JPS63274565A - Liquid crystal printer - Google Patents

Abstract

PURPOSE:To enable indication of delicate shading gradation by dividing an image to be displayed on a liquid into separate fractions, if necessary, indicated in a flashing manner, and controlling the total amount of the fractions and the amount of exposure to a sensitive element. CONSTITUTION:A liquid crystal head 3 is fixed to a copy table 10 in parallel with a sensitive element 2 in a housing 10, and provided with at least two rows of image display parts 30 corresponding to the rotary direction of the sensitive element 2. An image synchronizing control part 41, in response to an image signal, drives all the image display parts through synchronization with the moving speed of the sensitive element 2 and via an optical system 5 so that light emitted from the image display parts in the second and following rows may be projected to a part of the sensitive element to which light coming from the image display parts of the first row has once projected. In addition, a shading control part 42 controls the ON/OFF operation of the image display parts 30 in each row which projects light to the same parts of the sensitive elements 2 in response to the shading of an image signal. Thus a delicate shading gradation can be indicated and the resolution of the printer is improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid crystal printer device.

[Prior Art] A conventional liquid crystal printer device includes a photoreceptor housed in a housing, a liquid crystal head having an image display section disposed parallel to the photoreceptor, and a liquid crystal head that displays the photoreceptor based on an image signal. A control unit C includes an image control unit that drives the image display unit at a speed corresponding to the moving speed of the liquid crystal head, and an optical mechanism that transmits reflected light or transmitted light irradiated to the liquid crystal head to the photoreceptor. ing.

Further, a liquid crystal printer tiffl having the above structure is disclosed in, for example, US Pat. No. 4,194,833.

[Problems to be Solved by the Invention] In the conventional liquid crystal printer device described above, the image displayed on the image display section of the liquid crystal head and scrolled is transmitted to the photoconductor via an optical mechanism. Further, exposure and exposure are performed on the surface of the photoreceptor depending on the presence or absence of reflected light or transmitted light that is transmitted to the photoreceptor via the optical mechanism in a portion that is lit as an image on the image display section or a portion that is not lit. The configuration is such that black and white gradation print output is performed depending on whether the printout is performed or not. However, since only white or black gradations are printed and displayed on paper, intermediate gradations (one-degree gradation) cannot be performed.

Furthermore, dot printers conventionally used as output for word processors and small computers have had slow printing speeds, and electrophotographic laser printers have been expensive. Furthermore, although inexpensive and high-speed printers are required, increasing the speed of the one-type dot printer described above to meet this demand inevitably increases costs. or,
Even in the case of a single-type laser printer, there is a mechanical limit to the cost reduction.

The present invention realizes a low-cost, high-speed printer by combining a liquid crystal, its first circuit, and a general copier. ! ! The main purpose is to reproduce igI (dark riWi tone) and improve resolution.

[Means for Solving the Problems] The liquid crystal printer device of the present invention includes a photoconductor housed in a housing, a liquid crystal head having an image display section disposed parallel to the photoconductor, and an image signal. and an optical mechanism that transmits reflected light or transmitted light irradiated onto the liquid crystal head to the photoreceptor. In the liquid crystal printer device, the liquid crystal head has at least two rows of image display sections corresponding to the rotation direction of the photoreceptor, and the control device synchronizes with the moving speed of the photoreceptor, The image synchronization 1IIi unit drives all the image display units so that all the light emitted from the image display units in the first row illuminates the part of the photoreceptor that is irradiated by the light emitted from the image display units in the first row, and the shading of the image signal. The on-off setting for each image display unit that illuminates the same photoreceptor portion according to the
11 parts, and is characterized in that it is configured to perform exposure on the photoreceptor corresponding to the gradation.

[Function] According to the liquid crystal printer device of the present invention, the liquid crystal head, which is disposed parallel to the photoreceptor and has an image display section, has at least two rows of image display sections corresponding to the rotational direction of the photoreceptor. In addition, the control device uses image synchronization I! ll1lI! 1 and II
It has a certain part. The image synchronization control unit synchronizes with the moving speed of the photoreceptor, and controls the image synchronization control unit to synchronize with the moving speed of the photoreceptor so that all the light emitted from the uniform display portions in the second row and below is irradiated with the light emitted from the image display portion in the first row. All image display units are activated to further illuminate the area!
lvru. The gradation control unit controls the on-state of each image display unit to WatI4 a portion on the same photoreceptor according to the gradation of the image signal.
Control off. By the function of this gradation control section, exposure corresponding to the density gradation is performed on the photoreceptor according to the density pia of the image displayed on all of the above-mentioned uniform display sections.

