JPH05191572A - Contact image sensor unit - Google Patents

Abstract

PURPOSE:To realize the highly reliable contact image sensor unit capable of processing a large amount of reading matter to be used for industrial checking devices with erroneous reading prevented and haring its reading miss suppressed. CONSTITUTION:A fluorescent lamp 7 having the higher luminance compared with the conventional LED is used as a light source, a long distance can be taken from the reading matter and the light amount is sufficient enough to prevent the erroneous reading. An opening/closing section 2 is provided on a unit box 4, and from which the fluorescent lamp 7 is taken in and out. The seal member such as rubber packings 10 and 12 are arranged between the opening/closing section 2 and on the joint section with the glass to make the airtight structure. Thus, the maintenance such as replacement of the fluorescent light 7 of the light source is made easy, the good airtight is provided, and the entry of paper dusts can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact image sensor unit for reading an image in OA equipment, industrial inspection equipment and the like, and more particularly to a contact image sensor unit suitable for printed matter inspection equipment.

[0002]

2. Description of the Related Art A contact type image sensor unit irradiates an object to be read with light from a light source, and reflects the reflected light through a small light guide means such as a SELFOC lens or directly. Lead to. This photoelectric conversion unit converts an optical signal into an electric signal to obtain image information of the object to be read in the form of an electric signal. The OCR (Opt
It is used as a sensor for inspecting the quality of printed matter of an industrial inspection device, such as an ionic character reader) device.

The conventional contact type image sensor unit is
LED (Light Emitting D) as a light source
and a photo sensor module in which photo sensor elements whose main part is, for example, amorphous silicon (hereinafter abbreviated as a-Si) are arranged in the same width as the object to be read, and plate bodies on the front, rear, left, and right sides. To the photo sensor of the photo sensor module, and a unit housing in which a glass window is arranged on the surface that is joined to the object to be read by using a screw or an adhesive And a light guide means such as a SELFOC lens.

The use of an LED as a light source means that the LED can obtain light of a wavelength close to the visual sensitivity with low power consumption.
Moreover, the reason is that the light emitting element has excellent durability, stable light emitting ability, and high reliability.

However, in the conventional contact type image sensor unit using such an LED as a light source, since the brightness of the LED is low when the image of the object to be read is read at high speed, it is led from the object to be read. The photo sensor cannot pick up the image light sufficiently,
That is, there is a problem that the optical signal of the image cannot be surely converted into an electric signal, which causes a reading error. Specifically, the illuminance is about 3000 to 4000 lux, and the distance to the object to be read is up to 5 mm.
Since it can only be separated to a certain extent, there are severe restrictions on the placement position, and when performing high-speed reading, it is necessary to maintain a certain distance from the object to be read.
There is a problem that it is not easy to use such an LED.

Further, the unit casing is joined and assembled using the screws or the adhesive as described above, and its hermeticity is not sufficient. Therefore, particularly in the case of an industrial inspection device that processes a large amount of objects to be read at high speed, such as a print quality inspection device, paper dust or ink generated when the objects to be read are fed. There is a problem that mist or the like enters through the gap of the joint portion of the unit housing and adheres to the SELFOC lens or the photo sensor of the photo sensor module, hinders good reading, and causes a reading error.

[0007]

As described above, in the conventional contact type image sensor unit, since the LED is used as the light source, the brightness of the light source is low and the light quantity is insufficient for high-speed reading. Therefore, there is a problem that a read error occurs.

Further, since the unit casing is not always sufficiently airtight, paper dust, ink mist or the like enters the inside of the unit casing and adheres to the photosensor or SELFOC lens to cause a reading error. was there.

The present invention has been made to solve such a problem, and an object thereof is to provide a large amount of high-speed objects to be read such as those used in industrial inspection equipment such as a print quality inspection device. It is to realize a contact type image sensor unit which can be processed and has a high reliability in which occurrence of reading errors is suppressed.

[0010]

In order to achieve such an object, the contact image sensor unit of the present invention comprises:
A light source including a fluorescent lamp, a photo sensor module for reading an image of an original by light emitted from the light source, the light source and the photo sensor module are housed, and an opening / closing portion is provided so that the fluorescent lamp of the light source can be attached and detached. In addition, it is characterized by comprising a casing having a hermetically-sealed structure in which a sealing material is provided at the joint portion and the opening / closing portion.

