JPS6260356A - Picture forming device - Google Patents

Abstract

PURPOSE:To apply printing while forming plural kinds of pictures different in dot density by using one set of liquid crystal optical shutter array having plural shutter arrays different in arranging density, moving the liquid crystal shutters and placing each shutter array selectively corresponding to a light source. CONSTITUTION:The shutter arrays A1, A2 of the liquid crystal optical shutter 20 are selected by a shutter position setting device 21 based on picture information to lace them corresponding to a light source 16, the shutter part is driven by a liquid crystal drive circuit 33 to control the transmission of light from the light source 16 and to form a picture with prescribed dot density on a photosensitive drum 1. Since the arranging density of the shutter array A1 is 240-dot/inch, the dot density of the picture is 240-dot/inch and its 1/integral number, that is, 120, 80, 60, 48...-dot/inch. Further, the dot density of the shutter array A2 is 300-dot/inch and 150, 100, 75, 50...-dot/inch. Thus, plural kinds of pictures different in dot density is formed for printing and the picture information different in dot density is received in a wide applicable range.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus using a liquid crystal optical shutter.

[Technical background of the invention and its problems]

Recently, devices using liquid crystal optical shutters have been developed.
2. Description of the Related Art Among optical writing printers used as computer terminals or office equipment that perform side-by-side printing by single-light writing, printers that use liquid crystal optical shutters for optical writing have been developed.

This optical writing printer creates a dot (light spot) on the photoconductor by controlling the irradiation of light from the light source between the light source and the photoconductor.
The optical recording section is constructed by providing a liquid crystal optical shutter for forming an image gI (electrostatic latent image) consisting of the following. The liquid crystal light shutter is equipped with a shutter array formed by arranging minute shutter parts that control the transmission of light. It is constructed by forming a transparent electrode on the surface.

When printing with this printer,
Each shutter section in the shutter array of the liquid crystal optical shutter is selectively "opened" by a signal from the shutter drive circuit.
(light transmission) or "closed" (light non-transmission) to control transmission of light from the light source. This forms an image, for example, an electrostatic latent image representing characters, on the photoreceptor by combining a large number of dots (light spots). Furthermore, the electrostatic latent image on the photoreceptor is converted into a visible image and printed on recording paper.

In conventional optical writing printers, the liquid crystal optical shutter provided in the optical recording section is configured to include a single shutter array formed by arranging shutter sections at a predetermined density. Therefore, in a conventional optical writing printer, an image is formed and printed with a dot density corresponding to the arrangement density of the shutter parts in a set of shutter arrays provided in the liquid crystal optical shutter, and a dot density that is 1/an integer of that density. For other different dot densities, r.

Due to the different size and array density of the dots, it is not possible to form and print an image with the liquid crystal light shutter with the single shutter array, which limits the dot density in printing.

For example, when using a liquid crystal light shutter equipped with a shutter array in which shutter sections are arranged at a density that forms an image (for example, Chinese characters) with a dot density of 240 dots/inch, the dot density is 300 dots/inch. It is not possible to form and print images (for example, English characters) in dots and g/inches.

For this reason, conventional optical writing printers can only be used when receiving an image signal having a specific dot density defined by the arrangement density of the shutter portion of the liquid crystal optical shutter, which limits its use.

When the temporary paper is used to receive image signals with different dot densities, the image signals are sent to the printer's specific 2. It is necessary to use expensive conversion equipment to convert the signal into a signal with high density.

Therefore, there is a need for the development of an optical writing printer that can perform multiple types of printing with different dot densities.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide an image forming apparatus with a simple configuration that can form and print a plurality of types of images having different dot densities and can be used for a wide range of purposes.

[Summary of the invention]

The image forming apparatus of the present invention includes a light source, a photoreceptor, and means for converting an electrostatic latent image on the photoreceptor into a visible image, and further includes a plurality of devices for controlling transmission of light from the light source. A liquid crystal light shutter has a plurality of shutter arrays in which minute shutter parts are arranged at different densities, and a means for selectively moving each shutter array of the liquid crystal light shutter to a position corresponding to a light source is provided to correspond to the light source. The shutter section of the shutter array located at the position controls transmission from the light source to form an electrostatic latent image on the photoreceptor.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to drawings.

