JPS61132359A - Printer utilizing light-emitting semiconductor light source - Google Patents

Abstract

PURPOSE:To form color images with high reproduction accuracy through a simple construction, by a method wherein a plurality of light-emitting semiconductor light sources and image-forming optical members are provided as an exposure unit for forming a picture element image, and a multiplicity of such units are moved relatively to a photosensitive body to form a color image consisting of color picture elements on the photosensitive body. CONSTITUTION:A multiplicity of LEDs 1A-3A, masks 4A and lenses 5A are arranged to form projecting units. Color light spot images (a part thereof) 7-9 formed by the projecting units are controlledly moved by a forwardly moving force of the units to form light spots 7'-9', and while sequentially moving the light spots as indicated by 7''-9'', the light-emitting power of the LEDs at each time point is subjected to brilliance modulation based on reproduction information, whereby a film 6 is exposed to a row of overlapping light spots, namely, a collective image of picture element images. The projecting units are moved backward in synchronism with one-step feed of the film, and the film 6 is exposed to the collective image of the picture element images at each time point of the movement.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a printing device using a light emitting semiconductor light source, and particularly to a printer device for forming a color image on a photoreceptor.

BACKGROUND OF THE INVENTION Various types of printers have been proposed and put into practice for forming color images on photoreceptors, including electrophotographic systems, ink jet systems, and thermal transfer systems.
It was not possible to reduce the number of pixels capable of reproducing gradation in the image. For this reason, printing uses laser light, especially its scanning light, as a light source.Scanning printer devices are conventionally known for use in telecine, but the device is bulky and has the drawback of not being suitable for consumer use. There was. Solutions to this problem have been investigated from various angles. For example, Japanese Patent Application Laid-Open No. 152273/1987 uses a light emitting semiconductor element such as a light emitting diode as a light source to form a pixel, and uses the element to form an image. A printer device has been proposed that records a desired pixel image on a photoreceptor with a small number of units by arranging a plurality of units together with a lens and moving one or both of the lens or an element group relative to the photoreceptor. .

However, even in such a proposed example, many problems remain as to how to easily form an image, especially a color image, as a set of sharp pixel images.

Problems to be Solved by the Invention and Means for Solving the Problems The object of the present invention is to eliminate the problems of the above-mentioned conventional example and to provide a printer device that forms color images with high reproduction accuracy using a simple configuration. Ashi's feature is that it is equipped with a plurality of light emitting semiconductor light sources and an imaging optical member as an exposure unit that forms a pixel image, and a large number of these units are provided and moved relative to the photoreceptor to expose the photoreceptor. The point is that a color image made up of color pixels is formed on the body. In particular, in a preferred embodiment of the present invention, red light emitting diodes, green light emitting diodes, and blue light emitting diodes that emit red, green, and blue colors, respectively, are used as the light emitting semiconductors, and the brightness of each diode is controlled by a layer. By modulating each color image signal, the colored light is added to form a desired color pixel light.

As light emitting diodes, in addition to red and green light emitting diodes, blue light emitting diodes have been developed and become available in recent years, so each diode can be used to obtain a luminous flux of the desired color by adding colors. It has become.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

Embodiment FIG. 1 illustrates the main parts of the configuration of the projection system of the Grinter apparatus described below.
are red light emitting diodes.

A green light emitting diode and a blue light emitting diode are shown. The light emitting diodes IA to 3A respectively correspond to each pixel and constitute a color pixel light source by applying effective power and adding color thereto. 4 is a mask having a diffusion surface on the side facing the diodes IA to 3, and 4A indicates a pinhole drilled in the center thereof. 5A indicates a molded lens, and 6 indicates an instant development film applied as a photoreceptor. The luminous flux of each of the diodes IA to 3A is diffused by the diffusion surface on the back side of the mask 4, and then condensed by a condensing mirror (not shown), and the light spot image is immediately developed by a mold lens 5A through a pinhole 4A. The structure is such that an image is formed on the film 6 and a one-pixel image is exposed.