Since the fluorescent lamp as the light source emits light while repeatedly blinking due to the operating principle of the fluorescent lamp, the photosensor module is driven in a time-division manner, that is, so-called multiplex driving. If there is
Depending on the scanning timing and the timing of the blinking operation of the fluorescent lamp, the flicker caused by the blinking of the fluorescent lamp may cause a reading error of the photo sensor module.Therefore, use two or more fluorescent lamps as the light source. The light emission operation is performed by shifting the phase of each light emission timing. Alternatively, the light emission cycle of the fluorescent lamp may be adjusted to be relatively shorter than the scanning cycle.

[0012]

In the contact-type image sensor unit of the present invention, a fluorescent lamp is used as a light source, the brightness thereof is significantly higher than that of a conventional light source using an LED, and the distance from the object to be read is Since it can be made much larger than an LED, the light amount does not become insufficient even at the time of high-speed reading that requires a high brightness for the light source and requires a distance from the object to be read. Therefore, the occurrence of reading mistakes can be suppressed.

When a fluorescent lamp is used as a light source as described above, since the fluorescent lamp generally has a shorter service life than the LED, the life of the fluorescent lamp is longer than that of the LED. It is necessary to take it out of the case and replace it with a new one. Therefore, in order to easily perform such an operation, the contact-type image sensor unit of the present invention is provided with an opening / closing portion in the housing, and the fluorescent lamp is put in and taken out from the opening / closing portion. Since the housing is provided with the opening / closing portion in this manner, maintenance such as replacement of the light source is easy.

Further, since the casing has a hermetically sealed structure by disposing a sealing material at the joint portion and the opening / closing part, the hermeticity is sufficiently good, and paper dust or ink mist is contained inside the unit casing. Since these do not invade, the problem that they adhere to the photo sensor or the SELFOC lens and a reading error occurs is solved.

As a result, the contact-type image sensor unit of the present invention can process a large amount of objects to be read at high speed, suppress the occurrence of reading errors, and have high reliability. The contact image sensor unit is suitable for such industrial inspection equipment.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing the appearance of the contact image sensor unit of the present invention, and FIG. 2 is a sectional view thereof.

The contact type image sensor unit comprises a unit housing 4, a photo sensor module 5 housed in the unit housing 4, a fluorescent lamp 7 as a light source, and a SELFOC lens 9 as main components. ing.

The unit housing 4 accommodates the photosensor module 5, the fluorescent lamp 7, the SELFOC lens 9, and the reflector 11 therein. The reflector 11 is for efficiently irradiating the object to be read (not shown) with the light of the fluorescent lamp 7 through the glass 3.

As shown in FIG. 1, the unit housing 4 is composed of a main body 1 and an opening / closing section 2. The opening / closing section 2 is supported by a hinge 13 on one side in the longitudinal direction and is locked on the other side. A part, here a so-called snap lock 15, is locked. The snap lock 15 is unlocked to open the opening / closing part 2, and the fluorescent lamp 7 fixed to the main body 1 of the unit housing 4 is replaced or the photo is taken. It is arranged so that maintenance such as adjustment of the sensor module 5 can be performed. As described above, since the opening / closing section 2 is provided in the unit housing 4, maintenance such as replacement of the light source is easy.

The main body 1 and the opening / closing section 2 are
As shown in FIGS. 1 and 2, a die-cast molded metal component such as aluminum and a glass 3 arranged in an opening for reading are assembled by using a screw 6 or an adhesive. A rubber packing 10 for sealing the gap is provided at these joints. A rubber packing 12 is also provided on the surface where the main body 1 and the opening / closing part 2 are in contact with each other, and when the opening / closing part 2 is closed with respect to the main body 1, the rubber packing 12 completely seals the unit housing 4. It will be in the state of being. In this way, the rubber packings 10, 12, and 14 as sealing materials are arranged at the joint portion with the opening / closing portion 2 and the glass 3, the joint portion with the main body 1 of the housing, and the like to form a hermetically sealed structure. The sealing property of No. 4 is sufficiently good that paper dust, ink mist, etc. do not enter inside, and the problem that they adhere to the photo sensor or SELFOC lens and a reading error occurs is solved. It

The photosensor module 5 is formed by arranging photosensor elements using a-Si in the main part of the photosensor in an array with the same width as the object to be read, and an external drive circuit system (not shown). ) Is a so-called multiplex drive type photosensor module which is driven in a time division manner. In this embodiment, such an a-Si type photo sensor module is used so as to be particularly advantageous for high-speed driving.

The fluorescent lamp 7 as a light source is a fluorescent lamp which is lit by adjusting the discharge frequency by a power supply circuit (not shown) using an external inverter.

