JPH04153049A - Image-formation element and image reader and optical write head - Google Patents

Abstract

PURPOSE:To improve image-formation performance by providing a throttle plate between a lens array and a roof mirror array and a shade slit for varying transmission position of outgoing light arranged on the outgoing side of an image-formation element consisting of an optical path separation mirror in front of the lens array. CONSTITUTION:A lens array 4 is formed by arranging a plurality of lenses successively. A roof mirror array 2 is formed by arranging a plurality of roof- like reflecting surfaces successively at an arranging pitch of the lens array 4. Between the lens array 4 and the roof mirror array 2, a throttle plate 3 for shading stray lights among lenses adjacent to each other is provided. These are engaged with each other by basic pins and apertures and fixed in a frame 6. A shade slit 8 for shading unwanted lights in the direction of vertical scanning is attached to a cover glass 7. The cover glass 7 is formed slidably so as to shade unwanted beams other than the image-formation lights on the outgoing side when images with object points O1, O2 having different image heights are going to be imaged into image points I1, I2 on the outgoing side. Thus, image-formation performance can be improved.

Description

[Detailed description of the invention] Five five beans! The present invention relates to an imaging element, an image reading device, and an optical writing head, and is applicable to, for example, an image reading device used in a facsimile, an image scanner's original reading unit, a digital copying machine, and a light source for a self-scanning optical printer. It is something that will be done.

Figure 11 is a diagram showing a conventional example of a roof mirror lens array (RMLA). In the figure, 31 is a high-density roof mirror array, 32 is a high-density lens array, and 33 is an optical path separation mirror. The roof mirror lens array (RMLA) is arranged between an optical path separating mirror (SM) 33, a lens array (LA) 32, a roof mirror array (RMA) 31, and the lens array 32 and the roof mirror array 31. It is comprised of a diaphragm plate (not shown) provided therein, and a housing member for holding the components and blocking external light.

With such a configuration, the light from the object is reflected by the optical path separation mirror (SM) 33 and then imaged onto an image plane conjugate with the object plane. Then, an erect real image is formed in both the arrangement direction (Y direction) and orthogonal direction (X direction) of the lens array 32 and the roof mirror array 31. In particular, since an erect equal-magnification image is formed in the Y direction, the necessary width can be reduced by overlapping the images obtained by a single roof mirror array corresponding to the lens array 32 and the roof mirror array 31 in the Y direction. Cover. Furthermore, since the arrangement pitches of the lens array, diaphragm plate, and roof mirror array are almost the same, the light amount distribution of each lens is almost the same. Yes
The light amount distribution of each lens can be appropriately determined so that the light amount distribution in the directions is uniform.

FIG. 12 is a diagram showing a structure in which a roof mirror lens array (RMLA) is housed in a frame. In the figure, 34 is a pressure member (pressing spring), and 35 is a roof mirror array (R
MA), 36 is an aperture plate, 37 is a lens array (LA),
38 is an optical path separation mirror 39 is a frame, 40 is a cover (
contact) glass. The lens array 37, the aperture plate 36, and the roof mirror array 35 are engaged to form an integrated unit member.

Both ends of the frame 39 of the roof mirror lens array are open, and the unit member and the pressure member 34 are slidably inserted through the open portion of the frame 39 and fixed at a predetermined position within the frame 39. .

Furthermore, as shown in Fig. 12, the roof mirror lens array (RMLA) is capable of transmitting light (○) from different object heights on the object plane.
1, O, ) is the point (I
, ,I,), but if the image height is different, for example, the image height of the image point I,,I,.

h, the amount of light is different. However, if the structure is not such that it blocks light other than the effective imaging light beam, unnecessary light other than the respective conjugate points may reach the image point and the imaging performance may deteriorate.

As a known document describing the prior art related to the present invention, there is, for example, Japanese Unexamined Patent Publication No. 60-61273. This publication describes a light emitter array device in which dot array light emitters are arranged in two rows in a staggered manner in order to increase the dot density without causing the problem of electrical leakage.

