the Y2 direction in FIG. 2 (S240). Then, the LCD is driven for a predetermined period T, and the projected image is exposed onto the photosensitive paper P (8250-270
). Therefore, as shown in FIG. 6(d), the exposure area R4 in which the photosensitive paper P is exposed is the same as the exposure area R4 in step 210.
3 (FIG. 6(C)) to the left by one pixel.

When these processes are completed, turn off the lamp 3.S2
80), output a drive signal to the X-axis rotation mechanism 13 to rotate the glass flat plate 9 by a predetermined angle θ in the Y2 direction in FIG.
S290), that is, return to the reference position and end this routine.

Therefore, when this processing is completed, exposure processing is performed according to the image data by the processing from step 160 even in the portions that are conventionally unexposed because light is blocked by the wiring pattern 7b.

As explained above, according to the projection device of this embodiment,
Undesired unexposed portions due to the wiring pattern 7b between each pixel 78 are eliminated, and the adjacent pixels 7a are spaced apart from each other.
Since it is made equal to the length of one side of a, there is no possibility of overlapping exposure. As a result, an image corresponding to the image data is uniformly exposed on the photosensitive paper P, and the contrast and image quality are greatly improved. In addition, there is no need to increase the aperture ratio of the LCD panel 7a itself, and since the wiring pattern 7b can be made sufficiently large, the LCD panel 7a can be easily produced.

In this embodiment, the same image data is used at each position where the glass flat plate 9 is rotated in steps 160, 200° and 240, but separate image data is stored for each position, and the image By switching the resolution, in addition to the above effects, the resolution can be further improved. That is, 4
Separate image data is stored for each position, and the image data is switched one frame at a time in synchronization with rotational movement to each position, and the display screen of the LCD panel 7a is switched for each position.

Further, instead of the photosensitive paper P, the image may be projected onto a screen. In this case, the glass flat plate 9 may be rotated at a speed that allows the human eye to capture the image as an afterimage.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments; for example, R
, G, B filters are provided, and R, G, B
The present invention may be implemented in various ways without departing from the gist of the present invention, such as projecting an image in color by switching the respective screens, or a projection device using a CRT. Of course.

Effects of the Invention As detailed above, according to the projection device of the present invention, it is possible to irradiate even the position corresponding to the non-pixel area between each pixel, and moreover, because only a specific range is not irradiated redundantly. , which has an extremely excellent effect of improving image quality.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating the basic configuration of the present invention, FIG. 2 is a schematic configuration diagram of a projection device, FIG. 3 is an explanatory diagram showing the pixels and wiring pattern of an LCD panel, and FIG. 4 is a diagram of a glass flat plate. An explanatory diagram showing the change of the optical path due to rotation, Fig. 5 is a flowchart showing the exposure control routine, Fig. 6 is an explanatory diagram showing the exposure area exposed to photosensitive paper, and Fig. 7 is an explanatory diagram showing the area that cannot be irradiated, which is a problem with the conventional method. FIG. ]... Projection device 3... Lamp 7... L
CD panel 7a... Pixel 7b... Wiring pattern 9... Glass flat plate 13... × axis rotation mechanism
]5... Y-axis rotation mechanism]7... Projection control device 1
9...Electronic control device R1, R2, R3, R4...Exposure area P...Photosensitive paper

Claims (1)

[Scope of Claims] 1. Using a screen consisting of a plurality of pixels whose transmission of light, reflection of light, or emission of light can be controlled and a non-pixel area existing around the pixels, the light emitted from the screen or the light emitted from the screen is In a projection device that irradiates a projection surface with transmitted light emitted from the back surface or reflected light emitted from the front surface of the screen, the screen is defined as an adjacent area where a non-pixel area is formed between each pixel. an optical path changing means that sets the interval and the size of each pixel in an adjacent direction to be substantially equal, and is provided between the screen and the projection surface and changes the path of light from the screen; and the optical path changing means. A projection apparatus comprising: an irradiation position control means for driving a means to move the irradiation position onto the projection surface to a position corresponding to the non-pixel area before the driving.