At the same time, the amount of static electricity charged on the photoreceptor changes slightly, and the static electricity corresponding to the density gradation becomes a gradation. As a result, for example, a toner image formed on paper becomes an image display having density gradation.

[Example] An example of the liquid crystal printer device of the present invention will be described based on FIGS. 1, 2, 3, and 4. The liquid crystal printer device according to the embodiment of the present invention includes a housing 1, a photoreceptor 2,
It consists of 3 liquid crystal heads, a v4IIl@mount 4, and an optical mechanism 5.

Conventional housing 1, photoreceptor 2, and optical mechanism 5 can be used as they are. The features of this embodiment reside in the liquid crystal head 3 and the control device 14.

The housing 1 includes a document mounting table 10 in the form of a transparent substrate.

The photoreceptor 2 is housed within the housing 1 and
It is configured to rotate clockwise in FIGS. 1 and 2 by a rotating shaft 101 which is rotatably held in FIGS. The optical mechanism 5 includes a light rA501 and a lens 502.

The liquid crystal head 3 is disposed on the document table 10 in a position parallel to the photoreceptor 2. In this case, the liquid crystal head 3
is fixedly held on a part of the housing 1 by a fixed frame ff31 so that it can be viewed clearly on the document table 10. As a result, the liquid crystal head 3 can be removed from the document mounting table 10 as needed, or the original can be placed on the table 10 and used. Note that when the liquid crystal head 3 is removed from the original platen 10, the original to be copied (not shown) is placed on the original platen 10 in the same way as a normal electrophotographic apparatus. As a result, copy paper having an IN image corresponding to the original to be copied can be obtained.

The liquid crystal head 3 includes an image display section 30 on a lower surface 301 facing the photoreceptor 2 . The image display unit 30 includes five rows of image division display units 30a arranged in a rotational direction parallel to the axis X direction of the photoreceptor 2.

It has 30b, 30G, 30d, and 30e. Image classification display sections 30a and 30 in the first to fifth rows facing the photoreceptor 2
On the b130c, 30d, and 30e, there is an image synchronization control section 41, which will be described later, and a shading! It is possible to move while displaying an image according to the image signal from the lj sin part 42.

Each of the image division display sections 30a to 30e includes pixels A-F, Al
~F1, A2-F2, A3-F3, and A4-F4 are formed.

Ken 1111 device f4Lt, image synchronization III 111 part 4
1 and a density control section 42. The image@period control unit 41 synchronizes with the moving speed of the photoreceptor 2, and first directs all the reflected light emitted from the image segmentation display units 30b, 130C, 30d, and 30e in the second or lower rows from the image segmentation display unit 30a in the first column. It is configured so that the emitted reflected light irradiates a portion of the photoreceptor 2 to be irradiated. That is, the reflected light moves from the segmental exposure section 20 located at the moving position 1' on the photoreceptor 2 side corresponding to the first row to the moving position M2.
', 3', 4', 5- while irradiating while changing,
Thereafter, in the same way as in the case of the image division display section 30a, all other image division displays 1M53cl, 30c, 30d, 3
It is configured to drive 0e. Also, gradation system al
The first part 42 is connected to the same photoreceptor 2 depending on the density of the image signal.
In other words, with respect to the display movement of the image on the image section display sections 308 to 30e, the corresponding section exposure 1 of the photoreceptor 2 is sequentially moved by position i! Image segment display units 30a, 30b, 30G, 30d, 30e that respectively illuminate I20
Control on/off for each time. And light and shade 11111 part 4
2 is capable of displaying on-off signals for each pixel A to F of each image division display section 30a to 30e.

According to the liquid crystal printer Iil of the embodiment of the present invention configured as described above, the liquid crystal head 3 is fixedly held on the 1asut stand 10 in the form of a transparent substrate, as shown in FIGS. 1 and 2. When the liquid crystal printer device is operated in this state, each of the iii image division display sections 30a, 3 of the liquid crystal head 3
0b, 30c, 30d.

30e is controlled by the action of the image synchronization control section 41 of the control section '114, and is moved in the direction of arrow S1 while displaying an image in synchronization with the moving speed of the photoreceptor 2.