Furthermore, Japanese Patent Application Laid-Open No. 60-89380 relates to an optical writing device using a 1-magnification imaging element and a plurality of rows of dot array light emitters (one row of which is a linear light emitter). FIG. 13 is a block diagram of the optical writing device described in the above-mentioned publication, in which 50 is a light emitting dot, 51 is a dot array writing section, and 5 is a dot array writing section.
2a to 52c are light emitters, 53 is a linear writing part, 54.55
is an electrode, and 56 is a head. Considering that both ends of the paper are often always blank when printing, the light emitting body 52 is
It is divided as shown by 2a, 52b, and 52c, and the light emitting bodies 52b, 52c at both ends are always made to emit light by an ON signal, except in the case of a special original. FIG. 14 is another configuration diagram of the conventional optical writing device described in the above publication, and in the figure, 57.58
59 is a device, 59 is a 1-magnification imaging element, 60 is a photoreceptor, and parts having the same functions as those in the Ryuteki figure 13 are given the same reference numerals.

In FIG. 13, a dot array writing section 51 and a linear writing section 53 are shown.
However, in FIG. 14, a device 58 having only the dot array writing section 51 and a device 57 having only the linear writing section 53 are provided separately.

However, in both publications, a light source for an optical printer is constructed by combining multiple rows of dot-shaped light emitters and a 1x imaging element, but since the light emitting element rows are separated, the 1x imaging element ( Since a light-shielding slit structured to shield light other than the effective light beam is not provided on the output side of the convergent optical fiber array, the imaging performance may deteriorate.

l - Kazutoyo The present invention was made in view of the above-mentioned circumstances,
In order to block unnecessary light in the sub-scanning direction of a roof mirror lens array (RMLA), a slit having a structure whose light-blocking position is variable is provided to improve the imaging performance of an imaging element. Roof mirror lens array (RM
To block unnecessary light in the sub-scanning direction in an image reading device configured to combine LA) and multiple rows of photoelectric conversion elements, particularly in an image reading device configured to combine multiple rows of photoelectric conversion elements having different pixel densities. By arranging slits with variable light-shielding positions, unnecessary light is blocked and reading quality is improved, and the light is constructed by combining a roof mirror lens array (RMLA, ) and multiple rows of light emitting elements. Light sources for printers, especially optical writing heads that combine multiple rows of light emitting elements with different pixel densities, are equipped with slits that block unnecessary light in the sub-scanning direction and have variable light-shielding positions to improve image quality. The purpose of this invention is to provide an imaging element, an image reading device, and an optical writing head that improve reliability and switching speed of the light-shielding position by making the light-shielding slit a structure with no moving parts. It is something that

In order to achieve the above object, the present invention provides (1) a lens array in which a plurality of lenses are successively formed, and a plurality of reflecting surfaces are continuously formed at the arrangement pitch of the lens array; a diaphragm plate between the lens array and the roof mirror array for blocking stray light between adjacent lenses; and an optical path separation mirror provided in front of the lens array. In an imaging element consisting of a frame that houses optical members, a light-shielding slit is provided on the output side of the imaging element to change the transmission position of the output light; A slit that blocks unnecessary light and whose position is variable is formed of liquid crystal, electro-optical material, electrochemical material, etc. that has a shutter function without moving parts, or (3) a light source that illuminates the surface of the document; a lens array in which a plurality of lenses are consecutively formed; a roof mirror array in which a plurality of reflective surfaces are consecutively formed at the pitch of the lens array; and between the lens array and the roof mirror array, An image reading device including an imaging element including an aperture plate for blocking stray light between adjacent lenses, an optical path separating mirror provided in front of the lens array, and a frame for housing these optical members, A light-shielding slit that changes the transmission position of the incident light on the incident side of the imaging element, and intensity information of reflected light corresponding to the original at the imaging position where information on the original surface is projected and imaged by the imaging element. (4) A light source that illuminates the document surface and a plurality of lenses are formed in series. A lens array, a roof mirror array in which a plurality of reflective surfaces are successively formed at the arrangement pitch of the lens array, and stray light between adjacent lenses is blocked between the lens array and the roof mirror array. In the optical writing head, the optical writing head is equipped with an imaging element consisting of a diaphragm plate, an optical path separation mirror provided in front of the lens array, and a frame that houses these optical members, on the output side of the imaging element. A light system that combines an imaging element with a light-shielding slit that changes the transmission position of emitted light and a group of microscopic light emitting segments such as a light emitting diode array, a liquid crystal shutter array, or a fluorescent dot array tube, and provides multiple rows of the microscopic light emitting segments. It is characterized by being equipped with a printer light source. Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a configuration diagram for explaining one embodiment of the imaging element according to the present invention, in which 1 is a pressure member (pressing spring), 2
3 is a roof mirror array (RMA), 3 is a diaphragm plate, 4 is a lens array (LA), 5 is an optical path separation mirror, 6 is a frame, 7 is a cover (contact) glass, and 8 is a light shielding slit.