An optical writing type printer as an embodiment of the image forming apparatus of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 2 shows the overall structure of the optical writing printer, and FIG. 1 shows the optical recording section of the printer. In the figure, 1 is a photoconductive photosensitive drum, 2 is a capacitor that uniformly charges the surface of the photosensitive drum 1, and 3 is an optical recording unit that performs optical writing on the surface of the charged photosensitive drum 1. The unit 3 is driven by a recording control unit 4 that controls timing and the like based on recording information such as images, and irradiates the surface of the photosensitive drum 10 with light to erase charges on the light-irradiated portion of the photosensitive drum surface. It is designed to perform optical writing.

The electrostatic latent image formed on the surface of the photosensitive drum by optical writing in the optical recording section 3 is developed with toner by the developing device 5 .

Further, the recording paper 6 is fed by a paper feed roll 7,
After being temporarily stopped by the standby roll 8, the toner image on the surface of the photosensitive drum is sent to the transfer section 9 in synchronization with the toner image on the surface of the photosensitive drum. be done. This paper 6 is separated by a separation unit 10
The sheet is separated from the photosensitive drum 1 at a fixing device 11, and the toner image is fixed thereon, and the sheet is sent out by a sheet discharge roller 2.

Note that the photosensitive drum 9 on which the toner image was transferred to the paper 6 is
After the toner charge is neutralized by the static eliminator 13, the residual toner is cleaned by the cleaner 14, and the surface charge is neutralized by the eraser 15.

As shown in FIG. 1, the optical recording section 3 includes a light source 16, a liquid crystal optical shutter 20 provided between the light source 16 and the photosensitive drum 1, a shutter position setting device 21, an imaging lens, and e17. The light source 16 irradiates the surface of the photosensitive drum 10 with light from the light source 16 via the liquid crystal light shutter 20 and the imaging lens 17.
, liquid crystal light shutter 20 and shutter position setting device 2 =
1 constitutes a set of optical recording units. In addition,
16a is a reflection plate attached to the light source 16.

The liquid crystal light shutter 20 will be explained.

The liquid crystal light shutter 20 is horizontally elongated along the axial direction of the photosensitive drum l, and this liquid crystal light shutter 20 has a shutter array Al for 240 dots/inch and a shutter array Al for 300 dots/inch along its length. Two sets of shutter arrays, shutter array A for inches, are provided.

The structure of the liquid crystal light shutter 20 will be explained with reference to FIGS. 3 and 4. In the figure, 22 and 23 are a pair of upper and lower common boards and segment boards made of transparent plastic plates, and this pair of boards 22 and 23 are horizontally long. The space between the pair of substrates 22 and 23 surrounded by the sealing material 24 is filled with, for example, GH (dust, etc.).
A host) effect type liquid crystal (not shown) is filled.

The inner surface of the common board 22 has a groove along its entire length.
Three strip common electrodes C! *C.

C3 are formed in parallel with a minute interval.

A large number of rectangular segment electrodes S□ are provided on the inner surface of the segment substrate 23, facing the common '#L poles C1*C2 of the common substrate 22, respectively, along its length.
ISl...s s=esM... are arranged in two rows at a predetermined density, and are made to face the common electrodes 02eC2 of the common substrate 22, respectively, and are smaller than the segment electrodes S and Is. A large number of rectangular segment electrodes S3+S3, . . . , Sa+84, . Each of these common electrodes C1#Cz*”3 and segment electrodes 8
1 @s=ISl +Sa are transparent electrodes formed of transparent electrode materials.

Then, common electrodes C1, C, and segment electrodes S,
A shutter section &1+lL1... is formed at the portion where S,..., ISl... are opposed to each other, and this shutter section a1. By arranging al... in two rows in the longitudinal direction of the substrate, 240)'t/i, that is, shutter portion &l+lLl...(segment electrode S1*S1...
, SmaSB...) are arranged at a density of 240 dots per inch. Also: 2-gin electrode C,
, C, and segment electrodes Ss, S,..., 54eS
4... is the portion facing the shutter portion al
eA1... Smaller shutter section 11111...
A shutter array AI for 300 dots/inch is formed by arranging the shutter portions z, &2, . . . in two rows along the longitudinal direction of the substrate.

Sunawachi, shutter section & fim & l... (segment electrode Ss I S,..., S4 1 S4, =)
are formed in an array at a density of 300 dots per inch. In this way, there are two sets of shutter arrays A1.