To form one pixel of the projection system, a light emitting diode I
A large number of A to 3A lenses 5A are arranged side by side to form a projection system unit. Fig. 2 shows an example of the structure of the lens 5, which is molded as a single piece by plastic molding to form a double-lens shape 5A to 5C, and behind each lens is a light emitting diode as shown in Fig. 1. Light source sections corresponding to IA to 3A and the mask 4 are provided, respectively.

Such a projection system unit creates a color edge image (described later) by its reciprocating motion, and its accuracy is determined by a mask having a row of pinholes 4A and a fly-eye lens 5A shown in the second figure with an equal pitch row.
5C (fly's eye lens) can be easily obtained because it can be arranged with high precision.

3 to 5 are diagrams schematically showing the color two-dimensional image forming process according to the present invention. That is, as shown in FIG. 3, each of the color light point images 7 to 9 formed by the projection system unit shown in FIG.
Each light spot is formed by controlling the movement as shown in ~9', and is moved sequentially as shown in γ~g, while the brightness is modulated based on the reproduction information of the diode coloring power at each point in time. Yoshi 4th
As shown in the figure, a series of overlapping light spots, that is, a collective image of pixel images, is exposed onto the film 6. As will be described later, the projection system unit is moved back and forth in synchronization with one step of film advance, and exposes the film 6 to a collective image of pixel images at each time of movement.

Figure 5 illustrates the exposure process for forming a two-dimensional color image on a film by moving the film in steps in the vertical direction. 512 x 7 with a pitch of 0.13 jlll
To provide a glare device with 00 pixels, 16 sets of projection system units consisting of the above-mentioned light emitting diode I~3A, aperture 4A, and lens 5A are arranged in parallel to form color light spots at a pitch of 4.16 All. By reciprocating the unit by 4.16 RIIL, each point image is printed in 2.7 ms, the - row is printed in 85 m5, and in synchronization with this, a film or projection system unit is printed for each O,13j wing. The present invention provides a printer device that completes exposure of the entire surface of the film by one step feed 603 every 85 m5.

6 and 7 illustrate the reciprocating mechanism of the projection system unit. In the figures, ]O is the projection system unit, 11
is a support shaft, 12 is a slide bearing that slidably supports the support shaft 11, 13 is a coil unit integrated with the support shaft, 14 is a fixed yoke, 15 is a permanent magnet, 15AU
The projection system unit 10 is reciprocated by driving the p-coil unit 13 left and right by controlling the energization of a coil 16 wound around the coil unit 13 as a magnetic pole piece. Reference numeral 17 indicates a hole drilled in the coil unit 13, and is a hole for venting air when the coil unit moves left and right.

The driving amount of the coil unit 13 is based on each basic configuration of the projection system unit (light emitting diodes IA to 3A, aperture 4).
The projection system unit is configured to reciprocate by the pitch between A and lens 5A), and the projection system unit is reciprocated by applying a triangular wave signal to the coil unit as described later.

FIG. 8 shows an example of the step feeding mechanism for the instant printing film 6, and 18 and 19 indicate the pressure roller 220 and the roller 18.
A step motor for driving the shaft is shown, and is synchronized with the reciprocating motion of the projection system 10 by a transmission signal described later.
It performs step feeding. It should be noted that the commercially available instant printing film 6 has a bag filled with a developer at the film feeding start end, so the developer in the bag is discharged by the pressing force of the rollers 18 and 19, and the roller 18
, 19, the developer is uniformly applied to the exposed surface of the film at the same time during one step feeding, and the development work is simultaneously performed. FIG. 9 shows the horizontal scanning M information indicating the amount of drive of each unit and structure described above, in the horizontal direction of the projection system unit lO,
That is, a horizontal address signal that determines the exposure position in the reciprocating direction; 25 is a comparison circuit; 26 is a comparison output; 27 is a storage circuit for specifying the scanning video signal position; and an image input as a time-series signal from a terminal 28. One color of pixel signal (red, green.

The light emitting diode brightness modulation signal (either blue) is digitized by the AD converter 29 and stored.

The signal stored in the storage circuit 27 is an exposure completion signal 3, which will be described later.
1, the FIFO circuit (first-in, first-out circuit) sequentially transfers the memory contents to the buffer 33. 23 is a horizontal address counter,
1 each time the unit 10 moves forward or backward and the exposure is completed.
If there is a match, the next exposure image pixel signal is stored in the storage circuit 27 via the terminal 28 according to the output 26 signal, and the above operation is repeated. Reference numeral 34 denotes a drive signal generation circuit for reciprocating the projection system unit 10, which is composed of a triangular wave generation circuit.

