JPS61190348A - Recording device - Google Patents

Abstract

PURPOSE:To vary the quantity of light which forms an electrostatic latent image and to prevent a recording image from varying in density by varying the pulse width of an image signal stepwise according to the ambient temperature of a photosensitive body. CONSTITUTION:The ambient temperature T of the photosensitive body used for an electrophotographic recording device is detected by a temperature detector 14. Reference temperature setters 12 and 13 are set to temperatures T1 and T2 (T1<T2), thereby outputting a signal Sa from a comparator 9 when T<=T1, a signal Sb from a NOR gate 10 when T1<T<T2, or a signal Sc from a comparator 11 when T>=T2. The image signal with pulse width W from an input terminal 1 is converted into pulse signals with pulse widths W1, W2, and W3 (W1>W2>W3) by AND gates 3, 4, and 5 with delay pulses from a delay circuit 2. Then, AND gates 6, 7, and 8 output the image signals with the pulse widths W1, W2, and W3 to an AOM15 selectively according to the temperature band signals Sa, Sb, and Sc. The AOM15 supplies light to the photosensitive body by a quantity of light proportional to the input image signal, thereby forming an electrostatic latent image.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electrophotographic recording device.

[Conventional technology]

Conventionally, this type of recording apparatus forms an electrostatic latent image by constantly applying a fixed amount of light to a photoreceptor.

[Problem that the invention seeks to solve]

However, in such a method, the amount of charge on the photoreceptor varies depending on the temperature of the photoreceptor, and for example, as in the general 8e-As photoreceptor shown in FIG. If an electrostatic latent image is always formed with a constant light intensity, changes in the environmental temperature T will have a subtle effect on the recorded image quality, causing the recorded surface to become darker. It had the disadvantage that it became thinner.

[Means for solving problems]

The present invention prevents shading in recorded images by changing the pulse width of the image signal stepwise in accordance with the environmental temperature near the photoreceptor.

That is, the recording device of the present invention is an electrophotographic recording device, and includes a temperature detection means for detecting the environmental temperature near the photoreceptor, and a temperature range in which the detected environmental temperature is input and the print environmental temperature is set in advance. temperature band signal generating means for generating a temperature band signal indicating which band the temperature band signal is in; The present invention is characterized by comprising a pulse width converting means for converting the pulse width into a preset pulse width and applying the converted light to the means for generating light to form a static latent field on the photoreceptor.

〔Example〕

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

FIG. 1 is a circuit diagram of a main part of an embodiment of a recording apparatus according to the present invention.

The temperature detector 14 is not a thermistor or thermocouple,
An environmental temperature T near a photoreceptor (not shown) is detected. The reference temperature setter 12.13 is not a simple resistor, but has a temperature range Jl e in which the temperatures TI and T2 shown in FIG. 5 are set in advance.
t) e It is set as the boundary temperature of C. The comparator 9 detects when the temperature T detected by the temperature detector 14 is lower than the boundary temperature T1!・Outputs the irregular signal Sa. Comparator 1
1 outputs a high level signal Sc when the detected temperature T of the temperature detector 144I is equal to or higher than the boundary temperature T2. In the NOR gate lO, the detected temperature T of the temperature detector 14 is T1<T<T
In the case of z, a high level signal sb is output. That is, these high-level signals Sa, sb, and Sc are temperature band signals indicating that the detected temperature T has a low temperature zone a, a normal temperature zone S, and a high temperature zone cK, respectively.

An image signal having a pulse width W corresponding to a black-white ratio of 1:1 is input from an input terminal 1. This image signal is directly inputted to the analogue games 3 and 4.5 on the one hand, and at the same time inputted to the delay circuit 2 on the other hand, as shown in FIG.

This is shown in FIGS. 3 and 4. Delay time tl, respectively
A delayed pulse with t2, tl (tl<t2<13) is also input to 3, 4.5. Accordingly, the image signal pulse @W is the second factor.

As shown in FIGS. 3 and 4, the pulse width Wl,
Ws, Ws (Wt > W2 > Ws). Here, the pulse width W1. W2, W
The following temperature bands 51C are preset corresponding to the temperatures of the respective temperature bands a, t) and e. That is, in low temperature zone 1, the surface potential V is relatively high and a relatively large amount of light is required to form an electrostatic latent image, so the pulse width W is
1 is set to be large, 111a! On the other hand, in the bud region C, the pulse width W3 is set to be small, and in the room temperature region, the pulse width W2 is set to be intermediate in size between Wl and W2. ANDGATE 6.7.
Reference numeral 8 indicates inputs input from AND gates 3°4.5 corresponding to the temperature band signals 3a e Sb e Sc, that is, pulse widths Wt, Wz, Wl.
A OM (acousticopti(1
11Bodu151tor) l 5K output. The AOM 15 provides the photoreceptor with an amount of light proportional to one of the pulse widths Ws, W2, and Ws, and a static latent image is formed by this. Note that the AND gate 3 can be omitted if the pulse width W1 is set to be the same as the pulse width W.

Further, the circuit configuration of this embodiment is merely one example, and it goes without saying that a large number of similar, winged, or modified circuits may be formed using, for example, a microcomputer.

Pulse width conversion can also be performed using a monostable multivibrator.

Furthermore, the 81 degree band is not limited to three sections, agbec)Ic, and can of course be divided into two or four or more sections. Further, the present invention also provides a semiconductor laser e.
L E D # L CS (It(luid cr7
It can also be applied to change the switching time of 1'a1switch).

[Effects of the Invention] As explained above, the recording device of the present invention does not only change the pulse width of the image signal in stages according to the environmental temperature near the photoreceptor, but also change the pulse width of the photoreceptor depending on the temperature. Since the amount of light used to form an electrostatic latent image is changed in proportion to the amount of charged charge, the density of the printed area is compensated, so that it does not become darker or lighter. You can always make 5 stable records.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a main part of an embodiment of a recording apparatus according to the present invention, FIGS. 2, 3, and 4 are diagrams showing the pulse width forming process of the pulse width converting means, and FIG. 5 is a diagram showing the photoreceptor. FIG. 3 is a correlation diagram between environmental temperature and photoreceptor surface potential. l...Input terminal 2...Delay circuit 3.4, 5.6, 7.8...And gate 9.11.
... Comparator lO ... Noah gate 12.13 ... Reference temperature setter 14 ... Temperature detector 15 ... AOM

Claims (1)

[Scope of Claims] An electrophotographic recording device, comprising: a temperature detection means for detecting the environmental temperature near the photoconductor; temperature band signal generation means for generating a temperature band signal indicating whether the temperature band is within the band; inputting the image signal and the density band signal; A recording apparatus comprising a pulse width converting means for converting the pulse width into a set pulse width and applying the pulse width to a means for generating light to form an electrostatic latent image on a photoreceptor.