Here, an image division display section 30a on the liquid crystal head 3
- 30e, each image classification display section 30a, 30b
, 30c, 30d, and 130e, a case where the image is displayed blinking while moving the display position in order will be described. For example, as shown in FIG. 3, in the image division display section 30a in the first row, an image is displayed only on pixel A, and no image is displayed on the other pixels B to F. In this case, the light irradiated from the light source 50 onto the image division display section 30a becomes reflected light and is transmitted onto the photoreceptor 2 via the lens 502. Then, the reflected light from the image division display section 30a is exposed to the division exposure section 20 at the movement position gf1', as shown in FIG. in this case,
Since an image is displayed on the pixels of the image division display section 30a, the irradiation light from the light source 50 is absorbed, and the amount of reflected light is small. Moreover, since no image is displayed on pixels B-F, almost no irradiation light from the light source 50 is absorbed, and the amount of reflected light is large. As a result, only the portion a of the segmental exposure section 20 at the moving position 1' of the photoreceptor 2 corresponding to the pixel is not exposed. Further, other portions b to r of the segmental exposure section 20 at the moving position 1' corresponding to the pixel 8-F are exposed to the reflected light. As a result, part a of the segmental exposure section 20 is the blackest, and parts b-f
Until then, it is displayed whiter than part a. When the image display section 30a in the first column finishes displaying an image, the image section display section 30b in the second column starts displaying an image based on the signal from the grayscale control section 42. Then, in this second column, as shown in FIG. 3, if only pixels A1 and B1 display images, and no images are displayed in pixels 01 to F1, the image division display in the first column As shown in FIG.
moves from the moving position 1' to the moving position I2', and exposure corresponding to the image displayed on the image division display section 30b is performed. Therefore, the segmental exposure section 20 of the photoreceptor 2 at the moving position 1i12-
In addition to the exposure amount at the movement position *i', the light emitted from the light source 501 is reflected by the image division display section 30b. In this case, an image is displayed between each pixel A1 to F1, and the photoconductor 2 at the moving position 2- is divided by pixel A1.81 with a small amount of reflected light and pixels C1 to F1 which do not display an image and have a large amount of reflected light. The light is exposed to the exposure section 20. Then, in the segmental exposure section 20, the portion a1 is displayed the blackest, the portion b1 is displayed the next black, and the portions C1 to f1 are displayed the next black. Next, when the screen is shifted to the third column image division display section 30C, pixels A2 to C2 shown in FIG. 3 display images, and pixels B2, F2, and F2 do not display. Then,
The exposure amount of the photoreceptor 2 corresponding to this is the part a shown in FIG.
2 becomes 11 black, then parts b2, C2, d2, B2,
f2 is the subsequent exposure amount. When displaying an image on the image division display section 30d in the fourth column, pixels A3 to D3 display an image, and pixels E3 and F3 do not display an image. Then, as shown in FIG. 4, the exposure amount to the photoreceptor 2 is in the order of parts a3, b3, C3, and d3, followed by parts B3 and f3, which are displayed the whitest. Furthermore, the image display section 5e in the fifth column starts displaying an image, and in this case, the image is displayed between pixels A4 to E4, and the pixel F4 does not display an image. Correspondingly, the exposure amount of the photoreceptor 2 is as shown in FIG. 4, with the portion a4 being the blackest, and sequentially becoming b4, C4, d4, B4, and f4. The portion a4 becomes the blackest, and the portion molecule 4 becomes the whitest, and the six portions a4 to f4 have exposure amounts with varying gradations in sequence.

As described above, in the case of the embodiment of the present invention, a plurality of image division display units 308 are configured on the liquid crystal head 3 and are opposed to the photoreceptor 2 via the transparent substrate-shaped document mounting table 10 and the lens 502. When displaying an image on the image display unit 30 having a diameter of 30e and synchronizing with the moving speed of the photoconductor 2, the image division display units are arranged in five rows parallel to the axial direction of the photoconductor 2. The configuration is such that images 308 to 30e can be displayed in six stages in the axial direction of the photoreceptor 2, and can be displayed one after another in the direction S2 opposite to the rotational direction S1 of the photoreceptor 2. That is, image classification displays 30a to 30
e is a pixel group A-F, Al-F1, A2-F2, A3-F3, which faces the photoreceptor 2 and is parallel to the axial direction S of the photoreceptor 2;
Among A4 to F4, each pixel group can display an image in 6 stages, and if the ij image is not displayed among the 6 stages, the corresponding level! ! t1=, 2-13-14', 5
' Each part af, a1~ of the segmental exposure section 20 of the photoreceptor 2
The amount of exposure to f1, a2 to f2, a3 to f3, and a4 to f4 can be sequentially increased. This exposure amount is applied to the image display unit 30 from the light source 501, becomes reflected light, passes through the lens 502, and is applied onto the moving surface 201 of the photoreceptor 2. In this case, when an image is displayed on the image display section 30, the light source 501
The light irradiated onto the image is absorbed by the image, and the light irradiated onto the photoreceptor 2
The amount of light reaching the top is reduced. Therefore, depending on the number of times an image is displayed between each image section display edge 30a to 308, the amount of exposure to the photoreceptor 2 is controlled, and an arbitrary gray scale can be obtained.