35 is a light emitting diode for position detection provided in the projection system unit, 36 is a group of photodiodes provided opposite to the light emitting diode 35, and by detecting the light from the diode 35, a detection circuit 37 detects the current state of the projection system unit. It detects the position.

The details of the detection circuit 37 are not directly related to the present invention, so the details will be omitted, but the position signal is converted into an analog signal by the DA converter 38 and applied to the operational amplifier 39. As a result, the coil 16 of the coil unit 13 moves the coil unit 13 forward (or backward) by an amount corresponding to the output of the triangular wave generating circuit 34, thereby determining the horizontal position of the projection system unit, that is, the exposure position. The photodiode group 36 is provided around the area where the light emitting diode 35 moves, that is, the reciprocating range of the projection system unit.

The triangular wave generating circuit 34 outputs a horizontal scanning end signal to the terminal 41 every time a signal amount corresponding to the forward or backward movement completion position of the projection system unit is formed, that is, every scan, and the amplifier 42 outputs a horizontal scanning end signal. The signal is amplified in width and applied as a one-step drive signal to the step motor 20. As a result, each time the projection system unit 10 moves forward or backward, the instant printing film 6 is fed vertically by one step by the step motor 20.

On the other hand, the scanning end signal is applied from the terminal 41 to the counter 23, and the counter 23 is counted up. As a result, a medium horizontal scanning signal of the image pixel signal is input from the terminal 28.

The storage circuit 27 stores pixel signal components at each position corresponding to the number of horizontal luminance information for each color signal, and
The brightness modulation signals of each light emitting diode in each basic configuration of the projection system unit can be read out separately with some overlap. Regarding the light emitting diodes for one color in each basic configuration, The data selector 44 selects the output of the buffer 33 based on the output of the position detection circuit 37 each time the projection system unit moves and the signal of the photodiode group 36 changes, that is, the light emitted from the light emitting diode shifts. Output line 45, DA
Via the converter 50, a brightness modulation signal is applied to the light emitting diode IA.

As can be understood from the fact that each pixel image is exposed while being overlapped as shown in FIG. 4, the data selector 44 is configured to read out a portion of the data from the buffer 33 while being overlapped.

In the above explanation, the basic configuration of each projection system unit was explained for a single color image X, but it goes without saying that similar circuit configurations are required for other color emitting light emitting diodes in order to form color pixels. Na-.

In FIG. 9, 46 is a window function generator.

As mentioned above, each light-emitting diode of each projection system unit has a pixel of 4.16 pixels and exposes 33 pixels of O, I3G, and Otori. In addition, since the pixels are exposed repeatedly, each joint is made inconspicuous, so while each exposure position of the unit IO is determined by the photodiode group 36, each light emitting diode When the position is determined, the brightness of the unit 10 gradually increases to a brightness that faithfully reproduces the stored pixel signal, and then, when the unit 10 starts moving to the next exposure position, the brightness gradually decreases. Similarly, it is necessary to vary the brightness of each light emitting diode.

The window surface number generator 46 performs such modulation, and the ROMK provides a function output form that modulates the brightness at the overlapped portion of pixels when the unit 10 moves. 47 is a pickup coil that electromagnetically detects the moving speed of the projection system unit; 48 is an amplifier; 49 is a DA converter that converts the digital output of the window number generator 46 into analog using the output of the amplifier 48 as a reference signal; 50 is a pickup coil that electromagnetically detects the moving speed of the projection system unit; DA converter 49 output, terminal 45
A DA converter is shown for multiplying pixel data from.

The big amplifier 47 detects the speed while the unit 10 moves to each pixel exposure position (by the above modulation circuit network), and the output of the window function generator 46 is further corrected based on the speed signal. , the pixel information from the terminal 45 is corrected as the output of the DA converter 49. Therefore, the output of the window surface number generator 46 is corrected even if there is unevenness in the moving speed of the unit 10, and the joints of the overlapping parts are not noticeable at all.