A! are formed in parallel.

In the one shutter array AI, the segment electrode 8
118. ...and segment m1ss -8, ...
The electrodes S4+S4, . ...% al, &1・
... are arranged in an array with their positions shifted in the length direction of the substrate. Shifting the position of the shutter section in this way is an example of shutter array A! In all examples, the shutter portions 11 in one row. between the rows of irradiation points on the surface of the photosensitive drum that are irradiated with light that has passed through the shutter portions a1. This is to form an electrostatic latent image with high rt density on the surface of the photosensitive drum by irradiating the light that has passed through A1....

Furthermore, the segment electrodes 51sS1 in one column in one shutter array A and the segment electrodes S1+S1 in the other example are formed on the inner surface of the segment substrate 23 and are adjacent to each other with a positional shift. Segment electrodes S3°Ss... of one column and segments of the other column in the other shutter array AI are connected by common connection leads 25°25... tlEis
4 #84... are adjacent to each other with a positional shift and are connected by common connections +7-)26, 26... formed on the inner surface of the segment board 23.

Furthermore, one segment electrode 5lsS1... in the shutter array AI is provided with external connection leads 27.2, respectively.
7... is connected, and shutter array A! External connection leads 28, 28, . . . are connected to one of the segment electrodes S3+S3, . . . , respectively. The external connection leads 2f/, 27, . Each of these Lee? 2'1.27-..., 28
The tip portions of ゜28... are wide terminal portions 27m, 27m..., 28m, for connecting external connection conductors 32.
It is said to be 28m... Note that the common connection leads 25, 25, 26, 26, . . . and the external connection leads 27, 27, 28, 211, . In addition, the common electrode C1*
Cs*C3 uses each end as an external connection lead.

Further, as shown in FIG. 4, the common connection lead 25.2
5..., 26.26..., and external connection Lee Y27.
2: I..., 28.28..., terminal portion 27, .
27. ..., 28 turtle, 28a..., a low resistance metal film 29 is placed on the surface of the portion except for 28a...
．． 29... is the adhesion. Further, although not shown, a low resistance metal film is deposited on the surface of the common electrode C15c2+C3 except for the shutter portions aloal..., ``2h &2...''. is the common electrode C11c, +C3 and the external connection -Y
27°27..., 28.28..., etc. to reduce the electrical resistance, and the shutter part! Ll, al..., a
l #a! ... is provided to regulate the light transmission area. In the figure, 30.30..., 31.31... are shutter windows for light transmission regulated by this metal film (portion where transparent common electrode CI*cm I C3 is exposed)◎ Note that liquid crystal alignment films (not shown) are formed on the inner surfaces of the common substrate 22 and the segment substrate 23, respectively. Further, a polarizing plate (not shown) is provided on the outer surface of the common board 22.

The liquid crystal light shutter 2o configured in this way has the common electrode σ1 e C! m CB end and the external connection line? 27.21..., 211.28... terminal part' 7 & e 27 m..., 28**2gm
...Toku%g1 As shown in the figure, a flexible connecting conductor 32 is connected, and this connecting conductor 32 is connected to the liquid crystal light shutter 2.
It is connected to a liquid crystal drive circuit 33 that provides a drive signal to 0. In the shutter array 1, the common electrodes C1, C! and the common electrode c via the external connection lead 27.21... and common connection IJ-?25.25...
l.

C2 and segment electrodes s, ssi..., S2.

A voltage is applied between S,..., and the liquid crystal is operated to selectively "open" the shutter section 11181...
Or drive it "closed". Further, the shutter array A
2, the drive signal from the liquid crystal drive circuit 33 connects the end of the common electrode C3 to the external connection lead 28.2.
28... and common connection leads 26, 26..., common electrodes C,,C, and segment electrodes 53sS
A voltage is applied during 3...0.54sS4..., thereby selectively driving the shutter section &gm&3... to "open" or "close". In addition, this LCD light shade.

The sliding system 20 is, for example, time-division driving using two frequencies.

Note that the liquid crystal drive circuit 33 is included in the recording control section 4.

Next, the shutter position setting device 21 will be explained. 1st
In the figure, 34 is a holder that holds the liquid crystal light shutter 20, and this holder 34 holds the liquid crystal light shutter 20 on its common board 22.
The holder 34 is held so as to face the light source 16, and the holder 34 is provided so as to be linearly movable along the width direction of the liquid crystal light shutter 20 (the direction in which the shutter array is lined up).