Furthermore, the image display from the image division display section 30a in the first column to the image division display section 30e in the fifth column and the exposure amount on the photoreceptor 2 corresponding to this image display will be explained. .

FIG. 5 shows the image classification display sections 308 to 3 of the above-described embodiment.
The total amount of exposure to the photoreceptor is shown for the light reflected at 0e. Here, assuming that the amount of reflected light is constant, six gradations are obtained in five columns. Next, consider the case where exposure is performed by creating a light amount distribution for each column. That is, considering the state in which the illuminance emitted from the light source 501 (see FIG. 2) on the liquid crystal head 3 increases sequentially as it moves from the first column to the fifth column image division display section, the image becomes Classification display section 3Qa
When expressed as , the energy of the light reflected in that state is 0.2 as shown in the bar graph. In this case, 0.2.0° 4.0.6.0.8.
When the energy is 1.0 and everything between the 1st and 5th columns is displayed as white, the energy is 0.2 + 0.4 + 0.6 + 0.
．． The photoreceptor 2 is exposed to energy of 8+1.0-3.0.

When the potential of the photoreceptor 2 is sufficiently reduced in this state, the total exposure amount will be 3.0-0.2 when only the first row is changed to black.
-2.8, and if only the second row is black, the total exposure is 3.0-0.4
=2.6. Furthermore, not only the amount of exposure in the thermal state,
The "exposure" can also be changed depending on which part is displayed in black. However, compared to the case of uniform distribution, the number of 11 light gradations increases, and in the 6-step g-image display method shown in the above embodiment, 16 gray levels are displayed at 0.2 intervals from O to 3.0.
Gradation is possible. Actually, since there are sensitivity characteristics of the photoreceptor 2, it is possible to form an optimal light amount distribution and to have a linear relationship between the number and combination of thermal states and the print density.

[Effects] According to the configuration of the present invention, the image displayed on the liquid crystal head is flashed several times as necessary, and the total amount and the amount of light from the light source displayed on the image and exposed on the photoreceptor are By controlling , it is possible to obtain a density fI scheme. This results in a printer that can express not just black and white gradations, but subtle gradations.

Therefore, the resolution of the printer can be increased.

[Brief explanation of drawings]

FIG. 1 is a partially sectional perspective view of a main part of an embodiment of the present invention. FIG. 2 is a longitudinal sectional side view showing the main parts of the liquid crystal printer device according to the embodiment of the present invention. FIG. 3 shows the display W! on the liquid crystal head 3 in FIG. It is a bottom view explaining the state which shows the change of four images. FIG. 4 is a plan view showing the exposure amount on the photoreceptor 2 corresponding to FIG. 3. Figure 5 shows the liquid crystal head 3 and the image division display section 3.
It is an explanatory view explaining the relationship with the amount of reflected light from 0a to 30e. 1... Housing 2... Photoreceptor 20... Sectional exposure section 3... Liquid crystal head 30... @ Image display section 30a, 30b, 30G, 30d130e... Image section display section 4... #Al11 device 41...ii Image period control unit 42...Darkness control unit Fig. 2 Fig. 4 Fig. 3

Claims (1)

[Claims] (1) a photoconductor housed in a housing; a liquid crystal head having an image display section disposed parallel to the photoconductor;
a control device having an image control section that drives the image display section at a speed corresponding to a moving speed of the photoreceptor based on an image signal; and a control device that transmits reflected light or transmitted light irradiated to the liquid crystal head to the photoreceptor. In the liquid crystal printer device, the liquid crystal head has at least two rows of image display sections corresponding to the rotation direction of the photoreceptor, and the control device synchronizes with the moving speed of the photoreceptor, An image period control section that drives all image display sections so that all the light emitted from the image display sections in two or less rows illuminates the part of the photoreceptor that is irradiated by the light emitted from the first row of image display sections; and a gradation control section that controls on/off of each image display section that irradiates the same part of the photoreceptor according to the gradation of the signal, and is configured to expose the photoreceptor in accordance with the gradation of gradation. A liquid crystal printer device characterized by the following.