The lens array (LA) 4 is formed by a plurality of continuous lenses, and the roof mirror array (RMA) 2 is formed by a plurality of continuous roof-shaped reflective surfaces at the arrangement pitch of the lens array (LA) 4. It is formed by The lens array (
A diaphragm plate 3 is provided between the LA) 4 and the roof mirror array (RMA) 2 to block stray light between adjacent lenses. The lens array (LA) 4, the aperture plate 3, and the roof mirror array (RMA) 2 have a reference bin (formed on the lens array 4 and the roof mirror array 2) and a reference hole (formed on the aperture plate 3). The integrated unit member is fixed in the frame 6 of the roof mirror lens array, and a light shielding slit 8, which is a slit-shaped light shielding member that blocks unnecessary light in the sub-scanning direction, is attached to the cover (contact) glass 7. Mounting, object points at different image heights 0,,0. The images of are respectively image points I, , on the exit side.
When an image is formed on I, the cover (contact) glass 7 can be slid so as to block unnecessary light beams other than the imaged light on the exit side.

FIG. 2 is a diagram showing a state in which the cover (contact) glass 7 is slid, and the cover (contact) glass 7 is slid a predetermined amount in the planar direction, that is, in the direction of arrow P, along the end surface of the frame 6 to block stray light. shows.

FIG. 3 is a configuration diagram for explaining one embodiment of an image reading device according to the present invention, in which 10 is a pressure member, 1 is a roof mirror array (RMA), 12 is a diaphragm plate, and 13 is a pressure member. Lens array (LA), 14 is an optical path separation mirror, 15 is a frame, 16 is a cover (contact) glass, 17 is a same-magnification image sensor, 18 is an illumination light source (LED), 19
is a roof mirror lens array (RMLA), 20 is a roller, 21a is a liquid crystal shutter A, and 21b is a liquid crystal shutter B.

The lens array (LA) 13, aperture plate 12, and roof mirror array (HMA) 11 are connected to the reference bin (lens array 13).
(formed on the roof mirror array 11) and a reference hole (formed on the aperture plate 12), the integrated members are fixed in the sensor unit frame, and the illumination light source (LED light source) 18 and photoelectric conversion elements are arranged in multiple rows. A slit-shaped light-shielding member, such as a liquid crystal shutter (LCD shutter, LC8), is installed as a shutter without moving parts to block unnecessary light in the sub-scanning direction. In the figure, liquid crystal shutter (LC3) 21a and liquid crystal shutter (LC3) 21b are light-shielding liquid crystal shutters arranged in the form of slits, and images with different image heights can be created by applying a voltage to each. Point 0. ,0. Each image point I of the image of
, I.

It has a structure that blocks unnecessary light beams in the sub-scanning direction when an image is formed.

The equal-magnification image sensor 17, which is a photoelectric conversion element, may have, for example, a plurality of rows of pixels having different pixel densities, or a plurality of rows of elements (color sensors) sensitive to light of different wavelengths.

FIG. 4 is a diagram showing the structure of the light source in the optical writing head according to the present invention. In the figure, 9 is a phosphor dot array tube, and the parts that have the same functions as those in FIG. 1 are given the same reference numbers. be. Lens array (LA) 4, aperture plate 3, and roof mirror array (RMA) 2 are connected to the reference bin (lens array 4).
(formed on the roof mirror array 2) and a reference hole (formed on the aperture plate 3) are fixed in the optical writing unit, and a phosphor dot array tube provided with multiple rows of micro segment groups as a light source. Unnecessary light in the sub-scanning direction, that is, images of object points 01 and 01 with different image heights are transmitted to image points 1 and 01 on the exit side, respectively. , I, and has a structure in which a cover glass 7 with a light-shielding slit 8 provided on the output side is slid so as to block unnecessary light beams when images are formed on , I.