Reference numeral 35 denotes a drive mechanism for moving the holding body 34, such as a brush or a pull-action type solenoid, and a rod 36 reciprocated by this solenoid 35 is moved to the holding body 34.
It is connected to. A solenoid drive circuit 37 provides a drive signal to the solenoid 35. Then, the solenoid 35 is driven by the drive signal from the solenoid drive circuit 31, and the s"l door J6 is moved in the direction of the arrow, and the holding body 34 is linearly moved together, thereby moving the liquid crystal light shutter 20 in the width direction ( shutter array AI of the liquid crystal light shutter 20 and the shutter array AI of the liquid crystal light shutter 20 are selectively moved to a position facing the light source 16.

That is, by moving the liquid crystal light shutter 20 in the direction of the solid line arrow by a distance corresponding to the shutter arrays P and H,
By positioning one shutter array A1 corresponding to the light source 16 and moving the liquid crystal light shutter 20 in the direction of the dotted line arrow by a distance corresponding to the shutter array pitch,
The other shutter array A1t is positioned corresponding to the light source 16.

Note that the lunoid drive box 37 is included in the recording control section 4.

The operation of the optical recording section 3 in the optical writing printer configured in this way will be explained. In the optical recording section 3, the shutter position setting device 21 selects shutter arrays A and #A of the liquid crystal optical shutter 20 and positions them corresponding to the light source 16 based on the image information. The shutter section of the shutter array A1*A located at the shutter array A1*A is driven by the liquid crystal drive circuit 33, and the transmission of light from the light source 16 is controlled to produce photosensitive light. An image with a predetermined dot density is formed on the ram 1. That is, the solenoid 35 is driven by a drive signal from the solenoid drive circuit 37 based on the image information, and the liquid crystal light shutter 20 is moved in the direction of the solid line arrow through the opening, the door 36 and the holder 34, and one shutter array is moved. A is positioned corresponding to the light source 16.

Then, a drive signal based on the image information from the liquid crystal drive circuit 33 drives the shutter sections &ls&1 of the shutter array A1 to "open" or "close".

As a result, the light from the light source 16 is transmitted to the shutter section 1 of the shutter array A1! .

Transmission is controlled by al..., and this light is further irradiated onto the surface of the photosensitive drum 10 via the imaging lens Je17 to form an electrostatic latent image, that is, an image consisting of dots. The dot density of this temporary image is based on the arrangement density of the shutter sections ahaa1... in the shutter array A, and the arrangement density of the shutter sections altal-.
Since the dot/inch is 0 dots/inch, the dot density of the image is 24
0 de, g/inch and its 1/integer i.e. 120°8
0.60,48--do, to/inch. Generally, a dot density of 240 dots/inch is used when printing Kanji characters. Further, the solenoid 36 is driven by a drive signal from the solenoid drive circuit 32 to move the liquid crystal light shutter 20 in the direction of the dotted line arrow, and the other shutter array AI is positioned corresponding to the light source 16. Then, a drive signal from the liquid crystal drive circuit 33 drives the shutter sections am, shutter 2, etc. of the shutter array A to "open" or "close". In this way, the light from the light source 16 is transmitted to the shutter array A! Sha.

Transmission is controlled by the tag section and the tag section, and a latent image, that is, an image, is formed of dots on the surface of the photosensitive drum 1. The dot density of this image is the shutter array A
Shutter part 13°a at 3! ... is based on the arrangement density of the above-mentioned Sha.

Since the arrangement density of the rear portion 121m1 is 300 dots and V inches, the dot density of the image is 300 dots and 87 inches, and its l/integer, that is, 150% 100.75.50
...Do, G/inch.

Generally, a dot density of 300 dots/inch is used when printing all English characters (alphabet). In this way, by using the two shutter arrays AI and A in the liquid crystal light shutter 20, a wide range of dots 9. Density: 300, 240, 150, 100゜1
20.80.75.60,50.48... de.

An 87-inch image can be formed and printed.

Therefore, the optical writing glinter of the present invention has a decoder.

It can also be used both for receiving image information with a dot density of 240 dots/inch and for receiving image information with a dot density of 300 dots/inch.