In a general household power supply of 50 Hz or 60 Hz, blinking due to discharge occurs at a rate of 100 times or 120 times per second, but in an actual fluorescent lamp, a fluorescent substance having a long afterglow time is used. Flickering occurs even though it doesn't blink at all. When this flicker synchronizes with the reading scanning timing of the photo sensor module 5, the photo sensor may miss the image information that should be actually read and the photo sensor may miss it. This becomes remarkable especially when the blinking frequency of the fluorescent lamp 7 is relatively low with respect to the drive frequency of the photosensor module 5, and conversely, the higher the blinking frequency of the fluorescent lamp 7, the lower the probability. Therefore, a fluorescent lamp having a long afterglow time is used as the fluorescent lamp 7, and the discharge frequency thereof is set to be as high as possible for lighting.

Further, such a fluorescent lamp 7 has much higher brightness than the LED used as the conventional light source. Actually, the illuminance of this fluorescent lamp 7 is about 10000 lux to 12000 lux, which is more than 3 times higher than the illuminance of about 3000 lux to 4000 lux of an LED that is generally used as a light source. The distance between L
Since it can be remarkably large as compared with the ED, the light amount does not become insufficient even when performing high-speed reading which requires a high brightness of the light source and requires a distance from the object to be read. It is possible to suppress the occurrence of the reading error of the photo sensor.

Since the fluorescent lamp 7 as such a light source generally has a service life shorter than that of the LED and has a life longer than that of the LED, the fluorescent lamp 7 having the life more frequently is replaced by the unit housing. It is necessary to take it out from 4 and replace it with a new one. Therefore, in order to easily perform such an operation, the contact type image sensor unit of the present invention is provided with the opening / closing section 2 as described above, and the fluorescent lamp 7 is put in and taken out from the opening / closing section 2. In this way, since the housing is provided with the opening / closing portion, maintenance such as replacement of the fluorescent lamp 7 as the light source is easy.

The SELFOC lens 9 is a light guiding means for guiding the light emitted from the fluorescent lamp 7 as a light source and reflected by the object to be read to the photo sensor of the photo sensor module 5.

As described above, the contact-type image sensor unit of the present invention uses the fluorescent lamp 7 as a light source, which has a significantly higher brightness than that of the light source using the conventional LED, and is used for the object to be read. Since the distance can be made much larger than that of the LED, the light amount does not become insufficient even when high-speed reading is performed, and the occurrence of reading errors can be suppressed.

Further, when the fluorescent lamp 7 is used as the light source as described above, since the fluorescent lamp generally has a shorter service life than the LED, it needs to be replaced more frequently than the LED. The opening / closing part 2 is provided in the unit housing 4 so that the operation of taking out the lamp 7 from the unit housing 4 and replacing it with a new one can be easily performed, and the fluorescent lamp 7 is put in and taken out from the opening / closing part 2. Thereby, maintenance such as replacement of the fluorescent lamp 7 as the light source is easy.

Further, since the unit housing 4 has a hermetically sealed structure by disposing rubber packings 10 and 12 as a sealing material at the joint portion and the portion where the opening / closing portion 2 and the main body 1 are in contact with each other, the hermeticity is improved. This is good, and paper dust, ink mist, and the like will not enter the inside of the unit housing 4, and the problem that they will adhere to the photosensor or SELFOC lens and cause a reading error will be solved.

As a result, the contact-type image sensor unit of the present invention can process a large amount of objects to be read at high speed, suppress the occurrence of reading errors, and have high reliability. The contact image sensor unit is suitable for such industrial inspection equipment.

[0032]

As described above in detail, the contact type image sensor unit of the present invention processes a large amount of objects to be read at a high speed such as those used in industrial inspection equipment such as a print finish inspection device. It is possible to achieve high reliability by suppressing the occurrence of read errors.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a contact image sensor unit of the present invention.

FIG. 2 is a sectional view of the contact image sensor unit of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main body 2 ... Opening / closing part 3 ... Glass 4 ... Unit housing 5 ... Photo sensor module 6 ... Screw 7 ... Fluorescent lamp 9 ... SELFOC lens 10 ... Glass part rubber packing 11 ... Reflector 12 ... Opening part rubber packing 13 ... Hinges 14 ... Rubber packings at joints 15 ... Snap locks

Claims (1)

[Claims] 1. A light source made of a fluorescent lamp, a photosensor module for reading an image of an original by light emitted from the light source, a light source and the photosensor module,
A contact-type image sensor unit having an opening / closing part to which a fluorescent lamp of the light source is attachable / detachable, and a housing having a hermetically sealed structure in which a sealing material is disposed at the joint part and the opening / closing part.