FIG. 5 is a diagram showing a state in which the cover glass 7 is slid, and is in a state in which the cover glass 7 is slid along the end surface of the frame 6 in the in-plane direction, that is, in the direction of the arrow P to block unnecessary light beams.

The light source includes a phosphor dot array tube, a light emitting diode (LED) array, a liquid crystal shutter (LC3) array,
An electroluminescence (EL) array etc. can be used, and when multiple rows of micro segment groups are provided as a light source, writing at different pixel densities is facilitated by configuring the arrangement pitch of the segments to be different. . In the case of a liquid crystal shutter (LC3) array, since it is not a self-luminous light source, a separate illumination light source from the back side is used.

FIG. 6 is a diagram showing another embodiment of the light source in the optical writing head according to the present invention. In the figure, 8a and 8b are liquid crystal shutters (LC3), and the parts that have the same function as those in Figure 1 are the same. Reference numbers are included. In FIG. 4, the light-shielding slit 8, which is a slit-shaped light-shielding member, is attached to the cover (contact) glass 7, and the cover (contact) glass 7 is movable to block light.
The one shown in Fig. 6 has a structure in which a liquid crystal shutter (LCD shutter, LC3) is attached to the cover glass 7 on the exit side as a slit-shaped light shielding member, and images of object point 0+% Os at different image heights are obtained. are the respective image points I on the exit side
,, Unnecessary light flux in the sub-scanning direction when imaged on I is blocked by applying a voltage to each of the liquid crystal shutter (LC3) 8a and the liquid crystal shutter (LC3) 8b without having a movable part. It is structured.

In the above, the liquid crystal shutter (LC3) was explained as a slit that can change the position of blocking unnecessary light other than the effective imaging light flux.
L Z T (Lead (Plomb) Lanth
It is also possible to use an electro-optical material such as anum Zirconate Titanate, an electrochemical material such as tungsten oxide (WO, ), etc.

FIG. 7 is a block diagram of an electrophotographic recording apparatus that combines an optical writing head and an electrophotographic process.

22 is an optical writing head, 23 is a photoreceptor, 24 is a charger, 2
5 is a developing device, 26 is a transfer device, 27 is a cleaner, 28 is a static elimination lamp, and 29 is paper.

In the case of a copying machine, the reflected light from the original is imaged onto the photoreceptor 23 by a lens, and the charge on the surface of the photoreceptor 23, which has been uniformly charged by the charger 24, is selectively removed by the optical image, and the surface potential is increased. Creates high and low areas (latent image) based on the image.

Next, when development is performed in the developing device 25 with toner charged to a polarity opposite to that charged by the charging device 24, this toner adheres to the portion of the photoreceptor 23 that has not been irradiated with light, and is transferred under the action of the transfer device 26. This is transferred onto paper 29.

28 is a static elimination lamp, and 27 is a cleaner. Such an electrophotographic development process is called positive-positive development. Therefore, when considered as a printer, the area to be printed is the area that is not irradiated with light.

In printer applications, in order to reduce irradiation energy, negative-positive development is sometimes performed in which toner is attached to the area irradiated with light.

8 and 9 are configuration diagrams of photoelectric conversion elements that are the same-magnification image sensor of the image reading device in FIG. An example in which sensor row A and sensor row B are arranged is shown. Figure 9 shows
Three types of photoelectric conversion element arrays with different wavelength-specific sensitivities are sensor array R (sensor array sensitive to red), sensor array G (sensor array sensitive to green), and sensor array B (sensor array sensitive to blue). ) is shown.

FIG. 10 is a configuration diagram of the phosphor dots of the phosphor dot array tube of the optical writing head in FIG. It shows.

Shyness - As is clear from the above explanation, the present invention has the following effects.

(1) Imaging performance can be improved by arranging a slit with a variable light-blocking position for blocking unnecessary light in the sub-scanning direction of the roof mirror lens array (RMLA).