Further, the optical recording section 3 includes two shutter arrays A1 and one liquid crystal optical shutter 20 as a single optical recording unit.
, 3 are provided, and the liquid crystal light shutter 20 is moved by the shutter position setting device 2 to set each shutter array A1.
Since the configuration is such that mA and B are selectively set at positions corresponding to the light sources 16, an optical recording unit having one liquid crystal optical shutter each equipped with one set of shutter arrays,
Compared to a configuration in which two sets of cards are provided, the number of parts is small and the configuration for mounting in the optical writing glinter is simple.

5 and 6 show other embodiments of the liquid crystal optical shutter 20. FIG. In this embodiment, the liquid crystal light shutter 2
0, segment electrode s1 of shutter array A1
．． s, ... and shutter array A, segment) IEt
fiSa s 84... (Things that are in DH contact,
Connected by the common connection lead 38 formed on the segment substrate 23, the segment electrode i-pole s of the shutter array Al
* ISl..., S z * S 2... and shutter array A snow C)
A large number of electrode lines are formed in which mutually adjacent ones of 3..., S4*Sa, . . . are connected by common connection leads 25, 26°38. Further, on one side edge of the segment board 23, in place of the external connection lead 25, an external connection lead 39° is connected to the segment electrode 51eS1 of every other electrode line among the electrode lines. 39..., and on the other side edge of the segment substrate 23, in place of the external connection leads 26, segment electrodes 83. External connection leads 40, 40, . . . to be connected to S, . . . are formed.

In such a configuration, the number of external connection leads formed on both sides of the segment board 23 is reduced, making it easier to form the leads, and the external connection leads 39, 40 are easier to form.
The width of the terminal parts 39* and 40* can be increased,
This terminal portion 39a.

The adhesive strength between the terminal 40a and the terminal bonded thereto can be increased.

In addition, in the above-mentioned embodiment, one liquid crystal light shutter has two
Although two sets of shutter arrays are provided, the present invention is not limited to this, and three or more sets of shutter arrays having different arrangement densities of shutter parts may be provided.

Furthermore, the method of moving the liquid crystal light shutter to set the shutter array at a position corresponding to the light source is not limited to the case where the shutter is moved linearly as in the embodiment, and other methods such as moving the liquid crystal light shutter to the position corresponding to the photosensitive drum are also possible. It may be moved along the circumferential direction.

〔Effect of the invention〕

As explained above, according to the image forming apparatus of the present invention, one liquid crystal light shutter array having a plurality of shutter arrays with different arrangement densities of shutter parts is used, and this liquid crystal light shutter is moved to is selectively positioned corresponding to the light source, and the shutter section of the selected shutter array controls the transmission of light from the light source to form an image on the photoreceptor, making it possible to produce multiple types of images with different dot densities. Not only can it be formed and printed, but it can also be used in a wide range of applications that receive image information with different dot densities. Means for forming a plurality of types of images with different textures can be realized with an economical configuration.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention,
Fig. 1 is an explanatory diagram showing the optical recording section of the optical writing printer, Fig. 2 is an explanatory diagram showing the entire optical writing printer, Fig. 3 is a plan view showing the liquid crystal optical shutter, and Fig. 4 is the same liquid crystal optical shutter. 5 and 6 show other embodiments, FIG. 5 is a plan view showing a liquid crystal light shutter, and FIG. 6 is an enlarged plan view showing a segment board of the same liquid crystal light shutter. FIG. DESCRIPTION OF SYMBOLS 1... Photosensitive drum, 3... Optical recording part % 9... Transfer part 111... Fixing device, 16... Light source, 20...
Liquid crystal light shutter, 21...Shutter position setting device, 2
2... Common board, 23... Segment board, 51
eS2sSses4... Segment electrode, C,, C intention, C8... Como 78 flight s al I C3-.
・Shutter part % Al lA2...Shutter array.

Claims (1)

[Claims] A liquid crystal light shutter including a light source and a plurality of shutter arrays in which a plurality of shutter parts for controlling transmission of light from the light source are arranged at different densities, and a plurality of shutter arrays of the liquid crystal light shutter. a shutter device setting means that selectively moves to a position corresponding to the light source, and a photoreceptor that forms an electrostatic image by being irradiated with a light beam from the light source that has passed through a shutter portion of the shutter array in the liquid crystal light shutter. and means for converting the electrostatic image on the photoreceptor into a visible image.