In the basic configuration of the unit 100, 16 sets of three light emitting diodes, that is, 48 light emitting diodes are used, but individual unevenness in light emission is caused by the D/A output because the D/A converter 50 is provided for each diode. can be corrected by modifying, but it is also possible to simply set and adjust a correction resistor for each diode. With the above configuration, the unit 10 is horizontally connected to the coil 16.
When the pickup coil 4 is moved based on the excitation force,
7 detects the speed signal, the function output of the window surface number generator 46 is corrected according to the current speed, and during the movement of each light emitting diode unit 10, the pixel signal at the exposure position is faithfully reproduced. The light emission is controlled in such a manner that the light is modulated and exposed at such a brightness that the seam is not noticeable at the front and back double positions. Since the above-mentioned circuit network is provided for each diode, the correction due to such speed unevenness can be completely performed.

As described above, in the above embodiment of the present invention, a unit including a large number of sets of light emitting semiconductors such as diodes with different colors is driven by a coil, but a piezoelectric element 55 as shown in FIG.
By stacking a large number of layers and applying an alternating voltage of 58 t to each element, 59
This can also be realized by providing a laminated plate 55 for displacing the elements in the direction in the enlarged structure as shown in FIG. In FIG. 11, reference numeral 61 denotes an enlarged lever, and the unit 10 is reciprocated by the pivot point 62 of the end portion 62 where the displacement of the laminated plate 55 is increased by the lever ratio. Note that 63 is the drive source for the guide rail 64 of the unit 10, and 65 is the drive source shown in FIG.
36°47; According to such a conversion example, the piezoelectric element requires only a slightly higher voltage to drive, and the same drive as shown in Fig. 9 requires only 64 drive circuits instead of 39 amplifiers, allowing power-saving high-speed drive. There are advantages to being able to do so.

Further, in FIG. 9, the DA converter 50 uses a pulse modulation circuit or the like to adjust the duty ratio and frequency atl of the output pulse signal.
- It may be modulated.

Furthermore, it goes without saying that without using the fly's eye lens shown in the first figure, cylindrical lenses can be arranged orthogonally to each other and the intersection point can be used in place of the fly's eye lens.

As described in detail, the present invention combines a plurality of semiconductor elements such as LEDs with different colors and a multi-group reciprocating mechanism to easily print images (color images of No. G) onto instant printing film at low cost. This makes it easy to create a medium-speed, maintenance-free printer for home use.

Further, as described above, in the present invention, in order to form a high-quality image using a relatively small number of light emitting semiconductors such as LEDs and an optical system, the projection system unit is reciprocated to form a scanning system. As a result, since there are relatively few LEDs, variations in each LED can be adjusted individually, allowing for highly accurate placement of LED chips and long LEDs.
Difficulties in manufacturing such as creating a play are eliminated, and both image quality and manufacturing are excellent.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of the main parts of a projection section of a printer device according to the present invention. FIG. 2 is a cross-sectional view of a lens used in the first illustrated projection section. FIG. 3 is an explanation of forming an image using the first illustrated projection section. Figure 4 is an image formed by the third illustration and explanatory diagram. Figure 5 is an explanatory diagram showing the movement locus of the projection unit in the first diagram. 6th
8th is an overall perspective view of the illustrated mechanism. FIG. 9 is a reciprocating mechanism and a drive circuit for driving the step-feeding mechanism. FIG. 10 is a configuration diagram of a piezoelectric element unit used in the reciprocating mechanism. The figure shows a configuration diagram of a reciprocating mechanism using the first O-illustrated unit. ■A~3A; Light emitting semiconductors 5A~5C; Optical member 6; Films 11~17; Reciprocating mechanism

Claims (1)

[Claims] A plurality of exposure units each including a light emitting semiconductor forming a plurality of pixel light sources and an optical member forming a pixel image are arranged in parallel, and are moved back and forth relative to the photoreceptor surface, and in synchronization with the back and forth movement, A light-emitting semiconductor light source is used, characterized in that the light-emitting semiconductor light source is configured to sequentially print color pixels using light-emitting semiconductor light on the photoreceptor by relatively moving the photoreceptor and the exposure unit in the reciprocating cross directions. Printer device.