(2) In an image reading device that combines a roof mirror lens array (RMLA) and multiple rows of photoelectric conversion elements, especially in an image reading device that combines multiple rows of photoelectric conversion elements with different pixel densities, By providing a slit that blocks unnecessary light in the scanning direction and whose light-blocking position is variable, the reading quality can be improved.

(3) A light source for an optical printer that combines a roof mirror lens array (RMLA) and multiple rows of light emitting elements, especially an optical writing head that combines multiple rows of light emitting elements with different pixel densities. Image quality can be improved by providing a slit that can change the position of blocking unnecessary light in any direction.

(4) By making the light-shielding slit structure free of moving parts, reliability and speed of changing the light-shielding position are improved.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of an imaging element according to the present invention, FIG. 2 is a diagram showing a state in which the cover glass of FIG. 1 is slid, and FIG. FIG. 4 is a configuration diagram for explaining one embodiment of an image reading device.
FIG. 5 is a diagram showing the structure of the light source in the optical writing head according to the present invention. FIG. 5 is a diagram showing the state in which the cover glass of FIG. 4 is slid. FIG. FIG. 7 is a diagram showing the configuration of an electrophotographic recording device that combines an optical writing head and an electrophotographic process, and FIGS. FIG. 10 is a block diagram of the phosphor dots of the phosphor dot array tube in the optical writing head. FIG. 11 is a block diagram of the roof mirror lens array (R).
FIG. 12 is a diagram showing a configuration in which a roof mirror lens array (RMLA) is housed in a frame, FIG. 13 is a configuration diagram of a conventional optical writing device, and FIG. 14 is a diagram showing a conventional example of an optical writing device. 1 is another configuration diagram of a conventional optical writing device. 1... Pressure member (pressing spring), 2... Roof mirror array (RMA), 3... Aperture plate, 4... Lens array (LA), 5... Optical path separation mirror 6... Frame, 7...Cover (contact) glass, 8...
- Light-shielding slit.

Claims (1)

[Claims] 1. A lens array in which a plurality of lenses are continuously formed, a roof mirror array in which a plurality of reflecting surfaces are continuously formed at the arrangement pitch of the lens array, and the lens array. an imaging element that is arranged between the roof mirror array and includes an aperture plate for blocking stray light between adjacent lenses, an optical path separating mirror provided in front of the lens array, and a frame that accommodates these optical members; An imaging element characterized in that a light-shielding slit is provided on the output side of the imaging element to change the transmission position of the output light. 2. A claim characterized in that the slit, which blocks unnecessary light other than effective imaging light and whose position is variable, is formed of a liquid crystal, an electro-optical material, an electrochemical material, etc., which has a shutter function without moving parts. 1. The imaging element according to 1. 3. A light source that illuminates the document surface, a lens array in which a plurality of lenses are continuously formed, a roof mirror array in which a plurality of reflecting surfaces are continuously formed at the arrangement pitch of the lens array, and the lens. An aperture plate provided between the array and the roof mirror array for blocking stray light between adjacent lenses, an optical path separation mirror provided in front of the lens array, and a frame that accommodates these optical members. In an image reading device equipped with an imaging element, a light-shielding slit that changes a transmission position of incident light is provided on an incident side of the imaging element, and an imaging position where information on a document surface is projected and imaged by the imaging element. 1. An image reading device comprising: an equal-magnification image sensor having a plurality of rows of photoelectric conversion elements that read intensity information of reflected light corresponding to the document as intensity of an electric signal; 4. A light source that illuminates the document surface, a lens array in which a plurality of lenses are continuously formed, a roof mirror array in which a plurality of reflecting surfaces are formed in succession at the arrangement pitch of the lens array, and the lens. An aperture plate provided between the array and the roof mirror array for blocking stray light between adjacent lenses, an optical path separation mirror provided in front of the lens array, and a frame that accommodates these optical members. An optical writing head equipped with an imaging element includes an imaging element provided with a light-shielding slit on the output side of the imaging element to change the transmission position of the output light, a light emitting diode array, a liquid crystal shutter array, and a fluorescent dot array. An optical writing head comprising a combination of a group of minute light emitting segments such as tubes and an optical printer light source having a plurality of rows of the minute light emitting segments.